KR950005411Y1 - Chroma difference signal circuit - Google Patents

Abstract

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Description

Chroma Primary / Color Difference Circuit

1 is a block diagram of a conventional color difference signal output circuit.

2 is a block diagram of a conventional primary color signal output circuit.

3 is a detailed circuit diagram of the primary color signal matrix unit of FIG. 2;

4 is a circuit block diagram of a chroma primary / color difference signal according to the present invention.

5 is a detailed circuit diagram of the primary color signal matrix color output controller.

* Explanation of symbols for main parts of the drawings

A: integrated circuit Y: luminance signal

R, G, B: Primary color signal R-Y, G-Y, B-Y: Color difference signal

CY: Color output control signal 1: Luminance signal processor

2: chroma demodulator 3: primary color signal matrix unit

4: matrix color output control unit R0 to R12: resistance

Q1 to Q12: transistors D1 and D2: diodes

Vref: reference voltage

The present invention relates to a CHROMA primary color / color difference signal combined circuit, and more particularly to a chroma primary color / color difference signal combined circuit suitable for color television.

FIG. 1 is a block diagram of a conventional color difference signal output circuit. As shown therein, the luminance signal Y is output from the luminance signal processor 1 in the integrated circuit (a), and the color difference signal (i) is output from the chroma demodulator 2. RY, GY, BY) are configured to be output.

2 is a block diagram of a conventional primary color signal output circuit, in which the primary colors of the luminance signal Y from the luminance signal processor 1 and the color difference signals RY, GY, BY from the chroma demodulator 2 are shown in FIG. It is input to the signal matrix part 3, and it is comprised so that it may output as primary color signals R, G, and B.

FIG. 3 is a detailed circuit diagram of the primary color signal matrix part 3 of FIG. 2, in which the power supply terminal Vcc is connected to the collector and base of the transistor Q3 through the resistor R5 and the transistor Q4 as shown in FIG. Is connected to the base of the transistor Q3 and Q4, and the grounding resistors R3 and R4 are connected to the emitters of the transistors Q3 and Q4. The power supply terminal Vcc is connected to the collector of the transistor Q2. (R0) is connected to the collector of transistor Q1, and the luminance signal Y and the chrominance signal RY, GY, BY are connected so as to be applied to the bases of the transistors Q1, Q2. The emitters of (Q1) (Q2) are connected to the collector of the transistor (Q4) via resistors (R1) and (R2), respectively, and the primary color signals (R, G, B) are output from the collector of the transistor (Q1). The operation of the conventional circuit will be described.

The power is applied to the power supply terminal Vcc, and the luminance signal Y output from the luminance signal processing section 1 is applied to the base of the transistor Q1, and the color difference signals RY and GY output from the chroma demodulator 2. When BY is applied to the base of the transistor Q2, the color difference signals RY, GY, BY are compensated as a result of the luminance signal Y being added, and the primary color signals R, G, and B are output. That is, (R-Y) + Y = R, (G-Y) + Y = G, and (B-Y) + Y = B are output to the collector of transistor Q1.

However, in the conventional technology as described above, since the color difference signal output circuit and the primary color signal output circuit are separated, there is a problem in that it is difficult to change the output method according to the type of the set when used for color television.

SUMMARY OF THE INVENTION In view of the above-described problems, the present invention provides a chroma primary / chromatic signal combined circuit capable of receiving a luminance signal and a color difference signal and outputting a luminance signal and a color difference signal or a primary color signal according to a color output control signal. The present invention is described in detail with reference to the accompanying drawings.

4 is a circuit block diagram of a chroma primary / color difference signal according to the present invention, and as shown therein, a luminance signal processor 1 for outputting a luminance signal Y and a color difference signal RY, GY, BY are outputted. The chroma demodulator 2 and the luminance signal Y and the color difference signals RY, GY, BY, and receive the luminance signal Y and the color difference signals RY, GY, in accordance with the color output control signal CY. BY) or a matrix color output control section 4 for outputting primary color signals R, G, and B.

FIG. 5 is a detailed circuit diagram of the FIG. 4 matrix color output control section 4. As shown in FIG. 5, the power supply terminal Vcc is connected to the emitter of the transistor Q7 through the resistor R7, and the power supply terminal thereof. (Vcc) is connected to the base of the transistor (Q7) through the resistor (R8), and is connected to the base of the resistor (R10) and the transistor (Q6) through the resistor (R9) again, and the The collector is connected to the emitter of the transistor Q5 to which the color output control signal CY is applied to the base and the emitter of the transistor Q6, and the collectors of the transistors Q5 and Q6 are connected to the transistors Q8 and Q10. Are connected to the base of Q9 and connected so that the luminance signal Y output from the luminance signal processing section 1 is applied to the bases of the transistors Q1 and Q3, and the color difference signal output from the chroma demodulator 2. (RY, GY, BY) are connected to be applied to the base of transistors Q2, Q4. Connecting the power supply terminal to the collectors of the transistors Q3 (Q1 and Q4), and connecting the resistors R1 and R0 to the collectors of the transistors Q3 and Q4 and Q4, respectively. The emitters of the transistors Q3 and Q4 are connected to the collectors of the transistors Q8 and Q10, and the emitters of the transistors Q1 and Q2 are connected through the resistors R2 and R3 respectively. A collector side connection point (a) of the transistor Q3 by connecting the emitters of the transistors Q8, Q9 and Q10 to the resistors R4, R5 and R6. Is configured to output the luminance signal Y and to output the color difference signals RY, GY, BY and the primary color signals R, G, and B at the collector side connection points of the transistors Q1 and Q4. Referring to the effect of the present invention in detail as follows.

The luminance signal Y output from the luminance signal processing unit 1 is applied to the bases of the transistors Q1 and Q3, and the color difference signals RY, GY and BY output from the chroma demodulator 2 are transistors Q2 and Q4. Is applied to the base. At this time, the power applied to the power supply terminal Vcc is applied to the collector of the transistor Q2, and is applied to the collectors of the transistors Q3, Q1 and Q4 through the resistors R1 and R0, respectively, and the resistor R8. The voltage is applied to the base of the transistor Q7 and divided by the resistors R9 and R10 to apply a predetermined reference voltage Vref to the base of the transistor Q6. In addition, when the color output control signal CY supplied from the outside is applied to the base of the transistor Q5, and thus the color output control signal CY is applied at a voltage higher than the reference voltage Vref. Transistor Q5 is off and transistor Q6 is conductive.

Therefore, since the low potential signal is output to the collector of the transistor Q5 and the transistors Q8 and Q10 are turned off, the transistors Q3 and Q4 are also turned off.

At this time, the transistors Q1 and Q2 become conductive because the high potential signal is output to the collector of the transistor Q6 due to the conduction of the transistors Q7 and Q8 to conduct the transistor Q9. The color difference signals RY, GY, BY applied to the base of the transistor Q2 are compensated by the luminance signal Y applied to the base of the transistor Q1, and the connection point b which is a collector of the transistor Q4 is provided. The primary color signals R, G, and B are outputted.

At this time, the luminance signal Y is not output to the connection point a which is its collector by turning off the transistor Q3.

On the other hand, when the color output control signal CY is applied at a voltage lower than the reference voltage Vref, the transistor Q6 is turned off and the transistor Q5 is turned on.

Accordingly, since the low potential signal is output to the collector of the transistor Q6 and the transistor Q9 is turned off, the transistors Q1 and Q2 are also turned off.

At this time, since the high potential signal is output to the collector of the transistor Q5 due to the conduction of the transistors Q7 and Q5, the transistors Q8 and Q10 are conducted so that the transistors Q3 and Q4 are also conducted. Therefore, at this time, the luminance signal Y is outputted to the connection point a, which is its collector, by the luminance signal Y applied to the base of the transistor Q3, and the color difference signal RY applied to the base of the transistor Q4. , GY, BY).

Consequently, when the color output control signal CY is applied at a voltage higher than the reference voltage Vref, the primary color signals R, G, and B are output to the connection point b, which is the collector of the transistors Q1 and Q4. When the color output control signal CY is applied at a voltage lower than the reference voltage Vref, the luminance signal Y is output to the connection point a which is the collector of the transistor Q3, and the collectors of the transistors Q1 and Q4 are output. The color difference signals RY, GY, BY are output to the in connection point b.

As described in detail above, the present invention outputs the primary color signal according to the voltage of the color output control signal or outputs the luminance signal and the color difference signal, so that the two color signal output methods can be used in one-chip. According to the needs of the user, the output method can be conveniently changed.

Claims (2)

A luminance signal processor 1 for outputting the luminance signal Y, a chroma demodulator 2 for outputting the color difference signals RY, GY, BY, and the luminance signal Y and the color difference signals RY, GY, BY ) And a matrix color output control unit 4 for outputting primary color signals R, G, B or color difference signals RY, GY, BY and luminance signals Y according to the color output control signal CY. A chroma primary / color difference signal dual circuit. 2. The transistor Q5 according to claim 1, wherein the matrix color output control section 4 selectively conducts the voltage of the color output control signal CY by comparing the voltage of the color output control signal CY with the reference voltage Vref determined by the resistors R8 to R10 ( Q6), the transistors Q8 and Q10 subjected to conduction control by the voltage applied to the diode D1 and the resistor R11 according to the conduction of the transistor Q5, and the diode (Q6) according to the conduction of the transistor Q6. A transistor Q9 subjected to conduction control by the voltage applied to D2) and the resistor R12, a transistor Q3 outputting an input luminance signal Y under conduction control by the conduction of the transistor Q8, and Transistors Q1 and Q2 which are subjected to conduction control by the conduction of the transistor Q9 and output the primary color signals R, G and B from the input luminance signal Y and the color difference signals RY, GY and BY; Under the control of the conduction of the transistor Q10, the input color difference signals RY, GY, BY are outputted. Is a chroma primary / color difference signal combined circuit comprising a transistor (Q4).