JP5831974B2 - Sheet glass having edge polished by polishing tape, and method and apparatus for polishing sheet glass edge - Google Patents

Description

  The present invention relates to a flat glass such as a mobile phone display window, a liquid crystal panel, an organic EL panel, a plasma panel, a solar battery panel, a cover glass for an electronic component, a plate glass used for an optical filter, etc. The present invention relates to a plate glass whose strength is improved by polishing a part or one end face with a polishing tape, and a method for manufacturing the same, a polishing method, and a polishing apparatus.

  In many cases, the cracks in the plate glass originate from fine scratches existing at the edges (ridges or end faces) of the plate glass, and if there are scratches on the edge of the plate glass, they are fine. However, when a mechanical stress or a thermal stress is applied during the manufacture of the product or during the operation of the product, the scratches may be extended and the plate glass may be damaged.

  Moreover, the plate glass which has a corner | angular part in an edge part tends to produce glass waste, and this glass waste causes a contamination and a damage | wound on the main surface (upper surface or lower surface) of plate glass. In particular, when the glass sheet is used for a cover glass for an electronic component (for example, a cover glass for an imaging device) or an optical filter (for example, a near-infrared correction filter for an imaging device), contamination or scratches caused by glass waste It can be a big problem.

  For this reason, conventionally, flat glass used for various flat displays, cover glasses, and the like prevents scratches caused by glass dust, fine scratches at the edge, breakage due to chipping (chips), or the associated danger during work. For this reason, the edge portion has been chamfered by so-called C chamfering or R chamfering. By chamfering, fine scratches at the edge can be reduced, and the strength of the plate glass can be improved.

  Conventionally, in order to chamfer the edge part of plate glass, a substantially disc-shaped grinding wheel has been used. That is, chamfering is performed by rotating a substantially disk-shaped grinding wheel and pressing the disk surface or end surface of the grinding wheel against the edge of the plate glass.

  For example, a C-chamfering process has been performed in which only the ridge portion is removed by inclining and pressing the disk surface of a substantially disc-shaped grinding wheel (JP-A-2000-233351). Further, a chamfering process has been performed in which an inclined surface is provided on the end surface of the grinding wheel, and the inclined surface is pressed against the ridge portion of the plate glass to remove only the ridge portion (Japanese Patent Laid-Open No. 2003-231046: Patent Document 2, JP, 2011-51068, A: patent documents 3).

  Furthermore, an R chamfering process or a total shape process was performed in which an arc-shaped recess or a recess having a desired shape was formed on the end face of the grinding wheel, and the end face of the plate glass was removed following the end face shape of the grinding wheel ( JP 2002-59346 A: Patent Document 4; JP 2001-85710 A: Patent Document 5).

  In the conventional chamfering process as described above, a metal bond diamond wheel or the like in which metal powder is hardened and sintered and diamond abrasive grains are fixed is used as a grinding wheel, and wheels (grinding stones) having different abrasive grain sizes are used. In use, primary and secondary processing were performed. For the primary processing, a wheel using diamond particles of # 325 to # 600 in mesh size is used, and the average surface roughness Ra of the processed glass sheet edge is generally in the range of 0.5 μm to 1.0 μm. there were. In order to reduce the surface roughness, the secondary processing includes a finishing wheel using diamond particles of # 1000 to # 2000 with a mesh size formed in the same cross-sectional shape as the primary processing wheel. Used.

  Further, instead of the metal bond diamond wheel as described above, a chamfering wheel of a fiber structure in which a fiber space is filled with a resin, or abrasive grains such as silicon carbide and alumina of # 500 to # 2000 in mesh size are used. There has been proposed a chamfering wheel for a resin structure (Japanese Patent Laid-Open No. 2002-160147: Patent Document 6). While rotating the chamfering wheel (grinding stone), the peripheral portion of the wheel formed in a concave cross section was pressed against an end surface of a plate glass for liquid crystal display, and the like, and the processing was performed. In order to eliminate unevenness in processing and perform uniform polishing, the chamfering wheel was used with a rotation axis inclined at a predetermined angle with respect to a vertical line that is erected on the surface of the plate glass.

JP 2000-233351 A JP 2003-231046 A JP 2011-51068 A JP 2002-59346 A JP 2001-85710 A JP 2002-160147 A

  When chamfering is performed while pressing the grindstone (wheel) as described above against the edge of the plate glass and rotating, there is a problem that clogging of the grindstone and wear of the grindstone gradually progress. If the shape or the like of the processed part of the grindstone deteriorates due to clogging or wear, grinding scratches will occur at the edge of the plate glass, and the grindstone does not contact a part of the edge of the plate glass. Processing unevenness) and burning due to non-uniform processing pressure.

  Dressing and truing are performed when the shape of the processed part of the grindstone deteriorates, but high precision is indispensable for diamond wheels, and it takes time to adjust the position of the dressing and grindstone. Decreased. In addition, there is a problem that the cost increases because it is necessary to perform dressing or the like of the processed portion while leaving many unused areas of the grindstone, or to replace the grindstone as a lifetime.

  In addition, chamfering the edge of a plate glass using a grindstone has a problem that a mechanical impact is applied when the grindstone is brought into contact with a workpiece, and the plate glass is damaged by the impact, resulting in poor processing yield. It was.

  In a chamfered wheel (Patent Document 6) such as a resin structure having low rigidity compared to a metal bond diamond wheel, the impact on the edge of the plate glass is reduced, and the occurrence of chipping and scratches is reduced. However, since the wear of the grindstone is intense, the shape of the processed part changes rapidly and clogging occurs, which causes a problem that the frequency of dressing (or truing) of the grindstone is high.

  Further, in recent years, plate glass for liquid crystal displays and plate glass for thin electronic components (less than 1 mm) are required to be chamfered with edge portions (ridges and end surfaces) with higher accuracy. It was. However, if the edge of the plate glass is chamfered using a conventional grinding wheel, the accuracy of the resulting processed surface is insufficient, and fine scratches or chipping remain on the edge of the plate glass, preventing sufficient cracking. Did not become.

  In view of the above problems, an object of the present invention is to provide a plate glass whose edge portion is processed with high accuracy and imparted with high strength, a manufacturing method thereof, a polishing method, and a polishing apparatus.

  The plate glass according to the present invention that solves the above problems is a ridge portion of at least one side among the ridge portions at the boundary between the upper surface or the lower surface and the end surface of the rectangular plate glass having an end surface between the upper surface, the lower surface, and both surfaces thereof, or , At least one end face is a plate glass polished with a polishing tape and formed on a finished surface, and the finished surface has an average surface roughness Ra of 20 nm or less and a maximum valley depth Rv of 200 nm or less. Features.

  By polishing the ridge or end face of the plate glass by a method using a polishing tape, a finished surface having a highly accurate surface property is formed on the ridge or end face of the plate glass. By forming the ridge portion or the end surface on the finished surface having the above-described surface roughness Ra and maximum valley depth Rv, the strength of the plate glass is remarkably improved. The plate glass according to the present invention is capable of preventing the occurrence of cracks starting from fine scratches and chips on the peripheral edge, and preventing breakage due to mechanical stress or heat shock. Moreover, the process yield of a post process can be improved and the reliability of the product in which plate glass was incorporated can be improved.

  According to the present invention, there is provided a manufacturing method for manufacturing a plate glass having a ridge portion formed on a finished surface having a predetermined surface property, wherein the surface of an elastic pad member is disposed on the back surface of the polishing tape, and at least one side of the plate glass The surface of the polishing tape and the ridge of one side of the plate glass are disposed to face each other in order to chamfer the ridge of the sheet, and the surface of the polishing tape is applied by applying a predetermined pressing force to the polishing tape through the pad member. And a step of abutting and pressing the ridge portion on one side and a step of polishing the ridge portion on one side by moving the plate glass along a linear movement axis. Here, the surface of the polishing tape is composed of a polishing layer containing abrasive grains, and the average grain size of the abrasive grains is in the range of 0.2 μm to 3.0 μm. In the polishing step, the polishing tape may be stopped without running or may be running.

  In this way, the edge that is most likely to cause damage by placing one edge of the upper or lower surface of the glass sheet facing the surface of the polishing tape and abutting, pressing, and polishing (C-surface polishing). It is possible to remove cracks and chips in the part.

  By using a flexible polishing tape that contains fine abrasive grains on the surface and an elastic pad member, the edge (edge) of the chamfered surface (finished surface) has an acute angle. In addition, it is possible to form a finished surface which is polished and finished with high accuracy without newly causing scratches or chips on the edge of the plate glass. The glass sheet on which such a finished surface is formed has significantly improved strength and is less likely to crack or break.

  In the polishing step, the surfaces of the plate glass and the polishing tape move relative to each other, and the plate glass preferably reciprocates along a linear movement axis. Even if polishing is performed by moving the object to be polished (plate glass) relative to the polishing body (surface of the polishing tape) due to the flexibility and elasticity of the polishing tape and pad member, and the strength of the sheet glass, the object to be polished is being polished during polishing. Will not be damaged.

  Preferably, when the plate glass moves along the movement axis, the ridge portion on one side is inclined by a predetermined angle (θ) with respect to the movement axis. Since the ridge portion is inclined with respect to the moving axis, fine abrasive grains on the surface of the polishing tape can be efficiently applied to the ridge portion. Moreover, it can grind | polish efficiently in a short time, utilizing the width | variety (area) of a polishing tape effectively.

  The predetermined angle (θ) is preferably in the range of 5 to 60 degrees. In this range, it is preferable from the viewpoint of cost to adjust the angle (θ) according to the width of the polishing tape.

  Furthermore, the movement axis may be parallel to the longitudinal direction of the polishing tape, or may be inclined by a predetermined angle (β) with respect to the longitudinal direction of the polishing tape. It is efficient that the moving axis is inclined with respect to the longitudinal direction of the polishing tape depending on the width of the polishing tape and the running state.

  Further, according to the present invention, there is provided a manufacturing method for manufacturing a plate glass having a finished surface having a predetermined surface property, wherein the surface of the polishing tape is arranged by arranging the surface of an elastic pad member on the back surface of the polishing tape. And a step of arranging one end face of the plate glass to face each other, a step of abutting and pressing the surface of the polishing tape against one end face by applying a predetermined pressing force to the polishing tape through the pad member, and a plate glass Polishing one end face by moving along a linear movement axis. Here, the surface of the polishing tape is composed of a polishing layer containing abrasive grains, and the average grain size of the abrasive grains is in the range of 0.2 μm to 3.0 μm. In the polishing step, the polishing tape may be stopped without running or may be running.

  By the manufacturing method described above, it is possible to manufacture a plate glass in which the entire end surface is formed on the finished surface. After the ridge is formed on the finished surface, the remaining end surface may be formed on the finished surface by the above method. By polishing the entire end surface, there is no polishing residue and the removal of dirt and polishing debris is sufficiently performed, so that it is possible to prevent contamination and scratches on the main surface of the plate glass.

  The surface of the pad member may be a flat surface. Since the surface of the pad is a flat surface, the entire edge of one side can be brought into contact with the surface of the polishing tape disposed on the surface of the pad and polished.

  Further, the surface of the pad member may be a convex curved surface that is not flat. This is because it is possible to polish while protecting the polishing tape by restricting the contact of the corner portion of the plate glass (the portion formed between one end surface and the other end surface) to the polishing tape surface.

  As the pad member, it is preferable to use a first pad member having a Shore A hardness of 20 to 50. The elastic pad member can relieve the mechanical impact caused by the contact between the polishing tape and the edge of the glass sheet, and can be processed in accordance with the change of the shape of the edge along with the polishing.

  Furthermore, in the manufacturing method according to the present invention, a second pad member having a Shore A hardness of 90 or less may be disposed between the polishing tape and the first pad member. This is because an appropriate pad member is used according to specifications such as the material and thickness of the plate glass.

  The plate glass according to the present invention has a ridge or end surface polished and formed on a finished surface using a flexible polishing tape and an elastic pad member. Also, the cross section has an R-shaped curved surface. By forming the finished surface of the ridge portion so as to satisfy the surface properties such as the above-mentioned maximum valley depth and the cross-sectional shape having a curved surface, it is possible to obtain a plate glass with extremely few occurrence factors of chipping and cracking.

  During polishing, the polishing tape may be stopped and may run continuously or intermittently. Polishing in a short time is economical because the amount of the polishing tape used is reduced by polishing the polishing tape while it is stopped. When the polishing time is relatively long, the polishing efficiency can be increased by sequentially feeding new polishing tapes.

  Depending on the state of the plate glass, the pressing force for pressing the surface of the polishing tape against the ridge or end surface of the plate glass is small at the initial stage of polishing and may be gradually increased as the polishing progresses. For example, depending on the plate glass, there are sharp corners and ridges. In this case, if a strong pressing force is applied from the beginning of polishing, the sharp tape may damage the polishing tape or damage the polishing tape. There is a case. By adjusting the pressing force, polishing can be performed while protecting the polishing tape surface.

  Polishing can be performed either dry or wet. In the case of the wet type, polishing is performed while supplying an aqueous solution in which water or a surfactant is added to the surface of the polishing tape.

  The present invention also relates to a polishing apparatus for forming a ridge or end surface of a plate glass on a highly accurate finished surface. The polishing apparatus according to the present invention includes at least one ridge or at least one end surface among the ridges at the boundary between the upper surface or the lower surface and the end surface of a rectangular plate glass having end surfaces between the upper surface, the lower surface, and both surfaces thereof. A polishing apparatus for polishing a polishing tape to form a finished surface, a work unit for arranging a base and a plate glass, the plate glass being movable on the base along a movement axis parallel to the base And a polishing tape unit for disposing a polishing tape, and a polishing tape unit provided on the base so as to face the work unit. The work unit pivots a holding table for holding the glass plate so that one end surface of the glass plate is parallel to the movement axis and the upper or lower surface of the glass plate is parallel to the base, and the holding table is centered on the movement axis. And a first tilting means for tilting the upper or lower surface of the plate glass with respect to the base by a predetermined angle (α), and the holding base around the rotation axis perpendicular to the movement axis and parallel to the base. And second tilting means for tilting the upper surface or lower surface of the plate glass by a predetermined angle (θ) by rotating. The polishing tape unit includes a pad for disposing the polishing tape such that the surface containing the abrasive grains of the polishing tape faces one edge of the plate glass or the one end face, and a polishing perpendicular to the base for attaching the pad. A plate, a pressing means for moving the polishing plate in a direction parallel to the base and perpendicular to the movement axis so that the surface of the polishing tape is in contact with and pressed against a ridge of one side or one end surface; Polishing tape running means for running.

  In the present invention, when the polishing tape is disposed on the pad, the longitudinal direction of the polishing tape is preferably parallel to the movement axis.

  Further, the longitudinal direction (running direction) of the polishing tape disposed on the pad may be inclined by a predetermined angle (β) with respect to the movement axis depending on the width of the polishing tape, the running state, and the like. In order to incline the longitudinal direction of the polishing tape with respect to the movement axis, the polishing tape unit preferably includes polishing plate tilting means for tilting the polishing plate.

  Furthermore, the present invention moves a rectangular plate glass having an end surface between an upper surface, a lower surface, and both surfaces thereof along a horizontal movement axis, and at least of ridges at a boundary between the upper surface or the lower surface and the end surface of the plate glass. The present invention relates to a polishing method for polishing a ridge portion on one side with a surface having abrasive grains of a polishing tape to form a finished surface. The polishing method according to the present invention includes a step of arranging the plate glass so that one end surface of the plate glass is parallel to the movement axis and the upper or lower surface of the plate glass is horizontal, and the plate glass is pivoted about the movement axis. A first tilting step of tilting the upper or lower surface of the glass sheet by a predetermined angle (α) with respect to the horizontal, and the glass sheet by rotating the glass sheet about a rotation axis that is horizontal and perpendicular to the moving axis. A second tilting step of tilting the upper surface or lower surface of the sheet by a predetermined angle (θ) with respect to the horizontal, and disposing the polishing tape on the surface of the pad member so that the surface of the polishing tape faces the ridge of one side of the plate glass A step of applying a predetermined pressing force to the polishing tape through the pad member, abutting and pressing the surface of the polishing tape against a ridge on one side, and moving the plate glass along the movement axis Polishing a ridge on one side.

  Also in the above polishing method, the longitudinal direction of the polishing tape disposed on the pad member may be parallel to the movement axis, or may be inclined by a predetermined angle (β) with respect to the movement axis.

  According to the present invention, a ridge or end surface used for manufacturing a flat display such as a mobile phone display window, a liquid crystal panel, an organic EL panel, a plasma panel, a solar battery panel, a cover glass for an electronic component, an optical filter, etc. Can be processed with high accuracy to obtain a plate glass having improved strength. By using a polishing tape to polish the ridges or end faces of the plate glass, scratches and chips on the edge that cause damage can be sufficiently removed, and a highly accurate finished surface can be formed. Can do. By implementing the plate glass according to the present invention, the production yield of products such as various flat displays can be improved, and the quality and accuracy of products in which the plate glass is incorporated can be improved.

FIG. 1 is a diagram schematically showing a plate glass. 2 (A) and 2 (B) are diagrams schematically showing a process of forming a finished surface at the edge portion of the plate glass and a side surface shape of the formed finished surface. FIG. 2C is a diagram showing the angles of the surface of the plate glass and the polishing tape in the process of forming the finished surface of FIG. FIG. 3 is a plan view showing a polishing apparatus according to one embodiment of the present invention. FIG. 4 is a diagram schematically showing a polishing apparatus according to the present invention. FIG. 5 is a side view showing a polishing apparatus according to one embodiment of the present invention. FIG. 5A is a schematic view of the movable plate of the polishing apparatus according to the present invention. FIG. 5B is a schematic diagram of the central cross section of the inclined plate 35 of the polishing apparatus according to the present invention. FIG. 6 is a front view showing a polishing apparatus according to one embodiment of the present invention. FIG. 7A is a front view showing a polishing tape unit according to one embodiment of the present invention. FIG. 7B is a front view showing a state in which the polishing tape unit of one aspect according to the present invention is inclined. FIGS. 8A and 8B are diagrams schematically showing a plate glass manufacturing method, a polishing method, and a plate glass, a polishing tape surface, and a moving axis in a polishing apparatus according to one embodiment of the present invention. FIG. 9 is a diagram schematically showing a plate glass manufacturing method, a polishing method, a plate glass, a polishing tape surface, a moving axis, and the like in another embodiment of the present invention. FIGS. 10A and 10B are diagrams schematically showing a plate glass manufacturing method, a polishing method, a plate glass in a polishing apparatus, a polishing tape surface, and a moving direction thereof according to another embodiment of the present invention. FIGS. 11A to 11D are enlarged photographs of the finished surfaces of the plate glass of the example according to the present invention and the plate glass of the comparative example. FIG. 12 is an enlarged photograph of the finished surface of a plate glass according to Comparative Example 4 using a grindstone. FIG. 13 is a diagram schematically showing a four-point bending test method for measuring the edge strength of a sheet glass. FIG. 14 is a schematic diagram illustrating a method for polishing a ridge portion of a plate glass using the grindstone according to Comparative Example 4. FIGS. 15A and 15B are schematic views showing the shape of the corner of the plate glass and the shape of the pad, respectively.

  Various features of the present invention will now be described with reference to the preferred embodiments, which are not intended to limit the invention, with reference to the drawings. The drawings are simplified for illustrative purposes, and the scales do not necessarily coincide.

  FIG. 1 schematically shows a plate glass W. The plate glass W generally has a ridge at the boundary between the upper surface or the lower surface (main surface) and the end surface, and has a corner at the boundary between one end surface and the other end surface. In the plate glass according to the present invention, the ridges and end surfaces are polished by a polishing tape and formed on a highly accurate finished surface.

  FIG. 2 schematically shows the process of chamfering the plate glass W and the shape of the side surface of the formed finished surface. In FIG. 2A, a ridge is formed on the finished surface 30a by so-called C chamfering. In FIG. 2B, the entire finished surface 30b is formed from the ridge portion to the end surface by so-called R chamfering.

  In order to improve the strength of the plate glass W, the surface roughness or maximum valley depth of the finished surface 30a or 30b formed by removing the ridges by removing the ridges by polishing the edges and removing scratches and chippings. It is important to make it smaller. In order to impart sufficient mechanical strength to the plate glass W, it is effective to set the average surface roughness Ra of the finished surface 30a or 30b to 20 nm or less and the maximum valley depth Rv of the roughness curve to 200 nm or less.

  In order to obtain such a highly accurate finished surface, in the present invention, the ridge portion or end surface (edge portion) of the plate glass W is polished and finished with a polishing tape having a polishing layer containing fine abrasive grains on the surface. It is characterized by. In order to obtain a highly accurate finished surface 30a or 30b, the polishing can be performed by dividing into rough polishing, intermediate polishing and mirror finishing processes. In addition, efficient polishing can be performed by performing chamfering of the corner (FIG. 1) using a resin bond grindstone with less processing distortion and then polishing with a polishing tape.

  The average particle size of the abrasive grains contained on the surface of the polishing tape is preferably in the range of 0.2 μm or more (# 20000) or 3 μm or less (# 4000). When the average particle diameter exceeds 3 μm, relatively large scratches and chips before polishing can be removed, but it is preferable because fine scratches and chips are newly generated on the finished surface and sufficient strength cannot be given to the plate glass W. Absent. When the average particle size is less than 0.2 μm, the polishing efficiency is extremely lowered and the productivity is deteriorated, so that it is not industrially practical.

Hereinafter, an aspect of a polishing apparatus according to the present invention for polishing a ridge (or end surface) of a glass sheet W with a polishing tape to obtain a finished surface having a predetermined surface property will be described with reference to the drawings.

  FIG. 3 is a plan view of the polishing apparatus 1, and FIG. 5 is a side view of the polishing apparatus 1. A polishing apparatus 1 according to the present invention includes a work unit 3 and a polishing tape unit 4 provided on a base 2 so as to face each other.

  The work unit 3 is attached to a reciprocating mechanism provided on the base 2. Referring to FIG. 3, the reciprocating mechanism includes an LM guide 6 having a rail 32 parallel to the base 2, and a single-axis robot 5 having a rail (box) 31 parallel to the rail 32. As well shown in FIG. 5, a traveling body 7 parallel to the base 2 is connected to the LM guide 6 and the single-axis robot 5. The work unit 3 is attached to the traveling body 7, so that the work unit 3 can move along the rail 32 of the LM guide 6. The moving axis 13 of the work unit 3 is defined by the rail 32.

  The single-axis robot 5 is configured such that a nut (movable part) linearly reciprocates along a ball screw at a predetermined interval (stroke) by rotating a ball screw in a rail 31 with a motor. Since the traveling body 7 is connected to the movable portion of the single-axis robot 5, the traveling body 7 is driven and can reciprocate. The single-axis robot 5 may be one in which the nut rotates with respect to the fixed ball screw and reciprocates linearly by the motor being arranged coaxially with and coupled to the nut (movable part). Alternatively, the traveling body 7 may be linearly driven by other configurations.

  In order for the traveling body 7 to reciprocate accurately along the movement axis 13 (FIG. 3), it is preferable to use the single-axis robot 5 and the LM guide 6 together. May be reciprocated by an LM guide functioning as:

  Referring to FIG. 5, the work unit 3 includes a front plate 14 that is vertically attached to the traveling body 7, an inclined plate 37 that is attached in parallel to the front plate 14, an inclined plate 35 that is vertically attached to the inclined plate 37, and The holding plate 12 is held by a movable plate 35 ′ of the inclined plate 35. The holding table 12 is perpendicular to the front plate 14 and parallel to the base 2 in a state where the holding table 12 is not inclined by the inclined plate (35 or 37).

  As well shown in FIG. 3, a plate glass W is disposed on the upper surface of the holding table 12 for final polishing with a polishing tape. The plate glass W is arranged and fixed on the holding base 12 so that one end face thereof is parallel to the movement axis 13. The plate glass W is fixed by a fixing plate 33 and a fixing lever 34. Elastic sheets such as cloth and rubber are attached to the front surface of the holding table 12 on which the plate glass W is disposed and the back surface of the fixed plate 33 so that the plate glass surface is not damaged. In addition, the plate glass W may be fixed to the holding table 12 by a vacuum suction method, band fixing, or the like.

  In FIG. 6, a front view of the work unit 3 is partially overlapped with the polishing tape unit 4. A substantially U-shaped front plate 14 having an opening upwardly extends perpendicular to the traveling body 7 parallel to the base 2 and parallel to the movement axis 13. A substantially U-shaped inclined plate 37 is attached to the front plate 14 in parallel. In the drawing, the opening of the front plate 14 that overlaps the inclined plate 37 is indicated by a dotted line. Inside the opening of the inclined plate 37, a pair of inclined plates 35, 35 are provided perpendicular to the inclined plate 37 so as to face left and right.

  The inclined plate 37 has an arcuate screw groove on the left and right and an arcuate guide groove 39 on the bottom. Each of the screw groove and the guide groove 39 is formed so as to define a part of the circumference of a circle having a center C. A fixing screw 38 for fixing the inclined plate 37 to the front plate 14 at a predetermined angle passes through the left and right screw grooves. The inclined plate 37 is fixed to the front plate 14 by tightening the fixing screw 38 via a washer or the like (not shown). A rod (guide roller) 39a fixed to the front plate 14 passes through the guide groove 39. With the fixing screw 38 loosened, the inclined plate 37 is perpendicular to the base 2 along the guide groove 39 and the rod 39a. It can be rotated in a plane. In other words, the inclined plate 37 can rotate around an axis that passes through the center C and is perpendicular to the movement axis 13 and parallel to the base 2.

  As the tilt plate 37 rotates, the tilt plate 35 provided integrally with the tilt plate 37 also rotates, and the holding table 12 held between the movable plates 35 ′ located on the left and right is indicated by a one-dot chain line. And is inclined with respect to the movement axis 13 parallel to the base 2. When the holding table 12 is inclined at a desired angle with respect to the movement axis 13, the inclined plate 37 is fixed to the front plate 14 by a fixing screw 38.

  The inclined plate 35 integrally provided perpendicularly to the inclined plate 37 has a symmetrical configuration. A pair of left and right movable plates 35 ′ and 35 ′ parallel to the inclined plate 35 are provided inside the pair of left and right inclined plates 35 and 35. The movable plate 35 ′ holds the holding table 12.

  Referring to FIG. 5, the inclined plate 35 has an arcuate screw groove 35 a (solid line portion). The screw groove 35a penetrates the inclined plate 35 in order to insert the fixing screw 36 into the movable plate 35 'from the outside and tighten it. The fixing screw 36 preferably has a handle such as a clamp lever or a knob so that it can be efficiently tightened.

  Inside the inclined plate 35, an arcuate guide groove 35b (dotted line portion) having substantially the same shape as the screw groove is formed along the screw groove 35a. FIG. 5B schematically shows a central cross section of the inclined plate 35. The inner guide groove 35b is wider than the screw groove 35a and is formed so as not to penetrate the inclined plate 35.

  As well shown in FIG. 5, each of the screw groove 35a and the guide groove 35b is formed so as to define a part of the circumference of a circle whose center is C '. The rod (guide roller) 35'a (FIG. 15A) of the movable plate 35 'slides along the guide groove 35b. That is, the movable plate 35 ′ of the inclined plate 35 pivots about C ′ in a plane perpendicular to the front plate 14, and the movable plate 35 ′ pivots between the movable plates 35 ′ and 35 ′. The fixed holding base 12 is pivoted about the moving axis 13 passing through the center C ′ and tilted with respect to the base 2. When the holding base 12 is inclined with respect to the base 2 by a desired angle, the movable plate 35 ′ is fixed to the inclined plate 35 by tightening the fixing screw 36 from the outside of the inclined plate 35.

  As described above, the holding table 12 is tilted by the tilt plate 35 (from a state parallel to the base 2) and pivoted about the moving axis 13, or the holding table 12 is tilted by the tilt plate 37 (to the base 2). The tilt angle may be adjusted first by rotating around an axis perpendicular to the movement axis 13 and parallel to the base 2 (from a parallel state).

  FIG. 5 shows a side view of the polishing tape unit 4. The polishing tape unit 4 has a pair of fixed plates 50, 50 extending vertically from the base 2 and facing each other. A pair of inclined plates 46 and 46 are attached in parallel to the fixed plates 50 and 50 via rods (guide rollers) 49a (FIG. 7A). A guide bearing 48 made up of a shaft (shaft) and a nut (bearing) extends between the inclined plates 46 and 46. As shown in the front view of FIG. 7A, a pair of left and right guide bearings 48, 48 extend between the inclined plates 46, 46 and are integrally connected by a connecting member (not indicated). The guide bearing 48 may be a linear bush composed of a shaft and a cylindrical nut, a ball spline, a ball bearing guide, or the like.

  Referring to FIG. 5, a moving plate 42 is placed on the guide bearing 48 in parallel with the base 2. A polishing plate 27 extends vertically from the moving plate 42. A pad 26 is attached to the polishing plate 27 vertically to the base 2.

  When the rod of the air cylinder 43 is pushed out or pulled in by air pressure or a spring, the nut (movable part) of the guide bearing 48 reciprocates in the direction of the arrow 28 along the shaft. Instead of the air cylinder 43, other pressing means for giving a reciprocating movement to the nut (movable part) may be used. When the nut (movable part) of the guide bearing 48 reciprocates, the moving plate 42 and the polishing plate 27 attached to the moving plate 42 reciprocate along the arrow 28, and the surface of the polishing tape T disposed on the pad 26 moves. Then, the workpiece can approach the work unit 3 and be pressed against the object to be polished (plate glass W) with a predetermined pressing force (thrust), or can be moved away from the work unit 3.

  An inclined plate 46 is shown in FIG. 7A. In the figure, the fixed plate 50 is indicated by a dotted line. The inclined plate 46 has an arcuate thread groove for passing the fixing screw 47 on the left and right sides, and has an arcuate guide groove 49. Each of the left and right screw grooves and the guide groove 49 is preferably formed so as to define a part of the circumference of a circle centering on the center C ″ of the polishing tape T disposed on the pad 26. According to the configuration, the inclined plate 46 can rotate along the guide groove 49 and the rod (guide roller) 49a passing through the guide groove with the fixing screw 47 loosened.

  As well shown in FIG. 7B, when the inclined plate 46 rotates, the moving plate 42 is inclined from the state parallel to the base 2 and the polishing plate 27 is also inclined. When the polishing plate 27 is inclined, the longitudinal direction of the polishing tape T attached to the polishing plate 27 via the pad 26 is inclined with respect to the base 2 (the movement axis 13 of the work unit 3). In other words, the longitudinal direction of the polishing tape T can be tilted with respect to the movement axis 13 by rotating around an axis passing through C ″ that is perpendicular to the movement axis 13 and parallel to the base 2. When the longitudinal direction of T is inclined by a desired angle with respect to the movement axis 13, the inclined plate 46 is fixed to the fixed plate 50 by a fixing screw 47.

  The polishing tape T (FIG. 3) is disposed on the pad 26 of the polishing tape unit 4 so as to be able to run.

  By placing the pad 26 on the back surface of the polishing tape T, the surface of the polishing tape T is pressed against the portion to be polished (ridge portion) of the plate glass W via the pad. Due to the elasticity of the pad 26, the finished surface (30a) can be formed to have a curved surface, that is, the cross section has an R shape, and the strength of the plate glass can be further improved. As the pad 26, an elastic body of rubber, foamed resin, or a composite material thereof can be used.

  The elasticity of the pad 26 is preferably selected appropriately in order to form a highly accurate finished surface using a polishing tape having fine abrasive grains on the surface.

  If the elasticity of the pad 26 is too large (for example, the Shore A hardness is less than 20), the finished surface of the plate glass W is bent and the linearity of the edge portion is lost, which is not preferable. On the other hand, if the elasticity is too small (for example, Shore A hardness is over 90), the edge of the finished surface will have sufficient linearity, but the removal of scratches and chips generated on the workpiece due to mechanical impact will be insufficient. Since the strength of the plate glass W is lowered, it is not preferable.

  For this reason, the pad 26 may be a foamed resin plate having a Shore A hardness of 20 to 50 in order to reduce mechanical shock. Further, when the average particle size of the abrasive grains contained in the surface of the polishing tape T is 1 μm or less (# 8000), the foaming resin plate having high elasticity is not practical because the polishing rate is drastically decreased. Is preferably a combination of the above foamed resin plate and a rubber plate having a Shore A hardness of 80 to 90. By doing so, even when an abrasive tape having an extremely small average particle diameter (for example, 1 μm or less) is used, high-precision surface properties (Ra, Rv) are obtained without slowing the polishing rate very much. It is possible to form a finished surface having excellent linearity of the edge portion.

  FIG. 4 schematically shows the polishing tape unit 4 in which elastic pads 26A and 26B are arranged. For example, the pad 26A may be a rubber plate having a relatively small elasticity, and the pad 26B may be a foamed resin plate having a relatively large elasticity.

  FIG. 15 shows one mode and another mode related to the arrangement of the movement axis 13 and the surface of the polishing tape T. As shown in FIG. 16A, when the corner portion of the plate glass W is chamfered in an R shape in advance, polishing is performed by reciprocating the plate glass W in a state where the surface of the polishing tape T and the movement axis 13 are parallel. Is called.

  As shown in FIG. 16B, when the plate glass W has a corner portion that is not chamfered in advance or has a small chamfer (hereinafter referred to as a corner portion R ′), a polishing tape as shown in FIG. When the surface of T and the movement axis 13 of the plate glass W are in parallel, the corner R ′ that enters the polishing tape T damages the polishing tape T, so that the polishing tape T is torn and the polishing must be interrupted. There are things that must be done.

  For this reason, when the plate glass W having the corner R ′ is polished with the polishing tape T, it is preferable that the surface of the polishing tape T has a convex curved surface with respect to the plate glass W. Thus, in order to arrange the surface of the polishing tape T, it is preferable to attach the pad 26 along the curved surface of the polishing plate 27 having a convex curved surface on the surface facing the plate glass W. Alternatively, a pad 26 having a convex curved surface with respect to the plate glass W may be attached to the flat polishing plate 27. In this way, the contact of the corner portion R ′ entering the polishing tape T with the surface of the polishing tape T is limited, so that the polishing tape T is not damaged and the durability of the polishing tape T is improved. improves.

  The convex curved surface is an arc-shaped curved surface having a large radius of curvature, and is preferably a curved surface close to a flat surface. This is because if the curvature of the surface of the polishing tape T becomes larger than necessary, the contact area between the surface of the polishing tape T and the plate glass W becomes smaller and the polishing efficiency is lowered, which is not preferable. Further, when the interval (stroke) of the reciprocating movement of the plate glass W is small, the polishing difference between the central portion and both end portions of the polished portion (one side ridge portion) of the plate glass W (the polishing amount at both end portions is smaller than the central portion). This is not preferable.

  Referring to FIG. 3, the polishing tape unit 4 includes a supply roll 22 that supplies the polishing tape T and a winding roll 23 that winds up the polishing tape. The supply reel 22 is connected to a torque motor (not shown) in order to give an appropriate tension to the polishing tape T. The take-up reel 23 is connected to a stepping motor (not shown) and takes up the polishing tape T supplied from the supply reel 22. A stopper roller (not shown) for applying an appropriate tension to the polishing tape T is provided on the take-up reel 23 side. Further, the polishing tape unit 4 may have auxiliary rollers 24 and 25 for appropriately arranging the polishing tape T on the pad 26 disposed on the polishing plate 27.

  During polishing, the polishing tape T may be in a stationary state, or may be continuously or intermittently moved by the polishing tape running means. When polishing is completed in a short time, the polishing tape T may be used in a stationary state without running, and a new surface of the polishing tape T may be supplied for the next polishing after polishing. When polishing takes a long time, it is preferable to run the polishing tape continuously or intermittently in order to continuously supply a highly accurate and stable polishing surface, that is, the surface of the polishing tape containing abrasive grains.

  The polishing apparatus 1 further includes a control device for controlling the work unit 3 and the polishing tape unit 4. Moreover, you may have the water supply machine and water pipe for supplying the aqueous solution which added water or surfactant to the surface of the polishing tape T when performing grinding | polishing by wet.

  By the polishing apparatus 1 having the above-described configuration, the ridge portion (or end surface) of the plate glass W is in contact with and pressed against the surface of the polishing tape T in a state where the ridge portion (or end surface) is preferably inclined at a predetermined angle with respect to the movement axis 13. Then, the plate glass W is reciprocated along the movement axis 13 to perform polishing.

  8 (a) and 8 (b), the inclination angle α or the inclination angle θ of the glass sheet W by the first and second inclination means (35, 37) and the surface of the polishing tape or the side surface or the front surface of the moving axis 13 are shown. Each of the arrangements seen from FIG.

  As shown by a dotted line in FIG. 8A, in the state where the holding table 12 is not inclined, the plate glass W has an upper surface or a lower surface perpendicular to the surface of the polishing tape T and an end surface of the polishing tape T. Parallel to the surface. The plate glass W1 is tilted by the angle α by the first tilting means 35. As shown in FIG. 2C, the angle α corresponds to a so-called C chamfering angle.

  FIG. 8B shows a state in which the glass sheet W is tilted by the angle θ with respect to the movement axis 13 by the second tilting means 37. The angle θ is preferably in the range of 5 degrees to 60 degrees. The selection of the angle θ is regulated by the width of the polishing tape T used and the length of the portion to be polished (one side ridge) of the plate glass W. However, when the angle θ is less than 5 degrees, the polishing efficiency is not improved so much. . When the angle θ exceeds 60 degrees, the polishing efficiency is improved, but the contact resistance with the surface of the polishing tape T due to the reciprocating motion of the plate glass W increases, and stable polishing becomes difficult. Moreover, in the case of the thin plate glass W, glass may break. When the angle θ is small, the polishing tape can be effectively used by sequentially moving the plate glass W in the width direction of the unused polishing tape T.

  As a polishing method, in the state of the plate glass W1 (the ridge is parallel to the movement axis), the plate glass W1 may be polished back and forth along the movement axis, and the angle α and the angle θ are combined (ridges). The portion may be polished in a state where the portion is inclined by an angle θ with respect to the movement axis. Although the polishing efficiency may not be sufficient in the state of the plate glass W1, efficient polishing can be performed by inclining the traveling direction (longitudinal direction) of the polishing tape with respect to the movement axis. In addition, when the polishing is performed in a state where the angle α and the angle θ are combined, the abrasive tape can be effectively applied to the ridge portion by using a wide width of the polishing tape, and the polishing rate can be improved. But it is advantageous.

  FIG. 9 shows another polishing method for the plate glass W. The width Tw of the polishing tape T can be used as long as it is equal to or larger than the thickness (end face width) of the plate glass W, but the edge of the plate glass W is inclined by a predetermined angle with respect to the moving axis 13. When polishing is performed by pressing against the surface of the polishing tape T and reciprocating, the width of the polishing tape T is selected in consideration of the area of the reciprocation. The polishing is preferably performed within the width of the polishing tape T.

  As shown in FIG. 9A, the polishing tape T runs in the direction of the arrow 21 at a predetermined speed in a state where the end face (or ridge) of the plate glass W is inclined by θ ′ with respect to the movement axis 13. In this case, since the width Tw ′ used for polishing is smaller than the width Tw of the polishing tape T, there are unused portions on the surface of the polishing tape T, which is not economical. As shown in FIG. 9B, when the polishing tape T is run at an angle β with respect to the movement axis 13, the entire width Tw of the polishing tape T is sequentially covered with the plate glass W as the polishing tape T runs. Since it contacts the polishing portion, the width Tw of the polishing tape T is substantially equal to the width Tw ′ used for polishing. Further, while the polishing tape T is traveling in the direction of the arrow 21 in a state where the longitudinal direction of the polishing tape T is inclined with respect to the movement axis 13, the plate glass W is moved along the movement axis 13 at a predetermined reciprocal interval ( When reciprocating with a stroke (L), the movement of the plate glass W with respect to the surface of the polishing tape T becomes a zigzag shape, and the width Tw of the polishing tape T can be used effectively.

  The angle (θ ′ + β) is preferably in the range of 5 degrees to 60 degrees. Within this range, it is preferable to adjust so that the portion to be polished of the plate glass W does not protrude from the width of the polishing tape T during the reciprocating movement. This is to prevent the edge of the glass sheet W from being damaged by coming into contact with the step at the end in the width direction of the polishing tape T.

  FIG. 10 shows another polishing method for the plate glass W. 10A, the upper or lower surface of the glass sheet W is brought into contact with the surface of the polishing tape T so as to be perpendicular to and parallel to the longitudinal direction of the polishing tape T, and the polishing plate 27 is attached as shown in FIG. By reciprocating in an arc shape from the ridge portion on the upper surface of the plate glass W to the ridge portion on the lower surface, the entire end surface of the plate glass may be R-surface polished in an arc shape.

  The polishing tape used in the present invention is obtained by applying a solution in which abrasive grains are dispersed in a resin binder to a plastic base film, slitting a dried and cured sheet to the required width, and winding it on a reel It is.

  As the base film, a plastic film made of synthetic resin having flexibility is used. Specifically, from polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate and polybutylene naphthalate, polyolefin resins such as polyethylene and polypropylene, acrylic resins mainly composed of polyvinyl alcohol or methacryl alcohol, etc. The resulting film is used as a substrate film.

As abrasive grains (abrasive particles), alumina (Al ₂ O ₃ ), cerium oxide (CeO ₂ ), silica (SiO ₂ ), diamond, silicon carbide (SiC), chromium oxide (Cr ₂ O ₃ ), zirconia (ZrO) ₂ ), cubic boron nitride (cBN), and the like, and mixtures thereof having a particle size in the above range can be used.

Example 1
By the manufacturing method of Example 1 of this invention, the plate glass which has a highly accurate finishing surface in a ridge part was manufactured. A rectangular soda lime glass having a length of 700 mm, a width of 400 mm, and a thickness of 0.8 mm was used as the plate glass. Four corners of the plate glass were preliminarily rounded with a grindstone, and then the ridges on eight sides were polished with a polishing tape to form a finished surface. In polishing, the reciprocating movement of the plate glass is performed in a state where the ridge portion is inclined by 10 degrees with respect to the moving axis (θ = 10 °), and the plate glass is applied to the surface of the polishing tape at an angle of 45 degrees (α = 45 °). The amount of polishing (h in FIG. 2C) was 50 μm. In order to obtain a constant polishing amount as described above, the number of times of reciprocation of the plate glass (1 reciprocation = 1 pass) was adjusted by the abrasive grain size contained in the surface of the polishing tape. The surface of the polishing tape was parallel to the moving axis of the plate glass and was stationary. Polishing was performed while supplying a small amount of water to the surface of the polishing tape.

  The conditions in the production method of Example 1 are summarized as follows.

Polishing conditions (one side)
State of polishing tape: static Inclination angle (α) with respect to plane perpendicular to polishing tape surface of flat glass: 45 °
Polishing amount (h): 50 μm
Inclination angle (θ) with respect to movement axis of ridge: 10 °
Reciprocating stroke length (L): 150mm
Polishing tape width (Tw): 30 mm
Abrasive tape pressure (thrust): 15N

  GC (green carborundum) # 4000 (SiC: average abrasive grain size 3 μm) was used as the polishing tape, and a foamed resin pad having a Shore A hardness of 30 was used as the pad member. The number of round trips of the plate glass was 21 passes.

Example 2
In the manufacturing method of Example 2, GC # 6000 (average abrasive grain size 2 μm) was used as the polishing tape. The number of round trips of the plate glass was 24 passes. Other conditions were the same as in Example 1.

Example 3
In the manufacturing method of Example 3, GC # 10000 (average abrasive grain size 0.5 μm) was used as the polishing tape. As the pad member, a rubber plate having a Shore A hardness of 80 and a foamed resin plate having a Shore A hardness of 30 were used. The number of round trips of the plate glass was 31 passes. Other conditions were the same as in Example 1.

Comparative Example 1
In the manufacturing method of Comparative Example 1, GC # 1000 (average abrasive grain size 16 μm) was used as the polishing tape. The number of round trips of the plate glass was 7 passes. Other conditions were the same as in Example 1.

Comparative Example 2
In the manufacturing method of Comparative Example 2, GC # 2000 (average abrasive grain size 9 μm) was used as the polishing tape. The number of round trips of the plate glass was 11 passes. Other conditions were the same as in Example 1.

Comparative Example 3
In the manufacturing method of Comparative Example 3, GC # 3000 (average abrasive grain size 5 μm) was used as the polishing tape. The number of round trips of the plate glass was 17 passes. Other conditions were the same as in Example 1.

Comparative Example 4
In the manufacturing method of Comparative Example 4, a grindstone in which diamond abrasive grains having a mesh size of # 1000 (average particle diameter of 14 to 22 μm) were metal bonded was used. As shown in FIG. 14, the edge portions of the grindstone and the plate glass were disposed, and the chamfering of the ridge portion was performed by rotating the grindstone.

  Table 1 below shows the average surface roughness Ra and the maximum valley depth Rv of the roughness curve and the examples polished and polished as described above. The average surface roughness Ra and the maximum valley depth Rv were measured with a surface roughness meter (product name NewView 5000: manufactured by Zygo).

  By the manufacturing methods of Examples 1 to 4, a plate glass having a ridge portion formed on a highly accurate finished surface (average surface roughness Ra: 1.7 nm to 11.5 nm, maximum valley depth Rv: 32 nm to 162 nm) is obtained. It was. The number of reciprocating passes was about 20 to 30, and the polishing rate was sufficient. As for the finishing surface of the plate glass by the manufacturing method of a comparative example, there were many whose maximum valley depth exceeded 1000 nm.

  The enlarged photograph of the finishing surface of an Example and a comparative example is shown by FIG. The left side is an optical photograph by a digital microscope (product name VHX500: manufactured by KEYENCE), and the right side is a surface roughness meter (product name NewView 5000: manufactured by Zygo). 11A shows the finished surface according to Comparative Example 1, FIG. 11B shows the finished surface according to Comparative Example 2, FIG. 11C shows the finished surface according to Embodiment 1, and FIG.

  (A) and (B) according to the comparative example were insufficient as surface properties of the finished surface with many surface irregularities. (C) and (D) according to the example had a highly accurate finished surface free from irregularities and scratches. Moreover, by using the polishing tape, the finished surface had a curved surface, and the edge portion was excellent in linearity.

  FIG. 12 is an enlarged photograph of the finished surface of the plate glass obtained by the manufacturing method of Comparative Example 4. As a result of polishing with a grindstone, the finished surface is not formed into a curved surface. Moreover, there were polishing marks (wheel marks) on the surface, and many scratches were seen.

  The edge strength (MPa) of each plate glass of the example and the comparative example was measured. Edge strength refers to the strength of the edge of the glass. The edge strength was measured using a commercially available four-point bending tester based on a room temperature bending strength test method (JIS R1601). An edge strength test (four-point bending) method is schematically shown in FIG. The test was performed under the conditions of a load jig interval of 10 mm, a support jig interval of 30 mm, and a load speed of 5 mm / min.

  Table 1 lists the values obtained by averaging ten edge glasses obtained by testing ten plate glasses of Examples and Comparative Examples. The plate glass according to the present invention, which is formed on the finished surface by polishing the edge using a polishing tape containing fine abrasive grains on the surface, has an average surface roughness Ra and a maximum valley depth Rv value of the finished surface. As a result of the significant reduction, the edge strength was improved by a factor of 3 or more compared to the processing with the conventional grindstone. Thus, since the plate glass according to the present invention has significantly improved edge strength, it can prevent the plate glass from being damaged by mechanical stress or heat shock in the manufacturing process of the product using the plate glass. It is. Moreover, it is difficult to break even after the plate glass is incorporated into the product, and the reliability of the product can be improved.

  Those skilled in the art will appreciate that many different modifications are possible without departing from the spirit and aspects of the invention. Accordingly, it goes without saying that the embodiments of the present invention are merely examples, and do not limit the scope of the present invention.

W Sheet glass (to be polished)
T polishing tape Tw polishing tape width Tw ′ polishing width 1 polishing apparatus 2 base 3 work unit 4 polishing tape unit 5 single-axis robot 6 LM guide 7 traveling body 12 holding base 13 moving axis 21 polishing tape traveling direction 22 supply roll 23 winding Roll 24 Auxiliary roller 1
25 Auxiliary roller 2
26 Pad 26A Second pad means 26B First pad means 27 Polishing plate 28 Polishing plate moving direction 1
29 Polishing plate movement direction 2
30a Finished surface (ridge)
30b Finished surface (end face)
31 Rail 1
32 rail 2
33 fixed plate 34 fixed lever 35 inclined plate 1
35a Screw groove 35b Guide groove 35 'Movable plate 35'a Rod 1
35'b Screw hole 36 Fixing screw 1
37 Inclined plate 2
38 Fixing screw 2
39 Guide groove 1
39a Rod 2
40 Grinding wheel 42 Moving plate 43 Air cylinder 46 Inclined plate 3
47 Fixing screw 3
48 Guide bearing 49 Guide groove 2
49a Rod 3
50 fixed plate

Claims (21)

An upper surface, a lower surface and a ridge portion on at least one side of the upper surface of the rectangular plate glass having an end surface between both surfaces or a boundary between the lower surface and the end surface are polished with a polishing tape to form a finished surface. A plate glass having an average surface roughness Ra of 20 nm or less and a maximum valley depth Rv of 200 nm or less ,
The surface of the elastic pad member is disposed on the back surface of the polishing tape, and the surface of the polishing tape and the ridge of one side of the plate glass are arranged to face each other in order to chamfer at least one ridge of the plate glass. A step in which the surface of the polishing tape comprises a polishing layer containing abrasive grains, and
Contacting and pressing the surface of the polishing tape against the edge of the one side by applying a predetermined pressing force to the polishing tape through the pad member;
Polishing the edge of the one side by moving the plate glass along a linear movement axis, and
The average grain size of the abrasive grains is in the range of 0.2 μm to 3.0 μm,
In the polishing step, the polishing tape is stopped or running without running, and the plate glass is moved along the moving axis with the ridge portion of one side inclined by a predetermined angle (θ) with respect to the moving axis. And reciprocating the plate glass. It said predetermined angle (theta) is in the range of 60 degrees 5 degrees, process for the preparation of plate glass according to claim 1, characterized in that. The surface of the said pad member is a flat surface, The manufacturing method of the plate glass described in Claim 1 or 2 characterized by the above-mentioned. The method for producing a plate glass according to claim 1 or 2 , wherein the surface of the pad member is a convex curved surface. The method for producing a plate glass according to any one of claims 1 to 4 , wherein the moving axis is parallel to a longitudinal direction of the polishing tape. The method for producing a plate glass according to any one of claims 1 to 4 , wherein the moving axis is inclined by a predetermined angle (β) with respect to a longitudinal direction of the polishing tape. The said pad member is a 1st pad member which has a Shore A hardness in the range of 20-50, The manufacturing method of the plate glass in any one of Claim 1 thru | or 6 characterized by the above-mentioned. The method for producing a plate glass according to claim 7 , wherein a second pad member having a Shore A hardness of 90 or less is disposed between the polishing tape and the first pad member. . The method for producing a plate glass according to any one of claims 1 to 8 , wherein the finished surface has a curved surface. The method for producing a plate glass according to any one of claims 1 to 9 , wherein, in the polishing step, the polishing tape runs continuously or intermittently. The method for producing a plate glass according to any one of claims 1 to 10 , wherein the predetermined pressing force is gradually increased with the progress of polishing. Polishing at least one ridge or at least one end surface of the upper or lower surface of the rectangular plate glass having an end surface between the upper surface, the lower surface, and both surfaces thereof, among the ridges at the boundary between the lower surface and the end surface. A polishing apparatus for forming on a finished surface,
Base and
A work unit for placing the plate glass, the work unit provided on the base movably along a movement axis parallel to the base;
A polishing tape unit for disposing the polishing tape, the polishing tape unit provided on the base facing the work unit, and
The work unit is:
A holding table for holding the plate glass so that one end surface of the plate glass is parallel to the movement axis and the upper surface or the lower surface of the plate glass is parallel to the base;
First holding table tilting means for tilting the upper surface or the lower surface of the plate glass by a predetermined angle (α) with respect to the base by pivoting the holding table around the moving axis;
In order to incline the upper surface or the lower surface of the plate glass by a predetermined angle (θ) with respect to the base by rotating the holding base around a rotation axis perpendicular to the movement axis and parallel to the base. The second holding table tilting means,
The polishing tape unit is
A pad for disposing the polishing tape such that the surface containing the abrasive grains of the polishing tape faces one edge of the plate glass or the one end surface;
A polishing plate perpendicular to the base for mounting the pad;
A pressing means for moving the polishing plate in a direction parallel to the base and perpendicular to the movement axis so that the surface of the polishing tape is in contact with and pressed against the ridge portion of the one side or the one end surface;
Abrasive tape running means for running the abrasive tape;
A polishing apparatus comprising: The polishing apparatus according to claim 12 , wherein a longitudinal direction of the polishing tape disposed on the pad is parallel to the movement axis. The polishing tape unit includes polishing plate tilting means for tilting the polishing plate so that a longitudinal direction of the polishing tape is tilted by a predetermined angle (β) with respect to the moving axis. Item 14. The polishing apparatus according to Item 13 . Polishing apparatus according to any one of the said surface of the polishing tape is placed in the pad is a flat surface, to 12 claims, characterized in that 14. Polishing apparatus according to any one of the said surface of the polishing tape is placed in the pad is a convex curved surface, to 12 claims, characterized in that 14. A rectangular plate glass having an end surface between an upper surface, a lower surface, and both surfaces thereof is moved along a horizontal movement axis, and at least one of the ridges at the boundary between the upper surface or the lower surface and the end surface of the plate glass A polishing method for polishing a part with a surface having abrasive grains of an abrasive tape to form a finished surface,
Arranging the plate glass so that one end face of the plate glass is parallel to the movement axis and the upper surface or the lower surface of the plate glass is horizontal; and
A first inclining step of inclining the upper surface or the lower surface of the plate glass by a predetermined angle (α) with respect to the horizontal by pivoting the plate glass about the moving axis;
A second tilting step of tilting the upper surface or the lower surface of the plate glass by a predetermined angle (θ) with respect to the horizontal by rotating the plate glass about a rotation axis that is horizontal and perpendicular to the movement axis. When,
Arranging the polishing tape on the surface of the pad member such that the surface of the polishing tape faces the ridge of one side of the plate glass;
Applying a predetermined pressing force to the polishing tape via the pad member to abut and press the surface of the polishing tape against the ridge of the one side;
Polishing the ridge portion of the one side by moving the plate glass along the moving axis. The polishing method according to claim 17 , wherein a longitudinal direction of the polishing tape disposed on the pad member is parallel to the movement axis. The polishing method according to claim 17 , wherein a longitudinal direction of the polishing tape disposed on the pad member is inclined by a predetermined angle (β) with respect to the movement axis. The surface of the pad member is flat, abrasive method according to any one of claims 17 to 19, characterized in that. The surface of the pad member has a convex curved surface, abrasive method according to any one of claims 17 to 19, characterized in that.