JPH0319110Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field) The present invention relates to a composite audio device that includes a tape recorder and a composite device combined therewith, such as a record player, a radio receiver, and the like.

(Prior Art) In order to prevent unnecessary amplifier noise from being output through the output signal line during modes other than the normal playback mode, tape recorders incorporated in such composite audio equipment are configured to operate in modes other than the normal playback mode. A muting circuit is provided which is sometimes supplied with a muting signal to mute the output signal of the tape recorder. On the other hand, a composite audio device is usually provided with a signal switching circuit for selectively switching and outputting each output signal from a tape recorder and other composite equipment using a selection signal. In the signal switching circuit in , the selection signal for this signal switching is formed independently of the muting signal from the muting circuit, which makes the circuit configuration for forming and outputting the selection signal complicated, and it is difficult to use a simpler circuit configuration. Something was desired.

(Purpose) The present invention has been made in view of the above-mentioned circumstances, and is a composite audio device including a tape recorder equipped with such a muting circuit, in which each of the tape recorders and the composite device is controlled by a selection signal. When a signal switching circuit that selectively switches and outputs an output signal is provided, the circuit configuration can be made simpler by using the muting signal used to operate the muting circuit of the tape recorder as the selection signal. The purpose is to

(Example) Hereinafter, the present invention will be described in detail based on an example shown in the drawings. FIG. 1 is an overall circuit block diagram of this embodiment. The composite audio device A of this embodiment is formed by combining a tape recorder B and a composite device C such as a record player or a radio receiver.

The tape recorder B includes a reproducing magnetic head B1 that outputs a reproduced signal obtained by reproducing a signal recorded on a magnetic tape (not shown), and an amplifier B2 that amplifies the reproduced signal from the reproducing magnetic head B1. a muting circuit B3 for mutating the output signal of the tape recorder when a muting signal is applied to the tape recorder B when the tape recorder B is in a mode other than the playback mode; and a high-level muting signal when the tape recorder B is in a mode other than the playback mode. The mutating circuit B3
It has a muting signal forming circuit B4 which provides a muting signal to the circuit. On the other hand, the composite device C is a composite device main body C.
1 and mode selection signal output means C2 for outputting an operation mode selection signal indicating the operation mode of the composite device. The mode selection signal output means C2 includes a switch SW, and outputs a low-level operation mode selection signal when the switch SW is closed.

Reference numeral D represents a signal switching circuit which is a main part of this embodiment. This signal switching circuit D selectively switches and outputs each output signal from the tape recorder B and the composite device C. An output section D1 that connects the output signal lines l1 and l2 in common and outputs a selected output signal.
a signal forming means D2 for forming a first selection signal for selecting the tape recorder B and a second selection signal for selecting the composite device C, respectively, by a combination of the mutating signal and the operation mode selection signal; It is connected between the output signal line l2 of the device C and the output section D1, is opened by a first selection signal from the signal forming means D2, and is opened by a second selection signal from the signal forming means D2.
an analog switch D as a switch circuit that is closed by a selection signal and allows the output signal from the composite device C to be output from the output section D1;
3. E is a first lighting display circuit E1 driven by the first selection signal from the signal switching circuit D, and lights up to indicate that the output signal from the tape recorder B is being output from the output section D1, and a composite device C. a second lighting display circuit E that lights up to indicate that the output signal of is being output from the output section D1;
2. This is a lighting display circuit including 2.

Signal forming means D2 of the signal switching circuit D
is an inverter D20 and an AND gate D21
and an RS flip-flop D22.

Next, the operation will be explained.

When the tape recorder B is in the playback mode, the playback signal is outputted via the output section D1 of the signal switching circuit D without being muted because the muting signal is not applied from the mutating signal forming circuit B4 to the mutating circuit B3.
However, when the tape recorder B is in a mode other than the playback mode, the muting signal is given from the mutating signal forming circuit B4 to the muting circuit B3, so unnecessary signals such as amplifier noise are muted, and the signal switching circuit D It is no longer outputted via the output section D1. In this case, a high-level muting signal is input to the inverter D20 of the signal switching circuit D, and as a result, the AND gate D21
A low level signal is input to one input section of the . On the other hand, if the switch SW1 of the mode selection signal output means C2 of the composite device C is closed,
A low level operation mode selection signal is output to the other input of the AND gate D21 of the signal switching circuit D. In this case, the signal switching circuit D
Since the RS flip-flop D22 outputs a signal that closes the analog switch D3, the output signal of the composite device C is output from the output section D1 of the signal switching circuit D via the output signal line l2. In this way, in the composite audio device A of this embodiment, the muting signal when the tape recorder B is in a mode other than the playback mode is used as a selection signal for the signal switching operation of the signal switching circuit D. It becomes possible to further simplify the circuit configuration for switching.

FIG. 2 is an overall circuit block diagram of another embodiment, and parts corresponding to those in FIG. 1 are given the same reference numerals. Composite audio device according to the embodiment of FIG. 2
The noteworthy structure of A' is that the tape recorder B and composite equipment C are stereotypical ones, and that the composite equipment C includes multiple devices, two in the example, C', O'' One compound device C' is, for example, a record player, and the other compound device C'' is a radio receiver. In the figure, the subscript L attached to each symbol is
It is for the left channel, and the subscript of R is
Indicates that it is for the right channel.
Therefore, since this embodiment is of a stereo type, the tape recorder B has magnetic reproduction heads B1L and B1R, amplifiers B2L and B2R, muting circuits B3L and B3R, and muting signals for the left channel and right channel, respectively. The main body C1' of the record player C' has respective output sections for the left channel and the right channel, and the main body C1' of the record player C' has a forming circuit B4.
1'' also has respective output sections for the left channel and the right channel.The signal switching circuit D also includes a D flip-flop D2' for the record player C',
D flip-flop D2″ for radio receiver C″
and output section D for left channel and right channel.
1L, D1R, and analog switch D3 for the left channel and right channel of record player C'.
L', D3R' and analog switch D3L'' for the left channel and right channel of radio receiver C'',
D3R''.The record player C' and the radio receiver C'' each include operation mode selection output means C.
2', C2''.The lighting display circuit E is driven by the first selection signal from the signal switching circuit D, and the output signal from the tape recorder B is output to the output section D1.
A first lighting display circuit E1 that lights up to indicate that the output is being output from L and D1R, and a record player.
A second lighting display circuit E2 lights up to indicate that the output signal from C' is being output from the output parts D1L, D1R, and the output signal from the radio receiver C'' is output from the output parts D1L, D1R. The operation of this embodiment is the same as that of the embodiment shown in FIG. 1 except that the circuit configuration is a stereo type, so the operation will be explained below. is omitted.

(Effects) As described above, according to the present invention, there is provided a signal switching circuit that selectively switches and outputs each output signal from the tape recorder and the composite device, and the signal switching circuit has an output section and a signal switching circuit. The output section includes a forming means and a switch circuit, and the output section is commonly connected to an output signal line of the tape recorder and an output signal line of the composite device,
and outputs either an output signal from the tape recorder or an output signal from the composite device, and the signal forming means forms a selection signal based on the mutating signal and the operation mode selection signal. The switch circuit is provided in the middle of the output signal line of the composite device, and is turned on or off according to the selection signal to output the signal to the output signal line. As a result, the muting signal used in the operation of the muting circuit of the tape recorder can be used as a selection signal between the tape recorder and other composite equipment, thereby simplifying the circuit configuration. It became possible to convert

[Brief explanation of the drawing]

The drawings are overall circuit block diagrams of embodiments of the present invention; FIG. 1 is a circuit block diagram of one embodiment, and FIG. 2 is a circuit block diagram of another embodiment. A, A' are composite audio devices, B is a tape recorder, B3 is a mutating circuit, B4 is a mutating signal forming circuit, C is a composite device (C' is a record player, C'' is a radio receiver), C2, C
2' and C2'' are operation mode selection output means, D is a signal switching circuit, D1 is an output section (D1L is for the left channel, D1R is for the right channel), D2 is a signal forming means, and D3 is an analog switch.

Claims (1)

[Claims for Utility Model Registration] A muting circuit comprising a tape recorder and a composite device combined therewith, wherein the tape recorder is given a muting signal to mute the output signal of the tape recorder when the tape recorder is not in its playback mode. and the composite device further includes mode selection signal output means for outputting an operation mode selection signal indicating an operation mode of the composite device, wherein each output signal from a tape recorder and the composite device is selected. A signal switching circuit is provided for switching and outputting a signal, the signal switching circuit includes an output section, a signal forming means, and a switch circuit, and the output section is configured to switch between the output signal line of the tape recorder and the output signal line of the composite device. Output signal lines are commonly connected and output either an output signal from the tape recorder or an output signal from the composite device, and the signal forming means is configured to output the output signal from the tape recorder or the output signal from the composite device, and the signal forming means is configured to generate the mutating signal. and based on the operation mode selection signal, a selection signal is formed and output to the switch circuit, and the switch circuit is provided in the middle of the output signal line of the composite device and is configured to output the selection signal to the selection signal. 1. A composite audio device characterized in that the output signal line is made conductive or cut off by being turned on or off depending on the output signal line.