JPH0155763B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field The present invention relates to an automatic function switching device that can automatically switch functions in an audio device.

More specifically, the present invention electrically connects an audio source such as a tape deck, record player, tuner, etc. to an audio amplifier, and by operating the operation switch of the audio equipment on the audio source side, the sound source built in the audio amplifier side can be operated. The present invention relates to an improvement in an automatic function switching device that automatically switches a function switching analog switch to a corresponding source side.

(b) Prior Art A sound device is known in which a source device such as a radio tuner, tape deck, or record player is electrically connected to an amplifier. However, in such devices, a function changeover switch for switching the source is provided inside the amplifier, and when selecting a desired source, the function changeover switch is first switched to the position corresponding to the source. , and then operating the control knob for the desired source, which requires two operations, which has the drawback of making the operation complicated.

Therefore, recently, in order to avoid the complexity of operation, an automatic method called direct call has been developed, which allows source selection by simply operating the desired source's control knob without operating the amplifier's function switch. Function switching devices have been proposed and provided on the market.

However, in the automatic function switching device, the resulting switching operation is the same whether it is operated by a function switching switch built into the amplifier side or by a switch built into the source side. If this is simply a function switching of a source device other than a tape deck, it would not be a problem, but the output signals of sources such as tuners, record players, compacts, disc players, etc. are applied to the tape deck and the signals from those sources are recorded. Because it is necessary to listen to the monitor sound while listening to the monitor sound, normally only the tape deck switching function switch is set to perform a special operation. Unlike other function switching terminals, if the monitor switching operation is a toggle switch function that repeats ON-OFF independently (i.e., a function that switches the tape monitor ← → source every time a pulse is input), use a direct call. Regarding operations from external devices, it is not practical unless the following problems are solved.

(1) If the results of operations from the amplifier and external source equipment are the same, the function will switch between monitor and source every time a control signal is received from the tape deck. Specifically, if you press the play switch on the deck and pause it after it becomes a tape monitor, the control signal for switching the function from the deck will be interrupted, and when you release the pause, the control signal will be generated again, so you can use the tape monitor for the function. The position changes to the source, which is really inconvenient. Therefore, it is necessary to prevent switching from the tape monitor to the source even if a control signal is input multiple times from the tape deck. However, only the first control signal that comes in from the deck when the amplifier function is the source must be accepted and the signal changes from source to monitor.

(2) When switching functions within an amplifier, the tape deck and other functions operate differently. That is, by operating the function switch for switching to the tape monitor, only the tape monitor←→source is switched, but the other function switches are linked to each other and any one can be selected.
Since such a separate operation of the tape deck function switch departs from the main idea of direct call, which is to operate the source equipment to switch between functions, it is preferable that the tape monitor also operate in the same way as the multiple functions.

Next, to explain a specific example, the current function is a tuner and a tape monitor.
Suppose that it is turned on and you are listening to the monitor sound of the tuner signal being recorded on the tape deck.
When the built-in switch of the record player is turned on (PLAY) in this state, the amplifier function quickly switches from tuner to phono, and at the same time, the amplifier function turns off the tape monitor (i.e., source), and the tape deck's play status also changes. It is necessary to stop it.

(c) Purpose The present invention provides an automatic function switching device that can solve the problems of the prior art. In other words, conventionally the tape monitor of the recorder/player
When the playback device starts playing from the stop state with ON (AS ₆ , ON; AS ₅ , OFF), the tape monitor will turn off.
OFF (AS ₆ , OFF; AS ₅ , ON), and the reproduced signal from the tape cannot be heard. In order to solve this inconvenience, the present invention is configured as follows. That is, in an audio device comprising first audio equipment 1, 2 such as a phono or tuner, a second audio equipment 3 having a recording and playback function, and an audio amplifier Amp to which these first and second audio equipment are electrically connected. , the audio amplifier includes function switches S ₁ , S ₂ , for switching signals supplied from the first and second audio equipment.
S ₃ , S ₄ , S ₅ and control signals from the function switch or built-in operation switches 1', 2', and 3' of the first and second audio equipment.
A plurality of analog switches each corresponding to the first and second audio equipment to be controlled ON-OFF.
AS ₁ , AS ₂ , AS ₃ , AS ₄ , AS ₅ , AS ₆ , and a second audio equipment signal switching analog switch AS ₆ for switching to a signal from the second audio equipment in the analog switch. to the switch in connection with
An analog switch _AS5 for switching between ON and OFF modes is provided, and the analog switch on the audio amplifier side is automatically operated in response to the operation of the built-in operation switch on the first or second audio equipment side. Switching to the corresponding first or second audio equipment side,
and the switching modes of the second audio equipment signal switching analog switch AS ₆ and the source switching analog switch AS ₅ corresponding to the second audio equipment are controlled by the operation of the function switch and the first audio equipment signal switching mode.
This is different from the operation of the built-in switch on the second audio equipment side, and the second audio equipment switches the signal to the second audio equipment 3 side.
Function switch S ₅ for audio equipment signal switching
switches between the second audio equipment signal switching analog switch AS 6 and the source switching analog switch AS 5 without affecting other signal switching analog switches, and also switches between the second audio equipment signal switching analog switch AS ₆ and source switching analog switch AS ₅ . The control signal generated by operating the built-in operation switch 3' sets the analog switch for switching the second audio equipment signal only to the transmission side of the second audio equipment signal, and
When a control signal is applied to turn on the audio equipment signal switching analog switch, the second audio equipment signal switching analog switch is turned off.

(d) Configuration and Examples Next, the configuration and examples of the present invention will be explained with reference to FIG. 1.

Operation of external sources such as record player 1, tuner 2, tape deck 3, etc. When ON-OFF operation switches 1', 2', and 3' are operated, each source is switched to the built-in function switching circuit on the amplifier 4 side according to the operation. Control signals for function control are supplied via control signal lines a, d, e.

Furthermore, when one of the function switches S ₁ , S ₂ , S ₃ , S ₄ and S ₅ built into the amplifier 4 is pressed, the function switch switches from (+Vdd) to
A positive pulse is applied to the IC circuit 5 and it shifts to its function. In other words, in response to the pressed function switch, the analog switch
Only the corresponding switches among AS ₁ , AS ₂ , AS ₃ , and AS ₄ are turned ON, and the other analogue switches are turned OFF. At the same time, AS ₅ or AS ₆ on the side corresponding to the pressed function switch turns on, and the signal is transmitted to the subsequent amplifier circuit.
Supplied to Amp.

However, except for the tape monitor switch _S5 , each time a positive pulse is applied to the IC circuit ₅ by the switch S5, the output Q of the T-FF circuit 6,
Q is inverted and analog switches AS ₅ and AS ₆ are alternately controlled ON and OFF to switch the source to the tape monitor side. Since the transistor Q ₃ is conductive only when the tape monitor is ON due to the output of the IC circuit 5, the point P is at a low level (-Vee) only when the tape monitor is ON, and is at a high level when the tape monitor is OFF (that is, when the source is on). (+Vdd).

Next, the switching operation of the built-in functions on the amplifier 4 side by the operation switch of the source side audio equipment will be explained.

Now, when operating the operation switch 1' to listen to the performance of the record player 1, a positive pulse control signal is sent to the diode of the amplifier 4 via line a.
D ₁ is applied to the function switching IC5, and the corresponding
The output of the IC is supplied to the analog switch AS ₁ through line A', turning AS ₁ on, and at the same time, the IC circuit 5 and T-FF circuit 6 turn on the analog switch AS ₅ . and other analog switches AS ₂ , AS ₃ , AS ₄ and
Turn AS ₆ off.

Next, when listening to the tuner signal, if you put tape deck 3 into play mode to listen to it on the tape monitor, the tape deck will start playing.
A positive voltage is output only when ON, and the positive pulse from the tape deck is passed through line e to resistor _R1 .
is applied to turn on transistor _Q1 . As a precondition for this series of operations, before the tape deck 3 becomes play (ON), point (P) has a potential of +Vdd. This is because, as mentioned above, point (P) is (-Vee) when the tape monitor is ON, so the collector of transistor Q ₁ is also (-Vee), and even if a positive pulse is applied to the base, Q ₁ will not turn ON. It is from.

Therefore, the condition that multiple pulses from the tape deck are not accepted as raised in the problem described in item (1) above is satisfied.

Next, a case will be described in which the record player 1 of the external source device is put into the play state and a record is played back. Since it is called a direct call, when the record player 1 is put into the play state, other functions (such as a tuner) and the tape monitor that were operating just before must be reset so that the signal sound of the record player can be heard. For switching from tuner 2 to phono 1, the control signal is on line a.
The signal is input to the function switch IC5 via the diode _D1 , and the function of the amplifier 4 is set to phono. This operation is the same as turning on the function switch _S1 in the amplifier 4, and there is no particular problem. The problem is that at this time, the tape monitor must also be turned off, that is, switched to the source side (i.e.
(turn on AS ₅ ).

As mentioned above, the tape monitor terminal E' of the function switch IC5 in this circuit has the function of repeating ON←→OFF every time a pulse is input to the input side terminal E, so the tape monitor can be turned OFF ( In other words, in order to turn AS ₆ OFF and AS ₅ ON to switch to the source side, a positive pulse can be applied to the tape monitor terminal E from any of the external source devices. If that route is now, line a
, and the positive pulse is from here to diode D ₂ ,
It is supplied to the emitter of transistor Q ₂ via resistor R ₄ . Immediately before this pulse is applied, the tape monitor is on, so the potential at point (P) is (-Vee), and the base potential of transistor Q ₂ is sufficiently lowered, so Q ₂ is The input pulse is input from the collector of the transistor Q ₂ to the tape monitor terminal E through the diode D ₆ and switches the switch circuits AS ₅ and AS ₆ from the tape monitor to the source.

This also solves the problem described in item (2) above.

In this way, the functions built into the function switch IC 5 include the tape monitor terminal E, which only performs ON-OFF operation, as well as the Q ₁ , Q ₂ ,
By adding circuits such as Q ₃ , D ₂ , D ₃ , and D ₆ , it is possible to provide the same function as an amplifier's function switch during a direct call.

Next, analog switches AS ₁ to _{AS 4} in the figure are connected in series to the transmission path through which audio signals pass, and the audio signal output from phono 1, tuner 2, etc. is one of AS ₁ to _{AS 4} . The outputs of the switch group AS ₁ to _{AS 4} are transmitted to the subsequent amplifier circuit Amp via AS ₅ . Also,
The outputs of AS ₁ to _{AS 4} are transmitted to the tape deck 3 via line g and can be recorded there.

In addition, the playback signal from tape deck 3 passes through input terminal E'' of amplifier 4, and then is sent to the downstream amplifier circuit via AS ₆ .
Transmitted to Amp.

Furthermore, the line f is for stopping the tape deck 3 when a positive pulse is applied thereto. That is, positive pulses emitted during play from PHONO1, TUNER2, etc. are applied to _D2 and _D3 . If the tape monitor is ON at that time and tape deck 3 is in PLAY, point P is LOW, so in the case of Figure 1, turn Q ₂ ON from either D ₂ or D ₃ via R ₄ . At the same time, generate a positive pulse at f and stop the deck.
Pulse the tape monitor (line E) via _D6 to turn it OFF.

FIG. 2 shows another embodiment of the invention.

Next, the operation of this circuit will be explained.

As mentioned above, the tape monitor output terminal E' of the function switch IC5 in the present invention has the function of repeating ON←→OFF every time a pulse is input to the input terminal E, so the tape monitor is turned OFF (i.e., the source ) can be achieved by applying a positive pulse to tape monitor terminal E from any external input device. The route is, for example, line a, as described above, and is separated into two routes from there. One joins the line f for stopping the deck via diode _D9 and stops the deck. The other is diode D ₂ resistor R ₄
is applied to transistor Q ₂ via. Here, the point (P) corresponding to the base of the transistor _Q2 is set to be "LOW" when monitoring the tape and "HIGH" when sourcing, as described above. Therefore, LED1 lights up when monitoring the tape, and goes off when source.

Now, since point (P) is "LOW", the base potential of transistor _Q2 is biased sufficiently low. If a positive pulse is input there through the diode D ₂ and resistor R ₄ mentioned above, the transistor Q ₂ will immediately turn on, and a positive pulse will be applied to the tape monitor terminal E through the diode D ₁₁ . , turn off the tape monitor (= source)
shall be. That is, turn AS ₅ ON and AS ₆ OFF. In this way, the problem in item (2) above is solved.

Furthermore, in this embodiment, if the control signal from the tape deck 3 is continuously output as a positive DC when the switch is operated (playing), the emitter potential of _Q1 cannot be controlled. Connect the coupling capacitor C ₁ to create a one-shot pulse, and connect the collector, base, and emitter of Q ₁ from (+Vdd) to (−
Vee) This problem is solved by allowing it to float freely up to the vicinity.

In the embodiment shown in Fig. 1, the desired operation is obtained by applying a positive pulse to line e from switch 3' of the tape deck, but the signal from e is output continuously instead of as a pulse. If it is a DC voltage (that is, it stays HIGH during PLAY), the emitter of Q ₁ in Figure 1, that is, the line E, will be fixed at HIGH, so other key inputs S ₁ to S will be fixed from then on. This leads to a situation where ₄ is no longer accepted.

Therefore, whether it is a pulse or a DC that is applied to the e line, FIG. 2 is designed to be able to handle either case. In the same figure, if the current function is something other than a tape monitor (tape monitor OFF), the collector of _Q1 is HIGH, and when DC is applied from e, the signal passing through capacitor _C1 is transferred to _Q1 . join the base. Then, Q ₁ turns ON and applies a positive pulse to the tape monitor (line E) via D ₁₀ , turning the tape monitor ON (AS ₆ −ON, AS ₅ −OFF
). However, immediately after switching, point P becomes
Since it becomes LOW, the collector, base, and emitter of _Q1 maintain a negative voltage (because the potential at point P has become a negative potential). After that, PHONO or
When a positive pulse is applied from TUNER via line a or line d, HIGH is applied from D ₂ or D ₃ to the emitter of Q 2 via R ₄ , turning _{Q 2 ON} , and the tape monitor (line E ) can be applied to release the tape monitor state.

Even if a pulse is applied again from PHONO or TUNER after that, the base of Q ₂ remains HIGH (because LED 1 is off), so Q ₂
It never turns on, and the tape monitor (line E)
This prevents unnecessary pulses from being applied to the

(E) Effect As described above, according to the present invention, the built-in functions of the function switch IC are ON,
By adding the circuit of the present invention to a tape monitor terminal that only operates in the OFF state, it can be given the same function as the built-in function switching function of the amplifier when making a direct call from an external source device.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an automatic function switching device of the present invention, and FIG. 2 is a drawing showing another embodiment of the same device. 1...Record player, 2...Tuner,
3... Tape deck, 4... Amplifier, 5... Function switching IC, 6... T-FF circuit, D ₁ ~
D ₁₁ ... Diode, Q ₁ , Q ₂ , Q ₃ ... Transistor, AS ₁ to _{AS 6} ... Analog switch.

Claims (1)

[Scope of Claims] 1. An audio device comprising first audio devices 1 and 2, a second audio device 3 having a recording and playback function, and an audio amplifier 4 to which the first and second audio devices are electrically connected. (a) The audio amplifier includes function switches S ₁ , S ₂ , S ₃ , S ₄ for switching signals supplied from the first and second audio devices.
S ₅ and the control signal from the function switch or the control signal from the built-in operation switches 1', 2', and 3' of the first and second audio equipment.
A plurality of analog switches each corresponding to the first and second audio equipment to be controlled ON-OFF.
AS ₁ , AS ₂ , AS ₃ , AS ₄ , AS ₅ , AS ₆ , and a second audio equipment signal switching analog switch AS ₆ for switching to a signal from the second audio equipment in the analog switch. (b) built-in operation switches 1', 2', ₃ on the side of the first or second audio equipment; ′ automatically switches the analog switch on the audio amplifier 4 side to the corresponding first or second audio equipment side; (c) a second audio switch that switches the signal to the second audio equipment side; The function switch S ₅ for changing equipment signals can be used as an analog switch for changing other signals AS ₁ , AS ₂ ,
Switches between the second audio device signal switching analog switch AS ₆ and the source switching analog switch AS ₅ without affecting AS ₃ and AS ₄ , and (d) the built-in switch on the second audio device side. The control signal generated by the operation of the switch 3' sets the second audio equipment signal switching analog switch only to the transmission side of the second audio equipment signal, and the first audio equipment signal switching analog switch AS ₁ , AS ₂ , An automatic function switching device characterized in that when a control signal for turning on AS ₃ and AS ₄ is applied, the analog switch for switching the second audio equipment signal is turned off.