JPH039127Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a head shifting mechanism for a tape player, and more particularly to a mechanism for advancing the head to a playback position.

Recently, tape players have been proposed that use a cam mechanism driven by a motor to shift the head forward to the playback position. With this tape player, if the head and motor are left connected even after the head has completed its forward shift operation, unnecessary load will be placed on the motor, which will shorten its life and degrade performance. The operation of the cam mechanism interlocked with the head is separated from the motor drive section every cycle. The structure is such that a solenoid controls the start of engagement between the separated cam mechanism section and the motor drive section.

In such a tape player, when performing an eject operation in the middle of a head shift operation,
Since the eject operation cannot be performed unless the head is completely retracted from the cassette, it is necessary to retract the head even if the head is in the middle of a shift operation. However, if the head advances halfway and the cam mechanism has operated to some extent, it is difficult to disconnect the cam mechanism from the motor drive unit and return it to its initial state during the head shift. Make it unstable or
This is almost impossible as it requires a complex structure. For this reason, in reality, when attempting to eject during a head shift operation, the engagement between the head portion and the cam mechanism is released, and the head is moved backward to perform the eject operation. In this case, when the cassette is ejected, the power to the mechanism is turned off and the motor stops, leaving the cam mechanism in the middle of its operation.

In addition, even when the power is turned off, even when the power is turned off, the cam mechanism and the head are separated from each other, and the head is moved back, assuming that the power will be ejected from the state in which the power is turned off. There is.

If you try to play the tape in these conditions by reinserting the cassette or turning the power on again, the cam mechanism is still in the middle of operating, so it is not engaged with the head section, and the cam mechanism is not operating. The head shift operation cannot be performed until the cycle is completed and the head section is engaged again. On the other hand, since the solenoid drive for operating the head shift mechanism is performed during that time, it is necessary to drive the solenoid again to perform regeneration.

In particular, in the past, as a means to drive the solenoid again, the rotation of the reel base was detected, and at the end of the tape, tape end detection was performed to switch the run for auto reverse or auto eject for one-way playback. The solenoid was driven again using the signal from the section. Such a method requires a certain amount of detection time to reliably detect that the drive of the reel tape base has stopped at the end of the tape. Furthermore, the mechanism for shifting the head using a motor as described above requires a certain amount of operating time, unlike the mechanism for shifting the head portion all at once using a normal spring. Therefore, with the conventional type that detects the tape stop and indirectly detects the head position as described above, all operations from the cam mechanism activation to the solenoid reactivation are completed, and the tape is not played back. The disadvantage is that it takes a considerable amount of time to start.

In the present invention, in order to improve this drawback, a detector is provided to detect when the head moves forward, and the head comes to the playback position within a certain period of time after the solenoid is activated by inserting the cassette or turning on the power. It is an object of the present invention to provide a head shift mechanism in which the solenoid is driven again when there is no regeneration operation, thereby minimizing the time required to start a regeneration operation.

The present invention will now be explained in detail based on illustrated embodiments.

A pack detection switch SW1 is provided on the power supply line of the tape player. This pack detection switch SW1 is turned on when a cassette pack is inserted into the tape player. A power supply voltage detection section 1 is connected to this pack detection switch SW1. This power supply voltage detection section 1 monitors the voltage of the power supply line and generates an output when the power supply voltage reaches a certain value or more, and is constituted by a switching circuit using a transistor, a relay, and the like. A trigger pulse train generating section 2 is connected to the next stage of the power supply voltage detecting section 1 . This trigger pulse train generating section 2 continues to generate pulses at regular intervals when there is an output from the power supply voltage detecting section 1, and is configured by, for example, a free-running multi-function device, a differentiating circuit, etc. . Further, on the output side of the power supply voltage detection section 1,
Head position detection switch SW2 with one end grounded
is connected. This head position detection switch
SW2 is turned on when the head is held at the playback position.

Incidentally, a rectangular wave generating section 3 is connected to the subsequent stage of the trigger pulse train generating section 2. This rectangular wave generator 3 uses a circuit such as a monostable multivibrator, and when an input pulse is received from the trigger pulse train generator 2 in the previous stage, a predetermined signal is applied to the solenoid drive unit 4 in the next stage. It sends a square wave. A solenoid drive unit 4 connected to the rectangular wave generator 3 receives an input signal from the rectangular wave generator 3 and operates a head shift solenoid.
This drives the SOL, thereby moving the head toward the playback position.

Next, the operation of the head shift mechanism of the present invention having such a configuration will be explained.

When power is applied to the tape player mechanism power input, a cassette pack is inserted into the tape player and the pack detection switch SW1 is turned on, or if a pack is already inserted into the tape player, Mechanism When power is applied to the power supply line, the voltage of the power supply line rises, and in response to this, the power supply voltage detection section 1 generates an output. At this time, as described in the description of the prior art, the head is not at the reproduction position, so the head position detection switch SW2 is off. Therefore,
The output from the power supply voltage detection section 1 is input to the next stage trigger pulse train generation section 2, and pulses are sent from the trigger pulse train generation section 2 to the rectangular wave generation section 3 at regular intervals. Then, in response to the input of this pulse, an appropriate rectangular wave is sent from the rectangular wave generating section 3 to the solenoid driving section 4, which activates the solenoid driving section 4 and activates the head shift solenoid.
SOL is activated and moves the head to the playback position.
When the head is at the reproduction position, the head position detection switch SW2 is turned on, and the output from the power supply voltage detection section is not input to the trigger pulse train generation section 2. As a result, the next output from the trigger pulse train generation section 2 is Pulses will no longer occur.

On the other hand, if the head does not reach the playback position despite the operation of the head shift solenoid SOL, the head position detection switch SW2 will also remain off, so the output from the power supply voltage detection section will still be sent to the trigger pulse train generation section 2. As a result, the trigger pulse train generator generates the next pulse, and the same operation is repeated thereafter. Here, the output interval of the trigger pulses from the trigger pulse train generating section 2 is the time required for the cam mechanism and the head section to be connected by the head shift solenoid SOL, and for the head to reach the playback position as the cam mechanism operates. It needs to be larger than . The reason is,
This is because if the interval between trigger pulses is narrow, the next trigger pulse will be generated before the head reaches the playback position, and the head shift solenoid SOL will be driven again.

As shown in the above embodiments, the head shift mechanism of the present invention detects the position of the head using the head position detection switch SW2, and immediately operates the head shift solenoid SOL. Compared to a method in which the head position is detected using a signal from a tape end detection section and the solenoid is driven, this method has the advantage that the head position can be detected immediately and the head shift solenoid SOL can be redriven quickly. Furthermore, compared to the conventional type in which the head position is detected via a tape end detection section, the circuit configuration is simpler and the number of parts of the entire apparatus can be reduced.

In addition, there is a possibility that the head shift mechanism may malfunction, even if the solenoid is driven, if the load to start the cam mechanism is heavy due to a low temperature environment, etc., the head shift mechanism may malfunction. In some cases, the operation may be started by driving the solenoid two or three times. Also, even if the head shift mechanism operates,
In some cases, the mechanism for holding the head at the playback position after the shift operation malfunctions and the head cannot be held. In such a case, it does not mean that the mechanism has completely malfunctioned and cannot operate, but simply that
According to the present invention, since the regeneration operation is started within a relatively short period of time since the malfunction has occurred only twice, the present invention has the advantage that it does not cause any major trouble in use.

[Brief explanation of the drawing]

The drawing is a circuit diagram showing an embodiment of the head shift mechanism of the present invention. 1...Power supply voltage detection section, 2...Trigger pulse train generation section, 3...Square wave generation section, 4...Solenoid drive section, SW1...Pack detection switch, SW2
...Head position detection switch, SOL...Head shift solenoid.

Claims (1)

[Scope of Claim for Utility Model Registration] In a tape player that uses the power of a motor driven by a solenoid to move the head section to the playback position, a pack that turns on when a cassette pack is inserted into the tape player. a detection switch; a power supply voltage detection section that generates an output when the pack detection switch is on and the power is turned on; and a solenoid drive section that drives the solenoid at predetermined intervals using the output of the power supply voltage detection section. and a head position detection switch that is turned on when the head is held at the playback position and stops the solenoid drive section.