Method and apparatus for manufacturing glass plates

Abstract

In the manufacturing of glass plates, the distribution of deposits and scratches on the main surface of the glass plate can be monitored, and defects occurring during the glass plate manufacturing process can be identified. [Solution] When performing the inspection process P3, which inspects for surface defects 4 on the main surface 3a of the glass plate 3 cut from the glass ribbon 2, the inspection process P3 is performed before the cleaning process P8 in which the glass plate 3 is cleaned. In other words, the inspection process P3 is performed before any adhering material is removed from the glass plate 3 during cleaning, and when there is no risk of new scratches being created on the glass plate 3 as a result of cleaning. This allows monitoring of the distribution of surface defects 4 on the main surface 3a that originate from the cutting of the glass plate 3, and enables the detection of defects in the cutting of the glass plate 3 based on the presence of an excess of surface defects 4 or concentrated areas of surface defects 4.

Description

Technical Field

[0006] , ,

[0005] , ,

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

Background Art

[0002] In the manufacturing process of a glass plate, it is common to include a process of inspecting the presence or absence of defects in the glass plate for the purpose of determining the quality of the glass plate.

[0003] Patent Document 1 discloses a method for discriminating foreign matter as a defect contained inside the glass plate, bubbles as a defect also contained inside, and dust adhering to the surface of the glass plate when inspecting the defects of the glass plate.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The deposits such as the above-mentioned dust and glass powder on the glass plate can be removed by washing before shipping the glass plate as a product. Therefore, unlike the above-mentioned foreign matter and bubbles, the deposits do not become factors for determining the quality of the glass plate.

[0006] However, for example, when there is an excessive amount of glass powder on the main surface of the glass plate (two surfaces facing each other in the plate thickness direction of the glass plate), or when there is a location where the glass powder is concentrated on the main surface, it suggests that there is a problem in the manufacturing process of the glass plate. For example, if there is a location where the glass powder is concentrated near the edge of the glass plate, it suggests that there is a cutting defect when cutting out the glass plate. Therefore, it has been required to monitor the distribution of deposits on the main surface of the glass plate.

[0007] Similar to the above-mentioned deposits, it is also required to monitor the distribution of scratches on the main surface of the glass plate. This is because an excessive number of scratches on the main surface of the glass plate, or areas where scratches are concentrated on the main surface, suggests that a defect has occurred in the glass plate manufacturing process, such as breakage of the glass plate.

[0008] In light of the circumstances described above, the issue that needs to be resolved is to enable monitoring of the distribution of deposits and scratches on the main surface of glass plates during manufacturing, and to enable the detection of defects in the glass plate manufacturing process. [Means for solving the problem]

[0009] A first method for manufacturing a glass plate to solve the above problems comprises a processing step of performing a predetermined process on a glass plate using a processing apparatus, and an inspection step of inspecting for deposits and scratches on the main surface of the glass plate after the processing step as surface defects, wherein the inspection step includes a setting step of setting an inspection area on the main surface, a defining step of defining a standard size having an area less than or equal to the inspection area, and a notification step of notifying a control device that controls the processing apparatus if the number of surface defects per standard size in the inspection area exceeds a threshold, and further comprises a cleaning step of cleaning the glass plate, characterized in that the inspection step is performed before the cleaning step. Here, "main surface of the glass plate" means two opposing surfaces in the thickness direction of the glass plate. Also, "notification to the control device" does not mean only notification to the control device itself, but also includes notification to the operator if there is an operator who operates the control device.

[0010] In the first method for manufacturing glass plates, when the inspection process is performed, if the number of surface defects (adhesion and scratches) per standard size within the inspection area set on the main surface of the glass plate exceeds a threshold, a notification is sent to the control device that controls the processing device. Here, if the area of ​​the inspection area and the area of ​​the standard size are made the same through the setting and specification processes, and the control device receives a notification in the notification process, it is found that the distribution of surface defects is such that the number of surface defects within the inspection area is excessively high. On the other hand, if the area of ​​the standard size is made smaller than the area of ​​the inspection area through the setting and specification processes, and the control device receives a notification in the notification process, it is found that the distribution of surface defects is such that there are areas within the inspection area where surface defects are concentrated. Thus, in this manufacturing method, the distribution of adhesion and scratches on the main surface of the glass plate can be monitored by performing the inspection process. Furthermore, in this manufacturing method, the inspection process is performed before the cleaning process in which the glass plate is cleaned. In other words, the inspection process is performed before any deposits are removed from the glass plate during cleaning, and before any new scratches are likely to occur on the glass plate during cleaning. Therefore, any surface defects present on the main surface of the glass plate at the time of the inspection process are surface defects originating from the processing steps performed before the inspection process. Furthermore, if there are an excessive number of surface defects on the main surface of the glass plate, or if there are areas on the main surface where surface defects are concentrated, it suggests that a problem occurred in the processing steps. As a result, this manufacturing method makes it possible to identify the occurrence of problems in the glass plate manufacturing process (processing steps).

[0011] The second method for manufacturing a glass plate is a method for manufacturing a glass plate described above, wherein the control device, which receives notification in the notification step, changes the processing conditions for a predetermined process in the processing step.

[0012] In the second method for manufacturing glass plates, the control device, upon receiving notification, changes the processing conditions, thereby eliminating any problems that may arise in the processing steps due to these changes.

[0013] The third method for manufacturing a glass plate is the first or second method for manufacturing a glass plate described above, wherein the control device is equipped with a display device, and the display device displays a notification indicating that it has been notified.

[0014] In the third method for manufacturing glass plates, the display device shows that it has received notification, which is advantageous when, for example, there is an operator operating the control device. In other words, the operator can reliably recognize through the display that there are an excessive number of surface defects on the main surface of the glass plate, or that there are areas on the main surface where surface defects are concentrated.

[0015] The fourth method for manufacturing a glass plate is a method for manufacturing a glass plate according to any of the first to third methods described above, wherein in the inspection step, the upper end of the vertically positioned glass plate is supported by a support member, and in the setting step, the inspection area is set below the position where the support member is located on the main surface.

[0016] In the fourth method for manufacturing glass plates, the inspection area is set below the location of the support member on the main surface of the glass plate. Therefore, the support member is not present within the inspection area, and the risk of misidentifying the support member as a surface defect is reliably eliminated. As a result, it is advantageous for accurately monitoring the distribution of deposits and scratches on the main surface of the glass plate.

[0017] The fifth method for manufacturing a glass plate is the fourth method for manufacturing a glass plate described above, wherein in the setting step, at least the entire effective surface area of ​​the glass plate is included in the inspection area.

[0018] If there are an excessive number of surface defects or areas where surface defects are concentrated on the effective surface (the part that will later become the finished glass plate) of the main surface of the glass plate, there is a high risk that defects that degrade the quality of the finished glass plate have occurred during the processing. In the fifth method of manufacturing glass plates, since at least the entire area of ​​the effective surface is included in the inspection area, defects in the processing that degrade the quality of the finished glass plate can be accurately identified.

[0019] The sixth method for manufacturing a glass plate is a method for manufacturing a glass plate according to any of the first to fifth methods described above, further comprising a quality determination step for determining the quality of the glass plate, wherein the quality determination step includes an internal defect detection step for detecting foreign matter and bubbles present inside the glass plate as internal defects, targeting the effective surface of the glass plate, and a pass / fail determination step for determining whether the quality of the glass plate is acceptable or not based on the results of the internal defect detection step.

[0020] Internal defects (foreign matter and bubbles) present inside the glass plate cannot be removed even by washing the glass plate. In the sixth method for manufacturing glass plates, during the quality determination process, internal defects present inside the glass plate are detected in the internal defect detection process, and the pass / fail determination process determines the pass / fail status of the glass plate based on the results of the internal defect detection process. This prevents defective glass plates containing unacceptable internal defects from being shipped as finished glass plates.

[0021] The seventh method for manufacturing a glass plate is a configuration in which both the inspection process and the quality determination process are performed simultaneously using a single inspection device, as described in the sixth method for manufacturing a glass plate.

[0022] In the seventh method for manufacturing glass plates, the inspection process and the quality determination process are performed simultaneously, which increases the manufacturing efficiency of glass plates compared to when the two processes are performed at separate times. Furthermore, by performing the inspection process and the quality determination process with a single inspection device, the glass plate manufacturing line can be made more space-efficient.

[0023] The manufacturing method of the eighth glass plate is as follows: in the manufacturing method of the sixth or seventh glass plate described above, in the inspection process and the quality determination process, a first imaging system and a second imaging system are used. The first imaging system includes a first light source, a first imaging unit that images the first transmitted light irradiated from the first light source and transmitted through the glass plate, and a shielding member that shields a part of the first transmitted light to form a bright part and a dark part within the field of view of the first imaging unit. The second imaging system includes a second light source and a third light source, and a second imaging unit that images the second transmitted light irradiated from the second light source and transmitted through the glass plate in bright field while imaging the third transmitted light irradiated from the third light source and transmitted through the glass plate in dark field. Based on the image obtained by the first imaging system and the image obtained by the second imaging system, surface defects and internal defects are identified.

[0024] In the manufacturing method of the eighth glass plate, a first imaging system and a second imaging system are used in the inspection process and the quality determination process. Between both the surface defects existing on the main surface of the glass plate and the internal defects existing inside the glass plate, the features (such as the shape and color of the image, the presence or absence of the image itself, etc.) extracted from the image obtained by the first imaging system and the image obtained by the second imaging system are different. Thereby, it becomes possible to accurately distinguish between surface defects and internal defects.

[0025] The manufacturing method of the ninth glass plate is as follows: in the manufacturing method of any one of the first to eighth glass plates described above, it further includes a storage process for storing the glass plate or a transportation process for transporting the glass plate, and is configured to execute the inspection process before the execution of the storage process or the transportation process.

[0026] In the manufacturing method of the ninth glass plate, by executing the inspection process before the storage process or the transportation process, it is possible to grasp the occurrence of defects in the manufacturing process (processing process) of the glass plate at a convenient timing for the manufacturing of the glass plate.

[0027] The manufacturing method of the tenth glass plate is as follows: in the manufacturing method of any one of the first to ninth glass plates described above, it further includes a forming process for forming a glass ribbon from molten glass and a cutting process as a processing process for cutting out a glass plate from the glass ribbon, and is configured to execute the inspection process after the cutting process.

[0028] In the method for manufacturing the tenth glass plate, by performing an inspection process after the cutting process, it is possible to inspect deposits adhering to the main surface of the glass plate and scratches generated on the main surface of the glass plate due to the cutting process. Therefore, it is possible to grasp the occurrence of defects in the cutting process.

[0029] A glass plate manufacturing apparatus for solving the above problems includes a processing apparatus that performs a predetermined process on the glass plate, and an inspection apparatus that inspects deposits adhering to the main surface of the processed glass plate and scratches on the main surface as surface defects. The inspection apparatus includes a setting means for setting an inspection area on the main surface, a defining means for defining a reference size having an area smaller than the inspection area, and a notification means for notifying a control apparatus that controls the processing apparatus when the number of surface defects per reference size in the inspection area exceeds a threshold value. The glass plate manufacturing apparatus further includes a cleaning apparatus for cleaning the glass plate, and the inspection apparatus is arranged upstream of the cleaning apparatus on the manufacturing line.

[0030] In this glass plate manufacturing apparatus, it is possible to obtain the same operations and effects as those of the above-described first glass plate manufacturing method.

Effects of the Invention

[0033] The following describes embodiments of a glass plate manufacturing method and manufacturing apparatus with reference to the attached drawings. The X, Y, and Z directions shown in some of the drawings referenced in the description of the embodiments are mutually orthogonal directions.

[0034] <First Embodiment> As shown in the flowchart in Figure 1, the glass plate manufacturing method comprises, in order from the upstream process, a forming process P1 (Figure 2) in which a glass ribbon 2 is formed from molten glass 1; a cutting process P2 (Figure 2) in which a glass plate 3 is cut from the glass ribbon 2; an inspection process P3 (Figures 2, 3, and 4) in which any deposits and scratches on the main surface 3a of the glass plate 3 are inspected as surface defects 4; a quality determination process P4 (Figures 2, 3, and 4) in which the quality of the glass plate 3 is determined, which is performed simultaneously with the inspection process P3; a disposal process P5 in which glass plates 3 that fail the quality determination process P4 are discarded; a storage process P6 or a transport process P7 in which glass plates 3 that pass the quality determination process P4 are stored or transported; and a cleaning process P8 in which glass plates 3 are cleaned after storage or transport. These are the main processes.

[0035] Of the above processes P1 to P8, the cutting process P2, the inspection process P3, and the quality determination process P4 are composed of multiple processes included within them.

[0036] The cutting process P2 includes, in chronological order, a first cutting process P2a (Figure 2) in which a glass plate 5 with tabs is cut from the glass ribbon 2, and a second cutting process P2b (Figure 2) in which unnecessary parts 6,6 are separated and removed from the glass plate 5 with tabs to obtain a glass plate 3. The cutting process P2 is an example of a processing process that performs a predetermined treatment on the glass plate.

[0037] The inspection process P3 includes, in chronological order, a setting process P3a (Figure 3) for setting an inspection area 3x on the main surface 3a of the glass plate 3, a defining process P3b (Figure 3) for defining a standard size 3s having an area less than or equal to the inspection area 3x, and a notification process P3c for notifying the control device 8, which controls the cutting device 7, if the number of surface defects 4 present per standard size 3s within the inspection area 3x exceeds a threshold.

[0038] The quality determination process P4 includes an internal defect detection process P4a (Figures 3 and 4) which detects foreign matter and bubbles present inside the glass plate 3 as internal defects 9, targeting the effective surface 3b of the glass plate 3 (the part that will later become the finished glass plate) in a chronological order, and a pass / fail determination process P4b which determines whether the quality of the glass plate 3 is acceptable or not based on the results of the internal defect detection process P4a.

[0039] Each of the above processes P1 to P8 is carried out using the devices provided in the glass plate manufacturing apparatus 10 (hereinafter simply referred to as manufacturing apparatus 10). The devices provided in the manufacturing apparatus 10 include, in order from the upstream side of the glass plate 3 manufacturing line, a molding device 11 used in the molding process P1 (Figure 2), a cutting device 7 used in the cutting process P2 (Figure 2), an inspection device 12 used in the inspection process P3 and the quality determination process P4 (Figures 2 and 4), a loading device used in the storage process P6 or the transport process P7 (not shown), and a cleaning device used in the cleaning process P8 (not shown).

[0040] The molding apparatus 11 shown in Figure 2 is a device for molding glass ribbons 2 by the overflow downdraw method. As a modification of this embodiment, the molding apparatus 11 may be a device that molds glass ribbons 2 by the slot downdraw method, redraw method, float method, etc., instead of the overflow downdraw method.

[0041] The molding apparatus 11 comprises a molded body 13 having a wedge-shaped cross-section perpendicular to the X direction, and rollers (not shown) arranged in multiple vertical stages below the molded body 13. A groove 14 extending in the X direction is formed at the top of the molded body 13.

[0042] In the molding process P1 using the molding apparatus 11, first, molten glass 1 is continuously supplied to the groove 14 of the molded body 13, causing the molten glass 1 to overflow from the groove 14 to both sides (Z direction). Next, the molten glass 1 that has overflowed from the groove 14 is allowed to flow down along both sides of the molded body 13, and then fused at the lower end 15 of the molded body 13. This generates a plate-shaped molten glass 1 that will become the glass ribbon 2. After that, the plate-shaped molten glass 1 is sandwiched from both sides by rollers arranged in multiple stages above and below, and slowly cooled while being pulled downwards. This forms the glass ribbon 2. At both ends of the molded glass ribbon 2 in the width direction (X direction), there are unnecessary portions 6, including ear portions that are thicker than other parts.

[0043] The cutting apparatus 7 shown in Figure 2 comprises a first cutting apparatus 16 used in the first cutting process P2a and a second cutting apparatus 17 used in the second cutting process P2b. The cutting apparatus 7 is an example of a processing apparatus that performs predetermined processing on a glass plate.

[0044] The first cutting device 16 is a device for cutting out the portion of the glass ribbon 2 below the scribe line 18 as a glass plate 5 with tabs by breaking the glass ribbon 2 along the scribe line 18.

[0045] The first cutting device 16 includes a scribe wheel 19 that travels on the surface of the glass ribbon 2 and forms a scribe line 18, a folding bar 20 that contacts the glass ribbon 2 from the back side during folding and acts as a pivot point to curve the peripheral portion of the scribe line 18, a holding member 21 that changes the posture of the glass ribbon 2 while holding it during folding, and a first dust collector (not shown) having a suction port for sucking up glass powder generated during folding.

[0046] The folding bar 20 is formed to extend in the X direction. The folding bar 20 is movable along the thickness direction (Z direction) of the glass ribbon 2. This allows the folding bar 20 to move between a contact position in contact with the glass ribbon 2 and a standby position away from the glass ribbon 2. The folding bar 20 is in the contact position when the glass ribbon 2 is folded and in the standby position when not being folded. When in the contact position, the folding bar 20 contacts the point directly behind the scribe line 18 on the back surface of the glass ribbon 2, or a point slightly above the point directly behind it.

[0047] The holding member 21 comprises a pair of arms 22, 22 that each hold the widthwise ends of the glass ribbon 2. The holding member 21 is capable of rotational movement as indicated by arrow T about an axis (not shown) extending in the X direction, and changes its orientation as it rotates. As a result, the holding member 21 can assume a vertical orientation in which the arms 22 extend in the vertical direction (Y direction), and an inclined orientation in which the arms 22 are tilted by a predetermined angle relative to the vertical orientation.

[0048] The first dust collector has an opening that is elongated in the X direction. Immediately before folding, the suction opening is facing the scribe line 18 formed on the glass ribbon 2. On the other hand, immediately after folding, the suction opening is facing the lower end of the glass ribbon 2 (the end newly formed as a result of folding) and the upper end of the glass plate 5 with tabs.

[0049] In the first cutting device 16, at least one of the following conditions can be changed by the control device 8 described later: (A) the angular velocity of the rotational movement when the holding member 21 transitions from a vertical position to an inclined position, (B) the magnitude of the predetermined angle, (C) the speed at which the splitting bar 20 contacts the glass ribbon 2 (the speed at which the splitting bar 20 moves from the standby position to the contact position), and (D) the position of the contact position in the Z direction (the distance at which the splitting bar 20 at the contact position pushes the glass ribbon 2 from the back side to the front side).

[0050] In the first cutting step P2a using the first cutting device 16, first, a scribe line 18 is formed along the width direction of the glass ribbon 2 by the scribe wheel 19. Next, the posture of the holding member 21 that holds the glass ribbon 2 is changed from a vertical posture to an inclined posture, and the folding bar 20 is brought into contact with the glass ribbon 2. As a result, the peripheral part of the glass ribbon 2 around the scribe line 18 is curved with the folding bar 20 as a fulcrum so that the surface side becomes convex, and the glass ribbon 2 is broken along the scribe line 18. Then, a glass plate 5 with edges is cut out from the glass ribbon 2. The cut glass plate 5 with edges is held in place by the holding member 21. The glass powder generated during the breaking process is sucked up and collected by the suction port of the first dust collector.

[0051] The second cutting device 17 is a device for obtaining a glass plate 3 by breaking the glass plate 5 with tabs along two scribe lines 23, 23, thereby separating and removing the two unnecessary parts 6, 6 from the glass plate 5 with tabs.

[0052] The second cutting device 17 includes a transport mechanism 24 that transports the glass plate with tabs 5 received from the holding member 21 in a vertical position in the X direction, two scribe wheels 25, 25 that run on the surface of the glass plate with tabs 5 and form scribe lines 23, respectively, two folding bars 26, 26 that contact the glass plate with tabs 5 from the back side during folding, acting as pivot points that curve the peripheral portions of the two scribe lines 23, 23, two pushing bars 27, 27 that push both unnecessary parts 6, 6 from the front side to the back side during folding, respectively, and two second dust collectors (not shown) each having a suction port for sucking up glass powder generated during folding.

[0053] The transport mechanism 24 is equipped with a group of chucks 29 consisting of multiple (two in the illustrated example) chucks 28 that grip the upper end of the glass plate 5 with edges. The glass plate 5 with edges is suspended by the group of chucks 29 while being transported. The transport path through which the transport mechanism 24 transports the glass plate 5 with edges is divided into multiple sections, and a group of chucks 29 is located in each of these sections. The group of chucks 29 located in each section is capable of moving back and forth within that section. The glass plate 5 with edges is passed between the group of chucks 29 in adjacent sections and is sequentially transported to the scribe area A1 for forming the scribe line 23 and the folding area A2 for folding.

[0054] Each of the two folding bars 26, 26 is formed to extend in the Y direction. Each folding bar 26 is movable along the thickness direction (Z direction) of the glass plate 5 with ears. This allows each folding bar 26 to move between a contact position in contact with the glass plate 5 with ears and a standby position away from the glass plate 5 with ears. Each folding bar 26 is in the contact position when the glass plate 5 with ears is folded, and is in the standby position when not being folded. When in the contact position, each folding bar 26 contacts the point directly behind the scribe line 23 on the back surface of the glass plate 5 with ears, or a point slightly inward in the width direction from directly behind.

[0055] Each of the two push bars 27, 27 is formed to extend in the Y direction. Each push bar 27 is movable along the thickness direction of the glass plate 5 with tabs when it is broken.

[0056] Each of the two second dust collectors has an opening that is elongated in the Y direction. The suction opening just before folding faces the scribe line 23 formed on the glass plate 5 with the tabs. On the other hand, the suction opening just after folding faces the widthwise end of the glass plate 3 and the widthwise end of the unnecessary portion 6.

[0057] In the second cutting device 17, at least one of the following conditions can be changed by the control device 8 described later: (E) the speed at which the push bar 27 moves when pushing in the unwanted portion 6, (F) the distance at which the push bar 27 pushes in the unwanted portion 6, (G) the speed at which the folding bar 26 contacts the glass plate 5 with tabs (the speed at which the folding bar 26 moves from the standby position to the contact position), and (H) the position of the above contact position in the Z direction (the distance at which the folding bar 26 at the contact position pushes the glass plate 5 with tabs from the back side to the front side).

[0058] In the second cutting process P2b using the second cutting device 17, first, in the scribe area A1, two scribe wheels 25, 25 form two scribe lines 23, 23 along the vertical direction of the glass plate 5 with tabs. Next, in the folding area A2, two push bars 27, 27 push both unwanted parts 6, 6 from the front side to the back side, and two folding bars 26, 26 are brought into contact with the glass plate 5 with tabs. As a result, the periphery of each of the two scribe lines 23, 23 curves with the front side convex, using each folding bar 26 as a pivot point, and the glass plate 5 with tabs is folded along the two scribe lines 23, 23. Then, both unwanted parts 6, 6 are separated and removed from the glass plate 5 with tabs. The glass powder generated during folding is sucked up and collected by the suction ports of the two second dust collectors.

[0059] The inspection device 12 shown in Figure 2 is a device that can perform both the inspection process P3 and the quality determination process P4 independently.

[0060] The inspection device 12 includes a line sensor camera 30. In this embodiment, the line sensor camera 30 is installed in a fixed position and scans the main surface 3a (front and back surfaces) of the glass plate 3 by transporting the glass plate 3 in a vertical position using the transport mechanism 31. As a modification of this embodiment, the main surface 3a of the glass plate 3 may be scanned by moving the inspection device 12 relative to the glass plate 3 which is supported in a fixed position in a vertical position by the transport mechanism 31. The transport mechanism 31 includes a plurality of chucks 32 that can move in the X direction while gripping the upper and lower ends of the glass plate 3, respectively. Each chuck 32 functions as a support member that supports the upper or lower end of the glass plate 3. As a modification of this embodiment, the upper or lower end of the glass plate 3 may be supported by suction pads or the like.

[0061] The inspection device 12 can detect defects by scanning with the line sensor camera 30, identifying the type of defect (surface defect 4 or internal defect 9) contained in the glass plate 3, and locating the location of the defect on the main surface 3a of the glass plate 3. In Figure 3, surface defects 4 (adhered material and scratches) are represented by triangles, and internal defects 9 (foreign matter and bubbles) are represented by "x" marks. The inspection device 12 can also distinguish whether the internal defect 9 is foreign matter or bubbles. Foreign matter includes, for example, undissolved material or precipitated crystals derived from the glass raw materials that make up the molten glass 1. Bubbles include, for example, air mixed in during the manufacturing process of the glass plate 3 or volatile glass raw materials. Scratches, which are surface defects 4, are scratches that occurred on the main surface 3a of the glass plate 3 during the manufacturing process. Adhered material, which is a surface defect 4, includes glass powder, dust, dirt, etc. The specific mechanism by which the inspection device 12 identifies the type of defect and locates the defect will be described later.

[0062] In addition to the line sensor camera 30 described above, the inspection device 12 further includes setting means for setting process P3a, defining means for defining process P3b, and notification means for notification process P3c. The setting means and defining means may, for example, be an operation panel or operation buttons for setting the inspection area 3x and defining the reference size 3s. The notification means may, for example, be an alarm that sounds an alarm as a notification to the control device 8 (operator operating the control device 8) described later. Another example may be a line or cable that sends a signal as a notification to the control device 8 described later.

[0063] In the inspection process P3 using the inspection device 12, first, in conjunction with the execution of the setting process P3a and the defining process P3b, the rectangular inspection area 3x shown by the dashed line in Figure 3 is set by the setting means, and the standard size 3s shown by the shaded rectangle in Figure 3 is defined by the defining means.

[0064] In this embodiment, only the effective surface 3b of the glass plate 3 is set as the inspection area 3x. Of course, this is not limited to this, and the inspection area 3x may be wider than the effective surface 3b. However, in order to prevent the chuck 32 from being mistakenly detected as a surface defect 4 or internal defect 9, it is preferable to set the inspection area 3x so that it is located below the chuck 32 gripping the upper end of the glass plate 3 and above the chuck 32 gripping the lower end. The standard size 3s may be, for example, 500 mm square (500 mm x 500 mm) or 250 mm square (250 mm x 250 mm).

[0065] When performing the setup process P3a and the specification process P3b, the threshold described above is also set along with both processes P3a and P3b. The threshold is set to the acceptable limit of the number of surface defects 4 present per standard size 3s within the inspection area 3x. For example, the threshold may be 10 defects per 500mm square or 10 defects per 250mm square.

[0066] After the setting process P3a and the specification process P3b, as well as the setting of the threshold, the line sensor camera 30 is used to scan the main surface 3a of the glass plate 3. If the scanning results show that the number of surface defects 4 per standard size 3s exceeds the threshold at any location within the inspection area 3x, the notification process P3c is executed to notify the control device 8, which will be described later. On the other hand, if the number of surface defects 4 per standard size 3s is below the threshold at any location within the inspection area 3x, the notification process P3c is not executed.

[0067] In the quality determination process P4 using the inspection device 12, first, the line sensor camera 30 scans the main surface 3a of the glass plate 3 to perform the internal defect detection process P4a. Then, the pass / fail determination process P4b is performed to determine whether or not there are internal defects 9 in the inspection area 3x (effective surface 3b) that exceed the acceptable number or size. If there are no internal defects 9 that exceed the acceptable number or size, the quality of the glass plate 3 is determined to be acceptable; if there are internal defects 9 that exceed the acceptable number or size, the quality of the glass plate 3 is determined to be unacceptable.

[0068] In the disposal process P5, where the unacceptable glass plates 3 are discarded, one example is to drop the unacceptable glass plates 3 from the upper floor, where the second cutting device 17 and inspection device 12 are located, towards the lower floor, where the disposal area is provided.

[0069] The control device 8 shown in Figure 2 can change each of the conditions (A) to (D) in the first cutting device 16 and each of the conditions (E) to (H) in the second cutting device 17.

[0070] The control device 8 is equipped with a display device 33 (e.g., a display). When the control device 8 receives a notification (such as an alarm sound) when the notification process P3c is executed in the inspection process P3, the display device 33 displays a notification indicating that the notification has been received. This display includes a distribution map of surface defects 4 within the inspection area 3x (effective surface 3b) of the glass plate 3. From the distribution map, the concentrated areas of surface defects 4 within the inspection area 3x can be identified. These concentrated areas are locations where the number of surface defects 4 per standard size 3s exceeds a threshold. The operator who has checked the distribution map can then operate the control device 8 to change each of the conditions (A) to (H). Of course, the control device 8 may also be configured to automatically change each of the conditions (A) to (H) upon receiving a notification, without the operator's intervention.

[0071] Here, we illustrate how the control device 8 can change conditions (A) to (H). As a first example, suppose that the distribution map displayed on the display device 33 reveals that surface defects 4 are concentrated near the top and bottom edges of the effective surface 3b of the glass plate 3. In this case, it suggests that a problem occurred in the first cutting process P2a. Therefore, the control device 8 changes at least one of conditions (A) to (D). In addition to changing at least one of conditions (A) to (D) by the control device 8, or instead of changing it, the scribe wheel 19 may be replaced.

[0072] Next, as a second example, suppose that the distribution map displayed on the display device 33 reveals that surface defects 4 are concentrated near both sides (the two sides extending in the Y direction) of the effective surface 3b of the glass plate 3. In this case, it suggests that a problem occurred in the second cutting process P2b. Therefore, the control device 8 changes at least one of the conditions (E) to (H). In addition to changing at least one of the conditions (E) to (H) by the control device 8, or instead of changing them, the two scribe wheels 25, 25 may be replaced.

[0073] The loading device is a device that continuously loads glass plates 3 that have passed the quality judgment process P4 (pass / fail judgment process P4b) onto a pallet. Multiple glass plates 3 are loaded onto the pallet by the loading device. The pallet loaded with multiple glass plates is then packaged to form a glass package. Subsequently, if the multiple glass plates 3 are to be stored in the glass package, the storage process P6 is executed; if they are to be transported without storage, the transport process P7 is executed. As a variation of this embodiment, the transport process P7 may be executed after the storage process P6, or the storage process P6 may be executed after the transport process P7. In this embodiment, the inspection process P3 is executed after the cutting process P2 but before the storage process P6 and transport process P7 are executed. This allows for early detection of defects that occurred in the cutting process P2 and enables appropriate countermeasures to be taken.

[0074] The cleaning device is a device that continuously cleans multiple glass plates 3 taken out of a glass packaging after the storage process P6 or the transport process P7. The cleaning device is capable of supplying cleaning fluid to the glass plates 3 and cleaning the main surface 3a of the glass plates 3 with a rotating brush. In the cleaning process P8 using the cleaning device, as the glass plates 3 are cleaned, any adhering substances on the main surface 3a of the glass plates 3 are removed as much as possible.

[0075] In addition, after the storage process P6 or the transport process P7, and before the cleaning process P8, an end-face processing process may be performed on each end face of the multiple glass plates 3, which may involve grinding or polishing.

[0076] The following describes the mechanism by which the inspection device 12 identifies the type of defect and locates the defect.

[0077] As shown in Figure 4, the inspection device 12 comprises a first imaging system 34, a second imaging system 35, and an identification means 36. These are components of the line sensor camera 30 described above.

[0078] The first imaging system 34 includes a first light source 37, a first imaging unit 38 that images the first transmitted light L1 irradiated from the first light source 37 and transmitted through the glass plate 3, and a shielding plate 39 that acts as a shielding member to shield a part (for example, half) of the first transmitted light L1 to form bright and dark areas within the field of view of the first imaging unit 38. Here, when transmitted light is used as the measurement light to be imaged by the first imaging unit 38 and the second imaging unit 40 described later, the term "transmitted light" shall also include scattered light.

[0079] The first light source 37 is positioned on the front side of the glass plate 3, and the first imaging unit 38 is positioned on the back side of the glass plate 3. The optical axis of the first light source 37 extends so that light is incident approximately perpendicular to the surface of the glass plate 3. The optical axis of the first imaging unit 38 coincides with the optical axis of the first light source 37 so that the first imaging unit 38 can basically capture the first transmitted light L1. As a result, if there were no shielding plate 39, the first imaging unit 38 would be in a state to image the first transmitted light L1 in bright field, but in reality, a part of the first transmitted light L1 is blocked by the shielding plate 39, so the first transmitted light L1 is imaged in a state to image in semi-bright field.

[0080] On the other hand, the second imaging system 35 includes a second light source 41 and a third light source 42, and a second imaging unit 40. The second imaging unit 40 captures the second transmitted light L2, which is irradiated from the second light source 41 and passes through the glass plate 3, in bright-field imaging, and also captures the third transmitted light L3, which is irradiated from the third light source 42 and passes through the glass plate 3, in dark-field imaging.

[0081] The second light source 41 is positioned on the front side of the glass plate 3, and the second imaging unit 40 is positioned on the back side of the glass plate 3. The optical axis of the second light source 41 extends so that light is incident approximately perpendicular to the surface of the glass plate 3. The light receiving unit of the second imaging unit 40 is positioned on the optical path of the second transmitted light L2, which is separated by the beam splitter 43 (described later), so that the second imaging unit 40 can basically capture the second transmitted light L2. As a result, the second imaging unit 40 is in a state where it can image the second transmitted light L2 in bright-field.

[0082] The third light source 42 is positioned on the surface side of the glass plate 3. The optical axis of the third light source 42 extends so that light is incident on the surface of the glass plate 3 at an oblique angle. In this embodiment, a pair of third light sources 42 are provided. The light receiving section of the second imaging unit 40 is positioned off-axis from the optical axis of the third light source 42 so that the third transmitted light L3 does not basically enter the second imaging unit 40. As a result, the second imaging unit 40 is in a state where it images the third transmitted light L3 in dark field. The third transmitted light L3 is received by the second imaging unit 40 only in specific cases, such as when scattering occurs in the glass plate 3. Note that the inclination angle of the third transmitted light L3 is exaggerated in Figure 4, but the third transmitted light L3 also basically enters the beam splitter 43, which will be described later.

[0083] In the second imaging unit 40, light obtained by combining the second transmitted light L2 and the third transmitted light L3 is captured.

[0084] In this embodiment, as shown in Figures 4 and 5, the first light source 37, the second light source 41, and the third light source 42 are incorporated into a single light source unit 44. As a result, the first light source 37, the second light source 41, and the third light source 42 are arranged in close proximity, and the first transmitted light L1, the second transmitted light L2, and the third transmitted light L3 pass through substantially the same location on the glass plate 3. In this embodiment, the light source unit 44 lights up the first light source 37, the second light source 41, and the third light source 42 simultaneously. The light source unit 44 may also blink the first light source 37, the second light source 41, and the third light source 42 at different timings.

[0085] As shown in Figure 4, beam splitters 43 are positioned on the optical axis of the first imaging unit 38 and the optical axis of the second imaging unit 40. A shielding plate 39 is positioned between the beam splitter 43 and the first imaging unit 38. The beam splitter 43 separates the transmitted light irradiated from the light source unit 44 and passed through the glass plate 3 into two components: a first component including the first transmitted light L1, and a second component including the second transmitted light L2 and the third transmitted light L3. Specifically, the beam splitter 43 is one that transmits specific wavelengths and reflects other wavelengths. For example, a blue LED is used as the first light source 37, and red LEDs, which are of a different color from the first light source 37, are used as the second light source 41 and the third light source 42. As a result, the beam splitter 43 separates the light into two colors: the first transmitted light L1 originating from the first light source 37, and the second transmitted light L2 and the third transmitted light L3 originating from the second light source 41 and the third light source 42. In the illustrated example, the first component, including the first transmitted light L1, passes through the beam splitter 43 and is imaged by the first imaging unit 38, and the second component, including the second transmitted light L2 and the third transmitted light L3, is reflected by the beam splitter 43 and is imaged by the second imaging unit 40. Note that the first light source 37, the second light source 41, and the third light source 42 are not limited to LEDs, but may be, for example, metal halide lamps or laser light sources.

[0086] Furthermore, although not shown in the diagram, multiple light source units 44 are arranged along the Y direction, forming a line light source. Similarly, multiple first imaging units 38 and second imaging units 40 are also arranged along the Y direction, forming a line camera. As a result, when the glass plate 3 is transported along the X direction, inspection is performed on the inspection area 3x (effective surface 3b) of the glass plate 3.

[0087] The identification means 36 is connected to the first imaging unit 38 and the second imaging unit 40 by wire or wireless connection, and receives the imaging results from both imaging units 38 and 40. Both imaging units 38 and 40 output an image consisting of monochrome information, with bright areas being white and dark areas being black. Here, "image" refers to a candidate defect in the glass plate 3. The identification means 36 is composed of, for example, the CPU of a PC. Based on the shape, color, presence or absence of the image itself, etc., of the image obtained by the first imaging system 34 and the image obtained by the second imaging system 35, the identification means 36 identifies the type of defect in the glass plate 3 into surface defects 4 and internal defects 9. Although not shown in the diagram, the identification means 36 stores the identified type of defect in the glass plate 3 and its position on the main surface 3a in a storage means (for example, the memory of a PC).

[0088] <Second Embodiment> The second embodiment will now be described with reference to Figure 6. In the second embodiment, the notification step P3c included in the inspection step P3 is performed in the following manner.

[0089] In this embodiment, the scanning area 45 is defined as a region having the same area as the reference size 3s (the region shown as a shaded rectangle in Figure 6). The starting point SP is defined as one of the four corners of the inspection area 3x, and the ending point EP is defined as the diagonal position of the starting point SP. The position of the scanning area 45 is continuously transitioned within the inspection area 3x, and the number of surface defects 4 within the scanning area 45 is counted at each position. If the number of surface defects 4 present in the scanning area 45 exceeds a threshold at any position within the inspection area 3x, the notification process P3c is executed. The manner in which the scanning area 45 is continuously transitioned may differ from that of this embodiment; for example, the trajectory of the continuously transitioning scanning area 45 may form a spiral shape. The positions of the starting point SP and the ending point EP may also differ from those of this embodiment.

[0090] <Third Embodiment> The third embodiment will now be described with reference to Figure 7. In the third embodiment, the notification step P3c included in the inspection step P3 is performed in the following manner.

[0091] In this embodiment, once a surface defect 4 is detected within the inspection area 3x, the area centered on the surface defect 4 (the area shown as a shaded rectangle in Figure 7) is designated as the scanning area 45. The scanning area 45 has the same area as the reference size 3s. The number of surface defects 4 present within the scanning area 45 is then counted. This process is repeated each time a new surface defect 4 is detected within the inspection area 3x. At any point during the repetition, if the number of surface defects 4 present within the scanning area 45 exceeds a threshold, the notification process P3c is executed. The order in which new surface defects 4 are detected within the inspection area 3x may be based on their position within the inspection area 3x, or on the size of the surface defects 4.

[0092] <Other variations> Herein, the following modifications can also be applied to the above embodiment.

[0093] In the above embodiment, when notification step P3c is executed in inspection step P3, the control device 8 changes each of the conditions (A) to (H), but it is not limited to this. The control device 8 may be configured to control the suction force from the suction ports of the first and second dust collectors, and when notification step P3c is executed in inspection step P3, it may be modified to increase the suction force from the suction port of the first dust collector or the suction port of the second dust collector. In addition, the suction force may be made variable for each position of the suction port of the first dust collector in the X direction and the suction port of the second dust collector in the Y direction, and the suction force may be increased at the positions corresponding to the concentration of surface defects 4. Furthermore, the control device 8 may be configured to control the amount of air circulation in the glass plate 3 manufacturing line, and when notification step P3c is executed in inspection step P3, it may be modified to increase the amount of air circulation. Furthermore, if the control device 8 controls the cleaning device and the notification process P3c is executed in the inspection process P3, changes may be made to increase the amount of cleaning fluid supplied to the glass plate 3 or to increase the angular velocity (peripheral velocity) of the rotating brush.

[0094] In the above embodiment, glass plates 3 that fail the quality judgment process P4 (pass / fail judgment process P4b) are discarded in the disposal process P5. However, this is not limited to this, and as shown in the flowchart of Figure 8, if the notification process P3c is executed in the inspection process P3, the glass plates 3 may also be discarded in the disposal process P5. [Explanation of symbols]

[0095] 1. Molten glass 2 glass ribbons 3 glass plate 3a Main surface 3b Effective surface 3s standard size 3x Examination Area 4. Surface defects 7 Cutting device 8 Control device 9. Internal defects 10 Glass plate manufacturing equipment 12 Inspection equipment 16 First cutting device 17 Second cutting device 32 Chuck (support member) 33 Display device 34 First Imaging System 35 Second Imaging System 37 First light source 38 First Imaging Unit 39 Shielding plate (shielding member) 40 Second Imaging Unit 41 Second light source 42 Third light source L1 First transmitted light L2 Second transmitted light L3 Third transmitted light P1 Molding process P2 cutting process P2a First cutting process P2b Second cutting process P3 Inspection Process P3a setting process P3b Specified process P3c notification process P4 Quality judgment process P4a Internal Defect Detection Process P4b Pass / Fail Determination Process P6 Storage process P7 Transportation process P8 Cleaning Process

Claims

1. The process comprises a processing step of performing a predetermined process on a glass plate using a processing apparatus, and an inspection step of inspecting for deposits adhering to the main surface of the glass plate after the processing step and scratches on the main surface as surface defects. The aforementioned inspection process, A setting step of setting an inspection area on the main surface, A defining process for defining a standard size having an area less than or equal to the aforementioned inspection area, A notification step in which, when the number of surface defects present per standard size within the inspection area exceeds a threshold, a notification is sent to a control device that controls the processing apparatus. A method for manufacturing a glass plate containing, The process further comprises a cleaning step for cleaning the glass plate, A method for manufacturing a glass plate, characterized in that the inspection step is performed before the cleaning step.

2. A method for manufacturing a glass plate according to claim 1, characterized in that the control device that receives the notification in the notification step changes the processing conditions of the predetermined processing in the processing step.

3. The control device includes a display device, The method for manufacturing a glass plate according to claim 1 or 2, characterized in that the display device displays a message indicating that the notification has been received.

4. In the inspection process described above, the upper end of the glass plate, which is in a vertical position, is supported by a support member. The method for manufacturing a glass plate according to claim 1 or 2, characterized in that the inspection area is set below the position where the support member is located on the main surface during the setting step.

5. The method for manufacturing a glass plate according to claim 4, characterized in that the setting step includes at least the entire area of ​​the effective surface of the glass plate in the inspection area.

6. The process further includes a quality determination step for determining the quality of the glass plate, The aforementioned quality determination process, An internal defect detection step, which targets the effective surface of the glass plate and detects foreign matter and bubbles present inside the glass plate as internal defects, A pass / fail determination step, which determines whether the quality of the glass plate is acceptable or unacceptable based on the results of the internal defect detection step, A method for manufacturing a glass plate according to claim 5, characterized by including the following:

7. The method for manufacturing a glass plate according to claim 6, characterized in that both the inspection step and the quality determination step are performed simultaneously by a single inspection device.

8. In the inspection process and the quality determination process, a first imaging system and a second imaging system are used. The first imaging system comprises a first light source, a first imaging unit that images the first transmitted light irradiated from the first light source and transmitted through the glass plate, and a shielding member that shields a portion of the first transmitted light to form bright and dark areas within the field of view of the first imaging unit. The second imaging system comprises a second light source and a third light source, and a second imaging unit that captures the second transmitted light, which is irradiated from the second light source and passes through the glass plate, in bright-field imaging, while capturing the third transmitted light, which is irradiated from the third light source and passes through the glass plate, in dark-field imaging. A method for manufacturing a glass plate according to claim 6, characterized in that the surface defects and internal defects are identified based on the image obtained by the first imaging system and the image obtained by the second imaging system.

9. The process further comprises a storage step for storing the glass plate, or a transport step for transporting the glass plate. A method for manufacturing a glass plate according to claim 1 or 2, characterized in that the inspection step is performed before the storage step or the transport step is performed.

10. The process further comprises a molding step for forming a glass ribbon from molten glass, and a cutting step as the processing step for cutting the glass plate from the glass ribbon, A method for manufacturing a glass plate according to claim 1 or 2, characterized in that the inspection step is performed after the cutting step.

11. The apparatus comprises a processing device that performs a predetermined process on a glass plate, and an inspection device that inspects for deposits adhering to the main surface of the glass plate after processing and scratches on the main surface as surface defects, The aforementioned inspection device Setting means for setting an inspection area on the main surface, A defining means for defining a standard size having an area less than or equal to the aforementioned inspection area, A glass plate manufacturing apparatus having a notification means for notifying a control device that controls the processing apparatus when the number of surface defects present per standard size within the inspection area exceeds a threshold, The device further comprises a cleaning apparatus for cleaning the glass plate, A glass plate manufacturing apparatus characterized in that the inspection device is located upstream of the cleaning device on the manufacturing line.

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