Method and apparatus for manufacturing glass plates

Abstract

It reliably detects damage across almost the entire surface of the glass plate. [Solution] The method for manufacturing a glass plate includes a detection step S5 for detecting damage to a glass plate G being transported in the transport direction X, using a sensor group 13 that includes a plurality of sensors 12 capable of detecting the presence or absence of a glass plate G. The sensor group 13 comprises a sensor row 15 arranged along a direction perpendicular to the transport direction X. In the detection step S5, if some of the sensors 12 included in the sensor row 15 located within the passage range P of the glass plate G being transported in the transport direction X fail to detect the glass plate G, it is determined that the glass plate G is damaged.

Description

Technical Field

[0004] , , ,

[0005] , , ,

[0001] The present invention relates to a method and an apparatus for manufacturing a glass plate.

Background Art

[0002] The manufacturing process of a glass plate includes, for example, a forming process, a cutting process, an end face processing process, a cleaning process, etc. (see, for example, Patent Documents 1 and 2). In the forming process, a long glass ribbon is formed from molten glass. In the cutting process, the long glass ribbon is cut to obtain a glass plate of a predetermined size. In the end face processing process, end face processing such as grinding is performed on the end face of the glass plate. In the cleaning process, the glass plate is cleaned.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above-described end face processing process, since a cutting tool such as a grindstone directly contacts the end face of the glass plate, the glass plate is likely to be damaged such as cracked. Further, the damaged portion of the glass plate may occur not only around the end face of the glass plate but also in the central portion of the glass plate. When such a partially damaged glass plate is sent to a subsequent process, the glass plate may be entirely damaged in a processing apparatus (for example, a cleaning apparatus) in the subsequent process. In this case, it is necessary to remove glass powder and glass pieces generated due to the damage, and the manufacturing efficiency is reduced. Further, if the removal work is insufficient and glass pieces or the like remain, scratches are introduced into the subsequent glass plate by the glass pieces or the like, resulting in product defects. Therefore, it is desired to reliably detect damage to substantially the entire surface of the glass plate.

[0005] The present invention aims to reliably detect damage to substantially the entire surface of a glass plate. [Means for solving the problem]

[0006] (1) The present invention, devised to solve the above problems, is a method for manufacturing a glass plate, comprising a transport step of transporting a glass plate in a predetermined transport direction, and a detection step of detecting damage to a glass plate being transported in the transport direction using a sensor group including a plurality of sensors capable of detecting the presence or absence of a glass plate, wherein the sensor group comprises a row of sensors arranged along a direction intersecting the transport direction, and in the detection step, it is determined that the glass plate is damaged if some of the sensors included in the sensor row located within the passage range of the glass plate being transported in the transport direction are unable to detect the glass plate.

[0007] In this way, by transporting the glass plate in the transport direction, the sensor array scans the entire surface of the glass plate, ensuring reliable detection of damage to almost the entire surface. Furthermore, by removing the damaged glass plate upon detection, problems caused by sending damaged glass plates to subsequent processes can be prevented.

[0008] (2) In the configuration of (1) above, the glass plate is rectangular in shape with four corners, the sensor row comprises first corner sensors positioned at locations corresponding to two corners of the glass plate, and the sensor group comprises second corner sensors positioned at locations corresponding to the remaining two corners of the glass plate, separate from the sensor row, and the detection step preferably includes a corner detection step in which the first corner sensors and the second corner sensors detect damage to the corners of the glass plate.

[0009] In this way, during the corner detection process, damage to the corners can be reliably detected by the first and second corner sensors, which are positioned to correspond to the corners that are prone to damage.

[0010] (3) In the configuration of (2) above, it is preferable that the corner detection step be performed with the transport of the glass plate stopped.

[0011] When the transport of the glass plate is stopped in this manner, the orientation of the glass plate stabilizes. Therefore, in the corner detection process, damage to the corners of the glass plate can be detected with high accuracy.

[0012] (4) In the configuration of (3) above, the transport process preferably includes a posture change process in which the posture of the glass plate is changed from a horizontal posture to an inclined posture while the transport of the glass plate is stopped, and the corner detection process is preferably performed in the posture change process.

[0013] In this way, the orientation of the glass plate can be changed during the orientation change process, and the corner detection process can also be performed by utilizing the cessation of glass plate transport during the orientation change process. Therefore, since it is not necessary to stop the transport of the glass plate separately for the orientation change process and the corner detection process, the glass plate can be transported efficiently.

[0014] (5) In the configuration of (3) or (4) above, the sensor array is arranged along the front edge of the glass plate located on the front side in the transport direction of the glass plate whose transport has been stopped in the corner detection step, and the detection step preferably includes a front edge detection step in which the sensor array detects damage to the front edge of the glass plate while the transport of the glass plate has been stopped.

[0015] In this way, in addition to damage to the easily damaged corners, damage to the easily damaged front edges can also be detected with high accuracy while the glass plate is being transported (while the glass plate's position is stabilized).

[0016] (6) In any of the configurations (1) to (5) above, the detection step is preferably performed on a glass plate in an inclined position.

[0017] In this way, if the glass plate is wet with a liquid such as grinding fluid, the liquid will quickly fall off the glass plate. As a result, the amount of liquid adhering to the glass plate is reduced, and the accuracy of detecting glass plate breakage is less likely to be reduced by the liquid.

[0018] (7) In any of the configurations (1) to (6) above, in the conveying step, the glass plate is conveyed in the conveying direction using a plurality of conveying belts arranged with gaps therebetween, and the sensor group is preferably arranged to detect the glass plate located in the gap between the plurality of conveying belts.

[0019] By doing so, it is possible to prevent the situation where the conveying belt is erroneously detected as the glass plate. Therefore, there is an advantage that the detection accuracy of damage to the glass plate is improved.

[0020] (8) In any of the configurations (1) to (7) above, it preferably includes an end face processing step of processing the end face of the glass plate before the detection step, and a cleaning step of cleaning the glass plate after the detection step.

[0021] In the end face processing step, damage to the glass plate is likely to occur. Therefore, if the detection step is carried out between the end face processing step and the cleaning step, the effect of the present invention of preventing problems caused by the damaged glass plate being sent to the subsequent process becomes remarkable.

[0022] (9) In any of the configurations (1) to (8) above, the sensor is preferably an ultrasonic sensor.

[0023] By doing so, even when liquid adheres to the glass plate, the detection accuracy of damage to the glass plate is less likely to be reduced by the liquid.

[0024] (10) In any of the configurations (1) to (9) above, in the detection step, it is preferable to detect damage to the glass plate while injecting gas so as to cover the sensor surface of the sensor.

[0025] By doing so, it is possible to suppress the adhesion of foreign substances such as liquid to the sensor surface of the sensor by the gas. Therefore, it is possible to prevent the detection accuracy of damage to the glass plate from being reduced by foreign substances such as liquid.

[0026] (11) In any of the configurations (1) to (10) above, it is preferable that the sensor includes a cover surrounding the periphery of the sensor surface.

[0027] In this way, the cover can prevent foreign substances such as liquid from adhering to the sensor surface of the sensor. Also, due to the cover, the directivity of the sensor surface is improved, so that the situation where adjacent sensors interfere with each other can be suppressed. Therefore, it is possible to suppress a decrease in the detection accuracy of damage to the glass plate due to foreign substances such as liquid and mutual interference.

[0028] (12) In any of the configurations (1) to (11) above, it is preferable that the sensor group is arranged above the glass plate.

[0029] In this way, it becomes difficult for foreign substances such as liquid falling from the glass plate or the like to adhere to the sensor group. Therefore, it is possible to suppress a decrease in the detection accuracy of damage to the glass plate due to foreign substances such as liquid.

[0030] (13) The present invention devised to solve the above problems is a glass plate manufacturing apparatus including a conveyance device that conveys a glass plate in a predetermined conveyance direction and a detection device that detects damage to the glass plate conveyed in the conveyance direction. The detection device includes a sensor group including a plurality of sensors capable of detecting the presence or absence of the glass plate, and a determination unit that determines the presence or absence of damage to the glass plate based on the detection results of the sensor group. The sensor group includes a sensor row arranged along a direction intersecting the conveyance direction, and the determination unit determines that the glass plate is damaged when some of the sensors included in the sensor row located within the passage range of the glass plate conveyed in the conveyance direction cannot detect the glass plate.

[0031] In this way, the same operational effects as the corresponding configurations described above can be enjoyed.

Effects of the Invention

[0032] According to the present invention, damage to substantially the entire surface of the glass plate can be detected.

Brief Description of the Drawings

[0033] [Figure 1] This is a schematic plan view showing a glass plate manufacturing apparatus according to an embodiment of the present invention. [Figure 2] This is a plan view showing an enlarged view of the area surrounding the second conveying device included in the glass plate manufacturing apparatus according to this embodiment. [Figure 3] This is a magnified side view showing the area around the second conveying device included in the glass plate manufacturing apparatus according to this embodiment. [Figure 4] Figure 3, section AA, shows the state of the glass plate in a horizontal position. [Figure 5] Figure 3 is a cross-sectional view AA, showing the state of the glass plate in an inclined position. [Figure 6] This is a magnified side view showing the area around the sensor of a detection device included in the glass plate manufacturing apparatus according to this embodiment. [Figure 7] This is a plan view showing an example of a case where damage occurs to the glass plate during the detection step included in the manufacturing method of the glass plate according to this embodiment. [Modes for carrying out the invention]

[0034] Embodiments of the present invention will be described below with reference to the accompanying drawings.

[0035] As shown in Figure 1, the glass plate manufacturing apparatus according to this embodiment includes a conveying device 1 that performs a conveying process for conveying a glass plate G in a predetermined conveying direction X. The conveying device 1 comprises, in order from the upstream side in the conveying direction X, a first conveying device 2, a second conveying device 3, a third conveying device 4, and a fourth conveying device 5.

[0036] The glass plate G is a rectangular flat plate with four corners Gx. The glass plate G is transported by the first transport device 2, the second transport device 3, the third transport device 4, and the fourth transport device 5 in that order, with its side (for example, the long side) aligned with the transport direction X. The side of the glass plate G located on the front side in the transport direction X is called the front side Ga, the side of the glass plate G located on the rear side in the transport direction X is called the rear side Gb, and the side of the glass plate G aligned with the transport direction X is called the side side Gc. Furthermore, the portion of the glass plate G located between the front side Ga and the rear side Gb is called the central flat portion Gd.

[0037] Each conveying device 2 to 5 is equipped with multiple conveyor belts 6 for conveying the glass plate G in the conveying direction X while the glass plate G is placed on it. The multiple conveyor belts 6 are spaced apart in a direction perpendicular to the conveying direction X. In other words, a gap C is formed between adjacent conveyor belts 6 in a direction perpendicular to the conveying direction X. The conveyor belts 6 are made of rubber or other elastic material in an endless manner. Note that each conveying device 2 to 5 is not limited to belt conveyors equipped with conveyor belts 6, but may also be, for example, roller conveyors or floating conveyors.

[0038] Along the transport path of the first transport device 2, an end-face processing process S1 is performed in which the end face of the horizontally positioned glass plate G is ground (chamfered) using a grinding wheel 7 while grinding fluid is supplied. The grinding fluid is supplied to the contact area (grinding area) between the grinding wheel 7 and the end face of the glass plate G for purposes such as cooling and reducing friction. Along the transport path of the first transport device 2, the glass plate G is transported in a horizontal position.

[0039] The second conveying device 3 receives the glass plate G in a horizontal position from the first conveying device 2. Along the conveying path of the second conveying device 3, a posture change process S2 is performed to change the posture of the glass plate G from a horizontal position to an inclined position while the conveying of the glass plate G is stopped. The second conveying device 3 is capable of switching between a horizontal state where the conveying surface of the conveying belt 6 is aligned with the horizontal plane (see Figure 4) and an inclined state where the conveying surface of the conveying belt 6 is inclined with respect to the horizontal plane (see Figure 5). In other words, after receiving the glass plate G in a horizontal position from the first conveying device 2 using the conveying belt 6 in the horizontal state, the second conveying device 3 switches the conveying belt 6 from the horizontal state to the inclined state. This changes the posture of the glass plate G from a horizontal position to an inclined position. The inclined glass plate G is positioned at a predetermined position by moving it downward on the conveying surface of the inclined conveying belt 6 using rollers or the like. The inclination angle θ of the inclined glass plate G with respect to the horizontal plane is, for example, 1° to 15°. Furthermore, the conveying surface of the conveying belt 6 of the third conveying device 4 and the conveying surface of the conveying belt 6 of the fourth conveying device 5 are also inclined with respect to the horizontal plane.

[0040] The third conveying device 4 receives the inclined glass plate G from the second conveying device 3. Along the conveying path of the third conveying device 4, an extraction process S3 is performed as needed, in which the inclined glass plate G is extracted by an extraction device 8 equipped with multiple suction pads. When the extraction process S3 is performed, the inclined glass plate G is removed from the conveying path of the third conveying device 4 by the extraction device 8, as shown by the dashed line in the figure.

[0041] If the extraction process S3 is not performed, the inclined glass plate G is transported to the fourth transport device 5 from the third transport device 4. Along the transport path of the fourth transport device 5, the cleaning process S4 is performed in which the inclined glass plate G is cleaned by the cleaning device 9 while cleaning fluid is supplied.

[0042] The glass plate manufacturing apparatus further includes a detection device 11 that detects breakage of the glass plate G on the transport path of the second transport device 3.

[0043] As shown in Figures 2 to 5, the detection device 11 includes a sensor group 13 that includes a plurality of sensors 12 capable of detecting the presence or absence of the glass plate G, and a determination unit 14 that determines whether or not the glass plate G is damaged based on the detection results of the sensor group 13.

[0044] The sensor group 13 is positioned above the glass plate G located on the transport path of the second transport device 3. This makes it difficult for foreign matter such as liquids (e.g., grinding fluid) falling from the glass plate G or the transport belt to adhere to the sensor group. Therefore, it is possible to suppress a decrease in the detection accuracy of glass plate breakage due to foreign matter such as liquids.

[0045] As the sensor 12, ultrasonic sensors, fiber sensors, laser sensors, etc., can be used. However, if the glass plate G is wet with a liquid such as grinding fluid, it is preferable to use an ultrasonic sensor.

[0046] The sensor 12 is positioned to detect breakage of the glass plate G at a location corresponding to the gap C in the adjacent conveyor belt 6 of the second conveyor device 3 (see Figures 2 and 5). This prevents the sensor 12 from mistakenly detecting the conveyor belt 6 as the glass plate G.

[0047] The sensor group 13 includes a sensor row 15 consisting of a plurality of sensors 12 arranged in a row along the front edge Ga of the glass plate G, which has stopped on the transport path of the second transport device 3 for the attitude change process S2.

[0048] The sensor group 13 includes a first corner sensor 12x positioned at locations corresponding to two corners Gx formed on the front edge Ga of the glass plate G when it stops on the transport path of the second transport device 3 for the attitude change process S2, and a second corner sensor 12y positioned at locations corresponding to two corners Gx formed on the rear edge Gb of the glass plate G when it stops on the transport path of the second transport device 3 for the attitude change process S2 (see Figure 2). In this embodiment, the first corner sensor 12x is included in the sensor array 15 and also serves as sensor 12 of the sensor array 15. In other words, the first corner sensor 12x is used not only to detect damage to the corners Gx of the glass plate G, but also, for example, to detect damage to the side edges Gc of the glass plate G.

[0049] The determination unit 14 determines that the glass plate G is damaged if some of the sensors 12 included in the sensor array 15, which are located within the passage range P of the glass plate G being transported in the transport direction X, fail to detect the glass plate G during transport. Note that the determination unit 14 is not shown in drawings other than Figures 4 and 5.

[0050] If the size of the glass plate G is changed, the passage range P is changed according to the size in the direction perpendicular to the transport direction X of the glass plate G (the arrangement direction of the sensor array 15). In other words, the number of sensors 12 included in the sensor array 15 located within the passage range P changes depending on the size of the passage range P.

[0051] If the size of the glass plate G is changed, the placement positions of the corner sensors 12x and 12y can be changed according to the position of the corner Gx of the glass plate G. Alternatively, if the size of the glass plate G is fixed, the corner sensors 12x and 12y may be pre-placed at positions corresponding to the corner Gx of each size of glass plate G.

[0052] In this embodiment, the sensor array 15, including the first corner sensor 12x, is arranged to detect damage to the glass plate G when its orientation is changed to an inclined position in the orientation change step S2 (see Figure 5). That is, the sensor array 15 is arranged parallel to the surface of the inclined glass plate G. Similarly, although not shown in the figure, the second corner sensor 12y is also arranged to detect damage to the glass plate G when its orientation is changed to an inclined position in the orientation change step S2.

[0053] As shown in Figure 6, the sensor 12 comprises a sensor body 16 and a cylindrical cover 17 surrounding the sensor surface 16a of the sensor body 16. The sensor body 16 and the cover 17 are attached to a support 18. Here, the sensor surface 16a of the sensor body 16 refers to, for example, a transmitting surface that transmits a detection beam such as ultrasound, a receiving surface that receives a detection beam, or a transmitting and receiving surface that transmits and receives a detection beam. Note that the support 18 is not shown in Figures 2 and 7.

[0054] The tip of the cover 17 protrudes downward (towards the glass plate G) from the sensor surface 16a of the sensor body 16. The protrusion dimension D of the tip of the cover 17 from the sensor surface 16a is preferably, for example, 1 to 60 mm.

[0055] A gas nozzle 19 is provided below the tip of the cover 17, which injects gas F so as to cover the sensor surface 16a of the sensor body 16. In this embodiment, the gas nozzle 19 injects gas F from the front (downstream) side to the rear (upstream) side in the transport direction X. As gas F, for example, air or an inert gas such as nitrogen can be used, but from the viewpoint of preventing contamination of the glass plate G, it is preferable to use cleanroom air.

[0056] If the glass plate G is wet with a liquid such as grinding fluid, the liquid may splash around as the glass plate G is transported. By providing a cover 17 and a gas nozzle 19, it is possible to suppress the adhesion of such liquids and other foreign matter to the sensor surface 16a. Therefore, it is possible to suppress a decrease in the detection accuracy of glass plate G damage due to liquids and other foreign matter. Furthermore, the cover 17 can also limit the transmission range and / or reception range of the detection beam from the sensor surface 16a. Therefore, it is possible to suppress situations in which the sensors 12 included in the sensor group 13 interfere with each other.

[0057] Next, a method for manufacturing a glass plate according to this embodiment will be described. This manufacturing method uses the glass plate manufacturing apparatus described above.

[0058] As shown in Figure 1, this manufacturing method includes an end-face processing step S1 performed on the transport path of the first transport device 2, a posture changing step S2 performed on the transport path of the second transport device 3, a sampling step S3 performed on the transport path of the third transport device 4, and a cleaning step S4 performed on the transport path of the fourth transport device 5. These steps S1 to S4 are performed during the transport process in which the glass plate G is transported in the transport direction X by these transport devices 2 to 5.

[0059] This manufacturing method may include a cutting step as a pre-step to the end-face processing step S1, in which the glass plate G is cut to a desired size. Furthermore, as a post-step to the cleaning step S4, it may include an inspection step to inspect the cleaned glass plate G and a packaging step to package the glass plate G that has undergone the inspection step. The glass plate G obtained in this way is used as a substrate for liquid crystal displays, organic EL displays, and the like. Such a glass plate G is also called a display glass substrate.

[0060] In the end face processing step S1, the end face of the horizontally positioned glass plate G is ground using a grinding wheel 7 while supplying grinding fluid or the like. The end face processing step S1 may be carried out while the glass plate G is being transported by the first transport device 2, or it may be carried out with the glass plate G stopped on the transport path of the first transport device 2. The end face processing step S1 is not limited to a step of grinding the end face of the glass plate G, but may also be a step of polishing the end face of the glass plate G, or a step of performing both grinding and polishing. The end face processing step S1 may be a step of processing the end faces of two sides of the glass plate G, or a step of processing the end faces of all four sides of the glass plate G.

[0061] As shown in Figures 4 and 5, in the posture change process S2, with the transport of the glass plate G stopped on the transport path of the second transport device 3, the transport belt 6 is tilted to change the posture of the glass plate G from a horizontal posture (state in Figure 4) to a tilted posture (state in Figure 5).

[0062] In this embodiment, during the posture change process S2, a detection process S5 is also performed in which the sensor group 13 of the detection device 11 is used to detect damage to the glass plate G.

[0063] As shown in Figure 5, the detection step S5 is performed on the glass plate G, which has been changed to an inclined position. By inclining the glass plate G in the detection step S5, liquids such as grinding fluid fall off the glass plate G quickly, making it easier to detect damage to the glass plate G.

[0064] The detection step S5 includes a front edge detection step for detecting damage to the front edge Ga of the inclined glass plate G, a corner detection step for detecting damage to the corner Gx of the inclined glass plate G, a central plane detection step for detecting damage to the central plane Gd of the inclined glass plate G, and a rear edge detection step for detecting damage to the rear edge Gb of the inclined glass plate G. Damage to the side edge Gc of the glass plate G is detected in conjunction with at least one of the front edge detection step, corner detection step, central plane detection step, and rear edge detection step.

[0065] The posture change process S2 includes a positioning process in which the inclined glass plate G is stopped on the transport path of the second transport device 3 for positioning. The front edge detection process and corner detection process included in the detection process S5 are performed during this positioning process. As shown in Figure 2, the front edge detection process detects damage to the front edge Ga of the glass plate G while it is stopped in an inclined position, based on the detection results of the sensor row 15 included in the sensor group 13. The corner detection process detects damage to the four corners Gx of the glass plate G while it is stopped in an inclined position, based on the detection results of the corner sensors 12x and 12y included in the sensor group 13.

[0066] Here, as shown in Figure 7, in the case of a glass plate G having a damaged portion B, the glass plate G does not exist in the portion corresponding to the damaged portion B. Therefore, if the damaged portion B is included in the detection area of ​​the sensor 12 located within the passage range P, the glass plate G will not be detected by the sensor 12. Thus, damage to the glass plate G can be detected based on whether or not the glass plate G is detected by each sensor 12.

[0067] In the front edge detection process, the determination unit 14 determines that the front edge Ga of the glass plate G is damaged if some of the sensors 12 included in the sensor array 15 located within the passage range P of the glass plate G being transported in the transport direction X are unable to detect the front edge Ga of the glass plate G while it is stopped in an inclined position.

[0068] In the corner detection process, the determination unit 14 determines that the corner Gx of the glass plate G is damaged if some or all of the corner sensors 12x and 12y are unable to detect the corner Gx of the glass plate G while it is stopped in an inclined position.

[0069] By using these front edge detection and corner detection processes, damage to the easily damaged front edge Ga and corner Gx can be detected with high accuracy while the glass plate G is stationary.

[0070] In detection step S5, after the completion of the front edge detection step and the corner detection step, damage to the central flat portion Gd and the rear edge portion Gb of the glass plate G being transported in an inclined position is detected based on the detection results of the sensor array 15 included in the sensor group 13 (central flat portion detection step and rear edge detection step).

[0071] In the central plane detection process and the rear edge detection process, the inclined glass plate G is transported in the transport direction X by the transport belt 6 of the second transport device 3. As a result, the detection area of ​​the sensor array 15 is scanned over substantially the entire surface of the glass plate G. In the central plane detection process and the rear edge detection process, the determination unit 14 determines that the glass plate G is damaged if some of the sensors 12 included in the sensor array 15 located within the passage range P of the glass plate G being transported in the transport direction X fail to detect the glass plate G being transported in an inclined position. In other words, the determination unit 14 determines that the glass plate G is damaged if some of the sensors 12 included in the sensor array 15 located within the passage range P of the glass plate G detect the glass plate G, but the remaining sensors 12 included in the sensor array 15 located within the passage range P of the glass plate G do not detect the glass plate G. In this way, damage to substantially the entire surface of the glass plate G can be reliably detected.

[0072] Furthermore, after the rear edge Gb of the glass plate G passes through the detection area of ​​the sensor array 15, all of the sensors 12 included in the sensor array 15 located within the passage range P of the glass plate G will no longer detect the glass plate G. Therefore, in detection step S5, the fact that the rear edge Gb of the glass plate G has passed through the detection area of ​​the sensor array 15 can be detected separately from damage to the glass plate G.

[0073] The sampling process S3 is performed as needed. When the sampling process S3 is performed, the sampling device 8 uses suction to hold the target inclined glass plate G and extracts it outside the transport path of the third transport device 4.

[0074] In this embodiment, the sampling step S3 is performed when damage to the glass plate G is detected in the detection step S5. That is, glass plates G that are found to be damaged in the detection step S5 are removed by the sampling device 8 from the transport path of the third transport device 4 and are not transported to the washing step S4. The sampling step S3 is also performed, for example, when a sampling inspection of the glass plates G is required to confirm quality. In this case, the sampling device 8 removes glass plates G that were not found to be damaged in the detection step S5 for sampling inspection. The sampling step S3 may also be performed manually by an operator.

[0075] In the cleaning process S4, the glass plate G is cleaned by the cleaning device 9 while the cleaning solution is supplied. By cleaning the glass plate G in this inclined position, the cleaning solution falls quickly from the glass plate G, making it less likely for dirt caused by the cleaning solution to adhere to the glass plate G.

[0076] The cleaning device 9 preferably cleans the glass plate G by rubbing it with cleaning tools such as a cleaning disc or cleaning brush. However, in this case, if a damaged glass plate G is brought into the cleaning process S4, there is a risk that the damaged glass plate G will be further damaged by the cleaning device 9. If such secondary damage to the glass plate G occurs, it becomes necessary to remove the glass powder and glass fragments generated as a result of the damage, which reduces manufacturing efficiency. Furthermore, if the removal work is insufficient and glass fragments remain, these fragments may introduce scratches into subsequent glass plates G, resulting in product defects. Therefore, in this manufacturing method, in order to suppress the occurrence of such defects, a detection process S5 is performed after the end-face processing process S1 and before the cleaning process S4. This ensures that glass plates G damaged in the end-face processing process S1 or other processes are reliably detected before the cleaning process S4, preventing damaged glass plates G from being brought into the cleaning process S4.

[0077] The present invention is not limited to the configuration of the above embodiments, nor is it limited to the effects described above. The present invention can be modified in various ways without departing from the spirit of the invention.

[0078] In the above embodiment, the front edge detection step for detecting damage to the front edge Ga of the glass plate G and the corner detection step for detecting damage to the corner Gx of the glass plate G were described as being performed with the glass plate G stopped, but the embodiment is not limited to this. At least one of the front edge detection step and the corner detection step may be performed while the glass plate G is being transported.

[0079] In the above embodiment, the case in which the detection step S5 is performed on a glass plate G in an inclined position was described, but the position of the glass plate G when performing the detection step S5 is not particularly limited. For example, the detection step S5 may be performed on a glass plate G in a horizontal position.

[0080] In the above embodiment, the case in which the detection step S5 is performed after the end face machining step S1 and before the cleaning step S4 was described, but the timing of performing the detection step S5 is not limited to this. For example, the detection step S5 may be performed before the end face machining step S1 or after the cleaning step S4.

[0081] In the above embodiment, the case in which the first corner sensor 12x is included in the sensor row 15 was described, but the first corner sensor 12x may be placed at a position different from the sensor row 15.

[0082] In the above embodiment, the second corner sensor 12y may be omitted, and damage to substantially the entire surface of the glass plate G may be detected using only the sensor row 15. [Explanation of symbols]

[0083] 1. Conveying device 2. First conveying device 3. Second conveying device 4. Third conveying device 5. Fourth Conveyor Device 6. Conveyor belt 7 Sharpening stones 8 Sampling device 9. Washing device 11 Detection device 12 sensors 12x First Corner Sensor 12y Second corner sensor 13 Sensor Groups 14 Judgment section 15 Sensor array 16a Sensor surface 17 Cover 19 Gas nozzle C Gap F Gas G Glass plate Gx corner S1 End face machining process S2 Posture Change Process S3 sampling process S4 Cleaning process S5 Detection process X Conveying direction

Claims

1. A method for manufacturing a glass plate, comprising a transport step of transporting a glass plate in a predetermined transport direction, and a detection step of detecting damage to the glass plate being transported in the transport direction using a group of sensors including a plurality of sensors capable of detecting the presence or absence of the glass plate, The sensor group comprises a row of sensors arranged along a direction intersecting the transport direction, A method for manufacturing a glass plate, characterized in that, in the detection step, if a portion of the sensors included in the sensor array located within the passage range of the glass plate being transported in the transport direction fails to detect the glass plate, it is determined that the glass plate is damaged.

2. The glass plate is rectangular in shape and has four corners. The sensor array includes a first corner sensor positioned at a location corresponding to the two corners of the glass plate, The sensor group includes, separately from the sensor row, second corner sensors positioned at locations corresponding to the remaining two corners of the glass plate. The method for manufacturing a glass plate according to claim 1, wherein the detection step includes a corner detection step in which the first corner sensor and the second corner sensor detect damage to the corner of the glass plate.

3. The method for manufacturing a glass plate according to claim 2, wherein the corner detection step is performed while the transport of the glass plate is stopped.

4. The transport process includes a posture changing process in which the transport of the glass plate is stopped and the posture of the glass plate is changed from a horizontal posture to an inclined posture. The method for manufacturing a glass plate according to claim 3, wherein the corner detection step is performed in the orientation change step.

5. The sensor array is arranged along the front edge of the glass plate located on the forward side in the transport direction of the glass plate whose transport was stopped in the corner detection step. The method for manufacturing a glass plate according to claim 3 or 4, wherein the detection step includes a front edge detection step in which, with the transport of the glass plate stopped, the sensor array detects damage to the front edge of the glass plate.

6. The method for manufacturing a glass plate according to claim 1 or 2, wherein the detection step is performed on the glass plate in an inclined position.

7. In the aforementioned transport process, the glass plate is transported in the transport direction using a plurality of transport belts arranged with gaps between them. The method for manufacturing a glass plate according to claim 1 or 2, wherein the sensor group is arranged to detect the glass plate located in the gap.

8. The detection step includes an end-face processing step in which the end face of the glass plate is processed, A method for manufacturing a glass plate according to claim 1 or 2, comprising a cleaning step of cleaning the glass plate after the detection step.

9. The method for manufacturing a glass plate according to claim 1 or 2, wherein the sensor is an ultrasonic sensor.

10. The method for manufacturing a glass plate according to claim 1 or 2, wherein the detection step involves detecting damage to the glass plate while spraying gas to cover the sensor surface of the sensor.

11. The method for manufacturing a glass plate according to claim 1 or 2, wherein the sensor is provided with a cover surrounding the sensor surface.

12. The method for manufacturing a glass plate according to claim 1 or 2, wherein the sensor group is arranged above the glass plate.

13. A glass plate manufacturing apparatus comprising a conveying device for conveying glass plates in a predetermined conveying direction, and a detection device for detecting damage to the glass plates being conveyed in the conveying direction, The detection device comprises a group of sensors including a plurality of sensors capable of detecting the presence or absence of the glass plate, and a determination unit that determines whether or not the glass plate is damaged based on the detection results of the group of sensors. The sensor group comprises a row of sensors arranged along a direction intersecting the transport direction, The glass plate manufacturing apparatus is characterized in that the determination unit determines that the glass plate is damaged when a portion of the sensors included in the sensor array located within the passage range of the glass plate being transported in the transport direction fails to detect the glass plate.

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