JP2009069520A - Inspecting device for display panel, inspection system for display panel, method for manufacturing display panel, program, and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inspection device for a display panel and the like, which inspects a defect by once imaging without generating halation and insufficient sensitivity, when defect-inspecting an inspection pattern with a gradation displayed by stepwise change patterns in every divided screen in the display panel of screen division drive. <P>SOLUTION: A screen of a liquid crystal panel 11 is imaged by a camera, to be inspected. The inspection device for the display panel is provided with: source drivers 12a, 12b and a gate driver 13 for dividing the screen of the liquid crystal panel 11 into the plurality along at least one direction to be driven independently each other at the same time; and a liquid crystal panel lighting signal generator 20 for displaying the gradation stepwise change patterns as the inspection pattern, on the respective divided screens of the liquid crystal panel 11. The inspection device 10 for the liquid crystal panel includes an inversion data preparing circuit 24 and an input selection circuit 25 for arranging the stepwise change patterns of the gradations displayed on the respective divided screens of the liquid crystal panel 11, to be alternatively brought into an ascending order and a descending order, or the descending order and the ascending order, in every divided screen. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a display panel inspection apparatus that performs a defect inspection of a display panel by imaging a display panel such as a liquid crystal panel with an imaging apparatus, a display panel inspection method, a display panel manufacturing method, a program, and a recording medium. Is.

  For example, a display device such as a liquid crystal panel is inspected for quality by turning on the display panel in the latter half of the manufacturing process.

  In the conventional defect inspection of display panels, the conventional visual inspection is easy to deal with new models and new defect modes, and is suitable for sensory inspections such as detection of unevenness and spots, but overlooked and There are variations in judgment due to individual differences. In addition, display devices have recently become high-definition and the number of display pixels is in the order of millions of pixels, so that the defect positions and defect types found by visual observation are accurately recorded, corrected, and processed. It is difficult to provide feedback information for improvement.

  Note that in this specification, a pixel means a unit composed of three picture elements of red (R), green (G), and blue (B). In addition, a picture element refers to each of red (R), green (G), and blue (B) picture elements. Generally, the horizontal size of the picture element: vertical size = 1: 3.

  In order to deal with such problems, automatic inspection processes a signal obtained by imaging a lit display device with a camera such as a line sensor or an area sensor, and performs inspection. A method has been proposed.

  On the other hand, in the lighting inspection of a liquid crystal panel, in order to inspect various defects, an inspection pattern which is a large number of display patterns is used. Most basically, a full black display, so-called black solid screen, is used to detect bright spot defects, while a full white display, so-called color solid screen, is used to detect black spot defects.

  In the inspection using the above-described entire white display inspection pattern, if the luminance of the backlight is high, black spots are not noticeable, and it is difficult to find defects. Further, in the inspection using the inspection pattern for the entire black display described above, if the luminance of the backlight is low, the bright spot becomes inconspicuous and it becomes difficult to find a defect.

  Therefore, in the display panel inspection method disclosed in Patent Document 1, for example, when the bright spot defect inspection is performed in the entire black display inspection pattern, the backlight intensity is increased to increase the relative intensity of the bright spot with respect to the background. The backlight intensity suitable for the display mode and inspection purpose is controlled. This makes it easy for inspectors to find defects.

  Further, in the defect inspection method for the pattern to be inspected disclosed in Patent Document 2, as shown in FIG. 16, in the defect inspection of the memory chip 120 formed in a large number on the semiconductor wafer 101, the illumination light source 102 is half-processed. The memory chip 120 is irradiated with light through the mirror 103 and the objective lens 104, and the reflected light is imaged by the image sensor 105 to obtain a grayscale image signal.

  Here, as shown in FIG. 17A, the memory chip 120 includes a memory mat portion 121 composed of a repetitive pattern portion and a peripheral circuit 122 composed of a non-repetitive pattern portion. As shown, the memory mat portion 121 is darker than the peripheral circuit 122.

  When the brightness of each memory mat section 121 is compared by the first comparator 110a based on the grayscale image signal obtained by the image sensor 105, if there is a difference in the brightness, the memory While it is determined that the mat portion 121 is defective, the brightness of the peripheral circuits 122 of each memory chip 120 is compared by the second comparator 110b. It is determined that the circuit 122 is defective.

  However, the grayscale image signal obtained by the image sensor 105 makes a defect determination with the same detection sensitivity even though the dark memory mat portion 121 and the bright peripheral circuit 122 are mixed. Therefore, the detection sensitivity is not appropriate for both. As a result, there is a problem that erroneous determination is likely to occur.

  Therefore, in the defect inspection method for the pattern to be inspected disclosed in Patent Document 2, the gradation conversion unit 111a converts the dark memory mat unit 121 to increase the gradation, and the gradation conversion unit 111b performs a bright peripheral. Conversion is performed so that the gradation of the circuit 122 is lowered. As a result, the defect judgment is made with the gradation of the memory mat portion 121 and the gradation of the peripheral circuit 122 substantially the same gradation.

As a result, in Patent Document 2, since the detected image signal has the same brightness and contrast as a whole for an imaging target region in which light and dark are mixed, the defect determination accuracy is improved.
JP 2006-343688 A (published on December 21, 2006) JP-A-8-320294 (released on December 3, 1996) JP 2001-204049 A (released on July 27, 2001)

  By the way, since defects in the liquid crystal panel due to liquid crystal panel circuit defects or contamination of foreign matter are often manifested only in a specific display mode, the lighting inspection displays a plurality of display modes on the liquid crystal panel. Inspection is necessary.

  For example, Patent Document 3 discloses an inspection pattern in which a specific gradation pattern is repeated a plurality of times as shown in FIG. In this type of inspection pattern, high gradation and low gradation are repeated on the screen of the liquid crystal panel.

  On the other hand, in order to detect a defect in the source driver, an inspection pattern having a gradation step change pattern may be used. When automatically inspecting a display pattern having such a gradation distribution, there are a bright area and a dark area in one display screen. Therefore, if the imaging sensitivity is adjusted to one of the areas, a halation area is displayed on the image. On the other hand, there is a problem that a region with low sensitivity occurs.

  In particular, in recent years, in order to prevent a decrease in the pixel holding voltage due to the length of the signal line and to make the screen brightness uniform, the source driver is divided so that the upper and lower areas of the display screen become upper and lower source drivers. May be driven.

  In such a liquid crystal panel, when a gradation change pattern of gradation is displayed on the liquid crystal panel, as shown in FIG. 17, a defect is caused in a display mode in which the gradation change pattern of black → white gradation has a plurality of stages. Perform detection. Therefore, a plurality of stepwise change patterns of black to white gradation are repeated on one screen of the liquid crystal panel.

  However, in the conventional liquid crystal panel inspection apparatus disclosed in Patent Document 1, in order to uniformly increase or decrease the amount of transmitted light over the entire display unit with respect to these inspection patterns, a bright region is emphasized when the dark region is emphasized. Causes halation (saturation), but if the bright region is suppressed, the luminance of the dark region decreases.

  In addition, the conventional method for inspecting a defect in a pattern to be inspected in Patent Document 2 and the apparatus thereof only perform gradation conversion of a detected image signal in accordance with an imaging region, and in the preceding stage, the dynamic range of the CCD light-receiving element. However, it has a problem that it is impossible to image bright and dark patterns exceeding 1 at a time.

  The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to image a test pattern in which a gradation is displayed in a stepwise change pattern for each divided screen on a display panel that divides and drives the screen. Display panel inspection apparatus, display panel inspection method, display panel manufacturing method, program, and recording medium capable of performing inspection by single imaging without causing halation and lack of sensitivity when performing defect inspection by imaging with an apparatus Is to provide.

  In order to solve the above-described problems, the display panel inspection apparatus of the present invention is a display panel inspection apparatus that performs image inspection of a display panel by imaging the display panel screen with an imaging device. Screen division driving means for dividing the image into a plurality of parts in at least one direction and simultaneously driving them independently from each other; and inspection pattern display means for displaying a gradation step change pattern as an inspection pattern on each divided screen of the display panel; In addition, the inspection pattern display means alternately displays the gradation step change patterns displayed on the divided screens of the display panel in ascending order and descending order, or descending order and ascending order for each divided screen. It is characterized by having an ascending / descending order arrangement means.

  In order to solve the above-described problem, the display panel inspection method of the present invention is a display panel inspection method in which a display panel image is picked up by an imaging device and a defect inspection of the display panel is performed. A screen division driving process in which a plurality of screens are divided into at least one direction and simultaneously driven independently from each other, and an inspection pattern display process for displaying a gradation step change pattern as an inspection pattern on each divided screen of the display panel; And an ascending / descending order arranging step of arranging the gradation step change pattern displayed on each divided screen of the display panel alternately in ascending order and descending order or descending order and ascending order for each divided screen. It is characterized by that.

  In order to solve the above problems, a method for manufacturing a display panel according to the present invention includes a step of disposing a display panel at a position opposite to an imaging device in the display panel inspection device described above, and an imaging device in the display panel inspection device. And the step of inspecting the display panel disposed at the opposite position by the above-described display panel inspection method.

  According to the above invention, the screen of the display panel that is divided into a plurality of screens in at least one direction and is driven simultaneously and independently is imaged by the imaging device, and the display panel is inspected for defects. In the present invention, a gradation step change pattern is displayed as an inspection pattern on each divided screen of the display panel.

  In this case, conventionally, the gradation step change pattern displayed on each divided screen of the display panel is repeated in the same order for each divided screen. For this reason, in the imaging area including the boundary of the divided screen in the imaging device, since the white display portion and the black display portion are mixed, sensitivity adjustment that satisfies both of them cannot be performed at once, and halation occurs in the white display portion. Insufficient sensitivity was supposed to occur in the display area.

  On the other hand, in the present invention, the inspection pattern display means displays the gradation step change pattern displayed on each divided screen of the display panel alternately in ascending order and descending order or descending order and ascending order for each divided screen. Ascending / descending order arranging means is arranged.

  As a result, the imaging region including the boundary of the divided screen in the imaging device can be set as a white display portion or a black display portion.

  Therefore, in a display panel that divides and drives the screen, when an inspection pattern in which gradation is displayed in a stepwise change pattern for each divided screen is imaged by the imaging device and defect inspection is performed, halation and lack of sensitivity do not occur. It is possible to provide a display panel inspection apparatus, a display panel inspection method, and a display panel manufacturing method capable of performing inspection with a single imaging.

  In the display panel inspection apparatus of the present invention, the inspection pattern display means includes model information means for inputting model information including the number of screen divisions, and positive signal data of an inspection pattern for displaying a preset gradation. A positive signal data acquiring means for acquiring, and a control signal output means for outputting a control signal for displaying the inspection pattern on the screen division driving means, and the ascending / descending order arranging means includes the positive signal data. When the inverted data generating means for generating inverted inverted data and the control signal output means output a control signal for causing the screen division driving means to display the inspection pattern, the positive signal data and the inverted signal data are displayed. It is preferable to include a normal / inverted signal data switching means for switching so as to alternately output every divided screen of the panel.

  Thereby, specifically, the gradation step change pattern displayed on each divided screen of the display panel can be arranged so as to be alternately in ascending order and descending order, or descending order and ascending order for each divided screen. .

  In the display panel inspection apparatus of the present invention, the imaging device includes a sensitivity adjustment unit that performs sensitivity adjustment for each of a plurality of imaging elements along a gradation change direction in a gradation stepwise change pattern. preferable.

  Thus, the sensitivity adjustment unit of the imaging apparatus performs sensitivity adjustment for each of the plurality of image pickup elements along the gradation change direction in the gradation step change pattern, so that sensitivity suitable for gradation can be obtained. Therefore, inspection can be performed without causing halation and insufficient sensitivity.

  In the display panel inspection apparatus of the present invention, it is preferable that the imaging device is composed of a TDI sensor type camera.

  The TDI sensor type camera is a scanning camera, and by combining the scanning speed and the exposure cycle, a uniform and highly accurate captured image can be obtained by a single scan even for a wide display panel. .

  In the display panel inspection apparatus of the present invention, there are a plurality of light sources that irradiate the display panel from behind, and an irradiation unit that controls increase / decrease of the amount of light applied to the display panel of each light source, and the gradation is A light amount control means for controlling the irradiation means so that the higher the display area, the smaller the irradiation light amount of the light source to the display panel, and the lower the gradation, the larger the irradiation light amount of the light source to the display panel; It is preferable to provide.

  Conventionally, in the inspection with the entire white display inspection pattern, when the backlight luminance is high, the black spot becomes inconspicuous, making it difficult to find the defect, and in the inspection with the entire black display inspection pattern, the backlight luminance is high. When it was small, the bright spot was not noticeable, and it was difficult to find defects.

  Thus, for example, in the display panel inspection method disclosed in Patent Document 1, for example, by increasing the intensity of the entire backlight to increase the relative intensity of the luminescent spots with respect to the background during the luminescent spot defect inspection in the entire black display inspection pattern. Control of backlight intensity suitable for a plurality of display modes and inspection purposes has been performed.

  However, there are various inspection patterns. For example, in the inspection pattern using the gradation step change pattern, the method of increasing or decreasing the intensity of the entire backlight according to Patent Document 1 is appropriate for the imaging device. Cannot match the sensitivity.

  Therefore, in the present invention, the irradiating means has a plurality of light sources that irradiate the display panel from behind, and controls the increase and decrease of the amount of light irradiated to the display panel of each light source, and the light quantity control means has a high gradation. The irradiation means is controlled so that the amount of light applied to the display panel of the light source is reduced as the display area is reduced, and the amount of light applied to the display panel of the light source is increased as the display area is lower in gradation.

  Therefore, in the case of having an inspection pattern having two or more types of display areas with different gradations simultaneously, it is possible to detect a defect for each display area with high accuracy.

  By the way, in the present invention, when the screen of the display panel that is divided into a plurality of screens in at least one direction and is simultaneously driven independently is imaged by the imaging device and the display panel is inspected for defects, A problem arises when a gradational change pattern of gradation is displayed as an inspection pattern on a divided screen.

  That is, conventionally, the gradation step change pattern displayed on each divided screen of the display panel is repeated in the same order for each divided screen. For this reason, in the imaging region including the boundary of the divided screen in the imaging device, the white display portion and the black display portion are mixed, and thus it is not possible to adjust the amount of light satisfying both at once.

  On the other hand, in the present invention, the inspection pattern display means displays the gradation step change pattern displayed on each divided screen of the display panel alternately in ascending order and descending order or descending order and ascending order for each divided screen. Ascending / descending order arranging means is arranged.

  As a result, the imaging area including the boundary of the divided screen can be a white display portion or a black display portion.

  Therefore, it is possible to appropriately adjust the light amount of the irradiation unit that irradiates the white display portion or the black display portion in the imaging region including the boundary of the divided screen.

  In the display panel inspection apparatus of the present invention, it is preferable that the light source is a fluorescent tube, and the light amount control means controls the amount of light applied to the display panel of the fluorescent tube.

  Accordingly, since the light source is made of a fluorescent tube, for example, when a general fluorescent tube is used as a light source of a liquid crystal panel, the display panel has a test pattern having at least two types of display areas with different gradations simultaneously. In some cases, it is possible to detect a defect for each display region with high accuracy.

  In the display panel inspection apparatus of the present invention, it is preferable that the light source includes a light emitting element, and the light amount control unit controls the amount of light applied to the display panel by the light emitting element.

  Accordingly, since the light source is composed of a light emitting element, when using a light emitting element that has recently been used as a light source of a display panel, at least two types of display areas having different gradations are simultaneously provided on the display panel. In the case of having the inspection pattern, it is possible to detect the defect for each display region with high accuracy.

  In the display panel inspection apparatus of the present invention, it is preferable that the display panel inspection apparatus further includes a transport unit that transports and arranges the display panel at a position facing the imaging apparatus.

  Accordingly, it is possible to separate the display panel from the imaging device and other components. Therefore, it is possible to perform inspection while fixing components other than the display panel and sequentially replacing the display panel.

  The display panel inspection apparatus may be realized by a computer. In this case, the display panel inspection apparatus is realized by the computer by causing the computer to operate as the above-described means. The inspection program and a computer-readable recording medium recording the inspection program also fall within the scope of the present invention.

  As described above, the display panel inspection apparatus of the present invention divides the screen of the display panel into a plurality of screens in at least one direction and simultaneously drives them independently of each other, and each of the divided screens of the display panel. And an inspection pattern display means for displaying a gradation step change pattern as the inspection pattern, and the inspection pattern display means includes a gradation change displayed on each divided screen of the display panel. Ascending / descending order arranging means for arranging the patterns alternately in ascending order and descending order or descending order and ascending order for each divided screen is provided.

  In addition, as described above, the display panel inspection method of the present invention divides the screen of the display panel into a plurality of screens in at least one direction and simultaneously drives them independently of each other, and each of the divisions of the display panel. An inspection pattern display step for displaying a gradation step change pattern as an inspection pattern on the screen, and a gradation step change pattern displayed on each divided screen of the display panel are alternately arranged in ascending order for each divided screen. And an ascending / descending order arranging step of arranging in descending order or descending order and ascending order.

  In addition, as described above, the method for manufacturing a display panel according to the present invention includes the step of disposing the display panel at a position opposite to the imaging device in the display panel inspection device described above, and the imaging device in the display panel inspection device. And a step of inspecting the display panel disposed at the opposing position by the above-described display panel inspection method.

  Therefore, in a display panel that divides and drives the screen, when the inspection pattern in which the gradation is displayed in a step-change pattern for each divided screen is imaged by the imaging device and defect inspection is performed, halation and insufficient sensitivity occur. There is an effect that it is possible to provide a display panel inspection apparatus, a display panel inspection method, and a display panel manufacturing method capable of performing inspection with a single imaging.

  An embodiment of the present invention will be described with reference to FIGS. 1 to 15 as follows.

  A configuration of a liquid crystal panel inspection apparatus as an inspection apparatus for inspecting a liquid crystal panel as a display panel of the present embodiment will be described with reference to FIG. FIG. 2 is a block diagram showing a configuration of the liquid crystal panel inspection apparatus 10.

  As shown in FIG. 2, the liquid crystal panel inspection apparatus 10 includes, for example, a fluorescent tube 1a as five light sources for irradiating light, for example, to a transmissive liquid crystal panel 11 to be inspected, and light from the fluorescent tube 1a. A backlight unit 1 as an irradiating means comprising a diffusion plate 1b for diffusing light, a backlight control device 2 as a light quantity control means for controlling lighting of the backlight unit 1, and lighting of the liquid crystal panel 11. A liquid crystal panel lighting signal generator 20 as an inspection pattern display means, a camera 3 as an imaging device for imaging the liquid crystal panel 11 from the front, a scanning stage 4 of the camera 3, and a liquid crystal panel 11 captured by the camera 3 An image processing device 5 that performs image processing on the image of the image, an inspection control device 30, a transport conveyor (not shown) as transport means, a factory information system, And a not-shown communication device.

  The inspection control device 30 controls the entire liquid crystal panel inspection device 10, and starts preparation for inspection in response to an inspection request from a transport conveyor or a factory information system, and acquires and inspects model information to be inspected. In order to perform recipe setting, camera imaging condition setting, and inspection pattern display for inspection, the backlight control device 2, liquid crystal panel lighting signal generator 20, camera 3 imaging condition setting, and camera 3 scanning are performed. The drive on the stage 4 and the image processing apparatus 5 are controlled.

  In the present embodiment, the liquid crystal panel inspection apparatus 10 is provided independently of the liquid crystal panel 11 to be inspected, and is fixed as a part of the manufacturing apparatus. And the liquid crystal panel 11 moves on the conveyance line by a conveyance conveyor, for example, and is sequentially installed in the opposing position of the camera 3 in the liquid crystal panel test | inspection apparatus 10, and the front surface position of the backlight unit 1. FIG.

  The liquid crystal panel 11 includes a display screen 11a as a screen, a frame 11b, a wiring connection portion (not shown), and driver boards.

  In this embodiment, in order to perform high-speed driving, the source driver is dividedly driven as a divided structure.

  Therefore, in the present embodiment, the display screen 11a of the liquid crystal panel 11 is divided into, for example, two parts in the vertical direction, and the gradation is controlled on the frame 11b of the liquid crystal panel 11 as shown in FIG. Two source drivers 12a and 12b are provided. For example, the source driver 12a is provided on the frame 11b on the upper side (the upper side in FIG. 2) of the liquid crystal panel 11, and the source driver 12b is provided on the frame 11b on the lower side (the lower side in FIG. 2) of the liquid crystal panel 11. Is provided. In the present embodiment, the liquid crystal panel 11 is divided into two parts in the vertical direction for the sake of simplicity. However, the liquid crystal panel 11 is not necessarily limited to this, and is divided into a larger number of divisions such as three parts, four parts, etc. May be. In the present embodiment, although it is divided in the vertical direction, it is not necessarily limited thereto, and may be divided in the horizontal direction. Furthermore, the vertical division and the horizontal division may be combined.

  A gate driver 13 for controlling the scanning lines is provided on the frame 11b on the left side of the liquid crystal panel 11, for example (left side in FIG. 2). In the present invention, the source drivers 12a and 12b and the gate driver 13 have a function as screen division driving means.

  In the present embodiment, as will be described later, the liquid crystal panel lighting signal generator 20 is provided with a control circuit 26 that is a control circuit for controlling the source drivers 12a and 12b and the gate driver 13. However, the present invention is not necessarily limited to this, and the liquid crystal panel 11 may include a control circuit for controlling the source drivers 12a and 12b and the gate driver 13.

  Further, the liquid crystal panel 11 does not include a backlight that is necessary when the product is a product.

  The liquid crystal panel 11 installed in the liquid crystal panel inspection apparatus 10 is irradiated with light from the back through five fluorescent tubes 1a whose brightness can be controlled independently in the backlight unit 1, and diffuses this light. The light is diffused by the plate 1 b to enter the liquid crystal panel 11. Next, the transmitted light of the liquid crystal panel 11 is observed by the camera 3 installed in front of the liquid crystal panel 11.

  The camera 3 is controlled by the inspection control device 30, and the inspection image captured from the front of the liquid crystal panel 11 by the camera 3 is image-processed by the image processing device 5 and is subjected to density comparison, thereby determining defects. Is done.

  In the present embodiment, the camera 3 is a scanning TDI sensor type camera having a TDI (Time Drey Integrated) function, and as shown in FIG. 3, 1 × m (m is a natural number). And a line sensor composed of an image sensor 3a, which is a light receiving element made of a photodiode, and the image sensor 3a has n charges (n is a natural number satisfying n ≦ m) for each image sensor 3a. An amplifier unit 3b is provided as sensitivity adjustment means for amplification. The line sensor having the TDI function is composed of several tens of line sensors. By adjusting the scanning speed to the exposure period, pixels of one column to a plurality of columns of the liquid crystal panel 11 per exposure cycle can be obtained. An image can be taken.

  By controlling each amplifier unit 3b, it is possible to perform gain adjustment, which is sensitivity adjustment, for each region of the plurality of image pickup devices 3a in a direction perpendicular to the change direction of the gradation step change pattern of the display screen 11a. Become. Therefore, when n in the amplifier 1 to the amplifier n of the amplifier unit 3b is 16, for example, gain adjustment is performed for each of the imaging regions TAP1 to TAP16 parallel to the scanning direction as shown in FIG. It becomes possible.

  Each imaging region TAP1 to TAP16 does not need to correspond to each stage in the gradation step change pattern. For example, as shown in FIG. 11 to be described later, there are 16 imaging regions TAP1 to TAP16 (amplifier 1 to amplifier 16), but the number of stepwise change patterns is larger (for example, 8 bits, 256 floors). Key). Further, as long as the difference between adjacent step changes can be adjusted by one amplifier n, one amplifier n may straddle the boundary portion of the step changes.

  In this scanning type TDI sensor type camera, generally, there is a possibility that halation (saturation) occurs in a high light amount region or insufficient sensitivity occurs in a low light amount region when the light intensity of the inspection target exists. Also in this case, in the present embodiment, the halation and lack of sensitivity regions are obtained in the backlight unit 1 including the five fluorescent tubes 1a that can control the brightness independently by changing the inspection pattern display method. By controlling the amount of light, high-sensitivity inspection can be performed over the entire inspection object.

  The backlight control device 2, the liquid crystal panel lighting signal generation device 20, and the camera 3 are all controlled by the inspection control device 30 while being synchronized.

  By adopting such a configuration, it becomes possible to provide a defect inspection of the liquid crystal panel 11 regardless of the backlight specification of the final product.

  Here, in order to obtain the cause of the defect at the time of inspection, generally, inspection patterns which are various display patterns are displayed on the display screen 11 a of the liquid crystal panel 11.

  In the present embodiment, the display on the display screen 11 a of the liquid crystal panel 11 can be controlled by the liquid crystal panel lighting signal generator 20.

  By the way, as defects of the liquid crystal panel 11, for example, dot pixel defects such as black spots and bright spots, line defects such as black lines and bright lines, or phenomena such as spots / unevenness appear, but the cause of defects for these phenomena is uniform. There are various things.

  For example, a minute point defect is a point having a luminance higher than a desired luminance level when driven by giving a display signal due to abnormality of a TFT (Thin Film Transistor) constituting the display element of the liquid crystal panel 11, for example. Or a point having a luminance lower than a desired luminance level is displayed. In addition, the polarization state is disturbed by the presence of minute foreign matter in the liquid crystal layer, between the polarizing plate group and the TFT substrate, or between the polarizing plate group and the CF (Color Filter) substrate, and the level is similarly lower than the desired luminance level. A point with high luminance or a point with low luminance may be displayed. Note that one picture element in the color liquid crystal panel 11 is generally composed of three dots, and these dots are red (R) dots, green (G) dots, and blue (B) dots in one picture element. It has three colors. Regarding the description of the present embodiment, illustration of red (R) dots, green (G) dots and blue (B) dots is omitted, but the application target panel of the present invention is not limited.

  Next, line defects are those in which lines with higher or lower luminance than the desired luminance level are displayed due to abnormalities in the driver for driving the TFT or disconnection / short-circuiting of signal lines. .

  Spots and unevenness occur due to an abnormality in the film thickness of the thin film in the manufacturing process of the TFT substrate and the CF substrate, an abnormality in the cell gap of the liquid crystal layer between the TFT substrate and the CF substrate, and the like.

  An inspection pattern which is a display pattern displayed on the liquid crystal panel 11 in order to inspect the liquid crystal panel 11 will be described in detail with reference to FIGS.

  For example, as shown in FIG. 4A, the entire white display D1 inspection pattern is displayed. In this entire white display D1 inspection pattern, for example, in the normally black mode, the pixels of the liquid crystal panel 11 are in a state of, for example, gradation 255, that is, a transmission state with a light transmission amount of 100%. When it appears, the dot is always in the off state, and it can be understood that the dot has a defect. Further, in FIG. 4A, when a black line appears, it can be understood that the dot row is always in the off state, and that there is a defect in the source bus line that supplies data to the dot row. .

  Similarly, as shown in FIG. 4B, in the entire black display D2 inspection pattern, for example, in the normally black mode, all the dots on the liquid crystal panel 11 are in the state of, for example, gradation 0, that is, the light transmission amount is 0%. When a bright spot appears at this time, it can be grasped that the dot is always lit and a defect exists in the dot. Further, in FIG. 4B, when a bright line appears, it can be understood that the dot row is always lit and that a defect exists in the source bus line that supplies data to the dot row.

  In addition, as a cause of the defect, for example, when a charge is applied to a dot other than the corresponding dot in the vertical direction in the liquid crystal panel 11, there is a leak defect in which the charge flows into the dot due to the leakage of the wiring.

  In order to find such a leak defect, as shown in FIGS. 5A and 5B, a monochrome display D3 or a black-and-white display in which half of the liquid crystal panel 11 is displayed in white and the remaining half of the liquid crystal panel 11 is displayed in black. Inspect at D4.

  For example, in order to find a defect of so-called SD leak that occurs due to leakage of charge in the source (S) direction to the drain (D), as shown in FIGS. For example, a voltage of gradation 255 is applied to the dot source (S), and the display of the liquid crystal panel 11 is divided into two vertically and the inspection is performed with the gate (G) turned off for each half surface.

  In this inspection pattern, when the dot source (S) and drain (D) are short-circuited, as shown in FIGS. A bright spot indicating a gradation) is generated.

  That is, in the half-black display in which the gate (G) is off, if there is an SD leak in the dot, the voltage change of the source (S) voltage becomes the voltage change of the dot as it is via the drain (D). Therefore, if a bright spot defect exists in the black display region in the gate (G) off period, it can be understood that the defect is an SD leak defect.

  5A and 5B, when the inspection is performed in the monochrome display D3 or the black-and-white display D4, the corner of the white display portion in the monochrome display D3 is used when the liquid crystal panel 11 is aligned. It is necessary to check whether the corner angle of the liquid crystal panel 11 matches the predetermined position. In this case, if the corner of the white display portion in the monochrome display D3 is too bright, it is difficult to confirm the position. Therefore, in the white display portion, even when the alignment of the corners of the liquid crystal panel 11 is performed, the alignment can be easily performed by adjusting the light amount of the fluorescent tube 1a.

  Next, there is a defect that a specific gradation display becomes abnormal due to a defect of the source driver. In order to find such a driver defect, for example, as shown in FIG. 6, an inspection pattern of all gradation display D5 with gradation step change pattern (gradation) is displayed from the upper side to the lower side of the screen. . As a result, it is possible to find the line defect of the specific gradation line defect F1 which is a line defect having a conspicuous contrast at a specific gradation or the specific gradation defect F2 caused by the operation failure of a specific bit in the driver. For example, the minimum gradation 0 to the maximum gradation 255 are represented by 8 bits. For this reason, if one of the 8 bits is defective, a bright line defect appears in the gradation range using the defective bit.

  For simplicity, the number of gradation display is 3 bits, the number of picture elements in the direction parallel to the source bus line is 8, and the gradation display is performed in order from the upper edge side of the liquid crystal panel 11 (ascending order). Will be described with reference to FIGS. 7A to 7D.

  When the source driver is normal, gradations 0, 1, 2, 3,..., 6, 7 are displayed in order from the picture element on the upper edge side of the liquid crystal panel 11, as shown in FIG. However, if there is an abnormality in the first bit due to a defect in the source driver, it is displayed as shown in FIG. Similarly, a case where there is an abnormality in the second bit and the third bit is shown in FIGS. Therefore, in order to inspect a specific gradation defect in which a specific gradation display becomes abnormal due to such a defect of the source driver, gradation display is performed in gradation as a gradation distribution in a direction parallel to the source bus line. For example, when displaying a gradation distribution of 256 gradations on a picture element of 1080 pixels in the direction parallel to the source bus line, for example, 4 pictures per gradation, as shown in FIGS. The gradation stepwise change pattern is displayed using the element.

  In the present embodiment, as described above, the inspection pattern which is the display pattern of the liquid crystal panel 11 is for the sake of simplicity, the entire white display D1, the entire black display D2, the black and white display D3, the black and white display D4, and the all gradation display D5. 5 patterns. However, the present invention is not necessarily limited to this, and more inspection patterns can be used.

  By the way, when such a defect occurs in the liquid crystal panel 11, the point defect and the line defect can be recognized by a human visual inspection. For example, when the black point defect inspection in the entire white display D1 is performed, the backlight unit 1 When the light quantity of the fluorescent tube 1a is constant, the dots are finer than the liquid crystal panel 11 and may be overlooked. On the other hand, even when the light intensity of the fluorescent tube 1a in the backlight unit 1 is constant during the bright spot defect inspection in the entire black display D2, the dots are finer than the liquid crystal panel 11 and can be overlooked. There is sex.

  Further, not only for visual inspection but also when an image of the liquid crystal panel 11 is captured by the camera 3, since the camera 3 has a certain range of sensitivity to brightness, black spots or the like in the entire white display D1 are present. There is a possibility that it does not appear. In other words, when the inspector visually inspects, even if there is a difference in panel brightness as described above by the light amount adjustment function of the human eye, it can be handled, but the inspection is performed using mechanical means such as a camera. When performing, due to the limitation of the dynamic range, a region where the inspection accuracy is improved and a region where the inspection accuracy is lowered are mixed.

  Therefore, for example, in Patent Document 1, the relative intensity of the bright spot with respect to the background is increased by increasing the intensity of the backlight in the entire black display D2, and the intensity of the black dot is decreased by decreasing the intensity of the backlight in the entire white display D1. The relative strength with respect to the background is lowered. This makes it easy for inspectors to find defects.

  However, when performing monochrome display D3, black-and-white display D4, and all gradation display D5 as in the present embodiment, even if the intensity of the backlight unit 1 is increased or decreased, bright spots or black spots are displayed on the entire display screen 11a. An appropriate relative intensity with respect to the background cannot be obtained. For example, a bright region causes halation to emphasize a dark region, and conversely, the luminance of a dark region decreases to suppress a bright region.

  Therefore, in the present embodiment, when the liquid crystal panel 11 is inspected, the backlight control device 2 uses the backlight unit 2 for each region corresponding to the inspection pattern so as to reduce the density of the inspection pattern that causes a defect to appear. 1 controls the light quantity output of the fluorescent tube 1a. That is, for example, five fluorescent tubes 1a as a plurality in the backlight unit 1 can individually control to increase or decrease the amount of emitted light. In the liquid crystal panel inspection apparatus 10 of the present embodiment, the fluorescent tube 1a can be individually controlled in five regions in the vertical direction of the liquid crystal panel 11, but this is the liquid crystal panel to be inspected. This is because 11 drivers are common in the vertical direction of the liquid crystal panel 11.

  Here, the backlight control device 2 reduces the amount of light emitted from the fluorescent tube 1a in the display region where the light transmission amount of the liquid crystal panel 11 is large, and emits light from the fluorescent tube 1a in the display region where the light transmission amount of the liquid crystal panel 11 is small. The backlight unit 1 is controlled so as to increase the amount of light.

  Specifically, in the case of the entire white display D1 shown in FIG. 4A, as shown in FIG. 9A, the lighting pattern LP1 in which the light quantity of all the fluorescent tubes 1a is set to, for example, 50% luminance. . That is, in the entire white display D1 shown in FIG. 4A, since the defect of the liquid crystal panel 11 can be recognized even if the light quantity of the fluorescent tube 1a is not large, as shown in FIG. The brightness can be kept small.

  Further, in the case of the entire black display D2 shown in FIG. 4B, as shown in FIG. 9B, the lighting pattern LP2 in which the light amounts of all the fluorescent tubes 1a are set to 100% luminance, for example, is used. That is, in the entire black display D2 shown in FIG. 4B, it is difficult to recognize defects in the liquid crystal panel 11 unless the light quantity of the fluorescent tube 1a is large. As shown in FIG. For example, the luminance of 1a is set to a maximum of 100%.

  In the same way of thinking, in the case of the black and white display D3 shown in FIG. 5A, as shown in FIG. 9C, the light quantity of the fluorescent tubes 1a in the region 1 and the region 2 close to the white display part is set to, for example, the luminance. The lighting pattern LP3 is 50%, and the light quantity of the fluorescent tubes 1a in the regions 3 to 5 close to the black display region is, for example, 100% luminance. In the case of the black-and-white display D4 shown in FIG. 5B, as shown in FIG. 9D, the light quantity of the fluorescent tubes 1a in the regions 1 to 3 close to the black display part is set to, for example, 100% luminance, and white display is performed. For example, a lighting pattern LP4 in which the light quantity of the fluorescent tubes 1a in the region 4 and the region 5 near the part is 50% in luminance is used. Finally, in the case of the all gradation display D5 shown in FIG. 6, as shown in FIG. 9 (e), the light quantity of the fluorescent tube 1a in the region 1 is set to, for example, 50% luminance in the order from white display to black display. The light intensity of the fluorescent tube 1a in the area 2 is set to, for example, luminance 62.5%, the light intensity of the fluorescent tube 1a in the area 3 is set to 75%, for example, and the light quantity of the fluorescent tube 1a in the area 4 is set to, for example, 87.5%. For example, a lighting pattern LP5 in which the light quantity of the fluorescent tube 1a of No. 5 is 100% luminance is used. In this way, the output value of the fluorescent tube 1a of the backlight unit 1 is controlled so as to be opposite to the gradation level.

  As a result, the amount of black background light is reduced in the white display portion of the liquid crystal panel 11, and the amount of bright spot light is increased in the black display portion of the liquid crystal panel 11. Therefore, it becomes easy for an inspector to find a defect in human visual inspection. In addition, when the image of the liquid crystal panel 11 is captured by the camera 3, the sensitivity range of the camera 3 is obtained, and mechanical automatic detection by the camera 3 can be performed.

  As described above, in the present embodiment, the display screen 11a of the liquid crystal panel 11 is divided and driven by using the source drivers 12a and 12b as a divided structure. When the all gradation display D5 is displayed on the screen divided into two in the division driving by the source drivers 12a and 12b, as shown in FIGS. 19A and 19B, which are conventional explanatory diagrams, gradations are displayed. The stepwise gradation pattern is repeatedly displayed. Note that the gradation step change pattern may be in ascending order or descending order.

  In this case, when a specific gradation defect is inspected by visual inspection, the dynamic range of human eyes is excellent, and it is possible to perform inspection from a bright gradation to a dark gradation at a time. However, when the inspection is performed using the camera 3, the sensitivity at the dark gradation is insufficient when the sensitivity is adjusted to the bright gradation, and the halation is caused at the bright gradation when the sensitivity is adjusted to the dark gradation. Therefore, it has been necessary to once inspect an image in which the sensitivity is adjusted to the bright gradation, and to be inspected again in accordance with the sensitivity to the dark gradation.

  Here, in order to capture the display screen with the TDI sensor type camera, as shown in FIG. 20, for example, a range slightly wider than the liquid crystal panel 211 is captured. The range slightly wider than the liquid crystal panel 211 is divided into, for example, imaging areas TAP1 to TAP16 divided into, for example, 16 parts from the upper side to the lower side of the range, corresponding to the imaging possible area of the TDI sensor type camera.

  And when the irradiation light quantity of five fluorescent tubes in a backlight unit is constant, the gain which is a sensitivity of a camera is adjusted according to the magnitude | size of a gradation. Specifically, as shown in FIG. 21A, the gain is set lower as the gradation is higher (white side), and the gain is set higher as the gradation is lower (black side).

  As a result, the relationship between gradation and gain is as shown in FIG. At this time, in the imaging area TAP9 of the camera, as shown in FIG. 20, it extends over both the case where the gradation is maximum and the case where the gradation is minimum. As a result, even if the irradiation light amount of the central portion of the liquid crystal panel 211 is adjusted by using the method for controlling the irradiation light amount of the fluorescent tube of the backlight unit for each region, it is impossible to capture an image at a time. . This is because the sensitivity of the bright gradation portion and the dark gradation portion cannot be appropriately adjusted at a time.

  In order to solve this problem, in this embodiment, the gradation step change pattern displayed on each divided screen of the liquid crystal panel 11 is alternately in ascending order and descending order, or descending order and ascending order for each divided screen. It arrange | positions like this.

  As a result, as shown in FIG. 19A, as shown in FIG. 19A, the gradation step change pattern is in descending order → descending order from the upper side of the liquid crystal panel 211 for each divided screen. Descending order → ascending order. Further, as shown in FIG. 19B, as shown in FIG. 10B, as shown in FIG. 10B, the gradation step change pattern is in ascending order → ascending order from the upper side of the liquid crystal panel 211 for each divided screen. Ascending order → descending order. As a result, as shown in FIG. 10A, when the descending order is changed to ascending order, the central portion of the liquid crystal panel 11 is displayed in black, while as shown in FIG. 10B, the order is ascending order → descending order. The center portion of the liquid crystal panel 11 is displayed in white.

  Therefore, for example, as shown in FIG. 10A, when the descending order is changed to the ascending order, the display screen 11a of the liquid crystal panel 11 displays black in the entire area of the imaging area TAP9 as shown in FIG. It has become. That is, by inverting and displaying the inspection pattern in the upper or lower region, the inspection pattern does not have a sharp gradation change in the central portion of the display screen 11a. As a result, it is possible to set the gain that is the sensitivity of black display at the center of the display screen 11a.

  Further, for example, as shown in FIG. 10B, when the order is ascending order → descending order, the center portion of the display screen 11a of the liquid crystal panel 11 is displayed in white as shown in FIG. 12A. ing. Therefore, as shown in FIG. 12B, the entire area of the imaging area TAP9 is displayed in white.

  As described above, the inspection pattern in the upper area of the liquid crystal panel 11 or the inspection pattern in the lower area is inverted and displayed, so that an inspection pattern without a sharp gradation change is obtained in the central portion of the display screen 11a. . As a result, it is possible to appropriately capture an image with a gain that is a sensitivity of white display at the center of the display screen 11a.

  In the present embodiment, the inspection pattern display means is arranged so that the gradation stepwise change pattern in the divided screen of the liquid crystal panel 11 is alternately arranged in ascending order and descending order or descending order and ascending order for each divided screen. Ascending / descending order arranging means of the liquid crystal panel lighting signal generating device 20 is performed.

  The configuration of the liquid crystal panel lighting signal generator 20 will be described with reference to FIG. FIG. 1 is a block diagram showing the configuration of the liquid crystal panel lighting signal generator 20.

  As shown in FIG. 1, a liquid crystal panel lighting signal generator 20 includes a model information input unit 21 as a model information unit, a signal data storage unit 22, a signal data load unit 23 as a positive signal data acquisition unit, An inverted data creation circuit 24 as an order arrangement means and an inverted data creation means, an input selection circuit 25 as an ascending / descending order arrangement means and a normal / inverted signal data switching means, and a control circuit 26 as a control signal output means Have.

  The model information input unit 21 can input the model information of the liquid crystal panel 11 to be inspected. By inputting the model information of the liquid crystal panel 11 to be inspected from the model information input unit 21, The number of source drivers is input to the input selection circuit 25, and a signal ID corresponding to the inspection pattern to be displayed is input to the signal data load unit 23.

  In the present embodiment, the data of the inspection pattern to be displayed is registered in advance in the signal data storage unit 22 in the liquid crystal panel lighting signal generator 20, and is loaded every time the inspection is performed. However, the present invention is not necessarily limited to this, and test pattern data to be displayed may be input from the outside. In addition, the number of divisions of the source drivers 12a and 12b may not be input if the model is fixed, for example, vertically divided into two.

  The signal data loading unit 23 reads, for example, a descending gradation inspection pattern from the signal data storage unit 22 as a gradation step change pattern. Then, the gradation inspection pattern in descending order as the read gradation step change pattern is input to the input selection circuit 25 as a normal signal and also input to the inverted data generation circuit 24.

  The inverted data creation circuit 24 creates an ascending gradation test pattern as a gradation step change pattern which is a test pattern inverted with respect to the descending gradation test pattern as the gradation step change pattern described above. , Input to the input selection circuit 25. For example, in the case of 3 bits, the normal signal is (0, 1, 2, 3, 4, 5, 6, 7) and the inverted signal is (7, 6, 5, 4, 3, 2, 1, 0). It becomes.

  The input selection circuit 25 distributes the normal signal and the inverted signal to the source driver 12a that is the upper source driver and the source driver 12b that is the lower source driver. Here, when there are three or more source drivers, for example, a normal signal is distributed to even-numbered source drivers and an inverted signal is distributed to odd-numbered source drivers. Thus, for example, in the case of odd division such as three divisions, ascending order → descending order → ascending order alternately for each divided screen, or ascending order and descending order are alternately arranged so that descending order → ascending order → descending order. Established. Accordingly, the boundary of each divided screen is white → white or black → black, and white → black or black → white.

  In the input selection circuit 25, based on the number of source drivers input from the model information input unit 21, selection is performed alternately in ascending order and descending order, or descending order and ascending order for each divided screen, and each is inverted with a normal signal. The signal is distributed to the source drivers 12a and 12b and output.

  As a result, in the liquid crystal panel 11, as shown in FIGS. 10A and 10B, the gradation step change pattern is alternately changed in ascending order and descending order for each divided screen so that the central portion is displayed in black, or Displayed in descending and ascending order.

  Finally, the control circuit 26 outputs various control signals such as a video signal, a clock signal, and a timing signal, a reference voltage, and the like.

  By the way, in this Embodiment, as above-mentioned, each fluorescent tube 1a of the backlight unit 1 can set the irradiation light quantity separately. Therefore, the individual irradiation light amount setting of each fluorescent tube 1a in the backlight unit 1 and the gradation step change pattern in the divided screen of the liquid crystal panel 11 are alternately changed in ascending order and descending order or descending order and ascending order for each divided screen. The operation when combined with the arrangement will be described below.

  That is, as shown in FIG. 13A, the brightness of the fluorescent tube 1a of the backlight unit 1 is set lower as the gradation is higher (white side), and the backlight unit is lower as the gradation is lower (black side). It is necessary to set the luminance of one fluorescent tube 1a high.

  However, when the gradation step change pattern is in ascending order and ascending order or descending order and descending order for each divided screen, as shown in FIG. It is difficult to control the illumination light quantity of the fluorescent tube 1a.

  On the other hand, in the present embodiment, as shown in FIG. 14A, for example, when the gradation step change pattern is in ascending order and descending order for each divided screen, the central region 3 is displayed. Since white display is performed, as shown in FIG. 14B, it becomes easy to control the amount of light emitted from the fluorescent tube 1a in the central region 3.

  Further, after setting the gain, by setting the illumination light amount of the fluorescent tube 1a, it is possible to obtain more appropriate imaging conditions.

  The inspection control device 30 controls such a series of processing. The control flow of this process will be described with reference to FIG.

  As shown in FIG. 15, when there is an inspection processing request from the factory information system, the inspection control device 30 acquires inspection information from, for example, the signal data storage unit 22 (S1).

  Next, as a preparation for imaging, the gain setting of the camera 3 is performed (S2). At this time, the backlight control device 2 is controlled (S3), the lighting of the fluorescent tube 1a is switched (S4), and the liquid crystal panel lighting signal generator 20 is controlled (S5). An inspection pattern is displayed (S6).

  Next, imaging is performed by the camera 3 while controlling the scanning stage 4 (S7) (S8). Then, the imaging data of the camera 3 is subjected to image processing and inspection processing is performed (S9), and for example, the inspection result is output to the signal data storage unit 22 (S10).

  Thereafter, in order to perform an inspection using another inspection pattern, the process returns to S2 and S3 again, and the processes of S2 to S10 are repeated. Then, when the inspection process for all the target areas is finished, the inspection of the liquid crystal panel 11 is finished, and the next liquid crystal panel 11 is inspected.

  That is, in general, in the lighting inspection, it is necessary to inspect with a plurality of inspection patterns, and in accordance with the number of inspection patterns, setting of camera imaging conditions and display of inspection patterns for performing inspection are performed in advance. When the inspection of all the inspection patterns is completed, the inspection result is transmitted to the factory information system, and the liquid crystal panel 11 is carried out.

  In S1 and S10, for example, inspection information is acquired from the signal data storage unit 22 and, for example, the inspection result is output to the signal data storage unit 22. However, the present invention is not limited to this. For example, it is possible to output the inspection result to the factory information system.

  As described above, the liquid crystal panel inspection apparatus 10 according to the present embodiment includes the liquid crystal panel lighting signal generator 20 that controls the inspection pattern of the liquid crystal panel 11 and the display screen 11a controlled by the liquid crystal panel lighting signal generator 20. The camera 3 which is a means to image is provided. In the liquid crystal panel lighting signal generator 20 which is a signal generator in the liquid crystal panel inspection apparatus 10, the source drivers 12 a and 12 b are divided and operated simultaneously in at least one direction of the display screen 11 a of the liquid crystal panel 11. The liquid crystal panel 11 includes a model information input unit 21 that is a unit that inputs model information including the number of screen divisions, and a signal data load unit 23 that is a unit that loads signal data of an inspection pattern having a preset gradation. And inverted data creation circuit 24 which is means for creating inverted data obtained by inverting the signal data, and the source drivers 12a and 12b in the order of odd and even numbers at the timing of driving the liquid crystal panel 11 with the normal signal data and the inverted signal data. An input selection circuit 25 that is means for outputting to the gate driver 13 and a control circuit 26 that is means for outputting timing signals to the source drivers 12a and 12b and the gate driver 13 are provided.

  Further, the camera 3 performs gain adjustment for each of the plurality of imaging regions TAP1 to TAP16 in the direction perpendicular to the gradation change direction in the gradation change pattern of gradation. Furthermore, the display screen 11a controlled by the liquid crystal panel lighting signal generator 20 has a backlight control device 2 that controls the output value of the backlight unit 1 so as to be opposite to the gradation distribution. And the display screen 11a of the liquid crystal panel 11 is imaged with the camera 3, and quality determination is performed.

  In this way, in particular, in order to prevent a decrease in dot holding voltage due to the length of the signal line and to make the luminance of the display screen 11a uniform, the source driver is divided so that the upper and lower regions of the display screen 11a In the liquid crystal panel inspection apparatus 10 of the liquid crystal panel 11 driven by the drivers 12a and 12b, when an inspection pattern having a gradation distribution is displayed, inspection is performed with one imaging without causing halation or lack of sensitivity. Can be performed.

  In the present embodiment, the liquid crystal panel 11 is a transmission type, but in the present invention, a reflection type liquid crystal panel 11 may be used. In the present invention, the display panel may be a display panel using a light emitting element. In these cases, the backlight unit 1 is unnecessary.

  Finally, each block of the liquid crystal panel inspection apparatus 10, particularly the inspection control apparatus 30, the liquid crystal panel lighting signal generation apparatus 20, and the backlight control apparatus 2 may be configured by hardware logic, or as described below. It may be realized by software using

  That is, the liquid crystal panel inspection apparatus 10 includes a CPU (central processing unit) that executes instructions of a control program that realizes each function, a ROM (read only memory) that stores the program, and a RAM (random access memory) that expands the program. ), A storage device (recording medium) such as a memory for storing the program and various data. An object of the present invention is a recording medium in which a program code (execution format program, intermediate code program, source program) of a control program of the liquid crystal panel inspection apparatus 10 which is software for realizing the functions described above is recorded so as to be readable by a computer. Can also be achieved by reading the program code recorded in the recording medium and executing it by the computer (or CPU or MPU).

  Examples of the recording medium include a tape system such as a magnetic tape and a cassette tape, a magnetic disk such as a floppy (registered trademark) disk / hard disk, and an optical disk such as a CD-ROM / MO / MD / DVD / CD-R. Card system such as IC card, IC card (including memory card) / optical card, or semiconductor memory system such as mask ROM / EPROM / EEPROM / flash ROM.

  Further, the liquid crystal panel inspection apparatus 10 may be configured to be connectable to a communication network, and the program code may be supplied via the communication network. The communication network is not particularly limited. For example, the Internet, intranet, extranet, LAN, ISDN, VAN, CATV communication network, virtual private network, telephone line network, mobile communication network, satellite communication. A net or the like is available. Also, the transmission medium constituting the communication network is not particularly limited. For example, even in the case of wired such as IEEE 1394, USB, power line carrier, cable TV line, telephone line, ADSL line, etc., infrared rays such as IrDA and remote control, Bluetooth ( (Registered trademark), 802.11 wireless, HDR, mobile phone network, satellite line, terrestrial digital network, and the like can also be used. The present invention can also be realized in the form of a computer data signal embedded in a carrier wave in which the program code is embodied by electronic transmission.

  As described above, the liquid crystal panel inspection apparatus 10 according to the present embodiment images the display screen 11a of the liquid crystal panel 11 with the camera 3 and inspects the liquid crystal panel 11 for defects. The liquid crystal panel inspection apparatus 10 includes the source drivers 12a and 12b and the gate driver 13 that divide the display screen 11a of the liquid crystal panel 11 into a plurality of parts in at least one direction and simultaneously drive them independently of each other. A liquid crystal panel lighting signal generator 20 for displaying a gradation step change pattern as a test pattern is provided on the divided screen, and the liquid crystal panel lighting signal generator 20 is displayed on each divided screen of the liquid crystal panel 11. There is provided an ascending / descending order arrangement means for arranging the gradation stepwise change patterns alternately in ascending order and descending order or descending order and ascending order for each divided screen.

  Further, the inspection method for the liquid crystal panel 11 according to the present embodiment is an inspection method for the liquid crystal panel 11 in which the display screen 11a of the liquid crystal panel 11 is imaged by an imaging device and the display panel is inspected for defects. A screen division driving process for dividing the display screen 11a into a plurality of parts in at least one direction and simultaneously driving them independently, and an inspection pattern for displaying a gradation step change pattern as an inspection pattern on each divided screen of the liquid crystal panel 11 A display step and an ascending / descending order arranging step of arranging the gradation step change patterns displayed on each divided screen of the liquid crystal panel 11 alternately in ascending order and descending order or descending order and ascending order for each divided screen. Including.

  In addition, the manufacturing method of the liquid crystal panel 11 according to the present embodiment includes the step of disposing the liquid crystal panel 11 at the position facing the camera 3 in the liquid crystal panel inspection apparatus 10 described above, and the position facing the camera 3 in the liquid crystal panel inspection apparatus 10. And the step of inspecting the liquid crystal panel 11 arranged in the above-described manner by the inspection method for the liquid crystal panel 11 described above.

  According to said structure, the display screen 11a of the liquid crystal panel 11 which divides | segments the display screen 11a into a plurality in at least one direction and drives it mutually independently simultaneously is imaged with the camera 3, and the defect inspection of the liquid crystal panel 11 is performed. . In this embodiment, a gradation step change pattern is displayed as an inspection pattern on each divided screen of the liquid crystal panel 11.

  In this case, conventionally, the gradation step change pattern displayed on each divided screen of the liquid crystal panel 211 is repeated in the same order for each divided screen. For this reason, in the imaging area that includes the boundary of the split screen in the camera, the white display part and the black display part are mixed, so sensitivity adjustment that satisfies both of them cannot be performed at once, and halation occurs in the white display part, resulting in black display. The part was supposed to cause a lack of sensitivity.

  On the other hand, in the present embodiment, the liquid crystal panel lighting signal generation device 20 displays the gradation step change pattern displayed on each divided screen of the liquid crystal panel 11 alternately in ascending order and descending order for each divided screen. Alternatively, an inverted data generation circuit 24 and an input selection circuit 25 are provided as ascending / descending order arrangement means arranged in descending order and ascending order.

  As a result, the imaging region including the boundary of the divided screen in the camera 3 can be set as a white display portion or a black display portion.

  Therefore, in the liquid crystal panel 11 that divides and drives the display screen 11a, when the inspection pattern in which the gradation is displayed in a step change pattern for each divided screen is imaged by the camera 3 and defect inspection is performed, halation and insufficient sensitivity are caused. It is possible to provide a liquid crystal panel inspection apparatus 10, an inspection method for the liquid crystal panel 11, and a manufacturing method for the liquid crystal panel 11 that can be inspected by one-time imaging without occurring.

  Further, in the liquid crystal panel inspection apparatus 10 of the present embodiment, the liquid crystal panel lighting signal generation apparatus 20 includes a model information input unit 21 that inputs model information including the number of screen divisions, and an inspection that displays preset gradations. The signal data load unit 23 for acquiring the positive signal data of the pattern, and the control circuit 26 for outputting the control signal for displaying the inspection pattern on the source drivers 12a and 12b and the gate driver 13, and the ascending / descending order arrangement are provided. The means includes an inverted data generation circuit 24 that generates inverted data obtained by inverting the positive signal data, and a positive signal when the control circuit 26 outputs a control signal that causes the source drivers 12a and 12b and the gate driver 13 to display the inspection pattern. Input selection for switching the signal data and the inverted signal data so as to be alternately output for each divided screen of the liquid crystal panel 11 And a circuit 25.

  Thus, specifically, the gradation step change pattern displayed on each divided screen of the liquid crystal panel 11 may be arranged alternately in ascending order and descending order, or descending order and ascending order for each divided screen. it can.

  Further, in the liquid crystal panel inspection apparatus 10 of the present embodiment, the camera 3 includes an amplifier unit 3b that performs sensitivity adjustment for each of the plurality of imaging elements 3a along the gradation change direction in the gradation step change pattern. .

  Accordingly, the amplifier unit 3b of the camera 3 performs sensitivity adjustment for each of the plurality of image pickup devices 3a along the gradation change direction in the gradation change pattern of gradation, so that sensitivity suitable for gradation can be obtained. Therefore, inspection can be performed without causing halation and insufficient sensitivity.

  Moreover, in the liquid crystal panel inspection apparatus 10 of this Embodiment, the camera 3 consists of a TDI sensor type camera.

  The TDI sensor type camera is a scanning camera, and by combining the scanning speed and the exposure cycle, a uniform and highly accurate captured image can be obtained by a single scan even for a wide display panel. .

  Further, in the liquid crystal panel inspection apparatus 10 of the present embodiment, the backlight unit 1 includes a plurality of light sources that irradiate the liquid crystal panel 11 from behind, and controls increase / decrease in the amount of light applied to the liquid crystal panel 11 of each light source, A backlight that controls the backlight unit 1 so that the amount of light applied to the liquid crystal panel 11 of the light source is reduced as the display area has a higher gradation, and the amount of light applied to the liquid crystal panel 11 of the light source is increased as the display area has a lower gradation. And a light control device 2.

  Conventionally, when the backlight unit 1 has a high luminance in the inspection with the entire white display inspection pattern, the black spot becomes inconspicuous, making it difficult to find the defect, and in the inspection with the entire black display inspection pattern, When the luminance of 1 is small, the bright spot is not conspicuous, making it difficult to find defects.

  Thus, for example, in the display panel inspection method disclosed in Patent Document 1, for example, by increasing the intensity of the entire backlight to increase the relative intensity of the luminescent spots with respect to the background during the luminescent spot defect inspection in the entire black display inspection pattern. Control of backlight intensity suitable for a plurality of display modes and inspection purposes has been performed.

  However, there are various inspection patterns. For example, in the inspection pattern using the gradation step change pattern, the method of increasing or decreasing the intensity of the entire backlight according to Patent Document 1 is appropriate for the imaging device. Cannot match the sensitivity.

  Therefore, in the present embodiment, the backlight unit 1 has a plurality of, for example, fluorescent tubes 1a that irradiate the liquid crystal panel 11 from behind, and controls increase / decrease of the amount of light applied to the liquid crystal panel 11 of each fluorescent tube 1a. The backlight control device 2 reduces the amount of light applied to the liquid crystal panel 11 of the fluorescent tube 1a as the display area has a higher gradation, and reduces the amount of light applied to the liquid crystal panel 11 of the fluorescent tube 1a as the display area has a lower gradation. The backlight unit 1 is controlled to be large.

  Therefore, in the case of having an inspection pattern having two or more types of display areas with different gradations simultaneously, it is possible to detect a defect for each display area with high accuracy.

  By the way, in the present embodiment, the display screen 11a of the liquid crystal panel 11 that is divided into a plurality of display screens 11a in at least one direction and is driven simultaneously and independently is imaged by the camera 3 and defect inspection of the liquid crystal panel 11 is performed. When performing, when a gradation step change pattern is displayed as an inspection pattern on each divided screen of the liquid crystal panel 11, a problem arises.

  That is, conventionally, the gradation step change pattern displayed on each divided screen of the liquid crystal panel 211 is repeated in the same order for each divided screen. For this reason, in the imaging region including the boundary of the divided screen in the camera, the white display portion and the black display portion are mixed, so that it is impossible to adjust the amount of light satisfying both at once.

  On the other hand, in the present embodiment, the liquid crystal panel lighting signal generator 20 changes the gradation step change pattern displayed on each divided screen of the display panel alternately in ascending order and descending order for each divided screen, or An inversion data creation circuit 24 and an input selection circuit 25 are provided so as to be in descending order and ascending order.

  As a result, the imaging area including the boundary of the divided screen can be a white display portion or a black display portion.

  Therefore, the light amount of the backlight unit 1 that irradiates the white display portion or the black display portion in the imaging region including the boundary of the divided screen can be appropriately adjusted.

  Moreover, in the liquid crystal panel inspection apparatus 10 of this Embodiment, while a light source consists of the fluorescent tube 1a, the backlight control apparatus 2 controls the irradiation light quantity to the liquid crystal panel 11 of the fluorescent tube 1a.

  Accordingly, since the light source is composed of the fluorescent tube 1a, when a general fluorescent tube 1a is used as the light source of the liquid crystal panel 11, the liquid crystal panel 11 has at least two types of display areas having different gradations simultaneously. When it has, it becomes possible to detect the defect for every display area with high precision.

  Moreover, in the liquid crystal panel inspection apparatus 10 of this Embodiment, while a light source consists of a light emitting element, the backlight control apparatus 2 can control the irradiation light quantity to the liquid crystal panel 11 of a light emitting element.

  Accordingly, since the light source is composed of a light emitting element, when a light emitting element that has been used as a light source of the liquid crystal panel 11 in recent years is used, at least two kinds of display areas having different gradations are provided on the liquid crystal panel 11. In the case where the inspection pattern is included at the same time, it is possible to detect a defect for each display region with high accuracy.

  In addition, the liquid crystal panel inspection apparatus 10 according to the present embodiment includes a transport conveyor as a transport unit that transports and arranges the liquid crystal panel 11 at the front position of the backlight control device 2 and at the position facing the camera 3.

  Thereby, it is possible to separate the liquid crystal panel 11 from the camera 3 and other components. Therefore, it is possible to perform inspection while fixing the components other than the liquid crystal panel 11 and sequentially replacing the liquid crystal panel 11.

  The liquid crystal panel inspection apparatus 10 of the present embodiment may be realized by a computer. In this case, a liquid crystal panel that realizes the liquid crystal panel inspection apparatus 10 by a computer by operating the computer as each of the above-described means. The inspection program of the inspection apparatus 10 and a computer-readable recording medium on which the inspection program is recorded also fall within the category of the present embodiment.

  The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention.

  INDUSTRIAL APPLICABILITY The present invention can be applied to a display panel inspection apparatus, a display panel inspection method, a display panel manufacturing method, a program, and a recording medium that perform defect inspection of the display panel by imaging the display panel with an imaging device. .

  The display panel can be applied to transmissive and reflective liquid crystal panels, and as the light emitting element, an organic EL light emitting element, an inorganic EL light emitting element, an LED (Light Emitting Diode) or the like having a variable light emission luminance is used. It can also be used for conventional displays, field emission displays (FEDs), and plasma displays.

  Further, as the backlight of the liquid crystal panel, a plurality of fluorescent tubes or LEDs (Light Emitting Diodes) can be used.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates an embodiment of a liquid crystal panel inspection device according to the present invention, and is a block diagram illustrating a configuration of a liquid crystal panel lighting control device and a liquid crystal panel. It is a block diagram which shows the whole structure of the said liquid crystal panel test | inspection apparatus. It is a block diagram which shows the image pick-up element and amplifier part which were provided in the camera 3 in the said liquid crystal panel test | inspection apparatus. (A) is a top view which shows the defect in the test pattern of the whole surface white display of a liquid crystal panel, (b) is a top view which shows the defect in the whole surface black display of a liquid crystal panel. (A) is a top view which shows the defect in the inspection pattern of the monochrome display of a liquid crystal panel, (b) is a top view which shows the defect in the black-and-white display of a liquid crystal panel. It is a top view which shows the defect in the test | inspection pattern of the all gradation display which is a gradation change pattern in a liquid crystal panel. (A) is a figure which shows the step change pattern of the normal gradation in the case of 3 bits, (b) is a figure which shows the change pattern of the gradation when the 1st bit bit does not light in the case of 3 bits. (C) is a diagram showing a gradation change pattern when the second digit bit is not lit in the case of 3 bits, and (d) is a floor when the third digit bit is not lit in the case of 3 bits. It is a figure which shows the change pattern of a tone. (A) is a top view which shows the step change pattern of the normal gradation of the liquid crystal panel which has 1080 pixels in the vertical direction, (b) is sectional drawing which shows the step change pattern of the gradation. (A)-(e) is a top view which shows the lighting pattern of the backlight unit corresponding to the test | inspection pattern of the liquid crystal panel shown in FIGS. (A) is a top view which shows the test | inspection pattern which displayed the stepwise change pattern of the gradation which becomes an ascending order-> descending order on each divided screen of a liquid crystal panel, (b) is a descending order on each divided screen of a liquid crystal panel. → It is a plan view showing an inspection pattern displaying a gradation stepwise change pattern in ascending order. By adopting an inspection pattern in which the gradation stepwise change pattern from ascending order to descending order is displayed on each divided screen of the liquid crystal panel, the center of the liquid crystal panel becomes black and the imaging area TAP9 becomes black. It is a top view which shows the liquid crystal panel. (A) is a graph which shows the test pattern which displayed the gradation step change pattern which becomes an ascending order-> descending order on each division | segmentation screen of a liquid crystal panel, (b) is the imaging area TAP1-TAP16 at that time, and a gain It is a graph which shows the relationship. (A) is a graph which shows the test | inspection pattern which displayed the stepwise change pattern of the gradation which becomes an ascending order-> ascending order on each division | segmentation screen of a liquid crystal panel, (b) is the voltage of the fluorescent tube of each area | region at that time It is a graph which shows the relationship with a value. (A) is a graph which shows the test | inspection pattern which displayed the stepwise change pattern of the gradation which becomes an ascending order-> descending order on each division | segmentation screen of a liquid crystal panel, (b) is the voltage of the fluorescent tube of each area | region at that time It is a graph which shows a value. It is a figure which shows the control action of the test | inspection control apparatus of the said liquid crystal panel. It is a block diagram which shows the conventional defect apparatus. (A) is a top view which shows the structure of the memory chip which is an object area | region of the said defect apparatus, (b) is a graph which shows the difference in the brightness of the memory mat part and peripheral circuit in a memory chip. It is a figure which shows the test | inspection pattern in other conventional defect apparatuses. (A) is a top view which shows the test | inspection pattern which displayed the stepwise change pattern of the gradation which becomes an ascending order-> ascending order on each division | segmentation screen of a liquid crystal panel in another conventional defect apparatus, (b) is a liquid crystal It is a top view which shows the test | inspection pattern which displayed the stepwise change pattern of the gradation which becomes descending order-> descending order on each divided screen of a panel. By adopting an inspection pattern in which a gradation step change pattern from ascending order to ascending order is displayed on each divided screen of the liquid crystal panel, the center of the liquid crystal panel becomes black and white, and the imaging area TAP9 becomes black and white. It is a top view which shows the liquid crystal panel. (A) is a graph showing an inspection pattern in which gradation stepwise change patterns in ascending order → ascending order are displayed on each divided screen of the liquid crystal panel, and (b) is a gain of the imaging regions TAP1 to TAP16 at that time. It is a graph which shows.

Explanation of symbols

1 Backlight unit (irradiation means)
1a Fluorescent tube (light source)
2 Backlight control device (light quantity control means)
3 Camera (imaging device)
3b Amplifier section (sensitivity adjustment means)
4 Scanning stage 5 Image processing device 10 Liquid crystal panel inspection device (display panel inspection device)
11 Liquid crystal panel (display panel)
11a Display screen (screen)
11b Frame 12a Source driver (screen division drive means)
12b Source driver (screen division drive means)
13 Gate driver (screen division drive means)
20 Liquid crystal panel lighting signal generator (inspection pattern display means)
21 Model information input section (model information means)
22 signal data storage unit 23 signal data load unit (positive signal data acquisition means)
24 Inverted data creation circuit (ascending / descending order arranging means, inverted data creating means)
25 Input selection circuit (ascending / descending order arrangement means, forward / reverse signal data switching means)
26 Control circuit (control signal output means)
30 Inspection Control Devices TAP1-16 Imaging Area

Claims (12)

In the display panel inspection apparatus that performs the defect inspection of the display panel by imaging the screen of the display panel with an imaging apparatus,
A screen division driving means for dividing the display panel screen into a plurality of screens in at least one direction and simultaneously driving them independently from each other;
Each divided screen of the display panel is provided with inspection pattern display means for displaying a gradation step change pattern as an inspection pattern, and
The inspection pattern display means includes
There is provided an ascending / descending order arrangement means for arranging the gradation step change pattern displayed on each divided screen of the display panel alternately in ascending order and descending order or descending order and ascending order for each divided screen. A display panel inspection apparatus characterized by that. The inspection pattern display means includes
Model information means for inputting model information including the number of screen divisions,
A positive signal data acquisition means for acquiring positive signal data of an inspection pattern for displaying a preset gradation;
A control signal output means for outputting a control signal for causing the screen division driving means to display the inspection pattern;
The ascending / descending order arrangement means includes:
Inverted data creating means for creating inverted data obtained by inverting the positive signal data;
When the control signal output means outputs a control signal for displaying the inspection pattern on the screen division driving means, the positive signal data and the inverted signal data are switched so as to be alternately output for each divided screen of the display panel. 2. The display panel inspection apparatus according to claim 1, further comprising a normal / inverted signal data switching means.   3. The display panel according to claim 1, wherein the imaging device includes a sensitivity adjustment unit that performs sensitivity adjustment for each of a plurality of imaging elements along a gradation change direction in a gradation stepwise change pattern. Inspection equipment.   4. The display panel inspection apparatus according to claim 1, wherein the imaging apparatus is a TDI sensor type camera. A plurality of light sources for irradiating the display panel from behind, and an irradiating means for increasing / decreasing the amount of light applied to the display panel of each light source;
The irradiation unit is controlled so that the light amount irradiated to the display panel of the light source decreases as the display region with the higher gradation, and the light irradiation amount to the display panel of the light source increases in the display region with the lower gradation. 5. The display panel inspection apparatus according to claim 1, further comprising a light quantity control unit. The light source comprises a fluorescent tube,
6. The display panel inspection apparatus according to claim 5, wherein the light amount control means controls a light amount irradiated to the display panel of a fluorescent tube. The light source comprises a light emitting element,
The transmissive display panel inspection apparatus according to claim 5, wherein the light amount control unit controls a light amount irradiated to the display panel of the light emitting element.   The display panel inspection apparatus according to claim 1, further comprising a conveyance unit configured to convey and arrange the display panel at a position opposite to the imaging apparatus. In the display panel inspection method in which the screen of the display panel is imaged by an imaging device and the display panel is inspected for defects.
A screen division driving process in which the screen of the display panel is divided into a plurality of screens in at least one direction and simultaneously and independently driven;
An inspection pattern display step for displaying a gradation step change pattern as an inspection pattern on each divided screen of the display panel;
And an ascending / descending order arranging step of arranging gradation changing patterns displayed on each divided screen of the display panel alternately in ascending order and descending order or descending order and ascending order for each divided screen. A display panel inspection method characterized by the above. Disposing the display panel at a position facing the imaging device in the display panel inspection apparatus according to claim 1;
A method for manufacturing a display panel, comprising: a step of inspecting a display panel disposed at a position opposite to an imaging device in the display panel inspection apparatus by a display panel inspection method according to claim 9.   A display panel inspection program for operating the display panel inspection apparatus according to claim 1, wherein the computer functions as each of the above-described means.   The computer-readable recording medium which recorded the test | inspection program of the display panel of Claim 11.