JPH0142826Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cassette tape drive device, and more particularly to a tape protection mechanism against a cassette ejection operation while the tape is running.

Generally, during recording with a cassette tape recorder,
During playback, the tape is held between a capstan and a pinch roller. Therefore, if the cassette is ejected in this state due to an accident such as incorrectly inserting the eject button or the cassette mounting lid becoming unlatched, the cassette mounting lid will open and the cassette will be ejected, damaging the tape. become.

Conventionally, in order to prevent such erroneous operations, there are devices in which, for example, a stop button for stopping the running of the tape and an eject button for ejecting the cassette are used. Some devices protect the tape by stopping the tape when the button is operated while the tape is running, and then ejecting the button when the button is operated again. However, such a device has the disadvantage that the mechanical structure is complicated.

In addition, in cases where a stop button and an eject button are provided separately, the cassette is mechanically ejected by operating the eject button, and prior to this operation, a switch operated by the stop button is activated. A switch having contacts electrically connected in parallel is activated to stop the tape from running. Therefore, in such a device, a switch must be provided to stop the tape running in conjunction with the eject button, which increases the cost.

Also, some models use a mechanical locking mechanism to prevent the eject button from being operated while the tape is running.
In this case, there is a problem that the structure becomes complicated due to the provision of a mechanical locking mechanism.

The present invention was developed in view of the above circumstances, and does not require a switch or locking mechanism, and allows the eject operation to be performed while the vehicle is running by using a contact signal from an accidental erasure prevention switch that protects the tape from being recorded. The object of the present invention is to provide a cassette tape drive device that can reliably protect the tape.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the block diagram shown in FIG. 1 and the sectional view of the switch mechanism for detecting erroneous erasure prevention shown in FIG. 1 in the diagram
A running mode operation panel is provided with a stop switch 1A, a recording switch 1B, a playback switch 1C, a fast forward switch (not shown), a rewind switch, etc., and the tape is run according to the operated mode. A first inverter 2 pulls up its input through a pull-up resistor R1, connects it to a reference potential, that is, the "L" level, through a stop switch 1A, and provides an output to the base of the first transistor 3. The collector of this transistor 3 is connected to the power supply Vcc via the set terminal of a self-holding plunger 4 that performs a stopping operation, and the emitter is connected to a reference potential. 5 is an AND gate with 3 inputs, and the first input is connected to the power supply Vcc via a switch 6 for detecting accidental erasure prevention.
The second input is connected to the power supply Vcc via the recording switch 1B. Based on the output of the AND gate 5, a switching circuit (not shown) switches to the recording mode. And 7 is the second inverter, which pulls up the input with a resistor R2.
It is pulled up and connected to the reference potential via the playback switch 1C. The output of the second inverter 7 is then applied to the third input of the AND gate 5 and the base of the second transistor 8. The collector of this transistor 8 is connected to the power supply Vcc via the set terminal of a self-holding plunger 9 that performs a regeneration operation, and the emitter is connected to a reference position.

Further, the output of the second inverter 7 is applied to the base of a transistor 10, and the collector of this transistor 10 is connected to the reset terminal of the plunger 4. Then, the output of the first inverter 2 is applied to the base of the transistor 11.
The collector of the plunger 9 is connected to the reset terminal of the plunger 9. Therefore, when one of the solenoids 4 and 9 is set, the other is reset at the same time.

The detection switch 6 detects the accidental erasure prevention claw 10A of the cassette 10, for example, as shown in FIG. That is, if the claw 10A of the cassette 10, which is provided at a predetermined position for the purpose of preventing recorded contents from being inadvertently lost, is broken, recording on the tape of the cassette 10 will no longer be possible. Therefore, a lever 11 is rotatably provided so as to intersect with the insertion/ejection path of the cassette 10 (arrow X in FIG. 2), and the detection switch 6 is driven by this lever 11.

That is, the detection switch 6 is connected to the claw 1 of the cassette 10.
If 0A is present, it remains ON while the cassette 10 is being inserted, as shown in FIG. 3a. If the claw 10A is not present, the lever 11 is driven by the edge of the cassette during insertion and removal, and is turned ON for a short period of time as shown in FIG. 3c.

Therefore, the switch 6 is connected to the input of the first inverter 2 via the capacitor C, and a resistor R3 is inserted between this input and the reference potential to form a differentiating circuit. In this way, the differential pulse shown in FIG. 3b is obtained for the ON operation of switch 6 shown in FIG. 3a, and the differential pulse shown in FIG. 3d is obtained for the ON operation of switch 6 shown in FIG. The differential pulse shown in is obtained. Therefore, by applying the negative edge of this differential pulse to the input of the first inverter 2 in parallel with the output of the stop switch 1A, the negative trigger signal (Y shown in FIG. 3) is inverted by the inverter 2 and output to the transistor 3. Give it to ON
By driving the plunger 4, the running of the tape can be stopped.

In other words, by differentiating the output of the detection force switch 6 to prevent mistaken erasure and inputting it to the first inverter 2 in parallel with the output of the stop switch 1A, the detection switch 6 is activated during the discharge operation, thereby ensuring reliable operation. Tape running can be stopped.

Therefore, there is no need to provide a special locking mechanism or a separate switch; instead, the contact signal of the pre-installed accidental erasure prevention detection switch is differentiated and applied in parallel to the stop switch signal. It is also simple and inexpensive.

As described in detail above, the present invention uses a differentiated pulse obtained by differentiating the contact signal of the switch for detecting accidental erasure prevention, which detects the presence of the claw for preventing accidental erasure on the cassette, into the contact signal of the stop switch that stops the tape from running. Since the tapes are applied in parallel, it is possible to provide a cassette tape drive device which can reliably stop the running of the tape during an eject operation and thereby protect the tape with a simple and inexpensive configuration.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention.
FIG. 2 is a sectional view showing essential parts of the above embodiment, and FIG. 3 is a waveform diagram illustrating the operation of the above embodiment. 1A...stop switch, 1B...recording switch, 1C...playback switch, R3...resistance, C...
...capacitor.

Claims (1)

[Scope of utility model registration request] A cassette tape that allows recording on the tape due to the presence of a claw provided at a predetermined position on the cassette, a switch for detecting the prevention of mistaken erasure that detects the presence of the claw, and a contact signal of the switch for detecting the prevention of mistaken erasure is differentiated. 1. A cassette tape drive device comprising: a differential circuit which applies a differentiated pulse in parallel to a contact signal of a stop switch for stopping the running of the tape.