JPH0556590B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to an audio system, and particularly to an audio system that can reduce the number of signal lines.

<Prior art> In conventional audio systems such as car components, when a system is configured by connecting a set of tuners, cassette decks, compact disk devices, amplifiers, etc., two systems are used as control signals: a remote signal and a pause signal. A signal is required. Among these, the remote signal is a signal that informs that the set itself has operated, and the pause signal is a signal that stops other sets because it has operated.

FIG. 2 is a block diagram of such a conventional audio system, in which 1 is a tuner, 2 is a cassette deck, 3 is a compact disk device (referred to as a CD device), 4 is an amplifier, and 5 is a speaker. The tuner 1 has a main body section 1a, a control circuit 1b, and an audio signal output section 1c, the cassette deck 2 has a main body section 2a, a control circuit 2b, and an audio signal path switching section 2c, and the CD device 3 has a main body section 3a and a control circuit 1b. The amplifier 4 has a circuit 3b and an audio signal path switching section 3c, and the amplifier 4 has a main body section 4a, a control circuit 4b, and an audio signal input section 4c.

Further, RS is a remote signal that switches the audio signal path of the subsequent set or turns on the power of the amplifier 4. PS is a pause signal,
This is for turning off the previous set.

Priority is assigned between each set, and in Figure 2, CD device 3, cassette deck 2,
They are in the order of Chuyuna 1. Therefore, if the cassette deck 2 or CD device 3 is turned on while listening to audio from the tuner 1, the cassette deck or CD device is operated and the tuner 1 is turned off.

Now, when the tuner 1 is operated to output an audio signal, a high level remote signal RS is inputted to the control circuit 2b of the cassette deck 2 from the control circuit 1b. As a result, the control circuit 2b of the cassette deck switches the switch SW1 to the tuner 1 side, and at the same time inputs the remote signal RS to the control circuit 3b of the CD device 3. The control circuit 3b of the CD device 3 is a switch SW.
2 to the cassette deck side, and outputs the remote signal RS to the amplifier 4. The control circuit 4b of the amplifier 4 turns on the power of the amplifier when the remote signal RS becomes high level.

Then, when the cassette deck 2 is put into the play state while the audio from the tuner 1 is being outputted from the speaker 5 via the amplifier 4, the control circuit 2b of the cassette deck switches the switch SW1 to the main body 2a side, and also switches the CD device A high level remote signal RS is output to the tuner 3 side, and a high level pause signal PS is output to the tuner 1 side. The control circuit 3b of the CD device 3 is a remote signal
By inputting RS, the switch SW2 is switched to the cassette deck side, and at the same time, a high-level remote signal RS is input to the amplifier 4 to turn on the power of the amplifier. On the other hand, control circuit 1b of tuner 1
turns off the tuner when the pause signal PS is input.

Furthermore, when the CD device 3 is played while listening to audio from the cassette deck 2, the control circuit 3b of the CD device switches the switch SW2 to the main unit 3a side, and outputs a high-level remote signal RS to the amplifier 4. It also outputs a high-level pause signal PS to the cassette deck 2. This results in
The amplifier 4 turns on the power, and the control circuit 2b of the cassette deck 2 turns off the cassette deck.

<Problems to be Solved by the Invention> As described above, in the conventional audio system, each set is prioritized, and each set is serially controlled by two control signal lines, one for the remote signal and one for the pause signal. is connected and configured.

For this reason, the conventional audio system has a large number of control signal lines, which is disadvantageous in terms of cost, and also poses problems in terms of workability and space. These problems are especially important in cars where the audio system must be installed in a small space.
This is noticeable in audio systems.

Furthermore, in conventional audio systems, when the system is to be upgraded, measures such as re-prioritization are required, and the work required to upgrade the system is troublesome.

Furthermore, depending on how control signals such as remote signals and pause signals are output, pop noise may be generated.

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide an audio system that can reduce the number of control signal lines, eliminate the need to prioritize each set, and furthermore prevent the occurrence of pop noise.

<Means for Solving the Problems> FIG. 1 is a block diagram of an audio system according to the present invention.

1 is a tuner, 2 is a cassette deck, 3 is a compact disk device, 4 is an amplifier, and 5 is a speaker.

Regarding audio signals, each set is connected in series through audio lines AL1 to AL3, and regarding control signals, each set is connected in series through I/O lines CL1 to CL3.

<Function> Predetermined control circuit, for example, the control circuit 4 of the amplifier 4
Request code RQC from b at regular intervals
to other sets (compact disk device 3, cassette deck 2,
Output to tuner 1).

Upon receiving the request code RQC, the last played set outputs the control code IDC previously assigned to the set via the I/O line in synchronization with the request code.

The control code IDC is received by another set, and the other set performs audio signal route switching processing and other processing based on the control code IDC.

<Embodiment> FIG. 1 is a block diagram of an audio system according to the present invention.

1 is a tuner, 2 is a cassette deck, 3 is a compact disk device, 4 is an amplifier, and 5 is a speaker.

The tuner 1 has a main body part 1a, a control circuit 1b composed of a microcomputer, and an audio signal output part 1c, and the cassette deck 2 has a main body part 2a and a control circuit 2b.
and an audio signal path switching section 2c, the compact disk device 3 has a main body section 3a, a control circuit 3b, and an audio signal path switching section 3c, and the amplifier 4 has a main body section 4a, a control circuit 4b, and an audio signal input section 4c. have.

Audio signal output section 1c for each set 1 to 4
, the audio signal path switching sections 2c and 3c, and the audio signal input section 4c are sequentially connected in series by audio lines AL1 to AL3.

Further, the control circuits 1b to 4b of each set 1 to 4 are sequentially connected in series by one I/O line CL1 to CL3.

The control circuit 4b of the amplifier 4 sends a request code (for example, 1001) to the I/O line CL1 at regular intervals.
~CL3, and the control circuit of the set played last outputs the control code previously assigned to the set in response to (or in synchronization with) the generation (or reception) of the request code RQC. The control code IDC is, for example, 1011 for tuner 1, 1101 for cassette deck 2, and 1111 for compact disc device 3.

As is clear from this configuration, in the system shown in Fig. 1, there is no priority among the sets, and the control circuit of the set played last outputs the control code IDC in synchronization with the request code RQC, and the control circuit of the set played last outputs the control code IDC in synchronization with the request code RQC. The control circuits 2b to 3b of the cassette deck 2 and compact disk device 3 switch and control the switches SW1 and SW2 of the audio signal path switching sections 2c to 3c based on the control code, and the control circuit 4b of the amplifier 4 controls the switches SW1 and SW2 of the audio signal path switching sections 2c to 3c based on the control code. Turn on the power of 4a.

For example, if you play Kasettsu Detsuki 2,
The control circuit 2b of the cassette deck (a) switches the switch SW1 to the cassette body 2a, and (b) receives the request code RQC from the control circuit 4b of the amplifier 4 via the I/O line.
A control code that is assigned in advance in synchronization with the reception (occurrence) of the request code.
Output IDC (1101) to I/O lines CL1 to CL3.

This control code signal IDC is received by the other sets (tuner 1, compact disk device 3, amplifier 4), and the control circuit 1 of the other set
b, 3b, and 4b execute audio signal path switching processing and other processing based on the control code IDC. For example, the control circuit 1b of the tuner 1 stops the tuner, the control circuit 3b of the compact disk device 3 connects the switch SW2 to the cassette deck side, and the control circuit 4 of the amplifier 4 connects the switch SW2 to the cassette deck side.
b turns on the amplifier.

Also, when the compact disk device 3 is played while the cassette deck 2 is being played, the control circuit 3b of the compact disk device 3 (a) switches the switch SW1 to the main unit 3a, and (b) outputs the request code signal RQC from the amplifier 4.
When receiving the request code signal, the control code signal (1111) is output in synchronization with the request code signal.

Control circuit 1 for tuner 1 and cassette deck 2
When b and 2b receive the control code signal (1111), main units 1a and 2a (actually, since cassette deck 2 is currently playing, main unit 2
a), and also the control circuit 4a of the amplifier 4.
turns on the power.

Further, when the tuner 1 is played while the cassette deck 2 or the compact disk device 3 is being played, the control circuit 1b of the tuner 1 receives the request code RQC from the amplifier 4 and outputs the control code IDC in synchronization with the request code.
(1011) is output to I/O lines CL1 to CL3.

When the control circuits 3b and 2b of the compact disk device 3 and the cassette deck 2 receive the control code IDC (1011), the control circuits 3b and 2b of the main body parts 3a and 2
At the same time, the switch SW1 is switched to the tuner side and the switch SW2 is switched to the cassette deck side to establish an audio signal path between the tuner 1 and the amplifier 4. Further, the control circuit 4b of the amplifier 4 turns on the power of the amplifier.

Note that although the case where the request code RQC is generated from the amplifier has been described above, it does not necessarily have to be the amplifier.

<Effects of the Invention> According to the present invention, the control circuits of each set such as the amplifier, tuner, and cassette deck are sequentially connected through one I/O line, and a request code is sent from a predetermined control unit to the I/O line. The set that played last outputs the control code previously assigned to the set via the I/O line in synchronization with the reception of the request code, and performs the control code based on the control code. Since each set switches the audio signal route, the number of control signal lines can be reduced and there is no need to prioritize each set, which is advantageous in terms of cost and reduces wiring work and system up. Furthermore, it is advantageous in terms of space, and is suitable for application to car components where an audio system must be installed in a narrow space.

Furthermore, since the control code is output after receiving the request code, muting can be easily performed and pop noise can be prevented from occurring.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an audio system according to the present invention, and FIG. 2 is a block diagram of a conventional audio system. 1... Tuner, 1b... Control circuit, 2... Cassette deck, 2b... Control circuit, 2c... Audio signal path switching section, 3... Compact disk device, 3b... Control circuit, 3c... Audio path switching Part, 4...Amplifier, 4b...Control circuit.

Claims (1)

[Scope of Claims] 1. The control circuits of each set such as an amplifier, tuner, and cassette deck are sequentially connected in series through one I/O line, and the audio signal output section of each set is connected in series. At the same time, the audio signal output section is configured to select the audio signal from the previous set and the audio signal of the own set and input it to the subsequent set, and the request code is periodically sent to the I/O from the control circuit of the amplifier. The control section of the last played set responds to the request code and outputs the control code assigned to the set to the control section of the other set via the I/O line. The control section of each set other than the amplifier controls its own audio signal output section in response to the control code, switches the audio signal path, and outputs the audio signal between the last played set and the amplifier. An audio system characterized by establishing a route.