JPS6316030Y2 - - 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,
The connection point A between the capacitor 17 and the resistor 18 is
It is connected to the input terminal of the NAND circuit 19.
20 is a standby switch that controls the operation and 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. It is connected to connection point A of the circuit 16 . Further, the connection point A of the time constant circuit 16 is connected to the stop input terminal 4 of the operation circuit 1 via a resistor 26 and 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. 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 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 23 is in an open state and the standby switch 20 is in a closed state. In such a 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. 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. Furthermore, since the potential at the connection point A of the second time constant circuit 16 is at H level for a predetermined time, the NAND circuit 19
The output of is at 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. Since the output of the NAND circuit 19 holds the reproduction input terminal 3 at the L level for a longer period of time than the first time constant circuit 12 holds the operation circuit 1 in the inoperable state, the operation circuit 1 is in the operable state. When this happens, an H level signal for performing a reproducing operation is output from the reproducing output terminal 11. As a result, the reproducing plunger performs a suction operation to configure the reproducing state of the tape recorder, and at the same time, 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 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 23 may be closed. That is, in this case, 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, so that the recording output terminal and the playback input terminal of the operating circuit 1 are input. An H level signal is output to the playback output terminal 11 to configure the recording state of the tape recorder. In this case as well, the switching transistor 24 is reversed to a conductive state, and the capacitor 17 of the second time constant circuit 16 is turned on.
, 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 for the playback and recording operations is performed as described above, but the operation associated with the closing of the stop operation switch 7, which is the gist of the present invention, will now be explained. 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. Since the capacitor 17 is connected to the connection point A of the second time constant circuit 16 via the resistor 26, the capacitor 17 is rapidly charged when the stop operation switch 7 is closed. Therefore, if the stop operation switch 7 is closed immediately after turning on the power switch of the tape recorder while the standby switch 20 is closed, the capacitor 1
7 is rapidly charged and the output of the NAND circuit 19 becomes H level, when the operating circuit 1 is enabled to operate by the first time constant circuit 12 , the input for playback or recording of the operating circuit 1 is activated. Since the signal is cut off, no signal for performing each operation is output from the output terminal of the operating circuit 1. In the operating circuit 1 in this embodiment, a case has been described in which a control signal is input by grounding the input terminal by closing each operating switch. It is possible to use an operating circuit adapted for input. In addition, the second time constant circuit 16
Although the time constant is directly controlled by the stop operation switch 7, a switching element such as a transistor may also be used. As explained above, in the control circuit of the present invention, the time constant of the second time constant circuit that controls the input to the input terminal of the standby operation operation circuit is made as small as possible by the stop operation. If the power switch of the tape recorder is turned on while the standby switch is in the standby operation state, the standby operation can be canceled by immediately performing a stop operation, so the practicality 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.

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 having a time constant larger than the time constant of the first time constant circuit; and a second time constant having a time constant larger than the time constant of the first time constant circuit; 1. A control circuit for a tape recorder, comprising a constant circuit, wherein the time constant of the second time constant circuit is made as small as possible by closing the stop operation switch.