Inspection system, inspection apparatus, inspection method, and production method

Abstract

To accurately determine a tin surface of float glass.SOLUTION: A light source irradiates ultraviolet light onto an inspection target including float glass. A detector detects the intensity of visible light generated in an irradiation region on a surface of the inspection target irradiated with the ultraviolet light. A determination unit determines, based on the intensity of the visible light, whether the irradiation region is on a tin surface with tin distributed thereon. An embodiment of the present application can be implemented in any of an inspection system, an inspection apparatus, an inspection method, and a production method of functional float glass.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] TECHNICAL FIELD The present application relates to an inspection system, an inspection device, an inspection method, and a production method.The present application relates to a technique for determining the condition of a surface of an object to be inspected, including, for example, float glass. [Background technology]

[0002] Float glass is produced by a process in which molten glass is poured onto a float bath and shaped. Molten tin is stored in the float bath. Because tin has a greater specific gravity than glass, the molten glass floats to the surface of the float bath. The floating molten glass is stretched thinly and cooled to produce a float glass blank. As a result, a layer of tin is distributed on one side of the blank, and no tin is attached to the other side. The side with tin attached is called the tin side, tin-attached side, or B (Bottom) side. The side without tin is called the non-tin side or T (Top) side.

[0003] Depending on the application, float glass blanks may be distinguished between a tin side and a non-tin side. For example, Patent Document 1 describes a method for producing functional float glass, which includes a selection step in which a float glass surface is irradiated with light having a wavelength distribution of 300 nm or less to distinguish between a bottom side, on which surface luminescence is observed, and a top side, on which surface luminescence is not observed, and then selecting the top side; an adsorption step in which only the top side is contacted with a solution containing at least a silane compound to form a monomolecular film in which CF3 groups or CH3 groups are exposed on the surface; and a drying step in which the glass substrate is subsequently dried. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 3130244 Summary of the Invention [Problem to be solved by the invention]

[0005] Float glass may be surface-treated to be UV-blocking glass by applying an ultraviolet-blocking paint (sometimes simply referred to as "paint" in this application) to the surface (UV-blocking coating). However, no consideration was given to whether the tin side or the non-tin side should be the coating surface. In addition, not only flat float glass sheets but also tempered glass or curved glass, for example, can be subjected to surface treatment. The present application has been made in view of the above points, and one of the objects of the present invention is to provide an inspection system, an inspection device, an inspection method, and a production method that can accurately determine the tin surface. [Means for solving the problem]

[0006] (1) The present application has been made to solve the above-mentioned problems, and one aspect of the present application is an inspection system including a light source that irradiates an object under inspection, including float glass, with ultraviolet light; a detector that detects the intensity of visible light generated in an irradiated area on the surface of the object under inspection irradiated with the ultraviolet light; and a determination unit that determines, based on the intensity of the visible light, whether the irradiated area is on a tin surface on which tin is distributed.

[0007] (2) In another aspect of the present application, a light source is used to irradiate an object to be inspected, which includes float glass, with ultraviolet light; This is an inspection device that has a detector that detects the intensity of visible light generated in an irradiated area on the surface of the object being inspected where the ultraviolet light is irradiated, and determines whether the irradiated area is on a tin surface where tin is distributed based on the intensity of the visible light.

[0008] (3) Another aspect of the present application is an inspection method in an inspection system including a light source and a detector, in which the light source irradiates ultraviolet light onto the surface of an object to be inspected, including float glass, and the detector detects the intensity of visible light generated in an irradiated area on the surface of the object to be inspected, where the ultraviolet light is irradiated, and the method determines whether the irradiated area is on a tin surface on which tin is distributed, based on the intensity of the visible light.

[0009] (4) Another aspect of the present application may be a method for producing functional float glass, which includes carrying out the inspection method of (3) and applying an ultraviolet ray blocking paint to a non-tin surface facing in the opposite direction to the tin surface. [Effects of the Invention]

[0010] According to the present invention, the tin surface of float glass can be accurately determined. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic diagram showing a first configuration example of an inspection system according to the present embodiment. [Figure 2] FIG. 2 is a schematic block diagram showing an example of the functional configuration of an inspection device according to the present embodiment. [Figure 3] FIG. 1 is a first explanatory diagram for explaining the measurement principle for distinguishing a tin surface according to the present embodiment. [Figure 4] FIG. 2 is a second explanatory diagram for explaining the measurement principle for distinguishing tin surfaces according to the present embodiment. [Figure 5] FIG. 10 is a diagram illustrating an example of the spectral intensity of light emitted from an object under test. [Figure 6] FIG. 10 is a diagram showing an example of the integrated intensity of light emitted from an object under test. [Figure 7] FIG. 10 is a diagram showing an example of the state of an object to be inspected. [Figure 8] FIG. 4 is a diagram showing an example of a display screen according to the embodiment. [Figure 9] 10A and 10B are diagrams illustrating an example of measurement of the measured value of light emitted from an object under test. [Figure 10] FIG. 2 is a schematic diagram showing a second configuration example of the inspection system according to the present embodiment. [Figure 11] 1 is a flowchart illustrating an example of an inspection method according to the present embodiment. [Figure 12] 10A and 10B are diagrams illustrating examples of support forms for an object to be inspected according to the present embodiment. [Figure 13] FIG. 10 is a diagram showing an example of the tilt angle of the object under test. [Figure 14]FIG. 10 is a schematic diagram showing a third configuration example of the inspection system according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, the configuration of this embodiment will be described. Fig. 1 is a schematic diagram showing an example of the configuration of an inspection system S1 according to this embodiment. The inspection system S1 according to this embodiment includes an inspection device 10, a light source 20, and a detector 30. The object to be inspected by the inspection system S1 is mainly float glass or a product containing float glass as a material. The product is not limited to a final product, but may also include intermediate products generated in the production process. In this application, the object to be inspected may be referred to as an "inspection subject Sp." The object to be inspected may also be referred to as a sample.

[0013] The inspection device 10 determines whether the irradiated area of ​​the inspection object Sp, where the inspection light is irradiated, is located on a tin surface based on the intensity of the visible light transmitted in the detection signal input from the detector 30. The inspection device 10 determines whether the irradiated area is located on a tin surface based on, for example, whether the intensity of the visible light indicated in the detection signal is equal to or greater than a set detection threshold. The functions of the inspection device 10 are realized, for example, by causing a personal computer (PC) to execute a predetermined application program. The inspection device 10 may also be realized using general-purpose information devices other than PCs, such as tablet terminals, smartphones, and workstations. The inspection device 10 may also be configured using dedicated hardware. The following description mainly focuses on the case where the functions of the inspection device 10 are realized by a PC.

[0014] The light source 20 functions as an illumination source that irradiates the inspection object Sp with ultraviolet light as inspection light. The wavelength of the ultraviolet light is, for example, 210 to 350 nm, typically 280 nm. The light source includes a light-emitting element and an illumination lens. The light-emitting element emits light in response to power supply. The light-emitting element is, for example, an ultraviolet light-emitting diode (UV LED). The illumination lens focuses the ultraviolet light emitted from the light source 20 onto the surface of the inspection object Sp. The intensity of the light source 20 is set to a predetermined constant reference intensity. Note that in this application, the area of ​​the surface of the inspection object Sp that is irradiated with ultraviolet light from the light source 20 may be referred to as the "irradiation area." Furthermore, a surface of the surface of the inspection object Sp whose main normal direction is oriented vertically or in a direction approximately vertically may be referred to as the "bottom surface." The "bottom surface" is used to distinguish it from the "top surface," which is oriented in the opposite direction to the "bottom surface."

[0015] The detector 30 detects the intensity of light incident on the detector. The detector is equipped with a photosensitive element that can detect the intensity of light rays. A camera may be used as the detector 30. The camera can acquire the intensity of light rays emitted from each part as an image showing the distribution of light and dark. The detector 30 is, for example, an area camera. Both the light source 20 and the detector 30 are installed facing the surface of the object Sp to be inspected. The light source 20 and the detector 30 are, for example, suspended from the ceiling. For example, the direction of ultraviolet light emitted from the light source 20 is set to a direction that forms an acute angle with the horizontal plane. The position of the detector 30 in the horizontal plane is adjusted in advance so that the area of ​​the object Sp to be inspected that is irradiated with ultraviolet light faces the detection direction of the detector 30 (for example, the vertical direction). The light reaching the detector 30 includes a fluorescent component generated in the irradiated area on the surface of the specimen Sp and a reflected or diffracted ultraviolet component. The fluorescent light mainly contains a visible light component. The detector 30 has a detection band set to include at least the wavelength range of visible light. The detector 30 outputs a detection signal indicating the intensity of the detected light to the inspection device 10.

[0016] The object under test Sp has a shape that spreads out like a flat surface overall. The object under test Sp may be a flat plate or a bent plate with a curved surface (i.e., curved glass). The bottom surface of the object under test Sp is supported by three supporting members Bs01 to Bs03. In the example of FIG. 1, the surface of the object under test Sp is curved. The supporting members Bs01 to Bs03 are arranged at different positions on the base Bp. The positions of the supporting members Bs01 to Bs03 form a triangle with the positions as vertices. Since the bottom surface of the object under test Sp is supported at three different points, the object under test Sp can be stably placed on the supporting members Bs01 to Bs03 even if it has a curved surface. Elastic members are attached to the tips of the supporting members Bs01 to Bs03, respectively. The support materials Bs01 to Bs03 come into contact with the bottom surface of the object under test Sp via an elastic material, thereby absorbing vibrations or impacts from the base Bp.

[0017] The intensity of the fluorescence generated in the irradiated area of ​​the test object Sp is weak compared to the intensity of the ultraviolet light irradiated onto the test object Sp. Therefore, at least the light source 20, the detector 30, and the test object Sp may be shielded from light during the measurement period so that no light from the surroundings enters the darkroom.

[0018] Next, an example of the functional configuration of the inspection device 10 according to this embodiment will be described. Fig. 2 is a schematic block diagram showing an example of the functional configuration of the inspection device 10 according to this embodiment. The inspection device 10 includes a control unit 110 , an input / output unit 140 , an operation unit 150 , a display unit 160 , and a storage unit 170 . The control unit 110 executes processes for realizing the functions of the inspection device 10 and processes for controlling those functions. The control unit 110 may include general-purpose components such as a processor and be configured as a computer. The processor reads a program previously stored in the storage unit 170 and performs processes instructed by instructions written in the read program to realize the functions. In this application, performing processes instructed by instructions written in a program may be referred to as program execution, etc. Part or all of the control unit 110 is not limited to general-purpose hardware such as a processor, and may be configured to include dedicated hardware such as an LSI (Large Scale Integration) or an ASIC (Application Specific Integrated Circuit). Functional units that realize the functions of the control unit 110 will be described later.

[0019] The input / output unit 140 is connected to other devices wirelessly or via a wire to input and output various types of data. The input / output unit 140 includes, for example, an input / output interface or a communication interface. The input / output unit 140 is connected to, for example, the light source 20 and the detector 30.

[0020] The operation unit 150 receives a user operation and generates an operation signal corresponding to the received operation. The operation unit 150 may include dedicated components such as buttons, knobs, and dials, or general-purpose components such as a mouse and keyboard. The operation unit 150 may be an input interface that receives an operation signal wirelessly or via a wired connection from another device. The other device may be, for example, a remote controller, a portable device such as a multi-function mobile phone, or the like. The operation unit 150 outputs the acquired operation signal to the control unit 110.

[0021] Display unit 160 displays display information such as images, characters, and symbols based on display data input from control unit 110. Display unit 160 may include, for example, a liquid crystal display, an organic electroluminescence display, or the like.

[0022] In addition to the above programs, the storage unit 170 stores various data used in the processes executed by the control unit 110 and various data acquired by the control unit 110. The storage unit 170 includes, for example, a non-volatile (non-temporary) storage medium such as a ROM (Read Only Memory), a flash memory, or an HDD (Hard Disk Drive). The storage unit 170 also includes a volatile storage medium such as a RAM (Random Access Memory), a register, or the like.

[0023] The control unit 110 includes a measurement control unit 112, a determination unit 114, and a display processing unit . The measurement control unit 112 controls the measurement of visible light generated in response to ultraviolet light irradiated onto the test object Sp. For example, when a measurement is instructed in response to an operation, the measurement control unit 112 causes the light source 20 to irradiate the test object Sp with ultraviolet light and causes the detector 30 to detect visible light generated on the surface of the test object Sp.

[0024] The determination unit 114 acquires a detection signal indicating the intensity of the detected light from the detector 30. The determination unit 114 identifies the intensity of visible light from the light indicated by the detection signal. A detection threshold for the intensity of visible light is preset in the determination unit 114. For example, the detection threshold is set as a real value that is significantly greater than the intensity of visible light obtained by irradiating the non-tin surface of the test object Sp with ultraviolet light at a reference intensity and significantly smaller than the intensity of visible light obtained by irradiating the tin surface of the test object Sp with ultraviolet light at the reference intensity. When the identified intensity is equal to or greater than the detection threshold, the determination unit 114 determines that the ultraviolet light irradiated area of ​​the test object Sp is on the tin surface (the top surface in the example of FIG. 1). When the identified intensity is less than the detection threshold, the determination unit 114 determines that the ultraviolet light irradiated area of ​​the test object Sp is on the non-tin surface. The determination unit 114 outputs determination information indicating the determination result to the display processing unit 116.

[0025] The display processing unit 116 configures various display screens and outputs display data showing the configured display screens to the display unit 160. The display unit 160 displays the display screens based on the display data input from the display processing unit 116. The display screen includes, for example, a guide display related to the above-mentioned measurement. Specifically, a measurement button may be arranged on the display screen. The measurement button is an example of a screen component for instructing measurement by operation. When detecting the pressing of the measurement button, the measurement control unit 112 can determine that a measurement has been instructed. For example, the measurement control unit 112 detects the pressing of the measurement button when the position indicated by the operation signal input from the operation unit 150 indicates a position within the measurement button.

[0026] The display screen may include the measurement results obtained by the above-mentioned measurements. Specifically, the display processing unit 116 includes the determination information input from the determination unit 114 on the display screen. When a detection signal indicating a captured image of the surface of the test subject Sp is acquired from the detector 30, the display processing unit 116 may include the captured image indicated by the acquired detection signal on the display screen together with the determination information.

[0027] Next, the measurement principle for distinguishing between tin surfaces in this embodiment will be described. Tin surface distinction utilizes differences in fluorescence intensity due to differences in the surface on which the ultraviolet light irradiation area of ​​the test object is located. FIG. 3 shows a case where the float glass test object is arranged with the tin surface (B surface) on top and the non-tin surface (T surface) on the bottom, and ultraviolet light is directly irradiated onto the top surface from light source 20 (UV irradiation). Part of the ultraviolet light incident on the top surface is reflected, and the other part passes through the interior of the test object. Of the incident ultraviolet light, the ultraviolet light that passes through the interior of the test object is attenuated. Fluorescence corresponding to the intensity of the incident ultraviolet light is generated in the area of ​​the tin surface on the test object where the ultraviolet light is incident.

[0028] Figure 4 shows a case where the float glass under test is placed with the non-tin side (T side) on top and the tin side (B side) on the bottom, and ultraviolet light is directly irradiated from a light source onto the top side. In this case, no fluorescence is generated on the non-tin top side. When ultraviolet light passes through the top side of the test object and reaches the tin bottom side, fluorescence corresponding to its intensity is generated. Because ultraviolet light is attenuated as it passes through the inside of the test object, the intensity of the fluorescence generated is lower than in the example of Figure 3. Therefore, in the example of Figure 4, the intensity of the fluorescence generated by ultraviolet light irradiation is lower than in the example of Figure 3.

[0029] Figure 5 shows the measurement results of the spectral intensity of light emitted from the top surface of a test object when ultraviolet light of a fixed wavelength (280 nm) and intensity was irradiated onto the top surface. Measurements were performed using a spectrophotometer placed close to the top surface of the float glass, with the tin side (side B) and the non-tin side (side T) on top. The test object was a 3.1 mm thick float glass. In Figure 5, the peak of intensity at a wavelength of 280 nm represents the irradiated ultraviolet light. Fluorescence has components in a wide band from 300 nm to 750 nm. In the visible light band with wavelengths of 400 nm or longer, the intensity when the tin side is on top is significantly higher than the intensity when the non-tin side is on top.

[0030] Figure 6 shows the integrated intensity when the tin surface is the top surface and when the non-tin surface is the top surface. The integrated intensity is calculated by integrating the intensity for each wavelength shown in Figure 5 over wavelengths of 400 nm or more. As a result, the ratio of the integrated intensity when the tin surface is the top surface to the integrated intensity when the non-tin surface is the top surface was approximately 1.7 times. This result confirms that it is possible to determine whether the surface on which the ultraviolet light is irradiated is a tin surface or not, depending on the intensity of the fluorescence generated by ultraviolet light irradiation.

[0031] Next, we will consider the condition of the objects under inspection. Figure 7 is a diagram illustrating the condition of four types of objects under inspection. Each column in Figure 7 shows a visible light image and a fluorescent X-ray image of the tin surface of each object under inspection, one above the other. The display range of the fluorescent X-ray image corresponds to the area on the top surface of the object under inspection at the starting point of the arrow. The distribution of tin adhering to the object under inspection is shown by the distribution of shades in the fluorescent X-ray image. The size of the display range is 10 mm x 10 mm in all cases. Of the four types, the three on the left correspond to different areas on the surface of a float glass blank. The blank dimensions are 3.1 mm thick, 100 mm long, and 100 mm wide. The three areas are indicated, from left to right, as the R side, L side, and C side. The R side, L side, and C side respectively refer to the right end, left end, and center in the direction of travel of the glass ribbon in the float glass forming process. The remaining one of the four types represents tempered glass obtained by thermally tempering and bending the blank. Thermal tempering involves heating the blank and then rapidly cooling it. Bending involves deforming the blank while it is heated, either by its own weight or by applying an external force to it. Previously, it was anticipated that some of the tin adhering to the blank might fall off during thermal tempering or bending.

[0032] However, as shown in Figure 7, tin is distributed uniformly in all four types of test specimens, with no significant differences between them. This indicates that tin is distributed uniformly throughout the entire blank, and that thermal strengthening and bending do not affect the tin distribution. Conversely, this also indicates that it is possible to determine whether the surface is tin or non-tin, regardless of conditions such as thermal strengthening and bending, even by irradiating only a small portion of the test specimen with ultraviolet light.

[0033] Next, an example of a display screen according to this embodiment will be described. FIG. 8 is a diagram illustrating a display screen according to this embodiment. The left side of the display screen shows an example of a captured image of the surface of the test object Sp. The captured image is an image captured using a camera corresponding to the detector 30. The imaging element of the camera is mainly sensitive to visible light. The captured image is a monochrome image in which the brighter the area, the higher the intensity of light emitted from the test object Sp. The white parallelogram area from the center to the bottom left of the captured image indicates the area irradiated with ultraviolet light incident from the light source 20. The captured image shows a state in which fluorescence is emitted in the irradiated area. The dark area around it is a non-irradiated area that is not irradiated with ultraviolet light.

[0034] The right side of the display screen displays the detection characteristics and judgment results of the irradiated area obtained by analyzing the captured image. The judgment unit 114, for example, judges whether the density value of each pixel representing the captured image is equal to or greater than a predetermined reference density value. The density value is sometimes called a luminance value. The judgment unit 114 detects a spatially continuous area (blob) of pixels having density values ​​equal to or greater than the reference density value as the irradiated area. The judgment unit 114 attaches a label to the detected irradiated area to identify the area. The judgment unit 114 calculates the sum of the density values ​​of each pixel in the detected irradiated area as a measurement value. The calculated measurement value indicates the intensity of visible light emitted from the irradiated area. The judgment unit 114 can determine whether the surface having the irradiated area is a tin surface based on whether the calculated measurement value is greater than a predetermined lower limit. This lower limit value indicates the reference density value.

[0035] In Figure 8, the detected gray level indicates the most frequent density value in the detected illuminated area. The reference density value is the threshold density value used to detect the illuminated area. The total area indicates the number of pixels contained in the detected illuminated area. The number of labels corresponds to the number of illuminated areas detected from the captured image. The judgment label column describes the judgment result and the numerical value that is the basis of the judgment result. The average gradation level corresponds to the average value of the density values ​​within the detected irradiated area. The maximum gradation level is the maximum value of the density values ​​within the irradiated area. The judgment column describes a value that indicates whether the irradiated area is a tin surface or not. A value of 1 indicates that the irradiated area is a tin surface. A value of 0 indicates that the irradiated area is a non-tin surface. The measurement value indicates the sum of the density values ​​within the irradiated area. The lower limit corresponds to the threshold value for determining whether the irradiated area is a tin surface or not.

[0036] The lower limit used to judge the tin surface depends on the thickness of the float glass being inspected. This is because the intensity of the irradiated ultraviolet light varies depending on the thickness of the inspected object, and the brightness of the fluorescent light emitted from the irradiated area varies. Therefore, the judgment unit 114 sets a lower limit for each thickness of the inspected object, and compares it with the measurement value derived from the captured image obtained using that lower limit.

[0037] FIG. 9 shows examples of measurement values ​​for bent plates (i.e., curved glass) of different plate thicknesses. In FIG. 9, convex B indicates a case where the convex surface of the bent plate is a tin surface and is an ultraviolet irradiated area. Convex T indicates a case where the convex surface of the bent plate is a non-tin surface and is an irradiated area. Concave B indicates a case where the concave surface of the bent plate is a tin surface and is an irradiated area. Concave T indicates a case where the concave surface of the bent plate is a non-tin surface and is an irradiated area. According to FIG. 9, the measurement value when the irradiated area is on the tin surface is significantly larger than the measurement value when it is on the non-tin surface. This confirms the effectiveness of determining the tin surface based on measurement values ​​derived from the density values ​​of the captured image.

[0038] The measured values ​​tend to increase as the plate thickness increases. For every 2 mm increase in plate thickness, the measured values ​​increase by 20%. Furthermore, there is no significant difference in the measured values ​​whether the irradiated area is on a convex or concave surface. Furthermore, there is no significant difference in the measured values ​​between flat plates of the same thickness (not shown), between test pieces arranged in different orientations in the horizontal plane (not shown), or between test pieces arranged at different inclinations from the horizontal plane (not shown). This indicates that the tin surface can be identified using a common reference intensity for each plate thickness, regardless of the presence or absence of bending, unevenness, inclination, or orientation of the test piece.

[0039] According to FIG. 9, the ratio of the measured value for the concave B or concave T to the measured value for the convex B or convex T was almost constant (about 0.5) regardless of the plate thickness. Therefore, the inspection system S2 may include two light sources 20a and 20b and two detectors 30a and 30b, as illustrated in Fig. 10. Fig. 10 is a schematic diagram showing a second configuration example of the inspection system according to this embodiment. The light source 20a and the detector 30a are installed in a direction facing the upper surface of the object to be inspected Sp, similar to the light source 20 and the detector 30 illustrated in FIG. On the other hand, the light source 20b and the detector 30b are placed in a direction facing the bottom surface of the object Sp to be inspected.

[0040] The light source 20b and the detector 30b are supported, for example, on the floor of a room. For example, the direction of ultraviolet light emitted from the light source 20b is set to a direction at an acute angle with the horizontal plane. The position of the detector 30 in the horizontal plane is adjusted so that the area of ​​ultraviolet light irradiated on the bottom surface of the test object Sp is oriented in the detection direction (e.g., vertical direction) of the detector 30b. The base Bp may have an opening through which ultraviolet light is irradiated from the light source 20b onto the bottom surface of the test object Sp and visible light emitted from the bottom surface of the test object Sp passes to the detector 30b. The base Bp may have, for example, a lattice shape or a radial concentric circle shape.

[0041] When a measurement command is issued under this system configuration, the measurement control unit 112 causes the light source 20a to irradiate the top surface of the test object Sp with ultraviolet light and causes the detector 30a to detect visible light emitted from the top surface of the test object Sp. The measurement control unit 112 also causes the light source 20b to irradiate the bottom surface of the test object Sp with ultraviolet light and causes the detector 30b to detect visible light emitted from the bottom surface of the test object Sp. The time at which ultraviolet light is emitted from the light source 20b is set to be different from the time at which ultraviolet light is emitted from the light source 20a.

[0042] The determination unit 114 acquires, as a first measurement value, a measurement value measured on the top surface of the test object Sp as an ultraviolet ray irradiation area based on the detection signal acquired from the detector 30a. The determination unit 114 acquires, as a second measurement value, a measurement value measured on the bottom surface of the test object Sp as an ultraviolet ray irradiation area based on the detection signal acquired from the detector 30b. The determination unit 114 calculates the intensity ratio between the acquired first and second measurement values, compares the calculated intensity ratio with a predetermined reference value of the intensity ratio, and determines whether the top surface of the test object is a tin surface or a non-tin surface based on whether the calculated intensity ratio is equal to or greater than the reference value or equal to or less than the reciprocal of the reference value. A real number significantly greater than 1 (e.g., 1.2 to 1.8) is preset in the determination unit 114 as the reference value of the intensity ratio. This configuration enables the determination of a tin surface using a common reference value independent of the thickness of the test object. Therefore, even when a plurality of types of test objects are inspected on a common line, there is no need to adjust the reference values, which contributes to reducing the inspection cost.

[0043] Note that the determination unit 114 may cause the display processing unit 116 to present warning information when the calculated intensity ratio is greater than the reciprocal of the reference value but is equal to or less than the reference value. The display processing unit 116 may, for example, cause the display unit 160 to display a message on the display screen indicating that the measurement was not performed correctly as warning information. In this case, it indicates that there is no significant difference between the intensity of visible light from the top surface and the bottom surface of the test object Sp. Possible causes for this include mistaking the test object Sp for another object, incorrect installation of the test object Sp, or a malfunction of the light sources 20a, 20b or the detectors 30a, 30b. Therefore, the user who comes across the warning information can be prompted to check the settings of the testing system S2.

[0044] Next, an example of an inspection method according to this embodiment will be described below with reference to a flowchart shown in FIG. (Step S102) The measurement control unit 112 causes the light source 20a to irradiate the upper surface of the inspection object Sp with ultraviolet light (UV irradiation), and causes the detector 30a to detect visible light generated on the upper surface of the inspection object Sp. (Step S104) The determining unit 114 measures a first measurement value as an index of the visible light intensity a based on the detection signal from the detector 30a.

[0045] (Step S106) The measurement control unit 112 causes the light source 20b to irradiate the bottom surface of the test object Sp with ultraviolet light (UV irradiation), and causes the detector 30b to detect visible light generated on the bottom surface of the test object Sp. (Step S108) The determination unit 114 measures a second measurement value as an index of the visible light intensity b based on the detection signal from the detector 30b.

[0046] (Step S110) The determination unit 114 calculates the ratio of the first measurement value to the second measurement value as the intensity ratio a / b, and determines whether the intensity ratio a / b is equal to or greater than a predetermined reference value for the intensity ratio. If the intensity ratio a / b is equal to or greater than the reference value (YES in step S110), the process proceeds to step S114. If the intensity ratio a / b is less than the reference value (NO in step S110), the process proceeds to step S112.

[0047] (Step S112) The determination unit 114 determines whether the intensity ratio a / b is equal to or less than the reciprocal of the reference value. If the intensity ratio a / b is equal to or less than the reciprocal of the reference value (YES in step S112), the process proceeds to step S116. If the intensity ratio a / b is greater than the reciprocal of the reference value (NO in step S112), the display processing unit 116 is caused to present warning information, and the process in FIG. 11 is terminated. (Step S114) The determination unit 114 determines that the top surface of the object to be inspected Sp is a tin surface, and then ends the processing of FIG. (Step S116) The determination unit 114 determines that the bottom surface of the test object Sp is a tin surface, and then ends the processing of FIG.

[0048] Next, an example of a support method for the object Sp to be inspected will be described. As illustrated in Fig. 12, the irradiation area Is of ultraviolet light from the light source 20 onto the object Sp to be inspected may be set closer to one support member Bs02 than to either of the other two support members Bs01 and Bs03. This setting suppresses vibrations that occur in the irradiation area Is compared to when the irradiation area Is is equidistant from the three support members Bs01 to Bs03, and therefore allows for stable measurement of the intensity of visible light, thereby improving the reliability of the tin surface determination results.

[0049] Holding materials Sk01 to Sk03 may be further arranged on the base Bp, and the test object Sp may be placed on the holding materials Sk01 to Sk03 to be held thereon. The holding materials Sk01 to Sk03 may be flexible and have adhesive properties to the bottom surface of the test object Sp. For example, suction cups made of synthetic rubber, silicone resin, or the like may be used as the holding materials Sk01 to Sk03. The height of each holding material Sk01 to Sk03 may be equal to the height of the support materials Bs01 to Bs03. Each holding material may be placed such that it is sandwiched between two support materials in the direction from the center of gravity of the top surface of the base Bp. In the example of FIG. 12, one of the support materials Bs01 to Bs03 and one of the holding materials Sk01 to Sk03 are alternately arranged on a single circumference. By distributing two types of materials, it is possible to prevent one type of material from concentrating in a specific area. 12 illustrates an example in which the reference point in each direction of the support materials Bs01-Bs03 or the holding materials Sk01-Sk03 is the center of gravity, but this is not limiting. Depending on the shape of the board Bp, the equipment arrangement in the inspection system S1, and other requirements, a position other than the center of gravity may be set as the reference point. If the shape of the board Bp is polygonal, the reference point may be, for example, the circumcenter, incenter, orthocenter, or eccenter, etc.

[0050] Consider the case where the bent plate shown in FIG. 12 is the object Sp to be inspected, with the convex surface as the bottom, and is supported by three supports Bs01 to Bs03. In this case, the bent plate may tilt from the horizontal plane. Furthermore, the relative position and orientation of the object Sp to the supports Bs01 to Bs03 may change when the object Sp is attached or detached. Therefore, the tilt angle of the bent plate may change due to the change in position and orientation. Therefore, the orientation of the horizontal plane was changed and the tilt angle of the bent plate placed on the supports Bs01 to Bs03 was measured.

[0051] FIG. 13 is a diagram illustrating the inclination angles of the bent plates placed on the support members Bs01 to Bs03. The radius of curvature of the bent plates is 1000 mm (1000R). The support members Bs01 to Bs03 are placed at the vertices of an equilateral triangle with a side length of 15 cm. The inclination angles of the test object Sp vary depending on the azimuth angle, but are all less than 1 degree. This indicates that the test object Sp has a curved surface and is stably supported even if its position or orientation changes due to attachment or detachment.

[0052] The above-described determination of the tin surface may be performed independently of or synchronously with the production process in which the specimen Sp is an intermediate product or a final product. As illustrated in Fig. 14, the inspection system S3 may include an inspection device 10, a light source 20, and a detector 30, as well as a conveyor 22 and an inspected object detection unit 23. Fig. 14 is a schematic diagram showing a third configuration example of the inspection system according to this embodiment. The conveyor 22 transports the objects to be inspected Sp that are carried out from the previous process toward equipment for the next process. The previous process may include a production process for the objects to be inspected Sp. The objects to be inspected Sp are transported while being supported on the conveyor 22.

[0053] When the specimen Sp is a float glass, the pre-processing may include a part or all of the process of producing a raw float glass sheet, which includes, for example, a process of melting glass raw materials in a melting furnace, a process of pouring the molten glass into a float bath containing molten tin, a process of cooling the glass ribbon flowing out of the float bath in an annealing furnace, and a process of cutting the cooled series of float glass sheets.

[0054] The inspected object detection unit 23 detects the inspected object Sp transported on the conveyor 22. The inspected object detection unit 23 includes, for example, a light projector 23a and a light receiver 23b, and is installed at positions facing each other across the conveyor 22. The light receiver 23b includes a light receiving element that receives the inspection light projected from the light emitting element of the light projector 23a. When the inspection light is attenuated by the passage of the inspected object Sp, the received light intensity at the light receiver 23b becomes lower than a predetermined intensity threshold. At this time, the light receiver 23b can detect the passing inspected object Sp. When the received light intensity is equal to or higher than the detection threshold, the light receiver 23b does not detect the passing inspected object Sp. When the inspected object detection unit 23 detects the inspected object Sp, it outputs an inspected object detection signal indicating the detection to the inspection device 10.

[0055] When a test object detection signal is input from the test object detection unit 23, the measurement control unit 112 of the inspection device 10 causes the light source 20 to irradiate the test object Sp with ultraviolet light and causes the detector 30 to detect visible light generated on the top surface of the test object Sp. The determination unit 114 determines whether or not the top surface of the specimen Sp is a tin surface based on the intensity of visible light notified by the detection signal input from the detector 30. The determination unit 114 may notify the equipment in the subsequent process of determination information indicating the determination result.

[0056] If the specimen Sp is float glass, a post-process may include, for example, UV-blocking coating. In this case, a coating device may be included as equipment for performing the post-process. The coating device determines whether the top surface of the specimen Sp is a tin surface or not as a result of the determination indicated by the determination information input from the inspection device 10. The coating device applies an ultraviolet-blocking coating to the non-tin surface of the specimen Sp carried in from the conveyor 22.

[0057] The inspection system S3 may be realized as part of a production system for functional float glass coated with a UV-cut coating. This production system produces functional float glass by carrying out the steps of producing float glass, determining the tin side of the produced float glass as an inspection object Sp, and applying an ultraviolet-blocking paint to the non-tin side. In other words, this production system carries out a production method for functional float glass, including the steps of producing raw float glass sheets, determining the tin side of the produced raw float glass sheets as inspection objects Sp, and applying an ultraviolet-blocking paint to the non-tin side.

[0058] As described above, the inspection systems S1 to S3 according to this embodiment include light sources 20, 20a, 20b that irradiate ultraviolet rays onto an object to be inspected Sp, including float glass, detectors 30, 30a, 30b that detect the intensity of visible light generated in the irradiated area on the surface of the object to be inspected Sp irradiated with ultraviolet rays, and a judgment unit 114 that judges whether the irradiated area is on a tin surface on which tin is distributed, based on the intensity of the visible light. With this configuration, it is possible to accurately determine whether the surface of the object to be inspected Sp is a tin surface, regardless of the position of the irradiation area, the inclination, curvature, or processing state of the object to be inspected Sp.

[0059] It is preferable that the judgment unit 114 measures the intensity ratio between a first intensity of visible light generated in an irradiated area on a first surface (e.g., the top surface) facing a first direction of the test object Sp and a second intensity of visible light generated in an irradiated area on a second surface (e.g., the bottom surface) facing a second direction opposite to the first direction, and judges whether the first surface or the second surface is a tin surface based on whether the intensity ratio is greater than or equal to a reference value greater than 1 of a predetermined intensity ratio, or less than the reciprocal of the reference value. This configuration allows accurate determination of whether the ultraviolet ray irradiation area is a tin surface or not, using a common reference value that is independent of the thickness of the test object Sp. Furthermore, by using a common reference value, the inspection process can be shared for multiple types of test objects Sp with different thicknesses, thereby reducing the cost of inspection.

[0060] It is preferable that the determining unit 114 provides warning information when the intensity ratio is greater than the reciprocal of the reference value and smaller than the reference value. This configuration makes it possible to prompt a user who comes across the warning information to check the settings of the inspection system S1.

[0061] The object to be inspected Sp is preferably supported by three or more supporting members Bs01 to Bs03 arranged at different positions on the base Bp. With this configuration, one type of surface is determined that contacts the vertices of the supporting materials Bs01 to Bs03, so that the objects to be inspected Sp placed on the supporting materials Bs01 to Bs03 are stably supported.

[0062] The irradiation area where the ultraviolet light is irradiated is preferably set at a position that is biased relative to one of the support materials (for example, support material Bs01) compared to the other support materials (for example, support materials Bs02, Bs03). With this configuration, the irradiation area is set in an area with less vibration than the center of gravity of the support materials Bs01 to Bs03, making it possible to stabilize the measurement of the intensity of visible light generated in the irradiation area, and ultimately to accurately determine the tin surface.

[0063] The specimen Sp is preferably held on the base Bp using three or more holding members arranged at positions different from the support member. With this configuration, the specimen Sp placed on the apex of the support member is held by a holding member arranged at a different position, thereby further stabilizing the position of the specimen Sp.

[0064] It is preferable that the determining unit 114 determines the non-tin surface, which is the surface facing in the opposite direction to the tin surface, as the surface to be coated with the ultraviolet ray blocking paint. With this configuration, the ultraviolet ray blocking paint is applied to the non-tin surface of the object to be inspected Sp, and application to the tin surface is avoided, thereby improving the reliability of the object to be inspected Sp.

[0065] In addition, in the inspection method of the inspection systems S1 to S3 according to this embodiment, light sources 20, 20a, and 20b irradiate ultraviolet rays onto the surface of the object Sp to be inspected, which includes float glass, and detectors 30, 30a, and 30b detect the intensity of visible light generated in the irradiated area on the surface of the object Sp to be inspected, which is irradiated with ultraviolet rays, and determine whether the irradiated area is a tin surface on which tin is distributed, based on the intensity of the visible light. The inspection system S1 may be realized as part of a production system for functional float glass. The production system for functional float glass further executes a production method for functional float glass, in which an ultraviolet ray transmission preventing paint is applied to a non-tin surface, which is a surface facing in the opposite direction from the surface determined to be the tin surface.

[0066] The above has described in detail an embodiment of the present invention with reference to the drawings, but the specific configuration is not limited to that described above, and various design modifications can be made within the scope that does not deviate from the gist of the present invention.

[0067] For example, the inspection device 10 may be realized as part of a production facility that produces the object to be inspected Sp as an intermediate product, or may be a single device separate from the inspection system S1. The inspection device 10 may include an operation unit 150 and a display unit 160, or some or all of these may be omitted. The operation unit 150 and the display unit 160 may be connected to each other via an input / output unit 140 in a wired or wireless manner. The inspection device 10 may further include one or both of a light source 20 and a detector 30. In the inspection device 10, the measurement control unit 112 and the display processing unit 116 may be omitted in part or in whole.

[0068] Furthermore, part or all of the inspection device 10 in the above-described embodiment may be realized as an integrated circuit such as an LSI (Large Scale Integration). Each functional block of the inspection device 10 may be individually implemented as a processor, or part or all of the functional blocks may be integrated into a processor. Furthermore, the integrated circuit implementation method is not limited to LSI, and may be implemented using a dedicated circuit or a general-purpose processor. Furthermore, if an integrated circuit implementation technology that can replace LSI emerges due to advances in semiconductor technology, an integrated circuit based on that technology may be used. [Explanation of symbols]

[0069] S1 to S3... inspection system, 10... inspection device, 20, 20a, 20b... light source, 22... conveyor, 23... inspection object detection unit, 23a... light projector, 23b... light receiver, 30, 30a, 30b... detector, 110... control unit, 112... measurement control unit, 114... judgment unit, 116... display processing unit, 140... input / output unit, 150... operation unit, 160... display unit, 170... memory unit, Bp... base, Bs01 to Bs03... support material, Sk01 to Sk03... holding material, Sp... inspection object

Claims

1. a light source that irradiates an object to be inspected, including float glass, with ultraviolet light; a detector for detecting the intensity of visible light generated in an irradiated area on the surface of the object to be inspected that is irradiated with the ultraviolet light; and a determination unit that determines whether the irradiated area is on a tin surface where tin is distributed based on the intensity of the visible light. Inspection system.

2. the determination unit determines a first intensity of the visible light generated in an irradiation region on a first surface of the object under test facing a first direction; measuring an intensity ratio between the first and second intensities of the visible light generated in an irradiated area on a second surface facing in a second direction opposite to the first direction; Based on whether the intensity ratio is equal to or greater than a reference value that is greater than 1 of a predetermined intensity ratio, or equal to or less than the reciprocal of the reference value, Determine whether the first surface is a tin surface or whether the second surface is a tin surface. The inspection system of claim 1 .

3. The determination unit When the intensity ratio is greater than the reciprocal of the reference value and less than the reference value, Provide cautionary information The inspection system of claim 2 .

4. The test object is supported by three or more supports arranged at different positions on the base. The inspection system of claim 1 .

5. The irradiation area is set at a position offset relative to one of the support members relative to the other support members. The inspection system of claim 4 .

6. The test object is held on the base using three or more holding members arranged at positions different from the support member. The inspection system of claim 4 .

7. The determination unit The non-tin surface, which faces in the opposite direction to the tin surface, is defined as the surface to be coated with the ultraviolet ray transmission prevention paint. The inspection system of claim 1 .

8. The light source irradiates the test object including the float glass with ultraviolet light, causing a detector to detect the intensity of visible light generated in an irradiated area on the surface of the test object irradiated with the ultraviolet light; Based on the intensity of the visible light, it is determined whether the irradiated area is on a tin surface where tin is distributed. Inspection equipment.

9. 1. A method of inspection in an inspection system including a light source and a detector, comprising: the light source irradiates ultraviolet light onto the surface of the object to be inspected, the surface including the float glass; the detector detects the intensity of visible light generated in an irradiation area on the surface of the test object irradiated with the ultraviolet light; Based on the intensity of the visible light, it is determined whether the irradiated area is on a tin surface where tin is distributed. Testing method.

10. Execute the inspection method according to claim 9, The non-tin surface, which faces in the opposite direction to the tin surface, is coated with an ultraviolet light blocking paint. A method for producing functional float glass.

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