Facsimile Receiver Capable of Backwardly Feeding a Continuous Recording Medium After a Separate Sheet Is Cut Therefrom

This invention relates to a facsimile receiver for a continuous recording medium and, more particularly, to a facsimile receiver comprising an improved device for controllably feeding a continuous recording medium.

A facsimile receiver is generally supplied with facsimile signals from one or more cooperating facsimile transmitters. The facsimile signals, as called herein, comprise a sequence of image signals representative of a figure, namely, a picture or its equivalent, and a reproduction end signal following the image signal sequence. In a facsimile receiver for a continuous recording medium, a motor controllably feeds the recording medium while a recording head records thereon a figure in response to an image signal sequence. As will later be described with reference to a figure of the accompanying drawing, the motor further feeds the recording medium to a cutter placed considerably forwardly of the recording head and then stops feeding the recording medium, when the cutter cuts from the continuous recording medium a separate sheet on which the figure is recorded. When supplied with another image signal sequence, the receiver repeats the above-described operation. A considerable blank space has therefore been indispensable on each separate sheet. This means an objectionable loss of the recording medium. Furthermore, each separate sheet is unfavorably wider than the area of the figure.

It is therefore an object of the present invention to provide a facsimile receiver for a continuous recording medium, whereby a reduction to a minimum is possible in an unnecessary loss of the recording medium.

It is another object of this invention to provide a facsimile receiver of the type described, which is capable of successively producing those separate sheets of the recording medium on which figures are recorded, respectively, and which are of areas suitable to the respective figures.

Furthermore, a facsimile receiver according to this invention is readily adapted to operation responsive to redundancy reduced facsimile signals.

A facsimile receiver to which this invention is applicable comprises feeding means for feeding when put into operation a continuous recording medium along a preselected path of feed, recording means responsive to facsimile signals representative of figures for successively recording the figures on the continuous recording medium fed by the feeding means, signal producing means responsive to the facsimile signals for producing a cutter drive signal in timed relation to recording by the recording means of each of the figures, a cutter responsive to the cutter drive signal for cutting from the continuous recording medium a separate sheet on which the above-mentioned each figure is recorded, and coupling means between the recording means, signal producing means, and feeding means for controllably putting the feeding means into operation. In accordance with this invention, the coupling means comprises first means connected to the recording means for producing a first control signal during recording by the recording means of the above-mentioned each figure, second means connected to the recording means and signal producing means for producing a second control signal of a first predetermined duration after recording by the recording means of the above-mentioned each figure and before production by the signal producing means of the cutter drive signal, third means connected to the second means and signal producing means for producing a third control signal of a second predetermined duration after production by the signal producing means of the cutter drive signal, and drive means connected to the first through third means and feeding means for putting the feeding means into a first, a second, and a third phase of operation of feeding in response to the first control signal the continuous recording medium in a predetermined one of senses of the path, of further feeding in response to the second control signal the continuous recording medium in the above-mentioned one sense, and of feeding in response to the third control signal in the other of the senses the continuous recording medium from which the separate sheet is cut, respectively. The second predetermined duration should not be longer than the first predetermined duration. The feeding means is capable of feeding the continuous recording medium in whichever of the senses.

FIG. 1 is a schematic side view of a conventional electrostatic facsimile receiver for a continuous recording medium;

FIG. 2 shows a schematic side view of a facsimile receiver according to a preferred embodiment of this invention, together with a block diagram of a control circuit thereof;

FIG. 3 is a circuit diagram of a portion of the control circuit illustrated in FIG. 2;

FIG. 4, consisting of A-D is a time chart of signals appearing in the control circuit shown in FIG. 3; and

FIG. 5 is a time chart of other signals appearing in the control circuit depicted in FIG. 3.

Referring to FIG. 1, a conventional electrostatic facsimile receiver will be described at first for a better understanding of the present invention. The facsimile receiver is for a continuous recording medium supplied from a roll 10 thereof. Supplied with facsimile signals from one or more cooperating facsimile transmitters (not shown), the facsimile receiver reproduces original figures, namely, pictures or their equivalents, successively on the recording medium. When a reproduction start signal is derived from the facsimile signals, an electric motor 11 starts to drive a main feed roller 12 for feeding in cooperation with an unnumbered roller the recording medium along a preselected path of feed at a predetermined speed until a reproduction end signal is derived from the facsimile signals. In response to a sequence of image signals derived from the facsimile signals, a recording head 14 disposed between the roll 10 and the feed roller 12 scans transversely of the path of feed and thereby forms a latent image of the figure along a plurality of lines of scan spaced along the path of feed on the recording medium fed at the predetermined speed. A pinch roller 15 cooperates with the recording head 14. The speed of feed is determined by a density of the scanning lines. Forwardly along the path of the recording head 14, a developing unit 16 is positioned to develop the latent image into a visible image of the figure, which is thereafter fixed by a fixing unit 17 to form a reproduction of the original figure on the continuous recording medium. The feed roller 12 further feeds the continuous recording medium to a cutter 18 for cutting in response to a cutter drive signal derived from the reproduction end signal that separate sheet from the continuous recording medium on which the reproduction is formed. Inasmuch as the continuous recording medium travels a considerable distance from the recording head 14 to the cutter 18, the conventional facsimile receiver has the defects pointed out in the preamble of the instant specification.

Turning to FIG. 2, an electrostatic facsimile receiver according to a preferred embodiment of this invention comprises similar parts designated by like reference numerals as in FIG. 1. It should, however, be understood that the motor 11 is a reversible pulse motor controlled in a manner described later and that the cutter 18 is placed appreciably adjacent to the recording head 14 with the developing and fixing units 16-17 positioned further forwardly of the cutter 18. In the example being illustrated, the pinch roller 15 is also driven by the motor 11. Between the recording head 14 and the cutter 18, a detecting unit 21 is disposed for optically or otherwise detecting the recording medium passing thereby to produce a feed timing signal for putting auxiliary feed roller 22 into operation of feeding to the developing and fixing units 16-17 a separate sheet cut from the continuous recording medium.

Further referring to FIG. 2, the illustrated facsimile receiver is for facsimile signals FS of a band or redundancy reduction coding system, such as a runlength coding system, and comprises a main control circuit 25 and a pre-control circuit 26. The pre-control circuit 26 comprises a facsimile signal controller 27 and a transmission controller 28. The facsimile signal controller 27 may be a band expander circuit known in the art. Although not depicted in detail, the band expander circuit for the runlength coding system comprises a buffer memory for temporarily storing the facsimile signals FS, a decoder for successively deriving from the facsimile signals FS for each figure a reproduction start signal, a sequence of image signals, and a reproduction end signal E, and a line memory for temporarily storing the image signals for every line of scan to successively produce image signal units I, each corresponding to a predetermined number of lines of scan, and line step start signals A for the respective lines of scan. Responsive to the reproduction end signal E, the transmission controller 28 produces a page end signal AA. The line step start signals A and the page end signal AA are supplied to the main control circuit 25 to controllably drive the motor 11 in the manner described hereunder while the image signal units I are supplied to the recording head 14.

Referring to FIG. 2 again and to FIGS. 3 and 4 afresh, the main control circuit 25 comprises a drive unit comprising, in turn, a known pulse motor drive circuit 30 for the reversible pulse motor 11 and a first unit supplied with the line step start signals A from the pre-control circuit 27 for supplying a first control signal B to the drive unit during recording by the recording head 14 of each figure. In the example being illustrated, the drive unit comprises a clock generator 31 for generating clock pulses. The first unit comprises a first flip-flop circuit 33 set by each pulse of the line step start signals A to supply its set output as a step pulse of the first control signal B through a first OR gate 34 to a gating circuit 35 for gating the clock pulses as a first driving signal to the motor 11 through the motor drive circuit 30. The first unit further comprises a single counter 36 for counting the clock pulses gated by the gating circuit 35 to a predetermined count, such as one, two, three, or four, to produce a pulse of a stop signal D upon counting the gated clock pulses to the predetermined count. The stop signal resets the flip-flop circuit 33. During an interval between a pulse of the stop signal D and a next succeeding pulse of the line step start signals A, rotation of the motor 11 is suspended. In the meantime, the recording head 14 records the latent image partially along the predetermined number of scanning lines in response to the pertinent one of the image signal units I. The main feed roller 12 thus feeds the continuous recording medium towards the cutter 18 stepwise and consequently relatively slowly.

Referring to FIGS. 2 and 3 again and to FIG. 5 afresh, the main control circuit 25 further comprises a second unit responsive to the page end signal AA supplied from the pre-control circuit 26 for producing a second control signal AB of a first predetermined duration after recording by the recording head 14 of the figure. More particularly, the second unit comprises a second flip-flop circuit 41 set by the page end signal AA to supply its set output as the second control signal AB to the gating circuit 35 through a second OR gate 43 and the first OR gate 34 to make the gating circuit 35 supply, in turn, gated clock pulses as a second driving signal AC (left portion in FIG. 5) to the motor 11 through the motor drive circuit 30. The signal having passed through the second OR gate 43 is illustrated in FIG. 5 at AD, a first pulse depicted in the left half being now used. The second control signal AB is supplied also to a counter device 44 through the second OR gate 43 to make the counter device 44 count the gated clock pulses AC to a first prescribed count, such as 280, corresponding to the first predetermined duration and produce a first command signal AE (a first pulse in FIG. 5) when the count reaches the first prescribed count. The command signal AE resets the second flip-flop circuit 41. It is to be pointed out here that no line step start signals A (FIG. 4) are supplied to the first flip-flop circuit 33 until facsimile signals are supplied to the receiver for another subsequent figure and that the first flip-flop circuit 33 is kept in the reset state even when the single counter 36 counts the gated clock pulses AC to the count predetermined therefor. Inasmush as the first prescribed count for the counter device 44 is considerably large, the main feed roller 12 feeds the continuous recording medium to the cutter 18 continuously and consequently relatively rapidly. A trailing edge of the second control signal AB energizes a cutter drive signal producing unit comprising a first pulse generator 46, such as a monostable multivibrator, for supplying a cutter drive signal AF to the cutter 18 through an amplifier 47. It is now understood that the second unit is connected also to the signal producing unit to produce the second control signal AB before production by the signal producing unit of the cutter drive signal AF. Incidentally, a second pulse generator 48, such as a monostable multivibrator, produces a reverse feed command pulse AG in response to a trailing edge of the signal produced by the first pulse generator 46 for the cutter drive signal AF.

Further referring to FIGS. 2, 3, and 5, the main control circuit 25 comprises a third unit connected to the second unit and the signal producing unit for producing a third control signal AH of a second predetermined duration after production by the signal producing unit of the cutter drive signal AF. The second predetermined duration should not be longer than the first predetermined duration for the reason which will presently be rendered clear. For the time being, the second predetermined duration is selected to be equal to the first predetermined duration. In the illustrated example, the third unit comprises a third flip-flop circuit 49 set by the reverse feed command pulse AG to supply its set output as the third control signal AH to the motor drive circuit 30. The reverse feed command pulse AG is supplied also to the counter device 44 through the second OR gate 43 (a second pulse depicted in FIG. 5 at AD) and to the gating circuit 35 through the second and first OR gates 43 and 34 to again energize the counter device 44 and the gating circuit 35. The gated clock pulses AC (right portion in FIG. 5) are supplied through the motor drive circuit 30 controlled by the third control signal AH to the motor 11 as a third driving signal AC (the right portion). The gated clock pulses AC are counted again by the counter device 44 to the prescribed count, when the counter device 44 supplies a second command signal AE (a second pulse in FIG. 5) to the third flip-flop circuit 49 to reset the same. The main feed roller 12 reversedly or backwardly and relatively rapidly feeds the continuous recording medium from which the separate sheet is cut in response to the cutter drive signal AF next preceding the instant third command signal AH. In the meanwhile, the auxiliary feed roller 22 feeds the separate sheet through the developing and fixing units 16-17. It is to be mentioned here that the forward or leading edge of the continuous recording medium should be manually or otherwise placed slightly forwardly of the recording head 14 before reception by the receiver of facsimile signals. The backward feed returns a new leading edge of the continuous recording medium to the slightly forward position when the second predetermined duration is rendered equal to the first predetermined duration.

In order to insure presence of a recording medium always at the position of the recording head 14 despite possible play in the recording medium feeding mechanism and to thereby protect the recording head 14 against possible damage, the second predetermined duration may be rendered shorter than the first one. This is made possible by using as the counter device 44 a first and a second counter for counting the gated clock AC for the second and third driving signals to the first prescribed count mentioned above and to a second prescribed count corresponding to the shorter second predetermined duration, respectively.

When a much faster speed of feeding is desired before and after operation of the cutter 18 than the speed of feeding during the recording operation, use is possible as the clock generator 31 of a first and a second clock generator for generating first and second clock pulses of a lower and a higher repetition frequency. The gating circuit 35 should gate the first clock pulses in response to the first control signal B and the second clock pulses in response to the second and third control signals AB and AH. It is possible to select the predetermined count for the single counter 36 in consideration of the line density and to make the recording head 14 and the cutter 18 carry out recording and cutting while the recording medium is fed.