JP2003179946A - Chromaticity correcting equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent chromaticity from shifting which is displayed on a liquid crystal panel by a format of color television system in an input video signal. <P>SOLUTION: This chromaticity correcting equipment 20 is provided with an E<SP>2</SP>PROM 7 for outputting matrix variables corresponding to a format deciding signal outputted from a format deciding circuit 6 for deciding a format of an input video signal, and an RGB→XYZ conversion circuit 2 for correcting each chrominance signal component corresponding to the format, by multiplying each chrominance signal component of R, G, B of the input video signal by the matrix variables. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chromaticity correction device for a display device such as a color television or OA equipment, and in particular, the color reproducibility of a liquid crystal display device changes depending on the wavelength and brightness of light. The present invention relates to a chromaticity correction device that corrects chromaticity according to a color television format in an input video signal for the device.

[0002]

2. Description of the Related Art As a chromaticity correction technique for a conventional liquid crystal display device, for example, there is a technique described in Japanese Patent Application Laid-Open No. 5-27711.

Generally, in a liquid crystal display device, the light transmittance changes depending on the wavelength of light, and the change also changes depending on the voltage applied to the liquid crystal. The technique described in the above publication changes the matrix component based on the brightness level obtained from the input video signal, thereby keeping the chromaticity constant even if the voltage level changes, and enabling accurate color reproduction. is there.

The chromaticity correction device 100 described in the above publication is
As shown in FIG. 5, it is composed of an input terminal 101, a matrix conversion circuit 102, and a control circuit 103, and is connected to a liquid crystal drive circuit 104 that drives a liquid crystal panel 105.

Each color signal component of the input video signal, that is, R,
The G and B signals are input from the input terminal 101. Each color signal component is input to the matrix conversion circuit 102, each color signal component of the video signal for liquid crystal driving is obtained as the sum of the values obtained by multiplying each color signal component value by each coefficient, and is output to the liquid crystal driving circuit 104. It

Each color signal component of the input video signal is also input to the control circuit 103. The control circuit 103 obtains a luminance signal level value from each input color signal component, and based on the obtained luminance signal level value, the matrix circuit 10
A matrix signal of 2, that is, a control signal for changing the above-mentioned coefficient is generated and given to the matrix conversion circuit 102.

Here, if the coefficients in the matrix circuit 102 are a ₁₁ , a _12, etc., and the respective color signal components of red, green, and blue of the input video signal are R _in , G _in , and B _in ,
Red of the output video signal from the matrix conversion circuit 102,
Green and blue color signal components R _out , G _out , B _out
Is R _out = a ₁₁ · R _in + a ₁₂ · G _in + a ₁₃ · B _in G _out = a ₂₁ · R _in + a ₂₂ · G _in + a ₂₃ · B _in B _out = a ₃₁ · R _in + a ₃₂ · G _It is expressed as _in + a ₃₃ · B _in .

That is, the color signal components R _out , G _out , and B _out of the output video signal are values obtained by multiplying the color signal components R _in , G _in , and B _in of the input video signal by the coefficients a ₁₁ , a _12, etc. Expressed in Japanese.

By the way, the values of the coefficients a ₁₁ , a _12, etc. are changed by the control signal based on the luminance signal level value of the input video signal. That is, another color signal component is added to each color signal component of the input video signal according to the luminance signal level value of the input video signal. Therefore, the chromaticity point of the displayed liquid crystal panel screen moves to correct the chromaticity.

This is for correcting the chromaticity displayed on the liquid crystal panel with respect to the chromaticity of the input video signal due to the change of the light transmittance depending on the wavelength of the light. That is, since the color reproducibility range of the color picture tube and the liquid crystal panel according to the input video signal is different as shown in the xy chromaticity diagram shown in FIG. 6, the chromaticity of the input video signal is adjusted according to the color reproducibility range of the liquid crystal panel. Is to correct.

[0011]

However, in the above-mentioned conventional configuration, although it is possible to correct the chromaticity by moving the chromaticity point by multiplying each color signal component of the input video signal by a coefficient, the chromaticity can be corrected. Signals are in various color television formats, namely NTSC, P
When different signals are input by the AL system, SECAM system, etc., the chromaticity point does not move according to these formats, which causes a problem.

That is, as shown in the xy chromaticity diagram shown in FIG. 7, since the color reproducibility range differs depending on the format of the input video signal, if the chromaticity correction processing according to the format is not performed, it is displayed on the liquid crystal panel. There is a problem that the chromaticity shifts.

In addition, in reality, there are variations in the color characteristics of the display device such as a liquid crystal panel due to manufacturing errors of the component parts, etc., so that there is also a problem that the chromaticity varies from display device to display device.

The present invention has been made to solve the above problems, and an object thereof is to correct chromaticity shift due to different color reproducibility ranges depending on the format of a color television system in an input video signal. It is an object of the present invention to provide a chromaticity correction device capable of distributing a single-specification display device to various countries having different formats.

[0015]

In order to solve the above problems, a chromaticity correction device according to the present invention corrects a color signal component of an input video signal and outputs it to a display device. In the device, the format of the inputted video signal is discriminated, the format discrimination means for outputting the format discrimination signal, the matrix variable output means for outputting the matrix variable corresponding to the format discrimination signal, and each color signal of the inputted video signal It is characterized in that it is provided with a matrix conversion means for multiplying the component and the matrix variable and outputting to the display device.

As the video signal format, the NTSC system which is a color television system format,
There are PAL system, SECAM system, etc., but the chromaticity points output for the video signal input to the display device differ depending on these formats. Therefore, it is necessary to correct the chromaticity according to the format of the video signal.
Therefore, the format determining means determines the format of the video signal and outputs the format determination signal according to the determined format of the video signal.

In general, any color is a three primary color or R
Color mixing can be achieved by mixing (red), G (green), and B (blue). Therefore, correction of a certain color signal component of the video signal is achieved by adding the other color signal components at an appropriate ratio. Therefore, if the addition ratio of the color signal components of the three colors is set for each color using the matrix variable, each color signal component can be corrected.

Therefore, for example, as described in the above publication, according to the luminance signal level value of the input video signal,
A matrix variable for each format of the video signal may be prepared in advance, and the chromaticity may be corrected using this matrix variable. Therefore, the matrix variable output means outputs the matrix variable corresponding to the format discrimination signal.

The matrix conversion means multiplies each color signal component of the input video signal by a matrix variable corresponding to the format of the video signal and outputs the product to the display device.

Therefore, according to the above configuration, the matrix variable corresponding to the result of discriminating the format of the video signal,
Since each color signal component of the input video signal is multiplied and output to the display device, it is possible to correct the chromaticity according to the color reproducibility range that differs depending on the input video format. Misalignment can be corrected. This makes it possible to supply a display device having a single specification regarding color reproducibility to various countries having different video signal formats.

In order to solve the above-mentioned problems, the chromaticity correction apparatus according to the present invention has, in addition to the above-mentioned configuration, the matrix variable output means, the chromaticity and the luminance of each color component of the input video signal. It is characterized in that the matrix variable calculated by is output.

Therefore, with the above configuration, since the chromaticity and luminance of each color component can be easily obtained from the input video signal, the matrix variable output from the matrix variable output means can be easily calculated. it can.

In order to solve the above problems, a chromaticity correction device according to the present invention corrects a color signal component of an input video signal and outputs it to a display device.
Format determination means for determining the format of the input video signal and outputting the format determination signal, first matrix variable output means for outputting the first matrix variable corresponding to the format determination signal, and color characteristics of the display device. And a video input signal, a second matrix variable output means for outputting a second matrix variable corresponding to the color characteristic of the display device and the format discrimination signal measured by the color characteristic measuring means. And a matrix conversion means for multiplying each color signal component by the first matrix variable and the second matrix variable and outputting the result to the display device.

In addition to the above-mentioned structure, the above-mentioned structure is such that a color signal component of the input video signal is corrected according to the color characteristics of the display device.

That is, the first matrix variable corresponds to the matrix variable in the above configuration, and the second matrix variable is a matrix variable according to the color characteristic of the display device.

The color characteristics of the display device, for example, the chromaticity and the brightness of each color component differ depending on variations such as manufacturing error of the display device. Therefore, the color characteristic of the display device needs to be measured for each display device by the color characteristic measuring means.

In order to reflect the color characteristic of the display device measured by the color characteristic measuring means in the matrix variable in order to correct the chromaticity due to the variation in the color characteristic of the display device, this matrix is selected according to the format of the video signal. You need to define the variables. Therefore, the second matrix variable output means outputs the second matrix variable corresponding to the color characteristic of the display device and the format discrimination signal measured by the color characteristic measuring means.

The matrix conversion means multiplies each color signal component of the video input signal by the first matrix variable and the second matrix variable and outputs the product to the display device.

Therefore, with the above configuration, the first matrix variable corresponding to the discrimination result of the format of the video signal and the second matrix variable corresponding to the color characteristic of the display device and the format discrimination signal measured by the color characteristic measuring means. Since the matrix variables of and the color signal components of the input video signal are multiplied and output to the display device, the chromaticity shift due to the color reproducibility range that differs depending on the input video format and the component parts of the display device. It is possible to correct the chromaticity shift due to the variation of the color characteristics due to the manufacturing error of FIG.

In order to solve the above-mentioned problems, the chromaticity correction apparatus according to the present invention has, in addition to the above configuration, the first matrix variable output means, the chromaticity of each color component of the input video signal. And a luminance, and a second matrix variable calculated based on the chromaticity and luminance of each color component of the color characteristics of the display device is output. Is output.

Therefore, with the above configuration, since the chromaticity and luminance of each color component can be easily obtained from the input video signal, the first matrix variable output from the first matrix variable output means can be used. It can be calculated easily.

Since the chromaticity and luminance of each color component of the color characteristics of the display device can be easily measured, the second matrix variable output from the second matrix variable output means can be easily calculated. You can

In order to solve the above problems, the chromaticity correction device according to the present invention is characterized in that, in addition to the above configuration, the display device is a liquid crystal panel.

In the liquid crystal panel, the light transmittance changes according to the wavelength of light, and the change also changes depending on the voltage applied to the liquid crystal.

Therefore, with the above structure, since the display device is the liquid crystal panel, the chromaticity shift of the liquid crystal panel is caused by inputting the output from the chromaticity correction device to the liquid crystal drive circuit for driving the liquid crystal panel. It can be corrected effectively.

[0036]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] The following will describe one embodiment of the present invention with reference to FIG.

As shown in FIG. 1, the chromaticity correction device 20 of the present embodiment has an input terminal 1, an RGB → XYZ conversion circuit (matrix conversion means) 2, an XYZ → R'G'B 'conversion circuit (matrix conversion). Means) 3, format determination circuit (format determination means) 6, E ² PROM (Electric
an ally erasable programmable ROM (first matrix variable output means) 7, an E ² PROM (second matrix variable output means) 8, a matrix variable calculation circuit 9, and an optical measuring device (color characteristic measuring means) 10. Yes,
XYZ → R′G ′ is applied to the liquid crystal drive circuit 4 that drives the display of the liquid crystal panel (display device) 5 by correcting the chromaticity of the input video signal input to the input terminal 1 of the chromaticity correction device 20.
It is output from the B ′ conversion circuit 3.

The respective color signal components of the input video signal, that is, the R (red), G (green), and B (blue) R, G, and B signals which are the three primary colors of the colors, are the tristimulus values of the R, G, B signals. Space XY
It is input to the RGB → XYZ conversion circuit 2 for converting into a Z signal.

The tristimulus value space XYZ signal output from the RGB → XYZ conversion circuit 2 is R ′ for the liquid crystal drive circuit 4 which drives the tristimulus value space XYZ signal to drive the liquid crystal panel 5.
It is input to the XYZ → R′G′B ′ conversion circuit 3 for converting into G ′ and B ′ signals.

The R ', G', and B'signals converted for the liquid crystal drive circuit 4 by the XYZ → R'G'B 'conversion circuit 3 are output to the liquid crystal drive circuit 4, and based on this, the liquid crystal drive circuit. Four
Drives the liquid crystal panel 5.

On the other hand, H (horizontal synchronizing signal component), V (vertical synchronizing signal component) and burst signal component of the input video signal are
It is input to the format determination circuit 6. The format determination circuit 6 determines the format of the input video signal, that is, the color television system such as the NTSC system, the PAL system, and the SECAM system, based on the H, V, and burst signal components of the input video signal. A format discrimination signal corresponding to the format discrimination result of is output.

The format discriminating circuit 6 for outputting the format discriminating signal is disclosed in, for example, Japanese Unexamined Patent Publication No. 6-33500.
The format may be determined as described in Japanese Patent Publication No. That is, a comparator for comparing the respective detection signals obtained by detection with a plurality of detection circuits is provided, and the detection signals of each color television system are compared with the reference voltage. When only one detected signal is equal to or higher than the reference voltage, it is determined that the detected signal is a color television system. When a plurality of detected signals are higher than the reference voltage, the detected signals are compared with each other, and the level of the detected signal is detected with respect to the lower detected circuit among the detected circuits of each color television system. If the color television system is discriminated by increasing the number of signals to reduce the number of signals and shifting the detection signal level on the color television system side, which is considered to be an erroneous discrimination, in the direction in which malfunctions are less likely to occur, a more accurate discrimination can be performed. it can.

The format discrimination signal has E ² which holds in advance the first matrix variable corresponding to the format.
It becomes a control signal for selecting and outputting the first matrix variable from the PROM 7. The E ² PROM is a ROM that can electrically erase and write data. The first matrix variable selected based on the format determination signal is output to the RGB → XYZ conversion circuit 2.

In the RGB → XYZ conversion circuit 2, as will be described later, this first matrix variable and R, G, B are used.
The signal is multiplied and converted into a tristimulus value space XYZ signal, which is output to the XYZ → R′G′B ′ conversion circuit 3. That is, the first matrix variable is a matrix variable for converting the R, G, B signals into the tristimulus value space XYZ signal by applying the correction due to the difference in the format of the input video signal.

Further, the optical measuring device 10 uses a sensor or the like to display only the highest gradation of each of R (red), G (green), and B (blue) of the liquid crystal panel 5, and the chromaticity and luminance. And measure. Also, the chromaticity and luminance of W (white) when the highest gradations of all R, G, and B are displayed are measured.

The chromaticity / luminance data measured by the optical measuring device 10 is input to the matrix variable calculation circuit 9. In the matrix variable calculation circuit 9, matrix variables are calculated and calculated based on the chromaticity / luminance data which is the optical data as the color characteristics of the liquid crystal panel 5 measured by the optical measuring device 10 and the format discrimination signal. The matrix variables are output to the E ² PROM 8. The method of obtaining the matrix variables calculated by the matrix variable calculation circuit 9 will be described later.

In the E ² PROM 8, the matrix variables calculated by the matrix variable calculation circuit 9 are stored in NTSC.
It is stored for each format such as a system, a PAL system, and a SECAM system. Based on the format determination signal output from the format determination circuit 6, the stored second matrix variable is selected and XYZ → R′G′B ′.
Output to the conversion circuit 3. In the XYZ → R′G′B ′ conversion circuit 3, the second matrix variable and the tristimulus value space X
The YZ signal is multiplied and converted into R ′, G ′, and B ′ signals, which are output to the liquid crystal drive circuit 4. That is, the second matrix variable is a matrix that converts the tristimulus value space XYZ signal into R ′, G ′, and B ′ signals by performing correction based on the difference in the format of the input video signal and the color characteristics of the liquid crystal panel 5. Is a variable.

Note that, for example, the chromaticity and luminance data of a video signal standardized in a format such as the NTSC system, the PAL system, and the SECAM system is held in the matrix variable calculation circuit 9 in advance, and the format discrimination signal is used. It is possible to obtain a matrix variable suitable for each video signal. Alternatively, the variable calculated by the matrix variable calculating circuit 9 may be stored in the E ² PROM. Here, E which stores the matrix variable
² PROM is another nonvolatile memory FRAM (Flash RA
It may be configured by means for holding data such as M) and MRAM (Magnetic RAM).

The R ′, G ′, B ′ signals output from the XYZ → R′G′B ′ conversion circuit 3 are input to the liquid crystal drive circuit 4 that drives the liquid crystal panel 5, and the input video format and the liquid crystal panel 5 are input. It is possible to perform display in which the chromaticity of the liquid crystal panel 5 is corrected according to the color characteristics of. Therefore, R of the input video signal,
Within the color reproducibility range of each of the G and B color signal components, R ′, G ′,
Based on the B'signal, conversion is performed so as to match the color reproducibility range displayed on the liquid crystal panel 5.

Therefore, since the chromaticity is corrected by measuring the color characteristics of the liquid crystal panel 5, the chromaticity variation due to the liquid crystal drive circuit 4 of the liquid crystal panel 5 and the components of the liquid crystal panel 5 can also be corrected. it can.

Here, a method of obtaining the first matrix variable held in advance in the E ² PROM 7 in order to correct the chromaticity of the input video signal according to the format will be described.

The chromaticity of R (red) in the input video signal is x
_{Let r} , y _r , and luminance be Y _r . Similarly, G (green), B
The chromaticity of (blue) is x _g , y _g , x _b , y _b , the luminance is Y _g ,
Let be Y _b . The chromaticity of W (white) is x _w , y _w , and the luminance is Y _w . Note that these values are values determined by the format.

Letting K _ij be the matrix for linearly converting the RGB color space into the tristimulus value space XYZ, it is expressed as in equation (1).

[0054]

[Equation 1]

Generally, in the XYZ color system, chromaticity coordinates x _n ,
y _n and z _n are x _n = X _n / (X _n tens Y _n tens Z _n ) y _n = Y _n / (X _n tens Y _n tens Z _n ) ... (2) z _n = Z _n / It is defined by the formula (X _n tens Y _n tens Z _n ) = 1−x _n −y _n . Where X _n , Y _n , and Z _n
Is a tristimulus value, and the stimulus value Y _n is proportional to the photometric amount in the CIE color system, and substantially coincides with the amplitude of the luminance signal in the NTSC system.

When X _n and Z _n are represented by Y _n , X _n = (x _n / y _n ) Y _n Z _n = (z _n / y _n ) Y _n (3), respectively. Become.

Each of the tristimulus values X _n , Y _n , and Z _n is the amount of each primary color required to match a specific white color, and is represented by normalization. That is, the unit is set so that R = G = B = 1 for a specific white color. Therefore, from equation (1),

[0058]

[Equation 2]

The relational expression of is obtained.

Here, using Expression (3), focusing on the first to third columns of the matrix of Expression (4),

[0061]

[Equation 3]

It becomes

Further, focusing on the fourth column of the matrix of equation (4),

[0064]

[Equation 4]

Therefore, if K _ij is eliminated from the equations (5) and (6),

[0066]

[Equation 5]

It becomes

This solution Y _r , Y _g , and Y _b is given by equation (5).
, The transformation matrix K _ij can be determined with Y _w undetermined.

In this way, if the luminance Y _w of W (white) is designated, the chromaticity x _r of each color component in the input video signal,
The matrix K from y _r , x _g , y _g , x _b , y _b , x _w , y _w
All the elements of _ij can be determined, and the first matrix variable held in advance in the E ² PROM 7 is obtained.

Next, a method of obtaining the second matrix variable calculated and output by the matrix variable calculation circuit 9 will be described.

When the matrix for linearly converting the RGB color space into the tristimulus value space XYZ for the R ′, G ′ and B ′ signals of the video signal input to the liquid crystal drive circuit 4 is F, the following table is obtained. To be done.

[0072]

[Equation 6]

From equation (8),

[0074]

[Equation 7]

It becomes

Here, F ^-1 can be obtained in the same manner as K _ij described above. That is, it can be obtained from the chromaticity and luminance of each color component displayed on the liquid crystal panel 5. These are R (red), G (green), and
The highest gradation data of only B (blue) may be displayed, and the chromaticity and luminance of each color component may be measured by the optical measuring device 10. In addition, the chromaticity and brightness when only W (white) is displayed may be measured.

[Second Embodiment] The following will describe another embodiment of the present invention in reference to FIGS. 2 and 3.

The chromaticity correction device 30 of the present embodiment is different from the chromaticity correction device 20 of the first embodiment in that RGB → XYZ.
A matrix conversion circuit (matrix conversion means) 31 is provided instead of the conversion circuit 2 and the XYZ → R′G′B ′ conversion circuit 3, and E ² PROMs 7 and 8 are replaced with E ²
This is a configuration including a PROM (matrix variable output means) 32.

The chromaticity correction device 30 of the present embodiment forms the matrix conversion circuit 31 by combining the RGB → XYZ conversion circuit 2 and the XYZ → R'G'B 'conversion circuit 3 of FIG. E ² PROM 7 and 8 are collectively E ² PROM
By configuring 32, the circuit scale is reduced.

Therefore, the chromaticity correction device 30 of the present embodiment
Performs the same function as the chromaticity correction device 20 of the first embodiment and only summarizes the circuit configuration, and therefore the description of the configuration and function is omitted.

Here, how to obtain the matrix variables output from the E ² PROM 32 will be described.

The color misregistration is corrected by converting the color reproducibility range of the input video signal so that the chromaticity coordinates are matched with the R ', G', and B'signals of the video signal input to the liquid crystal drive circuit 4. It Therefore, making the chromaticity coordinates the same in the RGB color space means making the coordinates in the tristimulus value space XYZ also the same. Therefore, from Expression (1) and Expression (9),

[0083]

[Equation 8]

Holds.

In the matrix conversion circuit, the following relational expressions are established between the R ′, G ′ and B ′ signals of the video signal input to the liquid crystal drive circuit 4 and the R, G and B signals of the input video signal. . Here, M is the R, G, and B signals of the input video signal, and R ′ of the video signal input to the liquid crystal drive circuit 4,
It is a matrix for converting into G ′ and B ′ signals.

[0086]

[Equation 9]

From the equations (10) and (11), M = F ^-1 · K (12) holds.

The matrices K and F can be obtained from the video input signal and the chromaticity and luminance of each color component displayed on the liquid crystal panel 5, respectively. Therefore, since the matrix variable output from the matrix variable calculation circuit 9 is each matrix component of the matrix M, it can be obtained from the video input signal and the chromaticity and luminance of each color component displayed on the liquid crystal panel 5.

The matrix variable calculation circuit 9 holds in advance chromaticity / luminance data corresponding to the format of the input video signal, and the format discrimination signal selects the chromaticity / luminance data according to the format of the input video signal. .
Chromaticity selected according to the input video signal format
The matrix variables forming the matrix M are determined by the matrix variable calculation circuit 9 based on the luminance data and the chromaticity / luminance data measured by the liquid crystal panel 5.

The matrix conversion circuit 31 is realized by multiplying the matrix variable represented by the matrix M and each color signal component of the input video signal, and the matrix conversion circuit 31 is configured as shown in FIG. here,
Reference numerals 51 to 59 are multipliers, and 60 to 62 are adders.

For example, matrix-converted R'signal
Is the variable a in the R signal of the input video signal. ₁The value multiplied by
Variable a for the G signal of the input video signal₂Input with value multiplied by
Variable a for B signal of video signal₃Table with the sum of the values multiplied by
To be done. That is, R'is R ′ = R · a₁+ G ・ a₂+ B ・ a₃ It becomes a relationship. Similarly, matrix converted G '
The signal and the matrix-converted B'signal are each transformed.
Number b₁, B₂, B₃And variable c₁, C₂, C₃Using
hand, G ′ = R · b₁+ G ・ b₂+ B ・ b₃ B ′ = R · c₁+ G ・ c₂+ B ・ c₃ It can be expressed as. With the circuit configured as above
Matrix conversion is performed and chromaticity correction is performed.
It

[Third Embodiment] The following will describe another embodiment of the present invention in reference to FIG.

Unlike the chromaticity correction device 30 of the second embodiment, the chromaticity correction device 40 of the present embodiment outputs an E ² PROM 32 that outputs matrix variables based on the format of the input video signal and the color characteristics of the liquid crystal panel 5. Instead of the above, the E ² PROM 42 (matrix variable output means) for outputting the matrix variables only based on the format of the input video signal is provided.

That is, as shown in FIG. 4, the chromaticity correction device 40 has a structure including an input terminal 1, a matrix conversion circuit 31, a format determination circuit 6, and an E ² PROM 42.

Each color signal component of the input video signal, that is, R,
The G and B signals are input to the matrix conversion circuit 31. A matrix variable of the E ² PROM 42 holding matrix variables corresponding to the format is selected and input to the matrix conversion circuit 31 according to the format determination signal output from the format determination circuit 6.

The matrix conversion circuit 31 multiplies the R, G, B signals of the input video signal by a matrix variable, and outputs matrix-converted R ', G', B'signals. The matrix-converted video signal is input to the liquid crystal drive circuit 4 that drives the liquid crystal panel 5, and the liquid crystal panel 5 can be displayed by correcting the chromaticity according to the format of the input video signal. Here, the matrix variables held in the E ² PROM 42 are R ′ input to the liquid crystal drive circuit 4 within the color reproducibility range of R, G, B signals,
It is a variable for converting so that the chromaticity of the G ′ and B ′ signals are matched.

The color characteristics of the liquid crystal panel 5 are largely attributable to variations due to manufacturing errors of the liquid crystal drive circuit 4 and the liquid crystal panel 5 during manufacturing. Therefore, at the time of shipment, the color characteristic of the liquid crystal panel 5 is measured by the optical measuring device 10, the sensor, etc. shown in the other embodiment, and the matrix variable for correcting the color characteristic of the liquid crystal panel 5 is put into the format in the E ² PROM 42. It may be stored accordingly.

In this way, the matrix variable calculation circuit 9 and the optical measuring device 10 shown in FIGS. 1 and 2 can be omitted, so that the structure can be made very compact and the cost is low.

Further, the chromaticity correction apparatus of the present invention converts the color system of the color signal component of the input video signal into another color system, and according to the first chromaticity correction factor at the time of conversion. First conversion means for simultaneously performing the above correction, and reverse conversion from the other color system to the color system of the color signal component, and simultaneously performs correction according to the second chromaticity correction factor during the reverse conversion. A chromaticity correction device may be provided which includes a second conversion means.

According to the above arrangement, the color signal component of the input video signal is converted into another color system, for example, the tristimulus value space XYZ.
The first chromaticity correction factor, for example, the correction according to the difference in the format of the video signal is performed at the same time.
And second conversion means for performing reverse conversion from the color system to color signal components, and simultaneously performing correction in accordance with a second chromaticity correction factor, for example, color characteristics of the display device, at the time of reverse conversion. And a chromaticity correction device provided with.

Therefore, at the time of conversion / inverse conversion of the color system, the first
Since the video signal is corrected at the same time by using the matrix variable or the like according to the second chromaticity correction factor, the chromaticity of the display device can be efficiently corrected with respect to the two types of chromaticity correction factors.

[0102]

As described above, the chromaticity correction device according to the present invention corrects the color signal component of the input video signal and outputs it to the display device. Format determining means for determining the format and outputting a format determining signal, matrix variable outputting means for outputting a matrix variable corresponding to the format determining signal, and each color signal component of the input video signal and the matrix variable are multiplied. And a matrix conversion means for outputting to a display device.

Therefore, it is possible to correct the chromaticity in accordance with the different color reproducibility range according to the input video format, and it is possible to correct the chromaticity shift in the display device. This makes it possible to supply a display device having a single specification regarding color reproducibility to various countries having different video signal formats.

As described above, in the chromaticity correction apparatus according to the present invention, in addition to the above configuration, the matrix variable output means is a matrix calculated from the chromaticity and luminance of each color component of the input video signal. This is a configuration for outputting variables.

Therefore, there is an effect that the matrix variable output from the matrix variable output means can be easily calculated.

As described above, the chromaticity correction device according to the present invention corrects the color signal component of the input video signal and outputs it to the display device in the format of the input video signal. Format determining means for determining the color difference and outputting a format determining signal, a first matrix variable outputting means for outputting a first matrix variable corresponding to the format determining signal, and a color characteristic measuring means for measuring the color characteristic of the display device. And second matrix variable output means for outputting a second matrix variable corresponding to the color characteristic of the display device and the format discrimination signal measured by the color characteristic measuring means, and the first matrix variable for each color signal component of the video input signal.
And a matrix conversion means for multiplying the second matrix variable by the second matrix variable and outputting the result to the display device.

Therefore, it is possible to correct the chromaticity deviation due to the color reproducibility range which differs depending on the input video format and the chromaticity deviation due to the variation of the color characteristics due to the manufacturing error of the components of the display device. Has the effect.

As described above, in the chromaticity correction device according to the present invention, in addition to the above-mentioned configuration, the first matrix variable output means is based on the chromaticity and luminance of each color component of the input video signal. Output the calculated first matrix variable,
The second matrix variable output means is configured to output a second matrix variable calculated from the chromaticity and luminance of each color component of the color characteristics of the display device.

Therefore, further, the first matrix variable output from the first matrix variable output means,
It is possible to easily calculate the second matrix variable output from the second matrix variable output means.

As described above, the chromaticity correction device according to the present invention has a configuration in which the display device is a liquid crystal panel in addition to the above configuration.

Therefore, since the display device is a liquid crystal panel, the chromaticity shift of the liquid crystal panel is effectively corrected by inputting the output from the chromaticity correction device to the liquid crystal drive circuit that drives the liquid crystal panel. There is an effect that can be done.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a chromaticity correction device of the present embodiment.

FIG. 2 is a block diagram showing a configuration of a chromaticity correction device according to another embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of a matrix variable calculation circuit in FIG.

FIG. 4 is a block diagram showing a configuration of a chromaticity correction device according to another embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of a conventional chromaticity correction device.

FIG. 6 is an xy chromaticity diagram showing a color reproducibility range of an input video signal and a liquid crystal panel.

FIG. 7 is an xy chromaticity diagram showing a color reproducibility range of a liquid crystal panel and various format signals.

[Explanation of symbols]

1 input terminal 2 RGB → XYZ conversion circuit (matrix conversion means) 3 XYZ → R'G'B 'conversion circuit (matrix conversion means) 4 liquid crystal drive circuit 5 liquid crystal panel (display device) 6 format determination circuit (format determination means) 7 E ² PROM (first matrix variable output means) 8 E ² PROM (second matrix variable output means) 9 matrix variable calculation circuit 10 optical measuring device (color characteristic measuring means) 20 chromaticity correction device 30 chromaticity correction Device 31 Matrix conversion circuit (matrix conversion means) 32 E ² PROM (matrix variable output means) 40 Chromaticity correction device 42 E ² PROM (matrix variable output means)

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G09G 3/20 612 G09G 3/20 612U 642 642L 642P 650 650A 650M 3/36 3/36 H04N 11/06 H04N 11/06 11/24 F term (reference) 2H093 NA16 NA51 NA62 NC13 NC14 NC49 NC52 NC54 NC65 NC68 ND06 ND17 ND24 ND49 ND54 5C006 AA01 AA11 AA22 AF13 AF23 AF45 AF46 AF51 AF52 AF53 AF54 AF63 AF81 AF84 AF85 BB11 BC16 BF26 BF09 BF09 BF09 BF09 BF14 EA03 EC02 FA07 FA20 FA56 GA10 5C057 BA02 BA03 BA09 DA15 DA16 EA01 GF03 GG01 5C066 AA03 AA11 CA05 EA05 GA01 HA03 KE09 KE17 5C080 AA10 BB05 DD01 EE19 EE29 EE30 GG07 GG08 JJ02 JJ03 KK05 KK05 KK43

Claims (5)

[Claims] 1. A format determining means for correcting a color signal component of an input video signal and outputting the same to a display device for determining the format of the input video signal and outputting a format determination signal. A matrix variable output means for outputting a matrix variable corresponding to the format discrimination signal, and a matrix conversion means for multiplying each color signal component of the input video signal by the matrix variable and outputting the result to the display device. Characteristic chromaticity correction device. 2. The matrix variable output means outputs a matrix variable calculated from the chromaticity and luminance of each color component of the input video signal.
The chromaticity correction device described in. 3. A format determining means for correcting a color signal component of an input video signal and outputting the same to a display device for determining the format of the input video signal and outputting a format determination signal. A first matrix variable output means for outputting a first matrix variable corresponding to the format discrimination signal; a color characteristic measuring means for measuring the color characteristic of the display device; and a display device for the display device measured by the color characteristic measuring means. Second matrix variable output means for outputting a second matrix variable corresponding to the color characteristic and the format discrimination signal, and each color signal component of the video input signal is multiplied by the first matrix variable and the second matrix variable. And a matrix conversion means for outputting to a display device. 4. The first matrix variable output means comprises:
Outputting a first matrix variable calculated from the chromaticity and luminance of each color component of the input video signal, and the second matrix variable output means is the chromaticity of each color component of the color characteristics of the display device. The chromaticity correction apparatus according to claim 3, wherein the second matrix variable calculated from the brightness and the luminance is output. 5. The chromaticity correction device according to claim 1, wherein the display device is a liquid crystal panel.