Method for manufacturing glass articles

Abstract

To on-line measure the strain of sheet-like glass, such as a glass plate on a conveyance path to efficiently manufacture a small strain glass article.SOLUTION: A method for manufacturing a glass article includes a conveyance step of conveying a base material glass plate G1 having ear parts Gx at both ends in the width direction orthogonal to a plate drawing direction along a conveyance path. The conveyance step comprises: an ear part removal step of cutting and removing the ear parts Gx of the base material glass plate G1 on the conveyance path; and a strain measurement step of irradiating the product glass plate G2 from which the ear parts Gx is removed on the conveying path with a laser beam L to measure the strain thereof.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a glass article. [Background technology]

[0002] Glass plates used as glass articles such as substrates for various electronic devices need to be inspected for the degree of distortion present after being formed and annealed. This is because excessive distortion of the glass plate causes problems in subsequent processes. In particular, glass plates used as glass substrates for panel displays such as liquid crystal displays are required to have minimal distortion.

[0003] For example, in the manufacturing process of liquid crystal displays, TFTs and color filters are formed on the surface of glass plates. The process of forming TFTs and color filters involves heating the glass plate. Therefore, if the glass plate is significantly distorted, the release of the distortion caused by heating will cause the glass plate to deform, significantly reducing its dimensional stability. This can result in misalignment of the TFT pattern and uneven color in the color filter.

[0004] One method of inspecting distortion involves irradiating a glass plate with laser light to measure the retardation (phase difference due to birefringence) of the glass plate, and determining the state of distortion from the tendency of the retardation measurement results (see Patent Document 1). Such distortion inspection is usually performed by so-called offline measurement, in which a sample glass plate is removed from the glass plate transport path. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2017 / 221825 Summary of the Invention [Problem to be solved by the invention]

[0006] However, when measuring distortion offline, it is necessary to extract the glass sheet and set the extracted glass sheet in a distortion measurement device, which requires time for distortion measurement. As a result, when the distortion of the glass sheet worsens due to an unintended change in the forming conditions, it is difficult to quickly detect the increase in distortion. Furthermore, even when forming conditions such as the annealing temperature are intentionally adjusted to reduce the distortion of the glass sheet, it takes time to grasp the change in the distortion of the glass sheet that accompanies the adjustment of the forming conditions. Therefore, there is a problem that it is difficult to efficiently produce glass sheets (glass articles) with small distortion to be used as products.

[0007] An object of the present invention is to measure the distortion of sheet-like glass, such as a glass plate, online on the conveying path and efficiently manufacture glass articles with little distortion. [Means for solving the problem]

[0008] (1) The present invention, which was invented to solve the above-mentioned problems, is a method for manufacturing a glass article, which includes a conveying step of conveying a sheet-like glass having ears at both ends in a width direction perpendicular to the sheet drawing direction along a conveying path, and is characterized in that the conveying step includes an ear removal step of cutting and removing the ears of the glass on the conveying path, and a distortion measurement step of irradiating the glass from which the ears have been removed on the conveying path with laser light to measure distortion, after the ear removal step.

[0009] When measuring the strain of sheet glass online, it is considered to measure the strain of glass immediately after it has been formed and annealed. However, immediately after it has been formed and annealed, glass has edge portions formed during the forming process at both ends in the width direction perpendicular to the sheet drawing direction. These edge portions are thicker than the central portion in the width direction. Therefore, when measuring the strain of glass with edge portions, the strain of the entire glass is strongly affected by the strain of the edge portions. On the other hand, in glass articles that will become products, the edge portions are cut and removed. In other words, the state of strain of glass with edge portions may differ significantly from the state of strain of the glass article. Therefore, even if the forming conditions, etc., are adjusted based on the state of strain of glass with edge portions, it is difficult to efficiently produce a glass article with little strain. Therefore, in the present invention, as configured above, the strain of glass with edge portions removed, which is similar to the state of strain of the glass article, is measured online on the conveying path. This allows the state of strain of the glass article to be quickly grasped on the conveying path.

[0010] (2) In the above configuration (1), it is preferable that the strain measuring step scans the laser light along the width direction of the glass. Note that "scanning" may refer to a mode in which the irradiation position of the laser light with respect to the glass moves relatively. In other words, it is sufficient that at least one of the glass and the laser light moves, and for example, it also includes a mode in which only the glass is moved while the laser light is irradiated at a fixed position.

[0011] In a sheet of glass, the thermal history of a linear region along the drawing direction is unlikely to change even if the position in the drawing direction changes, whereas the thermal history of a linear region along the width direction changes significantly depending on the position in the width direction. Therefore, as in the above configuration, it is preferable to measure the strain distribution in the width direction by scanning the laser light along the width direction of the glass.

[0012] (3) In the configuration of (2) above, in the strain measurement process, the hanging glass in a vertical position may be transported in the width direction with the sheet drawing direction facing up and down, while the laser light is scanned in the width direction of the glass.

[0013] In this way, the laser light can be scanned across the width of the glass simply by moving the glass. Furthermore, when glass is formed using the down-draw method, the formed glass is in a vertical position. Therefore, there is an advantage that the position of the formed glass, which is in a vertical position, does not need to be significantly changed during the strain measurement process.

[0014] (4) In the above-described configuration (3), it is preferable that the distortion measuring step irradiates the laser light onto the center in the vertical direction of the hanging glass in a vertical position.

[0015] The upper end of a glass pane suspended in a vertical position may be subject to constraints imposed by supports such as chucks, and may exhibit a state of strain different from the actual strain. Furthermore, the lower end of a glass pane suspended in a vertical position may be free to deform, and may exhibit a state of strain different from the actual strain. In other words, it may be difficult to grasp the state of strain in the glass at the upper and lower ends of a glass pane suspended in a vertical position. In contrast, the vertical center of a suspended glass pane is less susceptible to these influences, and has the advantage of making it easier to grasp the state of strain in the glass.

[0016] (5) In the above configuration (1) or (2), the glass may be transported in a flat position in the distortion measuring step.

[0017] This prevents the glass from deforming freely and ensures that the effect of gravity acts uniformly over the entire glass, which has the advantage of making it easier to accurately grasp the state of distortion in the glass.

[0018] (6) In any of the above configurations (1) to (5), it is preferable to further include a forming step of forming a belt-shaped glass ribbon having ears at both ends in the width direction by a down-draw method, and a cutting step of cutting the glass ribbon along the width direction to obtain glass having ears, and to perform a conveying step including an ear removal step and a measurement step after the cutting step.

[0019] (7) In any of the above configurations (1) to (6), the glass is preferably a glass plate cut into a rectangular shape.

[0020] (8) In any of the above configurations (1), (2), and (5), the glass may be a band-shaped glass ribbon. [Effects of the Invention]

[0021] According to the present invention, distortion of glass can be measured online on the conveying path, and glass articles with little distortion can be efficiently manufactured. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a side view of a glass article manufacturing apparatus according to a first embodiment. FIG. [Figure 2] FIG. 1 is a plan view of a glass article manufacturing apparatus according to a first embodiment. [Figure 3] FIG. 3 is a view taken along the arrow AA in FIG. 2. [Figure 4] FIG. 2 is a cross-sectional view of a base glass ribbon. [Figure 5] FIG. 4 is a side view showing a main part of a glass article manufacturing apparatus according to a second embodiment. [Figure 6] FIG. 4 is a plan view showing a main part of a glass article manufacturing apparatus according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, XYZ represents a Cartesian coordinate system. The X and Y directions are horizontal, and the Z direction is vertical. In addition, the same reference numerals are used to designate corresponding components in each embodiment, and redundant description may be omitted. When only a portion of the configuration is described in each embodiment, the configuration of another embodiment previously described may be applied to the remaining portions of the configuration. In addition to the combinations of configurations explicitly stated in the description of each embodiment, configurations of multiple embodiments may be partially combined together even if not explicitly stated, provided that there is no particular problem with the combination.

[0024] (First embodiment) As shown in FIG. 1, the glass article manufacturing apparatus 1 according to the first embodiment uses an overflow downdraw method to manufacture a glass plate product G2 (see FIGS. 2 and 3) as a glass article.

[0025] 1 to 3, the manufacturing apparatus 1 includes, in order from the upstream side of the conveyance path, a forming furnace 2, an annealing furnace 3, a cooling section 4, a cutting section 5, an edge removal section 6, an inspection section 7, and a packaging section 8. In this embodiment, the forming furnace 2, the annealing furnace 3, the cooling section 4, and the cutting section 5 are provided on different floors in the vertical direction, while the cutting section 5, the edge removal section 6, the inspection section 7, and the packaging section 8 are provided on the same floor.

[0026] As shown in FIG. 1, forming furnace 2 includes forming body 10 and edge rollers 11 in an internal space defined by furnace walls (wall portions) 9. Forming body 10 has a generally wedge-shaped cross section with an overflow groove (not shown) formed at the upper end. Edge rollers 11 are disposed directly below forming body 10 and clamp the molten glass formed by forming body 10 from both the front and back sides. Edge rollers 11 include an internal cooling mechanism for cooling the molten glass.

[0027] In the forming furnace 2, the molten glass overflowing from above the overflow groove of the forming body 10 flows down along both side surfaces and joins at the lower end to form a sheet. The edge rollers 11 regulate the widthwise contraction of the molten glass to form a base glass ribbon GR1 of a predetermined width. As shown in Fig. 4, at both widthwise ends of the base glass ribbon GR1 that come into contact with the edge rollers 11, ear portions GRx that are relatively thicker than the widthwise central portion are formed.

[0028] As shown in FIG. 1, the annealing furnace 3 anneals the base glass ribbon GR1 formed in the forming furnace 2 to a temperature equal to or lower than the strain point, thereby reducing distortion of the base glass ribbon GR1.

[0029] The annealing furnace 3 is provided with annealer rollers 12 in an internal space partitioned by furnace walls (wall portions) 9. The annealer rollers 12 are arranged in a plurality of stages at intervals along the vertical direction. The annealer rollers 12 hold both widthwise end portions of the base glass ribbon GR1 from both the front and back sides, and guide (transport) the base glass ribbon GR1 downward.

[0030] As shown in FIG. 1 , the cooling unit 4 allows the base glass ribbon GR1, which has been annealed in the annealing furnace 3, to cool to a predetermined temperature range. The cooling unit 4 includes support rollers 13 that hold both widthwise ends of the base glass ribbon GR1 from both the front and back sides. A plurality of support rollers 13 are arranged at intervals along the vertical direction. The support rollers 13 guide (transport) the base glass ribbon GR1 to the cutting unit 5 below. At this time, the sheet drawing direction of the base glass ribbon GR1 coincides with the vertical direction (Z direction).

[0031] As shown in FIG. 1, the cutting section 5 includes a breaking device 14 that cuts the base glass ribbon GR1 transferred downward from the cooling section 4.

[0032] The slicing device 14 forms scribe lines S1 in the base glass ribbon GR1 along the width direction and applies bending stress to cut the base glass ribbon GR1 along the scribe lines S1. As a result, a rectangular base glass sheet G1 is obtained from the base glass ribbon GR1. Like the base glass ribbon GR1, the base glass sheet G1 has relatively thick edge portions Gx at both widthwise ends. The base glass sheet G1 is transported to a first delivery position P1 while being supported by the slicing device 14 in a vertical position. At this time, the slicing device 14 transports the base glass sheet G1 while clamping both widthwise ends of the base glass sheet G1 from both the front and back sides, for example.

[0033] 1 to 3, the manufacturing apparatus 1 includes a conveying device 15 that conveys a base glass sheet G1 (or a product glass sheet G2 from which the edge portions have been removed) in a vertical position along a predetermined conveying path through a cutting unit 5, an edge removing unit 6, an inspection unit 7, and a packaging unit 8 in that order. The sheet drawing direction of the base glass sheet G1 conveyed by the conveying device 15 coincides with the up-down direction (Z direction).

[0034] The conveying device 15 includes a first support portion 16 and a second support portion 17 that support and suspend the base glass sheet G1 in a vertical position at its upper end portion. In this embodiment, in order to simultaneously convey a plurality of base glass sheets G1 on the conveying path, a plurality of first support portions 16 and / or second support portions 17 are arranged on the conveying path.

[0035] The first support portion 16 and the second support portion 17 are configured by a chuck mechanism that clamps the upper end portion of the base glass plate G1.

[0036] The first support unit 16 receives the base glass sheet G1 from the bending and cutting device 14 at the first delivery position P1, and then transports the base glass sheet G1 in the vertical position along a direction perpendicular to its surface (X direction) to the second delivery position P2.

[0037] The second support unit 17 receives the base glass sheet G1 from the first support unit 16 at the second delivery position P2, and then transports the base glass sheet G1 (or the product glass sheet G2) in the vertical position along the width direction (Y direction) parallel to the surface of the base glass sheet G1 to the third delivery position P3. The width direction of the base glass sheet G1 transported by the second support unit 17 is perpendicular to the sheet drawing direction (Z direction) of the base glass sheet G1.

[0038] As shown in FIGS. 2 and 3, the edge removal unit 6 includes a slicing device (not shown) that cuts off the edge portions Gx of the base glass sheet G1 suspended by the second support members 17. The slicing device forms scribe lines S2 in the vertical direction on the base glass sheet G1 and applies bending stress to cut the base glass sheet G1 along the scribe lines S2. This removes the edge portions Gx from the base glass sheet G1, resulting in a product glass sheet G2 without the edge portions Gx. The product glass sheet G2 is transported to the inspection unit 7 while being supported by the second support members 17 in a vertical position.

[0039] As shown in Figures 2 and 3, the inspection unit 7 includes a distortion measuring device 18 that measures distortion of the product glass sheet G2 in a vertical position suspended by the second support unit 17. In this embodiment, the distortion measuring device 18 is configured as a birefringence measuring device that includes an irradiation unit 19 that irradiates the product glass sheet G2 with laser light L and a light receiving unit 20 that receives the laser light L that has passed through the product glass sheet G2. The distortion measuring device 18 measures the magnitude and azimuth angle of retardation, and determines the state of distortion from the tendency of the retardation measurement results. Note that the measurement time per point of the distortion measuring device 18 is preferably 0.1 seconds or less.

[0040] In this embodiment, the irradiating unit 19 and the light-receiving unit 20 are fixed (positioned) so as to face each other with the product glass sheet G2 sandwiched therebetween. The irradiating unit 19 irradiates the laser light L onto the vertical center G2a of the product glass sheet G2, and the light-receiving unit 20 receives the laser light L that has passed through the vertical center G2a of the product glass sheet G2. When the product glass sheet G2 is transported by the second support unit 17, the laser light L irradiated from the irradiating unit 19 scans the vertical center G2a of the product glass sheet G2 in the width direction (Y direction) along the scanning line L1. That is, the widthwise strain distribution in the vertical center G2a of the product glass sheet G2 (strictly speaking, the scanning line L1) is measured.

[0041] As shown in Figures 2 and 3, the packaging unit 8 includes a loading device 22 that loads and packages the product glass sheets G2 on a pallet 21. The loading device 22 receives the product glass sheets G2 from the second support unit 17 at the third delivery position P3. The loading device 22 then loads and packages the received product glass sheets G2 on the pallet 21. It is preferable to interpose protective sheets (not shown) such as interleaf paper between the product glass sheets G2 on the pallet 21. Although Figure 2 illustrates an example in which multiple product glass sheets G2 are stacked on the pallet 21 in a vertical position, multiple product glass sheets G2 may also be stacked on the pallet 21 in a flat position.

[0042] A method for manufacturing a glass article using the manufacturing apparatus 1 having the above configuration will be described below.

[0043] As shown in FIGS. 1 to 3, the method includes a molding step, a slow cooling step, a cooling step, a cutting step, a selvage removing step, an inspection step, and a packaging step.

[0044] In the forming step, a base glass ribbon GR1 is formed from molten glass. Specifically, the molten glass supplied to the forming body 10 in the forming furnace 2 overflows from the overflow groove and flows down both sides of the forming body 10. The molten glass is then fused and integrated at the lower end of the forming body 10 and formed into a sheet. Edge rollers 11 clamp the widthwise ends of the molten glass and guide it downward. As a result, a base glass ribbon GR1 of a predetermined width is sent to the annealing furnace 3.

[0045] In the annealing step, the base glass ribbon GR1 is annealed. Specifically, the base glass ribbon GR1 descending from the forming furnace 2 passes through the internal space (annealing space) of the annealing furnace 3. The base glass ribbon GR1 is annealed in accordance with a predetermined temperature gradient while being conveyed downward by the annealer rollers 12. This reduces distortion of the base glass ribbon GR1.

[0046] In the cooling step, the base glass ribbon GR1 is cooled. Specifically, the base glass ribbon GR1 that has passed through the annealing furnace 3 passes through the internal space (cooling space) of the cooling unit 4. The base glass ribbon GR1 is naturally cooled to a predetermined temperature range while being conveyed downward by the support rollers 13.

[0047] In the cutting process, a base glass plate G1 is obtained from the base glass ribbon GR1. Specifically, the base glass ribbon GR1 that has passed through the cooling section 4 is introduced into the cutting section 5. A scribing device 14 forms scribe lines S1 along the width direction in the base glass ribbon GR1, and the base glass ribbon GR1 is cut along the scribe lines S1. This results in a base glass plate G1 of predetermined dimensions. The base glass plate G1 has edge portions Gx at both ends in the width direction.

[0048] In the edge removing step, the edge portions Gx of the base glass sheet G1 are removed. Specifically, the base glass sheet G1 is introduced into the edge removing section 6 by the conveying device 15 (second support section 17). At this time, the base glass sheet G1 is conveyed in the width direction (Y direction) perpendicular to the sheet drawing direction while being suspended with the sheet drawing direction facing up and down. During this conveying process, a scribe line S2 is formed in the base glass sheet G1 along the sheet drawing direction by a breaking device (not shown), and the base glass sheet G1 is cut along this scribe line S2. As a result, a product glass sheet G2 from which the edge portions Gx have been removed is obtained.

[0049] The inspection process includes a distortion measuring step in which the distortion measuring device 18 measures the distortion of the product glass sheet G2 from which the edge portions Gx have been removed. Specifically, the product glass sheet G2 is introduced into the inspection unit 7 by the conveying device 15 (second support unit 17). During this process, the product glass sheet G2 is conveyed in the width direction (Y direction) perpendicular to the sheet drawing direction while suspended with the sheet drawing direction facing up and down. During this conveyance process, the distortion measuring device 18 irradiates the product glass sheet G2 with laser light L from the irradiating unit 19 and receives the laser light L that has passed through the product glass sheet G2 at the light receiving unit 20. This allows the distortion corresponding to the irradiation spot of the laser light L to be measured. The irradiation spot of the laser light L is scanned along the width direction of the product glass sheet G2 as the product glass sheet G2 is conveyed. Therefore, the widthwise distribution of the distortion of the product glass sheet G2 is measured.

[0050] The measurement results of the distortion are fed back to upstream processes such as the annealing process, and a process for improving the distortion is carried out as necessary. Examples of the process for improving the distortion include changing the forming conditions, such as adjusting the annealing temperature of the base glass ribbon GR1 in the annealing process.

[0051] Here, when measuring strain online, it is conceivable to measure the strain of the base glass ribbon GR1 or the base glass sheet G1. However, when measuring the strain of the glass GR1, G1 having the edge portions GRx, Gx in this way, it is strongly affected by the strain of the edge portions GRx, Gx. In other words, the strain state of the glass GR1, G1 having the edge portions GRx, Gx is significantly different from the strain state of the product glass sheet G2 from which the edge portions Gx have been removed. Therefore, even if the forming conditions, etc. are adjusted based on the strain state of the glass GR1, G1 having the edge portions GRx, Gx, it is difficult to efficiently manufacture a product glass sheet G2 with small strain. Therefore, in this embodiment, the strain of the product glass sheet G2 is measured online on the conveying path immediately after the edge portions Gx are removed. This allows accurate 100% inspection of at least one-dimensional strain (in this embodiment, the strain in the width direction perpendicular to the sheet drawing direction) even with online measurement. As a result, deterioration of strain can be quickly and accurately grasped.

[0052] Furthermore, the upper end of the product glass sheet G2 in the suspended vertical position may be affected by the constraint of the second support portion 17 and may exhibit a strain state different from the actual state. On the other hand, the lower end of the product glass sheet G2 in the suspended vertical position is free to deform, and therefore unintended strain may be released, causing a strain state different from the actual state. In other words, it may be difficult to grasp the actual strain of the product glass sheet G2 at the upper and lower ends of the product glass sheet G2 in the suspended vertical position. In contrast, the vertical center G2a of the product glass sheet G2 in the suspended vertical position is less susceptible to these influences, and the strain of the product glass sheet G2 can be accurately grasped. Therefore, in this embodiment, strain is measured at the vertical center G2a of the product glass sheet G2.

[0053] The central portion G2a of the product glass sheet G2, where the strain is measured, is included in a region from a lower limit position H1, which is ¼ of the total height based on the lower edge of the product glass sheet G2, to an upper limit position H2, which is ¾ of the total height. The lower limit position H1 of the central portion G2a is preferably ⅕, more preferably ¼, and even more preferably ⅓ of the total height of the product glass sheet G2. The upper limit position H2 of the central portion G2a is preferably ⅓, more preferably ¾, and even more preferably ⅔ of the total height of the product glass sheet G2.

[0054] In the packaging process, the product glass plate G2 that has passed the inspection unit 7 is introduced into the packaging unit 8. In detail, the loading device 22 receives the product glass plate G2 from the conveying device 15 (second support unit 17) at the third delivery position P3, and loads and packages it on a pallet 21.

[0055] The product glass plate G2 packed in the pallet 21 is used as a substrate or a cover for various devices such as a panel display such as a liquid crystal display or an organic EL display, a solar cell, a touch panel, lighting, etc. When used for these purposes, the product glass plate G2 may be cut to obtain one or more glass plates of desired dimensions.

[0056] Second Embodiment As shown in Figures 5 and 6, the difference between the glass article manufacturing apparatus and manufacturing method of the second embodiment and the first embodiment is that the distortion is measured while transporting the product glass plate G2 from which the edge portion Gx has been removed in a flat position (preferably horizontal position) on the transport path.

[0057] The manufacturing apparatus 31 according to this embodiment includes a conveying device 33 that conveys the product glass sheet G2 in a flat position in an inspection section 32. In this embodiment, the conveying device 33 includes a plurality of rollers 34 that are arranged at intervals along the conveying direction. In the inspection section 32, the product glass sheet G2 from which the edge portions Gx have been removed is placed in a flat position on the rollers 34. At this time, the orientation of the product glass sheet G2 is adjusted so that the width direction of the product glass sheet G2, which is perpendicular to the sheet drawing direction, coincides with the conveying direction (X direction).

[0058] The irradiation unit 36 ​​of the distortion measuring device 35 irradiates the lower surface of the product glass sheet G2 with laser light L, utilizing the space between adjacent rollers 34 in the conveying direction. The light receiving unit 37 of the distortion measuring device 35 receives the laser light L that has passed through the upper surface side of the product glass sheet G2. Note that the irradiation unit 36 ​​may be located on the upper surface side of the product glass sheet G2, and the light receiving unit 37 may be located on the lower surface side of the product glass sheet G2. Furthermore, the conveying device 33 is not limited to the rollers 34, and may be a belt conveyor or a floating-type conveying device as long as a measurement space for the distortion measuring device 35 can be secured.

[0059] In this way, when the product glass sheet G2 is transported by the rollers 34 with the irradiation unit 36 ​​and the light receiving unit 37 of the distortion measuring device 35 in a fixed position, the laser light L scans along the width direction (strictly speaking, the scanning line L1) perpendicular to the drawing direction of the product glass sheet G2. Therefore, the strain distribution in the width direction perpendicular to the drawing direction of the product glass sheet G2 can be measured.

[0060] Furthermore, when measuring the distortion of the product glass sheet G2 in a flat-laid position, the lower surface of the product glass sheet G2 is supported by the conveying device 33 (e.g., rollers 34). Therefore, the product glass sheet G2 is less likely to deform freely. Furthermore, the effect of gravity acts almost uniformly on the entire product glass sheet G2. Therefore, measuring the distortion of the product glass sheet G2 in a flat-laid position has the advantage of making it easier to accurately grasp the state of distortion.

[0061] In this embodiment, the edge portions Gx of the base glass sheet G1 may be removed while the base glass sheet G1 is in a vertical position, or the edge portions Gx may be removed after the base glass sheet G1 is changed from a vertical position to a flat position. In the former case, a vertically oriented product glass sheet G2 is obtained, so that the position needs to be changed from a vertical position to a flat position when the base glass sheet G1 is placed on the conveying device 33. In the latter case, a flatly oriented product glass sheet G2 is obtained, so that no major change in position is required when the base glass sheet G1 is placed on the conveying device 33. In this case, the base glass sheet G1 in a flat position may be placed on the conveying device 33 in advance, and the edge portions Gx may be removed on the conveying device 33.

[0062] The above describes a method for manufacturing a glass article according to an embodiment of the present invention, but the embodiment of the present invention is not limited to this, and various modifications can be made within the scope that does not deviate from the gist of the present invention.

[0063] In the above-described first and second embodiments, a product glass plate is manufactured as the glass article, but a glass roll may be manufactured by winding a product glass ribbon into a roll. In this case, the glass article manufacturing apparatus further includes, downstream of the cooling section, a cutting device that cuts and removes edge portions of the glass ribbon to obtain a product glass ribbon, a strain measuring device that irradiates the product glass ribbon with laser light to measure distortion, and a winding device that winds the product glass ribbon into a roll to obtain a glass roll. Similarly, the glass article manufacturing method further includes, downstream of the cooling step, a cutting step that cuts and removes edge portions of the glass ribbon to obtain a product glass ribbon, a strain measuring step that irradiates the product glass ribbon with laser light to measure distortion, and a winding step that winds the product glass ribbon into a roll to obtain a glass roll.

[0064] In the above first and second embodiments, the strain distribution in the width direction perpendicular to the drawing direction of the glass product is described. However, in these embodiments, the strain distribution in the drawing direction of the glass product may also be measured. However, while the thermal history of the linear region along the drawing direction is unlikely to change even if the position in the drawing direction changes, the thermal history of the linear region along the width direction changes significantly depending on the position in the width direction. Therefore, when measuring one-dimensional strain distribution, it is preferable to measure the strain distribution in the width direction.

[0065] In the above embodiment, a plurality of strain measuring devices may be arranged in a direction perpendicular to the conveying direction of the glass sheet product, thereby making it possible to measure two-dimensional strain distribution.

[0066] In the above embodiment, the strain measuring device may be moved in a direction perpendicular to the conveying direction of the glass product sheet. In this way, it is possible to measure the strain distribution not only in the conveying direction of the glass product sheet but also in a direction perpendicular to the conveying direction. Note that the position of the strain measuring device may be moved in a direction perpendicular to the conveying direction for each glass product sheet, and the measurement results for multiple glass sheets may be combined. In this way, the one-dimensional strain distributions of multiple glass products may be used to reproduce the two-dimensional (e.g., in-plane) strain distribution of a single glass product sheet.

[0067] In the above embodiment, online measurement of distortion of a product glass sheet and offline measurement may be used in combination. That is, as in the above embodiment, the distortion of the product glass sheet is measured online on the conveying path. When a distortion defect is detected by this online measurement, a sample product glass sheet is removed from the conveying path. Then, the distortion of the removed sample is precisely measured offline.

[0068] In the above-described embodiment, the inspection unit may further include, in addition to the distortion measuring device, a measuring device that measures, for example, thickness deviation (sheet thickness), streaks (striae), and the type, position (coordinates), and size of defects (e.g., bubbles, foreign matter, etc.) of the glass sheet (or glass ribbon). That is, in addition to measuring distortion, the inspection process may also include other inspections related to the quality of the product glass sheet, such as thickness deviation, streaks, and defects.

[0069] In the above embodiment, the overflow downdraw method is used as an example of the method for forming a glass ribbon, but the method is not limited thereto. As the method for forming a glass ribbon, for example, other downdraw methods such as a slot downdraw method or a redraw method, or a float method can be used.

[0070] In the above-described embodiments, the method for cutting the glass ribbon or glass plate (including removal of the edge portions) is not particularly limited, and any method can be appropriately selected, such as bending breaking (bending stress breaking), laser breaking (thermal stress breaking), or laser melting.

[0071] In the above-described embodiments, the drawing direction of the glass ribbon or glass plate can be observed as a striped pattern by, for example, irradiating light from a light source (e.g., a xenon light) onto the target glass in a darkroom while adjusting the angle of the glass, and projecting the transmitted light onto a screen. [Explanation of symbols]

[0072] 1 Manufacturing equipment 6 Ear removal part 7. Inspection Department 15. Conveying equipment 18 Strain measurement device 19 Irradiation unit 20 Light receiving part 31 Manufacturing equipment 32 Inspection Department 33 Conveyor equipment 35 Strain measurement device 36 Irradiation unit 37 Light receiving part G1 base glass plate G2 product glass plate GR1 Base Glass Ribbon GRx Base glass ribbon edge Gx Base glass plate edge

Claims

1. A method for manufacturing a glass article, comprising a conveying step of conveying a rectangular glass sheet having ear portions at both ends in a width direction perpendicular to a sheet drawing direction along a conveying path, The transporting step includes: an edge removing step of cutting and removing the edge of the glass plate on the conveying path; a distortion measuring step of measuring distortion of the glass sheet from which the edge portions have been removed by irradiating the glass sheet with a laser beam on the conveying path after the edge removing step, a glass article manufacturing method, characterized in that in the distortion measurement step, the laser light is scanned along the width direction of the glass plate only at the vertical center of the glass plate in a vertical position that is suspended with the plate drawing direction facing up and down.

2. 2. The method for manufacturing a glass article according to claim 1, wherein the strain measuring step comprises scanning the laser light along the width direction of the glass plate while transporting the glass plate along the width direction.

3. The method further includes a forming step of forming a belt-shaped glass ribbon having ear portions at both ends in the width direction by a down-draw method, and a cutting step of cutting the glass ribbon along the width direction to obtain the glass sheet having the ear portions, The method for manufacturing a glass article according to claim 1 or 2, wherein the conveying step including the edge removing step and the measuring step is carried out after the cutting step.

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