Glass plate manufacturing method and manufacturing device

Abstract

A method for manufacturing a glass plate comprises a first measuring step (P2) of measuring the thickness of the ear portion (Gx) by taking a glass original plate (G1) having an effective portion (Gy) and an ear portion (Gx) thicker than the effective portion (Gy) as an object, wherein in the first measuring step (P2), the thickness of the ear portion (Gx) is measured using an absorption-type measuring instrument, i.e., a first measuring device (3) (infrared thickness meter).

Description

Technical Field

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

[0002] As is well known, glass plates are used in displays represented by liquid crystal displays, organic EL displays, and the like.

[0003] In the manufacturing process of glass sheets, first, a glass ribbon is continuously formed from molten glass by a down-draw method (e.g., overflow down-draw method) or a float method. Next, the glass ribbon is cut along the width direction at a predetermined length. Thus, a glass original plate having thick-walled ears at both ends in the width direction is cut out from the glass ribbon. Next, the ears at both ends are separated from the glass original plate to obtain a glass sheet from the glass original plate. After that, the glass sheet is inspected, etc.

[0004] As an example of inspection, the plate thickness measurement disclosed in Patent Document 1 can be cited. In the measurement method disclosed in the document, the glass plate is measured while being transported in a suspended state. In addition, the plate thickness measurement uses a first CCD camera that detects a change in the height of the lower surface (the end surface at the lower end) of the glass plate, a second CCD camera that captures an image of the lower surface, a lifting mechanism that raises and lowers the second CCD camera according to the change in the height of the lower surface, and a control unit that processes the image of the lower surface to obtain the plate thickness.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2002-228422 Summary of the invention

[0008] Problems to be solved by the invention

[0009] In order to control the quality of glass sheets, it is sometimes necessary to know the thickness of the ear portion of the original glass sheet. However, in the method disclosed in Patent Document 1, it is not assumed to measure the thickness of the ear portion, and therefore it is expected to establish a mechanism for realizing such measurement.

[0010] In view of the above, a technical problem to be solved is to enable measurement of the plate thickness of the ear portion of a glass original plate having a thick ear portion when manufacturing a glass plate.

[0011] Solutions to Solve Problems

[0012] The manufacturing method of the glass plate for solving the above-mentioned problems includes a first measuring step of taking a glass original plate having an effective portion and an ear portion thicker than the effective portion as an object and measuring the plate thickness of the ear portion. The manufacturing method of the glass plate is characterized in that, in the first measuring step, the plate thickness of the ear portion is measured using an absorption-type measuring instrument.

[0013] In this method, an absorption type measuring instrument is used when performing the first measuring step. Since the absorption type measuring instrument can measure a wide range of plate thickness, it is possible to measure the plate thickness of the thick ear portion of the original glass plate without any problem.

[0014] In the above method, it is preferred that the glass original plate has ears at both ends while the effective part is sandwiched in the middle. When the direction of the ears connecting the two ends is set as the width direction, in the first measuring step, the thickness of the glass original plate is measured from one end to the other end along the width direction to obtain the thickness distribution of the glass original plate, and based on the thickness distribution of the glass original plate, the length of the glass original plate in the width direction is obtained.

[0015] In this way, the length of the glass original plate in the width direction (hereinafter referred to as the original plate width) is obtained based on the plate thickness distribution of the glass original plate, so that the quality of the glass plate obtained from the glass original plate can be properly managed. For example, for the purpose of preventing the quality of the glass plate from changing due to the increase or decrease of the original plate width, it is easy to manage the original plate widths of multiple glass original plates cut from a glass ribbon to be the same.

[0016] In the above method, it is preferred that the method includes a first conveying step of conveying the glass original plate in a suspended supported state along the width direction, and while executing the first conveying step, a first measuring step is executed using an absorption-type measuring device arranged in the conveying path of the glass original plate, and the plate thickness is measured at the upper part of the glass original plate.

[0017] In this way, the plate thickness is measured at the upper part of the original glass plate, in other words, near the suspended support portion. Therefore, even if the original glass plate is swung during the conveying process, the influence of the swung on the measurement result can be minimized because the portion with a small amplitude of the swung is measured. Therefore, the plate thickness distribution of the original glass plate can be accurately obtained.

[0018] In the above method, it is preferred that it includes: a splitting step of splitting the ear portion from the glass original plate, thereby obtaining a glass plate formed by the effective portion from the glass original plate; and a second measuring step of taking the glass plate as an object and measuring the thickness of the glass plate from one end to the other end of the glass plate along the width direction using a measuring device using a spectral interference method, thereby obtaining the thickness distribution of the glass plate.

[0019] In this way, when the second measurement step of obtaining the plate thickness distribution of the glass plate is performed, a measuring device of a spectral interference method capable of high-resolution measurement compared with an absorption method is used, thereby obtaining a fine plate thickness distribution of the glass plate.

[0020] In the above method, it is preferable that the length of the glass sheet in the width direction is acquired based on the thickness distribution of the glass sheet.

[0021] In this manner, the length of the glass sheet in the width direction is acquired based on the sheet thickness distribution of the glass sheet, and the quality management of the glass sheet can be further appropriately performed.

[0022] In the above method, it is preferred that the method includes a second conveying step of conveying the glass plate in a suspended state along the width direction, and while executing the second conveying step, a second measuring step is executed using a spectral interference measuring device arranged in the conveying path of the glass plate, and the thickness of the glass plate is measured at the upper part.

[0023] In this way, even if the glass sheet being conveyed vibrates due to the execution of the second conveying step, the influence of the vibration on the measurement result can be minimized. Therefore, the plate thickness distribution of the glass sheet can be obtained more accurately.

[0024] In addition, a glass plate manufacturing device for solving the above-mentioned problems includes a measuring device for measuring the thickness of a glass original plate having an effective portion and an ear portion thicker than the effective portion, and the glass plate manufacturing device is characterized in that the measuring device is an absorption type measuring device.

[0025] According to this device, the operations and effects described above with respect to the above-mentioned method for manufacturing a glass plate can be obtained in the same manner.

[0026] Effects of the Invention

[0027] According to the manufacturing method and manufacturing apparatus of a glass plate of the present invention, when manufacturing a plate glass, the plate thickness of the ear portion of a glass original plate having a thick ear portion can be measured. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a top view showing a method and an apparatus for manufacturing a glass plate.

[0029] Figure 2 It is a front view showing a method and an apparatus for manufacturing a glass plate.

[0030] Figure 3 It is a diagram showing the plate thickness distribution of the glass original plate.

[0031] Figure 4 It is a diagram showing the plate thickness distribution of the glass plate. DETAILED DESCRIPTION

[0032] Hereinafter, a method and an apparatus for manufacturing a glass sheet according to an embodiment will be described with reference to the accompanying drawings. Figure 1 as well as Figure 2 The X direction, Y direction, and Z direction shown in are mutually orthogonal directions. The X direction is equal to the width direction of the glass original plate G1 and the glass plate G2, and the Y direction is equal to the thickness direction of the glass original plate G1 and the glass plate G2. In addition, the Z direction is the up-down direction.

[0033] <Glass sheet manufacturing device>

[0034] First, a glass plate manufacturing apparatus 1 (hereinafter, simply referred to as a manufacturing apparatus 1) will be described.

[0035] Figure 1 as well as Figure 2 The manufacturing device 1 shown comprises: a plurality of conveying devices 2, which are used to convey a glass original plate G1 or a glass plate G2 in a vertical posture in a suspended supported state along the width direction (X direction); a first measuring device 3, which is used to measure the plate thickness along the width direction from one end G1a to the other end G1b of the glass original plate G1; a cutting device (not shown in the figure), which is used to obtain a glass plate G2 formed by an effective portion Gy from the glass original plate G1 by cutting the ear portion Gx from the glass original plate G1; and a second measuring device 4, which is used to measure the plate thickness along the width direction from one end G2a to the other end G2b of the glass plate G2.

[0036] Here, the glass original plate G1 and the glass plate G2 are described.

[0037] The glass original plate G1 is a glass original plate cut from a glass ribbon by cutting a glass ribbon continuously formed from molten glass by a down-draw method (e.g., overflow down-draw method) or a float method according to a predetermined length along the width direction. The glass original plate G1 has an effective portion Gy that will later become a glass plate G2 and an ear portion Gx that is thicker than the effective portion Gy, and the ear portions Gx are formed at both ends in the width direction by sandwiching the effective portion Gy in the middle. The glass plate G2 is formed by the effective portion Gy separated from the ear portion Gx by a cutting device. The thickness t1 of the glass plate G2 (effective portion Gy) is, as an example, 30 μm to 1100 μm, and the thickness t2 of the ear portion Gx is, as an example, 1200 μm to 3000 μm. The ratio of thickness (t2 / t1) is, as an example, 3 to 8.

[0038] In the conveying path (in the X direction) of the original glass plate G1 (glass plate G2) extending Figure 1 as well as Figure 2The manufacturing apparatus 1 is divided into a plurality of sections (the right side is the upstream side and the left side is the downstream side), and each section is provided with a transport device 2. That is, the manufacturing apparatus 1 has the same number of transport devices 2 as the number of sections. Each transport device 2 can reciprocate along the X direction and can move between the upstream end and the downstream end within the section to which it belongs.

[0039] Each conveying device 2 receives the original glass plate G1 or the glass plate G2 at the upstream end of the section to which it belongs. After conveying the received original glass plate G1 or the glass plate G2 to the downstream end of the section, each conveying device 2 hands over the original glass plate G1 or the glass plate G2 to the conveying device 2 belonging to the adjacent section. After handing over the original glass plate G1 or the glass plate G2, each conveying device 2 returns to the upstream end of the section to which it belongs in order to receive the next original glass plate G1 or the glass plate G2.

[0040] In the manufacturing apparatus 1, a plurality of glass original plates G1 transferred from an upstream process are sequentially transferred to a cutting device using a plurality of conveying devices 2, and a plurality of glass plates G2 cut from the glass original plates G1 are sequentially transferred from the cutting device to a downstream process.

[0041] Each conveying device 2 is provided with a chuck 5 as a supporting member capable of supporting (holding) the upper edge of the glass original plate G1 or the glass plate G2. The glass original plate G1 or the glass plate G2 is suspended by the chuck 5. When receiving and delivering the glass original plate G1 or the glass plate G2, the chuck 5 supports and releases the upper edge by opening and closing the claws provided on the chuck 5.

[0042] Here, as a variation of the present embodiment, the manufacturing device 1 may include a single conveying device capable of reciprocating along the conveying path of the glass original plate G1 (glass plate G2) instead of the plurality of conveying devices 2. That is, the glass original plate G1 and the glass plate G2 may be conveyed by a single conveying device. In addition, as another variation of the present embodiment, the conveying device 2 may include an adsorption pad capable of adsorbing the upper edge of the glass original plate G1 or the glass plate G2 as a supporting member instead of the chuck 5.

[0043] The first measuring device 3 is arranged on the conveying path of the glass original plate G1. The first measuring device 3 is an infrared thickness meter as an absorption type measuring device. The first measuring device 3 includes a light projector 6 and a light receiver 7. The light projector 6 and the light receiver 7 are arranged opposite to each other with the path line through which the glass original plate G1 passes during conveyance sandwiched between them. The light projector 6 and the light receiver 7 are arranged at the same height position in the up-down direction (Z direction). The light projector 6 can emit infrared rays 8 vertically to the surface G1s of the glass original plate G1.

[0044] When the first measuring device 3 measures the thickness of the glass original plate G1, the infrared rays 8 emitted by the light projector 6 are transmitted through (from the surface G1s side to the back surface G1t side) the glass original plate G1 and reach the light receiver 7. The infrared rays 8 attenuated at this time are detected as electrical signals and converted into current values, thereby measuring the thickness of the glass original plate G1.

[0045] The height position (position in the Z direction) of the first measuring device 3 is adjusted in such a manner that the plate thickness is measured at the upper part of the glass original plate G1. The purpose is to minimize the influence of the swing (swing along the Y direction) generated in the glass original plate G1 accompanying the transportation of the glass original plate G1 on the measurement result. Regarding the height position of the first measuring device 3, to explain in more detail, the height position of the first measuring device 3 is adjusted in such a manner that the plate thickness is measured at a position in the upper part of the glass original plate G1 that is lower than the position supported (held) by the chuck 5 and where there is no deformation of the glass original plate G1 associated with the support (holding) of the chuck 5. As an example of the height position of the first measuring device 3 (plate thickness measurement position), it is a position separated from the upper side (upper edge) of the glass original plate G1 by a distance of 100 mm to 300 mm downward.

[0046] The first measuring device 3 allows the glass original plate G1 to pass between the projector 6 and the light receiver 7, thereby continuously measuring the plate thickness from one end G1a to the other end G1b of the glass original plate G1 (for example, measuring at 1 mm intervals). Figure 2 The line 9 indicated by the double-dashed line in the figure measures the plate thickness from the left side to the right side of the figure. Here, as an example of the range of the plate thickness that can be measured by the first measuring device 3, it is more than 0 μm and less than 3200 μm. In addition, as an example of the resolution of the first measuring device 3, it is about 2 μm.

[0047] Here, as a modification of the present embodiment, an absorption-based measuring instrument other than the infrared thickness meter may be used as the first measuring device 3 .

[0048] The cutting device (not shown) is arranged on the conveying path of the glass original plate G1 (glass plate G2) at a position downstream of the first measuring device 3 and upstream of the second measuring device 4. As the cutting device, any device can be used as long as it can separate the ear portion Gx from the glass original plate G1. As an example, a device having a mechanism for forming a scoring line along the boundary line 10 between the ear portion Gx and the effective portion Gy for the glass original plate G1 in a suspended supporting state and a mechanism for breaking and cutting the glass original plate G1 along the scoring line can be used. In addition, a device that cuts the glass original plate G1 along the boundary line 10 by laser cutting or laser melting can also be used as the cutting device.

[0049] The second measuring device 4 is arranged on the conveying path of the glass plate G2. The second measuring device 4 includes a spectroscopic interferometer 11 and a mirror plate 12 as measuring instruments of a spectroscopic interference method. The spectroscopic interferometer 11 and the mirror plate 12 are opposed to each other with the path line through which the glass plate G2 passes during conveyance sandwiched between them. The spectroscopic interferometer 11 and the mirror plate 12 are arranged at the same height position in the up and down direction (Z direction). The spectroscopic interferometer 11 can emit a laser 13 perpendicularly to the surface G2s of the glass plate G2, and can receive reflected light. The mirror plate 12 has a flat reflecting surface 12a, and is arranged so that the reflecting surface 12a is parallel to the surface G2s and the back surface G2t of the glass plate G2.

[0050] When the thickness of the glass plate G2 is measured by the second measuring device 4, a portion of the laser light 13 emitted by the spectroscopic interferometer 11 that is reflected on the surface G2s of the glass plate G2 and a portion of the laser light reflected on the back surface G2t are received by the spectroscopic interferometer 11. Furthermore, a portion of the laser light 13 emitted by the spectroscopic interferometer 11 that is transmitted through (transmitted from the surface G2s side to the back surface G2t side) the glass plate G2 and then reflected by the reflecting surface 12a of the mirror plate 12 is received by the spectroscopic interferometer 11. Based on the interference of the light at this time, the thickness of the glass plate G2 is measured.

[0051] The second measuring device 4 (spectrometric interferometer 11 and mirror plate 12) is adjusted in height position (position in the Z direction) so as to measure the plate thickness at the upper part of the glass plate G2 for the same reason as the first measuring device 3. Specifically, the height position of the second measuring device 4 is adjusted so as to measure the plate thickness at a position of the upper part of the glass plate G2 that is lower than the position supported (held) by the chuck 5 and does not deform the glass plate G2 associated with the support (holding) of the chuck 5. In the present embodiment, the first measuring device 3 and the second measuring device 4 are located at the same height position. However, this is not limiting, and the two devices 3 and 4 may be located at different height positions.

[0052] The second measuring device 4 allows the glass plate G2 to pass between the spectroscopic interferometer 11 and the mirror plate 12, thereby continuously measuring the plate thickness from one end G2a to the other end G2b of the glass plate G2 (for example, measuring at 1 mm intervals). Figure 2 The line 14 represented by the double-dashed line in the figure measures the plate thickness from the left side to the right side of the figure. Here, the range of the plate thickness that can be measured by the second measuring device 4 is 0.05μm to 800μm as an example. In addition, the resolution of the second measuring device 4 is 0.01μm or less as an example. In this way, the second measuring device 4 has a smaller range of plate thickness that can be measured than the first measuring device 3, but on the other hand, the resolution of the measurement is higher.

[0053] Here, as a modification of the present embodiment, the mirror plate 12 may be omitted from the second measuring device 4. In this case, a portion of the laser light 13 emitted by the spectroscopic interferometer 11 that is reflected on the front surface G2s of the glass plate G2 and a portion of the laser light that is reflected on the back surface G2t are received by the spectroscopic interferometer 11. Based on the interference of the light at this time, the plate thickness of the glass plate G2 is measured.

[0054] <Method for producing glass plate>

[0055] Hereinafter, a method for producing a glass plate using the above-mentioned production apparatus 1 (hereinafter, simply referred to as a production method) will be described.

[0056] like Figure 1 As well as Figure 2 As shown, the manufacturing method includes: a first conveying step P1, using a conveying device 2 to convey a glass original plate G1 cut from a glass ribbon (not shown); a first measuring step P2, using a first measuring device 3 to measure the plate thickness of the glass original plate G1, thereby obtaining a plate thickness distribution of the glass original plate G1 (refer to Figure 3 ); a splitting step P3, using a cutting device to split the ear portion Gx from the glass original plate G1 that has undergone the first measuring step P2 to obtain a glass plate G2; a second conveying step P4, using a conveying device 2 to convey the glass plate G2; and a second measuring step P5, using a second measuring device 4 to measure the thickness of the glass plate G2, thereby obtaining a thickness distribution of the glass plate G2 (refer to Figure 4 ).

[0057] The first measurement step P2 is performed while the first conveying step P1 is being performed. When the first measurement step P2 is completed, Figure 3 The thickness distribution of the glass original plate G1 as shown. The thickness distribution of the glass original plate G1 includes the thickness distribution of the ear portion Gx and the thickness distribution of the effective portion Gy. Moreover, the length L1 of the glass original plate G1 in the width direction can be obtained based on the thickness distribution of the glass original plate G1. Moreover, the width (length along the width direction) of the ear portion Gx can also be grasped based on the thickness distribution of the glass original plate G1.

[0058] The dividing step P3 is performed while temporarily stopping the conveyance (conveying the glass original plate G1) by the conveying device 2. When the ear portion Gx is divided from the glass original plate G1 to obtain the glass plate G2, the conveyance (conveying the glass plate G2) by the conveying device 2 is restarted.

[0059] The second measurement step P5 is performed while the second conveying step P4 is being performed. When the second measurement step P5 is completed, the following is obtained: Figure 4The thickness distribution of the glass plate G2 shown in FIG. 1 does not include the thickness distribution of the ear portion Gx, but only includes the thickness distribution of the glass plate G2 (effective portion Gy). It should be noted that Figure 4 The thickness distribution of the glass sheet G2 shown is equivalent to Figure 3 The plate thickness distribution of the area surrounded by quadrilateral A is different from Figure 3 Furthermore, the length L2 of the glass sheet G2 in the width direction can be obtained based on the thickness distribution of the glass sheet G2.

[0060] After the second measurement step P5, the glass sheet G2 is subjected to inspections other than the measurement of the sheet thickness, and then is packaged on a pallet, for example, for shipment, storage, etc. As described above, the glass sheet G2 is manufactured.

[0061] Hereinafter, main functions and effects of the above-mentioned manufacturing apparatus 1 and manufacturing method will be described.

[0062] In the manufacturing device 1 and the manufacturing method described above, when measuring the thickness of the ear portion Gx of the glass original plate G1, an absorption-type measuring device, i.e., the first measuring device 3 (infrared thickness meter) is used. Since the absorption-type measuring device can measure a wide range of plate thickness, the plate thickness of the thick-walled ear portion Gx of the glass original plate G1 can be measured without any problem.

[0063] Description of Reference Numerals

[0064] 1 Glass sheet manufacturing device

[0065] 3. The first measuring device (infrared thickness meter)

[0066] 11 Spectral Interferometer

[0067] G1 Glass Plate

[0068] G1a One end of the original glass plate

[0069] G1b The other end of the original glass plate

[0070] G2 Glass Plate

[0071] G2a One end of the glass plate

[0072] G2b The other side of the glass plate

[0073] Gx Ear

[0074] Gy effective part

[0075] L1 Length of original glass plate

[0076] L2 Length of the glass plate

[0077] P1 First handling process

[0078] P2 First measurement process

[0079] P3 Segmentation process

[0080] P4 Second handling process

[0081] P5 Second measurement step.

Claims

1. A method for manufacturing a glass plate, comprising a first measuring step of measuring the plate thickness of a glass plate having an effective portion and an ear portion connected to the effective portion and thicker than the effective portion, The method for manufacturing the glass plate is characterized in that: In the first measuring step, the plate thickness of the ear portion is measured using an absorption type measuring instrument. The glass original plate sandwiches the effective part in the middle and has the ear parts at both ends. When the direction connecting the ears at both ends is set as the width direction, In the first measuring step, the thickness distribution of the glass original plate is obtained by measuring the plate thickness from one end to the other end of the glass original plate along the width direction. Based on the plate thickness distribution of the glass original plate, the length of the glass original plate in the width direction is acquired.

2. The method for manufacturing a glass plate according to claim 1, wherein: The method for manufacturing a glass plate includes a first conveying step of conveying the original glass plate in a suspended state along the width direction. While the first conveying step is being performed, the first measuring step is performed using the absorption type measuring device arranged on the conveying path of the glass original plate, and the plate thickness is measured at the upper part of the glass original plate.

3. The method for manufacturing a glass plate according to claim 1 or 2, characterized in that: The method for manufacturing the glass sheet comprises: a dividing step of dividing the ear portion from the glass original plate, thereby obtaining a glass plate formed of the effective portion from the glass original plate; and In the second measurement step, the glass plate is measured for thickness from one end to the other end of the glass plate along the width direction using a spectral interference measuring instrument to obtain a thickness distribution of the glass plate.

4. The method for manufacturing a glass plate according to claim 3, wherein: Based on the plate thickness distribution of the glass plate, the length of the glass plate in the width direction is obtained.

5. The method for manufacturing a glass plate according to claim 3, wherein: The method for manufacturing a glass plate includes a second conveying step of conveying the glass plate in a suspended state along the width direction. While the second conveying step is being performed, the second measuring step is performed using the spectral interference type measuring device arranged on the conveying path of the glass plate, and the plate thickness is measured at the upper part of the glass plate.

6. A glass plate manufacturing device, comprising a measuring device for measuring the thickness of a glass plate having an effective portion and an ear portion connected to the effective portion and thicker than the effective portion, The glass sheet manufacturing device is characterized in that: The measuring device is an absorption measuring device. The glass original plate sandwiches the effective part in the middle and has the ear parts at both ends. When the direction connecting the ears at both ends is set as the width direction, The glass plate manufacturing apparatus is configured to measure the thickness of the glass original plate from one end to the other end along the width direction using the measuring device to obtain a thickness distribution, and to obtain the length of the glass original plate in the width direction based on the thickness distribution.

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