KR900003482Y1 - Automatic surround mode changing circuit - Google Patents

Abstract

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Description

Surround mode automatic switching circuit

1 is a circuit diagram of the present invention.

* Explanation of symbols for main parts of the drawings

1: Stereo pilot signal detection circuit 2: Surround mode switching circuit

3: surround on / off switching circuit portion 4: surround on indicator lamp driving circuit portion

5: Surround mode indicating circuit unit 6: Surround mode switching unit

7: Decoder IC ₃ : Microcomputer for remote control reception

Q ₁ , -Q ₅ : Transistor LED ₁ -LED ₄ : Light Emitting Diode

D ₁ -D ₃ : Diode C ₁ : Capacitor

R ₁ -R ₁₇ : resistance

The present invention is designed to automatically switch the surround mode according to the contents of the TV broadcast, especially in the case of mono broadcasting, it sounds like stereo, and in the case of stereo broadcasting, the sound mode is more complicated, so It relates to an automatic switching circuit.

In the conventional surround mode automatic switching circuit, it is possible to give a choice of whether surround effects are added or not by surround on / off. Also, in the case of mono broadcasting, a pseudo stereo is made according to the broadcasting contents of a broadcasting station. In the case of stereo broadcasting, the mode that expands the stereo feeling is further selected so that the mode can be automatically switched (by the signal of the pilot). It was possible to know the state of the surround by.

In order to solve this problem, the present invention enables the on / off of the surround using the flip-flop output signal of the microcomputer IC for remote control reception, and also the surround on time using the stereo pilot signal of the voice multiple demodulation IC. In order to solve the conventional problems by enabling the automatic switching of the surround mode in accordance with the contents, it will be described in detail by the accompanying drawings as follows.

Surround mode indication of the audio left and right input signal terminals 10 and 20 with IC ₂ , surround mode switching unit, decoder unit, resistors R ₁₆ (R ₁₇ ) and light emitting diodes (LED ₃ ) (LED ₄ ) The input terminal 1 of the IC ₂ , which is connected to the input terminal of the circuit unit 5, and is configured inside the surround mode indicating circuit unit 5, may include a transistor Q ₁ , Q ₂ , and a diode D ₁ ( D ₂ ) connected to the points B and C in the surround mode switching circuit portion 2 composed of the capacitor C ₁ and the resistors R ₂ -R ₆ , respectively, and at the input of the surround mode switching circuit portion 2 IC ₁ , light emission. The stereo pilot signal detecting circuit unit 1 comprising a diode LED ₁ and a resistor R ₁ is connected, and a transistor Q ₃ (Q ₄ ) and a resistor R are connected to an output terminal of the surround mode switching circuit unit 2. _7- R ₁₁ ) connects only the input of the surround on / off switching circuit section 3 to the output terminal of the surround on / off switching circuit section 3 and the circuit. The flip-flop output signal terminal ₃ of the microcomputer IC (IC ₃ ) for remote control reception is connected between the input terminals of the round-on indicator lamp driving circuit section 4.

Reference numeral D ₃ is a diode B ⁺ is a power supply terminal.

Referring to the effect of the present invention configured as described above are as follows.

First, the voice multiple demodulation unit IC ₁ configured inside the stereo pilot signal detection circuit unit 1 enters a low state in the signal terminal ST of the stereo stereo in broadcast stereo, and the stereo pilot in mono broadcasting. In the signal terminal ST of the 'high' state appears in the high light emitting diode (LED ₁ ) is turned on during the stereo broadcast it is found that there is a broadcast in stereo.

In addition, when surround is turned on, since the high voltage is output from the flip-flop output signal terminal ③ of the microcomputer IC IC _{3 for} remote control reception, the transistor Q ₄ is turned on and the transistor Q ₄ is turned on. Is in a low state on the collector side of the transistor, and the transistor Q ₃ is also connected to the transistor, so that the potential becomes a high state at point C. Here, the voltages of the input terminals 1 and ₂ of the IC ₂ configured inside the surround mode indicating circuit section 5 are = (low. Dont care) = normal mode off = (high, low) = pseudo mode. (Pseudostereo mode) = (High, High) = Spatial mode (Stereo extended mode). When surround is turned off, point C is low and input terminal (2) of IC ₂ is irrelevant. If surround is ＂off＂ in this state, it is in normal mode.

When the next surround the "on", the potential of the point C is "high" and the state of the mono broadcast is determined by the voltage on the input terminal 2 of the _second IC. Herein, the case of mono broadcasting and stereo broadcasting will be described. First, in the case of mono broadcasting, since the signal terminal ST of the stereo pilot of the voice multiple demodulation unit IC IC ₁ is in a high state, the transistor Q ₁ is in a conductive state. At that point, the potential becomes a low state. As described above, since the potential at the point A is in a low state, the transistor Q ₂ is turned on to become a low state at the potential at the point B. The input terminal of the IC ₂ (①) is "high" the IC ₂ enter the terminal (②) is standing because the "low" surround mode is stereo sounds more like at the time of change mono broadcasts in doctor mode, i.e. pseudo stereo mode. Next, during stereo broadcasting, the stereo pilot signal terminal ST of the audio multiple demodulation unit IC ₁ is in a low state, and the transistor Q ₁ is in a closed state, and the potential at the A point is high. "since the transistor (Q ₂₎ is""the potential of the point B is" default barrel high "to the state. In this way, the input terminals ① and ② of the IC ₂ are all in a high state, and the mode is changed to the spatial mode, that is, the stereo extended mode, to further expand the stereo sound range. Where D ₁ and D ₄ are diodes to bring the potentials of the A and B points into a low state during surround shut-off.

In the pseudo mode, the light emitting diode (LED ₁ ) is turned on to indicate a pseudo stereo mode. In the spatial mode, the light emitting diode (LED ₁ ) is lit to indicate a range expansion during stereo broadcasting. At this time, the microcomputer IC (IC ₃ ) flip-flop output signal terminal (③) for remote control reception becomes “high” and the transistor (Q ₅ ) is turned on so that the light emitting diode (LED ₂ ) is turned on. It will indicate that the state.

The present invention, which operates as described above, enables the surround effect to be selected by the on / off switch of the surround, and provides convenience by automatically selecting the surround effect according to the broadcast contents of the broadcasting station during the surround on and off. To give.

Claims (1)

The input terminal 1 of the IC ₂ configured to connect the input terminal of the surround mode indicating circuit section 5 to the normal audio left / right input signal terminals 10 and 20 and to form the inside of the surround mode indicating circuit section 5 (2). ) Is connected to points B and C respectively configured inside the surround mode switching circuit unit 2, and a stereo pilot signal detection circuit unit 1 is connected to an input terminal of the surround mode switching circuit unit 2, and the surround mode switching circuit unit An output terminal of (2) is connected to an input terminal of the surround on / off switching circuit unit 3, and a remote controller is received between the output terminal of the surround on / off switching circuit unit 3 and the input terminal of the surround on / off lamp driving circuit unit 4. A surround mode automatic switching circuit configured by connecting a flip-flop output signal terminal ( ₃ ) other than the microcomputer IC (IC ₃ ) of the circuit.