Glass plate inspection device and inspection method

Abstract

The invention provides a glass plate inspection device and an inspection method capable of detecting defects of a glass plate with high precision. A glass plate (G) inspection device (100) for inspecting defects (D) of a rectangular glass plate (G) is provided with: a stage (23) on which the glass plate (G) is placed; a first illumination (13) configured so as to emit inspection light (Lx) from a first side surface (Gsx) of the glass plate (G) to the glass plate (G) placed on the table (23); a second illumination (15) configured so as to emit inspection light (Ly) from a second side surface (Gsy) adjacent to the first side surface (Gsx) of the glass plate (G) to the glass plate (G) placed on the stage (23); and a defect detection unit (33) that detects scattered light (Ls) generated by a defect (D) of the glass plate (G).

Description

TECHNICAL FIELD

[0001] The present application relates to an inspection apparatus and an inspection method for a glass sheet. BACKGROUND

[0002] For example, as an inspection apparatus for a glass sheet for a FPD (Flat Panel Display), there is known an apparatus that irradiates light to both side surfaces of a glass sheet being conveyed on a conveying path, i.e., two side surfaces that are substantially parallel with respect to a conveying direction, and detects a defect of the glass sheet by detecting scattered light from the glass sheet that is scattered due to the defect (for example, refer to Patent Documents 1 to 3).

[0003] PRIOR ART DOCUMENTS

[0004] PATENT DOCUMENTS

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2009-216628

[0006] Patent Document 2: Japanese Patent Application Laid-Open No. 2012-7993

[0007] Patent Document 3: Japanese Patent No. 3329233 SUMMARY

[0008] PROBLEMS TO BE SOLVED BY THE INVENTION

[0009] However, in an apparatus that irradiates light to both side surfaces of a glass sheet being conveyed on a conveying path, i.e., two side surfaces that are substantially parallel with respect to a conveying direction, and detects a defect of the glass sheet, as in the above-described inspection apparatus, it is difficult to detect a defect such as a fine scratch having a directivity of light with high precision.

[0010] Therefore, an object of the present application is to provide an inspection apparatus and an inspection method for a glass sheet that can detect a defect of a glass sheet with high precision.

[0011] TECHNICAL SOLUTION TO THE PROBLEM

[0012] The present application is constituted by the following structure.

[0013] (1) An inspection apparatus for a glass sheet that inspects a defect of a glass sheet formed in a rectangular shape, wherein

[0014] The inspection apparatus for a glass sheet has:

[0015] a stage that places the glass sheet;

[0016] a first illuminator configured to incident inspection light to the glass sheet placed on the stage from a first side surface of the glass sheet;

[0017] The second illumination is configured to make the inspection light incident on the glass plate placed on the worktable from a second side surface of the glass plate adjacent to the first side surface.

[0018] The defect detection section detects scattered light generated by a defect of the glass plate.

[0019] (2) An inspection method of a glass plate, in which a defect of a glass plate formed in a rectangular shape is inspected, wherein

[0020] The inspection light is made incident from a first side surface and a second side surface adjacent to the first side surface of the glass plate, respectively.

[0021] The scattered light generated by the defect of the glass plate is detected.

[0022] Effects of the Invention

[0023] According to the present application, it is possible to provide an inspection device and an inspection method of a glass plate capable of detecting a defect of a glass plate with high precision. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a perspective view of an inspection device of a glass plate according to the present embodiment.

[0025] Figure 2 is a schematic side view illustrating the structure of the inspection device of the glass plate according to the present embodiment.

[0026] Figure 3 is a schematic view showing the arrangement of a first illumination and a second illumination with respect to a glass plate.

[0027] Figure 4 is a schematic sectional view of a glass plate and a first illumination.

[0028] Figure 5 is a block diagram showing a control system of the inspection device of the glass plate.

[0029] Figure 6 is a graph showing a luminance value of scattered light generated by a defect. DETAILED DESCRIPTION

[0030] Hereinafter, an embodiment of the present application will be described in detail with reference to the drawings.

[0031] <Inspection Device>

[0032] First, an inspection device of a glass plate according to the present embodiment will be described. In addition, in the following drawings, arrows X, Y indicate two directions orthogonal in a horizontal plane, and an arrow Z indicates a vertical up-and-down direction.

[0033] Figure 1is a perspective view of an inspection device 100 of a glass sheet G according to the present embodiment. Figure 2 is a schematic side view illustrating a configuration of the inspection device 100 of the glass sheet G according to the present embodiment.

[0034] As shown in Figure 1 and Figure 2 , the inspection device 100 of the glass sheet according to the present embodiment is provided with a stage 11, a first illuminator 13, a second illuminator 15, and a defect detection mechanism section 17. The inspection device 100 is a device that detects defects of a glass sheet G.

[0035] The glass sheet G that is an inspection object of the inspection device 100 is, for example, a thin glass sheet having a thickness of about 0.4 mm to 2.0 mm, and is, for example, a glass sheet for a flat panel display (FPD) such as an LCD (Liquid Crystal Display) or an OLED (Organic Light-Emitting Diode).

[0036] The glass sheet G is formed into a smooth band-shaped glass band by floating molten glass in a floatation furnace on molten tin in a floatation furnace and annealing in an annealing furnace, and then cut by a cutting tool to be formed into a rectangular shape in plan view. The glass sheet G sometimes has various defects in a manufacturing process, and the inspection device 100 detects defects present in the glass sheet G. As the defects present in the glass sheet G, foreign matters mixed at the time of manufacturing, traces of bubbles, scratches caused by contact with a carrying roller or the like at the time of carrying, and the like, including defects of about 10 μm to 100 μm in size. The inspection device 100 is preferably used for detection of fine defects in a glass sheet G after chemical treatment (etching treatment), and is excellent in detection of defects such as latent damage that is difficult to confirm before the chemical treatment.

[0037] The stage 11 is provided at an upper portion of a stand 21. A work table 23 is disposed at an upper portion of the stage 11. The rectangular glass sheet G that is an inspection object is, for example, taken out from a production line and placed on the work table 23 of the stage 11.

[0038] The first illuminator 13 and the second illuminator 15 are disposed at the stage 11. The first illuminator 13 and the second illuminator 15 each have a light source such as an LED (Light Emitting Diode), and are formed in a long strip shape. In addition, as the light source of the first illuminator 13 and the second illuminator 15, various light sources other than the LED, such as a metal halide lamp, an ultrahigh-pressure mercury lamp, a halogen lamp, or a xenon lamp, can be used.

[0039] Figure 3is a schematic view showing the arrangement of the first illuminator 13 and the second illuminator 15 with respect to the glass plate G. Figure 4 is a schematic cross-sectional view of the glass plate G and the first illuminator 13.

[0040] As shown in Figure 3 and Figure 4 The first illuminator 13 and the second illuminator 15 have light- emitting surfaces 13a, 15a on one side thereof, and emit linear inspection light Lx, Ly from the light-emitting surfaces 13a, 15a. In the placement table 11, the first illuminator 13 is arranged along the Y direction at the edge portion on the X direction side of the work table 23, and the second illuminator 15 is arranged along the X direction at the edge portion on the Y direction side of the work table 23. In this way, the first illuminator 13 and the second illuminator 15 are arranged at the edge portions of the work table 23 in a mutually orthogonal manner, and emit inspection light Lx, Ly in mutually orthogonal directions.

[0041] The first illuminator 13 and the second illuminator 15 are arranged so that the light-emitting surfaces 13a, 15a thereof are substantially perpendicular to the main surface of the work table 23. As a result, the inspection light Lx emitted from the light-emitting surface 13a of the first illuminator 13 is incident on the glass plate G placed on the work table 23 of the placement table 11 from one side surface, i.e., the first side surface Gsx in the Y direction, and the inspection light Ly emitted from the light-emitting surface 15a of the second illuminator 15 is incident on the glass plate G placed on the work table 23 of the placement table 11 from one side surface, i.e., the second side surface Gsy in the X direction. The first side surface Gsx and the second side surface Gsy, which are the side surfaces of the glass plate G, are adjacent to each other.

[0042] In addition, the first illuminator 13 is rotatable in the Z direction in the same plane as the main surface of the glass plate G placed on the work table 23, i.e., in the XY plane. As a result, the first illuminator 13 is rotatable to adjust the position so as to be arranged without a gap with respect to the first side surface Gsx of the glass plate G placed on the work table 23. That is, the inspection light Lx emitted from the light-emitting surface 13a of the first illuminator 13 can be made to be incident on the first side surface Gsx of the glass plate G in the full length range uniformly. Furthermore, the first illuminator 13 is tiltable with respect to the first side surface Gsx of the glass plate G placed on the work table 23 in the substantially Y direction. As a result, the first illuminator 13 can adjust the angle of emission of the inspection light Lx with respect to the first side surface Gsx of the glass plate G placed on the work table 23. That is, the angle of incidence of the inspection light Lx emitted from the light-emitting surface 13a of the first illuminator 13 on the first side surface Gsx of the glass plate G can be adjusted, and the inspection light Lx can be made to be totally reflected in the glass plate G favorably.

[0043] Likewise, the second illumination 15 is capable of rotating in the Z direction in the same plane as the main surface of the glass plate G placed on the work table 23, that is, the XY plane. Thus, the second illumination 15 is capable of rotating to adjust the position so as to be gaplessly arranged with respect to the second side surface Gsy of the glass plate G placed on the work table 23. That is, the inspection light Ly irradiated from the light emitting surface 15a of the second illumination 15 is capable of being equally incident in the entire length range with respect to the second side surface Gsy of the glass plate G. Also, the second illumination 15 is capable of tilting with respect to the second side surface Gsy of the glass plate G placed on the work table 23 in the substantially X direction as an axis. Thus, the second illumination 15 is capable of adjusting the irradiation angle of the inspection light Ly with respect to the second side surface Gsy of the glass plate G placed on the work table 23. That is, the incident angle of the inspection light Ly irradiated from the light emitting surface 15a of the second illumination 15 toward the second side surface Gsy of the glass plate G is capable of being adjusted to make the inspection light Ly well totally reflect within the glass plate G.

[0044] Note that the first illumination 13 and the second illumination 15 are preferably capable of rotating in the Z direction in the same plane as the main surface of the glass plate G placed on the work table 23, that is, the XY plane, by a rotation angle of about ±2°. Also, the first illumination 13 is preferably capable of tilting with respect to the first side surface Gsx of the glass plate G placed on the work table 23 in the substantially Y direction as an axis by a tilt angle of about ±30°, and the second illumination 15 is preferably capable of tilting with respect to the second side surface Gsy in the substantially X direction as an axis by a tilt angle of about ±30°. That is, the incident angle of the inspection light Lx irradiated from the light emitting surface 13a of the first illumination 13 toward the first side surface Gsx of the glass plate G, and the incident angle of the inspection light Ly irradiated from the light emitting surface 15a of the second illumination 15 toward the second side surface Gsy of the glass plate G are capable of being adjusted in a range of about -30° to 30°.

[0045] The defect detection mechanism section 17 has a moving mechanism 31, a defect detection section 33, and a microscope (imaging section) 35. The defect detection section 33 and the microscope 35 are mounted on the moving mechanism 31.

[0046] The moving mechanism 31 has a frame 41 of a gate type. The lower portions of both ends of the frame 41 are leg portions 43. A linear motion mechanism 45 is provided to these leg portions 43, and the linear motion mechanism 45 is supported in a movable manner to rails 34 extending in the X direction on both sides of the placement table 11. Also, the frame 41 is arranged so as to cross the work table 23 in the Y direction, and is capable of reciprocating in the X direction above the work table 23 by the linear motion mechanism 45.

[0047] The defect detection section 33 is mounted on one face 41a of the frame 41. The defect detection section 33 is constituted by a plurality of cameras 51. The plurality of cameras 51 constituting the defect detection section 33 are respectively arranged in the Y direction on the one face 41a of the frame 41 in a state of facing downward and are supported. The defect detection section 33 photographs and detects the scattered light Ls from the glass plate G placed on the stage 23 by the plurality of cameras 51 and outputs the detection data. In the defect detection section 33, the scattered light Ls from the glass plate G placed on the stage 23 can be detected in the entire region in the Y direction by the plurality of cameras 51 arranged in the Y direction. Therefore, by moving the defect detection section 33 mounted on the frame 41 in the X direction by the moving mechanism 31, the defect detection section 33 can detect the scattered light Ls in the entire region of the glass plate G.

[0048] The microscope 35 is mounted on the other face 41b of the frame 41. The microscope 35 is provided with an electronic camera and an auto-focusing lens section 35a at a lower end thereof. The microscope 35 is supported to the frame 41 via a microscope moving mechanism 55. The microscope 35 is moved in the Y direction which is the longitudinal direction of the frame 41 and in the Z direction which is the vertical direction by the microscope moving mechanism 55. The microscope 35 enlarges and photographs a defective portion of the glass plate G placed on the stage 23 and outputs the photographed data.

[0049] Figure 5 is a block diagram showing a control system of the inspection device 100 of the glass plate G.

[0050] As Figure 5As shown, the inspection apparatus 100 is provided with a control section (PLC: Programmable Logic Controller) 61. The control section 61 is connected to the first illumination 13, the second illumination 15, the moving mechanism 31, and the microscope moving mechanism 55. The first illumination 13 and the second illumination 15 are controlled to be turned on and off by the control section 61. In the defect detection mechanism section 17, the operations of the moving mechanism 31 and the microscope moving mechanism 55 are controlled by the control section 61. In addition, the control section 61 is connected to a microscope control section 64 and an inspection control section 62. The microscope control section 64 controls the microscope 35 based on a control signal from the control section 61, and transmits captured data from the microscope 35. The inspection control section 62 is, for example, a personal computer (PC), controls the defect detection section 33, and transmits detection data from the defect detection section 33. The inspection control section 62 detects a defect D in the glass plate G and finds a position of the defect D based on the detection data from the defect detection section 33. In addition, the inspection control section 62 is provided with a display section 63 such as a display. By transmitting data of an inspection result from the inspection control section 62 to the display section 63, information about the defect D existing in the glass plate G, that is, defect information is displayed. As the defect information, for example, an image of the defect D, a position of the defect D in the glass plate G, a size of the defect D, and the like are displayed.

[0051] However, the inspection light Lx, Ly incident from the adjacent first side surface Gsx and the second side surface Gsy of the glass plate G decreases in illuminance with a distance from an incident end thereof. Therefore, the scattered light Ls generated by the defect D also decreases in luminance with a distance from the incident end of the inspection light Lx, Ly, and the detection sensitivity of the scattered light Ls in the camera 51 of the defect detection section 33 decreases. Therefore, the control section 61 is provided with a correction table (threshold value) that corrects a decrease in the detection sensitivity caused by a decrease in the illuminance corresponding to the distance from the incident end, and is provided with a correction function that equalizes the detection sensitivity of the scattered light Ls based on the correction table. In addition, as the correction function, it is also possible to automatically adjust an aperture of the camera 51 constituting the defect detection section 33 according to the distance from the incident end of the inspection light Lx, Ly.

[0052] <Inspection method>

[0053] Next, the sequence of the inspection of the glass plate G by the inspection apparatus 100 using the above-described structure will be described.

[0054] First, a rectangular glass plate G taken out from a production line, for example, is arranged on the work table 23 of the placement table 11 of the inspection apparatus 100. Thereby, the light projection surface 13a of the first illumination 13 is arranged opposite to the first side surface Gsx of the glass plate G in the Y direction, and the light projection surface 15a of the second illumination 15 is arranged opposite to the second side surface Gsy of the glass plate G in the X direction (refer to FIG. 1).Figure 3 and Figure 4 ).

[0055] Here, the glass sheet G of the present embodiment has a top surface (upper surface) Gt which becomes the surface side when formed by a float bath, and a bottom surface (lower surface) Gb which is a handling surface which is in contact with molten tin after which it is in contact with a handling roller or the like when handled by a handling device. In order to detect defects of the glass sheet G with a certain degree of accuracy, when the glass sheet G is arranged on the work table 23, it is preferable to arrange it in a manner such that the same surface of the glass sheet G is always on top. In particular, it is preferable to arrange it in a manner such that the top surface (upper surface) Gt is always on top, i.e. the bottom surface (lower surface) Gb is always on the bottom.

[0056] Next, the inspection device 100 is operated, and inspection is started. When the inspection of the inspection device 100 is started, the first illumination 13 and the second illumination 15 are lit by the control section 61. Thereby, the inspection light Lx, Ly which is irradiated from the light projection surfaces 13a, 15a of these first and second illuminations 13, 15 is incident on the adjacent first and second side surfaces Gsx, Gsy of the glass sheet G.

[0057] If the inspection light Lx, Ly is incident on the glass sheet G, in the defect detection mechanism section 17, the frame 41 of the moving mechanism 31 is moved in the X direction, and the scattered light Ls which is emitted from the top surface Gt of the glass sheet G due to scattering of the inspection light Lx, Ly by the defect D is detected by the plurality of cameras 51 of the defect detection section 33. Thereby, the scattered light Ls in the entire area of the glass sheet G is detected by the defect detection section 33.

[0058] However, there are defects which have a light directivity among the defects D which exist in the glass sheet G. In such a defect D which has a light directivity, sometimes the irradiated inspection light Lx or Ly directly passes through, and hardly generates scattered light Ls.

[0059] Here, for the glass sheet G in which there are fine defects D1, D2, D3 which have a light directivity and whose lengths are 20 μm, 35 μm, and 55 μm, the luminance values of the scattered light Ls were measured in the case where the inspection light Lx was irradiated toward the first side surface Gsx, in the case where the inspection light Ly was irradiated toward the second side surface Gsy, and in the case where the inspection light Lx, Ly was irradiated toward the first and second side surfaces Gsx, Gsy, respectively. Figure 6 is a graph which shows the luminance values of the scattered light Ls which is generated by the defects D1, D2, D3.

[0060] As Figure 6As shown, in the case where the inspection light Lx is irradiated to the first side surface Gsx of the glass plate G, the scattered light Ls of a brightness of the detectable brightness cd or more is generated at the defects Dl, D2 of 20 μm and 35 μm, but the scattered light Ls of a brightness reaching the detectable brightness cd is not generated at the defect D3 of 55 μm. On the other hand, in the case where the inspection light Ly is irradiated to the second side surface Gsy of the glass plate G, the scattered light Ls of a brightness of the detectable brightness cd or more is generated at the defect D3 of 55 μm, but the scattered light Ls of a brightness reaching the detectable brightness cd is not generated at the defects Dl, D2 of 20 μm and 35 μm. In such a condition, in the case where the inspection lights Lx, Ly are respectively irradiated to the first side surface Gsx and the second side surface Gsy of the glass plate G, the scattered light Ls of a brightness of the detectable brightness cd or more is generated at each of the defects Dl, D2, D3 of 20 μm, 35 μm, and 55 μm.

[0061] In the inspection method using the inspection device 100 according to the present embodiment, the inspection lights Lx, Ly are respectively incident from the adjacent first side surface Gsx and second side surface Gsy of the rectangular glass plate G by the first illumination 13 and the second illumination 15, and thus the defects D having the directivity of light can be detected with high accuracy.

[0062] If the defects D of the glass plate G are detected by the defect detection section 33, the control section 61 performs a photographing process of the defects D based on the detection data. In the photographing process, the microscope 35 is moved to the position of each of the detected defects D in the glass plate G by the moving mechanism 31 and the microscope moving mechanism 55. Then, the defects D are photographed by the microscope 35 at the position of the defects D, and the photographed data are transmitted to the control section 61 and the inspection control section 62. In the photographing process of the defects D by the microscope 35, continuous photographing is performed by the microscope 35 moved in the up-and-down direction by the microscope moving mechanism 55.

[0063] The inspection control section 62 causes the display section 63 to display defect information constituted by the detection data of the defects D from the defect detection section 33 and the photographed data from the microscope 35. In the display section 63, based on the defect information, an image of the defects D, the position of the defects D in the glass plate G, the size of the defects D, and the like are displayed. Thus, by referring to the display of the defect information in the display section 63, the inspector can easily and accurately confirm and recognize the position, the kind, and the size of the defects D in the glass plate G.

[0064] As explained above, according to the inspection device 100 and the inspection method of the glass sheet G according to the present embodiment, the inspection light Lx, Ly is made to be incident from the first side surface Gsx and the second side surface Gsy, which are adjacent side surfaces of the rectangular glass sheet G, to detect the defect D, and thus, for example, compared to a device that irradiates light to both sides of the glass sheet G being carried on a production line, that is, to two side surfaces that are substantially parallel with respect to the carrying direction, to detect the defect D, the defect D such as a fine scratch having directionality of light can also be detected with high precision.

[0065] In addition, the microscope 35 captures the position where the scattered light Ls detected by the defect detection section 33 with high precision, and thus, the size, the kind, and the like of the defect D of the glass sheet G can be accurately determined.

[0066] Further, the defect detection section 33 and the microscope 35 are mounted on the same moving mechanism 31 and are moved in parallel with respect to the glass sheet G, and thus, the shift between the position where the scattered light Ls detected by the defect detection section 33 is generated and the position where the scattered light Ls is captured by the microscope 35 can be suppressed.

[0067] In addition, according to the inspection method according to the present embodiment, when the defect D is inspected by the inspection device 100, the bottom surface Gb that becomes a carrying surface in the manufacturing process is disposed with the bottom surface Gb facing downward, and thus, the defect D of the bottom surface Gb generated at the time of manufacturing, at the time of carrying, and the like can be detected with high efficiency and high precision. Further, by inspecting the glass sheet G after chemical processing, the defect D such as a latent scratch that is difficult to confirm before the chemical processing can be detected with high precision.

[0068] Note that, in the above-described embodiment, a case where the inspection light Lx, Ly is made to be incident from the first side surface Gsx, which is one of the side surfaces along the Y direction, and the second side surface Gsy, which is one of the side surfaces along the X direction, of the glass sheet G is exemplified, but the inspection light can also be made to be incident from the first side surface Gsx and the opposite surface of the first side surface Gsx, and the second side surface Gsy and the opposite surface of the second side surface Gsy.

[0069] Thus, the present application is not limited to the above-described embodiments, and the present application also includes the cases where the structures of the embodiments are combined with each other, the cases where the structures of the embodiments are changed and applied by a person skilled in the art based on the description of the specification and publicly known technologies, and the like, and these cases are included in the scope to be claimed.

[0070] As described above, the following matters are disclosed in the present specification.

[0071] (1) An inspection device of a glass sheet that inspects a defect of a glass sheet formed in a rectangular shape, in which

[0072] The inspection device of the glass sheet includes:

[0073] a worktable on which the glass plate is placed;

[0074] a first illuminator configured to irradiate the glass plate placed on the worktable with inspection light from a first side surface of the glass plate;

[0075] a second illuminator configured to irradiate the glass plate placed on the worktable with inspection light from a second side surface of the glass plate adjacent to the first side surface; and

[0076] a defect detection section that detects scattered light generated by a defect of the glass plate.

[0077] According to the glass plate inspection apparatus, inspection light is irradiated from adjacent first and second side surfaces of a rectangular glass plate to detect defects, so defects such as fine scratches having directionality of light can be detected with high accuracy, as compared with an apparatus that irradiates light to two side surfaces substantially parallel to a conveyance direction of a glass plate conveyed on a production line to detect defects.

[0078] (2) The glass plate inspection apparatus according to (1), further comprising a camera section that captures a position of generation of the scattered light detected by the defect detection section.

[0079] According to the glass plate inspection apparatus, the position of generation of the detected scattered light is captured with high accuracy by the camera section, so the size, type, and the like of the defect of the glass plate can be accurately determined.

[0080] (3) The glass plate inspection apparatus according to (2), further comprising a moving mechanism configured to be able to move in parallel with respect to a main surface of the worktable, the defect detection section and the camera section being mounted on the moving mechanism.

[0081] According to the glass plate inspection apparatus, the defect detection section and the camera section are mounted on the same moving mechanism and move in parallel with respect to the glass plate, so the shift between the position of generation of the scattered light detected by the defect detection section and the position of the camera section at which the scattered light is captured can be suppressed.

[0082] (4) The glass plate inspection apparatus according to any one of (1) to (3), wherein at least one of the first illuminator and the second illuminator is configured to be able to rotate in a plane that is the same as a main surface of the glass plate placed on the worktable.

[0083] According to the glass plate inspection apparatus, by rotating the first illumination and / or the second illumination in the Z direction as an axis in the same plane as the main surface of the glass plate, i.e., the XY plane, the first illumination and the second illumination can be arranged in parallel with high accuracy with respect to the adjacent first side surface and the second side surface of the glass plate on the stage. Thus, the inspection light can be caused to be incident from the first side surface and the second side surface well, and the inspection accuracy can be improved.

[0084] (5) The glass plate inspection apparatus according to any one of (1) to (4), wherein at least one of the first illumination and the second illumination is configured to be able to be inclined with respect to the corresponding first side surface or second side surface of the glass plate placed on the stage.

[0085] According to the glass plate inspection apparatus, the first illumination can be inclined with respect to the first side surface with the Y direction as an axis to adjust the inclination of the first illumination, and / or the second illumination can be inclined with respect to the second side surface with the X direction as an axis to adjust the inclination of the second illumination. Thus, the inspection light incident from the first side surface and the second side surface can be accurately totally reflected inside the glass plate, and the inspection accuracy can be improved.

[0086] (6) The glass plate inspection apparatus according to any one of (1) to (5), wherein at least one of the first illumination and the second illumination is configured to be able to adjust an incident angle of the inspection light irradiated from the first illumination or the second illumination to the corresponding first side surface or second side surface of the glass plate.

[0087] According to the glass plate inspection apparatus, the incident angle of the inspection light irradiated from the first illumination to the first side surface and / or the incident angle of the inspection light irradiated from the second illumination to the second side surface can be adjusted. Thus, the inspection light incident from the first side surface and the second side surface can be accurately totally reflected inside the glass plate, and the inspection accuracy can be improved.

[0088] (7) A glass plate inspection method of inspecting a defect of a glass plate formed in a rectangular shape, in which

[0089] causing inspection light to be incident from a first side surface and a second side surface adjacent to the first side surface of the glass plate, respectively,

[0090] detecting scattered light generated by the defect of the glass plate.

[0091] According to the glass plate inspection method, the inspection light is caused to be incident from the adjacent first side surface and the second side surface of the glass plate to detect the defect, and thus even a defect such as a fine scratch having a light directivity can be detected with high accuracy, as compared with a case where the light is irradiated to both sides of the glass plate being carried on a production line, i.e., two side surfaces parallel with respect to the carrying direction, to detect the defect.

[0092] (8) The glass sheet inspection method according to (7), wherein the glass sheet is disposed with the lower surface of the glass sheet that becomes a handling surface in a manufacturing process facing downward, and the scattered light is detected from the upper surface side of the glass sheet.

[0093] According to the glass sheet inspection method, the defect of the lower surface of the glass sheet that is a handling surface at the time of manufacturing, at the time of handling, or the like can be detected efficiently and with high precision.

[0094] (9) The glass sheet inspection method according to (7) or (8), wherein the glass sheet after chemical treatment is inspected.

[0095] According to the glass sheet inspection method, the defect such as a latent damage that is difficult to confirm before chemical treatment can be detected with high precision.

[0096] This application is based on Japanese Patent Application No. 2024-090662 filed on June 4, 2024, and Japanese Patent Application No. 2025-087323 filed on May 26, 2025, the contents of which are incorporated herein by reference.

[0097] Mark Description

[0098] 13 first illumination;

[0099] 15 second illumination;

[0100] 23 stage;

[0101] 31 moving mechanism;

[0102] 33 defect detection section;

[0103] 35 microscope (imaging section);

[0104] 100 inspection device;

[0105] Ls scattered light;

[0106] Lx, Ly inspection light;

[0107] D defect;

[0108] G glass sheet;

[0109] Gsx first side surface;

[0110] Gsy second side surface;

[0111] bottom surface (lower surface);

[0112] Gt top surface (upper surface).

Claims

1. An apparatus for inspecting a glass sheet for defects, wherein the glass sheet has a rectangular shape, and wherein the apparatus for inspecting the glass sheet comprises: a stage on which the glass sheet is placed; a first illuminator configured to direct inspection light toward the glass sheet placed on the stage from a first side of the glass sheet; a second illuminator configured to direct inspection light toward the glass sheet placed on the stage from a second side of the glass sheet adjacent to the first side; and a defect detection unit configured to detect scattered light generated by defects of the glass sheet.

2. The apparatus for inspecting the glass sheet according to claim 1, wherein the apparatus for inspecting the glass sheet further comprises a camera configured to capture a position of the scattered light detected by the defect detection unit.

3. The apparatus for inspecting the glass sheet according to claim 2, wherein the apparatus for inspecting the glass sheet further comprises a moving mechanism configured to move in parallel with respect to a main surface of the stage, and wherein the defect detection unit and the camera are mounted on the moving mechanism.

4. The apparatus for inspecting the glass sheet according to claim 1, wherein at least one of the first illuminator and the second illuminator is configured to be rotatable in a plane parallel to a main surface of the glass sheet placed on the stage.

5. The apparatus for inspecting the glass sheet according to any one of claims 1 to 4, wherein at least one of the first illuminator and the second illuminator is configured to be tiltable with respect to a corresponding first side or second side of the glass sheet placed on the stage.

6. The apparatus for inspecting the glass sheet according to any one of claims 1 to 4, wherein at least one of the first illuminator and the second illuminator is configured to adjust an angle of incidence of the inspection light emitted from the first illuminator or the second illuminator with respect to a corresponding first side or second side of the glass sheet.

7. A method for inspecting a glass sheet for defects, wherein the glass sheet has a rectangular shape, and wherein the method comprises: directing inspection light toward the glass sheet from a first side and a second side adjacent to the first side of the glass sheet, respectively; and detecting scattered light generated by defects of the glass sheet.

8. The method for inspecting the glass sheet according to claim 7, wherein the glass sheet is arranged with a lower surface of the glass sheet, which becomes a conveying surface in a manufacturing process, facing downward, and the scattered light is detected from an upper surface side of the glass sheet.

9. The method for inspecting the glass sheet according to claim 7 or 8, wherein the glass sheet is inspected after a chemical treatment. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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