JP2021062447A - 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 and b2. The laminated structure 2 includes a plurality of laminates 4 laminated on one another, and the laminates 4 include a plurality of optical films laminated on one another. The laminated structure 2 has two opposing end faces f1 and f2, and 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 2. 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 and f2 are cut by the pair of rotary blades b1 and b2 almost simultaneously so that at least a part of at least one of the end faces is not flat.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

Since there are various types and uses of image display devices, the light receiving surface of the polarizing plate may be processed into a deformed shape according to the design requirements of the image display device. A variant means a shape that is different from a perfect quadrilateral with all corners at right angles. For example, in order to match the shape of the polarizing plate with the structure of the image display device, the four corners of the rectangular polarizing plate may be chamfered, a notch may be formed at the end of the polarizing plate, or the end of the polarizing plate may be formed. The entire part is processed into a curve.

When the above-mentioned laminated structure is processed into a deformed shape by a rotary blade, the rotary blade is pressed against the end face of the laminated structure with the laminated structure fixed by a clamp in the laminating direction of the laminated body, and the end face is cut. Will be done. In order to process each laminated body constituting the laminated structure into a deformed shape with high accuracy, the relative position and relative of the rotary blade to the end face of the laminated structure are compared with the case where the entire end face of the laminated structure is machined into a flat surface. It is necessary to control the target movement speed more precisely. 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 having a deformed shape. is there. Optical members other than the polarizing plate are also processed into irregular shapes according to their uses. 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 body is: The laminated structure includes a plurality of optical films laminated to each other, the laminated structure has two opposing end faces, and the two opposing end faces of the laminated structure are substantially parallel to the laminated direction of the laminated structure. The upper surface and the lower surface of the structure are substantially perpendicular to the stacking direction, the laminated structure is sandwiched by clamps in contact with the upper surface and the lower surface of the laminated structure, and the rotary blade extends along the stacking direction. 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, and the side surface of one rotary blade is in contact with one end face of the laminated structure. The side surface of the other rotary blade is in contact with the other end face of the laminated structure, and the two opposing end faces of the laminated structure are omitted by a pair of rotary blades so that at least a part of one end face is not flat. It is cut at the same time.

The two opposite end faces of the laminated structure may be substantially parallel to the longitudinal direction of each of the upper surface and the lower surface of the laminated structure.

In the process of cutting all the end faces of the laminated structure with the rotary blade, the position where the pair of rotary blades are installed may change, and in the process of cutting all the end faces of the laminated structure with the rotary blade, the clamps are laminated from beginning to end. It is not necessary to turn with respect to the rotation axis substantially parallel to the direction.

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 distance between the pair of rotary blades may vary, and in the cutting process, the clamp may move along a direction substantially parallel to the two opposing end faces of the laminated structure.

The method for manufacturing an optical member according to one aspect of the present invention may further include a processing step performed before the cutting process, and all corners of the upper surface and the lower surface of the laminated structure before the processing process are right angles. It may be a certain quadrilateral, and in the processing process, the laminated structure may be processed so that the upper surface and the lower surface of the laminated structure have different shapes from the quadrilateral.

The upper surface and the lower surface of the laminated structure used in the cutting process may be quadrilaterals having all angles at right angles, and in the cutting process, the upper surface and the lower surface of the laminated structure may have different shapes from the quadrilaterals. As such, the two opposing end faces of the laminated structure may be cut substantially simultaneously with a pair of rotary blades.

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. (A) in FIG. 3 is a schematic view showing an upper surface of a laminated structure with chamfered corners and a rotary blade abutting on an end surface of the laminated structure in a cutting process, and (b) in FIG. ) Is a schematic view of the upper surface of the laminated structure before the corners are chamfered. FIG. 4 is a schematic view showing the upper surface of the laminated structure in the cutting process and the rotary blade abutting on the end surface of the laminated structure in the cutting process. FIG. 5A is a schematic view showing the upper surface of the laminated structure in which the notch is formed and the rotary blade that is brought into contact with the end face of the laminated structure in the cutting process. b) is a schematic view showing an upper surface of a laminated structure in which the entire pair of end faces are processed into a curved surface, and a rotary blade that is brought into contact with the end faces of the laminated structure in a cutting process. FIG. 6 is a schematic view showing an upper surface of a laminated structure in which the entire end face is processed into a curved surface, and a rotary blade that is brought into contact with the end face of the laminated structure in a cutting process. FIG. 7A is a top view of the laminated structure rotated around a rotation axis substantially parallel to the laminating direction of the laminated structure, and FIG. 7B is a twisted laminated structure of the 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 includes, 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, and a reflective film. 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 4. 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 process, the two opposing end faces (first end face f1 and second end face f2) of the laminated structure 2 are substantially simultaneously (used by a pair of rotary blades) so that at least a part of one end face is not flat. Cut (in parallel). In other words, the upper surface and the lower surface of the laminated structure 2 after the cutting process have a shape different from that of a perfect quadrilateral having all angles at right angles. A shape that differs from a perfect quadrilateral with all corners at right angles is referred to as a "variant". The specific shape of the variant is not limited. As long as at least one end face after cutting is not flat, the shape and dimensions of one end face cut at the same time may be the same as the shape and dimensions of the other end face cut at the same time, and the one end face cut at the same time. The shape and dimensions of the end face of one may differ from the shape and dimensions of the other end face cut at the same time. A part of the end face after cutting may not be flat, and the other part of the end face after cutting may be flat. 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 shape of the laminated structure 2 shown in FIGS. 1, 3 and 4 is a substantially rectangular parallelepiped. 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 and the second end surface f2 are substantially parallel to the longitudinal direction (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 each of the upper surface tf and the lower surface uf of the laminated structure 2 in the lateral direction (X-axis direction). 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 laminated body 4. 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 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 longitudinal direction (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 process, 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, and after the cutting process, the positions are located at both ends of the first end surface f1. The corners to be formed and the corners located at both ends of the second end surface f2 are chamfered, and both ends of the first end surface f1 and both ends of the second end surface f2 are curved surfaces. In other words, the upper surface tf and the lower surface uf of the laminated structure 2 that have undergone the cutting process are not completely rectangular, but are irregular shapes having four corners having curvatures.

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 into irregular shapes with high accuracy. For example, the distance between the first end surface f1 and the second end surface f2 in the unchamfered portion is uniformly controlled. Further, the intersection angle between the flat portion of the first end surface f1 and the flat portion of the third end surface f3, the intersection angle between the flat portion of the first end surface f1 and the flat portion of the fourth end surface f4, the flat portion of the second end surface f2 and the first The intersection angle of the three end surface f3 with the flat portion and the intersection angle of the flat portion of the second end surface f2 and the flat portion of the fourth end surface f4 are 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. 7A, 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. 7B, 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. In particular, 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 Easy to twist. 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. 3A, 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. 3A, 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. It may be translated along 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 into a non-planar shape. 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. 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 the direction substantially parallel to the first end surface f1 and the second end surface f2 (Y-axis direction), respectively. The position 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. As shown in (b) in FIG. 3, the upper surface tf'and the lower surface of the laminated structure 2'before the processing process may be quadrilaterals in which all the corners are right angles, and in the processing process, The laminated structure 2'may be processed so that the upper surface tf'and the lower surface of the laminated structure 2'are deformed. The processing step may be, for example, punching or cutting of the laminated structure 2'. 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).

The method for manufacturing the optical member does not have to include the above-mentioned processing step. When the method for manufacturing the optical member does not include the above processing step, as shown in (b) in FIG. 3, the upper surface tf'and the lower surface of the laminated structure 2'used in the cutting process are all. It may be a quadrilateral with right angles, and in the cutting process, the two opposite end faces (first) of the laminated structure 2'so that the upper surface tf'and the lower surface of the laminated structure 2'are deformed. The end face f1'and the second end face f2') may be cut by a pair of rotary blades (first rotary blade b1 and second rotary blade b2) substantially simultaneously (in parallel).

The third end surface f3 and the fourth end surface f4, which are substantially parallel to each of the upper surface tf and the lower surface uf of the laminated structure 2 in the lateral direction (X-axis direction), are similar to the first end surface f1 and the second end surface f2. A pair of rotary blades (first rotary blade b1 and second rotary blade b2) may cut at substantially the same time (in parallel). The third end surface f3 and the fourth end surface f4 may be cut non-simultaneously using the first rotary blade b1 or the second rotary blade b2, respectively.

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 is preferable not to turn with respect to the rotation axis a12 (the central axis of the clamp 12) substantially parallel to the (axial direction). That is, it is preferable that the clamp 12 does not rotate from the time when the cutting of the end face of the laminated structure 2 is started to the time when the cutting of all the end faces is completed. 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. 7B. 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.

In the process of cutting all the end faces of the laminated structure 2 with the rotary blade, the clamp 12 does not rotate from beginning to end, and in the process of cutting all the end faces of the laminated structure 2 with the rotary blade, the first rotary blade b1 and the second The position where each of the rotary blades b2 is installed may be freely changed. For example, as shown in FIG. 4, the first rotary blade b1 is installed at one end (position p2) of the fourth end surface f4, and the first rotary blade b1 that moves from the position p2 to the position p1 causes the fourth end surface f4. It may be cut. After cutting the fourth end surface f4, the first rotary blade b1 is installed at one end (position p1) of the fourth end surface f4, and the second rotary blade b2 is installed at the other end (position p2) of the fourth end surface f4. The cutting of the first end surface f1 by the one 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 second rotary blade b2 is installed at one end (position p3) of the third end surface f3, and the second rotary blade b2 moves from the position p3 to the position p4. The three end faces f3 may be cut. However, as long as the two opposing end faces are cut substantially simultaneously with a pair of rotary blades so that at least a part of one end face is not flat, the first end face f1, the second end face f2, and the third end face f3 The cutting order of the fourth end face f4 is not limited, and the combination of each end face and the rotary blade for cutting each end face is not limited.

The clamp 12 may rotate freely from beginning to end in the process of cutting all the end faces of the laminated structure 2 with the rotary blade, and the positions where the first rotary blade b1 and the second rotary blade b2 are installed are also flexible. May change to. The clamp 12 may rotate freely from beginning to end in the process of cutting all the end faces of the laminated structure 2 with the rotary blade, and the positions where the first rotary blade b1 and the second rotary blade b2 are installed are fixed. It may have been.

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 or 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 or 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 or 2'may be cut by the first rotary blade b1 or the second rotary blade b2 described above.

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 present invention is not necessarily limited to the embodiments described above. Various modifications of the present invention can be made without departing from the spirit of the present invention. The following modified examples are also included in the present invention.

The shape of each end face after the cutting process is not limited as long as the two facing end faces are cut substantially simultaneously so that at least a part of at least one of the two facing end faces of the laminated structure is not flat. .. Two opposing end faces may be cut substantially simultaneously with a pair of rotary blades so that only a part of the end faces after the cutting step is not flat. The two opposing end faces may be cut substantially simultaneously by a pair of rotary blades so that the entire end face after the cutting step does not become flat. The shape of the laminated structure before the cutting process is not limited as long as the laminated structure is a pillar body having two opposite end faces and the two opposite end faces are substantially parallel to the stacking direction of the laminated body. The two opposing end faces in the laminated structure before the cutting process do not have to be parallel. At least one of the two opposing end faces in the laminated structure before the cutting process does not have to be a perfect flat surface.

As shown in (a) in FIG. 5, the narrow third end surface f3 and the fourth end surface f4 may be cut substantially simultaneously by the first rotary blade b1 or the second rotary blade b2, and the laminated body 4 may be cut. A notch 50 (recess) extending in the stacking direction (Z-axis direction) may be formed on the fourth end surface f4 after cutting. In the case of (a) in FIG. 5, the shape of the notch portion 50 seen from the stacking direction (Z-axis direction) of the laminated body 4 is substantially rectangular. However, the shape of the notch 50 is not limited. For example, the shape of the notch portion 50 seen from the stacking direction (Z-axis direction) of the laminated body 4 may be a quadrangle other than a rectangle, a triangle, another polygon, a semicircle, a semi-ellipse, or another curve. .. The four corners of the laminated structure 2 shown in FIG. 5A may be chamfered in the same manner as in the above embodiment. The notch may be formed on both sides of the third end surface f3 and the fourth end surface f4. The shape and dimensions of the notch formed on the third end surface f3 may be the same as the shape and dimensions of the notch formed on the fourth end surface f4. The shape and dimensions of the notch formed on the third end surface f3 may be different from the shape and dimensions of the notch formed on the fourth end surface f4. By simultaneous cutting of the wide first end surface f1 and second end surface f2, the notch extending in the stacking direction (Z-axis direction) of the laminated body 4 is at least one of the first end surface f1 and the second end surface f2 after cutting. It may be formed on one end face. Notches extending in the stacking direction (Z-axis direction) of the laminated body 4 may be formed on both sides of the first end surface f1 and the second end surface f2 after cutting.

As shown in FIG. 5B, the wide first end surface f1 and second end surface f2 may be cut substantially simultaneously by the first rotary blade b1 or the second rotary blade b2, and after the cutting step, The entire first end surface f1 and the second end surface f2 may be curved surfaces (convex surfaces). The entire first end surface f1 and the second end surface f2 after the cutting step may be concave surfaces. The entire first end surface f1 after the cutting process may be a convex surface, and the entire second end surface f2 after the cutting process may be a concave surface.

As shown in FIG. 6, the wide first end surface f1 and the second end surface f2 may be cut substantially simultaneously by the first rotary blade b1 or the second rotary blade b2, and the first end surface f1 after the cutting step is It may be a flat surface, and the entire second end surface f2 after the cutting step may be a curved surface (convex surface). The entire second end surface f2 after the cutting step may be a concave surface.

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 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 (9)

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 has two opposing end faces.
The two opposite end faces of the laminated structure are 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 surface of one of the laminated structures.
The side surface of the other rotary blade is in contact with the other end surface of the laminated structure.
The two opposing end faces of the laminated structure are cut substantially simultaneously by the pair of rotary blades so that at least a part of the one end face is not flat.
Manufacturing method of optical member. The two opposing end faces of the laminated structure are substantially parallel to the longitudinal direction of each 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 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.
The method for manufacturing an optical member according to claim 1 or 2. 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 any one of claims 1 to 3. In the cutting process, the distance between the pair of rotary blades fluctuates,
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 4. Further provided with a processing process performed before the cutting process,
The upper surface and the lower surface of the laminated structure before the processing step are quadrilaterals having all angles at right angles.
In the processing step, the laminated structure is processed so that the upper surface and the lower surface of the laminated structure each have a shape different from that of the quadrilateral.
The method for manufacturing an optical member according to any one of claims 1 to 5. The upper surface and the lower surface of the laminated structure used in the cutting step are quadrilaterals having all angles at right angles.
In the cutting step, the two opposing end faces of the laminated structure are substantially simultaneously formed by the pair of rotary blades so that the upper surface and the lower surface of the laminated structure each have a shape different from that of the quadrilateral. Be cut,
The method for manufacturing an optical member according to any one of claims 1 to 5. 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 7. The rotary blade is an end mill.
The method for manufacturing an optical member according to any one of claims 1 to 8.

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