KR900006369Y1 - External input sound hearing circuit at reproducing vcr - Google Patents

Abstract

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Description

External input audio listening circuit during playback

The accompanying drawings are circuit diagrams of the present invention.

* Explanation of symbols for main parts of the drawings

F1: T flip-flop I 1- I 3: Inverter

Q1-Q6: Transistor G1: And Gate

G2: Oagate

The present invention relates to a circuit capable of listening to external input voice through a headphone during playback in a video tape recorder.

Conventionally, during playback, only the audio being played by the video tape recorder can be heard through the headphones.

The present invention was conceived to improve such a point, and an object thereof is to provide a circuit that can enjoy the sound of a television or an audio during reproduction.

The present invention will be described in detail with reference to the accompanying drawings.

In the video tape recorder, the system control unit (1), audio reproduction circuit (2), audio output circuit (3), audio recording circuit (4), audio recording output circuit (5), and headphone output circuit (6) ) Flip flip F1, AND gate G1, OA gate G2, and inverter I1 added to the audio external circuit (7), the audio recording input circuit (8), and the key input circuit (9). -I3) and transistors Q1-Q6.

The inverter I1 and the transistors Q1 and Q2 constitute a switching unit 10 and are connected to the audio recording circuit 4, the audio external input circuit 7 and the audio recording input circuit 8, and the inverter I2. And transistors Q3 and Q4 form a switching unit 20 and are connected to an audio recording output circuit 5, an audio recording circuit 4 and a switching unit 30, and an inverter I3 and transistors Q5 and Q6. The switch 30 is configured to connect to the headphone output circuit 6, the audio output circuit 3 and the switching unit 20.

In addition, the flip-flop F1 operates by using the output of the key input circuit 9 as a clock signal, and the AND gate G1 inputs the reproduction control terminal of the system controller 1 and the output terminal of the flip-flop F1 into two inputs. The output terminal is connected to the switching units 10, 20, and 30, and the input terminal of the OR gate G2 is connected to the recording control terminal of the system control unit 1 and the output terminal of the AND gate G1. The output terminal is connected to an audio recording circuit 4.

The operation of the circuit of the present invention having such a configuration will be described.

The switching unit 10-30 switches each signal by the output of the AND gate G1, and the switching 10 is connected to the inverting output through the output of the AND gate G1 and the respective inverters I1-I3. The transistors Q1 and Q2 are driven to switch the output of the audio external circuit 7 or the output of the audio recording input circuit 8. When the transistor Q1 is turned on, the audio external input is supplied to the audio recording circuit 4. When the transistor Q2 is turned on, the audio recording signal is applied to the audio recording circuit 4.

Meanwhile, when the transistor Q3 is turned on, the switching unit 20 causes the recording signal, which is an output signal of the audio recording circuit 4, to be applied to the cellular phone output circuit 6 through the switching unit 30, and the transistor Q4 is applied. When on, the recording signal of the audio recording circuit 4 is switched to be applied to the audio recording output circuit 5.

In addition, the switching unit 30 causes the recording circuit of the audio recording circuit 4 through the switching unit 20 to be applied to the headphone output circuit 6 when the transistor Q5 is turned on, and the transistor Q6 is turned on. If so, the output signal of the audio output circuit 3 is switched to apply to the headphone output circuit 6.

The operation in the case of listening to the voice being played through the headphones in the playback state will be described first.

When an arbitrary key of the key input circuit 9 is inputted, the output Q of the flip-flop F1 is at a low level. At this time, a high state regeneration control signal is applied to the AND gate G1 by the system controller 1. However, the output of the AND gate G1 also becomes low level, and the transistors Q2, Q4, and Q6 of the switching units 10-30 are turned on, respectively.

Therefore, the output signal of the audio reproduction circuit 2 passing through the audio output circuit 3 is output to the headphone output circuit 6 through the transistor Q6 of the switching unit 30, so that the signal being reproduced by the headphones can be felt. Will be.

Secondly, the operation in the case where it is desired to listen to the external input through headphones during playback will be described.

When the external input selection key of the key input circuit 9 is inputted, the output Q of the flip-flop F1 becomes high level, and the reproduction control signal of the high state is output from the system controller 1 as described above, and the AND gate Since it is applied to G1, the AND gate G1 becomes high level and the output of the oragate G2 also becomes high level, so that the audio recording circuit 4 operates.

Accordingly, the transistors Q1, Q3 and Q5 of the switching unit 10 are turned on so that the output of the audio external circuit 7 is applied to the audio recording circuit 4 through the transistor Q1 and the output thereof is the transistor Q3. Since it is applied to the headphone output circuit 6 through Q5, it is possible to listen to the external input using the headphone.

Finally, the operation in the recording mode will be described.

The recording control signal in the high state is output from the system control unit 1, the reproduction control signal is output in the low state, and the output of the AND gate G1 becomes low level, and the transistors Q2, Q4 and Q6 are turned on. . In addition, since the output of the oar gate G2 becomes high and is applied to the recording control input of the audio recording circuit 4, the output signal of the audio recording input circuit 8 is transmitted to the audio recording circuit 4 through the transistor Q2. The recording signal output of the audio recording circuit 4 is applied to the audio recording output circuit 5 through the transistor Q4.

On the other hand, since the audio reproducing circuit 2 does not operate, no signal is output to the headphone output circuit 6 even though the transistor Q6 is turned on.

As described above, according to the present invention, a video tape recorder having a more convenient function can be provided by allowing a user to select and listen to a desired voice during playback of the video tape recorder.

Claims (1)

And gate G1 for inputting the reproduction control signal of the system control unit 1 and the output Q of the flip-flop F1 and applying the output to one input of the switching unit 10-30 and the oragate G2. And the transistors Q1 and Q2 are driven by the output signal of the AND gate G1 to output the output signal of the audio external circuit 7 and the output signal of the audio recording input circuit 8 to the audio recording circuit 4. Transistors Q3 and Q4 are driven by the switching unit 10 and the output of the AND gate G1 to apply the output of the audio recording circuit 4 to the audio recording output circuit 5 and the switching unit 30. Transistors Q5 and Q6 are driven by the switching unit 20 and the output signal of the AND gate G1 to output the audio recording circuit 4 and the audio output circuit through the switching unit 20. A switching section 30 for applying the output of (3) to the headphone output circuit 6, and the recording control signal and end of the system control section 1; The output Q is synchronized with the output of the orifice G1 and the key input circuit 9 that inputs the output of the output G1 and outputs a recording control signal to the audio recording circuit 4. And a flip-flop (F1) applied to the input of the external input audio listening circuit during reproduction.