JP2000111447A - Image inspection device and method with improved calibration method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve calibration for obtaining an address on the image pick-up element of each pixel of a display in an image inspection device and method for inspecting the picture quality of the display. SOLUTION: A picture quality inspection device 40 is provided with a camera part 16, an image memory 28, an address calculation means 30, an address storage device 34, a pixel array storage means 42, and an address estimation means 44. The pixel array storage means 42 stores such array data as the position relationship among pixels R, G, and B. A display 12 displays a monochromatic (green) calibration pattern. The green calibration pattern is picked up by the image pick-up element of the camera part 16 and is stored in the image memory 28. The address calculation means 30 calculates an address on the image pick-up element of a green display pixel based on stored image data for calibration. The address estimation means 42 estimates the address of the display pixel of another color based on the address data of the green display pixel and array data being stored at the pixel array storage means 42.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image quality inspection apparatus and method for inspecting image quality of a display device,
The present invention relates to an image quality inspection apparatus and method, and relates to an improvement in a calibration method for obtaining an address of each pixel of a display device on an image sensor based on bright and dark image data obtained by photographing an image displayed on the display device by an image sensor.

[0002]

FIG. 1 shows a conventional image quality inspection apparatus 10 for inspecting the image quality of a color flat panel display device 12. As shown in FIG.
FIG. 3 is a block diagram showing the configuration of FIG. In the image quality inspection of the color flat panel display device 12 such as an LCD panel, the brightness of each display pixel of the color flat panel display device 12 displaying the test pattern is measured using a camera having a CCD image pickup device or the like. Based on the result, the quality of the display of the measured color flat panel display device 12 is determined. In the image quality inspection apparatus 10 shown in FIG. 1, in order to create image data for reproducing the brightness of the display pixels of the color flat panel display device 12, addresses on an image sensor corresponding to each pixel of the color flat panel display device 12 are created. Is performed.

The conventional image quality inspection apparatus 10 includes a display driving unit 14, a camera unit 16, a rotating plate 18, an optical lens unit 20, a motor 22, a motor control unit 24, an A / D converter 26, an image memory 28, an address calculation. Means 30, presampling processing means 32, address storage device 34, CP
A U36 and a bus 38 are provided. Transmission of necessary control signals and data is performed via the bus 38.

[0004] The display driving section 14 outputs a driving signal to the color flat panel display device 12 based on a signal from the CPU 36 as a processor. The color flat panel display device 12 displays a desired pattern such as a calibration pattern and a test pattern based on a drive signal from the display drive unit 14. The camera unit 16, the rotating plate 18, and the optical lens unit 20 capture images of the displayed pattern,
It is arranged so as to face the display surface of the color flat panel display device 12. The optical lens unit 20 has a diaphragm and a focus adjustment mechanism for forming an image (pattern) on the camera unit 16, and the rotating plate 18 mounts four types of optical filters of red, green, blue and transparent. ing. The camera unit 16 has a built-in CCD image pickup device and the like, and photographs the color flat panel display device 12 that displays a desired pattern via an optical lens unit 20 and an optical filter mounted on the rotating plate 18. The motor 22 rotates the rotary plate 18 on which the optical filter is mounted based on the control signal of the motor control means 24, and selects the optical filter mounted on the rotary plate 18.

[0005] The output signal of the camera section 16 is converted into digital light and dark image data by an A / D converter 26, and the converted light and dark image data is stored in an image memory 28.
The address calculating unit 30 calculates the address of each pixel on the image sensor corresponding to each display pixel of the color flat panel display device 12 using the light and dark image data stored in the image memory 28. The calculated address is stored in the address storage device 34, and is read or rewritten as necessary. The pre-sampling processing means 32 performs pre-sampling processing for converting the photographed light and dark image data into an image corresponding to the display pixels of the color flat panel display device 12 using the address obtained by the address calculating means 30. The CPU 36 controls a series of processes for obtaining image data, processes the captured image data, and detects loss of display pixels of the color flat panel display device 12 and uneven display.

In order for the pre-sampling means 32 to perform pre-sampling processing of the captured light and dark image data, position (address) information for associating the pixels of the color flat panel display device 12 with the pixels of the image sensor of the camera section 16. is necessary. This address information is called "sampling address". Here, the “pre-sampling process” refers to re-sampling the captured light and dark image data,
Is a process of converting the image data into image data having the same size as the display resolution. The sampling address indicates that the center of each pixel of the color flat panel display device corresponds to which position of which pixel on the image sensor from which the light and dark image data has been captured. A calibration method for calculating a sampling address has been proposed in Japanese Patent Application Laid-Open Nos. 8-29360 and 10-31730.

[0007]

Conventionally, an image quality inspection apparatus 1
In the calibration of 0, R (red), G (green), B
The calibration pattern is displayed in each of the colors (blue) and W (white), a color filter that transmits light of the same color as the color of the displayed pattern is selected, light and dark image data is taken in, and a sampling address is set for each color. Was calculated. This is a color flat panel display device 1
In order to detect a defect that occurs in each of the R, G, and B pixels that constitute the two display pixels and a defect that occurs in the white display in which the R, G, and B pixels are lit at the same intensity, a test of each color is performed. This is for accurately sampling light and dark image data when a pattern is displayed.

FIG. 2 shows an arrangement of three types of display pixels of R, G, and B in the color flat panel display device 12. In the conventional image quality inspection apparatus 10, for example, R
In order to inspect a defect that occurs in the display of the pixel, the color flat panel display device 12 displaying the test pattern for lighting only the R pixel is photographed, and the bright and dark image data is pre-sampled and inspected. Therefore, it is necessary to display a calibration pattern for lighting only the R pixel and calculate a sampling address corresponding to the R pixel. Similarly, in order to inspect a defect that occurs in the display of the G pixel and the B pixel, the G pixel and the B pixel are inspected.
The sampling addresses of the pixels also had to be calculated individually. Further, in order to detect a defect that occurs in white display, it is necessary to calculate a sampling address corresponding to a display pixel including R, G, and B pixels.

However, the time required to calculate the sampling address is long, and it takes several tens of seconds to process all of R, G, B, and W. In this case, the inspection throughput decreases. Therefore, conventionally, the address of each color flat panel display device 12 to be inspected is not calculated, and the address of each lot of the color flat panel display device 12 to be mass-produced is calculated. This is because the positional accuracy required when the color flat panel display device 12 to be inspected is installed in the image quality inspection device 10 is high, so that if the tolerance of the installation position is satisfied, an error in the sampling address is not a problem. This is because the reproducibility of display by the pixels could be obtained.

However, in recent years, the definition of the color flat panel display device 12 has been advanced, and the display pixels have been rapidly miniaturized. Along with this, the influence of errors in the sampling address due to a slight shift in the installation position has become great, and the accuracy of the image data created by the pre-sampling process has been reduced. Therefore, it is not sufficient to calculate the sampling address for each lot of the color flat panel display device 12 to be inspected, and it is necessary to calculate the sampling address for each color flat panel display device 12 individually. It is necessary to prevent the throughput from decreasing due to an increase in the address calculation processing time. In order to solve the above problem, a high-speed calibration method is required to reduce the decrease in throughput even if an address is calculated for each color flat panel display device 12 to be inspected. Therefore, an object of the present invention is to provide an image quality inspection apparatus and an image quality inspection method that can solve the above-described problems. This object is achieved by a combination of features described in the independent claims. The dependent claims define further advantageous embodiments of the present invention.

[0011]

According to a first aspect of the present invention, there is provided a display apparatus having a plurality of display pixels of a plurality of colors. An image sensor that captures a test pattern for inspecting the display device, and the calibration pattern and the test pattern captured by the image sensor.
Image memory for storing image data for calibration and image data for test, which are light and dark image data, pixel array storage means for storing array data indicating an array of the display pixels of the plurality of colors, and the image data for calibration Address calculating means for calculating an address on the image sensor of the display pixel of at least one color for displaying the calibration pattern based on the address, the address calculated by the address calculating means, and the pixel array storing means Address estimating means for estimating an address on the image sensor of the display pixel of a color different from the display pixel whose address has been calculated by the address calculating means based on the array data stored in the address calculating means; Test image data and the address estimated by the address estimating means. Based on less, to provide a quality inspection apparatus characterized by comprising a processor for detecting a failure of the display of the display device.

In one aspect of the present embodiment, the image quality inspection apparatus converts the bright and dark image data into the image data based on the address calculated by the address calculating means or the address estimated by the address estimating means. The display device further includes a pre-sampling unit that converts the image data into image data having the same number of pixels as the display device. In another aspect of the embodiment, the calibration pattern is displayed by the display pixels of one color. In still another aspect of the present embodiment, the calibration pattern is displayed by the green display pixels. In still another aspect of the present embodiment, the address estimating means may include a multiplier and an adder for performing multiplication and addition based on the array data. In yet another aspect of this embodiment,
The image data for calibration and the image data for test are two times the display resolution of the display device.
The display resolution may be twice or more.

According to a second aspect of the present invention, there is provided an image processing apparatus comprising: a display device having a plurality of display pixels of a plurality of colors periodically arranged; A calibration method for determining an address on the image sensor of the display pixels of the plurality of colors of the display device, wherein the display device includes the display pixels of at least one of the display pixels of the plurality of colors. Displaying a calibration pattern to be lit; photographing the calibration pattern with the image sensor to generate image data for calibration; and, based on the image data for calibration, Before one of the at least one color of display pixels to be displayed Calculating the address of the display pixel on the image sensor, and the display pixel displaying the calibration pattern based on the address of the display pixel displaying the calibration pattern on the image sensor. Estimating addresses of the different display pixels on the image data.

In order to solve the above problem, a third aspect of the present invention is directed to a third aspect of the present invention, wherein a plurality of display pixels of a plurality of colors of the display device are displayed based on bright and dark image data of the display device photographed by an image sensor. An image quality inspection method for inspecting a display defect of a display device, which performs a calibration for obtaining an address on an image pickup device, wherein the display device includes a calibration device for lighting at least one of the display pixels of the plurality of colors. Displaying the calibration pattern, photographing the calibration pattern with the image sensor, generating calibration image data, and displaying the calibration pattern based on the calibration image data. Before one color of the display pixels of one color Calculating the address of the display pixel on the image sensor, and the display pixel displaying the calibration pattern based on the address of the display pixel displaying the calibration pattern on the image sensor. Estimating addresses of the different display pixels on the image data.

In one embodiment of the present invention, the step of displaying the calibration pattern may include the step of displaying the calibration pattern that turns on only the green display pixels. In another aspect of the present embodiment, based on the address calculated in the step of calculating the address, or the address estimated in the step of estimating the address, the bright and dark image data, the same pixel as the display device The method may further include a pre-sampling step of converting the image data into a number of image data. The above summary of the present invention does not list all of the necessary features of the present invention, and sub-combinations of these features may also constitute the present invention.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described through embodiments of the present invention. However, the following embodiments do not limit the claimed invention and have the features described in the embodiments. Not all combinations are essential to the solution of the invention. FIG. 3 shows an embodiment of the image quality inspection device 40 of the present invention for inspecting the color flat panel display device 12. This image quality inspection device 40
Are the display drive unit 14, the camera unit 16, the rotating plate 1
8, optical lens unit 20, motor 22, motor control means 2
4, an A / D converter 26, an image memory 28, an address calculating means 30, a presampling processing means 32, an address storage device 34, a CPU 36, a bus 38, a pixel array storing means 42, and an address estimating means 44. Configurations denoted by the same reference numerals as those shown in FIG. 1 are the same or similar to the configurations in FIG. This image quality inspection apparatus 40 is configured as shown in FIG.
The image quality inspection device 10 shown in FIG.
And an address estimating means 44 is newly added. The pixel array storage means 42 stores a positional relationship between R, G, and B pixels, an interval between each of R, G, and B pixels,
And / or means for storing array data such as the total number of pixels. The pixel array storage unit 42 may store these array data in advance, or may calculate and store these array data based on data input by the user.

Color flat panel display device 1
2 displays a calibration pattern and various test patterns based on a drive signal from the display drive unit 14. The display drive unit 14 includes the CPU 3
A drive signal for displaying images such as a calibration pattern and various test patterns is output to the color flat panel display device 12 based on the signal from the control unit 6. The display drive unit 14 can also output a drive signal for specifying the color and brightness (gradation) of an image displayed on the color flat panel display device 12. In the first embodiment of the present invention, when performing the calibration for obtaining the sampling address in the image quality inspection device 40, the color flat panel display device 12 is configured to use a single color, for example, a green calibration pattern for lighting only G pixels. Is displayed. The calibration pattern will be described later with reference to FIG.

The camera section 16, the rotating plate 18, and the optical lens section 20 are arranged so as to face the display surface of the color flat panel display device 12 so as to capture images such as the displayed calibration pattern and test pattern. Is done. The optical lens unit 20 includes the camera unit 16
The diaphragm 18 has at least four types of optical filters of red, green, blue and transparent. The rotating plate 18 may be provided with an optical filter of another color (intermediate color) according to the test item. The camera unit 16 includes an image pickup device such as a CCD image pickup device, and includes an optical lens unit 20 and a rotating plate 18.
A bright / dark image of the color flat panel display device 12 for displaying an image is captured via an optical filter mounted on the device. The motor 22 rotates the rotary plate 18 on which the optical filter is mounted based on the control signal of the motor control means 24, and selects the optical filter mounted on the rotary plate 18. For example, a color flat panel display device 1
When the image displayed in 2 is a green calibration pattern, a green optical filter is selected.

An output signal of the camera section 16 is converted into digital light and dark image data by an A / D converter 26, and the converted light and dark image data is stored in an image memory 28.
When a green calibration pattern is captured by the camera unit 16, the image data for calibration that has been digitally converted by the A / D converter 26 is stored in the image memory 28. Similarly, when a test pattern is photographed by the camera unit 16, the test image data digitally converted by the A / D converter 26 is stored in the image memory 28.

The address calculating means 30 comprises an image memory 28
Image data for green calibration stored in
The color flat panel display device 12 uses the array data of the G pixels stored in the pixel array storage unit 42.
A sampling address indicating the correspondence between the G pixel and each pixel on the image sensor of the camera unit 16 is calculated. G calculated
The address data of the pixel is stored in the address storage device 34, and is read out or rewritten as needed. The address storage device 34 is a storage device such as a large-capacity memory or a hard disk which can read and write data. The address estimating means 44 includes the address storage device 3
4, the address data of the G pixel is read out, and the address of the R pixel and the B pixel is calculated using the array data between the R, G, and B pixels stored in the pixel array storage unit 42. The address data obtained by the address estimating means 44 is also stored in the address storage device 34, and is used for taking in image data of various test patterns for inspection. The method of calculating the addresses of the R pixel and the B pixel by the address estimating means 44 will be described later in detail.

The pre-sampling processing means 32 uses the address data obtained by the address calculating means 30 and the address estimating means 44 to convert light and dark image data photographed by the image pickup device of the camera section 16 into display pixels of the color flat panel display device 12. Is converted to an image corresponding to. CP
U36 controls a series of processes for obtaining image data, processes the captured test image data based on the address data obtained by the address calculating means 30 and the address estimating means 44, and generates a color flat panel display device. Twelve display pixels are detected, for example, and display irregularities are detected. Transmission of necessary control signals and data is performed via the bus 38.

The camera section 16 is required to have a resolution higher than the display resolution of the color flat panel display device 12. This is to detect micro defects occurring in one pixel of the color flat panel display device 12. Further, since the arrangement of the pixels of the color flat panel display device 12 and the arrangement of the image pickup devices of the camera section 16 have a regular lattice-like structure, the camera section 1
Moire fringes easily occur in the bright and dark image data captured in step 6. Image data in which moire fringes have occurred cannot be used for image quality inspection because it does not accurately reproduce the light and dark states of the pixels of the inspection object. Therefore, light and dark image data is captured using a camera having a resolution twice or more the display resolution of the color flat panel display device 12. For example, in the inspection of a color flat panel display device having a resolution of 800 × 600 pixels, images can be taken with a camera having a resolution of 1600 × 1600 pixels or more, and bright and dark image data without moire fringes can be obtained with high accuracy.

The pre-sampling processing means 32 performs a process of re-sampling the light and dark image data and converting it into image data having the same size as the display resolution of the color flat panel display device 12. In the image quality inspection, image data resampled to the same size as the display resolution of the color flat panel display device 12 is used. The pixels of the pre-sampled image data correspond to the display pixels of the color flat panel display device 12 on a one-to-one basis. By performing the pre-sampling process, the color flat panel display device 1
The difference between the brightness of the two display pixels can be treated as the difference between the pixel values of each pixel in the image data. here,
“Pixel value” refers to the brightness of light input to the CCD image sensor. Further, since the capacity of the image data is reduced, the throughput of the image quality inspection can be improved. Hereinafter, a method of calculating the sampling address will be described.

FIG. 4 shows an example of a calibration pattern according to the first embodiment of the present invention. The calibration pattern is a pattern displayed on the color flat panel display device 12 in order to obtain a sampling address for associating a pixel of the color flat panel display device 12 with a pixel on the image sensor. The bright points of the calibration pattern are preferably arranged as far away from each other as possible in order to obtain the sampling address with high accuracy. In the example shown in FIG. 4, the calibration pattern is a green 2
There are five bright spots, and these bright spots are arranged so as to divide the LCD panel (color flat panel) into sixteen. This pattern is formed by the optical lens unit 20 and the rotating plate 18.
Camera unit 1 via a green optical filter mounted on
It is taken into 6.

FIG. 5 shows a CCD built in the camera unit 16.
4 shows a bright point on a CCD image of a calibration pattern captured by an image sensor. In the CCD image, a pixel having the largest pixel value is searched for from image data in the vicinity of the bright point, and that pixel is set as the central pixel Pn of the bright point. Focusing on this pixel Pn and the left and right pixels Pn-1 and Pn + 1, the center of gravity is determined as a real number from the pixel values of these three pixels, and is used as the address in the X direction of the center of the bright spot.

FIG. 6 shows an example in which the center address (center of gravity) of a luminescent spot in the X direction is obtained from the pixel values of Pn-1, Pn and Pn + 1. In FIG. 6, the X value indicated by the arrow is a point that divides the total pixel value of the pixels Pn, Pn-1 and Pn + 1 into two in the X direction, and becomes the real number address of the bright point in the X direction. Similar processing is performed for the pixel Pn in FIG. 5 and the pixels above and below it, and the address of the center of the luminescent spot in the Y direction is determined by a real number. These processes are performed for all the bright points, and the address (X, Y) corresponding to the center of each bright point is obtained. 2
From the addresses of the five bright spots, the addresses corresponding to all the G pixels of the color flat panel display device 12 are obtained by interpolation.

The method of calculating (estimating) the addresses of the R and B pixels by the address estimating means 44 will be described below. FIG. 7 is a diagram showing the intensity distribution of light emitted from the display pixels of the color flat panel display device 12. As shown in FIG. The light emitted from the R, G, and B pixels reflects the structure of the display pixel and is arranged such that the centers of the intensity distributions are distributed at equal intervals. Also, when the center of the G pixel coincides with the center of the entire display pixel, the center of the intensity distribution measured by turning on all the R, G, and B pixels and measuring as white light coincides with the center of the light emitted by the G pixel. As described with reference to FIGS. 4 to 6, the method of obtaining the address is as follows. First, the color flat panel display device 1 displaying the calibration pattern is displayed.
2, the image data for calibration, which is the light and dark image data, is generated, and the center of gravity is calculated from the pixel value distribution of the pixels corresponding to the pattern (CCD image) on the light and dark image data. Further, the address calculated from the light and dark image data obtained by capturing the calibration pattern for displaying white color matches the address of the G pixel.

FIG. 8 shows addresses in the X direction of R, G, and B pixels. Color flat panel display device 12
Are periodically arranged at regular intervals, so that the intensity distribution of light emitted from successive display pixels is also periodically repeated at regular intervals. Therefore, sampling addresses calculated from the light intensity distribution are also at equal intervals. From the structure and the periodicity of the arrangement of the display pixels of the color flat panel display device 12, the addresses of the R, G, and B pixels are periodically arranged at equal intervals as shown in FIG. Utilizing this relationship, the address estimating unit 44 calculates the address based on the array data indicating the positional relationship of each pixel stored in the pixel array storing unit 42.
The address of a pixel of another color is estimated from the address of a pixel of one color of interest. From the relationship between the green light and the white light shown in FIG. 7, the address of the G pixel can be replaced with the address for white display. Therefore, it is preferable that the address of the G pixel is accurately obtained from the bright and dark image data, and the address of the R and B pixels is calculated by the address estimating unit 44 based on the address of the G pixel. In addition, since the camera unit 16 having a built-in CCD image pickup device or the like generally has a high sensitivity to light in a green wavelength range and can shoot an image with good contrast, an address is calculated using a calibration pattern displayed by G pixels. Is preferred. In the first embodiment of the present invention, R, G, B, W
From the light and dark image data obtained by photographing only one color calibration pattern, the address of the one color pixel on the image sensor is calculated, and the other three color addresses are estimated from the address data. Processing time can be reduced to 1/4.

In the following, a method for obtaining the X addresses of the R and B pixels from the sampling addresses of the G pixels in the X direction will be described. Xg is the X address of three consecutive G pixels
(n-1), Xg (n), and Xg (n + 1). From FIG. 8, since the R pixel included in the n-th display pixel is located between the n-th pixel and the G pixel included in the n-th display pixel, the X address Xr (n) of this R pixel is It can also be stopped by an expression. Xr (n) = (Xg (n−1) + 2 × Xg (n)) ÷ 3 (1) The B pixels included in the n-th display pixel are n-th and n + 1.
Since the pixel is located between the G pixels included in the number-th display pixel, the X address Xb (n) of the B pixel can be determined by the following equation. Xb (n) = (2 × Xg (n) + Xg (n + 1)) ÷ 3 (2) As shown in FIG. 9, the Y address of each pixel is similarly arranged, so that three consecutive Y address of G pixel of Yg (n-
Assuming that 1), Yg (n), and Yg (n + 1), the Y addresses of the R pixel and the B pixel included in the n-th display pixel can be obtained by the following equations, respectively. Yr (n) = (Yg (n-1) + 2 × Yg (n)) ÷ 3 (3) Yb (n) = (2 × Yg (n) + Yg (n + 1)) ÷ 3 (4) Since equations (1) to (4) can be executed by multiplication and addition of coefficients, the address estimating means 44 uses a multiplier, an adder, and a memory for temporarily storing the read address and the calculated address. Can be configured.

FIG. 10 shows RGB pixels at four corners of the color flat panel display device 12. In the first embodiment shown in FIG. 4, the calibration pattern is composed of 25 green luminous points, but in the second embodiment, the calibration pattern is composed of at least two luminous points. The camera unit 16 corresponding to each pixel of the color flat panel display device 12 is
Is obtained on the image sensor.

The calibration pattern may be composed of at least two bright points of the same color, or may be composed of at least two bright points of different colors. In this embodiment, for example, an example will be described in which a pattern in which the G pixel at the upper left corner and the R pixel at the lower right corner are turned on is used as a calibration pattern. In this case, the address calculating means 30 calculates the X address and Y address of the G pixel at the upper left corner and the X address and Y address of the R pixel at the lower right corner. By obtaining the X address and the Y address of the two points, the address estimating means 44 can be used by the pixel array storing means 4.
2 based on array data such as data of the number of pixels in the X direction and the number of pixels in the Y direction, data indicating the interval between R pixels and G pixels, and / or data indicating the interval between RGB pixels. The X address and the Y address of the G pixel at the lower corner can be obtained. Address estimating means 44
Can determine the addresses of all the G pixels based on the addresses of the G pixels at the upper left corner and the G pixels at the lower right corner, and the array data stored in the pixel array storage unit 42. The addresses of the R pixel and the B pixel are determined by the address estimating unit 44 based on the address of the G pixel as described with reference to FIGS. As described above, by using the calibration pattern in which at least two display pixels on the color flat panel display device 12 are turned on and the pixel array data stored in the pixel array storage unit 42, R,
The respective addresses of the G and B pixels are obtained by the address estimating means 44. It is easier to calculate the address if the display pixels to be lit as the calibration pattern are of the same color, but the address can be calculated even when the display pixels of different colors are lit as the calibration pattern. It is clear from the example.

FIG. 11 shows an embodiment of the calibration method of the present invention when a single-color calibration pattern is displayed. In step S1, a green calibration pattern is displayed on the color flat panel display device 12. In step S2, an optical filter that transmits green light and is mounted on the rotating plate 18 is selected in order to photograph the color flat panel display device 12 displaying the green calibration pattern. In step S3, the image sensor of the camera unit 16 captures an image of the color flat panel display device 12, and captures calibration image data that is bright and dark image data. In step S4, the address calculating means 30 calculates the sampling address of the G pixel based on the image data for calibration. In step S5, the calculated address data of the G pixel is stored in the address storage device. Step S6
Then, the address estimating means 44 determines the address of the R pixel based on the address data of the G pixel, and stores the address data of the R pixel in the address storage device 34 in step S7. In step S8, as in step S6, the address estimating unit 44 obtains the address of the B pixel based on the address data of the G pixel, and stores the address data of the B pixel in the address storage unit 34 in step S9. The order of steps S6 and S7 and steps S8 and S9 may be interchanged.

In the above description, the color flat panel display device 12 has been described as a display device to be inspected. However, the present invention is not limited to this, and a plurality of types of pixels are periodically arranged. The present invention can be applied to such a display device as long as it is such a display device. Further, in the LCD panel, display pixels in a square arrangement as shown in FIG. 2 or a delta arrangement (triangle type)
It is clear that the present invention can be applied to the display pixels of the above. In the above description, the address of the G pixel is calculated from the light and dark image on the image sensor, and then the address of the other pixel is calculated (estimated). However, the present invention is not limited to this. The address of the pixel or the B pixel may be calculated from the light and dark image on the image sensor.

In the above description and FIG. 3, the address calculating means 30 and the address estimating means 44 are shown as separate components, but these means are configured as one means having their respective functions. It is also possible. Further, in the present invention, even when a calibration pattern of a different color is displayed, the time for obtaining the respective addresses of the R, G, and B pixels can be significantly reduced as compared with the conventional image quality inspection apparatus. . As described above, the present invention has been described using the embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments.
It is apparent to those skilled in the art that various changes or improvements can be added to the above embodiment. It is apparent from the description of the appended claims that embodiments with such changes or improvements can be included in the technical scope of the present invention.

[0035]

According to the present invention, high-speed calibration can be performed for each color flat panel display device to be inspected.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a conventional image inspection apparatus 10.

FIG. 2 is a diagram showing an arrangement of R, G, and B display pixels in a color flat panel display device 12;

FIG. 3 is an image quality inspection apparatus 40 according to the embodiment of the present invention.
FIG. 3 is a block diagram showing the configuration of FIG.

FIG. 4 shows an example of a calibration pattern.

FIG. 5 shows one bright spot on a CCD image of a calibration pattern captured by a camera unit 16;

FIG. 6 shows a relationship between a pixel value and an address.

FIG. 7 is a diagram showing an intensity distribution of light emitted from a display pixel of the color flat panel display device 12.

FIG. 8 shows addresses of R, G, and B pixels in the X direction arranged at equal intervals.

FIG. 9 shows addresses of R, G, and B pixels in the Y direction arranged at equal intervals.

FIG. 10 shows a color flat panel display device 12.
3 shows RGB pixels at four corners.

FIG. 11 shows an example of a calibration method according to the present embodiment.

[Explanation of symbols]

Reference Signs List 10 image quality inspection device, 12 color flat panel display device, 14 display drive unit, 16 camera unit, 18 rotating plate, 20.
-Optical lens unit, 22 ... motor, 24 ... motor control means, 26 ... A / D converter, 28 ... image memory, 30 ... address calculation means, 32 ... pre-sampling Processing means, 34 ... address storage device, 3
6 CPU, 38 bus, 40 image quality inspection device, 42 pixel array storage means, 44 address estimation means

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[Procedure amendment]

[Submission date] October 8, 1998 (1998.10.
8)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Figure 3

[Correction method] Change

[Correction contents]

FIG. 3

Claims (10)

[Claims] 1. An image sensor for photographing a calibration pattern displayed by at least one color display pixel of a display device having display pixels of a plurality of colors, and a test pattern for inspecting the display device; An image memory for storing the calibration pattern and the test pattern photographed by the element as calibration image data and test image data, which are bright and dark image data, respectively, and array data indicating an array of the display pixels of the plurality of colors. A pixel array storing unit that stores an address of the at least one color display pixel that displays the calibration pattern on the image sensor based on the calibration image data; and By calculation means And it calculated the address, on the basis of the said sequence data stored in the pixel array storing unit, of the display pixels of different color and the display pixels calculated the address in the address calculation unit,
An address estimating unit for estimating an address on the image sensor, and a processor for detecting a display defect of the display device based on the test image data and the address estimated by the address estimating unit. Image quality inspection device. 2. The method according to claim 1, further comprising: converting the bright and dark image data based on the address calculated by the address calculating unit or the address estimated by the address estimating unit.
The image quality inspection apparatus according to claim 1, further comprising a pre-sampling unit that converts the image data into image data having the same number of pixels as the display apparatus. 3. The image quality inspection apparatus according to claim 1, wherein the calibration pattern is displayed by the display pixels of one color. 4. The image quality inspection apparatus according to claim 3, wherein the calibration pattern is displayed by the green display pixels. 5. The image quality inspection apparatus according to claim 1, wherein said address estimating means has a multiplier and an adder for performing multiplication and addition based on said array data. 6. The image quality inspection apparatus according to claim 2, wherein the calibration image data and the test image data have a display resolution that is at least twice the display resolution of the display device. 7. The image processing apparatus according to claim 7, wherein the plurality of display pixels of the plurality of colors are displayed on the display device based on image data obtained by photographing an image displayed by a display device having a plurality of display pixels of a plurality of colors periodically with an image sensor. A calibration method for determining an address on an image sensor, wherein the display device displays a calibration pattern for lighting at least one of the display pixels of the plurality of colors. Photographing with an image sensor, generating calibration image data, based on the calibration image data, at least one color of the display pixels of the at least one color display pixel that displays the calibration pattern; Calculating an address on the image sensor And estimating an address on the image data of the display pixel different from the display pixel displaying the calibration pattern based on the address on the image sensor of the display pixel displaying the calibration pattern. Performing the calibration. 8. A display of a display device, comprising: performing calibration for obtaining addresses of display pixels of a plurality of colors of the display device on the image sensor based on bright and dark image data of the display device photographed by the image sensor. An image quality inspection method for inspecting a defect, the method comprising: causing the display device to display a calibration pattern for lighting at least one of the display pixels of the plurality of colors; and Photographing and generating image data for calibration; and capturing the display pixel of at least one color of the display pixels of at least one color that displays the calibration pattern based on the image data for calibration. Calculating the address on the element And estimating an address on the image data of the display pixel different from the display pixel displaying the calibration pattern based on the address on the image sensor of the display pixel displaying the calibration pattern. Performing an image quality inspection method. 9. The image quality inspection method according to claim 8, wherein displaying the calibration pattern includes displaying the calibration pattern that turns on only the green display pixels. 10. The image processing apparatus according to claim 1, further comprising: converting the bright / dark image data into an image having the same number of pixels as the display device based on the address calculated in the step of calculating the address or the address estimated in the step of estimating the address. The method of claim 8, further comprising a pre-sampling step of converting the data into data.