JPS6316029Y2 - - 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, there are many operating circuits that control the operation of such plungers that 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; 19 is a NAND circuit whose input terminal is connected to the connection point A between the capacitor 17 and the resistor 18;
It constitutes a standby signal generation circuit that outputs a time control signal set by the second time constant circuit 16 when power is supplied. 20 is a standby switch that controls the operation/non-operation of the standby function; one terminal 20a is connected to the output terminal of the NAND circuit 19, and the other terminal 20b is connected to the playback input terminal 3 via a diode 21; It is also connected to the recording input terminal 2 via a diode 22 and a selection switch 23. Reference numeral 24 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 through a resistor 25. circuit 1
It is connected to connection point A of 6. Further, the connection point A of the time constant circuit 16 is a resistor 26
and is connected to the stop input terminal 4 of the operating circuit 1 via a diode 27. 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 , and the resistance value is smaller than that of the resistor 18 constituting the second time constant circuit 16 . The resistance values of 25 and 26 are set to much smaller values so that their time constants are smaller than the time constant of the first time constant circuit 12. The present invention is constructed as described above, and its operation will be explained next. When standby operation is not performed, standby switch 20 is open as shown. In such a state, when power is supplied to the power supply line 13, power is supplied to the operation circuit 1, and the first time constant circuit 12 and the second
Current is supplied to the time constant circuit 16 . As a result, 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. On the other hand, the output signal of the NAND circuit 19 is output for a time L set by the time constant of the second time constant circuit 16 .
(Low) level, but standby switch 20
Since it is open, there is no effect on the operating circuit 1. 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. 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 switch 7 is closed while the tape recorder is in operation,
The operating circuit 1 is reset, the output signals for performing each operation disappear, and the tape recorder is returned to its 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 23 is in an open state and the standby switch 20 is in a closed state. In this state, when the set time comes, the timer device supplies power to the tape recorder, and the power line 13 becomes a predetermined voltage. When power is supplied to the power supply line 13, 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. In this state, the standby switch 20 is closed, so the reproduction input terminal 3 of the operating circuit 1 is at the L level.
The output of the NAND circuit 19 maintains the L level of the reproduction input terminal 3 by the first time constant circuit 12.
Since this is carried out for a longer period of time than the operation circuit 1 is kept in the inoperable state, when the operation circuit 1 becomes operable, an H level signal for performing the reproducing operation is output from the reproducing output terminal 11. As a result, the reproducing plunger performs a suction operation, the tape recorder is set to the reproducing state, and the switching transistor 24 is reversed to a conductive state, and the second
The capacitor 17 forming the time constant circuit 16 is rapidly charged. Therefore, when the playback operation starts, the NAND circuit 1
9 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 performing the recording operation, the selection switch 2
All you have to do is close 3. That is, in this case, since an L level signal is input to the recording input terminal 2 and the playback input terminal 3 of the operating circuit 1 via the standby switch 20, the operating circuit 1
An H level signal is output to the recording output terminal and the reproduction output terminal 11 of the tape recorder, thereby configuring the recording state of the tape recorder. In this case as well, the switching transistor 24 is reversed to the conductive state and the second
Since the capacitor 17 of the time constant circuit 16 is rapidly charged, the signals to the recording input terminal 2 and the reproduction input terminal 3 of the operating circuit 1 are cut off immediately after the recording operation is started. 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. and the connection point A of the second time constant circuit 16 via the resistor 26
Since the capacitor 17 is connected to the stop switch 7, the capacitor 17 is rapidly charged when the stop operation switch 7 is closed. Therefore, when the standby switch 20 is closed, if the stop operation switch 7 is closed immediately after turning on the power switch of the tape recorder, the capacitor 17 is rapidly charged and the output of the NAND circuit 19 is Since the input signal is set to H level, when the operating circuit 1 is enabled to operate by the first time constant circuit 12 , the input signal for playback or recording of the operating circuit 1 is cut off, and the operating circuit No signal for performing each operation is output from the output terminal 1. 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
We have explained the case where a transistor is used as a switching element to control the time constant of
It is of course possible to use elements such as field effect transistors. Furthermore, this embodiment includes a standby signal generation circuit that outputs a time control signal set by the second time constant circuit 16 when power is supplied.
Although the NAND circuit 19 is used, other circuit configurations are also possible. As explained above, the control circuit of the present invention adjusts the time constant of the second time constant circuit that controls the input to the input terminal of the operation circuit as much as possible when the tape recorder is switched to the operating state by standby operation. Since the signal input to the input terminal of the operating circuit is cut off by reducing the time constant of the second time constant circuit, it is possible to prevent unnecessary input operations to the operating circuit. When the time constant of the first time constant circuit is made larger than that of the first time constant circuit, it becomes possible to easily set the value, and the practical value of the present invention is very large.

[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, 20...Standby switch, 23...
Selection switch, 24...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 operation circuit in an inoperable state for a predetermined period of time after power is supplied; and a standby function to control activation/deactivation of a standby function. a second time constant circuit having a capacitor that starts charging operation when power is supplied and having a time constant larger than the time constant of the first time constant circuit; 2. A standby signal generation circuit that inputs a control signal to the playback input terminal or recording input terminal of the operating circuit for a period of time set by the time constant circuit, and operates when a signal is output from the playback output terminal of the operating circuit. and a switching element that rapidly charges a capacitor constituting the second time constant circuit, and when starting standby, the switching element rapidly charges the capacitor, thereby causing the input terminal for playback or recording from the standby signal generation circuit to 1. A control circuit for a tape recorder, characterized in that input operation of a control signal to an input terminal is cut off.