JPS6312415Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tape recorder, and particularly to a tape recorder having a so-called standby function that automatically enters a playback or recording mode when power is supplied by a timer device.

High-grade tape recorders called tape decks are generally constructed so that each operation is switched by the suction operation of a plunger. Currently, many operating circuits for controlling the operation of such plungers are implemented as ICs (integrated circuits). The present invention aims to provide a control circuit for a tape recorder that uses such an IC-based operation circuit and has a standby function, and will be described in detail below with reference to the drawings.

The illustrated circuit is one embodiment of the control circuit of the present invention. In the figure, 1 is an IC-based operation circuit, which has an input terminal into which signals obtained by pressing each operation button are input, and an output terminal that outputs signals for performing each operation according to each operation. It is equipped with 2, 3 and 4 are input terminals for recording, playback and stop, respectively; 5, 6 and 7 are operation switches for recording, playback and stop, respectively, and when they are closed, input terminals 2, 3 of the operation circuit 1 are connected. . 8 is the power terminal, 9 is the ground terminal, 10
is an operation control terminal for controlling the operation of the operation circuit 1, and 11 is an output terminal for reproduction, and when the voltage applied to the operation control terminal 10 exceeds a predetermined value, the operation circuit 1 is input to the input terminal. It becomes operational to output a signal to the output terminal in response to the signal. 12 is a first time constant circuit connected to the operation control terminal 10 to keep the operation circuit 1 in an inoperable state for a predetermined period of time after power is supplied to the power supply line 13;
It is composed of. 16 is capacitor 1
7 and a resistor 18, and a connection point A between the capacitor 17 and the resistor 18 is connected to the input terminal of the NAND circuit 19. The output terminal of the NAND circuit 19 is connected to the playback input terminal 3 via a diode 20 and to the recording input terminal 2 via a diode 21 and a selection switch 22. A standby switch 23 controls activation/deactivation of the standby function, and is connected in parallel to the resistor 18, which together with the resistor 24 constitutes the second time constant circuit 16 . Reference numeral 25 denotes a switching transistor which is inverted to a conductive state when a signal is output from the reproduction output terminal 11 of the operating circuit 1, and its emitter is grounded and its collector is connected to the second time constant circuit via a resistor 26. It is connected to connection point A of 16 . Further, the connection point A of the second time constant circuit 16 is connected to the stop input terminal 4 of the operation circuit 1 via a resistor 27 and a diode 28. 29 is a diode for discharge. In such a circuit, the time constant of the first time constant circuit 12 is smaller than the time constant of the second time constant circuit 16 ;
Resistor 2 compared to the resistance value of resistor 18 that constitutes
The resistance values of 4, 26 and 27 are set to much smaller values so that the time constant of the second time constant circuit 16 is smaller than the time constant of the first time constant circuit 12 . The standby switch 23 is closed in the standby non-operating state, and enters the standby operating state when opened.

The present invention is constructed as described above, and its operation will be explained next. When standby operation is not performed, standby switch 23 is closed as shown. In such a state, when power is supplied to the power line 13 by turning on the power switch, power is supplied to the operating circuit 1 and current is supplied to the first time constant circuit 12 and the second time constant circuit 16 . be done. Since the standby switch 23 is closed, the resistor 24 with a small resistance value becomes the resistor 1.
8, the capacitor 17 constituting the second time constant circuit 16 is rapidly charged, and the output of the NAND circuit 19 becomes H (high) level, and has no effect on the operating circuit 1. .
When the time set by the time constant of the first time constant circuit 12 has elapsed, the voltage applied to the operation control terminal 10 increases to a predetermined value, and the operation circuit 1 becomes operable. In such a state, when a regeneration operation is performed, the regeneration operation switch 6 is closed and the regeneration input terminal 3 of the operation circuit 1 is grounded, so that the regeneration output terminal 11 receives an H (high) signal for performing the regeneration operation.
A level signal is output, and a reproducing plunger (not shown) performs a suction operation to configure the reproducing state of the tape recorder. Furthermore, if the recording operation switch 5 and the playback operation switch 6 are operated simultaneously, a signal for performing a recording operation is output, and a recording state is established. Similarly, when a fast forward or rewind operation switch (not shown) is operated, the operation circuit 1 outputs a signal corresponding to each operation, thereby configuring each operating state of the tape recorder. When the stop operation switch 7 is closed while the tape recorder is in the operating state, the operating circuit 1 is reset, the output signals for performing each operation disappear, and the tape recorder is returned to the stopped state.

As described above, the normal operation is performed, but the standby operation will be explained next. First, a case will be described in which a reproducing operation is started at a set time using a timer device. In this case, the selection switch 22 and the standby switch 23 are in an open state, and in this state, when the set time comes, power is supplied to the tape recorder from the timer device and the power supply line 13 becomes a predetermined voltage. The power line 13
When power is supplied to the operating circuit 1, the operating circuit 1 remains inoperable for a predetermined period of time as described above. Further, since the potential at the connection point A of the second time constant circuit 16 is at the H level for a predetermined time, the output of the NAND circuit 19 is at the L level during that time, and the reproduction input terminal 3 of the operating circuit 1 is at the L level.
It's on the level. The output of the NAND circuit 19 maintains the L level of the reproduction input terminal 3.
Since the time constant circuit 12 holds the operation circuit 1 in an inoperable state for a longer time, the operation circuit 1
When it becomes operable, the reproducing output terminal 11 outputs an H level signal for performing a reproducing operation. As a result, the reproducing plunger performs a suction operation to establish the reproducing state of the tape recorder, and at the same time, the switching transistor 25 is turned on and the capacitor 17 constituting the second time constant circuit 16 is rapidly charged. Therefore, when the reproduction operation is started, the output of the NAND circuit 19 is inverted from the L level to the H level, and the signal to the reproduction input terminal 3 of the operating circuit 1 is cut off. As described above, the standby operation for the playback operation is performed, but when the recording operation is performed, the selection switch 22 may be closed. That is, in this case, since the L level signal that is the output of the NAND circuit 19 is input to the recording input terminal 2 and the playback input terminal 3 of the operating circuit 1, the recording output terminal of the operating circuit 1 Then, an H level signal is output to the playback output terminal 11, thereby configuring the recording state of the tape recorder. In this case as well, the switch transistor 25 is reversed to a conductive state and the capacitor 17 of the second time constant circuit 16 is rapidly charged, so that the signals to the recording input terminal 2 and playback input terminal 3 of the operating circuit 1 are not recorded. As soon as the operation starts, it is immediately cut off.

The standby operation of the playback and recording operations is performed as described above, but the operation associated with the closing of the stop operation switch 7 will now be described. When the stop operation switch 7 is closed, the stop input terminal 4 of the operation circuit 1 is grounded, so the operation circuit 1 is reset and the tape recorder is returned to the stopped state. However, the stop input terminal 4 is connected to a diode. 28 and the resistor 27 to the connection point A of the second time constant circuit 16 , the capacitor 17 is rapidly charged when the stop operation switch 7 is closed. Therefore, when the standby switch 23 is open, the stop operation switch 7 is turned on immediately after turning on the power switch of the tape recorder.
If the capacitor 17 is closed, the capacitor 17 is rapidly charged and the output of the NAND circuit 19 becomes H level.
When the operation circuit 1 is enabled for operation, the input signal for playback or recording of the operation circuit 1 is cut off, and the signals for performing each operation are not output from the output terminal of the operation circuit 1. do not have.

The operation circuit 1 in this embodiment has been described for the case where a control signal is input by grounding the input terminal by closing each operation switch, but an H level signal is controlled by closing each operation switch. It is possible to use an operating circuit adapted for input as a signal. Also, the second time constant circuit 16
Although a case has been described in which a transistor is used as a switching element for controlling the time constant of , it is of course possible to use an element such as a field effect transistor.

As explained above, the control circuit of the present invention changes the time constant of the second time constant circuit that controls the input to the input terminal of the operating circuit when power is supplied by the standby timer device to the standby function. The standby switch during non-operation is used to minimize the power consumption, and the capacitor constituting the second time constant circuit is fully charged under normal operating conditions, so that the standby switch cannot be operated during normal operating conditions. Even if the second time constant circuit does not input a signal to the input terminal of the operating circuit, the operating circuit will not output a reproduction or recording signal and cause malfunction.

[Brief explanation of the drawing]

The illustrated circuit is one embodiment of the control circuit of the present invention. Explanation of main drawing numbers, 1... Operation circuit, 5... Recording operation switch, 6... Playback operation switch, 7
... Stop operation switch, 10 ... Operation control terminal, 12 ... First time constant circuit, 16 ... Second time constant circuit, 22 ... Selection switch, 23 ... Standby switch, 25 ... Switching transistor .

Claims (1)

[Scope of utility model registration request] In a tape recorder that has a standby function that automatically enters playback or recording mode when power is supplied by a timer device, recording, playback,
An operation that outputs signals for performing each operation in response to signals input by operating the fast forward, rewind, and stop operation switches, and becomes operable when the voltage applied to the operation control terminal exceeds a predetermined value. a first time constant circuit connected to the operation control terminal to hold the operating circuit in an inoperable state for a predetermined period of time after power is supplied; A control signal is inputted to a playback input terminal or a recording input terminal for a predetermined period of time, and a second time constant circuit having a time constant larger than the time constant of the first time constant circuit and the operation/non-operation of a standby function are controlled. When the standby function is not in operation, the standby switch makes the time constant of the second time constant circuit as small as possible, and fully charges the capacitor constituting the second time constant circuit in the normal operating state. A control circuit for a tape recorder, characterized in that the control circuit is made to