JP2013117432A - Glass substrate inspection device and glass substrate manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a glass substrate inspection device and a glass substrate manufacturing method which enable inspection of condition of a glass substrate or the like including such as material, thickness, and end face condition, with a simple configuration.SOLUTION: A glass substrate inspection device acquires images of a glass substrate irradiated with light from a light source, and inspects the glass substrate on the basis of image data of the images. The device includes: imaging means for acquiring the glass substrate with a plurality of images; and thickness detection means for calculating thickness of the glass substrate on the basis of the image data of the images acquired by the imaging means.

Description

  The present invention relates to a glass substrate inspection apparatus for inspecting the glass substrate based on image data obtained by irradiating a glass substrate with light from a light source and a method for manufacturing the glass substrate inspected by the glass substrate inspection apparatus.

  Conventionally, as described in, for example, Patent Literature 1 to Patent Literature 5, there is a method of irradiating a light-transmitting object with light and capturing an image, and identifying the color of the light-transmitting object from the captured image information. Are known. According to this method, the material or the like of the light transmissive object can be determined based on the identified color.

JP 2000-162045 A JP 2001-133328 A Japanese Patent Laid-Open No. 3-200025 JP 2002-207994 A JP 2000-28435 A

  In the above conventional technology, for example, it is difficult to obtain information on the thickness of a light transmitting object such as a glass substrate or the state of the end face of the glass substrate, and it is insufficient as a method for inspecting the state of the glass substrate or the like . Further, when the glass substrate is being inspected, foreign matter may adhere to the surface of the glass substrate, and the foreign matter may become a surface foreign matter defect of the glass substrate product.

  The present invention has been made in view of the above circumstances, and is a glass substrate inspection apparatus that inspects the state of a glass substrate or the like with a simple configuration, and an inspection process that inspects a glass substrate using the inspection apparatus. It aims at providing the manufacturing method of the glass substrate which has this.

  The present invention employs the following configuration in order to achieve the above object.

  The present invention captures an image of a glass substrate irradiated with light from a light source and captures the glass substrate in a plurality of images in a glass substrate inspection apparatus that inspects the glass substrate based on image data of the image. And a plate thickness detecting unit that calculates a plate thickness of the glass substrate based on image data of the image captured by the imaging unit.

  According to the present invention, the state of a glass substrate or the like can be inspected with a simple configuration.

It is a figure which shows an example of the hardware constitutions of the glass substrate test | inspection apparatus of 1st embodiment. It is a figure for demonstrating the imaging device of 1st embodiment. It is a figure for demonstrating the glass substrate accommodated in the cassette and cassette. It is a figure explaining the function which the analysis device of a first embodiment has. It is a figure which shows the example of the image imaged with the imaging device of 1st embodiment. It is a figure which shows an example of the table | surface of a glass substrate material and a specific color. It is a 1st figure explaining the detection of the state of an end surface. It is a flowchart explaining operation | movement of the glass substrate test | inspection apparatus of 1st embodiment. It is a figure explaining the function which the analysis device of a second embodiment has. It is a flowchart explaining operation | movement of the glass substrate test | inspection apparatus of 2nd embodiment. It is a figure explaining the function which the analysis device of a third embodiment has. It is a figure which shows the example of the image imaged with the imaging device of 3rd embodiment. It is a figure explaining the board thickness calculation part of 3rd embodiment. It is a flowchart explaining calculation of the plate | board thickness of the glass substrate by the plate | board thickness calculation part of 3rd embodiment. It is a figure explaining the pair edge detection in 3rd embodiment. It is a figure explaining the setting of the area | region by the area | region setting part of 3rd embodiment. It is a figure explaining the imaging device of 4th embodiment. It is a figure which shows the example of the positional relationship of the camera and cassette of 4th embodiment. It is a figure explaining the imaging device of a fifth embodiment.

(First embodiment)
A first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram illustrating an example of a hardware configuration of the glass substrate inspection apparatus according to the first embodiment.

  The glass substrate inspection apparatus 100 of this embodiment includes an analysis apparatus 200 and an imaging apparatus 300. The glass substrate inspection apparatus 100 according to the present embodiment inspects the glass substrate 500 without contacting the glass substrate 500 to be described later by using a result obtained by analyzing the image data captured by the imaging apparatus 300 by the analysis apparatus 200. . The glass substrate 500 inspected by the glass substrate inspection apparatus 100 of the present embodiment is, for example, a glass substrate for a magnetic recording medium.

  In the analysis device 200 of this embodiment, an arithmetic processing device 210, a memory device 220, an auxiliary storage device 230, an interface device 240, an input device 250, an output device 260, and a drive device 270 are connected via a bus B.

  The input device 250 includes a keyboard, a mouse, an operation switch, and the like, and is used for inputting various signals. The output device 260 includes a display device and is used to display various windows and data. The interface device 240 includes a modem, a LAN card, and the like, and is used for connecting the glass substrate inspection device 100 to a network, for example.

  The glass substrate inspection program of the present invention is at least a part of various programs for controlling the glass substrate inspection apparatus 100. The glass substrate inspection program is provided, for example, by distributing the recording medium 280 or downloading from a network. The recording medium 280 on which the glass substrate inspection program is recorded is a recording medium on which information is optically, electrically or magnetically recorded, such as a CD-ROM, flexible disk, magneto-optical disk, ROM, flash memory, etc. Various types of recording media such as a semiconductor memory for electrically recording information can be used.

  When the recording medium 280 on which the glass substrate inspection program is recorded is set in the drive device 270, the glass substrate inspection program is installed in the auxiliary storage device 230 from the recording medium 280 via the drive device 270. The glass substrate inspection program downloaded from the network is installed in the auxiliary storage device 230 via the interface device 240.

  The auxiliary storage device 230 stores the installed glass substrate inspection program and also stores necessary files, data, and the like. The memory device 220 reads and stores the glass substrate inspection program from the auxiliary storage device 230 when the computer is activated. The arithmetic processing unit 210 implements various processes as described later according to a glass substrate inspection program stored in the memory device 220.

  The imaging device 300 according to the present embodiment includes an illumination device 310, a driving device 320, and a camera 330, and performs imaging in a state where light is emitted from the illumination device 310 to a glass substrate. The driving device 320 moves the lighting device 310 and the cassette in a state where the cassette 400 (see FIG. 2) in which the glass substrate to be inspected is stored in the lighting device 310 is fixed.

  Hereinafter, an imaging apparatus 300 according to the present embodiment will be described with reference to FIG. The imaging device 300 and the analysis device 200 may be separated from each other, and in that case, they may be connected via a LAN (Local Area Network) or the like. Further, a plurality of imaging devices 300 may be connected to the analysis device 200 for use.

  FIG. 2 is a diagram for explaining the imaging apparatus according to the first embodiment. FIG. 2A is a diagram illustrating a state where a cassette 400 in which a glass substrate to be imaged is stored is arranged in the imaging apparatus 300, and FIG. 2B illustrates the cassette base 340 of the imaging apparatus 300. It is a figure to do.

  In the imaging apparatus 300 of the present embodiment, the illumination device 310 is disposed on the illumination device base 301, and the cassette base 340 is disposed so as to cover the illumination device 310. The cassette base 340 may be provided with a slit 341 (see FIG. 2B) that transmits light emitted from the lighting device 310. The illuminating device 310 of this embodiment is implement | achieved by LED etc., for example. On the cassette base 340, a cassette 400 in which a glass substrate as an inspection object is stored is disposed. Details of the cassette base 340 and the cassette 400 will be described later.

  A column 302 for mounting the camera 330 is attached to the column fixing base 305, and the camera 330 is fixed to the column 302. The camera of this embodiment is a CCD (Charge Coupled Device) camera or the like, for example. Further, a cover 303 is covered on the support fixing base 305 so as to cover the illumination device 310, the cassette 400, and the camera 330. The cover 303 of the present embodiment has a light shielding property that prevents light outside the imaging apparatus 300 from passing through the cover 303.

  In the present embodiment, the illumination device 310 is disposed on the illumination device pedestal 301, the cassette pedestal 340 covering the illumination device 310 is disposed, and the cassette 400 is disposed in the state where the cassette 400 is disposed. The lighting device 310, the cassette base 340, and the cassette 400 are fixed. In the following embodiment, a state in which the illumination device 310 and the cassette 400 are fixed to each pedestal is referred to as a fixed body 350.

  The drive device 320 of this embodiment is, for example, a single axis slider robot. The fixed body 350 is mounted on the driving device 320 so that the lighting device base 301 and the lighting device 310 horizontally move on the axis of the driving device 320. In this case, the fixed body 350 moves horizontally while being guided around the field of view of the camera 330.

  In the present embodiment, the moving direction of the fixed body 350 is a direction orthogonal to the direction in which the imaging surface 331 of the camera 330 faces. In FIG. 2A, when the direction in which the imaging surface 331 of the camera 330 faces is the Y2 direction, the moving direction of the fixed body 350 is the X1 direction or the X2 direction.

  The camera 330 of the present embodiment continuously captures a plurality of images of light transmitted through the cassette 400 when the fixed body 350 is moving on the driving device 320. Details of the captured image will be described later.

  FIG. 2B is a top view of the cassette base 340. The cassette base 340 may be provided with a slit 341. The light emitted from the illumination device 310 passes through the slit 341 and is applied to the cassette 400. By irradiating the cassette 400 with light that has passed through the slit 341, an image that can improve the accuracy of analysis by the analysis apparatus 200 can be taken. The width W of the slit 341 is not particularly limited, and is determined according to the performance of the illumination device 310 and the camera 330. For example, when an LED is used as the illumination device 310, the width W of the slit 341 may be set to about 3 mm to 7 mm. When a light source with high linearity such as a laser beam is used as the illumination device 310, the width of the slit 341 The width W may be set to 3 mm or less, or a lattice-like slit may be used.

  The imaging apparatus 300 of the present embodiment may perform imaging based on an imaging instruction from the analysis apparatus 200. Image data of an image captured by the imaging device 300 is stored in the memory device 220 of the analysis device 200 or the like. The analysis device 200 performs various analyzes described below based on the image data acquired from the imaging device 300, and inspects the glass substrate 500 stored in the cassette 400.

  Below, with reference to FIG. 3, the glass substrate 500 (500A-500C) accommodated in the cassette 400 and the cassette 400 is demonstrated. FIG. 3 is a view for explaining the cassette and the glass substrate housed in the cassette.

  In the present embodiment, the cassette 400 includes a case 410, a lid 420, and a bottom plate 421. The lid 420 of this embodiment is a light-transmitting one that covers an opening for guiding the light transmitted through the glass substrate 500 in the cassette 400 to the camera 330. The bottom plate 421 is a light-transmitting material that covers an opening for allowing light emitted from the illumination device 310 to enter the cassette 400. In the case 410 and the lid 420 of the present embodiment, a plurality of grooves 430 are formed to support the glass substrates 500 separately for each sheet. The glass substrate 500 is stored in the cassette 400 in a state where the glass substrate 500 is inserted into the groove 430 and separated one by one. Furthermore, the glass substrate 500 is held in the cassette 400 in a state of being separated one by one by a groove formed in the lid 420, and the glass substrate 500 stored when the cassette 400 is moved is prevented from moving. .

  The cassette 400 of the present embodiment can take an image of light transmitted through the bottom plate 421, the glass substrate 500, and the lid 420 by the camera 330 with the above configuration. Note that the glass substrate 500 of the present embodiment has a disk shape with a circular hole formed in the center.

  Next, functions of the analysis apparatus 200 of the present embodiment will be described. FIG. 4 is a diagram for explaining functions of the analysis apparatus according to the first embodiment.

  The analysis apparatus 200 according to this embodiment includes a drive control unit 211, an imaging control unit 212, an image data acquisition unit 213, a position correction unit 214, a pace processing unit 215, a color extraction unit 216, a material determination unit 217, and a plate thickness calculation unit 218. And an end face state detection unit 219.

  In the analysis apparatus 200 of this embodiment, the drive control unit 211 controls the drive device 320 to control the operation of the fixed body 350. Specifically, for example, upon receiving an image capturing instruction, the drive control unit 211 slides the fixed body 320 on the axis of the drive device 320 at a constant speed.

  The imaging control unit 212 controls the camera 330. Specifically, the imaging control unit 212 causes the camera 330 to capture an image at predetermined intervals when the stationary body 350 starts a sliding operation in response to an image capturing instruction. In the present embodiment, the drive control unit 211 and the imaging control unit 212 can continuously capture a plurality of light images transmitted through the cassette 400.

  In the analysis apparatus 200 of this embodiment, the image data acquisition unit 213 acquires image data of an image captured by the imaging apparatus 300. The color extraction unit 216 extracts a specific color image from the image data. The material determination unit 217 determines the material of the glass substrate 500 based on the color of the extracted image. The plate thickness calculation unit 218 calculates the plate thickness of the glass substrate 500 based on the image data. The end surface state detection unit 219 performs inspection of the state of the end surface of the glass substrate 500 and the like. The processing of each unit will be described below.

  The image data acquisition unit 213 acquires image data of an image captured by the imaging device 300. Note that image data of a plurality of images captured by the imaging device 300 may be stored in the memory device 220 of the analysis device 200.

  The position correction unit 214 corrects the acquired image data so that it is always displayed at the same position on the output device 260. The image data captured by the imaging apparatus 300 may be shifted in the position of the image on the glass substrate 500 to be inspected due to, for example, a shift when the cassette 400 is placed on the cassette base 340 or a variation in the cassette 400. is there. Therefore, the position correction unit 214 corrects the position of the image data by performing pattern matching with a predetermined reference image. In the present embodiment, the corrected image is always displayed at the same position by this position correction, so that color extraction can be performed within a predetermined area.

  The pace processing unit 215 performs preprocessing for color extraction from image data. The pace processing unit 215 removes noise from image data, for example, and designates a predetermined area for color extraction to be described later.

  Details of processing of the color extraction unit 216, the material determination unit 217, the plate thickness calculation unit 218, and the end surface state detection unit 219 will be described later.

  Here, an image captured by the camera 330 of the present embodiment will be described with reference to FIG.

  In the imaging apparatus 300 according to the present embodiment, for example, the cassette 400 in which 25 glass substrates are stored is imaged in five times so that five glass substrates are captured in one image. In the present embodiment, the glass substrates stored in the cassette 400 are photographed as a plurality of images for every predetermined number, so that all the glass substrates stored in the cassette 400 are included in one field of view of the camera 330. It is possible to obtain a higher resolution image than that obtained by imaging. In the present embodiment, when the distance between the fixed body 350 and the camera 330 is set so that all the glass substrates accommodated in the cassette 400 fall within one field of view, as an enlarged image by the zoom function of the camera 330 A high-resolution image may be acquired. Alternatively, a high-resolution image may be acquired by bringing the distance between the fixed body 350 and the camera 220 closer to the cassette 400.

  FIG. 5 is a diagram illustrating an example of an image captured by the imaging apparatus according to the first embodiment. FIG. 5 shows a case where the cassette 400 containing the glass substrates 500A to 500C of different materials shown in FIG. 3 is placed on the cassette base 340 and imaged. In the present embodiment, the captured image is displayed on the output device 260 of the analysis device 200.

  Each image captured by the imaging apparatus 300 according to the present embodiment is an image obtained by partially capturing the cassette 400 from the upper surface.

  The lid 420 of the cassette 400 according to the present embodiment transmits light emitted from the illumination device 310. Therefore, when color extraction is not performed, the images 51 to 53 include three types of light images that have passed through the glass substrates 500A to 500C, respectively. That is, the image 51 includes an image of light of a color corresponding to the material of the glass substrate 500A that has passed through the glass substrate 500A housed in the cassette 400. The image 52 includes an image of light of a color corresponding to the material of the glass substrate 500B that has passed through the glass substrate 500B housed in the cassette 400. The image 53 includes an image of light of a color corresponding to the material of the glass substrate 500C that has passed through the glass substrate 500C housed in the cassette 400.

  In the present embodiment, by performing color extraction, only an image of a predetermined color can be extracted and displayed. In the following description of the embodiment, an image of light transmitted through the glass substrate is referred to as an image of the glass substrate.

  Next, extraction of an image of a predetermined color by the color extraction unit 216 will be described. The image shown in FIG. 5 is an image when the slit 341 is provided in the cassette base 340.

  Images 51 to 53 are examples of images captured by the camera 330 in a state where the light S that has passed through the slit 341 is irradiated on the cassette 400 in which the glass substrates 500 </ b> A to 500 </ b> C are stored, and is a top view of the cassette 400. . The images 51 to 53 include an image S1 of light transmitted through the glass substrates 500A to 500C and images 500GA to 500GC of the glass substrates 500A to 500C in a state where light is irradiated.

  Below, the example which performed the process of the color extraction part 216 with respect to the image 51 is demonstrated.

  In the present embodiment, the pace processing unit 215 designates an area 511 of the image 400G as an area for performing color extraction. The region 511 is set so as to include, for example, a groove 430 into which the glass substrate 500A is inserted. The color extraction unit 216 analyzes the image of the region 511 and specifies whether the color of the image 500GA is a color to be extracted from the result. Note that colors to be extracted are set in advance in the analysis apparatus 200 of the present embodiment. In the analysis apparatus 200 of the present embodiment, the color to be extracted can be arbitrarily set by setting a range of HSV values to be described later. An area 512 is an area specified in the processing of the end face state detection unit 516 described later. The regions 511 and 512 can be arbitrarily set according to the coordinates input by the input device 250 of the analysis device 200.

  The color extraction unit 216 according to the present embodiment calculates an HSV value represented by HSV (hue, saturation, brightness) from image data based on R, G, B system component representation acquired from the imaging apparatus 300. The color extraction unit 216 identifies and extracts the region as the set color region when there is a region having an HSV value within the set value range or more.

  For example, when a blue image is extracted in the present embodiment, an HSV value range corresponding to blue is set in the analysis apparatus 200. The color extraction unit 216 calculates the area of the region within the range where the HSV value is set in the region 511, and if this area is equal to or larger than the set value, the color of the image 500GA is specified as blue. Then, the color extraction unit 216 extracts the blue image 500GA and causes the output device 260 to display the image 500GA.

  Next, the material determination unit 217 will be described. The material determination unit 217 determines the material of the glass substrate 500A based on the color of the image data extracted by the color extraction unit 216. In the analysis apparatus 200 of the present embodiment, for example, a glass substrate material in which the glass substrate material and the color of the image data are associated with each other and the table 60 of the specific color are stored in the auxiliary storage device 230 or the like. FIG. 6 is a diagram illustrating an example of a table of glass substrate materials and specific colors.

  In the glass substrate material and the specific color table 60, for example, the specific color A indicating a color and the material 1 that becomes a color when light is transmitted are associated with each other. Further, for example, the specific color B indicating b color and the material 2 that becomes b color when light is transmitted are associated with each other. The material determination unit 217 determines the material of the glass substrate 500A based on the HSV value of the image data extracted by the color extraction unit 216.

  The plate thickness calculation unit 218 calculates the plate thickness of the glass substrate 500A from the image data extracted by the color extraction unit 216. With reference to FIG. 5, the calculation of the plate thickness by the plate thickness calculation unit 218 of the present embodiment will be described.

  The plate thickness calculation unit 218 analyzes the region 511 and detects two locations where the change in HSV value is equal to or greater than a set value. The plate thickness calculation unit 218 of the present embodiment inspects, for example, two points where the HSV value of the image data changes from a value indicating black as the background image to a value indicating the color of the image 500GA, and calculates the distance between the two points. It is detected as the thickness of the glass substrate 500A.

  The plate thickness calculation unit 218 searches (scans) the region 511 in the X1 to X2 direction, and detects the points P1 and P2 where the HSV value changes. Points P1 and P2 are points on the boundary between the image 500GA and the background. The plate thickness calculation unit 218 sets the width t1 from the point P1 to the point P2 as the plate thickness of the glass substrate 500A. The width t1 is calculated based on the number of pixels from the point P1 to the point P2 and the resolution of the camera 330. Further, the scanning direction of the region 511 may be both the X1 to X2 directions and the X2 to X1 directions.

  Further, the plate thickness calculation unit 218 of the present embodiment may calculate the width t1 at a plurality of locations by shifting the scanning line in the region 511 in the Y1-Y2 direction, and this average may be used as the plate thickness of the glass substrate 500A.

  The end surface state detection unit 219 detects the state of the end surface of the glass substrate 500A. The detection of the end face state will be described below with reference to FIG. FIG. 7 is a first diagram illustrating detection of the state of the end face. FIG. 7A is a diagram illustrating a state in which the end surface processing is performed on the glass substrate 500A, and FIG. 7B is a diagram illustrating a state in which the end surface processing is not performed on the glass substrate 500A. . The end surface treatment in the present embodiment refers to a processing process in which processing such as polishing or etching is performed on the end surface of the glass substrate 500A to remove scratches or irregularities on the end surface to make a mirror surface. The end surface of the glass substrate 500 indicates an outer peripheral end surface 500H that is an outer peripheral surface of the glass substrate 500 and an inner peripheral end surface 500I that is an inner peripheral surface of the glass substrate 500.

  When the end surface treatment is applied to the glass substrate 500, the outer peripheral end surface 500H and the inner peripheral end surface 500I are mirror surfaces. When the light S is irradiated so as to pass through the center O of the inner periphery of the glass substrate 500, the light S passes through the glass substrate 500 and forms an image 70 of transmitted light as shown in FIG.

  On the other hand, for example, when the end surface treatment is not performed on the inner peripheral end surface 500I of the glass substrate 500A, the inner peripheral end surface 500I has irregularities. Therefore, the light S is scattered by the unevenness of the inner peripheral end surface 500I, and the amount of light S transmitted through the glass substrate 500A is small. When the end surface treatment is not performed on the inner peripheral end surface 500I of the glass substrate 500A, as shown in FIG. 7B, the light S is transmitted through the outer peripheral end surface 500H, but is scattered by the inner peripheral end surface 500I. The image 70 is not formed. Alternatively, even when the transmitted light image 70 is formed, the luminance is weak and the image 70 is an image connected by a thin line or a thin line.

  The end face state detection unit 219 of the present embodiment detects whether or not the end face processing is performed on the glass substrate 500A using this principle. The end face state detection unit 219 scans the image data in the area 512 shown in FIG. 5 in the X1 to X2 direction. Then, the end face state detection unit 219 detects whether or not the image 500GA of the glass substrate 500 is interrupted in the region 512.

  Specifically, when the end surface state detection unit 219 detects two places where the change in the HSV value of the image data is equal to or greater than the set value in the scan from the X1 direction to the X2 direction in the region 512, for example, the image 500GA is not interrupted. Is detected. Further, the end face state detection unit 219 detects that the image 500GA is interrupted when it does not detect a portion where the change in the HSV value of the image data is equal to or greater than the set value in the scanning from the X1 to the X2 direction in the region 512.

  When the image 500GA is not interrupted, it indicates that an image of transmitted light transmitted through the center O of the glass substrate 500A (corresponding to the image 70 in FIG. 7) is not formed. Therefore, the end surface state detection unit 219 detects that the end surface processing is not performed.

  Further, when the image 500GA is interrupted, it indicates that an image of transmitted light that has passed through the center O of the glass substrate 500A (corresponding to the image 70 in FIG. 7) is formed. Therefore, the end surface state detection unit 219 detects that the end surface processing is performed.

  Note that the end surface state detection unit 219 may detect whether or not the end surface processing is performed based on the intensity of the luminance of the transmitted light image. For example, the end surface state detection unit 219 of the present embodiment may detect that the image 500GA is not interrupted when the intensity of the transmitted light image has a luminance intensity equal to or lower than a set value. The intensity of luminance is a value set in advance in the analysis apparatus 200, for example.

  Further, the end surface state detection unit 219 of the present embodiment may perform scanning in the region 512 from the X1 direction to the X2 direction a plurality of times while shifting from the Y1 direction to the Y2 direction or from the Y2 direction to the Y1 direction. The end face state detection unit 219 detects that the end face processing has been performed when it is detected that the image 500GA is interrupted a predetermined number of times or more in a plurality of scans in the X1 to X2 direction. May be. Note that the scanning direction of the region 512 may be both the X1 to X2 directions and the X2 to X1 directions.

  In the image 51 of FIG. 5, in the image 500GA1 among the images 500GA of the plurality of glass substrates 500A, the transmitted light image S1 (corresponding to the image 70 of FIG. 7) transmitted through the glass substrate 500 in the region 512 is not formed. Therefore, it can be seen that the glass substrate 500A corresponding to the image GA1 in the image 51 is not subjected to the end face processing or the end face processing is insufficient.

  In the images 500GA2 and 500GA3, an image S1 of transmitted light that has passed through the glass substrate 500A in the region 512 is formed. Therefore, it can be seen that the glass substrate 500A captured as the images 500G2 and 500G3 is sufficiently subjected to the end face processing.

  In the end face state detection unit 219 of the present embodiment, the scanning line may be shifted from the Y1 direction to the Y2 direction in the region 512, and detection may be performed at a plurality of locations. In the present embodiment, the end surface processing of the glass substrate 500A may not be performed when a predetermined number or more are detected when the end surface processing is not performed.

  In this embodiment, each process in the color extraction unit 216, the material determination unit 217, the plate thickness calculation unit 218, and the end surface state detection unit 219 calculates an HSV value from image data based on R, G, and B system component expressions. The image is extracted using the HSV value, but the present invention is not limited to this. The processing of the color extraction unit 216, the material determination unit 217, the plate thickness calculation unit 218, and the end face state detection unit 219 can be similarly performed using, for example, RGB values instead of HSV values. In the present embodiment, the image 51 has been described as an example. However, the color extraction unit 216, the material determination unit 217, the plate thickness calculation unit 218, and the end surface state detection unit 219 Perform the process.

  Next, the operation of the glass substrate inspection apparatus 100 of the present embodiment will be described with reference to FIG. FIG. 8 is a flowchart for explaining the operation of the glass substrate inspection apparatus according to the first embodiment.

In the glass substrate inspection apparatus 100 of the present embodiment, in the imaging apparatus 300, when the cassette 400 is installed on the cassette base 340 (step S801) and the focus of the camera 330 and the light amount of the illumination device 310 are set (step S802). ), Imaging is performed (step S803). In the present embodiment, the fixed body 350 on which the cassette 400 is mounted is slid along the axis of the driving device 320, and the cassette 400 is imaged at a predetermined timing by the camera 330.
The captured image is sent to the analysis apparatus 200, and acquired by the analysis apparatus 200 as image data by the image data acquisition unit 213 of the analysis apparatus 200.

  The analysis apparatus 200 corrects the position of the image data using the position correction unit 214, and designates an area for color extraction using the pace processing unit 215 (step S804). Next, the analysis apparatus 200 calculates the difference in hue of the image data in the region by the color extraction unit 216 (step S805). Next, the color extraction unit 216 calculates an HSV value represented by HSV (hue, saturation, brightness) from the image data based on R, G, B system component representation (step S806). Subsequently, the color extraction unit 216 searches for a region of the set value range in which the calculated HSV value is set in the analysis apparatus 200, and extracts a corresponding region (step S807). Subsequently, the color extraction unit 216 calculates the area of the extracted region (step S808). Next, the analysis apparatus 200 determines the color of the extracted region by using the material determination unit 217 (step S809), and determines the material of the glass substrates 500A to 500C with reference to the glass substrate material and the table 60 of the specific color. (Step S810).

  Next, the analysis apparatus 200 calculates the plate thickness of the glass substrates 500A to 500C from the calculated area of the area by the plate thickness calculation unit 218 (step S811). Next, the analysis apparatus 200 detects the end surface states of the glass substrates 500A to 500C by the end surface state detection unit 219 (step S812). And the glass substrate inspection apparatus 100 outputs the result of step S810-step S812 as a test result (step S813).

  Note that any of the processing by the material determination unit 217, the processing by the plate thickness calculation unit 218, and the processing by the end face state detection unit 219 according to the present embodiment may be performed first, or two or more processings may be performed in parallel. And you can do it.

  Through the above processing, the glass substrate inspection apparatus 100 according to the present embodiment can inspect whether the glass substrates 500 of different materials are mixed in the cassette 400, for example. In addition, the glass substrate inspection apparatus 100 according to the present embodiment can inspect whether, for example, glass substrates 500 having different plate thicknesses are mixed in the cassette 400. In addition, the glass substrate inspection apparatus 100 according to the present embodiment includes, for example, a glass substrate 500 that is not subjected to an inspection as to whether or not a glass substrate 500 whose plate thickness is outside an allowable value is mixed in the cassette 400 and is not subjected to end face processing. It is possible to inspect whether or not they are mixed. Further, the number of glass substrates stored in the cassette 400 can be counted to check whether or not a predetermined number of glass substrates are stored.

  In the present embodiment, since the glass substrate 500 can be inspected without contacting the glass substrate stored in the cassette 400, there is no possibility of scratching the glass substrate 5 during the inspection. In the present embodiment, even when the lid 420 and the bottom plate 421 are set in the cassette 400, the state of the glass substrate 500 including the material, plate thickness, end face state, etc. of the glass substrate 500 can be inspected. Therefore, there is no possibility that foreign matter adheres to the glass substrate 500 during the inspection.

  In the present embodiment, the glass substrate 500 has a disk shape (doughnut shape) in which a circular hole is formed at the center, but is not limited thereto. The glass substrate inspection apparatus 100 of the present embodiment is applicable as long as the inspection object is light transmissive and plate-shaped. In the present embodiment, a plurality of glass substrates 500 are stored in the cassette 400. However, one glass substrate 500 may be stored in the cassette 400. In the present embodiment, the glass substrate 500 to be inspected is stored in the cassette 400. However, the present invention is not limited to this. In the present embodiment, the inspection object may not be stored in the cassette 400.

(Second embodiment)
A second embodiment of the present invention will be described below with reference to the drawings. The second embodiment of the present invention is different from the first embodiment in that the type of the cassette arranged on the illumination pedestal is discriminated and an image of a color specified based on the type of the cassette is extracted. In the following description of the second embodiment, only differences from the first embodiment will be described, and those having the same functional configuration as the first embodiment are used in the description of the first embodiment. The same reference numerals as the reference numerals are assigned, and the description thereof is omitted.

  FIG. 9 is a diagram for explaining functions of the analysis apparatus according to the second embodiment. 200A of analysis apparatuses of this embodiment have the cassette discrimination | determination part 221 in addition to each part which the analysis apparatus 200 of 1st embodiment has. The cassette discriminating unit 221 of this embodiment discriminates the type of the cassette 400 based on the color of the lid 420 of the image data cassette 400. In the analysis apparatus 200A of this embodiment, for example, a cassette discrimination table in which the color of the cassette 400 and the type of the cassette 400 are associated is stored, and the cassette discrimination unit 221 refers to the cassette discrimination table and refers to the cassette 400. Determine the type.

  Further, the color extraction unit 216 of the present embodiment sets the color of the image extracted from the image data based on the determination result by the cassette determination unit 221. In the analysis apparatus 200A of the present embodiment, for example, a correspondence table in which the type of the cassette 400 is associated with the color of the image is stored. The color extraction unit 216 refers to the correspondence table and sets a color corresponding to the type of the cassette 400 as a color to be extracted.

  FIG. 10 is a flowchart for explaining the operation of the glass substrate inspection apparatus according to the second embodiment.

  The processing from step S1001 to step S1003 in FIG. 10 is the same as the processing from step S801 to step S803 in FIG. 200 A of analyzers discriminate | determine the kind of cassette 400 from the image data imaged by step S1003 by the cassette discrimination | determination part 221 (step S1004). Subsequently, the analysis apparatus 200A sets a color to be extracted based on the determined type of the cassette 400 by the color extraction unit 216, and extracts an image of the set color (step S1005).

  The processing from step S1006 to step S1014 is the same as the processing from step S805 to step S813 in FIG.

  With the above configuration, in this embodiment, the glass substrate 500 can be inspected based on the type of the cassette 400.

(Third embodiment)
A third embodiment of the present invention will be described below with reference to the drawings. The third embodiment of the present invention differs from the first embodiment in that the processing of the plate thickness calculation unit is further detailed in order to improve the accuracy of plate thickness calculation. In the following description of the third embodiment, only differences from the first embodiment will be described, and those having the same functional configuration as the first embodiment are used in the description of the first embodiment. The same reference numerals as the reference numerals are assigned, and the description thereof is omitted.

  FIG. 11 is a diagram for explaining functions of the analysis apparatus according to the third embodiment. The analysis apparatus 200B of the present embodiment includes an imaging control unit 212A and a plate thickness calculation unit 231.

  The imaging control unit 212A of this embodiment causes the camera 330 to capture a plurality of images so that a predetermined number of images of the glass substrate 500 stored in the cassette 400 are included. Further, the imaging control unit 212A of the present embodiment causes the camera 330 to capture an image in which the glass substrate 500 housed in the end of the cassette 400 is located at the center of the image.

  For example, when the fixed body 350 slides in the X1 direction from X2 in FIG. 12A, the imaging control unit 212A displays an image in which the image of the glass substrate 500 at the left end of the cassette 400 is centered (corresponding to the image 54 in FIG. 12). ) To the imaging apparatus 300. Subsequently, the imaging control unit 212A causes the imaging device 300 to capture an image (corresponding to the images 51 to 53 in FIG. 5) in which a predetermined number of images of the glass substrate 500 are contained. Then, the imaging control unit 212A causes the imaging device 300 to capture an image (corresponding to the image 55 in FIG. 12) in which the image of the rightmost glass substrate 500 of the cassette 400 is centered. Therefore, in the present embodiment, an image corresponding to the image 54 is captured first, and an image corresponding to the image 55 is captured last.

  Note that the imaging control unit 212A of the present embodiment may control the camera 330 so as to capture an image in accordance with, for example, a preset timing. In addition, for example, when the image data of a captured image is stored in the memory device 220, the imaging control unit 212A of the present embodiment may store the image data with an identifier indicating the order of imaging.

  The plate thickness calculation unit 231 of the present embodiment determines whether or not a predetermined number of glass substrates 500 are stored in the cassette 400 and calculates the plate thickness of the glass substrate 500. Details of the plate thickness calculator 231 will be described later.

  Here, with reference to FIG. 12, the image which the imaging control part 212A of this embodiment images with the camera 330 is demonstrated. FIG. 12 is a diagram illustrating an example of an image captured by the imaging apparatus of the third embodiment. 12A is an example of an image including a predetermined number of images of the glass substrate 500, and FIG. 12B is such that the images of the glass substrate 500 stored at both ends of the cassette 400 are in the center. This is a captured image.

  Since images 51, 52, and 53 shown in FIG. 12A are the same as those in the first embodiment, description thereof is omitted.

  An image 54 shown in FIG. 12B is an image captured so that the image 500GA1 of the glass substrate 500 stored at the left end of the cassette 400 is located at the center. An image 55 illustrated in FIG. 12B is an image captured so that the image 500GA4 of the glass substrate 500 housed at the right end of the cassette 400 is located at the center. In the following description, an image obtained so that the images of the glass substrates 500 housed at both the left and right ends of the cassette 400 are positioned at the center in the width direction of the image is referred to as a center arrangement image.

  For example, when the width of the centrally arranged image 54 is W10, the centrally arranged image 54 is imaged so that the center of the image 500GA1 is at the midpoint of the width W10. For example, when the width of the central arrangement image 55 is W20, the central arrangement image 55 is picked up so that the center of the image 500GA4 is at the middle point of the width W20.

  In the present embodiment, the center arrangement images 54 and 55 are used when calculating the thicknesses of the glass substrates 500 accommodated at the left and right ends of the cassette 400. In the present embodiment, this configuration can suppress the influence of aberration caused by the lens of the camera 330 when calculating the plate thickness of the glass substrate 500 accommodated at both the left and right ends of the cassette 400. In this embodiment, this configuration also reduces the influence of image distortion due to variations in molding of the lid 420 of the cassette 400, for example.

  Hereinafter, the plate thickness calculation unit 231 of this embodiment will be described with reference to FIG. FIG. 13 is a diagram illustrating a plate thickness calculation unit according to the third embodiment.

  The plate thickness calculation unit 231 according to the present embodiment includes an image determination unit 232, an area setting unit 233, a gray scale processing unit 234, a pair edge detection unit 235, an inter-edge calculation unit 236, and a determination unit 237.

  The image determination unit 232 according to the present embodiment determines whether the image of the image data stored in the memory device 220 or the like is a centrally arranged image. For example, 25 cassettes 500 can be stored in the cassette 400 of the present embodiment, and five images corresponding to the images 51 to 53 correspond to the images of the five glass substrates 500 and the images 54 and 55. It is assumed that two images (center arrangement image) are included. In this case, the image determination unit 232 determines that the first image captured first and the seventh image captured last are the centrally arranged images.

  The area setting unit 233 sets a predetermined area in the center arrangement image when calculating the plate thickness in the center arrangement image. Details of the area set by the area setting unit 233 will be described later.

  The gray scale processing unit 234 performs processing for converting RGB image data into gray scale image data.

  The pair edge detection unit 235 detects, from the grayscale image data converted by the grayscale processing unit 234, a pair edge composed of an up edge whose brightness increases and a down edge whose brightness decreases.

  The edge-to-edge calculator 236 calculates the distance between the edges of the up edge and the down edge detected by the pair edge detector 235.

  The determination unit 237 determines whether or not the distance between the edges calculated by the edge calculation unit 236 is within a predetermined range. In the present embodiment, when the distance between the edges is not within the predetermined range, it is determined that the appropriate glass substrate 500 is not stored in the cassette 400.

  Further, the plate thickness calculation unit 231 of the present embodiment can execute the same processing as the plate thickness calculation unit 218 described in the first embodiment, in addition to the processing by each unit described above.

  Hereinafter, the calculation of the plate thickness by the plate thickness calculation unit 231 of the present embodiment will be described with reference to FIG. FIG. 14 is a flowchart for explaining the calculation of the thickness of the glass substrate by the thickness calculation unit of the third embodiment.

  When receiving a plate thickness calculation instruction, the plate thickness calculation unit 231 according to the present embodiment acquires image data from the memory device 220 (step S1401). Subsequently, the plate thickness calculation unit 231 determines whether or not the acquired image data is the image data of the centrally arranged image by the image determination unit 232 (step S1402).

  In step S1402, when the image data is not the image data of the centrally arranged image, the plate thickness calculation unit 231 converts the acquired image data into grayscale image data by the grayscale processing unit 234 (step S1403). Subsequently, the plate thickness calculation unit 231 uses the pair edge detection unit 235 to detect a pair edge composed of an up edge in which the brightness increases and a down edge in which the brightness decreases in the region where the grayscale image data is set (step S1404). In the present embodiment, it is assumed that a pair edge detection area in the grayscale image data is set in advance.

  Subsequently, the plate thickness calculator 231 uses the edge-to-edge calculator 236 to calculate the distance between the up edge and the down edge (hereinafter, edge distance) (step S1405). Subsequently, the determination unit 237 determines whether the distance between the edges is within the set value range (step S1406). The set value range is set in advance.

  In step S1406, when the distance between the edges is within the set value range, the plate thickness calculation unit 231 outputs the distance between the edges as the plate thickness (step S1407), and ends the process. The output form may be displayed on, for example, the output device 260 of the analysis device 200 or may be stored in the memory device 220. If the distance between the edges is not within the set value range in step S1406, the plate thickness detection unit 231 assumes that the appropriate glass substrate 500 is not stored in the cassette 400, and outputs that fact to the output device 260 or the like (step S1406). S1408), the process is terminated.

  Hereinafter, pair edge detection according to the present embodiment will be described with reference to FIG. FIG. 15 is a diagram for explaining pair edge detection in the third embodiment.

  FIG. 15 shows an image 52 as an example. The image 52 includes an image 500 GB of five glass substrates 500. In FIG. 15, detection of paired edges in a preset region S <b> 10 in the image data of the image 52 will be described.

  The pair edge detection unit 235 scans the image data in the X1-X2 direction, and detects an up edge in which the brightness increases and a down edge in which the brightness decreases. In FIG. 15, the point PA is the up edge and the point PB is the down edge. The distance t10 between the point PA and the point PB is the thickness of the glass substrate 500.

  In FIG. 15, only the region S <b> 10 has been described, but in the present embodiment, the same processing is performed on the images of all the glass substrates 500 included in the image 52.

  In this embodiment, by converting image data into grayscale image data and calculating the plate thickness by pair edge detection in this way, the accuracy of plate thickness calculation can be improved while reducing the load of image analysis processing. .

  Returning to FIG. 14, the case where the image data acquired in step S1402 is the image data of the center position image will be described.

  If the plate thickness calculation unit 231 is the image data of the center position image, the plate thickness calculation unit 231 determines whether or not the processing from step S1410 to step S1416 described later has been repeated a predetermined number of times (step S1409).

When the predetermined number of times is not repeated in step S1409, the plate thickness calculation unit 231 sets a region in the image data by the region setting unit 233 (step S1410).
The area setting unit 233 according to the present embodiment sets a plurality of preset areas in the specified order. Details of the area setting by the area setting unit 233 will be described later.

  Subsequently, the plate thickness calculation unit 231 uses the gray scale processing unit 234 to set the acquired image data as gray scale image data (step S1411). Subsequently, the plate thickness calculation unit 231 detects whether the pair edge detection unit 235 detects an up edge where the brightness increases and a down edge where the brightness decreases within the region set in the region setting unit 233 in the grayscale image data. It is determined whether or not (step S1412).

  When both the up edge and the down edge are not detected in step S1412, the plate thickness calculation unit 231 proceeds to step S1415 described later. When an up edge and a down edge are detected in step S1412, the inter-edge calculation unit 236 calculates an inter-edge distance (step S1413). Subsequently, the determination unit 237 determines whether or not the edge distance is within the set value range (step S1414).

  If the distance between edges is within the set value range in step S1414, the plate thickness calculation unit 231 sets the distance between edges as the plate thickness, and proceeds to step S1407.

  If the distance between the edges is not within the set value range in step S1414, the plate thickness calculating unit 231 determines whether the area of the image of the specific color is equal to or larger than the set value in the region set in step S1410 ( Step S1415). Here, the area of the image of the specific color is obtained from the number of pixels of the RGB value or HSV value within a preset set value range. The set value is a preset value.

  If the area of the image of the specific color is greater than or equal to the set value in step S1415, the plate thickness calculation unit 231 calculates the plate thickness from the area of the corresponding pixel (step S1416). The processing of the plate thickness calculation unit 231 in step S1415 and step S1416 is the same as the plate thickness calculation processing described in the first embodiment.

  Subsequently, the plate thickness calculation unit 231 proceeds to step S1407, outputs the calculated plate thickness, and ends the process. If the area of the image of the specific color is less than the set value in step S1416, the plate thickness calculation unit 231 returns to step S1409.

  With reference to FIG. 16, setting of areas by the area setting unit 233 of this embodiment will be described below. FIG. 16 is a diagram for explaining region setting by the region setting unit according to the third embodiment.

  FIG. 16A is a diagram illustrating an example in which distortion or the like is not generated in the image 500GA1 of the glass substrate 500 stored in the right end of the cassette 400, and FIG. 16B is stored in the right end of the cassette 400. It is a figure which shows the example which distortion etc. produced in the image 500GA1 of the glass substrate 500. FIG. In FIG. 16, only the glass substrate image 500GA1 stored at the right end of the cassette 400 will be described, but the same applies to the image of the glass substrate stored at the left end of the cassette 400.

  The image 500GA1 of the glass substrate 500 stored at the right end of the cassette 400 is easily affected by sagging or variation of the lid 420 of the cassette 400. For example, in FIG. 16A, the image 500GA1 is captured, whereas the image 500GA1 ′ in FIG. This is due to variations in the shape of the lid 420 due to sagging, scratches, wear, etc. when the lid 420 is molded.

  In the present embodiment, in order to calculate the thickness of the glass substrate 500 stored at the right end of the cassette 400 from the image 500GA1 included in the center position image 54 with high accuracy, only the image 500GA1 is set to an arbitrary number of times. A plurality of different plate thickness calculation processes are performed.

  Regions R1, R2, and R3 in FIGS. 16A and 16B are regions set by the region setting unit 233. In this embodiment, the regions R1, R2, and R3 are set in this order.

  The processing from step S1409 to step S1416 in FIG. 14 will be specifically described below with reference to FIG.

  When the plate thickness calculation unit 231 acquires the image data of the center position image, the region setting unit 233 first sets the region R1 as image data in step S1410. In step S1411, the image data is converted to grayscale image data. In step S1412, it is determined whether both the up edge and the down edge are detected in the region R1. In the image 54A in FIG. 16A, the region R1 includes a point P11 that is an up edge and a point P12 that is a down edge. Accordingly, the edge distance calculation unit 236 calculates the edge distance in step S1413, and the edge distance is determined to be within the set value range in step S1414.

  Next, the processing from step S1409 to step S1416 in FIG. 14 will be specifically described with reference to FIG.

  When the plate thickness calculation unit 231 acquires the image data of the center position image, the region setting unit 233 first sets the region R1 as image data in step S1410. In step S1411, the image data is converted to grayscale image data. In step S1412, it is determined whether both the up edge and the down edge are detected in the region R1. In the image 54B of FIG. 16B, there are no points that become an up edge or a down edge in the region R1. Therefore, the plate thickness calculation unit 231 determines in step S1415 whether or not the area of the image of the specific color is greater than or equal to the set value. However, the image 500GA1 ′ of the glass substrate 500 is not included in the region R1. Therefore, the plate thickness calculation unit 231 next determines whether or not the processing for the number of plate thickness detections of the center position image set in advance in step S1409 is completed.

  Here, since the plate thickness detection count is three, the plate thickness calculation unit 231 repeats the processing from step S1410 again.

  In step S1410, the region setting unit 233 next sets a region R2 in the image 54B. Subsequently, the image data is grayscale image data, and it is determined whether or not an up edge and a down edge are detected in the region R2. In the region R2, the up edge and the down edge can be detected, but the distance between the edges is outside the set value range.

  Accordingly, in step S1415, the plate thickness calculation unit 231 determines whether the area of the specific color image in the region R2 is equal to or larger than a set value. In the region R2, since the image 500GA1 ′ is in a missing state, the area of the image of the specific color does not exceed the set value.

  Therefore, the plate thickness detection unit 231 sets the region R3 by the region setting unit 233 again in step S1410. In the region R3, the up edge and the down edge can be detected, and the distance between the edge distances is within the set value range. Therefore, the distance between the edges calculated in the region R3 is the plate thickness of the glass substrate 500 corresponding to the image 500GA1 ′. Output as.

  In the present embodiment, by calculating the plate thickness of the glass substrate 500 accommodated at the left and right ends of the cassette 400 as described above, the influence of variations in molding of the lid 420 of the cassette 400 in the plate thickness calculation is reduced. It is possible to improve the accuracy of thickness calculation.

  In the present embodiment, the number of plate thickness calculation processes is three, but the number of sheet thickness calculation processes can be set arbitrarily.

  In the present embodiment, a setting value (threshold value) used for the determination in step S1415 is set for each region set by the region setting unit 233. The setting value used in the determination in step S1415 is a threshold value for determining whether or not an image of a specific color exists in the area.

  For example, the area of the region R1 is wider than the area of the region R2. Therefore, the setting value serving as a reference for determining that an image of a specific color exists in the region R1 is smaller than the setting value in the region R2.

  Further, the regions R1, R2, and R3 may be set depending on, for example, the tendency of the molding of the cassette 400 to vary. In the present embodiment, at least one of the regions R1, R2, and R3 is set to include a part of the image 500GA1.

  Furthermore, in the present embodiment, the region R1, R2, and R3 that have the highest possibility of calculating the plate thickness may be learned, and the region setting order by the region setting unit 233 may be changed. For example, if the region R1 often lacks an image and the region R3 often includes a good image, the region setting unit 233 may change the region setting order so that the region R3 is set first. good.

(Fourth embodiment)
Hereinafter, a fourth embodiment of the present invention will be described with reference to the drawings. The fourth embodiment of the present invention is different from the third embodiment in that a camera that captures an image for calculating a plate thickness and a camera that captures an image for detecting an end face state are separately provided. Is different. Therefore, in the following fourth embodiment of the present invention, only differences from the third embodiment will be described, and those having the same functional configuration as the third embodiment will be described in the description of the third embodiment. The reference numerals used are given and the description thereof is omitted.

  FIG. 17 is a diagram illustrating an imaging apparatus according to the fourth embodiment.

  The imaging apparatus 300A of the present embodiment includes a camera 330A for capturing images used for the plate thickness calculation process and the material determination process. The camera 330 </ b> A is arranged such that the imaging surface 331 </ b> A is inclined with respect to the opening surface virtually formed by the opening of the cassette 400.

  In the present embodiment, by using an image captured by the camera 330A tilted with respect to the opening as described above, it is possible to reduce the influence of the aberration of the camera 330A on the image used for thickness calculation and material determination.

  In the present embodiment, the image data of the image captured by the camera 330 and the image data of the image captured by the camera 330A are stored in the memory device 220 so as to be identifiable. The plate thickness calculation unit 231 and the material determination unit 217 obtain image data of an image captured by the camera 330A and calculate the plate thickness. The end surface state detection unit 219 acquires image data of an image captured by the camera 330 and detects the end surface state.

  FIG. 18 is a diagram illustrating an example of the positional relationship between the camera and the cassette according to the fourth embodiment. In the present embodiment, when θ is an angle between the normal line of the opening surface 402 virtually formed by the opening 401 of the cassette 400 and the direction in which the imaging surface 331A of the camera 330A faces, θ is 30 degrees or more and 90 degrees. It is preferable that it is less than degree. More preferably, the angle θ is about 60 degrees. In addition, it is more preferable that θ is 40 degrees or more and 80 degrees or less, and it is more preferable that θ is 50 degrees or more and 70 degrees or less.

(Fifth embodiment)
The fifth embodiment of the present invention will be described below with reference to the drawings. The fifth embodiment of the present invention is different from the third embodiment in that the imaging surface of the camera is inclined. Therefore, in the following fifth embodiment of the present invention, only differences from the third embodiment will be described, and those having the same functional configuration as the third embodiment will be described in the description of the third embodiment. The reference numerals used are given and the description thereof is omitted.

  FIG. 19 is a diagram illustrating an imaging apparatus according to the fifth embodiment. The imaging apparatus 300B of this embodiment includes a camera 330B. The camera 330B is attached to the column 302 by an operation control unit 332 that operates (rotates) so that the angle of the imaging surface with respect to the opening surface 402 becomes a predetermined angle. The operation control unit 332 rotates the camera 330B in accordance with the moving direction of the fixed body 350.

  In the present embodiment, for example, when the fixed body 350 is moving in the A direction, the imaging surface 331B of the camera 330B is parallel to the opening surface 402 of the cassette 400, and the end surface state detection unit 219 detects the end surface state. An image to be used is taken. When the fixed body 350 is moving in the B direction, the operation control unit 332 rotates the camera 330B so that the angle between the imaging surface 331B of the camera 330B and the opening surface 402 of the cassette 400 becomes approximately 60 degrees. Then, an image used for plate thickness calculation by the plate thickness calculation unit 231 and material determination by the material determination unit 217 is captured.

  In the present embodiment, by rotating the camera 330B in accordance with the operation of the fixed body 350 as described above, the same effect as in the fourth embodiment can be obtained without providing two cameras. In the present embodiment, the camera 330B may be tilted when the fixed body 350 is moving in the A direction, and the camera 330B may be returned to a position perpendicular to the opening surface 402 when moving in the B direction. .

  In the above embodiment, the camera 330 is fixed, and the fixed body 350 to which the illumination device 310 and the cassette 400 are fixed moves in a direction orthogonal to the imaging surface 331 of the camera 330. It is not limited. For example, the camera 330 may move in a direction orthogonal to the imaging surface 331 on the cassette 400 installed on the cassette base 340.

  Furthermore, in this embodiment, for example, only the cassette 400 may be fixed, and the camera 330 and the illumination device 310 may move in a direction orthogonal to the imaging surface 331. That is, in the present embodiment, it is only necessary that the positional relationship between the camera 330 and the illumination device 310 is always the same.

  Although there is no restriction | limiting in particular as the glass substrate 500 used as the object of the measurement of this invention, For magnetic recording media, for photomasks, for displays, such as a liquid crystal and organic EL, for optical components, such as an optical pick-up element and an optical filter, etc. A specific example is a glass substrate.

  The glass type of the glass substrate 500 is appropriately selected for each application, but may be amorphous glass or crystallized glass, and a tempered glass having a tempered layer on the surface layer of the glass substrate (for example, Or chemically tempered glass).

  Moreover, there is no restriction | limiting in particular also as the manufacturing method of the glass substrate 500 (henceforth a glass substrate) before a process, The thing made by the float process may be used, the thing made by the fusion method may be used, and the downdraw method It may be made of or may be made by a press molding method.

  Among them, the glass substrate for a magnetic recording medium is required to have a level that is stricter than the shape characteristics (plate thickness deviation, end surface treatment state, etc.) required for other glass substrate products. A glass substrate manufacturing method including an inspection process having an inspection method using the substrate inspection apparatus 100 and an inspection method using the glass substrate inspection apparatus 100 is most preferably applied.

  Generally, the manufacturing process of the glass substrate for magnetic recording media and the magnetic disk includes the following processes. (1) After processing the glass base substrate formed by the float method, fusion method, down draw method or press molding method into a disk shape, chamfering is performed on the inner peripheral side surface and the outer peripheral side surface. (2) Grinding is performed on the upper and lower main planes of the glass substrate. (3) End face polishing is performed on the side surface portion and the chamfered portion of the glass substrate. (4) Polish the upper and lower main planes of the glass substrate. The polishing step may be only primary polishing, primary polishing and secondary polishing may be performed, or tertiary polishing may be performed after secondary polishing. (5) A glass substrate for a magnetic recording medium is manufactured by precision cleaning of the glass substrate. (6) A thin film such as a magnetic layer is formed on a glass substrate for a magnetic recording medium to manufacture a magnetic disk.

  In the manufacturing process of the glass substrate for magnetic recording medium and the magnetic disk, glass substrate cleaning (inter-process cleaning) or etching of the glass substrate surface (inter-process etching) may be performed between the processes. Furthermore, when high mechanical strength is required for the glass substrate for magnetic recording media, a strengthening step (for example, a chemical strengthening step) for forming a reinforcing layer on the surface layer of the glass substrate is performed before the polishing step, after the polishing step, or the polishing step. You may carry out between.

  In the present invention, the glass substrate for a magnetic recording medium may be amorphous glass, crystallized glass, or tempered glass (for example, chemically tempered glass) having a tempered layer on the surface layer of the glass substrate. Further, the glass base substrate of the glass substrate 500 of the present invention may be manufactured by a float method, may be manufactured by a fusion method, or may be manufactured by a press molding method.

  The glass substrate inspection apparatus 100 of the present invention can be used for inspection of a glass substrate for magnetic recording medium during processing in the end surface polishing step (3) of the manufacturing process of the glass substrate for magnetic recording medium and the magnetic disk. Further, in the manufacturing process of the magnetic recording medium glass substrate and the magnetic disk, the inspection of the glass substrate for magnetic recording medium (5) manufactured by precision cleaning of the glass substrate (final inspection of the glass substrate for magnetic recording medium), It can be used for shape inspection of a magnetic disk (6) manufactured by forming a thin film such as a magnetic layer on a glass substrate for a magnetic recording medium.

  The glass substrate inspection apparatus 100 of the present invention is particularly preferably used for shape inspection of a glass substrate for magnetic recording medium (final inspection of the glass substrate for magnetic recording medium).

  As mentioned above, although this invention has been demonstrated based on each embodiment, this invention is not limited to the requirements shown in the said embodiment. With respect to these points, the gist of the present invention can be changed without departing from the scope of the present invention, and can be appropriately determined according to the application form.

DESCRIPTION OF SYMBOLS 100 Glass substrate inspection apparatus 200, 200A, 200B Analysis apparatus 210 Arithmetic processing apparatus 211 Drive control part 212 Imaging control part 213 Image data acquisition part 214 Position correction part 215 Pace processing part 216 Color extraction part 217 Material determination part 216, 231 Plate thickness Calculation unit 219 End surface state detection unit 221 Cassette discriminating unit 300 Imaging device 301 Illumination device base 305 Support column fixing base 310 Illumination device 320 Driving device 330, 330A, 330B Camera 340 Cassette base 341 Slit 500 (500A to 500C) Glass substrate

Claims (15)

In a glass substrate inspection apparatus that takes an image of a glass substrate irradiated with light from a light source and inspects the glass substrate based on image data of the image,
Imaging means for imaging a glass substrate with a plurality of images;
A glass substrate inspection apparatus comprising plate thickness detection means for calculating a plate thickness of the glass substrate based on image data of the image taken by the imaging means. The glass substrate is
An opening for a light source for making light from the light source incident;
An imaging aperture for capturing an image of the glass substrate with the imaging means;
Is stored in a cassette having
Drive control means for moving the cassette within an imaging field of view of the imaging means;
The glass substrate inspection apparatus according to claim 1, further comprising an imaging control unit that causes the imaging unit to capture the plurality of images from the imaging opening side of the moving cassette.   The glass substrate inspection apparatus according to claim 2, wherein the cassette has the imaging opening on an upper surface of the cassette. The cassette is disposed on the light source;
The drive control means includes
The glass substrate inspection apparatus according to claim 2 or 3, wherein the light source and the cassette are moved together. The plate thickness calculating means includes
5. The image data of an image obtained by using the image pickup surface of the image pickup unit as an image having an angle with respect to a normal line of a plane formed by the image pickup opening is used. Glass substrate inspection equipment.   6. The glass according to claim 2, further comprising an operation control unit configured to operate an imaging surface of the imaging unit so as to have an angle with respect to a normal line of a plane formed by the imaging opening. Board inspection equipment. The imaging means includes
The glass substrate inspection apparatus according to any one of claims 2 to 6, further comprising tilted imaging means arranged so that an imaging surface has an angle with respect to a normal line of a plane formed by the imaging opening. The plate thickness calculating means includes
A gray scale processing means that uses the image data as gray scale data;
A pair edge detection means for detecting a pair edge composed of an up edge in which brightness is increased and a down edge in which brightness is decreased in a predetermined region of the grayscale data;
The glass substrate inspection apparatus according to any one of claims 1 to 7, wherein a distance between the up edge and the down edge is a plate thickness of the glass substrate. The plate thickness calculating means includes
When the up edge and the down edge are not detected by the pair edge detection means, or when the distance between the up edge and the down edge is not within the first set value range,
The glass substrate inspection apparatus according to claim 8, wherein the thickness of the glass substrate is calculated based on a result of detecting a change in gradation of the image data in the predetermined area. The plate thickness calculating means includes
The glass substrate inspection apparatus according to claim 9, wherein two points where the gradation changes within the predetermined region are checked, and a width between the two points is calculated as a plate thickness of the glass substrate. The plate thickness calculating means includes
When the width between the two points is not within the second set value range, a predetermined area different from the predetermined area is set, and the up edge and the down edge are set by the pair edge detection means in the another predetermined area The glass substrate inspection apparatus according to claim 10, wherein it is determined whether or not is detected.   The glass substrate inspection apparatus according to claim 1, further comprising a material determination unit that determines a material of the glass substrate based on the image data.   The glass substrate inspection apparatus according to claim 1, further comprising an end surface state detection unit configured to detect whether or not processing is performed on an end surface of the glass substrate based on the image data.   The glass substrate inspection apparatus according to any one of claims 1 to 13, wherein the glass substrate is a disk-shaped glass substrate for a magnetic recording medium having a circular hole in the center. A method for producing a glass substrate for a magnetic recording medium,
A method for manufacturing a glass substrate for a magnetic recording medium, comprising an inspection step by the glass substrate inspection apparatus according to any one of claims 1 to 13.

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