JPH095162A - White balance adjusting/evaluating system - Google Patents

Abstract

PURPOSE: To provide a white balance adjusting/evaluating system which can adjust white balance quickly while reducing burden on adjustment, evaluation and the like significantly. CONSTITUTION: A white luster video signal SAV of a reference white is supplied to a color display device 14 from a video signal generator 16, an actual white luster displayed on a screen of the color display device 14 is received by a color photodetecting probe 18 and a photoelectric conversion output Ci obtained undergoes an analysis processing by a color analyzer 20 to generate a measuring data Dxy Y of chromaticity coordinates (x,y) and luminance Y. The measuring data Dxy Y is transmitted to the video signal generator 16 through a communication line conforming with RS232C standard and the white raster video signal SAV containing the measuring data Dxy Y is outputted. As a result, the white raster and the measuring data Dxy Y are displayed on the screen 14 simultaneously. Thus, an inspecting person can evaluate and adjust the quality of the white balance simply by giving a glance at them.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a white balance adjustment evaluation system for performing white balance adjustment and evaluation of a color display device.

[0002]

2. Description of the Related Art In a color display device using a cathode ray tube (CRT) or a liquid crystal (LCD), if the white balance adjustment is poor, in the case of a black and white image, the entire screen is colored,
A clear black-and-white image cannot be obtained because only a part of a certain brightness is colored, and in the case of a color image, the color will be superimposed on the above-mentioned unclear black-and-white image, and correct color reproduction will be performed. Disappear.

Therefore, manufacturers of color display devices and the like pre-adjust white balance during product inspection. That is, in the CRT color display device, the three primary colors (R, G,
By setting the emission energy of each phosphor of B) to a predetermined ratio, the above-mentioned LCD color display device is
The white balance of each of the primary colors (R, G, B) is adjusted by adjusting the voltages applied to the liquid crystal pixels to a predetermined ratio.

A conventional adjustment evaluation system for performing such white balance adjustment will be described with reference to FIG.

The white raster W is displayed by supplying the reference white video signal Sw output from the video signal generator 4 to the color display device 2, and the three primary colors (R,
G, B), the white raster light W is photoelectrically converted by using a color light receiving probe 6 having three photoelectric elements having a predetermined spectral sensitivity, and photoelectric conversion outputs C _R , C _G ,
C _B is supplied to the color analyzer 8.

The color analyzer 8 has a photoelectric conversion output C
By performing predetermined signal processing on _R , C _G , and C _B , the radiant energies K _R , K _G , and K _B of the three primary colors (R, G, B) of the white raster W are obtained, and these radiant energies are further calculated. The chromaticity coordinates (x, y) of the white raster W and the luminance Y are calculated from K _R , K _G , and K _B , and these calculation results are displayed on the display panel.

Furthermore, since the calculation result displayed on the display panel of the color analyzer 8 is difficult for the inspector to intuitively see, the microcomputer 10 and the color monitor 1
2 is installed side by side, the data of the calculation result of the color analyzer 8 is transmitted to the microcomputer 10 through the RS232C communication line, and a predetermined computer graphics process is performed based on the data of the calculation result. The actual hue and brightness of the white raster W are displayed on the color monitor 12 as an image that is visually easy to understand.

Then, the inspector uses the color analyzer 8
Chromaticity coordinates (x, y) and luminance Y displayed on the display panel of
The white balance of the color display device 2 is evaluated while observing the calculation result and the display image on the color monitor 12, and the above adjustment operation, that is, the electrode voltage and the drive voltage of the color display device 2 is adjusted. Primary colors (R, G,
White balance adjustment is performed by adjusting each applied voltage to the liquid crystal pixel of B) to a predetermined ratio.

[0009]

By the way, the above-mentioned prior art is capable of performing accurate white balance adjustment, but has a problem that the operability is not good for the inspector.

That is, as an operation procedure for the inspector to adjust the white balance, first, the quality of the white balance is evaluated by observing the display images of the display panel of the color analyzer 8 and the color monitor 12, and then the evaluation / judgment. The adjustment operation for white balance adjustment of the color display device 2 is performed based on
Again, the display image of the color analyzer 8 and the display image of the color monitor 12 are used to evaluate the quality of the white balance after the adjustment operation, and based on the evaluation / judgment, the white balance adjustment of the color display device 2 is performed again. It was necessary to repeat the operation so as to perform the adjustment operation of.

In particular, the color display device 2 to be measured.
Since the color analyzer 8 which is a measuring device and the microcomputer 10 and the color monitor 12 are inevitably arranged apart from each other, the inspector repeatedly changes the line of sight to these devices and changes his / her position. Since it must be done, it puts a burden on the inspector, and it is difficult to improve productivity in a production line for inspecting a large number of color display devices. I couldn't say.

The present invention has been made in view of the above problems of the prior art, and provides a white balance adjustment evaluation system which can reduce the burden of adjustment and evaluation at the same time and at the same time enable quick white balance adjustment. The purpose is to provide.

[0013]

In order to achieve such an object, the present invention provides a white raster which is actually displayed on the color display device by supplying a reference white video signal to the color display device to be measured. In a white balance adjustment evaluation system for performing white balance adjustment by evaluating the hue and luminance of a color, a white raster that is actually displayed on the color display device is received, and a color that generates photoelectric conversion output for each of the three primary colors is generated. A light receiving unit, a color analyzing unit for calculating the hue and luminance of the white raster based on the photoelectric conversion output of the color light receiving unit, and a video signal of the reference white including measurement data representing the hue and the luminance. The video signal generating means supplies the color display device.

[0014]

The color light receiving means generates photoelectric conversion output for each of the three primary colors of the white raster which is actually displayed on the color display device, and the color analyzing means calculates the hue and brightness of the white raster, and the video signal generating means. Thus, a video signal including the measurement data representing the hue and the luminance is formed in the reference white video signal, and the video signal is supplied to the color display device to be measured. As a result, the white raster and the measurement data representing the measured hue and luminance are displayed simultaneously on the screen of the color display device, and the white raster is evaluated and the white balance of the color display device is adjusted without changing the viewpoint. It will provide a system capable of performing.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a white balance adjustment evaluation system according to the present invention will be described below with reference to the drawings. First, the overall system configuration will be described with reference to FIG.

A video signal generator 16 for outputting a video signal S _AV for reproducing and displaying a white raster on the color display device 14 to be measured, and a white raster image projected on the screen of the color display device 14 are color receiving probes. A color analyzer 20 to be measured at 18 and an RS232C communication line for data transmission between the video signal generator 16 and the color analyzer 20 are provided.

The color light receiving probe 18 has three primary colors (R,
G, B) has three built-in photoelectric elements having different spectral sensitivities, and the photoelectric conversion output C _i (where i = 1 to 3) of the white raster received by each photoelectric element is colored. Supply to the analyzer 20 one by one.

That is, the spectral distribution of the light output of the color display device 14 is W _λ , the radiant energy level of the three primary colors (R, G, B) is K _i (where i = 1 to 3), and the three primary colors (R, G,
_Let B i _λ (where i = 1 to 3) be the spectral distribution for each unit energy in B), and _let S i _λ (where i = 1 to 3) be the spectral sensitivity of each of the three photoelectric elements given above: Formula (1)
And (2) holds,

[0019]

[Equation 1]

[0020]

[Equation 2]

The photoelectric conversion output C _{i represented by the} above equation (2)
(However, i = 1 to 3) is supplied to the color analyzer 20. In addition, λ is a wavelength, and i = 1 corresponds to red (R), i = 2 corresponds to green (G), and i = 3 corresponds to blue (B).

The color analyzer 20 performs predetermined signal processing on the photoelectric conversion outputs C ₁ , C ₂ and C ₃ described above to obtain radiant energies K ₁ and K of the three primary colors (R, G and B) of the white raster. ₂ and K ₃ are calculated, and the chromaticity coordinates (x, y) and brightness Y of the white raster are calculated from these radiant energies K ₁ , K ₂ and K ₃ .

That is, the spectral distribution W _{i λ} and the spectral sensitivity S _{i λ} shown in the above equations (1) and (2) are fixed factors, and the radiant energies K ₁ , K ₂ and K _{3 to be obtained} are variables independent of the wavelength λ. Therefore, by substituting the equation (1) into the equation (2), the photoelectric conversion outputs C ₁ , C ₂ , and C ₃ can be expressed as the following equation (3).

[0024]

(Equation 3)

Therefore, the color analyzer 20 is
The radiant energy K ₁ , K ₂ , K ₃ of each primary color is calculated by performing the inverse matrix operation of the above equation (3) using the photoelectric conversion output C _i as the input of the A _ij matrix.

Further, the spectral sensitivities S _1λ , S _2λ and S _3λ of the photoelectric elements of the color light receiving probe 18 are CIE.
Since the three stimulus values X _λ , Y _λ , and Z _λ are approximated, the chromaticity coordinates (x, y) and the brightness Y are calculated based on the calculated radiant energies K ₁ , K ₂ , and K _3. The hue and brightness of the white raster actually displayed on the color display device 14 are obtained. Furthermore, the color analyzer 20
The measurement data D _xyY of chromaticity coordinates (x, y) and luminance Y is transmitted to the video signal generator 16 via a communication line connected to an output interface compliant with RS232C.

Next, the structure of the video signal generator 16 will be described.

This device 16 is a microprocessor (CP).
U) is implemented by a computer system capable of program control, and a central processing unit (CPU) 22 that controls the entire operation and a central control unit 22 for the inspector
An operation unit 24 including an operation panel and a keyboard for inputting a desired command, a timing generation circuit 26 that generates various timing signals that define the operation timing of the device 16, and various test pattern data. The test pattern generating circuit 28 for generating

Further, a communication interface 30 compliant with RS232C connected to the color analyzer 20 by a communication line is provided, and the chromaticity coordinates (x, y) from the color analyzer 20 are synchronized with a predetermined timing by a handshake method or the like. And the measurement data D _xyY of the brightness Y are received and sequentially stored in the random access memory (RAM) 32.

Video data storage memory (VRAM) 34
Has a storage capacity for storing pixel data corresponding to the number of pixels and the pixel array set in the color display device 14 (data in which the ratio of the three primary colors of each pixel is digitized). The test pattern data supplied from the generation circuit 28 and the measurement data D _xyY supplied from the random access memory 32 are written in the storage area addressed by the central control unit 22, and the once stored pixel data is timing generated. In synchronization with a predetermined read control timing from the circuit 26,
Read to the look-up table 36.

More specifically, when the inspector specifies the type of color display device (NTSC, PAL, SECAM, HDTV, etc.) and the type of test pattern to the central control unit 22 via the operation unit 24. The central control unit 22 instructs the test pattern generation circuit 28 to write the test pattern data of the designated method in the video data storage memory 34. Furthermore, the communication interface 3
The latest measurement data D _xyY transferred from the color analyzer 20 via 0 is read from the random access memory 32 and written in a predetermined storage area of the video data storage memory 34. Therefore, in the video data storage memory 34, the pixel data of a predetermined area in the pixel data corresponding to the test pattern is replaced with the measurement data D _xyY and held, and the held pixel data is sequentially stored at a predetermined timing. Read to look-up table.

The look-up table 36 converts each pixel data read from the video data storage memory 34 into three primary colors (R, R
G, B) is converted into grayscale data representing each grayscale level and output via the video signal output interface 38.
The video signal output interface 38 has three primary colors (R,
Each gradation of G, B) is D / A to the analog video signal S _AV.
Convert the color display system (NTSC, PAL,
Output at a timing synchronized with SECAM, HDTV, etc.).

Next, the operation of this embodiment having such a configuration will be described in accordance with the actual white balance adjustment operating procedure.

First, as shown in FIG. 1, the video signal generator 16 and the color analyzer 20 are connected by a communication line.
The video signal output interface 38 is connected to the color display device 14, which is the object to be measured.

Next, the inspector sets white balance adjustment through the operation unit 24. As a result, the pixel data of the white raster corresponding to the reference white is stored in the video data storage memory 34 from the test pattern generation circuit 28, and the three primary colors (R, G, B) of the white raster are transmitted via the video signal output interface 38. ), The video signal S _AV representing each gradation level is output, and a white raster is displayed on the screen of the color display device 14.

Next, the color light-receiving probe 18 is brought into contact with the screen of the color display device 14 to receive the white raster light, and the color analyzer 20 performs the predetermined signal processing to obtain the actual hue of the white raster. The measurement data D _xyY representing the brightness is generated and transmitted to the video signal generator 16.

The measurement data D _xyY is also stored in a predetermined area of the video data storage memory 34. As a result, the measurement data D _xyY is digitized on the screen of the color display device 14 as shown in FIG. The measurement display is displayed side by side on a white raster. In this embodiment, the white raster is displayed in the central portion of the screen and the measurement display is shown in the upper empty area around the white raster. However, the measurement display is shown in other areas of the empty area. May be.

The inspector evaluates and judges the quality of the white balance on the basis of the numerical values of the measurement display, and when these numerical values deviate from the predetermined white balance, the color display device 14 is adjusted. Then, the white balance adjustment is completed by finally repeating these values until the values satisfy the predetermined original white balance condition.

As described above, according to this embodiment, the measurement display of the white raster and its measurement data D _xyY is simultaneously displayed on the screen of the color display device 14 to be measured. Since it is possible to perform white balance evaluation and adjustment without shifting the line of sight from, it is possible to significantly reduce the burden of operation and at the same time enable quick white balance adjustment.

Next, another embodiment will be described with reference to FIG.
In the figure, parts that are the same as or correspond to those in FIG.

The difference from the previous embodiment shown in FIG. 1 is described. This embodiment has a built-in arithmetic circuit 40 for directly inputting the photoelectric conversion output Ci of the color light receiving probe 18,
The arithmetic circuit 40 has the same signal processing function as that of the color analyzer 20 (see FIG. 1), and the central processing unit 2
It is realized by a unit board that can be attached to and detached from two buses. Then, the arithmetic circuit 40 calculates the chromaticity coordinates (x, x) of the white raster of the color display device 14 based on the photoelectric conversion output Ci.
y) and the measurement data D _xyY representing the luminance Y and calculated and stored in a predetermined area of the video data storage memory 34 via the random access memory 32. As a result, as shown in FIG.
The measurement data D _xyY is displayed on the screen of the color display device 14 side by side in a white raster as a numerical measurement display.

According to this embodiment, since a separate color analyzer can be omitted, a space-saving and simple white balance adjustment evaluation system can be provided.

[0043]

According to the present invention as described above,
By supplying the color display device with the measurement data of the hue and brightness obtained by measuring the white raster actually reproduced on the color display device, which is the device under test, and supplying it to the color display device. Since the white raster and the measurement data are displayed at the same time, the inspector, etc.
The quality of white balance can be evaluated and adjusted simply by looking at the display surface of the color display device.

As a result, the white balance adjustment can be performed without changing the viewpoint or changing the body position to see various measuring instruments as in the conventional case, so that the operation load is greatly reduced and It has an excellent function of being able to speed up the work.

[Brief description of drawings]

FIG. 1 is a block diagram for explaining a system configuration of an embodiment according to the present invention.

FIG. 2 is an explanatory diagram for explaining a display state on a screen of a color display device which is a device to be measured.

FIG. 3 is a block diagram for explaining a system configuration of another embodiment according to the present invention.

FIG. 4 is an explanatory diagram showing a system configuration of a conventional white balance adjustment evaluation system.

[Explanation of symbols]

14 ... Color display device, 16 ... Video signal generator, 18
… Color receiving probe, 20… Color analyzer, 2
2 ... Central processing unit, 24 ... Operation unit, 26 ... Timing generation circuit, 28 ... Test pattern generation circuit, 30 ... Communication interface, 32 ... Random access memory, 34 ... Video data storage memory, 36 ... Look-up table,
38 ... Video signal output interface, 40 ... Arithmetic circuit.

Claims (1)

[Claims] 1. A white for adjusting white balance by supplying a reference white video signal to a color display device to be measured and evaluating the hue and luminance of a white raster actually displayed on the color display device. In a balance adjustment evaluation system, a color light receiving unit that receives a white raster actually displayed on the color display device to generate a photoelectric conversion output for each of three primary colors, and the photoelectric conversion output of the color light receiving unit Color analysis means for calculating the hue and luminance of the white raster, and video signal generating means for supplying the reference white video signal with measurement data representing the hue and luminance to the color display device. Characteristic white balance adjustment evaluation system.