Plate thickness measuring method, shape and plate thickness measuring method, plate thickness measuring apparatus, and shape and plate thickness measuring apparatus

Abstract

To provide a plate thickness measuring method, a shape and plate thickness measuring method, a plate thickness measuring device, and a shape and plate thickness measuring device having high measurement accuracy.SOLUTION: The plate thickness measurement method includes capturing, by an imaging unit, a reflection image of structured illumination by a light transmissive plate-shaped body including a first surface and a second surface opposite to the first surface, and acquiring, by a processing unit, information on inclinations of the first surface and the second surface and information on a plate thickness of the light transmissive plate-shaped body in which an influence of the inclinations of the first surface and the second surface is reduced, based on the reflection image, and outputting the information on the plate thickness.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a plate thickness measurement method, a shape and plate thickness measurement method, a plate thickness measurement device, and a shape and plate thickness measurement device. [Background technology]

[0002] For example, Patent Document 1 discloses a method for measuring thickness distribution using a displacement sensor that measures the thickness by irradiating light from one side of a light-transmitting plate such as a transparent substrate and detecting the reflection positions on the front and back sides. In this method, at least three sensors are arranged around the displacement sensor, and the sensors measure the positional relationship between the displacement sensor and the light-transmitting plate, and the thickness distribution of the light-transmitting plate is measured while constantly controlling the position and attitude of the displacement sensor relative to the light-transmitting plate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-154021 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the method of Patent Document 1, if the positional relationship between the displacement sensor and the at least three sensors deviates from a predetermined positional relationship, the measurement accuracy may decrease.

[0005] One aspect of the present disclosure aims to provide a plate thickness measurement method, a shape and plate thickness measurement method, a plate thickness measurement device, and a shape and plate thickness measurement device with high measurement accuracy. [Means for solving the problem]

[0006] A plate thickness measurement method according to one embodiment of the present disclosure includes using an imaging unit to capture a reflected image of structured illumination by a translucent plate-like body including a first surface and a second surface opposite the first surface, and using a processing unit to obtain information regarding the tilt of the first surface and the second surface, as well as information regarding the plate thickness of the translucent plate-like body with the effect of the tilt of the first surface and the second surface reduced, based on the reflected image, and outputting the information regarding the plate thickness.

[0007] A shape and thickness measurement method according to one embodiment of the present disclosure includes using an imaging unit to capture a reflected image of structured illumination by a translucent plate-like body including a first surface and a second surface opposite the first surface, and outputting information regarding the shapes of the first surface and the second surface, as well as information regarding the thickness of the translucent plate-like body, obtained based on the reflected image, by a processing unit.

[0008] A plate thickness measuring device according to one embodiment of the present disclosure includes an imaging unit that captures a reflected image of structured illumination by a translucent plate-like body including a first surface and a second surface opposite the first surface, and a processing unit that acquires, based on the reflected image, information regarding the tilt of the first surface and the second surface, as well as information regarding the plate thickness with the influence of the tilt of the first surface and the second surface reduced, and outputs information regarding the plate thickness of the translucent plate-like body.

[0009] A shape and thickness measuring device according to one embodiment of the present disclosure includes an imaging unit that captures a reflected image of structured illumination by a translucent plate-like body including a first surface and a second surface opposite the first surface, and a processing unit that outputs information regarding the shapes of the first surface and the second surface, and information regarding the thickness of the translucent plate-like body, obtained based on the reflected image. [Effects of the Invention]

[0010] According to one aspect of the present disclosure, it is possible to provide a plate thickness measurement method, a shape and plate thickness measurement method, a plate thickness measurement device, and a shape and plate thickness measurement device with high measurement accuracy. [Brief explanation of the drawings]

[0011] [Figure 1]1 is a schematic diagram showing the overall configuration of a plate thickness measuring device according to a first embodiment. [Figure 2] 3A and 3B are diagrams showing an example of structured illumination in the plate thickness measuring device according to the first embodiment. [Figure 3] 2 is a block diagram showing the hardware configuration of a processing unit included in the plate thickness measuring device according to the first embodiment. FIG. [Figure 4] 3 is a block diagram showing the functional configuration of a processing unit included in the plate thickness measuring device according to the first embodiment. FIG. [Figure 5] 4 is a flowchart showing an example of the operation of the plate thickness measuring device according to the first embodiment. [Figure 6] 3 is a diagram showing an image captured by an imaging unit included in the plate thickness measuring device according to the first embodiment. FIG. [Figure 7] 10 is a diagram showing an example of a one-dimensional gradation value distribution of a captured image corresponding to a second direction. FIG. [Figure 8] 10A and 10B are diagrams illustrating changes in one-dimensional gradation value distribution of a captured image according to the inclination of the surface of a light-transmitting plate. [Figure 9A] FIG. 10 is a diagram illustrating a method for calculating plate thickness by ray tracing. [Figure 9B] FIG. 10 is a diagram showing an example of an incorrect plate thickness in a plate thickness calculation method using ray tracing. [Figure 10A] FIG. 1 is a first diagram illustrating the influence of a surface inclination in a plate thickness calculation method using ray tracing. [Figure 10B] FIG. 2 is a second diagram illustrating the influence of the inclination of the surface in the plate thickness calculation method by ray tracing. [Figure 11] FIG. 10 is a block diagram showing the functional configuration of a processing unit included in the shape and plate thickness measuring device according to the second embodiment. [Figure 12] 10 is a flowchart showing an example of the operation of the shape and plate thickness measuring device according to the second embodiment. [Figure 13] FIG. 10 is a schematic diagram showing the configuration of a plate thickness measuring device according to a modified example. [Figure 14] FIG. 10 is a block diagram showing the functional configuration of a processing unit included in a plate thickness measuring device according to a modified example. [Figure 15]10 is a flowchart showing an example of the operation of a plate thickness measuring device according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments for carrying out the present disclosure will be described in detail with reference to the drawings. However, the embodiments shown below exemplify a plate thickness measurement method, a plate shape and plate thickness measurement method, a plate thickness measurement device, and a shape and plate thickness measurement device for embodying the technical ideas of the embodiments of the present disclosure, and are not limited to the following. Note that the size, positional relationship, etc. of components shown in each drawing may be exaggerated for clarity. In each drawing, the same components are assigned the same reference numerals, and duplicate explanations will be omitted as appropriate.

[0013] In the drawings shown below, directions are represented using a Cartesian coordinate system having X, Y, and Z axes. The first direction X along the X axis corresponds to the extension direction of the linear patterns constituting the stripe pattern included in the structured lighting. The second direction Y along the Y axis corresponds to the direction perpendicular to the first direction X. The third direction Z corresponds to the direction perpendicular to both the first direction X and the second direction Y. However, the above directional expressions merely describe the relationship between relative positions, orientations, directions, etc., and do not necessarily correspond to the relationship during use. "Placing" is not limited to direct contact, but also includes indirect placement, for example, via another member.

[0014] [First embodiment] <Overall configuration of plate thickness measuring device according to first embodiment> The overall configuration of a plate thickness measuring device according to a first embodiment of the present disclosure will be described with reference to Figures 1 and 2. Figure 1 is a schematic diagram showing the overall configuration of a plate thickness measuring device 100 according to a first embodiment of the present disclosure. Figure 2 is a diagram showing an example of structured illumination 1 in the plate thickness measuring device 100.

[0015] The thickness measuring device 100 is a device for measuring the thickness of a light-transmitting plate 3. The light-transmitting plate 3 includes a first surface 3a and a second surface 3b opposite to the first surface 3a. The thickness is the distance in the Z direction between the first surface 3a and the second surface 3b. When the light-transmitting plate 3 has a two-dimensional thickness distribution in the first direction X and the second direction Y, the thickness measuring device 100 measures the two-dimensional thickness distribution. Visible light means light with a wavelength of 360 nm or more and 830 nm or less. The light-transmitting plate 3 may have holes, recesses, etc. in some parts.

[0016] 1, the plate thickness measuring device 100 has an imaging unit 2 that captures an image of structured illumination 1 reflected by a light-transmitting plate 3. The plate thickness measuring device 100 also has a processing unit 4 that acquires, based on the reflected image, information about the tilt of the first surface 3 a and the second surface 3 b, as well as information about the plate thickness of the light-transmitting plate 3 with the influence of the tilt of the first surface 3 a and the second surface 3 b reduced, and outputs the information about the plate thickness.

[0017] For example, when measuring the thickness of the light-transmitting plate 3 based on the reflected image of the structured illumination 1 by the light-transmitting plate 3, if the first surface 3a and the second surface 3b of the light-transmitting plate 3 are tilted, the position of the reflected image will be shifted due to the tilt. This position shift of the reflected image due to the tilt can become an error factor, and the accuracy of measuring the thickness of the light-transmitting plate 3 may decrease.

[0018] In an embodiment of the present disclosure, the processing unit 4 acquires information about the tilt of the first surface 3a and the second surface 3b, as well as information about the plate thickness with the influence of the tilt of the first surface 3a and the second surface 3b reduced, based on the reflection image of the structured illumination 1 by the light-transmitting plate 3. For example, the processing unit 4 acquires information about the plate thickness by ray tracing calculations that take into account the tilt of the first surface 3a and the second surface 3b of the light-transmitting plate 3 acquired based on the reflection image. This reduces the influence of the tilt of the first surface 3a and the second surface 3b, thereby improving the measurement accuracy of the plate thickness measurement method and the plate thickness measurement device 100. Furthermore, because the plate thickness measurement device 100 does not use a displacement sensor or at least three sensors arranged around the displacement sensor, there is no decrease in measurement accuracy due to the positional relationship between the displacement sensor and the at least three sensors. As described above, an embodiment of the present disclosure can provide a plate thickness measurement method and a plate thickness measurement device with high measurement accuracy. Details of a method for acquiring information relating to plate thickness with reduced influence of the tilt of the first surface 3a and the second surface 3b will be described later with reference to FIGS. 9A, 9B, 10A, and 10B.

[0019] 1, the plate thickness measuring device 100 is configured to capture, by an imaging unit 2, a reflected image of structured illumination 1 projected onto a first surface 3a of a light-transmitting plate 3 placed on a mounting surface 5. The image Im captured by the imaging unit 2 is input into a processing unit 4 such as a PC (Personal Computer), and is subjected to image analysis by the processing unit 4.

[0020] The structured illumination 1 includes a stripe pattern consisting of multiple linear patterns each extending in a first direction X. The structured illumination 1 can be obtained, for example, by arranging a stripe pattern on the light-emitting surface of a light source. In FIG. 2, the dark portion width L1 is the width of a dark portion in the structured illumination 1. The bright portion width L2 is the width of a bright portion in the structured illumination 1. L1 + L2 corresponds to the light-dark cycle. When the stripe pattern of the structured illumination 1 is realized by coloring black portions of a translucent resin film, the bright portions correspond to the translucent portions of the resin film, and the dark portions correspond to the black portions of the resin film.

[0021] 1, the imaging unit 2 has a lens 21 and an imaging element 22 that captures an image through the lens 21. The imaging element 22 includes a charge coupled device (CCD), a complementary metal oxide semiconductor (CMOS), or the like. The imaging element 22 is an area sensor having a plurality of pixels aligned in each of the first direction X and the second direction Y. The imaging unit 2 may be any type of camera, such as an area camera, a line camera, a video camera, or a still camera. The imaging unit 2 may also be any type of light receiving device, such as an array of photosensors, as long as it can identify a reflected image.

[0022] In the plate thickness measuring device 100, the imaging unit 2 and the light source that provides the structured illumination 1 are arranged so that the optical axis 2C of the lens 21 of the imaging unit 2 and the normal 1N of the structured illumination 1 (specifically, the light-emitting surface of the light source on which the stripe pattern is arranged) form approximately the same angle θ with respect to the normal direction 3N of the first surface 3a of the light-transmitting plate 3. The angle θ is preferably between 40° and 50°, at which point the reflected image on the first surface 3a and the reflected image on the second surface 3b are the farthest apart.

[0023] <Configuration of Processing Unit 4> 3 is a block diagram showing the hardware configuration of the processing unit 4 included in the plate thickness measuring device 100. The processing unit 4 has a CPU (Central Processing Unit) 401, a ROM (Read Only Memory) 402, a RAM (Random Access Memory) 403, an HDD (Hard Disk Drive) / SSD (Solid State Drive) 404, and an I / F (Interface) 405. These are connected to each other so as to be able to communicate with each other via a system bus B. In addition to the hardware configuration shown in FIG. 3, the processing unit 4 may also have an operation unit such as a keyboard or a touch panel, or a display unit such as a liquid crystal display panel.

[0024] The CPU 401 is a computing device that reads instruction codes and data from the ROM 402 or HDD / SSD 404 onto the RAM 403 and executes the instruction codes to realize the overall control and functions of the processing unit 4. The ROM 402 and HDD / SSD 404 are non-volatile storage devices that can retain programs and data even when the power is turned off. The ROM 402 and HDD / SSD 404 store processing programs and data that the CPU 401 executes to control each function of the plate thickness measurement device 100. The RAM 403 is a volatile storage device that temporarily stores programs or data. The I / F 405 is an interface that connects input / output devices such as a display device, touch panel, speaker, earphone, microphone, and keyboard to the processing unit 4. The I / F 405 also enables communication between the processing unit 4 and devices other than the processing unit 4 via a public communication network, a LAN (Local Area Network), a short-range communication standard, or the like. Devices other than the processing unit 4 that communicate with the processing unit 4 include PCs, servers, etc.

[0025] The functions realized by the CPU 401 executing the instruction codes may be realized by an electronic circuit designed for a specific purpose executing various processes. Examples of electronic circuits designed for a specific purpose include a field programmable gate array (FPGA) and an application specific integrated circuit (ASIC). Some of the functions realized by the CPU 401 executing the instruction codes may be realized by an external device other than the processing unit 4, or may be realized by distributed processing between the processing unit 4 and a device other than the processing unit 4. The processing unit 4 and the device other than the processing unit 4 that performs distributed processing may be a PC, a server, etc.

[0026] 4 is a block diagram showing the functional configuration of the processing unit 4. The processing unit 4 has a tilt calculation unit 41, a thickness calculation unit 42, and an output unit 43. The functions of the tilt calculation unit 41 and the thickness calculation unit 42 are realized by the CPU 401 executing instruction codes, etc. The function of the output unit 43 is realized by the I / F 405 and the CPU 401 executing instruction codes, etc.

[0027] The tilt calculation unit 41 has a functional configuration that acquires information TL1 regarding the tilt of the first surface 3a of the light-transmitting plate 3 and information TL2 regarding the tilt of the second surface 3b of the light-transmitting plate 3 based on the reflected image captured in the captured image Im. The tilt calculation unit 41 acquires the information TL1 regarding the tilt of the first surface 3a and the information TL2 regarding the tilt of the second surface 3b by calculation. The tilt calculation unit 41 passes the acquired information TL1 regarding the tilt of the first surface 3a and the information TL2 regarding the tilt of the second surface 3b to the plate thickness calculation unit 42. Note that the information TL1 regarding the tilt of the first surface 3a and the information TL2 regarding the tilt of the second surface 3b may be numerical data regarding the tilt of the first surface 3a and the second surface 3b, or may be signals corresponding to the tilt of the first surface 3a and the second surface 3b.

[0028] The thickness calculation unit 42 has a functional configuration that acquires information Th about the thickness of the light-transmitting plate 3, with the influence of the tilt of the first surface 3a and the second surface 3b reduced, based on the reflected image captured in the captured image Im. In an embodiment of the present disclosure, the thickness calculation unit 42 acquires the information Th about the thickness of the light-transmitting plate 3 by ray tracing calculation that takes into account the tilt of the first surface 3a and the second surface 3b received from the tilt calculation unit 41. The thickness calculation unit 42 also acquires information about the two-dimensional distribution of the thickness in the first direction X and the second direction Y as the thickness information Th. The thickness calculation unit 42 passes the acquired thickness information Th to the output unit 43. Note that the thickness information Th may be a signal corresponding to the thickness, in addition to numerical data of the thickness.

[0029] The output unit 43 has a functional configuration that outputs information Th about the plate thickness received from the plate thickness calculation unit 42. The output unit 43 outputs the information Th about the plate thickness to a device other than the processing unit 4. The device other than the processing unit 4 is a PC (Personal Computer), a server, a display device, a storage device, etc. The output unit 43 may output the information Th about the plate thickness to a storage device such as the HDD / SSD 404 that the processing unit 4 has, or a display device, etc.

[0030] <Operation of the Plate Thickness Measuring Device 100> The operation of the plate thickness measuring device 100 will be described with reference to FIGS. 5 to 8, 9A, 9B, 10A, and 10B. FIG. 5 is a flowchart showing an example of the operation of the plate thickness measuring device 100. FIG. 6 is a diagram showing an example of an image Im captured by the imaging unit 2. FIG. 7 is a diagram showing an example of a one-dimensional gradation value distribution of the captured image Im corresponding to the second direction Y. FIG. 8 is a diagram explaining changes in the one-dimensional gradation value distribution of the captured image Im according to the inclination of the surface of the light-transmitting plate 3. FIG. 9A is a diagram explaining a plate thickness calculation method using ray tracing. FIG. 9B is a diagram showing an example of an incorrect plate thickness in the plate thickness calculation method using ray tracing. FIG. 10A is a first diagram explaining the influence of surface inclination in the plate thickness calculation method using ray tracing. FIG. 10B is a second diagram explaining the influence of surface inclination in the plate thickness calculation method using ray tracing.

[0031] Below, the flow of operation of the plate thickness measuring device 100 will be explained in accordance with the flowchart of Figure 5, and details of the captured image Im obtained during the operation of the plate thickness measuring device 100 will be explained with appropriate reference to Figures 6 to 8, Figures 9A, 9B, Figures 10A and 10B.

[0032] 5, the plate thickness measuring device 100 starts the operation of Fig. 5 when, for example, an operation input to start measurement is received from the operator of the plate thickness measuring device 100 via an operation unit of the plate thickness measuring device 100. It is assumed that, before the plate thickness measuring device 100 starts the operation of Fig. 5, a light-transmitting plate 3 is placed on the placement surface 5 shown in Fig. 1 and structured illumination 1 is applied to the light-transmitting plate 3.

[0033] First, in step S11, the plate thickness measuring device 100 inputs an image Im captured by the imaging unit 2 to the processing unit 4. As shown in FIG. 6 , the captured image Im captures a reflection image 30 of the structured illumination 1 reflected by the light-transmitting plate 3. The reflection image 30 includes a first reflection image 31 reflected by the first surface 3 a of the structured illumination 1 and a second reflection image 32 reflected by the second surface 3 b of the structured illumination 1. A pair of the first reflection image 31 and the second reflection image 32 is obtained corresponding to one linear pattern among the stripe patterns included in the structured illumination 1. The first reflection image 31 is an image of one linear pattern reflected by the first surface 3 a of the light-transmitting plate 3. The second reflection image 32 is an image of the one linear pattern reflected by the second surface 3 b of the light-transmitting plate 3. Because the stripe pattern is made up of multiple linear patterns, the captured image Im shown in FIG. 6 captures multiple pairs of the first reflection image 31 and the second reflection image 32.

[0034] The coordinate axis Cx corresponds to the first direction X in the captured image Im. The coordinate axis Cy corresponds to the second direction Y in the captured image Im. The coordinates on the coordinate axes Cx and Cy are expressed in units of pixels that make up the captured image Im. On the coordinate axis Cy, the position of the first reflected image 31 is defined as pixel n, and the position of the second reflected image 32 is defined as pixel n+α.

[0035] In FIG. 7, one-dimensional gradation value distribution Lm1 is an image diagram representing a one-dimensional gradation value distribution on the coordinate axis Cy of the first reflection image 31. One-dimensional gradation value distribution Lm2 is an image diagram representing a one-dimensional gradation value distribution on the coordinate axis Cy of the second reflection image 32. One-dimensional gradation value distribution Lm3 is an image diagram representing a one-dimensional gradation value distribution in which the one-dimensional gradation value distribution Lm1 and the one-dimensional gradation value distribution Lm2 are superimposed. The one-dimensional gradation value distribution Lm3 is obtained in the captured image Im. In the one-dimensional gradation value distribution Lm1, one-dimensional gradation value distribution Lm2, and one-dimensional gradation value distribution Lm3, the horizontal axis represents the position on the coordinate axis Cy, and the vertical axis represents the gradation value. Areas with high gradation values ​​correspond to bright areas of the structured illumination 1. Areas with low gradation values ​​correspond to dark areas of the structured illumination 1.

[0036] In the plate thickness measuring device 100, the widths of the dark areas in the structured illumination 1 (corresponding to the image widths W1 and W2) and the light-dark cycles (corresponding to the cycles T1 and T2) are optimized to prevent overlap between the dark areas in the first reflected image 31 and the dark areas in the second reflected image 32 in the one-dimensional gradation value distribution Lm3. For example, if the light-transmitting plate 3 is a typical glass substrate for liquid crystal displays with a thickness of 0.3 mm to 1.3 mm and the image is captured at an angle of 40° to 50°, the structured illumination 1 is determined to have a bright area width L2 of approximately 0.9 mm to 1.3 mm and a dark area width L1 of the black portion of approximately 0.05 mm to 0.1 mm in the example shown in FIG. 2. As a result, the dark areas in the first reflected image 31 and the dark areas in the second reflected image 32 do not overlap in the one-dimensional gradation value distribution Lm3. As a result, in the image analysis by the processing unit 4, the one-dimensional gradation value distribution of the first reflection image 31 and the one-dimensional gradation value distribution of the second reflection image 32 can be easily extracted individually, and information TL1 regarding the inclination of the first surface 3a and information TL2 regarding the inclination of the second surface 3b can be obtained with high accuracy.

[0037] Next, in step S12 of FIG. 5, the tilt calculation unit 41 of the plate thickness measurement device 100 calculates and acquires information TL1 about the tilt of the first surface 3a based on the first reflected image 31 captured in the captured image Im. For example, the plate thickness measurement device 100 first extracts only the one-dimensional gradation value distribution of the first reflected image 31 from the captured image Im captured by the imaging unit 2 using the tilt calculation unit 41. Specifically, the tilt calculation unit 41 finds low gradation value portions that appear periodically in the captured image Im, and determines the portion with the largest amount of gradation value decrease as the one-dimensional gradation value distribution of the first reflected image 31. Alternatively, the tilt calculation unit 41 recognizes one (e.g., the first one) of the two low gradation value portions that form the longer interval 14 in the captured image Im (see the one-dimensional gradation value distribution Lm3 in FIG. 7 ) as being due to the first reflected image 31. As a result, the gradient calculation unit 41 can extract only the one-dimensional gradation value distribution of the first reflection image 31 from the captured image Im.

[0038] When the first surface 3a of the light-transmitting plate 3 has undulations corresponding to the partial tilt of the surface, the positions of the low gradation value portions in the one-dimensional gradation value distribution of the first reflection image 31 captured by the imaging unit 2 will be shifted from the positions of the low gradation value portions in the one-dimensional gradation value distribution given by an ideal flat surface with no undulations. Figure 8 shows how the positions of the low gradation value portions in the one-dimensional gradation value distribution Lm1-1 of the first reflection image 31 will be shifted from the positions of the low gradation value portions in the one-dimensional gradation value distribution Lm1-0 given by the ideal flat surface when the first surface 3a has undulations corresponding to the partial tilt of the surface.

[0039] 8, the positions of the low gradation value portions in the one-dimensional gradation value distribution of the first reflection image 31 are shifted in the +Cy direction and the -Cy direction relative to the positions of the low gradation value portions in the one-dimensional gradation value distribution of the reflection image provided by the ideal plane. The +Cy direction indicates the direction in which the arrow of the coordinate axis Cy points, and the -Cy direction indicates the direction opposite to the +Cy direction. The negative deviation amount e1 is the amount by which the positions of the low gradation value portions in the one-dimensional gradation value distribution Lm1-1 are shifted in the -Cy direction relative to the positions of the low gradation value portions in the one-dimensional gradation value distribution Lm1-0. The positive deviation amount e2 is the amount by which the positions of the low gradation value portions in the one-dimensional gradation value distribution Lm1-1 are shifted in the +Cy direction relative to the positions of the low gradation value portions in the one-dimensional gradation value distribution Lm1-0.

[0040] The tilt calculation unit 41 obtains information TL1 about the tilt of the first surface 3a of the light-transmitting plate 3 from the amount of positional deviation of the first reflection image 31 relative to the reflection image of an ideal plane. From another perspective, the information TL1 about the tilt of the first surface 3a is a differential value of the uneven shape of the first surface 3a. The information TL1 about the tilt of the first surface 3a is obtained based on the amount of positional deviation of low gradation value portions in the one-dimensional gradation value distribution of the first reflection image 31. Therefore, in the captured image Im, information TL1 about the tilt of the first surface 3a is not obtained at positions where the low gradation value portions do not exist, but is obtained only at positions where the low gradation value portions exist. For example, if the spacing between adjacent dark areas in the structured illumination 1 is 1 mm, information TL1 about the tilt of the first surface 3a is obtained at intervals of 0.7 mm to 1.3 mm on the first surface 3a, corresponding to the spacing between adjacent dark areas. The distance is wider on the side farther from the camera and narrower on the side closer to the camera.

[0041] The method disclosed in Japanese Patent No. 4645068, for example, can be applied to the method of acquiring the information TL1 regarding the inclination of the first surface 3a of the light-transmitting plate 3 using the plate thickness measuring device 100. The content disclosed in Japanese Patent No. 4645068 is incorporated herein by reference.

[0042] 5, the tilt calculation unit 41 of the plate thickness measurement device 100 assigns the tilt of the first surface 3a obtained in step S12 to the light-transmitting plate model used when acquiring information TL2 about the tilt of the second surface 3b. As a result, the first surface 3a of the light-transmitting plate model becomes tilted.

[0043] Next, in step S14, the tilt calculation unit 41 of the plate thickness measuring device 100 calculates information TL2 regarding the tilt of the second surface 3b based on the second reflected image 32 captured in the captured image Im when the first surface 3a of the translucent plate model is tilted.

[0044] If there is a tilt at the position on the first surface 3a that overlaps in top view with the position on the second surface 3b where the tilt information TL2 is acquired, the tilt of the first surface 3a will affect the amount of positional deviation of the low gradation value portions of the second reflected image 32 from the positions of the low gradation value portions of the reflected image provided by the ideal plane. This effect of the tilt of the first surface 3a may reduce the accuracy of acquiring the information TL2 about the tilt of the second surface 3b.

[0045] In the plate thickness measuring device 100, the tilt of the first surface 3a obtained in step S12 is assigned to the translucent plate model. This allows the plate thickness measuring device 100 to reduce the influence of the tilt of the first surface 3a and acquire information TL2 regarding the tilt of the second surface 3b with high accuracy. Note that the method for acquiring the information TL2 regarding the tilt of the second surface 3b can be the same as the method for acquiring the information TL1 regarding the tilt of the first surface 3a, except that the tilt of the first surface 3a is assigned to the first surface 3a in the translucent plate model. Furthermore, from the perspective of reducing the influence of the tilt of the first surface 3a, the operation of acquiring the information TL1 regarding the tilt of the first surface 3a in step S12 needs to be performed before the operation of acquiring the information TL2 regarding the tilt of the second surface 3b in step S14.

[0046] Next, in step S15, the thickness calculation unit 42 of the thickness measurement device 100 imparts the inclination of the first surface 3a obtained in step S12 to the translucent plate model used to acquire information Th about the plate thickness of the translucent plate 3. The thickness calculation unit 42 also imparts the inclination of the second surface 3b obtained in step S14 to the second surface 3b of the translucent plate model. As a result, the first surface 3a and the second surface 3b of the translucent plate model are each inclined.

[0047] Next, in step S16, the thickness calculation unit 42 of the thickness measurement device 100 performs ray tracing calculations to obtain information Th about the thickness of the translucent plate 3. The thickness calculation unit 42 performs ray tracing calculations with the inclination of the first surface 3 a and the second surface 3 b of the translucent plate 3 being imparted to the translucent plate model, thereby enabling the ray tracing calculations to be performed taking into account the inclination of the first surface 3 a and the second surface 3 b of the translucent plate 3.

[0048] Ray tracing calculations that take into account the inclination of the first surface 3a and the second surface 3b will be described in detail. As shown in FIGS. 9A and 9B , in the ray tracing calculations, the plate thickness calculation unit 42 calculates a first image height h1 at which a ray Rn, which is emitted from a pixel n indicating the position of the first reflected image 31 in a direction defined by the center of the angle of view of the lens 21 (see FIG. 1 ) and the position of the pixel n, is reflected by the first surface 3a of the light-transmitting plate 3 and reaches the light-emitting surface 10 of the light source that provides the structured illumination 1. In other words, the ray tracing calculations for the first reflected image 31 are reverse ray tracing calculations for the optical path of the ray Rn, which is emitted from the light-emitting surface 10 of the light source that provides the structured illumination 1, until it reaches the imaging surface of the imaging unit 2. The direction defined by the center of the angle of view of the lens 21 and the position of the pixel n is, for example, the direction from the pixel n toward the center of the angle of view of the lens 21.

[0049] The plate thickness calculation unit 42 also calculates a second image height h2 at which a light ray Rn+α, emitted from pixel n+α indicating the position of the second reflected image 32 in a direction defined by the center of the angle of view of the lens 21 and the position of pixel n+α, is refracted by the first surface 3a of the light-transmitting plate 3, passes through the interior of the light-transmitting plate 3, is reflected by the second surface 3b of the light-transmitting plate 3, passes through the interior of the light-transmitting plate 3, is refracted by the first surface 3a of the light-transmitting plate 3, and reaches the light-emitting surface 10 of the light source that provides structured illumination 1. In other words, the ray tracing calculation for the second reflected image 32 is a reverse ray tracing calculation for the optical path of the light ray emitted from the light-emitting surface 10 of the light source that provides structured illumination 1 until it reaches the imaging surface of the imaging unit 2. Note that the direction defined by the center of the angle of view of the lens 21 and the position of pixel n+α is, for example, the direction from pixel n+α toward the center of the angle of view of the lens 21.

[0050] The plate thickness calculation unit 42 calculates the first image height h1 and the second image height h2 while changing the plate thickness t at point P on the light-transmitting plate 3. As shown in FIG. 9A , the plate thickness t when the first image height h1 and the second image height h2 match becomes the correct value of the plate thickness at point P on the light-transmitting plate 3.

[0051] 9B, when the first image height h1 and the second image height h2 do not match, the plate thickness t is not the correct value of the plate thickness at point P on the light-transmitting plate 3. Therefore, the plate thickness calculation unit 42 repeats the calculations of the first image height h1 and the second image height h2 while changing the plate thickness t until the first image height h1 and the second image height h2 match.

[0052] The thickness calculation unit 42 calculates the thickness t at each pixel constituting the first reflected image 31 and the second reflected image 32 captured in the captured image Im, thereby calculating the thickness t at each of multiple points P located at different positions on the light-transmitting plate 3, and thereby calculating the two-dimensional thickness distribution of the light-transmitting plate 3. The thickness calculation unit 42 can acquire the two-dimensional thickness distribution as information Th relating to the thickness of the light-transmitting plate 3.

[0053] As shown in Figures 10A and 10B, when the second surface 3b of the light-transmitting plate 3 is tilted, the reflection direction of the light ray Rn+α by the second surface 3b is different from when the second surface 3b is not tilted. When the second surface 3b is tilted at an angle Δ1 as shown in Figure 10A, the plate thickness t obtained by ray tracing calculation is calculated as a plate thickness smaller than the actual plate thickness. The angle Δ1 is the angle at which the position of the surface changes in the +Z direction as it moves toward the +Y direction. From another perspective, the angle Δ1 is the angle at which the plate thickness decreases as it moves toward the +Y direction. Note that the +Y direction indicates the direction of the Y-axis arrow, and the -Y direction indicates the opposite direction from the +Y direction. The +Z direction indicates the direction of the Z-axis arrow, and the -Z direction indicates the opposite direction from the +Z direction.

[0054] On the other hand, when the second surface 3b is inclined at an angle Δ2 as shown in Figure 10B, the plate thickness t obtained by ray tracing calculation is calculated as a plate thickness greater than the actual plate thickness. The angle Δ2 is the angle at which the position of the surface changes in the -Z direction as it moves in the +Y direction. From another perspective, the angle Δ2 is the angle at which the plate thickness increases as it moves in the +Y direction.

[0055] 10A and 10B show a case where only the second surface 3b of the light-transmitting plate 3 is inclined, but the same applies to a case where only the first surface 3a of the light-transmitting plate 3 is inclined, or a case where both the first surface 3a and the second surface 3b of the light-transmitting plate 3 are inclined. That is, when the plate thickness decreases toward the +Y direction, the plate thickness t obtained by the ray tracing calculation is calculated to be smaller than the actual plate thickness. On the other hand, when the plate thickness increases toward the +Y direction, the plate thickness t obtained by the ray tracing calculation is calculated to be larger than the actual plate thickness. When a plate thickness t that differs from the actual plate thickness is calculated, the plate thickness measurement accuracy decreases.

[0056] 5, the plate thickness calculation unit 42 performs ray tracing calculations that take into account the tilt of the first surface 3 a and the second surface 3 b of the light-transmitting plate 3, thereby acquiring plate thickness information Th that reduces the influence of the tilt of the first surface 3 a and the second surface 3 b. By reducing the influence of the tilt of the first surface 3 a and the second surface 3 b, the plate thickness measurement accuracy by the plate thickness measurement method and the plate thickness measurement device 100 is improved.

[0057] 5, the plate thickness measuring device 100 determines, via the processing unit 4, whether or not to terminate the plate thickness measurement by the plate thickness measuring device 100. For example, the processing unit 4 determines to terminate the plate thickness measurement when receiving an operation input to terminate the measurement from the operator of the plate thickness measuring device 100 via the operation unit of the plate thickness measuring device 100.

[0058] If it is determined in step S17 that the operation is to be ended (step S17, YES), the plate thickness measuring device 100 ends the operation. On the other hand, if it is determined in step S17 that the operation is not to be ended (step S17, NO), the plate thickness measuring device 100 repeats the operations from step S11 onwards until it is determined in step S17 that the operation is to be ended.

[0059] In this manner, the plate thickness measuring device 100 can measure plate thickness.

[0060] The processing unit 4 acquires the information Th about the plate thickness by ray tracing calculation that takes into account the tilt of the first surface 3a and the second surface 3b of the light-transmitting plate 3. This reduces the influence of the tilt of the first surface 3a and the second surface 3b on the plate thickness, thereby increasing the accuracy of acquiring the information Th about the plate thickness.

[0061] The imaging unit 2 has a plurality of pixels aligned in each of the first direction X and the second direction Y, and the processing unit 4 outputs information relating to the two-dimensional distribution of the plate thickness t in the first direction X and the second direction Y. Since the imaging unit 2 has a plurality of pixels aligned in each of the first direction X and the second direction Y, the plate thickness measuring device 100 can simultaneously measure the plate thickness distribution over a wide area of ​​the light-transmitting plate 3. This improves the efficiency of plate thickness measurement and shortens the time required for plate thickness measurement.

[0062] [Second embodiment] Next, a shape and thickness measuring device according to a second embodiment of the present disclosure will be described. Note that the same names and symbols as those in the already described embodiments indicate the same or similar components or configurations, and detailed descriptions will be omitted as appropriate. This also applies to the modified examples described below.

[0063] <Configuration of shape and plate thickness measuring device according to the second embodiment> Fig. 11 is a block diagram showing the functional configuration of a processing unit 4a included in a shape and thickness measuring device 200 according to the second embodiment of the present disclosure. In Fig. 11, the shape and thickness measuring device 200 and the processing unit 4a are both shown with the same reference numerals to indicate that the shape and thickness measuring device 200 includes the processing unit 4a.

[0064] The shape and thickness measuring device 200 differs from the thickness measuring device 100 according to the first embodiment of the present disclosure in that the processing unit 4a acquires information about the shape of the first surface 3a and the second surface 3b of the translucent plate 3 based on the reflected image of the structured illumination by the translucent plate 3, and outputs the information about the shape.

[0065] As shown in Fig. 11, the processing unit 4a has a shape calculation unit 44. The function of the shape calculation unit 44 is realized by the CPU 401 (see Fig. 3) executing instruction codes, etc. However, the function of the shape calculation unit 44 may be realized by an FPGA, an ASIC, etc., or may be realized by distributed processing between the processing unit 4a and a device other than the processing unit 4a. The device other than the processing unit 4a that performs distributed processing with the processing unit 4a is a PC, a server, etc.

[0066] The shape calculation unit 44 acquires information about the shapes of the first surface 3a and the second surface 3b of the light-transmitting plate 3 based on the reflection image 30 of the structured illumination 1 by the light-transmitting plate 3 (see FIG. 6 ). For example, the shape calculation unit 44 acquires information Sh1 about the shape of the first surface 3a and information Sh2 about the shape of the second surface 3b based on the information about the inclination of the first surface 3a and the second surface 3b acquired by the inclination calculation unit 41. More specifically, the shape calculation unit 44 acquires information Sh1 about the shape of the first surface 3a by an integral calculation, with the constraint that the first surface 3a is substantially flat. Furthermore, the shape calculation unit 44 acquires information Sh2 about the shape of the second surface 3b by an integral calculation, with the constraint that the second surface 3b is substantially flat. Note that the information Sh1 about the shape of the first surface 3a and the information Sh2 about the shape of the second surface 3b may be numerical data indicating the shapes, or may be a signal corresponding to the shapes.

[0067] The method disclosed in Japanese Patent No. 4645068, for example, can be applied to the method of acquiring the information Sh1 about the shape of the first surface 3a and the information Sh2 about the shape of the second surface 3b of the light-transmitting plate 3 using the plate thickness measuring device 100. The content disclosed in Japanese Patent No. 4645068 is incorporated herein by reference.

[0068] In the measurement results of the shapes of the first surface 3a and the second surface 3b, the shape measurement accuracy required for the surfaces according to the shapes is, for example, in the range of about 0.01 μm to 0.1 μm. On the other hand, in the measurement results of the thickness distribution of the light-transmitting plate 3, the measurement accuracy required for the thickness distribution is, for example, in the range of about 1 μm to 10 μm. The surface irregularities according to the shapes of the first surface 3a and the second surface 3b are superimposed on the thickness distribution of the light-transmitting plate 3.

[0069] The shape calculation unit 44 passes the acquired information Sh1 regarding the shape of the first surface 3a and information Sh2 regarding the shape of the second surface 3b to the output unit 43. The output unit 43 outputs the information Sh1 regarding the shape of the first surface 3a and the information Sh2 regarding the shape of the second surface 3b to a device other than the processing unit 4. The device other than the processing unit 4 is a PC, a server, a display device, a storage device, etc. The output unit 43 may output the information Sh1 regarding the shape of the first surface 3a and the information Sh2 regarding the shape of the second surface 3b to a storage device such as the HDD / SSD 404 included in the processing unit 4, a display device, etc.

[0070] <Operation of Shape and Plate Thickness Measuring Device 200> Fig. 12 is a flowchart showing an example of the operation of the shape and thickness measuring device 200. In Fig. 12, the shape and thickness measuring device 200 starts the operation of Fig. 12 when, for example, an operation input to start measurement is received from the operator of the shape and thickness measuring device 200 via an operation unit of the shape and thickness measuring device 200. It is assumed that, before the shape and thickness measuring device 200 starts the operation of Fig. 12, a light-transmitting plate 3 is placed on the placement surface 5 shown in Fig. 1 and structured illumination 1 is applied to the light-transmitting plate 3.

[0071] The operation of the shape and thickness measuring device 200 from step S21 to step S26 in Fig. 12 is the same as the operation of the thickness measuring device 100 from step S11 to step S16 in Fig. 5. Therefore, duplicated explanations will be omitted here, and differences from the operation of the thickness measuring device 100 shown in Fig. 5 will be mainly explained.

[0072] 12, the shape calculation unit 44 of the shape and plate thickness measuring device 200 acquires information Sh1 about the shape of the first surface 3a based on the information TL1 about the inclination of the first surface 3a acquired by the inclination calculation unit 41. The shape calculation unit 44 passes the acquired information Sh1 about the shape of the first surface 3a to the output unit 43.

[0073] Subsequently, in step S28, the shape calculation unit 44 of the shape and plate thickness measuring device 200 acquires information Sh2 about the shape of the second surface 3b based on the information TL2 about the inclination of the second surface 3b acquired by the inclination calculation unit 41. The shape calculation unit 44 passes the acquired information Sh2 about the shape of the second surface 3b to the output unit 43.

[0074] Note that the operation of acquiring information Sh2 about the shape of the second surface 3b shown in step S28 may be performed before the operation of acquiring information Sh1 about the shape of the first surface 3a shown in step S27. Also, the operation of step S27 and the operation of step S28 may be performed in parallel. Furthermore, at least one of the operation of step S27 and the operation of step S28 may be performed before the operation of step S25 or the operation of step S26. In addition, the operations from step S26 to step S28 may be performed in parallel.

[0075] Subsequently, in step S29, the shape and thickness measuring device 200 determines, via the processing unit 4, whether or not to terminate the measurement of the shape and thickness by the shape and thickness measuring device 200. For example, the processing unit 4 determines to terminate the measurement of the shape and thickness when an operation input for terminating the measurement is received from the operator of the shape and thickness measuring device 200 via an operation unit included in the shape and thickness measuring device 200.

[0076] If it is determined in step S29 that the operation is to be ended (YES in step S29), the shape and thickness measuring device 200 ends the operation. On the other hand, if it is determined in step S29 that the operation is not to be ended (NO in step S29), the shape and thickness measuring device 200 repeats the operations from step S21 onwards until it is determined in step S29 that the operation is to be ended.

[0077] In this manner, the shape and thickness measuring device 200 can measure the shape and thickness.

[0078] As described above, in the embodiment of the present disclosure, information Sh1 about the shape of the first surface 3a and information Sh2 about the shape of the second surface 3b can be acquired in parallel with acquiring information Th about the thickness of the light-transmitting plate 3. Furthermore, the shape and thickness measuring device 200 acquires information Th about the thickness of the light-transmitting plate 3 while reducing the influence of the tilt of the first surface 3a and the second surface 3b. For example, the processing unit 4a acquires information Th about the thickness by ray tracing calculation that takes into account the tilt of the first surface 3a and the second surface 3b of the light-transmitting plate 3 acquired based on the reflected image. As a result, the embodiment of the present disclosure can provide a shape and thickness measuring method and a shape and thickness measuring device 200 that reduce the influence of the tilt of the first surface 3a and the second surface 3b and have high measurement accuracy.

[0079] The shape and thickness measuring device 200 acquires information Th about the thickness of the light-transmitting plate 3 by ray tracing calculations that take into account the tilt of the first surface 3a and the second surface 3b of the light-transmitting plate 3. This reduces the influence of the tilt of the first surface 3a and the second surface 3b on the thickness information Th obtained, increasing the accuracy of acquiring the information Th about the thickness.

[0080] The imaging unit 2 has a plurality of pixels aligned in each of the first direction X and the second direction Y, and the processing unit 4a outputs information relating to the two-dimensional distribution of plate thickness in the first direction X and the second direction Y. Since the imaging unit 2 has a plurality of pixels aligned in each of the first direction X and the second direction Y, the shape and plate thickness measuring device 200 can simultaneously measure the shape distribution and plate thickness distribution over a wide area of ​​the light-transmitting plate 3. This improves the efficiency of shape and plate thickness measurement and shortens the time required for shape and plate thickness measurement.

[0081] [Variations] Next, a modified example of a plate thickness measuring device will be described.

[0082] <Configuration of Plate Thickness Measuring Device According to Modification> Fig. 13 is a schematic diagram showing the configuration of a plate thickness measuring device 100a according to a modified example. Fig. 14 is a block diagram showing the functional configuration of a processing unit 4b included in the plate thickness measuring device 100a.

[0083] The plate thickness measuring device 100a differs from the plate thickness measuring device 100 according to the first embodiment of the present disclosure in that the imaging unit 2 has a plurality of pixels aligned in a second direction Y perpendicular to the first direction X, and the processing unit 4b acquires information relating to the plate thickness in a cross section perpendicular to the first direction X. The plate thickness measuring device 100a shown in Fig. 13 also differs from the plate thickness measuring device 100 according to the first embodiment of the present disclosure in that it has a moving unit 6 that moves the light-transmitting plate 3 relative to the imaging unit 2 in the first direction X.

[0084] 13, the imaging unit 2 is a line camera equipped with an imaging element 22 having a plurality of pixels aligned only in the second direction Y. The imaging unit 2 outputs a line image Im1 captured by the imaging element 22 to the processing unit 4b.

[0085] The moving unit 6 is placed on the placement surface 5. The moving unit 6 is a moving mechanism that moves a moving table on which the light-transmitting plate 3 is placed in the first direction X, thereby moving the light-transmitting plate 3 relative to the imaging unit 2 in the first direction X. The moving unit 6 includes, for example, a linear stage including the moving table, and a driving unit that moves the moving table on the linear stage. A motor such as a stepping motor can be used as the driving unit. Note that the moving unit 6 may move the imaging unit 2 in the first direction X, or may move both the light-transmitting plate 3 and the imaging unit 2 in the first direction X, as long as it can move the light-transmitting plate 3 relative to the imaging unit 2 in the first direction X.

[0086] 14, the processing unit 4b has a plate thickness calculation unit 42b that acquires information Th1 about the plate thickness in a cross section perpendicular to the first direction X. The processing unit 4b also has a splicing unit 45 that acquires information Th2 about the two-dimensional distribution of the plate thickness in the first direction X and the second direction Y by splicing the information Th1 about the plate thickness in the first direction X.

[0087] The output unit 43 outputs information Th2 relating to the two-dimensional distribution of plate thickness acquired by the joining unit 45 to a device other than the processing unit 4b. The device other than the processing unit 4b is a PC, a server, a display device, a storage device, etc. The output unit 43 may output information Th2 relating to the two-dimensional distribution of plate thickness to a storage device such as the HDD / SSD 404 included in the processing unit 4b, a display device, etc.

[0088] The functions of the plate thickness calculation unit 42b and the joining unit 45 are realized by the CPU 401 (see FIG. 3) executing instruction codes, etc. However, the functions of the plate thickness calculation unit 42b and the joining unit 45 may be realized by an FPGA, an ASIC, etc., or may be realized by distributed processing between the processing unit 4b and a device other than the processing unit 4b. The processing unit 4b and the device other than the processing unit 4b that performs distributed processing may be a PC, a server, etc.

[0089] <Operation of the plate thickness measuring device 100a> FIG. 15 is a flowchart showing an example of the operation of the plate thickness measuring device 100a.

[0090] 15, the plate thickness measuring device 100a starts the operation of Fig. 15 when, for example, an operation input to start measurement is received from the operator of the plate thickness measuring device 100a via an operation unit of the plate thickness measuring device 100a. Note that before the plate thickness measuring device 100a starts the operation of Fig. 15, it is assumed that a light-transmitting plate 3 is placed on the placement surface 5 shown in Fig. 13 and structured illumination 1 is applied to the light-transmitting plate 3.

[0091] First, in step S31, the plate thickness measuring device 100a inputs the line image Im1 captured by the imaging unit 2 to the processing unit 4b.

[0092] Next, in step S32, the tilt calculation unit 41 of the plate thickness measuring device 100a calculates and obtains information TL1 regarding the tilt of the first surface 3a in a cross section perpendicular to the first direction X based on the first reflected image 31 appearing in the line image Im1.

[0093] Next, in step S33, the tilt calculation unit 41 of the plate thickness measurement device 100a assigns the tilt of the first surface 3a obtained in step S32 to the light-transmitting plate model used when acquiring information TL2 about the tilt of the second surface 3b. As a result, the first surface 3a of the light-transmitting plate model becomes tilted.

[0094] Next, in step S34, the tilt calculation unit 41 of the plate thickness measuring device 100a calculates and obtains information TL2 regarding the tilt of the second surface 3b in a cross section perpendicular to the first direction X based on the second reflected image 32 captured in the line image Im1 when the first surface 3a of the translucent plate-like body model is tilted.

[0095] Next, in step S35, the thickness calculation unit 42b of the thickness measurement device 100a imparts the inclination of the first surface 3a obtained in step S32 to the light-transmitting plate model used to acquire information Th1 about the thickness of the light-transmitting plate 3. Furthermore, the thickness measurement device 100 causes the thickness calculation unit 42 to impart the inclination of the second surface 3b obtained in step S34 to the second surface 3b of the light-transmitting plate model. As a result, the first surface 3a and the second surface 3b of the light-transmitting plate model are each inclined.

[0096] Next, in step S36, the thickness calculation unit 42b of the thickness measurement device 100a acquires information Th1 about the thickness of the translucent plate 3 in a cross section perpendicular to the first direction X by ray tracing calculation. The thickness calculation unit 42 performs ray tracing calculation with the inclination of the first surface 3a and the second surface 3b added to the translucent plate model, thereby enabling the ray tracing calculation to be performed taking into account the inclination of the first surface 3a and the second surface 3b of the translucent plate 3. The thickness calculation unit 42b passes the acquired information Th1 about the thickness of the translucent plate 3 to the stitching unit 45. The stitching unit 45 stores the information Th1 about the thickness received from the thickness calculation unit 42b in a storage device such as the RAM 403 (see FIG. 3).

[0097] Subsequently, in step S37, the plate thickness measuring device 100a determines whether or not information Th1 about plate thickness has been acquired for all cross sections by the joining unit 45. For example, the joining unit 45 determines whether or not information Th1 about plate thickness has been acquired for all cross sections by determining in advance the number of cross sections to be acquired and determining whether or not the number of pieces of information Th1 about plate thickness that have been acquired reaches the predetermined number of cross sections.

[0098] If it is determined in step S37 that the information has not been acquired (step S37, NO), in step S38, the plate thickness measuring device 100a causes the moving unit 6 to move the light-transmitting plate 3 relative to the imaging unit 2 by a predetermined distance in the first direction X. When the light-transmitting plate 3 has moved the predetermined distance, the plate thickness measuring device 100a stops the movement of the light-transmitting plate 3 by the moving unit 6. Thereafter, the plate thickness measuring device 100a returns to step S31 and performs the operations from step S31 onwards again. The plate thickness measuring device 100a repeats the operations from step S31 onwards until it is determined in step S37 that the information has been acquired. The splicing unit 45 stores the plate thickness information Th1 for the predetermined number of cross sections in the RAM 403 (see FIG. 3 ) or the like.

[0099] On the other hand, if it is determined in step S37 that the information has been acquired (step S37, YES), in step S39, the thickness measuring device 100a causes the joining unit 45 to join together the information Th1 about the thickness of a predetermined number of cross sections in the first direction X. The joining unit 45 can acquire information Th2 about the two-dimensional distribution of the thickness in the first direction X and the second direction Y.

[0100] Next, in step S40, the plate thickness measuring device 100a determines, via the processing unit 4b, whether or not to terminate the plate thickness measurement by the plate thickness measuring device 100a. For example, the processing unit 4b determines to terminate the plate thickness measurement when an operation input to terminate the measurement is received from the operator of the plate thickness measuring device 100a via the operation unit of the plate thickness measuring device 100a.

[0101] If it is determined in step S40 that the operation is to be ended (step S40, YES), the plate thickness measuring device 100a ends the operation. On the other hand, if it is determined in step S40 that the operation is not to be ended (step S40, NO), the plate thickness measuring device 100a repeats the operations from step S31 onwards until it is determined in step S40 that the operation is to be ended.

[0102] In this manner, the plate thickness measuring device 100a can measure the plate thickness.

[0103] In the plate thickness measuring device 100a, the imaging unit 2 has a plurality of pixels aligned only in the second direction Y, and the processing unit 4 outputs information Th1 relating to the plate thickness in a cross section perpendicular to the first direction X. Since the imaging unit 2 has a plurality of pixels aligned only in the second direction Y, the number of pixels in the second direction Y can be increased. Increasing the number of pixels in the second direction Y increases the spatial resolution of plate thickness measurement in the second direction Y. This spatial resolution can also be expressed as resolution or density.

[0104] In the plate thickness measuring device 100a, the moving unit 6 moves the light-transmitting plate 3 relative to the imaging unit 2 in the first direction X. The processing unit 4b acquires information about the two-dimensional distribution of the plate thickness in the first direction X and the second direction Y by connecting information Th1 about the plate thickness in a cross section perpendicular to the first direction X to the first direction X, and outputs the information about the two-dimensional distribution of the plate thickness. Increasing the number of pixels in both the first direction X and the second direction Y increases the spatial resolution of the plate thickness measurement in both the first direction X and the second direction Y.

[0105] In this modification, a modification of the plate thickness measuring device has been described, but similar modifications are possible in the shape and plate thickness measuring device. That is, in the shape and plate thickness measuring device according to the modification, the processing unit outputs information about the shape in a cross section perpendicular to the first direction X, as well as information about the plate thickness. This increases the number of pixels in the second direction Y, and improves the spatial resolution of measuring the shape and plate thickness in the second direction Y.

[0106] Furthermore, in a shape and thickness measuring device according to a modified example, the moving unit moves the light-transmitting plate 3 relative to the imaging unit 2 in the first direction X. The processing unit acquires information about the two-dimensional distribution of the shape and thickness in the first direction X and the second direction Y by combining information about the shape in a cross section perpendicular to the first direction X and information about the thickness in the first direction. The processing unit outputs information about the two-dimensional distribution of the shape and thickness in the first direction X and the second direction. This increases the number of pixels in both the first direction X and the second direction Y, thereby improving the spatial resolution of measuring the shape and thickness in both the first direction X and the second direction Y.

[0107] Although the preferred embodiments have been described in detail above, the present disclosure is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments of the present disclosure without departing from the scope of the claims.

[0108] All numbers such as ordinal numbers and quantities used in the description of the embodiments of the present disclosure are provided as examples to specifically explain the technology of the present disclosure, and the present disclosure is not limited to the illustrated numbers. Furthermore, the connection relationships between components are provided as examples to specifically explain the technology of the present disclosure, and do not limit the connection relationships that realize the functions of the present disclosure.

[0109] The thickness measurement method, shape and thickness measurement method, thickness measurement device, and shape and thickness measurement device according to embodiments of the present disclosure have high measurement accuracy and can be widely used for thickness measurement, shape measurement, thickness inspection, and shape inspection of glass substrates used in flat panel displays such as liquid crystal displays, glass substrates (raw plates) used for window glass in automobiles, ships, aircraft, buildings, etc., transparent plates such as resin plates, etc. Furthermore, glass substrates with microholes used as semiconductor substrates require highly accurate measurement of the thickness over a wide area. The thickness measurement method, shape and thickness measurement method, thickness measurement device, and shape and thickness measurement device according to embodiments of the present disclosure can be particularly suitably used for thickness measurement, shape measurement, thickness inspection, and shape inspection of such glass substrates with microholes. [Explanation of symbols]

[0110] 1 Structured lighting 10 Light-emitting surface 1N normal 2. Imaging unit 2C optical axis 21 Lens 22 Image sensor 3 Translucent plate 3a 1st page 3b 2nd side 3N normal direction 30 Reflection image 31 1st reflection image 32 Second reflection image 4, 4a, 4b Processing section 41 Tilt calculation unit 42, 42b Plate thickness calculation section 43 Output section 44 Shape calculation section 45 Joint 401 CPU 402 ROM 403 RAM 404 HDD / SSD 405 Interface 5. Placement surface 6 Moving part 14 intervals 100, 100a Plate thickness measuring device 200 Shape and thickness measuring device Cx, Cy coordinate axes e1 Negative deviation amount e2 Positive deviation amount h1 1st image height h2 2nd image height Im Captured Image Im1 Line Image L1 dark area width L2 Bright area width Lm1, Lm1-0, Lm1-1, Lm2, Lm3 One-dimensional tone value distribution n, n+α pixels P point Rn, Rn+α ray TL1 Information about the tilt of the first surface TL2 Information about the tilt of the second surface Th: Plate thickness information Th1 Information about the plate thickness in one cross section Th2 Information on the two-dimensional distribution of plate thickness T1, T2 period t Plate thickness X first direction Y Second direction Z third direction W1, W2 Image width θ angle Δ1, Δ2 angle

Claims

1. capturing an image of the structured illumination reflected by a light-transmitting plate-like body including a first surface and a second surface opposite to the first surface, using an imaging unit; The processing unit acquiring information about the inclination of the first surface and the second surface and information about the thickness of the light-transmitting plate-like body in which the influence of the inclination of the first surface and the second surface has been reduced, based on the reflected image; and outputting information about the plate thickness.

2. The plate thickness measurement method according to claim 1 , wherein the processing unit acquires information about the plate thickness by ray tracing calculation taking into account inclinations of the first surface and the second surface.

3. the structured illumination includes a stripe pattern consisting of a plurality of linear patterns each extending in a first direction; the imaging unit has a plurality of pixels aligned in each of the first direction and a second direction perpendicular to the first direction, The plate thickness measurement method according to claim 1 , wherein the processing unit outputs information regarding a two-dimensional distribution of the plate thickness in the first direction and the second direction.

4. the structured illumination includes a stripe pattern consisting of a plurality of linear patterns each extending in a first direction; the imaging unit has a plurality of pixels aligned only in a second direction perpendicular to the first direction, The plate thickness measurement method according to claim 1 , wherein the processing unit acquires information about the plate thickness in a cross section perpendicular to the first direction.

5. a moving unit moving the light-transmitting plate relative to the imaging unit in the first direction; The processing unit acquires information about the two-dimensional distribution of the plate thickness in the first direction and the second direction by connecting information about the plate thickness in a cross section perpendicular to the first direction in the first direction, and outputs information about the two-dimensional distribution of the plate thickness. The plate thickness measurement method according to claim 4.

6. capturing an image of the structured illumination reflected by a light-transmitting plate-like body including a first surface and a second surface opposite to the first surface, using an imaging unit; a processing unit that outputs information about the shapes of the first surface and the second surface and information about the thickness of the light-transmitting plate-like body, the information being obtained based on the reflected image;

7. The processing unit Based on the reflected image, information regarding the inclination of the first surface and the second surface and information regarding the plate thickness in which the influence of the inclination of the first surface and the second surface is reduced are acquired; The shape and plate thickness measuring method according to claim 6 , further comprising: acquiring information about the shapes of the first surface and the second surface based on information about the inclinations of the first surface and the second surface.

8. the structured illumination includes a stripe pattern consisting of a plurality of linear patterns each extending in a first direction; the imaging unit has a plurality of pixels aligned in each of the first direction and a second direction perpendicular to the first direction, The shape and thickness measuring method according to claim 6 , wherein the processing unit outputs information relating to two-dimensional distributions of the shape and the thickness in the first direction and the second direction.

9. the structured illumination includes a stripe pattern consisting of a plurality of linear patterns each extending in a first direction; the imaging unit has a plurality of pixels aligned only in a second direction perpendicular to the first direction, The shape and thickness measuring method according to claim 6 , wherein the processing unit acquires information about the shape and information about the thickness in a cross section perpendicular to the first direction.

10. a moving unit moving the light-transmitting plate relative to the imaging unit in the first direction; The processing unit acquires information about the shape in a cross section perpendicular to the first direction and information about the plate thickness in the first direction, and information about the two-dimensional distribution of the shape and the plate thickness in the first direction and the second direction, The shape and thickness measuring method according to claim 9 , wherein the processing unit outputs information regarding two-dimensional distributions of the shape and the thickness in the first direction and the second direction.

11. an imaging unit that captures an image of the structured illumination reflected by a light-transmitting plate-like body including a first surface and a second surface opposite to the first surface; a processing unit that acquires, based on the reflected image, information regarding the inclination of the first surface and the second surface, and information regarding the thickness of the light-transmitting plate-like body in which the influence of the inclination of the first surface and the second surface has been reduced, and outputs the information regarding the thickness.

12. an imaging unit that captures an image of the structured illumination reflected by a light-transmitting plate-like body including a first surface and a second surface opposite to the first surface; a processing unit that outputs information regarding the shapes of the first surface and the second surface, and information regarding the thickness of the light-transmitting plate-like body, obtained based on the reflected image.

Images