JPH05205454A - Acoustic device - Google Patents

Abstract

PURPOSE:To provide an acoustic device preventing the occurrence of the regenerative sound of an audio signal occurring in the case of the high speed running operation of a cassette deck without using two stages of muting circuits. CONSTITUTION:When the cassette deck 4 is selected by operating a mode key 11a, power source voltage is supplied to the cassette deck 4 from a power source circuit 5 and further an audio signal selection circuit 6 is switched to a cassette deck side 4. When an FF key or an REW key is operated in the operatable state of the cassette deck 4, the audio signal selection circuit 6 is switched to an AM receiving circuit 2 side from the cassette deck and the audio signal picked up by a magnetic head at the time of operating the FF and the REW is cut and then the occurrence of a noise at the time of operating the FF and the REW is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an audio device that uses a plurality of audio devices such as a vehicle audio device.

[0002]

2. Description of the Related Art FIG. 2 shows a conventional on-vehicle audio system in which a radio receiver, a CD (compact disc) changer and a cassette deck are combined. In FIG. 2, 1
Is an FM receiving circuit, 2 is an AM receiving circuit, 3 is a plurality of CDs
The CD changer 4 that takes out one CD from the magazine in which the CD is stored and plays back is a cassette deck. These audio devices are operated by being supplied with power from the power circuit 5, and the audio output signals of the audio devices are , Line 1a,
It is input to the audio signal switching circuit 6 via 2a, 3a and 4a. Reference numeral 7 is a control circuit including a microcomputer, and the control circuit 7 includes an FM receiving circuit 1, A
A PLL circuit of the M receiving circuit 2 and the like are included. Reference numeral 8 is a communication line for communicating between the control circuit 7 and the CD changer 3. Various operation command signals are input from the control circuit 7 to the CD changer 3 via the communication line 8 and the CD changer 3 also changes to the CD changer 3. Various status signals of No. 3 such as a status signal indicating whether the magazine is set in the CD changer 3 are input to the control circuit 7. Reference numeral 9 is a line that connects the control circuit 7 and the cassette deck 4. Through this line 9, various operation command signals are transmitted from the control circuit 7 to the cassette deck 4, and at the same time, from the cassette deck 4 to the control circuit 7. Various status information, such as an on / off signal of a switch which is turned on when the cassette is set at the reproducing position of the cassette deck 4, is transmitted. Reference numeral 10 denotes a silence detecting circuit for detecting a silent portion between the songs of the audio signal output from the cassette deck 4. The detection result of the silence detecting circuit 10 is input to the control circuit 7 and used for the cueing operation of the song. It Reference numeral 11 denotes various keys 1 for issuing various operation commands to the above-mentioned audio equipment.
1a, 11b, 11c, 11d ... Is a key matrix circuit, and the operated key is discriminated by the control circuit 7, and the audio signals 1, 2,
An operation command is output to 3 and 4. Of the above keys,
The key 11a is a mode key for selecting one of a plurality of audio devices, and a switching signal is sent from the control circuit 7 every time the mode key 11a is operated, the audio signal switching circuit 6,
It is output to the power supply circuit 5. For example, the current FM receiving circuit 1
When the mode key 11a is operated in the state where is operating, the power supply from the power supply circuit 5 to the FM receiving circuit 1 is stopped, the power is supplied to the cassette deck 4, and the audio signal switching circuit 6 operates as the FM receiving circuit. The output signal of 1 is switched to the output signal of the cassette deck 4, and the audio signal is switched so that only the output signal of the cassette deck 4 is passed. As described above, in this embodiment, the mode key 1
Each time 1a is operated, the audio equipment is sequentially switched in a predetermined order of FM receiving circuit 1 → cassette deck 4 → CD changer 3 → AM receiving circuit 2 → FM receiving circuit 1 → cassette deck 4 ... It is a thing. Reference numeral 11c is an FF key for giving a fast forward (FF) command of the magnetic tape to the cassette deck 4. When the operation of the FF key 11c is judged by the control circuit 7, the control circuit 7 sends a fast forward command signal to the cassette deck 4. Is supplied, the cassette deck 4 performs a fast forward (FF) operation of the magnetic tape. Reference numeral 11d is a REW key for giving a fast rewind (REW) command. When the operation of the REW key 11d is judged by the control circuit 7, a fast rewind command signal is supplied from the control circuit 7 to the cassette deck 4. The cassette deck 4 performs a fast rewind (REW) operation of the magnetic tape. Reference numeral 12 denotes a first muting circuit. The first muting circuit 12 outputs a muting control signal from the control circuit 7 when switching the audio equipment, for example, when switching from FM broadcast reception to AM broadcast reception. The muting operation is performed for a short time. Reference numeral 13 denotes a second muting circuit. The second muting circuit 13 performs a muting operation when the cassette deck 4 is performing a fast forward (FF) operation or a fast rewind (REW) operation. Yes, by the second muting circuit 13, FF, RE
This prevents the reproduced sound of the audio signal picked up by the magnetic head half-touched on the magnetic tape at the time of W from being output from the speaker 15. Reference numeral 14 is an amplifier for amplifying an audio signal, and 15 is a speaker.

Next, the operation of the above conventional example will be described.
When the mode key 11a of the key matrix circuit 11 is operated, a switching signal is supplied from the control circuit 7 to the power supply circuit 5 and the audio signal switching circuit 6, and the power supply voltage is supplied and the audio output signal is switched. Further, a muting control signal is supplied from the control circuit 7 to the first muting circuit 12 at the time of switching the audio device, and muting is performed for a short time to prevent noise from being generated at the time of switching the audio device. Also, when the cassette deck 4 is operating,
When the FF key 11c or the REW key 11d is operated, the control circuit 7 causes the first and second muting circuits 1 to operate.
The muting control signal is supplied to 2 and 13 and muting is applied to prevent the reproduced sound of the audio signal picked up by the magnetic head half-touching the magnetic tape from being output from the speaker 15. ..

[0004]

However, the above-mentioned conventional audio device includes the first muting circuit 12 for preventing the generation of noise when switching the audio equipment or switching the mode of each audio equipment. In order to prevent the reproduced sound of the audio signal picked up by the magnetic head from being output from the speaker 15 during the FF operation or the REW operation of the cassette deck 4, a second muting circuit 13 for supplementing the lack of mute is required. However, there is a problem that the circuit configuration is complicated and the number of parts is large.

The present invention solves the above-mentioned conventional problems, and provides an acoustic device capable of performing the same muting operation as the conventional one without providing the second muting circuit 13 in the above-mentioned conventional example. It is a thing.

[0006]

In order to achieve the above object, the present invention selects a plurality of audio equipments including a cassette deck and one of the plurality of audio equipments to make them operable. Selecting means, an audio signal switching circuit for selecting an audio output signal of the audio equipment selected by the selecting means from audio output signals of the plurality of audio equipment, and a high-speed running means for fast-forwarding or fast-rewinding the cassette deck. And a switching means for switching the audio signal switching circuit from the cassette deck to another audio device when the high-speed traveling means operates while the cassette deck is selected by the selecting means. It is a thing.

[0007]

The present invention has the above-mentioned structure, and the cassette deck is selected from the plurality of audio equipment by the selection means.
And when the magnetic tape is put in a high-speed running state by the high-speed running means, the audio signal switching circuit is switched from the cassette deck to another audio device, so that the audio signal picked up by the magnetic head from the high-speed running magnetic tape is It is cut by the audio signal switching circuit. For this reason, the audio signal picked up by the magnetic head is not reproduced during high-speed traveling, which is the same as muting performed by the muting circuit 13 of the conventional example.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. In FIG. 1, the same parts as those in the conventional example shown in FIG. 2 are designated by the same reference numerals. In FIG. 2, when the mode key 11a is operated to switch to the cassette deck 4, a switching signal is supplied from the control circuit 7 to the power circuit 5 and the audio signal switching circuit 6, and a power voltage is supplied from the power circuit 5 to the cassette deck 4. The audio signal switching circuit 6 is switched so as to transmit only the audio output signal of the cassette deck 4 to the muting circuit 12. The cassette deck 4 which is ready for operation in this way
When the cassette is inserted into the play state, the play state is set, and the audio output signal is transmitted to the audio signal switching circuit 6 through the line 4a and further transmitted to the muting circuit 12, the amplifier 14, and the speaker 15 to perform the reproducing operation.

During such a reproducing operation, the FF
When the key 11c or the REW key 11d is operated, this key operation is determined by the control circuit 7, and the control circuit 7 gives an FF or REW operation command to the cassette deck 4, and the cassette deck 4 performs the FF operation or the REW operation. Also FF
When the operation of the key 11c or the REW key 11d is determined, the audio signal switching circuit 6 is switched from the cassette deck 4 to the AM receiving circuit 2. For this reason, the audio signal picked up by the magnetic head during the FF and REW operations is not transmitted through the audio signal switching circuit 6, so that the reproduced sound of the audio signal picked up by the magnetic head during the FF and REW operation is the speaker. 15 is not output.

During operation of the cassette deck 4, A
Since the power supply voltage is not supplied from the power supply circuit 5 to the M reception circuit 2, the AM reception circuit 2 is in the inoperative state,
No audio signal is output from the receiving circuit 2, and the audio output signal of the AM receiving circuit 2 is not output from the speaker 15 via the audio signal switching circuit 6.

As described above, according to the present embodiment, the pickup signal of the magnetic head is cut by the audio signal switching circuit 6 during the FF and REW operations of the cassette deck. The muting circuit 13 is unnecessary, the circuit configuration is simplified, and the number of parts can be reduced. Further, when the silence detecting circuit 10 detects a silent portion between songs during the FF and REW operations, the detection signal is supplied to the control circuit 7 and the cassette deck 4
Is switched to the play operation state, the audio signal switching circuit 6 is switched to the cassette deck 4 side, and the reproducing operation of the cassette deck 4 is restarted.

[0012]

The present invention has the above-described structure, and during high speed running operation of the cassette deck, the audio signal switching circuit switches from the cassette deck side to the other audio equipment side, and therefore runs at high speed. The audio signal picked up from the magnetic tape is not reproduced, and it is similar to muting performed by the muting circuit in the conventional example. The circuit configuration is simple and the same muting function as the conventional example can be exhibited. I have.

[Brief description of drawings]

FIG. 1 is a block diagram of an audio device according to a first embodiment of the invention.

FIG. 2 is a block diagram of a conventional audio device.

[Explanation of symbols]

 1 FM receiving circuit 2 AM receiving circuit 3 CD changer 4 Cassette deck 5 Power supply circuit 6 Audio signal switching circuit 7 Control circuit 10 Silence detection circuit 11a Mode key 11c Fast forward key 11d Rewinding key 12 Muting circuit 14 Amplifier 15 Speaker

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location G11B 33/06 M 7177-5D

Claims (1)

[Claims] 1. A plurality of audio equipments including a cassette deck, a selection means for selecting one of the plurality of audio equipments to make it operable, and an audio output signal of the plurality of audio equipments. The audio signal switching circuit for selecting the audio output signal of the audio device selected by the selecting means, the high speed running means for fast-forwarding or fast-rewinding the cassette deck, and the cassette deck selected by the selecting means. An audio device comprising switching means for switching the audio signal switching circuit from the cassette deck to another audio device when the high-speed traveling means operates.