JP2022061531A - Method for producing glass plate - Google Patents

Abstract

To accurately discriminate between types of defects of a glass plate during transportation thereof in a vertical posture.SOLUTION: A method for producing a glass plate G comprises: a molding step S1 of molding a glass ribbon Gr using a down-draw method; a cutting step S3 of cutting a glass plate G by cutting the molded glass ribbon Gr into a prescribed length; a transportation step S4 of transporting the cut glass plate G in a vertical posture in parallel to a principal surface of the glass plate G; and an inspection step of inspecting the glass plate G during the transportation step S4. The inspection step comprises: a first inspection step S6 of specifying coordinates of a defect of the glass plate G; and a second inspection step S7 of discriminating a type of the defect positioned in the coordinates specified in the first inspection step S6.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for manufacturing a glass plate, which comprises a step of inspecting the presence or absence of defects contained in the molded glass plate during transportation.

As is well known, various glass plates such as glass plates for flat panel displays (FPDs) such as liquid crystal displays and electroluminescence displays are made by molding molten glass melted in a melting furnace into a strip-shaped glass ribbon. It is manufactured by cutting the glass ribbon to a predetermined size after it has been sufficiently cooled. Here, in addition to the float method, a down draw method such as an overflow down draw method (fusion method) or a slot down draw method is generally used for forming the glass ribbon.

In the down draw method, the glass ribbon is formed in a vertical position. From the viewpoint of space saving of manufacturing equipment, the cutting process, selvage cutting process, transport process, inspection process, and packing process are performed in the vertical posture for the purpose of omitting the process of changing the posture of the glass plate. There is.

However, when the glass plate is transported in a vertical posture, the glass plate is liable to shake because the upper end is suspended and supported for transportation. If the inspection is performed in this state, the portion displaced in the plate thickness direction due to shaking tends to be out of focus, and it is difficult to perform an accurate inspection. Examples of the inspection process for solving this problem include those disclosed in Patent Document 1. In the inspection process disclosed in the same document, the upper and lower parts of the glass plate in the vertical posture are sandwiched and a tensile force is applied in the vertical direction to suppress the amplitude of the shaking and prevent the inspected part from being out of focus. There is.

By the way, typical defects of the glass plate include foam defects and foreign matter defects (for example, exfoliated matter from a refractory or the like), and the influence on the quality of the glass plate differs between the foam defects and the foreign matter defects. Therefore, the permissible size of bubble defects and the permissible size of foreign matter defects are different, and even if the defects have the same size, the pass / fail criteria differ depending on the type of defect. Further, by feeding back the information on the type of defect to the upstream process such as the melting process and the molding process, it is possible to reduce the defect and improve the yield. Therefore, it is necessary to distinguish between foam defects and foreign matter defects. Examples of the inspection method for that purpose include those disclosed in Patent Document 2. In the inspection process disclosed in the same document, the bright-field optical system and the dark-field optical system are combined to identify the coordinates of the defect, an image of the defect is imaged, and the type of the defect is identified based on the image of the image of the defect. ing.

Japanese Unexamined Patent Publication No. 2009-2367771 Japanese Unexamined Patent Publication No. 2018-112411

However, in the conventional inspection method described in Patent Document 2, since the coordinates of the defect and the type of the defect are specified at the same time, it is difficult to image the defect of the glass plate with high accuracy and accurately identify the type. ..

The technical subject of the present invention is to accurately identify the types of defects in a vertically oriented glass plate.

The present invention, which was devised to solve the above problems, comprises a molding process of forming a glass ribbon by a down-draw method, a cutting process of cutting a glass plate by cutting the molded glass ribbon at a predetermined length, and a cutting process of cutting out a glass plate. A method for manufacturing a glass plate, comprising a transporting step of transporting the cut out glass plate in a vertical position in parallel with the main surface of the glass plate, and an inspection step of inspecting the glass plate during the transporting step. In the inspection step, a first inspection step of specifying the coordinates of the defect of the glass plate and a second inspection step of identifying the type of the defect located at the coordinates specified in the first inspection step are performed. It is characterized by being prepared. According to such a configuration, by separating the identification of the coordinates of the defect and the identification of the type of the defect into separate steps, it is possible to accurately identify the type of the defect with respect to the glass plate conveyed in the vertical posture.

In the above configuration, it is preferable that the upper portion and the lower portion of the glass plate are sandwiched in the inspection step. According to such a configuration, the amplitude of the shaking of the glass plate can be suppressed to be small, and the glass plate can be inspected accurately.

In the above configuration, it is preferable that the holding mechanism for holding the glass plate applies a tensile force to the glass plate in the vertical direction and the width direction. According to such a configuration, the amplitude of the shaking of the glass plate can be suppressed to be smaller, and the glass plate can be inspected more accurately.

In the above configuration, it is preferable that the first inspection step includes a linear light source along the vertical direction and a line sensor camera. According to such a configuration, the entire main surface of the glass plate can be imaged by passing the linear light source and the line sensor camera once through the glass plate, so that the coordinates of the defects of the entire main surface of the glass plate can be quickly obtained. Can be identified.

In the above configuration, the second inspection step has an imaging system, and the imaging system includes a light source unit that irradiates the glass plate with inspection light and the defect located at the coordinates specified in the first inspection step. It is preferable to have a microscopic optical unit that magnifies the image of the above and an image pickup unit that captures the magnified image of the defect. According to such a configuration, the image of the defect can be imaged at an appropriate magnification, and the defect can be directly magnified and visually observed, so that the type of the defect can be identified more accurately.

In the above configuration, it is preferable to drive the imaging system in the vertical direction and the width direction of the glass plate. With such a configuration, the imaging system can be easily moved to the coordinates of the defect identified in the first inspection step.

In the above configuration, in the transfer step, the glass plate is carried in to the second inspection step and the glass plate is carried out from the second inspection step, and the glass plate is carried out to the second inspection step. It is preferable to keep the imaging system on standby below the lower end of the glass plate during the loading and unloading of the glass plate from the second inspection step. Generally, when the magnification of the imaging system is increased, the focal length of the imaging system becomes shorter. Therefore, it is necessary to make the distance between the image pickup system and the glass plate closer than that of the conventional inspection method, and there is a possibility that the glass plate and the image pickup system collide with each other during the transportation of the glass plate. By making the image pickup system stand by below the lower end of the glass plate, it is possible to prevent the glass plate from colliding with the image pickup system during loading into the second inspection process and during removal from the second inspection step.

In the above configuration, the image pickup system is placed in the width direction below the lower end of the glass plate during the loading of the glass plate into the second inspection step and the loading of the glass plate from the second inspection step. It is preferable to make it stand by in the substantially central part of the above. According to such a configuration, the collision between the image pickup system and the glass plate is prevented, and the moving distance of the image pickup system from the standby position to the coordinates of the defect specified in the first inspection step is shortened, so that the second inspection step It can reduce the time required for.

In the above configuration, in the first inspection step, the coordinates of the defect with respect to the end face of the glass plate are recorded, and in the second inspection step, the end face of the glass plate is detected by using the position detecting means. It is preferable to move the imaging system to a coordinate position with respect to the end face. Due to mechanical errors in the transport process, the glass plates carried into the second inspection process do not always stop at the same position. When the reference of the coordinates of the second inspection step is constant regardless of the stop position of the glass plate, if the variation of the stop position of the glass plate is large, the defect to be imaged is out of the field of view of the imaging system and cannot be imaged. The type may not be identifiable. By detecting the position of the end face of the glass plate in the second inspection step and using it as a reference for the coordinates, the imaging system can be moved to a position where the defect can be accommodated in the field of view.

In the above configuration, the inspection step further includes a third inspection step in which the inspector visually inspects the appearance of the glass plate, and the third inspection step is performed in parallel with the second inspection step. Is preferable. By carrying out the second inspection step and the third inspection step in parallel, the inspection time and the inspection space can be shortened as compared with the case where the second inspection step and the third inspection step are carried out individually.

In the above configuration, in the inspection step, the upper region in the vertical direction of the glass plate is inspected in the third inspection step, the lower region is inspected in the second inspection step, and the third inspection step It is preferable that the area to be inspected in the second inspection step is wider than the area to be inspected. Defects in the glass plate occur continuously along the flow direction in the molding process, that is, the vertical direction. By dividing the area to be inspected in the second inspection step and the third inspection step into upper and lower parts, the entire range can be inspected in the width direction in each inspection step, and the distribution of defects in the width direction can be obtained. In addition, the glass plate is suspended, supported and transported from above in a vertical position, but by setting the area to be inspected in the second inspection process to the lower side of the glass plate, equipment for carrying out the second inspection process and equipment for carrying out the second inspection process, It is possible to prevent the interference of the equipment for transporting the glass plate. In addition, the third inspection step is to inspect the appearance of the glass plate such as pulse and uneven thickness, and it is not necessary to inspect a wide area. By making the area to be inspected in the second inspection step wider than the area to be inspected in the third inspection step, it is possible to specify as many types of defects whose coordinates are specified in the first inspection step as possible.

In the above configuration, it is preferable that the second inspection step excludes the region to be inspected in the third inspection step. Defects in the glass plate occur continuously along the vertical direction. Therefore, it is not necessary to inspect the entire range in the vertical direction, but it is sufficient to inspect the entire range in the width direction. According to such a configuration, the time required for the second inspection step and the third inspection step can be shortened.

In the above configuration, it is preferable that the number of the defects identified in the second inspection step is smaller than the number of the coordinates of the defects specified in the first inspection step. The first inspection step can be inspected in a time required to pass the line sensor camera once through the glass plate. On the other hand, in the second inspection step, since the imaging system is driven for the coordinates of the defects specified in the first inspection step and the image is taken, the number of defects whose coordinates are specified in the first inspection step is larger than a certain number. In that case, the inspection time of the second inspection step is longer than that of the first inspection step. Therefore, the number of defects imaged in the second inspection step is limited to a certain number or less. With such a configuration, it is possible to prevent the time required for the inspection process from becoming longer than necessary.

According to the present invention as described above, the types of defects in the vertically oriented glass plate can be accurately identified.

It is a schematic diagram of the manufacturing method of a glass plate. It is a schematic diagram of a molding process and a slow cooling process. It is a schematic diagram of a cutting process. It is a schematic diagram of a transport process. It is a schematic diagram of the selvage cutting process. It is a schematic diagram of the 1st inspection process. It is a schematic diagram of a bright-field inspection machine and a dark-field inspection machine. It is a schematic diagram of the 2nd inspection process. It is a schematic diagram of an imaging system. It is a schematic diagram of the 3rd inspection process.

An embodiment of the method for manufacturing a glass plate according to the present invention will be described.

FIG. 1 shows an embodiment of a method for manufacturing a glass plate according to the present invention. The glass plate manufacturing apparatus 1 includes a molding step S1 in which the molten glass Gm is stretched downward X to form a strip-shaped glass ribbon Gr, and a slow cooling step S2 in which the glass ribbon Gr formed in the molding step S1 is slowly cooled. A cutting step S3 for cutting the glass ribbon Gr slowly cooled in the slow cooling step S2 to a predetermined size to obtain a glass plate G, and a transporting step for transporting the cut glass plate G in a vertical posture in the width direction Y. S4, an ear cutting step S5 for removing thick portions (ears) formed at both ends in the width direction Y, and a first inspection step S6 for inspecting the glass plate G obtained in the ear cutting step S5. The second inspection step S7, the third inspection step S8, and the packing step S9 for packing the glass plate G that has passed the inspection are provided.

In the molding step S1, the glass ribbon Gr is molded from the molten glass Gm melted in a melting furnace (not shown) using the overflow downdraw method. Specifically, as shown in FIG. 2, the molded body 21 is arranged in the molded body 2, and the molten glass Gm overflowing from the top 211 of the molded body 21 having a wedge-shaped cross section on both sides is formed on the outer surface portion of the molded body 21. The glass ribbon Gr is molded by fusing and integrating at the lower end portion 213 of the molded body while flowing down along the 212. In this case, the molten glass Gm (or glass ribbon Gr) is guided by the edge roller 22 and stretched downward X. The molding step S1 is not limited to the one using the overflow down draw method, and for example, another down draw method such as a slot down draw method or a redraw method, or a float method may be used.

In the slow cooling step S2, the glass ribbon Gr is slowly cooled. The slow cooling furnace is provided with a predetermined temperature gradient in the internal space toward the downward X. As shown in FIG. 2, the glass ribbon Gr continuous with the molded body 21 is guided by the annealing roller 31 arranged in the slow cooling unit 3, and moves downward X in the internal space of the slow cooling furnace as it moves downward. It is slowly cooled so that the temperature becomes low. Along with this, the internal strain of the glass ribbon Gr is removed.

In the cutting step S3, the glass ribbon Gr is cut to a predetermined length. As shown in FIG. 3, the cutout portion 4 includes an arm 41, and first, both ends of the glass ribbon Gr in the width direction Y are sandwiched by chucks 42 attached to the arm 41. Next, with the support bar 44 supporting the glass ribbon Gr from the back surface, the wheel cutter 43 is run along the width direction Y of the glass ribbon Gr along the planned cutting line of one main surface of the glass ribbon Gr. The ribbon line 46 is formed. After that, the arm 41 rotates around the fulcrum bar 45 and applies bending stress along the scribe line 46 to cut (cut) the glass ribbon Gr along the scribe line 46. As a result, a glass plate G having a predetermined length can be obtained from the glass ribbon Gr. In the present embodiment, in the cutting step S3, the glass ribbon Gr is cut in a vertical posture (for example, a vertical posture), and the obtained glass plate G is conveyed in the vertical posture in the transport step S4. The cutting method of the glass ribbon Gr is not limited to cutting by bending stress, and may be, for example, laser cutting or laser fusing.

In the transport step S4, the glass plate G produced in the cutting step S3 is transported to each step after the selvage cutting step S5 in a vertical posture. As shown in FIG. 4, the transport unit 5 includes an upper holding mechanism 51, an upper guide rail 52, and a moving body 53. The upper holding mechanism 51 holds the upper portion of the glass plate G in the vertical posture, and then the moving body 53 moves along the upper guide rail 52 extending in the width direction Y of the glass plate G to convey the glass plate G.

In the selvage cutting step S5, both ends (ears) of the glass plate G in the width direction Y are cut. Both ends of the glass plate G in the width direction Y may be relatively thicker than the central portion in the width direction Y, and both ends thereof are called selvage portions. As shown in FIG. 5, the selvage cutting portion 6 includes a holding portion 61, a wheel cutter 62, and a support bar 63 in the first station ST1. The glass plate G transported to the first station ST1 by the transport step S4 is delivered to the sandwiching portion 61, and the upper portion is suspended and supported in a vertical posture. The wheel cutter 62 forms a scribe line 67 along the upward direction X of the glass plate G in a state of being supported by the support bar 63 from the back surface of the glass plate G. After that, the glass plate G is delivered to the upper holding mechanism 51 in the transport step S4 and is transported to the second station ST2. The second station ST2 includes a holding portion 64, a pressing portion 65, and a support bar 66. The glass plate G transported to the second station ST2 by the transport step S4 is delivered to the holding portion 64, and the upper portion is suspended and supported in a vertical posture. The pressing portion 65 bends the glass plate G with the support bar 66 as a fulcrum by pushing the selvage portion 68 toward the back surface side. As a result, bending stress is applied to the scribe line 67 and its vicinity, and the glass plate G is cut in the upward direction X along the scribe line 67. The glass plate G from which the selvage portion 68 has been removed is transported to the inspection step by the transport step S4.

The inspection steps include a first inspection step S6 for specifying the coordinates of defects in the glass plate G, a second inspection step S7 for specifying the type of defects in the glass plate G, and defects and first inspections that regularly appear in the flow direction. It has a third inspection step S8 for inspecting defects that cannot be detected in the inspection step S6 and the second inspection step S7. Hereinafter, the first inspection step S6, the second inspection step S7, and the third inspection step S8 will be described in detail.

In the first inspection step S6, as shown in FIG. 6, a first inspection device 7 including a support mechanism 71, a bright field inspection machine 72, and a dark field inspection machine 73 is used. The glass plate G transported to the first inspection step S6 by the transport step S4 is delivered to the support mechanism 71. Specifically, the upper holding mechanism 711 sandwiches the upper part of the glass plate G, and the lower holding mechanism 712 holds the lower part of the glass plate G, respectively. As a result, the amplitude of the shaking of the glass plate G during inspection can be suppressed to a small value, and the coordinates of the defect can be accurately specified.

The chucks constituting the upper pinching mechanism 711 and the lower pinching mechanism 712 are connected to the air cylinder 713, respectively. The air cylinder 713 can send compressed air from an air supply device (for example, an air compressor) (not shown), and sucks the air remaining in the air cylinder 713 by an air suction device (for example, a vacuum pump) (not shown). It is possible to discharge. Then, the air pressure in the air cylinder 713 is adjusted by the air supply device and the air suction device, and a predetermined force is applied by moving the piston contained in the cylinder by the pressure. The upper downstream chuck group 7111 is upward and downstream, the upper upstream chuck group 7112 is upward and upstream, the lower downstream chuck group 7121 is downward and downstream, and the lower upstream chuck group 7122 is downward. By moving in the direction and upstream, a tensile force is applied to the glass plate. That is, the glass plate G is subjected to tensile force in the vertical direction X and the width direction Y. As a result, the amplitude of the shaking of the glass plate G can be suppressed to be smaller, and the coordinates of the defect can be specified more accurately.

After the tensile force is applied to the glass plate G, as shown in FIG. 7, the main surface of the glass plate G is imaged by using the first inspection device 7 provided with the bright field inspection machine 72 and the dark field inspection machine 73. .. The bright field inspection machine 72 includes a bright field light source 721 and a bright field camera 722. The bright-field camera 722 is arranged on the optical axis of the bright-field light source 721 so that the light emitted from the bright-field light source 721 to the glass plate G and transmitted through the glass plate G can be captured. A light-shielding plate 723 that forms a bright part and a dark part in the field of view of the bright-field camera 722 is installed between the glass plate G and the bright-field camera 722. The dark field inspection machine 73 includes a dark field light source 731 and a dark field camera 732, and the dark field camera 732 can capture the light scattered by the defect of the glass plate G by irradiating the glass plate G from the dark field light source 731. As such, it is arranged at a position off the optical axis of the dark field light source 731. Further, a plurality of bright-field light sources 721 and dark-field light sources 731 are arranged along the vertical direction X of the glass plate G to form a linear light source. Further, a plurality of bright-field cameras 722 and dark-field cameras 732 are similarly arranged along the vertical direction X to form line sensor cameras, respectively. As a result, the entire main surface of the glass plate G can be imaged by passing the linear light source and the line sensor camera once through the glass plate G, so that the coordinates of the defects of the entire main surface of the glass plate G can be quickly identified. .. As shown in FIG. 7, the bright-field light source 721 and the dark-field light source 731 may be unitized so that the imaging position of the bright-field inspection machine 72 and the imaging position of the dark-field inspection machine 73 on the glass plate G match. .. In that case, a beam splitter 74 is installed between the glass plate G and the light-shielding plate 723 using a dark-field light source 731 having a wavelength different from that of the bright-field light source 721, and the light and the dark-field camera imaged by the bright-field camera 722. The light imaged by the 732 is separated. Further, the bright field light source 721 and the dark field light source 731 may not be unitized, and the optical paths of the bright field inspection machine 72 and the dark field inspection machine 73 may be made independent. In this embodiment, the LED light source is used as the bright field light source 721 and the dark field light source 731, but a metal halide lamp or a laser light source may be used.

The bright field inspection machine 72 and the dark field inspection machine 73 can be integrally moved in the width direction Y of the glass plate G. While moving in the width direction Y of the glass plate G, the entire main surface of the glass plate G is imaged. By comparing the obtained bright-field image and dark-field image, the presence or absence of defects is identified, and the coordinates are recorded in a database (not shown). The reference of the coordinates is the upper end and the downstream end face of the glass plate G.

After the completion of the first inspection step S6, the glass plate G is handed over to the upper holding mechanism 51 of the transporting step S4, and then is transported to the second inspection step S7.

In the second inspection step S7, as shown in FIG. 8, a second inspection device 8 including a support mechanism 81, an image pickup system 82, and an image pickup system drive mechanism 83 is used. The glass plate G transported to the second inspection step S7 by the transport step S4 is delivered to the support mechanism 81. Specifically, the upper holding mechanism 811 holds the upper part of the glass plate G, and the lower holding mechanism 812 holds the lower part of the glass plate G, respectively.

The chucks constituting the upper pinching mechanism 811 and the lower pinching mechanism 812 are connected to the air cylinder 813, respectively. Like the air cylinder 713, the air cylinder 813 is connected to an air supply device and an air suction device (not shown) to apply a predetermined force. The upper downstream chuck group 8111 is in the upward and downstream sides, the upper upstream chuck group 8112 is in the upward and upstream sides, the lower downstream chuck group 8121 is in the downward and downstream sides, and the lower upstream chuck group 8122 is in the lower direction. A tensile force is applied to the vertical direction X and the width direction Y of the glass plate G on the direction and the upstream side. The tensile force is preferably 120 N or more.

With the upper pinching mechanism 811 and the lower pinching mechanism 812 sandwiching the glass plate G, the position detecting means 84 is used to detect and record the positions of the upper end surface and the downstream end surface of the glass plate G. As the position detecting means 84, for example, a transmission type laser sensor or the like can be used. As a result, the imaging system can be moved to a position where defects can be accommodated in the field of view of the imaging unit 823.

As shown in FIG. 9, the image pickup system 82 includes a light source unit 821, a microscopic optical unit 822, and an image pickup unit 823. The light source unit 821 irradiates the glass plate G with inspection light, magnifies the image of the defect of the glass plate G by the microscopic optical unit 822, and images the image on the image pickup unit 823. The image of the defect includes an image in which the inspection light is reflected by the defect and an image in which the light reflected by the back surface of the glass plate G is blocked by the defect. In the present embodiment, the LED light source is used as the light source unit 821, but a metal halide lamp or a laser light source may be used.

The image pickup system 82 is attached to the vertical drive mechanism 832, and the vertical drive mechanism 832 is attached to the width direction drive mechanism 831. The vertical drive mechanism 832 and the width direction drive mechanism 831 are provided with a servomotor, a linear motion guide, and a ball screw, and are driven in the vertical direction X and the width direction Y, respectively. As a result, the image pickup system 82 can move to an arbitrary position in the region to be inspected in the second inspection step S7 of the glass plate G and take an image. The driving method of the vertical drive mechanism 832 and the width direction drive mechanism 831 is not limited to the ball screw, and a timing belt, a chain, or the like may be used. Further, a linear motor may be used as an alternative to the servo motor and the ball screw.

When the glass plate G is carried into the second inspection step S7 in the transport step S4, it is preferable that the image pickup system 82 stands by in the region A below the lower end of the glass plate G shown in FIG. As a result, it is possible to prevent the glass plate G from coming into contact with the image pickup system 82 even if the glass plate G is greatly shaken during delivery to the second inspection step S7. Further, the imaging system 82 stands by in the region B at the substantially central portion in the width direction Y of the glass plate G, so that the coordinates of the defect identified in the first inspection step S6 are located on the upstream side or the downstream side of the farthest upper side. Even if there is, the distance traveled to the coordinates of the defect can be shortened. When the glass plate G is carried out from the second inspection step S7, it is preferable to make the image pickup system 82 stand by in the area A or the area B as in the case of carrying in the glass plate G.

After the glass plate G is sandwiched by the upper sandwiching mechanism 811 and the lower sandwiching mechanism 812, the imaging system 82 is moved to the coordinates of the defect specified in the first inspection step S6. The reference of the coordinates is the upper end surface and the downstream end surface of the glass plate G detected by the position detecting means 84. When the image pickup system 82 moves from the area A or the area B to the coordinates of the defect, the image pickup system 82 passes between the lower downstream side chuck group 8121 and the lower upstream side chuck group 8122. The number of coordinates to be imaged is limited to a predetermined number or less so that the time required for the second inspection step S7 is within the transport tact time. After imaging the defect at the coordinates to be imaged, the imaging system 82 passes between the lower downstream side chuck group 8121 and the lower upstream side chuck group 8122 again, moves to the area A or the area B, and stands by.

The type of defect is specified based on the image of the defect imaged in the second inspection step S7. The type of the identified defect is associated with the information on the number and coordinates of the defect identified in the first inspection step S6, and is stored in a database (not shown).

As shown in FIG. 10, in the third inspection step S8, the third inspection apparatus 9 provided with the third inspection table 91, the third inspection light source 92, and the light source cover 93 is used. In the third inspection step S8, the inspector stands on the third inspection table 91 at a predetermined height and cannot find the veins and uneven thickness of the glass plate G in the first inspection step S6 and the second inspection step S7. Visually detect defects and defects that appear regularly in the flow direction. By irradiating the end face of the glass plate G with the inspection light from the third inspection light source 92, the visibility of defects such as pulse and uneven thickness is improved and the detection is facilitated. Further, by covering the end faces of the third inspection light source 92 and the glass plate G with the openable light source cover 93, the light that did not enter the end face of the glass plate G is shielded, and the workability of the inspector is improved. .. Since the light source cover 93 is opened and closed by the toggle mechanism, the glass plate G can be strongly sandwiched and light can be shielded more effectively. In the present embodiment, the LED light source is used as the third inspection light source 92, but a metal halide lamp, a laser light source, or the like may be used.

The third inspection device 9 is arranged at a position common to the second inspection device 8 so that the second inspection step S7 and the third inspection step S8 can be performed in parallel. This makes it possible to shorten the time required for the inspection process and save space. Further, the lower region C in the vertical direction X of the glass plate G is inspected in the second inspection step S7, and the upper region D narrower than the region C is inspected in the third inspection step S8. Defects in the glass plate G occur continuously along the flow direction in the molding process, that is, the vertical direction X. By dividing the area to be inspected by the glass plate G into the lower area C and the upper area D, the entire range can be inspected in the width direction Y in each inspection process, and defects in the width direction Y can be inspected. Distribution is obtained. Further, in the transport step S4, the glass plate G is suspended, supported and transported from above in a vertical posture, but by setting the region to be inspected in the second inspection step S7 to the lower side of the glass plate G, the second inspection step It is possible to prevent interference between the equipment for carrying out S7 and the transport unit 5. Further, the third inspection step S8 inspects the appearance of the glass plate G such as the veins and uneven thickness, and it is not necessary to inspect a wide area. By making the area C wider than the area D, it is possible to specify as many types of defects whose coordinates are specified in the first inspection step S6 as possible. As a result, the time required for the second inspection step S7 and the third inspection step S8 can be shortened.

Further, it is preferable to reduce the number of defects identified in the second inspection step S7 to be smaller than the number of coordinates of the defects specified in the first inspection step S6. The first inspection step S6 can be inspected in a time required only once the line sensor camera is passed through the glass plate G. On the other hand, in the second inspection step S7, the imaging system 82 is driven for the coordinates of the defects specified in the first inspection step S6 to take an image, so that the number of defects whose coordinates are specified in the first inspection step S6 is increased. When it is more than a certain number, the inspection time of the second inspection step S7 is longer than that of the first inspection step S6. Therefore, the number of defects imaged in the second inspection step S7 is limited to a certain number or less. With such a configuration, it is possible to prevent the time required for the second inspection step S7 from becoming longer than necessary.

The inspection result of the glass plate G is determined based on the results of the first inspection step S6, the second inspection step S7, and the third inspection step S8.

After the completion of the second inspection step S7 and the third inspection step S8, the glass plate G is handed over to the upper holding mechanism 51 of the transfer step S4. If the inspection is passed, the glass plate G is transported to the packing process S9, and if the inspection is not passed, the glass plate G is disposed of at a disposal location (not shown).

According to the glass plate manufacturing apparatus 1 according to the present embodiment configured as described above, regarding the glass plate G conveyed in the vertical posture by dividing the identification of the coordinates of the defect and the identification of the type of the defect into separate steps. , The type of defect can be identified accurately.

The present invention is not limited to the configuration of the above embodiment, and is not limited to the above-mentioned action and effect. The present invention can be modified in various ways without departing from the gist of the present invention.

In the above embodiment, in the first inspection step S6 and the second inspection step S7, the upper part and the lower part of the glass plate G are sandwiched and tensile force is applied in the vertical direction X and the width direction Y, but the present invention is limited to this. Not done. It is not always necessary to apply a tensile force to the glass plate G, and the lower portion of the glass plate G may not be sandwiched but only the upper portion may be sandwiched.

In the above embodiment, in the first inspection step S6, the bright field inspection machine 72 and the dark field inspection machine 73 specify the coordinates of the defect by using the light transmitted through the glass plate G, but the present invention is not limited to this. A method of specifying the coordinates of the defect by using the light reflected from the glass plate G may also be used.

In the above embodiment, in the first inspection step S6, the glass plate G is passed through the line sensor camera for inspection, but the inspection is not limited to this. The line sensor camera may be fixed and the glass plate G may be relatively moved to take an image of the entire glass plate.

In the above embodiment, in the second inspection step S7, the image pickup system 82 uses the light reflected by the glass plate G to image the defect, but the present invention is not limited to this. A method of imaging defects using light transmitted through the glass plate G may also be used.

In the above embodiment, in the second inspection step S7, the image pickup system 82 is made to stand by in the area A or the area B when the glass plate G is carried in or out, but the present invention is not limited to this. The image pickup system 82 may move in the direction perpendicular to the surface of the glass plate and stand by when the glass plate G is carried in or out.

In the above embodiment, the third inspection device 9 is arranged on the upper part of the second inspection device 8, and the second inspection step and the third inspection step are performed in parallel, but the present invention is not limited to this. The third inspection device 9 may be arranged on the downstream side of the second inspection device 8, and the third inspection step S8 may be carried out after the completion of the second inspection step S7. Further, the entire surface of the glass plate G may be inspected in the second inspection step S7 and the third inspection step S8, or the third inspection step may be omitted.

INDUSTRIAL APPLICABILITY The present invention can be suitably used for manufacturing a glass plate including a step of inspecting the presence or absence of defects contained in the molded glass plate during transportation.

S1 Molding process S2 Slow cooling process S3 Cutting process S4 Transport process S5 Ear cutting process S6 First inspection process S7 Second inspection process S8 Third inspection process S9 Packing process 1 Glass plate manufacturing device 7 First inspection device 71 Support mechanism 72 Bright-field inspection machine 73 Dark-field inspection machine 8 Second inspection device 81 Support mechanism 82 Imaging system 821 Light source unit 822 Microscopic optical unit 823 Imaging unit 84 Position detection means 9 Third inspection device G Glass plate Gr Glass ribbon

Claims (13)

A molding process of forming a glass ribbon by the down draw method, a cutting process of cutting out a glass plate by cutting the molded glass ribbon at a predetermined length, and a glass plate of the cut out glass plate in a vertical position. A method for manufacturing a glass plate, comprising a transporting step of transporting the glass plate in parallel with the main surface of the glass plate and an inspection step of inspecting the glass plate during the transporting step.
The inspection step includes a first inspection step of specifying the coordinates of the defect of the glass plate and a second inspection step of identifying the type of the defect located at the coordinates specified in the first inspection step. A method for manufacturing a glass plate. The method for manufacturing a glass plate according to claim 1, wherein in the inspection step, the upper portion and the lower portion of the glass plate are sandwiched. The method for manufacturing a glass plate according to claim 2, wherein the holding mechanism for holding the glass plate applies a tensile force to the glass plate in the vertical direction and the width direction. The method for manufacturing a glass plate according to any one of claims 1 to 3, wherein the first inspection step includes a linear light source along the vertical direction and a line sensor camera. The second inspection step has an imaging system and has an imaging system.
The imaging system includes a light source unit that irradiates the glass plate with inspection light, a microscopic optical unit that magnifies an image of the defect located at coordinates specified in the first inspection step, and an enlarged image of the defect. The method for manufacturing a glass plate according to any one of claims 1 to 4, wherein the image pickup unit is provided with an image pickup unit. The method for manufacturing a glass plate according to claim 5, wherein the imaging system is driven in the vertical direction and the width direction of the glass plate. In the transfer step, the glass plate is carried into the second inspection step and the glass plate is carried out from the second inspection step.
During the loading of the glass plate into the second inspection step and the loading of the glass plate from the second inspection step, the imaging system is kept on standby below the lower end of the glass plate. The method for manufacturing a glass plate according to any one of claims 5 or 6. During the loading of the glass plate into the second inspection step and the loading of the glass plate from the second inspection step, the imaging system is placed in a substantially central portion in the width direction below the lower end of the glass plate. The method for manufacturing a glass plate according to claim 7, wherein the glass plate is kept on standby. In the first inspection step, the coordinates of the defect with respect to the end face of the glass plate are recorded.
The second inspection step is any one of claims 5 to 8, wherein the end face of the glass plate is detected by using a position detecting means, and the image pickup system is moved to a coordinate position with respect to the end face. The method for manufacturing a glass plate according to. The inspection step further includes a third inspection step in which the inspector visually inspects the appearance of the glass plate.
The method for manufacturing a glass plate according to any one of claims 1 to 9, wherein the third inspection step is performed in parallel with the second inspection step. In the inspection step, the upper region in the vertical direction of the glass plate is inspected in the third inspection step, and the lower region is inspected in the second inspection step.
The method for manufacturing a glass plate according to claim 10, wherein the area to be inspected in the second inspection step is wider than the area to be inspected in the third inspection step. The method for manufacturing a glass plate according to claim 11, wherein the second inspection step excludes a region to be inspected in the third inspection step. The glass according to any one of claims 1 to 12, wherein the number of the defects identified in the second inspection step is smaller than the number of coordinates of the defects specified in the first inspection step. How to make a board.

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