JPS6028062B2 - Recording switching circuit in tape recorder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a recording switching circuit in a tape recorder.

Most tape recorders normally record by pressing the play button and record button at the same time, but with those that use soft-touch non-lot buttons, when you try to playback, you accidentally press the play button and record button at the same time. In some cases, the previously recorded portion of the tape may be erased by touching the record button.To prevent this, a dual-purpose locking safety switch is provided to select between the left channel and the right channel. There is something that prevents the transition to recording operation.

However, in this conventional example, the playback button, record button, and safety switch function as a simple AND function for the recording operation, so the safety switch must be pressed after pressing all of them to start the recording operation. If the safety switch is released and then the safety switch is pressed again, the recording operation will be performed again, which may lead to erasure or other inconveniences.

The present invention has been made in view of this point, and provides a green tone switching circuit in which, in order to perform a recording operation after releasing the safety switch, it is necessary to press not only the safety switch but also the playback button and the record button. We aim to provide the following.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

The FF circuit 1, which switches the entire unit to recording operation, connects the PLAY (playback) terminal to the set terminal S via the AND circuit 2, and the RE
C (recording) end is connected, and its reset end R
An FF (fast forward) end, a REW (winding tassel) end, and a STOP (stop) end are connected to the OR circuit 3. S, is the right channel safety switch, S2 is the left channel safety switch, both of which are normally closed, and the diodes D, and D2
connected in series between the common connection of and ground.

That is, when both switches S and S2 are opened (released), the FF circuit 1 is reset by the action of the diode D2, and the output Q is set to L level and Q is set to H level. Drop the H level pulse to ground. Outputs Q and Q of FF circuit 1 are capstan motor M
This pitch control switching circuit 4 applies a voltage to the fixed terminal of the pitch variable resistor 5 when the transistor Q3 is turned on due to the conduction of the transistor Q, and the voltage is applied to the fixed terminal of the pitch variable resistor 5 when the transistor Q2 is turned on. When Q is conductive, a voltage is applied to the movable terminal of the pitch variable resistor. 6 is a drive circuit for the capstan motor M, and the rotation speed of the capstan motor M is determined by a signal from the variable pitch resistor 5.

Reference numeral 7 denotes a recording drive circuit, which is activated by conduction of the transistor Q to operate the recording bias circuit and to enable the left and right erasing heads and the left and right erasing heads to operate.

D3 is a light emitting element that displays the recording status. In addition, the left and right erasing and recording heads are operated by the left and right safety switches S, S2.
connected by a switch that moves to the In the above configuration, it is assumed that the FF circuit 1 is in a reset state when the power is turned on, that is, its output Q is directed to the L level and the output Q is directed to the H level.

Therefore, when the power is turned on, the transistors Q2 and Q4 become conductive, and a voltage is applied to the movable terminal of the pitch variable resistor 5, so that the capstan motor M is in a state where its speed pitch can be changed. In this case, if the reproduction state is set, the reproduction speed can be changed by the variable pitch resistor 5. Also, at this time, press the play button and record button to play.
Even if an H level pulse is applied to the AY and REC terminals, the right channel safety switch S and the left channel safety switch S
2 are both closed, the H pulse from the AND circuit 2 is not input to the set end S of the FF circuit 1 because the diode D is conductive. To move to recording operation,
All you have to do is operate both the right channel safety switch S and the left channel safety switch S2 to open them, then press the playback button and the record button to input an H level pulse to the PLAY end and the REC end.

As a result, an H level pulse is output from AND circuit 2, and F
The F circuit 1 is set to a set state and its output Q is inverted to H level. For this reason, the recording drive circuit 7 uses the transistor Q5.
The light emitting diode D3 also lights up to indicate the recording operation. At this time, pitch control switching circuit 4
'Ma transistor Q. Since Q3 is conductive, a voltage is applied to the variable pitch resistor 5 in its fixed state, and the variable resistor 5 has no variable function, so the capstan motor M rotates at a constant speed that cannot be changed. do.
From the above, the entire process shifts to recording operation. Next, when the right channel safety switch S and the left channel safety switch S2 are closed (released), diode D2 becomes conductive, so F
The output Q of the F circuit 1 is inverted to L level and Q is inverted to H level, so that the pitch control switching circuit 4 allows the pitch variable resistor 5 to have its variable function, and the recording drive circuit 7 changes the pitch of the transistor Q5. Blocking it will stop that operation.

In other words, the recording operation is canceled. Next, when the right channel safety switch S and the left channel safety switch S2 are opened, the diode D2 is cut off, but the safe state of the FF circuit 1 is not restored, so the release state of the recording operation remains unchanged.

In other words, there is no transition to recording operation. In order to shift to the recording operation, it is necessary to press the playback button and the record button again to apply an H level pulse to the PLAY end and the REC end.

From the above, according to the present invention, even if the safety button is released during the recording operation to cancel the recording operation and the safety button is operated again, the recording operation will not proceed, and the intended purpose is fully achieved. It becomes like this.

[Brief explanation of the drawing]

The figure is a circuit diagram showing one embodiment of the present invention. 1...FF circuit, 4...Pitch control switching circuit, 5...
...Pitch variable resistor, 6... Capstan motor drive circuit, 7... Recording drive circuit, M...
・Capstan motor, S...Right channel safety switch, S2...Left channel safety switch.

Claims (1)

[Claims] 1 Switch the entire unit to recording operation by outputting the set state,
an FF circuit that cancels the recording operation by outputting a reset state, and a circuit that generates an H level set signal to the FF circuit by simultaneous operation of a record button and a play button;
In a non-operated state, the set input of the FF circuit is grounded to cut off the application of the set signal to the FF circuit, and in a locked state due to operation, the set signal can be applied to the FF circuit. 1. A recording switching circuit for a tape recorder, comprising a safety switch that resets the FF circuit by releasing the locked state in the set state.