JPH0332124B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a car stereo device having a function of selectively recording audio signals from a radio receiving circuit and a microphone amplifying circuit onto tape.

[Prior art and problems to be solved by the invention]

Generally speaking, cassette car stereo systems with recording include microphone recording, radio broadcast recording (AR recording),
It is necessary to switch between the three types of microphone mixing and microphone mixing during playback, and this switching is performed using a changeover switch.

In a car stereo device that has a conventional recording function, switching between microphone recording, radio broadcast recording (AR recording), and microphone mixing during playback can be performed using a switch located on the front panel. However, due to design requirements for in-vehicle equipment, there are cases where there is no room to install a switch on the front panel of the car stereo device.
In this case, there is a problem in that it is necessary to provide an appropriate switching means to replace the changeover switch.

SUMMARY OF THE INVENTION In view of the above-mentioned problems with the conventional type, an object of the present invention is to perform insertion/non-insertion of a microphone jack and playback/reproduction when selectively recording audio signals from a radio reception circuit and a microphone amplification circuit onto tape in a car stereo device. By switching between microphone recording, radio broadcast recording, and mixing of the microphone input and tape playback signal based on the logic of the recording state, there is no need to separately install a dedicated switch to switch between these states, and the space for installing a switch is saved. The purpose is to enable effective use.

[Means to solve the problem]

In the present invention, in a car stereo device having a function of selectively recording audio signals from a radio reception circuit and a microphone amplification circuit onto tape, a detection means for detecting whether or not a microphone jack is inserted into a microphone jack insertion portion; When the detection means detects that the microphone jack is not inserted, power is supplied to the radio receiving circuit, and when the detection means detects that the microphone jack is inserted, the microphone is supplied with power. Switching means that supplies power to the amplifier circuit, playback/recording disabled state, playback state,
a changeover switch means for switching to any one of the recording states; a changeover switch means that is activated when the changeover switch means is in the recording state; recording means for recording on tape the audio signal output from the circuit powered by the circuit; and the switching means are in a playback state, and the detecting means detects that a microphone jack is inserted. a radio receiving circuit, audio from a microphone amplifying circuit, characterized in that it is equipped with a reproduction means which is activated when the audio signal is recorded on a tape and mixes and reproduces the audio signal recorded on the tape with the output of the microphone amplifying circuit. A car stereo device is provided that has the ability to selectively record signals to tape.

[Embodiment] A circuit diagram of a car stereo device having a recording function as an embodiment of the present invention is shown in the drawings.

The emitter circuit of the first transistor 2 controlled by the second transistor 3 is connected to a relay coil of a relay 4 serving as switching means for supplying power to the radio receiving circuit and the microphone amplifier circuit. The first movable contact of relay 4 is connected to power supply circuit PL1 via diode D1, and the second movable contact is connected to power supply circuit PL3.
connected to. The first upper fixed contact of the relay 4 is connected to the power supply circuit PL2 via the diode D2, and the first lower fixed contact of the relay 4 is directly connected to the second
The lower contact of is connected to the microphone amplifier circuit via diode D. The changeover switch 51 is a switch that switches to the lower contact when both the conditions of pressing the record button and inserting the cassette pack are satisfied. The interlocking changeover switch 52 is a switch that switches to the upper contact point when a cassette pack is inserted. The switch 53 is a switch that is closed during radio broadcast recording. The recording head 81 is connected to an equalization amplifier circuit 83 and a recording amplifier circuit 84 via playback/recording switching contacts 82P, 82R. A first terminal 711 of a microphone jack insertion portion 71 serving as a microphone jack insertion detection means is connected to a third terminal 713 via a resistor R1.
It is also connected to a microphone amplifier circuit 72, a power amplifier circuit 73, and a speaker 74 via a capacitor C1. The second terminal of the microphone jack insertion portion 71 is connected to the base of the first transistor 2 via resistors R2 and R3. Note that the switch 53 is also closed during normal listening to radio broadcasts. The present invention is directed to the recording function, and a description of normal listening to radio broadcasts is omitted.

Explain the operation. First, it is assumed that the changeover switch 51 is on the recording side (lower contact closed) and no microphone jack is inserted. Therefore, the base of the second transistor 3 is connected to the microphone jack insertion portion 71.
The second transistor 3 is turned on, and the first transistor 2 is turned off. As a result, the relay 4 is turned off, and the upper fixed contact of both the first and second movable contacts of the relay 4 is closed. Therefore, the power supply voltage (+B)
are the changeover switch 52, the changeover switch 51, the power supply circuit PL1, the diode D1, the contacts of the relay 4,
The signal is supplied to the radio receiving circuit 9 through the diode D2 and the power supply circuit PL2, thereby recording the radio broadcast.

When the microphone jack is inserted into the microphone jack insertion part 71 in the above-mentioned state, the first contact 711 and the second contact 712 of the microphone jack insertion part 71 are opened, the second transistor 3 is turned off, and the first transistor 2 is thereby turned on. As a result, the relay 4 is turned on, and the lower fixed contact of both the first and second movable contacts of the relay 4 is closed. As a result, the power supply circuit PL1 is connected to the diode D
At the same time, the power supply circuit PL1 is disconnected from the power supply circuit PL2, and the power supply voltage supply to the radio reception circuit 9 is cut off.
This allows microphone recording. in this way,
Switching between radio broadcast recording and microphone recording is performed by removing or inserting the microphone jack.

Next, when the selector switch 51 is set to the playback side (upper contact closed) and a microphone jack is inserted, the second transistor is turned off, the first transistor is turned on, and the relay 4 is turned on. Also, the lower fixed contact becomes a closed circuit. Thereby, the power supply circuit PL3 is connected to the microphone amplifier circuit 72 via the second lower fixed contact of the relay 4 and the diode D3. As a result, microphone mixing is performed during tape performance.

〔Effect of the invention〕

According to the present invention, in the car stereo device,
When selectively recording audio signals from a radio receiving circuit and a microphone amplification circuit onto tape, microphone recording, radio broadcast recording, and microphone input and tape playback signals are determined by the logic of microphone jack insertion/non-insertion and playback/recording status. By switching the mixing of the two, there is no need to separately provide a dedicated switch for switching these states, and the space for providing the switch can be used effectively.

[Brief explanation of the drawing]

The drawing is a schematic circuit diagram of a car stereo device having a recording function as an embodiment of the present invention. (Explanation of symbols), 2...first transistor, 3
...Second transistor, 4...Relay, 51...
Recording button pressed, cassette pack insertion response changeover switch, 52...Cassette pack insertion response changeover switch, 53...Radio broadcast recording switch, 71
... Microphone jack insertion part, 72 ... Microphone amplification circuit, 73 ... Power amplification circuit, 74 ... Speaker, 81 ... Playback/recording head, 82 ... Playback/
Recording switching contact, 83... Equalization amplifier circuit, 84...
Recording amplifier circuit, 9...Radio broadcast receiving circuit, R
1, R2, R3, R4, R5...Resistance, C1, C
2... Capacitor, D1, D2, D3... Diode, PL1, PL2, PL3, PL4... Power supply circuit.

Claims (1)

[Scope of Claims] 1. In a car stereo device having a function of selectively recording audio signals from a radio receiving circuit and a microphone amplifier circuit onto tape, a detection means for detecting whether a microphone jack is inserted into a microphone jack insertion portion. When the detection means detects that the microphone jack is not inserted, power is supplied to the radio receiving circuit, and when the detection means detects that the microphone jack is inserted. Switching means for supplying power to the microphone amplification circuit; a playback/recording disabled state; a playback state;
a changeover switch means for switching to any one of the recording states; a changeover switch means that is activated when the changeover switch means is in the recording state; recording means for recording on tape the audio signal output from the circuit powered by the circuit, and the switching means detecting that the switching means is in a playback state and the detecting means detects that a microphone jack is inserted. A radio reception circuit, an audio signal from a microphone amplification circuit, characterized in that it is equipped with a reproduction means that is activated when the audio signal is recorded on a tape, and mixes and reproduces the audio signal recorded on the tape and the output of the microphone amplification circuit. A car stereo device that has the function of selectively recording to tape.