Method and apparatus for manufacturing glass plates

Abstract

To ensure reliable detection of damage to the lower edge of a glass plate when the support configuration is changed during the vertical transport process in the manufacturing of glass plates. [Solution] In the transport process P1, in which the glass plate G is transported in a vertical position, the support configuration is changed from one in which the upper edge Ga and lower edge Gb of the glass plate G are supported, to one in which the glass plate G is suspended by supporting only the upper edge Ga, and then the shape inspection process P3 is performed to inspect for shape defects in the lower edge Gb.

Description

Technical Field

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

Background Art

[0002] The manufacturing process of a glass plate typically includes a process of inspecting defects such as foreign matters and bubbles contained in the glass plate (see Patent Document 1), and a process of transferring the inspected glass plate to a pallet for packaging. When executing both processes, the glass plate may be conveyed in a vertical posture.

[0003] In the inspection process, for example, after supporting the upper side and the lower side of the glass plate in a vertical posture with a chuck or the like, the glass plate is horizontally conveyed in the plate width direction. Then, an inspection device (such as a line sensor camera) is installed on the conveyance path of the glass plate, and defects contained in the glass plate are inspected as the glass plate passes through the point where the device is installed.

[0004] In the transfer process, for example, after supporting only the upper side of the inspected glass plate with a chuck or the like and suspending the glass plate, the glass plate is continuously horizontally conveyed in the plate width direction. Then, after switching the conveyance direction of the suspended glass plate from the plate width direction to the plate thickness direction, the glass plate is loaded onto a pallet.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] As mentioned above, when the support configuration for glass plates is switched during vertical transport, the support for the lower edge of the glass plate is released. This can sometimes cause damage to the lower edge of the glass plate due to the resulting shock and vibration. Therefore, to prevent damaged glass plates from being mistakenly shipped as products, it was desirable to be able to reliably detect any damage to the lower edge caused by the switch in support configuration.

[0007] In light of the circumstances described above, the issue that needs to be resolved is to ensure that any damage to the lower edge of a glass plate that occurs when the support configuration is changed midway through the vertical transport of the glass plate during its manufacturing process can be reliably detected. [Means for solving the problem]

[0008] A first method for manufacturing a glass plate to solve the above problems is a method for manufacturing a glass plate that includes a transport step for transporting a glass plate in a vertical position, wherein the transport step allows switching between a support configuration between an upper and lower edge support configuration in which the upper edge of the glass plate is supported and a suspended support configuration in which the glass plate is suspended by supporting the upper edge, and further includes a shape inspection step for inspecting shape defects of the lower edge, wherein the shape inspection step is performed after switching from the upper and lower edge support configuration to the suspended support configuration.

[0009] In the first method for manufacturing glass plates, the glass plate support configuration is switched from top and bottom edge support to suspension support during the transport process, and then a shape inspection process is performed. In other words, after releasing the support for the bottom edge of the glass plate, the shape defects of the bottom edge are inspected. As a result, damage to the bottom edge caused by the switch in support configuration can be reliably identified. Furthermore, in this manufacturing method, the shape inspection process allows for inspection not only of damage but also of shape defects in the bottom edge other than damage (for example, leftover pieces when cutting the glass plate). Therefore, it becomes possible to identify shape defects caused by factors other than the release of support for the bottom edge.

[0010] The second method for manufacturing a glass plate is the same as the first method for manufacturing a glass plate described above, but with the shape inspection process performed during transport of the glass plate in a suspended support configuration in the plate width direction, a lower edge inspection sensor that detects the presence or absence of glass is installed at a height position through which the lower edge passes during the transport of the glass plate, and in the shape inspection process, the distance the glass plate has been transported in the plate width direction while the lower edge inspection sensor detects the presence of glass is measured as the lower edge dimension, and if the lower edge dimension falls outside the normal dimension range, it is determined that there is a shape defect in the lower edge.

[0011] In the second method for manufacturing glass plates, the shape inspection process is performed while the glass plate is being transported, making it possible to inspect for shape defects at the bottom edge while the glass plate is being moved toward its target location (for example, a location where pallets for packaging the glass plates are installed). This improves the efficiency of glass plate manufacturing. Furthermore, in this manufacturing method, a sensor that detects the presence or absence of glass is used when performing the shape inspection process, which has the following advantages (1) and (2) compared to, for example, a method of inspecting shape defects by imaging the glass plate with a camera: (1) When performing the shape inspection process, the glass plate is transported in a suspended support configuration in the width direction, so the glass plate is prone to shaking in the thickness direction, but the sensor that detects the presence or absence of glass can reduce the impact of shaking. On the other hand, when imaging the glass plate with a camera, the camera is prone to losing focus on the glass plate due to the effects of shaking. (2) Inspection can be performed with simple control.

[0012] The third method for manufacturing a glass plate is the first or second method for manufacturing a glass plate described above, wherein the shape inspection step includes inspecting for shape defects in the upper edge in addition to the shape defects in the lower edge.

[0013] In the third method for manufacturing glass plates, the shape inspection process also inspects for shape defects in the upper edge, thus preventing situations where glass plates with shape defects in the upper edge are mistakenly shipped as products.

[0014] The fourth method for manufacturing a glass plate is the same as the third method for manufacturing a glass plate described above, but with an upper edge inspection sensor installed at a height where the upper edge passes during the transport of the glass plate to detect the presence or absence of glass. In the shape inspection step, the distance the glass plate has been transported in the width direction while the upper edge inspection sensor detects the presence of glass is measured as the upper edge dimension, and if the upper edge dimension falls outside the normal dimension range, it is determined that there is a shape defect in the upper edge.

[0015] In the fourth method for manufacturing glass plates, the same actions and effects as those in the second method for manufacturing glass plates described above can be obtained when inspecting for shape defects in the upper edge of the glass plate.

[0016] The fifth method for manufacturing a glass plate is the fourth method for manufacturing a glass plate described above, wherein the normal dimensional range for the upper edge is the same as the normal dimensional range for the lower edge.

[0017] In the fifth method for manufacturing glass plates, the shape defects of the upper and lower edges of the glass plate are judged using the same criteria, making it possible to easily control the quality of the glass plate.

[0018] The sixth method for manufacturing a glass plate is a method for manufacturing a glass plate according to any of the second to fifth methods described above, wherein the normal dimension range of the lower edge dimension includes the design dimension in the width direction of the glass plate.

[0019] The sixth method for manufacturing glass plates prevents defective glass plates from being mistakenly shipped as products, even if there is no damage to the bottom edge of the glass plate, but the dimensions of the bottom edge deviate from the design dimensions beyond the tolerance range.

[0020] The seventh method for manufacturing a glass plate is the method for manufacturing a glass plate according to any of the second to sixth methods described above, wherein the sensor for inspecting the lower edge is a photoelectric sensor.

[0021] In the method for manufacturing the seventh glass plate, since the sensor for inspecting the lower side portion is a photoelectric sensor, it is possible to inspect the shape defect of the lower side portion of the glass plate in a non-contact manner.

[0022] The method for manufacturing the eighth glass plate is the method for manufacturing the fourth or fifth glass plate described above, in which an upper side portion support member that supports the upper side portion in an upper and lower side support form and a suspension support form is provided, and a lower side portion support member that supports the lower side portion in an upper and lower side support form is provided. The sensor for inspecting the upper side portion is installed at a height position below the lower end of the upper side portion support member, and the sensor for inspecting the lower side portion is installed at a height position below the upper end of the lower side portion support member.

[0023] In the method for manufacturing the eighth glass plate, by installing the sensor for inspecting the upper side portion at a height position below the lower end of the upper side portion support member, it is possible to avoid the upper side portion support member from entering the detection range where the sensor detects the presence or absence of glass. This is advantageous for the sensor to accurately detect the presence or absence of glass. Further, by installing the sensor for inspecting the lower side portion at a height position below the upper end of the lower side portion support member, it is possible to accurately grasp the breakage of the lower side portion caused by the lower side portion support member releasing the support of the lower side portion.

[0024] The method for manufacturing the ninth glass plate is the method for manufacturing any one of the first to eighth glass plates described above, and further includes a defect inspection step of inspecting the defects of the glass plate based on the image obtained by imaging the glass plate, and the defect inspection step is executed during the conveyance of the glass plate in the upper and lower side support form in the plate width direction.

[0025] In the method for manufacturing the ninth glass plate, when executing the defect inspection step, the glass plate is conveyed in the upper and lower side support form when being conveyed in the plate width direction. That is, the upper side portion and the lower side portion of the glass plate being conveyed are respectively supported. Therefore, the sway in the plate thickness direction of the glass plate being conveyed is prevented, and the problem that the focus does not match the glass plate during imaging of the glass plate can be avoided. As a result, it is possible to accurately inspect the defects of the glass plate.

[0026] The manufacturing method of the tenth glass plate is such that, in the manufacturing method of the ninth glass plate described above, the glass plate has an effective surface existing at the center and a non-effective surface surrounding the effective surface, and in the defect inspection process, only the defects included in the effective surface of the glass plate are inspected.

[0027] In the manufacturing method of the tenth glass plate, by narrowing the inspection target to the defects included in the effective surface of the glass plate, it becomes possible to shorten the inspection time and reduce the load on the inspection apparatus.

[0028] The manufacturing method of the eleventh glass plate is such that, in the manufacturing method of the tenth glass plate described above, in the shape inspection process, at least the shape defects in the non-effective surface are inspected.

[0029] In the manufacturing method of the eleventh glass plate, since at least the shape defects in the non-effective surface are inspected, at least for the parts of the glass plate where breakage is likely to occur, inspection of shape defects is carried out. When the glass plate is conveyed in a vertical posture, in order to avoid the occurrence of scratches and contamination on the effective surface, it is common to support the part corresponding to the non-effective surface. Therefore, inevitably, breakage is more likely to occur in the non-effective surface than in the effective surface. Thus, by inspecting at least the shape defects in the non-effective surface, it is advantageous for grasping the occurrence of breakage. Even if there is no breakage in the effective surface at the time when the shape inspection process is executed, there may be cases where the breakage in the non-effective surface reaches the effective surface later, so from this perspective as well, it is effective to inspect at least the shape defects in the non-effective surface.

[0030] A glass plate manufacturing apparatus for solving the above problems is characterized by comprising a conveying device for conveying glass plates in a vertical position along a conveying path, wherein the conveying device has an upper edge support member capable of supporting the upper edge of the glass plate and a lower edge support member capable of supporting the lower edge of the glass plate, the conveying device being able to switch between an upper and lower edge support configuration in which the upper edge and lower edge are supported by the upper edge support member and the lower edge support member respectively, and a suspended support configuration in which the upper edge is supported by the upper edge support member and the glass plate is suspended, and the conveying path includes an upstream conveying path for conveying glass plates in the upper and lower edge support configuration and a downstream conveying path for conveying glass plates in the suspended support configuration, and further comprising a shape inspection device for inspecting shape defects of the lower edge, wherein the shape inspection device is located in the downstream conveying path.

[0031] This manufacturing apparatus makes it possible to obtain the same effects and benefits as the first glass plate manufacturing method described above. [Effects of the Invention]

[0032] According to the glass plate manufacturing method and manufacturing apparatus of this disclosure, when the support configuration for transporting the glass plate in a vertical position is changed during the manufacturing of the glass plate, it becomes possible to reliably detect damage to the lower edge of the glass plate that occurs as a result of the change. [Brief explanation of the drawing]

[0033] [Figure 1] This is a side view showing a method for manufacturing glass plates and the manufacturing apparatus. [Figure 2] This is a plan view showing a method for manufacturing glass plates and the manufacturing apparatus. [Figure 3] This is a side view showing the shape inspection process in the manufacturing method of glass plates. [Modes for carrying out the invention]

[0034] 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 each drawing referenced in the description of the embodiments are mutually orthogonal directions.

[0035] As shown in Figures 1 and 2, the glass plate manufacturing method includes a transport step P1 in which the glass plate G is transported horizontally in the plate width direction (X direction) in a vertical position. In this manufacturing method, while the transport step P1 is being executed, the following steps are performed in order from the upstream side: a defect inspection step P2 for inspecting defects in the glass plate G, a shape inspection step P3 for inspecting shape defects in the upper edge Ga and lower edge Gb of the glass plate, and a disposal step P4 for discarding glass plates G that fail at least one of the defect inspection step P2 and the shape inspection step P3. For glass plates G that pass both the defect inspection step P2 and the shape inspection step P3, a loading step P5 is performed downstream of the disposal step P4 in which the glass plates G are loaded onto a pallet 1. Each of the steps P1 to P5 is performed for each of the multiple glass plates G that are continuously transported from the upstream side.

[0036] The glass plate G is rectangular in shape and has an upper edge Ga and a lower edge Gb extending in the X direction, and side edges Gc, Gc extending in the Y direction. The glass plate G has an effective surface G1 located in the center (the part enclosed by the dashed line in Figure 1) and an ineffective surface G2 surrounding the effective surface G1. The upper edge Ga, lower edge Gb, and side edges Gc, Gc are all included in the ineffective surface G2. The effective surface G1 is the part that will later become a glass plate product, and the ineffective surface G2 is the part that will not become a glass plate product and will later be discarded. The thickness of the glass plate G is, for example, 0.4 mm to 0.7 mm, and the length of one side of the glass plate G is, for example, 1000 mm to 3500 mm. The glass plate G is used, for example, as a glass substrate or cover glass for display devices.

[0037] The glass plate G can be obtained using the downdraw method (such as the overflow downdraw method or the slot downdraw method), the float method, or the redraw method. The glass plate G in this embodiment was obtained by the following procedure.

[0038] First, the glass ribbon formed by the overflow downdraw method is cut in the width direction, and a glass plate with thick ears is cut from the glass ribbon. Next, the ears at both ends in the width direction are cut and removed from the glass plate with ears to obtain a glass plate G. The glass plate G obtained in the same procedure is sent to the area where defect inspection process P2 is performed. The upper edge Ga and lower edge Gb of the glass plate G are edges formed when the glass plate with ears is cut from the glass ribbon. On the other hand, the side edges Gc,Gc of the glass plate G are edges formed when the ears are cut and removed from the glass plate with ears.

[0039] This manufacturing method uses a glass plate manufacturing apparatus 2 (hereinafter simply referred to as manufacturing apparatus 2). Manufacturing apparatus 2 includes a conveying device 3 used in the conveying process P1, a defect inspection device 4 used in the defect inspection process P2, a shape inspection device 5 used in the shape inspection process P3, a waste chute 6 used in the waste disposal process P4, and a loading device 7 used in the loading process P5.

[0040] The conveying device 3 is a device for conveying a glass plate G along a conveying path while supporting it in a vertical position. The conveying path includes an upstream conveying path S1 and a downstream conveying path S2 which is connected to the downstream side of the upstream conveying path S1. In other words, the upstream conveying path S1 is connected to the upstream end of the downstream conveying path S2 at its downstream end.

[0041] The upstream transport path S1 is a path for transporting the glass plate G in an upper and lower edge support configuration, where the upper edge Ga and lower edge Gb of the glass plate G are supported, respectively. On the other hand, the downstream transport path S2 is a path for transporting the glass plate G in a suspended support configuration, where only the upper edge Ga of the glass plate G is supported, and the glass plate G is suspended. In other words, the transport device 3 can switch the support configuration of the glass plate G between the upper and lower edge support configuration and the suspended support configuration during the execution of the transport process P1. The switch in the support configuration of the glass plate G from the upper and lower edge support configuration to the suspended support configuration is performed at the point where the downstream end of the upstream transport path S1 and the upstream end of the downstream transport path S2 connect.

[0042] The defect inspection device 4 described above is located in the upstream transport path S1. On the other hand, the shape inspection device 5 and the waste chute 6 described above are located in the downstream transport path S2. As a result, the defect inspection process P2 is performed on the glass plate G in the upper and lower edge support configuration. Meanwhile, the shape inspection process P3 and the waste process P4 are performed on the glass plate G in the suspended support configuration after switching from the upper and lower edge support configuration to the suspended support configuration.

[0043] The conveying device 3 includes a plurality of upper chucks 3a as upper edge support members capable of supporting the upper edge Ga of the glass plate G, and a plurality of lower chucks 3b as lower edge support members capable of supporting the lower edge Gb of the glass plate G.

[0044] Each upper chuck 3a and each lower chuck 3b can support the upper edge Ga and lower edge Gb, respectively, as they grip the glass plate G from both the front and back sides. Each upper chuck 3a supports the upper edge Ga of the glass plate G both when the conveying device 3 is in an upper and lower edge support configuration and when it is in a suspension support configuration. On the other hand, each lower chuck 3b supports the lower edge Gb of the glass plate G only when the conveying device 3 is in an upper and lower edge support configuration. Each upper chuck 3a grips the upper edge Ga at a point slightly below the edge (upper edge). Similarly, each lower chuck 3b grips the lower edge Gb at a point slightly above the edge (lower edge). The edges of the glass plate G are cut surfaces formed, for example, by scribe cutting, and may have minute cracks. Therefore, if the upper chuck 3a and the lower chuck 3b grip the edge, a small crack may start and propagate, potentially damaging the glass plate G. As in this embodiment, by gripping the upper chuck 3a and the lower chuck 3b at a position slightly away from the edge, the risk of the glass plate G being damaged can be effectively eliminated.

[0045] Here, three glass plates G are shown in the area indicated in Figures 1 and 2 of the glass plate G transport path (the transport path that transports the glass plate G in the width direction of the plate). The upper edge Ga of each glass plate G is supported by two upper chucks 3a. In the following description, two upper chucks 3a that support the upper edge Ga of the same glass plate G together will be referred to as an upper chuck group 3A. There are three sets of upper chuck groups 3A1 to 3A3 in the area indicated in Figures 1 and 2. Upper chuck group 3A1 is located in the upstream transport path S1, and upper chuck groups 3A2 and 3A3 are located in the downstream transport path S2.

[0046] Each of the upstream transport path S1 and the downstream transport path S2 is divided into multiple transport sections, with one set of upper chuck groups 3A placed in each transport section. In other words, there are three transport sections in the area shown in Figures 1 and 2 where there are three sets of upper chuck groups 3A1 to 3A3 (one transport section in the upstream transport path S1 and two transport sections in the downstream transport path S2). The upper chuck groups 3A placed in each transport section can move back and forth within the transport section along a guide rail (not shown) extending in the X direction. Furthermore, an upper chuck group 3A can receive a glass plate G from an adjacent upper chuck group 3A at the upstream end of the transport section, and can pass the glass plate G to an adjacent upper chuck group 3A at the downstream end of the transport section. As a result, the glass plate G is passed between multiple sets (three sets in the area shown in Figures 1 and 2) of upper chuck groups 3A as it is sent to the downstream side of the transport path.

[0047] In the following explanation, two lower chucks 3b that support the same lower edge Gb of the glass plate G together will be referred to as a lower chuck group 3B.

[0048] The lower chuck group 3B is positioned in the same transport section as the upper chuck group 3A1 and can reciprocate within the transport section in synchronization with the upper chuck group 3A1 along a guide rail (not shown) extending in the X direction. The lower chuck group 3B begins supporting the lower edge Gb of the glass plate G at the upstream end of the transport section and releases support from the lower edge Gb at the downstream end of the transport section. The lower chuck group 3B can also pull the lower edge Gb of the glass plate G downwards.

[0049] In the transport process P1 using the transport device 3, first, the glass plate G, which is in an upper and lower edge support configuration with its upper edge Ga and lower edge Gb supported by the upper chuck group 3A1 and lower chuck group 3B respectively, is sent downstream along the upstream transport path S1. Then, the glass plate G is passed over the point where the defect inspection device 4 is located along the upstream transport path S1. At this time, the lower edge Gb is pulled downward by the lower chuck group 3B in order to prevent shaking or warping of the glass plate G during inspection.

[0050] After the glass plate G has passed the location where the defect inspection device 4 is positioned, the support of the lower edge Gb by the lower chuck group 3B is released, and the support configuration of the glass plate G is switched from upper and lower edge support configuration to suspension support configuration. In this embodiment, from the time of switching to suspension support configuration until the glass plate G is loaded onto the pallet 1, there is no opportunity to support or come into contact with the lower edge Gb of the glass plate G. After that, the transport of the glass plate G is temporarily stopped, and the glass plate G is transferred from the upper chuck group 3A1 to the upper chuck group 3A2.

[0051] Next, in the downstream transport path S2, the glass plate G, which is suspended and supported only by its upper edge Ga by the upper chuck group 3A2, is sent downstream. The glass plate G is then passed over the point in the downstream transport path S2 where the shape inspection device 5 is located. After that, the transport of the glass plate G is temporarily stopped within the downstream transport path S2, and the glass plate G is transferred from the upper chuck group 3A2 to the upper chuck group 3A3.

[0052] Next, the glass plate G, which is suspended and supported only by its upper edge Ga by the upper chuck group 3A3, is sent downstream along the downstream transport path S2. The transport process P1 is completed when the glass plate G is sent to the point where the waste chute 6 is located along the downstream transport path S2. After the transport process P1, the glass plate G is either transported towards the pallet 1 or discarded without being transported (details will be described later).

[0053] In this embodiment, multiple upper chucks 3a and multiple lower chucks 3b are used as upper and lower support members capable of supporting the upper and lower edges Ga and Gb of the glass plate G, respectively, but this is not limited to this configuration. For example, one or more suction pads may be used as upper and lower support members.

[0054] The defect inspection device 4 is a device for inspecting defects in a glass plate G that is supported by its upper and lower edges, based on images taken of the glass plate G. The defect inspection device 4 inspects for defects in the glass plate G that include at least foreign matter and bubbles contained in the effective surface G1, and damage to the side edges Gc, Gc.

[0055] The defect inspection device 4 is equipped with a line sensor camera 4a that extends in the vertical direction (Y direction). The line sensor camera 4a is installed in a fixed position and scans the glass plate G being transported by the transport device 3 (upper chuck group 3A1 and lower chuck group 3B).

[0056] In the defect inspection process P2 using the defect inspection device 4, the line sensor camera 4a scans and detects at least foreign matter and bubbles contained within the effective surface G1, and damage to the side edges Gc, Gc. If there are no foreign matter or bubbles exceeding the acceptable number or size on the effective surface G1, and there is no damage to either of the two side edges Gc, Gc, the glass plate G being inspected is judged as acceptable. On the other hand, if there are foreign matter or bubbles exceeding the acceptable number or size on the effective surface G1, or if there is damage to either of the two side edges Gc, Gc, the glass plate G being inspected is judged as unacceptable. Thus, the defect inspection process P2 is completed.

[0057] In this embodiment, the line sensor camera 4a is installed in a fixed position and scans the glass plate G being transported by the transport device 3; however, this is not limited to this configuration. The transport of the glass plate G by the transport device 3 may be temporarily stopped, and the line sensor camera 4a may be moved in the X direction while scanning the glass plate G.

[0058] The shape inspection device 5 is a device for inspecting the upper edge Ga and lower edge Gb of a glass plate G in a suspended support configuration for shape defects such as damage or incomplete cutting. The shape inspection device 5 is equipped with an upper edge inspection sensor 5a and a lower edge inspection sensor 5b, and both sensors 5a and 5b are installed at fixed positions on the downstream transport path S2.

[0059] The upper edge inspection sensor 5a and the lower edge inspection sensor 5b are installed at heights where the upper edge Ga and lower edge Gb pass, respectively, during the transport of the glass plate G, and are capable of detecting the presence or absence of glass at their respective installation locations. The height at which the lower edge inspection sensor 5b is installed can be adjusted according to the length of the side edge Gc of the glass plate G, and the longer the side edge Gc, the lower the height of the lower edge inspection sensor 5b is adjusted accordingly. In this embodiment, retroreflective laser sensors, which are a type of photoelectric sensor, are used as both sensors 5a and 5b. The wavelength of the laser light emitted by the retroreflective laser sensor is between 0.4 μm and 2.5 μm.

[0060] As shown in Figure 3(a), the upper edge inspection sensor 5a is installed below height position H1, where H1 is the height at which the lower end of the upper chuck 3a supporting the upper edge Ga of the glass plate G passes. This prevents the upper chuck 3a from entering the detection range of the upper edge inspection sensor 5a. For example, height position H1 is approximately 15 mm below the edge (upper edge) of the upper edge Ga.

[0061] The bottom edge inspection sensor 5b is positioned below height H2, where H2 is the height of the upper end of the lower chuck 3b when it was supporting the bottom edge Gb of the glass plate G. In Figure 3(a), the position of the lower chuck 3b when it was supporting the bottom edge Gb is shown by a dashed line, even though the lower chuck 3b has already released its support for the bottom edge Gb. As a result, the bottom edge inspection sensor 5b detects the presence or absence of glass, including the area where the lower chuck 3b was supporting (gripping).

[0062] The shape inspection process P3 using the shape inspection device 5 will be explained below with reference to Figures 3(a) to 3(c).

[0063] In the shape inspection process P3, the upper edge inspection sensor 5a and the lower edge inspection sensor 5b detect the presence of glass and measure the distance the glass plate G is transported in the plate width direction (X direction) as the upper edge dimension L1 and the lower edge dimension L2, respectively. In this embodiment, the distance the glass plate G is transported in the plate width direction is determined to be the distance the upper chuck 3a moves in the X direction.

[0064] For example, when a glass plate G is being transported at a constant transport speed V, the upper chuck 3a is moving at a constant speed V. In this case, if the lower edge inspection sensor 5b detects the presence of glass only for a detection time T, the lower edge dimension L2 is measured as the product of V and T (L2 = V × T). Also, if there is acceleration or deceleration in the transport speed V of the glass plate G (the moving speed V of the upper chuck 3a), the lower edge dimension L2 is measured by integrating V with respect to T.

[0065] The measured upper edge dimension L1 and lower edge dimension L2 are determined to be within the normal dimensional range (dimensional tolerance range). The normal dimensional range includes the design dimension W in the width direction of the glass plate G. The upper limit of the normal dimensional range is set to, for example, W+5mm to W+50mm, and the lower limit is set to, for example, W-50mm to W-5mm. The normal dimensional range for the upper edge dimension L1 is the same as the normal dimensional range for the lower edge dimension L2. The design dimension W can be set, for example, based on the dimensions of each generation of the glass substrate. Also, if a glass plate of the desired generation dimensions is trimmed and cut from the glass plate G in a later process, the design dimension W can be set to a value obtained by adding the dimension of the part removed by trimming to the dimension of the desired generation.

[0066] If both the upper edge dimension L1 and the lower edge dimension L2 are within the normal dimensional range, the glass plate G being inspected is judged to be acceptable. Figure 3(a) shows a glass plate G that has no shape defects in either the upper edge Ga or the lower edge Gb, and both the upper edge dimension L1 and the lower edge dimension L2 are within the normal dimensional range, and is judged to be acceptable.

[0067] If at least one of the upper edge dimension L1 and the lower edge dimension L2 falls outside the normal dimensional range, the glass plate G being inspected is judged as unacceptable. Figure 3(b) shows a glass plate G that is judged as unacceptable because it has damage to the lower edge Gb, the lower edge dimension L2 is shorter than the normal dimensional range, and the lower edge Gb has a defective shape. Damage to the lower edge Gb often occurs when the support configuration of the glass plate G is switched from an upper and lower edge support configuration to a suspension support configuration, as the support to the lower edge Gb is released.

[0068] Figure 3(c) shows a glass plate G that has a remaining piece at the bottom edge Gb (a portion that should have been removed from the glass plate G by cutting), and the bottom edge dimension L2 is longer than the normal dimension range, resulting in a defective shape of the bottom edge Gb, which leads to it being judged as unacceptable. The remaining piece is caused by a cutting defect when cutting and removing the ear portion from a glass plate with an ear portion.

[0069] Note that while Figures 3(b) and (c) illustrate cases where there is a shape defect in the lower edge Gb, shape defects can also occur in the upper edge Ga. For example, damage to the upper edge Ga often occurs when the glass plate G is transferred between adjacent upper chuck groups 3A, 3A.

[0070] As described above, once it is determined whether the glass plate G to be inspected passes or fails, the shape inspection process P3 is completed.

[0071] In this embodiment, retroreflective laser sensors are used as the upper edge inspection sensor 5a and the lower edge inspection sensor 5b, but this is not limited to them. Reflective laser sensors, transmissive laser sensors, or ultrasonic sensors may be used as both sensors 5a and 5b. With a retroreflective laser sensor, even if the lower edge Gb of the glass plate G shakes and the incident angle of the laser light changes, shape defects in the glass plate G can be accurately detected, and the light source and light receiving unit can be integrated, thus simplifying the wiring. With a reflective laser sensor, even if the glass plate G is a transparent object, shape defects in the glass plate G can be accurately detected, and the light source and light receiving unit can be integrated, thus simplifying the wiring. With a transmissive laser sensor, even if the lower edge Gb of the glass plate G shakes and the incident angle of the laser light changes, shape defects in the glass plate G can be accurately detected. With an ultrasonic sensor, even if the glass plate G is a transparent object, shape defects in the glass plate G can be accurately detected.

[0072] Furthermore, the light source used in the photoelectric sensor may be a laser or an LED. If the light source is a laser, the detection area of ​​the glass plate G can be narrowed, thereby improving the positional accuracy when detecting defects in the shape of the glass plate G. If the light source is an LED, the light emitted from the light source is diffused, so even if the lower edge Gb of the glass plate G shakes and the incident angle of the laser light changes, defects in the shape of the glass plate G can be accurately detected.

[0073] Furthermore, the light emitted from the light source may be visible light or infrared light. If the light emitted from the light source is visible light, the light emitted from the light source can be visually confirmed, making it easy to adjust the area for detecting the glass plate G. If the light emitted from the light source is infrared light, the transmittance to glass is low, making it easier to detect shape defects in the glass plate G, especially when using transmissive or retroreflective sensors.

[0074] Furthermore, in this embodiment, the upper edge inspection sensor 5a and the lower edge inspection sensor 5b are installed in fixed positions, and both sensors 5a and 5b detect the presence or absence of glass while the glass plate G is being transported by the transport device 3 (upper chuck group 3A2), but this is not limited to this configuration. Alternatively, the transport of the glass plate G by the transport device 3 may be temporarily stopped, and both sensors 5a and 5b may be moved in the X direction while detecting the presence or absence of glass.

[0075] Furthermore, in this embodiment, only shape defects of the upper edge Ga and lower edge Gb, i.e., shape defects of the non-effective surface G2, are inspected by the upper edge inspection sensor 5a and the lower edge inspection sensor 5b, but this is not limited to this. One or more intermediate inspection sensors may be installed between the two sensors 5a and 5b, and the presence or absence of glass may be detected at the height position where the sensors are installed, thereby also inspecting for shape defects of the effective surface G1.

[0076] The waste chute 6 shown in Figures 1 and 2 is equipment for disposing of glass plates G. The waste chute 6 is located at the downstream end of the downstream transport path S2. The opening of the waste chute 6 is sized to allow vertically oriented glass plates G to pass through, and it connects the upper floor, where the defect inspection device 4 and shape inspection device 5 are located, to the lower floor, where the waste area 8 is located.

[0077] In the disposal process P4 using the waste chute 6, for glass plates G that fail at least one of the defect inspection process P2 and the shape inspection process P3, the support of the upper edge Ga of the glass plate G by the upper chuck group 3A3 is released at the downstream end of the downstream transport path S2. This allows the glass plate G to fall from the upper floor to the lower floor through the waste chute 6, and the glass plate G is disposed of in the disposal area 8. This completes the disposal process P4.

[0078] As shown in Figure 2, the loading device 7 is a device for loading glass plates G onto the pallet 1 in a vertical position. The loading device 7 is capable of loading glass plates G onto the pallet 1 and also works in cooperation with a sheet installation device (not shown) that places protective sheets S on top of the glass plates G loaded onto the pallet 1.

[0079] In the loading process P5 using the loading device 7, first, glass plates G that have passed both the defect inspection process P2 and the shape inspection process P3 reach the downstream end of the downstream transport path S2, and are then transferred from the upper chuck group 3A3 to the chucks 7a, 7a on the loading device 7. The loading device 7 moves in the thickness direction (Z direction) with the upper edge Ga of the glass plate G supported and suspended by the chucks 7a, 7a, and transports the glass plate G to the pallet 1. After that, the loading device 7 loads the glass plate G onto the pallet 1, and the sheet installation device places a protective sheet S on top of the glass plate G. As the loading process P5 continues to be executed, a laminate 9 is formed on the pallet 1 in which glass plates G and protective sheets S are alternately stacked. This completes the loading process P5.

[0080] In this embodiment, the areas where shape defects occur may not be the cut surfaces formed by properly cutting the glass plate G, but rather cracks. In the loading process P5 of this embodiment, the glass plates G are loaded onto the pallet 1 in a vertical position. Therefore, if a shape defect occurs on the lower edge Gb of the glass plate G, when loading the glass plate G onto the pallet 1, or when storing or transporting the laminate 9 loaded on the pallet 1, the area with the shape defect may come into contact with the pallet 1, causing the crack to propagate and potentially resulting in significant damage to the glass plate G. If the glass plates G loaded on the pallet 1 are significantly damaged in this way, the resulting fragments and glass powder may adhere to the glass plates G contained in the laminate 9, potentially impairing the quality of multiple glass plates G. According to this embodiment, since shape defects on the lower edge Gb of the glass plate G are detected, such problems can be prevented. [Explanation of Symbols]

[0081] 2. Glass plate manufacturing apparatus 3. Conveying device 3a Upper chuck (upper edge support member) 3b Lower chuck (lower edge support member) 5. Shape inspection device 5a Sensor for inspecting the upper edge 5b Sensor for inspecting the lower edge G Glass plate G1 Effective surface G2 Non-effective surface Ga upper part Gb lower edge H1 Height position H2 Height position L1 Top edge dimension L2 Bottom edge dimension P1 Conveying Process P2 Defect Inspection Process P3 Shape Inspection Process S1 Upstream transport route S2 Downstream transport path

Claims

1. A method for manufacturing glass plates, comprising a conveying process for transporting glass plates in a vertical position, In the aforementioned transport process, the support configuration can be switched between an upper and lower edge support configuration, in which the upper and lower edges of the glass plate are supported respectively, and a suspended support configuration, in which the upper edge is supported and the glass plate is suspended. The process further includes a shape inspection step for inspecting for shape defects in the lower edge portion, A method for manufacturing a glass plate, characterized in that the shape inspection step is performed after switching from the upper and lower edge support configuration to the suspension support configuration.

2. The shape inspection process is performed during transport of the glass plate in the suspended support configuration in the width direction of the plate. A sensor for inspecting the bottom edge is installed at a height position over which the bottom edge passes during the transport of the glass plate, to detect the presence or absence of glass. The method for manufacturing a glass plate according to claim 1, characterized in that, in the shape inspection step, the distance the glass plate is transported in the plate width direction while the lower edge inspection sensor detects the presence of glass is measured as the lower edge dimension, and if the lower edge dimension falls outside the normal dimension range, it is determined that there is a shape defect in the lower edge.

3. The method for manufacturing a glass plate according to claim 2, characterized in that the shape inspection step involves inspecting for shape defects in the upper part in addition to the shape defects in the lower part.

4. A sensor for inspecting the upper edge of the glass plate is installed at a height position where the upper edge passes during the transport of the glass plate, to detect the presence or absence of glass. The method for manufacturing a glass plate according to claim 3, characterized in that, in the shape inspection step, the distance the glass plate is transported in the width direction of the plate while the upper edge inspection sensor detects the presence of glass is measured as the upper edge dimension, and if the upper edge dimension falls outside the normal dimension range, it is determined that there is a shape defect in the upper edge.

5. The method for manufacturing a glass plate according to claim 4, characterized in that the normal dimension range in the upper dimension is the same as the normal dimension range in the lower dimension.

6. The method for manufacturing a glass plate according to any one of claims 2 to 5, characterized in that the normal dimension range of the lower edge dimension includes the design dimension of the glass plate in the plate width direction.

7. The method for manufacturing a glass plate according to any one of claims 2 to 5, characterized in that the lower edge inspection sensor is a photoelectric sensor.

8. An upper edge support member is provided to support the upper edge in the upper and lower edge support configuration and the suspension support configuration, and a lower edge support member is provided to support the lower edge in the upper and lower edge support configuration. The upper edge inspection sensor is installed at a height below the lower end of the upper edge support member. The method for manufacturing a glass plate according to claim 4 or 5, characterized in that the lower edge inspection sensor is installed at a height below the upper end of the lower edge support member.

9. The system further includes a defect inspection step for inspecting defects in the glass plate based on an image of the glass plate, A method for manufacturing a glass plate according to any one of 2 to 5, characterized in that the defect inspection step is performed during transport of the glass plate in the upper and lower side support configuration in the plate width direction.

10. The glass plate has an effective surface located in the center and an ineffective surface surrounding the effective surface, The method for manufacturing a glass plate according to claim 9, characterized in that the defect inspection step involves inspecting only defects contained in the effective surface of the glass plate.

11. The method for manufacturing a glass plate according to claim 10, characterized in that the shape inspection step involves inspecting for shape defects in at least the non-effective surface.

12. Equipped with a conveying device that transports glass plates in a vertical position along a transport path, The transport device includes an upper support member capable of supporting the upper edge of the glass plate and a lower support member capable of supporting the lower edge of the glass plate. The conveying device is capable of switching between a top and bottom support configuration, in which the top and bottom edges are supported by the top and bottom support members, respectively, and a suspended support configuration, in which the top edge is supported by the top support member and the glass plate is suspended from it. The glass plate manufacturing apparatus includes an upstream transport path for transporting the glass plate in the upper and lower side support configuration and a downstream transport path for transporting the glass plate in the suspension support configuration, The device further includes a shape inspection device for inspecting shape defects in the lower edge portion. A glass plate manufacturing apparatus characterized in that the shape inspection device is located in the downstream transport path.

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