CN113182998A

CN113182998A - Method and apparatus for manufacturing polished glass plate for display

Info

Publication number: CN113182998A
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: 2021-07-30
Anticipated expiration: 2038-01-31
Also published as: CN117817547A; CN108296982B; CN113182998B; CN117697620A; CN108296982A

Abstract

The main purpose of the present invention is to provide a method and an apparatus for efficiently producing a polished glass plate for display. The method for manufacturing a polished glass plate for display is characterized in that a plurality of glass plates are conveyed on a conveyance path arranged in a first direction, the plurality of glass plates on the conveyance path are supplied to a plurality of grinders arranged in parallel with the conveyance path, respectively, the plurality of glass plates are polished by any one of the plurality of grinders, respectively, and the plurality of glass plates polished by any one of the plurality of grinders are collected to the conveyance path, respectively.

Description

Method and apparatus for manufacturing polished glass plate for display

The present application is a divisional application of an application having an application date of 2018, 31/1/78, an application number of 201810094236.4, and an invention name of "method for producing a ground glass sheet for display and apparatus for producing the same".

Technical Field

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

Background

Since fine irregularities or undulations on the surface of a polished glass plate for display used in applications represented by a liquid crystal display or the like cause image distortion, the fine irregularities or undulations are removed by polishing.

Conventionally, as a polishing method, a method called continuous polishing has been typically used (patent document 1). The continuous grinding is a technique in which a plurality of grinders are provided along a conveyance path, and all of the grinders are used to grind the workpiece in stages from the upstream side to the downstream side.

[ Prior art documents ]

[ patent document ]

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

Disclosure of Invention

Problems to be solved by the invention

However, in the conventional continuous polishing, since the polishing machine is provided in series with the conveyance path, there are the following problems.

For example, when a glass sheet is broken by 1 grinder among a plurality of grinders, if the broken glass sheet is not completely removed from the conveyance path, the quality of the subsequent glass sheet is degraded, and therefore the conveyance path must be completely stopped until the removal operation is completed. And thus is inefficient.

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 polished glass plate for display.

Means for solving the problems

In order to achieve the above object, the present application provides a method for manufacturing a ground glass plate for display, characterized in that,

conveying a plurality of glass plates on a conveying path arranged in a first direction,

feeding the plurality of glass plates on the conveyance path to a plurality of grinders arranged in parallel with the conveyance path,

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

and a plurality of glass plates polished by any one of the plurality of grinders are collected into the conveyance path.

In order to achieve the above object, the present invention provides an apparatus for manufacturing a polished glass plate for display, comprising:

a conveyance path configured to convey a plurality of glass plates in a first direction;

a plurality of grinders arranged in parallel with the conveyance path; and

and a plurality of transfer machines for supplying the plurality of glass plates from the conveyance path to any one of the plurality of grinders and for collecting the glass plates from any one of the plurality of grinders to the conveyance path.

Effects of the invention

According to the present invention, a method and an apparatus for efficiently manufacturing a polished glass plate for display can be provided.

Drawings

Fig. 1 is a plan view and a 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 the manufacturing method according to the first embodiment of the present invention.

Fig. 3 is a time chart showing the 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 symbols

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 area

201 interval (c)

301 intermediate transfer machine

G glass plate

a first glass plate group

b second glass plate group

A third glass plate group

Fourth glass plate group

a1 first glass plate

b2 second glass plate

Detailed Description

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

In the drawings for describing the embodiments of the present invention, coordinates are defined by arrows in the drawings, and the description will be made using the coordinates as necessary. In the present specification, the "X direction" refers not only to a direction from the root to the tip of an arrow indicating an X coordinate, but also to a 180-degree reversed direction from the tip to the root. Similarly, the "Y direction" and the "Z direction" refer not only to the direction from the root to the tip of the arrow indicating the Y, Z coordinate, but also to the 180-degree opposite direction from the tip to the root. 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 downstream or downstream side, and the root side of the arrow in the Y direction is also referred to as upstream or upstream side. The tip side of the arrow in the Z direction is also referred to as "upper" or "upper" and the root side of the arrow in the Z direction is also referred to as "lower" or "lower".

In the drawings of the present specification, when the same structural units are consecutive, reference numerals may be omitted in order to avoid the drawings from becoming complicated.

In the present specification, the term "transfer" is a generic concept including "supply" and "collection" of glass plates.

Fig. 1 is a plan view and a sectional view of a manufacturing apparatus for a polished glass plate for display according to a first embodiment of the present invention. Fig. 2 is a schematic view showing a flow of a method for producing a polished glass plate according to a first embodiment of the present invention. Fig. 3 is a time chart showing a method for producing a polished glass plate for display according to the first embodiment of the present invention.

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

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

Further, with the manufacturing apparatus of 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 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 collected into the conveyance path 102. With such a configuration, the glass sheet G can be efficiently polished. That is, when an abnormality occurs in 1 grinding machine as in the conventional continuous grinding in-line arrangement, the influence of the 1 grinding machine is not exerted on the whole, and therefore, the efficiency is high. The reason is that since a plurality of grinders are provided in parallel with the conveyance path 102, even if a glass sheet is broken by one grinder 103, for example, the removal operation and the 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 in-line continuous polishing, after the removal operation of the broken glass plate from the conveyance path is completed, the normal operation of the polishing machines other than the polishing machine in which the abnormality has occurred is resumed, and the polishing machine in which the abnormality has occurred needs to perform the recovery operation such as pad replacement in the operation area different from the conveyance path. In the conventional continuous polishing, since all the grinders are used to polish the glass sheet in stages from the upstream side to the downstream side, the glass sheet is polished by 1 grinder less during the recovery operation of the grinders, and the quality may be deteriorated as compared with the normal state.

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

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

That is, conventionally, there is a polishing method in which a plurality of glass plates are polished by 1 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 the structure is such that only 1 glass plate is ground by 1 grinder, various grinding conditions can be adjusted according 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. Therefore, a higher quality glass sheet can be provided.

In addition, in the case of the polishing method in which a plurality of glass plates are polished by 1 polishing machine, the glass plates are likely to be jammed during mounting and/or collection, and the efficiency is poor.

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

It should be noted that if the size of the glass plate is small compared to the size of the grinding table of the grinder, it is also possible to grind a plurality of glass plates with 1 grinder.

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

The glass plate may be conveyed by a so-called step-feed method in which the conveyance path 102 is continuously operated at ordinary times, or conveyed and stopped at a time.

The parallel connection is a connection method in which paths are branched to form a plurality of paths, such as parallel connection of circuits.

The supply means transferring the glass sheet from the conveyance path to the grinder, and the collection means transferring the glass sheet after grinding from the grinder to the conveyance path.

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

In addition, the plurality of grinders are preferably independently controllable. The 1 grinding machine in which the abnormality has occurred may be stopped, and the other grinding machines may not be stopped, so that the efficiency is high. It should be noted that "independently controllable" means that the grinders 103 are independently movable. That is, the start and stop of the exercise, the adjustment of the exercise speed, and the like can be set independently. Specifically, when the fluctuation in the flatness of the conveyed glass sheet G is large, the polishing conditions can be set independently for each polishing machine according to the flatness of the supplied glass sheet. In addition, in the case of an abnormality in each polishing apparatus or at the time of maintenance, only 1 polishing apparatus can be operated differently from the other polishing apparatuses. Flexible operation for improving efficiency can be performed.

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

In the present embodiment, the plurality of grinders 103 is constituted by a plurality of pairs of grinders facing each other via the conveyance path 102, and is 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 made about 1/2, and the conveyance time of the glass sheet can be suppressed, which is efficient. The present invention is not limited to this, and a plurality of grinders 103 may be arranged in a staggered manner with the conveyance path 102 therebetween.

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

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

In fig. 2, the passage of time is represented 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 central broken line, and the direction of the arrow is set to the conveyance direction downstream side. The grinders 103 are disposed opposite to each other across the conveyance path 102. Of the plurality of grinders 103, the plurality of grinders 103 disposed on one side of the conveyance path 102 are defined as a first system 103A (a grinder group 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 via the conveyance path 102 are defined as a second system 103B (a grinder group 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 indicated as an area surrounded by a dotted line.

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

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

In addition, in (1), a plurality of adjacent glass plates, the rearmost of which is the first glass plate a1, are set as the first glass plate group a. That is, the glass plate group is arranged in a row from the first glass plate a1 to the right side of the sheet. In (6), a plurality of adjacent glass plates with the second glass plate b2 as the foremost are set as the second glass plate group b. That is, the glass plate group is arranged in a row from the second glass plate b2 to the left side of the sheet. In addition, in (1), the glass plate group polished by the first system 103A is set as a third glass plate group a. In (1), the glass plate group polished by the second system 103B is set as a fourth glass plate group B. The number of glass sheets of each glass sheet group is in principle the same as the number of grinding mills belonging to a system. However, there is no limitation to the case where the glass sheet is broken halfway, or the like.

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

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

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

Then, in (3), the first glass plate group a is conveyed to a transfer preparation position to be transferred to any one of the grinders 103. In the present embodiment, the transfer unit 106 for supply and recovery is provided in front of the grinding mill 103 (fig. 1), and can supply the first glass plate group a to the first system 103A in the state of (3).

At this time, the third glass plate group a collected into the conveyance path 102 is also conveyed together with the first glass plate group a to the same extent.

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

Then, in (5), the glass sheets on the conveyance path 102 (the third glass sheet group a) are conveyed downstream, and the second glass sheet group b next to the second glass sheet b2 is conveyed. Here, as shown in (5) of fig. 2, the third glass plate group a that has been polished can be conveyed while narrowing the interval between the adjacent glass plates in order to be conveyed quickly to the downstream side. That is, the conveyance path 102 narrows the interval between adjacent glass plates among the plurality of glass plates that have been polished. Thus, the efficiency of the entire 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 on the most downstream side. In the present application, a grinder that grinds the second glass plate b2 is set as the second grinder 103 d. The second grinder 103d is located on the downstream side of the first grinder 103 c. In the present embodiment, the grinder located on the most downstream side is used.

Then, the second system 103B performs the same movement as that in (1) and thereafter. That is, the fourth glass plate group B after completion of polishing is recovered to the conveyance path 102, and during this time, a new next glass plate is conveyed to close the gap with the second glass plate B2.

Fig. 3 is an example of a time chart showing the operation of each glass plate group described in fig. 2. Each column of the table shows the behavior of each glass plate group. The direction of the table row from the upper lattice to the lower lattice represents the passage of time. Each row indicates the same time. Further, "…" indicates that the glass sheet set is advanced to the next process step in the next grinding zone. The (1) to (6) of fig. 2 correspond to the first to sixth lines of fig. 3.

As described above, in the present embodiment, the following configuration is preferable. That is, when the grinder positioned on the most upstream side with respect to the conveyance direction of the conveyance path 102 among the plurality of grinders 103 is set as the first grinder 103c, the glass sheet G ground by the first grinder 103c among the plurality of glass sheets G is set as the first glass sheet a1, and the glass sheet conveyed immediately after the first glass sheet a1 among the plurality of glass sheets G is set as the second glass sheet b2, it is preferable that the conveyance path 102 convey the second glass sheet b2 to the downstream side in the conveyance direction than the first glass sheet a1 when the first glass sheet a1 is in either the feeding state, the grinding state, or the recovery state.

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

The supply, the polishing, or the collection is a time during which the first glass plate a1 is immediately separated from the conveyance path 102 by the transfer unit 106 and then starts and ends at the moment when the first glass plate a1 is placed on the conveyance path 102 by the transfer unit 106.

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

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

Here, the synchronous motion means that the plurality of grinders can start and/or end the operation at the same timing as a result of being independently controlled. Alternatively, a common program can be used to control the synchronized grinding machines. The term "identical time" means a concept of a range of ± 3 seconds or less allowed based on the exact identity. Further, the term "movement" is a concept including polishing, setting of a glass plate before polishing, taking out of a glass plate after polishing, and the like.

The present embodiment 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 are moved in synchronization in each of the plurality of systems, and the movement cycles of the plurality of grinders 103 are different between the plurality of systems, whereby the conveyance or preparation of the next glass plate group can be advanced during the time consumed by the other system, and finer control can be performed. At least one grinder is independently controlled at the time of abnormality, so that it is not necessary to stop the entire line as described above, thereby being efficient.

As in the present embodiment, a two-system batch system may be used. In a normal situation, in the first system 103A, the plurality of grinding mills 103 are moved synchronously, in the second system 103B, the plurality of grinding mills 103 are moved synchronously, and the movement period of the first system 130A is different from the movement period of the second system 103B, whereby the transport or preparation of the next glass plate group can be advanced during the time consumed by the other systems. In case of an abnormality, at least one grinder is independently controlled, so that it is not necessary to stop the entire line as described above, thereby being efficient. In addition, if the system is a dual system, the transfer machine for supply or recovery can be easily shared. In addition, 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 realize a balance that the number of transfer machines is reduced as much as possible and transfer of all glass plates to be transferred is completed within an allowable time.

In the case of the batch type of the double system, it is preferable to provide only 1 transfer unit 106 for supplying and collecting the glass sheets G between any pair of grinders. By sharing the transfer unit in the pair of grinders, the number of transfer units 106 can be reduced, and the apparatus configuration can be simplified.

Here, an example of the operation in the abnormal state will be described. In fig. 2 (1), it is assumed that any one of the third glass plate groups a is broken during grinding in any one of the first systems 103A.

At this time, in fig. 2 (2), the transfer unit 106 does not collect the broken glass plate. This space 201 is thereby left unfilled.

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

Then, in fig. 2 (4), the glass sheet to be polished by the abnormal polishing machine is not supplied to the first system 103A. Is conveyed downstream together with the other glass sheet (third glass sheet group a) that normally ends grinding. Then, the glass plate to be polished by the polishing machine having the abnormality is judged to be insufficiently polished by an inspection process or the like, and re-polishing or the like is performed.

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

The transfer device 106 is provided on a guide member connecting 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 enables smooth transfer to 3 positions.

The transfer unit 106 according to the present embodiment can be suspended from a guide rail connecting any pair of grinders (one of the first systems 103A and one of the second systems 103B) in the X direction, and moved to 3 positions, i.e., the first system 103A, the conveyance path 102, and the second system 103B. After the glass plates G are moved to the respective positions, the glass plates G are moved up and down in the Z direction, and can be transferred by the jigs. The present embodiment is not limited to this, but the transfer device is preferably movable only in the X direction. The device structure can be simplified.

The transfer unit 106 may convey the glass sheet G by holding the surface to be polished or the polished surface of the glass sheet G with the suction jig. Further, a back pad or a carrier described later may be held by a claw jig or the like.

In the case of the batch type of the two systems, it is preferable to shift the movement cycle by a half period in the first system 103A and the second system 103B. That is, the multiple grinders 103 have a first system 103A and a second system 103B with movement periods staggered by half a period. Preparation to either system can be performed in an equal time.

Here, the staggered half cycle is a concept of a range of ± 3 seconds or less allowed based on a completely staggered half cycle.

Similarly, in the case of a batch type of a plurality of systems, it is preferable to periodically shift the time amount obtained by dividing the time required for grinding the glass sheet G by the number of systems. Preparation to either system can be performed in an equal time.

Further, as shown in fig. 2 (5) and (6), when the first glass plate group a is in any one of the supply, the polishing, and the recovery, the conveyance path 102 preferably conveys the plurality of glass plates G constituting the second glass plate group b to the vicinity of any one of the plurality of polishing machines. The second glass plate group b can be conveyed downstream in the feeding or grinding or recovery of the first glass plate group a. That is, the time spent by the subsequent glass plate by the preceding glass plate exceeds the time spent by the preceding glass plate, and the subsequent glass plate is conveyed to the vicinity of the predetermined polishing machine to be polished. The time consumed for transportation does not substantially become a rate-limiting factor in production, and the efficiency is high.

After the end of conveyance, the second glass-plate group b may stand by until the first glass-plate group a is discharged from the grinder 103.

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

In principle, it is preferable from the viewpoint of efficiency that no space is provided between the glass plates during the conveyance of the glass plates, but by providing the space 201 in the state of (6), the glass plates after grinding (for example, the fourth glass plate group B) can be smoothly collected into the conveyance path 102.

Here, the portion where the interval of the width of the glass plate or more is provided between the plurality of glass plates G may be only the polishing region. In other conveyance, the interval between the plurality of glass sheets G is made as small as possible to be less than the width of 1 glass sheet, thereby enabling efficient production.

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 the 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. Outside the polishing zone 111 of the conveyance path 102, the second glass plate group b may be conveyed in a state where adjacent glass plates are not spaced apart from each other or in a state where the spacing is small. The interval is set only when necessary, thereby enabling efficient production.

Here, the state where the gap is small means a state where the gap is smaller than the width of any one of the plurality of glass plates.

The conveyance path 102 includes a first area 102A and a second area 102B, and the first area 102A and the second area 102B can independently control the start and/or stop of conveyance and/or the conveyance speed. Specifically, in the embodiment of fig. 1, the conveyor provided between a pair of grinders (first area 102A) and the conveyor provided between adjacent grinders in the same system (second area 102B) can be independently controlled. Thus, for example, even if the conveyance of the first glass sheet G is stopped, the subsequent glass sheet can be conveyed to close the gap during the stop time. Further, even if the subsequent glass plate is delayed for some reason, the gap with the preceding glass plate can be closed. Further, even when the space 201 is formed, the size of the space can be adjusted. This can improve the degree of freedom in conveying the glass sheet G.

In fig. 2, it is preferable to classify glass sheets G having similar qualities in advance for each glass sheet group. For example, if the quality of a glass plate group is originally good to some extent, adjustment such as setting the polishing time of the glass plate group short can be performed. On the other hand, if the glass sheet group is poor in quality, the polishing of the glass sheet 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 polishing zone 111 and downstream of the second glass plate b 2. That is, the conveyance path 102 conveys the first glass plate a1 to the downstream side of the second glass plate b 2. After (6), the first glass plate a1 is preferably recovered and conveyed to the downstream side while the second glass plate b2 is ground or the like. The conveyance order is in the same order downstream of the polishing zone 111, and thus management and tracking of the quality of the glass sheet G and the like are facilitated.

By being able to track the glass sheet G, it is possible to determine which grinder 103 the glass sheet G has been ground by. Further, if the quality of the glass sheet G is inspected, it is possible to grasp the state of each grinding machine 103, for example, when the timing of replacing the grinding pad is close, and efficient production such as prevention of generation of defective products can be performed.

Further, the conveyance path 102 preferably includes a glass supply path and a glass collection path, and the glass supply path is arranged along the glass collection 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. Thus, the glass sheet G to be polished can be conveyed downstream without waiting for the supply of the glass sheet G to the transfer machine. That is, in fig. 3, the "standby" of the third glass plate group a during 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 judge whether or not the glass plate is polished by looking at the appearance.

Here, the glass supply path and the recovery path may be vertically arranged in the Z direction or may be arranged in the X direction. It is preferable to arrange the devices vertically in the Z direction because the installation area of the devices can be reduced.

Further, the plurality of glass sheets G may be conveyed from the glass supply path, polished by the first system 103A, transferred to the second system 103B, polished, and collected by the glass collection path.

As shown in fig. 1, in the present embodiment, it is preferable that the plurality of glass plates G are 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, the plurality of glass plates G are conveyed, supplied, ground, and recovered in a state of being attached to the back pad 104, and the plurality of ground glass plates G are 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 surface plate has a large influence on the quality of the glass sheet G when polished, but if there is a defect in the back pad 104, the polishing surface plate is configured to be separated from the polishing machine as in the back pad 104, and only the back pad needs to be taken out from the conveyance path 102 and corrected, and the operation of the polishing machine 103 itself does not need to be stopped.

Here, the region of the conveyance path 102 to which the glass sheet G and the back pad 104 are bonded is referred to as a bonding region 110. Also, the region where the glass sheet G is separated 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 a region for carrying only may be present therebetween. The sticking region 110 is provided upstream of the polishing region 111, and the separation region 112 is provided downstream of the polishing region 111.

Further, it is preferable that the plurality of back pads 104 are circulated by conveying the plurality of back pads 104 conveyed to the downstream side of the plurality of grinders 103 to the upstream side of the plurality of grinders 103. By reusing the plurality of back pads 104, mass production of glass plates of the same quality can be performed. The manufacturing apparatus may further include a reverse path 105 for transferring the back pad 104 from the separation region 112 to the attachment region 110, and may circulate the plurality of back pads 104.

Here, in fig. 1, a backward path 105 for tracing back the back pad 104 upstream is provided below the conveyance path 102. That is, the back pad 104 from which the glass sheet G has been separated by the separation area 112 is conveyed downward in the Z direction by a mechanism such as a lifter, and is placed on the reverse path 105. Similarly, when the back pad 104 arrives at the sticking area 110, it is conveyed upward in the Z direction by a mechanism such as a lifter. This can reduce the installation area of the device. Further, the present configuration is not limited thereto, 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.

In addition, the number of the back pads 104 to be circulated is preferably (number of grinders/number of systems) × (number of systems + n) and n is an integer of 1 or more. In the parallel batch polishing as in the present embodiment, the supplied back pad 104 is automatically determined as a specific back pad group in each batch of a certain polishing machine 103. Since a slight individual difference occurs in manufacturing between the plurality of grinders 103 and the back pad 104, there is a combination that can provide glass plates having good compatibility with each other, i.e., high quality. The combination of the grinder 103 and the back pad 104 can be determined every time without disassembling the combination.

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

Also, if the number of the back pads 104 is 40(n ═ 2), for example, in the

first grinder

103c, 2 kinds of back pads 104 are alternately supplied between each lot. That is, by preparing 2 back pads 104 having good compatibility with the first grinder 103c, it is possible to continuously supply glass sheets G having stable quality.

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

In order to reduce the number of compatible back pads 104 that must be prepared as much as possible, n is preferably 2 or more than n is 1, and n is preferably 4 or more than n is 3. That is, the number of back pads 104 is particularly preferably set to an integral multiple of the number of grinders.

In order to prevent the combination with the back pad 104 group suitable for the grinder 103 from being disassembled, it is preferable to perform the same normal operation as the other back pads (glass plates) in the same system in a state where the back pad is empty even when the glass plate G is not attached. That is, even in the case where any one of the plurality of glass plates is not attached to any one of the plurality of back pads 104 in the circulation, it is preferable to perform the same movement as in the case where any one of the plurality of back pads 104 is attached. In the case where the glass sheet G is not attached, it is assumed that the glass sheet G cannot be conveyed when the glass is broken during attachment.

When an abnormality of an arbitrary back pad, that is, when repair is required, it is preferable to insert another back pad as a substitute at the position of the arbitrary back pad. It is possible to combine the back pad 104 set adapted to the grinder 103 without disassembly.

In addition, when an arbitrary back pad is abnormal, that is, when repair is required, it is preferable that the movement of the arbitrary back pad is continued as the arbitrary back pad exists, without the subsequent back pad closing the gap after the arbitrary back pad is removed from the cycle. It is possible to combine the back pad 104 set adapted to the grinder 103 without disassembly.

In addition, if an example of the above-described abnormal operation is performed, even when a back pad is used, the combination with the back pad 104 set suitable for the grinder 103 can be prevented from being disassembled.

In the separation area 112, it is preferable that 1 glass sheet G of the plurality of glass sheets G is separated from 1 back pad 104 of the plurality of back pads 104, and then a new back pad to which a new glass sheet is attached is conveyed to the polishing area. After the success of the separation in the separation zone can be confirmed and no failure such as breakage of the glass sheet G occurs, a new glass sheet is conveyed from the upstream side. This can suppress collision of the glass sheets G on the conveyance path 102.

It is preferable that the time when all of the plurality of glass plates of the same system are separated from the back pad 104 is earlier than the time when the plurality of glass plates G polished by the next system start to be conveyed to the separation zone. For example, in the case of the batch type of the dual system, the time when 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 time when the plurality of glass sheets G polished by the second system 103B start to be conveyed to the separation area. Thus, the separation of the glass sheets of the preceding batch (for example, the first system 103A) can be completed within the time consumed for the next batch (for example, the second system 103B), and the conveyance of the glass sheets G in the separation zone can be suppressed from being jammed at the rate of speed regulation.

In addition, at least a part of the plurality of glass plates is preferably ground a plurality of times by different back pads. Thereby, not only the individual difference due to the grinder 103 but also the variation in quality due to the individual difference of the back pad 104 can be reduced. As a specific configuration example, a glass plate which has been polished insufficiently in the glass plate which has been polished for the first time by the separation region 112 may be sorted and traced back to the attachment region 110, and attached to a back pad different from the first time to be polished for the second time. Further, a new attachment region 110, a polishing region 111, and a separation region 112 may be provided downstream of the separation region 112 to perform the second polishing.

In the case of the present embodiment, it is preferable that 4 or more grinders are provided. Can efficiently produce a large number of glass sheets with good quality. Further, 40 or less is preferable as the upper limit. When the number of polishing units is more than 40, the length of the polishing zone 111 of the conveyance path 102 tends to be too long. In this case, the glass sheet G may take time to pass through the polishing region 111, and the polishing process may be more rate-limiting than other processes. This can be suppressed.

Further, since the surface of the glass sheet 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 grinders is 40 or less, the conveyance path is not too 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-mentioned problem of speed limitation and the problem of 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.

Further, a moisture supply device for supplying moisture to the surface of the glass sheet G is preferably provided in the polishing zone 111 and/or on the downstream side of the polishing zone 111 on the conveyance path 102. It is preferable that water be supplied to the surface of the glass sheet after polishing in the polishing zone 111 and/or on the downstream side of the polishing zone 111. The above-mentioned problem of contamination can be suppressed. It is preferable to supply moisture before drying the surface of the glass sheet after grinding. The water supply device may also serve as a cleaning device.

A first modification of the present embodiment will be described with reference to fig. 3. Fig. 3 is an enlarged view of only a part of the first grinder 103c as a representative. In this 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 unit 106, polished at the first position 103X, then supplied to the second position 103Y by the intermediate transfer unit 301, polished at the second position 103Y, and then collected to the conveyance path 102 by the transfer unit 106.

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

With such a configuration, the glass sheet G is polished at 2 positions, and variations 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 the present specification, the first position 103X and the second position 103Y are defined as concepts belonging to 1 grinder. Even if the control systems or the structures of the apparatuses at the first position 103X and the second position 103Y are independent of each other, the grinding is performed by 1 grinder until the supplied and recovered from the conveyance path 102.

The term "the same residence time" means a concept of a range of ± 3 seconds or less on the basis of the exact same.

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

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

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 the finish polishing, the quality of the glass sheet G can be improved.

In the case of this modification, it is preferable that 10 or more grinders be used. By providing a plurality of such grinders 103, a large number of glass sheets with good quality can be efficiently produced. From the viewpoint of suppressing the above-mentioned problem of rate limiting and the problem of contamination, the upper limit of the number of grinders is preferably 20 or less.

As a second modification, the number of positions may be increased by 1 more than 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 times of the glass sheet G at the first polishing position 103X, the second polishing position 103Y, and the third polishing position are preferably the same.

The glass sheet G is polished at 3 positions, and variations 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.

Further, if the residence time is the same, the glass sheet G does not stand by, and the production efficiency is improved.

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

Preferably, the third polishing amount at the third polishing position is equal to or less than the second polishing amount at the second polishing position 103Y, and the second polishing amount is 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 finish polishing at the second polishing position 103Y and the third polishing position in stages.

In the case of the second modification, it is preferable that 2 or more grinders are used. By providing a plurality of such grinders 103, a large number of glass sheets with good quality can be efficiently produced. From the viewpoint of suppressing the above-mentioned problem of the rate limitation and the problem of the contamination, the upper limit of the grinding mill is preferably 14 or less.

All the grinders 103 of the first embodiment may have the first position 103X and the 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 and second modifications, the back pad 104 may be used as in the first embodiment. In this case, it is preferable to perform polishing at the first polishing position 103X and the second polishing position 103Y using different back pads. Thereby, not only the individual difference due to the grinder 103 but also the variation in quality due to the individual difference of the back pad 104 can be reduced.

In this case, a back pad replacing area is provided in the area where the intermediate transfer unit 301 is provided. After the polishing at the first polishing position 103X is completed, the glass sheet G is peeled off from the back pad 104 and replaced with a new back pad. Then, polishing is performed at the second polishing 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. The individual difference due to the back pad 104 can be further reduced.

A method for producing a polished glass plate for display according to a second embodiment of the present invention will be described below. The apparatus configuration 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 in fig. 1 are used. Note that explanations of terms, preferred embodiments, and descriptions of modifications are the same as those of the first embodiment unless otherwise specified below.

In the second embodiment, unlike the first embodiment, no system is configured, and the timings of starting polishing by the plurality of polishing machines 103 are different from each other. Are always independently moved. That is, the time when grinding is started differs among the plurality of grinders 103. By independently controlling the respective grinders 103, the degree of freedom of grinding of the glass sheet G can be increased. Further, the influence of the vibration of the plurality of grinders 103 on peripheral equipment and buildings can be reduced. Specifically, if the timings at which polishing starts are different, resonance of vibrations from the plurality of polishing machines 103 can be prevented. Moreover, if the intervals between the different timings are appropriately determined, it is also possible to cancel out the vibrations of the grinders 103 from each other.

In the second embodiment, the second grinder 103d for grinding the second glass sheet b2 is preferably a grinder located on the most downstream side in the conveying direction. Since the first glass plate a1 is ground at the most upstream, if the second glass plate b2 is carried to the most downstream, the amount of conveyance time of this second glass plate b2 can be used as the grinding/recovery time of the preceding glass plate that has been in grinding by the second grinder 103d, and therefore, the efficiency is high. Further, while the second glass sheet b2 is being supplied to the intermediate grinders, the most downstream grinders can be prevented from becoming empty and standing by, and therefore the efficiency is high.

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

In the second embodiment, it is preferable that at least a temporary gap 201 is formed at least partially between the plurality of glass sheets G in the polishing region 111. The interval 201 is preferably equal to or greater than the width of any of the plurality of glass plates. In the glass plate conveyance, although it is preferable that no space is provided between the glass plates from the viewpoint of efficiency, by providing the space 201 in the state of (6), the glass plate after polishing (for example, the fourth glass plate 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 the glass plate after polishing is not inserted (collected) in front of the conveyance path 102 on the downstream side of a certain glass plate while passing through the polishing zone, the gap with the preceding glass plate can be closed. This can be determined by associating information on the polishing state of the polishing machine on the downstream side of the current position of a certain glass sheet with the motion control of the conveyance path. With such a configuration, the production can be performed more efficiently.

In addition, the gap 201 is preferably formed at least temporarily between all the glass sheets during the passage through the polishing zone 111. Particularly, on the upstream side of the polishing zone 111, the intervals 201 are formed by adjusting the conveyance speed of all of the plurality of glass sheets G. When it is determined that the glass sheet after polishing is not inserted (collected) in front of the conveyance path 102 on the downstream side of the downstream side as it flows downstream, the gap between the glass sheet and the preceding glass sheet is closed. With this configuration, the polished glass sheet can be collected without waiting time, and the next glass sheet can be quickly supplied to the empty polishing machine, which is efficient.

The interval 201 preferably varies while passing through the polishing region 111. The conveyance speed of the plurality of glass sheets G may be controlled to gradually widen the interval. As a result of the polished glass plate being collected into the space 201, the space 201 can be narrowed. Furthermore, the space from the preceding glass plate may be filled. Can be produced efficiently and flexibly.

Further, it is preferable that a plurality of first transfer devices for supplying the plurality of glass sheets G on the conveyance path 102 to the plurality of grinders 103 are provided, and at least a part of the conveyance path 102 is stopped when the plurality of first transfer devices take out the plurality of glass sheets G from the conveyance path 102. Thus, the first transfer unit can easily grip the glass sheet G, and can suppress glass breakage due to gripping damage.

Further, it is preferable that a plurality of second transfer devices are provided for collecting the plurality of glass sheets G polished by the plurality of grinders 103 to the conveyance path 102, and when the plurality of second transfer devices place the plurality of glass sheets G on the conveyance path 102, at least a part of the conveyance path 102 is stopped. Thus, the second transfer unit can easily separate the glass sheet G, and can suppress glass breakage caused by contact between the glass sheet G and the moving conveyance path 102.

The first transfer unit and the second transfer unit may be the transfer unit 106 described in the first embodiment.

Further, while a part of the conveyance path 102 is stopped, the subsequent conveyance path can continue to move, and the subsequent glass sheet G can be filled in the gap, enabling more efficient production.

Further, the conveyance path 102 preferably includes a glass supply path and a glass collection path, and the glass supply path is arranged along the glass collection 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, the conveyance order of all the glass sheets G in the polishing zone 111 is scattered from that before the polishing zone, and control, quality control, and tracking are complicated. Further, it is possible to judge whether or not the glass plate is finished by polishing by looking at the appearance. In particular, if the conveyance path 102 is temporarily stopped at the time of glass supply and the time of glass collection, the conveyance path 102 is frequently stopped, and therefore, if the action is divided as in this configuration, conveyance can be made smooth.

It is preferable that the conveyance path 102 has a plurality of glass-plate placing spaces, and that, at the time of collection, a sensor detects a vacant space in the plurality of glass-plate placing spaces in which no glass plate is placed, and places the polished glass plate G in the vacant space. Since the space in which the glass sheets are already placed can be distinguished from the empty space, the collision of the glass sheets with each other can be reduced. In particular, in the second embodiment, when the number of conveyance paths is 1 when the glass sheet is collected from the downstream side grinding mill (when the glass sheet is taken as both the glass supply path and the collection path), it is necessary to place the glass sheet in a state where a predetermined glass sheet to be ground from now is mixed with a ground glass sheet collected from the upstream side grinding mill, and therefore, it is necessary to appropriately find an empty space, which is preferable.

Here, the space for placing the glass sheet is a section suitable for the size of the glass sheet G. The conveyance path 102 may connect the glass plate mounting spaces in a partitioned manner. In this case, the glass sheet G cannot be placed across the space for placing the adjacent glass sheet. That is, when the space in which the glass plate is already placed and the empty space alternate, the interval 201 corresponds to one empty space.

The sensor is preferably any one of a load sensor provided on the bottom surface of the plurality of placement spaces, an image authentication sensor for imaging the conveyance path 102, an optical sensor for detecting changes in the amount of reflected light or light, and a non-contact sensor of an inductive type, a capacitance type, or an air back pressure detection type. The presence or absence of the glass plate G can be determined by existing sensors, and therefore the apparatus configuration is simplified.

In the present application, a polished glass plate for display is a polished glass substrate used for display devices such as liquid crystal and OLED.

In the embodiment of the present invention, it is preferable that the supply, transfer, and collection are performed in a state where the surface to be polished and the polished surface of the glass sheet G are not in contact with each other. Since the surface to be polished and the polished surface are formed on the device, they are relatively fine, and the remaining traces, contaminated substances, and the like transferred can be suppressed by this structure.

In the embodiment of the present invention, the glass sheet G preferably has a size of 1500mm × 1800mm or more. Since such a large glass plate is likely to be broken during polishing or transfer, and high processing work or a long time is required for transfer, a parallel polishing method as in the embodiment of the present invention is suitable. 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, and more preferably 0.5mm or less. Since such thin glass plates are likely to be broken during polishing or transfer, and transfer requires a high degree of handling and a long time, a parallel polishing method as in the embodiment of the present invention is suitable. 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, it is preferable that the glass sheet G is 1500mm × 1800mm or more, and the thickness of the glass sheet G after polishing is 0.7mm or less. Since such a large and thin glass plate is likely to be broken during polishing or transfer, and a high processing operation or a long time is required for transfer, a parallel polishing method as in the embodiment of the present invention is suitable.

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

Industrial applicability

The present invention is suitably used in the field of manufacturing methods for polished glass plates for display, which require high efficiency.

Claims

1. A method for manufacturing a polished glass plate for display,

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

feeding the plurality of glass plates on the conveyance path to a grinder unit comprising a plurality of grinders arranged in parallel with the conveyance path,

a plurality of glass plates ground by any one of the grinders are collected in the conveyance path,

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

the plurality of glass plates are subjected to the conveyance, the plurality of glass plates are subjected to the supply, the plurality of glass plates are ground by the plurality of grinders of the grinder unit, and the plurality of glass plates are subjected to the recovery in a state where the plurality of glass plates are attached to a back pad,

separating the plurality of glass plates after polishing from the plurality of back pads respectively on a downstream side of the plurality of polishing units in the conveyance path,

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

2. The method for manufacturing a ground glass plate for display according to claim 1, wherein,

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

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

setting a glass plate conveyed immediately after the first glass plate among the plurality of glass plates as a second glass plate,

and conveying the second glass plate downstream of the first glass plate in the conveying direction when the first glass plate is in any one of the feeding state, the polishing state, and the recovering state.

3. The method for manufacturing a ground glass plate for display according to claim 2, wherein,

the multiple grinders usually belong to the same system with all grinders moving synchronously, and at least one grinder is independently controlled in case of an abnormality.

4. The method for manufacturing a ground glass plate for display according to claim 2, wherein,

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

in the normal time, the user can select the standard,

within each of said plurality of systems, said plurality of grinding mills are moved in synchronism,

the movement periods of the plurality of grinders are different between the respective systems of the plurality of systems,

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

5. The method for manufacturing a ground glass plate for display according to claim 2, wherein,

setting a plurality of grinders disposed on one side of the conveyance path among the plurality of grinders as a first system,

a second system of plural grinding machines disposed on the opposite side of the first system with the conveyance path therebetween,

in the normal time, the user can select the standard,

within the first system, the plurality of grinding mills are moved synchronously,

within the second system, the plurality of grinding mills are moved synchronously,

the movement periods of the first system and the second system are different,

6. The method for manufacturing a ground glass plate for display according to claim 5,

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

7. The method for manufacturing a ground glass plate for display according to claim 1 or 2, wherein,

the plurality of grinders are constituted by a plurality of pairs of grinders facing each other with the conveyance path therebetween.

8. The method for manufacturing a ground glass plate for display according to claim 7, wherein,

the plurality of transfer units for supplying and collecting the glass plate are provided only one between any one of the pair of grinders.

9. The method for manufacturing a ground glass plate for display according to claim 1, wherein,

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

10. The method for manufacturing a ground glass plate for display according to claim 1, wherein,

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

11. The method for manufacturing a ground glass plate for display according to claim 9 or 10, wherein,

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

12. The method for manufacturing a ground glass plate for display according to claim 9 or 10, wherein,

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

13. The method for manufacturing a ground glass plate for display according to claim 1, wherein,

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

14. The method for manufacturing a ground glass plate for display according to claim 1 or 2, wherein,

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

passing the glass plate through the first polishing position and the second polishing position to polish the glass plate,

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

15. The method for manufacturing a ground glass plate for display according to claim 14, wherein,

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

16. The method for manufacturing a ground glass plate for display according to claim 14, wherein,

the number of the grinders is more than 10.

17. The method for manufacturing a ground glass plate for display according to claim 1 or 2, wherein,

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

passing the glass plate through the first polishing position, the second polishing position, and the third polishing position to polish the glass plate,

the residence times of the glass sheet at the first, second, and third polishing positions are the same.

18. The method for manufacturing a ground glass plate for display according to claim 17, wherein,

a 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.

19. The method for manufacturing a ground glass plate for display according to claim 17, wherein,

the plurality of grinding mills are more than 2.

20. The method for manufacturing a ground glass plate for display according to claim 1 or 2, wherein,

the number of the grinders is 4 or more and 40 or less.

21. The method for manufacturing a ground glass plate for display according to claim 1 or 2, wherein,

when a region in the conveyance path where the plurality of grinders are arranged in parallel is referred to as a grinding region,

the length of the grinding zone is less than 100 m.

22. The method for manufacturing a ground glass plate for display according to claim 1 or 2, wherein,

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

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

supplying moisture before drying the surface of the ground glass sheet.

23. The method for manufacturing a ground glass plate for display according to claim 1 or 2, wherein,

the size of the plurality of glass plates G is 2200mm x 2200mm or more.

24. The method for manufacturing a ground glass plate for display according to claim 23, wherein,

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

25. The method for manufacturing a ground glass plate for display according to claim 1 or 2, wherein,

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

26. The method for manufacturing a ground glass plate for display according to claim 1 or 2, wherein,

any one of the plurality of grinders grinds only one glass sheet in one grinder motion.

27. The method for manufacturing a ground glass plate for display according to claim 1 or 2, wherein,

the time at which the grinding is started differs between the plurality of grinders.

28. The method for manufacturing a ground glass plate for display according to claim 27, wherein,

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

29. The method for manufacturing a ground glass plate for display according to claim 27, wherein,

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

the interval is greater than or equal to the width of any one of the plurality of glass plates.

30. The method for manufacturing a ground glass plate for display according to claim 29, wherein,

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

31. The manufacturing method of a ground glass plate for display according to claim 29 or 30,

the spacing varies during the time it is passing through the polishing zone.

32. The method for manufacturing a ground glass plate for display according to claim 27, wherein,

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

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

33. The method for manufacturing a ground glass plate for display according to claim 27, wherein,

a plurality of second transfer machines for recovering the plurality of glass plates polished by the plurality of polishing machines to the conveying path,

when the plurality of second transfer units place the plurality of glass plates on the conveyance path, at least a part of the conveyance path is stopped.

34. The method for manufacturing a ground glass plate for display according to claim 27, wherein,

the conveying path has a plurality of glass plate placing spaces,

detecting, by a sensor, a vacant space in the plurality of glass-plate placing spaces in which the glass plate is not placed during the collection,

and placing the ground glass plate in the empty space.

35. The method for manufacturing a ground glass plate for display use according to claim 34, wherein,

the sensor is any one of a load sensor provided on the bottom surface of the plurality of placement spaces, an image authentication sensor for capturing an image of the conveyance path, and an optical sensor for detecting a change in reflected light or light amount.

36. An apparatus for manufacturing a polished glass plate for display, comprising:

a conveyance path that extends in a first direction and conveys a plurality of glass plates;

a back pad attaching part which is positioned at the upstream side of the conveying path and attaches back pads to the plurality of glass plates respectively;

a plurality of grinders arranged in parallel with the conveyance path and configured to grind the glass plate conveyed in the conveyance path in a state of being attached to the back pad;

a back pad separating unit for separating the ground glass plate from the back pad;

and a circulating part for circulating the separated back pad to the back pad attaching part.

37. The manufacturing apparatus of a ground glass plate for display according to claim 36,

38. The manufacturing apparatus of a ground glass plate for display according to claim 36,

39. The manufacturing apparatus of a ground glass plate for display according to claim 36,

the plurality of grinding mills constitute a plurality of systems,

in the normal time, the user can select the standard,

the movement periods of the plurality of grinders are different among the respective systems of the plurality of systems,

40. The manufacturing apparatus of a ground glass plate for display according to claim 36,

the plurality of grinders having; a first system disposed on one side of the conveyance path; and a second system disposed on the opposite side of the first system with the conveyance path therebetween,

in the normal time, the user can select the standard,

the movement periods of the first system and the second system are different,

41. The manufacturing apparatus of a ground glass plate for display according to claim 40,

42. The manufacturing apparatus of a ground glass plate for display according to claim 40 or 41, wherein,

43. The manufacturing apparatus of a ground glass plate for display according to claim 42,

only one of the transfer unit is provided between any one of the plurality of pairs of grinders.

44. The manufacturing apparatus of a ground glass plate for display according to claim 36,

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

45. The manufacturing apparatus of a ground glass plate for display according to claim 36,

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

46. The manufacturing apparatus of a ground glass plate for display according to claim 44 or 45, wherein,

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

47. The manufacturing apparatus of a ground glass plate for display according to claim 44 or 45, wherein,

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

48. The manufacturing apparatus of a ground glass plate for display according to claim 36,

49. The manufacturing apparatus of a ground glass plate for display according to claim 36 or 37,

the number of the grinders is 4 or more and 40 or less.

50. The manufacturing apparatus of a ground glass plate for display according to claim 36 or 37,

the length of the grinding zone is less than 100 m.

51. The manufacturing apparatus of a ground glass plate for display according to claim 36 or 37,

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

supplying moisture to the surface of the ground glass sheet before drying.

52. The manufacturing apparatus of a ground glass plate for display according to claim 36 or 37,

the size of the glass plate G is 2200mm x 2200mm or more.

53. The manufacturing apparatus of a ground glass plate for display according to claim 36 or 37,

the thickness of the glass plate G after polishing is 0.7mm or less.

54. The manufacturing apparatus of a ground glass plate for display according to claim 36 or 37,

in the polishing, the polishing margin of the glass plate is 5.0 μm or less.

55. The manufacturing apparatus of a ground glass plate for display according to claim 36 or 37,

any one of the grinders grinds only one glass sheet in one movement of the grinder.

56. The manufacturing apparatus of a ground glass plate for display according to claim 36 or 37,

the timings at which the grinding is started are different from each other among the plurality of grinders.

57. The manufacturing apparatus of a ground glass plate for display according to claim 56,

58. The manufacturing apparatus of a ground glass plate for display according to claim 56,

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

when the plurality of first transfer units take out the glass plate from the conveyance path, at least a part of the conveyance path is stopped.

59. The manufacturing apparatus of a ground glass plate for display according to claim 56,

when the plurality of second transfer units place the glass plate on the conveyance path, at least a part of the conveyance path is stopped.

60. The manufacturing apparatus of a ground glass plate for display according to claim 56,

the conveying path has a glass plate placing space,

detecting, by a sensor, a vacant space in the glass-plate placing space in which the glass plate is not placed during the collection,

and placing the ground glass plate in the empty space.

61. The manufacturing apparatus of a ground glass plate for display according to claim 60, wherein,