JP2013075340A - Method for observing and system for observing glass plate polishing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for observing and a system for observing a glass plate polishing apparatus capable of reducing a breakage generation ratio of glass plates.SOLUTION: In the system for observing, an abnormal attracting state of a glass plate G to an attracting sheet 22 is always observed, the polishing to the glass plate G is not carried out, the polishing part 18 is stopped, an alarming sound is generated from an alarm 58, and the abnormality is notified to an operator, when the abnormality is determined. The system for observing has a determining part 20 having an imaging part 16 between a plate attracting part 14 and the polishing part 18 in the glass plate polishing apparatus 10 of usual facilities having a glycerin applying part 12, the plate attracting part 14, and the polishing part 18. The imaging part 16 illuminates the attracting sheet 22 moving from the plate attracting part 14 to the polishing part 18 by a light 38, and images the reflective light of the same by a camera 40. Further, the determining part 20 determines whether or not the glass plate G is normally attracted by the attracting sheet 22 based on the image imaged by the camera 40.

Description

  The present invention relates to a monitoring method and a monitoring system for a glass plate polishing apparatus.

  A glass plate for FPD (Flat Panel Display) used for liquid crystal displays, plasma displays, etc. is formed by forming molten glass into a plate shape, and then cutting it into a glass plate of a predetermined rectangular size by a cutting device, followed by a chamfering device. The end face is chamfered by the chamfering grindstone. Thereafter, the glass plate is manufactured into a thin glass plate satisfying the flatness required for the FPD glass plate by removing fine irregularities and undulations on the surface with a polishing apparatus. As the size of the glass plate, those whose vertical and horizontal dimensions exceed 1000 mm are mainstream, and the thickness thereof is 0.7 mm or less.

  The polishing apparatus disclosed in Patent Document 1 includes a plate attaching stage for attaching a glass plate to an adsorption sheet stretched on a film frame, a film frame attaching stage for attaching the film frame to a carrier, and a film frame attached. And a polishing stage for polishing by pressing the polishing surface of the glass plate adhered to the suction sheet against the polishing pad of the polishing surface plate, with the carrier and the polishing surface plate relatively close to each other.

  The adsorbing sheet is composed of a self-adsorbing porous member. In order to prevent drying of the non-polished surface of the glass plate adsorbed on the adsorbing sheet or to increase the self-adsorbing power of the adsorbing sheet. Further, the glass plate is adsorbed to the adsorbing sheet through the liquid. In the wafer polishing method disclosed in Patent Document 2, the liquid is adsorbed between the non-polished surface of the wafer and the plate by interposing a liquid such as glycerin between the non-polished surface of the wafer and the wafer mounting plate. I am raising my power. The adsorbing force of the adsorbing sheet increases as the glycerin application amount increases up to a predetermined application amount. However, when the glycerin application amount exceeds the predetermined application amount, the adsorbing force tends to decrease.

  In addition, before placing the glass plate on the suction sheet, whether or not foreign matter such as glass pieces, suction sheet pieces, polishing tool pieces, and abrasives adheres to the suction surface of the suction sheet is imaged by a camera or the like. Inspection is performed by detection means such as means and sensors.

JP 2004-122351 A JP-A-6-61203

  In the polishing apparatus, it is desired to monitor whether or not the glass plate is normally adsorbed to the adsorbing sheet. However, it is difficult to monitor visually in a polishing apparatus having complicated facilities. In particular, in the apparatus for polishing by adsorbing the non-polished surface of the glass plate to the lower surface of the adsorption sheet, such as the polishing apparatus shown in Patent Document 1, the equipment is complicated and the adsorption sheet must be looked up from below the carrier. Therefore, it was very difficult to perform visual monitoring.

  This invention is made | formed in view of such a situation, and it aims at providing the monitoring method and monitoring system of the glass plate grinding | polishing apparatus which can monitor the adsorption | suction state of the glass plate with respect to an adsorption sheet.

  First, the abnormal form of the adsorption state of the glass plate with respect to the adsorption sheet will be described.

  The first abnormal form is a form in which the adsorbing power of the adsorbing sheet is reduced due to excessive application amount of glycerin to the adsorbing sheet and insufficient application amount.

  The second abnormal form is a form in which two or more glass plates are adsorbed to the adsorbing sheet. This form includes a form in which a new glass plate is adsorbed on the glass piece remaining on the adsorption sheet.

  The third abnormal form is a form in which the glass plate is not adsorbed on the adsorbing sheet.

  A 4th abnormal form is a form from which the glass plate deviated from the regular position with respect to the frame, and was adsorbed by the adsorption sheet.

  The present invention has been made paying attention to the first to fourth abnormal forms. The present invention will be described below.

  In order to achieve the above object, the present invention provides a liquid application step of applying a liquid to an adsorption sheet that adsorbs a glass plate, and an adsorption step of adsorbing the non-polished surface of the glass plate to the adsorption sheet applied with the liquid And an imaging step of irradiating illumination light toward the suction sheet and imaging the reflected light, and determining whether or not the glass plate is normally sucked by the suction sheet based on the picked-up image There is provided a monitoring method for a glass plate polishing apparatus, comprising: a determination step; and a polishing step for polishing a polishing surface of the glass plate adsorbed on the adsorption sheet.

  In order to achieve the above object, the present invention also provides a liquid application means for applying a liquid to an adsorption sheet that adsorbs a glass plate, and adsorbs the non-polished surface of the glass plate to the adsorption sheet to which the liquid is applied. Whether or not the glass plate is normally adsorbed to the adsorbing sheet based on the picked-up image, the picking-up means, the imaging means for irradiating illumination light toward the adsorbing sheet and imaging the reflected light, and the picked-up image There is provided a monitoring system for a glass plate polishing apparatus, comprising: determination means for determining; and polishing means for polishing a polishing surface of the glass plate adsorbed on the adsorption sheet.

  According to the present invention, in a glass plate polishing apparatus having a liquid application process, an adsorption process, and a polishing process, an imaging process and a determination process are provided between the adsorption process and the polishing process. In the imaging step, the suction sheet moving from the suction step to the polishing step is illuminated, and the reflected light is picked up by the imaging means. The determination step determines whether or not the glass plate is normally adsorbed on the adsorption sheet based on the image captured by the imaging unit.

  Therefore, this invention can monitor the adsorption | suction state of the glass plate with respect to an adsorption sheet. Further, by arranging the image pickup means in the polishing apparatus, visual monitoring is unnecessary, and the determination can be performed in a complicated polishing apparatus with facilities.

  The determination step of the present invention calculates an average value of the luminance of the image, compares the average value with a range of optimal luminance when the liquid application amount stored in advance is an optimal value, When the average value is within the optimum luminance range, it is determined that the glass plate has been normally adsorbed to the adsorption sheet. When the average value is out of the optimum luminance range, the adsorption sheet is determined. It is preferable to determine that the glass plate is not normally adsorbed.

  The determination means of the present invention calculates an average value of the luminance of the image, compares the average value with a range of optimal luminance when the liquid application amount stored in advance is an optimal value, When the average value is within the optimum luminance range, it is determined that the glass plate has been normally adsorbed to the adsorption sheet. When the average value is out of the optimum luminance range, the adsorption sheet is determined. It is preferable to determine that the glass plate is not normally adsorbed.

  The present invention determines the first abnormal form described above.

  If the glass plate is adsorbed to the adsorption sheet in a state in which the amount of liquid applied to the adsorption sheet is greater than the optimum value, the imaging means uses the amount of reflected light from the adsorption sheet to be greater than the amount of reflected light from the glass plate. Receives a lot of light. For this reason, the imaging means images the color of the suction sheet (for example, black having a luminance lower than that of the glass plate), and the average luminance is less than the lower limit value of the optimum luminance range. It is determined that the glass plate is not normally adsorbed to the adsorbing sheet due to an excessive amount.

  In addition, when the glass plate is adsorbed to the adsorption sheet in a state in which the amount of liquid applied to the adsorption sheet is less than the optimum value, the imaging unit reflects the reflected light from the glass plate more than the amount of reflected light from the adsorption sheet. Receives a lot of light. For this reason, the imaging unit images the color of the glass plate (for example, white having high luminance), and the average luminance is higher than the upper limit of the optimum luminance range. It is determined that the plate is not normally sucked by the suction sheet.

  On the other hand, when the amount of liquid applied to the suction sheet is the optimum value, the imaging unit receives the reflected light from the suction sheet and the reflected light from the glass plate that is approximately the same amount as the reflected light. For this reason, the image pickup means picks up a gray image in which the color of the glass plate (for example, white) and the color of the suction sheet (for example, black) are mixed, and the average luminance falls within the range of the optimum luminance. Then, it is determined that the glass plate is normally adsorbed to the adsorbing sheet.

  The determination step of the present invention calculates an area of a white portion included in the image, compares the white area with a reference white area stored in advance, and the white area is less than the reference white area. In this case, it is determined that one glass plate is normally adsorbed to the adsorption sheet. When the white area is equal to or larger than the reference white area, at least two glass plates are adsorbed to the adsorption sheet. It is preferable to determine that it is present.

  The determination means according to the present invention calculates an area of a white portion included in the image, compares the white area with a reference white area stored in advance, and the white area is less than the reference white area. In this case, it is determined that one glass plate is normally adsorbed to the adsorption sheet. When the white area is equal to or larger than the reference white area, at least two glass plates are adsorbed to the adsorption sheet. It is preferable to determine that it is present.

  The present invention determines the second abnormal form described above.

  When at least two glass plates are adsorbed on the suction sheet, the illumination light is reflected from at least two glass plates, and the image of that portion becomes white. The determination means determines the second abnormal form by calculating a white area of the white portion and comparing the calculated white area with a reference white area. In order to distinguish between the reflected light from the suction sheet and the reflected light from the glass plate, the color of the suction sheet is preferably a color lower than the brightness of the glass plate, such as black.

  The determination step of the present invention calculates an area of a black portion included in the image, compares the black area with a reference black area stored in advance, and the black area is less than the reference black area. In this case, it is determined that the glass plate is normally adsorbed on the adsorption sheet, and when the black area is equal to or larger than the reference black area, it is determined that the glass plate is not adsorbed on the adsorption sheet. Is preferred.

  The determination unit according to the present invention calculates an area of a black portion included in the image, compares the black area with a reference black area stored in advance, and the black area is less than the reference black area. In this case, it is determined that the glass plate is normally adsorbed on the adsorption sheet, and when the black area is equal to or larger than the reference black area, it is determined that the glass plate is not adsorbed on the adsorption sheet. Is preferred.

  The present invention determines the third abnormal form described above.

  When the glass plate is not attracted to the suction sheet, the image pickup unit captures reflected light from, for example, a black suction sheet, so that the image becomes black. The determination unit calculates the black area of the black portion and determines the third abnormal form by comparing the calculated black area with a reference black area.

  The adsorbing sheet of the present invention is arranged around the glass plate adsorbed and held by the adsorbing sheet, and adsorbs a frame that comes into contact with the polishing tool in the polishing step together with the glass plate, The determination step calculates an interval between the glass plate and the frame based on the image, compares the calculated interval with a pre-stored reference interval, and the calculated interval is equal to or less than the reference interval. It is preferable to determine that the glass sheet is not normally adsorbed to the adsorbing sheet.

  The adsorbing sheet of the present invention adsorbs a frame that is disposed around the glass plate adsorbed and held by the adsorbing sheet and contacts the polishing tool in the polishing process together with the glass plate, and the determination The means calculates an interval between the glass plate and the frame based on the image, compares the calculated interval with a pre-stored reference interval, and the calculated interval is equal to or less than the reference interval, or In the case of a reference interval or more, it is preferable to determine that the glass plate is not normally sucked by the suction sheet.

  The present invention determines the above-described fourth abnormal form.

  For example, when the imaging unit captures a white frame and, for example, a white glass plate, the imaging unit simultaneously captures, for example, a black suction sheet existing between the frame and the glass plate. The determination means calculates an interval between the glass plate and the frame based on the black image (number of pixels) of the adsorption sheet. If the calculated interval is equal to or less than the reference interval, or more than the reference interval, the adsorption sheet It is determined that the glass plate is not normally adsorbed.

  In the adsorption step of the present invention, the glass plate is adsorbed to the adsorption sheet with the non-polished surface as an upper surface, and in the imaging step, the adsorption sheet is irradiated with the illumination light from below the adsorption sheet. Is preferred.

  In the adsorbing means of the present invention, the glass plate is adsorbed to the adsorbing sheet with the non-polished surface as an upper surface, and in the imaging means, the adsorbing sheet is irradiated with the illumination light from below the adsorbing sheet. Is preferred.

  According to the present invention, the present invention having imaging means is applied to an apparatus for polishing by adsorbing the non-polished surface of the glass plate to the lower surface of the adsorption sheet, that is, a polishing apparatus that is very difficult to visually monitor. Is particularly effective.

  According to the monitoring method and the monitoring system of the glass plate polishing apparatus of the present invention, the adsorption state of the glass plate with respect to the adsorption sheet can be monitored.

Side view of glass plate polishing apparatus in which monitoring system for glass plate polishing apparatus of embodiment is installed The perspective view which showed the structure of the imaging part of embodiment The block diagram which showed the structure of the determination part of embodiment Explanatory drawing which shows the application amount excessive state of glycerol with respect to an adsorption sheet Explanatory drawing which shows the application amount of glycerin with respect to an adsorption sheet being too small Explanatory drawing showing the optimum amount of glycerin applied to the suction sheet Explanatory drawing which shows the image by which at least 2 glass plate was adsorb | sucked to the adsorption sheet Explanatory drawing which showed the image where the glass plate is not adsorbed to the adsorption sheet Explanatory drawing showing the distance between the glass plate and the frame Explanatory drawing showing two monitoring points at each corner of the glass plate Explanatory drawing which shows the relationship between the light which injects into a glass plate, and the light reflected by the grinding | polishing surface and non-polishing surface of a glass plate Explanatory drawing which shows the relationship between the light which injects into two glass plates, and the light reflected by the grinding | polishing surface and non-polishing surface of a glass plate.

  Preferred embodiments of a monitoring method and a monitoring system for a glass plate polishing apparatus according to the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a side view of a glass plate polishing apparatus 10 in which a monitoring system for a glass plate polishing apparatus according to an embodiment is installed.

  A polishing apparatus 10 shown in FIG. 1 includes a glycerin application unit (liquid application process) 12, a plate adsorption unit (adsorption process) 14, and an imaging unit (imaging process) 16 from the upstream side to the downstream side of the glass plate G processing process. A polishing part (polishing step) 18 and an external part (not shown) are arranged in this order. In addition, a determination unit (determination step) 20 is connected to the imaging unit 16, and an image signal captured by the imaging unit 16 is output to the determination unit 20. The determination unit 20 performs signal processing on the image signal to determine whether or not the glass plate G is normally sucked to the suction sheet 22.

  The polishing apparatus 10 is a polishing apparatus that polishes a polishing surface of a large glass plate G (for example, a side exceeding 1800 mm and a thickness of 0.2 mm to 0.7 mm) to a flatness necessary for a glass plate for a liquid crystal display. .

  In the glycerin application unit 12, a film frame 28 is attached to the lower part of the carrier 26 of the polishing head 24, and the adsorption sheet 22 is stretched on the film frame 28. Glycerin (liquid) 32 is applied from the nozzle (liquid applying means) 30 to the entire lower surface of the suction sheet 22 that is the surface that holds the glass plate G by suction. In addition, although glycerin 32 is illustrated as a liquid, water may be sufficient and polyethyleneglycol may be sufficient. However, since glycerin 32 is harder to dry than water, glycerin 32 is preferable. The glycerin 32 is also suitable as an antifouling liquid for the edge of the glass plate G by the polishing liquid used in the polishing section 18.

  The suction sheet 22 to which the glycerin 32 is applied is conveyed to the plate suction unit 14 by the movement of the polishing head 24 indicated by the arrow A. Here, the non-polished surface of the glass plate G is placed on the lower surface of the suction sheet 22 via the glycerin 32. Adsorbed and held. In the suction method, first, the glass plate G is placed on the table 34 by the robot 60. Next, the carrier 26 is moved downward toward the glass plate G, and the non-polished surface of the glass plate G is sucked by the suction sheet 22. Next, the carrier 26 is moved up to the original position, and then a roller (adsorption means) 36 disposed on the side of the carrier 26 is run on the polished surface of the glass plate G to adsorb the non-polished surface of the glass plate G. The sheet 22 is pressed and brought into close contact. The adsorption method is an example.

  The glass plate G sucked and held by the suction sheet 22 passes above the imaging unit 16 by the movement of the polishing head 24 indicated by the arrow B, that is, the movement from the plate suction unit 14 to the polishing unit 18. At this time, the glass plate G and the suction sheet 22 are illuminated by the light 38 of the imaging unit 16, and the reflected light is received by the light receiving element of the camera (imaging means) 40, so that the glass plate G and the suction sheet 22 are imaged. Is done. The image signal from the camera 40 is output to the determination unit 20 as described above.

  The glass plate G that has passed above the imaging unit 16 is conveyed to the polishing unit 18 by the continuous movement of the polishing head 24 indicated by the arrow B. Here, the polishing surface of the glass plate G is pressed against the polishing pad 42 and polished. In the polishing method, a pressure fluid is supplied between the carrier 26 and the suction sheet 22, and the pressure of the pressure fluid is transmitted to the glass plate G through the suction sheet 22, thereby polishing the polished surface of the glass plate G. Press against the pad 42. Then, the carrier 26 is rotated (including rotation and revolution) by the rotation shaft 44 and the polishing pad 42 is rotated to polish the polishing surface of the glass plate G. This polishing method is also an example.

  A frame 46 that is pressed against the polishing pad 42 together with the glass plate G is adsorbed to the suction sheet 22. The frame 46 is called a dummy plate, surrounds the periphery of the glass plate G, and prevents the polishing pressure from concentrating on the edge portion of the polishing surface of the glass plate G. The frame 46 is made of a material that is not worn by polishing with the polishing pad 42, and examples thereof include stainless steel, iron, aluminum, polyethylene, and polyurethane.

  The glass plate G whose polished surface has been polished by the polishing unit 18 is conveyed to the outside (not shown) 18 by the movement of the polishing head 24 as indicated by arrow C, and is removed from the suction sheet 22 here, and then the next step ( For example, it is conveyed to a cleaning process.

  Next, the imaging unit 16 and the determination unit 20 will be described.

  FIG. 2 is a perspective view illustrating the configuration of the imaging unit 16, and is a perspective view of the carrier 26 moving in the arrow B (see FIG. 1) looking up from below.

  The imaging unit 16 includes a rod-like fluorescent lamp that is a light 38 and a line sensor that is a camera 40. The light 38 is arranged in a direction orthogonal to the moving direction indicated by the arrow B. A reflector 48 that collects the illumination light from the light 38 on the glass plate G and the suction sheet 22 is attached below the light 38.

  In the line sensor, the light receiving elements are arranged in a direction orthogonal to the moving direction indicated by the arrow B, and receive the illumination light from the light 38 reflected by the glass plate G, the suction sheet 22 and the frame 46. To do. The line sensor outputs an image signal for each line in the orthogonal direction of the glass plate G, the suction sheet 22 and the frame body 46, so that the glass plate G and the suction sheet 22 are moved by the movement of the carrier 26 indicated by the arrow B. All the lines of the frame 46 are scanned, and the image signals of all the lines indicating the glass plate G, the suction sheet 22 and the frame 46 can be acquired. An area sensor may be used instead of the line sensor.

  FIG. 3 is a block diagram illustrating a configuration of the determination unit 20 according to the embodiment.

  The image signal from the camera 40 is amplified by the amplifier 50 and output to the image signal processing unit 52 of the determination unit 20. The image signal processing unit 52 determines whether or not the glass plate G is normally sucked on the suction sheet 22 based on the image captured by the camera 40 and causes the display 54 to display the image.

  The determination result is output to the CPU 56 that controls the polishing apparatus 10 in an integrated manner. Based on the result, the CPU 56 stops the operation of the polishing unit 18 of the polishing apparatus 10, generates a warning sound from the alarm 58, controls the robot 60, and controls the glass plate G for the table 34 shown in FIG. Or change the mounting position.

  Next, a determination method by the image signal processing unit 52 and a control operation by the CPU 56 will be described.

  First, the inventors of the present application have found the following form as a result of examining and experimenting on the abnormal form of the adsorption state of the glass plate G with respect to the adsorption sheet 22.

  The first abnormal form is a form in which the adsorbing force of the adsorbing sheet 22 decreases due to an excessive application amount of glycerin 32 to the adsorbing sheet 22 and an excessive application amount. In this case, the glass plate G is displaced with respect to the suction sheet 22 during the polishing of the glass plate G in the polishing unit 18, and the glass plate G falls from the suction sheet 22 while the glass plate G is being transported by the carrier 26. Or

  The second abnormal form is a form in which two or more glass plates G are adsorbed on the adsorbing sheet 22. This form includes a form in which a new glass plate G is adsorbed on the glass piece remaining on the adsorption sheet 22.

  The third abnormal form is a form in which the glass sheet G is not adsorbed to the adsorbing sheet 22 at all.

  The fourth abnormal form is a form in which the glass plate G deviates from the normal position with respect to the frame 46 and is adsorbed by the adsorbing sheet 22.

  In the monitoring system of the embodiment, the first to fourth abnormal forms are constantly monitored, and when it is determined as abnormal, the polishing of the glass plate G is not performed and the polishing unit 18 is stopped or an alarm is issued. A warning sound is generated from 58 to notify the operator of the abnormality.

  That is, in the monitoring system of the embodiment, in the glass plate polishing apparatus 10 of a normal facility having the glycerin application unit 12, the plate adsorption unit 14, and the polishing unit 18, an imaging unit is provided between the plate adsorption unit 14 and the polishing unit 18. 16 is provided.

  The imaging unit 16 illuminates the glass plate G and the suction sheet 22 moving from the plate suction unit 14 to the polishing unit 18 with the light 38 and images the reflected light with the camera 40. And the determination part 20 determines whether the glass plate G was normally adsorb | sucked to the adsorption | suction sheet | seat 22 based on the image imaged with the camera 40. FIG.

  Therefore, the monitoring system of the embodiment can constantly monitor the suction state of the glass plate G with respect to the suction sheet 22. Further, by arranging the imaging unit 16 in the polishing apparatus 10, visual monitoring is unnecessary and the determination can be performed in the polishing apparatus 10 having complicated facilities.

  Next, a method for determining the first abnormal form described above will be described.

  The image signal processing unit 52 of the determination unit 20 calculates the average value of the luminance of the image, and compares this average value with the range of the optimal luminance when the pre-stored application amount of glycerin 32 is the optimal value. To do. When the average value is within the optimum luminance range, the image signal processing unit 52 determines that the glass plate G is normally adsorbed to the adsorption sheet 22, while the average value is the optimum luminance. When it is out of the range, it is determined that the glass sheet G is not normally sucked by the suction sheet 22.

  FIG. 4 is an explanatory view showing a state in which the amount of glycerin 32 applied to the adsorbing sheet 22 is excessive. When the glass plate G is adsorbed to the adsorbing sheet in a state where the amount of glycerin 32 applied to the adsorbing sheet 22 is larger than the upper limit of the optimum value range, the camera 40 reflects light from the polishing surface Ga of the glass plate G. More reflected light from the suction sheet 22 is received.

  FIG. 11 is an explanatory diagram showing the relationship between light incident on the glass plate G and light reflected by the polished surface Ga and the non-polished surface Gb of the glass plate G. The refractive index (absolute refractive index: the following refractive index is the same) of the glass plate G is approximately 1.5. FIG. 11 shows an example of the glass plate G existing in the air having a refractive index of about 1.0. The light emitted from the light 38 and applied to the glass plate G is partially reflected by the polishing surface Ga of the glass plate G, but the remaining light travels into the glass plate G, and Reflected by the non-polished surface Gb. Then, the reflected light of the non-polished surface Gb of the glass plate G is emitted from the polished surface Ga of the glass plate G. The glass plate manufactured by the float method having a thickness of 0.7 mm or less has a reflectance of less than 10% and a transmittance of 90% or more at a visible light wavelength of 0.38 to 0.78 μm.

  However, as shown in FIG. 4, when a large amount of glycerin 32 having a refractive index of approximately 1.45 is applied to the non-polished surface Gb of the glass plate G, the light traveling inside the glass plate G is The glass plate G is hardly reflected by the non-polished surface Gb, enters the glycerin 32 from the non-polished surface Gb of the glass plate G, travels inside the glycerin 32, is reflected by the adsorption sheet 22, and polishes the glass plate G. The reflected light of the suction sheet 22 is emitted from the surface Ga.

  In FIG. 4, the amount of light received by the camera 40 is more reflected light from the suction sheet 22 emitted from the polishing surface Ga of the glass plate G than light reflected from the polishing surface Ga.

  For this reason, the camera 40 images the color of the suction sheet 22 (for example, black having a luminance lower than that of the glass plate), and the average luminance is lower than the lower limit of the optimum luminance range. Therefore, the image signal processing unit 52 determines that the glass plate G is not normally adsorbed to the adsorbing sheet 22 due to an excessive application amount of glycerin 32.

  FIG. 5 is an explanatory diagram showing a state in which the amount of glycerin 32 applied to the suction sheet 22 is too small. The state where the amount of glycerin 32 applied to the suction sheet 22 is less than the optimum value will be described in detail. The glass plate G is in a state where the glycerin 32 and the bubbles 33 are mixed between the glass plate G and the suction sheet 22. When adsorbed on the suction sheet 22, the camera 40 reflects the reflected light from the polishing surface Ga of the glass plate G and the non-polishing surface Gb emitted from the polishing surface Ga of the glass plate G rather than the reflected light from the suction sheet 22. Receives a lot of reflected light.

  That is, the state in which the application amount of glycerin 32 is too small shown in FIG. 5 is similar to the state of the glass plate G existing in the air shown in FIG. Therefore, part of the light emitted from the light 38 and applied to the glass plate G is reflected by the polishing surface Ga of the glass plate G, but the remaining light travels into the glass plate G, and the glass plate G Reflected by the non-polished surface Gb of G, the reflected light of the non-polished surface Gb of the glass plate G is emitted from the polished surface Ga of the glass plate G. The camera 40 receives light reflected from the suction sheet 22 without being reflected by the non-polished surface Gb of the glass plate G, but is emitted from the polished surface Ga of the glass plate G and from the polished surface Ga of the glass plate G. A large amount of reflected light from the non-polished surface Gb is received. For this reason, the camera 40 images the color of the glass plate G (for example, white with high luminance), and the average luminance is higher than the upper limit value of the optimum luminance range. It is determined that the glass plate G is not normally adsorbed to the adsorbing sheet 22 by the application amount of 32 being too small.

  FIG. 6 is an explanatory view showing an optimum state of the application amount of glycerin 32 to the suction sheet 22. When the amount of glycerin 32 applied to the suction sheet 22 is the optimum value, the camera 40 reflects the amount of reflected light from the suction sheet 22 and the amount of reflected light (polishing) from the glass plate G that is substantially the same as the amount of reflected light. The sum of the reflected light from the surface Ga and the reflected light from the non-polished surface Gb) is received. For this reason, the camera 40 images a gray color in which the color of the glass plate G (for example, white) and the color of the suction sheet 22 (for example, black) are mixed, and the average luminance is within the range of the optimal luminance. The signal processing unit 52 determines that the glass plate G has been normally sucked by the suction sheet 22.

  When a camera 40 having 256 gradations (8 bits) per pixel is used, for example, 0 to 50 gradations are defined as black, 51 to 200 gradations are defined as gray, and 201 to 256 gradations are defined as white. Thus, the first abnormal form can be determined. In the camera 40, the optimum luminance range is defined as 51 to 200 gradations, but preferably 80 to 120 gradations. The gradation is an example, and the gradation level is set as appropriate. The range of optimum luminance is a range obtained from experimental values. The brightness received by the camera 40 can be adjusted by the brightness of the illumination, the aperture of the camera 40, and a gain on software.

  Next, a method for determining the second abnormal form described above will be described.

  The image signal processing unit 52 shown in FIG. 3 calculates the area of a white portion (hereinafter referred to as a white area) included in the image, and this white area is a predetermined area (hereinafter referred to as a reference white area). If it is less than that, it is determined that one glass plate G is normally adsorbed to the adsorbing sheet 22, and if the white area is equal to or larger than the reference white area, at least two glass plates G are adsorbed to the adsorbing sheet 22. Is determined to be adsorbed.

  FIG. 7 is an explanatory view showing an image in which at least two glass plates are adsorbed on the adsorbing sheet. The image shown in FIG. 7 is an image displayed on the display 54 shown in FIG. 3, and a black area B, a gray area Gr, a frame-shaped white area W1, and an irregularly-shaped white area W2 are shown. .

  The black area B shows an area where the amount of glycerin 32 is excessively applied and the suction sheet 22 positioned between the four sides of the glass plate G and the frame 46, and the gray area Gr has the optimum amount of glycerin 32 applied. The area. The white area W1 indicates the frame 46. And white area W2 has shown the area where the application amount of glycerin 32 is insufficient, or the area where at least 2 glass plates G are adsorbed.

  FIG. 12 is an explanatory diagram showing the relationship between the light incident on the two glass plates G1 and G2 and the light reflected on the polished and non-polished surfaces of the glass plates, respectively. The glass plate G1 is a glass plate on the camera 40 and light 38 side, and the glass plate G2 is a glass plate on the suction sheet side. The non-polishing surface G1b of the glass plate G1 and the polishing surface G2a of the glass plate G2 are in close contact. In addition, when glass plates are laminated, it is known that the glass plate surfaces are bonded to each other on the laminated surface and are in close contact with a certain degree of bonding force. This bonding force is a silanol group (Si-OH) present on both glass surfaces. It is thought to be due to the formation of chemical bonds by mutual hydrogen bonds and partial dehydration condensation, van der Waals forces between the surfaces of both glass plates, and the like.

  A part of the light emitted from the light 38 and applied to the glass plate G1 is reflected by the polishing surface G1a of the glass plate G1, but the remaining light travels into the glass plate G1 and travels inside. A part of the light is reflected by the non-polished surface G1b of the glass plate G1. A part of the remaining light that is not reflected by the non-polished surface G1b of the glass plate G1 is reflected by the polished surface G2a of the glass plate G2. Further, the remaining light that has not been reflected by the polished surface G2a of the glass plate G2 is reflected by the non-polished surface G2b of the glass plate G2. The reflected light of each of the non-polished surface G1b, the polished surface G2a, and the non-polished surface G2b is emitted from the polished surface G1a of the glass plate G1.

  That is, when at least two glass plates G are adsorbed to the adsorption sheet 22, the illumination light is reflected from at least two glass plates G, so the image of that portion is white as in the white area W2. Become. The image signal processing unit 52 calculates the area of the white area W2 in order to distinguish between the form in which at least two glass plates G are adsorbed on the adsorbing sheet 22 and the form in which the application amount of glycerin 32 is excessive, By comparing the calculated white area with a reference white area where it is determined that at least two glass plates G are adsorbed, it is determined whether or not the second abnormal form is present. The reference white area is stored in advance in the image signal processing unit, is an area obtained by experiments, and can also be expressed as an area ratio with respect to the area of the non-polished surface of the glass plate G. When expressed as an area ratio, for example, when a camera 40 with 256 gradations (8 bits) per pixel is used, the area of 180 gradations or more with respect to the area of the non-polished surface of the glass plate G is 10% or more. Is determined that at least two glass plates G are adsorbed to the adsorption sheet 22.

  Next, a method for determining the third abnormal form described above will be described.

  The image signal processing unit 52 shown in FIG. 3 calculates an area of a black portion included in the image (hereinafter referred to as a black area), and the black area is a predetermined area (hereinafter referred to as a reference black area). If it is less than that, it is determined that the glass plate G is normally adsorbed to the adsorbing sheet 22, and if the black area is equal to or larger than the reference black area, it is determined that the glass plate G is not adsorbed to the adsorbing sheet 22. To do.

  FIG. 8 is an explanatory diagram showing an image in which the glass plate is not adsorbed on the adsorbing sheet. The image shown in FIG. 8 is an image displayed on the display 54 shown in FIG. 3, and a black area B and a white area W1 are shown.

  The black area B shows the excessive application amount area of glycerin 32 or the state in which the glass plate G is not adsorbed to the adsorbing sheet 22 and the adsorbing sheet 22 positioned between the four sides of the glass plate G and the frame body 46. The white area W1 indicates the frame 46.

  That is, when the glass sheet G is not adsorbed to the adsorbing sheet 22, the illumination light is reflected from the adsorbing sheet 22, so that the image of that portion becomes black like a black area B as shown in FIG. . In order to distinguish between the form in which the glass sheet G is not adsorbed by the adsorbing sheet 22 as shown in FIG. 8 and the form in which the application amount of glycerin 32 is excessive as shown in FIG. The area of the black area B is calculated, and the third abnormal form is determined by comparing the calculated black area with the reference black area that is determined that the glass sheet is not adsorbed to the adsorption sheet 22. The reference black area is stored in advance in the image signal processing unit, is an area obtained by experiments, and can also be expressed as an area ratio with respect to the area of the non-polished surface of the glass plate G. When expressed as an area ratio, for example, when a camera 40 of 256 gradations (8 bits) per pixel is used, the area of 40 gradations or less with respect to the area of the non-polished surface of the glass plate G is 50% or more. Is determined as a state in which the glass sheet G is not adsorbed to the adsorbing sheet 22.

  Next, a method for determining the above-described fourth abnormality form will be described.

  The image signal processing unit 52 calculates the interval between the glass plate G and the frame 46 based on the image. When the calculated interval is equal to or less than the reference interval or equal to or greater than the reference interval, the glass plate G is normal on the suction sheet 22. It is determined that it is not adsorbed on the surface.

  FIG. 9 is an explanatory diagram showing a distance between the glass plate and the frame. The image shown in FIG. 9 is an image displayed on the display 54 shown in FIG. 3 and is an enlarged image of the vicinity of the corner portion of the glass plate G. The gray area Gr, the white area W1, and the black area B are It is shown.

  The gray area Gr is an area where the application amount of glycerin 32 is optimum, and the white area W1 indicates the frame 46. The black area B indicates the suction sheet 22 positioned between the four sides of the glass plate G and the frame body 46.

  The image signal processing unit 52 shown in FIG. 3 includes the number of pixels at the interval P between one side M1 of the glass plate G and one side N1 of the frame 46 facing the one side M1, and one side M2 adjacent to the one side M1. When the distance between the glass plate G and the frame 46 is calculated based on the number of pixels in the interval Q between the side N2 of the frame 46 facing the one side M2 and the calculated interval is smaller than the reference interval, or If it is larger, it is determined that the glass plate G is not normally adsorbed to the adsorbing sheet 22. The determination in this case is carried out at a total of 8 points (a to h points) of 2 points each in the corner portion of the glass plate G shown in FIG.

  In the case where the interval is not more than the reference interval (for example, 3 mm or less) or not less than the reference interval (for example, 15 mm), the placement position of the glass plate G with respect to the table 34 is shown in FIG. The CPU 56 controls the operation of the robot 60.

  As described above, according to the monitoring system of the embodiment, the first to fourth abnormal forms can be monitored.

  In the embodiment, the polishing apparatus 10 that performs polishing by adsorbing the non-polished surface of the glass plate G to the lower surface of the adsorption sheet 22 is illustrated. This polishing apparatus 10 is particularly effective because it is very difficult to visually monitor the adsorption form of the glass plate G with respect to the adsorption sheet 22. Note that the monitoring system of the embodiment can also be applied to a polishing apparatus that performs polishing by adsorbing the non-polished surface of the glass plate G to the upper surface of the suction sheet 22.

In addition, the chip | tip along the four sides of the glass plate G and the chip | tip of a corner | angular part can also be detected based on the image information of the glass plate G imaged with the camera 40 of embodiment. That is, the image information along the four sides of the glass plate G and the corner information are compared with the reference shape information without a chip, and the area corresponding to the chip is calculated from the number of pixels of the difference. For example, when a camera 40 having 256 gradations (8 bits) per pixel is used, a glass plate G having a large amount of chipping is determined if the area of 40 gradations or less is 12.5 cm ² or more.

  G ... Glass plate, 10 ... Polishing device, 12 ... Glycerin coating unit, 14 ... Plate adsorption unit, 16 ... Imaging unit, 18 ... Polishing unit, 20 ... Determination unit, 22 ... Adsorption sheet, 24 ... Polishing head, 26 ... Carrier 28 ... Film frame, 30 ... Nozzle, 32 ... Glycerin, 34 ... Table, 36 ... Roller, 38 ... Light, 40 ... Camera, 42 ... Polishing pad, 44 ... Rotating shaft, 46 ... Frame, 48 ... Reflector, 50 ... Amplifier, 52 ... Image signal processor, 54 ... Display, 56 ... CPU, 58 ... Alarm, 60 ... Robot

Claims (12)

A liquid application step of applying a liquid to an adsorption sheet that adsorbs a glass plate;
An adsorption step of adsorbing the non-polished surface of the glass plate to the adsorption sheet coated with the liquid;
An imaging step of irradiating illumination light toward the suction sheet and imaging the reflected light;
A determination step of determining whether or not the glass plate is normally adsorbed to the adsorption sheet based on the captured image;
A polishing step of polishing the polishing surface of the glass plate adsorbed on the adsorption sheet;
A method for monitoring a glass plate polishing apparatus, comprising:   The determination step calculates an average value of luminance of the image, compares the average value with a range of optimum luminance when the liquid application amount stored in advance is an optimum value, and the average value is When it is in the range of the optimum luminance, it is determined that the glass plate is normally adsorbed to the adsorption sheet. When the average value is out of the range of the optimum luminance, the glass on the adsorption sheet is determined. The method for monitoring a glass plate polishing apparatus according to claim 1, wherein it is determined that the plate is not normally adsorbed.   The determination step calculates an area of a white portion included in the image, compares the white area with a reference white area stored in advance, and if the white area is less than the reference white area It is determined that one glass plate is normally adsorbed to the suction sheet, and if the white area is equal to or larger than the reference white area, it is determined that at least two glass plates are adsorbed to the suction sheet. The monitoring method of the glass plate grinding | polishing apparatus of Claim 1 or 2 to do.   The determination step calculates an area of a black portion included in the image, compares the black area with a reference black area stored in advance, and if the black area is less than the reference black area Determining that the glass plate is normally adsorbed to the adsorbing sheet, and determining that the glass plate is not adsorbed to the adsorbing sheet when the black area is equal to or larger than the reference black area. The monitoring method of the glass plate grinding | polishing apparatus of 2 or 3. The adsorbing sheet is arranged around the glass plate adsorbed and held by the adsorbing sheet, and adsorbs a frame that comes into contact with the polishing tool in the polishing step together with the glass plate,
The determination step calculates an interval between the glass plate and the frame based on the image, compares the calculated interval with a pre-stored reference interval, and the calculated interval is equal to or less than the reference interval. Or the monitoring method of the glass plate grinding | polishing apparatus in any one of Claim 1 to 4 which determines with the said adsorption | suction sheet not adsorbing | sucking the said glass plate normally when it is more than the said reference | standard space | interval. In the adsorption step, the glass plate is adsorbed to the adsorption sheet with the non-polished surface as an upper surface,
The monitoring method of the glass plate polishing apparatus according to claim 1, wherein the suction sheet is irradiated with the illumination light from below the suction sheet in the imaging step. A liquid application means for applying a liquid to an adsorption sheet for adsorbing a glass plate;
Adsorbing means for adsorbing the non-polished surface of the glass plate to the adsorbing sheet coated with the liquid;
Imaging means for irradiating illumination light toward the suction sheet and imaging the reflected light;
Determination means for determining whether or not the glass plate is normally sucked to the suction sheet based on the captured image;
Polishing means for polishing the polishing surface of the glass plate adsorbed on the adsorption sheet;
A monitoring system for a glass plate polishing apparatus, comprising:   The determination unit calculates an average value of the luminance of the image, compares the average value with a range of optimal luminance when the liquid application amount stored in advance is an optimal value, and the average value is When it is in the range of the optimum luminance, it is determined that the glass plate is normally adsorbed to the adsorption sheet. When the average value is out of the range of the optimum luminance, the glass on the adsorption sheet is determined. The monitoring system for a glass plate polishing apparatus according to claim 7, wherein it is determined that the plate is not normally adsorbed.   The determination means calculates an area of a white portion included in the image, compares the white area with a reference white area stored in advance, and if the white area is less than the reference white area It is determined that one glass plate is normally adsorbed to the suction sheet, and if the white area is equal to or larger than the reference white area, it is determined that at least two glass plates are adsorbed to the suction sheet. The monitoring system for a glass plate polishing apparatus according to claim 7 or 8.   The determination means calculates an area of a black portion included in the image, compares the black area with a reference black area stored in advance, and if the black area is less than the reference black area Determining that the glass plate is normally adsorbed to the adsorbing sheet, and determining that the glass plate is not adsorbed to the adsorbing sheet when the black area is equal to or larger than the reference black area. A monitoring system for a glass plate polishing apparatus according to 8 or 9. The adsorbing sheet is arranged around the glass plate adsorbed and held by the adsorbing sheet, and adsorbs a frame that comes into contact with the polishing tool in the polishing step together with the glass plate,
The determination unit calculates an interval between the glass plate and the frame based on the image, compares the calculated interval with a reference interval stored in advance, and the calculated interval is equal to or less than the reference interval. In this case, the monitoring system for a glass plate polishing apparatus according to any one of claims 7 to 10, wherein the glass plate is determined not to be normally adsorbed to the adsorbing sheet. In the adsorption means, the glass plate is adsorbed to the adsorption sheet with the non-polished surface as an upper surface,
The monitoring system for a glass plate polishing apparatus according to any one of claims 7 to 11, wherein in the imaging means, the suction sheet is irradiated with the illumination light from below the suction sheet.

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