KR910000748Y1 - Boardcasting signal interference prevention circuit of color tv - Google Patents

Abstract

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Description

Interference prevention circuit of broadcast signal of color TV

1 is a circuit diagram of the present invention.

2 is a conventional circuit diagram.

* Explanation of symbols for main parts of the drawings

1: Arm color IC 1-1: Arm (R-Y) output

1-2: Arm (B-Y) Output 1-3: Output Terminal

2: secam color IC 4: pendant circuit

TR ₁ , TR ₂ , TR ₃ : Transistor

The present invention is a cause of phase distortion, mutual interference, etc. due to the difference in input voltage when two types of PAL, SECAM, and NTSC transmission systems can be accommodated at the same time in color TV. The present invention relates to a broadcast signal mutual interference prevention circuit of a color TV that eliminates the noise and obtains a clear and clean picture quality.

In the case of the Phase Alternation by Line method proposed in West Germany and used in West Germany, Austria, UK, etc., high voltage is inputted to color TV, while Secam (Shecam, which is proposed in France, and used in the Soviet Union, East Germany, France, etc.). In the case of SECNM, Suquence de couledurs avec memorie combined color sequential system, low voltage is inputted to color TV so that it does not interfere with the broadcast signal of arm when receiving Secam method. The (RY) and (BY) output signals are directly input to the matrix circuit of the PAL / Seccam dual-use IC, which compares the input Secam (RY) and D _R , D _R (BY) signals to the ident circuit. While forcibly applying voltage or grounding, the Secam color signal was taken to scan the red, green, and blue signals into the water pipe while maintaining stability. Interference between chrominance signals occurs, which is fine for black and white TVs. However, when receiving color TVs, there are many problems such as noise on the screen, and white balance changes when adjusting color.

The present invention to eliminate this drawback is to connect the circuit consisting of transistors, resistors and capacitors between the conventional arm color IC and the Sekkham sekam color IC to stop the operation of the incident circuit of the Sekam color IC at the arm type input As a result, it is to be scanned in the water pipe, and when the Sekam method is input, it is scanned in the water pipe through the ident circuit so that only one signal is input in the two types of both to prevent mutual interference. The explanation is as follows.

In a color TV, an arm (RY) output (1-1) and an arm (BY) output (1-2) of an arm color IC (1) and an external Secam (RY) input (2-1) and a Secam (BY) The input circuit (2-2) is input simultaneously. The incident circuit (4) and the matrix circuit (5) are integrated in the high matrix circuit (5) integrally with the Secam color IC (2) with the switch (3). The (RY) output (5-1), the blue (BY) output (5-2) and the green (GY) output (5-3) are supplied to an external water pipe, respectively, while the arm color IC (1) The collector of the transistor TR ₂ supplied to the base through the capacitor C ₁ with the input power source B + supplied to the collector of the transistor TR ₁ connected to the base connected to the base is grounded. The collector of the transistor TR3, which is connected to the BY) output (1-2) and supplied to the base via the capacitor C ₁ (C ₂ ) resistor R _{2 with the} input power source B + grounded, is the arm RY. ), the output (1-1) connected to each transistor (TR ₁₎ (TR ₂₎ (the emitter is grounded and the bias of the TR ₃₎ for adjusting the low (R ₁₎ input power (B +) is supplied through the supply even ahyideon bit circuit 4 and sekam color IC (2) to determine the sekam signal.

The present invention, when receiving the arm type broadcast signal, the transistor (TR1) is turned on because the "H" is caught on the base of the transistor (TR1) through the output terminal (1-3) of the arm color IC (1), the incident The input power of the circuit 4 becomes "Low" and the operation is stopped, and at the same time, "L" is also applied to the base of the transistors TR2 and TR3 so that the transistors TR2 and TR2 are turned off, and the arm color IC 1 arms ( RY) output (1-1) and arm (BY) output (1-2) signals are output as red, blue, and green (5-1) (5) via matrix switch (3). -2) (5-3) is injected into the water tube.

On the other hand, when receiving the Secam method, the Secam method is applied because the transistor TR ₁ is turned off because “L” is applied to the base of the transistor TR ₁ through the output terminal 1-3 of the arm color IC 1. Input power B ^- is supplied to the incident circuit 4 of the IC 2 and is normally operated. At the same time, "H" is applied to the base of the transistors TR ₂ and TR ₃ , respectively. The arm (RY) output (1-1) and the arm (BY) output (1-2) are both grounded and extinguished.

Therefore, the matrix circuit 5 is operated only by the input of the Secam (RY) input (2-1) and the Secam (BY) input (2-2) to output red, blue, and green outputs (5-1) (5-2). (5-3) is injected into the water pipe.

By selecting and inputting only one type of signal required by the two types of combined TVs like this, the interference between the two signals is prevented to create a clearer and clearer picture quality.

Claims (1)

The arm (RY) output, arm (BY) output, secam (RY) input, and secam (BY) input of the arm color IC 1 are all input to the method switch 3, and the matrix circuit 4 selects the matrix and selects the matrix. The incident circuit of the Secam color IC 2 via the collector circuit resistor R ₁ of the transistor TR ₁ connected to the base having the Secam color IC 2 output to the circuit 5 and grounded to the emitter TR ₁ . 4) Input power (B +) is supplied to the base, input power (B +) is supplied to the base, and the collector of two transistors (TR ₂ ) (TR ₃ ) with the emitter grounded is arm (BY) output (1-2). ), And the interference signal of the broadcast signal of the color TV connected to the arm (RY) output (1-1), respectively.