JPWO2011043064A1 - Display defect inspection apparatus and display defect inspection method for display panel - Google Patents

Abstract

The display defect inspection apparatus (1) of the liquid crystal display panel (2) is a liquid crystal display panel that drives the liquid crystal display panel (2) so that a plurality of display colors are displayed in the display area of the liquid crystal display panel (2). The drive part (5) is provided. Then, the liquid crystal display panel drive unit (5) displays the liquid crystal display panel (5) so that the plurality of display colors displayed in the display area are displayed based on the order of the brightness of each of the plurality of display colors. To drive.

Description

  The present invention relates to a display defect inspection apparatus and a display defect inspection method for inspecting the presence or absence of a display defect such as a bright spot defect of a display panel such as a liquid crystal display panel.

  In recent years, there has been a strong demand for liquid crystal display panels capable of displaying higher-quality images. However, it is difficult to prevent the occurrence of display defects with the current liquid crystal display panel manufacturing technology. For this reason, in order to provide a high-quality liquid crystal display panel with reduced display defects, a display defect inspection (image quality inspection) process is performed in the manufacturing process.

  In addition, bright spots (abnormal lighting due to leaks between picture elements, which appear brighter than the display screen) defects, black spots (abnormal lighting due to non-lighting etc., from the display screen) In general, the inspection process for the presence or absence of display defects on the display panel, such as defects that appear dark, defects, defects (such as scratches and alignment unevenness), and unevenness, is generally performed by the inspector's eyes.

  The visual inspection process by the inspector is performed using a limit sample which is a sample of the lowest quality that can be handled as a non-defective product. For example, in the inspection of bright spot defects, pass / fail (presence / absence of bright spot defects) is determined by an inspector comparing a liquid crystal display panel and a limit sample.

  In addition, for example, a method has been proposed in which a predetermined pattern is displayed on a liquid crystal display panel and visually inspected. More specifically, a method is disclosed in which two types of checkered patterns having different patterns are alternately displayed on a liquid crystal display panel, and the displayed checkered pattern is visually inspected (see, for example, Patent Document 1).

JP-A-8-241046

  Here, in the conventional visual inspection described above, a sudden change in screen brightness caused by switching the screen display causes an illusion phenomenon in the inspector's vision, which makes it difficult to visually recognize display defects. It was.

  Factors that cause such problems include the time required for light adaptation and dark adaptation of the human eye. That is, for example, when the display on the liquid crystal display panel is switched from white display with high luminance to black display with low luminance, the time required for dark adaptation becomes longer due to a sudden change in screen luminance. Therefore, for a few seconds immediately after switching from white display to black display, a state in which display defects existing on the black display screen cannot be recognized at all continues. Similarly, when the display on the liquid crystal display panel is switched from a black display with a low luminance to a green display with a high luminance, the time required for light adaptation becomes longer due to a sudden change in screen luminance. Therefore, for a few seconds immediately after switching from black display to green display, a state in which display defects existing on the green display screen cannot be recognized at all continues.

  As a result, when the display defect inspection of the display panel is performed visually, there has been a problem that the inspector misses the display defect. In particular, there is a problem that point defects such as a bright spot defect, a black spot defect, and a defect defect that are difficult to visually recognize occur.

  Therefore, the present invention has been made in view of the above-described problems, and can improve the accuracy of detection of display defects on a display panel when visual inspection of display defects of a display panel such as a liquid crystal display panel is performed. An object of the present invention is to provide a display defect inspection apparatus and a display defect inspection method for a display panel.

  In order to achieve the above object, a display defect inspection apparatus for a display panel according to the present invention provides a plurality of displays in a display area of a display panel including a display area in which a plurality of pixels each having a plurality of types of colored layers are two-dimensionally arranged. A display defect inspection apparatus for a display panel that inspects the presence or absence of a display defect in a pixel by displaying a color, and includes a display panel driving unit that drives the display panel so that the display color is displayed in the display area The display panel driving unit drives the display panel so that the plurality of display colors displayed in the display area are displayed based on the order of the brightness of each of the plurality of display colors.

  According to this configuration, it is possible to reduce the luminance difference of the display surface luminance in the display colors before and after being displayed in the display area, and to prevent a sudden change in the display surface luminance when the color display is changed. . Therefore, when the display defect inspection of the display panel is performed visually, it is possible to shorten the time required for light and dark adaptation, and thus it is possible to effectively suppress the occurrence of the illusion phenomenon in the inspector's vision. . As a result, it is possible to improve the detection accuracy of visual display defects.

  In the display defect inspection apparatus for a display panel according to the present invention, the display panel drive unit may be configured to drive the display panel so that a plurality of display colors are displayed in order of decreasing luminance.

  According to this configuration, a plurality of display colors are displayed in order from the lowest brightness, and the time required for light adaptation is much shorter than the time required for dark adaptation, so the time required for display defect inspection of the display panel Can be effectively shortened.

  In the display defect inspection apparatus for a display panel according to the present invention, the display panel driving unit may drive the display panel so that a plurality of display colors are displayed in order of increasing luminance.

  The display defect inspection apparatus for a display panel according to the present invention further includes a light source luminance adjustment unit for adjusting the luminance of a light source that emits irradiation light to the display panel, and the light source luminance adjustment unit is provided in the display area. In order to adjust the display surface luminance in each display color to be displayed, the luminance of the light source may be changed.

  According to the configuration, in order to adjust the display surface brightness in each display color displayed in the display area, the brightness of the display surface in the display colors before and after being displayed in the display area is changed by changing the brightness of the light source. The brightness difference can be further reduced. Therefore, it is possible to prevent a sudden change in display surface luminance when changing the color display, and therefore it is possible to further reduce the time required for light and dark adaptation when performing visual inspection of display defects on the display panel. . As a result, it is possible to prevent the occurrence of an illusion phenomenon in the inspector's vision, and it is possible to further improve the accuracy of visual detection of display defects.

  In the display defect inspection apparatus for a display panel according to the present invention, the light source luminance adjustment unit is configured to change the luminance of the light source so that the display surface luminances of the display colors displayed in the display area are substantially the same. It is good.

  According to this configuration, it is possible to eliminate a luminance difference in display surface luminance between display colors before and after being displayed in the display area. Accordingly, it is possible to reliably prevent a sudden change in display surface luminance when changing the color display, so that the time required for light and dark adaptation is not required when visual inspection of display defects on the display panel is performed. As a result, it is possible to reliably prevent the occurrence of an illusion phenomenon in the visual sense of the inspector, and it is possible to further improve the accuracy of visual display defect detection.

  In addition, the display defect inspection apparatus for a display panel according to the present invention has an excellent characteristic that it can improve the accuracy of visual detection of display defects. Therefore, the display defect inspection apparatus for a display panel of the present invention is preferably used when the display defect is a bright spot defect or a black spot defect. Moreover, the display defect inspection apparatus for a display panel of the present invention is suitably used when the display panel is a liquid crystal display panel.

  According to the display defect inspection method for a display panel of the present invention, a plurality of display colors are displayed on a display area of a display panel including a display area in which a plurality of pixels including a plurality of types of colored layers are two-dimensionally arranged. A display defect inspection method for a display panel for inspecting for the presence or absence of display defects, characterized in that a plurality of display colors displayed in a display area are displayed based on the order of the brightness of each of the plurality of display colors. To do.

  According to this configuration, it is possible to reduce the luminance difference of the display surface luminance in the display colors before and after being displayed in the display area, and to prevent a sudden change in the display surface luminance when the color display is changed. . Therefore, when the display defect inspection of the display panel is performed visually, it is possible to shorten the time required for light and dark adaptation, and thus it is possible to effectively suppress the occurrence of the illusion phenomenon in the inspector's vision. . As a result, it is possible to improve the detection accuracy of visual display defects.

  In the display defect inspection method for a display panel according to the present invention, a plurality of display colors may be displayed in order of increasing luminance.

  According to this configuration, a plurality of display colors are displayed in order of increasing luminance, and generally, the time required for light adaptation is extremely short compared with the time required for dark adaptation. It is possible to effectively shorten the time required.

  In the display defect inspection method for a display panel of the present invention, a plurality of display colors may be displayed in order of increasing luminance.

  Further, in the display defect inspection method for a display panel of the present invention, the brightness of the light source that irradiates the display panel with the illumination light is changed in accordance with the display color displayed in the display area. It is good also as a structure which adjusts the display surface brightness | luminance in each of the display color displayed.

  According to this configuration, by adjusting the luminance of the light source, it is possible to adjust the display surface luminance in each color display and further reduce the luminance difference between the display colors in the display colors before and after being displayed in the display area. become. Therefore, it is possible to prevent a sudden change in display surface luminance when changing the color display, and therefore it is possible to further reduce the time required for light and dark adaptation when performing visual inspection of display defects on the display panel. . As a result, it is possible to prevent the occurrence of an illusion phenomenon in the inspector's vision, and it is possible to further improve the accuracy of visual detection of display defects.

  In the display defect inspection method for a display panel of the present invention, the luminance of the light source may be changed so that the display surface luminance in each display color displayed in the display area is substantially the same.

  According to this configuration, it is possible to eliminate a luminance difference in display surface luminance between display colors before and after being displayed in the display area. Accordingly, it is possible to reliably prevent a sudden change in display surface luminance when changing the color display, so that the time required for light and dark adaptation is not required when visual inspection of display defects on the display panel is performed. As a result, it is possible to reliably prevent the occurrence of an illusion phenomenon in the visual sense of the inspector, and it is possible to further improve the accuracy of visual display defect detection.

  Further, the display defect inspection method for a display panel of the present invention has an excellent characteristic that it can improve the accuracy of visual detection of display defects. Therefore, the display defect inspection method for a display panel of the present invention is preferably used when the display defect is a bright spot defect or a black spot defect. The display defect inspection method for a display panel according to the present invention is preferably used when the display panel is a liquid crystal display panel.

  ADVANTAGE OF THE INVENTION According to this invention, the detection accuracy of the display defect of a display panel by visual observation can be improved.

It is a conceptual diagram which shows the structure of the defect inspection apparatus for test | inspecting the presence or absence of the display defect of the liquid crystal display panel which concerns on the 1st Embodiment of this invention. It is a top view for demonstrating the structure of the liquid crystal display panel inspected by the display defect inspection apparatus of the liquid crystal display panel which concerns on the 1st Embodiment of this invention. It is sectional drawing for demonstrating the structure of the liquid crystal display panel inspected by the display defect inspection apparatus of the liquid crystal display panel which concerns on the 1st Embodiment of this invention. It is a flowchart for demonstrating the display defect inspection method of the liquid crystal display panel which concerns on the 1st Embodiment of this invention. It is a flowchart for demonstrating the display defect inspection method of the liquid crystal display panel which concerns on the 2nd Embodiment of this invention. It is a flowchart for demonstrating the display defect inspection method of the liquid crystal display panel which concerns on the 3rd Embodiment of this invention. It is a flowchart for demonstrating the display defect inspection method of the liquid crystal display panel which concerns on the 4th Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following embodiment.

(First embodiment)
FIG. 1 is a conceptual diagram showing the configuration of a defect inspection apparatus for inspecting the presence or absence of display defects in a liquid crystal display panel according to the first embodiment of the present invention, and FIG. 2 is a first embodiment of the present invention. It is a top view for demonstrating the structure of the liquid crystal display panel inspected by the display defect inspection apparatus of the liquid crystal display panel which concerns on a form. FIG. 3 is a cross-sectional view for explaining the configuration of the liquid crystal display panel inspected by the display defect inspection apparatus for the liquid crystal display panel according to the first embodiment of the present invention.

  The defect inspection apparatus 1 is an apparatus for inspecting the presence or absence of display defects in individual liquid crystal pixels of the liquid crystal display panel 2, displays a predetermined color on the liquid crystal display panel 2, and visually checks the liquid crystal display panel 2. This is to inspect the presence or absence of display defects such as bright spot defects and black spot defects.

  In addition, the defect inspection apparatus 1 is provided on the inspection table 3 on which the liquid crystal display panel 2 to be inspected is installed, and on the back surface of the inspection table 3, and one surface of the liquid crystal display panel 2 (that is, the back surface 2b). And a backlight 4 which is a light source arranged so as to face the light source. The defect inspection apparatus 1 is connected to the liquid crystal display panel 2, connected to the liquid crystal display panel driving unit 5 for driving the liquid crystal display panel 2, and the backlight 4, and connected to the backlight 4. And a light source driving unit 6 for driving.

  As shown in FIG. 1, the light source driving unit 6 includes a light source luminance adjusting unit 6 a for adjusting the luminance of the backlight 4.

  Further, the liquid crystal display panel 2 to be inspected by the liquid crystal display panel inspection method according to the present embodiment is a first substrate provided on the incident side of the display light by the backlight 4 as shown in FIGS. A TFT substrate 24, a CF substrate 25 that is a second substrate disposed opposite the TFT substrate 24, and a liquid crystal that is a display medium layer sandwiched between the TFT substrate 24 and the CF substrate 25. A layer 26 and a sealing material 27 provided in a frame shape are provided for adhering the TFT substrate 24 and the CF substrate 25 to each other and enclosing the liquid crystal layer 26.

  The sealing material 27 is formed so as to go around the liquid crystal layer 26, and the TFT substrate 24 and the CF substrate 25 are bonded to each other via the sealing material 27. The liquid crystal display panel 2 includes a plurality of photo spacers (not shown) for regulating the thickness of the liquid crystal layer 26 (that is, the cell gap).

  As shown in FIG. 2, the liquid crystal display panel 2 is formed in a rectangular shape, and in the longitudinal direction of the liquid crystal display panel 2, the TFT substrate 24 protrudes from the CF substrate 25 on the upper side, and the protruding region A plurality of display lines such as gate lines and source lines are drawn out to form a terminal region T.

  In the liquid crystal display panel 2, a display area (display surface) D for displaying an image is defined in an area where the TFT substrate 24 and the CF substrate 25 overlap. Here, the display area D is configured by arranging a plurality of pixels, which are the minimum unit of an image, in a matrix.

  Further, as shown in FIG. 2, the sealing material 27 is provided in a rectangular frame shape surrounding the entire periphery of the display area D.

  Further, the CF substrate 25 is provided on the display light emitting side so as to face each other with the TFT substrate 24 and the liquid crystal layer 26 interposed therebetween.

  The TFT substrate 24 includes, for example, a glass substrate (not shown), a thin film transistor (TFT) as a switching element having a gate electrode, a source electrode, and a drain electrode (not shown) formed on the glass substrate, a transparent insulating layer, and a pixel. It consists of an electrode and an alignment film.

  The CF substrate 25 is provided for each pixel, for example, between a black matrix (not shown) provided in a grid shape and a frame shape as a light shielding portion on a glass substrate, and between each grid of the black matrix. A color filter (not shown) including a plurality of types of colored layers (that is, a red layer R, a green layer G, and a blue layer B) is provided. The CF substrate 25 is provided so as to cover the common electrode (not shown) provided so as to cover the black matrix and the color filter, the above-described photo spacer provided in a column shape on the common electrode, and the common electrode. And an alignment film (not shown).

  The black matrix is provided between adjacent colored layers and has a role of partitioning these multiple types of colored layers. This black matrix is made of a metal material such as Ta (tantalum), Cr (chromium), Mo (molybdenum), Ni (nickel), Ti (titanium), Cu (copper), Al (aluminum), or a black pigment such as carbon. It is formed of a dispersed resin material or a resin material in which a plurality of colored layers having light transmittance are laminated.

  The liquid crystal layer 26 is made of, for example, a nematic liquid crystal material having electro-optical characteristics.

  In the liquid crystal display panel 2, in a pixel configured for each pixel electrode, when a gate signal is sent from the gate bus line and the TFT is turned on, a data signal is sent from the source bus line to the source electrode. A predetermined charge is written into the pixel electrode through the drain electrode and the drain electrode, a potential difference is generated between the pixel electrode and the common electrode, and a predetermined voltage is applied to the liquid crystal layer. The liquid crystal display panel 2 adjusts the transmittance of light incident from the backlight 4 by utilizing the change in the alignment state of the liquid crystal molecules according to the magnitude of the applied voltage. The configuration is displayed.

  The liquid crystal display panel 2 is driven by driving the liquid crystal display panel 2 by the liquid crystal display panel driving unit 5 described above.

  As shown in FIG. 1, the defect inspection apparatus 1 includes a CPU 7 as a control unit that controls the liquid crystal display panel driving unit 5 and the light source driving unit 6, and a memory 8 that is a storage unit. The CPU 7 is connected to the liquid crystal display panel driving unit 5 and the light source driving unit 6 and a memory 8. The CPU 7 controls each unit in accordance with a program stored in the memory 8. It has a configuration.

  When the liquid crystal display panel driving unit 5 is driven by the CPU 7, the liquid crystal display panel driving unit 5 is configured to drive the liquid crystal display panel 2 so that display colors are displayed in the display area D. ing. Similarly, when the CPU 7 drives the light source luminance adjustment unit 6 a of the light source driving unit 6, the light source luminance adjustment unit 6 a adjusts the luminance of the backlight 4 that irradiates the liquid crystal display panel 2 with irradiation light. It has a configuration to adjust.

  Next, a display defect inspection method for the liquid crystal display panel according to the present embodiment will be described. The display defect inspection method for a liquid crystal display panel according to the present embodiment is a liquid crystal display panel 2 including a color filter having a display region D in which a plurality of pixels provided with the plurality of types of colored layers are two-dimensionally arranged. In this method, a plurality of display colors are displayed in the display area D to visually inspect the presence or absence of display defects in the pixels.

  And in this embodiment, in order to prevent that an illusion phenomenon arises in the vision of the inspector who performs a visual inspection, there exists the characteristic in the point which suppresses the rapid change of screen brightness by switching of a screen display. More specifically, the present embodiment is characterized in that the liquid crystal display panel driving unit 5 drives the liquid crystal display panel 2 so that a plurality of display colors are displayed in order of increasing luminance.

  FIG. 4 is a flowchart for explaining the display defect inspection method for the liquid crystal display panel according to the first embodiment of the present invention. In the present embodiment, a case where the entire display area D of the liquid crystal display panel 2 (that is, all pixels) is displayed with the same gradation (solid pattern) will be described as an example.

  First, the backlight 4 is driven by the light source driving unit 6 connected to the backlight 4 as the light source, and the liquid crystal display panel 2 is irradiated with the irradiation light from the backlight 4 (step S1).

  Next, the liquid crystal display placed on the inspection table 3 by the liquid crystal display panel driving unit 5 connected to the liquid crystal display panel 2 in a state where the liquid crystal display panel 2 is irradiated with the light emitted from the backlight 4. The panel 2 is driven and black display is performed in the display area D (step S2).

At this time, since the luminance of black display in the standard backlight luminance (light source luminance) is approximately 0 cd / m ² , when the standard backlight luminance (light source luminance) is 1, the display area D (Hereinafter referred to as “display surface luminance”) is approximately 0 cd / m ² .

  Next, in the state where black display is performed in the display area D, the presence or absence of display defects of the liquid crystal display panel 2 is visually inspected (step S3).

  Next, the liquid crystal display panel driving unit connected to the liquid crystal display panel 2 in a state where the light emitted from the backlight 4 is irradiated to the liquid crystal display panel 2 (that is, in a state where the luminance of the backlight 4 is constant). 5, the liquid crystal display panel 2 is driven to perform blue display in the display area D (step S <b> 4).

At this time, since the luminance of the blue display is generally about 10% of the luminance of the white display, for example, when the luminance of the white display in the standard backlight luminance is 300 cd / m ² , the luminance of the blue display is 33 cd / m ² . Accordingly, when the backlight luminance (light emission amount) is 1 (constant), the display surface luminance is 33 × 1 = 33 cd / m ² .

  Next, in the state where blue display is performed in the display area D, the presence or absence of display defects of the liquid crystal display panel 2 is visually inspected (step S5).

At this time, since the display surface luminance during black display before blue display is 0, the change in display surface luminance (that is, the difference in display surface luminance) when changing from black display to blue display is 33-0. = 33 cd / m ² . Accordingly, the change in display surface brightness can be made smaller than, for example, the change in surface brightness when changing from black display to white display (300-0 = 300 cd / m ² ). It is possible to prevent a sudden change in display surface luminance when changing the display. Therefore, the time required for light adaptation can be shortened, so that the occurrence of the illusion phenomenon in the inspector's vision can be effectively suppressed, and as a result, the detection accuracy of visual display defects is improved. It becomes possible to do.

  Next, the liquid crystal display panel driving unit connected to the liquid crystal display panel 2 in a state where the light emitted from the backlight 4 is irradiated to the liquid crystal display panel 2 (that is, in a state where the luminance of the backlight 4 is constant). 5, the liquid crystal display panel 2 is driven to display red in the display area D (step S6).

At this time, since the luminance of the red display is generally about 20% of the luminance of the white display, for example, when the luminance of the white display in the standard backlight luminance is 300 cd / m ² , the luminance of the blue display is 69 cd / m ² . Accordingly, when the backlight luminance (light emission amount) is 1 (constant), the display surface luminance is 69 × 1 = 69 cd / m ² .

  Next, in the state where the red display is performed in the display area D, the liquid crystal display panel 2 is visually inspected for display defects (step S7).

At this time, since the display surface luminance during blue display before red display is 33 cd / m ² , the change in display surface luminance when changing from blue display to red display is 69−33 = 36 cd / m ^2. It becomes. Accordingly, as in the case of the blue display described above, the change in the display surface brightness can be made smaller than, for example, the change in the surface brightness (300 cd / m ² ) when changing from black display to white display. Therefore, it is possible to prevent a sudden change in display surface luminance when changing the color display.

  Next, the liquid crystal display panel driving unit connected to the liquid crystal display panel 2 in a state where the light emitted from the backlight 4 is irradiated to the liquid crystal display panel 2 (that is, in a state where the luminance of the backlight 4 is constant). 5, the liquid crystal display panel 2 is driven to display gray in the display area D (step S8).

At this time, since the luminance of gray display is generally 50% of the luminance of white display, for example, when the luminance of white display at the standard backlight luminance is 300 cd / m ² , the luminance of blue display is 150 cd. / M ² . Accordingly, when the backlight luminance (light emission amount) is 1 (constant), the display surface luminance is 150 × 1 = 150 cd / m ² .

  Next, in the state where gray display is performed in the display area D, the presence or absence of display defects of the liquid crystal display panel 2 is visually inspected (step S9).

At this time, since the display surface luminance at the time of red display before performing gray display is 69 cd / m ² , the change in the display surface luminance when changing from red display to gray display (that is, the difference in display surface luminance) is 150−69 = 81 cd / m ² . Therefore, as in the case of the blue display and the red display described above, the change in the display surface brightness is, for example, compared to the change in the surface brightness (300 cd / m ² ) when changing from the black display to the white display. Since the size can be reduced, it is possible to prevent a sudden change in display surface luminance when changing the color display.

  Next, the liquid crystal display panel 2 is moved by the liquid crystal display panel driving unit 5 in a state where the light emitted from the backlight 4 is irradiated on the liquid crystal display panel 2 (that is, in a state where the luminance of the backlight 4 is constant). By driving, green display is performed in the display area D (step S10).

At this time, since the brightness of the green display is generally about 70% of the brightness of the white display, for example, when the brightness of the white display at the standard backlight brightness is 300 cd / m ² , the brightness of the blue display is 195 cd / m ² . Accordingly, when the backlight luminance (light emission amount) is 1 (constant), the display surface luminance is 195 × 1 = 195 cd / m ² .

  Next, in the state where the green display is performed in the display area D, the liquid crystal display panel 2 is visually inspected for display defects (step S11).

At this time, since the display surface brightness at the time of gray display before the green display is 150 cd / m ² , the change of the display surface brightness when changing from the gray display to the green display is 195−150 = 45 cd / m ^2. It becomes. Therefore, as in the case of the blue display, red display, and gray display described above, the change in display surface brightness is changed to, for example, the change in surface brightness (300 cd / m ² ) when changing from black display to white display. Compared to this, it is possible to reduce the display surface luminance when the color display is changed.

  Next, the liquid crystal display panel 2 is moved by the liquid crystal display panel driving unit 5 in a state where the light emitted from the backlight 4 is irradiated on the liquid crystal display panel 2 (that is, in a state where the luminance of the backlight 4 is constant). Driven to perform white display in the display area D (step S12).

In this case, for example, when the luminance of white display at the standard backlight luminance is 300 cd / m ² and the luminance (light emission amount) of the backlight is 1 (constant), the display surface luminance is 300 × 1 = 300 cd / m ² .

  Next, in the state where the white display is performed in the display area D, the liquid crystal display panel 2 is visually inspected for display defects (step S13).

At this time, since the display surface brightness during the green display before the white display is 195 cd / m ² , the change in the display surface brightness when changing from the green display to the white display is 300−195 = 105 cd / m ^2. It becomes. Accordingly, as in the case of the above-described blue display, red display, gray display, and green display, for example, a change in surface brightness (300 cd / m) when the display surface brightness change is changed from black display to white display, for example. ^As compared with ² ), it is possible to make it smaller, so that it is possible to prevent an abrupt change in display surface luminance when the color display is changed.

  As described above, in the present embodiment, a plurality of display colors (black, blue, red, gray, green, and white in the present embodiment) displayed in the display area D are displayed for each of the plurality of display colors. By displaying in order of decreasing luminance (ie, black → blue → red → gray → green → white), the display surface luminance difference in the display colors before and after being displayed in the display area D is reduced, and color display is performed. It is configured to prevent a sudden change in display surface luminance when changing.

  According to the present embodiment described above, the following effects can be obtained.

  (1) In the present embodiment, the defect inspection apparatus 1 includes a liquid crystal display panel drive unit 5 that drives the liquid crystal display panel 2 so that a predetermined display color is displayed in the display area D. And the liquid crystal display panel drive part 5 is set as the structure which drives the liquid crystal display panel 2 so that the several display color displayed on the display area D is displayed in order with the low brightness | luminance of each of several display colors. Therefore, it is possible to reduce the luminance difference of the display surface luminance in the display colors before and after being displayed in the display area D, and to prevent a sudden change in the display surface luminance when the color display is changed. Therefore, when visual inspection of the display defect of the liquid crystal display panel 2 is performed, it is possible to reduce the time required for light and dark adaptation, and thus it is possible to effectively suppress the occurrence of an illusion phenomenon in the visual perception of the inspector. become. As a result, it is possible to improve the detection accuracy of visual display defects.

  (2) In addition, a plurality of display colors are displayed in ascending order of luminance, and generally, the time required for light adaptation is extremely short compared with the time required for dark adaptation, so that it can be used for display defect inspection of liquid crystal display panels. It is possible to effectively shorten the time required.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. Further, since the configuration of the defect inspection apparatus and the configuration of the liquid crystal display panel are the same as those in the first embodiment, detailed description thereof is omitted here.

  In the first embodiment, the color display is performed in a state where the luminance of the backlight 4 as the light source is constant. However, in the present embodiment, the display color corresponding to the display color displayed in the display area D is used. Thus, the display surface brightness is adjusted by changing the brightness of the backlight 4.

  More specifically, in the present embodiment, the liquid crystal display panel driving unit 5 drives the liquid crystal display panel 2 so that a plurality of display colors are displayed in order of decreasing luminance, and the light source luminance adjusting unit 6a includes: There is a feature in that the brightness of the backlight 4 is changed in order to adjust the display surface brightness in each of the display colors displayed in the display area D.

  FIG. 5 is a flowchart for explaining a display defect inspection method for a liquid crystal display panel according to the second embodiment of the present invention.

  First, the light source driving unit 6 connected to the backlight 4 as the light source drives the backlight 4 to irradiate the liquid crystal display panel 2 with the light emitted from the backlight 4 (step S21).

  Next, the liquid crystal display panel drive unit 5 drives the liquid crystal display panel 2 while irradiating the liquid crystal display panel 2 with the irradiation light from the backlight 4, and performs black display in the display region D (step S22). ).

  Here, in order to improve the detection accuracy of the bright spot defect by visual observation in the black display, the light source luminance adjusting unit 6a of the light source driving unit 6 adjusts so that the luminance of the backlight 4 is maximized in the step S21. . That is, for example, when the setting range of the luminance of the backlight 4 is 0 to 2, the light source luminance adjusting unit 6a sets the luminescent spot of the backlight 4 to be 2, which is the maximum value of the setting range.

At this time, since the luminance of black display in the standard backlight luminance is approximately 0 cd / m ₂ , even when the backlight luminance (light source luminance) is 2, the display surface luminance is 0 cd / m. the m ^2.

  Then, in the state where the black display is performed in the display area D, the presence or absence of display defects of the liquid crystal display panel 2 is visually inspected (step S23).

  Next, the luminance of the backlight 4 is adjusted by the light source luminance adjusting unit 6a (step S24).

  Next, the liquid crystal display panel 2 is driven by the liquid crystal display panel driving unit 5 in a state where the liquid crystal display panel 2 is irradiated with the irradiation light from the backlight 4 whose luminance is adjusted, and blue display is performed in the display region D. Is performed (step S25).

  Here, since the bright spot is more noticeable in the blue display than in the black display, in order to improve the detection accuracy of the bright spot defect visually in the blue display, the light source brightness adjusting unit 6a has a lower display surface brightness in step S24. The brightness of the backlight 4 is adjusted so that the display surface brightness is optimal for detecting the bright spot defect.

  That is, for example, when the luminance setting range of the backlight 4 is 0 to 2, the light source driving unit 6 sets the bright spot of the backlight 4 to 1 which is an intermediate value of the setting range.

At this time, as in the case of the first embodiment, the luminance of blue display at the standard backlight luminance is set to 33 cd / m ² . Since the luminance of the backlight is 1, the display surface luminance is 33 × 1 = 33 cd / m ² .

  Then, in the state where blue display is performed in the display area D, the presence or absence of display defects of the liquid crystal display panel 2 is visually inspected (step S26).

At this time, since the display surface luminance during black display before blue display is approximately 0 cd / m ² , the change in display surface luminance when changing from black display to blue display (that is, the difference in display surface luminance) ) Is 33−0 = 33 cd / m ² . Accordingly, as in the case of the first embodiment described above, the change in display surface luminance is changed to, for example, a change in surface luminance (300-0 = 300 cd / m ² ) when changing from black display to white display. Compared to this, it is possible to reduce the display surface luminance when the color display is changed.

  Next, the luminance of the backlight 4 is adjusted by the light source luminance adjusting unit 6a (step S27).

  Next, the liquid crystal display panel drive unit 5 drives the liquid crystal display panel 2 in a state where the liquid crystal display panel 2 is irradiated with the irradiation light from the backlight 4 whose luminance is adjusted, and the display area D is displayed in red. Is performed (step S28).

Here, since the black spot defect is more conspicuous than the bright spot defect in the red display, the light source luminance adjustment unit 6a detects the black spot defect in step S27 in order to improve the black spot defect detection accuracy in the red display. The luminance of the backlight 4 is adjusted so that the optimal display surface luminance is obtained. For example, as in the case of the first embodiment, when the luminance of the red display at the standard backlight luminance is 69 cd / m ² , the light source driving unit 6 detects the black spot defect with the luminance of the display surface. The luminance of the backlight 4 is set to 1.45 so that the optimum luminance (about 100 cd / m ² ) is obtained.

That is, in this case, since the luminance of red display at the standard backlight luminance is 69 cd / m ² and the luminance of the backlight is 1.45, the display surface luminance is 69 × 1.45 = 100 cd. / M ² .

  Then, with the red display in the display area D, the presence or absence of display defects in the liquid crystal display panel 2 is visually inspected (step S29).

At this time, since the display surface brightness at the time of blue display before performing red display is 33, the change of the display surface brightness when changing from blue display to red display is 100−33 = 67 cd / m ² . Accordingly, the change in display surface brightness can be made smaller than, for example, the change in surface brightness when changing from black display to white display (300-0 = 300 cd / m ² ). It is possible to prevent a sudden change in display surface luminance when changing the display.

  Next, the luminance of the backlight 4 is adjusted by the light source luminance adjusting unit 6a (step S30).

  Next, the liquid crystal display panel 2 is driven by the liquid crystal display panel driving unit 5 in a state where the liquid crystal display panel 2 is irradiated with the irradiation light from the backlight 4 whose luminance is adjusted. Is performed (step S31).

Here, in the gray display, the black spot defect is more conspicuous than the bright spot defect in the same manner as the red display described above. The unit 6a adjusts the luminance of the backlight 4 so as to obtain the optimal display surface luminance for detecting black spot defects. For example, as in the case of the first embodiment, when the gray display luminance at the standard backlight luminance is set to 150 cd / m ² , the light source driving unit 6 detects the black spot defect with the display surface luminance. The brightness of the backlight 4 is set to 0.67 so that the optimum brightness (about 100 cd / m ² ) is obtained.

That is, in this case, gray display luminance is a 150 cd / ^{m 2,} because the brightness of the backlight is 0.67, the display surface luminance becomes ^{150 × 0.67 = 100cd / m 2} .

  Then, in the state where gray display is performed in the display area D, the presence or absence of display defects of the liquid crystal display panel 2 is visually inspected (step S32).

At this time, since the display surface brightness at the time of red display before performing gray display is 100 cd / m ² , the change of the display surface brightness when changing from red display to gray display is 100−100 = 0 cd / m ² . Become. That is, in the present embodiment, the light source luminance adjusting unit 6a is configured so that the display surface luminance in each of the display colors displayed in the display area D (in this case, gray and red) is substantially the same. Change the brightness.

  With such a configuration, it is possible to prevent a change in display surface luminance from occurring, and thus it is possible to reliably prevent a sudden change in display surface luminance from occurring when the color display is changed. Therefore, the time required for light adaptation is eliminated, so that it is possible to reliably prevent the occurrence of an illusion phenomenon in the inspector's vision, and as a result, it is possible to dramatically improve the accuracy of visual display defect detection. become.

  Next, the luminance of the backlight 4 is adjusted by the light source luminance adjusting unit 6a (step S33).

  Next, the liquid crystal display panel 2 is driven by the liquid crystal display panel driving unit 5 in a state where the liquid crystal display panel 2 is irradiated with the irradiation light from the backlight 4 whose luminance is adjusted, and the display area D is displayed in green. Is performed (step S34).

Here, in the green display, the black spot defect is more conspicuous than the bright spot defect in the same manner as the red display and the gray display described above. Therefore, in order to improve the black spot defect detection accuracy in the green display in the step S33. The light source luminance adjusting unit 6a adjusts the luminance of the backlight 4 so as to obtain the optimal display surface luminance for detecting the black spot defect. For example, as in the case of the first embodiment, when the luminance of green display at the standard backlight luminance is set to 195 cd / m ² , the light source driving unit 6 detects the black spot defect with the display surface luminance. The brightness of the backlight 4 is set to 0.51 so that the optimum brightness (about 100 cd / m ² ) is obtained.

That is, in this case, green display luminance a 195cd / ^{m 2,} because the brightness of the backlight is 0.51, the display surface luminance becomes ^{195 × 0.51 = 100cd / m 2} .

  Then, with the green display in the display area D, the presence or absence of display defects in the liquid crystal display panel 2 is visually inspected (step S35).

At this time, since the display surface brightness in the gray display before the green display is 100 cd / m ² , the change in the display surface brightness when changing from the gray display to the green display is 100−100 = 0 cd / m ² . Become. That is, the light source luminance adjusting unit 6a changes the luminance of the backlight 4 so that the display surface luminances in the display colors displayed in the display area D (in this case, green and gray) are substantially the same. Therefore, since it is possible to prevent the change in display surface luminance, it is possible to reliably prevent the occurrence of a sudden change in display surface luminance when the color display is changed.

  Next, the luminance of the backlight 4 is adjusted by the light source luminance adjusting unit 6a (step S36).

  Next, the liquid crystal display panel drive unit 5 drives the liquid crystal display panel 2 in a state in which the liquid crystal display panel 2 is irradiated with the irradiation light from the backlight 4 whose luminance is adjusted, and white display is performed in the display region D. Is performed (step S37).

Here, in the white display as well as the above-described red display, gray display, and green display, since the black spot defect is more conspicuous than the bright spot defect, in order to improve the detection accuracy of the black spot defect visually in the white display, In step S <b> 36, the light source luminance adjusting unit 6 a adjusts the luminance of the backlight 4 so as to obtain the optimal display surface luminance for detecting the black spot defect. For example, as in the case of the first embodiment, when the luminance of white display at the standard backlight luminance is set to 300 cd / m ² , the light source driving unit 6 detects the black spot defect with the luminance of the display surface. The brightness of the backlight 4 is set to 0.33 so that the optimum brightness (about 100 cd / m ² ) is obtained.

That is, in this case, since the luminance of white display is 300 cd / m ² and the luminance of the backlight is 0.33, the display surface luminance is 300 × 0.33 = 100 cd / m ² .

  Then, in the state where the white display is performed in the display area D, the presence or absence of display defects of the liquid crystal display panel 2 is visually inspected (step S38).

At this time, since the display surface luminance during green display before white display is 100 cd / m ² , the change in display surface luminance when changing from green display to white display is 100−100 = 0 cd / m ² . Become. That is, the light source luminance adjusting unit 6a changes the luminance of the backlight 4 so that the display surface luminances in the display colors displayed in the display area D (in this case, white and green) are substantially the same. Therefore, since it is possible to prevent the change in display surface luminance, it is possible to reliably prevent the occurrence of a sudden change in display surface luminance when the color display is changed.

  Thus, in the present embodiment, as in the case of the first embodiment described above, a plurality of display colors displayed in the display area D (in this embodiment, black, blue, red, gray, green , And white) in the order of luminance of each of a plurality of display colors (that is, black → blue → red → gray → green → white) and adjusting the luminance of the backlight 4 to display in each color display A configuration that adjusts the surface brightness, further reduces the brightness difference of the display surface brightness in the display colors before and after being displayed in the display area D, and prevents a sudden change in the display surface brightness when the color display is changed. It is said.

  According to the present embodiment described above, the following effects can be obtained in addition to the effects (1) to (2) described above.

  (3) In the present embodiment, the defect inspection apparatus 1 includes a light source luminance adjusting unit 6a for adjusting the luminance of the backlight 4, which is a light source that irradiates the liquid crystal display panel 2 with irradiation light. . The light source luminance adjusting unit 6a is configured to change the luminance of the backlight 4 in order to adjust the display surface luminance in each display color displayed in the display area D. Therefore, by adjusting the luminance of the backlight 4, it is possible to adjust the display surface luminance in each color display and further reduce the luminance difference of the display surface luminance in the display colors before and after being displayed in the display area D. Become. Accordingly, it is possible to prevent a sudden change in display surface luminance when changing the color display, and therefore it is possible to further reduce the time required for the light and dark adaptation when the display defect inspection of the liquid crystal display panel 2 is visually performed. become. As a result, it is possible to prevent the occurrence of an illusion phenomenon in the inspector's vision, and it is possible to further improve the accuracy of visual detection of display defects.

  (4) In the present embodiment, the light source luminance adjustment unit 6a is configured to change the luminance of the backlight 4 so that the display surface luminance in each display color displayed in the display area D is substantially the same. . Accordingly, it is possible to eliminate the luminance difference in display surface luminance between the display colors before and after being displayed in the display area D. Accordingly, it is possible to reliably prevent a sudden change in display surface luminance when changing the color display, and therefore, when the display defect inspection of the liquid crystal display panel 2 is visually performed, the time required for the light and dark adaptation becomes unnecessary. As a result, it is possible to reliably prevent the occurrence of an illusion phenomenon in the visual sense of the inspector, and it is possible to further improve the accuracy of visual display defect detection.

(Third embodiment)
Next, a third embodiment of the present invention will be described. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. Further, since the configuration of the defect inspection apparatus and the configuration of the liquid crystal display panel are the same as those in the first embodiment, detailed description thereof is omitted here.

  FIG. 6 is a flowchart for explaining a display defect inspection method for a liquid crystal display panel according to the third embodiment of the present invention.

  As shown in FIG. 6, in this embodiment, instead of step S24 (setting the backlight luminance to 1) in the second embodiment described above, the light source luminance adjusting unit 6a provided in the light source driving unit 6 is used. Thus, the brightness of the backlight 4 is set to be 2 which is the maximum value of the setting range (step S24a).

In this case, as in the case of the first embodiment, when the luminance of blue display at the standard backlight luminance is 33 cd / m ² , the luminance of the backlight 4 is 2, and thus the display surface luminance. Is 33 × 2 = 66 cd / m ² .

This, compared to the case of Example 2, to reduce the luminance difference between a gray display state of the display surface luminance (100 cd / ^{m 2)} and the blue display time of the display surface luminance (66 cd / ^{m 2),} the blue display This is to improve the detection accuracy of bright spot defects and black spot defects visually. In other words, in the present embodiment, the luminance of the backlight 4 is adjusted so that the display surface luminance is optimal for detecting bright spot defects and black spot defects in blue display.

  Other steps are the same as in the case of the second embodiment described above, and detailed description thereof is omitted here.

  Also in the present embodiment described above, the same effects as the effects (1) to (4) described above can be obtained.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. Further, since the configuration of the defect inspection apparatus and the configuration of the liquid crystal display panel are the same as those in the first embodiment, detailed description thereof is omitted here.

  In the first and second embodiments, a plurality of display colors (black, blue, red, gray, green, and white in this embodiment) displayed in the display area D are displayed in a plurality of display colors. Each of the luminances is displayed in order of decreasing brightness (that is, black → blue → red → gray → green → white). On the other hand, in the present embodiment, a plurality of display colors are not displayed in the order of low luminance (that is, a plurality of display colors are displayed in order at random), and only the luminance of the backlight 4 is adjusted. It is characterized in that the display surface brightness is adjusted to reduce the difference in display surface brightness between the display colors before and after the display area D is displayed.

  FIG. 7 is a flowchart for explaining a display defect inspection method for a liquid crystal display panel according to the fourth embodiment of the present invention.

  First, the same processing as Steps S21 to S23 described in the second embodiment described above is performed, and the presence or absence of a display defect in the liquid crystal display panel 2 is visually observed in a state where black display is performed in the display region D. I do.

  Next, the same processing as in Steps S24a to S26 described in the third embodiment is performed, and in the state where blue display is performed in the display region D, the presence or absence of display defects in the liquid crystal display panel 2 is visually checked. I do.

  Next, the luminance of the backlight 4 is adjusted by the light source luminance adjusting unit 6a (step S27a).

  Next, the liquid crystal display panel 2 is driven by the liquid crystal display panel driving unit 5 in a state where the liquid crystal display panel 2 is irradiated with the irradiation light from the backlight 4 whose luminance is adjusted, and the display area D is displayed in green. (Step S28a).

Here, as in step S33 of the second embodiment described above, in order to improve the accuracy of visual detection of black spot defects in green display, the light source luminance adjustment unit 6a is optimal for detecting black spot defects in step S27a. The brightness of the backlight 4 is adjusted so that the display surface brightness is as good as possible. For example, when the green display brightness in the standard backlight brightness is set to 195 cd / m ² , the light source drive unit 6 has the display surface brightness that is optimal for detecting black spot defects (about 100 cd / m ² ). Thus, the brightness of the backlight 4 is set to 0.51.

  Then, with the green display in the display area D, the presence or absence of display defects in the liquid crystal display panel 2 is visually inspected (step S29a).

At this time, since the display surface brightness at the time of blue display before performing the green display is 66 cd / m ² , the change of the display surface brightness when changing from the blue display to the green display is 100−66 = 34 cd / m ² . Become. Therefore, since it is possible to prevent the change in display surface luminance, it is possible to reliably prevent the occurrence of a sudden change in display surface luminance when the color display is changed.

  Next, the luminance of the backlight 4 is adjusted by the light source luminance adjusting unit 6a (step S30a).

  Next, the liquid crystal display panel drive unit 5 drives the liquid crystal display panel 2 in a state where the liquid crystal display panel 2 is irradiated with the irradiation light from the backlight 4 whose luminance is adjusted, and the display area D is displayed in red. (Step S31a).

Here, similarly to step S27 of the second embodiment described above, in order to improve the accuracy of visual detection of black spot defects in red display, in step S30a, the light source luminance adjustment unit 6a is optimal for detecting black spot defects. The brightness of the backlight 4 is adjusted so that the display surface brightness is as good as possible. For example, when the red display luminance in the standard backlight luminance is 69 cd / m ² , the light source driving unit 6 has the display surface luminance that is optimum for detecting black spot defects (about 100 cd / m ² ). Thus, the brightness of the backlight 4 is set to 1.45.

  Then, in the state where the red display is performed in the display area D, the presence or absence of display defects of the liquid crystal display panel 2 is visually inspected (step S32a).

At this time, since the display surface brightness at the time of the green display before the red display is 100 cd / m ² , the change in the display surface brightness when changing from the green display to the red display is 100−100 = 0 cd / m ² . Become. That is, as in the case of the second embodiment described above, the light source luminance adjustment unit 6a has substantially the same display surface luminance in each of the display colors displayed in the display area D (in this case, red and green). Thus, the luminance of the backlight 4 is changed. Therefore, since it is possible to prevent the change in display surface luminance, it is possible to reliably prevent the occurrence of a sudden change in display surface luminance when the color display is changed.

  Next, the luminance of the backlight 4 is adjusted by the light source luminance adjusting unit 6a (step S33a).

  Next, the liquid crystal display panel drive unit 5 drives the liquid crystal display panel 2 in a state in which the liquid crystal display panel 2 is irradiated with the irradiation light from the backlight 4 whose luminance is adjusted, and white display is performed in the display region D. Is performed (step S34a).

Here, as in step S36 of the second embodiment described above, in order to improve the accuracy of visual detection of black spot defects in white display, in step S33a, the light source luminance adjustment unit 6a is optimal for detecting black spot defects. The brightness of the backlight 4 is adjusted so that the display surface brightness is as good as possible. For example, when the luminance of white display at the standard backlight luminance is 300 cd / m ² , the light source drive unit 6 has a display surface luminance that is optimum for detecting black spot defects (about 100 cd / m ² ). Thus, the bright spot of the backlight 4 is set to 0.33.

  Then, in a state where white display is performed in the display area D, the presence or absence of display defects of the liquid crystal display panel 2 is visually inspected (step S35a).

At this time, since the display surface brightness at the time of red display before the white display is 100 cd / m ² , the change of the display surface brightness when changing from the red display to the white display is 100−100 = 0 cd / m ² . Become. That is, as in the case of the second embodiment described above, the light source luminance adjustment unit 6a has substantially the same display surface luminance in each of the display colors displayed in the display area D (in this case, white and red). Thus, the luminance of the backlight 4 is changed. Therefore, since it is possible to prevent the change in display surface luminance, it is possible to reliably prevent the occurrence of a sudden change in display surface luminance when the color display is changed.

  Next, the luminance of the backlight 4 is adjusted by the light source luminance adjusting unit 6a (step S36a).

  Next, the liquid crystal display panel 2 is driven by the liquid crystal display panel driving unit 5 in a state where the liquid crystal display panel 2 is irradiated with the irradiation light from the backlight 4 whose luminance is adjusted. Is performed (step S37a).

Here, similarly to step S30 of the second embodiment described above, in order to improve the accuracy of visual detection of black spot defects in gray display, in step S36a, the light source luminance adjustment unit 6a is optimal for detecting black spot defects. The brightness of the backlight 4 is adjusted so that the display surface brightness is as good as possible. For example, when the gray display luminance in the standard backlight luminance is 150 cd / m ² , the light source driving unit 6 has the display surface luminance that is optimum for detecting black spot defects (about 100 cd / m ² ). Thus, the brightness of the backlight 4 is set to 0.67.

  Then, in a state where gray display is performed in the display region D, the presence or absence of display defects of the liquid crystal display panel 2 is visually inspected (step S38a).

At this time, since the display surface luminance at the time of white display before gray display is 100 cd / m ² , the change in the display surface luminance when changing from white display to gray display is 100−100 = 0 cd / m ² . Become. That is, as in the case of the second embodiment described above, the light source luminance adjustment unit 6a has substantially the same display surface luminance in each of the display colors (in this case, gray and white) displayed in the display area D. Thus, the luminance of the backlight 4 is changed. Therefore, since it is possible to prevent the change in display surface luminance, it is possible to reliably prevent the occurrence of a sudden change in display surface luminance when the color display is changed.

  As described above, in the present embodiment, unlike the first and second embodiments described above, a plurality of display colors displayed in the display area D are arranged in the order of decreasing luminance of each of the plurality of display colors ( That is, even when not displaying in black → blue → red → gray → green → white), the display surface brightness in each color display is adjusted by adjusting the brightness of the backlight 4 and displayed in the display area D. The display surface luminance difference between the display colors before and after the display is reduced to prevent a sudden change in the display surface luminance when the color display is changed.

  According to the present embodiment described above, the same effects as the effects (3) to (4) described above can be obtained.

  In addition, you may change the said embodiment as follows.

  In the first embodiment, each of the plurality of display colors is displayed in the order of low luminance (that is, black → blue → red → gray → green → white). (White → green → gray → red → blue → black). That is, the liquid crystal display panel drive unit 5 may drive the liquid crystal display panel 2 so that a plurality of display colors are displayed in order of increasing luminance.

  In this case, for example, in a state where the luminance (light emission amount) of the backlight is set to 1 (constant), a plurality of display colors displayed in the display area D are reversed from the case of the first embodiment described above. By displaying each of the plurality of display colors in descending order, the difference in display surface brightness between the display colors before and after being displayed in the display area D is reduced. In this case, the same effect as the effect (1) described above can be obtained.

  In the second embodiment, the plurality of display colors displayed in the display area D are in the order of decreasing luminance of the plurality of display colors (that is, black → blue → red → gray → green → white). The display surface brightness in each color display is adjusted by adjusting the brightness of the backlight 4, but the brightness is displayed in order of increasing brightness (ie, white → green → grey → red → blue → black). It is also good. In other words, the liquid crystal display panel driving unit 5 drives the liquid crystal display panel 2 so that a plurality of display colors are displayed in order of increasing luminance, and the light source luminance adjusting unit 6a controls the display colors displayed in the display area D. In order to adjust the display surface brightness in each, the brightness of the backlight 4 may be changed.

  In this case, contrary to the case of the second embodiment described above, the plurality of display colors displayed in the display area D are displayed in order from the higher luminance of each of the plurality of display colors, and the backlight. By changing the brightness of 4, the display surface brightness in each color display is adjusted, and the brightness difference of the display surface brightness in the display colors before and after being displayed in the display area D is reduced. In this case, the same effect as the effect (3) described above can be obtained.

  Further, in this case, as in the case of the second embodiment described above, the light source luminance adjustment unit 6a is configured so that the display surface luminances in the display colors displayed in the display area D are substantially the same. 4 may be changed. In this case, the same effect as the effect (4) described above can be obtained.

  In the above embodiment, a liquid crystal display panel has been described as an example of a display panel. However, the present invention can be applied to other display panels such as an electroluminescence display panel, a plasma display panel, and a field emission display panel. Can be applied.

  Further, in the above embodiment, black, blue, red, gray, green, and white have been described as examples of the plurality of display colors displayed in the display area D. However, the display defect inspection of the liquid crystal display panel 2 is performed. When performing the above, the plurality of display colors displayed in the display area D are not limited to these colors, and may be other colors (for example, cyan, magenta, yellow).

  Examples of utilization of the present invention include a display defect inspection apparatus and a display defect inspection method for inspecting the presence or absence of display defects such as bright spot defects of a display panel such as a liquid crystal display panel.

DESCRIPTION OF SYMBOLS 1 Defect inspection apparatus 2 Liquid crystal display panel 3 Inspection table 4 Backlight (light source)
5 Liquid crystal display panel drive unit 6 Light source drive unit 6a Light source brightness adjustment unit 7 CPU
8 memory

  The present invention relates to a display defect inspection apparatus and a display defect inspection method for inspecting the presence or absence of a display defect such as a bright spot defect of a display panel such as a liquid crystal display panel.

  In recent years, there has been a strong demand for liquid crystal display panels capable of displaying higher-quality images. However, it is difficult to prevent the occurrence of display defects with the current liquid crystal display panel manufacturing technology. For this reason, in order to provide a high-quality liquid crystal display panel with reduced display defects, a display defect inspection (image quality inspection) process is performed in the manufacturing process.

  In addition, bright spots (abnormal lighting due to leaks between picture elements, which appear brighter than the display screen) defects, black spots (abnormal lighting due to non-lighting etc., from the display screen) In general, the inspection process for the presence or absence of display defects on the display panel, such as defects that appear dark, defects, defects (such as scratches and alignment unevenness), and unevenness, is generally performed by the inspector's eyes.

  The visual inspection process by the inspector is performed using a limit sample which is a sample of the lowest quality that can be handled as a non-defective product. For example, in the inspection of bright spot defects, pass / fail (presence / absence of bright spot defects) is determined by an inspector comparing a liquid crystal display panel and a limit sample.

  In addition, for example, a method has been proposed in which a predetermined pattern is displayed on a liquid crystal display panel and visually inspected. More specifically, a method is disclosed in which two types of checkered patterns having different patterns are alternately displayed on a liquid crystal display panel, and the displayed checkered pattern is visually inspected (see, for example, Patent Document 1).

JP-A-8-241046

  Here, in the conventional visual inspection described above, a sudden change in screen brightness caused by switching the screen display causes an illusion phenomenon in the inspector's vision, which makes it difficult to visually recognize display defects. It was.

  Factors that cause such problems include the time required for light adaptation and dark adaptation of the human eye. That is, for example, when the display on the liquid crystal display panel is switched from white display with high luminance to black display with low luminance, the time required for dark adaptation becomes longer due to a sudden change in screen luminance. Therefore, for a few seconds immediately after switching from white display to black display, a state in which display defects existing on the black display screen cannot be recognized at all continues. Similarly, when the display on the liquid crystal display panel is switched from a black display with a low luminance to a green display with a high luminance, the time required for light adaptation becomes longer due to a sudden change in screen luminance. Therefore, for a few seconds immediately after switching from black display to green display, a state in which display defects existing on the green display screen cannot be recognized at all continues.

  As a result, when the display defect inspection of the display panel is performed visually, there has been a problem that the inspector misses the display defect. In particular, there is a problem that point defects such as a bright spot defect, a black spot defect, and a defect defect that are difficult to visually recognize occur.

  Therefore, the present invention has been made in view of the above-described problems, and can improve the accuracy of detection of display defects on a display panel when visual inspection of display defects of a display panel such as a liquid crystal display panel is performed. An object of the present invention is to provide a display defect inspection apparatus and a display defect inspection method for a display panel.

In order to achieve the above object, a display defect inspection apparatus for a display panel according to the present invention provides a plurality of displays in a display area of a display panel including a display area in which a plurality of pixels each having a plurality of types of colored layers are two-dimensionally arranged. A display defect inspection apparatus for a display panel that inspects the presence or absence of display defects in pixels by displaying colors, and a display panel driving unit that drives the display panel so that display colors are displayed in the display area ; A light source luminance adjustment unit for adjusting the luminance of the light source that emits irradiation light to the display panel , the light source luminance adjustment unit adjusts the luminance of the light source to be constant, and the display panel driving unit The display panel is driven so that a plurality of display colors displayed in the display area are displayed based on the order of the brightness of each of the plurality of display colors.

According to the same configuration, the brightness of the display surface is sharply changed when the color display is changed by reducing the brightness difference of the display surface brightness in the display colors before and after being displayed in the display area without adjusting the brightness by the light source. Can be prevented from occurring. Therefore, when the display defect inspection of the display panel is performed visually, it is possible to shorten the time required for light and dark adaptation, and thus it is possible to effectively suppress the occurrence of the illusion phenomenon in the inspector's vision. . As a result, it is possible to improve the accuracy of visual display defect detection without adjusting the luminance with the light source .

  In the display defect inspection apparatus for a display panel according to the present invention, the display panel drive unit may be configured to drive the display panel so that a plurality of display colors are displayed in order of decreasing luminance.

  According to this configuration, a plurality of display colors are displayed in order from the lowest brightness, and the time required for light adaptation is much shorter than the time required for dark adaptation, so the time required for display defect inspection of the display panel Can be effectively shortened.

In the display defect inspection device for a display panel of the present invention, the display panel drive unit, yet good a configuration in which a plurality of display colors to drive the display panel to be displayed in order of brightness.

Also, the display defect inspection device for a display panel of the present invention, has excellent characteristics that it is possible to improve the detection accuracy of the display defect visually. Therefore, the display defect inspection apparatus for a display panel of the present invention is preferably used when the display defect is a bright spot defect or a black spot defect. Moreover, the display defect inspection apparatus for a display panel of the present invention is suitably used when the display panel is a liquid crystal display panel.

According to the display defect inspection method for a display panel of the present invention, a plurality of display colors are displayed on a display area of a display panel including a display area in which a plurality of pixels including a plurality of types of colored layers are two-dimensionally arranged. A display defect inspection method for a display panel for inspecting for the presence or absence of display defects , with a plurality of display colors displayed in a display area in a state where the luminance of a light source that irradiates irradiation light to the display panel is constant . The display is based on the order of the brightness of each of the plurality of display colors.

According to the same configuration, the brightness of the display surface is sharply changed when the color display is changed by reducing the brightness difference of the display surface brightness in the display colors before and after being displayed in the display area without adjusting the brightness by the light source. Can be prevented from occurring. Therefore, when the display defect inspection of the display panel is performed visually, it is possible to shorten the time required for light and dark adaptation, and thus it is possible to effectively suppress the occurrence of the illusion phenomenon in the inspector's vision. . As a result, it is possible to improve the accuracy of visual display defect detection without adjusting the luminance with the light source .

  In the display defect inspection method for a display panel according to the present invention, a plurality of display colors may be displayed in order of increasing luminance.

  According to this configuration, a plurality of display colors are displayed in order of increasing luminance, and generally, the time required for light adaptation is extremely short compared with the time required for dark adaptation. It is possible to effectively shorten the time required.

Further, in the display defect inspection method for a display panel of the present invention, yet good as configured to display a plurality of display colors in descending order of luminance.

Also, the display defect inspection method for a display panel of the present invention is provided with excellent characteristics that it is possible to improve the detection accuracy of the display defect visually. Therefore, the display defect inspection method for a display panel of the present invention is preferably used when the display defect is a bright spot defect or a black spot defect. The display defect inspection method for a display panel according to the present invention is preferably used when the display panel is a liquid crystal display panel.

  ADVANTAGE OF THE INVENTION According to this invention, the detection accuracy of the display defect of a display panel by visual observation can be improved.

It is a conceptual diagram which shows the structure of the defect inspection apparatus for test | inspecting the presence or absence of the display defect of the liquid crystal display panel which concerns on the 1st Embodiment of this invention. It is a top view for demonstrating the structure of the liquid crystal display panel inspected by the display defect inspection apparatus of the liquid crystal display panel which concerns on the 1st Embodiment of this invention. It is sectional drawing for demonstrating the structure of the liquid crystal display panel inspected by the display defect inspection apparatus of the liquid crystal display panel which concerns on the 1st Embodiment of this invention. It is a flowchart for demonstrating the display defect inspection method of the liquid crystal display panel which concerns on the 1st Embodiment of this invention. It is a flowchart for demonstrating the display defect inspection method of the liquid crystal display panel which concerns on the 2nd Embodiment of this invention. It is a flowchart for demonstrating the display defect inspection method of the liquid crystal display panel which concerns on the 3rd Embodiment of this invention. It is a flowchart for demonstrating the display defect inspection method of the liquid crystal display panel which concerns on the 4th Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following embodiment.

(First embodiment)
FIG. 1 is a conceptual diagram showing the configuration of a defect inspection apparatus for inspecting the presence or absence of display defects in a liquid crystal display panel according to the first embodiment of the present invention, and FIG. 2 is a first embodiment of the present invention. It is a top view for demonstrating the structure of the liquid crystal display panel inspected by the display defect inspection apparatus of the liquid crystal display panel which concerns on a form. FIG. 3 is a cross-sectional view for explaining the configuration of the liquid crystal display panel inspected by the display defect inspection apparatus for the liquid crystal display panel according to the first embodiment of the present invention.

  The defect inspection apparatus 1 is an apparatus for inspecting the presence or absence of display defects in individual liquid crystal pixels of the liquid crystal display panel 2, displays a predetermined color on the liquid crystal display panel 2, and visually checks the liquid crystal display panel 2. This is to inspect the presence or absence of display defects such as bright spot defects and black spot defects.

  In addition, the defect inspection apparatus 1 is provided on the inspection table 3 on which the liquid crystal display panel 2 to be inspected is installed, and on the back surface of the inspection table 3, and one surface of the liquid crystal display panel 2 (that is, the back surface 2b). And a backlight 4 which is a light source arranged so as to face the light source. The defect inspection apparatus 1 is connected to the liquid crystal display panel 2, connected to the liquid crystal display panel driving unit 5 for driving the liquid crystal display panel 2, and the backlight 4, and connected to the backlight 4. And a light source driving unit 6 for driving.

  As shown in FIG. 1, the light source driving unit 6 includes a light source luminance adjusting unit 6 a for adjusting the luminance of the backlight 4.

  Further, the liquid crystal display panel 2 to be inspected by the liquid crystal display panel inspection method according to the present embodiment is a first substrate provided on the incident side of the display light by the backlight 4 as shown in FIGS. A TFT substrate 24, a CF substrate 25 that is a second substrate disposed opposite the TFT substrate 24, and a liquid crystal that is a display medium layer sandwiched between the TFT substrate 24 and the CF substrate 25. A layer 26 and a sealing material 27 provided in a frame shape are provided for adhering the TFT substrate 24 and the CF substrate 25 to each other and enclosing the liquid crystal layer 26.

  The sealing material 27 is formed so as to go around the liquid crystal layer 26, and the TFT substrate 24 and the CF substrate 25 are bonded to each other via the sealing material 27. The liquid crystal display panel 2 includes a plurality of photo spacers (not shown) for regulating the thickness of the liquid crystal layer 26 (that is, the cell gap).

  As shown in FIG. 2, the liquid crystal display panel 2 is formed in a rectangular shape, and in the longitudinal direction of the liquid crystal display panel 2, the TFT substrate 24 protrudes from the CF substrate 25 on the upper side, and the protruding region A plurality of display lines such as gate lines and source lines are drawn out to form a terminal region T.

  In the liquid crystal display panel 2, a display area (display surface) D for displaying an image is defined in an area where the TFT substrate 24 and the CF substrate 25 overlap. Here, the display area D is configured by arranging a plurality of pixels, which are the minimum unit of an image, in a matrix.

  Further, as shown in FIG. 2, the sealing material 27 is provided in a rectangular frame shape surrounding the entire periphery of the display area D.

  Further, the CF substrate 25 is provided on the display light emitting side so as to face each other with the TFT substrate 24 and the liquid crystal layer 26 interposed therebetween.

  The TFT substrate 24 includes, for example, a glass substrate (not shown), a thin film transistor (TFT) as a switching element having a gate electrode, a source electrode, and a drain electrode (not shown) formed on the glass substrate, a transparent insulating layer, and a pixel. It consists of an electrode and an alignment film.

  The CF substrate 25 is provided for each pixel, for example, between a black matrix (not shown) provided in a grid shape and a frame shape as a light shielding portion on a glass substrate, and between each grid of the black matrix. A color filter (not shown) including a plurality of types of colored layers (that is, a red layer R, a green layer G, and a blue layer B) is provided. The CF substrate 25 is provided so as to cover the common electrode (not shown) provided so as to cover the black matrix and the color filter, the above-described photo spacer provided in a column shape on the common electrode, and the common electrode. And an alignment film (not shown).

  The black matrix is provided between adjacent colored layers and has a role of partitioning these multiple types of colored layers. This black matrix is made of a metal material such as Ta (tantalum), Cr (chromium), Mo (molybdenum), Ni (nickel), Ti (titanium), Cu (copper), Al (aluminum), or a black pigment such as carbon. It is formed of a dispersed resin material or a resin material in which a plurality of colored layers having light transmittance are laminated.

  The liquid crystal layer 26 is made of, for example, a nematic liquid crystal material having electro-optical characteristics.

  In the liquid crystal display panel 2, in a pixel configured for each pixel electrode, when a gate signal is sent from the gate bus line and the TFT is turned on, a data signal is sent from the source bus line to the source electrode. A predetermined charge is written into the pixel electrode through the drain electrode and the drain electrode, a potential difference is generated between the pixel electrode and the common electrode, and a predetermined voltage is applied to the liquid crystal layer. The liquid crystal display panel 2 adjusts the transmittance of light incident from the backlight 4 by utilizing the change in the alignment state of the liquid crystal molecules according to the magnitude of the applied voltage. The configuration is displayed.

  The liquid crystal display panel 2 is driven by driving the liquid crystal display panel 2 by the liquid crystal display panel driving unit 5 described above.

  As shown in FIG. 1, the defect inspection apparatus 1 includes a CPU 7 as a control unit that controls the liquid crystal display panel driving unit 5 and the light source driving unit 6, and a memory 8 that is a storage unit. The CPU 7 is connected to the liquid crystal display panel driving unit 5 and the light source driving unit 6 and a memory 8. The CPU 7 controls each unit in accordance with a program stored in the memory 8. It has a configuration.

  When the liquid crystal display panel driving unit 5 is driven by the CPU 7, the liquid crystal display panel driving unit 5 is configured to drive the liquid crystal display panel 2 so that display colors are displayed in the display area D. ing. Similarly, when the CPU 7 drives the light source luminance adjustment unit 6 a of the light source driving unit 6, the light source luminance adjustment unit 6 a adjusts the luminance of the backlight 4 that irradiates the liquid crystal display panel 2 with irradiation light. It has a configuration to adjust.

  Next, a display defect inspection method for the liquid crystal display panel according to the present embodiment will be described. The display defect inspection method for a liquid crystal display panel according to the present embodiment is a liquid crystal display panel 2 including a color filter having a display region D in which a plurality of pixels provided with the plurality of types of colored layers are two-dimensionally arranged. In this method, a plurality of display colors are displayed in the display area D to visually inspect the presence or absence of display defects in the pixels.

  And in this embodiment, in order to prevent that an illusion phenomenon arises in the vision of the inspector who performs a visual inspection, there exists the characteristic in the point which suppresses the rapid change of screen brightness by switching of a screen display. More specifically, the present embodiment is characterized in that the liquid crystal display panel driving unit 5 drives the liquid crystal display panel 2 so that a plurality of display colors are displayed in order of increasing luminance.

  FIG. 4 is a flowchart for explaining the display defect inspection method for the liquid crystal display panel according to the first embodiment of the present invention. In the present embodiment, a case where the entire display area D of the liquid crystal display panel 2 (that is, all pixels) is displayed with the same gradation (solid pattern) will be described as an example.

  First, the backlight 4 is driven by the light source driving unit 6 connected to the backlight 4 as the light source, and the liquid crystal display panel 2 is irradiated with the irradiation light from the backlight 4 (step S1).

  Next, the liquid crystal display placed on the inspection table 3 by the liquid crystal display panel driving unit 5 connected to the liquid crystal display panel 2 in a state where the liquid crystal display panel 2 is irradiated with the light emitted from the backlight 4. The panel 2 is driven and black display is performed in the display area D (step S2).

At this time, since the luminance of black display in the standard backlight luminance (light source luminance) is approximately 0 cd / m ² , when the standard backlight luminance (light source luminance) is 1, the display area D (Hereinafter referred to as “display surface luminance”) is approximately 0 cd / m ² .

  Next, in the state where black display is performed in the display area D, the presence or absence of display defects of the liquid crystal display panel 2 is visually inspected (step S3).

  Next, the liquid crystal display panel driving unit connected to the liquid crystal display panel 2 in a state where the light emitted from the backlight 4 is irradiated to the liquid crystal display panel 2 (that is, in a state where the luminance of the backlight 4 is constant). 5, the liquid crystal display panel 2 is driven to perform blue display in the display area D (step S <b> 4).

At this time, since the luminance of the blue display is generally about 10% of the luminance of the white display, for example, when the luminance of the white display in the standard backlight luminance is 300 cd / m ² , the luminance of the blue display is 33 cd / m ² . Accordingly, when the backlight luminance (light emission amount) is 1 (constant), the display surface luminance is 33 × 1 = 33 cd / m ² .

  Next, in the state where blue display is performed in the display area D, the presence or absence of display defects of the liquid crystal display panel 2 is visually inspected (step S5).

At this time, since the display surface luminance during black display before blue display is 0, the change in display surface luminance (that is, the difference in display surface luminance) when changing from black display to blue display is 33-0. = 33 cd / m ² . Accordingly, the change in display surface brightness can be made smaller than, for example, the change in surface brightness when changing from black display to white display (300-0 = 300 cd / m ² ). It is possible to prevent a sudden change in display surface luminance when changing the display. Therefore, the time required for light adaptation can be shortened, so that the occurrence of the illusion phenomenon in the inspector's vision can be effectively suppressed, and as a result, the detection accuracy of visual display defects is improved. It becomes possible to do.

  Next, the liquid crystal display panel driving unit connected to the liquid crystal display panel 2 in a state where the light emitted from the backlight 4 is irradiated to the liquid crystal display panel 2 (that is, in a state where the luminance of the backlight 4 is constant). 5, the liquid crystal display panel 2 is driven to display red in the display area D (step S6).

At this time, generally, the red display luminance, for white display is about 20% of the luminance of, for example, when white display luminance in a standard backlight luminance of 300 cd / m ^2, the luminance of the red display Is 69 cd / m ² . Accordingly, when the backlight luminance (light emission amount) is 1 (constant), the display surface luminance is 69 × 1 = 69 cd / m ² .

  Next, in the state where the red display is performed in the display area D, the liquid crystal display panel 2 is visually inspected for display defects (step S7).

At this time, since the display surface luminance during blue display before red display is 33 cd / m ² , the change in display surface luminance when changing from blue display to red display is 69−33 = 36 cd / m ^2. It becomes. Accordingly, as in the case of the blue display described above, the change in the display surface brightness can be made smaller than, for example, the change in the surface brightness (300 cd / m ² ) when changing from black display to white display. Therefore, it is possible to prevent a sudden change in display surface luminance when changing the color display.

  Next, the liquid crystal display panel driving unit connected to the liquid crystal display panel 2 in a state where the light emitted from the backlight 4 is irradiated to the liquid crystal display panel 2 (that is, in a state where the luminance of the backlight 4 is constant). 5, the liquid crystal display panel 2 is driven to display gray in the display area D (step S8).

At this time, generally, gray display of luminance, since white display is 50% of the luminance of, for example, when white display luminance in a standard backlight luminance of 300 cd / m ^2, the luminance of the gray display 150 cd / m ² . Accordingly, when the backlight luminance (light emission amount) is 1 (constant), the display surface luminance is 150 × 1 = 150 cd / m ² .

  Next, in the state where gray display is performed in the display area D, the presence or absence of display defects of the liquid crystal display panel 2 is visually inspected (step S9).

At this time, since the display surface luminance at the time of red display before performing gray display is 69 cd / m ² , the change in the display surface luminance when changing from red display to gray display (that is, the difference in display surface luminance) is 150−69 = 81 cd / m ² . Therefore, as in the case of the blue display and the red display described above, the change in the display surface brightness is, for example, compared to the change in the surface brightness (300 cd / m ² ) when changing from the black display to the white display. Since the size can be reduced, it is possible to prevent a sudden change in display surface luminance when changing the color display.

  Next, the liquid crystal display panel 2 is moved by the liquid crystal display panel driving unit 5 in a state where the light emitted from the backlight 4 is irradiated on the liquid crystal display panel 2 (that is, in a state where the luminance of the backlight 4 is constant). By driving, green display is performed in the display area D (step S10).

At this time, in general, the green display of luminance, since white display is 70% of the brightness of, for example, when white display luminance in a standard backlight luminance of 300 cd / m ^2, green display brightness Is 195 cd / m ² . Accordingly, when the backlight luminance (light emission amount) is 1 (constant), the display surface luminance is 195 × 1 = 195 cd / m ² .

  Next, in the state where the green display is performed in the display area D, the liquid crystal display panel 2 is visually inspected for display defects (step S11).

At this time, since the display surface brightness at the time of gray display before the green display is 150 cd / m ² , the change of the display surface brightness when changing from the gray display to the green display is 195−150 = 45 cd / m ^2. It becomes. Therefore, as in the case of the blue display, red display, and gray display described above, the change in display surface brightness is changed to, for example, the change in surface brightness (300 cd / m ² ) when changing from black display to white display. Compared to this, it is possible to reduce the display surface luminance when the color display is changed.

  Next, the liquid crystal display panel 2 is moved by the liquid crystal display panel driving unit 5 in a state where the light emitted from the backlight 4 is irradiated on the liquid crystal display panel 2 (that is, in a state where the luminance of the backlight 4 is constant). Driven to perform white display in the display area D (step S12).

In this case, for example, when the luminance of white display at the standard backlight luminance is 300 cd / m ² and the luminance (light emission amount) of the backlight is 1 (constant), the display surface luminance is 300 × 1 = 300 cd / m ² .

  Next, in the state where the white display is performed in the display area D, the liquid crystal display panel 2 is visually inspected for display defects (step S13).

At this time, since the display surface brightness during the green display before the white display is 195 cd / m ² , the change in the display surface brightness when changing from the green display to the white display is 300−195 = 105 cd / m ^2. It becomes. Accordingly, as in the case of the above-described blue display, red display, gray display, and green display, for example, a change in surface brightness (300 cd / m) when the display surface brightness change is changed from black display to white display, for example. ^As compared with ² ), it is possible to make it smaller, so that it is possible to prevent an abrupt change in display surface luminance when the color display is changed.

  As described above, in the present embodiment, a plurality of display colors (black, blue, red, gray, green, and white in the present embodiment) displayed in the display area D are displayed for each of the plurality of display colors. By displaying in order of decreasing luminance (ie, black → blue → red → gray → green → white), the display surface luminance difference in the display colors before and after being displayed in the display area D is reduced, and color display is performed. It is configured to prevent a sudden change in display surface luminance when changing.

  According to the present embodiment described above, the following effects can be obtained.

  (1) In the present embodiment, the defect inspection apparatus 1 includes a liquid crystal display panel drive unit 5 that drives the liquid crystal display panel 2 so that a predetermined display color is displayed in the display area D. And the liquid crystal display panel drive part 5 is set as the structure which drives the liquid crystal display panel 2 so that the several display color displayed on the display area D is displayed in order with the low brightness | luminance of each of several display colors. Therefore, it is possible to reduce the luminance difference of the display surface luminance in the display colors before and after being displayed in the display area D, and to prevent a sudden change in the display surface luminance when the color display is changed. Therefore, when visual inspection of the display defect of the liquid crystal display panel 2 is performed, it is possible to reduce the time required for light and dark adaptation, and thus it is possible to effectively suppress the occurrence of an illusion phenomenon in the visual perception of the inspector. become. As a result, it is possible to improve the detection accuracy of visual display defects.

  (2) In addition, a plurality of display colors are displayed in ascending order of luminance, and generally, the time required for light adaptation is extremely short compared with the time required for dark adaptation, so that it can be used for display defect inspection of liquid crystal display panels. It is possible to effectively shorten the time required.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. Further, since the configuration of the defect inspection apparatus and the configuration of the liquid crystal display panel are the same as those in the first embodiment, detailed description thereof is omitted here.

  In the first embodiment, the color display is performed in a state where the luminance of the backlight 4 as the light source is constant. However, in the present embodiment, the display color corresponding to the display color displayed in the display area D is used. Thus, the display surface brightness is adjusted by changing the brightness of the backlight 4.

  More specifically, in the present embodiment, the liquid crystal display panel driving unit 5 drives the liquid crystal display panel 2 so that a plurality of display colors are displayed in order of decreasing luminance, and the light source luminance adjusting unit 6a includes: There is a feature in that the brightness of the backlight 4 is changed in order to adjust the display surface brightness in each of the display colors displayed in the display area D.

  FIG. 5 is a flowchart for explaining a display defect inspection method for a liquid crystal display panel according to the second embodiment of the present invention.

  First, the light source driving unit 6 connected to the backlight 4 as the light source drives the backlight 4 to irradiate the liquid crystal display panel 2 with the light emitted from the backlight 4 (step S21).

  Next, the liquid crystal display panel drive unit 5 drives the liquid crystal display panel 2 while irradiating the liquid crystal display panel 2 with the irradiation light from the backlight 4, and performs black display in the display region D (step S22). ).

  Here, in order to improve the detection accuracy of the bright spot defect by visual observation in the black display, the light source luminance adjusting unit 6a of the light source driving unit 6 adjusts so that the luminance of the backlight 4 is maximized in the step S21. . That is, for example, when the setting range of the luminance of the backlight 4 is 0 to 2, the light source luminance adjusting unit 6a sets the luminescent spot of the backlight 4 to be 2, which is the maximum value of the setting range.

At this time, since the luminance of black display in the standard backlight luminance is approximately 0 cd / m ₂ , even when the backlight luminance (light source luminance) is 2, the display surface luminance is 0 cd / m. the m ^2.

  Then, in the state where the black display is performed in the display area D, the presence or absence of display defects of the liquid crystal display panel 2 is visually inspected (step S23).

  Next, the luminance of the backlight 4 is adjusted by the light source luminance adjusting unit 6a (step S24).

  Next, the liquid crystal display panel 2 is driven by the liquid crystal display panel driving unit 5 in a state where the liquid crystal display panel 2 is irradiated with the irradiation light from the backlight 4 whose luminance is adjusted, and blue display is performed in the display region D. Is performed (step S25).

  Here, since the bright spot is more noticeable in the blue display than in the black display, in order to improve the detection accuracy of the bright spot defect visually in the blue display, the light source brightness adjusting unit 6a has a lower display surface brightness in step S24. The brightness of the backlight 4 is adjusted so that the display surface brightness is optimal for detecting the bright spot defect.

  That is, for example, when the luminance setting range of the backlight 4 is 0 to 2, the light source driving unit 6 sets the bright spot of the backlight 4 to 1 which is an intermediate value of the setting range.

At this time, as in the case of the first embodiment, the luminance of blue display at the standard backlight luminance is set to 33 cd / m ² . Since the luminance of the backlight is 1, the display surface luminance is 33 × 1 = 33 cd / m ² .

  Then, in the state where blue display is performed in the display area D, the presence or absence of display defects of the liquid crystal display panel 2 is visually inspected (step S26).

At this time, since the display surface luminance during black display before blue display is approximately 0 cd / m ² , the change in display surface luminance when changing from black display to blue display (that is, the difference in display surface luminance) ) Is 33−0 = 33 cd / m ² . Accordingly, as in the case of the first embodiment described above, the change in display surface luminance is changed to, for example, a change in surface luminance (300-0 = 300 cd / m ² ) when changing from black display to white display. Compared to this, it is possible to reduce the display surface luminance when the color display is changed.

  Next, the luminance of the backlight 4 is adjusted by the light source luminance adjusting unit 6a (step S27).

  Next, the liquid crystal display panel drive unit 5 drives the liquid crystal display panel 2 in a state where the liquid crystal display panel 2 is irradiated with the irradiation light from the backlight 4 whose luminance is adjusted, and the display area D is displayed in red. Is performed (step S28).

Here, since the black spot defect is more conspicuous than the bright spot defect in the red display, the light source luminance adjustment unit 6a detects the black spot defect in step S27 in order to improve the black spot defect detection accuracy in the red display. The luminance of the backlight 4 is adjusted so that the optimal display surface luminance is obtained. For example, as in the case of the first embodiment, when the luminance of the red display at the standard backlight luminance is 69 cd / m ² , the light source driving unit 6 detects the black spot defect with the luminance of the display surface. The luminance of the backlight 4 is set to 1.45 so that the optimum luminance (about 100 cd / m ² ) is obtained.

That is, in this case, since the luminance of red display at the standard backlight luminance is 69 cd / m ² and the luminance of the backlight is 1.45, the display surface luminance is 69 × 1.45 = 100 cd. / M ² .

  Then, with the red display in the display area D, the presence or absence of display defects in the liquid crystal display panel 2 is visually inspected (step S29).

At this time, since the display surface brightness at the time of blue display before performing red display is 33, the change of the display surface brightness when changing from blue display to red display is 100−33 = 67 cd / m ² . Accordingly, the change in display surface brightness can be made smaller than, for example, the change in surface brightness when changing from black display to white display (300-0 = 300 cd / m ² ). It is possible to prevent a sudden change in display surface luminance when changing the display.

  Next, the luminance of the backlight 4 is adjusted by the light source luminance adjusting unit 6a (step S30).

  Next, the liquid crystal display panel 2 is driven by the liquid crystal display panel driving unit 5 in a state where the liquid crystal display panel 2 is irradiated with the irradiation light from the backlight 4 whose luminance is adjusted. Is performed (step S31).

Here, in the gray display, the black spot defect is more conspicuous than the bright spot defect in the same manner as the red display described above. The unit 6a adjusts the luminance of the backlight 4 so as to obtain the optimal display surface luminance for detecting black spot defects. For example, as in the case of the first embodiment, when the gray display luminance at the standard backlight luminance is set to 150 cd / m ² , the light source driving unit 6 detects the black spot defect with the display surface luminance. The brightness of the backlight 4 is set to 0.67 so that the optimum brightness (about 100 cd / m ² ) is obtained.

That is, in this case, gray display luminance is a 150 cd / ^{m 2,} because the brightness of the backlight is 0.67, the display surface luminance becomes ^{150 × 0.67 = 100cd / m 2} .

  Then, in the state where gray display is performed in the display area D, the presence or absence of display defects of the liquid crystal display panel 2 is visually inspected (step S32).

At this time, since the display surface brightness at the time of red display before performing gray display is 100 cd / m ² , the change of the display surface brightness when changing from red display to gray display is 100−100 = 0 cd / m ² . Become. That is, in the present embodiment, the light source luminance adjusting unit 6a is configured so that the display surface luminance in each of the display colors displayed in the display area D (in this case, gray and red) is substantially the same. Change the brightness.

  With such a configuration, it is possible to prevent a change in display surface luminance from occurring, and thus it is possible to reliably prevent a sudden change in display surface luminance from occurring when the color display is changed. Therefore, the time required for light adaptation is eliminated, so that it is possible to reliably prevent the occurrence of an illusion phenomenon in the inspector's vision, and as a result, it is possible to dramatically improve the accuracy of visual display defect detection. become.

  Next, the luminance of the backlight 4 is adjusted by the light source luminance adjusting unit 6a (step S33).

  Next, the liquid crystal display panel 2 is driven by the liquid crystal display panel driving unit 5 in a state where the liquid crystal display panel 2 is irradiated with the irradiation light from the backlight 4 whose luminance is adjusted, and the display area D is displayed in green. Is performed (step S34).

Here, in the green display, the black spot defect is more conspicuous than the bright spot defect in the same manner as the red display and the gray display described above. Therefore, in order to improve the black spot defect detection accuracy in the green display in the step S33. The light source luminance adjusting unit 6a adjusts the luminance of the backlight 4 so as to obtain the optimal display surface luminance for detecting the black spot defect. For example, as in the case of the first embodiment, when the luminance of green display at the standard backlight luminance is set to 195 cd / m ² , the light source driving unit 6 detects the black spot defect with the display surface luminance. The brightness of the backlight 4 is set to 0.51 so that the optimum brightness (about 100 cd / m ² ) is obtained.

That is, in this case, green display luminance a 195cd / ^{m 2,} because the brightness of the backlight is 0.51, the display surface luminance becomes ^{195 × 0.51 = 100cd / m 2} .

  Then, with the green display in the display area D, the presence or absence of display defects in the liquid crystal display panel 2 is visually inspected (step S35).

At this time, since the display surface brightness in the gray display before the green display is 100 cd / m ² , the change in the display surface brightness when changing from the gray display to the green display is 100−100 = 0 cd / m ² . Become. That is, the light source luminance adjusting unit 6a changes the luminance of the backlight 4 so that the display surface luminances in the display colors displayed in the display area D (in this case, green and gray) are substantially the same. Therefore, since it is possible to prevent the change in display surface luminance, it is possible to reliably prevent the occurrence of a sudden change in display surface luminance when the color display is changed.

  Next, the luminance of the backlight 4 is adjusted by the light source luminance adjusting unit 6a (step S36).

  Next, the liquid crystal display panel drive unit 5 drives the liquid crystal display panel 2 in a state in which the liquid crystal display panel 2 is irradiated with the irradiation light from the backlight 4 whose luminance is adjusted, and white display is performed in the display region D. Is performed (step S37).

Here, in the white display as well as the above-described red display, gray display, and green display, since the black spot defect is more conspicuous than the bright spot defect, in order to improve the detection accuracy of the black spot defect visually in the white display, In step S <b> 36, the light source luminance adjusting unit 6 a adjusts the luminance of the backlight 4 so as to obtain the optimal display surface luminance for detecting the black spot defect. For example, as in the case of the first embodiment, when the luminance of white display at the standard backlight luminance is set to 300 cd / m ² , the light source driving unit 6 detects the black spot defect with the luminance of the display surface. The brightness of the backlight 4 is set to 0.33 so that the optimum brightness (about 100 cd / m ² ) is obtained.

That is, in this case, since the luminance of white display is 300 cd / m ² and the luminance of the backlight is 0.33, the display surface luminance is 300 × 0.33 = 100 cd / m ² .

  Then, in the state where the white display is performed in the display area D, the presence or absence of display defects of the liquid crystal display panel 2 is visually inspected (step S38).

At this time, since the display surface luminance during green display before white display is 100 cd / m ² , the change in display surface luminance when changing from green display to white display is 100−100 = 0 cd / m ² . Become. That is, the light source luminance adjusting unit 6a changes the luminance of the backlight 4 so that the display surface luminances in the display colors displayed in the display area D (in this case, white and green) are substantially the same. Therefore, since it is possible to prevent the change in display surface luminance, it is possible to reliably prevent the occurrence of a sudden change in display surface luminance when the color display is changed.

  Thus, in the present embodiment, as in the case of the first embodiment described above, a plurality of display colors displayed in the display area D (in this embodiment, black, blue, red, gray, green , And white) in the order of luminance of each of a plurality of display colors (that is, black → blue → red → gray → green → white) and adjusting the luminance of the backlight 4 to display in each color display A configuration that adjusts the surface brightness, further reduces the brightness difference of the display surface brightness in the display colors before and after being displayed in the display area D, and prevents a sudden change in the display surface brightness when the color display is changed. It is said.

  According to the present embodiment described above, the following effects can be obtained in addition to the effects (1) to (2) described above.

  (3) In the present embodiment, the defect inspection apparatus 1 includes a light source luminance adjusting unit 6a for adjusting the luminance of the backlight 4, which is a light source that irradiates the liquid crystal display panel 2 with irradiation light. . The light source luminance adjusting unit 6a is configured to change the luminance of the backlight 4 in order to adjust the display surface luminance in each display color displayed in the display area D. Therefore, by adjusting the luminance of the backlight 4, it is possible to adjust the display surface luminance in each color display and further reduce the luminance difference of the display surface luminance in the display colors before and after being displayed in the display area D. Become. Accordingly, it is possible to prevent a sudden change in display surface luminance when changing the color display, and therefore it is possible to further reduce the time required for the light and dark adaptation when the display defect inspection of the liquid crystal display panel 2 is visually performed. become. As a result, it is possible to prevent the occurrence of an illusion phenomenon in the inspector's vision, and it is possible to further improve the accuracy of visual detection of display defects.

  (4) In the present embodiment, the light source luminance adjustment unit 6a is configured to change the luminance of the backlight 4 so that the display surface luminance in each display color displayed in the display area D is substantially the same. . Accordingly, it is possible to eliminate the luminance difference in display surface luminance between the display colors before and after being displayed in the display area D. Accordingly, it is possible to reliably prevent a sudden change in display surface luminance when changing the color display, and therefore, when the display defect inspection of the liquid crystal display panel 2 is visually performed, the time required for the light and dark adaptation becomes unnecessary. As a result, it is possible to reliably prevent the occurrence of an illusion phenomenon in the visual sense of the inspector, and it is possible to further improve the accuracy of visual display defect detection.

(Third embodiment)
Next, a third embodiment of the present invention will be described. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. Further, since the configuration of the defect inspection apparatus and the configuration of the liquid crystal display panel are the same as those in the first embodiment, detailed description thereof is omitted here.

  FIG. 6 is a flowchart for explaining a display defect inspection method for a liquid crystal display panel according to the third embodiment of the present invention.

  As shown in FIG. 6, in this embodiment, instead of step S24 (setting the backlight luminance to 1) in the second embodiment described above, the light source luminance adjusting unit 6a provided in the light source driving unit 6 is used. Thus, the brightness of the backlight 4 is set to be 2 which is the maximum value of the setting range (step S24a).

In this case, as in the case of the first embodiment, when the luminance of blue display at the standard backlight luminance is 33 cd / m ² , the luminance of the backlight 4 is 2, and thus the display surface luminance. Is 33 × 2 = 66 cd / m ² .

This, compared to the case of Example 2, to reduce the luminance difference between a gray display state of the display surface luminance (100 cd / ^{m 2)} and the blue display time of the display surface luminance (66 cd / ^{m 2),} the blue display This is to improve the detection accuracy of bright spot defects and black spot defects visually. In other words, in the present embodiment, the luminance of the backlight 4 is adjusted so that the display surface luminance is optimal for detecting bright spot defects and black spot defects in blue display.

  Other steps are the same as in the case of the second embodiment described above, and detailed description thereof is omitted here.

  Also in the present embodiment described above, the same effects as the effects (1) to (4) described above can be obtained.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. Further, since the configuration of the defect inspection apparatus and the configuration of the liquid crystal display panel are the same as those in the first embodiment, detailed description thereof is omitted here.

  In the first and second embodiments, a plurality of display colors (black, blue, red, gray, green, and white in this embodiment) displayed in the display area D are displayed in a plurality of display colors. Each of the luminances is displayed in order of decreasing brightness (that is, black → blue → red → gray → green → white). On the other hand, in the present embodiment, a plurality of display colors are not displayed in the order of low luminance (that is, a plurality of display colors are displayed in order at random), and only the luminance of the backlight 4 is adjusted. It is characterized in that the display surface brightness is adjusted to reduce the difference in display surface brightness between the display colors before and after the display area D is displayed.

  FIG. 7 is a flowchart for explaining a display defect inspection method for a liquid crystal display panel according to the fourth embodiment of the present invention.

  First, the same processing as Steps S21 to S23 described in the second embodiment described above is performed, and the presence or absence of a display defect in the liquid crystal display panel 2 is visually observed in a state where black display is performed in the display region D. I do.

  Next, the same processing as in Steps S24a to S26 described in the third embodiment is performed, and in the state where blue display is performed in the display region D, the presence or absence of display defects in the liquid crystal display panel 2 is visually checked. I do.

  Next, the luminance of the backlight 4 is adjusted by the light source luminance adjusting unit 6a (step S27a).

  Next, the liquid crystal display panel 2 is driven by the liquid crystal display panel driving unit 5 in a state where the liquid crystal display panel 2 is irradiated with the irradiation light from the backlight 4 whose luminance is adjusted, and the display area D is displayed in green. (Step S28a).

Here, as in step S33 of the second embodiment described above, in order to improve the accuracy of visual detection of black spot defects in green display, the light source luminance adjustment unit 6a is optimal for detecting black spot defects in step S27a. The brightness of the backlight 4 is adjusted so that the display surface brightness is as good as possible. For example, when the green display brightness in the standard backlight brightness is set to 195 cd / m ² , the light source drive unit 6 has the display surface brightness that is optimal for detecting black spot defects (about 100 cd / m ² ). Thus, the brightness of the backlight 4 is set to 0.51.

  Then, with the green display in the display area D, the presence or absence of display defects in the liquid crystal display panel 2 is visually inspected (step S29a).

At this time, since the display surface brightness at the time of blue display before performing the green display is 66 cd / m ² , the change of the display surface brightness when changing from the blue display to the green display is 100−66 = 34 cd / m ² . Become. Therefore, since it is possible to prevent the change in display surface luminance, it is possible to reliably prevent the occurrence of a sudden change in display surface luminance when the color display is changed.

  Next, the luminance of the backlight 4 is adjusted by the light source luminance adjusting unit 6a (step S30a).

  Next, the liquid crystal display panel drive unit 5 drives the liquid crystal display panel 2 in a state where the liquid crystal display panel 2 is irradiated with the irradiation light from the backlight 4 whose luminance is adjusted, and the display area D is displayed in red. (Step S31a).

Here, similarly to step S27 of the second embodiment described above, in order to improve the accuracy of visual detection of black spot defects in red display, in step S30a, the light source luminance adjustment unit 6a is optimal for detecting black spot defects. The brightness of the backlight 4 is adjusted so that the display surface brightness is as good as possible. For example, when the red display luminance in the standard backlight luminance is 69 cd / m ² , the light source driving unit 6 has the display surface luminance that is optimum for detecting black spot defects (about 100 cd / m ² ). Thus, the brightness of the backlight 4 is set to 1.45.

  Then, in the state where the red display is performed in the display area D, the presence or absence of display defects of the liquid crystal display panel 2 is visually inspected (step S32a).

At this time, since the display surface brightness at the time of the green display before the red display is 100 cd / m ² , the change in the display surface brightness when changing from the green display to the red display is 100−100 = 0 cd / m ² . Become. That is, as in the case of the second embodiment described above, the light source luminance adjustment unit 6a has substantially the same display surface luminance in each of the display colors displayed in the display area D (in this case, red and green). Thus, the luminance of the backlight 4 is changed. Therefore, since it is possible to prevent the change in display surface luminance, it is possible to reliably prevent the occurrence of a sudden change in display surface luminance when the color display is changed.

  Next, the luminance of the backlight 4 is adjusted by the light source luminance adjusting unit 6a (step S33a).

  Next, the liquid crystal display panel drive unit 5 drives the liquid crystal display panel 2 in a state in which the liquid crystal display panel 2 is irradiated with the irradiation light from the backlight 4 whose luminance is adjusted, and white display is performed in the display region D. Is performed (step S34a).

Here, as in step S36 of the second embodiment described above, in order to improve the accuracy of visual detection of black spot defects in white display, in step S33a, the light source luminance adjustment unit 6a is optimal for detecting black spot defects. The brightness of the backlight 4 is adjusted so that the display surface brightness is as good as possible. For example, when the luminance of white display at the standard backlight luminance is 300 cd / m ² , the light source drive unit 6 has a display surface luminance that is optimum for detecting black spot defects (about 100 cd / m ² ). Thus, the bright spot of the backlight 4 is set to 0.33.

  Then, in a state where white display is performed in the display area D, the presence or absence of display defects of the liquid crystal display panel 2 is visually inspected (step S35a).

At this time, since the display surface brightness at the time of red display before the white display is 100 cd / m ² , the change of the display surface brightness when changing from the red display to the white display is 100−100 = 0 cd / m ² . Become. That is, as in the case of the second embodiment described above, the light source luminance adjustment unit 6a has substantially the same display surface luminance in each of the display colors displayed in the display area D (in this case, white and red). Thus, the luminance of the backlight 4 is changed. Therefore, since it is possible to prevent the change in display surface luminance, it is possible to reliably prevent the occurrence of a sudden change in display surface luminance when the color display is changed.

  Next, the luminance of the backlight 4 is adjusted by the light source luminance adjusting unit 6a (step S36a).

  Next, the liquid crystal display panel 2 is driven by the liquid crystal display panel driving unit 5 in a state where the liquid crystal display panel 2 is irradiated with the irradiation light from the backlight 4 whose luminance is adjusted. Is performed (step S37a).

Here, similarly to step S30 of the second embodiment described above, in order to improve the accuracy of visual detection of black spot defects in gray display, in step S36a, the light source luminance adjustment unit 6a is optimal for detecting black spot defects. The brightness of the backlight 4 is adjusted so that the display surface brightness is as good as possible. For example, when the gray display luminance in the standard backlight luminance is 150 cd / m ² , the light source driving unit 6 has the display surface luminance that is optimum for detecting black spot defects (about 100 cd / m ² ). Thus, the brightness of the backlight 4 is set to 0.67.

  Then, in a state where gray display is performed in the display region D, the presence or absence of display defects of the liquid crystal display panel 2 is visually inspected (step S38a).

At this time, since the display surface luminance at the time of white display before gray display is 100 cd / m ² , the change in the display surface luminance when changing from white display to gray display is 100−100 = 0 cd / m ² . Become. That is, as in the case of the second embodiment described above, the light source luminance adjustment unit 6a has substantially the same display surface luminance in each of the display colors (in this case, gray and white) displayed in the display area D. Thus, the luminance of the backlight 4 is changed. Therefore, since it is possible to prevent the change in display surface luminance, it is possible to reliably prevent the occurrence of a sudden change in display surface luminance when the color display is changed.

  As described above, in the present embodiment, unlike the first and second embodiments described above, a plurality of display colors displayed in the display area D are arranged in the order of decreasing luminance of each of the plurality of display colors ( That is, even when not displaying in black → blue → red → gray → green → white), the display surface brightness in each color display is adjusted by adjusting the brightness of the backlight 4 and displayed in the display area D. The display surface luminance difference between the display colors before and after the display is reduced to prevent a sudden change in the display surface luminance when the color display is changed.

  According to the present embodiment described above, the same effects as the effects (3) to (4) described above can be obtained.

  In addition, you may change the said embodiment as follows.

  In the first embodiment, each of the plurality of display colors is displayed in the order of low luminance (that is, black → blue → red → gray → green → white). (White → green → gray → red → blue → black). That is, the liquid crystal display panel drive unit 5 may drive the liquid crystal display panel 2 so that a plurality of display colors are displayed in order of increasing luminance.

  In this case, for example, in a state where the luminance (light emission amount) of the backlight is set to 1 (constant), a plurality of display colors displayed in the display area D are reversed from the case of the first embodiment described above. By displaying each of the plurality of display colors in descending order, the difference in display surface brightness between the display colors before and after being displayed in the display area D is reduced. In this case, the same effect as the effect (1) described above can be obtained.

  In the second embodiment, the plurality of display colors displayed in the display area D are in the order of decreasing luminance of the plurality of display colors (that is, black → blue → red → gray → green → white). The display surface brightness in each color display is adjusted by adjusting the brightness of the backlight 4, but the brightness is displayed in order of increasing brightness (ie, white → green → grey → red → blue → black). It is also good. In other words, the liquid crystal display panel driving unit 5 drives the liquid crystal display panel 2 so that a plurality of display colors are displayed in order of increasing luminance, and the light source luminance adjusting unit 6a adjusts the display colors displayed in the display area D. In order to adjust the display surface brightness in each, the brightness of the backlight 4 may be changed.

  In this case, contrary to the case of the second embodiment described above, the plurality of display colors displayed in the display area D are displayed in order from the higher luminance of each of the plurality of display colors, and the backlight. By changing the brightness of 4, the display surface brightness in each color display is adjusted, and the brightness difference of the display surface brightness in the display colors before and after being displayed in the display area D is reduced. In this case, the same effect as the effect (3) described above can be obtained.

  Further, in this case, as in the case of the second embodiment described above, the light source luminance adjustment unit 6a is configured so that the display surface luminances in the display colors displayed in the display area D are substantially the same. 4 may be changed. In this case, the same effect as the effect (4) described above can be obtained.

  In the above embodiment, a liquid crystal display panel has been described as an example of a display panel. However, the present invention can be applied to other display panels such as an electroluminescence display panel, a plasma display panel, and a field emission display panel. Can be applied.

  Further, in the above embodiment, black, blue, red, gray, green, and white have been described as examples of the plurality of display colors displayed in the display area D. However, the display defect inspection of the liquid crystal display panel 2 is performed. When performing the above, the plurality of display colors displayed in the display area D are not limited to these colors, and may be other colors (for example, cyan, magenta, yellow).

  Examples of utilization of the present invention include a display defect inspection apparatus and a display defect inspection method for inspecting the presence or absence of display defects such as bright spot defects of a display panel such as a liquid crystal display panel.

DESCRIPTION OF SYMBOLS 1 Defect inspection apparatus 2 Liquid crystal display panel 3 Inspection table 4 Backlight (light source)
5 Liquid crystal display panel drive unit 6 Light source drive unit 6a Light source brightness adjustment unit 7 CPU
8 memory

Claims (16)

A display panel that inspects for the presence or absence of display defects in the pixels by displaying a plurality of display colors in the display region of a display panel that includes a display region in which a plurality of pixels of a plurality of types of colored layers are two-dimensionally arranged. A display defect inspection device,
A display panel driving unit for driving the display panel so that the display color is displayed in the display area;
The display panel driving unit drives the display panel so that the plurality of display colors displayed in the display area are displayed based on the order of brightness of each of the plurality of display colors. Display panel display defect inspection device.   The display defect inspection apparatus for a display panel according to claim 1, wherein the display panel driving unit drives the display panel so that the plurality of display colors are displayed in order of increasing brightness.   The display defect inspection apparatus for a display panel according to claim 1, wherein the display panel driving unit drives the display panel so that the plurality of display colors are displayed in order of increasing brightness. A light source luminance adjusting unit for adjusting the luminance of a light source that emits irradiation light to the display panel;
The light source luminance adjustment unit changes the luminance of the light source in order to adjust the display surface luminance in each of the display colors displayed in the display area. A display defect inspection apparatus for a display panel according to claim 1.   The display panel according to claim 4, wherein the light source luminance adjustment unit changes the luminance of the light source so that the display surface luminances of the display colors displayed in the display area are substantially the same. Display defect inspection equipment.   The display defect inspection apparatus for a display panel according to claim 1, wherein the display defect is a bright spot defect.   The display defect inspection apparatus for a display panel according to any one of claims 1 to 5, wherein the display defect is a black spot defect.   The display defect inspection apparatus for a display panel according to any one of claims 1 to 7, wherein the display panel is a liquid crystal display panel. A display panel that inspects for the presence or absence of display defects in the pixels by displaying a plurality of display colors in the display region of a display panel that includes a display region in which a plurality of pixels of a plurality of types of colored layers are two-dimensionally arranged. A display defect inspection method,
A display defect inspection method for a display panel, wherein the plurality of display colors displayed in the display area are displayed based on the order of brightness of each of the plurality of display colors.   The display defect inspection method for a display panel according to claim 9, wherein the plurality of display colors are displayed in the descending order of the luminance.   The display defect inspection method for a display panel according to claim 9, wherein the plurality of display colors are displayed in the descending order of the luminance.   A display surface in each of the display colors displayed in the display area by changing the luminance of a light source that irradiates the display panel with irradiation light corresponding to the display color displayed in the display area. The brightness | luminance is adjusted, The display defect inspection method of the display panel of any one of Claims 9-11 characterized by the above-mentioned.   13. The display defect inspection method for a display panel according to claim 12, wherein the luminance of the light source is changed so that the display surface luminance in each of the display colors displayed in the display area is substantially the same.   The display defect inspection method for a display panel according to claim 9, wherein the display defect is a bright spot defect.   The display defect inspection method for a display panel according to claim 9, wherein the display defect is a black spot defect.   The display defect inspection method for a display panel according to any one of claims 9 to 15, wherein the display panel is a liquid crystal display panel.

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