Control Device for a Recording and Reproducing Apparatus

1. Field of the Invention

This invention relates to the control of a tape recorder/reproducer using the tape drive motor to provide force for achieving mode changing under control of a solenoid.

2. Description of the Prior Art

The prior art contains examples of a mode control mechanism for a tape recorder using small capacity solenoids for selecting respective operating modes and employing a flywheel driven by the tape drive motor as the source of the principal motive force for change-over from one operating mode to another. The devices in the prior art generally require a plurality of solenoids, for example, a separate solenoid for each mode, such as, record, reproduce, fast forward and so forth, into which it is desired to place the tape recorder. The large number of solenoids with their supports and wiring increase the size, weight, cost, complexity and power drain of the tape recorder.

An object of this invention is to provide a control device adapted for use in a recording and reproducing apparatus, and wherein change-over between a plurality of different operating modes can be accomplished under the control of a single solenoid.

Another object of this invention is to provide a control device for a recording and reproducing apparatus which allows easy change-over between a plurality of operating modes by timed control of the energization of a single solenoid.

Still another object of this invention is to provide a control device in a tape recording and reproducing apparatus, wherein actuation of the solenoid for controlling mode change-over and the movement of a magnetic head and pinch roller to an operating position are synchronized.

A further object of this invention is to provide a control device, as aforesaid, wherein control signals for controlling energizing of the solenoid are timed in response to rotational speed signals corresponding to the rotation of the tape drive motor to allow accurate operational timing of the energization of the solenoid and, hence, of the mode change-over.

A further object of this invention is to provide a control device for a tape recording and reproducing apparatus, as aforesaid, which allows control of the mode of operation by means of a small capacity solenoid.

A still further object of this invention is to provide a control device for a tape recording and reproducing apparatus having a simplified mode change-over mechanism.

An additional object of this invention is to provide a control device for a tape recording and reproducing apparatus which permits a reduction in the size and manufacturing cost of the apparatus.

According to an aspect of the invention, in a recording and reproducing apparatus having a stopped condition and at least first and second operating modes and a drive motor, a control device comprises actuating means driven by the drive motor for changing between the stopped condition and one of said first and second operating modes, electrically controlled means for initiating the function of the actuating means, and means responsive to a characteristic of a signal to the electrically controlled means for selectively preventing changing to the second mode.

According to another aspect of the invention, the control device for the recording and reproducing apparatus comprises a solenoid, eccentric means rotatable about an axis, first means actuated by the solenoid and driven by the drive motor for turning the eccentric means through a part of a revolution from a first angular position to a second angular position and for holding the eccentric means in its second angular position, mode changing means having at least first and second conditions and being acted upon by coupling means actuated by the eccentric means for changing the mode changing means from its first to its second condition, and means actuated by the solenoid for preventing the coupling means from actuating the mode changing means in response to the previously mentioned characteristics of an energization signal applied to the solenoid. Further, means actuated by the solenoid are provided for rotationally returning the eccentric means from its second angular position back to its first angular position.

The above, and other objects, features and advantages of the present invention, will become apparent from the following description read in conjunction with the accompanying drawings in which like reference numerals designate the same elements.

FIG. 1 is a schematic plan view of a control device for a recording and reproducing apparatus according to an embodiment of the present invention;

FIG. 2 is a partial plan view of some of the elements of the device shown on FIG. 1, and which are isolated for ease in observing the arrangement and operation thereof;

FIG. 3 is a partial plan view of other elements of the device shown on FIG. 1, and which are isolated for ease in observing the arrangement and operation thereof;

FIG. 4 is a partial plan view similar to FIG. 2, but showing the respective elements in a different condition during operation of the device;

FIG. 5 is a partial plan view similar to FIG. 4, but showing a subsequent condition of the elements;

FIG. 6 is a partial plan view similar to FIG. 3, but showing the respective elements in a different operational position;

FIG. 7 shows an energization signal effective to establish the reproducing mode of the recording and reproducing apparatus;

FIG. 8 shows an energization signal effective to establish the recording mode of the recording and reproducing apparatus;

FIG. 9 schematically shows a digital form of a control circuit that may be employed with the device of FIG. 1; and

FIG. 10 shows a block diagram of an analog form of a control circuit that may be employed with the device of FIG. 1.

Referring to FIG. 1, there is shown generally at 10 an embodiment of a control device for a tape recording and reproducing apparatus according to the present invention. A tape drive motor 12, which operates continuiously so long as a power supply switch (not shown) of the apparatus is turned on, drives a flywheel 14 through a drive belt 16. A pinion 18 on the axis of the flywheel 14 is thus continuously rotated.

The pinion 18 is disposed adjacent a partly toothed gear 20 having a toothed region 22 and an untoothed region 24 on its perimeter. In the illustrated position of partly toothed gear 20, the untoothed region 24 is adjacent pinion 18 so that the latter can rotate while gear 20 is at rest. The partly toothed gear 20 is rotatable about a shaft 26 which is affixed to a base plate (not shown). An eccentric actuating cam 28 is attached to rotate with partly toothed gear 20. A spring 30 biased between a post 32 affixed to the base plate (not shown) and a pin 34 on partly toothed gear 20 urges partly toothed gear 20 in a counterclockwise direction about its axis 26 when partly toothed gear 20 is positioned as shown on FIG. 1. A three-legged lever 36, is turnable about post 32 and includes a first leg 38 having a hook 40 at its end, a second leg 44 having a pin 46 protruding therefrom and a third leg 51 having an abutment surface 53 at its end. The hook 40 is engageable with a pin 42 protruding from partly toothed gear 20 to prevent counterclockwise rotation of the partly toothed gear 20 under the urging of spring 30 from the position shown on FIG. 1. The pin 46 protruding from second leg 44 of three-legged lever 36 engages a hole 48 in an operating slide 50. The abutment surface 53 of third leg 51 of three-legged lever 36 is also engageable by pin 42, as hereinafter described, to form another stop for partly toothed gear 20 in the course of the operation of control device 10. The slide 50 is attached by any suitable means, such as a rivet 52, to an armature 54 of a control solenoid 56. A return spring 58 urges slide 50 and armature 54 downward, as viewed on FIG. 1. A guide slot 60 in slide 50 receives a guide post 62 affixed to the base plate (not shown) and guides the lower end of slide 50 which is retained on guide post 62 by any suitable means, such as a C-ring 64.

An L-shaped lever 66 is pivotable about a pivot pin 68 which is affixed to the base plate (not shown). A head board or carriage 70 carrying record or reproduce heads 72 and a pinch roller 74 is urged to an inactive position, that is, in the downward direction as viewed on FIG. 1, by return spring 76a and 76b. A pin 78 on head board 70 is engageable by one leg 80 of L-shaped lever 66. The downward urging of return springs 76a and 76b acting through pin 78 tends to rotate L-shaped lever 66 in a clockwise direction, as viewed on FIG. 1. A second leg 82 of L-shaped lever 66 bears against the peripheral cam surface of eccentric actuating cam 28. The second leg 82 of L-shaped lever 66 is also pivotally connected, as by a pivot 84, to an idler bar 86. As the L-shaped lever 66 turns about its axis 68, head board or carriage 70 is moved up and down, that is, to and from an operative position, and idler bar 86 is moved from side to side, as will be later explained.

A control circuit 128 is connected, as indicated at 130, to the tape drive motor 12 for sensing and controlling the speed of the latter. Circuit 128 is further connected, as indicated at 132, with solenoid 56 for controlling the energizing of the latter.

The control device 10 has the following sequence of operations for establishing the reproducing mode of the tape recording and reproducing apparatus:

When solenoid 56 is energized by control circuit 128, the upward motion of slide 50 against the force of return spring 58 turns three-legged lever 36 in the clockwise direction about post 32. Such turning of three-legged lever 36 immediately moves the legs of three-legged lever 36 into the positions shown in the isolated view of FIG. 2 from which non-essential parts have been omitted for clarity of description. Thus, hook 40 is moved out of engagement with pin 42 thereby permitting spring 30 to turn the partly toothed gear 20 counterclockwise until its toothed portion 22 engages the teeth on continuously rotating pinion 18. Partly toothed gear 20 is thereupon further turned counterclockwise by pinion 18.

Referring to the isolated view of FIG. 3, it will be seen that cam plate 104 is turned about its pivot 106 to the position depicted in dot-dash lines in response to the upward movement of pin 114 with slide 50. The eccentric actuating cam 28 turns with partly toothed gear 20 in the direction of the arrow of FIG. 3 and, in bearing against the leg 82 of L-shaped lever 66, begins turning L-shaped lever 66 counterclockwise about its axis 68. The pin 84 connecting the end of leg 82 with idler bar 86 begins moving the idler bar toward the right. At the same time, the leg 80 of L-shaped lever 66, in bearing against pin 78 on head board 70 (FIGS. 2 and 3), begins moving head board 70 upward, that is, toward the operative position. If solenoid 56 remains energized during this procedure, the abutment face 120 of hook 118, being elevated by the turning of cam plate 104 to the position shown in dot-dash lines on FIG. 3, remains disengaged from actuating pin 126. Consequently, actuating pin 126 slides rightward in elongated slot 124 with the rightward movement of idler bar 86 without causing corresponding movement of switch actuating bar 88. As a result, switch actuating bar 88 remains in its reproduce position shown on FIG. 1 while idler bar 86 moves to the right. The control element 100 of record-reproduce switch 102 consequently stays in the illustrated reproduce position while the head board 70 is moved to its operative position for contacting heads 72 and pinch roller 74 with the magnetic tape (not shown).

At the completion of the above operating sequence, the operating condition shown in the isolated view of FIG. 4 is achieved. As long as solenoid 56 remains energized, armature 54 holds slide 50 in the upward position and maintains three-legged lever 36 in the position shown on FIG. 4, and in which abutment surface 53 of third leg 51 is engageable by pin 42 and prevents further counterclockwise rotation of partly toothed gear 20 under the urging of spring 30. With pin 42 bearing against abutment surface 53, toothed region 22 of partly toothed gear 20 is held out of contact with pinion 18. The lobe of eccentric actuating cam 28 holds L-shaped lever 66 in its extreme counterclockwise rotational position about its pivot 68 and thus holds head board 70 in its fully upward, or operative position for reproducing of signals recorded on a tape, while idler bar 86 is held in its fully rightward position.

When solenoid 56 is deenergized, return spring 58 moves slide 50 in the downward direction and consequently turns three-legged lever 36 in the counterclockwise direction about post 32 to the position shown on FIG. 5. This turning of lever 36 disengages abutment surface 53 of third leg 51 from pin 42 and permits spring 30 to rotate partly toothed gear 20 and eccentric actuating cam 28 in the counterclockwise direction back toward the stopped position shown in FIG. 1. The rotation of eccentric actuating cam 28 in this fashion permits L-shaped lever 66 to be turned clockwise under the urging of return springs 76a and 76b acting on head board or carriage 70 for moving the latter to its inoperative position while idler bar 86 is moved leftward in the drawing. As idler bar 86 moves leftward, pin 126 rides under hook 118 of cam plate 104 until abutment face 120 again engages actuating pin 126 to reestablish the condition shown on FIG. 1. Finally, the stopped condition is reached when pin 42 on gear 20 is again held by hook 40.

The following sequence of operations of the control device 10 occurs when establishing the recording mode of the tape recording and reproducing apparatus:

Returning again to FIGS. 1 and 2, it will be appreciated that, if solenoid 56 is only momentarily energized to release pin 42 from hook 40 and to establish the engagement of pinion 18 with the toothed region 22 of partly toothed gear 20 and then is again deenergized, cam plate 104 is permitted to return to its solid line position shown on FIG. 3 before actuating pin 126 has passed abutment face 120 of hook 118. Consequently, as idler bar 86 is moved rightward in response to rotation of eccentric actuating cam 28 and the resulting turning of lever 66, actuating pin 126 engages abutment face 120, as shown on FIG. 6, and displaces cam plate 104 and switch actuating bar 88 toward the right, as shown by the arrow. This motion of switch actuating bar 88 moves control element 100 of record-reproduce switch 102 rightward to its record position. The rightward motion of cam plate 104 moves its cam 116 away from the possibility of contact with pin 114 on slide 50. Solenoid 56 may then be reenergized to turn three-legged lever 36 in the clockwise direction to the position of FIG. 4 in which abutment surface 53 is engaged by pin 42 to properly stop the rotation of the partly toothed gear 20 in the operative position. Since there is no engagement of cam 116 with pin 114, cam plate 104 remains in its counterclockwise position shown on FIG. 6 and actuating pin 126 engages face 120 to draw the cam plate 104 and the attached switch actuating bar 88 fully to the right and thus to actuate record-reproduce switch 102 fully into its record position.

When solenoid 56 is deenergized at the end of a recording operation, lever 36 is turned to release abutment surface 53 from pin 42 and thereby permit the return of gear 20 and the other elements of device 10 to their original positions, as described above in connection with the termination of a reproducing operation. In the course of such return movement of idler bar 86 the leftward motion of actuating pin 126 causes the latter to bear against the left end 162 of elongated slot 124, and thereby returns switch actuating bar 88 and control element 100 to the reproduce positions shown on FIG. 1. Thus, upon deenergization of solenoid 56, record-reproduce switch 102 is always returned to the reproduce position in preparation for the next operation.

The sequence of signals to solenoid 56 for establishing the reproducing mode is shown on FIG. 7. At time t.sub.1, solenoid 56 is energized and, in order to achieve the reproducing mode, solenoid 56 is continuously energized, as previously described, thus permitting head board or carriage 70 to be displaced to its operative position without changing record-reproduce switch 102 from its reproduce position.

The sequence of signals to solenoid 56 for establishing the recording mode is shown on FIG. 8. Energizing of the solenoid for a short interval, as at 134 between times t.sub.1 and t.sub.2, initiates the motion of partly toothed gear 20. At time t.sub.2, idler bar 86 has not moved far enough to prevent engagement of the face 120 of hook 118 by actuating pin 126. Consequently, when solenoid 56 is deenergized at time t.sub.2, cam plate 104 is returned to the position shown on FIGS. 1 and 6 and switch actuating bar 88 is displaced to the right by engagement of actuating pin 126 with face 120, as previously explained. Thereafter, at time t.sub.3, the solenoid is again energized, as indicated at B on FIG. 8, in order to move the three-legged lever 36 into the position shown on FIG. 4. Time t.sub.3 can be any time during the turning of partly toothed gear 20 after cam 116 has been moved out of the possibility of contact with pin 114 and before pinion 18 becomes disengaged from the toothed region 22 of partly toothed gear 20.

It will be apparent to one skilled in the art that more than two functions can be controlled by properly timing the energization signals to the single solenoid 56. For example, record-reproduce switch 102 may have three functional positions including, for example, a reproduce position at one extreme of its range of movement, a record position at the other extreme of its range of movement and a third function, such as, an erase operation or the like, at an intermediate position between the extremes. A second hook (not shown) could be provided on cam plate 104, and, by suitably timing the reenergization of the solenoid, hook 118 or the second hook (not shown) could be selectively engaged by the actuating pin 126 for thereby placing the record-reproduce switch 102 in the selected position.

Referring to FIG. 9, one embodiment of control circuit 128 is shown which employs a digital technique for controlling the timing of solenoid 56. A manual controller 136 which may include switches and other controls (not shown) may directly provide a drive voltage on a line 138 to tape drive motor 12. A speed signal generator in tape drive motor 12, such as a pulse generator (not shown), generates an output pulse one or more times per revolution of the motor shaft, and such output pulses are supplied as a speed signal on a line 140 to a speed detector 142. Depending on whether the frequency of the pulses constituting the speed signal is too fast or too slow with respect to a reference, speed detector 142 generates a signal for servo 144 which is thereupon effective to increase or decrease the motor speed in order to achieve and maintain the desired motor speed. The output pulses representing the speed of motor 12 are also supplied through detector 142 to a counter 145. When counter 145 has accumulated predetermined numbers of input pulses after being activated by a command signal on a command line 148, counter 145 applies a signal to a solenoid controller 146. The solenoid control command line 148 from manual controller 136 to counter 145 determines the control functions to be performed by solenoid controller 146. For example, when the reproduce function is selected at manual controller 136, the solenoid controller 146 is commanded to energize the solenoid 56 and to maintain it in the energized condition, as shown in the waveform of FIG. 7, so long as a reproducing operation is being performed. Alternatively, if the recording function is selected at manual controller 136, the solenoid controller 146 is made to produce the pulsed waveform shown on FIG. 8 under the control of the counter 145. In other words, counter 145 is activated by a command signal on line 148 indicating selection of the recording function and counts the pulses representing motor speed. Upon the counting of a first number of such pulses in the interval A on FIG. 8, counter 145 signals controller 146 to deenergize solenoid 56, as at the time t.sub.2, and, thereafter, upon the further counting of a second number of the pulses, counter 145 signals controller 146 to reenergize solenoid 56, as at the time t.sub.3 on FIG. 8. It will be appreciated that, in the control circuit 128 of FIG. 9, the control of the deenergizing and reenergizing of the solenoid 56 on the basis of the pulses counted by counter 145 ensures that such deenergizing and reenergizing will occur with the gear 20, and hence the other parts of control device 10, in precisely predetermined positions for ensuring correct mode selection by the device 10.

Referring now to FIG. 10 in which like reference numerals indicate like apparatus, it will be seen that a control circuit 128 for use with a device according to this invention may employ a resistance capacitance time constant timer 150 which may be substituted for the counter 145 of the control circuit of FIG. 9. The timer 150 receives a command signal on solenoid control command line 148 and provides a selected time signal to solenoid controller 146. Timer 150 may be appropriately enabled to produce the solenoid energizing signal on FIG. 7 or on FIG. 8 depending on the command on the command line 148. Speed signals from tape drive motor 12 may be optionally omitted from timer 150 which thereupon relies on predetermined time constants to properly time the deenergization and reenergization of solenoid 56 as shown on FIG. 8 when the recording mode is selected.

Having described specific embodiments of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims.