Dial Input Device

1. Field of the Invention

This invention relates to a dial input device which forms the input block of an information processing unit of a printing apparatus or the like.

2. Prior Art

Conventionally, a dial input device of this kind includes a dial rotatably mounted as a character entry key on a support frame and having the hirakana letters representative of the Japanese syllabary and the alphabet letters circumferentially evenly assigned thereto, and a push button arranged inside the dial as a settling key for settling an input. The dial is annuluar or ring-shaped, and the push button has a circular shape for being fitted in the ring-shaped dial. The dial incorporates a click mechanism and is rotated together with the push button in both directions to make a click stop whenever it is rotated through an angle corresponding to each of the hirakana or alphabet letters circumferentially evenly assigned thereto. The click mechanism of the dial is comprised of a toothed gear-shaped portion formed on the peripheral bottom surface of the dial and a plate spring for clicking into each recess of the toothed gear-shaped portion.

According to the conventional dial input device, patterns utilized in identifying an input of any of hirakana letters and alphabet letters are obtained e.g. by bringing eight brushes provided on the dial and eight contact members provided on the support frame into sliding contact with each other. The eight contact members are each arranged on the support frame in a manner concentric with the dial. Each contact member in an annular form has electrically conductive and electrically non-conductive portions arranged in a mixed and alternating manner. The eight brushes are arranged on the dial in a manner corresponding to the eight contact members. The identifying patterns composed of eight bits are obtained based on continuity and discontinuity between each of the eight brushes and each of the eight contact members. The hirakana letters and the alphabet letters are identified or represented by the identifying patterns.

A first problem with this kind of conventional dial input device is that since it is required to arrange a plurality of brushes radially so as to obtain a required number of identifying patterns, the dial is inevitably designed to have an increased radial width, and the diameter of the push button is reduced accordingly. The respective diameters of a dial and a push button are generally defined from the ergonomic point of view. An excessively large or small dial or push button is hard to handle, and can be a cause of an erroneous operation of the device by the user.

A second problem with the conventional dial input device is that since the plate spring, employed in the click mechanism, is directly engaged with the toothed gear-shaped portion of the dial, frictional resistance against sliding of the dial is large, so that clicking rotation of the dial can be impaired due to aging of the click mechanism i.e. abrasion of the gear-shaped portion. Further, the plate spring is difficult to adjust for the optimum spring force, which makes it difficult to set a manipulating force required of a user such that he can turn the dial in a smooth agreeable manner.

A third problem with the conventional dial input device is that the push button rotates together with the dial. This does not interfere with operation itself. However, when an indication such as "SETTLE" is printed on the push button, the indication turns with rotation of the dial. This is not sightly.

It is a first object of the invention to provide a dial input device which can be designed such that a dial thereof has a reduced radial width and can be operated with accuracy.

It is a second object of the invention to provide a dial input device which is capable of performing a clicking operation in a smooth agreeable manner.

It is a third object of the invention to provide a dial input device which does not cause a sense of disorder during operation e.g. through improperly oriented indications on push buttons thereof.

To attain the first object of the invention, there is provided a dial input device, comprising a support member, a dial rotatably arranged on the support member and having a plurality of kinds of characters circumferentially allocated thereto, n (n.gtoreq.1) first contact member(s) arranged in a manner concentric with the dial, each of which is circumferentially divided into s (s.gtoreq.2) divisional parts and formed by electrically conductive portions and electrically non-conductive portions arranged in a mixed manner, a second contact member arranged in a manner concentric with the dial and circumferentially divided into m (m.gtoreq.2) divisional parts each of which is formed by an electrically conductive portion alone, n.times.s first brushes arranged on the dial in a manner circumferentially corresponding to the s divisional parts of each of the n first contact member(s), and a second brush arranged on the dial in a manner corresponding to the second contact member, wherein the characters are expressed by k (k.ltoreq.2.sup.(n.times.s) .times.m) identifying patterns out of 2.sup.(n.times.s) .times.m identifying patterns formed by a combination of bit patterns of n.times.s bits generated by contact between the electrically conductive portions and the electrically non-conductive portions of each of the divisional parts of the first contact member and the n.times.s first brushes, and m grouping patterns generated by contact between the m parts of the second contact member and the second brush.

In the dial input device according to the first aspect of the invention, 2.sup.(n.times.s) .times.m identifying patterns are formed by a combination of bit patterns of n.times.s bits which vary with rotation of the dial, i.e. in a manner corresponding to a rotational angle of the dial about its axis, and m grouping patterns which vary or remain the same with rotation of the dial, i.e. in a manner corresponding to the same rotational angle of the dial. More specifically, the n first contact member(s), which provide the bit patterns, is/are divided into divisional parts. The s divisional parts, in a circumferential row, of each of the n first contact member(s) generates a plurality of i.e. s bits per first contact member, which form part of the bit patterns, and at the same time, the same bit patterns of n.times.s bits are caused to appear m times at the maximum per one rotation of the dial in a manner corresponding to the m grouping patterns formed by the second contact member. Since the bit patterns are formed by bits generated by the divisional parts obtained by circumferentially dividing the first contact member, the number (n) of first contact members can be reduced. Further, the use of the second contact member prevents the divisional parts from being divided into excessively small portions of the electrically conductive and electrically non-conductive portions in order to form a required number of bit patterns. As a result, it is possible to prevent occurrence of machining and electrically-sensing errors due to such excessively small electrically conductive and electrically non-conductive portions.

Preferably, when a hamming distance between a first-kind identifying code of J (J=n.times.s+m) bits encoded according to the combination of the bit patterns and the grouping patterns, which represents a desired one of the characters, and a second-kind identifying code which represents a character adjacent to the desired one of the characters is equal to H (J.gtoreq.H.gtoreq.2), 2.sup.H -2 third-kind identifying codes formed by inverting G (G=1, 2, . . . H-1) bits of H bits of the first-kind identifying code are unassigned identifying codes which do not correspond to any of the characters, the H bits of the first-kind identifying code having different values from values of corresponding bits of the second-kind identifying code.

According to this preferred embodiment, when the selected character is changed from any one character to an adjacent one thereto by rotation of the dial, it is possible to prevent occurrence of so-called hazards, i.e. unstable states ascribable to variations in threshold values of elements of an identifying circuit or the like as well as delay time of operation of the elements. More specifically, by taking into account the hamming distance between identifying codes to be assigned to respective characters adjacent to each other in respect of position on the dial, the identifying codes to be assigned to characters are determined such that the third-kind identifying codes which can occur in a transient state caused by rotation of the dial for changing the selected character are set to dead or unassigned codes. This prevents an identifying code corresponding to another character from occurring during rotation of the dial in changing the selected character from one character to another adjacent thereto, which can cause an erroneous identifying operation by the identifying circuit or the like. As a result, the malfunction of the dial input device can be prevented.

To attain the second object, according to a first aspect of the invention, there is provided a dial input device, comprising a support member, a dial rotatably arranged on the support member and having a plurality of kinds of characters circumferentially allocated thereto, and a click mechanism for rotating the dial in a clicking manner such that the dial clicks in a manner corresponds to allocations of the plurality of kinds of characters, the click mechanism having a waved-surface portion circumferentially continuously formed on the dial, a click ball arranged on the support member for engagement with the waved-surface portion of the dial, a ball-receiving recess formed in the support member for receiving the click ball in a manner such that the click ball can be projected therefrom and retracted therein, and a coiled spring received within the ball-receiving recess for urging the click ball toward the waved-surface of the dial.

In the dial input device according to the second aspect of the invention, the click ball is engaged with the waved-surface portion of the dial. This makes it possible to decreases frictional resistance against sliding rotation of the dial, and thereby improve the touch to the dial during clicking operation of the same, as well as minimize the wear of the waved-surface of the dial and the click ball. Further, the use of the coiled spring makes it easy to adjust the urging force of the click ball, whereby the touch of the dial can be optimized with ease.

To attain the third object, according to a third aspect of the invention, there is provided a dial input device, comprising a support member, a dial in an annular form rotatably arranged on the support member and having a plurality of kinds of characters circumferentially allocated thereto, and a push button arranged on the support member at a location inward of the dial as viewed in plan view in a manner such that the push button cannot be rotated relative to the support member.

According to the dial input device of the third aspect of the invention, the push button is attached to the support member in a fixed or unrotatable manner. Therefore, the push button is not rotated when the dial is operated, so that the user does not feel a sense of disorder, which can be caused, in particular, by improperly orientated indications which are printed on elements of the push button for respectively showing the functions thereof.

Preferably, the push button comprises a first push button having an annular shape and arranged inward of the dial, and a second push button having a circular shape and arranged inward of the first push button.

According to this preferred embodiment, dead space inside the dial can be utilized for accommodating a plurality of sets of function buttons.

Further preferably, the first push button is divided into four button elements such that a pair of button elements of the four button elements are disposed at longitudinally opposite locations and a pair of button elements of the four button elements are disposed at transversally opposite locations.

According to this further preferred embodiment, a plurality of sets of function buttons can be incorporated at locations adjacent to the dial, so that operating elements of the dial input device can be arranged in a concentrated manner.

Still more preferably, the dial is a character entry key for entering Japanese hirakana letters, Japanese katakana characters, and alphabet letters, the pair of button elements of the first push button disposed at the transversally opposite locations being a character conversion key and a character non-conversion key, respectively, the pair of button elements of the first push button disposed at the longitudinally opposite locations being a case shift key and a key for selecting between the Japanese hirakana letters, the Japanese katakana letters, and the alphabet letters, respectively, the second push button being a select/return key.

According to this still more preferred embodiment, keys required in entering characters, such as alphabet letters and Japanese hirakana or katakana letters, can be arranged in one section in a concentrated manner, which makes excellent the operability of the dial input device.

The above and other objects, features, and advantages of the invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.

FIG. 1A is a plan view of an appearance of a stamp-making apparatus incorporating a dial input device, according to an embodiment of the invention;

FIG. 1B is a front view of an appearance of the stamp-making apparatus;

FIG. 2 is a plan view showing an internal construction of a mechanical block of the stamp-making apparatus;

FIG. 3 is a schematic plan view showing a ribbon feeder provided in the mechanical block;

FIG. 4 is a plan view showing a function link mechanism provided in the mechanical block in its "OFF" position;

FIG. 5 is a plan view showing the function link mechanism in its "OPEN" position;

FIG. 6 is a plan view showing the function link mechanism in its "INPUT/PLATE-MAKING" position;

FIG. 7 is a plan view showing the function link mechanism in its "EXPOSURE" position;

FIG. 8 is a side elevation showing a lid-opening link of the function link mechanism and component parts associated therewith;

FIGS. 9A and 9B are views each showing an internal construction of a function switch, which are useful in explaining operations thereof;

FIG. 10 is a plan view of a lock mechanism and component parts associated therewith from which a dial of the function switch is removed;

FIG. 11 is a cross-sectional view showing the function switch and the lock mechanism as well as component parts associated therewith;

FIG. 12 is an enlarged plan view showing a printing device of the mechanical block and component parts associated therewith;

FIG. 13 is a plan view showing an exposure system of the mechanical block and component parts associated therewith;

FIG. 14 is an enlarged plan view showing the exposure system of the mechanical block and component parts associated therewith;

FIG. 15A is a front elevation showing an ultraviolet ray source of the exposure system and component parts associated therewith;

FIG. 15B is a side elevation showing the ultraviolet rays source of the exposure system and component parts associated therewith;

FIG. 16 is a plan view showing the ultraviolet ray source of the exposure system and component parts associated therewith;

FIG. 17 is a plan view showing a presser plate of the exposure system and component parts associated therewith;

FIG. 18 is an enlarged side elevation showing the pressure plate and a presser plate holder of the exposure system;

FIG. 19 is a diagram schematically showing a feed path of an ink ribbon;

FIG. 20A is a plan view showing a ribbon cartridge;

FIG. 20B is a plan view showing a mechanical block body from which the FIG. 20A ribbon cartridge is removed;

FIG. 21 is an enlarged side elevation showing the ribbon cartridge mounted in the mechanical block body;

FIG. 22 is a plan view showing the mechanical block exclusive of the function switch, in which the ribbon cartridge has just been mounted;

FIG. 23A is a partial perspective view showing a second path-setting pin;

FIG. 23B is a partial perspective view showing a tension pin;

FIG. 24 is a plan view showing a pocket of the mechanical block from which a lid is removed and component parts associated with the pocket;

FIGS. 25A and 25B are diagrams which are useful in explaining construction of a stamp body of a square stamp, in which:

FIG. 25A shows the stamp body of the square stamp in a state mounted in the pocket; and

FIG. 25B shows the bottom of the stamp body of the square stamp;

FIGS. 25C and 25D are diagrams which are useful in explaining construction of a stamp body of a business stamp, in which:

FIG. 25C shows the stamp body of the business stamp in a state mounted in the pocket; and

FIG. 25D shows the bottom of the stamp body of the business stamp;

FIG. 26 is a cross-sectional view showing the pocket as well as a detecting device and component parts associated therewith;

FIG. 27 is a front elevation showing the pocket as well as the detecting device and the component parts associated therewith;

FIG. 28 is a partial plan view showing part of the pocket as well as the detecting device and the component parts associated therewith;

FIG. 29 is a cross-sectional view which is useful in explaining one of two states of detecting operation of the detecting device;

FIG. 30 is a cross-sectional view which is useful in explaining the other of two states of detecting operation of the detecting device;

FIG. 31A is a diagram showing a pattern for discriminating a stamp body of a small square stamp;

FIG. 31B is a diagram showing a pattern for discriminating a stamp body of a large square stamp;

FIG. 31C is a diagram showing a pattern for discriminating a stamp body of a personal name stamp;

FIG. 31D is a diagram showing a pattern for discriminating a stamp body of a small business stamp;

FIG. 31E is a diagram showing a pattern for discriminating a stamp body of a large business stamp;

FIG. 31F is a diagram showing a pattern for discriminating a stamp body of an address stamp;

FIG. 31G is a diagram showing a pattern for discriminating a maximum size stamp body;

FIG. 32 is a diagram showing a structure of a stamp body;

FIG. 33 is a diagram showing a structure of a plate-making sheet;

FIG. 34 is a plan view showing an operating dial of an operating block and component parts associated therewith;

FIG. 35 is a diagram schematically showing the operating dial of the operating block and component parts associated therewith;

FIG. 36 is an enlarged cross-sectional view showing the operating dial;

FIG. 37 is an enlarged cross-sectional view showing a click mechanism of a character entry key;

FIG. 38 is a diagram which is useful in explaining a mechanism of entering characters by the character entry key;

FIG. 39 is a diagram showing identifying patterns corresponding to the characters several of which are explicitly shown in FIG. 38;

FIG. 40 is a diagram showing a mechanism of the character entry key for entering characters, according to another embodiment of the invention; and

FIG. 41 is a diagram showing identifying patterns corresponding to the characters several of which are explicitly shown in FIG. 40.

The invention will now be described in detail with reference to the drawings showing embodiments thereof.

Referring first to FIGS. 1A and 1B, there is shown a stamp-making apparatus 1 incorporating a dial input device according to an embodiment of the invention. The stamp-making apparatus makes a desired stamp by exposing a stamp body having a stamp surface made of ultraviolet-curing resin to ultraviolet rays via a mask of an ink ribbon printed with a stamp image including images of characters and pictures. The dial input device is a device for entering the characters used in the stamp (stamp characters). FIG. 1A is a plan view of the apparatus, while FIG. 1B is a front elevation of the same.

As shown in these figures, the stamp-making apparatus 1 includes a casing 2 having upper and lower divisional portions, an electronic block 3 arranged in a front part of the casing 2, and a mechanical block 4 arranged in a rear part of the same. The mechanical block 4 is comprised of a mechanical block body 5, a pocket 6 formed in a central area of the mechanical block for receiving therein a stamp body A as a stamping-making object material from which a stamp is made, and a lid 7 for opening and closing the pocket 6, which is formed with a window. In a left side portion of the mechanical block 4 as viewed in the figures, a function switch (operating knob) 8 is provided for switching the operation of the stamp-making apparatus 1 e.g. to printing or exposure, as well as for permitting the lid 7 to be opened. In a right side portion of the mechanical block 4, an inserting slot 9a for feeding a plate-making sheet B from which a stamp character label, referred to hereinafter, is made, and a take-out slot 9b for delivering the plate-making sheet B. Further, the mechanical block 4 has a maintenance cover 10 removably mounted on part thereof outside the pocket 6, and an ink ribbon cartridge 11 carrying an ink ribbon C is mounted under the maintenance cover 10.

The electronic block 3 has an operating block 21 arranged in a top thereof and contains an information processing system therein. The operating block 21 includes a push button group 22 and an operating dial 23 which form an input block of the information processing system, and an indicator 24 which forms an output block of the same. The operating dial 23 has a trial structure of an execution key 31 having a circular shape and arranged in the center thereof, a cursor/conversion key 32 having four divisional blocks arranged along the periphery of the execution key 31 to form a annular shape, and a character entry key 33 having an annular shape and arranged along the outer periphery of the cursor/conversion key 32. On the surface of the character entry key 33, hirakana letters representative of the Japanese syllabary, not shown, are printed. The stamp characters are input or entered in the following manner: First, a predetermined button 22a of the push button group 22 is pushed to set the size of a stamp (i.e. stamp image). Then, desired hirakana letters are entered by selecting, i.e. setting each of desired hirakana letters to a triangle (inverted delta) mark 25 by turning the character entry key 33, and pushing the execution key 31 whenever each of the desired hirakana letters is selected, i.e. set to the triangle mark 25. Desired ones of the input hirakana letters are converted to kanji characters by operating the cursor/conversion key 32. When desired stamp characters are formed on the display 24, the execution key 31 is pushed again to settle the inputting of the desired characters. The construction of the operating dial 23 will be described in detail hereinafter.

Now, a sequence of operations for making a stamp will be briefly described with reference to FIGS. 1A and 1B, and 2. First, the function switch 8 is operated to open the lid 7, and a stamp body A is set in the pocket 6. As the stamp body A is set, a type or kind thereof is detected by a detecting device 66, described in detail hereinafter, and based on results of the detection, the information processing system controls the input block and the output block thereof. Then, the function switch 8 is operated to shift the function of the apparatus to plate-making, and the push button group 22 and the operating dial 23 are operated to enter stamp characters. When the entry of stamp characters is completed, the plate-making sheet B on which a stamp character label is provided is set by inserting the same into the inserting slot 9a.

Then, a predetermined button 22a of the push button group 22 is operated to cause the apparatus to execute the plate-making operation, i.e. printing of the stamp characters. The printing is effected simultaneously on the ink ribbon C and the plate-making sheet B. When the printing is completed, the ink ribbon C is fed or advanced to set a portion thereof printed with the stamp characters for exposure to ultraviolet rays, and at the same time plate-making sheet B is discharged from the take-out slot 9b. When it is confirmed by the plate-making sheet B that there is no error in the printed stamp characters, the function switch 8 is operated to shift the function of the apparatus to exposure, thereby causing the same to perform exposure of the stamp body to ultraviolet rays. The apparatus may be configured such that after operating the function switch 8, a predetermined button 22a is operated to cause the apparatus to start the exposure.

When the exposure is completed, the function switch 8 is operated to open the lid 7, and then the stamp body A is removed from the pocket 6 for washing. The washing completes the stamp. Before or after completion of the stamp, the stamp character label is peeled off the plate-making sheet B to affix the same to the back of the stamp.

Next, the component devices of the stamp-making apparatus 1 will be described, one by one.

The function switch 8 arranged in the mechanical block 4 can be turned clockwise from an "OFF" position in which the apparatus is set on stand-by to an "OPEN" position, or anticlockwise from the "OFF" position to an "input/plate-making" position, and further to an "exposure" position (see FIG. 1A). In the "OPEN" position, the lid 7 provided on the pocket 6 is popped up to open, and in the "INPUT/PLATE-MAKING" position and the "EXPOSURE" position, mechanical operations of a printing block and a stamp body A, referred to hereinafter, are carried out. The function switch 8 also serves as a switch for switching between electrical modes of the apparatus. By an electrical mode-switching operation of the function switch 8, a corresponding one of lamps 12 (no lamp for the "OFF" position) provided adjacent to the function switch 8 is lighted to indicate the selected position.

The ribbon cartridge 11 is constructed such that it is removable from the mechanical block body 5, and it is replaceable together with a casing thereof when the ink ribbon C is used up. As shown in FIG. 2, the ribbon cartridge 11 has a take-up reel 13 arranged at one end thereof and a supply reel 14 arranged at the other end thereof. The ink ribbon C is rolled out from the supply reel 14, fed along a feed path in the form of a rotation of an inverted-L shape as viewed in FIG. 2, and taken up by the take-up reel 13. The feed path in the form of a rotation of an inverted-L shape has a shorter side portion which the printing block faces and a longer side portion which the exposure block faces. The printing block faces the ink ribbon C and the plate-making sheet B simultaneously, and the exposure block faces the ink ribbon C printed with the image of the stamp characters.

The ink ribbon C is comprised of a transparent ribbon tape and ink coated thereon. In the present embodiment, it has a thickness of 6 .mu.m. When the printing block of the apparatus carries out printing on the ink ribbon C, a portion of ink coated on the ink ribbon, which defines a character, is transferred to the plate-making sheet B, whereby the ribbon tape of the ink ribbon C is formed with a negative image by a transparent portion from which the portion of ink defining the character has been transferred, while the plate-making sheet B is formed with a positive image by the transferred portion of ink defining the character. The ink ribbon C is sent forward to the exposure block, where the negative image-formed portion thereof is used as a mask in carrying out the exposure, while the plate-making sheet B is delivered from the apparatus for a user to confirm the stamp characters and affix part (label) of the plate-making sheet B to the stamp thus made.

As shown in FIG. 33, the plate-making sheet B is a laminate of a base sheet Ba and an adhesive sheet Bb, generally in the form of a strip. The adhesive sheet Bb is formed with cutting lines Bc defining a rectangular area. The rectangular area of the adhesive sheet Bb is peeled off the base sheet Ba along the cutting lines Bc to form the stamp character label Bd to be affixed to the back of the stamp. There are provided several types of the stamp body A which are different in shape from each other so as to meet needs of stamps, and there are also provided respective corresponding types of the plate-making sheet which are different in the shape of an area of the stamp character label Bd (shape and size of an area defined by cutting lines).

On the other hand, as shown in FIG. 32, the stamp body A is comprised of a stock Aa (formed of a resin in the present embodiment), a thin sponge Ab (foamed urethane) affixed to a front end of the stock Aa, a non-ultraviolet-curing resin base Ac affixed to the sponge Ab, and an ultraviolet-curing resin affixed to the resin base Ac for forming a stamp surface Ad. The ultraviolet-curing resin portion (stamp surface Ad) of the stamp body A is exposed to ultraviolet rays with the ink ribbon C as a mask, whereby portions of the stamp surface Ad corresponding to the stamp characters are cured. In this state, the stamp body A is taken out of the pocket 6, and washed with water to remove uncured portions of the stamp surface, which are soluble in water, from the stamp surface Ad. Thus the stamp is completed. Symbol Ae in the figure designates a cap made of resin. In stead of the ultraviolet-curing resin, ultraviolet-softening resin may be used. In such a case, the reversed relationship of the ink ribbon C and the plate-making sheet B in respect of positiveness and negativeness makes it possible to make the same stamp as made in the present embodiment.

As shown in FIG. 2, in the stamp-making apparatus 1, the ink ribbon C wound around there supply reel 14 is rolled out therefrom, and fed via a first path-setting pin 51 to the printing block, and further via a second path-setting pin 52 and a first guide pin 53 to the exposure block. From the exposure block, the ink ribbon C is advanced to the take-up reel 13 via a second guide pin 54 and a tension pin 55 to be taken up by the take-up reel 13. In the printing block, a print head 56 and a platen roller 57 arranged in a manner sandwiching the ink ribbon C operates to push the ink ribbon C forward while printing a character on the ink ribbon C. In the exposure block, a presser plate 8 holds the ink ribbon C between the stamp body A and itself to carry out the exposure of the stamp body to ultraviolet rays.

As shown in FIG. 3, the mechanical block 4 incorporates a ribbon feeder 61 which rotates the take-up reel 13 and the platen roller 57 to feed the ink ribbon C. Further, as shown in FIG. 4, the mechanical block 4 incorporates a function link mechanism 62 comprised of a lid-opening link 62a for locking/unlocking the lid 7, a head-moving link 62b for moving the print head 56 of the printing block to and from the platen roller 57, a ribbon-holding link 62c for moving the presser plate 58 of the exposure block forward or backward, and a main link 62d for actuating the lid-opening link 62a, the head-moving link 62b and the ribbon-holding link 62c.

First, the ribbon feeder 61 will be described in detail with reference to FIG. 3. The ribbon feeder 61 has a drive motor 101 arranged below the bottom of the function switch 8 as a driving force source, and a reel shaft 102 fitted on the take-up reel 13 and a roller shaft 103 having the platen roller 57 fitted thereon are driven for rotation by the drive motor 101. The drive motor 101 has an output shaft 104 on which an output gear 105 is rigidly fitted. The output gear 105 is mated with a driving force-transmitting gear 106, which in turn is mated with a main gear 107. The main gear 107 transmits part of the driving force via a reel reduction gear train 108 to the reel shaft 102 for one route of transmission, and the rest of the driving force via a roller reduction gear train 109 to the roller shaft 103 for the route of transmission.

The output shaft 104 of the drive motor 101 has a clutch arm 110 rotatably supported thereon, and the driving force-transmitting gear 106 is rotatably supported on the clutch arm 110. The clutch arm 110 rotates with rotation of the output shaft 104 in a free-running manner, thereby causing the driving force-transmitting gear 106 to be mated with the main gear 107 in a disengageable manner. That is, when the driving motor 101 rotates, the clutch arm 110 rotates to cause the driving force-transmitting gear 106 to mate with the main gear 107, thereby causing the driving force of the drive motor 101 to be transmitted to the take-up reel 13 and the platen roller 57. Inversely, when the drive motor 101 is not in operation, if torque is input from the take-up reel 13 or the platen roller 57, the driving force-transmission gear 106 is moved away from the main gear 107 to be disengaged therefrom.

This makes it possible to easily pull the plate-making sheet B alone from the apparatus since the platen roller 57 readily rotates (reversely) without receiving any load of the drive motor 101, when the plate-making sheet B is erroneously inserted into the stamp-making apparatus. Alternatively, the clutch 110 may be rotated in a manner linked to the switching operation of the function switch 8. It should be noted that the reel shaft 102 is a slide shaft which absorbs a change in the circumferential speed of the taken-up reel 13 in an increasing direction as the ink ribbon C is taken up by the take-up reel 13 by occurrence of sliding.

Next, with reference to FIGS. 4 to 8, the function link mechanism 62 will be described in detail. The function link mechanism 62 is comprised of a frame 121, the lid-opening link 62a rotatably supported by the frame 121 in a state extending perpendicular to the frame 121, the head-moving link 62b in the form of a plate rotatably supported on the frame 121, the ribbon-holding link 62c in the form of a plate supported on the frame 121 in a manner movable forward and backward, the main link 62d in the form of a plate rotatably supported on the frame 121, and a ribbon-holding cam 122 interposed between the main link 62d and the ribbon-holding link 62c. Various kinds of gears of the ribbon feeder 61 are arranged between the frame 121 and the ribbon-holding link 62c, and the main link 62d is arranged below the frame 121 in a manner extending along therewith.

The main link 62d is engaged with an eccentric pin 123 of the function switch 8 on an input side, and is rotated about a support shaft 124 by rotation of the function switch 8 in a normal or reverse direction. The main link 62d has a tongue 125 integrally formed therewith at an extreme end on an output side, with a first pin 126 provided at a forward end, and a second pin 127 provided at a root of the tongue 125. The tongue 125 is engaged with a lower portion of the lid-opening link 62a, the first pin 126 is engaged with the head-moving link 62b, and further, the second pin 127 is engaged with the ribbon-holding link 62c via the ribbon-holding cam 122.

The lid-opening link 62a is a unitary member comprised of an opening link body 128, a pair of support shafts 129, 129 formed at opposite longitudinal ends of the opening link body 128 in a manner projecting therefrom, a pair of hooks 130, 130 extending from the opposite ends of the opening link body 128 toward the lid 7, a lever 131 extending downward from the opening link body 128 in a manner corresponding to the tongue of the main link 62d, and a switching operation portion 132 which extends forward from the opening link body 128 in a bending manner (see FIG. 8). A coiled spring 133 is stretched between the lever 131 and the frame 121 whereby the lid-opening link 62a is urged for rotation in such a direction that the tip of a hook 130 thereof is hooked on a hook catch 7a of the lid 7.

When the function switch 8 is rotated from the "OFF" position to the "OPEN" position, the tongue 125 of the main link 62d is rotated forward to push the lever 131 of the lid-opening link 62a against the pulling force of the coiled spring 133 whereby the hook 130 is disengaged from the hook catch 7a. The underside of the lid 7 has a plate spring 7b mounted thereon for stably retaining the stamp body A received in the pocket 6. When the hook 130 is disengaged, the lid 7 is popped upward by a reactionary force of the urging force of the plate spring 7b acting on the stamp body A (see FIGS. 5 and 8). Even when no stamp body A is received within the pocket 6, the lid 7 is popped upward by the action of a lock member 171 of a lock mechanism 63 described hereinafter (see FIG. 10) when the function switch 8 is turned to the "OPEN" position.

When the lid-opening link 62a is disengaged from the lid 7, the switching operation portion 132 causes detecting ends of the detecting device 66 to project into the pocket 6. Then, when the function switch 8 rotated to the "OPEN" position is released, the coiled spring 133 acts by way of the lid-opening link 62a and the main link 62d such that the function switch 8 automatically returns from the "OPEN" position to the "OFF" position. On the other hand, when the lid 7 is closed, it is pushed toward the pocket 6 against the urging force of the plate spring 7b, whereby the hook 130 of the lid-opening link 62a climbs on the hook catch 7a to be hooked thereon.

The head-moving link 62b incorporates the print head 56 at one end thereof, and arranged such that it is rotated about a support shaft 135 provided at a holding portion of the print head 56. The head-moving link 62b is formed with an engaging surface 136 at a tail end thereof, which is brought into contact with the first pin 126 of the main link 62d, and a coiled spring 137 is stretched between the tail end of the head-moving link 62b and the frame 121. The coiled spring 137 urges the one end of the head-moving link 62b for rotation about the support shaft 135 toward the platen roller 57, and at the same time rotationally urges the engaging surface 136 against the first pin 126. The engaging surface 136 includes a sloped surface 138, a first stationary surface 139 provided on the one end side of the sloped surface 138 in a manner forming an arcuate surface concentric with the support shaft 124 of the main link 62d and a second stationary surface 140 provided on the tail end side of the sloped surface 138. When the first pin 126 is brought into contact with the second stationary surface 140 through rotation of the main link 62d, the print head 56 is away from the platen roller 57, whereas when the first pin 126 faces the first stationary surface 139, the print head 56 is in contact with the platen roller 57. When the ribbon cartridge 11 is mounted or removed, the head-moving link 62b is further rotated by means of a jig, not shown in the figure, in such a direction that the print head 56 is moved away from the platen roller 57.

When the function switch 8 is rotated from the "OFF" position to the "INPUT/PLATE-MAKING" position as shown in FIG. 6, the first pin 126 of the main link 62d is moved from the second stationary surface 140 down the sloped surface 138 to the first stationary surface 139, whereby the head-moving link 62b is moved by the pulling force of the coiled spring 137 to urge the print head 56 against the platen roller 57. Inversely, when the function switch 8 is rotated from the "INPUT/PLATE-MAKING" position to the "OFF" position, the first pin 126 is moved from the first stationary surface 139 up the sloped surface 138 to the second stationary surface 140, whereby the head-moving link 62b is rotated against the pulling force of the coiled spring 137 to move the print head 56 away from the platen roller 57.

When the function switch 8 is further rotated from the "INPUT/PLATE-MAKING" position to the "EXPOSURE" position, the first pin 126 is further moved on the first stationary surface, whereby the print head 56 remains in contact with the platen roller 57 (see FIG. 7). Similarly, when the function switch 8 is rotated from the "OFF" position to the "OPEN" position, the first pin 126 is moved further toward the front side on the second surface 140, whereby the print head 56 remains away from the platen roller 57 (see FIG. 5). When the coiled spring 137 has brought the print head 56 into contact with the platen roller 57, the first pin 126 is slightly away from the first stationary surface 139, whereby the print head 56 is positively held in contact with the platen roller 57.

The ribbon-holding link 62c is generally T-shaped, and has each of left, right, and forward end portions thereof formed with a guide slot 142. The guide slots 142 are respectively engaged with three projections 143 erected on the frame 121, whereby the ribbon-holding link 62c is mounted on the frame 121 in a state slightly floated on the frame 121 such that it can be moved forward and backward. Each guide slot 142 is in the form of a key hole, while the projection 143 is formed with a disk-shaped retaining portion, not shown, at an upper end thereof. The ribbon-holding link 62c is mounted in the frame 121 by positioning the retaining portion to a circular portion of the guide slot 142 and then pushing the former into the latter, whereby the ribbon-holding link 62c is guided forward and backward by the projections 143 of the frame 121 each sliding along an elongate slot portion of a corresponding one of the guide slots 142. Further, the ribbon-holding link 62c has two support pins 144, 144 erected on each of the right and left ends thereof outside the guide slots 142, and the presser plate 58 and the first and second guide pins 53, 54 are mounted on the support pins 144, 144 (see FIG. 13).

From an intermediate portion of the ribbon-holding link 62c, a spring-holding piece 145 having a bent end portion extends backward, and a coiled spring 146 is interposed between the spring-holding piece 145 and the frame 121. The coiled spring 146 urges the ribbon-holding link 62c in a forward direction, i.e. toward the front end of the stamp-making apparatus. From a front-side portion of the ribbon-holding link 62c branches an engaging portion 147 which the ribbon-holding cam 122 abuts.

The ribbon-holding cam 122 is a unitary member having an upper cam 149 and a lower cam 150 in the form of a laminate of two plate cams. The ribbon-holding cam 122 is rotatably mounted on the frame 21 via a support shaft 151. The lower cam 150 is in the shape of a circular disk from which a sector-shaped portion is cut out, while the upper cam 149 is in the shape of a semicircular disk. The engaging portion 147 of the ribbon-holding link 62c is in contact with the peripheral end of the upper cam 149, and the second pin 127 of the main link 62d is engaged with a cut-out portion of the lower cum 150 (see FIG. 6).

FIG. 6 shows the function switch 8 in the "INPUT/PLATE-MAKING" position. When the function switch 8 is rotated from this position to the "EXPOSURE" position, the second pin 127 of the main link 62d pushes one radial end wall of the cut-out portion of the lower cam 150 to move or rotate the ribbon-holding cam 122 in an anticlockwise direction. This rotation of the ribbon-holding cam 122 eventually causes the engaging portion 147 of the ribbon-holding link 62c to drop from a peripheral end portion of the upper cam 149 onto a chord portion of the same, whereby the ribbon-holding link 62c is displaced forward by the urging force of the coiled spring 146. Since the ribbon-holding cam 122 is constructed such that it is freely rotatable about its rotational axis, so that it is instantly rotated to a position in which the chord portion of the upper cam 149 and a contacting surface of the engaging portion 147 of the ribbon-holding link 62c entirely face each other. This rotation also brings the other radial end wall of the cut-out portion of the lower cam 150 to a position in substantial contact with the second pin 127 (see FIG. 7).

The guide slot 142 also serves as a stopper for restricting the forward movement of the ribbon-holding link 62c. That is, when an inner wall defining the rear end of the elongate slot of each guide slot 142 strikes the projection 143, the ribbon-holding link 62c is stopped in a forward extremity position. Therefore, when the engaging portion 147 of the ribbon-holding link 62c entirely faces the chord portion of the upper cam 149, the urging force of the coiled spring 146 does not actually act on the chord portion of the upper cam 149, so that the engaging surface of the engaging portion is slightly spaced from the chord portion of the upper cam 149.

On the other hand, when the function switch 8 is rotated from the "EXPOSURE" position through the "INPUT/PLATE-MAKING" position to the "OFF" position, the second pin 127 displaces the other radial end wall of the cut-out portion of the lower cam 150 to rotate the ribbon-holding cam 122 in a clockwise direction. This rotation of the ribbon-holding cam 122 causes the engaging portion 147 of the ribbon-holding link 62c to return from the chord portion of the upper cam 149 to the peripheral end portion of the same, whereby the ribbon-holding link 62c is moved backward against the urging force of the coiled spring 146. In this state, the ribbon-holding cam 122 which is freely rotatable supports the ribbon-holding link 62c urged by the coiled spring 146 to thereby hold the ribbon-holding link 62c in a backward position (see FIG. 4). When the function switch 8 is further moved from the "OFF" position to the "OPEN" position, the other radial end wall of the cut-out portion of the lower cam 150 is in contact with the second pin 127 become substantially parallel with a direction of movement of the second pin 127, so that the ribbon-holding cam 122 only rotates slightly in a clockwise direction, and the ribbon-holding link 62c remains held in the backward position (see FIG. 5).

Thus, when the function switch 8 is rotated from the "OFF" position to the "OPEN" position, the hook 130 is disengaged from the hook catch 7a of the lid 7 to permit the lid 7 to open, and when the same is rotated from the "OFF" position to the "INPUT/PLATE-MAKING" position, the print head 56 displaces the ink ribbon C to urge same against the platen roller 57 to permit printing. Further, when the function switch 8 is rotated from the "INPUT/PLATE-MAKING" position to the "EXPOSURE" position, the presser plate 58 displaces the ink ribbon C to urge the same against the stamp body A to permit exposure. If the lid 7 is carelessly opened during exposure to ultraviolet rays, or if the exposure is carried out with the lid 7 being open, ultraviolet rays undesirably leak out of the apparatus. To avoid this inconvenience, the stamp-making apparatus incorporates the lock mechanism 63 which locks the lid 7 in a closed state during printing and exposure, and inhibits the function of the apparatus from shifting to printing and exposure when the lid 7 is open.

The lock mechanism 63 is arranged in the function switch 8. Now, for easy understanding purposes, description will be first made of the construction of the function switch 8. As shown in FIGS. 9A and 9B, the function switch 8 includes a dial 161 formed with a mark 162 on its top for indicating an active position of the switch, a click member 163 attached to the underside of the dial 161 and received in the space within the same, and an eccentric pin 123 in engagement with the main link 62d. The function switch 8 is rotatably mounted on a seat plate 2a of the casing 2, via a shaft 164. The click member 163 has a pair of click arms 165, 165 extending radially in a winding manner, and positioned in centrosymmetry. The resilient properties of each click arm 165 urges a circular portion 165a at an end thereof against a corresponding one of click-engaging portions 166 formed on the seat plate 2a.

Each click-engaging portion 166 is a sequence of four convex portions 166a and three concave portions 166b each located between adjacent ones of the convex portions 166a. States of the circular portion 165a of each click arm dropped in or engaged with any of the three concave portions 166b of the corresponding click-engaging portion 166 correspond to the "OFF" position, the "INPUT/PLATE-MAKING" position, and the "EXPOSURE" position, respectively (see FIG. 9A). An intermediate portion of the outermost convex portion corresponds to the "OPEN" position, and in this position, no clicking engagement occurs between the click arms and the click-engaging portions (see FIG. 9B). This enables the function switch 8 to automatically smoothly return from the "OPEN" position to the "OFF" position. A rotational angle between the "OFF" position and the "OPEN" position through which the function switch 8 should rotate is set to 15 degrees, and a rotational angle between the "OFF" position and the "EXPOSURE" position is set to 30 degrees.

On the other hand, as shown in FIGS. 10 and 11, the lock mechanism 63 includes the lock member 171 arranged in a boundary between the function switch 8 and the pocket 6. The lock member 171 is mounted on the seat plate 2a of the casing 2 such that it is urged upward by a lock spring 172 and is vertically movable. The lock member 171 is comprised of a body 173 guided by the seat plate 2a in a vertically movable manner, a push arm 174 which extends from the body 173 toward the pocket 6 and then bends upward, and a lock arm 175 which extends from the body 173 toward the function switch 8 and then bends upward.

The push arm 174 faces a lid-seating portion 6a of the pocket 6 from below, and when the lid 7 is opened, the push arm 174 projects out of the lid-seating portion 6a, whereas when the lid 7 is closed, the push arm 174 is pushed downward to be retracted into the lid-seating portion 6a. That is, when the lid 7 is opened, the lock member 171 is displaced upward by the lock spring 172, and when the lid 7 is closed, the lock member 171 is moved downward against the urging force of the lock spring 172. When the lock member 171 is moved upward, the lock arm 175 is engaged in an engaging groove 176 formed in a side wall of the function switch 8, to inhibit rotation of the function switch 8. Inversely, when the lock member 171 is moved downward, the lock arm 175 is disengaged from the engaging groove 176 of the function switch 8 to cancel the inhibition of rotation of the function switch 8.

The engaging groove 176 is an elongate groove which extends circumferentially, and when the function switch 8 is to be rotated between the "OFF" position and the "OPEN" position (normally, this operation is not carried out), the rotation of the function switch 8 is permitted. Inversely, when an attempt is made to rotate the function switch 8 from the "OFF" position to the "INPUT/PLATE-MAKING" position or the "EXPOSURE" position, the rotation of the function switch 8 is inhibited. This construction of the lock mechanism inhibits the rotation of the function switch 8 when the lid 7 is open, thereby making it impossible to start printing and exposure.

The mechanism of locking the lid in a closed state during printing and exposure by the stamp-making apparatus is achieved by the main link 62d and the lid-opening link 62a. That is, when the function switch 8 is in the "INPUT/PLATE-MAKING" position or the "EXPOSURE" position, the lid is locked in a closed state by the lid-opening link 62a. This prevents the exposure from being carried out when the lid 7 is open, and the lid from being opened during the exposure.

Next, a printing device 64 provided for the printing block will be described with reference to FIG. 12. The printing device 64 includes the print head (printing mechanism) 56 for printing stamp characters on the ink ribbon C, and the platen roller (feeding mechanism)57 for feeding the ink ribbon C in a manner timed to printing operations of the print head 56. Further, the casing 2 is formed with a feeding passage 181 through which the plate-making sheet B is fed to a contacting area between the print head 56 and the platen roller 57 and a delivery passage 182 through which the plate-making sheet B is delivered. The feeding passage 181 is formed with the inserting slot 9a which is open to the outside of the apparatus, at an upstream end thereof, and the delivery passage 182 is formed with the take-out slot 9b which is open to the outside of the apparatus, at a downstream end thereof.

The platen roller 57 is a drive roller as described hereinabove, and when the ink ribbon C is rolled out from the supply reel 14, it pulls in the plate-making sheet B between the print head 56 and itself to thereby bring a portion of the ink ribbon C and a portion of the plate-making sheet B, one upon the other, onto the print head 56. The print head 56 is a thermal head, and thermally transfer ink coated on the ribbon tape of the ink ribbon C to the plate-making sheet B. This transfer of the ink peels a portion of ink corresponding to a stamp character off the ink ribbon C to reveal a corresponding portion of the transparent base of the ribbon tape, while the peeled portion of the ink is attached to the plate-making sheet B as the stamp character.

On the feeding passage 181 faces a sensor 183 which detects insertion of the plate-making sheet B and a feeding reference position of the same. The plate-making sheet inserted into the feeding passage 181 is sent forward by the platen roller 57 in response to results of the detection of the sensor 183 whereby printing is started from one end of the stamp character label Bd on the plate-making sheet. One of walls defining the delivery passage 182 on a left-hand side, as viewed in FIG. 12, is formed with a separating nail 184 at an upstream end thereof, whereby the ink ribbon C and the plate-making sheet B fed one upon the other are separated from each other. Thereafter, the ink ribbon C is sent forward to the exposure block, while the plate-making sheet B is delivered via the delivery passage 182 out of the apparatus.

Next, the exposure system 65 provided for the exposure block will be described with reference to FIGS. 13 and 14. The exposure system 65 includes an ultraviolet ray source 191 arranged in a manner opposed to the stamp surface Ad of the stamp body A set in the pocket 6, and the presser plate 58, arranged between the ultraviolet ray source 191 and the stamp surface Ad of the stamp body A. The stamp surface Ad of the stamp body A set in the pocket 6, the presser plate 58, and the ultraviolet ray source 191 are arranged such that they are spaced from each other by a gap in a manner parallel to each other. The ink ribbon C is positioned between the stamp surface Ad and the presser plate 58. The presser plate 58 is formed of a transparent resin or the like and is caused to move forward to displace the ink ribbon C so as to urge the same against the stamp surface Ad of the stamp body A. That is, when the exposure is carried out, the presser plate 58 urges the ink ribbon C against the stamp surface Ad of the stamp body A, and then the ultraviolet ray source 191 is lighted to expose the stamp surface Ad to ultraviolet rays using the ink ribbon C as a mask (see FIG. 13).

The ultraviolet ray source 191 is a self-heating hot-cathode tube which is also called a semi-hot tube. As shown in FIG. 15A (front elevation), FIG. 15B (side elevation) and FIG. 16 (plan view), the ultraviolet ray source 191 is supported on a fluorescent tube holder 193 provided on a base plate 192. The ultraviolet ray source 191 has a pair of overtemperature cutouts 194, 194 arranged on longitudinal opposite ends thereof, for detecting expiration of the service life of the ultraviolet ray source 191 and failure of the same. Each overtemperature cutout 194 is constructed in the form of a hollow cylinder, and arranged such that it extends crosswise at right angles to the longitudinal axis of the ultraviolet ray source 191 and touches ultraviolet ray source 191 from underside thereof (i.e. from the holder side). Each overtemperature cutout 194 is held from underneath by a hold arm 194 extending from the fluorescent tube holder 193, and at the same time urged against the ultraviolet ray source 191 by the hold arm 195 having the resilient properties.

It is preferred that a reflector, not shown, is provided at the rear of the ultraviolet ray source 191 whereby the ultraviolet rays are caused to be emitted forward in a concentrated manner. Further, the overtemperature cutouts 194 may be provided in a manner spaced from the ultraviolet ray source 191 to thereby inhibit conduction of heat from the ultraviolet ray source 191 to the overtemperature cutouts 194. This makes it possible to improve a rise in the amount of ultraviolet rays emitted from the ultraviolet ray source 191.

The presser plate 58, as shown in FIGS. 17 and 18, is formed of a rectangular-shaped transparent resin or the like, and has longitudinal opposite ends thereof mounted on presser plate holders 201, 201. Each presser plate holder 201 is fitted on two support pins 144, 144 erected on each of the ends of the ribbon-holding link 62c (see FIG. 14). The presser plate 58 is comprised of a presser plate body 202, a pair of upper and lower guide nails 203, 203 extending backward from each of opposite ends of the presser plate body 202, and plates 204 each extending from the presser plate body 202 into space between the corresponding upper and lower guide nails 203, 203. Each plate 204 is formed with an outwardly projecting shaft portion 205 at a vertically intermediate location of the presser plate 58 for guiding the forward and backward swinging motion of the presser plate 58.

Although omitted in the figure, the presser plate body 202 is slightly bent in a direction away from the stamp body A, i.e. toward the ultraviolet ray source side along the longitudinal axis, whereby when the ink ribbon C is urged against the stamp surface Ad of the stamp body A by the presser plate 58, the ink ribbon C is outstretched or spread on the stamp surface Ad. Further, the presser plate body 202 is formed with guide pieces 206, 206 which extend upward from the top of the longitudinal opposite ends thereof in a manner obliquely bent backward. They guide the ink ribbon C into space between the presser plate 58 and the stamp body A properly when the ink ribbon cartridge 11 is mounted in the stamp-making apparatus. Further, each of the longitudinal opposite ends of the presser plate body 202 is chamfered to form a chamfered portion having a segmental cross-section. When the exposure is carried out, the ink ribbon C is bent along the chamfered portions so that no wrinkles are formed (see FIG. 13). In FIGS. 17 and 18, reference numerals 208, 209 designate ribs for increasing the rigidity of the presser plate body 202.

On the other hand, each presser plate holder 201 is formed with a pair of V-shaped grooves 210, 210 for guiding the pair of upper and lower guide nails 203, 203, transversely or forward and backward, and recesses 211 for respectively guiding the outwardly projecting shaft portions 205 such that they are rotatable about the longitudinal axis thereof. That is, the presser plate 58 is mounted on the presser plate holders 201, 201 at the longitudinal opposite ends thereof such that the guide nails 203 are respectively engaged with the V-shaped grooves 210, and the outwardly projecting shaft portions 205 are respectively engaged with the recesses 211 whereby the presser plate 58 is capable of moving forward and backward over a slight distance and swinging transversely. Further, in this state, a pair of spring pieces 212, 212 respectively extending from the presser plate holders 201 are urged against the outer or rear side of the opposite ends of the presser plate 58, whereby the presser plate 58 is urged toward the forward extremity position in which the nail portions of the guide nails 203 abut the bottoms of the V-shaped grooves 210, respectively.

As the ribbon-holding link 62c is moved forward from the state shown in FIG. 14 (or FIG. 2), the presser plate holders 201, 201 are moved forward, whereby the presser plate 58 makes a parallel translation toward the stamp surface Ad of the stamp body A. The stroke of movement of the ribbon-holding link 62c is slightly longer than the distance between the presser plate 58 and the stamp surface Ad of the stamp body A, and therefore, when the ribbon-holding link 62c reaches the forward extremity position, the presser plate 58 and the stamp surface Ad of the stamp body A strikes or abuts each other, so that the presser plate 58 receives a reactionary force from the stamp surface Ad to make a slight backward displacement with respect to the presser plate holders 201. Since the backward movement of the presser plate 58 is caused by the reactionary force from the stamp surface Ad, this reactionary force and the urging forces applied on the presser plate 58 become balanced to bring the presser plate 58 into contact along the stamp surface Ad of the stamp body A (see FIG. 13). That is, the presser plate 58 catches and brings the ink ribbon C into intimate contact with the stamp surface Ad of the stamp body A without forming any gap.

Further, as shown in FIG. 18, each presser plate holder 201 has a guide pin-holding portion 214 integrally formed therewith, and a corresponding one of the support pins 144 extends through the guide pin-holding portion 214. The guide pin-holding portions 214 have respective ribbon-sliding members 215 mounted thereon. Each ribbon-sliding member 215 is segmental in cross-section, with an arcuate surface thereof facing toward the presser plate side. The ribbon-sliding member 215 is formed with a pair of holding pieces 216 at a vertically intermediate portion thereof, each projecting to the front side and having a round through hole extending in a longitudinal direction. The round through holes of the holding pieces 216 of the ribbon-sliding members 215 are fitted in a pair of shaft projections 217 formed on the guide pin-holding portion 214, respectively, such that the holding pieces 216 are fitted on the guide pin-holding portion 214 from the outside, whereby the ribbon-sliding member 215 is mounted on the guide pin-holding portion 214 in a manner swingable about the axis of the shaft projections 217.

The guide pin-holding portions 214 and the ribbon-sliding members 215 are arranged outside an area of the presser plate 58 and the stamp body A (see FIGS. 14 and 17), and the guide pin-holding portion 214 and the ribbon-sliding member 215 located on the right-hand side as viewed in the figures form the first guide pin 53, and the guide pin-holding portion 214 and the ribbon-sliding member 215 located on the left-hand side form the second guide pin 54. That is, the first guide pin 53 and the second guide pin 54 guide the ink ribbon C through space between the presser plate 58 and the stamp surface Ad of the stamp body A such that the ink ribbon C is fed in parallel with the presser plate 58 and the stamp body A without interfering with any of them.

Although detailed description is made hereafter, since the guide pin-holding portions 214 form part of the presser plate holder 201, the first guide pin 53 and the second guide pin 54 are moved in the same direction as the presser plate 58 (driven by the ribbon-holding link 62c) is translated forward. This movement decreases the tension of the ink ribbon C stretched between the first and second guide pins 53, 54, whereby the ink ribbon C is urged against the stamp surface Ad of the stamp body A with reduced tension, i.e. without forming any vertical wrinkles thereon.

Now, the above-mentioned state of the ink ribbon C is described in further detail with reference to FIGS. 2 and 13. Referring to FIG. 2, when the ink ribbon C is fed or advanced, the pulling force of the take-up reel 13 causes strong tension of the ink ribbon C, so that vertical wrinkles are formed on the ink ribbon C due to its very small thickness. Therefore, if the ink ribbon C is urged against the stamp surface Ad of the stamp body A as it is, there remain the wrinkles formed on the ink ribbon C urged against the stamp surface Ad, so that deformed images (negative) of the stamp characters on the ink ribbon C are used in carrying out the exposure of the stamp surface Ad to the ultraviolet rays. On the other hand, if the ink ribbon C is loosened, the exposure can be carried out with the images of the stamp characters being out of position. To eliminate these inconveniences, as shown in FIG. 13, the first guide pin 53 and the second guide pin 54 are moved forward in accordance with the forward movement of the presser plate 58, whereby the tension of the ink ribbon C is reduced, and at the same time, a slight stretching force is applied to the ink ribbon C by the tension pin 55, which is moderate enough not to produce any wrinkles on the ink ribbon C.

Further, the ink ribbon C in the exposure position shown in FIG. 13 is bent backward at the longitudinal opposite ends of the presser plate 58 by the tension pin 55 and the second path-setting pin 52, and the chamfered portions formed at the longitudinal opposite ends of the presser plate 58 operate to prevent undesired wrinkles from being produced on the ink ribbon C.

Now, the feed path of the ink ribbon C will be described with reference to FIG. 19. The ink ribbon C rolled out from the supply reel 14 is properly guided by the first path-setting pin 51 to the printing device 64. From the printing device 64, the ink ribbon C is fed to the second path-setting pin 52, at which the ink ribbon C is largely bent. Then, it is properly guided by the first guide pin 53 and the second guide pin 54 to the exposure system 65 between them. Finally, the ink ribbon C is advanced via the tension pin 55, and taken up by the take-up reel 13. This feed path of the ink ribbon C is for feeding or advancing the ink ribbon C or for setting the same on standby for feeding. A feed path of the ink ribbon C during the exposure of the stamp body A to ultraviolet rays is different from the above feed path, as described hereinabove, and from a feed path of the same when the ribbon cartridge 11 is carried separately from the plate-making apparatus. Before describing the feed path of the ink ribbon C taken when the ribbon cartridge 11 is carried as an separate piece, the construction of the ribbon cartridge 11 per se including the reels and the pins will be described.

As shown in FIGS. 20A and 21, the ribbon cartridge 11 includes a cartridge case 221 comprised of a base plate 222 in the form of an inverted L-shape, and a plurality of legs 223 extending from the base plate 222, as well as the reels and pins each attached to the cartridge case 221 in a cantilever manner. The ribbon cartridge 11 is mounted in the mechanical block body 5 by fitting the legs 223 in a receiving block 5a with the base plate 222 being positioned above. The legs 223 are arranged at corners of the inverted L-shaped cartridge case 221, as shown in FIGS. 20A.

At an end of a shorter-side portion of the base plate 222, the supply reel 14 extends downward in a rotatable manner, and at an end of a longer-side of the base plate 222, the take-up reel 13 extends downward in a rotatable manner. Further, at a location downstream of the supply reel 14 along the feed path of the ink ribbon C, the first path-setting pin 51 reinforced with ribs extends downward from the base plate 222, and at a location downstream of the first path-setting pin 51, there is provided a path-changing member 224 constructed in a manner movable forward and backward. At a location upstream of the take-up reel 13, the tension pin 55 is provided in a manner urged by a coiled spring 225 such that it can be moved forward and backward on the base plate 222. As shown in FIG. 20B, arranged in the receiving block 5a of the mechanical block body 5 are the reel shaft 102 of the take-up reel 13, a reel shaft 226 of the supply reel 14, the print head 56, the platen roller 57, the feeding passage 181 and the delivery passage 182, the second path-setting pin 52, the first and second guide pins 53, 54, the presser plate 58, the ultraviolet ray source 191, etc.

As shown in FIG. 21, the supply reel 14 (identical with the take-up reel 13) has a shaft 228 in the form of a hollow cylinder around which the ink ribbon C is wound, an upper engaging portion 229 extending from an upper end of the shaft 228, and a lower engaging portion 230 extending from a lower end of the shaft 228, whereby the supply reel 14 is rotatably held on the base plate 222 by the upper engaging portion 229, and on the mechanical block body 5 by the lower engaging portion 230. The upper engaging portion 229 is comprised of a hollow cylindrical portion 231, and an flanged end portion 232 continuously extending from an upper end of the hollow cylindrical portion 231. In a manner corresponding to this construction of the upper engaging portion 229, the base plate 222 is formed with a shaft-holding portion 233 for sliding contact with the hollow cylindrical portion 231 such that the hollow cylindrical portion 231 can rotate in the shaft-holding portion 233, and a stepped portion 234 on which the bottom of the flange of the flanged end portion 232 is seated. The bottom of the flanged end portion 232 and the stepped portion 234 are each in the form of sawteeth, and the supply reel 14 is rotatable only in one direction when the flanged end portion 232 is brought into contact (engaged) with the stepped portion 234.

In this case, when the ribbon cartridge 11 is mounted in the mechanical block body 5, the supply reel 14 is slightly pushed upward, whereby the flanged end portion 232 is disengaged from the stepped portion 234 to permit free rotation of the supply reel 14. On the other hand, when the ribbon cartridge 11 is not mounted in the mechanical block body 5, the supply reel 14 is displaced downward by empty load to cause the flanged end portion 232 to engage with the stepped portion 234, to set or form a rotation-inhibiting stop. The rotation-inhibiting stop is provided for preventing the ink ribbon C from becoming loose. In the case of the take-up reel 13, the rotation-inhibiting stop inhibits the ink ribbon from moving in a direction opposite to a feeding direction, and in the case of the supply reel 14, the rotation-inhibiting stop therefor inhibits the ink ribbon from moving in the feeding direction. It goes without saying that both the take-up reel 13 and the supply reel 14 are permitted to be rotated in respective directions in which the ink ribbon becomes tight. For a ribbon cartridge 11 provided for replacement, the base plate 222 is provided with a plate, not shown, on the top thereof for urging the flanged end portion 232 against the stepped portion 234, and the ribbon cartridge 11 is wrapped and provided in this state, i.e. with the flanged end portion 232 being urged on the stepped portion 234.

As shown in FIGS. 20A and 21, the path-changing member 224 is comprised of a slider 236 slidably arranged at the corner of the base plate 222, and a path-changing pin 237 integrally formed with the slider 236. The slider is arranged such that the top thereof is exposed to the outside and at the same time flush with the top of the base plate 222. The path-changing pin 237 is moved transversely as the slider 236 slides, and stretches the ink ribbon between the take-up reel 13 and the supply reel 14 in a manner bent at right angles, when in the backward extremity position thereof. Before the ink ribbon cartridge 11 is mounted on the mechanical block body 5, the ink ribbon C is held in a state stretched to be bent at right angles, and after the ribbon cartridge 11 is mounted on the mechanical block body 5, the path-changing pin 237 is moved forward to the forward extremity position (see FIG. 22).

By the above arrangement, when the ribbon cartridge 11 is mounted, the path-changing pin 237 and the tension pin 55 cooperate to control the path of the ink ribbon C such that the ink ribbon C does not interfere with the presser plate 58, the stamp body A, the second path-setting pin 52, etc., and the path-changing pin 237 and the first path-setting pin 51 cooperate to control the path of the ink ribbon C such that the ink ribbon C does not interfere with the print head 56, the platen roller 57, etc. Then, after the ribbon cartridge 11 is mounted, the path-changing pin 237 is moved to thereby set the path of the ink ribbon C in position for feeding or for being on standby for feeding.

The tension pin 55 is comprised of a sliding contact portion 239 having a semicircular cross-section, and a support plate 240 supporting the sliding contact portion 239, and a coiled spring. 225 arranged between the tension pin 55 and the base plate 222 urges the tension pin 55 in a direction for stretching the ink ribbon C. The urging force of the coiled spring 225 is moderate enough not to produce any wrinkles on the stretched ink ribbon C, and the tension pin 55 functions so as not to make the ink ribbon loose. That is, in a ribbon cartridge 11 for replacement, the take-up reel 13 and the supply reel 14 are in the rotation-inhibited state as described above, and the ink ribbon C is stretched between the take-up reel 13 and the supply reel 14. The tension pin 55 abutting the ink ribbon C prevents the ink ribbon C from becoming loose due to vibrations and the like.

Further, as described hereinbefore, when the presser plate 58 and the first and second guide pins 53, 54 are simultaneously moved forward toward the stamp body A to carry out the exposure, the tension pin 55 stretches the ink ribbon C to such a degree as will neither make the ink ribbon C loose nor produce any wrinkles on the ink ribbon C. If the tension pin 55 is not required to have the function described in the preceding paragraph, the tension pin 55 may be provided on the mechanical block body 5. This variation makes the tensioning function of the tension pin 55 more stable.

Further, as shown in FIGS. 23A and 23B, the sliding contact portion 242 of the second path-setting pin 52 and sliding contact portion 239 of the tension pin 55 are each formed such that it has a convex shape, similarly to a usual pulley, whereby the ink ribbon C is prevented from falling off the sliding contact portions 239, 242 when the ink ribbon C is fed in a state in which the width thereof extends vertically. This construction of the sliding contact portions 239, 242 also prevents the ink ribbon C from being fed in a state displaced laterally, i.e. in a state shifted to an upper or lower side of the feed path even if the ink ribbon C is not fed exactly perpendicularly to the sliding contact portions 239 and 242. That is, the ink ribbon C in sliding contact with the sliding contact portions 239 and 242 is fed along the path in a state such that the center of the width of the ink ribbon C expands slightly. The sliding contact portions 242, 239 of the second path-setting pin 52 and the tension pin 55, and the swingable ribbon-sliding members 215 of the first and second guide pins 53, 54 cooperate to hold the ink ribbon C at a fixed position in a vertical direction to thereby cause the ink ribbon C to face the exposure system 65 in parallel therewith.

Next, the detecting device 66, the operation of which is linked to the opening and closing of the lid 7, will be described. The detecting device 66 detects the mounting of the stamp body A in the pocket 6, and at the same time discriminates the type of the mounted stamp body A. The stamp body A includes various types having respective different shapes, e.g. ones for a square stamp, a personal name stamp, a business stamp, an address stamp, etc. The stamp bodies A for these different types of the stamp are identical in length, but different in width and thickness. It should be noted that the above "length" means a size of the stamp body A between the stamp surface Ad and the surface on an opposite side thereof, the above "width" means a size of the stamp body A between the surfaces of opposite lateral ends thereof in its position mounted in the pocket 6, and the above "thickness" means a size of the stamp body between an upper side surface and a lower side surface of the stamp body in its position mounted in the pocket 6. To set each of these various types of the stamp body A different in width and thickness to a fixed position with respect to the directions along the width and the thickness of the stamp body A, in the present embodiment, as shown in FIGS. 24 and 25A to 25D, four bosses 251, 251, 251, 251, long and short, are provided on the bottom 6b of the pocket 6 such that they extend perpendicularly upward from the bottom, and the stamp body A is formed with fitting holes Af for fitting corresponding ones of the bosses therein, respectively.

The four bosses 251, 251, 251, 251 are arranged to form a T shape, and in a manner corresponding thereto, a stamp body A for a square stamp, for example, is formed with two fitting holes Af, Af (see FIGS. 25A and 25B), and a stamp body A for a business stamp, for example, is formed with four fitting holes Af, Af, Af, Af (see FIGS. 25C and 25D). The number of the fitting holes Af and the depth of each of them depend on the type of the stamp body A, whereby each stamp body A is mounted in the pocket 6 such that the center of the stamp surface Ad of the stamp body A mounted in the pocket 6 is positioned to a fixed location.

Further, the back surface Ag, i.e. the surface on the side opposite to the stamp surface Ad is formed with a plurality of small holes Ah (type-detecting holes) at respective central locations i.e. at intermediate locations along the thickness of the stamp body A, in a horizontally symmetrical manner. The small holes Ah cooperate with a switch array 262 of the detecting device 66, described hereinafter, to detect the type of the stamp body A (see FIGS. 31A.about.31G). The stamp character label Bd of the plate-making sheet B printed with stamp characters and delivered to the outside of the apparatus separately from the ink ribbon C is affixed to the back surface Ag of the stamp body A, whereby the small holes Ah are concealed.

The detecting device 66, as shown in FIGS. 26 to 28, includes switch holders 261 (also serving as the walls of the pocket 6) arranged opposed to the back surface Ag of the stamp body A, and the switch array 262 formed of six detecting switches 263 supported on the switch holders. Each detecting switch 263 is comprised of a switch body 262 formed e.g. of a push switch, and a switch top 265 having one end for being projected into the pocket 6. The switch top 265 is formed by a plate portion 266 and a detecting projection including the one end 267 extending at right angles to the plate portion 266, with a lower part of the plate portion 266 being guided by a guide projection 268 formed in the switch holder 261 and the detecting projection 267 being guided by a guide hole 269 formed in the switch holder 261 for forward and backward motions thereof.

The switch body 264 is fixed to the reverse side surface of a base plate 270 such that a plunger 271 thereof abuts the plate portion 266 of the switch top 265. The plunger 271 urges the switch top 265 toward the pocket 6 by its urging force. A state of the one end of the detecting projection 267 projected into the pocket 6 via the guide hole 269 through the switch holder 261, and a state of the same being retracted against the urging force of the plunger 271 correspond to ON-OFF states of the detecting switch 263, respectively.

On the other hand, a switch-operating portion 132 of the lid-opening link 62a is caused to abut the plate portion 266 of the switch holder 261, thereby urging the plate portion 266 against the urging force of the plunger 271. With rotation of the lid-opening link 62a, all the switch tops 265 are moved forward or backward. The switch-operating portion 132 and the switch top 265 may be formed as a unitary member. Alternatively, the switch top 265 and the detecting switch 263 may be formed as a unitary member, and the switch-operating block 132 may move the base plate 270.

When the lid-opening link 62a rotates in a clockwise direction as viewed in FIG. 26 to hold the lid 7 open, the switch top 265 moves forward (toward the base plate 270 side) so that the detecting projection 267 is retracted from within the pocket 6. This cancels the detecting mode of the detecting device 66, and the stamp body A can be mounted or removed without interference to the detecting projection 267. On the other hand, when the lid-opening link 62a is rotated in an anticlockwise direction to hold the lid 7 closed, the switch top 265 moves backward (to the pocket 6 side) so that the detecting projection 267 projects into the pocket 6. This sets the detecting mode of the detecting device 66. In this mode of the detecting device, if the stamp body A is mounted in the pocket 6, the switch top 265 is brought into contact with the stamp body A to turn off the detecting switch 263 whereby the mounting of the stamp body A is detected (see FIG.29). Inversely, if the stamp body A is not mounted, the switch top 265 projects to the maximum extent to turn on the detecting switch 263, whereby the removal of the stamp body A is detected.

Actually, when any of the detecting switches 263 of the switch array 262 is turned off, mounting of the stamp body A is detected, whereas when all of the detecting switches 263 are turned on, removal of the stamp body A is detected. Alternatively, instead of setting or canceling the detecting mode of the detecting device 66, opening of the lid 7 may be detected by detecting the retraction of the detecting projections 267 of the switch top 265 shown in FIG. 26 from within the pocket 6, or a priority detection signal for inhibiting the exposure may be generated by the detection of the retraction of the detecting projections 267.

Further, the detecting switches 263 of the switch array 262 are each in ON or OFF state depending on whether a corresponding small hole Ah exists in the stamp body A, as shown in FIG. 29 or 30. Therefore, the type of the stamp body A can be determined from a pattern of ON/OFF states of the six detecting switches 263.

FIGS. 31A to 31G show the relationship between small holes Ah in the stamp body A and the six detecting switches 263 (detecting projections 267). Provision of the six detecting switches 263 for detecting presence or absence of the small holes Ah makes it possible to detect 2.sup.6 -1, i.e. 63 types of patterns. A stamp body A for a square stamp or the like, which is small in width, has no small holes Ah corresponding to two outermost detecting switches 263, 263 on respective opposite sides, and the two detecting switches 263, 263 project into space beside the stamp body A. That is, a stamp body having a small width, such as a stamp body for a square stamp, is recognized as a pattern for a stamp body having imaginary small holes Ah at outermost locations thereof.

In other words, out of the 63 types of patterns, ones having small holes Ah at outermost locations of the stamp body A are assigned to stamp bodies A for the square stamps and the like which have small widths, whereby stamp bodies which do not have a sufficient width for possible small holes Ah corresponding to all the detecting switches 263 can be discriminated, without decreasing the number of possible patterns of small holes. The six detecting switches 263 include spare switches, and in practice, four detecting switches 263 are sufficient.

Next, the dial input device 68 comprised of the operating dial 23 and an internal mechanism associated therewith will be described with reference to FIGS. 34 and 35. FIG. 35 shows details of corresponding component parts and elements appearing in FIG. 34 as well as the function switch 8 and component parts associated therewith in a diagrammatic manner. Particularly, it should be noted that the operating dial actually in a circular form is represented in a rectangular form. As shown in the figures, the operating dial 23 is comprised of the execution key 31 having a circular shape and arranged in the center, the cursor/conversion key 32 having four divisional blocks and arranged along the outer periphery of the execution key 31 to form an annular shape, and the character entry key 33 having an annular shape and arranged along the outer periphery of the cursor/conversion key 32. The execution key 31 serves as a settling key for settling the inputting of characters (i.e. entering input characters in a settled manner e.g. after kana-kanji character conversion) and also as a return key for feeding lines. The cursor/conversion key 32 is comprised of a conversion key 32a on the front side, a non-conversion key 32b on the triangle mark 25 side, a selection key 32c arranged on the left side as viewed in the figure for selecting an upper or lower case (i.e. capital or small letters), and another selection key 32d arranged on the right side for selecting hirakana letters, katakana letters or alphabet letters. These keys 32a to 32d also serve as cursor keys for moving a cursor in respective directions, i.e. toward the bottom and the top, and the left and the right, in the screen of the display. Each of these keys is printed with letters indicative of the specific functions thereof.

The character entry key (dial) 33 is constructed such that it is rotatable in both directions, and makes fifty-four click stops (in a manner corresponding to fifty-four divisions of the circumference of the dial) to make a full turn in one direction. On the surface of the character entry key 33, characters 33a including the hirakana letters of the Japanese syllabary, Japanese punctuation marks, etc. are printed in a manner corresponding to the fifty-four divisions. Further, characters 33b including the alphabet, Arabic numerals, international punctuation marks, etc. are printed in a manner parallel with the characters 33a.

The entry or inputting of stamp characters is carried out by first pushing the predetermined button 22a of the push button group 22 to thereby specify the type of a stamp body A (i.e. the size of a stamp or stamp image), then setting selected hirakana character to the triangle mark 25 by turning the character entry key 33, and pushing the execution key 31 whenever each of the selected hirakana letters is set to the triangle mark 25, followed by converting desired ones of the entered hirakana letters to kanji characters by operating the cursor/conversion key 32. When desired stamp characters are formed on the display 24, the execution key 31 is again pushed to settle the inputting of the desired characters.

FIG. 36 shows a cross-section of the operating dial 23. As shown in the figure, the execution key 31, the cursor/conversion key 32 and the character entry key 33 are formed of respective separate members. The execution key 31 and the cursor/conversion key 32 are supported by a key frame 282 extending from a base plate 281 such that the keys 31 and 32 can be depressed with a finger, and the character entry key 33 is rotatably supported by the casing (support member) 2 of the apparatus. According to this construction, the execution key 31 and the cursor/conversion key 32 are prevented from rotating together with the character entry key 33, and hence the letters printed on the execution key 31 and the cursor/conversion key 32 are prevented from rotating with rotation of the character entry key 33, thereby preventing a user from feeling a sense of disorder from letters oriented in a wrong direction.

Next, the click mechanism for rotating the character entry key 33 in a clicking manner will be described in detail. As shown in FIG. 37, the click mechanism is comprised of a waved-surface portion 283 formed on the underside of the character entry key 33, a click ball 284 which engages with the waved-surface portion 283, a ball-receiving recess 285 formed in the upper surface of the casing 2 at a location facing the waved-surface portion of the character entry key for receiving the click ball 285 therein, and a coiled spring arranged within the ball-receiving recess 285 for urging the click ball 284 upward such that the click ball can be projected from and retracted into the ball-receiving recess 285. The waved-surface portion 283 is circumferentially formed on the character entry key 33 to form an annular shape and consists of fifty-four pairs of concave and convex portions. The click ball 284 is urged upward by the coiled spring 286 for being engaged with the waved-surface portion 283.

Whenever the character entry key 33 is rotated by one click, the click ball 284 moves over a convex portion of the waved-surface portion 283 and then engages with an adjacent concave portion. Thus, the character entry key 33 is rotated intermittently, i.e. in a clicking manner, and makes a full turn when fifty-four clicks have been successively made in one direction. During the clicking rotation of the character entry key 33 by engagement of its waved-surface portion 283 with the click ball 284, the click ball 284 spins whenever friction is caused between the waved-surface portion 283 and the click ball 284. This decreases frictional resistance against sliding rotation of the character entry key 33, while reliably stopping the character entry key 33 at each proper position. As a result, the character entry key 33 can be operated in a smooth and regulated manner, which makes the character entry key 32 light and crisp to the touch. Further, since friction between the waved-surface portion 283 and the click ball 284 can be made very small, the lives of these component parts can be prolonged. Still further, the use of the coiled spring 286 makes it easy to adjust the urging force of the click ball 284, which enables the touch of the character entry key 33 to be optimized with ease.

Next, the mechanism of inputting or entering the characters 33a will be described in detail with reference to FIG. 38. This input mechanism is comprised of brushes and contact points (contact members). The figure shows the relationship between the brushes arranged on the character entry key 33 and the contact points provided on the base plate 281. Under the character entry key 33, there are provided two first contact members 291, 291 and a single second contact member 292 inside the first contact members, each extending circumferentially in a manner concentric with the character entry key 33. Each of the first contact members 291 is divided into two separate divisional parts 291a, 291a each extending in a circumferential direction and consisting of electrically conductive portions and electrically non-conductive portions arranged in a mixed and alternating manner. The electrically conductive portions serve as "ON" elements, whereas the electrically non-conductive portions serve as "OFF" elements. The second contact member 292 has four divisional parts 292a, 292a, 292a, 292a arranged circumferentially, each formed of an electrically conductive portion alone which serves as an "ON" element.

On the other hand, four first brushes 293, 293, 293, 293 are arranged by twos at diametrically opposite or centrosymmetrical locations in a manner corresponding to the respective divisional portions 291a of the two first contact members 291. Further, there is provided a second brush 294 corresponding to the second contact member 292. The second brush 294 is arranged at a location inward of and adjacent to the inner one of the two first brushes 293, 293, i.e. inwardly in parallel therewith. This arrangement enables these four first brushes 293 to slide on the four divisional parts 291a of the first contact members 291, respectively, and the single second brush 294 to slide on the second contact member 292, as the character entry key 33 is rotated in either direction.

FIG. 39 is a table listing the ON/OFF states of the divisional parts of the first and second contact members dependent on continuity between each divisional part and a corresponding one of the brushes 293, 294 which varies with the positions of the electrically conductive portions (ON elements) of the divisional parts thereof. In the table, "1" represents an ON state (continuity), while "0" an OFF state (discontinuity). As indicated in FIG. 38, the four divisional parts 291a of the first contact members 291 correspond to bits designated by "No. 1" to "No. 4", and the four divisional parts 292a of the second contact member 292 correspond to bits designated by "No. 5" to "No. 8". Characters entered via the dial input device 68 are identified based or the ON/OFF states of the divisional parts of the first and second contact members. For instance, when the divisional part 292a corresponding to the bit "No. 5" is in contact with the brush 294, which means that it is in the ON state, i.e. when the bit "No. 5" is equal to "1", one of Japanese hirakana letters of "" to "" (which is selected) is identified based on the ON/OFF states of the divisional parts 291a i.e. patterns formed by "1" and "0" of the bits "No. 1" to "No. 4". Similarly, when the divisional part 292a corresponding to the bit "No. 6", "No. 7" or "No. 8" is in the ON state, one of Japanese hirakana letters "" to "", "" to "", or "" to "SP" is identified in the same manner according to patterns of bits shown in the figure.

For a full turn of the character entry key 33, 2.sup.4 =16 bit patterns are obtained according to a combination of ON/OFF states the four divisional parts 291a of the first contact members 291 associated with the four first brushes 293, and at the same time four grouping patterns are obtained from the ON/OFF states of the four divisional parts 292a of the second contact member 292 associated with the second brush 294. Therefore, sixty-four identifying patters are obtained (16.times.4=64) from a combination of the bit patterns and the grouping patterns. In the present embodiment of the invention, however, the characters 33a are identified by using fifty-four of the sixty-four identifying patterns. As described above, in the present embodiment, 2.sup.(2.times.2) .times.4=64 identifying patterns are formed through a combination of bit patterns based on states of 2 (divisional parts).times.2 (first contact members)=4 bits which vary in a manner corresponding to a rotational angle of the dial (character entry key) about its axis, and the 4 grouping patterns which vary or remain the same in a manner corresponding to the same rotational angle of the dial. That is, according to the present embodiment of the invention, the dial input device is constructed such that the first contact member(s) forming or generating the bit patterns is divided into divisional parts which provide patterns of a plurality of bits per one annular row of divisional parts, and the same bit patterns by the divisional parts of the first contact member(s) repeatedly appear m times at the maximum in a manner corresponding to m grouping patterns generated by the second contact member.

It is noted that, as shown in FIG. 39, when the electrical connection (defining a specific bit pattern) of the second contact members 292 changes from "1000" (at the bit numbers No. 5.about.No. 8) to "0100", the bit pattern "0101" (defined by bit values at the bit numbers No. 1.about.No. 4 of the first contact members 291) does not change. Also, when the electrical connection of the second contact members 292 changes from "0100" to "0010", the bit pattern "1100" does not change. Further, when the electrical connection of the second contact members 292 changes from "0010" to "0001", the bit pattern "0101" does not change.

Since each first contact member is circumferentially divided to provide bit patterns, it is not required to increase the number of first contact members 291. As a result, the character entry key 33 can be designed with a reduced size. That is, the character entry key 33 can be formed to have an inner (or outer) diameter and a radial width with preference to ease of operation of the same. Further, in the present embodiment, the second contact member is additionally employed, so that the character entry mechanism of the dial input device is formed by a total of three contact members each of which extends circumferentially to form a substantially annular shape (i.e. an annular sequence of divisional parts thereof). This prevents the divisional parts from being divided into excessively small conductive and electrically non-conductive portions so as to form a required number of bit patterns. As a result, machining and electrically-sensing errors are prevented from being caused by such excessively small conductive and electrically non-conductive portions.

Next, the input mechanism for entering the above-mentioned characters 33a according to another embodiment will be described with reference to FIGS. 40 and 41. The input mechanism is basically similar in construction to the input mechanism shown in FIGS. 38 and 39 except that the second contact member 292 is circumferentially divided into six divisional parts and that the electrically conductive and electrically non-conductive portions of the first contact members 291 and the second contact member 292 are arranged differently from those in the first embodiment. The differences result from the use of identifying patterns of an increased number of bits so as to avoid a "hazard", i.e. an unstable state which can occur e.g. in a circuit for identifying patterns or identifying codes assigned to respective characters when the dial is rotated so as to change the character selected by the character entry key from one character to another adjacent thereto. The input mechanism in FIGS. 40 and 41 is constructed such that it can provide identifying patterns in such a hazard-avoiding manner.

Now, for the purpose of an aid to understanding construction of the present embodiment, the terms of "identifying codes" and "hamming distance" used in the following description will be explained. Similarly to FIG. 39, FIG. 41 shows the ON/OFF states of the divisional parts of the contact members 291, 292 associated with the brushes 293, 294. "1" represents the ON state and "0" the OFF state in the FIG. 41 table, as well. As shown in FIG. 40, the four divisional parts 291a of the first contact members 291 correspond to bits designated by "No. 1" to "No. 4" in FIG. 41, and the six divisional parts 292a of the second contact member 292 correspond to bits designated by "No. 5" to "No. 10". A code formed by a sequence of values of the bits No. 1 to No. 10 is referred to as an "identifying code". For instance, when an identifying code for a character (Japanese hirakana character) "" shown in FIG. 40 is named CA, the identifying code CA is expressed as [1100100000] (i.e. CA=""=[1100100000]). Similarly, let it be assumed that an identifying code for a character "" adjacent to the character "" is named CB, and expressed as ["1000100000] (i.e. CB=""=[1000100000]). The identifying codes CA and CB are different from each other only in one correspondent bit, i.e. the bit "No. 2". Such a relationship between two identifying codes as found between the identifying codes CA and CB, in which one is different from the other only in one bit, is expressed as "the identifying code CA and the identifying code B have a hamming distance H (CA, CB) of 1 (i.e. H (CA, CB)=1).

Next, description will be made of possibility of an erroneous identification of a character occurring when the dial is rotated so as to change the selected character from one character to another adjacent thereto. For instance, when CC=""=[1000010000] holds, as shown in FIG. 41, the hamming distance H (CB, CC) between the identifying code CB for the character "" and the identifying code CC for the character "" is equal to 2. In this case, when the dial is rotated so as to change the selected character from the character "" to the character "", or from the character "" to the character "", there can appear an identifying code CD=[1000110000] or an identifying code CE=[1000000000] in a transient state depending on which of the two bits "No. 5" and "No. 6" changes first, due to variations in threshold values of elements of the identifying circuit or the like as well as delay time, etc. If such a state occurs, and if there exists another character which corresponds to the identifying code CD or CE, there is a possibility that the transient identifying code CD or CE is erroneously identified as an identifying code for a selected character, resulting in a malfunction of the dial input device 68.

To eliminate this inconvenience, according to the input mechanism shown in FIGS. 40 and 41, identifying codes for characters corresponding to an identical divisional part 292a of the second contact member 292 in which the bit "No. 5" is equal to 1, such as characters "" to "", are formed such that the identifying codes for two characters adjacent to each other have a hamming distance H of 1, similarly to that between the identifying codes "CA" and "CB" for the respective characters "" and "", whereby an erroneous identification of a wrong character is prevented from occurring even in a transient state. Further, two characters adjacent to each other but corresponding to respective different divisional parts 292a of the second contact member 292 have respective identifying codes assigned thereto, which are formed such that they have a hamming distance H of 2, similarly to that between the identifying codes "CB" and "CC" assigned to the respective characters "" and "", and at the same time a identifying code such as the identifying code "CD" or "CE", which can occur transiently, is set to a dead or unassigned identifying code which does not correspond to any character. Therefore, even in a transient state, there is no fear of an erroneous identification of an undesired character. Thus, according to this input mechanism, it is possible to avoid hazards and thereby prevent erroneous identification of an undesired character and malfunction of the dial input device 68.

When any one of the identifying codes is desired to be changed e.g. for the purpose of reinforcing mechanical strength of the brushes 293, 294 and/or the contact members 291, 292, e.g. when it is desired to change the bit "No. 4" of the identifying code CB for the character "" to "1" to thereby set CF=""=[1001100000], the following investigation is carries out: The hamming distance H (CA, CF) between the identifying code CF for the character "" and the identifying code CA for one of two adjacent characters "" (CA=""=[1100100000]) is equal to 2, and possible transient identifying codes are CG=[1101100000] and CH=[1000100000]. Further, the hamming distance H (CC, CF) between the identifying code CF for the character "" and the identifying code CC for the other of the adjacent characters "" is equal to 3, and possible transient identifying codes are CI=[1000100000], CJ=[1001000000], CK[1001110000], CL=[1000000000], CM=[1000110000], and CN=[1001010000]. Out of the six transient identifying codes, the identifying code CN is assigned to the character "", so that there is fear that the character "" is erroneously identified when the dial is rotated to change the selected character from the character "" to the character "" or from the character "" to the character "".

To eliminate this inconvenience, it is preferred that the identifying code for the character "" is changed to CP=""=[1010010000], whereby it becomes possible to change the identifying code for the character "" from CB to CF while maintaining the hamming distance H of 1 between the identifying code for "" and the identifying codes for "" or "" as well as to turn all the transient identifying codes such as CN into dead or unassigned identifying codes, so that hazards can be avoided to thereby prevent an erroneous identification of a character.

That is, according to the present embodiment, identifying codes are assigned to characters, while taking into account the hamming distance between identifying codes to be assigned to respective characters adjacent to each other. More specifically, when the hamming distance H.gtoreq.2 holds (H=3 in the above example) between a identifying code for any one of the characters (e.g. CF for the character "" in the above example) and another identifying code for a character adjacent thereto (e.g. CC for the character "" in the above example), 2.sup.H -2 identifying codes (2.sup.3 -2=6 identifying codes in the above example) obtained by inverting G bits (G=1, 2, . . . , H-1: G=1, 2 in the above example), out of H bits (e.g. three bits of "No. 5", "No. 6" and "No. 7" in the above example) having different values between the two codes, e.g. CI, CJ and CK obtained by inverting one bit, and CL, CM and CN by inverting two bits, can be set to dead or unassigned identifying codes which do not correspond to any character. This makes it possible to avoid hazards which can occur in an identifying circuit or the like and thereby prevent an erroneous identification of a character and malfunction of the dial input device. Although the brushes are provided on character entry key, and the contact points are provided on the base plate in the embodiments in FIGS. 38 to 41, this is not limitative, but may be arranged in a reversed manner, i.e. with the contact points on the character entry key and the brushes on the base plate. Further, the dial input device of the invention can be applied as an input device to other electronic machines. In such a case, it goes without saying that the number of the first contact members, the number of divisional parts thereof in circumferential rows, and the number of divisional parts of the second contact member are determined according to the number of identifying patterns required.

It is further understood by those skilled in the art that the foregoing is preferred embodiments of the invention, and that various changes and modifications may be made without departing from the sprit and scope thereof.