JP2021062448A - Method of manufacturing optical member - Google Patents

Abstract

To provide the manufacturing method of an optical member excellent in the accuracy of the shape and dimension.SOLUTION: A method for manufacturing an optical member includes a cutting process in which a laminated structure 2 is cut with a pair of rotary blades b1,b2. The laminated structure 2 includes a plurality of laminates 4 and the laminates 4 include a plurality of optical films. The laminated structure 2 is rectangular or cubic, and each end face of the laminated structure 2 is parallel to the laminated direction. The laminated structure 2 is sandwiched by clamps 12 that come into contact with an upper face tf and a lower face uf of the laminated structure. One of the rotary blades b1 comes into contact with one end face f1 of the laminated structure 2, the other of the rotary blades b2 comes into contact with the other end face f2 of the laminated structure 2, and the opposing end faces f1,f2 are cut by the pair of rotary blades b1,b2 simultaneously. In a process in which all the end faces of the laminated structure 2 are cut by the rotary blades, the rotary blades b1,b2 are installed in different positions, and the clamps 12 do not rotate at all relative to a rotation axis a12 almost in parallel with the laminated direction of the laminates 4.SELECTED DRAWING: Figure 3

Description

The present invention relates to a method for manufacturing an optical member.

A polarizing plate, which is a type of optical member, is used in an image display device such as a liquid crystal display, an organic EL display, a smartphone, a smart watch, or an instrument panel of a vehicle. The polarizing plate is a laminate of a plurality of optical films such as a polarizer film and a protective film. With the refinement or miniaturization of image display devices, high accuracy is required for the shape and dimensions of the polarizing plate. For example, Patent Document 1 below discloses a method of improving the accuracy of the shape and dimensions of each laminated body by cutting the end face (cut surface) of the laminated structure composed of a plurality of laminated bodies laminated with each other with a rotary blade. doing.

Japanese Unexamined Patent Publication No. 2004-148419

When the above-mentioned laminated structure is processed by a rotary blade, the rotary blade is pressed against the end face of the laminated structure and the end face is cut while the laminated structure is fixed by a clamp in the laminating direction of the laminated body. .. In order to process each laminated body constituting the laminated structure with high accuracy, it is necessary to precisely control the relative position and relative moving speed of the rotary blade with respect to the end face of the laminated structure. However, in the process of cutting the end face of the laminated structure, a moment is likely to be generated at the portion of the end face of the laminated structure in contact with the rotary blade due to the force exerted by the rotary blade on the end face of the laminated structure. Due to the force or moment exerted by the rotary blade, part or all of the laminated structure may deviate from a predetermined position, or part or all of the laminated structure may be around a rotation axis substantially parallel to the laminating direction of the laminated structure. The laminated structure is twisted by rotating to. Due to the misalignment or twist of the laminated structure as described above, it becomes difficult to precisely control the relative position and relative moving speed of the rotary blade with respect to the end face of the laminated structure. For the above reasons, it is difficult to precisely cut the end face of the laminated structure by the conventional cutting method using a rotary blade, and it is difficult to improve the accuracy of the shape and dimensions of each laminated body. Optical members other than the polarizing plate are also precisely processed according to the application. Therefore, the above technical problem may occur in the manufacture of an optical member other than the polarizing plate.

An object of the present invention is to provide a method for manufacturing an optical member having excellent shape and dimensional accuracy.

The method for manufacturing an optical member according to one aspect of the present invention includes a cutting step of cutting a laminated structure with a pair of rotary blades, the laminated structure includes a plurality of laminated bodies laminated to each other, and the laminated structures are mutually laminated. A plurality of laminated optical films are included, the laminated structure is a substantially rectangular body or a substantially cubic body, each end face of the laminated structure is substantially parallel to the stacking direction of the laminated structure, and the upper surface and the lower surface of the laminated structure are substantially parallel to each other. , Approximately perpendicular to the stacking direction, the laminated structure is sandwiched by clamps in contact with the upper and lower surfaces of the laminated structure, the rotary blade extends along the stacking direction, and the side surfaces of the rotary blade are laminated. Approximately parallel to the end face of the structure, the rotation axis of the rotary blade is substantially parallel to the side surface of the rotary blade, and the side surface of one rotary blade is on one end face of two opposing end faces of the laminated structure. The side surface of the other rotary blade is in contact with the other end face of the two opposing end faces of the laminated structure, and the two opposite end faces of the laminated structure are cut substantially simultaneously by the pair of rotary blades to form the laminated structure. In the process of cutting all end faces of the body with rotary blades, the position where the pair of rotary blades are installed changes, and in the process of cutting all end faces of the laminated structure with rotary blades, the clamps are substantially parallel to the stacking direction. Does not turn with respect to the rotating axis.

The upper surface and the lower surface of the laminated structure may be substantially rectangular, and the two end faces to be cut at substantially the same time may be substantially parallel to the long sides of the upper surface and the lower surface of the laminated structure.

In the cutting process, the pair of rotary blades may move along two opposing end faces of the laminated structure.

In the cutting process, the clamp may move along a direction substantially parallel to the two opposing end faces of the laminated structure.

The laminate may include at least one pressure-sensitive adhesive layer.

The rotary blade may be an end mill.

According to the present invention, there is provided a method for manufacturing an optical member having excellent shape and dimensional accuracy.

FIG. 1 is a schematic side view of a laminated structure, a clamp, and a rotary blade. FIG. 2 is a cross-sectional view of each laminated body constituting the laminated structure shown in FIG. 1, and the cross section shown in FIG. 2 is substantially parallel to the laminating direction of the laminated body. FIG. 3 is a schematic view showing the upper surface of the laminated structure and the rotary blade that is brought into contact with the end face of the laminated structure in the cutting process. (A) in FIG. 4 is a top view of the laminated structure rotated around a rotation axis substantially parallel to the laminating direction of the laminated structure, and (b) in FIG. 4 is a twisted laminated structure. It is a top view.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the drawings, equivalent components are labeled with equivalent reference numerals. The present invention is not limited to the following embodiments. X, Y and Z shown in each figure mean three coordinate axes orthogonal to each other. The directions indicated by the XYZ coordinate axes in each figure are common to each figure.

The method for manufacturing the optical member according to the present embodiment is, for example, a polarizing plate (including a reflective polarizing plate), a retardation film, a brightness improving film, a film with an antiglare function, a film with a surface antireflection function, a reflective film, and the like. It may be a method for producing a semi-transmissive reflective film or a viewing angle compensating film.

The outline of the manufacturing method of the optical member which concerns on this embodiment is shown in FIGS. 1 to 3. The method for manufacturing an optical member according to the present embodiment includes a cutting step of cutting the laminated structure 2 with a pair of rotary blades (first rotary blade b1 and second rotary blade b2). In the cutting step, two opposing end faces (first end face f1 and second end face f2) of the laminated structure 2 are cut substantially simultaneously (in parallel) by a pair of rotary blades. The details of the laminated structure 2 and the cutting process are as follows.

The laminated structure 2 includes a plurality of laminated bodies 4 laminated to each other, and each laminated body 4 includes a plurality of optical films laminated to each other. The stacking direction (Z-axis direction) of the laminated body 4 in the laminated structure 2 is the same as the stacking direction of the optical film in each laminated body 4. The optical film means a film-like (layered) member that constitutes an optical member. The optical film is, for example, at least one film selected from the group consisting of a polarizing element film, a protective film, an adhesive layer, a release film, an optical compensation layer, a hard coat layer, a touch sensor layer, an antistatic layer and an antifouling layer. It may be (layer). The laminated structure of the laminated structure 2 is not limited.

The laminated structure 2 shown in FIGS. 1 and 3 is a substantially rectangular parallelepiped. However, the laminated structure may be a substantially cube. The laminated structure 2 has a first end surface f1, a second end surface f2, a third end surface f3, and a fourth end surface f4. The first end surface f1 and the second end surface f2 face each other and are substantially parallel to each other. The third end surface f3 and the fourth end surface f4 face each other and are substantially parallel to each other. The first end surface f1, the second end surface f2, the third end surface f3, and the fourth end surface f4 are each substantially parallel to the stacking direction (Z-axis direction) of the optical film. The upper surface tf and the lower surface uf of the laminated structure 2 are substantially perpendicular to the laminating direction (Z-axis direction). The shapes and dimensions of the first end surface f1 and the second end surface f2 that face each other are substantially the same as each other. The shapes and dimensions of the third end face f3 and the fourth end face f4 that face each other are substantially the same as each other. The shapes and dimensions of the upper surface tf and the lower surface uf facing each other are substantially the same as each other. The upper surface tf and the lower surface uf are substantially rectangular. The first end surface f1 and the second end surface f2 are substantially parallel to the long sides (Y-axis direction) of the upper surface tf and the lower surface uf of the laminated structure 2, respectively. The third end surface f3 and the fourth end surface f4 are substantially parallel to the short sides (X-axis direction) of the upper surface tf and the lower surface uf of the laminated structure 2. The first polishing pad 12a is in contact with the upper surface tf of the laminated structure 2, and the second polishing pad 12b is in contact with the lower surface uf of the laminated structure 2. The laminated structure 2 is clamped and fixed in the laminating direction (Z-axis direction) by the clamp 12 composed of the first polishing pad 12a and the second polishing pad 12b. Each end face of the laminated structure 2 to be polished in the cutting step protrudes outward from between the first polishing pad 12a and the second polishing pad 12b.

As shown in FIG. 1, the laminated structure 2 is composed of a first protective sheet 6a, a plurality of laminated bodies 4, and a second protective sheet 6b. The plurality of laminated bodies 4 are laminated between the first protective sheet 6a and the second protective sheet 6b. The pair of adjacent laminates 4 are not adhered to each other and are separable. The first protective sheet 6a and the laminated body 4 are also not adhered to each other and are separable. The second protective sheet 6b and the laminated body 4 are also not adhered to each other and are separable. The first protective sheet 6a and the second protective sheet 6b may each be a resin such as polystyrene.

As shown in FIG. 2, each laminated body 4 includes a plurality of laminated optical films 8a, 8b, 8c, 8d, 8e, 10a and 10b. The laminated structure of the laminated body 4 is not limited. The laminated structure of the laminated body 4 may be the same as the laminated structure of the optical member after completion. For example, when the optical member is a polarizing plate, the laminated structure of the laminated body 4 may be the same as the laminated structure of the polarizing plate. That is, each of the laminated bodies 4 may be a polarizing plate. For example, the optical film 8a may be a polarizer film. The optical film 8b may be the first protective film. The optical film 8c may be a second protective film. The optical film 10a may be the first pressure-sensitive adhesive layer, and the optical film 10b may be the second pressure-sensitive adhesive layer. That is, the laminated structure 2 may include an adhesive layer as an optical film. The optical film 8d may be the first release film. The optical film 8e may be a second release film. The first protective film (8b) may be formed directly on one surface of the polarizing film (8a). The first protective film (8b) may be attached to one surface of the polarizer film (8a) via an adhesive such as an ultraviolet curable resin. The second protective film (8c) may be formed directly on the other surface of the polarizer film (8a). The second protective film (8c) may be attached to the other surface of the polarizing film (8a) via an adhesive such as an ultraviolet curable resin.

The polarizer film may be a film-like polyvinyl alcohol (PVA) -based resin produced by steps such as stretching, dyeing, and crosslinking. The thickness of the polarizing film may be, for example, 1 μm or more and 50 μm or less. The vertical width and the horizontal width of the polarizer film may be, for example, 30 mm or more and 600 mm or less. The thickness of the laminated body 4 may be, for example, 10 μm or more and 1200 μm or less.

The first protective film and the second protective film may be any translucent thermoplastic resin. The resins constituting the first protective film and the second protective film are, for example, a chain polyolefin resin, a cyclic olefin polymer resin (COP resin), a cellulose ester resin (triacetyl cellulose, etc.), and a polyester resin. , Polycarbonate resin, (meth) acrylic resin, polystyrene resin, or a mixture or copolymer thereof. The composition of the first protective film may be the same as the composition of the second protective film. The composition of the first protective film may be different from the composition of the second protective film. The thickness of the first protective film may be, for example, 5 μm or more and 90 μm or less. The thickness of the second protective film may also be, for example, 5 μm or more and 90 μm or less.

The first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer may each be a layer made of a pressure-sensitive adhesive. Each of the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer may be an optical transparent adhesive (OCA) film. For example, the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer are made from a pressure-sensitive adhesive such as an acrylic pressure-sensitive pressure-sensitive adhesive, a rubber-based pressure-sensitive pressure-sensitive adhesive, a silicone-based pressure-sensitive pressure-sensitive adhesive, or a urethane-based pressure-sensitive pressure-sensitive adhesive. It may be configured. The composition of the first pressure-sensitive adhesive layer may be different from the composition of the second pressure-sensitive adhesive layer. The thickness of the first pressure-sensitive adhesive layer may be, for example, 2 μm or more and 500 μm or less. The thickness of the second pressure-sensitive adhesive layer may also be, for example, 2 μm or more and 500 μm or less.

The resin constituting the first release film and the second release film, respectively, may be the same as the above-mentioned resin constituting the first protective film or the second protective film. The composition of the first release film may be the same as the composition of the second release film. The composition of the first release film may be different from the composition of the second release film. The thickness of the first release film may be, for example, 5 μm or more and 200 μm or less. The thickness of the second release film may also be, for example, 5 μm or more and 200 μm or less.

The first rotary blade b1 and the second rotary blade b2 each extend along the stacking direction (Z-axis direction) of the laminated body 4. The side surface s1 of the first rotary blade b1 is substantially parallel to each end surface of the laminated structure 2. The side surface s2 of the second rotary blade b2 is also substantially parallel to each end surface of the laminated structure 2. The rotation axis a1 of the first rotary blade b1 is substantially parallel to the side surface s1 of the first rotary blade b1. The rotation axis a2 of the second rotary blade b2 is substantially parallel to the side surface s2 of the second rotary blade b2.

The first rotary blade b1 has a blade (edge) formed on its side surface s1. By pressing the side surface s1 of the first rotary blade b1 that rotates around the rotation axis a1 against the end face of the laminated structure 2, the end face of the laminated structure 2 is cut. The second rotary blade b2 also has a blade (edge) formed on its side surface s2. By pressing the side surface s2 of the second rotary blade b2 that rotates around the rotation axis a2 against the end face of the laminated structure 2, the end face of the laminated structure 2 is cut. The width of each rotary blade in the stacking direction (Z-axis direction) of the laminated body 4 may be equal to or larger than the width of the laminated structure 2 in the stacking direction.

The first rotary blade b1 and the second rotary blade b2 may be end mills, respectively. However, the first rotary blade b1 and the second rotary blade b2 are not limited to end mills. For example, the first rotary blade b1 and the second rotary blade b2 may each be a rotary blade in which a plane blade is arranged on a side surface.

In the cutting step, the first end surface f1 and the second end surface f2, which are substantially parallel to the long sides (Y-axis direction) of the upper surface tf and the lower surface uf of the laminated structure 2, are cut by the following methods.

As shown in FIG. 3A, the side surface s1 of the first rotary blade b1 cuts the entire first end surface f1 while being in contact with the first end surface f1 of the laminated structure 2. The side surface s2 of the second rotary blade b2 cuts the entire second end surface f2 while being in contact with the second end surface f2 facing the first end surface f1.

In the cutting step, the cutting of the first end surface f1 by the first rotary blade b1 and the cutting of the second end surface f2 by the second rotary blade b2 are performed substantially at the same time. Since the first end surface f1 and the second end surface f2 face each other, the pressure exerted by the first rotary blade b1 on the first end surface f1 and the pressure exerted by the second rotary blade b2 on the second end surface f2 are easily balanced. The moment exerted by the one rotary blade b1 on the first end surface f1 and the moment exerted by the second rotary blade b2 on the second end surface f2 are likely to cancel each other out. Therefore, a part or the whole of the laminated structure 2 is unlikely to shift in a direction (XY plane direction) substantially perpendicular to the laminated direction (Z-axis direction) of the laminated body 4. For the same reason, it is difficult for a part or the whole of the laminated structure 2 to rotate around the rotation axis a12 (the central axis of the clamp) substantially parallel to the stacking direction (Z-axis direction) of the laminated body 4. That is, by cutting the first end surface f1 and the second end surface f2 that face each other substantially at the same time, the misalignment and twist of the laminated structure 2 are suppressed. Therefore, it is possible to precisely control the relative position and relative moving speed of each rotary blade with respect to each end surface of the laminated structure 2, and the first end surface f1 and the second end surface f2 are cut with high accuracy. be able to. By the above mechanism, the accuracy of the shape and dimensions of the laminated structure 2 and the laminated body 4 is improved. That is, the upper surface tf, the lower surface uf, and each laminated body 4 of the laminated structure 2 are processed with high accuracy. For example, the distance between the first end surface f1 and the second end surface f2 is uniformly controlled. Further, the intersection angle between the first end surface f1 and the third end surface f3, the intersection angle between the first end surface f1 and the fourth end surface f4, the intersection angle between the second end surface f2 and the third end surface f3, and the second end surface f2. The intersection angle with the fourth end surface f4 is uniformly controlled. For example, the number of laminated bodies 4 constituting the laminated structure 2 is 100, and the total thickness of the pressure-sensitive adhesive layer to the thickness of the laminated structure 2 in the stacking direction (Z-axis direction) is 17%. The thickness of each laminated body 4 is 190 μm, the length of the long side of each laminated body 4 before the cutting process (width of the laminated body 4 in the Y direction) is 155 mm, and the length of each laminated body 4 before the cutting process is 155 mm. When the length of the short side (width of the laminated body 4 in the X direction) is 75 mm, the deviation width of the length of the short side of the laminated body 4 after the cutting process from the design value is about 0.008 mm at the maximum. Yes, the deviation width of the intersection angle from 90 ° is about 0.16 ° at the maximum. On the other hand, when the first end surface f1 and the second end surface f2 are not cut at the same time and the first end surface f1 and the second end surface f2 are cut separately by one rotary blade, the length of the short side of the laminated body 4 is designed. The maximum deviation width from the value is about 0.044 mm, and the deviation width from 90 ° of the intersection angle is about 0.29 °.

In the direction perpendicular to the stacking direction (Z-axis direction) (XY plane direction), the widths of the first end surface f1 and the second end surface f2 are larger than the widths of the third end surface f3 and the fourth end surface f4, respectively. The larger the width of the end face in the direction perpendicular to the stacking direction (Z-axis direction) (XY plane direction), the easier it is for the rotary blade to exert a moment on the end face. Therefore, if the wide first end surface f1 and the second end surface f2 are cut non-simultaneously using only one rotary blade, as shown in FIG. 4A, the rotary blade ( Due to the force F exerted by b1) on the laminated structure 2, the entire laminated structure 2 is rotated around the rotation axis a12 (central axis of the clamp 12) substantially parallel to the stacking direction (Z-axis direction), and the stacking structure 2 is laminated. The structure 2 is easily displaced from a predetermined position, and as shown in FIG. 4B, each laminated body 4 constituting the laminated structure 2 has a rotation axis substantially parallel to the stacking direction (Z-axis direction). The laminated structure 2 is easily twisted by rotating around a12 (the central axis of the clamp 12). In particular, the central portion of the laminated structure 2 in the laminated direction (Z-axis direction) is particularly easy to rotate, and as the number of laminated structures 4 constituting the laminated structure 2 increases, the position of the laminated structure 2 shifts and twists. easy. When each laminated body 4 includes a pressure-sensitive adhesive layer such as a first pressure-sensitive adhesive layer and a second pressure-sensitive adhesive layer as the optical films 10a and 10b, the pressure-sensitive adhesive layer is softer than other optical films, so that the laminated structure 2 is twisted. easy. As a result, in the cutting process, it is difficult to precisely control the shapes of the first end surface f1 and the second end surface f2, and the upper surface tf, the lower surface uf, and each laminated body 4 of the laminated structure 2 are highly accurate. It is difficult to process it into a deformed shape. On the other hand, in the case of the present embodiment, by the above mechanism, it is possible to suppress the misalignment and twist of the laminated structure 2 during cutting of the first end surface f1 and the second end surface f2 having a large width.

Since the misalignment and twisting of the laminated structure 2 are suppressed by the above mechanism, the number of laminated bodies 4 constituting the laminated structure 2 can be increased according to the present embodiment. By increasing the number of laminated bodies 4 to be cut in a batch, the time required for the cutting process is shortened, and the productivity of the optical member is improved. Further, according to the present embodiment, even when each of the laminated bodies 4 constituting the laminated structure 2 includes an adhesive layer, it is possible to easily suppress the displacement and twist of the laminated structure 2.

As shown in FIG. 3, the dotted line and the arrow extending from the first rotary blade b1 indicate the movement path and the movement direction of the first rotary blade b1 in the cutting process. The moving path and moving direction of the first rotary blade b1 may be relative to the laminated structure 2. That is, the first rotary blade b1 itself may move, and the laminated structure 2 itself may move. As shown in FIG. 3, the dotted line and the arrow extending from the second rotary blade b2 indicate the movement path and the movement direction of the second rotary blade b2 in the cutting process. The moving path and moving direction of the second rotary blade b2 may be relative to the laminated structure 2. That is, the second rotary blade b2 itself may move, and the laminated structure 2 itself may move. As indicated by the dotted lines and arrows extending from the first rotary blade b1 and the second rotary blade b2, in the cutting process, the first rotary blade b1 and the second rotary blade b2 face each other with the first end surface f1 and the second end surface. You may move along f2. In the cutting step, the first rotary blade b1 and the second rotary blade b2 may be translated along the opposite first end surface f1 and second end surface f2. By moving the first rotary blade b1 and the second rotary blade b2 in parallel, the moments acting on the first end surface f1 and the second end surface f2 are likely to cancel each other out, and the rotation and twist of the laminated structure 2 are caused. Easy to be suppressed. For the same reason, the pressure exerted by the first rotary blade b1 on the first end surface f1 may be substantially equal to the pressure exerted by the second rotary blade b2 on the second end surface f2, and the first in a direction substantially parallel to the first end surface f1. The moving speed of the one rotary blade b1 may be substantially the same as the moving speed of the second rotary blade b2 in a direction substantially parallel to the second end surface f2. In the process of cutting the first end surface f1 and the second end surface f2, the distance between the first rotary blade b1 and the second rotary blade b2 may be freely changed. By controlling the distance between the first rotary blade b1 and the second rotary blade b2, the first end surface f1 and the second end surface f2 are precisely machined. In the process of cutting the first end surface f1 and the second end surface f2, the position of the clamp 12 may be fixed. Alternatively, in the process of cutting the first end surface f1 and the second end surface f2, the first rotary blade b1 and the second rotary blade b2 in a direction substantially parallel to the first end surface f1 and the second end surface f2 (Y-axis direction). The positions may be fixed, and the clamp 12 may move along a direction (Y-axis direction) substantially parallel to the first end surface f1 and the second end surface f2. That is, the laminated structure 2 sandwiched between the clamps 12 may pass between the first rotary blade b1 and the second rotary blade b2.

The method for manufacturing an optical member may further include a processing step performed before the cutting step. The laminated structure 2 and each laminated body 4 may be formed by the processing step. The processing means used in the processing process may be punching or cutting. The cutting means used in the processing step may be a cutting tool or a laser (for example, a CO ₂ gas laser or an excimer laser).

In a series of processes of cutting all the end faces (first end face f1, second end face f2, third end face f3 and fourth end face f4) of the laminated structure 2 with the above rotary blade, the clamp 12 is set in the stacking direction (Z). It does not turn with respect to the rotation axis a12 (the central axis of the clamp 12) substantially parallel to (axial direction). That is, the clamp 12 does not rotate from the time when the cutting of the end faces of the laminated structure 2 is started to the time when the cutting of all the end faces is completed. However, the clamp 12 may rotate when none of the end faces of the laminated structure 2 has been cut at all. After the cutting of all the end faces of the laminated structure 2 is completed, the clamp 12 may rotate. If the clamp 12 is swiveled during a series of processes of cutting all the end faces of the laminated structure 2 with a rotary blade, the laminated structure is interlocked with the clamp 12 as shown in FIG. 4B. Each laminated body 4 constituting the body 2 rotates around a rotation axis a12 (central axis of the clamp 12) substantially parallel to the stacking direction (Z-axis direction), and the laminated structure 2 is easily twisted. On the other hand, if the clamp 12 does not rotate from beginning to end in the process of cutting all the end faces of the laminated structure 2 with the rotary blade, the twist of the laminated structure 2 is suppressed. As a result, it is easy to precisely control the shapes of all the end faces of the laminated structure 2, and it is easy to process the upper surface tf, the lower surface uf, and each laminated body 4 of the laminated structure 2 into irregular shapes with high accuracy.

As described above, the clamp 12 does not rotate from beginning to end in the process of cutting all the end faces of the laminated structure 2 with the rotary blade. Therefore, in the process of cutting all the end faces of the laminated structure 2 with the rotary blade, the positions where the first rotary blade b1 and the second rotary blade b2 are installed change freely. For example, the positions p1, p2, p3 and p4 shown in FIG. 3 are the positions where the first rotary blade b1 and the second rotary blade b2 are installed in the cutting process. The position p1 is a corner portion where the first end surface f1 and the fourth end surface f4 intersect. The position p2 is a corner portion where the second end surface f2 and the fourth end surface f4 intersect. The position p3 is a corner portion where the first end surface f1 and the third end surface f3 intersect. The position p4 is a corner portion where the second end surface f2 and the third end surface f3 intersect. As long as the two opposing end faces are cut substantially simultaneously by the pair of rotary blades, the positions where the first rotary blade b1 and the second rotary blade b2 are installed are not limited. As long as two opposing end faces are cut substantially simultaneously by a pair of rotary blades, the cutting order of the first end face f1, the second end face f2, the third end face f3, and the fourth end face f4 is not limited, and each end face and each The combination of rotary blades for cutting the end face is not limited.

For example, the third end surface f3 and the fourth end surface f4, which are substantially parallel to the short sides (X-axis direction) of the upper surface tf and the lower surface uf of the laminated structure 2, are the same as the first end surface f1 and the second end surface f2. , The pair of rotary blades (first rotary blade b1 and second rotary blade b2) may be cut substantially simultaneously (in parallel). For example, the first rotary blade b1 may be installed at position p3, the second rotary blade b2 may be installed at position p1, and the first rotary blade b1 may be installed at position p1 in parallel with the movement of the first rotary blade b1 from position p3 to position p4. The double rotary blade b2 may move from position p1 to position p2.

The third end surface f3 and the fourth end surface f4 may be cut non-simultaneously by using the first rotary blade b1 or the second rotary blade b2, respectively. For example, at the start of the cutting process, the first rotary blade b1 may be installed at the position p2, and the fourth end surface f4 may be cut by the first rotary blade b1 that moves from the position p2 to the position p1. After cutting the fourth end surface f4, the first rotary blade b1 may be installed at the position p1 and the second rotary blade b2 may be installed at the position p2. Then, the cutting of the first end surface f1 by the first rotary blade b1 and the cutting of the second end surface f2 by the second rotary blade b2 may be performed substantially at the same time. After simultaneous cutting of the first end surface f1 and the second end surface f2, the first rotary blade b1 may be installed at the position p3, and the third end surface f3 is cut by the first rotary blade b1 moving from the position p3 to the position p4. You can.

In the cutting step, in addition to the first rotary blade b1 or the second rotary blade b2, another rotary blade may be used. That is, in the cutting process, three or more rotary blades may be used.

The method for manufacturing the optical member may further include a step of forming a hole penetrating the laminated structure 2 in the laminating direction of the laminated body 4. Before the above-mentioned cutting step, a hole penetrating the laminated structure 2 may be formed. After the above cutting step, a hole penetrating the laminated structure 2 may be formed. The means for forming the hole penetrating the laminated structure 2 may be a punching device, a rotary blade such as a drill, or a laser. The laser may be, for example, a CO ₂ gas laser or an excimer laser. The inner wall of the hole penetrating the laminated structure 2 may be cut by the first rotary blade b1 or the second rotary blade b2 described above.

In the method for manufacturing an optical member, after a cutting step, at least one corner of the four corners of the laminated structure 2 seen from the stacking direction (Z-axis direction) of the laminated body 4 is formed on the first rotary blade b1 or the first rotary blade b1. A step of chamfering may be provided by using the two-turn blade b2. The chamfered corners may be, for example, a curved surface.

The method for manufacturing an optical member is a step of forming a notch (recess) extending in the stacking direction (Z-axis direction) of the laminated body 4 on at least one of the four end faces of the laminated structure 2 after the cutting step. May be further prepared. For example, the notch may be formed on at least one of the narrow third end face f3 and the fourth end face f4. The shape of the notch portion seen from the stacking direction (Z-axis direction) of the laminated body 4 is not limited. The shape of the notch portion seen from the stacking direction (Z-axis direction) of the laminated body 4 is, for example, a quadrangle such as a substantially rectangular shape or a substantially square, a triangle, another polygon, or a semicircle, a semi-ellipse, or another curve. It may be.

The laminated structure 2 that has undergone the above steps may be used as one laminated optical film. Each laminated body 4 constituting the laminated structure 2 that has undergone the above steps may be used as an optical member.

The optical member obtained by the manufacturing method according to the present invention may be used in an image display device such as a liquid crystal display, an organic EL display, a smartphone, a smart watch, or an instrument panel of a vehicle.

2 ... Laminated structure, 4 ... Laminated body, 6a ... First protective sheet, 6b ... Second protective sheet, 8a, 8b, 8c, 8d, 8e ... Optical film, 10a, 10b ... Optical film (adhesive layer), 12 ... Clamp, 12a ... First polishing pad, 12b ... Second polishing pad, a1 ... Rotation axis of the first rotary blade, a12 ... Rotation axis substantially parallel to the laminating direction of the laminated body, a2 ... Rotation of the second rotary blade Axis line, b1 ... 1st rotary blade, b2 ... 2nd rotary blade, f1 ... 1st end surface, f2 ... 2nd end surface, f3 ... 3rd end surface, f4 ... 4th end surface, tf ... upper surface, uf ... lower surface.

Claims (6)

Equipped with a cutting process that cuts the laminated structure with a pair of rotary blades
The laminated structure includes a plurality of laminated bodies laminated with each other.
The laminate includes a plurality of optical films laminated to each other.
The laminated structure is a substantially rectangular parallelepiped or a substantially cube, and is
Each end face of the laminated structure is substantially parallel to the laminating direction of the laminated body.
The upper surface and the lower surface of the laminated structure are substantially perpendicular to the laminated direction.
The laminated structure is sandwiched by clamps in contact with the upper surface and the lower surface of the laminated structure.
The rotary blade extends along the stacking direction and
The side surface of the rotary blade is substantially parallel to the end face of the laminated structure.
The rotation axis of the rotary blade is substantially parallel to the side surface of the rotary blade.
The side surface of one of the rotary blades is in contact with the end face of one of the two opposing end faces of the laminated structure.
The side surface of the other rotary blade is in contact with the other end face of the two opposing end faces of the laminated structure.
The two opposing end faces of the laminated structure are cut substantially simultaneously by the pair of rotary blades.
In the process of cutting all the end faces of the laminated structure with the rotary blades, the positions where the pair of rotary blades are installed change.
From beginning to end in the process of cutting all the end faces of the laminated structure with the rotary blade, the clamp does not rotate with respect to a rotation axis substantially parallel to the stacking direction.
Manufacturing method of optical member. The upper surface and the lower surface of the laminated structure are substantially rectangular.
The two end faces, which are cut substantially at the same time, are substantially parallel to the long sides of the upper surface and the lower surface of the laminated structure.
The method for manufacturing an optical member according to claim 1. In the cutting step, the pair of rotary blades move along two opposing end faces of the laminated structure.
The method for manufacturing an optical member according to claim 1 or 2. In the cutting step, the clamp moves along a direction substantially parallel to the two opposing end faces of the laminated structure.
The method for manufacturing an optical member according to any one of claims 1 to 3. The laminate comprises at least one pressure-sensitive adhesive layer.
The method for manufacturing an optical member according to any one of claims 1 to 4. The rotary blade is an end mill.
The method for manufacturing an optical member according to any one of claims 1 to 5.

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