Inspection device and inspection method

Abstract

To provide an inspection device and an inspection method that enable proper inspection of a liquid crystal display panel.SOLUTION: An inspection device includes: a superimposed body to be overlaid with a liquid crystal display panel in the thickness direction of the liquid crystal display panel; and a mechanism that fixes one of the liquid crystal display panel and the superimposed body, and moves the other of the liquid crystal display panel and the superimposed body in the in-plane direction of the liquid crystal display panel.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present disclosure relates to an inspection device and an inspection method. [Background technology]

[0002] Patent Document 1 discloses an inspection device. In this inspection device, a front polarizer, a liquid crystal panel used as a standard, a back polarizer, and a backlight are imaged from the front polarizer side to obtain a first image. Next, the front polarizer and the backlight are imaged from the front polarizer side to obtain a second image. Next, a correction coefficient is calculated based on the first and second images. Next, the front polarizer, the liquid crystal panel to be inspected, the back polarizer, and the backlight are imaged from the front polarizer side to obtain an inspection image. Next, positions that are defect candidates are extracted, and defect determination is performed on the defect candidate positions using the correction coefficient (paragraphs 0025, 0040, 0041, 0042, 0049, 0054, and 0055). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4610656 Summary of the Invention [Problem to be solved by the invention]

[0004] In the inspection device disclosed in Patent Document 1, the detected defects may not be defects originating in the liquid crystal panel being inspected, but rather defects originating in the front polarizing plate, rear polarizing plate, or backlight. For this reason, the inspection device may not be able to properly detect defects in the liquid crystal panel.

[0005] In view of this problem, an aspect of the present disclosure provides an inspection device and an inspection method that can appropriately inspect, for example, a liquid crystal display panel. [Means for solving the problem]

[0006] The inspection device of the first aspect of the present disclosure includes a stack that is stacked on a liquid crystal display panel in the thickness direction of the liquid crystal display panel, and a mechanism that fixes one of the liquid crystal display panel and the stack and moves the other of the liquid crystal display panel and the stack in the surface direction of the liquid crystal display panel.

[0007] An inspection method according to a second aspect of the present disclosure includes the steps of stacking the liquid crystal display panel and the stacked object together in the thickness direction of the liquid crystal display panel, and fixing one of the liquid crystal display panel and the stacked object and moving the other of the liquid crystal display panel and the stacked object in the surface direction of the liquid crystal display panel. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram showing an inspection device of a first embodiment and a liquid crystal display (LCD) panel inspected using the inspection device. [Figure 2] 1 is a perspective view schematically illustrating a stage, contact terminals, a stacked object, and a camera provided in the inspection device of the first embodiment, as well as an LCD panel inspected using the inspection device. FIG. [Figure 3] 1 is a cross-sectional view schematically illustrating a stack of objects provided in an inspection device of a reference example, foreign matter adhering to the stack of objects, and an LCD panel inspected using the inspection device. [Figure 4] 1 is a cross-sectional view schematically illustrating a stack of objects provided in the inspection device of the first embodiment, foreign matter adhering to the stack of objects, and an LCD panel inspected using the inspection device. [Figure 5] FIG. 2 is a top view schematically illustrating an LCD panel inspected by the inspection device of the first embodiment. [Figure 6]FIG. 2 is a top view schematically illustrating a backlight provided in the inspection device of the first embodiment. [Figure 7A] 1 is a top view schematically illustrating a backlight provided in the inspection device of the first embodiment and an LCD panel inspected using the inspection device, the backlight being positioned at a first position. FIG. [Figure 7B] 3 is a top view schematically illustrating a backlight provided in the inspection device of the first embodiment and an LCD panel inspected using the inspection device, the backlight being positioned at a second position. FIG. [Figure 7C] 10 is a top view schematically illustrating a backlight provided in the inspection device of the first embodiment and an LCD panel inspected using the inspection device, the backlight being positioned at a third position. FIG. [Figure 7D] 10 is a top view schematically illustrating a backlight provided in the inspection device of the first embodiment and an LCD panel inspected using the inspection device, the backlight being positioned at a fourth position. FIG. [Figure 8] 3 is a flowchart showing the flow of processing performed by the inspection device of the first embodiment. [Figure 9] 3A to 3C are diagrams showing the contents of image processing performed by an extraction unit and a synthesis unit provided in the inspection device of the first embodiment. [Figure 10] 3A to 3C are diagrams showing an image acquired by a camera provided in the inspection device of the first embodiment, and shift components and fixed components acquired by an extraction unit provided in the inspection device. [Figure 11] 3A and 3B are diagrams showing a display quality image generated by a synthesis unit provided in the inspection device of the first embodiment. [Figure 12] 3A to 3C are diagrams illustrating image processing performed by an extraction unit provided in the inspection device of the first embodiment. [Figure 13] 1 is a cross-sectional view schematically illustrating a stack and a camera provided in an inspection device of a reference example, and an LCD panel inspected by the inspection device. [Figure 14]1 is a cross-sectional view schematically illustrating a stack and a camera provided in the inspection device of the first embodiment, and an LCD panel inspected by the inspection device. [Figure 15] FIG. 10 is a diagram showing an inspection device according to a first modified example of the first embodiment. [Figure 16] 10 is a diagram showing an inspection device according to a second embodiment and an LCD panel inspected using the inspection device. FIG. [Figure 17] FIG. 10 is a perspective view schematically illustrating a stage, contact terminals, a stacked object, and a camera provided in an inspection device of a second embodiment, as well as an LCD panel inspected using the inspection device. [Figure 18] 10 is a cross-sectional view schematically illustrating a stack of objects provided in an inspection device of a second embodiment, foreign matter adhering to the stack of objects, and an LCD panel inspected using the inspection device. FIG. [Figure 19A] FIG. 10 is a top view schematically illustrating a backlight provided in the inspection device of the second embodiment and an LCD panel inspected using the inspection device, with the LCD panel placed in a first position. [Figure 19B] FIG. 10 is a top view schematically illustrating a backlight provided in the inspection device of the second embodiment and an LCD panel inspected using the inspection device, with the LCD panel placed in a second position. [Figure 19C] FIG. 10 is a top view schematically illustrating a backlight provided in the inspection device of the second embodiment and an LCD panel inspected using the inspection device, with the LCD panel placed in a third position. [Figure 19D] FIG. 10 is a top view schematically illustrating a backlight provided in the inspection device of the second embodiment and an LCD panel inspected using the inspection device, with the LCD panel placed in a fourth position. [Figure 19E] FIG. 11 is a top view schematically illustrating a backlight provided in the inspection device of the second embodiment and an LCD panel inspected using the inspection device, with the LCD panel positioned at a sixteenth position. [Figure 20]10 is a flowchart showing the flow of processing performed by the inspection device of the second embodiment. [Figure 21] 10A and 10B are diagrams showing the contents of image processing performed by an extraction unit and a synthesis unit provided in the inspection device of the second embodiment. [Figure 22] 10A and 10B are diagrams showing an image acquired by a camera provided in an inspection device of a second embodiment, and a shift component and a fixed component acquired by an extraction unit provided in the inspection device. [Figure 23] 10A and 10B are diagrams showing a display quality image generated by a synthesis unit provided in the inspection device of the second embodiment. [Figure 24] 10A and 10B are diagrams illustrating image processing performed by an extraction unit provided in the inspection device of the second embodiment. [Figure 25] 1 is a cross-sectional view schematically illustrating a stack and a camera provided in an inspection device of a reference example, and an LCD panel inspected by the inspection device. [Figure 26] 10 is a cross-sectional view schematically illustrating a stack and a camera provided in an inspection device of a second embodiment, and an LCD panel inspected by the inspection device, with the LCD panel placed in a first position. FIG. [Figure 27] 10 is a perspective view schematically illustrating a stack and a camera provided in an inspection device of a second embodiment, and an LCD panel inspected by the inspection device, the LCD panel being placed in a first position. FIG. [Figure 28] 10 is a cross-sectional view schematically illustrating a stack and a camera provided in the inspection device of the second embodiment, and an LCD panel inspected by the inspection device, with the LCD panel positioned at the 16th position. FIG. [Figure 29] FIG. 11 is a perspective view schematically illustrating a stack and a camera provided in the inspection device of the second embodiment, and an LCD panel inspected by the inspection device, with the LCD panel positioned at the 16th position. [Figure 30] 10A and 10B are diagrams showing an inspection device according to a third embodiment and an LCD panel inspected using the inspection device. [Figure 31]FIG. 10 is a cross-sectional view schematically illustrating a stage, contact terminals, a stacked object, a mechanism, and a camera provided in an inspection device of a third embodiment, as well as an LCD panel inspected using the inspection device. [Figure 32] FIG. 11 is a perspective view schematically illustrating a stage, contact terminals, a stacked object, and a camera provided in an inspection device of a third embodiment, as well as an LCD panel inspected using the inspection device. [Figure 33] 10 is a flowchart showing the flow of processing performed by the inspection device of the third embodiment. [Figure 34] 10A and 10B are diagrams showing the contents of image processing performed by an extraction unit and a synthesis unit provided in the inspection device of the third embodiment. [Figure 35] 10A and 10B are diagrams showing the contents of image processing performed by a correction unit provided in the inspection device of the third embodiment. [Figure 36] 10A and 10B are diagrams showing an image acquired by a camera provided in an inspection device of a third embodiment, and a shift component and a fixed component acquired by an extraction unit provided in the inspection device. [Figure 37] 10A to 10D are diagrams showing an image acquired by a camera provided in an inspection device of a third embodiment, a saved image generated by a synthesis unit provided in the inspection device, and a brightness ratio distribution image acquired by a correction unit provided in the inspection device. [Figure 38] 10A to 10C are diagrams showing a luminance ratio distribution image, an average luminance image, and a display quality image acquired by a correction unit provided in the inspection device of the third embodiment. [Figure 39] FIG. 10 is a cross-sectional view schematically illustrating a state in which the first LCD panel is placed at a first position, of a stack of objects, a camera, and a first LCD panel provided in an inspection device of a third embodiment. [Figure 40] 10 is a cross-sectional view schematically illustrating a state in which the first LCD panel is positioned at the sixteenth position, of a stack of objects and a camera provided in the inspection device of the third embodiment, and a first LCD panel. FIG. [Figure 41]A cross-sectional view schematically illustrating a stack and a camera provided in an inspection device of a third embodiment, and a second LCD panel inspected by the inspection device, with the second LCD panel positioned at the inspection position. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the same or equivalent elements are designated by the same reference numerals, and redundant description will be omitted.

[0010] 1. First embodiment 1.1 Inspection equipment Fig. 1 is a diagram showing an inspection device of a first embodiment and a liquid crystal display (LCD) panel inspected using the inspection device, and Fig. 2 is a perspective view schematically showing a stage, contact terminals, a stacked object, and a camera provided in the inspection device of the first embodiment, and an LCD panel inspected using the inspection device.

[0011] 1 is used for automatic inspection of the display quality of an LCD panel 11. Inspecting the display quality includes inspecting whether or not there are any unevenness or point defects in the LCD panel 11 that may cause display abnormalities in LCDs manufactured using the LCD panel 11.

[0012] As shown in FIGS. 1 and 2, the inspection device 1 includes a stage 21, a circuit 22, contact terminals 23, a superposed object 24, a mechanism 25, a camera 26, an extracting unit 28, a synthesizing unit 29, and a control unit 31.

[0013] The LCD panel 11 has a plate-like shape. The LCD panel 11 has a first main surface 11a, a second main surface 11b, and an end surface 11c. The first main surface 11a and the second main surface 11b are located on opposite sides of each other. The end surface 11c extends from the edge of the first main surface 11a to the edge of the second main surface 11b.

[0014] The LCD panel 11 includes an electrode 41. The electrode 41 is exposed on a first main surface 11a of the LCD panel 11. The LCD panel 11 modulates the polarization direction of light passing through the LCD panel 11 in accordance with a signal input to the electrode 41.

[0015] The LCD panel 11 is placed on the stage 21. The stage 21 horizontally supports the placed LCD panel 11 from below in the vertical direction DZ.

[0016] The stage 21 has a frame-like shape. The stage 21 has a first main surface 21a and a second main surface 21b. The stage 21 is placed horizontally. The first main surface 21a and the second main surface 21b are on opposite sides to each other.

[0017] A groove 21c and a hole 21d are formed in the stage 21. The groove 21c has a bottom surface 21e and a side surface 21f.

[0018] The groove 21c of the stage 21 is formed in the first main surface 21a of the stage 21. The groove 21c has a planar shape that matches the planar shape of the LCD panel 11. This allows the LCD panel 11 to be accommodated in the groove 21c. The second main surface 11b of the LCD panel 11 contacts the bottom surface 21e of the groove 21c. As a result, the stage 21 horizontally supports the LCD panel 11 from below in the vertical direction DZ. The end surface 11c of the LCD panel 11 contacts the side surface 21f of the groove 21c. This allows the stage 21 to restrict movement of the LCD panel 11 in the surface direction of the LCD panel 11, which is parallel to the horizontal directions DX and DY. The horizontal directions DX and DY are perpendicular to each other.

[0019] The hole 21d of the stage 21 penetrates the stage 21 in the thickness direction of the stage 21, which is parallel to the vertical direction DZ, and extends from the first main surface 21a of the stage 21 to the second main surface 21b of the stage 21. The hole 21d has a planar shape smaller than the planar shape of the LCD panel 11. The hole 21d extends from the center of the bottom surface 21e of the groove 21c of the stage 21 to the second main surface 21b of the stage 21. This allows the stage 21 to support the edge of the LCD panel 11 from below in the vertical direction DZ. Furthermore, the center of the LCD panel 11 can be illuminated with light from below in the vertical direction DZ through the hole 21d. The hole 21d is formed so that the entire active area of ​​the LCD panel 11 fits within the center of the LCD panel 11, which is illuminated by light.

[0020] The circuit 22 outputs a signal that drives the LCD panel 11 .

[0021] The contact terminal 23 is electrically connected to the circuit 22. The contact terminal 23 comes into contact with the electrode 41 and is electrically connected to the electrode 41. As a result, the contact terminal 23 inputs a signal for driving the LCD panel 11 to the electrode 41.

[0022] 1 and 2, the stack 24 includes a first polarizing plate 51, a second polarizing plate 52, and a backlight 53. The stack 24 may include components other than the first polarizing plate 51, the second polarizing plate 52, and the backlight 53.

[0023] The laminate 24 is overlapped with the LCD panel 11 in the thickness direction of the LCD panel 11. The first polarizing plate 51 is disposed on the first main surface 11a of the LCD panel 11, parallel to the LCD panel 11, and overlapped with the LCD panel 11 in the thickness direction of the LCD panel 11. The second polarizing plate 52 and the backlight 53 are disposed below the second main surface 11b of the LCD panel 11, parallel to the LCD panel 11, and overlapped with the LCD panel 11 in the thickness direction of the LCD panel 11. The second polarizing plate 52 and the backlight 53 are disposed on the second main surface 11b in the order shown. As a result, the backlight 53, the second polarizing plate 52, the LCD panel 11, and the first polarizing plate 51 are arranged in the thickness direction of the LCD panel 11 in the order shown. The backlight 53, the second polarizer 52, the LCD panel 11, and the first polarizer 51 are arranged in the order shown from bottom to top in the vertical direction DZ.

[0024] The backlight 53 emits light 61. The second polarizing plate 52 selectively transmits light having a first polarization direction contained in the emitted light 61. The LCD panel 11 modulates the polarization direction of the transmitted light in accordance with a signal input to the electrode 41. The first polarizing plate 51 selectively transmits light having a second polarization direction contained in the light whose polarization direction has been modulated. As a result, the stack of the second polarizing plate 52, LCD panel 11, and first polarizing plate 51 has a light transmittance corresponding to the signal. Furthermore, the stack of the backlight 53, second polarizing plate 52, LCD panel 11, and first polarizing plate 51 emits light corresponding to the signal. The second polarization direction is, for example, perpendicular to the first polarization direction.

[0025] The mechanism 25 fixes the stage 21. As a result, the mechanism 25 fixes the LCD panel 11 placed on the stage 21.

[0026] The mechanism 25 moves the superposed object 24 in the surface direction of the LCD panel 11. As a result, the mechanism 25 moves the superposed object 24 in the surface direction relative to the fixed LCD panel 11 and camera 26. The mechanism 25 includes a guide mechanism, a drive mechanism, etc. The guide mechanism guides the superposed object 24 in the surface direction of the LCD panel 11 so that the superposed object 24 does not move in the thickness direction of the LCD panel 11. The drive mechanism applies a force required to move the superposed object 24 to the superposed object 24. The drive mechanism may be omitted, and the force required to move the superposed object 24 may be applied to the superposed object 24 or a support body supporting the superposed object 24 by the user of the inspection device 1.

[0027] The camera 26 is disposed above the backlight 53, the second polarizing plate 52, the LCD panel 11, and the first polarizing plate 51 in the vertical direction DZ. The camera 26 captures images of the backlight 53, the second polarizing plate 52, the LCD panel 11, and the first polarizing plate 51 from above in the vertical direction DZ. The camera 26 captures an image of the area where the LCD panel 11 and the overlapping object 24 are overlapped with each other, and obtains an image of the captured area.

[0028] The extraction unit 28 extracts the components originating from the LCD panel 11 from the acquired image.

[0029] The synthesis unit 29 synthesizes the extracted components to generate a display quality image that indicates the display quality of the LCD panel 11. The generated display quality image indicates the distribution of luminance in the surface direction of the LCD panel 11. The generated display quality image is used to determine the display quality of the LCD panel 11. The display quality may be determined using automatic determination software or visually by a user of the inspection device 1. Synthesizing the components to generate a display quality image includes generating a display quality image that is an image of the area to be inspected from the multiple components, each of which is an image of a portion of an area included in the area to be inspected.

[0030] The control unit 31 controls the circuit 22 , the mechanism 25 , the extraction unit 28 and the synthesis unit 29 .

[0031] Under the control of the control unit 31, the circuit 22 outputs a signal to transmit light 61 through the stack of the second polarizer 52, the LCD panel 11, and the first polarizer 51 while the display quality of the LCD panel 11 is being inspected. As a result, while the display quality of the LCD panel 11 is being inspected, the circuit 22 turns on the stack of the backlight 53, the second polarizer 52, the LCD panel 11, and the first polarizer 51, and causes the stack to emit light necessary to generate a display quality image showing the luminance distribution.

[0032] Under the control of the control unit 31, the mechanism 25 moves the overlapping object 24 in the surface direction of the LCD panel 11 and places the overlapping object 24 at multiple different positions in a plane parallel to the surface direction while the display quality of the LCD panel 11 is being inspected.

[0033] The camera 26, under the control of the control unit 31, captures a plurality of images when the overlapping object 24 is placed at a plurality of positions.

[0034] The extracting unit 28, under the control of the control unit 31, extracts a plurality of components originating from the LCD panel 11 from the plurality of acquired images.

[0035] The synthesis unit 29 synthesizes the extracted components under the control of the control unit 31 to generate a display quality image.

[0036] The extraction unit 28, the synthesis unit 29, and the control unit 31 are configured by a microcontroller and peripheral circuits. The microcontroller includes a processor and memory. The processor executes a program stored in the memory to cause the microcontroller and peripheral circuits to perform the processes performed by the extraction unit 28, the synthesis unit 29, and the control unit 31. All or part of the processes performed by the microcontroller may be performed by dedicated electronic circuits.

[0037] 1.2 Distinguishing between unevenness and point defects on LCD panels and foreign matter attached to stacked objects, as well as unevenness and point defects on stacked objects Fig. 3 is a cross-sectional view schematically illustrating a stacked object provided in the inspection device of the reference example, a foreign substance adhering to the stacked object, and an LCD panel inspected using the inspection device. Fig. 4 is a cross-sectional view schematically illustrating a stacked object provided in the inspection device of the first embodiment, a foreign substance adhering to the stacked object, and an LCD panel inspected using the inspection device.

[0038] 3, while the display quality of the LCD panel 11 is being inspected using the inspection device of the reference example, neither the superposed object 24 nor the LCD panel 11 moves. Therefore, neither the foreign matter 71 attached to the superposed object 24 nor the point defect 72 in the LCD panel 11 moves. Therefore, the foreign matter 71 attached to the superposed object 24 and the point defect 72 in the LCD panel 11 cannot be distinguished from each other. The same can be said about the unevenness and point defect in the superposed object 24 as about the foreign matter 71 attached to the superposed object 24. The same can be said about the unevenness in the LCD panel 11 as about the point defect 72 in the LCD panel 11.

[0039] In contrast, as shown in Figure 4, while the display quality of the LCD panel 11 is being inspected using the inspection device 1 of the first embodiment, the superposed object 24 moves but the LCD panel 11 does not move. Therefore, the foreign matter 71 attached to the superposed object 24 moves but the point defect 72 in the LCD panel 11 does not move. Therefore, the foreign matter 71 attached to the superposed object 24 and the point defect 72 in the LCD panel 11 can be distinguished from each other. The same can be said about the unevenness and point defect in the superposed object 24 as about the foreign matter 71 attached to the superposed object 24. The same can be said about the unevenness in the LCD panel 11 as about the point defect 72 in the LCD panel 11.

[0040] The inspection device 1 utilizes this to extract components originating from the LCD panel 11 from the image acquired by the camera 26. The extracted components are fixed components that do not move in the plane direction of the LCD panel 11.

[0041] 1.3 LCD panel active area, mura and point defects 5 is a top view that schematically illustrates an LCD panel that is inspected using the inspection device of the first embodiment. In FIG. 5, the transmittance of the LCD panel 11 is expressed by the type of hatching.

[0042] 5, the LCD panel 11 has an active area 11d. The LCD panel 11 modulates the polarization direction of light passing through the active area 11d in accordance with a signal input to the electrode 41. Therefore, an LCD manufactured using the LCD panel 11 displays an image using the light passing through the active area 11d.

[0043] 5, the LCD panel 11 has mura 81 and point defects 82. Images of the mura 81 and point defects 82 are included in the display quality image. Therefore, the mura 81 and point defects 82 are discovered when the display quality of the LCD panel 11 is inspected using the inspection device 1.

[0044] 1.4 Backlight brightness uniformity area, unevenness and point defects Fig. 6 is a top view schematically illustrating the backlight provided in the inspection device of the first embodiment. In Fig. 6, the brightness of the light emitted by the backlight is expressed by the density of halftone dots.

[0045] 6, the backlight 53 has a uniform brightness area 91. Light emitted from within the uniform brightness area 91 has a uniform brightness distribution. Light emitted from outside the uniform brightness area 91 has a non-uniform brightness distribution.

[0046] 6, the backlight 53 has mura 101 and point defects 102. Images of the mura 101 and point defects 102 are removed when components originating from the LCD panel 11 are extracted from the image, and are not included in the display quality image. Therefore, the mura 101 and point defects 102 do not hinder the detection of the mura 81 and point defects 82.

[0047] 1.5 Position of LCD panel and overlapping objects The first polarizing plate 51 and the second polarizing plate 52 move in the same manner as the backlight 53. Furthermore, foreign matter adhering to the first polarizing plate 51 and the second polarizing plate 52 affects the inspection of the display quality of the LCD panel 11, just like foreign matter adhering to the backlight 53. Furthermore, unevenness and point defects on the first polarizing plate 51 and the second polarizing plate 52 affect the inspection of the display quality of the LCD panel 11, just like the unevenness 101 and point defects 102 on the backlight 53. For this reason, the following description of the superposed object 24 will focus on the backlight 53.

[0048] Fig. 7A is a top view schematically illustrating a backlight provided in the inspection apparatus of the first embodiment and an LCD panel inspected using the inspection apparatus, the backlight being positioned at a first position. Fig. 7B is a top view schematically illustrating a backlight provided in the inspection apparatus of the first embodiment and an LCD panel inspected using the inspection apparatus, the backlight being positioned at a second position. Fig. 7C is a top view schematically illustrating a backlight provided in the inspection apparatus of the first embodiment and an LCD panel inspected using the inspection apparatus, the backlight being positioned at a third position. Fig. 7D is a top view schematically illustrating a backlight provided in the inspection apparatus of the first embodiment and an LCD panel inspected using the inspection apparatus, the backlight being positioned at a fourth position.

[0049] The backlight 53 is disposed at a plurality of different positions in a plane parallel to the surface direction of the LCD panel 11 while the display quality of the LCD panel 11 is being inspected using the inspection device 1. The plurality of positions at which the backlight 53 is disposed are four positions consisting of a first position P101 shown in Fig. 7A, a second position P102 shown in Fig. 7B, a third position P103 shown in Fig. 7C, and a fourth position P104 shown in Fig. 7D. The plurality of positions may be three or less positions or five or more positions.

[0050] When the backlight 53 is disposed at each of the first position P101, the second position P102, the third position P103, and the fourth position P104, the entire uniform brightness area 91 of the backlight 53 and a portion of the active area 11d of the LCD panel 11 overlap with each other. The camera 26 captures an imaging area 111 including an area where the entire uniform brightness area 91 of the backlight 53 and a portion of the active area 11d of the LCD panel 11 overlap with each other. The imaging area 111 to be captured moves in the direction in which the backlight 53 moves. The imaging area 111 may be moved by panning and tilting the camera 26, by shifting an image sensor provided in the camera 26 in a direction perpendicular to the optical axis of the camera 26, by shifting an area to be cropped from an image acquired by the camera 26, or by shifting the range of pixel signals read from the image sensor provided in the camera 26.

[0051] The first position P101, the second position P102, the third position P103, and the fourth position P104 are set so that the uniform brightness area 91 of the backlight 53 scans the entire active area 11d of the LCD panel 11. The first position P101, the second position P102, the third position P103, and the fourth position P104 are set, for example, so that the uniform brightness area 91 of the backlight 53 overlaps with a first corner, a second corner, a third corner, and a fourth corner of the active area 11d of the LCD panel 11, respectively.

[0052] 1.6 Operation Fig. 8 is a flowchart showing the flow of processing performed by the inspection device of the first embodiment. Fig. 9 is a diagram showing the content of image processing performed by the extraction unit and synthesis unit provided in the inspection device of the first embodiment. Fig. 10 is a diagram showing an image acquired by a camera provided in the inspection device of the first embodiment, and shift components and fixed components acquired by the extraction unit provided in the inspection device. Fig. 11 is a diagram showing a display quality image generated by the synthesis unit provided in the inspection device of the first embodiment.

[0053] After the LCD panel 11 is set on the stage 21, the inspection device 1 executes steps S101 to S107 shown in FIG.

[0054] In step S101, the control unit 31 initializes an identifier i, which indicates a position in a plane parallel to the surface direction of the LCD panel 11, to 1.

[0055] In the next step S102, the mechanism 25 moves the backlight 53 in the surface direction of the LCD panel 11 to place the backlight 53 at the i-th position in a plane parallel to the surface direction of the LCD panel 11.

[0056] In the following step S103, camera 26 captures an image of imaging area 111 including the area where the entire uniform brightness area 91 of backlight 53 and part of the active area 11d of LCD panel 11 overlap each other to obtain the i-th image.

[0057] In the following step S104, the control unit 31 determines whether the identifier i has reached the upper limit value 4. If it is determined that the identifier i has reached the upper limit value 4, step S106 is executed. If it is determined that the identifier i has not reached the upper limit value 4, step S105 is executed, and then step S102 is executed again.

[0058] In step S105, the control unit 31 increments the identifier i.

[0059] 9 and 10, camera 26 acquires a first image I101, a second image I102, a third image I103, and a fourth image I104 when backlight 53 is placed at first position P101, second position P102, third position P103, and fourth position P104, respectively. First image I101, second image I102, third image I103, and fourth image I104 may be continuous scanning images acquired continuously by camera 26 while mechanism 25 moves backlight 53 without stopping it.

[0060] In step S106, as shown in Figures 9 and 10, the extraction unit 28 separates the first image I101 into a first shift component A101 and a first fixed component B101, separates the second image I102 into a second shift component A102 and a second fixed component B102, separates the third image I103 into a third shift component A103 and a third fixed component B103, and separates the fourth image I104 into a fourth shift component A104 and a fourth fixed component B104.

[0061] The first shift component A101, the second shift component A102, the third shift component A103, and the fourth shift component A104 are components that move in the surface direction of the LCD panel 11. When the backlight 53 moves, these components move relative to the image of a fixed object, for example, the image 11p of the LCD panel 11. These components do not move in the first image I101, the second image I102, the third image I103, and the fourth image I104.

[0062] The first fixed component B101, the second fixed component B102, the third fixed component B103, and the fourth fixed component B104 are components that do not move in the surface direction of the LCD panel 11. When the backlight 53 moves, these components do not move relative to the image of a fixed object, for example, the image 11p of the LCD panel 11. If the direction opposite to the direction in which the imaging area 111 moves is referred to as the "opposite direction," then these components move in the first image I101, the second image I102, the third image I103, and the fourth image I104 by the same distance as the distance in which the imaging area 111 moves in the opposite direction.

[0063] In the first embodiment, the backlight 53 moves, but the LCD panel 11 does not move. Therefore, the first shift component A101, the second shift component A102, the third shift component A103, and the fourth shift component A104 are components originating from the backlight 53. Therefore, the first shift component A101, the second shift component A102, the third shift component A103, and the fourth shift component A104 include an image 101p of the unevenness 101 of the backlight 53 and an image 102p of the point defect 102 of the backlight 53. In addition, the first fixed component B101, the second fixed component B102, the third fixed component B103, and the fourth fixed component B104 are components originating from the LCD panel 11. Therefore, the first fixed component B101, the second fixed component B102, the third fixed component B103, and the fourth fixed component B104 include an image 81p of the mura 81 on the LCD panel 11 and an image 82p of the point defect 82 on the LCD panel 11.

[0064] As a result, the first fixed component B101, the second fixed component B102, the third fixed component B103, and the fourth fixed component B104 do not reflect foreign matter attached to the backlight 53, unevenness 101 of the backlight 53, and point defects 102 of the backlight 53, but reflect unevenness 81 and point defects 82 of the LCD panel 11.

[0065] When separating each of the first image I101, the second image I102, the third image I103, and the fourth image I104 into a shift component and a fixed component, the extraction unit 28 compares each image with other images and separates each image into a shift component and a fixed component using pattern recognition, etc. The other images are, for example, images acquired before or after each image.

[0066] When the extraction unit 28 separates each image into a shift component and a fixed component, the extraction unit 28 may use multiple images acquired while the backlight 53 is moving to improve the accuracy of the separation of each image into a shift component and a fixed component.

[0067] FIG. 12 is a diagram illustrating image processing performed by an extraction unit provided in the inspection device of the first embodiment.

[0068] Graph G101 shown in FIG. 12 shows the distribution of luminance of an image. Graph G102 shown in FIG. 12 shows the distribution of luminance of another image to be compared with the image. Graph G103 shown in FIG. 12 shows the distribution of luminance of a shift component extracted from the image. Graph G104 shown in FIG. 12 shows the distribution of luminance of a fixed component extracted from the image. In each of graphs G101, G102, G103, and G104, the horizontal axis represents position and the vertical axis represents luminance. The coordinate value 0 on the horizontal axis indicates the position of the edge of the active area 11d of the LCD panel 11.

[0069] 12, graphs G101 and G102 each show a peak PK101 resulting from foreign matter adhering to the backlight 53, unevenness 101 in the backlight 53, or point defect 102 in the backlight 53, and a peak PK102 resulting from unevenness 81 or point defect 82 in the LCD panel 11. The position at which peak PK101 appears in graph G101 and the position at which peak PK101 appears in graph G102 are different from each other. The position at which peak PK102 appears in graph G101 and the position at which peak PK102 appears in graph G102 are the same. Peak PK101 appears in graph G103, which shows the distribution of the luminance of the shift component, i.e., the component originating from the backlight 53. Furthermore, peak PK102 appears in graph G104, which shows the distribution of the luminance of the fixed component, i.e., the component originating from the LCD panel 11.

[0070] 9 and 11, the combining unit 29 combines the first fixed component B101, the second fixed component B102, the third fixed component B103, and the fourth fixed component B104 to generate a display quality image F1. The generated display quality image F1 shows the overall luminance distribution of the area to be inspected, for example, the active area 11d of the LCD panel 11. The display quality image F1 includes an image 81p of the mura 81 of the LCD panel 11 and an image 82p of the point defect 82 of the LCD panel 11. The display quality image F1 does not reflect foreign matter attached to the backlight 53, the mura 101 of the backlight 53, or the point defect 102 of the backlight 53, but reflects the mura 81 and the point defect 82 of the LCD panel 11.

[0071] 1.7 Advantages of the inspection device of the first embodiment When the display quality of the LCD panel 11 is inspected using the inspection device 1 of the first embodiment, a display quality image F1 is generated that does not reflect foreign matter attached to the backlight 53, unevenness 101 in the backlight 53, and point defects 102 in the backlight 53, but reflects unevenness 81 and point defects 82 in the LCD panel 11. Therefore, based on the generated display quality image F1, it is possible to inspect whether or not unevenness 81 and point defects 82 exist in the LCD panel 11, without being affected by foreign matter attached to the backlight 53, unevenness 101 in the backlight 53, and point defects 102 in the backlight 53. Therefore, the display quality of the LCD panel 11 can be inspected appropriately.

[0072] FIG. 13 is a cross-sectional view that schematically illustrates a stack and a camera provided in the inspection device of the reference example, as well as an LCD panel inspected by the inspection device.

[0073] As shown in FIG. 13 , when the display quality of the LCD panel 11 is inspected using the inspection apparatus of the reference example, when the entire area to be inspected, e.g., the active area 11d of the LCD panel 11, is imaged, the imaging area 111 imaged by the camera 26 cannot fit within the uniform brightness area 91 of the backlight 53. As a result, the edges of the area to be inspected cannot be properly inspected. This drawback of the inspection apparatus of the reference example becomes particularly pronounced when the first polarizer 51, the second polarizer 52, and the backlight 53 are the same types as the first polarizer 51, the second polarizer 52, and the backlight 53, respectively, provided in an LCD manufactured using the LCD panel 11. In other words, this drawback of the inspection apparatus of the reference example becomes particularly pronounced when the first polarizer 51, the second polarizer 52, and the backlight 53 have planar shapes similar to those of the LCD panel 11. This drawback occurs because the inspection device 1 cannot bring two adjacent components, namely the first polarizing plate 51, the LCD panel 11, the second polarizing plate 52, and the backlight 53, into close contact with each other.

[0074] FIG. 14 is a cross-sectional view that schematically illustrates a stack and a camera that are provided in the inspection device of the first embodiment, and an LCD panel that is inspected by the inspection device.

[0075] 14, when the display quality of the LCD panel 11 is inspected using the inspection device 1 of the first embodiment, the area to be inspected, for example, the entire active area 11d of the LCD panel 11, is imaged multiple times. This makes it possible to narrow the imaging area 111 imaged by the camera 26 and place the imaging area 111 within the uniform brightness area 91 of the backlight 53. This makes it possible to properly inspect the edges of the area to be inspected.

[0076] Furthermore, when the display quality of the LCD panel 11 is inspected using the inspection device 1 of the first embodiment, the uniform brightness area 91 can be placed directly below the imaging area 111 when each of the first image I101, second image I102, third image I103, and fourth image I104 is acquired. This allows the LCD panel 11 to be properly inspected without being affected by the non-uniform brightness distribution of the backlight 53.

[0077] 1.8 Visual Inspection FIG. 15 is a diagram showing an inspection device according to a first modified example of the first embodiment.

[0078] The inspection device 1M of the first modified example of the first embodiment is used for visual inspection of the display quality of the LCD panel 11.

[0079] For this reason, the inspection apparatus 1M does not include the camera 26, extraction unit 28, synthesis unit 29, or control unit 31. In the inspection apparatus 1M, the area where the entire uniform brightness area 91 of the backlight 53 and a part of the active area 11d of the LCD panel 11 overlap each other can be visually observed from the position where the camera 26 is disposed in the inspection apparatus 1. When an observer finds unevenness and point defects that do not move when the backlight 53 moves in the in-plane direction of the LCD panel 11, the observer can recognize the unevenness and point defects as unevenness 81 and point defect 82 of the LCD panel 11. This makes it possible to inspect the LCD panel 11 for the presence or absence of unevenness 81 and point defect 82 without being affected by foreign matter attached to the backlight 53, unevenness 101 of the backlight 53, and point defect 102 of the backlight 53. This allows the display quality of the LCD panel 11 to be appropriately inspected.

[0080] 2. Second embodiment The following describes the differences between the second embodiment and the first embodiment. For points that are not described, the second embodiment also employs the same configuration as that employed in the first embodiment.

[0081] 2.1 Inspection equipment Fig. 16 is a diagram showing an inspection device of the second embodiment and an LCD panel inspected using the inspection device. Fig. 17 is a perspective view schematically showing a stage, contact terminals, a stacked object, and a camera provided in the inspection device of the second embodiment, and an LCD panel inspected using the inspection device.

[0082] In the inspection device 2 of the second embodiment, as shown in FIGS. 16 and 17, a mechanism 25 fixes the stacked object 24.

[0083] The mechanism 25 moves the stage 21 and the contact terminals 23 in the surface direction of the LCD panel 11. As a result, the mechanism 25 moves the LCD panel 11 placed on the stage 21 in the surface direction. As a result, the mechanism 25 moves the LCD panel 11 in the surface direction relative to the fixed superposition object 24 and camera 26.

[0084] 2.2 Distinguishing between unevenness and point defects on LCD panels and foreign matter attached to stacked objects, as well as unevenness and point defects on stacked objects FIG. 18 is a cross-sectional view that schematically illustrates a stack of objects provided in the inspection device of the second embodiment, foreign matter adhering to the stack of objects, and an LCD panel that is inspected using the inspection device.

[0085] 18, while the display quality of the LCD panel 11 is being inspected using the inspection device 2 of the second embodiment, the superposed object 24 does not move, but the LCD panel 11 moves. Therefore, the foreign matter 71 attached to the superposed object 24 does not move, but the point defect 72 on the LCD panel 11 moves. Therefore, the foreign matter 71 attached to the superposed object 24 and the point defect 72 on the LCD panel 11 can be distinguished from each other. The same can be said about the unevenness and point defect on the superposed object 24 as about the foreign matter 71 attached to the superposed object 24. The same can be said about the unevenness on the LCD panel 11 as about the point defect 72 on the LCD panel 11.

[0086] The inspection device 2 utilizes this to extract components originating from the LCD panel 11 from the image acquired by the camera 26. The extracted components originating from the LCD panel 11 are shift components that move in the surface direction of the LCD panel 11.

[0087] 2.3 Position of LCD panel and overlapping objects Fig. 19A is a top view schematically illustrating a backlight provided in the inspection apparatus of the second embodiment and an LCD panel inspected using the inspection apparatus, the LCD panel being positioned at a first position. Fig. 19B is a top view schematically illustrating a backlight provided in the inspection apparatus of the second embodiment and an LCD panel inspected using the inspection apparatus, the LCD panel being positioned at a second position. Fig. 19C is a top view schematically illustrating a backlight provided in the inspection apparatus of the second embodiment and an LCD panel inspected using the inspection apparatus, the LCD panel being positioned at a third position. Fig. 19D is a top view schematically illustrating a backlight provided in the inspection apparatus of the second embodiment and an LCD panel inspected using the inspection apparatus, the LCD panel being positioned at a fourth position. FIG. 19E is a top view schematically illustrating a backlight provided in the inspection device of the second embodiment and an LCD panel inspected using the inspection device, with the LCD panel positioned at the 16th position.

[0088] The LCD panel 11 is placed at a plurality of different positions in a plane parallel to the surface direction of the LCD panel 11 while the display quality of the LCD panel 11 is being inspected using the inspection device 2. The plurality of positions at which the LCD panel 11 is placed are 16 positions consisting of a first position P201 shown in Fig. 19A, a second position P202 shown in Fig. 19B, a third position P203 shown in Fig. 19C, a fourth position P204 shown in Fig. 19D, ..., and a 16th position P216 shown in Fig. 19E. The plurality of positions may be 15 or less positions or 17 or more positions.

[0089] When backlight 53 is disposed at each of first position P201, second position P202, third position P203, fourth position P204, ..., sixteenth position P216, all or part of uniform brightness area 91 of backlight 53 overlaps with part of active area 11d of LCD panel 11. Camera 26 captures an image of imaging area 111 including an area where all or part of uniform brightness area 91 of backlight 53 overlaps with part of active area 11d of LCD panel 11. The imaged imaging area 111 does not move.

[0090] The first position P201, the second position P202, the third position P203, the fourth position P204, ..., the sixteenth position P216 are set so that the uniform brightness area 91 of the backlight 53 can scan the entire active area 11d of the LCD panel 11. The first position P201, the second position P202, the third position P203, the fourth position P204, ..., the sixteenth position P216 are arranged in a matrix of 4 rows and 4 columns, for example.

[0091] 2.4 Operation Fig. 20 is a flowchart showing the flow of processing performed by the inspection device of the second embodiment. Fig. 21 is a diagram showing the content of image processing performed by the extraction unit and synthesis unit provided in the inspection device of the second embodiment. Fig. 22 is a diagram showing an image acquired by a camera provided in the inspection device of the second embodiment, and shift components and fixed components acquired by the extraction unit provided in the inspection device. Fig. 23 is a diagram showing a display quality image generated by the synthesis unit provided in the inspection device of the second embodiment.

[0092] After the LCD panel 11 is set on the stage 21, the inspection device 1 executes steps S111 to S117 shown in FIG.

[0093] In step S111, the control unit 31 initializes an identifier i, which indicates a position in a plane parallel to the surface direction of the LCD panel 11, to 1.

[0094] In the next step S112, the mechanism 25 moves the LCD panel 11 in the surface direction of the LCD panel 11 to place the LCD panel 11 at the i-th position in a plane parallel to the surface direction of the LCD panel 11.

[0095] In the following step S113, the camera 26 captures an image of the imaging area 111 including the area where all or part of the uniform brightness area 91 of the backlight 53 and part of the active area 11d of the LCD panel 11 overlap each other to obtain the i-th image.

[0096] In the following step S114, the control unit 31 determines whether the identifier i has reached the upper limit value of 16. If it is determined that the identifier i has reached the upper limit value of 16, step S116 is executed. If it is determined that the identifier i has not reached the upper limit value of 16, step S115 is executed, and then step S112 is executed again.

[0097] In step S115, the control unit 31 increments the identifier i.

[0098] 21 and 22, camera 26 acquires a first image I201, a second image I202, a third image I203, a fourth image I204, ..., and a sixteenth image I216 when LCD panel 11 is placed at first position P201, second position P202, third position P203, fourth position P204, ..., and sixteenth position P216. First image I201, second image I202, third image I203, fourth image I204, ..., and sixteenth image I216 may be continuous scanning images acquired continuously by camera 26 while mechanism 25 moves LCD panel 11 without stopping.

[0099] In step S116, as shown in Figures 21 and 22, the extraction unit 28 separates the first image I201 into a first shift component A201 and a first fixed component B201, separates the second image I202 into a second shift component A202 and a second fixed component B202, separates the third image I203 into a third shift component A203 and a third fixed component B203, separates the fourth image I204 into a fourth shift component A204 and a fourth fixed component B204, ..., separates the sixteenth image I216 into a sixteenth shift component A216 and a sixteenth fixed component B216.

[0100] The first shift component A201, the second shift component A202, the third shift component A203, the fourth shift component A204, ..., the sixteenth shift component A216 are components that move in the surface direction of the LCD panel 11. When the LCD panel 11 moves, these components move relative to the image of a fixed object, for example, the image of the backlight 53. These components move within the first image I101, the second image I102, the third image I103, and the fourth image I104, which do not move.

[0101] The first fixed component B201, the second fixed component B202, the third fixed component B203, the fourth fixed component B204, ..., the sixteenth fixed component B216 are components that do not move in the plane direction of the LCD panel 11. When the LCD panel 11 moves, these components do not move relative to the image of a fixed object, for example, the image of the backlight 53. These components do not move within the first image I201, the second image I202, the third image I203, and the fourth image I204, which do not move.

[0102] In the second embodiment, the LCD panel 11 moves, but the backlight 53 does not move. Therefore, the first shift component A201, the second shift component A202, the third shift component A203, the fourth shift component A204, ..., the sixteenth shift component A216 are components originating from the LCD panel 11. Therefore, the first shift component A201, the second shift component A202, the third shift component A203, the fourth shift component A204, ..., the sixteenth shift component A216 include an image 81p of the mura 81 of the LCD panel 11 and an image 82p of the point defect 82 of the LCD panel 11. Furthermore, the first fixed component B201, the second fixed component B202, the third fixed component B203, the fourth fixed component B204, ..., the sixteenth fixed component B216 are components originating from the backlight 53. Therefore, the first fixed component B201, the second fixed component B202, the third fixed component B203, the fourth fixed component B204, ..., the sixteenth fixed component B216 include the image 101p of the unevenness 101 of the backlight 53 and the image 102p of the point defect 102 of the backlight 53.

[0103] As a result, the first shift component A201, the second shift component A202, the third shift component A203, the fourth shift component A204, ..., the sixteenth shift component A216 do not reflect foreign matter adhering to the backlight 53, the unevenness 101 of the backlight 53, and the point defect 102 of the backlight 53, but reflect the unevenness 81 and the point defect 82 of the LCD panel 11.

[0104] When separating each of the first image I201, the second image I202, the third image I203, the fourth image I204, ..., and the sixteenth image I216 into shift components and fixed components, the extraction unit 28 compares each image with other images and separates each image into shift components and fixed components using pattern recognition or the like. The other images are, for example, images acquired before or after each image.

[0105] When the extraction unit 28 separates each image into a shift component and a fixed component, the accuracy of the separation of each image into a shift component and a fixed component may be improved by using multiple images acquired while the LCD panel 11 is moving.

[0106] FIG. 24 is a diagram illustrating image processing performed by an extraction unit provided in the inspection device of the second embodiment.

[0107] Graph G201 shown in FIG. 24 shows the distribution of luminance of an image. Graph G202 shown in FIG. 24 shows the distribution of luminance of another image to be compared with the image. Graph G203 shown in FIG. 24 shows the distribution of luminance of a shift component extracted from the image. Graph G204 shown in FIG. 24 shows the distribution of luminance of a fixed component extracted from the image. In each of graphs G201, G202, G203, and G204, the horizontal axis represents position and the vertical axis represents luminance. The coordinate value 0 on the horizontal axis indicates the position of the edge of the active area 11d of the LCD panel 11.

[0108] 24 , graphs G201 and G202 each show a peak PK201 resulting from mura 81 or point defect 82 in the LCD panel 11, and a peak PK202 resulting from mura 101 or point defect 102 in the backlight 53. The position at which peak PK201 appears in graph G201 and the position at which peak PK101 appears in graph G202 are different from each other. The position at which peak PK202 appears in graph G201 and the position at which peak PK202 appears in graph G202 are the same. Peak PK201 appears in graph G203, which shows the distribution of the luminance of the shift component, i.e., the component originating from the LCD panel 11. Furthermore, peak PK202 appears in graph G204, which shows the distribution of the luminance of the fixed component, i.e., the component originating from the backlight 53.

[0109] In the following step S117, as shown in FIGS. 21 and 23, the combining unit 29 combines the first shift component A201, the second shift component A202, the third shift component A203, the fourth shift component A204, ..., and the sixteenth shift component A216 to generate a display quality image F2. The generated display quality image F2 indicates the distribution of luminance. The display quality image F2 includes an image 81p of the unevenness 81 of the LCD panel 11 and an image 82p of the point defect 82 of the LCD panel 11. The display quality image F2 does not reflect foreign matter attached to the backlight 53, the unevenness 101 of the backlight 53, or the point defect 102 of the backlight 53, but reflects the unevenness 81 and the point defect 82 of the LCD panel 11.

[0110] 2.5 Advantages of the inspection device of the second embodiment When the display quality of the LCD panel 11 is inspected using the inspection device 2 of the second embodiment, a display quality image F2 is generated that does not reflect foreign matter attached to the backlight 53, unevenness 101 in the backlight 53, and point defects 102 in the backlight 53, but reflects unevenness 81 and point defects 82 in the LCD panel 11. Therefore, based on the generated display quality image F2, it is possible to inspect whether or not unevenness 81 and point defects 82 exist in the LCD panel 11, without being affected by foreign matter attached to the backlight 53, unevenness 101 in the backlight 53, and point defects 102 in the backlight 53. Therefore, the display quality of the LCD panel 11 can be inspected appropriately.

[0111] FIG. 25 is a cross-sectional view that schematically illustrates a stack and a camera provided in the inspection device of the reference example, as well as an LCD panel inspected by the inspection device.

[0112] 25, when the display quality of an LCD panel 11 is inspected using the inspection device of the reference example, when the area to be inspected, for example, the entire active area 11d of the LCD panel 11, is imaged, the imaging area 111 imaged by the camera 26 cannot be contained within the uniform brightness area 91 of the backlight 53. Furthermore, the imaging area 111 imaged by the camera 26 cannot be contained within the area 121 that is not affected by the viewing angle characteristics of the LCD panel 11. In other words, it is impossible to avoid imaging the edge of the area to be inspected from a direction significantly tilted from the direction directly facing the area. Therefore, it is not easy to properly inspect the edge of the area to be inspected.

[0113] Fig. 26 is a cross-sectional view schematically illustrating a stack of objects and a camera provided in the inspection apparatus of the second embodiment, and an LCD panel inspected by the inspection apparatus, with the LCD panel positioned at a first position. Fig. 27 is a perspective view schematically illustrating a stack of objects and a camera provided in the inspection apparatus of the second embodiment, and an LCD panel inspected by the inspection apparatus, with the LCD panel positioned at a first position. Fig. 28 is a cross-sectional view schematically illustrating a stack of objects and a camera provided in the inspection apparatus of the second embodiment, and an LCD panel inspected by the inspection apparatus, with the LCD panel positioned at a sixteenth position. Fig. 29 is a perspective view schematically illustrating a stack of objects and a camera provided in the inspection apparatus of the second embodiment, and an LCD panel inspected by the inspection apparatus, with the LCD panel positioned at a sixteenth position.

[0114] As shown in FIGS. 26 to 29, when the display quality of an LCD panel 11 is inspected using the inspection device 2 of the second embodiment, the area to be inspected, for example, the entire active area 11d of the LCD panel 11, is imaged multiple times. This allows the imaging area 111 captured by the camera 26 to be narrowed and placed within the uniform brightness area 91 of the backlight 53. Furthermore, the imaging area 111 captured by the camera 26 can be placed within an area 121 that is not affected by the viewing angle characteristics of the LCD panel 11. This means that it is possible to avoid capturing an image of the edge of the area to be inspected from a direction significantly tilted from the front-on direction. This makes it easy to properly inspect the edge of the area to be inspected.

[0115] Furthermore, when the display quality of the LCD panel 11 is inspected using the inspection device 2 of the second embodiment, the uniform brightness area 91 can be placed directly below the imaging area 111 when each of the first image I201, second image I202, third image I203, fourth image I204, ..., and sixteenth image I216 is acquired. Therefore, the LCD panel 11 can be properly inspected without being affected by the non-uniform brightness distribution of the backlight 53.

[0116] 3 Third embodiment The following describes the differences between the third embodiment and the second embodiment. For points that are not described, the third embodiment also employs the same configuration as that employed in the second embodiment.

[0117] 3.1 Inspection equipment Fig. 30 is a diagram showing an inspection device of a third embodiment and an LCD panel inspected using the inspection device. Fig. 31 is a cross-sectional view schematically showing a stage, contact terminals, a stacked object, a mechanism, and a camera provided in the inspection device of the third embodiment, and an LCD panel inspected using the inspection device. Fig. 32 is a perspective view schematically showing a stage, contact terminals, a stacked object, and a camera provided in the inspection device of the third embodiment, and an LCD panel inspected using the inspection device.

[0118] In the inspection device 3 of the third embodiment, as shown in FIGS. 30 to 32, the camera 26 is disposed at a large distance from the LCD panel 11. This allows the angle of view of the camera 26 to be narrowed even when the area to be inspected, for example, the entire active area 11d of the LCD panel 11, is imaged in one shot. This prevents the edge of the area to be inspected from being imaged from a direction significantly tilted from a direction directly facing the edge. This prevents the image captured by the camera 26 from being affected by the viewing angle characteristics of the LCD panel 11. This allows the edge of the area to be inspected to be properly inspected.

[0119] The inspection device 3 is equipped with a telephoto lens 27. The telephoto lens 27 has a long focal length. Therefore, the telephoto lens 27 narrows the angle of view of the camera 26 and increases the resolution of the image acquired by the camera 26. The telephoto lens 27 has a focal length that allows the entire uniform brightness area 91 of the backlight 53 to fit within the imaging area 111 imaged by the camera 26.

[0120] When LCD panel 11 is a first LCD panel, camera 26 captures a plurality of images when the first LCD panel is placed at a plurality of positions under the control of control unit 31. When LCD panel 11 is a second LCD panel to be inspected, camera 26 captures an image when the second LCD panel is placed at an inspection position under the control of control unit 31. The second LCD panel may be the same LCD panel as the first LCD panel, or may be a different LCD panel from the first LCD panel.

[0121] As shown in FIG. 30, the inspection device 3 includes a correction unit 30.

[0122] The control unit 31 controls the circuit 22 , the mechanism 25 , the extraction unit 28 , the synthesis unit 29 and the correction unit 30 .

[0123] When the LCD panel 11 is the first LCD panel, the extraction unit 28 extracts, according to the control by the control unit 31, a plurality of components respectively derived from the superimposed object 24 or foreign matters adhering to the superimposed object 24 from the plurality of images acquired. [[ID={2]]

[0124] The synthesis unit 29 synthesizes the extracted plurality of components to generate a stored image.

[0125] When the LCD panel 11 is the second LCD panel, the correction unit 30 corrects the image acquired with the stored image to generate a display quality image indicating the display quality of the LCD panel 11.

[0126] The extraction unit 28, the synthesis unit 29, the correction unit 30, and the control unit 31 are constituted by a microcontroller and peripheral circuits. The microcontroller includes a processor and a memory. The processor executes a program stored in the memory to cause the microcontroller and peripheral circuits to perform the processes performed by the extraction unit 28, the synthesis unit 29, the correction unit 30, and the control unit 31. All or part of the processes performed by the microcontroller may be performed by dedicated electronic circuits.

[0127] 3.2 Operation FIG. 33 is a flowchart showing the flow of processing performed by the inspection apparatus of the third embodiment. FIG. 34 is a diagram showing the content of image processing performed by the extraction unit and synthesis unit provided in the inspection apparatus of the third embodiment. FIG. 35 is a diagram showing the content of image processing performed by the correction unit provided in the inspection apparatus of the third embodiment. FIG. 36 is a diagram showing an image acquired by a camera provided in the inspection apparatus of the third embodiment, and shift components and fixed components acquired by the extraction unit provided in the inspection apparatus. FIG. 37 is a diagram showing an image acquired by a camera provided in the inspection apparatus of the third embodiment, a saved image generated by the synthesis unit provided in the inspection apparatus, and a brightness ratio distribution image acquired by the correction unit provided in the inspection apparatus. FIG. 38 is a diagram showing a brightness ratio distribution image, an average brightness image, and a display quality image acquired by the correction unit provided in the inspection apparatus of the third embodiment. FIG. 39 is a cross-sectional view schematically showing a superposed object, a camera, and a first LCD panel provided in the inspection apparatus of the third embodiment, with the first LCD panel disposed in a first position. Fig. 40 is a cross-sectional view schematically illustrating a state in which a stacked object and a camera provided in the inspection device of the third embodiment, and a first LCD panel, with the first LCD panel arranged at position 16. Fig. 41 is a cross-sectional view schematically illustrating a stacked object and a camera provided in the inspection device of the third embodiment, and a second LCD panel inspected by the inspection device, with the second LCD panel arranged at the inspection position.

[0128] After the first LCD panel is set on the stage 21, the inspection apparatus 3 executes steps S121 to S127 shown in Fig. 33, and after the second LCD panel is set on the stage 21, the inspection apparatus 3 executes steps S128 to S130 shown in Fig. 33. In the third embodiment, once steps S121 to S127 have been executed, steps S128 to S130 can be executed repeatedly without executing steps S121 to S127 again. In other words, steps S121 to S127 need only be executed during the first inspection, and do not necessarily need to be executed during the second and subsequent inspections.

[0129] In step S121, the control unit 31 initializes to 1 an identifier i indicating a position in a plane parallel to the surface direction of the first LCD panel.

[0130] In the following step S122, mechanism 25 moves the first LCD panel in the surface direction of the first LCD panel to place the first LCD panel at the i-th position in a plane parallel to the surface direction of the first LCD panel.

[0131] In the following step S123, camera 26 captures an image of imaging area 111 including the area where the first LCD panel and backlight 53 are superimposed on each other, and acquires the i-th image.

[0132] In the following step S124, the control unit 31 determines whether the identifier i has reached the upper limit value of 16. If it is determined that the identifier i has reached the upper limit value of 16, step S126 is executed. If it is determined that the identifier i has not reached the upper limit value of 16, step S125 is executed, and then step S122 is executed again.

[0133] In step S125, the control unit 31 increments the identifier i.

[0134] Through steps S121 to S125, as shown in Figures 34 and 36, camera 26 acquires first image I301, second image I302, third image I303, fourth image I304, ..., and sixteenth image I316 when the first LCD panel is positioned at first position P301, second position P302, third position P303, fourth position P304, ..., and sixteenth position P316, respectively.

[0135] In step S126, as shown in Figures 34 and 36, the extraction unit 28 separates the first image I301 into a first shift component A301 and a first fixed component B301, separates the second image I302 into a second shift component A302 and a second fixed component B302, separates the third image I303 into a third shift component A303 and a third fixed component B303, separates the fourth image I304 into a fourth shift component A304 and a fourth fixed component B304, ..., separates the sixteenth image I316 into a sixteenth shift component A316 and a sixteenth fixed component B316.

[0136] In the following step S127, as shown in Figures 34 and 37, the synthesis unit 29 synthesizes the first fixed component B301, the second fixed component B302, the third fixed component B303, the fourth fixed component B304, ..., and the sixteenth fixed component B316 to generate a saved image C3. The generated saved image C3 represents the distribution of luminance. The saved image C3 includes an image 101p of the unevenness 101 of the backlight 53 and an image 102p of the point defect 102 of the backlight 53.

[0137] In the following step S128, mechanism 25 places the second LCD panel at the inspection position by moving the second LCD panel toward the surface of LCD panel 11. As shown in Fig. 41, the inspection position at which the second LCD panel is placed is a position where the entire active area 11d of the second LCD panel falls within imaging area 111 imaged by camera 26.

[0138] In the following step S129, as shown in Figures 35 and 37, camera 26 captures an image I3 by capturing an image area 111 including the area where the entire active area 11d of the second LCD panel and the backlight 53 are overlapped with each other.

[0139] In the following step S130, the correction unit 30 generates a display quality image F3 from the image I3 and the saved image C3, as shown in FIGS. 35, 37, and 38. The generated display quality image F3 indicates the distribution of luminance. The display quality image F3 includes an image 81p of the unevenness 81 of the LCD panel 11 and an image 82p of the point defect 82 of the LCD panel 11. The display quality image F3 does not reflect the foreign matter attached to the backlight 53, the unevenness 101 of the backlight 53, or the point defect 102 of the backlight 53, but reflects the unevenness 81 and point defect 82 of the second LCD panel.

[0140] When generating a display quality image F3 from image I3 and saved image C3, the correction unit 30 generates a brightness ratio distribution image D3 from image I3 and saved image C3 as shown in FIG. 37, and generates a display quality image F3 from the brightness ratio distribution image D3 and average brightness image E3 as shown in FIG. 38.

[0141] When generating a brightness ratio distribution image D3 from image I3 and stored image C3, correction unit 30 divides image I3 by stored image C3 to generate brightness ratio distribution image D3. The generated brightness ratio distribution image D3 is generated by dividing image I3, which shows the distribution of brightness, by stored image C3, which also shows the distribution of brightness, and therefore indicates the distribution of the ratio of the brightness of image I3 to the brightness of stored image C3.

[0142] When generating the display quality image F3 from the brightness ratio distribution image D3 and the average brightness image E3, the correction unit 30 multiplies the generated brightness ratio distribution image D3 by the average brightness image E3 to generate the display quality image F3. The average brightness image E3 to be multiplied is an image having uniform brightness. The uniform brightness of the average brightness image E3 is the average of the brightnesses of the stored images C3. The display quality image F3 indicates the distribution of brightness because it is generated by multiplying the brightness ratio distribution image D3, which indicates the distribution of brightness ratios, by the average brightness image E3, which indicates the distribution of brightness.

[0143] 3.3 Advantages of the inspection device of the third embodiment When the display quality of the LCD panel 11 is inspected using the inspection device 3 of the third embodiment, a display quality image F3 is generated that does not reflect foreign matter attached to the backlight 53, unevenness 101 in the backlight 53, and point defects 102 in the backlight 53, but reflects unevenness 81 and point defects 82 in the LCD panel 11. Therefore, based on the generated display quality image F3, it is possible to inspect whether or not unevenness 81 and point defects 82 exist in the LCD panel 11, without being affected by foreign matter attached to the backlight 53, unevenness 101 in the backlight 53, and point defects 102 in the backlight 53. Therefore, the LCD panel 11 can be inspected appropriately.

[0144] When an LCD panel is inspected using the inspection device disclosed in Patent Document 1 (Japanese Patent No. 4610656), shading correction, viewing angle characteristic correction, etc. are performed only by taking into account the front polarizer and backlight, so the viewing angle characteristic of the LCD panel cannot be corrected. Furthermore, the image obtained shows the distribution of transmittance, not the distribution of luminance. For this reason, it is not possible to determine the display quality from the obtained image using ordinary automatic evaluation software.

[0145] In contrast, when the display quality of the LCD panel 11 is inspected using the inspection device 3 of the third embodiment, it is possible to suppress the influence of the viewing angle characteristics of the LCD panel 11. Furthermore, since a display quality image F3 indicating the luminance distribution is generated, it is possible to judge the display quality from the obtained display quality image F3 using ordinary automatic judgment software.

[0146] The present disclosure is not limited to the above-described embodiments, and may be replaced with a configuration that is substantially the same as the configuration shown in the above-described embodiments, a configuration that has the same effect, or a configuration that can achieve the same purpose. [Explanation of symbols]

[0147] 1, 1M, 2, 3 Inspection device, 11 LCD panel, 11a first main surface, 11b second main surface, 11c edge surface, 11d active area, 11p image, 21 stage, 21a first main surface, 21b second main surface, 21c groove, 21d hole, 21e bottom surface, 21f side surface, 22 circuit, 23 contact terminal, 24 superposed object, 25 mechanism, 26 camera, 27 telephoto lens, 28 extraction unit, 29 synthesis unit, 30 correction unit, 31 control unit, 41 electrode, 51 first polarizing plate, 52 second polarizing plate, 53 backlight, 61 light, 71 foreign matter, 72 point defect, 81 unevenness, 81p image, 82 point defect, 82p image, 91 uniform brightness area, 101 Mura, 101p image, 102 point defect, 102p image, 111 imaging area, 121 area not affected by viewing angle characteristics, DX horizontal direction, DY horizontal direction, DZ vertical direction, P101 first position, P102 second position, P103 third position, P104 fourth position, I101 first image, I102 second image, I103 third image, I104 fourth image, A101 first shift component, A102 second shift component, A103 third shift component, A104 fourth shift component, B101 first fixed component, B102 second fixed component, B103 third fixed component, B104 fourth fixed component, F1 display quality image, G101, G102, G103, G104 graph, PK101, PK102 Peak, P201 1st position, P202 2nd position, P203 3rd position, P204 4th position, P216 16th position, I201 1st image, I202 2nd image, I203 3rd image, I204 4th image, I216 16th image, A201 1st shift component, A202 2nd shift component, A203 3rd shift component, A204 4th shift component, A216 16th shift component, B201 1st fixed component, B202 2nd fixed component, B203 3rd fixed component, B204 4th fixed component, B216 16th fixed component, F2 Display quality image, G201, G202, G203, G204 Graph, PK201,PK202 peak, P301 first position, P302 second position, P303 third position, P304 fourth position, P316 16th position, I301 first image, I302 second image, I303 third image, I304 fourth image, I316 16th image, A301 first shift component, A302 second shift component, A303 third shift component, A304 fourth shift component, A316 16th shift component, B301 first fixed component, B302 second fixed component, B303 third fixed component, B304 fourth fixed component, B316 16th fixed component, I3 image, C3 saved image, D3 brightness ratio distribution image, E3 average brightness image, F3 display quality image.

Claims

1. a laminate that is laminated on the liquid crystal display panel in the thickness direction of the liquid crystal display panel; a mechanism for fixing the stack and moving the liquid crystal display panel in a surface direction of the liquid crystal display panel; a camera capturing an image of an area where the liquid crystal display panel and the overlapping object are overlapped from the thickness direction; an extracting unit that extracts a plurality of components derived from the overlapping object or a foreign substance attached to the overlapping object from a plurality of images respectively acquired by the camera when the liquid crystal display panel is a first liquid crystal display panel and the first liquid crystal display panel is disposed at a plurality of different positions in a plane parallel to the surface direction; a synthesis unit that synthesizes the plurality of components to obtain a saved image; a correction unit that corrects an image acquired by the camera using the stored image when the liquid crystal display panel is a second liquid crystal display panel; An inspection device comprising:

2. The laminate includes a polarizing plate and a backlight. The inspection device according to claim 1 .

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