WO2014132506A1 - Method for detecting display panel defects and device for detecting display panel defects - Google Patents

Abstract

The method for detecting display panel defects according to the present invention includes a picture element lighting step (S2) for lighting at least the blue (B) picture elements of a display panel; an image data acquisition step (S3) for imaging a plurality of picture elements and acquiring image data thereof; defective region candidate extraction steps (S4, S5) for extracting, as a defective region candidate, a pixel of the image data for which the absolute value of a contrast value that is the difference between the imaged-pixel luminance signal level of the pixel and the non-defective-pixel luminance signal level of a non-defective pixel is at or above a threshold value; a defective region picture element identification step (S6); and defect determination steps (S7, S8) for calculating a degree of defectiveness by multiplying a correction coefficient that is different for each picture element color by the contrast value and determining that a picture element of a given color is defective if the degree of defectiveness exceeds a determination value.

Description

Display panel defect detection method and display panel defect detection apparatus

The present invention relates to a defect detection method and a defect detection apparatus for each display pixel in a display panel, and more particularly to improvement of defect detection sensitivity.

The liquid crystal display panel is inspected for defects in each display pixel of the liquid crystal display panel in the latter half of the manufacturing process. The defect handled in this specification is, for example, a bright spot defect caused by the occurrence of foreign matter in the liquid crystal layer in the liquid crystal display panel. For this reason, a bright spot defect mainly caused by a defect due to, for example, a short circuit or disconnection of wiring in a TFT (Thin Film Transistor) thin film transistor is not included.

Inspecting whether or not each display pixel of the liquid crystal display panel is defective is a visual inspection in which the lit liquid crystal display panel is visually inspected by an operator, and the liquid crystal display panel is a line sensor or an area sensor. There is an automatic inspection performed by a defect detection apparatus that processes a signal obtained by imaging with a simple sensor camera.

For example, a defect detection method using the defect detection apparatus disclosed in Patent Document 1 is known as the automatic inspection.

In the defect detection method disclosed in Patent Document 1, a defect part candidate includes, for example, a plurality of types of color picture elements in a large defect part including a red picture element and a green picture element adjacent thereto. In this case, it is determined that a single color does not include a plurality of types of color picture elements, and it is possible to prevent the occurrence of erroneous detection of a defect by determining the quality of a defective part candidate based on the determined determination criterion for the single color. It has been proposed to do so.

In order to solve this problem, a defect detection method of a defect detection apparatus disclosed in Patent Document 1 includes a step of capturing a pixel composed of a plurality of picture elements and acquiring it as image data, and a luminance of the pixel of the image data. Extracting a pixel having an absolute value of a contrast value, which is a difference between a signal amount and a luminance signal amount of the pixel when the pixel has no defect, as a defective part candidate, and a picture of the defective part candidate A step of specifying a prime color and a step of calculating a defect degree by multiplying the contrast value by a correction coefficient that varies depending on the color of the picture element and determining a defect when the defect degree is larger than a determination value are executed. To do. When one defect site candidate includes a plurality of types of color picture elements, the contrast value for each color of the picture element is multiplied by a correction coefficient that differs depending on the color of the picture element, and the total is calculated as a defect degree. Including a step of calculating.

As a result, since defects are detected for each color of the picture element, for example, when a plurality of types of color picture elements are included in a large defective part including a red picture element and a green picture element adjacent thereto, It is possible to prevent erroneous detection that the defect is only a red picture element.

In the defect detection method of the defect detection apparatus disclosed in Patent Document 1, the backlight is turned on, but each pixel of the display panel is detected without being turned on.

Japanese Patent Publication “Japanese Patent Laid-Open No. 2011-196685 (published on October 6, 2011)”

By the way, in the automatic inspection performed by the defect detection device and the visual inspection performed by the operator's visual observation of the lit liquid crystal display panel, for example, in the case of a minute defect having a size of one picture element or less, The difference from the detection sensitivity of the defect detection device is large, and the defect detection device detects even a minute defect exceeding the visual limit level.

Here, it is human beings who view the liquid crystal display panel, and it is not necessary to recognize and repair the defect as a defect if it cannot be recognized as a defect by human eyes.

However, the defect detection method using the conventional defect detection apparatus has a problem in that defects are detected more excessively than visual detection, and the process yield is reduced.

The present invention has been made in view of the above-described conventional problems, and its purpose is to reduce the number of defects that are detected excessively more than visual detection, and thus to suppress a reduction in process yield. A defect detection method and a display panel defect detection apparatus are provided.

In order to solve the above problem, a defect detection method for a display panel according to one embodiment of the present invention includes at least a blue (B) pixel among red (R), green (G), and blue (B) picture elements in a display panel. And a pixel lighting process for lighting the blue (B) picture element by applying an applied voltage to the picture element, and image data obtained by picking up pixels comprising a plurality of picture elements of the display panel and obtaining them as image data The absolute value of the contrast value, which is the difference between the acquisition step and the imaging pixel luminance signal amount of the pixel of the image data and the non-defective pixel luminance signal amount of the non-defective pixel of the image data in the non-defective pixel in which the pixel is not defective, is obtained. A defective part candidate extracting step for extracting pixels having a threshold value or more as a defective part candidate, a defective part pixel specifying step for specifying the color of the pixel of the defective part candidate, and a correction coefficient that differs depending on the color of the pixel Above Calculating a defectivity by multiplying the last value, the defect degree picture element the color is greater than the determination value is characterized in that it comprises a defect determination step of determining that the defect.

In order to solve the above problems, a display panel defect detection device according to one embodiment of the present invention includes at least a blue (B) pixel among red (R), green (G), and blue (B) picture elements in a display panel. The pixel lighting means for lighting the blue (B) picture element by applying an applied voltage to the picture element of (), and the pixel composed of a plurality of picture elements of the display panel are picked up by an imaging camera as image data A contrast value that is a difference between a captured pixel luminance signal amount of a pixel of the image data and a non-defective pixel luminance signal amount of the non-defective pixel of the image data in a non-defective pixel in which the pixel is not defective; A defective part candidate extracting unit that extracts a pixel having an absolute value equal to or greater than a threshold value as a defective part candidate, a defective part pixel specifying unit that specifies a color of a pixel of the defective part candidate, and a color of the pixel Different correction The number was calculated defectivity by multiplying the above contrast value, the defect degree picture element the color is greater than the determination value is characterized in that it comprises a determining defect determining means to be defective.

According to one aspect of the present invention, there is provided a display panel defect detection method and a display panel defect detection apparatus capable of reducing the number of defects that are detected excessively more than visual detection, and thereby suppressing a decrease in process yield. The effect of doing.

It is a flowchart which shows the defect detection method of the display panel by the defect detection apparatus of the display panel in Embodiment 1 of this invention. It is a block diagram which shows the structure of the defect detection apparatus for performing the defect detection method of the said display panel. (A) is a top view which shows the whole structure of a liquid crystal display panel, (b) is a liquid crystal in a state where only a backlight is lit and red (R), green (G) and blue (B) picture elements are not lit. It is a principal part top view which shows the structure of a display panel, (c) turns on a backlight, and is a blue (B) picture among red (R), green (G), and a blue (B) picture element. It is a principal part top view which shows the structure of the liquid crystal display panel of the state which only lighted up. It is a top view which shows the pixel arrangement | sequence of the said liquid crystal display panel. In the display panel defect detection method, it is a diagram illustrating an example of a correction coefficient when a bright spot defect occurs in each of red (R), green (G), and blue (B) picture elements. (A) is a principal part top view which shows the brightness | luminance difference of a background picture element and a defect when only a backlight is lighted when a blue (B) picture element has a defect, (b) is a backlight. Illustrated main plane showing the luminance difference between the background picture element and the defect when only the blue (B) picture element is lit up among the red (R), green (G), and blue (B) picture elements. FIG. It is a flowchart which shows the defect detection method of the display panel in Embodiment 2 of this invention. (A) shows the defect detection method of the said display panel, Comprising: When there exists a defect over both a red (R) picture element and a green (G) picture element, when only a backlight is lighted It is a principal part top view which shows the brightness | luminance difference of a background picture element and a defect, (b) lights up a backlight, and is red among red (R), green (G), and blue (B) picture elements. It is a principal part top view which shows the luminance difference of a background picture element when a picture element of (R) and a blue (B) picture element are lighted, and a defect. It is a flowchart which shows the defect detection method of the display panel in Embodiment 3 of this invention. (A) shows the defect detection method of the said display panel, Comprising: The brightness | luminance difference of a background picture element and a defect when only a backlight is lighted when a green (G) picture element has a defect is shown. It is a principal part top view, (b) is a background picture element and defect when lighting a backlight and lighting all the picture elements of red (R), green (G), and blue (B) picture elements It is a principal part top view which shows the brightness | luminance difference with. It is a flowchart which shows the defect detection method of the display panel in Embodiment 4 of this invention.

[Embodiment 1]
An embodiment of the present invention will be described below with reference to FIGS.

The configuration of the defect detection apparatus 10 according to the present embodiment will be described with reference to FIG. FIG. 2 is a block diagram showing a configuration of the defect detection apparatus 10 of the present embodiment and the liquid crystal display panel 1 that is a defect detection target.

As shown in FIG. 2, the defect detection apparatus 10 according to the present embodiment includes a display panel operation unit 2 for applying a display input signal to a liquid crystal display panel 1 as a display panel, an imaging camera 11, and a defect site detection. Unit 12, color identification unit 13, defect determination unit 14, and result output unit 15. In addition, after detecting the defective part of the pixel in the defect detection apparatus 10 of the present embodiment, the defective part is repaired.

The liquid crystal display panel 1 is composed of a plurality of pixels composed of picture elements of three colors of red (R: Red), green (G: Green), and blue (B: Blue) arranged in a matrix. . The liquid crystal display panel 1 includes a panel body composed of a TFT (thin film transistor) (not shown) substrate, a color filter substrate, and a liquid crystal layer interposed therebetween, and a back disposed on the back surface of the panel body. With lights. Therefore, the liquid crystal display panel 1 can apply a voltage for each picture element by the display panel operation unit 2. In the present embodiment, the liquid crystal display panel 1 is used as a display panel. However, the present invention is not limited to the liquid crystal display panel and may be another display panel.

The display panel operation unit 2 can turn on / off the backlight and apply a driving signal for lighting to each of the red (R), green (G), and blue (B) picture elements. It has become.

The imaging camera 11 captures the liquid crystal display panel 1 and acquires it as image data, and includes a sensor camera such as a line sensor or an area sensor. Therefore, the imaging camera 11 captures a column or row of pixels along a line, or captures a region of a certain size, that is, a certain matrix region, and acquires it as image data. In the present embodiment, the sensor camera is a monochrome camera.

The defective part detection unit 12 calculates the absolute value of the contrast value, which is the difference between the imaging pixel luminance signal amount of the pixel of the image data and the non-defective pixel luminance signal amount of the non-defective pixel in the non-defective pixel in which the pixel is not defective. A pixel having a value equal to or greater than a threshold value is extracted as a candidate defect part.

The color specifying unit 13 specifies the color of the defective part candidate pixel. In addition, the defect determination unit 14 calculates a defect degree by multiplying the contrast value by a correction coefficient that varies depending on the color of the pixel, and if the defect degree is larger than the determination value, the pixel of the color is defective. It comes to judge. Further, the result output unit 15 displays which picture element in the image data of the liquid crystal display panel 1 is defective.

A defect detection method in the defect detection apparatus 10 having the above configuration will be described with reference to FIGS. FIG. 1 is a flowchart showing a defect detection method of the liquid crystal display panel 1 in the present embodiment. FIG. 3A is a plan view showing the overall configuration of the liquid crystal display panel 1. FIG. 3B is a main part plan view showing the configuration of the liquid crystal display panel 1 in a state where only the backlight is lit and the red (R), green (G), and blue (B) picture elements are not lit. FIG. 3C shows a liquid crystal display panel 1 in a state in which the backlight is turned on and only the blue (B) picture element among the red (R), green (G), and blue (B) picture elements is lit. It is a principal part top view which shows the structure of this.

In the present embodiment, the defect to be handled is a bright spot defect that is caused by the occurrence of foreign matter in the liquid crystal layer in the liquid crystal display panel. For this reason, a bright spot defect mainly caused by a defect due to, for example, a short circuit or disconnection of wiring in a TFT (Thin Film Transistor) thin film transistor is not included.

When the defect detection apparatus 10 of the present embodiment detects a defect generated in a picture element, first, as shown in FIG. 1, the backlight in the liquid crystal display panel 1 is turned on (S1). Subsequently, in the picture element lighting step, at least the blue (B) picture element is lit among the red (R), green (G), and blue (B) picture elements (S2).

Next, when the display pattern of the above-mentioned lighting state is displayed on the liquid crystal display panel 1, in the image data acquisition step, the display pattern is imaged by the imaging camera 11 and acquired as image data (S3). In the present specification, the magnitude of the signal output by the light receiving element according to the intensity of light received by the light receiving element of the imaging camera 11 is referred to as “luminance signal amount”. Therefore, the value of each pixel of the image data is a luminance signal amount.

Specifically, when the backlight in the liquid crystal display panel 1 is turned on and no voltage is applied to any of the red (R), green (G), and blue (B) picture elements, ( a) As shown in (b), in the image data, the luminance of the red picture element Rp, the green picture element Gp, and the blue picture element Bp of the liquid crystal display panel 1 is low. In this state, when the blue picture element Bp is turned on, the luminance of the blue picture element Bp is increased as shown in FIG.

Next, in the defective part candidate extraction step, the defective part detection unit 12 calculates a contrast value for the image data and creates a contrast image (S4). Here, the contrast value refers to the luminance signal amount of the picture element of the image data and the display pattern displayed on the liquid crystal display panel 1 normally, that is, the picture element is defective. This is the difference from the luminance signal amount when there is no signal. As the luminance signal amount when there is no defect in the picture element, a value obtained in advance may be used, but each time it may be a non-defective pixel luminance signal amount predicted from the obtained image data.

Here, an example of a method for obtaining a contrast value by adopting a method of predicting non-defective pixel luminance signal amounts from obtained image data will be described with reference to FIG. FIG. 4 is a plan view showing a picture element array 1a of red (R), green (G), and blue (B) picture elements of the liquid crystal display panel 1. FIG. In this arrangement, red (R), green (G), and blue (B) picture elements are arranged in the horizontal direction to form one unit, and this one unit is in the vertical and horizontal directions. Each is arranged in multiple numbers. Here, the red picture element constituting the unit of the m-th row and the n-th column is indicated by Rmn, the green picture element is indicated by Gmn, and the blue picture element is indicated by Bmn.

First, in the picture element array 1a of the liquid crystal display panel 1 shown in FIG. 4, the pattern has a spatial period of one unit in the horizontal direction. For example, there is no defective picture element R21 with respect to the defective picture element R22. R23 is a pixel of the same phase that is one cycle apart horizontally. If the phase is the same even if the period is different, the luminance signal amounts should be similar, and the average of the luminance signal amount of the picture element R21 and the luminance signal quantity of the picture element R23 indicates that the pattern is displayed normally. In this case, that is, the luminance signal amount of the pixel R22 when there is no defect should be approximated.

Therefore, for example, the contrast value CR22 in the defective pixel R22 is
CR22 = R22− (R21 + R23) / 2
Can be obtained as

This eliminates variations in the luminance signal amount caused by the spatial periodicity of the display pattern and the spatial periodicity of the picture element array 1a on the liquid crystal display panel 1 from the image data.

Subsequently, as shown in FIG. 1, in the defective part candidate extracting step, defective part candidates are extracted from the contrast image of the image data (S5). That is, since the contrast value of a normal pixel without a defect should be about 0 by the above-described calculation of the contrast value, the liquid crystal display panel 1 corresponding to a pixel having a value greatly different from 0 in the contrast image. The site is likely a defect. Therefore, a picture element having an absolute value of the contrast value larger than a certain threshold value may be extracted as a defective part candidate.

Next, in the defective part picture element specifying step, the color specifying unit 13 specifies the color of the picture element that is the object for each pixel included in the defective part candidate (S6). The color is specified based on the luminance signal amount in the image data. However, it is not necessarily limited to this. For example, a display pattern for alignment is displayed on the liquid crystal display panel 1, the display pattern is captured by the imaging camera 11 as image data, and the display pattern and the display pattern in the image data are collated to establish a correspondence relationship. The registration information to be specified is created, the picture element corresponding to the pixel is specified based on the pixel position and the registration information, and further, based on the design information of the liquid crystal display panel 1, the picture element corresponding to the pixel is selected from the specified picture element. You may specify by specifying the color of a picture element.

Next, in the defect determination step, the defect determination unit 14 calculates the defect degree based on the specified color (S7). The correction coefficient, which is the ratio between the absolute value of the contrast value and the defect level, differs depending on the display pattern and the color of the picture element. Three examples are shown below.

For example, a picture element that is controlled to be displayed in black based on the display pattern is displayed in black when normal. If the picture element to be displayed in black is displayed in red (R), green (G), or blue (B) (contrast value is positive), it is considered a bright spot defect. The eye sensitivity is high for green (G) and low for blue (B). In order to make the defect degree coincide with the sensitivity of the human eye, when the picture element to be displayed in black is displayed in blue (B), the picture element to be displayed in black is green by multiplying by a small correction coefficient. When displayed in (G), a large correction coefficient is multiplied. Since the imaging camera 11 is a monochrome camera, it is unknown which color the bright spot defect is displayed. However, since the probability that a bright spot defect is displayed in a color different from the original color of the picture element is extremely rare, it is estimated that the color is specified by the color specifying unit 13 and is multiplied by the correction coefficient. And

Also, picture elements that are controlled to be brightly displayed based on the display pattern are displayed in the colors of the red (R), green (G), and blue (B) picture elements when normal. The When a picture element to be displayed in any one of red (R), green (G), and blue (B) is displayed in black (contrast value is negative), it is considered to be a black spot defect. However, in order to perform correction according to the sensitivity of the human eye, when the picture element to be displayed in blue is displayed in black, a small correction coefficient is obtained after multiplying the contrast value by -1 to make the sign positive. Multiply Further, in the case where a picture element to be displayed in green is displayed in black, the sign is positive by multiplying the contrast value by −1, and then multiplied by a large correction coefficient. As a result, the degree of defect is set to a value close to the sensitivity of the human eye.

Also, picture elements that are controlled to be brightly displayed based on the display pattern are displayed in the colors of the red (R), green (G), and blue (B) picture elements when normal. The When a picture element to be displayed in red (R), green (G), or blue (B) is displayed in white (contrast value is positive), it is considered as a white point defect. However, since correction is performed according to the sensitivity of the human eye, a large correction coefficient is multiplied when the picture element to be displayed in blue (B) is displayed in white. In addition, when a picture element to be displayed in green (G) is displayed in white, a small correction coefficient is multiplied. As a result, the degree of defect is set to a value close to the sensitivity of the human eye. The white defect occurs when ink is not placed on the color filter and all light is transmitted.

A specific example of the correction coefficient will be described with reference to FIG. FIG. 5 is a diagram illustrating an example of the correction coefficient in the case where a bright spot defect has occurred in each of the red (R), green (G), and blue (B) picture elements.

That is, when a bright spot defect has occurred in each of the red (R), green (G), and blue (B) picture elements, as shown in FIG. The visual sensitivity / luminance signal amount is used as a correction coefficient. For example, it is assumed that the luminance signal amounts of image data in red (R), green (G), and blue (B) colors displayed on the liquid crystal display panel 1 are 0.4, 0.3, and 0.3. Further, it is assumed that the human visual sensitivity is 0.3, 0.6, and 0.1. In this case, the correction coefficient for red (R) is 0.3 / 0.4 = 0.75, the correction coefficient for green (G) is 0.6 / 0.3 = 2.0, and is related to blue (B). The correction coefficient is 0.1 / 0.3 = 0.33. The visual sensitivity of each color of red (R), green (G), and blue (B) can be specified by measuring each color displayed on the liquid crystal display panel 1 with a color luminance meter.

As described above, an appropriate correction coefficient is selected based on the display pattern, the sign of the contrast value, and the color specified by the color specifying unit 13, and multiplied by the contrast value. The correction coefficient is a value to be set depending on the color of the picture element and the sensitivity of the light receiving element with respect to the color of the picture element, and may be a correction coefficient other than the above.

In addition, when the defect part candidate is composed of a plurality of picture elements, the defect degrees of the plurality of picture elements may be summed to obtain the defect degree of the entire defect part candidate. That is, when one defect includes picture elements of a plurality of types of colors, the degree of defect is calculated by multiplying the contrast value for each color by a correction coefficient that differs depending on the color and summing up the defects.

Subsequently, as shown in FIG. 1, the defect is determined in the defect determination step (S8). Specifically, for each defective part candidate extracted in S5, the defect degree is compared with the determination value, and if the defect degree is larger than the determination value, it is determined as a defect.

Finally, the result output unit 15 outputs information on the part determined to be defective (S9). The information regarding the part determined to be a defect includes a defect sitting value, a color, and a defect type in the display panel. The defect sitting value in the liquid crystal display panel 1 is obtained by converting the coordinate value of the defect in the contrast image into the sitting face in the liquid crystal display panel 1 based on information for specifying a picture element corresponding to each pixel of the pixel data. Is possible. Also, the types of defects include black spot defects, bright spot defects, white spot defects, and the like.

According to the present embodiment, even when the defect includes a plurality of color picture elements, the defect degree is corrected in accordance with the ratio of the included colors, so that it is possible to make a determination based on an appropriate standard, and erroneous detection Can be detected and defects can be accurately detected.

In the present embodiment, description of the following operations is omitted, but defect repair is performed as a subsequent process.

The defect detection method in the above-described defect detection apparatus 10 will be described based on a specific example of FIGS. FIG. 6A is a main part plan view showing a luminance difference between the background picture element and the defect when only the backlight is turned on when the blue (B) picture element has a defect. FIG. 6B shows the background picture element when the backlight is turned on and only the blue (B) picture element among the red (R), green (G), and blue (B) picture elements is lit. It is a principal part top view which shows the luminance difference with a defect.

As shown in FIG. 6A, for example, it is assumed that a defect F exists in the blue picture element Bp. At this time, only the backlight is turned on, and when the red (R), green (G), and blue (B) picture elements are not turned on, the picture elements are controlled to be displayed in black achromatic colors. Therefore, when it is normal, that is, when there is no defect, it is displayed in a dark black achromatic color. Therefore, as shown in FIG. 6A, a part of the contrast picture is brightly displayed with the blue picture element Bp, so that it is considered to be a defect F. That is, when one or more of the red picture element Rp, the green picture element Gp, and the blue picture element Bp are displayed brightly, it becomes a defect F because it becomes a certain luminance difference or more.

However, human visual sensitivity is high for green (G) and low for red (R) and blue (B). Therefore, in order to match the detection sensitivity of the defect detection apparatus 10 with the human visual sensitivity, the display panel operation unit 2 applies a voltage to blue (B). The visual sensitivity ratio is approximately when normalized so that the sum of red (R), green (G), and blue (B) is 1.
Red (R): Green (G): Blue (B) = 0.3: 0.6: 0.1
It becomes.

Therefore, it is preferable to increase the applied voltage in the order of blue (B), red (R), and green (G). In the present embodiment, for example, red (R) is displayed on the display panel operation unit 2 so that the applied voltage ratio is red (R) = 0, green (G) = 0, and blue (B) = 15. And a voltage is applied to blue (B). At this time, since the input signal to be applied is the voltage [V] and not the luminance value, the input signal is adjusted so as to obtain a desired background luminance value.

Thereby, as shown in FIG. 6A, for example, the defect F existing in the blue picture element Bp is not the defect F as shown in FIG. 6B.

Therefore, it is possible to provide a defect detection method for the liquid crystal display panel 1 that can more efficiently reduce the overdetection of the defect F than the visual detection, and further suppress the reduction in the process yield.

As described above, in the defect detection method of the liquid crystal display panel 1 in the defect detection apparatus 10 of the present embodiment, at least one of the red (R), green (G), and blue (B) picture elements in the liquid crystal display panel 1. A pixel lighting process for lighting the blue (B) picture element by applying an applied voltage to the blue (B) picture element, and imaging a pixel composed of a plurality of picture elements of the liquid crystal display panel 1 by the imaging camera 11 The difference between the image data acquisition step of acquiring the image data as image data, and the amount of imaging pixel luminance signal of the pixel of the image data and the amount of non-defective pixel luminance signal of the non-defective pixel of the image data in the non-defective pixel where the pixel is not defective A defective part candidate extracting step of extracting a pixel whose absolute value of a certain contrast value is equal to or greater than a threshold value as a defective part candidate; a defective part pixel specifying step of specifying a color of a pixel of the defective part candidate; Depending on the color of Different correction factors to calculate the defectivity by multiplying the above contrast value, the defect degree picture element the color is greater than the determination value and a defect determination step of determining that the defect.

That is, conventionally, when a defect of the liquid crystal display panel 1 is detected by a defect detection device, the image data acquisition process and the defective part candidate are performed without applying a voltage to each pixel constituting the pixel of the liquid crystal display panel 1. The extraction process, the defective part picture element identification process, and the defect determination process are performed in this order to detect the defect. However, in the automatic inspection performed by the defect detection apparatus 10 and the visual inspection performed by the operator's visual inspection of the lit display panel, for example, in the case of a defect having a size of one picture element or less, the human visual detection sensitivity and the defect The difference from the detection sensitivity of the detection device is large, and the defect detection device will detect even a microdefect exceeding the visual limit level. For example, as shown in FIG. 6A, when the defect F exists in the blue picture element Bp, the difference in brightness between the background brightness of the blue picture element Bp and the brightness of the defect F is large. Immediately, it is determined that the defect F exists in the blue picture element Bp.

Here, the person who views the liquid crystal display panel 1 is a human, and if it cannot be recognized as a defect by human eyes, the defect does not need to be recognized and repaired. As a result, the defect detection method using the conventional defect detection apparatus has a problem that the defect is over-detected rather than the visual detection and the process yield decreases. Here, a defect determination step of calculating a defect degree by multiplying the contrast value by a correction coefficient that differs depending on the color of the picture element, and determining that the pixel of the color is a defect when the defect degree is larger than a determination value A method of changing the correction coefficient in is also conceivable. However, since there is a difference in the background luminance of the picture element between when the picture element is lit and when it is not lit, accurate defect detection is difficult with the method of changing the correction coefficient.

Therefore, in the defect detection apparatus 10 of the present embodiment, when performing the conventional image data acquisition process, defective part candidate extraction process, defective part pixel identification process, and defect determination process, first, in the pixel lighting process. Then, an applied voltage is applied to at least the blue (B) picture element among the red (R), green (G), and blue (B) picture elements in the liquid crystal display panel 1, and the blue (B) picture element is obtained. Light.

Here, at least the blue (B) picture element is turned on in human visual observation when only the backlight is turned on, and in addition to the backlight, red (R), green (G), blue ( This is because the brightness difference from when each of the B) picture elements is lit is the largest in the case of the blue (B) picture element. That is, when only the backlight is turned on, the blue (B) picture element has a luminance of the blue (B) picture element among the red (R), green (G), and blue (B) picture elements. Smallest. For this reason, when the defect exists in the blue (B) picture element, the brightness of the defect is high. Therefore, the defect detection method using the conventional defect detection apparatus can easily extract the defect of the blue (B) picture element. Tend. On the other hand, as shown in FIG. 6B, when the defect is detected by turning on the blue picture element Bp as in this embodiment, the luminance between the background brightness of the blue picture element Bp and the brightness of the defect F is obtained. Since the difference is small, it is difficult to extract as a defect.

Here, since the blue (B) picture element is often lit when viewing the liquid crystal display panel 1, the human visual observation does not recognize a defect existing in the blue (B) picture element. There are many cases. For this reason, even if such a defect detection method is adopted, there is substantially no problem.

Therefore, among the red (R), green (G), and blue (B) picture elements, the blue (B) picture element whose defect is frequently detected more frequently than the visual detection is turned on to detect the defect. Do. Accordingly, it is possible to provide a defect detection method for the liquid crystal display panel 1 that can efficiently reduce the overdetection of defects rather than the visual detection and thereby suppress a decrease in process yield.

[Embodiment 2]
The following will describe another embodiment of the present invention with reference to FIGS. The configurations other than those described in the present embodiment are the same as those in the first embodiment. For convenience of explanation, members having the same functions as those shown in the drawings of the first embodiment are given the same reference numerals, and explanation thereof is omitted.

In the defect detection method of the defect detection apparatus 10 of the first embodiment, in the picture element lighting process, the applied voltage is applied only to the blue (B) picture element among the green (G) and blue (B) picture elements. The blue (B) picture element was turned on.

However, in the defect detection method for the liquid crystal display panel 1 in the defect detection apparatus 10 of the present embodiment, each of the red (R), green (G), and blue (B) pictures in the liquid crystal display panel 1 in the picture element lighting step. The difference is that blue (B) and red (R) picture elements are lit so that the applied voltage applied to each picture element is blue (B)> red (R). .

That is, in human visual observation, the luminance difference between when only the backlight is lit and when each of the red (R), green (G), and blue (B) picture elements is lit in addition to the backlight is The red (R) picture element is the second largest after the blue (B) picture element. For this reason, in addition to the blue (B) picture element, the red (R) picture element is lit so that the applied voltage applied to each picture element is blue (B)> red (R). The difference in luminance between the background luminance of the blue (B) and red (R) picture elements and the luminance of the defect is reduced. As a result, it becomes difficult to be extracted as a defect.

Therefore, among the red (R), green (G), and blue (B) picture elements, the blue (B) and red (R) picture elements whose defects are more frequently detected than the visual detection are turned on. Then, defect detection is performed. Accordingly, it is possible to provide a defect detection method for the liquid crystal display panel 1 that can more efficiently reduce the number of defects that are detected excessively than the visual detection, and that can suppress a decrease in the process yield.

A defect detection method in the defect detection apparatus 10 according to the present embodiment will be described with reference to FIGS. FIG. 7 is a flowchart showing a defect detection method of the liquid crystal display panel 1 in the present embodiment. FIG. 8A shows a defect detection method of the liquid crystal display panel 1, where only the backlight is present when there is a defect extending over both the red (R) picture element and the green (G) picture element. It is a principal part top view which shows the brightness | luminance difference of a background picture element when a is lighted, and a defect. In FIG. 8B, the backlight is turned on, and among the red (R), green (G), and blue (B) picture elements, the blue (B) picture element and the red (R) picture element are displayed. It is a principal part top view which shows the brightness | luminance difference of a background picture element and a defect when it lights.

When the defect detection apparatus 10 of the present embodiment detects a defect occurring in a picture element, first, as shown in FIG. 7, the backlight in the liquid crystal display panel 1 is turned on (S1). Subsequently, in the picture element lighting step, the blue (B) and red (R) picture elements among the red (R), green (G), and blue (B) picture elements in the liquid crystal display panel 1 Lights up so that the applied voltage applied to the picture element is blue (B)> red (R) (S11).

Since the subsequent steps S3 to S9 are the same as those described in the flowchart shown in FIG. 1 in the first embodiment, the description thereof is omitted here.

A specific example of the defect detection method in the defect detection apparatus 10 will be described.

As shown in FIG. 8A, for example, it is assumed that there is a defect F straddling the red picture element Rp and the green picture element Gp. At this time, only the backlight is turned on, and when the red (R), green (G), and blue (B) picture elements are not turned on, the picture elements are controlled to be displayed in black achromatic colors. Therefore, when it is normal, that is, when there is no defect, it is displayed in a dark black achromatic color. Therefore, as shown in FIG. 8A, a part of each red picture element Rp and green picture element Gp is brightly displayed on the contrast screen, so that it is considered to be a defect F. That is, when one or more of the red picture element Rp, the green picture element Gp, and the blue picture element Bp are displayed brightly, it becomes a defect F because it becomes a certain luminance difference or more.

However, human visual sensitivity is high for green (G) and low for red (R) and blue (B). Therefore, in order to match the detection sensitivity of the defect detection apparatus 10 with the human visual sensitivity, the display panel operation unit 2 applies voltages to red (R) and blue (B). The visual sensitivity ratio is approximately when normalized so that the sum of red (R), green (G), and blue (B) is 1.
Red (R): Green (G): Blue (B) = 0.3: 0.6: 0.1
It becomes.

Therefore, it is preferable to increase the applied voltage in the order of blue (B), red (R), and green (G). In the present embodiment, for example, the display panel operation unit 2 uses red (R) so that the applied voltage ratio is red (R) = 10, green (G) = 0, and blue (B) = 15. And a voltage is applied to blue (B). At this time, since the input signal to be applied is the voltage [V] and not the luminance value, the input signal is adjusted so as to obtain a desired background luminance value.

Accordingly, as shown in FIG. 8A, for example, the defect F existing across the red picture element Rp and the green picture element Gp is converted into a red picture as shown in FIG. The element Rp is no longer a defect F.

That is, in the example shown in FIGS. 8A and 8B, the luminance difference between the luminance value of the defect F located in the red picture element Rp and the luminance value of the red picture element Rp becomes small. The contrast volume is reduced. For this reason, it becomes difficult for the defect detection apparatus 10 to detect the defect F having a small contrast volume and a visual limit level or more. The luminance value refers to the magnitude of a signal output from the imaging camera 11 according to the intensity of light received by the imaging camera 11. The contrast volume is the absolute value of the difference between the luminance value of the imaging camera 11 for a certain picture element and the predicted value of the luminance value when the picture element is normally displayed on the screen of the liquid crystal display panel 1. The value added in the area.

Therefore, it is possible to provide a defect detection method for the liquid crystal display panel 1 that can more efficiently reduce the number of defects that are detected excessively than visual detection, and that can suppress a decrease in process yield.

[Embodiment 3]
The following will describe still another embodiment of the present invention with reference to FIGS. The configurations other than those described in the present embodiment are the same as those in the first embodiment and the second embodiment. For convenience of explanation, members having the same functions as those shown in the drawings of Embodiment 1 and Embodiment 2 are given the same reference numerals, and explanation thereof is omitted.

In the defect detection method of the defect detection apparatus 10 of the first embodiment, in the picture element lighting process, the applied voltage is applied only to the blue (B) picture element among the green (G) and blue (B) picture elements. The blue (B) picture element was turned on.

However, in the defect detection method for the liquid crystal display panel 1 in the defect detection apparatus 10 of the present embodiment, each of the red (R), green (G), and blue (B) pictures in the liquid crystal display panel 1 in the picture element lighting step. The difference is that the voltage applied to each pixel is lit so that the applied voltage is blue (B)> red (R) ≧ green (G).

That is, in human visual observation, the luminance difference between when only the backlight is lit and when each of the red (R), green (G), and blue (B) picture elements is lit in addition to the backlight is , Blue (B) picture element, red (R) picture element, and green (G) picture element. For this reason, in addition to the blue (B) picture element, red (R) and green (G) picture elements are applied to each picture element with a blue (B)> red (R) ≧ green (G ) To light up. As a result, the luminance difference between the background luminance of the blue (B), red (R), and green (G) picture elements and the luminance of the defect becomes small, so that it is difficult to be extracted as a defect.

Therefore, if all of the red (R), green (G), and blue (B) picture elements are lit and defect detection is performed, defects are more reliably detected than visual detection. Therefore, it is possible to provide a defect detection method for a display panel that can reduce the process yield and, in turn, suppress a decrease in process yield.

A defect detection method in the defect detection apparatus 10 according to the present embodiment will be described with reference to FIGS. FIG. 9 is a flowchart showing a defect detection method of the liquid crystal display panel 1 in the present embodiment. FIG. 10A shows a defect detection method for the liquid crystal display panel 1, and the background pixel and defect when only the backlight is turned on when the green (G) pixel is defective. It is a principal part top view which shows a luminance difference. FIG. 10B shows the luminance difference between the background picture element and the defect when the backlight is turned on and all of the red (R), green (G), and blue (B) picture elements are lit. It is a principal part top view which shows.

When the defect detection apparatus 10 of the present embodiment detects a defect occurring in a picture element, first, the backlight in the liquid crystal display panel 1 is turned on as shown in FIG. 9 (S1). Subsequently, in the picture element lighting step, the applied voltage for applying the red (R), green (G), and blue (B) picture elements in the liquid crystal display panel 1 to the picture elements is blue (B)> Lights up so that red (R) ≧ green (G) (S21).

Since the subsequent steps S3 to S9 are the same as those described in the flowchart shown in FIG. 1 in the first embodiment, the description thereof is omitted here.

A specific example of the defect detection method in the defect detection apparatus 10 will be described.

As shown in FIG. 10A, for example, it is assumed that a defect F exists in the green picture element Gp. At this time, only the backlight is turned on, and when the red (R), green (G), and blue (B) picture elements are not turned on, the picture elements are controlled to be displayed in black achromatic colors. Therefore, when it is normal, that is, when there is no defect, it is displayed in a dark black achromatic color. Therefore, as shown in FIG. 10A, when a part of the green picture element Gp is displayed brightly on the contrast screen, it is considered to be a defect F. That is, when one or more of the red picture element Rp, the green picture element Gp, and the blue picture element Bp are displayed brightly, it becomes a defect F because it becomes a certain luminance difference or more.

However, human visual sensitivity is high for green (G) and low for red (R) and blue (B). Therefore, in order to match the detection sensitivity of the defect detection apparatus 10 with the human visual sensitivity, the display panel operation unit 2 applies voltages to red (R) and blue (B). The visual sensitivity ratio is approximately when normalized so that the sum of red (R), green (G), and blue (B) is 1.
Red (R): Green (G): Blue (B) = 0.3: 0.6: 0.1
It becomes.

Therefore, it is preferable to increase the applied voltage in the order of blue (B), red (R), and green (G). In this embodiment, for example, red (R) is displayed on the display panel operation unit 2 so that the applied voltage ratio is red (R) = 10, green (G) = 5, and blue (B) = 15. A voltage is applied to green (G) and blue (B). At this time, since the input signal to be applied is the voltage [V] and not the luminance value, the input signal is adjusted so as to obtain a desired background luminance value.

As a result, as shown in FIG. 10A, for example, the defect F existing in the green picture element Gp becomes the defect F after the picture element is turned on as shown in FIG. Disappear.

Therefore, it is possible to provide a defect detection method for the liquid crystal display panel 1 that can reliably and efficiently reduce overdetection of defects as compared with visual detection, and thus can suppress a decrease in process yield.

[Embodiment 4]
The following will describe still another embodiment of the present invention with reference to FIG. The configurations other than those described in the present embodiment are the same as those in the first to third embodiments. For convenience of explanation, members having the same functions as those shown in the drawings of Embodiments 1 to 3 are given the same reference numerals, and descriptions thereof are omitted.

In the defect detection method of the defect detection apparatus 10 according to the first to third embodiments, in any of the embodiments, after performing the pixel lighting process for lighting at least the blue (B) pixel, The defect detection is employed in the lighting defect detection procedure in which the image data acquisition process, the defective part candidate extraction process, the defective part pixel identification process, and the defect determination process are performed in this order.

However, if only the defect detection procedure at the time of lighting is performed, the defect detection apparatus 10 cannot grasp how many defects F actually exist.

Therefore, in the defect detection method of the liquid crystal display panel 1 in the defect detection apparatus 10 of the present embodiment, both the lighting defect detection procedure and the non-lighting defect detection procedure in which no pixel is lit are performed. Thereby, the defect F which exists actually can be grasped.

A defect detection method for the liquid crystal display panel 1 in the defect detection apparatus 10 of the present embodiment will be described with reference to FIG. FIG. 11 is a flowchart showing a defect detection method of the liquid crystal display panel 1 in the present embodiment.

When a defect occurring in a picture element of the liquid crystal display panel 1 of the present embodiment is detected by the defect detection device 10, first, the backlight in the liquid crystal display panel 1 is turned on as shown in FIG. S1). Subsequently, in the picture element lighting step, at least each blue (B) picture element among the red (R), green (G), and blue (B) picture elements in the liquid crystal display panel 1 is lit (S31). . That is, the pixel lighting process of S31 is the same as the pixel lighting process of any of the first to third embodiments (S2 shown in FIG. 1, S11 shown in FIG. 7, and FIG. 9). S21). Thereafter, steps S3 to S9 are performed. Since steps S3 to S9 are the same as those described in the flowchart shown in FIG. 1 in the first embodiment, the description thereof is omitted. As a result, the lighting defect detection procedure shown in S31 to S9 is performed. Therefore, a defect detection result at the visual inspection level is obtained.

However, there are cases where it is desired to grasp the actual detailed occurrence of defects.

Therefore, in the defect detection method of the liquid crystal display panel 1 of the present embodiment, the defect at the time of non-lighting in which the defect is detected without lighting the red (R), green (G), and blue (B) picture elements. Run the detection procedure.

Specifically, as shown in FIG. 11, the red (R), green (G), and blue (B) picture elements are turned off (S32), and then the steps S3 to S9 are similarly executed. .

This makes it possible to grasp the actual details of the occurrence of defects.

In addition, when adopting the defect detection method of the liquid crystal display panel 1 of the present embodiment, it is preferable that the processing time has a margin.

Further, in the present embodiment, after performing the defect detection procedure at the time of lighting, the defect detection procedure at the time of non-lighting is performed. However, the present invention is not necessarily limited to this. It is also possible to perform a lighting defect detection procedure after performing the above. That is, either the lighting defect detection procedure or the non-lighting defect detection procedure may be performed first. This is because, regardless of which is performed first, it is possible to grasp the true level defect and the visual observation level defect.

(Summary)
The defect detection method for the display panel (liquid crystal display panel 1) according to the first aspect of the present invention is at least one of red (R), green (G), and blue (B) picture elements in the display panel (liquid crystal display panel 1). Applying an applied voltage to the blue (B) picture element to light the blue (B) picture element, a plurality of picture element lighting steps (S2, S11, S21), and a plurality of display panels (liquid crystal display panel 1) An image data acquisition step (S3) in which pixels consisting of picture elements are captured and acquired as image data, and the non-defective pixels of the image data in the non-defective pixels in which the pixels are not defective and the imaging pixel luminance signal amount of the pixels of the image data A defective part candidate extraction step (S4, S5) for extracting a pixel whose absolute value of the contrast value, which is the difference from the non-defective pixel luminance signal amount, is greater than or equal to a threshold value as a defective part candidate, and the picture of the defective part candidate The prime color Defect site picture element identification step (S6) to be determined, and the degree of defect is calculated by multiplying the contrast value by a correction coefficient that differs depending on the color of the picture element. If the degree of defect is greater than the judgment value, the picture of the color And a defect determination step (S7, S8) for determining that the element is a defect.

The defect detection apparatus 10 for the display panel (liquid crystal display panel 1) according to the fifth aspect of the present invention is a red (R), green (G), or blue (B) picture element in the display panel (liquid crystal display panel 1). A plurality of picture element lighting means (display panel operation unit 2) for applying an applied voltage to at least a blue (B) picture element to light up the blue (B) picture element, and the display panel (liquid crystal display panel 1). Image data acquisition means (imaging camera 11) that captures a pixel consisting of a picture element and acquires it as image data; and the amount of imaging pixel luminance signal of the pixel of the image data and the image data of a non-defective pixel in which the pixel is not defective A defective part candidate extracting means (defective part detecting unit 12) for extracting, as a defective part candidate, a pixel whose absolute value of a contrast value, which is a difference between the non-defective pixel and the non-defective pixel luminance signal amount, is a threshold value or more; Lack of Defect part pixel specifying means (color specifying part 13) for specifying the color of the part candidate picture element and the correction coefficient that differs depending on the color of the picture element are multiplied by the contrast value to calculate the defect degree. Defect determining means (defect determining unit 14) that determines that the picture element of the color is defective when larger than the determination value is characterized.

According to one aspect of the present invention, when performing a conventional image data acquisition process, a defective part candidate extraction process, a defective part pixel identification process, and a defect determination process, first, in the pixel lighting process, in the display panel An applied voltage is applied to at least the blue (B) picture element among the red (R), green (G), and blue (B) picture elements to light the blue (B) picture element.

Here, at least the blue (B) picture element is turned on in human visual observation when only the backlight is turned on, and in addition to the backlight, red (R), green (G), blue ( This is because the brightness difference from when each of the B) picture elements is lit is the largest in the case of the blue (B) picture element. That is, when only the backlight is turned on, the blue (B) picture element has a luminance of the blue (B) picture element among the red (R), green (G), and blue (B) picture elements. Smallest. For this reason, when the defect exists in the blue (B) picture element, the brightness of the defect is high. Therefore, the defect detection method using the conventional defect detection apparatus can easily extract the defect of the blue (B) picture element. Tend. On the other hand, if the defect detection is performed by turning on the blue (B) picture element as in the present invention, the brightness difference between the background brightness of the blue (B) picture element and the brightness of the defect becomes small. It becomes difficult to extract.

Here, since the blue (B) picture element is often lit when viewing the display panel, a defect existing in the blue (B) picture element may not be recognized in human visual observation. Many. For this reason, even if such a defect detection method is adopted, there is substantially no problem.

Therefore, among the red (R), green (G), and blue (B) picture elements, the blue (B) picture element whose defect is frequently detected more frequently than the visual detection is turned on to detect the defect. Do. Accordingly, it is possible to provide a display panel defect detection method and a display panel defect detection apparatus that can efficiently reduce overdetection of defects rather than visual detection, and thus can suppress a decrease in process yield. it can.

The defect detection method for the display panel (liquid crystal display panel 1) according to aspect 2 of the present invention is the same as the defect detection method for the display panel (liquid crystal display panel 1) according to aspect 1, in the picture element lighting step (S11). Application that applies at least blue (B) and red (R) picture elements to each of the red (R), green (G), and blue (B) picture elements in (liquid crystal display panel 1) It is preferable to light up so that the voltage is blue (B)> red (R).

That is, in human visual observation, the luminance difference between when only the backlight is lit and when each of the red (R), green (G), and blue (B) picture elements is lit in addition to the backlight is The red (R) picture element is the second largest after the blue (B) picture element. For this reason, in addition to the blue (B) picture element, the red (R) picture element is lit so that the applied voltage applied to each picture element is blue (B)> red (R). As a result, the difference in luminance between the background luminance of the blue (B) and red (R) picture elements and the luminance of the defect becomes small, so that it is difficult to be extracted as a defect.

Therefore, among the red (R), green (G), and blue (B) picture elements, the blue (B) and red (R) picture elements whose defects are more frequently detected than the visual detection are turned on. Then, defect detection is performed. Accordingly, it is possible to provide a display panel defect detection method that can more efficiently reduce the number of defects that are detected excessively than visual detection, and that can suppress a decrease in process yield.

The defect detection method for the display panel (liquid crystal display panel 1) according to aspect 3 of the present invention is the display panel defect detection method according to aspect 2, in the pixel lighting step (S21), the red (R) in the display panel, It is preferable that the green (G) and blue (B) picture elements are lit so that the applied voltage applied to each picture element is blue (B)> red (R) ≧ green (G).

That is, in human visual observation, the luminance difference between when only the backlight is lit and when each of the red (R), green (G), and blue (B) picture elements is lit in addition to the backlight is , Blue (B), red (R), green (G) picture elements in order. For this reason, in addition to the blue (B) picture element, red (R) and green (G) picture elements are applied to each picture element with a blue (B)> red (R) ≧ green (G ) To light up. As a result, the luminance difference between the background luminance of the blue (B), red (R), and green (G) picture elements and the luminance of the defect becomes small, so that it is difficult to be extracted as a defect.

Therefore, if all of the red (R), green (G), and blue (B) picture elements are lit and defect detection is performed, defects are more reliably detected than visual detection. Therefore, it is possible to provide a defect detection method for a display panel that can reduce the process yield and, in turn, suppress a decrease in process yield.

The defect detection method for the display panel (liquid crystal display panel 1) in aspect 4 of the present invention is the defect detection method for the display panel (liquid crystal display panel 1) in aspect 1, 2, or 3, wherein the pixel lighting step is performed. In addition, the non-lighting defect detection procedure (S32 to S9) in which the image data acquisition process, the defective part candidate extraction process, the defective part pixel identification process, and the defect determination process are performed in this order and the pixel lighting process are performed. Thereafter, it is preferable to perform both of the above-described image data acquisition step, defect portion candidate extraction step, defect portion pixel element identification step, and defect determination step in the lighting defect detection procedure (S31 to S9) in this order.

In other words, if the defect detection is performed only by the lighting defect detection procedure that performs picture element lighting, as described above, it is possible to reliably reduce the overdetection of defects rather than the visual detection, thereby reducing the process yield. It is possible to provide a display panel defect detection method capable of suppressing the above.

However, if only the defect detection procedure at the time of lighting is performed, it becomes impossible to grasp how many true defects actually exist in the defect detection apparatus.

Therefore, in the present invention, both the lighting defect detection procedure and the non-lighting defect detection procedure are performed. Thereby, the true defect which exists actually can be grasped | ascertained.

Incidentally, either the lighting defect detection procedure or the non-lighting defect detection procedure may be performed first. This is because, regardless of which is performed first, it is possible to grasp the true level defect and the visual observation level defect.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the technical means disclosed in different embodiments can be appropriately combined. Such embodiments are also included in the technical scope of the present invention.

The present invention can be used for detecting or repairing defects in display panels such as a liquid crystal display panel, an organic EL display panel, a plasma display, an LCD display panel and the like composed of multicolor picture elements.

1 Liquid crystal display panel (display panel)
2 Display panel operation section (picture element lighting means)
DESCRIPTION OF SYMBOLS 10 Defect detection apparatus 11 Imaging camera (Image data acquisition means)
12 Defective part detection unit (defective part candidate extraction means)
13 color identification part (defect part picture element identification means)
14 Defect determination unit (defect determination means)
15 Result output part F Defect Rp Red picture element Gp Green picture element Bp Blue picture element

Claims (5)

1. A picture in which an applied voltage is applied to at least the blue (B) picture element among the red (R), green (G), and blue (B) picture elements on the display panel to light the blue (B) picture element. An elementary lighting process,
   An image data acquisition step of capturing pixels as a plurality of picture elements of the display panel and acquiring them as image data;
   The absolute value of the contrast value, which is the difference between the imaging pixel luminance signal amount of the pixel of the image data and the non-defective pixel luminance signal amount of the non-defective pixel of the non-defective pixel in which the pixel is not defective, is greater than or equal to a threshold value. A defective part candidate extraction step of extracting a certain pixel as a defective part candidate;
   A defective part picture element specifying step for specifying the color of the defective part candidate picture element;
   A defect determination step of calculating a defect degree by multiplying the contrast value by a correction coefficient that varies depending on the color of the pixel and determining that the pixel of the color is defective when the defect degree is larger than a determination value. A defect detection method for a display panel, comprising:
2. In the picture element lighting step, at least the blue (B) and red (R) picture elements are selected from the red (R), green (G), and blue (B) picture elements in the display panel. The applied voltage applied to
   Blue (B)> Red (R)
   The display panel defect detection method according to claim 1, wherein the display panel is lit so that
3. In the picture element lighting step, an applied voltage for applying each of the red (R), green (G), and blue (B) picture elements in the display panel to the picture elements is:
   Blue (B)> Red (R) ≧ Green (G)
   The display panel defect detection method according to claim 2, wherein the display panel is lit so that
4. Without performing the picture element lighting step, non-lighting defect detection procedure for performing the image data acquisition step, the defective portion candidate extraction step, the defective portion pixel element identification step and the defect determination step in this order,
   After performing the picture element lighting step, performing both the image data acquisition step, the defective portion candidate extraction step, the defective portion pixel element identification step, and the defect determination step in this order in the lighting defect detection procedure. 4. The display panel defect detection method according to claim 1, 2, or 3.
5. A picture in which an applied voltage is applied to at least the blue (B) picture element among the red (R), green (G), and blue (B) picture elements on the display panel to light the blue (B) picture element. Elementary lighting means,
   An image data acquisition means for acquiring, as image data, imaging a pixel composed of a plurality of picture elements of the display panel with an imaging camera;
   The absolute value of the contrast value, which is the difference between the imaging pixel luminance signal amount of the pixel of the image data and the non-defective pixel luminance signal amount of the non-defective pixel of the non-defective pixel in which the pixel is not defective, is greater than or equal to a threshold value. A defective part candidate extracting means for extracting a certain pixel as a defective part candidate;
   A defective part pixel specifying means for specifying the color of the defective part candidate picture element;
   Defect determination means for calculating a defect degree by multiplying the contrast value by a correction coefficient that varies depending on the color of the pixel and determining that the pixel of the color is defective when the defect degree is larger than a determination value. A display panel defect detection apparatus comprising:

Images