JPH0418089Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Technical Field> The present invention relates to a mode switching device for a tape recorder or the like, and particularly relates to a device that performs mode switching using the rotational force of a rotating body.

<Prior art> Conventionally, mode switching devices for tape recorders, etc., have a function of pressing the playback button when transitioning from stop mode to playback mode, as shown in Japanese Patent Application Laid-Open No. 56-148754 "Mode Switching Device for Tape Recorders, etc." There is a mode switching device that has a structure in which a drive motor is driven in conjunction with the operation, and the rotational force of the drive motor rotates a rotating body having a cam.The sub-chassis is raised in conjunction with the cam, thereby bringing the magnetic head into contact with the tape.

By the way, in a device having such a structure, the rotating body is locked with a lock member to prevent free rotation of the rotating body in the stop mode, but such a lock cannot be applied to the touch switch type playback button operation. Therefore, there are some that are released by the operation of an activated electromagnetic solenoid.

However, with the conventional mode switching device that uses such an electromagnetic solenoid to release the lock of the rotating body,
If, for example, the power is cut off due to a power outage while the sub-chassis is moving forward in the direction of the playback position according to the operation of the playback button, the movement of the mechanism including the sub-chassis will be interrupted in the middle, and the The cassette holder itself cannot be ejected and the cassette tape cannot be removed. Moreover, in a device having this electromagnetic solenoid structure, a signal from the touch switch type playback button is received by a flip-flop circuit or the like for storing and retaining the signal, and the output signal of the flip-flop circuit or the like is used to control the electromagnetic solenoid and the Controls the drive motor. Therefore, even if the power is turned back on after the power outage is restored, the output signal from the flip-flop circuit remains de-energized, so the drive motor does not rotate and the cassette holder ejects as described above. Impossibility cannot be avoided.

In order to avoid these situations, after turning on the power again, operate the regeneration button to set the flip-flop circuit, etc. again to the set state, supply power to the drive motor, and switch the mechanism including the subchassis to the regeneration state once. Then, the mechanism including the sub-chassis must be returned to the stop mode by operating a stop button, which is inconvenient to use.

<Purpose of the invention> In view of the above-mentioned problems of the conventional device, the present invention automatically generates motor drive control pulses from a pulse generation circuit without operating any buttons when the power of a tape recorder, etc. is turned on, and generates motor drive control pulses for a certain period of time. The object of this invention is to drive the drive motor to return the mechanism including the subchassis to the stop mode, thereby making it possible to eject the cassette holder and improving the operability of the tape recorder and the like.

<Example> An example of the present invention will be described in detail below based on the accompanying drawings.

In FIG. 1, 2 is a lock arm installed on the main chassis 1 so as to be slidable in the lateral direction (in the directions of arrows A and B), and a lock arm 2 has engaging protrusions 2a' at both ends of its horizontal portion. A regeneration lock portion 2b having a portion 2a and an engaging protrusion 2b' extends.

Further, the lock arm 2 has a spring 3 suspended between its end on the regeneration lock portion 2b side and the main chassis 1, so that the lock arm 2 engages the stop lock portion 2a with a first engagement protrusion 7d of the cam gear 7, which will be described later. The lock arm 2 is biased in the direction of the arrow A (direction of arrow A) where the mating protrusion 2a' can engage (hereinafter referred to as the first position), and the lock arm 2 has an electromagnetic solenoid 4 at its end on the stop lock portion 2a side. The interlocking operating rod 4a is engaged, and the regeneration lock portion 2b is engaged with a second engagement protrusion 7e of the cam gear 7, which will be described later, from the first position based on the attraction operation of the electromagnetic solenoid 4. It is designed to slide in a direction (in the direction of arrow B) where the projection 2b' can engage (hereinafter referred to as the second position).

5 is a support shaft 5 provided on the main chassis 1
This is a sub-chassis operating arm having an L-shape on the upper surface, which is pivotally supported at one end on the stop lock part 2a,
A sliding protrusion 5b is provided on the lower surface of the horizontal part that crosses over the reproduction lock part 2b, and the upper end of the vertical part at the other end can come into contact with and separate from the sub-chassis 12, which will be described later. The contact surface 5c is always biased by a spring 6 suspended between the other end of the horizontal portion and the main chassis 1 in the direction of the position away from the sub-chassis 12 (described later) (in the direction of arrow C).

7 is a support shaft 7a provided on the main chassis 1.
It is a cam gear that is pivotally supported so as to rotate only in the direction of arrow D, and has a toothless part 7b on its peripheral gear, and the toothless part 7 as seen in the rotation direction of the cam gear 7.
On the upper surface of the distal end side of b, there is the regeneration lock part 2b.
A second engagement protrusion 7e that can be engaged with and disengaged from the engagement protrusion 2b' of
It is equipped with Further, the upper surface of the cam gear 7 is further provided with a cam 7c which is an annular band whose radius of curvature is gradually changed around the support shaft 7a. When viewed from above, a first engaging protrusion 7b is provided at a position opposite to the toothless portion 7b.

The cam 7c has a maximum diameter of 7f ₁ as viewed from the support shaft 7a on its inner surface 7f.
The maximum diameter portion is set to 7f ₁ , and the minimum diameter portion slightly forward of the rotational direction of the cam gear 7 is 7f ₂ , and a sloped portion 7f ₃ is formed between the maximum and minimum diameter portions.

Reference numeral 8 denotes a driving gear that is pivotally supported together with a pulley 8b on a support shaft 8a provided on the main chassis 1, and a transmission belt 10 is stretched between the pulley 8b and a pulley 9b attached to a motor shaft 9a. The cam gear 7 is simultaneously driven by a drive motor 9 which is a drive source through
When the teeth of the cam gear 7 are engaged, the cam gear 7 is driven.

11 is a support shaft 11 protruding from the main chassis 1;
This is a starting spring that is wound around a and has one end that can be freely engaged with and detached from the first engagement protrusion 7d of the cam gear 7, and the other end that is engaged with the engagement pin 11b on the main chassis 1. and lock arm 2 above.
When the engaging protrusion 2a' of the stopping lock part 2a engages with the first engaging protrusion 7d of the cam gear 7 and the cam gear 7 is in the stopped state, the cam gear 7 is in the most compressed state and takes an energy storage state. It is configured like this.

Reference numeral 12 denotes a sub-chassis which is installed on the main chassis 1 so as to be able to reciprocate back and forth, and erasing and recording/playback heads 13 and 14 are fixedly mounted on the board surface. Further, this sub-chassis is always biased in the direction of arrow C by a spring 15 suspended between its front end and the main chassis 1, and this bias causes the tape of the cassette tape 16 to cause the two heads 13, 14 are arranged to take stop positions separated from each other.

Reference numeral 17 denotes a power supply section, which supplies power from a commercial power source or a battery as a direct current component to each circuit section.

19 is a mechanism control circuit connected to the power supply section 17 via a power switch 18;
For example, as shown in the figure, an RS type flip-flop circuit (hereinafter referred to as FF circuit) 20 and this FF circuit 20
It is inserted between the set input terminal S and the above power switch 18, and is turned on by pressing the play button PB.
a playback switch 21 consisting of a touch switch that sets the FF circuit 20;
It is inserted between the 0 reset input terminal R and the power switch 18, and is turned on by pressing the stop button SB.
The stop switch 22 is a touch switch that resets the FF circuit 20.

23 is a solenoid drive circuit located between the output terminal Q of the FF circuit 20 and the electromagnetic solenoid 4, and when the FF circuit 20 is in the set state and a regeneration enable signal is obtained from the output terminal Q, this is activated. Based on this, the electromagnetic solenoid 4 is driven. Further, 24 is a motor drive circuit located between the output terminal Q and the drive motor 9, and based on the input of the regeneration enable signal, the power supply unit 17
A power supply voltage of 1 is supplied to the drive motor 9 to drive the drive motor 9.

Reference numeral 25 denotes an auxiliary mechanism control circuit (hereinafter referred to as a pulse generation circuit) provided between the power switch 18 and the motor drive circuit 24, which drives the motor for a certain period of time when the power supply voltage is first supplied from the power supply section 17. A control pulse is output, and the drive motor 9 is rotated for a certain period of time by the motor drive circuit.

Also, between the pulse generation circuit 25 and the motor drive circuit 24 and the output terminal Q of the FF circuit 20,
Diodes 26 and 27 for preventing backflow are connected between the motor drive circuit 24 and the motor drive circuit 24.

Since the present invention is constructed as described above, the playback button can be pressed while the power switch 18 is turned on.
When the PB is operated, a set signal is generated in the mechanism control circuit 19 based on the operation of the playback button.
When inputting to the set input terminal S of the FF circuit 20, the FF circuit 20 enters the set state, and the solenoid drive circuit 2
A regeneration enable signal is input from the output terminal Q of the FF circuit 20 to the FF circuit 3 and the motor drive circuit 24. Then, based on this, the electromagnetic solenoid 4 performs a suction operation, and the motor drive circuit 24 supplies a power supply voltage to the drive motor 9 to start rotating the drive motor 9. Then, in accordance with the attraction operation of the electromagnetic solenoid 4, the lock arm 2 moves laterally in the direction of arrow B and moves from the first position to the second position, and the engaging protrusion 2a' of the stop lock portion 2a and the cam gear are connected to each other. 7 is disengaged, and based on this disengagement, the cam gear 7 is caused to rotate in the direction of arrow D by the biasing force of the starting spring 11, and This meshes with the drive gear 8 driven by the drive motor 9 and further rotates in the same direction. Then, as the cam gear 7 rotates in the direction of arrow D, the diameter of the cam inner surface 7f of the cam 7c that contacts the sliding protrusion 5b of the sub-chassis operating arm 5 gradually becomes smaller, so that the sub-chassis operating arm 5 is moved by the spring 6. While rotating in the direction of arrow D, the sub chassis 1 is rotated through the contact surface 5c.
Advance 2. Then, as the rotation of the cam gear 7 progresses, the second engagement protrusion 7e of the cam gear 7 engages with the engagement protrusion 2b' of the regeneration lock part 2b, thereby blocking the rotation of the cam gear 7. When the rotation of the cam gear 7 is stopped, the sliding protrusion 5b of the sub-chassis operating arm 5 touches the minimum diameter portion 7f ₂ of the cam inner surface 7f.
The sub-chassis operating arm 5
The sub-chassis 12 is placed in the most advanced position (playback position) via
, and the playback mode shown in FIG. 2 is entered.

In this state, the cam gear 7 has made approximately one full rotation since the beginning, and since the drive gear 8 is located at the front end of the toothless portion 7b, the cam gear 7 is driven by the drive gear 8. It's becoming less common.

Next, when the stop button SB is operated from the regeneration mode, a reset signal is input to the FF circuit 20 in the mechanism control circuit 19, so the regeneration enable signal is deactivated, and according to the solenoid drive circuit 23,
The electromagnetic solenoid 4 stops the suction operation, and the drive motor 9 also stops rotating according to the motor drive circuit 24. Then, as the electromagnetic solenoid 4 stops attracting, the lock arm 2 instantly returns from the second position to the first position by the return force of the spring 3, so that the second engagement of the cam gear 7 The engagement between the protrusion 7e and the engagement protrusion 2b' of the regeneration lock part 2b is released, and the engagement protrusion 2a' of the stop lock part 2a engages with the first engagement protrusion of the cam gear 7. 7d.

As a result, the rotation preventing force on the cam gear 7 is eliminated, so that the return force of the spring 6 is applied to the cam gear ₇ via the sliding protrusion 5b of the sub-shear operating arm 5 located at the smallest diameter portion 7f2 on the inner surface of the cam 7c. By rotating the cam gear 7 in the direction of the arrow D, the sliding protrusion 5b slides in the direction of the slope _7f , and in conjunction with this, the cam gear 7 is further rotated in the direction of the arrow D. Rotate. Then, when the first engagement protrusion 7d of the cam gear 7 engages with the engagement protrusion 2a' of the stop lock portion 2a, its rotation is stopped. In this state, the above sub chassis 1
2, the erasing, recording and reproducing heads 13 and 14 have returned to the position separated from the tape of the cassette 16 by the return force of the spring 15, and are in the stop mode shown in FIG.

Therefore, if the power is cut off due to, for example, a power outage while the sub-chassis 12 is moving to the playback position in accordance with the operation of the playback button, the playback from the output terminal Q of the FF circuit 20 in the mechanism control circuit 19 Since the enabling signal is deenergized and the rotation of the drive motor 9 is stopped according to the motor drive circuit 24, the rotation of the cam gear 7 meshing with the drive gear 8 via the transmission belt 10 is also interrupted. As a result, the forward movement of the sub-chassis 12 is stopped midway through the sub-chassis operating arm 5. Further, since the electromagnetic solenoid 4 stops the suction operation when the regeneration enable signal is deenergized, the lock arm 2 moves laterally in the direction of arrow A due to the return force of the spring 3, and moves from the second position to the first position. After returning to the position, the engagement protrusion 2b' of the regeneration lock part 2b is disengaged from the second engagement protrusion 7e of the cam gear 7, and the engagement protrusion 2a' of the stop lock part 2a is disengaged from the second engagement protrusion 7e of the cam gear 7. It waits at the engagement position with the first engagement protrusion 7d.

When the power outage recovers from such a power outage state, the pulse generation circuit 25 outputs a motor drive control pulse with a fixed time width, and this pulse is given to the motor drive circuit 24 through the backflow prevention diode 26. , the circuit 24 applies a power supply voltage to the drive motor 9 for a certain period of time to drive the drive motor 9. Then, the rotation of the drive motor 9 rotates the cam gear 7 whose rotation is being interrupted in the direction of arrow D via the transmission belt 10, and the sub-chassis operating arm whose sliding protrusion 5b is brought into sliding contact with the cam inner surface 7f. 5, the sub chassis 12 is once advanced to the reproduction position. However, at this time, the lock arm 2 is already in the first position due to the power outage.
, and the engagement protrusion 2b' of the regeneration lock part 2b is disengaged from the engagement position with the second engagement protrusion 7e.
The cam gear 7 rotates until it reaches the playback position,
Even if the second engagement protrusion 7e reaches the engagement position with the engagement protrusion 2b' of the regeneration lock part 2b, the second engagement protrusion 7e cannot be engaged with the regeneration lock part 2b. In other words, the cam gear 7 is not stopped from rotating.
Subsequently, the return force of the spring 6 is applied to the sliding protrusion 5b of the sub-chassis operating arm 5 and the cam inner surface 7f in the same manner as when returning from the regeneration mode to the stop mode.
, and rotates in the direction of arrow D.

As a result, the stop lock portion 2 of the cam gear 7
When the engaging protrusion 2a' of the cam gear 7a engages with the first engaging protrusion 7d of the cam gear 7, it enters a stop mode and stops.

Therefore, when the power is restored and the power is turned on again, the mechanism including the subchassis is automatically returned to the stop mode without pressing any button, and the cassette holder can then be immediately opened by the eject operation. to remove the cassette tape.

In addition, in the present invention, not only when the mechanism including the sub-chassis stops during the transition from the stop mode to the regeneration mode due to a power outage as described above, but also when the above-mentioned stop lock part 2a is locked due to an impact etc. in the stop mode. The engagement between the mating projection 2a' and the first engaging projection 7d of the cam gear 7 is released, and the cam gear 7 is caused to rotate in the direction of arrow D by the biasing force of the activation spring 11, and the tooth portion Even if the rotation is stopped when the drive gear 8 is engaged with the drive gear 8, when the power switch 18 is turned on and the power is supplied to the pulse generation circuit 25, the same operation as described in the case of a power outage is performed. , the mechanism including the sub-chassis can be automatically returned to the stop mode via the regeneration mode.

<Effects of the invention> As described above, according to the invention, even if the mechanism including the sub-chassis stops in the middle of transitioning from stop mode to regeneration mode due to a power outage or other cause,
Simply by turning the power back on, the mechanism can automatically return to stop mode without pressing any buttons, and during this time the lock arm is in the first position with the electromagnetic solenoid de-energized. , it is possible to return the mechanism to the stop mode in a short time without having to temporarily stop the mechanism in the regeneration mode, and therefore the inconveniences of the prior art can be solved.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the configuration of a tape recorder in a stop mode, which is equipped with an embodiment of the mode switching device according to the present invention, and FIG. 2 is a schematic diagram of the configuration of the same tape recorder in a playback mode. 4...Electromagnetic solenoid, 7...Cam gear, 7c
...Cam, 9...Drive motor, 12...Sub chassis, 13, 14...Erasing and recording/playback head, 17...Power supply, 19...Mechanism control circuit, 25...Pulse generation circuit, PB...Playback Button, SB...stop button.

Claims (1)

[Claims for Utility Model Registration] A rotating body that switches a mechanism including a sub-chassis on which a magnetic head is placed by a cam from a stop mode to a playback mode and from a playback mode to a stop mode during one revolution, and stopping the rotating body. A lock arm is movable between a first position in which the rotating body is locked in the mode position and a second position in which the rotating body is locked in the playback mode position, and is normally held in the first position by a spring; an electromagnetic solenoid that moves and holds the lock arm in a second position; a drive source that rotates the rotating body; and a drive source that energizes the electromagnetic solenoid and the drive source to stop the rotating body when a playback button is operated. The lock at the mode position is released and the mechanism is switched from the stop mode to the regeneration mode by the rotation of the rotary body, and when the stop button is operated, the energization to the electromagnetic solenoid is stopped to lock the rotor at the regeneration mode position. an auxiliary mechanism control circuit that operates the drive source for a predetermined period of time when the power is turned on; is provided so that when the power is turned on again while the rotating body is stopped during mode switching due to a power outage, etc., the auxiliary mechanism control circuit operates the drive source and returns the mechanism to the stop mode. Features: Mode switching device for tape recorders, etc.