CN113182998B

CN113182998B - Method and apparatus for manufacturing display glass plate

Info

Publication number: CN113182998B
Application number: CN202110360092.4A
Authority: CN
Inventors: 菅山胜美; 铃木聪; 中野笃史
Original assignee: Asahi Glass Co Ltd
Current assignee: AGC Inc
Priority date: 2018-01-31
Filing date: 2018-01-31
Publication date: 2024-03-22
Anticipated expiration: 2038-01-31
Also published as: CN108296982A; CN108296982B; CN117817547A; CN117697620A; CN113182998A

Abstract

The main object of the present invention is to provide a method and an apparatus for efficiently producing a glass plate for display use. The method for manufacturing the polished glass plate for display is characterized in that a plurality of glass plates are conveyed on a conveying path arranged along a first direction, the plurality of glass plates on the conveying path are respectively supplied to a plurality of polishing machines arranged in parallel with the conveying path, the plurality of glass plates are respectively polished by any one of the plurality of polishing machines, and the plurality of glass plates polished by any one of the plurality of polishing machines are respectively recovered to the conveying path.

Description

Method and apparatus for manufacturing display glass plate

The present application is a divisional application of application number 201810094236.4, entitled "method and apparatus for manufacturing a display ground glass sheet", having application number 2018, 1, 31.

Technical Field

The present invention relates to a method and an apparatus for manufacturing a display glass plate.

Background

In a display glass plate used for applications such as a liquid crystal display, fine irregularities or undulations on the surface thereof cause deformation of an image, and therefore, the fine irregularities or undulations are removed by polishing.

Conventionally, a method called continuous polishing has been typically used as a polishing method (patent document 1). The continuous polishing is a technique in which a plurality of polishing machines are provided along a conveying path, and polishing is performed stepwise from an upstream side to a downstream side using all the polishing machines.

[ Prior Art literature ]

[ patent literature ]

[ patent document 1 ] Japanese patent application laid-open No. 2015-98075

Disclosure of Invention

Problems to be solved by the invention

However, the conventional continuous polishing has the following problems because the polishing machine is provided in-line with respect to the conveying path.

For example, if breakage of the glass sheet occurs in 1 of the plurality of grinders, if the broken glass sheet is not completely removed from the conveying path, the quality of the subsequent glass sheet is degraded, and therefore the conveying path has to be completely stopped until the removal operation is completed. And therefore poor efficiency.

In view of such a background, a main object of the present invention is to provide a method and an apparatus for efficiently producing a display glass plate.

Means for solving the problems

In order to achieve the above object, the present application provides a method for producing a glass sheet for display use, characterized by comprising the steps of,

On a conveying path arranged in a first direction, a plurality of glass sheets are conveyed,

the plurality of glass plates on the conveying path are respectively supplied to a plurality of grinders arranged in parallel with the conveying path,

grinding the plurality of glass sheets with any one of the plurality of grinders respectively,

and recovering the plurality of glass plates polished by any one of the plurality of grinders to the conveying path.

In order to achieve the above object, the present application provides an apparatus for producing a display glass sheet, comprising:

a conveying path configured to convey a plurality of glass sheets along a first direction;

a plurality of grinders disposed in parallel with the conveying path; and

And a plurality of transfer units for supplying and recovering the plurality of glass sheets from the conveyance path to and from any one of the plurality of grinders.

Effects of the invention

According to the present invention, a method and an apparatus for efficiently producing a display glass sheet can be provided.

Drawings

Fig. 1 is a plan view and a cross-sectional view of a manufacturing apparatus according to a first embodiment of the present invention.

Fig. 2 is a schematic diagram showing a flow of a manufacturing method according to a first embodiment of the present invention.

Fig. 3 is a time chart showing a manufacturing method according to the first embodiment of the present invention.

Fig. 4 is an enlarged view showing a first modification of the first embodiment of the present invention.

Description of the reference numerals

101. First direction

102. Conveying path

102A first region

102B second region

103. Grinding machine

103A first System

103B second System

103c first grinder

103d second grinder

103X first position

103Y second position

104. Back cushion

105. Reverse road

106. Transfer machine

110. Attachment area

111. Grinding zone

112. Separation zone

201. Spacing of

301. Intermediate transfer machine

G glass plate

a first glass plate group

b second glass plate group

A third glass plate group

B fourth glass plate group

a1 First glass plate

b2 Second glass plate

Detailed Description

Hereinafter, a method and an apparatus for manufacturing a display glass sheet according to an embodiment of the present invention will be described with reference to the drawings.

In the drawings for explaining the embodiments of the present invention, coordinates are defined by arrows in the drawings, and the coordinates are used as needed for explanation. In the present specification, the "X direction" refers not only to a direction from the root toward the tip of an arrow indicating an X coordinate, but also to a direction from the tip toward the root, which is 180 degrees inverted. The "Y direction" and "Z direction" also refer to not only the direction from the root toward the tip of the arrow representing the Y, Z coordinate, but also the direction from the tip toward the root, which is 180 degrees opposite. In this specification, the Y direction is also referred to as a first direction or a conveying direction. The tip side of the arrow in the Y direction is also referred to as the downstream or downstream side, and the root side of the arrow in the Y direction is also referred to as the upstream or upstream side. The front end side of the arrow in the Z direction is also referred to as the upper side or the upper side, and the root side of the arrow in the Z direction is also referred to as the lower side or the lower side.

In the drawings of the present specification, when the same structural units are continuous, reference numerals may be omitted to avoid complicating the drawings.

In the present specification, the term "transfer" is used in a generic sense including "supply" and "recovery" of glass sheets.

Fig. 1 is a plan view and a cross-sectional view of an apparatus for manufacturing a glass sheet for display use according to a first embodiment of the present invention. Fig. 2 is a schematic view showing a flow of a method for producing a display glass sheet according to a first embodiment of the present invention. Fig. 3 is a diagram showing a time chart of a method for producing a display glass sheet according to the first embodiment of the present invention.

First, an example of the basic structure of the manufacturing apparatus will be described with reference to fig. 1.

The first embodiment has a conveyance path 102 for conveying a plurality of glass sheets G, which is arranged along a first direction 101. A plurality of grinders 103 are provided in parallel with the conveyance path 102. The glass sheet conveying apparatus further includes a plurality of transfer machines 106 for supplying the plurality of glass sheets G from the conveying path 102 to any one of the plurality of grinding machines 103 and collecting the plurality of glass sheets G from any one of the plurality of grinding machines 103 to the conveying path 102.

Further, with the manufacturing apparatus according to the first embodiment, the plurality of glass sheets G on the conveyance path 102 are supplied to the plurality of grinders 103 arranged in parallel with the conveyance path 102, the plurality of glass sheets G are each ground by any one of the plurality of grinders 103, and the plurality of glass sheets G ground by any one of the plurality of grinders 103 are each collected in the conveyance path 102. With such a structure, the glass plate G can be polished effectively. That is, when abnormality occurs in the 1-stage polishing machine as in the conventional continuous polishing in-line, the influence of the 1-stage polishing machine does not affect the whole, and therefore the efficiency is high. Since a plurality of grinders are arranged in parallel with the conveyance path 102, even if, for example, a glass sheet breaks in one grinder 103, the removal operation and subsequent grinding and conveyance of the glass sheet can be performed in parallel.

Further, from the viewpoint of the quality of the glass sheet G, the following advantages are also provided.

That is, in the conventional continuous polishing in-line arrangement, after the completion of the removal operation of the broken glass sheet from the conveying path, the polishing machine other than the polishing machine in which the abnormality has occurred, which has to perform the recovery operation such as pad replacement in a work area different from the conveying path, is restarted. Since all conventional continuous polishing is performed stepwise from the upstream side to the downstream side, the glass plate is polished by 1 polishing machine less during the recovery operation of the polishing machine, and the quality may be deteriorated as compared with the normal state.

However, in the present embodiment, since each glass sheet G is originally polished by any one of the grinders 103, even if one of the 1 grinders is stopped, the glass sheets polished by the other grinders are not affected by the waves. That is, a glass sheet of stable quality can be produced.

In addition, any one of the above-mentioned plurality of grinders preferably grinds only one glass sheet in one movement of the grinder. This has the following advantages.

That is, there has been a polishing method for polishing a plurality of glass plates by using a 1-stage polishing machine. In this case, all the glass plates in the same polishing machine have substantially the same polishing conditions, and the polishing conditions cannot be adjusted according to the respective glass qualities.

However, if a structure in which only 1 glass plate is ground by using 1 grinder, various grinding conditions can be adjusted corresponding to the quality of 1 glass plate. Examples thereof include polishing time, polishing rate, polishing pressure, polishing liquid supply amount, platen angle, and the like. Accordingly, a higher quality glass sheet can be provided.

In addition, in the case of a polishing method in which a plurality of glass sheets are polished by a 1-stage polishing machine, jamming of the glass sheets tends to occur during placement and/or recovery, and efficiency is poor.

However, if a structure in which only 1 glass plate is ground by 1 grinder and there are a plurality of glass plates per unit, it is difficult to cause jamming of the glass plates, and efficient production can be performed.

It should be noted that if the size of the glass plate is small compared with the size of the polishing table of the polishing machine, a plurality of glass plates may be polished by 1 polishing machine.

In the present embodiment, the first direction 101 is shown as a straight line, but is not limited thereto. Or may be bent or curved.

The conveyance of the glass sheet may be performed by continuously operating the conveyance path 102 at ordinary times, or by so-called step feeding in which conveyance is stopped at a while.

The parallel connection means a connection method such as parallel connection of so-called circuits in which paths are branched to form a plurality of paths.

The supply means transferring the glass sheet from the conveyor to the grinder, and the recovery means transferring the glass sheet after polishing from the grinder to the conveyor.

In addition, the positions of the plurality of grinders 103 are preferably different from those on the conveying path 102. Since polishing is performed at a position different from the conveying path 102, even if abnormality occurs in 1 polishing machine, the conveying path 102 does not need to be stopped, and the efficiency is high.

Further, the plurality of grinders are preferably individually controllable. The 1 grinding machine which is abnormal may be stopped, and the other grinding machines may not be stopped, so that the efficiency is high. By "independently controllable" is meant that the grinding machine 103 is independently movable. That is, start and stop of the movement, adjustment of the movement speed, and the like can be set independently. Specifically, when the variation in flatness of the glass sheet G to be conveyed is large, each polishing machine can independently set polishing conditions according to the flatness of the glass sheet to be supplied. In addition, only 1 polishing apparatus can be operated differently from other polishing apparatuses at abnormal time or maintenance time. Flexible operation for improving efficiency can be performed.

Here, the abnormal condition refers to, for example, a case where glass is broken, a case where the grinder itself is broken, or the like.

In the present embodiment, the plurality of grinders 103 are constituted by a plurality of pairs of grinders facing each other through the conveyance path 102, and are provided in parallel with the conveyance path 102. Compared with a configuration in which the grinder 103 is provided only on one side, the conveyance path length can be set to about 1/2, and the conveyance time of the glass sheet can be suppressed, so that the efficiency is high. The present invention is not limited to this, and a plurality of grinders 103 may be arranged alternately with each other across the conveyance path 102.

In the present embodiment, the number of grinding machines 103 is 22 (11 pairs), but the present invention is not limited to this.

The flow of the method for producing a display glass sheet according to the first embodiment of the present invention will be described in detail below with reference to fig. 2 and 3. Along with the description using fig. 2, the reference numerals of fig. 1 will be described.

In fig. 2, the time passes are shown in the order of (1) to (6). Further, a longer time elapses between (5) and (6) than between the other numbers.

In each of the states (1) to (6), the conveyance path 102 is indicated by a dotted line in the center, and the direction of the arrow is set to the downstream side in the conveyance direction. The grinders 103 are disposed to face each other through the conveyance path 102. The plurality of grinders 103 disposed on one side of the conveyance path 102 among the plurality of grinders 103 are referred to as a first system 103A (a grinder set surrounded by a broken line on the upper side of the drawing), and the plurality of grinders 103 disposed on the opposite side of the first system 103A through the conveyance path 102 are referred to as a second system 103B (a grinder set surrounded by a broken line on the lower side of the drawing). In (2), (3), the position of the grinder of the first system 103A is represented as an area surrounded by a broken line.

Further, the grinder 103 located on the most upstream side with respect to the conveying direction of the conveying path 102 among the plurality of grinders 103 is set as the first grinder 103c. In the present embodiment, the grinders 103 are arranged to face each other, and therefore there are 2 grinders 103 located on the most upstream side, but any one of them may be used as the first grinder 103c. The region in which the plurality of grinders 103 are juxtaposed in the conveyance path 102 is also referred to as a grinding region 111.

In addition, a1 is referred to as a first glass plate, and b2 conveyed immediately after the first glass plate a1 is referred to as a second glass plate.

In (1), a plurality of adjacent glass plates having the first glass plate a1 as the last glass plate are set as the first glass plate group a. Namely, the glass plate group is arranged in a row from the first glass plate a1 to the right side of the paper surface. In (6), the adjacent glass plates having the second glass plate b2 as the forefront are set as the second glass plate group b. Namely, the glass plate group is arranged in a row from the second glass plate b2 to the left side of the paper surface. In (1), the glass sheet set polished by the first system 103A is set as a third glass sheet set a. In (1), the glass sheet set polished by the second system 103B is set as a fourth glass sheet set B. The number of glass sheets of each glass sheet group is in principle the same as the number of grinders belonging to a system. However, there is no limitation to the abnormality such as the case where the glass plate breaks halfway.

Hereinafter, a flow of polishing a glass plate will be specifically described with reference to fig. 2.

In fig. 2, in (1), a third glass sheet group a is ground by a first system 103A, a fourth glass sheet group B is ground by a second system 103B, the first glass sheet group a is conveyed to the vicinity of any one of the grinders 103, and a second glass sheet group B having a second glass sheet B2 as the forefront is conveyed immediately after the first glass sheet group a.

Then, in (2), the third glass plate group a after polishing is recovered in the conveying path 102. During this time, the second glass plate b2 is conveyed, filling the space 201 with the first glass plate a 1.

Then, in (3), the first glass plate group a is conveyed to a transfer preparation position where it is transferred to any one of the grinders 103. In the present embodiment, the transfer unit 106 for supplying and collecting is provided in front of the grinder 103 (fig. 1), and the first glass sheet group a can be supplied to the first system 103A in the state of (3).

At this time, the third glass plate group a collected into the conveying path 102 is conveyed to the same extent as the first glass plate group a.

Then, in (4), the first glass sheet group a is supplied to the first system 103A, and then the third glass sheet group a and the second glass sheet b2 are conveyed to the downstream side.

Then, in (5), the glass sheet (third glass sheet group a) on the conveyance path 102 is conveyed downstream, and the second glass sheet group b immediately following the second glass sheet b2 is conveyed. Here, as in (5) of fig. 2, the third glass plate group a that has been ground can be conveyed so as to narrow the interval between adjacent glass plates for rapid conveyance to the downstream side. That is, the conveyance path 102 narrows the interval between adjacent glass plates among the polished glass plates and conveys the glass plates. Thereby, the efficiency of the whole production can be improved.

Then, in (6), the second glass plate group b is conveyed to the vicinity of any one of the grinders 103. The second glass sheet b2 is conveyed to the vicinity of the grinder located at the most downstream side. In this application, a grinder that grinds the second glass plate b2 is set as the second grinder 103d. The second grinder 103d is located on the downstream side of the first grinder 103 c. In the present embodiment, the grinding machine is disposed at the most downstream side.

Then, the same movement as that of (1) and thereafter is performed on the second system 103B side. That is, the fourth glass plate group B after polishing is recovered to the conveying path 102, and during this period, a new next glass plate is conveyed, and the gap from the second glass plate B2 is filled.

Fig. 3 is an example of a time chart showing the operation of each glass sheet set described in fig. 2. The columns of the table show the operation of each glass plate group. The direction of the rows of the table from the top to the bottom indicates the passage of time. In each row, the same time is referred to. Further, "…" indicates that the glass sheet set proceeds to the next step in the next polishing zone. Fig. 2 (1) to (6) correspond to the first row to the sixth row of fig. 3.

As described above, in the present embodiment, the following configuration is preferable. That is, when the grinder located on the most upstream side in the conveyance direction of the conveyance path 102 among the plurality of grinders 103 is the first grinder 103c, the glass plate G ground by the first grinder 103c among the plurality of glass plates G is the first glass plate a1, and the glass plate conveyed immediately after the first glass plate a1 among the plurality of glass plates G is the second glass plate b2, it is preferable that the conveyance path 102 conveys the second glass plate b2 downstream in the conveyance direction than the first glass plate a1 when the first glass plate a1 is in any state of being fed, being ground, or being recovered.

Thus, the second glass sheet b2 can be conveyed downstream during the supply, polishing, or recovery of the first glass sheet a 1. That is, since the subsequent glass sheet is conveyed downstream beyond the preceding glass sheet during the time taken for the preceding glass sheet, the time taken for conveyance does not substantially become a bottleneck in production, and efficiency is high.

The time during which the first glass sheet a1 is being supplied, polished, or recovered is the time during which the first glass sheet a1 starts immediately after being separated from the conveyance path 102 by the transfer machine 106 and ends at the instant when the first glass sheet a1 is being placed on the conveyance path 102 by the transfer machine 106.

As shown in fig. 2, the plurality of grinders 103 are preferably operated as a batch connected in parallel to the conveyance path 102.

In the present embodiment, the two-system batch type of the first system 103A and the second system 103B is used, but the batch type of the single system may be used. That is, it is preferable that all grinders are synchronized and belong to the same system at normal times, and at least one grinder is independently controlled at abnormal times. In the normal operation, the control is facilitated by operating synchronously and simultaneously. In the case of an abnormality, as described above, it is not necessary to stop the entire line, and the efficiency is high.

Here, the synchronous motion means that the motions can be started and/or ended at the same time as a result of the plurality of grinders being independently controlled. Or a common program may be used to control the synchronous grinding mill. The same time is a concept of allowing a range of ±3 seconds or less based on the exact same point. The term "movement" means a concept including polishing, setting of a glass plate before polishing, and removal of a glass plate after polishing.

The present invention is not limited to the two-system batch type, and the plurality of grinders 103 may be a multi-system batch type classified into two or more systems. In general, the plurality of grinders 103 move synchronously in each of the plurality of systems, and the movement cycle of the plurality of grinders 103 varies among the plurality of systems, so that the conveyance or preparation of the next glass sheet set can be advanced during the time consumed by the other systems, and finer control can be performed. In the event of an anomaly, at least one of the grinders is controlled independently, so that the entire line does not need to be stopped as described above, resulting in high efficiency.

In addition, the present embodiment may be a batch type of a dual system. In general, in the first system 103A, the plurality of grinders 103 move synchronously, and in the second system 103B, the plurality of grinders 103 move synchronously, and the movement cycle of the first system 130A is different from that of the second system 103B, whereby the conveyance or preparation of the next glass sheet set can be advanced during the time consumed by the other systems. In the event of anomalies, at least one of the grinders is controlled independently, so that it is not necessary to stop the whole line, as described above, and therefore the efficiency is high. Further, if the system is a dual system, the transfer units for supply and recovery can be easily shared. Further, it is easy to complete the transfer of all the transfer objects during a waiting time such as polishing of a certain glass plate. That is, it is easy to achieve a trade-off of reducing the number of transfer machines as much as possible and completing the transfer of all glass sheets that need to be transferred within an allowable time.

In the case of a batch type of twin system, it is preferable that only 1 transfer machine 106 for supplying and recovering the glass sheets G is provided between any pair of grinding machines. By sharing the transfer units in a pair of grinding machines, the number of transfer units 106 can be reduced, and the device structure can be simplified.

An example of the operation at the time of abnormality will be described. In fig. 2 (1), it is assumed that any one of the third glass sheet group a is broken during polishing in any one of the first systems 103A.

At this time, in fig. 2 (2), the transfer machine 106 does not collect the broken glass sheet. This allows the space 201 to be left empty without being filled.

Then, in fig. 2 (3), the other glass plate (third glass plate group a) that normally has finished polishing and the glass plate (first glass plate group a) that has been polished from now on are synchronously conveyed by the same movement amount.

Then, in (4) of fig. 2, the glass plate to be ground by the grinder in which abnormality has occurred is not supplied to the first system 103A. Is conveyed downstream together with the other glass sheets (third glass sheet group a) for which grinding normally ends. Then, the glass plate polished by the abnormal polishing machine is judged to be insufficiently polished by an inspection step or the like, and is subjected to re-polishing or the like.

During such continuous operation, recovery operations of the polishing machine, polishing pad, and the like, in which the abnormality has occurred, are performed.

The transfer machine 106 is provided on a guide member that connects any pair of grinders, and can transfer the glass sheet G to any pair of grinders and a conveyance path between any pair of grinders. This allows smooth transfer to 3 positions.

In the transfer machine 106 of the present embodiment, any one pair of grinding machines (one of the first system 103A and one of the second system 103B) can be suspended from a guide rail connecting the two systems in the X direction, and can be moved to 3 positions of the first system 103A, the conveying path 102, and the second system 103B. After moving to each position, the glass sheet G can be transferred by the jigs by moving up and down in the Z direction. The transfer machine is not limited to this embodiment, but is preferably movable only in the X direction. The device structure can be simplified.

The transfer machine 106 may convey the glass sheet G by holding the scheduled surface for polishing or the polished surface of the glass sheet G with an adsorption jig. Further, a back pad or a carrier to be described later may be held by, for example, a claw clip or the like.

In the case of a batch type of two systems, it is preferable that the movement periods be shifted by half a period in the first system 103A and the second system 103B. That is, the plurality of grinders 103 has a first system 103A and a second system 103B with motion periods staggered by half periods. The preparation to any system can be performed in an equal time.

Here, the half cycle is shifted in terms of a concept that allows a range of ±3 seconds or less based on the completely shifted half cycle.

Also, in the case of a multi-system batch type, it is preferable to shift the period by an amount of time obtained by dividing the time required for grinding the glass sheet G by the number of systems thereof. The preparation to any system can be performed in an equal time.

Further, as in (5) and (6) of fig. 2, when the first glass plate group a is in any one of the states of being supplied, polished, and recovered, the conveyance path 102 conveys the plurality of glass plates G constituting the second glass plate group b to the vicinity of any one of the plurality of grinders. The second glass sheet group b can be conveyed downstream in the supply or grinding or recovery of the first glass sheet group a. That is, the time taken for the subsequent glass plate to pass through the preceding glass plate exceeds the preceding glass plate, and the subsequent glass plate is conveyed to the vicinity of the predetermined grinder to be ground. The time consumed for transportation does not become a limit of production, so that the efficiency is high.

After the conveyance is completed, the second glass sheet set b may stand by until the first glass sheet set a is discharged from the grinder 103.

Further, as shown in fig. 2 (6), it is preferable that the space 201 is formed between at least a part of the plurality of glass plates G constituting the second glass plate group b in a state where the plurality of glass plates G constituting the second glass plate group b are respectively transported to the vicinity of any one of the plurality of grinders 103. That is, the conveyance path 102 preferably conveys the second glass sheet group b so that at least a part of the plurality of glass sheets constituting the second glass sheet group b forms a space. The distance 201 is preferably equal to or greater than the width of any one of the plurality of glass plates.

In this case, from the viewpoint of efficiency, it is preferable that no gap is provided between the glass sheets during the conveyance of the glass sheets, but in the state of (6), the gap 201 is provided, so that the polished glass sheets (for example, the fourth glass sheet group B) can be smoothly collected into the conveyance path 102.

Here, the portion where the interval of the glass plates having a width equal to or greater than the width is provided between the plurality of glass plates G may be only the polishing region. In other conveyance, the interval between the glass sheets G is set to be smaller than the width of 1 glass sheet as much as possible, whereby efficient production can be performed.

The gap 201 is preferably formed during the process of conveying the plurality of glass sheets G constituting the second glass sheet group b to the vicinity of any one of the plurality of grinders 103. That is, the conveyance path preferably forms the gap in a process of conveying the plurality of glass sheets constituting the second glass sheet group to the vicinity of any one of the plurality of grinders, respectively. The second glass sheet group b may be conveyed in a state where adjacent glass sheets are not spaced apart from each other or in a state where the spacing is small, except for the polishing region 111 of the conveyance path 102. The intervals are set only when necessary, whereby efficient production can be performed.

Here, the state in which the interval is small means a state in which the width of any one of the plurality of glass plates is smaller.

The conveyance path 102 includes a first region 102A and a second region 102B, and the first region 102A and the second region 102B can independently control the start and/or stop of conveyance and/or the conveyance speed, respectively. Specifically, in the embodiment of fig. 1, the conveyor (first zone 102A) disposed between a pair of grinders and the conveyor (second zone 102B) disposed between adjacent grinders within the same system can be independently controlled. Thus, for example, even if the conveyance of the forefront glass sheet G is stopped, the following glass sheet can be conveyed to fill the gap during the stop time. Further, even if the subsequent glass plate is delayed for some reason, the interval with the preceding glass plate can be filled. Further, even when the interval 201 is formed, the size of the interval can be adjusted. In this way, the degree of freedom in conveying the glass sheet G can be improved.

In fig. 2, it is preferable that glass sheets G having similar quality are classified in advance for each glass sheet group. For example, if the glass plate group is a glass plate group having a good quality to some extent, adjustment such as setting the polishing time of the glass plate group to be short may be performed. On the other hand, if the glass plate group is poor in quality, polishing of the glass plate group can be performed with emphasis. In this way, the polishing time can be adjusted and optimized for each system.

Further, the first glass plate a1 is preferably conveyed downstream of the second glass plate b2 on the downstream side of the polishing zone 111. That is, the conveyance path 102 conveys the first glass plate a1 downstream of the second glass plate b 2. After (6), the first glass plate a1 is preferably recovered and conveyed to the downstream side during polishing or the like of the second glass plate b 2. Further downstream than the polishing zone 111, the conveyance sequence is in the original order, and thus management and tracking of the quality and the like of the glass sheet G are facilitated.

By being able to track the glass sheet G, it is possible to determine which grinder 103 the glass sheet G is ground. Further, if the quality of the glass sheet G is checked, the state of each grinder 103, for example, the time when the grinding pad is replaced is close, can be grasped, and efficient production can be performed to prevent occurrence of defective products.

Further, the conveyance path 102 preferably includes a glass supply path and a glass recovery path, and the glass supply path is disposed along the glass recovery path. That is, the glass sheet G polished from now on passes through the glass supply path, and the glass sheet G polished already passes through the recovery path. The supply path and the recovery path convey the glass sheet G in the same direction. Accordingly, the glass sheet G to be polished can be conveyed downstream without waiting for the glass sheet G to be polished to be supplied to the transfer machine. That is, in fig. 3, the "standby" of the third glass plate group a in the supply of the first glass plate group a can be eliminated. In fig. 3, the "standby" of the fourth glass plate group B during the supply of the second glass plate group B can be eliminated. Further, it is possible to determine whether or not the glass sheet is polished by looking at the appearance.

Here, the glass supply path and the collection path may be vertically arranged in the Z direction or may be arranged in the X direction. If the devices are arranged vertically in the Z direction, the installation area of the devices can be reduced, which is preferable.

The plurality of glass sheets G may be conveyed by the glass supply path, polished by the first system 103A, transferred to the second system 103B, polished, and recovered by the glass recovery path.

As shown in fig. 1, in the present embodiment, a plurality of glass plates G are preferably attached to any one of the plurality of back pads 104 on the upstream side of the plurality of grinders 103 in the conveyance path 102, and the plurality of glass plates G are conveyed, supplied, ground, and recovered in a state attached to the back pad 104, and the plurality of ground glass plates G are preferably separated from the plurality of back pads 104 on the downstream side of the plurality of grinders 103 in the conveyance path 102. The polishing platen has a large influence on the quality of the glass sheet G when polished, but by having a structure in which the polishing platen is separated from the polishing machine like the back pad 104, when there is a failure in the back pad 104, only the back pad needs to be removed from the conveyance path 102 and corrected, and the operation of the polishing machine 103 itself may not be stopped.

Here, the region of the conveyance path 102 to which the glass sheet G and the back pad 104 are attached is referred to as an attaching region 110. The region separating the glass plate G from the back pad 104 is referred to as a separation region 112. The attachment region 110 and the polishing region 111, and the polishing region 111 and the separation region 112 may be adjacent to each other, or may have a region between them, in which only conveyance is performed. An attaching region 110 is provided upstream of the polishing region 111, and a separating region 112 is provided downstream of the polishing region 111.

Further, the plurality of back pads 104 are preferably circulated by conveying the plurality of back pads 104 conveyed downstream of the plurality of grinders 103 to the upstream of the plurality of grinders 103. By recycling the plurality of back pads 104, the same quality glass sheet can be mass produced. The manufacturing apparatus may further include a reverse path 105 for conveying the back pad 104 from the separation area 112 to the attachment area 110, and circulate the plurality of back pads 104.

Here, in fig. 1, a reverse path 105 for tracing back pad 104 to the upstream side is provided below conveying path 102. That is, the back pad 104 from which the glass sheet G is separated by the separation section 112 is conveyed downward in the Z direction by a structure such as an elevator, and is placed on the reverse path 105. Similarly, when the back pad 104 arrives at the attaching area 110, the back pad is conveyed upward in the Z direction by a structure such as an elevator. This can reduce the installation area of the device. The present invention is not limited to this configuration, and may be provided so as to be flush with the conveyance path 102.

In the present embodiment, the back pad may be a structure in which the back pad is attached to a frame made of, for example, metal, which is called a carrier.

The number of back pads 104 to be circulated is preferably (number of grinders/number of systems) × (number of systems+n) and n=an integer of 1 or more. In the case of the parallel batch polishing as in the present embodiment, the back pad 104 to be supplied is naturally determined as a specific back pad group in each batch of a certain polishing machine 103. In the plurality of grinders 103 and the back pad 104, slight individual differences occur at the time of manufacture, and thus there is a combination capable of providing glass plates that are compatible with each other, i.e., high quality. The combination can be polished with each determined combination of the polishing machine 103 and the back pad 104 without disassembling the combination.

For example, in the case where the number of the grinders 103 is 20, if the number of systems is set to two, the number of the back pads 104 to be circulated is 30 if n=1, the number of the back pads 104 to be circulated is 40 if n=2, the number of the back pads 104 to be circulated is 50 if n=3, and the number of the back pads 104 to be circulated is 60 if n=4. If the number of back pads 104 is 30 (n=1), for example, in the first grinder 103c, 3 kinds of back pads 104 are alternately supplied between batches. That is, by preparing 3 back pads 104 having good compatibility with the first grinder 103c, it is possible to continuously supply the glass sheet G having stable quality.

Also, if the number of back pads 104 is 40 (n=2), for example, in the first grinder 103c, 2 kinds of back pads 104 are alternately supplied between batches. That is, by preparing 2 back pads 104 having good compatibility with the first grinder 103c, it is possible to continuously supply the glass sheet G having stable quality.

Similarly, 5 kinds of back pads are alternately supplied in the case of n=3, and 3 kinds of back pads are alternately supplied in the case of n=4.

Here, in order to reduce the number of back pads 104 having good compatibility that must be prepared as much as possible, n=2 is more preferable than n=1, and n=4 is more preferable than n=3. That is, the number of back pads 104 is particularly preferably set to be an integer multiple of the number of grinders.

In order to prevent the combination of the back pad 104 group and the polishing machine 103 from being disassembled, even when the glass plate G is not attached, it is preferable to perform the same normal operation as the other back pad (glass plate) in the same system in a state where the back pad is empty. That is, even when any one of the plurality of back pads 104 is not attached to any one of the plurality of glass plates, the same movement as that in the case where any one of the plurality of back pads 104 is attached to any one of the plurality of back pads 104 is preferably performed. When the glass sheet G is not attached, for example, it is assumed that breakage of the glass occurs during attachment and the glass sheet is not caught up with conveyance.

In addition, when any of the back pads is abnormal, that is, when repair is required, another back pad as a substitute is preferably inserted into the position of the any back pad. Can be combined with a set of back pads 104 suitable for the grinder 103 without disassembly.

In addition, in the case where any back pad is abnormal, that is, in the case where repair is required, it is preferable that after the any back pad is removed from the cycle, the subsequent back pad does not fill the gap, and the movement is continued as in the case where the any back pad exists. Can be combined with a set of back pads 104 suitable for the grinder 103 without disassembly.

If an example of the above-described operation in the abnormal state is performed, even when the back pad is used, the combination with the back pad 104 group suitable for the grinder 103 may not be disassembled.

In the separation zone 112, it is preferable that after 1 glass plate G of the plurality of glass plates G is separated from 1 back pad 104 of the plurality of back pads 104, a new back pad to which a new glass plate is attached is transported to the polishing zone. After it can be confirmed that the separation in the separation zone was successful and that a failure such as breakage of the glass sheet G did not occur, a new glass sheet was conveyed from the upstream side. This can suppress collision of the glass sheets G on the conveyance path 102.

It is preferable that the timing at which all of the plurality of glass sheets having the same system are separated from the back pad 104 is earlier than the timing at which the plurality of glass sheets G polished by the next system start to be conveyed to the separation area. For example, in the case of a batch type of two systems, the timing at which all of the plurality of glass sheets G in the first system 103A are separated from the back pad 104 is preferably earlier than the timing at which the plurality of glass sheets G polished in the second system 103B start to be conveyed to the separation area. In this way, the separation of the glass sheets in the preceding batch (for example, the first system 103A) can be completed within the time consumed by the glass sheets in the next batch (for example, the second system 103B), and the occurrence of congestion due to the conveyance of the glass sheets G in the separation area as a speed limit can be suppressed.

In addition, at least a portion of the plurality of glass sheets is preferably subjected to multiple grinding by different back pads. This can reduce not only the individual difference of the grinder 103 but also the variation in quality due to the individual difference of the back pad 104. As a specific configuration example, among the glass plates that have been finished with the first polishing by the separation section 112, a glass plate that has not been sufficiently polished may be sorted and the like and traced back to the attachment section 110, and attached to a back pad different from the first polishing and subjected to the second polishing. Further, a new attachment zone 110, polishing zone 111, and separation zone 112 may be provided downstream of the separation zone 112 to perform the second polishing.

In the case of the present embodiment, the number of grinding machines is preferably 4 or more. Can efficiently produce a large number of glass sheets of good quality. Further, 40 or less are preferable as the upper limit. If the number of the polishing sections is greater than 40, the length of the polishing region 111 of the conveying path 102 tends to be too long. In this case, the glass sheet G may pass through the polishing zone 111 and consume time, and the polishing process may be a relatively high rate limit as compared with other processes. This can be suppressed.

Further, since the surface of the glass plate G after polishing is activated, when moisture during polishing evaporates from the glass surface and becomes dry, dirt is easily attached and easily contaminated. If the number of grinding machines is 40 or less, the conveyance path is not excessively long, and this can be prevented.

The length of the polishing region 111 is preferably 100m or less, more preferably 80m or less, and still more preferably 70m or less. The above problems of speed limitation and pollution can be suppressed. The lower limit of the length of the polishing region 111 is not particularly limited, but is, for example, 10m or more.

In addition, it is preferable that a moisture supply device for supplying moisture to the surface of the glass sheet G is provided in the polishing region 111 on the conveyance path 102 and/or downstream of the polishing region 111. Further, it is preferable that moisture is supplied to the surface of the glass sheet after polishing in the polishing region 111 and/or downstream of the polishing region 111. The above-described problem of contamination can be suppressed. The moisture is preferably supplied before the surface of the glass sheet after grinding is dried. The water supply device may also be a cleaning device.

A first modification of the present embodiment will be described with reference to fig. 3. Fig. 3 shows only a part of the first grinder 103c as a representative enlarged view. In the present modification, the polishing machine 103 includes a first polishing position 103X and a second polishing position 103Y, and the glass sheet G is polished by passing the glass sheet G through the first polishing position 103X and the second polishing position 103Y.

Specifically, the glass sheet G is supplied from the conveyance path 102 to the first position 103X by the transfer machine 106, polished at the first position 103X, then supplied to the second position 103Y by the intermediate transfer machine 301, polished at the second position 103Y, and then recovered by the transfer machine 106 to the conveyance path 102.

At this time, the residence time of the glass sheet G at the first position 103X and the second position 103Y is the same.

By adopting such a configuration, the glass sheet G is polished at 2 positions, and the variation in quality due to individual differences of the polishing machine 103 can be reduced as compared with polishing at 1 position as in the first embodiment.

In addition, if the residence time is the same, the glass sheet G does not have a waiting time, and the production efficiency is improved.

Here, in this specification, the first position 103X and the second position 103Y are defined as belonging to the concept of 1 grinder. Even if the control systems or structures of the devices at the first position 103X and the second position 103Y are independent of each other, the polishing is performed by 1 polishing machine until the devices are supplied from the conveying path 102 and recovered.

The term "residence time is the same" means that the range of ±3 seconds or less is allowed based on the complete identity.

The term "the same residence time" may also mean the same polishing time. After polishing at the first position 103X, if the glass sheet G can be made to have a desired quality, the glass sheet G may be left alone without polishing at the second position 103Y.

The intermediate transfer unit 301 may be a robot arm in which the intermediate transfer unit itself does not move in the Y direction. The intermediate transfer machine 106 may be of a type in which itself moves in the Y direction.

The second polishing amount at the second polishing position 103Y is preferably equal to or less than the first polishing amount at the first polishing position 103X. By using the second polishing position 103Y as finish polishing, the quality of the glass sheet G can be improved.

In the present modification, the number of grinding machines is preferably 10 or more. By providing a plurality of such grinders 103, a large number of glass sheets having good quality can be efficiently produced. From the viewpoint of suppressing the above problems of speed limitation and contamination, the upper limit of the grinder is preferably 20 or less.

In addition, as a second modification, 1 more position may be added to the configuration shown in fig. 3. That is, the first polishing position 103X, the second polishing position 103Y, and the third polishing position are provided, and the glass sheet G is polished by passing the glass sheet G through the first polishing position 103X, the second polishing position 103Y, and the third polishing position, and the residence time of the glass sheet G at the first polishing position 103X, the second polishing position 103Y, and the third polishing position is preferably the same.

The glass sheet G is polished at 3 positions, and compared with polishing at 1 position as in the first embodiment, variations in quality due to individual differences of the polishing machine 103 can be reduced.

Further, if the residence time is the same, the glass sheet G does not have a waiting time, and the production efficiency is improved.

In the second modification, the third polishing position and the second intermediate transfer machine are added only to the first modification, and therefore, the illustration is omitted.

The third polishing amount at the third polishing position is preferably equal to or less than the second polishing amount at the second polishing position 103Y, and the second polishing amount is preferably equal to or less than the first polishing amount at the first polishing position 103X. The quality of the glass sheet G can be improved by performing the finish polishing in stages at the second polishing position 103Y and the third polishing position.

In the case of the second modification, the number of grinding machines is preferably 2 or more. By providing a plurality of such grinders 103, a large number of glass sheets having good quality can be efficiently produced. From the viewpoint of suppressing the above problems of speed limitation and contamination, the upper limit of the grinder is preferably 14 or less.

All the grinders 103 of the first embodiment may have a first position 103X and a second position 103Y as in the present modification. By unifying the structure (number of positions) of the grinder 103, control becomes easy.

In the first modification and the second modification, the back pad 104 may be used in the same manner as in the first embodiment. At this time, polishing is preferably performed using different back pads at the first polishing position 103X and the second polishing position 103Y. This can reduce not only the individual difference of the grinder 103 but also the variation in quality due to the individual difference of the back pad 104.

In this case, a back pad exchanging area is provided in the area where the intermediate transfer unit 301 is provided. After polishing at the first polishing position 103X is completed, the glass plate G is peeled off from the back pad 104 and replaced with a new back pad. And then grinding is performed at the second grinding position 103Y.

In the second modification, polishing may be performed using different back pads at the second polishing position 103Y and the third polishing position. Individual differences due to the back pad 104 can be further reduced.

Hereinafter, a method for producing a display glass sheet according to a second embodiment of the present invention will be described. The device structure of the second embodiment is the same as that of fig. 1 of the first embodiment, and therefore, the illustration is omitted and the same reference numerals as those of fig. 1 are used. The explanation of the terms, the preferred embodiments, and the description related to the modification are the same as those of the first embodiment unless otherwise specified below.

In the second embodiment, unlike the first embodiment, no system is constituted, and the timings at which the grinding of the plurality of grinders 103 starts are different from each other. Always moving independently of each other. That is, the timings at which the grinding is started are different among the plurality of grinders 103. By controlling each grinder 103 independently, the degree of freedom in grinding of the glass sheet G can be increased. Further, the influence of vibration of the plurality of grinders 103 on peripheral devices and buildings can be reduced. Specifically, if the timings at which grinding is started are different, resonance of vibrations from the plurality of grinders 103 can be prevented. Moreover, if the intervals between the different moments are appropriately determined, the vibrations of the grinders 103 can also be canceled out from each other.

In addition, in the second embodiment, the second grinder 103d that grinds the second glass plate b2 is preferably a grinder that is located on the most downstream side in the conveyance direction. Since the first glass plate a1 is ground most upstream, if the second glass plate b2 is conveyed most downstream, the amount of conveyance time of the second glass plate b2 can be used as the grinding/recovery time of the preceding glass plate that is already being ground in the second grinder 103d, and thus the efficiency is high. Further, during the period of supplying the second glass sheet b2 to the intermediate grinder in the middle, the condition that the grinder at the most downstream is empty and is in the standby state can be suppressed, and therefore, the efficiency is high.

Here, in the second embodiment, the grinders 103 are arranged opposite to each other, and therefore there are 2 grinders 103 located at the most downstream side, but any one of them may be used as the second grinder 103 d.

In the second embodiment, at least a temporary space 201 is preferably formed between at least a part of the plurality of glass sheets G in the polishing region 111. The space 201 is preferably equal to or greater than the width of any one of the plurality of glass plates. In the glass sheet conveyance, it is preferable that no gap is provided between the glass sheets, but in the state of (6), the gap 201 is provided, so that the polished glass sheets (for example, the fourth glass sheet group B) can be smoothly collected into the conveyance path 102.

Here, the interval 201 may be temporary. That is, when it is determined that a glass sheet after polishing is not inserted (recovered) to the front of the conveyance path 102 while a certain glass sheet passes through the polishing zone, the gap from the preceding glass sheet can be closed. This can be determined by correlating information on the grinding condition of the grinder on the downstream side of the current position of a certain glass sheet with the movement control of the conveyance path. By adopting such a structure, production can be performed more efficiently.

In addition, the space 201 is preferably formed at least temporarily between all glass sheets during passage through the grinding zone 111. In particular, on the upstream side of the polishing zone 111, the gap 201 is formed by adjusting the conveyance speed of each of the plurality of glass sheets G. When it is determined that the polished glass sheet is not inserted (recovered) in front of the conveyance path 102 on the downstream side with the downstream flow, the gap from the preceding glass sheet is closed. With this configuration, the polished glass sheet can be recovered without waiting time, and the next glass sheet can be fed to the empty polishing machine quickly, so that the efficiency is high.

The interval 201 preferably varies during the passage through the polishing zone 111. The conveyance speeds of the plurality of glass sheets G may be controlled to gradually widen the interval. Further, as a result of the polished glass plate being recovered to the space 201, the space 201 can be narrowed. Furthermore, the spacing from the preceding glass plate may also be padded. Efficient and flexible production is enabled.

Further, the conveyor system is provided with a plurality of first transfer machines that supply the plurality of glass sheets G on the conveyor path 102 to the plurality of grinders 103, respectively, and when the plurality of first transfer machines take out the plurality of glass sheets G from the conveyor path 102, at least a part of the conveyor path 102 is preferably stopped. Thus, the first transfer machine can easily grip the glass sheet G, and breakage of the glass due to gripping damage can be suppressed.

Further, the glass sheet conveying apparatus is provided with a plurality of second transfer machines for respectively collecting the plurality of glass sheets G polished by the plurality of grinders 103 to the conveying path 102, and when the plurality of second transfer machines place the plurality of glass sheets G on the conveying path 102, at least a part of the conveying path 102 is preferably stopped. This facilitates separation of the glass sheet G by the second transfer unit, and can suppress breakage of the glass caused by contact between the glass sheet G and the moving conveyance path 102.

The first transfer machine and the second transfer machine may be the transfer machine 106 according to the first embodiment.

In addition, the subsequent conveyance path can continue to move while a part of the conveyance path 102 is stopped, and the subsequent glass sheet G can be fed with the gap, thereby enabling more efficient production.

Further, the conveyance path 102 preferably includes a glass supply path and a glass recovery path, and the glass supply path is disposed along the glass recovery path. That is, the glass sheet G polished from now on passes through the glass supply path, and the glass sheet G polished already passes through the recovery path. The supply path and the recovery path convey the glass sheet G in the same direction. In the second embodiment, in the polishing zone 111, all the glass sheets G are transported in a scattered state compared with the polishing zone before, and control, quality control, and tracking are complicated. Further, it can be judged whether or not the glass plate is polished by looking at the appearance. In particular, if the conveyance path 102 is configured to stop temporarily when glass is supplied and when glass is recovered, the conveyance path 102 stops frequently, so if the action is divided as in the present configuration, the conveyance can be made smooth.

The conveyance path 102 preferably has a plurality of glass plate mounting spaces, and at the time of collection, a sensor is used to detect an empty space in which no glass plate is mounted among the plurality of glass plate mounting spaces, and a polished glass plate G is mounted in the empty space. Since the space where the glass plates have been placed can be distinguished from the empty space, collisions between the glass plates can be reduced. In particular, in the second embodiment, when the number of the conveyance paths is 1 at the time of recovery from the downstream side grinder (both the glass supply path and the recovery path), the glass sheet must be placed in the mixing between the scheduled glass sheet to be ground from now on and the ground glass sheet recovered from the upstream side grinder, and therefore, it is necessary to appropriately find the empty space, which is preferable in this embodiment.

Here, the glass plate mounting space means a section suitable for the size of the glass plate G. The conveyance path 102 may connect the glass plate mounting space in a partitioned manner. In this case, the glass plate G cannot be placed across the adjacent glass plate placing space. That is, when the space where the glass plate has been placed is alternated with the empty space, the space 201 becomes the amount of one empty space.

The sensor is preferably any one of a load sensor provided on the bottom surface of the plurality of mounting spaces, an image authentication sensor that captures images of the conveyance path 102, an optical sensor that detects a change in reflected light or light quantity, and a non-contact sensor that senses an inductive or electrostatic capacitance or air back pressure. The presence or absence of the glass sheet G can be determined by existing sensors, and therefore the device structure becomes simple.

In the present application, the display glass polishing plate refers to a polished glass substrate used for display devices typified by liquid crystal, OLED, and the like.

In the embodiment of the present invention, the supply, transfer, and recovery are preferably performed in a state where the surface to be polished and the surface to be polished of the glass sheet G are not in contact with each other. The surface to be polished and the surface to be polished are equipment formation surfaces, and therefore are relatively fine, and the present structure can suppress the residual of transferred traces, contaminants, and the like.

In the embodiment of the present invention, the glass plate G preferably has a size of 1500mm×1800mm or more. Since such a large glass plate is easily broken during polishing or during transfer, and a high processing operation or a long time is required for transfer, the parallel polishing method is preferable as in the embodiment of the present invention. The upper limit of the size of the glass plate G is not particularly limited, but is, for example, 4000mm×4000mm or less.

In the embodiment of the present invention, the thickness of the glass sheet G after polishing is preferably 0.7mm or less, more preferably 0.5mm or less. Since such a thin glass plate is easily broken during polishing or during transfer, and a high processing operation or a long time is required for transfer, the parallel polishing method is preferable as in the embodiment of the present invention. The upper limit of the thickness of the glass plate G is not particularly limited, but is, for example, 0.01mm or more.

In the embodiment of the present invention, the glass plate G is preferably 1500mm×1800mm or more, and the thickness of the glass plate G after polishing is preferably 0.7mm or less. Since such a large and thin glass plate is easily broken during polishing or transfer, and a high processing operation or a long time is required for transfer, the parallel polishing method is suitable as in the embodiment of the present invention.

In the embodiment of the present invention, the polishing remaining amount is preferably 5.0 μm or less. Since the polishing time must be longer as the polishing margin increases, the polishing time can be shortened by the present configuration. The polishing time can be made difficult to be the rate limit of production.

Industrial applicability

The present invention is suitably used in the field of a method for producing a glass plate for display use, which requires high efficiency.

Claims

1. A method for producing a ground glass plate for display, characterized by comprising the steps of,

on a conveying path arranged along a first direction, a plurality of glass plates are respectively conveyed,

the plurality of glass plates on the conveying path are respectively supplied to a grinder unit composed of a plurality of grinders arranged in parallel with the conveying path,

the plurality of glass plates ground by any one of the plurality of grinders are respectively recovered to the conveying path,

a grinder of the plurality of grinders that is located on the most upstream side in the conveying direction of the conveying path is set as a first grinder,

attaching the plurality of glass plates to each of a plurality of back pads on an upstream side of the plurality of grinder units in the conveyance path,

the plurality of glass sheets are conveyed while being attached to a back pad, the plurality of glass sheets are supplied, the plurality of glass sheets are ground by the plurality of grinders of the grinder unit, the plurality of glass sheets are recovered,

Separating the polished glass plates from the back pads on the downstream side of the polishing units in the conveying path,

circulating the plurality of back pads by conveying the plurality of back pads to an upstream side of the plurality of grinder units,

the total number of the plurality of back pads circulated satisfies (number of grinders/number of systems) × (number of systems + n), and n is an integer of 1 or more,

the plurality of grinders typically belong to the same system in which all grinders move synchronously, with at least one grinder being independently controlled in the event of an anomaly.

2. The method for producing a glass sheet for display use according to claim 1, wherein,

the plurality of grinders are categorized into a plurality of systems,

in the normal course of time, the process is carried out,

within each of the plurality of systems, the plurality of grinders move synchronously,

the movement cycle of the plurality of grinders differs between the systems of the plurality of systems,

in the event of an anomaly, at least one mill is independently controlled.

3. The method for producing a glass sheet for display use according to claim 1, wherein,

a plurality of grinders disposed on one side of the conveying path among the plurality of grinders is set as a first system,

A plurality of grinders disposed on the opposite side of the first system across the conveying path are set as a second system,

in the normal course of time, the process is carried out,

within the first system, the plurality of grinders move synchronously,

in the second system, the plurality of grinders move synchronously,

the first system and the second system have different periods of motion,

in the event of an anomaly, at least one mill is independently controlled.

4. The method for producing a glass plate for display use according to claim 3, wherein,

in the first system and the second system, the movement periods are staggered by half periods.

5. The method for producing a glass sheet for display use according to claim 1, wherein,

the plurality of grinders are constituted by a plurality of pairs of grinders facing each other across the conveying path.

6. The method for producing a glass sheet for display use according to claim 5, wherein,

the plurality of transfer machines for supplying and recovering the glass sheet are provided only one between any one of the plurality of pairs of grinders.

7. The method for producing a glass sheet for display use according to claim 1, wherein,

the total number of the plurality of back pads circulated is an integer multiple of the number of grinders.

8. The method for producing a glass plate for display use according to claim 7, wherein,

any one of the plurality of back pads in the cycle performs the same movement as in the case where any one of the plurality of glass plates is attached, even in the case where any one of the plurality of glass plates is not attached.

9. The method for producing a glass plate for display use according to claim 7, wherein,

when any one of the back pads of the cycle is removed from the cycle, another back pad is inserted into the removed portion.

10. The method for producing a glass sheet for display use according to claim 1, wherein,

at least a portion of the plurality of glass sheets is ground multiple times by different back pads.

11. The method for producing a glass sheet for display use according to claim 1, wherein,

the first grinder is provided with a first grinding position and a second grinding position,

passing the glass sheet through the first polishing location and the second polishing location to polish the glass sheet,

the residence time of the glass sheet at the first polishing location and the second polishing location is the same.

12. The method for producing a glass sheet for display use according to claim 11, wherein,

the second amount of grinding at the second grinding location is less than the first amount of grinding at the first grinding location.

13. The method for producing a glass sheet for display use according to claim 11, wherein,

the number of the grinding machines is more than 10.

14. The method for producing a glass sheet for display use according to claim 1, wherein,

the first grinder is provided with a first grinding position, a second grinding position and a third grinding position,

passing the glass sheet through the first polishing location, the second polishing location, and the third polishing location to polish the glass sheet,

the residence time of the glass sheet at the first polishing location, the second polishing location, and the third polishing location is the same.

15. The method for producing a glass sheet for display use according to claim 14, wherein,

the third polishing amount at the third polishing position is equal to or less than the second polishing amount at the second polishing position,

the second polishing amount is equal to or less than the first polishing amount at the first polishing position.

16. The method for producing a glass sheet for display use according to claim 14, wherein,

The number of the grinding machines is more than 2.

17. The method for producing a glass sheet for display use according to claim 1, wherein,

the number of grinding machines is more than 4 and less than 40.

18. The method for producing a glass sheet for display use according to claim 1, wherein,

when a region in which the plurality of grinders are juxtaposed in the conveying path is referred to as a grinding region,

the length of the grinding area is below 100 m.

19. The method for producing a glass sheet for display use according to claim 1, wherein,

when the region of the conveying path where the plurality of grinders are provided is referred to as a grinding region,

in the grinding zone and/or on the downstream side of the grinding zone,

moisture is supplied before the surface of the glass sheet after grinding is dried.

20. The method for producing a glass sheet for display use according to claim 1, wherein,

the plurality of glass plates G has a size of 2200mm×2200mm or more.

21. The method for producing a glass sheet for display use according to claim 20, wherein,

the thickness of the plurality of glass plates G after polishing is 0.5mm or less.

22. The method for producing a glass sheet for display use according to claim 1, wherein,

In the polishing, a polishing margin of the plurality of glass plates is 5.0 μm or less.

23. The method for producing a glass sheet for display use according to claim 1, wherein,

any one of the plurality of grinders grinds only one glass sheet during a single grind movement.

24. The method for producing a glass sheet for display use according to claim 1, wherein,

the grinding is started at different times between the plurality of grinders.

25. The method for producing a glass sheet for display use according to claim 24, wherein,

setting a glass plate ground by the first grinder among the plurality of glass plates as a first glass plate,

a glass plate of the plurality of glass plates that is conveyed immediately after the first glass plate is set as a second glass plate,

setting a grinder for grinding the second glass plate as a second grinder,

the second grinder is a grinder located at the most downstream side in the conveying direction.

26. The method for producing a glass sheet for display use according to claim 24, wherein,

At least a portion of the plurality of glass sheets forming at least a temporary spacing between the plurality of glass sheets within the grinding zone,

the spacing is equal to or greater than the width of any one of the plurality of glass sheets.

27. The method for producing a glass sheet for display use according to claim 26, wherein,

the gap is formed at least temporarily between all of the glass sheets that are passing through the grinding zone.

28. The method for producing a ground glass for display according to claim 26 or 27, wherein,

the interval varies during the time that the grinding zone is being passed.

29. The method for producing a glass sheet for display use according to claim 24, wherein,

the glass plate conveying device comprises a plurality of first transfer machines for respectively supplying a plurality of glass plates on the conveying path to the plurality of grinding machines,

when the plurality of first transfer machines take out the plurality of glass plates from the conveying path, at least a part of the conveying path is stopped.

30. The method for producing a glass sheet for display use according to claim 24, wherein,

the glass plate conveying device comprises a plurality of second transfer machines for respectively recovering a plurality of glass plates which are respectively ground by the plurality of grinding machines to the conveying path,

When the plurality of second transfer machines load the plurality of glass plates on the conveying path, at least a part of the conveying path is stopped.

31. The method for producing a glass sheet for display use according to claim 24, wherein,

the conveying path is provided with a plurality of glass plate carrying spaces,

during the recovery, the empty space on which the glass plate is not placed is detected by a sensor,

and placing the polished glass plate in the empty placing space.

32. The method for producing a glass sheet for display use according to claim 31, wherein,

the sensor is any one of a load sensor provided on the bottom surface of the plurality of glass plate mounting spaces, an image authentication sensor that captures an image of the conveyance path, and an optical sensor that detects a change in reflected light or light quantity.