JPH09200791A - Color saturation adjustment circuit - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To adjust the color saturation in a color display monitor without impairing a proper color image with a simple circuit. SOLUTION: The three primary color signals R, G, B input from input terminals 1, 2, 3 are combined into a luminance signal by resistors 4, 5, 6 and then from a collector of a transistor 10 to transistors 19, 20 ,. 21 are input to the base. The three primary color signals R, G, B input to the emitters of the transistors 19, 20, 21 from the same input terminals 1, 2, 3 are subtracted by the brightness signal levels by the transistors 19, 20, 21 and the The three primary color signals R, G and B are output from the collector. These signals R, G, B
The color saturation becomes relatively higher on the color display monitor by the luminance signal level.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color display monitor for inputting three primary color signals of red (R), green (G) and blue (B), and more particularly to the color saturation of an image projected on this monitor. The present invention relates to a color saturation adjusting circuit for adjusting.

[0002]

2. Description of the Related Art In a color display monitor of a type that inputs signals of three primary colors of R, G and B, that is, a color receiver, in order to reproduce a correct color image, the RG is used in its electron gun section.
The method is based on the method of controlling the RGB electron beams by the B primary color signal component. By the way, the ratio of human eyes' brightness is R for the three primary colors.
Since the ratio is (red) 30%, G (green) 59%, and B (blue) 11%, the brightness can be correctly reproduced by adding the input three primary color signals at this ratio. .

On the other hand, the efficiency of the phosphor used in the current color receiver is R,
G and B are not the same. In particular, blue has poor luminous efficiency with respect to current. There are also variations in gm. Therefore, in the current color receiver, when amplifying the primary color signals, the correct color image is obtained by changing the amplification degree of each axis according to the light emission efficiency, instead of amplifying the primary color signals of the three axes at the same ratio. ing.

However, since this type of color display monitor has conventionally been designed to display character information and the like,
It does not have a color saturation adjustment circuit. Therefore, when this type of color display monitor is used as a multi-type monitor and various video signals are input and displayed, there is a problem that an image cannot be displayed in a natural color tone. .

Therefore, as a color saturation adjusting circuit, there is a circuit shown in FIG. 5 disclosed in Japanese Patent Laid-Open No. 6-245220. This circuit amplifies each of the three primary color signals to generate C
Amplifiers 7 to 9 which are input to a predetermined cathode of RT10,
Amplifiers 4 to 6 for amplifying the primary color signals branched from the input circuits to the amplifiers 7 to 9, a combining circuit 16 for combining the outputs from the amplifiers 4 to 6, and an input from the combining circuit 16 are inverted. The amplifier 15 which amplifies and inputs to the first grid 14 of the CRT 10, the amplifiers 7 to 9 and the amplifier 15
Of gain control terminals 20 and 21 for controlling the gain of the control circuit (not shown).

In the above circuit, the luminance signal Y output from the amplifiers 4, 5, and 6 is output to the luminance signal Y by the synthesizing circuit 16.
And supplies it to the first grid 14 of the CRT (color receiver) 10. In the color receiver, the first grid 14 is common to all electron guns, and therefore the first grid 14 is
In the grid 14, it is impossible to change the transfer of the luminance signal in accordance with the luminous efficiency of RGB and the variation of gm. In addition, since the gains are common to the three axes on the signal supply side to the cathodes 11, 12, and 13, the transfer cannot be changed, so that a correct color image cannot be obtained as it is.

In order to obtain a correct color image, it is necessary to adjust the electron guns with different factors such as different sensitivities, elimination of gm variation, and uniform phosphor luminous efficiency. In the text of the above-mentioned conventional example, it is stated that the output ratio of the signals output from the amplifiers 4, 5 and 6 can be changed to adjust the white balance, but the addition ratio of the primary color signals in creating the Y signal can be changed. However, the transfer to each axis cannot be changed, and a correct color image cannot be obtained. Further, if the ratio of the signal levels of the three axes is changed before the input to this conventional example, the ratio of the transfer to the cathode can be changed, but the level of the input signal to the amplifiers 7, 8 and 9 input to the cathode However, the balance is lost on the three axes, and the color depth of each of the three axes is different.

Further, according to this conventional example, since the Y signal is applied to the first grid 14, the cathodes 11, 12, 1
Since the dynamic range required by the amplifier circuits 7 to 9 that drive the circuit 3 becomes large, it is generally necessary to increase the power supply voltage of the circuit, and the power loss of the output circuit becomes large.
Along with this, it becomes necessary to use a large load resistance, and there is a problem that the output frequency band is limited. Further, the amplifier 15 for driving the first grid 14 is required, which causes a problem that the circuit becomes very complicated.

FIG. 6 is a block diagram showing another example of a conventional color saturation adjusting circuit. Input three primary color signals R,
G and B are converted into a Y signal, an R-Y color difference signal, and a BY color difference signal by the matrix circuit 61. The color difference signals R-Y and B-Y are amplified to a required level by the amplifier circuit 62. Further, by inputting the output of the amplifier circuit 62 and the Y signal to the matrix circuit 63, the color difference signals R-Y, G-Y and B-from the matrix circuit 63.
Y is obtained and the respective color difference signals are added to the Y signal by the adder circuits 64, 65 and 66, whereby R, G, and
I am getting a B signal.

Here, in the case of increasing the color saturation, it is possible to increase only the color component of the input primary color signal by setting the amplitude of each color difference signal to be large in the amplifier circuit 62. Increases the saturation of color. When lowering the color saturation, each color difference signal R
By setting the amplitudes of -Y and BY to be small, it is possible to reduce only the color components of the input primary color signals,
This results in low color saturation. In extreme cases,
If the output of the amplifier circuit 62 is set to zero, only the color components of the primary color signals are lost, and the signals output from the adder circuits 64, 65, 66 are monochrome signals. However, this circuit requires a large number of circuit elements, and in particular, the matrix circuits 61 and 63 are complicated, so that the cost of the circuit is increased and the reliability of the circuit is deteriorated.

Further, Japanese Patent Application No. 6-269384 proposes a device for reducing the color saturation in a color display monitor or the like for inputting primary color signals. In this device, the color saturation is increased. There was a problem that I could not do it.

[0012]

In the conventional color saturation adjusting circuit as described above, a correct color image cannot be obtained or a large number of circuit elements are required, so that the cost of the circuit is increased and the reliability is improved. There have been many problems such as deterioration of the property, and further, there is a problem that the saturation of color cannot be increased.

Therefore, the present invention has been made to solve the above problems, and it is possible to raise and lower the color saturation in a color display monitor with a simple circuit and obtain a correct color image. It is an object of the present invention to provide a highly reliable color saturation adjustment circuit.

[0014]

According to a first aspect of the present invention, there is provided a luminance signal generating circuit for synthesizing input red, green and blue primary color signals to generate a luminance signal, and a red primary color signal level. A first subtraction circuit that reduces the brightness signal level created by the brightness signal creation circuit; a second subtraction circuit that subtracts the brightness signal level created by the brightness signal creation circuit from the green primary color signal level; And a third subtraction circuit that subtracts the luminance signal level created by the luminance signal creation circuit from the blue primary color signal level. Color saturation is calculated from the subtraction results of the first, second, and third subtraction circuits. It is provided with a configuration for obtaining red, green, and blue signals of the three primary colors that have been enhanced.

According to a second aspect of the present invention, there is provided a luminance signal generating circuit for synthesizing input red, green and blue primary color signals to generate a luminance signal, and the luminance signal generating circuit for the red primary color signal level. A first adding circuit for adding the created luminance signal level, and a second adding circuit for adding the brightness signal level created by the brightness signal creating circuit to the green primary color signal level
And a third adder circuit for adding the luminance signal level created by the brightness signal creating circuit to the blue primary color signal level, and these third, second, and third adder circuits are provided. A configuration is provided in which the red signal, the green signal, and the blue signal of the three primary colors with reduced color saturation are obtained from the addition result.

According to a third aspect of the present invention, there is provided a first level adjusting circuit for adjusting the level of the luminance signal produced by the luminance signal producing circuit, and the subtracted red of the first, second and third subtracting circuits. A second, a third, and a fourth level adjusting circuit for adjusting the levels of the primary color signals of the subtracted green and the subtracted blue, respectively, and are linked with the level adjustment of the first level adjusting circuit. It has a configuration for adjusting the levels of the second, third, and fourth level adjusting circuits.

According to a fourth aspect of the present invention, the luminance signal generating circuit switches whether to generate a luminance signal or not.
Switch and the second, third and fourth switches for stepwise switching the levels of the subtracted red, subtracted green and subtracted blue primary color signals of the first, second and third subtraction circuits, respectively. And a configuration for switching the second, third, and fourth switches in conjunction with switching of the first switch.

According to a fifth aspect of the present invention, there is provided a first level adjusting circuit for adjusting the level of the luminance signal produced by the luminance signal producing circuit, and the red to be added of the first, second and third adding circuits. A second, a third, and a fourth level adjusting circuit for adjusting the levels of the primary color signals for the added green, the added green, and the added blue, respectively, and are linked with the level adjustment of the first level adjusting circuit. It has a configuration for adjusting the levels of the second, third, and fourth level adjusting circuits.

According to a sixth aspect of the present invention, the luminance signal generating circuit switches whether or not a luminance signal is generated.
Switch and second, third, and fourth switches for stepwise switching the levels of the primary color signals of red, green, and blue to be added of the first, second, and third adder circuits, respectively. And a configuration for switching the second, third, and fourth switches in conjunction with switching of the first switch.

According to a seventh aspect of the present invention, in the luminance signal generating circuit, the three resistors for inputting the red, green and blue primary color signals to one end and the other end of these three resistors are commonly used as an emitter. And a transistor amplifier circuit connected to
The first subtraction circuit is configured by a transistor amplifier circuit that inputs the red primary color signal to the emitter and inputs the collector output of the transistor of the luminance signal generation circuit to the base, and the second subtraction circuit is the green subtraction circuit. The third subtraction circuit inputs the primary color signal to the emitter and the collector output of the transistor of the luminance signal generating circuit to the base, and the third subtraction circuit inputs the blue primary color signal to the emitter and outputs the luminance signal. It is configured by a transistor amplifier circuit that inputs the collector output of the transistor of the signal generation circuit to the base, and obtains the red signal, the green signal, and the blue signal from the collectors of the transistors of the first, second, and third subtraction circuits. I have it.

According to the eighth aspect of the present invention, in the luminance signal generating circuit, three resistors for inputting each of the red, green and blue primary color signals to one end and the other end of these three resistors are commonly used as an emitter. And a transistor amplifier circuit connected to
The first adder circuit is configured by a transistor amplifier circuit that inputs the red primary color signal to the emitter and inputs the polarity inversion signal of the collector output of the transistor of the brightness signal generating circuit to the base, and the second adder circuit. Is a transistor amplifier circuit which inputs the green primary color signal to the emitter and inputs the polarity inversion signal of the collector output of the transistor of the luminance signal generating circuit to the base, and the third adder circuit is the blue primary color signal. To the emitter,
The brightness signal generating circuit is composed of a transistor amplifier circuit which inputs the polarity inversion signal of the collector output of the transistor to the base, and the red signal and the green signal are output from the collectors of the transistors of the first, second and third adding circuits. , A configuration for obtaining a green signal.

[0022]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram showing the configuration of the first embodiment of the present invention. 1, 2 and 3 are input terminals for inputting the three primary colors of red (R), green (G) and blue (B) signals,
4, 5 and 6 are resistors for synthesizing luminance signals (Y signals), 7 and 2
5, 26, 27 are transistors 10, 19, 20, 21
Power source for operating the transistor, 8 and 9 are base bias resistors of the transistor 10, 10 is a transistor for amplifying the Y signal, 11 is a variable resistor inserted on the collector side of the transistor 10, and 12, 22, 23 and 24 are transistors. 1
Resistors inserted on the emitter side of 0, 19, 20, 21
Reference numerals 13, 14, 15 are variable resistors inserted between the input terminals 1, 2, 3 and the emitters of the transistors 19, 20, 21 respectively, and 16, 17, 18 are transistors 19, 20, 21.
The resistors 28, 29, 30 inserted in the collector side of the transistors are output terminals for R, G, B signals output from the collectors of the transistors 19, 20, 21.

Next, the operation of this embodiment will be described. Consider, for example, the case where three primary color signals created by the NTSC standard are input to an RGB color display monitor to receive an image. The red primary color signal R input from the input terminal 1, the green primary color signal G input from the input terminal 2, and the blue primary color signal B input from the input terminal 3 are respectively connected to resistors 4, 5, 6 respectively.
Is input to the Y signal synthesizing circuit formed centering on the transistor 10. The resistors 4, 5 and 6 of the Y signal synthesizing circuit add the R, G and B primary color signals at a ratio of about 3: 6: 1 to form a Y signal, and the Y signal is applied to the emitter of the transistor 10. It is input, this is amplified by the transistor 10 and output from the collector.

At the same time, the primary color signal R input from the input terminal 1 is input to the emitter of the transistor 19 via the variable resistor 13. Similarly, the primary color signal G input from the input terminal 2 is input to the emitter of the transistor 20 via the variable resistor 14, and the primary color signal B input from the input terminal 3 is input to the emitter of the transistor 21 via the variable resistor 15. To be done. The bases of the transistors 19, 20 and 21 are the transistors 10 of the Y signal combining circuit described above.
The Y signal which is the output of is supplied.

As a result, at the collector of the transistor 19, an R signal obtained by subtracting the level of the Y signal input to the base from the level of the primary color signal R input to the emitter is obtained. Similarly, a G signal obtained by subtracting the level of the Y signal input to the base from the level of the primary color signal G input to the emitter is obtained at the collector of the transistor 20, and the collector of the transistor 21 is provided at the emitter. A B signal is obtained by subtracting the level of the Y signal input to the base from the level of the input primary color signal B.
Therefore, at the output terminals 28 to 30, three primary color signals R, G, B obtained by subtracting a Y signal of a certain level from the levels of the input primary color signals R, G, B are obtained.

That is, in the above circuit, since only a certain level of the luminance (Y) signal level is reduced from the primary color signals R, G, B composed of the luminance component and the color component, the color components are relatively This means an increase in color saturation. By amplifying the signal in which the Y signal component is relatively reduced and supplying it to the picture tube of the color display, it is possible to obtain a highly saturated image.

According to the present embodiment, the input primary color signals R, G, B are added to create a Y signal, and the Y signal is subtracted from the three primary color signals R, G, B. ,
The color saturation on the RGB color display monitor can be increased with a simple circuit, and the Y signal is added to the primary color signals R, G and B at a ratio of about 3: 6: 1. Since it is created by doing so, it is possible to obtain the correct color image.

Further, since the circuit is simple, the cost of the circuit can be reduced and the reliability of the circuit can be improved. Further, in this example, the Y signal is sent to the CRT.
It is not necessary to increase the dynamic range of the output circuit of the cathode because it is not necessary to transfer it to the grid, and it is possible to eliminate problems such as large power loss and limitation of the output frequency band.

Further, if the resistance value of the variable resistor 11 is changed,
Primary color signals R, G, B are applied to the respective transistors 19, 20, 21.
Since the level of the Y signal subtracted from is changed, the degree of color saturation can be changed.

FIG. 2 is a circuit showing the configuration of the second embodiment of the present invention. In this example, the Y signal output from the collector of the transistor 10 has its polarity inverted by the inverter 31 and is input to the bases of the transistors 19, 20, and 21. Therefore, in the collector of the transistor 19, the level of the primary color signal R input to the emitter is increased by the level of the Y signal level input to the base R.
A signal is obtained. Similarly, a G signal whose level is increased by the level of the Y signal input to the base from the primary color signal G input to the emitter is obtained at the collector of the transistor 20, and the primary color input to the emitter is obtained at the collector of the transistor 21. From the signal B, a B signal whose level is increased by the level of the Y signal input to the base is obtained.

Therefore, at the output terminals 28 to 30, the signals R, G and B of the three primary colors obtained by adding the Y signals of a certain level to the respective input three primary color signals R, G and B are obtained. As a result, only the luminance signal Y of a certain level is increased in the three primary color signals R, G, B composed of the luminance component and the color component, so that the color component is relatively decreased. , The color saturation will decrease.

According to the present embodiment, the input primary color signals R, G, B are added to each other to create a Y signal, and the Y signal is added to the primary color signals R, G, B to obtain RGB color signals. The color saturation on the display monitor can be reduced with a simple circuit. Other effects are similar to those of the first embodiment.

Furthermore, in this example, when the resistance value of the variable resistor 11 is changed, the primary color signals R,
Since the level of the Y signal added to G and B changes, the color saturation can be changed.

FIG. 3 is a circuit diagram showing the configuration of the third embodiment of the present invention. In this example, transistors 19 and 2
Variable resistors 13 and 1 inserted on the base side of 0 and 21
The variable resistors 4 and 15 and the variable resistor 11 inserted on the collector side of the transistor 10 are interlocking variable resistors as shown by 34. As a result, in order to increase the decrease amount of the Y (luminance) component from the three primary color signals R, G, B, the variable resistor 1 inserted in the collector side of the transistor 10 is increased.
When the resistance value of 1 is decreased, the variable resistances 13, 14, 15
The resistance value of the transistors 19, 20 and 21 is also reduced in conjunction with the increase of the amplification factor of the transistors 19, 20 and 21.
The primary color signals R, G, and B can always have proper luminance signal components, and an image with proper luminance can always be obtained on the color display even if the color saturation is adjusted. Other effects are similar to those of the first embodiment. Although the circuit for increasing the color saturation has been described in this example, a circuit for decreasing the color saturation as shown in FIG. 2 can obtain the same effect with the same configuration.

FIG. 4 is a circuit diagram showing the configuration of the fourth embodiment of the present invention. In this example, the Y signal synthesis resistors 4, 5,
The switch 32 is inserted between the common terminal of the transistor 6 and the emitter of the transistor 10, and
Fixed resistors 33, 34 and 35 are inserted in the bases of 0 and 21, and resistors 36, 37 and 38 and a switch 32 are connected in parallel to these fixed resistors 33, 34 and 35, respectively. However, it is assumed that the four switches 32 are turned on / off in conjunction with each other.

In this circuit, when the color saturation is not adjusted, the switch 32 is turned off so that the Y signal from the combined resistors 4, 5 and 6 is not inputted to the emitter of the transistor 10, and the transistor 19 is turned on. , 20,
The base resistance of 21 is only fixed resistances 33, 34 and 35. As a result, the primary color signals R, G, B input from the input terminals 1, 2, 3 are directly input to the transistors 19, 2, respectively.
The collectors of 0 and 21 are output to the output terminals 18, 29 and 30, and the color saturation is not adjusted.

Next, when adjusting the color saturation, the switch 32 is turned on so that the Y signal from the combined resistors 4, 5, 6 is input to the emitter of the transistor 10, and the transistor 19, Base resistors 20 and 21 are fixed resistors 33 and 36, and fixed resistors 34 and 3
7. The fixed resistance 35 and the resistance 38 are arranged in parallel to reduce the resistance value thereof to increase the amplification rates of the transistors 19, 20, 21 and subtract the Y signal component from the primary color signals R, G, B, and output. R, G, B obtained from terminals 28, 29, 30
The luminance signal component included in the signal is optimized.

In the present embodiment, an image with appropriate brightness can always be obtained on the color display even if the color saturation is adjusted, and whether or not the color saturation is adjusted can be selected. . Other effects are similar to those of the first embodiment.

[0039]

As described above, according to the invention of claim 1 or 7, it is possible to increase the degree of color saturation in a color display monitor without impairing a proper color image with a simple circuit.

According to the invention of claim 2 or 8, the color saturation in the color display monitor can be reduced without impairing a proper color image with a simple circuit.

According to the third aspect of the present invention, it is possible to continuously and stably change the color saturation while increasing the color saturation while correcting the decrease of the luminance signal component.

According to the invention of claim 4 or 6, it is possible to select and adjust whether or not the color saturation is adjusted.

According to the fifth aspect of the present invention, it is possible to continuously and stably change the color saturation to a lower level while correcting the increase in the luminance signal component.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a first embodiment of a color saturation adjustment circuit of the present invention.

FIG. 2 is a circuit diagram showing a second embodiment of a color saturation adjustment circuit of the present invention.

FIG. 3 is a circuit diagram showing a third embodiment of a color saturation adjustment circuit of the present invention.

FIG. 4 is a circuit diagram showing a fourth embodiment of a color saturation adjusting circuit of the present invention.

FIG. 5 is a circuit diagram showing an example of a conventional color saturation adjustment circuit.

FIG. 6 is a block diagram showing another example of a conventional color saturation adjustment circuit.

[Explanation of reference numerals] 1, 2, 3 ... Input terminals 4, 5, 6 ... Luminance signal synthesizing resistors 7, 25, 26, 27 ... Power supply 8, 9 ... Bias resistor 10, 19, 20, 21 ... Transistor 11, 13, 14, 15 ... Variable resistance 12, 22, 23 ... Emitter resistance 16, 17, 18 ... Collector resistance 28, 29, 30 ... Output terminal 31 ... Inverter 32 ... Switch 33, 34, 35 ... Fixed resistance

Claims (8)

[Claims] 1. A brightness signal creating circuit for creating a brightness signal by synthesizing input red, green, and blue primary color signals, and a brightness signal created by the brightness signal creating circuit from the red primary color signal level. A first subtraction circuit that reduces the level; a second subtraction circuit that reduces the brightness signal level created by the brightness signal creation circuit from the green primary color signal level; and a brightness signal creation circuit from the blue primary color signal level And a third subtraction circuit for reducing the luminance signal level created by the above, and the three primary color red signals and green signals whose color saturation is increased from the subtraction results of the first, second and third subtraction circuits, A color saturation adjustment circuit characterized by obtaining a blue signal. 2. A luminance signal generating circuit for synthesizing input red, green, and blue primary color signals to generate a luminance signal, and a luminance signal generated by the luminance signal generating circuit at the red primary color signal level. A first adder circuit for adding levels; a second adder circuit for adding the luminance signal level created by the brightness signal creating circuit to the green primary color signal level; and a brightness signal for the blue primary color signal level. A third adder circuit for adding the luminance signal levels created by the creating circuit, and the three primary color red signals with reduced color saturation from the addition results of the first, second and third adder circuits, A color saturation adjusting circuit characterized by obtaining a green signal and a blue signal. 3. A first level adjusting circuit for adjusting the level of a brightness signal created by said brightness signal creating circuit, and subtracted red, subtracted green of said first, second and third subtraction circuits, Second, third, and fourth level adjustment circuits for adjusting the levels of the respective subtracted blue primary color signals are provided, and the second, third, and third levels are adjusted in conjunction with the level adjustment of the first level adjustment circuit. 2. The color saturation adjusting circuit according to claim 1, wherein the level of the fourth level adjusting circuit is adjusted. 4. A first switch for switching whether or not a luminance signal is generated by the luminance signal generation circuit, and subtracted red, subtracted green, and subtracted of the first, second, and third subtraction circuits. Second, third, and fourth switches for switching the levels of the respective blue primary color signals in stages are provided, and the second, third, and fourth switches are interlocked with the switching of the first switch. The color saturation adjusting circuit according to claim 1, wherein the color saturation adjusting circuit is switched. 5. A first level adjusting circuit for adjusting the level of a brightness signal created by said brightness signal creating circuit, and red, green to be added of said first, second and third adder circuits, Second, third, and fourth level adjusting circuits for adjusting the levels of the respective primary color signals of the added blue are provided, and the second, third are linked with the level adjustment of the first level adjusting circuit. 3. The color saturation adjusting circuit according to claim 2, wherein the level of the fourth level adjusting circuit is adjusted. 6. A first switch for switching whether or not to generate a luminance signal by the luminance signal generating circuit, and a red, a green, and a sum to be added of the first, second, and third adder circuits. Second, third, and fourth switches for switching the levels of the respective blue primary color signals in stages are provided, and the second, third, and fourth switches are interlocked with the switching of the first switch. The color saturation adjustment circuit according to claim 2, wherein the color saturation adjustment circuit is switched. 7. The luminance signal generating circuit is configured to control the red, green,
The first subtraction circuit is composed of three resistors for inputting each of the blue primary color signals to one end, and a transistor amplifier circuit for commonly connecting the other end of these three resistors to the emitter. The second subtraction circuit inputs the primary color signal to the emitter and inputs the collector output of the transistor of the luminance signal generating circuit to the base, and the second subtraction circuit inputs the green primary color signal to the emitter to generate the luminance signal. The third subtraction circuit inputs the blue primary color signal to the emitter, and the base of the collector output of the transistor of the luminance signal generation circuit. And a transistor amplifier circuit for inputting to each of the first, second and third subtraction circuits. Wherein the data red signal, green signal, the color saturation adjusting circuit according to claim 1, wherein the obtaining a green light. 8. The luminance signal generating circuit comprises:
It is composed of three resistors for inputting each of the blue primary color signals to one end thereof, and a transistor amplifier circuit in which the other ends of these three resistors are commonly connected to the emitter. The primary color signal is input to the emitter, and the polarity amplification signal of the collector output of the transistor of the luminance signal generating circuit is input to the base, and the second adder circuit inputs the green primary color signal to the emitter. And a transistor amplification circuit that inputs the polarity inversion signal of the collector output of the transistor of the luminance signal generation circuit to the base, and the third addition circuit inputs the blue primary color signal to the emitter to generate the luminance signal. It is composed of a transistor amplifier circuit which inputs the polarity inversion signal of the collector output of the transistor of the circuit to the base. 2, the third of the red from the collectors of the transistors of the summing circuit, the green signal, the color saturation adjusting circuit according to claim 2, wherein the obtaining a green light.