Glass plate inspection method, glass plate inspection device, and glass plate manufacturing method

Abstract

The invention provides a glass plate inspection method, an inspection device and a glass plate manufacturing method, which can inspect the shape of a glass plate with high precision. This glass plate inspection method inspects the shape of a glass plate (G) placed on a placement surface (5a) formed by a plurality of protrusions (5). The glass plate (G) includes a reference glass plate (G1) and a sampling glass plate (G2). A method for inspecting a glass plate (G) comprises: a measurement step (S63) for measuring the shape of a sample glass plate (G2); and an evaluation step (S64) for evaluating the shape of the sampling glass plate (G2) by comparing a reference shape specified by the reference glass plate (G1) with the measured value of the shape of the sampling glass plate (G2).

Description

Technical Field

[0001] The present invention relates to a glass plate inspection method and inspection device, and a glass plate manufacturing method. Background Art

[0002] In recent years, light and flexible thin-walled glass substrates are used in displays such as liquid crystal displays and organic EL displays. Thin film transistors (TFTs) are formed by uniformly coating various films on the surface of the glass substrate used for the display using an optical process (exposure process, development process, etc.).

[0003] In order to form a thin film transistor with high precision, a glass substrate is required to have high dimensional accuracy. Therefore, in the manufacturing process of a glass plate, a process of inspecting the shape of the manufactured glass plate is implemented.

[0004] As an apparatus used in such an inspection process, for example, Patent Document 1 discloses an inspection apparatus (glass plate measuring apparatus) having a stage on which a glass plate is placed and an optical measuring mechanism that utilizes irradiation and reflection of light for measurement. The stage in the inspection apparatus has a plurality of grooves extending in the transverse direction on its surface (see paragraph 0030 of the document).

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2021-148446 Summary of the invention

[0008] Problems to be solved by the invention

[0009] In conventional inspection devices, the surface of the stage is formed into an uneven shape by grooves. Therefore, when a thin glass plate is placed on the surface, the glass plate bends at the position of the grooves, making it impossible to perform high-precision inspection of the shape of the glass plate, such as warping.

[0010] The present invention has been made in view of the above circumstances, and a technical object of the present invention is to inspect the shape of a glass plate with high accuracy.

[0011] Solutions to Solve Problems

[0012] (1) The present invention is a glass plate inspection method for solving the above-mentioned problems, and the shape of a glass plate placed on a placing surface is inspected. The glass plate inspection method is characterized in that the placing surface is formed by a plurality of convex portions, and the glass plate includes a reference glass plate and a sampling glass plate. The glass plate inspection method includes: a measuring step of measuring the shape of the sampling glass plate; and an evaluation step of evaluating the shape of the sampling glass plate by comparing a reference shape determined by the reference glass plate with a measured value of the shape of the sampling glass plate.

[0013] According to this configuration, the shape of the sample glass plate measured in the measuring step is compared with the reference shape determined by the reference glass plate in the evaluation step, so that the shape of the sample glass plate can be inspected with high accuracy even when a plurality of recessed portions such as grooves are present on the mounting surface.

[0014] (2) In the glass plate inspection method described in (1) above, the glass plate inspection method may include: a preparation step of measuring the shapes of a plurality of the reference glass plates; and a calculation step of calculating the reference shape based on the measurement values ​​obtained in the preparation step.

[0015] According to this configuration, in the preparation step, the reference shape is calculated based on a plurality of reference glass plates, and thus the accuracy of the reference shape serving as a reference for evaluating the sample glass plate can be improved.

[0016] (3) In the glass sheet inspection method described in (2) above, in the calculation step, an average value of shapes of a plurality of reference glass sheets may be calculated as the reference shape.

[0017] According to this configuration, by using the average value of the shapes of the plurality of reference glass plates as the reference shape, it is possible to further improve the accuracy of the reference shape that serves as a reference for evaluating the sample glass plate.

[0018] (4) In the glass plate inspection method described in any one of (1) to (3) above, it may be that, in the preparation step, the shape of the upper surface of the reference glass plate is measured in a state where the reference glass plate is placed on the loading surface, and in the measurement step, the shape of the upper surface of the sampling glass plate is measured in a state where the sampling glass plate is placed on the loading surface.

[0019] (5) In the glass plate inspection method described in any one of (1) to (3) above, the convex portion may be formed by a long strip member, the loading surface may be formed by arranging the long strip members side by side at a specified interval, the width of the convex portion may be greater than 50 mm and less than 200 mm, and the interval between the convex portions may be greater than 50 mm and less than 200 mm.

[0020] (6) The method for manufacturing a glass plate of the present invention is a method for manufacturing a glass plate for solving the above-mentioned problems, and is characterized in that the method for manufacturing a glass plate uses the glass plate inspection method described in any one of (1) to (5) above to perform an inspection step.

[0021] (7) The present invention is a glass plate inspection device for solving the above-mentioned problems, comprising: a loading surface on which a glass plate is loaded; and a measuring unit which measures the shape of the glass plate loaded on the loading surface, wherein the glass plate inspection device is characterized in that the loading surface is composed of a plurality of convex portions, and the glass plate includes a reference glass plate and a sampling glass plate, and the glass plate inspection device comprises: a storage unit which stores a reference shape determined by the reference glass plate; and an evaluation unit which evaluates the shape of the sampling glass plate by comparing the shape of the sampling glass plate with the reference shape.

[0022] According to this configuration, the shape of the sample glass plate measured by the measuring unit is compared with the reference shape by the evaluating unit, so that the shape of the sample glass plate can be inspected with high accuracy even when a plurality of recessed portions such as grooves are present on the mounting surface.

[0023] Effects of the Invention

[0024] According to the present invention, the shape of a glass plate can be inspected with high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a perspective view of the inspection device.

[0026] Figure 2 It is a top view of the inspection device.

[0027] Figure 3 yes Figure 2 A cross-sectional view of the carrying portion taken along the line of sight III-III.

[0028] Figure 4 It is a side view showing the operation of the positioning unit of the inspection device.

[0029] Figure 5 This is a front view showing the operation of the positioning unit of the inspection device.

[0030] Figure 6 : is a block diagram showing the control unit of the inspection device.

[0031] Figure 7 1 is a flowchart showing a method for manufacturing a glass plate.

[0032] Figure 8 It is a flowchart which shows the inspection process.

[0033] Fig. 9 It is a front view showing the inspection process.

[0034] Fig.10 It is a top view showing the inspection process.

[0035] Fig.11 It is a front view showing the inspection process.

[0036] Fig.12 It is a front view showing the inspection process.

[0037] Fig.13 It is a top view showing the inspection process.

[0038] Fig.14 It is a front view showing the inspection process.

[0039] Fig.15 It is a front view showing the inspection process.

[0040] Fig.16 It is a top view showing the inspection process.

[0041] Description of Reference Numerals

[0042] 1. Inspection device

[0043] 3. Measurement Department

[0044] 4. Control Unit

[0045] 5 platforms (convex part)

[0046] 5a Upper surface of the platform (loading surface)

[0047] 17 Storage

[0048] 19 Evaluation Department

[0049] G1 reference glass plate

[0050] G2 Sampling Glass Plate

[0051] S6 Inspection Process

[0052] S61 Preparation process

[0053] S62 calculation process

[0054] S63 Measurement process

[0055] S64 Evaluation process

[0056] W platform width (convex width)

[0057] D: The distance between the terraces (the distance between the convex parts). DETAILED DESCRIPTION

[0058] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Figures 1 to 16 An embodiment of a glass plate inspection device and a glass plate manufacturing method using the inspection device of the present invention will be described.

[0059] like Figure 1 as well as Figure 2 As shown, the inspection device 1 includes: a placement section 2 for placing a glass plate G; a measuring section 3 for measuring the shape of the glass plate G placed on the placement section 2; and a control section 4 for controlling the placement section 2 and the measuring section 3.

[0060] The glass plate G to be inspected is, for example, a rectangular glass original plate (mother glass plate) from which one or more product glass plates are extracted. The thickness of the glass original plate and the product glass plate is, for example, 0.05 mm to 1.2 mm. The size of the glass original plate is, for example, 1000 mm × 1000 mm to 3500 mm × 3500 mm, and the size of the product glass plate is, for example, 700 mm × 700 mm to 3500 mm × 3500 mm. The product glass plate is used, for example, as a substrate or cover glass for a display. It should be noted that the substrate and cover glass of the display are not limited to flat panels, but can also be used in curved panels and foldable panels.

[0061] Hereinafter, one surface of the glass plate G is referred to as a first main surface Ga, and the other surface is referred to as a second main surface Gb. In addition, the sides of the glass plate G are referred to as a first side GS1, a second side GS2, a third side GS3, and a fourth side GS4.

[0062] The placement section 2 includes a plurality of stages 5 , a plurality of support members 6 provided between the stages 5 , positioning portions 7 a and 7 b for positioning the glass sheet G, and a guide member 8 for guiding the glass sheet G to the stages 5 .

[0063] The platform 5 is a long strip-shaped member, and is arranged so that its length direction is along the carrying-in direction A1 and the carrying-out direction A2 of the glass plate G. The platform 5 is made of a metal such as an aluminum alloy. The upper surface 5a of the platform 5 functions as a mounting surface for the glass plate G. The upper surface 5a of the platform 5 has a plurality of ejection holes 5b for ejecting gas.

[0064] The plurality of platforms 5 are arranged at predetermined intervals in the width direction X orthogonal to the longitudinal direction Y. With this arrangement, a groove 9 is formed between two adjacent platforms 5. The placement portion 2 is configured by alternately arranging the platforms 5 and the grooves 9. In other words, the placement portion 2 is configured by alternately arranging the convex portions formed by the platforms 5 and the concave portions formed by the grooves 9.

[0065] The width W (width of the upper surface 5a) of the platform 5 as a convex portion is preferably greater than 50 mm and less than 200 mm. The lower limit of the width W is more preferably greater than 80 mm, and more preferably greater than 100 mm. The upper limit of the width W is more preferably less than 180 mm, and more preferably less than 150 mm. The interval D of the platform 5 in the width direction X, that is, the width of the groove 9, is preferably greater than 50 mm and less than 200 mm. The lower limit of the interval D is more preferably greater than 70 mm, and more preferably greater than 80 mm. The upper limit of the interval D is more preferably less than 180 mm, and more preferably less than 150 mm.

[0066] The upper surfaces 5a of the plurality of platforms 5 arranged at regular intervals constitute a rectangular placement surface for placing the glass plate G. Figure 1 as well as Figure 2 As shown, the placement surface has a first corner portion 10a, a second corner portion 10b, a third corner portion 10c, and a fourth corner portion 10d.

[0067] like Figure 3 As shown, the placement surface is configured as an inclined surface that gradually inclines downward along its diagonal direction, that is, from the third corner 10c toward the first corner 10a. The angle θ formed by the placement surface with respect to the horizontal direction (horizontal line H) is preferably 0.1° or more and 5° or less.

[0068] The support member 6 is disposed between the adjacent platforms 5 in the width direction X. In other words, the support member 6 is provided within the range of the groove portion 9 in the mounting portion 2. The plurality of support members 6 are disposed at predetermined intervals in the longitudinal direction Y of the platform 5.

[0069] The supporting member 6 is configured to be movable in the up-down direction. Specifically, the supporting member 6 is configured to be movable to a standby position, in which the supporting member 6 is below the upper surface 5a of the platform 5, and a supporting position, in which the supporting member 6 supports the glass plate G at a position above the upper surface 5a of the platform 5.

[0070] The positioning parts 7a and 7b include a first positioning part 7a and a second positioning part 7b. The first positioning part 7a contacts the first side GS1 of the glass plate G placed on the placement part 2 to position the first side GS1, and the second positioning part 7b contacts the second side GS2 of the glass plate G placed on the placement part 2 to position the second side GS2.

[0071] Each positioning portion 7a, 7b is configured to be movable in the vertical direction and the horizontal direction. Figure 4As shown, the first positioning portion 7a is configured to be able to move up and down to a standby position (a position indicated by a solid line) and a retreat position (a position indicated by a single dot-dash line), in which the first positioning portion 7a is below the upper surface 5a of the platform 5 at the standby position, and the retreat position is above the standby position and in which the first positioning portion 7a is separated from the first side GS1 of the glass plate G in the horizontal direction. Moreover, the first positioning portion 7a is configured to be able to move horizontally to the retreat position and the positioning position (a position indicated by a double dot-dash line) in contact with the first side GS1 of the glass plate G.

[0072] like Figure 5 As shown, the second positioning portion 7b is configured to be able to move up and down to a standby position (a position indicated by a solid line) and a retreat position (a position indicated by a single dot-dash line), in which the second positioning portion 7b is below the upper surface 5a of the platform 5 at the standby position, and the retreat position is above the standby position and in which the second positioning portion 7b is separated from the second side GS2 of the glass plate G in the horizontal direction. Moreover, the second positioning portion 7b is configured to be able to move horizontally to the retreat position and the positioning position (a position indicated by a double dot-dash line) in contact with the second side GS2 of the glass plate G.

[0073] The guide member 8 is provided at a position separated from the end of the stage 5 in the longitudinal direction Y. In the present embodiment, the guide member 8 is composed of, for example, a guide roller in contact with the second main surface Gb as the lower surface of the glass plate G. The structure of the guide member 8 is not limited to the present embodiment.

[0074] like Figure 1 as well as Figure 2 As shown, the measurement unit 3 includes a sensor unit 11 and driving units 12 a and 12 b for moving the sensor unit 11 .

[0075] The sensor unit 11 is composed of, for example, a laser displacement meter, but the structure of the sensor unit 11 is not limited to this embodiment. The sensor unit 11 is preferably composed of a non-contact displacement meter such as a laser displacement meter or an ultrasonic displacement meter.

[0076] The driving parts 12a and 12b include a first driving part 12a supporting the sensor part 11 and a second driving part 12b supporting the first driving part 12a. The first driving part 12a includes a first strip-shaped supporting part 13 extending along the width direction X and a second supporting part 14 supporting an end of the first supporting part 13. The first supporting part 13 is configured to reciprocate the sensor part 11 along the width direction X. The second supporting part 14 is a strip-shaped member (leg) extending in the up-down direction.

[0077] The second driving unit 12b is configured as a pair of supporting platforms that support the second supporting unit 14 of the first driving unit 12a in a movable manner. The second driving unit 12b is configured as a strip-shaped member extending along the carrying-in and carrying-out directions A1 and A2 of the glass sheet G. The second driving unit 12 is arranged outside the mounting unit 2 in the width direction X in a manner parallel to the platform 5.

[0078] The second drive unit 12b includes a guide rail 15 for guiding the second support portion 14 of the first drive unit 12a. With this configuration, the second drive unit 12b can reciprocate the first drive unit 12a along the longitudinal direction Y of the stage 5 or the carrying-in and carrying-out directions A1 and A2.

[0079] The control unit 4 is composed of a computer that controls the placement unit 2 and the measuring unit 3 and performs various calculations. The control unit 4 performs control related to the gas ejection operation performed by the ejection hole 5b of the stage 5 in the placement unit 2, the operation of the support member 6 in the placement unit 2, the operation of the sensor unit 11 and the drive units 12a and 12b in the measuring unit 3, and calculations related to the data measured by the measuring unit 3.

[0080] like Figure 6 As shown, the control unit 4 mainly includes a calculation processing unit 16 , a storage unit 17 , and a communication control unit 18 .

[0081] The calculation processing unit 16 can obtain, by calculation processing, a numerical value related to the "reference shape" required for inspecting the glass sheet G. The calculation processing unit 16 includes an evaluation unit 19 that determines the quality of the glass sheet G to be inspected based on the reference shape.

[0082] The storage unit 17 can store various data and programs required for inspecting the glass plate G, measurement values ​​of the glass plate G, and various information such as determination results determined by the evaluation unit 19 of the calculation processing unit 16. The communication control unit 18 can perform signal transmission and reception with the placement unit 2 and the measurement unit 3.

[0083] Hereinafter, a method of inspecting the glass sheet G and a method of manufacturing the glass sheet G using the inspection device 1 having the above-mentioned configuration will be described.

[0084] like Figure 7 As shown, the method for manufacturing the glass sheet G includes a forming step S1 , an annealing step S2 , a cooling step S3 , a first cutting step S4 , a second cutting step S5 , and an inspection step S6 .

[0085] In the forming step S1, a glass ribbon is continuously formed from molten glass using a forming device. The forming device has a forming body capable of performing an overflow down-draw method. The forming body allows molten glass to overflow from an overflow trough formed on the upper portion thereof and flow down along the side wall surfaces on both sides of the forming body. Moreover, the forming body allows the molten glass flowing down to fuse at the lower end of each side wall surface. Thus, a glass ribbon having a predetermined width is formed. It should be noted that the forming body may also perform other down-draw methods such as a slit down-draw method.

[0086] The annealing process S2 is performed in an annealing furnace arranged below the forming device. In the annealing process S2, the glass ribbon is conveyed downward by rollers arranged in the annealing furnace. A predetermined temperature gradient is set in the annealing furnace, and the glass ribbon is annealed by passing through the annealing furnace. In the cooling process S3 after the annealing process S2, the glass ribbon is cooled to near room temperature while passing through a cooling area arranged below the annealing furnace.

[0087] In the first cutting step S4, the middle portion of the glass ribbon is cut along the width direction by a first cutting device disposed below the cooling zone, thereby cutting out a glass sheet G of a predetermined size. That is, in the first cutting step S4, a scoring line along the width direction is formed at the middle portion of the glass ribbon moving downward by a scoring device (scoring step), and a portion of the glass ribbon is broken along the scoring line to form a single glass sheet G (breaking step).

[0088] The second cutting step S5 is a step of removing the end portion (unnecessary portion) in the width direction of the glass sheet G cut out in the first cutting step S4. The second cutting step S5 is similar to the first cutting step S4, in which a scoring line is formed on a portion of the glass sheet G (scoring step), and then the end portion of the glass sheet G is broken by a breaking device (breaking step).

[0089] In the inspection step S6 , the shape of the glass sheet G is measured by the inspection device 1 , and the quality of the glass sheet G is determined based on the measured value.

[0090] like Figure 8 As shown, the inspection step S6 includes a preparation step S61 , a calculation step S62 , a measurement step S63 , and an evaluation step S64 .

[0091] In the preparation step S61, first, a plurality of glass plates (hereinafter referred to as "reference glass plates") G1 that serve as a reference for inspection are selected from the glass plate G formed through the second cutting step S5. The reference glass plate can be composed of, for example, 3 to 10 qualified glass plates. Thereafter, the shape of the reference glass plate G1 is measured using the inspection device 1, thereby obtaining data related to the "reference shape" used in the evaluation step S64. The specific implementation of the preparation step S61 is described below.

[0092] like Figure 1 as well as Figure 2 As shown, in the preparation process S61, the reference glass plate G1 is carried into the loading section 2. In this carrying-in process, the first principal surface Ga of the reference glass plate G1 is set as the upper surface, and the second principal surface Gb is set as the lower surface. The reference glass plate G1 is sent to the stage 5 along the carrying-in direction A1 in a state where the second principal surface Gb contacts the guide member 8. At this time, the guide member 8 guides the second principal surface Gb of the reference glass plate G1 along the carrying-in direction A1 while rotating. In addition, in the carrying-in process, the gas is ejected from the ejection hole 5b under the control of the control unit 4. In this way, the contact between the reference glass plate G1 and the stage 5 can be avoided, and the damage of the reference glass plate G1 in the carrying-in process can be prevented. During the period when the reference glass plate G1 is carried into the loading section 2, the positioning parts 7a and 7b are located in the standby position, so they do not contact the reference glass plate G1.

[0093] like Figure 4 as well as Figure 5 As shown, when the reference glass plate G1 is carried into the placement section 2, the positioning sections 7a and 7b move from the standby position to the retracted position, and then move from the retracted position to the contact position.

[0094] After that, the platform 5 stops the ejection of gas. As a result, the reference glass plate G1 contacts the upper surface 5a of the platform 5. At this time, the upper surface 5a of the platform 5 guides the reference glass plate G1 along the direction of its inclination, that is, along the direction from the third corner portion 10c of the mounting surface toward the first corner portion 10a. As a result, the first side GS1 of the reference glass plate G1 contacts the first positioning portion 7a located at the contact position. In addition, the second side GS2 of the reference glass plate G1 contacts the second positioning portion 7b located at the contact position. Through the above, the reference glass plate G1 is positioned at the reference measurement position that can be measured by the measurement unit 3.

[0095] Next, the measuring unit 3 measures the shape of the reference glass plate G1 placed on the placing unit 2 under the control of the control unit 4. Specifically, the measuring unit 3 measures the warping amount of the reference glass plate G1 placed on the placing surface (the upper surface 5a of the platform 5) (hereinafter referred to as the "first warping amount") and the warping amount of the reference glass plate G1 when the reference glass plate G1 is floated from the placing surface (hereinafter referred to as the "second warping amount").

[0096] like Fig. 9As shown, the sensor unit 11 measures the first warpage amount of the reference glass plate G1 while moving along the width direction X. That is, the sensor unit 11 irradiates the first principal surface Ga of the reference glass plate G1 with the laser light L while moving along the width direction X above the groove portion 9, and receives the laser light L reflected from the first principal surface Ga, thereby measuring the distance (first warpage amount) from the sensor unit 11 to the first principal surface Ga of the reference glass plate G1.

[0097] In the preparation step S61, the sensor unit 11 measures the first warpage amount for the plurality of reference glass plates G1. Fig.10 As shown, a plurality of measuring points MP (measuring areas) are set on each reference glass plate G1, and the distance between the sensor unit 11 and the first main surface Ga of the reference glass plate G1 is measured at each measuring point MP. The spacing between each measuring point MP is set to, for example, not less than 10 mm and not more than 200 mm. It should be noted that each measuring point MP can be set at an equal spacing, or can be set at different spacings according to the position or direction on the reference glass plate G1. In the present embodiment, the measuring points MP are set at an equal spacing in the width direction X and the length direction Y of the platform 5, and include positions corresponding to the convex portion (platform 5) and positions corresponding to the concave portion (groove portion 9).

[0098] The sensor unit 11 is Fig.10 As shown by arrow B1, the sensor unit 11 moves along the width direction X relative to the reference glass plate G1 placed on the placement unit 2, and measures the first warpage amount at each measurement point MP. After completing the measurement of the measurement points MP of one row along the width direction X, the sensor unit 11 moves along the longitudinal direction Y of the stage 5, and measures the next row along the width direction X. By repeating the above sequence, the first warpage amount is measured for all the measurement points MP of the reference glass plate G1. The sensor unit 11 transmits the obtained measurement data related to the first warpage amount to the communication control unit 18 of the control unit 4.

[0099] When measuring the second warpage amount, the placing unit 2 is controlled by the control unit 4 to eject gas from the ejection hole 5b of the stage 5. Fig.11 As shown, the reference glass plate G1 supported on the upper surface 5a of the platform 5 floats from the upper surface 5a. The sensor unit 11 measures the shape of the first main surface Ga of the reference glass plate G1 while moving along the width direction X in a state where the reference glass plate G1 floats from the platform 5. That is, the sensor unit 11 irradiates the laser light L to the first main surface Ga of the reference glass plate G1 while moving, and receives the laser light L reflected from the first main surface Ga, thereby measuring the distance (second warpage amount) from the sensor unit 11 to the first main surface Ga of the reference glass plate G1.

[0100] The second warp amount is measured for the plurality of reference glass plates G1 in the same manner as the first warp amount. In addition, the second warp amount is measured for each measurement point MP set for each reference glass plate G1.

[0101] The sensor unit 11 performs the second warpage measurement similarly to the first warpage measurement while repeatedly reciprocating in the width direction X relative to the reference glass plate G1 placed on the placement unit 2 (see FIG. 1 ). Fig.10 ). The sensor unit 11 transmits the measurement data related to the second warpage amount to the communication control unit 18 of the control unit 4. After the preparation step S61 is completed, the used reference glass plate G1 is discarded.

[0102] The calculation step S62 is a step of calculating a reference shape based on the measurement value of the reference glass plate G1 obtained in the preparation step S61.

[0103] The calculation processing unit 16 of the control unit 4 calculates the average value of the measurement data sent from the measurement unit 3. That is, the calculation processing unit 16 calculates the average value for each measurement point of the first warpage amount (the distance between the sensor unit 11 and the first main surface Ga of the reference glass plate G1) of the plurality of reference glass plates G1. In addition, the calculation processing unit 16 calculates the average value for each measurement point MP of the second warpage amount of the plurality of reference glass plates G1. The calculated average value becomes a reference value for judging the quality of the sample glass plate G2 in the subsequent evaluation step S64.

[0104] The calculation processing unit 16 creates a "reference shape" based on the average value of the measurement data calculated at each measurement point. Here, the "reference shape" means a set of reference values ​​(average values) calculated at each measurement point of the reference glass plate G1. Fig.10 The reference value (average value) calculated in the preparation step S61 is set at the plurality of measurement points MP set for the reference glass plate G1 as shown. The control unit 4 records the data related to the reference shape in the storage unit 17 .

[0105] In the measuring step S63, the shape of the sample glass plate G2 selected from the glass plate G formed through the second cutting step S5 is measured. The sample glass plate G2 may be selected, for example, at a predetermined time interval or at a predetermined number of sheets. The predetermined time interval and the predetermined number of sheets are appropriately selected according to the manufacturing conditions and inspection results of the glass plate G. In the measuring step S63, the sample glass plate G2 is placed on the upper surface 5a of the platform 5 of the placement unit 2 in the same manner as when the reference glass plate G1 is measured.

[0106] Then, the measurement unit 3 of the inspection device 1 performs measurement on each measurement point MP set on the first main surface Ga of the sample glass plate G2. The measurement point MP set on the sample glass plate G2 is set at the same position as the measurement point MP set on the reference glass plate G1.

[0107] In the measurement step S63 , in addition to measuring the shape of the sample glass plate G2 , that is, the first warpage amount and the second warpage amount at each measurement point MP of the sample glass plate G2 , the deflection difference and the plate thickness of the sample glass plate G2 are also measured.

[0108] When measuring the deflection difference of the sample glass plate G2 in the measuring step S63, the sample glass plate G2 is supported by the supporting member 6. Fig.12 As shown in FIG. 1 , the support member 6 moves from the standby position to the support position, and a portion of the sampling glass plate G2 is lifted. When the support member 6 is at the support position, the upper end of the support member 6 is located above the upper surface 5a of the platform 5. The sampling glass plate G2 supported by the support member 6 is separated from the upper surface 5a of the platform 5.

[0109] like Fig.12 As shown, the sensor unit 11 irradiates the laser L to the first principal surface Ga serving as the upper surface of the sampling glass plate G2 while moving along the width direction X, and receives the laser L reflected from the first principal surface Ga, thereby measuring the distance from the sensor unit 11 to the first principal surface Ga of the sampling glass plate G2.

[0110] like Fig.13 As shown, the sensor unit 11 moves along the path indicated by arrow B2 so as to pass directly above the support member 6 while repeatedly reciprocating along the width direction X. Thus, the distance between the sensor unit 11 and the first main surface Ga of the sampling glass plate G2 between two support members 6 adjacent to each other in the width direction X is measured.

[0111] Thereafter, the sample glass plate G2 is unloaded from the mounting section 2, turned upside down, and re-loaded into the mounting section 2. Thus, the sample glass plate G2 is mounted on the mounting surface of the mounting section 2 with the second principal surface Gb being the upper surface and the first principal surface Ga being the lower surface.

[0112] After that, the sampling glass plate G2 is supported again by the support member 6, and the distance between the sensor unit 11 and the second main surface Gb of the sampling glass plate G2 is measured by the sensor unit 11. The sensor unit 11 transmits the measured data to the communication control unit 18 of the control unit 4.

[0113] Fig.14 as well as Fig.15is a conceptual diagram for explaining the method for calculating the deflection difference of this embodiment. In this method, Fig.14 As shown in FIG. 1 , the first deflection d1 of the sample glass plate G2 is measured when the sample glass plate G2 is supported by the support member 6 with the first main surface Ga facing upward. Fig.15 As shown, the second deflection d2 of the sample glass plate G2 is measured when the second main surface Gb is facing upward and supported by the support member 6. Then, the difference (|d1-d2|) between the first deflection d1 and the second deflection d2 is calculated and evaluated as "deflection difference".

[0114] The processing unit 16 of the control unit 4 detects the deflection (d1, d2) of the sample glass plate G2 at the middle position between two supporting members 6 adjacent to each other in the width direction X based on the measurement data sent from the sensor unit 11, and calculates the deflection difference. The control unit 4 records the data related to the deflection difference calculated by the processing unit 16 in the storage unit 17.

[0115] When measuring the thickness of the sample glass plate G2 in the measuring step S63, the sensor unit 11 of the measuring unit 3 irradiates the sample glass plate G2 with the laser light L within the range of the groove 9 so as not to overlap with the support member 6. Fig.16 As shown, the sensor unit 11 measures the plate thickness of the sample glass plate G2 while reciprocating along the longitudinal direction Y of the stage 5 and along the path indicated by the arrow B3.

[0116] The sensor unit 11 of the measuring unit 3 can irradiate the first main surface Ga as the upper surface and the second main surface Gb as the lower surface of the sample glass plate G2 with laser light L, receive the reflected laser light L, and measure the plate thickness based on the difference in optical path length. Specifically, when the plate thickness of the sample glass plate G2 is d [mm], the optical path length difference is L [mm], and the refractive index of the sample glass plate G2 is n, the plate thickness can be measured based on d = L / 2n. The sensor unit 11 sends the measurement data related to the plate thickness to the communication control unit 18 of the control unit 4. After the measurement step S63 is completed, the used sample glass plate G2 is discarded.

[0117] In the evaluation step S64 , the evaluation unit 19 of the calculation processing unit 16 determines whether the shape of the sample glass plate G2 measured in the measurement step S63 is good or bad.

[0118] Specifically, the evaluation unit 19 compares the measured value of the first warpage amount at each measurement point MP of the sampled glass sheet G2 in the measurement step S63 with the reference value (reference shape) set for each measurement point MP in the preparation step S61 .

[0119] That is, the evaluation unit 19 calculates the difference between the measured value of the first warpage amount at each measurement point MP of the sample glass plate G2 and the reference value of the first warpage amount set for each measurement point MP of the reference shape. Next, the evaluation unit 19 determines whether the difference is within the range of the threshold value of the first warpage amount stored in the storage unit 17.

[0120] The evaluation unit 19 determines the sample glass plate G2 as “good” when the difference in the first warp amount is within the threshold range. The evaluation unit 19 determines the sample glass plate G2 as “bad” when the difference in the first warp amount exceeds the threshold range.

[0121] In the evaluation step S64 , the evaluation unit 19 of the calculation processing unit 16 compares the measured value of the second warpage amount of the sample glass plate G2 measured in the measurement step S63 with the reference shape and determines whether the measured value is good or bad, similarly to the determination of the first warpage amount.

[0122] In the evaluation step S64, the evaluation unit 19 of the calculation processing unit 16 also determines the quality of the measured values ​​of the deflection difference and the plate thickness of the sample glass plate G2 measured in the measurement step S63. The storage unit 17 of the control unit 4 stores threshold values ​​related to the deflection difference and the plate thickness. The evaluation unit 19 determines whether the measured values ​​of the deflection difference and the plate thickness of the sample glass plate G2 are within the range of the threshold value. When the measured values ​​of the deflection difference and the plate thickness are within the range of the threshold value, the evaluation unit 19 determines that the sample glass plate G2 is "good". When the measured values ​​of the deflection difference and the plate thickness exceed the range of the threshold value, the evaluation unit 19 determines that the sample glass plate G2 is "bad".

[0123] In the evaluation step S64, when the sampled glass sheet G2 is found to be defective, this information is transmitted to the forming step S1 or the annealing step S2. In the forming step S1 or the annealing step S2, the forming conditions or the annealing conditions are corrected to eliminate the shape defect of the glass ribbon.

[0124] In addition, when the sample glass plate G2 is determined to be defective, the glass plates G produced between when the sample glass plate G2 is last determined to be good and when it is again determined to be good are discarded.

[0125] According to the inspection device 1 and the manufacturing method of the glass plate G of the present embodiment described above, the shape of the sampled glass plate G2 is measured using the measuring step S63 of the inspection step S6 (inspection method), and the measurement result is compared with the reference shape in the evaluation step S64. Thus, even when there are multiple recessed portions (groove portions 9) on the loading surface of the loading portion 2, the shape of the sampled glass plate G2 can be inspected with high precision.

[0126] It should be noted that the present invention is not limited to the configuration of the above-described embodiment, nor is it limited to the above-described effects. The present invention can be modified in various ways without departing from the gist of the present invention.

[0127] In the above-mentioned embodiment, the loading surface is inclined at an angle θ relative to the horizontal direction, but the present invention is not limited thereto. It is also possible to configure the loading surface to be able to switch between an inclined state and a state in which the loading surface is aligned with the horizontal plane. In addition, it is also possible that the loading surface is fixed to be aligned with the horizontal plane, so that the first side GS1 and the second side GS2 of the reference glass plate G1 or the sampling glass plate G2 are in contact with the positioning parts 7a and 7b, and the sampling glass plate G2 is moved to perform positioning.

[0128] In the above-mentioned embodiment, when preparing the reference shape, the average value of a plurality of measurement data is calculated for each measurement point, but the present invention is not limited thereto and may be performed by calculating the median of a plurality of measurement data or calculating the average value after excluding the maximum value and the minimum value from a plurality of measurement data.

[0129] In the above-mentioned embodiment, the plurality of protrusions are formed by the long strip-shaped platform 5, but the present invention is not limited thereto. Alternatively, the protrusions may be formed by a grid-shaped platform, and the recesses may be formed by the holes between the grids. Alternatively, the recesses may be formed in a grid-shaped manner, and the platforms may be arranged between the grids.

Claims

1. A method for inspecting a glass plate, comprising inspecting the shape of a glass plate placed on a placement surface, The glass plate inspection method is characterized in that: The mounting surface is formed by a plurality of convex portions, The glass plates include a reference glass plate and a sampling glass plate. The glass plate inspection method comprises: a measuring step of measuring the shape of the sampling glass plate; and an evaluation step of evaluating the shape of the sample glass plate by comparing a reference shape determined by the reference glass plate with a measured value of the shape of the sample glass plate.

2. The glass plate inspection method according to claim 1, characterized in that: The glass plate inspection method includes: a preparation step of measuring shapes of a plurality of reference glass plates; and a calculation step of calculating the reference shape based on the measurement values ​​obtained in the preparation step.

3. The glass plate inspection method according to claim 2, characterized in that: In the calculation step, an average value of shapes of a plurality of reference glass plates is calculated as the reference shape.

4. The glass plate inspection method according to claim 2 or 3, characterized in that: In the preparation step, the shape of the upper surface of the reference glass plate is measured in a state where the reference glass plate is placed on the placement surface. In the measuring step, the shape of the upper surface of the sampling glass plate is measured in a state where the sampling glass plate is placed on the placement surface.

5. The method for inspecting a glass sheet according to any one of claims 1 to 3, characterized in that: The convex portion is formed by a long strip member. The mounting surface is formed by arranging the elongated members side by side at a predetermined interval. The width of the convex portion is not less than 50 mm and not more than 200 mm, The interval between the convex portions is greater than or equal to 50 mm and less than or equal to 200 mm.

6. A method for manufacturing a glass plate, characterized in that: The method for manufacturing the glass plate uses the glass plate inspection method according to any one of claims 1 to 3 to perform an inspection step.

7. A glass plate inspection device comprising: a placement surface on which a glass plate is placed; and a measuring unit for measuring a shape of the glass plate placed on the placement surface. The glass plate inspection device is characterized in that: The mounting surface is composed of a plurality of convex portions. The glass plates include a reference glass plate and a sampling glass plate. The glass plate inspection device includes: a storage unit that stores a reference shape determined by the reference glass plate; and an evaluation unit that evaluates the shape of the sample glass plate by comparing the shape of the sample glass plate with the reference shape.

Images