JP2009031332A - Device and method for inspecting transmissive display panel, method for manufacturing transmissive display panel, program and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect a defect in each display region with high accuracy, in the case that an inspection pattern simultaneously having at least two kinds or more display regions with mutually different gray scale levels exists on a transmissive display panel. <P>SOLUTION: Defect inspection is conducted for a liquid crystal panel 11 performing a gray scale display by controlling fluctuation of transmitted light quantity. The inspecting device includes: a backlight unit 1 which has a plurality of fluorescent tubes 1a through which the liquid crystal panel 11 is irradiated with fluorescence from behind and controls the fluctuation of irradiating light quantity of each fluorescent tube 1a toward the liquid crystal panel 11; a liquid crystal panel turn-on controlling device 3 which displays the inspection pattern simultaneously having at least two kinds or more display regions with mutually different gray scales on the liquid crystal panel 11; and a backlight controller 2 which controls the backlight unit 1 in such a way that the higher the gray scale levels of the display region, the irradiating light quantity of the fluorescent tubes 1a is made smaller, and the lower the gray scale levels of the display region, the irradiating light quantity of the fluorescent tubes 1a is made larger. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a transmissive display that performs defect inspection of a transmissive display panel by irradiating a backlight from the back of the transmissive display panel such as a transmissive liquid crystal panel and extracting defective portions of the transmissive display panel. The present invention relates to a panel inspection apparatus, a transmissive display panel inspection method, a transmissive display panel manufacturing method, a program, and a recording medium.

  In the inspection process of the liquid crystal panel production line, the transmitted light of the liquid crystal panel is observed by an inspector in a state where the backlight is uniformly illuminated as a lighting inspection of the liquid crystal panel, or is observed using a sensor such as a camera.

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

For example, in the display panel inspection method disclosed in Patent Document 1, a plurality of display modes and inspections such as increasing the relative intensity of the bright spot with respect to the background by increasing the intensity of the backlight at the time of the bright spot defect inspection in black display, for example. The backlight intensity suitable for the purpose is controlled. This makes it easy for inspectors to find defects.
JP 2006-343688 A (published on December 21, 2006) JP 2002-244097 A (released on August 28, 2002)

  However, in the above conventional liquid crystal panel inspection apparatus, although it is possible to improve the inspection accuracy when performing uniform display on the entire surface of the panel, a defect that appears only when a specific light and dark pattern exists in the panel Even when emphasizing, the amount of light transmitted through the entire panel is increased or decreased in proportion to the illumination intensity. For this reason, there is a problem that the bright region is saturated to emphasize the dark region, or conversely, the luminance of the dark region is decreased to suppress the bright region.

  For example, as an inspection pattern for detecting a leak defect due to a short circuit between a source and a drain, for example, in Patent Document 2, a display screen in a transmissive display panel is divided into two, one being displayed in black and the other being displayed in white. And the case where the one is displayed in white and the other is displayed in black. In such a case, the above problem occurs.

  The present invention has been made in view of the above-described problems of the related art, and its object is to display in the case where a transmissive display panel has an inspection pattern having at least two kinds of display areas of different gradations at the same time. A transmissive display panel inspection apparatus, a transmissive display panel inspection method, a transmissive display panel manufacturing method, a program, and a recording medium that detect defects in each region with high accuracy are provided.

  In order to solve the above-described problems, the inspection apparatus for a transmissive display panel according to the present invention performs a defect inspection of a transmissive display panel, which is an inspection object, that performs gradation display by controlling increase / decrease in the amount of light transmission. In an inspection apparatus for a transmissive display panel, the transmissive display panel includes a plurality of light sources that irradiate the transmissive display panel from behind, and an irradiating unit that controls increase / decrease of the amount of light applied to the transmissive display panel by each light source; Inspection pattern display means for displaying an inspection pattern having at least two different gradation display areas simultaneously on the display panel, and the amount of light applied to the transmissive display panel of the light source decreases as the display area has a higher gradation. And a light amount control means for controlling the irradiating means so as to increase the amount of light applied to the transmissive display panel of the light source as the display area has a lower gradation. It is characterized in. The light transmission amount refers to the light transmission amount per unit area.

  In addition, in order to solve the above-described problem, the inspection method for a transmission display panel according to the present invention performs defect display by controlling increase / decrease in the amount of light transmission, and inspects the defect of the transmission display panel as an inspection object. In the inspection method for a transmissive display panel, a step of providing a plurality of light sources for irradiating the transmissive display panel from behind, and a transmissive display panel having at least two kinds of display areas of different gradations simultaneously The step of displaying an inspection pattern, and the amount of light emitted to the transmissive display panel of the light source is reduced as the display area has a higher gradation, and the light source irradiates the transmissive display panel of the light source as the display area has a lower gradation. And a step of controlling to increase the amount of light.

  According to another aspect of the present invention, there is provided a method for manufacturing a transmissive display panel, including a step of disposing a transmissive display panel at a front surface position of an irradiation unit in the transmissive display panel inspection apparatus described above, And a step of inspecting the transmissive display panel disposed in front of the irradiation means in the transmissive display panel inspection apparatus by the above-described transmissive display panel inspection method.

  According to the invention, the irradiating means has a plurality of light sources that irradiate the transmissive display panel from the back, and controls the increase and decrease of the amount of light applied to the transmissive display panel by each light source. In the defect inspection in the case where an inspection pattern having at least two types of display areas with different gradations is displayed on the transmission type display panel at the same time, the light amount control means is configured such that the display area with higher gradations has a light source transmission type. The irradiation unit is controlled so as to reduce the amount of light applied to the display panel and to increase the amount of light applied to the transmissive display panel of the light source as the display area has a lower gradation.

  For this reason, in order to accurately inspect the defects of the transmissive display panel that becomes apparent only when it is generated when the transmissive display panel to be inspected is turned on under specific conditions, for example, irradiation The intensity for each light source of the means can be controlled based on the gradation of the transmissive display panel.

  As a result, defects appearing on the transmissive display panel can be inspected under optimum conditions for each display area of the transmissive display panel, and defect detection accuracy can be improved. That is, the inspector or the inspection equipment can observe the entire surface of the transmissive display panel under a uniform amount of irradiation light, so that the defect can be easily found.

  In particular, for example, when a defect inspection of a transmissive display panel is performed by processing an image captured by a camera with a computer, a panel transmitted light condition suitable for the range of the dynamic range of the camera can be set. As a result, it is not necessary to perform imaging a plurality of times while changing the exposure time and gain setting of the camera, and the inspection can be performed quickly.

  Therefore, when the transmissive display panel has an inspection pattern having at least two types of display areas with different gradations at the same time, the transmissive display panel inspection apparatus and the transmissive display panel can detect defects in each display area with high accuracy. A display panel inspection method and a transmissive display panel manufacturing method can be realized.

  Further, in the inspection device for a transmissive display panel according to the present invention, the inspection pattern divides the display screen of the transmissive display panel into two, one of the divided screens is displayed in black and the other is displayed in white. Preferably, one of the divided screens is displayed in white and the other is displayed in black.

  As a result, it is possible to accurately detect a so-called SD leak defect that occurs due to leakage of charge in the source (S) direction to the drain (D).

  In the inspection apparatus for a transmissive display panel according to the present invention, the inspection pattern is divided and displayed in display areas of different gradations obtained by dividing at least three parts from the minimum gradation to the maximum gradation of the transmissive display panel. It is preferable to consist of things.

  As a result, the inspection pattern divided and displayed in the display area of different gradations obtained by dividing at least three from the minimum gradation to the maximum gradation of the transmissive display panel is used. A specific gradation line defect or a line defect of a specific gradation defect caused by an operation failure of a specific bit in the driver can be found with high accuracy.

  In the inspection apparatus for a transmissive display panel according to the present invention, the light amount control means is a light for measuring a light transmission amount by a standard light amount of a light source for each gradation of each display area of the transmissive display panel in the inspection pattern. It is preferable to include a transmission amount measurement unit and a part output setting unit that determines the output of each light source based on the light transmission amount of each display region obtained by the light transmission amount measurement unit.

  Thus, when a defect for each display area is detected by the light transmission amount measuring means and the part output setting means, specifically, it is easy to detect visually or in the detection by the camera, and is within the measurement dynamic range of the camera. The light transmission amount can be set so that

  In the transmissive display panel inspection apparatus according to the present invention, the imaging means for imaging the transmitted light from the light source in the transmissive display panel and the image captured by the imaging means are subjected to image processing and density comparison is performed. It is preferable that image processing means for extracting a defective portion is provided.

  Thereby, the transmitted light from the light source is picked up by the image pickup means, the image picked up by the image pickup means is image processed by the image processing means, and the defective portion can be extracted by comparing the light and shade.

  In the transmissive display panel inspection apparatus of the present invention, it is preferable that the imaging means is an area sensor type camera.

  According to the above invention, the imaging means is an area sensor type camera. That is, the area sensor has a wider imaging range than the line sensor. However, in the area sensor, generally, the gain setting for adjusting the amount of imaged light and the control of the exposure time are uniform over the entire capturing area. Therefore, if the inspection object has a gradation based on gradation, saturation (high light amount region) or insufficient sensitivity (low light amount region) may occur. That is, when the imaging means is an area sensor type camera, the output of the element is generally obtained by multiplying the received light amount determined by the exposure time by a uniform analog gain over the entire sensor. Therefore, when the range of the intensity of the panel transmitted light is wide, the dynamic range of the camera element is exceeded, and saturation or information loss occurs.

  Therefore, in the present invention, when such an area sensor type camera is used, high sensitivity inspection can be performed over the entire inspection target by controlling the amount of light emitted from the light source in the display area of the transmissive display panel. it can.

  In the transmissive 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 transmissive display panel of the fluorescent tube.

  Accordingly, since the light source is made of a fluorescent tube, when a general fluorescent tube is used as the light source of the transmissive display panel, the transmissive display panel simultaneously has at least two kinds of display areas having different gradations. In this case, it is possible to realize a transmissive display panel inspection apparatus, a transmissive display panel inspection method, and a transmissive display panel manufacturing method that detect defects in each display region with high accuracy.

  In the inspection apparatus for a transmissive display panel according to the present invention, it is preferable that the light source includes a light emitting element, and the light amount control unit controls an irradiation light amount of the light emitting element to the transmissive display panel.

  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 a transmissive display panel in recent years is used, the transmissive display panel has at least two kinds of different gradations. Realizing a transmissive display panel inspection device, a transmissive display panel inspection method, and a transmissive display panel manufacturing method for detecting a defect in each display region with high accuracy when having an inspection pattern having a display region at the same time Can do.

  In the inspection apparatus for a transmissive display panel according to the present invention, the light amount control unit stores a lighting pattern including a lighting position of each light source and an irradiation light amount in the irradiation unit corresponding to the inspection pattern by the inspection pattern display unit. It is preferable that a pattern storage means is provided.

  Thus, when the inspection pattern is determined, the lighting pattern storage unit can call the lighting pattern including the lighting position and the irradiation light amount of each light source in the irradiation unit corresponding to the inspection pattern at any time to control lighting of each light source of the irradiation unit. The lighting control can be performed quickly.

  In the transmissive display panel inspection apparatus of the present invention, it is preferable that the light amount control means includes a life control means for determining the output of each light source in consideration of the life of the light source.

  That is, when the light quantity control means controls increase / decrease of the irradiation light quantity of the light source of the irradiation means, an appropriate light transmission amount cannot be obtained unless the life of the light source is taken into consideration.

  In contrast, in the present invention, the lifetime control means determines the output of each light source in consideration of the lifetime of the light source. As a result, the effective voltage with respect to the fluorescent tube can be sequentially controlled so as to appropriately compensate for the luminance change in the region corresponding to each light source of the image captured by the imaging unit.

  In the inspection apparatus for a transmissive display panel according to the present invention, it is preferable that the transmissive display panel includes transport means for transporting and arranging the transmissive display panel at a front position of the irradiation means.

  Thereby, in the present invention, it is possible to separate the transmissive display panel from the irradiation means and other components. Therefore, it is possible to perform inspection while fixing constituent elements other than the transmissive display panel and sequentially replacing the transmissive display panel. Moreover, it is not necessary to provide an irradiation intensity adjustment function for each light source in the irradiation means in the final product.

  The transmissive display panel inspection apparatus may be realized by a computer. In this case, the transmissive display panel inspection apparatus is realized by a computer by operating the computer as each of the means. The inspection program for the inspection apparatus for the mold display panel and the computer-readable recording medium on which the inspection program is recorded also fall within the scope of the present invention.

  As described above, the inspection apparatus for a transmissive display panel according to the present invention includes a plurality of light sources that irradiate the transmissive display panel from behind, and controls the increase and decrease of the amount of light emitted from each light source to the transmissive display panel. Irradiation means, inspection pattern display means for displaying an inspection pattern having at least two kinds of display areas of different gradations simultaneously on the transmission display panel, and transmission display of the light source as the display area has higher gradation A light amount control means is provided for controlling the light amount applied to the transmissive display panel of the light source so as to decrease the light amount applied to the panel, and to increase the light amount applied to the transmissive display panel of the light source.

  Further, as described above, the inspection method of the transmission type display panel according to the present invention is different from the step of providing a plurality of light sources for irradiating the transmission type display panel from behind, and at least two types of the transmission type display panel. A step of displaying an inspection pattern having a gradation display area at the same time; and a display area having a higher gradation reduces the amount of light applied to the transmission display panel of the light source, and the display area has a lower gradation. And controlling to increase the amount of light applied to the transmissive display panel.

  In addition, as described above, the method for manufacturing a transmissive display panel according to the present invention includes the step of disposing the transmissive display panel at the front position of the irradiation means in the inspection apparatus for the transmissive display panel described above, and the transmissive display. And a step of inspecting the transmissive display panel arranged at the front position of the irradiation means in the panel inspection apparatus by the above-described transmissive display panel inspection method.

  Therefore, in the case where the transmission type display panel has an inspection pattern having at least two types of display areas with different gradations at the same time, the inspection apparatus for the transmission type display panel that detects defects in each display area with high accuracy, There is an effect that it is possible to realize a method for inspecting a mold display panel and a method for manufacturing a transmission display panel.

  An embodiment of the present invention will be described with reference to FIGS. 1 to 9 as follows.

  A configuration of a liquid crystal panel inspection apparatus 10 as an inspection apparatus for inspecting a liquid crystal panel as a transmission type display panel according to the present embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing the configuration of the liquid crystal panel inspection apparatus 10.

  As shown in FIG. 1, the liquid crystal panel inspection apparatus 10 irradiates, for example, five fluorescent tubes 1a as light sources and irradiates light from the rear surface to the transmission type liquid crystal panel 11 to be inspected, and the light from the fluorescent tubes 1a. A backlight unit 1 as an irradiating means comprising a diffusion plate 1b to be diffused, a backlight control device 2 as a light amount control means for controlling lighting of the backlight unit 1, and an inspection for controlling lighting of the liquid crystal panel 11. A liquid crystal panel lighting control device 3 as a pattern display means, a camera 4 as an image pickup means for picking up transmitted light from the liquid crystal panel 11 from the front, and image processing for image processing of an image of the liquid crystal panel 11 picked up by the camera 4 And an image processing apparatus 5 as means.

  In the present embodiment, the liquid crystal panel inspection apparatus 10 is independent 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 conveyance lines, such as a conveyor as a conveyance means which is not shown in figure, and is sequentially installed in the liquid crystal panel test | inspection apparatus 10. FIG. The liquid crystal panel 11 includes a source driver that controls gradation, a gate driver that controls scanning lines, and a control circuit that controls these source drivers and gate drivers. Therefore, the liquid crystal panel 11 does not include a backlight that is necessary when it becomes a product.

  Then, the liquid crystal panel 11 installed in the liquid crystal panel inspection apparatus 10 is irradiated with light from the back through the five fluorescent tubes 1a whose brightness can be independently controlled in the backlight unit 1, and this light is diffused to the diffusion plate 1b. The liquid crystal panel 11 is made to enter by being diffused by. Next, the transmitted light of the liquid crystal panel 11 is observed by the camera 4 installed in front of the liquid crystal panel 11.

  The camera 4 is controlled by the image processing device 5, and the inspection image picked up from the front of the liquid crystal panel 11 by the camera 4 is image-processed by the image processing device 5 and is subjected to density comparison, thereby obtaining a defect. Is determined. Note that a method for discriminating a defect by performing image processing by the image processing device 5 and performing density comparison is a known technique, and thus description thereof is omitted.

  The camera 4 can be provided with a line sensor, for example. As a result, the line sensor has the capture cycle≈exposure cycle, and as will be described later, the backlight unit including the five fluorescent tubes 1a capable of independently controlling the brightness in the light amount adjustment that cannot be handled by gain adjustment. The inspection accuracy can be improved by performing the measurement at 1.

  Note that the camera 4 is not limited to the one provided with the line sensor, but may be provided with the area sensor. In the area sensor, generally, the gain setting for adjusting the light amount and the control of the exposure time are uniform over the entire capturing area. Accordingly, if the light intensity of the inspection target exists, saturation (high light amount region) or insufficient sensitivity (low light amount region) may occur. Also in this case, in the present embodiment, the entire amount of the inspection object is controlled by controlling the amount of light in the saturated and insensitive areas by the backlight unit 1 including the five fluorescent tubes 1a capable of independently controlling the luminance. Can perform high-sensitivity inspection.

  The backlight control device 2, the liquid crystal panel lighting control device 3, and the image processing device 5 are all controlled by the liquid crystal panel inspection device 10 in synchronization. In the present invention, the liquid crystal panel lighting control device 3 is not necessarily essential for the liquid crystal panel inspection device 10. As described above, since the liquid crystal panel 11 includes the source driver, the gate driver, and the control circuit for controlling the source driver and the gate driver, the liquid crystal panel 11 side without the liquid crystal panel lighting control device 3 is provided. This is because the display control of the inspection pattern of the liquid crystal panel 11 can be performed.

  By adopting such a configuration, defect inspection of the liquid crystal panel 11 can be realized regardless of the backlight specification of the final product.

  Here, at the time of inspection, the transparency of the liquid crystal panel 11 can be controlled by the liquid crystal panel lighting control device 3. For example, as shown in FIGS. 2 (a) and 2 (b), a uniform inspection pattern such as a full black display or a full white display is displayed, or as shown in FIGS. 2 (c) and 2 (d). Is divided into two parts, and the upper part of the panel is displayed in white and the lower part of the panel is displayed in black. On the contrary, in the screen divided into two, the upper part of the panel is displayed in black and the lower part of the panel is displayed in white. A pattern can be displayed. In addition, a non-uniform inspection pattern having a gradation from the upper part of the panel to the lower part of the panel can be displayed.

  An inspection pattern for inspecting the liquid crystal panel 11 will be described in detail with reference to FIGS. In FIGS. 3A and 3B to FIG. 5, gray display is used for simplification. However, the display is not limited to this, and color display may be used.

  That is, as defects of the liquid crystal panel 11, for example, phenomena such as pixel defects such as black spots and bright spots and line defects such as black lines and bright lines appear. However, the causes of defects for these phenomena are not uniform but various. is there. Therefore, in order to obtain the cause of the defect, it is common to display various inspection patterns on the screen of the liquid crystal panel 11.

  For example, as shown in FIG. 3A, in the inspection pattern of the entire white display 21, for example, in the normally black mode, all the pixels of the liquid crystal panel 11 are in the state of, for example, the gradation 255, that is, the light transmission amount is 100%. If a black dot appears at that time, the pixel is always turned off, and it can be understood that the pixel has a defect. Further, in FIG. 3A, when a black line appears, it can be grasped that the pixel column is always in the off state, and that there is a defect in the data bus line that supplies data to the pixel column. .

  Similarly, as shown in FIG. 3B, in the entire black display 22 inspection pattern, for example, in the normally black mode, all the pixels of the liquid crystal panel 11 are in, for example, a state of gradation 0, that is, a light transmission amount of 0%. When a bright spot appears at this time, it can be understood that the pixel is always lit and a defect exists in the pixel. Further, in FIG. 3B, when a bright line appears, it can be understood that the pixel column is always in a lighted state, and a defect exists in the data bus line that supplies data to the pixel column.

  Further, as a cause of the defect, for example, as shown in FIGS. 4A and 4B, when charges are applied to pixels other than the corresponding pixel in the vertical direction in the liquid crystal panel 11, the charges are caused by leakage of wiring. There is a leak defect that flows into the pixel.

  In order to find such a leak defect, as shown in FIGS. 4A and 4B, a monochrome display 23 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 24.

  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 source (S) of the pixel, the liquid crystal panel 11 is divided into upper and lower parts, and the gate (G) is turned off for each half surface for inspection. As a result, there are two types of inspection patterns, black and white display 23 and black and white display 24, as shown in FIGS.

  In this inspection pattern, when the source (S) and the drain (D) of the pixel 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 turned off, if an SD leak exists in the pixel, the voltage change of the source (S) voltage becomes the voltage change of the pixel as it is through 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.

  Next, as a defect of the liquid crystal panel 11, there is a driver defect in which the liquid crystal element has a maximum transmittance only when a driver unit (not shown) of the liquid crystal panel 11 has a defect and a specific gradation is displayed.

  In order to find such a driver defect, it is necessary to perform inspection while changing the display gradation in the direction in which the driver is shared. For example, when the driver is common in the panel vertical direction, as shown in FIG. 2E, the inspection pattern of the all gradation display 25 in which the transmittance is gradation is displayed from the upper side to the lower side of the screen. As a result, as shown in FIG. 5, the line defect of the specific gradation line defect 25a, which is a line defect having a conspicuous contrast at a specific gradation, or the specific gradation defect 25b caused by the operation failure of a specific bit in the driver is found. can do. 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.

  Therefore, it is possible to find a contrast defect and a malfunction of a specific bit in the driver by the inspection pattern of the all gradation display 25.

  4A and 4B, when the inspection is performed in the black and white display 23 or the black and white display 24, the corner of the white display portion in the black and white display 23 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 black and white display 23 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.

  In this embodiment, as shown in FIGS. 2A to 2E, the display pattern for inspection of the liquid crystal panel 11 is simple, and the entire white display 21, the entire black display 22, and the black and white display 23 are displayed. , Black and white display 24 and all gradation display 25. However, the present invention is not necessarily limited to this, and more display patterns for inspection 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 human visual inspection. For example, when the black point defect inspection in the entire white display 21 is performed, the backlight unit 1. When the light quantity of the fluorescent tube 1a is constant, the pixels 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 luminescent spot defect inspection in the entire black display 22, the pixels are finer than the liquid crystal panel 11 and can be overlooked. There is sex.

  Further, not only for visual inspection but also when the image of the liquid crystal panel 11 is captured by the camera 4, the camera 4 has a certain range of sensitivity to brightness. 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 22, and the intensity of the black dot is decreased in the entire white display 21 by decreasing the intensity of the backlight. The relative strength with respect to the background is lowered. This makes it easy for inspectors to find defects.

  However, when the monochrome display 23, the black-and-white display 24, and the full gradation display 25 are performed as in the present embodiment, the background of bright spots or black spots on the entire screen even if the intensity of the backlight unit 1 is increased or decreased. It is not possible to obtain an appropriate relative strength for. For example, there is a problem that a bright region is saturated to emphasize a dark region, or conversely, a luminance of a dark region is decreased 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, the plurality of fluorescent tubes 1a, for example, as a plurality in the backlight unit 1 can be individually controlled 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 21 shown in FIG. 2A, as shown in FIG. 6A, the lighting pattern 31 is set such that the light quantity of all the fluorescent tubes 1a is set to, for example, 50% luminance. . That is, in the entire white display 21 shown in FIG. 2A, 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 22 shown in FIG. 2B, as shown in FIG. 6B, the lighting pattern 32 in which the light quantity of all the fluorescent tubes 1a is set to 100%, for example, is used. That is, in the entire black display 22 shown in FIG. 2B, it is difficult to recognize defects in the liquid crystal panel 11 unless the amount of light in 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 FIGS. 2C to 2E, the luminance of the fluorescent tube 1a is controlled by the backlight control device 2 as shown in FIGS. 3C to 3E.

  Specifically, in the case of the black-and-white display 23 shown in FIG. 2C, as shown in FIG. 6C, the light quantity of the fluorescent tubes 1a in the regions 1 and 2 close to the white display region is set to, for example, the luminance 50. %, And a lighting pattern 33 in which the light quantity of the fluorescent tubes 1a in the regions 3 to 5 near the black display region is set to, for example, 100% luminance. In the case of the black and white display 24 shown in FIG. 2 (d), as shown in FIG. 6 (d), 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. The lighting pattern 34 is set such that the light quantity of the fluorescent tubes 1a in the region 4 and the region 5 close to the part is, for example, 50% luminance. Finally, in the case of the all gradation display 25 shown in FIG. 2E, as shown in FIG. 6E, the light quantity of the fluorescent tube 1a in the region 1 is set to, for example, the luminance 50 in the order from white display to black display. %, The light quantity of the fluorescent tube 1a in the area 2 is set to 62.5%, for example, the light quantity 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 87.5%, for example. And a lighting pattern 35 in which the light quantity of the fluorescent tube 1a in the region 5 is set to 100% luminance, for example.

  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 4, the sensitivity range of the camera 4 is obtained, and mechanical automatic detection by the camera 4 can be performed.

  In the present embodiment, the light intensity setting value of each fluorescent tube 1a in the backlight unit 1 corresponds to each of the five inspection patterns shown in FIGS. Accordingly, when the inspection pattern is different from the above five patterns, the light amount setting value of each fluorescent tube 1a also changes in accordance with the inspection pattern i. In the present embodiment, as shown in FIG. 1, the backlight control device 2 stores a lighting pattern including the lighting position of each light source and the amount of emitted light in the backlight unit 1 corresponding to such an inspection pattern. A lighting pattern storage unit 2a is provided as lighting pattern storage means composed of a lookup table. Therefore, the backlight control device 2 can control lighting of each fluorescent tube 1a of the backlight unit 1 by selecting a lighting pattern corresponding to the inspection pattern from the lighting pattern storage unit 2a. .

  Here, a method of setting the luminance of the fluorescent tube 1a will be described. That is, in the present embodiment, the following method can be used as a method for setting the luminance of the fluorescent tube 1a.

  For example, in the state where the all gradation display 25 shown in FIG. 2 is displayed and the fluorescent tube 1a is set to the standard light quantity as shown in FIG. 7A, each of the regions 5 to 1 in each fluorescent tube 1a is displayed. Measure light transmission. The target maximum light transmission amount is calculated by adding a certain offset to the measured transmission amount. Then, by calculating “maximum allowable light transmission amount ÷ target maximum light transmission amount = fluorescent tube intensity”, the intensities of the fluorescent tubes 1a in the respective regions 5 to 1 are set as shown in FIG. 7B. That is, the target maximum light transmission amount is obtained by adding an offset to the measured light transmission amount so that a defect is conspicuous with respect to the background and taking into account variations in the liquid crystal panel 11. It can be said that the amount of transmission. The light quantity setting of the fluorescent tube 1a is performed before the inspection.

  7A and 7B, specifically, the maximum allowable light transmission amount is 3.3, 3.3 ÷ 1.0 = 3.3 in the region 5, and 3.3 ÷ 2 in the region 3. 0.0 = 1.7, and in region 1, 3.3 / 3.0 = 1.1.

  Thereby, it is possible to set the irradiation light amount of the fluorescent tube 1 a suitable for the dynamic range of the camera 4. That is, in this embodiment, the irradiation intensity of the fluorescent tube 1a can be changed so as to be inversely proportional to the light transmission amount for each portion of the liquid crystal panel 11 to be inspected. As a result, the inspector or the inspection equipment can observe the entire surface of the liquid crystal panel 11 under a uniform amount of irradiation light, so that the defect can be easily found.

  In the present embodiment, the light quantity setting of the fluorescent tube 1a described above is performed by the light transmission amount measuring unit 2b as the light transmission amount measuring means provided in the backlight control device 2 and the region output as shown in FIG. It can be performed by the part output setting unit 2c as setting means. That is, the light transmission amount measuring unit 2 b measures the light transmission amount with the standard light amount of the fluorescent tube 1 a in each gradation of the liquid crystal panel 11. The part output setting unit 2c determines the output of the fluorescent tube 1a for each part from the light transmission amount obtained by the light transmission amount measurement unit 2b.

  In this embodiment, each time an inspection is performed, the lookup table can be corrected each time the measurement result of the light transmission amount measuring unit 2b is measured. As a result, the light transmission amount for each display gradation of the liquid crystal panel 11 is read out from the lookup table without obtaining the light transmission amount measurement unit 2b each time, so that the light amount setting of the fluorescent tube 1a can be set in a short time. It can be carried out.

  A liquid crystal panel inspection method in the liquid crystal panel inspection apparatus 10 having the above configuration will be described based on the flowchart of FIG. FIG. 8 is a flowchart showing a liquid crystal panel inspection method. It is assumed that the irradiation light quantity of the fluorescent tube 1a is set according to the gradation of the liquid crystal panel 11, that is, the light transmission amount, as the previous stage of this flowchart. That is, the inspection patterns described here are the five inspection patterns shown in FIGS. 2A to 2E, and the lighting patterns are the five lighting patterns shown in FIGS. 6A to 6E.

  First, as shown in FIG. 8, the liquid crystal panel lighting control device 3 changes the entire white display 21 as an inspection pattern of the liquid crystal panel 11 (S1). Next, the backlight control device 2 changes the backlight unit 1 to the lighting pattern 31 (S2). In this state, a defect inspection is performed in which an image of the liquid crystal panel 11 is captured by the camera 4 and image processing is performed by the image processing device 5 (S3). As a result, if a defect is found (S4), the defect type and the defect position are stored (S5). If no defect is found in S4, the process proceeds to the inspection of the entire black display 22 shown in FIG.

  In the inspection of the entire black display 22 of the liquid crystal panel 11, the liquid crystal panel lighting control device 3 changes the entire black display 22 as the inspection pattern of the liquid crystal panel 11 (S6). Next, the backlight control device 2 changes the backlight unit 1 to the lighting pattern 32 (S7). In this state, a defect inspection is performed in which an image of the liquid crystal panel 11 is captured by the camera 4 and image processing is performed by the image processing device 5 (S8). As a result, if a defect is found (S9), the defect type and the defect position are stored (S10). If no defect is found in S9, the process proceeds to the inspection of the monochrome display 23 shown in FIG.

  In the inspection of the monochrome display 23 of the liquid crystal panel 11, the liquid crystal panel lighting control device 3 changes the inspection pattern of the liquid crystal panel 11 to the monochrome display 23 (S11). Next, the backlight control device 2 changes the backlight unit 1 to the lighting pattern 33 (S12). In this state, a defect inspection is performed in which an image of the liquid crystal panel 11 is captured by the camera 4 and image processing is performed by the image processing apparatus 5 (S13). As a result, if a defect is found (S14), the defect type and the defect position are stored (S15). If no defect is found in S14, the process proceeds to the inspection of the black and white display 24 shown in FIG.

  In the inspection of the black and white display 24 on the liquid crystal panel 11, the liquid crystal panel lighting control device 3 changes the inspection pattern of the liquid crystal panel 11 to the black and white display 24 (S16). Next, the backlight control device 2 changes the backlight unit 1 to the lighting pattern 34 (S17). In this state, a defect inspection is performed in which an image of the liquid crystal panel 11 is captured by the camera 4 and image processing is performed by the image processing device 5 (S18). As a result, if a defect is found (S19), the defect type and the defect position are stored (S20). If no defect is found in S19, the process proceeds to the inspection of all gradation display 25 shown in FIG.

  In the inspection of the all gradation display 25 of the liquid crystal panel 11, the liquid crystal panel lighting control device 3 changes the inspection pattern of the liquid crystal panel 11 to the all gradation display 25 (S21). Next, the backlight control device 2 changes the backlight unit 1 to the lighting pattern 35 (S22). In this state, a defect inspection is performed in which an image of the liquid crystal panel 11 is captured by the camera 4 and image processing is performed by the image processing device 5 (S23). As a result, if a defect is found (S24), the defect type and the defect position are stored (S25). If no defect is found in S23, the defect stored so far is extracted and the inspection results are integrated (S26).

  By this processing, it becomes possible to realize defect inspection of the liquid crystal panel 11 using the light intensity control function for each region in the backlight unit 1.

  The inspection pattern of the liquid crystal panel 11 shown in FIGS. 2A to 2E and the lighting pattern of the backlight unit 1 shown in FIGS. 6A to 6E are combined to enter the camera 4. Since the amount of light is substantially constant over the entire surface of the liquid crystal panel 11, the entire panel surface can be inspected under uniform conditions even with an area type camera in which it is difficult to adjust the gain for each region.

  That is, by changing the control target value for each part of the backlight unit 1 in accordance with the lighting pattern in which a predetermined defect appears, the transmitted light intensity on the entire surface of the liquid crystal panel 11 can be kept substantially constant. .

  Therefore, when the liquid crystal panel 11 is mechanically inspected using the camera 4 such as a digital camera, the irradiation light amount condition on the entire surface of the liquid crystal panel 11 is kept within a certain range, and the panel transmitted light intensity is kept within the dynamic range of the camera 4. Thus, the saturation of the image of the camera 4 and the influence of the quantization error can be reduced, and the inspection accuracy can be increased.

  In the present embodiment, the backlight unit 1 is composed of a plurality of fluorescent tubes 1a capable of independently controlling the amount of irradiation light. However, the present invention is not necessarily limited to this, and for example, an LED (Light Emitting Diode) can be used. The LEDs are arranged in a matrix. As a result, the amount of light emitted from the LEDs can be independently controlled not only in the vertical direction but also in the horizontal direction. Also, the LED is small in size and can handle fine patterns. As a result, the degree of freedom in arrangement is very high and it is possible to deal with complicated patterns. Further, the LED has a longer lifetime than the fluorescent tube 1a. Further, the fluorescent tube 1a may have an influence on the inspection because the illuminance at the end portion of the fluorescent tube 1a is first deteriorated over time, but such a problem does not occur in the LED.

  The backlight control device 2 does not perform the irradiation light amount control for the life of the fluorescent tube 1a. However, the present invention is not limited to this, and the irradiation light amount control considering the life of the fluorescent tube 1a can be performed. It is.

  In this case, as shown in FIG. 1, the backlight control device 2 is provided with a light life control unit 2d. The control of the amount of light emitted from the fluorescent tube 1a in the light life controller 2d will be described below.

For example, as shown in FIG. 9A, the luminance average of the screen area of the entire white display 21 corresponding to the i-th fluorescent tube 1a, for example, for the last 5 hours is Ii, and the target luminance is Id. At this time, as shown in FIG. 9B, when the luminance average Ii falls to 90% or less of the target luminance Id, the light life control unit 2d adjusts the voltage of the fluorescent tube 1a. For example, when the current fluorescent tube input voltage is Vi, the changed voltage Vi ′ is
Vi ′ = Id / Ii
And Since it becomes impossible to adjust when the voltage Vi 'after changing over the power adjustment limit V _Max, shall replace the fluorescent tubes 1a. The voltages of the four patterns of fluorescent tubes 1a other than the entire white display 21 are adjusted in proportion to the fluorescent tube input voltage Vi in the inspection pattern of the entire white display 21.

  Thereby, the light quantity control of the fluorescent tube 1a according to the inspection pattern can be performed in consideration of the life of the fluorescent tube 1a. In FIG. 9B, the replacement time of the fluorescent tube 1a is described as, for example, 23 hours. However, this is described as such for convenience of explanation, and in actuality, It will not be replaced in a short time due to the life of the fluorescent tube 1a.

  Finally, each block of the liquid crystal panel inspection device 10, particularly the image processing device 5, the liquid crystal panel lighting control device 3, and the backlight control device 2 may be configured by hardware logic, or the CPU may be configured as follows. And may be realized by software.

  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 includes a plurality of light sources that irradiate the liquid crystal panel 11 from behind, and the backlight unit that controls increase / decrease of the amount of light applied to the liquid crystal panel 11 by each light source. 1 and a liquid crystal panel lighting control device 3 for displaying a test pattern having at least two types of display areas with different gradations simultaneously on the liquid crystal panel 11, and a display area with higher gradations to the liquid crystal panel 11 of the light source. There is provided a backlight control device 2 that controls the backlight unit 1 so as to reduce the amount of irradiation light and to increase the amount of light irradiated to the liquid crystal panel 11 of the light source as the display area has a lower gradation.

  In addition, the method for inspecting the liquid crystal panel 11 according to the present embodiment includes a step of providing a plurality of light sources for irradiating the liquid crystal panel 11 from behind, and a liquid crystal panel 11 having at least two types of display areas with different gradations simultaneously. The step of displaying the inspection pattern, and the display area with higher gradation reduces the amount of light applied to the liquid crystal panel 11 of the light source, and the display area with lower gradation increases the amount of light applied to the liquid crystal panel 11 of the light source. And a controlling step.

  Moreover, 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 front position of the backlight unit 1 in the liquid crystal panel inspection apparatus 10 described above, and the backlight unit in the liquid crystal panel inspection apparatus 10. And a step of inspecting the liquid crystal panel 11 arranged at the front surface position 1 by the inspection method for the liquid crystal panel 11 described above.

  Thereby, in order to inspect the defect of the liquid crystal panel 11 which becomes apparent only when it is generated when the liquid crystal panel 11 to be inspected is turned on under a specific condition, in the backlight unit 1 The intensity of each fluorescent tube 1a can be controlled based on the gradation of the liquid crystal panel 11. As a result, defects appearing in the fluorescent tube 1a can be inspected under optimum conditions for each display area of the liquid crystal panel 11, and defect detection accuracy can be improved. That is, since the inspector or the camera 4 can observe the entire surface of the liquid crystal panel 11 under a uniform amount of irradiation light, the defect can be easily found.

  In particular, when a defect inspection of the liquid crystal panel 11 is performed by processing an image captured by the camera 4 with a computer, a panel transmission light condition suitable for the dynamic range of the camera 4 can be set. As a result, it is not necessary to perform imaging a plurality of times while changing the exposure time and gain setting of the camera 4, and the inspection can be performed quickly.

  Therefore, in the case where the liquid crystal panel 11 has an inspection pattern having at least two types of display areas having different gradations at the same time, the liquid crystal panel inspection apparatus 10 that detects defects in each display area with high accuracy, and the inspection of the liquid crystal panel 11 The method and the manufacturing method of the liquid crystal panel 11 can be realized.

  Further, in the liquid crystal panel inspection apparatus 10 of the present embodiment, the inspection pattern is divided into two when the display screen on the liquid crystal panel 11 is divided and one of the divided screens is displayed in black and the other is displayed in white. This includes the case where one is displayed in white and the other is displayed in black.

  As a result, it is possible to accurately detect a so-called SD leak defect that occurs due to leakage of charge in the source (S) direction to the drain (D).

  In the liquid crystal panel inspection apparatus 10 of the present embodiment, the gradation of the liquid crystal panel 11 from the gradation 0 which is the minimum gradation to the gradation 255 which is the maximum gradation is divided into at least three, for example, seven, Since the inspection pattern divided and displayed in the display area is used, a specific gradation line defect that is a line defect having a conspicuous contrast at a specific gradation, or a line defect of a specific gradation defect that is caused by a malfunction of a specific bit in the driver. It can be discovered with high accuracy.

  Further, in the liquid crystal panel inspection device 10 of the present embodiment, the backlight control device 2 measures the light transmission amount by the standard light amount of the fluorescent tube 1a for each gradation of each display area of the liquid crystal panel 11 in the inspection pattern. A transmission amount measurement unit 2b and a part output setting unit 2c that determines the output of each fluorescent tube 1a based on the light transmission amount of each display area obtained by the light transmission amount measurement unit 2b. preferable.

  As a result, when a defect for each display area is detected by the light transmission amount measurement unit 2b and the part output setting unit 2c, specifically, it is easy to detect visually or in detection by the camera 4, and the measurement dynamics of the camera 4 are detected. The light transmission amount can be set so as to be within the range.

  Moreover, in the liquid crystal panel inspection apparatus 10 of this Embodiment, the transmitted light from the fluorescent tube 1a is imaged with the camera 4, and the image imaged with the camera 4 is image-processed with the image processing apparatus 5, and a light / dark comparison is carried out. By doing so, a defective portion can be extracted.

  Moreover, in the liquid crystal panel inspection apparatus 10 of this Embodiment, it is preferable that the camera 4 is an area sensor type camera.

  That is, the area sensor has a wider imaging range than the line sensor. However, in the area sensor, generally, the gain setting for adjusting the amount of imaged light and the control of the exposure time are uniform over the entire capturing area. Therefore, if the inspection object has a gradation based on gradation, saturation (high light amount region) or insufficient sensitivity (low light amount region) may occur. That is, when the camera 4 is an area sensor type camera, the output of the element is generally obtained by multiplying the received light amount determined by the exposure time by a uniform analog gain for the entire sensor. As a result, if the range of the intensity of the panel transmitted light is wide, the dynamic range of the camera element is exceeded, so saturation or missing of information occurs.

  Therefore, in the present embodiment, when such an area sensor type camera is used, high sensitivity inspection is performed on the entire inspection object by controlling the amount of light emitted from the light source in the display area of the liquid crystal panel 11. Can do.

  Depending on the optical conditions of the camera 4, when the emission intensity of the fluorescent tube 1 a is increased in a region where the amount of light transmission is large, or when the gain is increased to increase the sensitivity of the camera 4, reflection in the lens or camera element Ghosts resulting from the structure may occur.

  However, in the liquid crystal panel inspection apparatus 10 of the present embodiment, it is possible to avoid a decrease in inspection accuracy due to ghosts by reducing the irradiation intensity of the fluorescent tube 1a only in a region where ghosts may occur. become.

  Further, in the liquid crystal panel inspection apparatus 10 of the present embodiment, the light source is composed of the fluorescent tube 1a. Therefore, when the 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. To realize a liquid crystal panel inspection apparatus 10, a liquid crystal panel 11 inspection method, and a liquid crystal panel 11 manufacturing method for detecting defects in each display area with high accuracy in the case of having an inspection pattern having display areas of different gradations simultaneously. Can do.

  Moreover, in the liquid crystal panel test | inspection apparatus 10 of this Embodiment, a light source can be comprised from light emitting elements, such as LED. That is, in the case of using a light emitting element that has been used as a light source of the liquid crystal panel 11 in recent years, the liquid crystal panel 11 has an inspection pattern having at least two kinds of display areas of different gradations simultaneously. A liquid crystal panel inspection apparatus 10 that detects defects for each display area with high accuracy, a liquid crystal panel inspection apparatus 10 that detects defects for each display area with high precision, a liquid crystal panel lighting control apparatus 3 inspection method, and a liquid crystal panel 11 manufacturing method. can do.

  In the present embodiment, as described above, the backlight control device 2 as the light amount control means controls to increase or decrease the amount of light applied to the liquid crystal panel 11 of the light emitting element such as the fluorescent tube 1a or the LED. Yes.

  However, in the present invention, the present invention is not necessarily limited to this, and the light amount control means can also be configured by a shutter mechanism provided between the backlight unit 1 and the liquid crystal panel 11. That is, if a louver type shutter is provided as a shutter mechanism and the louver can be freely changed from fully closed to fully open, the amount of light applied to the liquid crystal panel 11 of the light source by the backlight unit 1 can be changed. Become.

  Moreover, in the liquid crystal panel inspection apparatus 10 of this Embodiment, the backlight control apparatus 2 memorize | stores the lighting pattern containing the lighting position and irradiation light quantity of each light source in the backlight unit 1 corresponding to a liquid crystal, for example, a look-up table etc. The lighting pattern memory | storage part 2a as a lighting pattern memory | storage means is provided.

  Thus, when the inspection pattern is determined, the lighting pattern storage unit 2a calls the lighting pattern including the lighting position and the irradiation light amount of each light source in the backlight unit 1 corresponding to the inspection pattern from time to time, and each light source of the backlight unit 1 Since the lighting control can be performed, the lighting control can be performed quickly.

  Moreover, in the liquid crystal panel inspection apparatus 10 of this Embodiment, the backlight control apparatus 2 is provided with the light lifetime control part 2d which determines the output of each fluorescent tube 1a in consideration of the lifetime of the fluorescent tube 1a. preferable.

  That is, when the backlight control device 2 controls to increase or decrease the amount of light emitted from the fluorescent tube 1a of the backlight unit 1, an appropriate light transmission amount cannot be obtained unless the life of the fluorescent tube 1a is taken into consideration.

  On the other hand, in this embodiment, the light life control unit 2d determines the output of each fluorescent tube 1a in consideration of the life of the fluorescent tube 1a. As a result, the effective voltage for the fluorescent tube 1a can be sequentially controlled so as to appropriately compensate for the luminance change in the region corresponding to each fluorescent tube 1a of the image captured by the camera 4.

  Moreover, in the liquid crystal panel inspection apparatus 10 of this Embodiment, it is preferable to provide the conveyor as a conveyance means which conveys and arrange | positions the liquid crystal panel 11 to the front surface position of the backlight unit 1. FIG.

  Thereby, in this Embodiment, it is possible to isolate | separate the liquid crystal panel 11, the backlight unit 1, and another component. 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. Further, it is not necessary to provide the backlight unit 1 with an irradiation intensity adjustment function for each light source in the final product.

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

  The present invention relates to a transmissive display that performs defect inspection of a transmissive display panel by irradiating a backlight from the back of the transmissive display panel such as a transmissive liquid crystal panel and extracting defective portions of the transmissive display panel. The present invention can be applied to a panel inspection apparatus, a transmissive display panel inspection method, a transmissive display panel manufacturing method, a program, and a recording medium.

  The transmissive display panel can be applied to a transmissive display panel such as a transmissive liquid crystal panel or a projector. Furthermore, a plurality of fluorescent tubes or LEDs (Light Emitting Diodes) can be used as the backlight.

It is a block diagram which shows one Embodiment of the liquid crystal panel test | inspection apparatus in this invention. (A)-(e) is a top view which shows the display pattern for the test | inspection of the liquid crystal panel which is a test object of 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 of a liquid crystal panel. (A)-(e) is a top view which shows the lighting pattern of the backlight unit corresponding to the display pattern for a test | inspection of the liquid crystal panel shown to Fig.2 (a)-(e). (A) (b) is a graph which shows how to obtain | require the setting intensity | strength in a fluorescent tube. It is a flowchart which shows the test | inspection method of the liquid crystal panel in said liquid crystal panel test | inspection apparatus. (A) (b) is a graph which shows how to obtain | require the setting intensity | strength by the light life control part in the backlight control apparatus of the said liquid crystal panel test | inspection apparatus.

Explanation of symbols

1 Backlight unit (irradiation means)
1a Fluorescent tube (light source)
2 Backlight control device (light quantity control means)
2a lighting pattern storage unit (lighting pattern storage means)
2b Light transmission measurement unit (light transmission measurement means)
2c Part output setting part (part output setting means)
2d Light life control unit (light life control means)
3. Liquid crystal panel lighting control device (inspection pattern display means)
4 Camera (imaging means)
5 Image processing device (image processing means)
10 Liquid crystal panel inspection device (Transmission display panel inspection device)
11 Liquid crystal panel (transmission type display panel)
21 Fully white display (inspection pattern)
22 Fully black display (inspection pattern)
23 Black and white display (inspection pattern)
24 Black and white display (inspection pattern)
25 All gradation display (inspection pattern)
31-35 lighting pattern

Claims (15)

In a transmissive display panel inspection apparatus that performs gradation display by controlling increase / decrease in light transmission amount, and inspects a defect of a transmissive display panel that is an inspection object,
A plurality of light sources that irradiate the transmissive display panel from behind, and an irradiating means that controls increase / decrease in the amount of light applied to the transmissive display panel of each light source;
Inspection pattern display means for displaying an inspection pattern having at least two types of display areas of different gradations simultaneously on the transmissive display panel;
The above-mentioned irradiation is performed so that the display area with the higher gradation has a smaller amount of light applied to the transmissive display panel of the light source and the display area with the lower gradation has a larger amount of light applied to the transmissive display panel of the light source. An inspection apparatus for a transmissive display panel, comprising: a light amount control means for controlling the means.   In the inspection pattern, the display screen of the transmissive display panel is divided into two, where one of the divided screens is displayed in black and the other is displayed in white, and one of the divided screens is displayed in white and the other is displayed in black. The inspection apparatus for a transmissive display panel according to claim 1, further comprising:   2. The inspection pattern is formed by being divided and displayed in display areas of different gradations obtained by dividing at least three parts from the minimum gradation to the maximum gradation of the transmissive display panel. Inspection equipment for transmissive display panels. The light amount control means includes
A light transmission amount measuring means for measuring a light transmission amount by a standard light amount of a light source for each gradation of each display area of the transmission type display panel in the inspection pattern;
4. A part output setting means for determining the output of each light source based on the light transmission amount of each display area obtained by the light transmission amount measuring means. Inspection equipment for transmissive display panels. In the transmissive display panel, imaging means for imaging transmitted light from a light source;
5. The image processing unit according to claim 1, further comprising an image processing unit configured to perform image processing on an image captured by the imaging unit and perform density comparison to extract a defective portion. Inspection device for transmissive display panels.   6. The inspection apparatus for a transmissive display panel according to claim 5, wherein the imaging means is an area sensor type camera. The light source comprises a fluorescent tube,
The transmissive display panel inspection apparatus according to claim 1, wherein the light amount control unit controls an amount of light applied to the transmissive display panel of a fluorescent tube. The light source comprises a light emitting element,
The transmissive display panel inspection apparatus according to claim 1, wherein the light amount control unit controls an amount of light emitted from the light emitting element to the transmissive display panel. The light amount control means includes
9. The transmission according to claim 7, further comprising a lighting pattern storage unit that stores a lighting pattern including a lighting position of each light source and an irradiation light amount in the irradiation unit corresponding to the inspection pattern displayed by the inspection pattern display unit. Type display panel inspection equipment.   10. The transmissive display panel according to claim 1, wherein the light quantity control unit includes a lifetime control unit that determines an output of each light source in consideration of a lifetime of the light source. Inspection device.   11. The inspection apparatus for a transmissive display panel according to claim 1, further comprising transport means for transporting and arranging the transmissive display panel at a front position of the irradiation means. In the inspection method of the transmissive display panel, which performs gradation display by controlling the increase / decrease in the amount of light transmission, performs the defect inspection of the transmissive display panel that is the inspection object,
Providing a plurality of light sources for irradiating the transmissive display panel from behind;
Displaying the inspection pattern having at least two kinds of display areas of different gradations simultaneously on the transmissive display panel;
The display area with higher gradation is controlled to reduce the amount of light applied to the transmissive display panel of the light source, and the display area with lower gradation is controlled to increase the amount of light applied to the transmissive display panel of the light source. And a transmissive display panel inspection method. Arranging the transmissive display panel at a front position of the irradiation means in the transmissive display panel inspection apparatus according to claim 1;
And a step of inspecting the transmissive display panel disposed in front of the irradiation means in the transmissive display panel inspection apparatus by the transmissive display panel inspection method according to claim 12. A method for manufacturing a transmissive display panel.   A transmissive display panel inspection program for operating the transmissive display panel inspection device according to any one of claims 1 to 11, comprising: a transmissive display panel for causing a computer to function as each of the above means; Inspection program.   A computer-readable recording medium in which the inspection program for a transmissive display panel according to claim 14 is recorded.