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 apparatus and an inspection method. [Background technology]

[0002] Patent Document 1 discloses an inspection device. In the inspection device, a front polarizer, a liquid crystal panel used as a standard, a rear polarizer, and a backlight are imaged from the front polarizer side to obtain a first image. Then, the front polarizer and the backlight are imaged from the front polarizer side to obtain a second image. Then, a correction coefficient is calculated based on the first image and the second image. Then, the front polarizer, the liquid crystal panel to be inspected, the rear polarizer, and the backlight are imaged from the front polarizer side to obtain an inspection image. Then, positions that are defect candidates are extracted, and defect judgment is performed on the positions that are defect candidates using the correction coefficients (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 from the liquid crystal panel being inspected, but rather defects originating from the front polarizing plate, the rear polarizing plate, or the backlight. Therefore, the inspection device may not be able to properly detect defects in the liquid crystal panel.

[0005] In view of this problem, an object of one aspect of the present disclosure is to provide an inspection apparatus and an inspection method that can appropriately inspect a liquid crystal display panel, for example. [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 for fixing one of the liquid crystal display panel and the stack and moving 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 of a second aspect of the present disclosure includes the steps of overlapping the liquid crystal display panel and the overlapping object on each other in the thickness direction of the liquid crystal display panel, and fixing one of the liquid crystal display panel and the overlapping object and moving the other of the liquid crystal display panel and the overlapping object in the surface direction of the liquid crystal display panel. [Brief description 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. [Diagram 2] 1 is a perspective view that illustrates a stage, contact terminals, a stack, and a camera that are provided in the inspection apparatus of the first embodiment, as well as an LCD panel that is inspected using the inspection apparatus. [Diagram 3] 1 is a cross-sectional view showing a schematic diagram of a stack provided in an inspection apparatus of a reference example, a foreign substance adhering to the stack, and an LCD panel inspected using the inspection apparatus. [Figure 4] 1 is a cross-sectional view that illustrates a schematic diagram of a stack provided in the inspection apparatus of the first embodiment, a foreign substance attached to the stack, and an LCD panel inspected using the inspection apparatus. [Diagram 5] FIG. 2 is a top view diagrammatically illustrating an LCD panel inspected by the inspection apparatus of the first embodiment. [Figure 6]FIG. 2 is a top view diagrammatically illustrating a backlight provided in the inspection device of the first embodiment. [Figure 7A] 1 is a top view illustrating a schematic diagram of a backlight provided in the inspection apparatus of the first embodiment and an LCD panel inspected using the inspection apparatus, the backlight being disposed at a first position. FIG. [Figure 7B] 3 is a top view illustrating a schematic diagram of a backlight provided in the inspection apparatus of the first embodiment and an LCD panel inspected using the inspection apparatus, the backlight being disposed at a second position. FIG. [Figure 7C] 4 is a top view illustrating a schematic diagram of a backlight provided in the inspection apparatus of the first embodiment and an LCD panel inspected using the inspection apparatus, the backlight being disposed in a third position. FIG. [Figure 7D] 1 is a top view illustrating a schematic diagram of a backlight provided in the inspection apparatus of the first embodiment and an LCD panel inspected using the inspection apparatus, the backlight being disposed at a fourth position. FIG. [Figure 8] 4 is a flowchart showing a flow of processing performed by the inspection device of the first embodiment. [Figure 9] 4 is a diagram showing the contents of image processing performed by an extraction unit and a synthesis unit provided in the inspection device of the first embodiment. FIG. [Figure 10] 3A to 3C are diagrams showing an image acquired by a camera provided in the inspection device of the first embodiment, and a shift component and a fixed component acquired by an extraction unit provided in the inspection device. [Figure 11] 4A to 4C are diagrams showing a display quality image generated by a synthesis unit provided in the inspection device of the first embodiment. [Figure 12] 4A to 4C 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 showing a schematic diagram of a stack and a camera provided in an inspection apparatus of a reference example, and an LCD panel inspected by the inspection apparatus. [Figure 14]1 is a cross-sectional view illustrating a stack and a camera provided in the inspection apparatus of the first embodiment, and an LCD panel inspected by the inspection apparatus. [Figure 15] FIG. 13 is a diagram showing an inspection device according to a first modified example of the first embodiment. [Figure 16] 13 is a diagram showing an inspection device according to a second embodiment and an LCD panel inspected using the inspection device. FIG. [Figure 17] 13 is a perspective view that illustrates a stage, contact terminals, a stack, and a camera that are provided in an inspection apparatus of a second embodiment, as well as an LCD panel that is inspected using the inspection apparatus. FIG. [Figure 18] 11 is a cross-sectional view illustrating a schematic diagram of a stack provided in an inspection apparatus of a second embodiment, a foreign substance attached to the stack, and an LCD panel inspected using the inspection apparatus. FIG. [Figure 19A] 11 is a top view illustrating a backlight provided in an inspection apparatus according to a second embodiment and an LCD panel inspected using the inspection apparatus, the LCD panel being disposed at a first position. FIG. [Figure 19B] 13 is a top view illustrating a schematic diagram of a backlight provided in an inspection apparatus of a second embodiment and an LCD panel inspected using the inspection apparatus, the LCD panel being disposed at a second position. FIG. [Figure 19C] 13 is a top view illustrating a schematic diagram of a backlight provided in the inspection apparatus of the second embodiment and an LCD panel inspected by the inspection apparatus when the LCD panel is disposed in a third position. FIG. [Figure 19D] 13 is a top view illustrating a schematic diagram of a backlight provided in the inspection apparatus of the second embodiment and an LCD panel inspected using the inspection apparatus, the LCD panel being disposed in a fourth position. FIG. [Figure 19E] 16 is a top view showing a schematic diagram of a backlight provided in the inspection apparatus of the second embodiment and an LCD panel inspected using the inspection apparatus, the LCD panel being disposed at a sixteenth position. FIG. [Figure 20]10 is a flowchart showing a flow of processing performed by an inspection device according to a second embodiment. [Figure 21] 13A to 13C 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] 13A to 13C 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. [Diagram 23] 13 is a diagram showing a display quality image generated by a synthesis unit provided in the inspection device of the second embodiment. FIG. [Figure 24] 13A to 13C are diagrams illustrating image processing performed by an extraction unit provided in an inspection device of a second embodiment. [Diagram 25] 1 is a cross-sectional view showing a schematic diagram of a stack and a camera provided in an inspection apparatus of a reference example, and an LCD panel inspected by the inspection apparatus. [Figure 26] 11 is a cross-sectional view illustrating a stack and a camera provided in an inspection apparatus of a second embodiment, and an LCD panel inspected by the inspection apparatus, the LCD panel being disposed in a first position. FIG. [Figure 27] 11 is a perspective view showing a stack and a camera provided in an inspection apparatus of a second embodiment, and an LCD panel inspected by the inspection apparatus, the LCD panel being placed in a first position. FIG. [Figure 28] 16 is a cross-sectional view showing a schematic diagram of a stack and a camera provided in an inspection apparatus of a second embodiment, and an LCD panel inspected by the inspection apparatus, the LCD panel being positioned at a sixteenth position. FIG. [Figure 29] 16 is a perspective view showing a schematic diagram of a stack and a camera provided in an inspection apparatus of a second embodiment, and an LCD panel inspected by the inspection apparatus, the LCD panel being positioned at a sixteenth position. FIG. [Diagram 30] 13 is a diagram showing an inspection device according to a third embodiment and an LCD panel inspected using the inspection device. FIG. [Diagram 31]13 is a cross-sectional view that illustrates a stage, contact terminals, a stack, a mechanism, and a camera that are provided in an inspection apparatus of a third embodiment, as well as an LCD panel that is inspected using the inspection apparatus. FIG. [Diagram 32] FIG. 11 is a perspective view that illustrates a stage, contact terminals, a stack, and a camera that are provided in an inspection apparatus of a third embodiment, as well as an LCD panel that is inspected using the inspection apparatus. [Diagram 33] 13 is a flowchart showing a flow of processes performed by an inspection device according to a third embodiment. [Diagram 34] 13A to 13C 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. [Diagram 35] 13A to 13C are diagrams illustrating the contents of image processing performed by a correction unit provided in the inspection device of the third embodiment. [Diagram 36] 13A to 13C 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] 13A to 13C are diagrams showing an image acquired by a camera provided in an inspection device of a third embodiment, a stored 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] 13A to 13C 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] 13 is a cross-sectional view illustrating a schematic diagram of a stack, a camera, and a first LCD panel provided in an inspection device of a third embodiment, in a state where the first LCD panel is disposed at a first position. FIG. [Diagram 40] 13 is a cross-sectional view illustrating a schematic diagram of a stack, a camera, and a first LCD panel provided in an inspection apparatus of a third embodiment, in a state where the first LCD panel is disposed at a sixteenth position. FIG. [Diagram 41]13 is a cross-sectional view showing a schematic diagram of a stack and a camera provided in an inspection apparatus of a third embodiment, and a second LCD panel inspected by the inspection apparatus, the second LCD panel being positioned at an inspection position. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0010] 1. First embodiment 1.1 Inspection equipment Fig. 1 is a diagram showing an inspection device of the first embodiment and a liquid crystal display (LCD) panel inspected using the inspection device. Fig. 2 is a perspective view 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 is unevenness and point defects in the LCD panel 11 that may cause display abnormalities in an LCD 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 on opposite sides to 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 on 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. This allows the stage 21 to horizontally support 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 the LCD panel 11 from moving in the surface direction of the LCD panel 11 that 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 parallel to the vertical direction DZ, and reaches 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 reaches 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. As a result, the stage 21 supports the edge of the LCD panel 11 from below in the vertical direction DZ. Also, the center of the LCD panel 11 can be irradiated 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 in the center of the LCD panel 11 that is irradiated with light.

[0020] The circuit 22 outputs a signal for driving 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. In this way, the contact terminal 23 inputs a signal for driving the LCD panel 11 to the electrode 41.

[0022] 1 and 2, the laminate 24 includes a first polarizing plate 51, a second polarizing plate 52, and a backlight 53. The laminate 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, is disposed parallel to the LCD panel 11, and is 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 under the second main surface 11b of the LCD panel 11, are disposed parallel to the LCD panel 11, and are 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 described order. 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 described order in the thickness direction of the LCD panel 11. The backlight 53, the second polarizer 52, the LCD panel 11, and the first polarizer 51 are arranged in the vertical direction DZ from the bottom to the top in the order shown.

[0024] The backlight 53 emits light 61. The second polarizing plate 52 selectively transmits light having a first polarization direction included in the emitted light 61. The LCD panel 11 modulates the polarization direction of the transmitted light according to a signal input to the electrode 41. The first polarizing plate 51 selectively transmits light having a second polarization direction included in the light whose polarization direction has been modulated. As a result, the laminate consisting of the second polarizing plate 52, the LCD panel 11, and the first polarizing plate 51 has a light transmittance according to the signal. In addition, the laminate consisting of the backlight 53, the second polarizing plate 52, the LCD panel 11, and the first polarizing plate 51 emits light according 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 overlapped object 24 in the surface direction of the LCD panel 11. As a result, the mechanism 25 moves the overlapped 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, and the like. The guide mechanism guides the overlapped object 24 in the surface direction of the LCD panel 11 so that the overlapped object 24 does not move in the thickness direction of the LCD panel 11. The drive mechanism applies a force required to move the overlapped object 24 to the overlapped object 24. The drive mechanism may be omitted, and the force required to move the overlapped object 24 may be applied to the overlapped object 24 or a support supporting the overlapped object 24 by a user of the inspection device 1.

[0027] Camera 26 is disposed above backlight 53, second polarizing plate 52, LCD panel 11, and first polarizing plate 51 in the vertical direction DZ. Camera 26 captures images of backlight 53, second polarizing plate 52, LCD panel 11, and first polarizing plate 51 from above in the vertical direction DZ. Camera 26 captures an image of an area where LCD panel 11 and 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 may be determined 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 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] The circuit 22, under the control of the control unit 31, outputs a signal for transmitting light 61 through the stack of the second polarizing plate 52, the LCD panel 11, and the first polarizing plate 51 while the display quality of the LCD panel 11 is being inspected. As a result, the circuit 22 turns on the stack of the backlight 53, the second polarizing plate 52, the LCD panel 11, and the first polarizing plate 51 while the display quality of the LCD panel 11 is being inspected, and causes the stack to emit light necessary to generate a display quality image showing the distribution of luminance.

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

[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 with 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 the 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 a dedicated electronic circuit.

[0037] 1.2 Distinguishing between unevenness and point defects on LCD panels and foreign objects attached to stacked objects, as well as unevenness and point defects on stacked objects Fig. 3 is a cross-sectional view showing a stack provided in the inspection device of the reference example, a foreign substance attached to the stack, and an LCD panel inspected using the inspection device. Fig. 4 is a cross-sectional view showing a stack provided in the inspection device of the first embodiment, a foreign substance attached to the stack, 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 overlapping object 24 nor the LCD panel 11 moves. Therefore, neither the foreign matter 71 attached to the overlapping object 24 nor the point defect 72 in the LCD panel 11 moves. Therefore, the foreign matter 71 attached to the overlapping 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 defects in the overlapping object 24 as about the foreign matter 71 attached to the overlapping 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] 4, while the display quality of the LCD panel 11 is being inspected using the inspection device 1 of the first embodiment, the overlapping object 24 moves, but the LCD panel 11 does not move. Therefore, the foreign matter 71 attached to the overlapping object 24 moves, but the point defect 72 in the LCD panel 11 does not move. Therefore, the foreign matter 71 attached to the overlapping 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 overlapping object 24 as about the foreign matter 71 attached to the overlapping 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 captured 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 Pixel Defects Fig. 5 is a top view that diagrammatically illustrates an LCD panel inspected by 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 by 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 found when the display quality of the LCD panel 11 is inspected using the inspection device 1.

[0044] 1.4 Backlight luminance uniformity area, unevenness and point defects Fig. 6 is a top view that diagrammatically illustrates 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 prevent the mura 81 and point defects 82 from being found.

[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, similar to foreign matter adhering to the backlight 53. Furthermore, unevenness and point defects of the first polarizing plate 51 and the second polarizing plate 52 affect the inspection of the display quality of the LCD panel 11, similar to unevenness 101 and point defects 102 of the backlight 53. For this reason, hereinafter, the overlapping object 24 will be described with a focus on the backlight 53.

[0048] FIG. 7A is a top view of a backlight provided in the inspection apparatus of the first embodiment and an LCD panel inspected using the inspection apparatus, the backlight being arranged in a first position. FIG. 7B is a top view of a backlight provided in the inspection apparatus of the first embodiment and an LCD panel inspected using the inspection apparatus, the backlight being arranged in a second position. FIG. 7C is a top view of a backlight provided in the inspection apparatus of the first embodiment and an LCD panel inspected using the inspection apparatus, the backlight being arranged in a third position. FIG. 7D is a top view of a backlight provided in the inspection apparatus of the first embodiment and an LCD panel inspected using the inspection apparatus, the backlight being arranged in 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 illustrated in Fig. 7A, a second position P102 illustrated in Fig. 7B, a third position P103 illustrated in Fig. 7C, and a fourth position P104 illustrated 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 part of the active area 11d of the LCD panel 11 are overlapped with each other. The camera 26 captures an image capturing area 111 including an 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 are overlapped with each other. The captured image capturing area 111 moves in the direction in which the backlight 53 moves. The movement of the image capturing area 111 may be performed by panning and tilting the camera 26, or by shifting an image sensor provided in the camera 26 in a direction perpendicular to the optical axis of the camera 26, or by shifting an area to be cropped from an image acquired by the camera 26, or by shifting a range of pixel signals read out from an 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 luminance 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 luminance 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 contents of image processing performed by an extraction unit and a 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 a shift component and a fixed component acquired by an extraction unit provided in the inspection device. Fig. 11 is a diagram showing a display quality image generated by a 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 apparatus 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 plane direction of the LCD panel 11 to place the backlight 53 at the i-th position in a plane parallel to the plane direction of the LCD panel 11.

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

[0057] In the following step S104, the control unit 31 judges whether or not the identifier i has reached the upper limit value 4. If it is judged that the identifier i has reached the upper limit value 4, step S106 is executed. If it is judged 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, the camera 26 acquires a first image I101, a second image I102, a third image I103, and a fourth image I104 when the backlight 53 is disposed at a first position P101, a second position P102, a third position P103, and a fourth position P104, respectively. The first image I101, the second image I102, the third image I103, and the fourth image I104 may be continuous scanning images acquired continuously by the camera 26 while the mechanism 25 moves the 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 with respect to an 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 called the "opposite direction," these components move the same distance as the distance the imaging area 111 moves in the opposite direction in the first image I101, the second image I102, the third image I103, and the fourth image I104.

[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 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.

[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 the shift component and the fixed component.

[0067] FIG. 12 is a diagram for explaining 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 where the edge of the active area 11d of the LCD panel 11 is located.

[0069] As shown in FIG. 12, in each of the graphs G101 and G102, a peak PK101 originating from a foreign substance attached to the backlight 53, an unevenness 101 of the backlight 53, or a point defect 102 of the backlight 53, and a peak PK102 originating from an unevenness 81 or a point defect 82 of the LCD panel 11 appear. The position where the peak PK101 appears in the graph G101 and the position where the peak PK101 appears in the graph G102 are different from each other. The position where the peak PK102 appears in the graph G101 and the position where the peak PK102 appears in the graph G102 are the same. The peak PK101 appears in the graph G103 showing the distribution of the luminance of the shift component, i.e., the component originating from the backlight 53. In addition, the peak PK102 appears in the graph G104 showing the distribution of the luminance of the fixed component, i.e., the component originating from the LCD panel 11.

[0070] In the next step S107, as shown in Fig. 9 and Fig. 11, the synthesis unit 29 synthesizes 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 distribution of the overall luminance 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 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 F1 does not reflect the foreign matter attached to the backlight 53, the unevenness 101 of the backlight 53, and the point defect 102 of the backlight 53, but reflects the unevenness 81 and the point defect 82 of the LCD panel 11.

[0071] 1.7 Advantages of the inspection device according to 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 of the backlight 53, and point defects 102 of the backlight 53, but reflects unevenness 81 and point defects 82 of 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 of the LCD panel 11 exist, without being influenced by foreign matter attached to the backlight 53, unevenness 101 of the backlight 53, and point defects 102 of the backlight 53. Therefore, the display quality of the LCD panel 11 can be appropriately inspected.

[0072] FIG. 13 is a cross-sectional view that typically 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 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. Therefore, the edge of the area to be inspected cannot be properly inspected. This drawback of the inspection device of the reference example is particularly noticeable when the first polarizing plate 51, the second polarizing plate 52, and the backlight 53 are the same types as the first polarizing plate, the second polarizing plate, and the backlight provided in the LCD manufactured using the LCD panel 11, respectively. That is, this drawback of the inspection device of the reference example is particularly noticeable when the first polarizing plate 51, the second polarizing plate 52, and the backlight 53 have a planar shape close to the planar shape of the LCD panel 11. This drawback occurs because the inspection device 1 does not allow two adjacent components included in the first polarizing plate 51, the LCD panel 11, the second polarizing plate 52, and the backlight 53 to be in close contact with each other.

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

[0075] 14, when the display quality of the LCD panel 11 is inspected using the inspection device 1 of the first embodiment, an area to be inspected, for example, the entire active area 11d of the LCD panel 11, is imaged multiple times. Therefore, the imaging area 111 imaged by the camera 26 can be narrowed to fit within the uniform brightness area 91 of the backlight 53. Therefore, the edge of the area to be inspected can be properly 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 luminance area 91 can be disposed directly under the imaging area 111 when each of the first image I101, the second image I102, the third image I103, and the fourth image I104 is acquired. Therefore, the LCD panel 11 can be appropriately inspected without being affected by the non-uniform luminance 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 apparatus 1M according to the first modified example of the first embodiment is used for visual inspection in which the display quality of the LCD panel 11 is visually inspected.

[0079] Therefore, the inspection device 1M does not include the camera 26, the extraction unit 28, the synthesis unit 29, and the control unit 31. In the inspection device 1M, an 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 are overlapped with each other is visually observed from the position where the camera 26 is arranged in the inspection device 1. When an observer finds unevenness and point defects that do not move when the backlight 53 moves in the surface direction of the LCD panel 11, the observer can recognize the unevenness and point defects as unevenness 81 and point defects 82 of the LCD panel 11. This makes it possible to inspect whether or not unevenness 81 and point defects 82 of the LCD panel 11 exist without being affected by foreign matter attached to the backlight 53, unevenness 101 of the backlight 53, and point defects 102 of the backlight 53. Therefore, the display quality of the LCD panel 11 can 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 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 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 planar direction of the LCD panel 11. As a result, the mechanism 25 moves the LCD panel 11 placed on the stage 21 in the planar direction. As a result, the mechanism 25 moves the LCD panel 11 in the planar direction relative to the fixed overlapping object 24 and camera 26.

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

[0085] 18, while the display quality of the LCD panel 11 is being inspected using the inspection device 2 of the second embodiment, the overlapping object 24 does not move, but the LCD panel 11 moves. Therefore, the foreign matter 71 attached to the overlapping object 24 does not move, but the point defect 72 in the LCD panel 11 moves. Therefore, the foreign matter 71 attached to the overlapping 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 overlapping object 24 as about the foreign matter 71 attached to the overlapping 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.

[0086] The inspection device 2 utilizes this to extract a component originating from the LCD panel 11 from the image captured by the camera 26. The extracted component originating from the LCD panel 11 is a shift component moving 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 of a backlight provided in the inspection apparatus of the second embodiment and an LCD panel inspected using the inspection apparatus, the LCD panel being arranged in a first position. FIG. 19B is a top view of a backlight provided in the inspection apparatus of the second embodiment and an LCD panel inspected using the inspection apparatus, the LCD panel being arranged in a second position. FIG. 19C is a top view of a backlight provided in the inspection apparatus of the second embodiment and an LCD panel inspected using the inspection apparatus, the LCD panel being arranged in a third position. FIG. 19D is a top view of a backlight provided in the inspection apparatus of the second embodiment and an LCD panel inspected using the inspection apparatus, the LCD panel being arranged in a fourth position. FIG. 19E is a top view illustrating a schematic diagram of a backlight provided in the inspection apparatus of the second embodiment and an LCD panel inspected using the inspection apparatus, the LCD panel being disposed at the sixteenth position.

[0088] The LCD panel 11 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 inspected using the inspection device 2. The plurality of positions at which the LCD panel 11 is disposed are 16 positions consisting of a first position P201 illustrated in Fig. 19A, a second position P202 illustrated in Fig. 19B, a third position P203 illustrated in Fig. 19C, a fourth position P204 illustrated in Fig. 19D, ..., a 16th position P216 illustrated in Fig. 19E. The plurality of positions may be 15 or less positions or 17 or more positions.

[0089] When the backlight 53 is disposed at each of the first position P201, the second position P202, the third position P203, the fourth position P204, ..., the sixteenth position P216, the whole or a part of the uniform luminance area 91 of the backlight 53 and a part of the active area 11d of the LCD panel 11 are overlapped with each other. The camera 26 captures an image of an imaging area 111 including an area where the whole or a part of the uniform luminance area 91 of the backlight 53 and a part of the active area 11d of the LCD panel 11 are overlapped with each other. The imaging area 111 to be captured does not move.

[0090] The first position P201, the second position P202, the third position P203, the fourth position P204, ..., and the sixteenth position P216 are set so that the uniform luminance 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, ..., and the sixteenth position P216 are arranged in a matrix of, for example, 4 rows and 4 columns.

[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 contents of image processing performed by an extraction unit and a 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 a shift component and a fixed component acquired by an extraction unit provided in the inspection device. Fig. 23 is a diagram showing a display quality image generated by a 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 apparatus 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 next step S113, camera 26 captures an image of imaging area 111 including an area where all or part of uniform luminance area 91 of backlight 53 and part of active area 11d of LCD panel 11 overlap each other to obtain an i-th image.

[0096] In the following step S114, the control unit 31 judges whether or not the identifier i has reached the upper limit value 16. If it is judged that the identifier i has reached the upper limit value 16, step S116 is executed. If it is judged that the identifier i has not reached the upper limit value 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, the 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 the LCD panel 11 is placed at the first position P201, the second position P202, the third position P203, the fourth position P204, . . . , and a sixteenth position P216. The first image I201, the second image I202, the third image I203, the fourth image I204, . . . , and the sixteenth image I216 may be continuous scanning images acquired continuously by the camera 26 while the mechanism 25 moves the 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 an image of a fixed object, for example, an 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 surface 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 in the first image I201, the second image I202, the third image I203, and the fourth image I204 that 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, ..., and 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, ..., and the sixteenth shift component A216 include 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. In addition, the first fixed component B201, the second fixed component B202, the third fixed component B203, the fourth fixed component B204, ..., and 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, ..., the sixteenth image I216 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.

[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 the shift component and the fixed component may be improved by using multiple images acquired while the LCD panel 11 is moving.

[0106] FIG. 24 is a diagram for explaining 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 where the edge of the active area 11d of the LCD panel 11 is located.

[0108] As shown in Fig. 24, a peak PK201 resulting from unevenness 81 or point defect 82 of the LCD panel 11 and a peak PK202 resulting from unevenness 101 or point defect 102 of the backlight 53 appear in each of the graphs G201 and G202. The position where the peak PK201 appears in the graph G201 and the position where the peak PK101 appears in the graph G202 are different from each other. The position where the peak PK202 appears in the graph G201 and the position where the peak PK202 appears in the graph G202 are the same. The peak PK201 appears in the graph G203 showing the distribution of the luminance of the shift component, i.e., the component derived from the LCD panel 11. Also, the peak PK202 appears in the graph G204 showing the distribution of the luminance of the fixed component, i.e., the component derived from the backlight 53.

[0109] In the next step S117, as shown in Figs. 21 and 23, the synthesis unit 29 synthesizes 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 shows 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 the foreign matter attached to the backlight 53, the unevenness 101 of the backlight 53, and 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 according to 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 of the backlight 53, and point defects 102 of the backlight 53, but reflects unevenness 81 and point defects 82 of 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 of the LCD panel 11 exist, without being influenced by foreign matter attached to the backlight 53, unevenness 101 of the backlight 53, and point defects 102 of the backlight 53. Therefore, the display quality of the LCD panel 11 can be appropriately inspected.

[0111] FIG. 25 is a cross-sectional view that typically 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] As shown in Fig. 25, when the display quality of the 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. Also, 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. That is, it is impossible to avoid imaging the edge of the area to be inspected from a direction greatly tilted from the direction facing directly. For this reason, it is not easy to properly inspect the edge of the area to be inspected.

[0113] FIG. 26 is a cross-sectional view that typically illustrates a state in which the LCD panel is arranged at a first position, of the stacked object and the camera provided in the inspection device of the second embodiment, and the LCD panel inspected by the inspection device. FIG. 27 is a perspective view that typically illustrates a state in which the LCD panel is arranged at a first position, of the stacked object and the camera provided in the inspection device of the second embodiment, and the LCD panel inspected by the inspection device. FIG. 28 is a cross-sectional view that typically illustrates a state in which the LCD panel is arranged at a 16th position, of the stacked object and the camera provided in the inspection device of the second embodiment, and the LCD panel inspected by the inspection device. FIG. 29 is a perspective view that typically illustrates a state in which the LCD panel is arranged at a 16th position, of the stacked object and the camera provided in the inspection device of the second embodiment, and the LCD panel inspected by the inspection device.

[0114] As shown in Fig. 26 to Fig. 29, when the display quality of the 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 in a number of separate times. Therefore, the imaging area 111 imaged by the camera 26 can be narrowed and placed within the uniform brightness area 91 of the backlight 53. Also, the imaging area 111 imaged 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. That is, it is possible to avoid imaging the edge of the area to be inspected from a direction greatly tilted from the direction facing directly. Therefore, it is 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 luminance area 91 can be disposed directly under the imaging area 111 when each of the first image I201, the second image I202, the third image I203, the fourth image I204, ..., the sixteenth image I216 is acquired. Therefore, the LCD panel 11 can be appropriately inspected without being affected by the non-uniform luminance 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 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 the third embodiment and an LCD panel inspected using the inspection device. Fig. 31 is a cross-sectional view that typically shows 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 that typically shows 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 Fig. 30 to Fig. 32, the camera 26 is disposed far away 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 allows the edge of the area to be inspected to be prevented from being imaged from a direction significantly tilted from a direction directly facing the edge of the area to be inspected. This allows the image captured by the camera 26 to be prevented 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 includes 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 captured 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 captured by the camera 26.

[0120] When LCD panel 11 is a first LCD panel, camera 26 obtains a plurality of images when the first LCD panel is placed at a plurality of positions, in accordance with the control of control unit 31. When LCD panel 11 is a second LCD panel to be inspected, camera 26 obtains an image when the second LCD panel is placed at an inspection position, in accordance with 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] The extraction unit 28, under the control of the control unit 31, extracts multiple components originating from the overlapping object 24 or foreign matter attached to the overlapping object 24 from multiple images acquired when the LCD panel 11 was the first LCD panel.

[0124] A synthesis unit 29 synthesizes the extracted components to generate a storage image.

[0125] The correction unit 30 corrects the image acquired when the LCD panel 11 is the second LCD panel using 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 configured 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 the 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 a dedicated electronic circuit.

[0127] 3.2 Operation FIG. 33 is a flowchart showing the flow of processing performed by the inspection device of the third embodiment. FIG. 34 is a diagram showing the contents of image processing performed by the extraction unit and synthesis unit provided in the inspection device of the third embodiment. FIG. 35 is a diagram showing the contents of image processing performed by the correction unit provided in the inspection device of the third embodiment. FIG. 36 is a diagram showing an image acquired by a camera provided in the inspection device of the third embodiment, and a shift component and a fixed component acquired by the extraction unit provided in the inspection device. FIG. 37 is a diagram showing an image acquired by a camera provided in the inspection device of the third embodiment, a saved image generated by a synthesis unit provided in the inspection device, and a luminance ratio distribution image acquired by a correction unit provided in the inspection device. FIG. 38 is a diagram 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. FIG. 39 is a cross-sectional view that typically illustrates a state in which the first LCD panel is disposed at a first position, of the superimposed object and camera provided in the inspection device of the third embodiment, and the first LCD panel. Fig. 40 is a cross-sectional view showing a stack and a camera provided in the inspection apparatus of the third embodiment, and a first LCD panel, the first LCD panel being arranged at position 16. Fig. 41 is a cross-sectional view showing a stack and a camera provided in the inspection apparatus of the third embodiment, and a second LCD panel inspected by the inspection apparatus, the second LCD panel being arranged at the inspection position.

[0128] The inspection apparatus 3 executes steps S121 to S127 shown in Fig. 33 after the first LCD panel is set on the stage 21, and executes steps S128 to S130 shown in Fig. 33 after the second LCD panel is set on the stage 21. 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. That is, steps S121 to S127 need only be executed during the first inspection, and do not necessarily need to be executed during the second or subsequent inspections.

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

[0130] In the next 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 next 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 to obtain an i-th image.

[0132] In the next step S124, the control unit 31 determines whether or not the identifier i has reached the upper limit value 16. If it is determined that the identifier i has reached the upper limit value 16, step S126 is executed. If it is determined that the identifier i has not reached the upper limit value 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 a first image I301, a second image I302, a third image I303, a fourth image I304, ..., a sixteenth image I316 when the first LCD panel is positioned at a first position P301, a second position P302, a third position P303, a fourth position P304, ..., a 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 next step S127, as shown in Fig. 34 and Fig. 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 indicates a 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 next step S128, mechanism 25 moves the second LCD panel in the surface direction of LCD panel 11 to place the second LCD panel at the inspection position. 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 capturing area 111 including the area where the entire active area 11d of the second LCD panel and backlight 53 are overlapped with each other.

[0139] In the next step S130, the correction unit 30 generates a display quality image F3 from the image I3 and the stored 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, and 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 stored image C3, the correction unit 30 generates a brightness ratio distribution image D3 from image I3 and stored 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 luminance ratio distribution image D3 from the image I3 and the stored image C3, the correction unit 30 divides the image I3 by the stored image C3 to generate the luminance ratio distribution image D3. The generated luminance ratio distribution image D3 is generated by dividing the image I3 showing the distribution of luminance by the stored image C3 showing the distribution of luminance, and therefore indicates the distribution of the ratio of the luminance of the image I3 to the luminance of the 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 brightness of the stored images C3. The display quality image F3 shows the distribution of brightness because it is generated by multiplying the brightness ratio distribution image D3, which shows the distribution of brightness ratios, by the average brightness image E3, which shows the distribution of brightness.

[0143] 3.3 Advantages of the inspection device according to 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 of the backlight 53, and point defects 102 of the backlight 53, but reflects unevenness 81 and point defects 82 of 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 of the backlight 53, and point defects 102 of the backlight 53. Therefore, the LCD panel 11 can be inspected appropriately.

[0144] When a liquid crystal panel is inspected using the inspection device disclosed in Patent Document 1 (JP Patent Publication No. 4610656), only the front polarizing plate and the backlight are taken into consideration when performing shading correction, viewing angle characteristic correction, etc., so the viewing angle characteristic of the liquid crystal panel cannot be corrected. In addition, the image obtained shows the distribution of transmittance, but not the distribution of luminance. For this reason, it is not possible to judge the display quality from the obtained image using normal automatic judgment 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 distribution of luminance 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 action and 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 end 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 superposition, 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 luminance ratio distribution image, E3 average luminance image, F3 display quality image.

Claims

1. a laminate that is laminated on the liquid crystal display panel in a thickness direction of the liquid crystal display panel; a mechanism for fixing one of the liquid crystal display panel and the stack and moving the other of the liquid crystal display panel and the stack in a surface direction of the liquid crystal display panel; An inspection device comprising:

2. a camera for capturing an image of an area where the liquid crystal display panel and the overlapping object are overlapped with each other; an extracting unit that extracts a plurality of components originating from the liquid crystal display panel from a plurality of images respectively captured by the camera when the other of the two 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; The inspection apparatus according to claim 1 .

3. the one being the liquid crystal display panel, the other is the stack, The plurality of components are fixed components that do not move in the plane direction.

3. The inspection device according to claim 2.

4. The one is the stack, the other is the liquid crystal display panel, The plurality of components are shift components that move in the plane direction.

3. The inspection device according to claim 2.

5. The one is the stack, the other is the liquid crystal display panel, a camera for capturing an image of an area where the liquid crystal display panel and the overlapping object are overlapped with each other from the thickness direction; an extraction unit that extracts a plurality of components originating from the overlapped object or a foreign substance attached to the overlapped 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 for synthesizing the plurality of components to obtain a saved image; a correction unit that corrects an image captured by the camera using the stored image when the liquid crystal display panel is a second liquid crystal display panel; The inspection apparatus according to claim 1 .

6. The laminate includes a polarizing plate and a backlight.

6. An inspection device according to claim 1.

7. stacking the liquid crystal display panel and the stack together in a thickness direction of the liquid crystal display panel; fixing one of the liquid crystal display panel and the stack, and moving the other of the liquid crystal display panel and the stack in a plane direction of the liquid crystal display panel; An inspection method comprising:

Images