TWI845603B - Method for manufacturing optical thin film - Google Patents

Abstract

A method for manufacturing an optical film is provided, which can suppress the generation of cracks in an optical film including a polarizer even when an end milling cutter is used. The method for manufacturing a cut optical film of the present invention comprises: overlapping a plurality of optical films including a polarizer to form a workpiece; and a cutting step of cutting the workpiece with an end milling cutter, wherein the workpiece is configured such that the absorption axis directions of the polarizers of the plurality of optical films are respectively set in the same direction, and the angle between the side A of the workpiece including the cutting starting point of the end milling cutter or the tangent line B of the workpiece at the cutting starting point and the absorption axis of the polarizer is 0°~30° or 150°~180°.

Description

Method for manufacturing optical thin film

Field of the invention The present invention relates to a method for manufacturing an optical film.

Background technology In image display devices such as mobile phones and notebook personal computers, various optical films (such as polarizing plates) are used to realize image display and/or improve the performance of the image display. In recent years, optical laminates are also expected to be used in automobile dashboards and smart watches, and the shape of optical laminates is also expected to be processed into a desired shape. During such processing, the end face is cut with an end mill. In the cutting process of the end mill, high-precision cutting can be performed, but on the other hand, there is a tendency for cracks to be generated in the optical film during cutting. In particular, the generation of interfacial cracks when the end milling cutter contacts the processed surface, and the generation of interfacial cracks when cutting optical films such as polarizers that contain films that are easily torn in a predetermined direction are common problems in cutting processes using end milling cutters. Prior Art Literature Patent Literature

[Patent Document 1] Japanese Patent Publication No. 2007-187781 [Patent Document 2] Japanese Patent Publication No. 2018-022140

Summary of invention Problem to be solved by the invention

The present invention is made to solve the above-mentioned known problems. Its main purpose is to provide a method for manufacturing an optical film, which can suppress the generation of cracks in an optical film including a polarizer while using an end mill. Means for solving the problem

The manufacturing method of the optical film processed by cutting of the present invention comprises: overlapping a plurality of optical films including polarizers to form a workpiece; and a cutting step of cutting the workpiece with an end milling cutter, wherein the workpiece is configured such that the absorption axis directions of the polarizers of the plurality of optical films are respectively set to the same direction, and the angle between the side A of the workpiece including the cutting starting point of the end milling cutter or the tangent line B of the workpiece at the cutting starting point and the absorption axis of the polarizer is 0°~30° or 150°~180°. In one embodiment, the manufacturing method comprises cutting the outer peripheral surface of the workpiece with the end milling cutter in the cutting step. In one embodiment, the workpiece is a roughly rectangular shape consisting of a long side and a short side, the absorption axis of the polarizer is parallel to the long side, and the cutting starting point is set on the long side. In one embodiment, the workpiece is a roughly rectangular shape consisting of a long side and a short side, the absorption axis of the polarizer is parallel to the short side, and the cutting starting point is set on the short side. In one embodiment, a concave portion or a hole portion is provided on one side of the short side, and the cutting starting point is provided on the other short side. In one embodiment, the workpiece has a hole portion, and the cutting step includes cutting the inner circumference of the hole portion with the end milling cutter, and the angle between the tangent B' of the workpiece at the cutting starting point of the end milling cutter and the absorption axis of the polarizer is 0°~30° or 150°~180°. In one embodiment, the workpiece is a roughly rectangular shape consisting of a long side and a short side, and the absorption axis of the polarizer is parallel to the long side. In one embodiment, the workpiece is a roughly rectangular shape consisting of a long side and a short side, and the absorption axis of the polarizer is parallel to the short side. According to other aspects of the present invention, a method for manufacturing a cut optical film set can be provided. This manufacturing method includes manufacturing a cut first optical film and a second optical film using the above-mentioned method for manufacturing a cut optical film, and forming the first optical film and the second optical film in a manner that can be configured so that the absorption axis of the polarizer constituting the first optical film is perpendicular to the absorption axis of the polarizer constituting the second optical film. In one embodiment, the outer diameter of the end milling cutter is less than 10 mm. In one embodiment, the torsion angle of the end milling cutter is 0°. Effect of the invention

According to the present invention, a method for manufacturing an optical film by cutting is provided, with the absorption axis direction of the polarizer of the optical film including the polarizer as the reference and a specific position as the starting point of cutting. The method can suppress the generation of cracks in the optical film including the polarizer while using an end milling cutter.

Types used to implement the invention

The following is a description of specific embodiments of the present invention with reference to the drawings, but the present invention is not limited to these embodiments. In addition, for ease of viewing, the drawings are presented in a schematic manner, and the ratios and angles of length, width, thickness, etc. in the drawings are different from the actual situation.

A. Method for manufacturing optical film The method for manufacturing optical film after cutting of the present invention comprises: overlapping a plurality of optical films containing polarizers to form a workpiece; and cutting the workpiece with an end mill. The workpiece is configured so that the absorption axis directions of the polarizers of the plurality of optical films are in the same direction. In this specification, "the same direction" includes the situation of substantially the same direction, specifically including the situation of the angle between 0° and 5° with each direction.

A-1. Formation of workpiece The optical film including the polarizer may be a single polarizer or a film including the polarizer and other layers. As for the other layers, for example, a protective layer for protecting the polarizer, a layer composed of any appropriate optical functional layer, etc. In one embodiment, a polarizing plate is used as an optical film including the polarizer. The polarizing plate may have a polarizer and a protective layer arranged on at least one side of the polarizer. In addition, as a film including the polarizer, a laminate of a polarizing plate and a surface protective film and/or a spacer may be used. The surface protective film or the spacer is releasably laminated on the polarizing plate through any appropriate adhesive. In this specification, the "surface protection film" is a film that temporarily protects the polarizing plate, and is different from the protective layer (layer that protects the polarizer) possessed by the polarizing plate.

Polarizers are mainly obtained by subjecting resin films (such as polyvinyl alcohol-based resin films) to various treatments such as swelling treatment, stretching treatment, dyeing treatment with dichroic substances (such as iodine, organic dyes, etc.), bridging treatment, cleaning treatment, drying treatment, etc. Generally speaking, polarizers obtained by stretching treatment have the characteristic of being prone to cracking, but according to the present invention, cracking can be prevented and optical films containing polarizers can be cut.

There is no particular restriction on the thickness of the optical film containing the polarizer, and an appropriate thickness can be adopted according to the purpose, such as 20μm~200μm. There is no particular restriction on the thickness of the polarizer, and an appropriate thickness can be adopted according to the purpose. The thickness of the polarizer is generally around 1μm~80μm, preferably 3μm~40μm.

The size of the optical film including the polarizer is not particularly limited, and an appropriate size can be adopted according to the purpose. In one embodiment, the optical film including the polarizer is rectangular and includes a side parallel to the absorption axis of the polarizer, and the length of the side parallel to the absorption axis of the polarizer is 10 mm to 400 mm, and the length of the other sides is 10 mm to 500 mm. In this specification, the so-called "parallel" includes substantially parallel situations, specifically including situations where the angle formed with the two directions is 0° to 5°.

FIG1 is a schematic three-dimensional diagram for explaining the cutting process, and a workpiece 1 is shown in this figure. As shown in FIG1, a workpiece 1 is formed by overlapping a plurality of optical films. When the optical film is formed into the workpiece, it is mainly cut into any suitable shape. Specifically, the optical film can be cut into a rectangular shape, or a shape similar to a rectangular shape, or a shape suitable for the purpose (such as a circle). In the example shown in the figure, the optical film is cut into a rectangular shape, and the workpiece 1 has outer peripheral surfaces (cutting surfaces) 1a, 1b facing each other, and outer peripheral surfaces (cutting surfaces) 1c, 1d perpendicular thereto. The workpiece 1 is preferably clamped from the top and bottom by a clamping mechanism (not shown). The total thickness of the workpiece is, for example, 8 mm to 100 mm, preferably 8 mm to 50 mm, more preferably 8 mm to 20 mm, more preferably 9 mm to 15 mm, and more preferably about 10 mm. With such a thickness, it is possible to prevent damage caused by pressing of the clamping mechanism or impact of cutting. The optical film overlaps the workpiece to form such a total thickness. The number of sheets of optical film constituting the workpiece can be, for example, 10 to 500 sheets (10 to 300 sheets in one embodiment; 10 to 50 sheets in other embodiments). The clamping mechanism (e.g., a jig) can be made of a soft material or a hard material. In the case of soft materials, the hardness (JIS A) is preferably 20°~80°, more preferably 60°~80°, and the thickness is 0.3mm~5mm. If the hardness is too high, there may be residual pressure marks from the clamping mechanism. If the hardness is too low or too thick, there may be misalignment due to deformation of the fixture, resulting in insufficient cutting accuracy.

A-2. Cutting process Next, the workpiece 1 is cut with the end mill 20. Cutting can be performed by bringing the cutting edge of the end mill into contact with the outer peripheral surface of the workpiece 1. Cutting can be performed over the entire periphery of the outer peripheral surface of the workpiece, or only at a predetermined position. In addition, for a workpiece having a hole, the inner peripheral surface can be cut by bringing the cutting edge of the end mill into contact with the inner peripheral surface of the hole. A vertical milling cutter is mainly used as the end mill 20. During the cutting process, only the end mill can be moved, only the workpiece can be moved, or both the end mill and the workpiece can be moved.

As shown in FIG. 2 and FIG. 3 , the end milling cutter 20 has a rotation axis 21 extending along the lamination direction (lead vertical direction) of the workpiece 1, and a cutting edge 22 which is formed as the outermost diameter of the main body and rotates around the rotation axis 21. The cutting edge 22 can be formed as the outermost diameter twisted along the rotation axis 21 as shown in FIG. 2 (it can also have a predetermined twist angle), or it can be formed to extend in a direction substantially parallel to the rotation axis 21 as shown in FIG. 3 (the twist angle can also be 0°). In addition, "0°" means substantially 0°, and also includes the case where it is twisted by a small angle due to processing errors, etc. In the case where the cutting edge has a predetermined twist angle, it is preferably a twist angle of 70° or less, more preferably 65° or less, and more preferably 45° or less. The cutting edge 22 includes a cutting edge 22a, a front blade 22b, and a back blade 22c. The number of blades of the cutting edge 22 can be appropriately set as long as the desired number of contacts described later can be obtained. The number of blades in FIG2 is 3 and the number of blades in FIG3 is 2, but the number of blades can be 1, 4, or more than 5. The number of blades is preferably 2. If such a structure is used, the rigidity of the blade can be ensured, and the recess can also be ensured so that the shavings can be discharged normally.

In one embodiment, the outer diameter of the end milling cutter is less than 10 mm, preferably 3 mm to 9 mm, and more preferably 4 mm to 7 mm. In addition, in this specification, the "outer diameter of the end milling cutter" refers to twice the distance from the rotation axis to the first cutting edge.

The cutting conditions can be appropriately set according to the desired shape. For example, the end milling cutter speed is preferably 1000rpm~60000rpm, and more preferably 10000rpm~40000rpm. The feed rate of the end milling cutter (relative speed to the workpiece) is preferably 500mm/min~10000mm/min, and more preferably 500mm/min~2500mm/min.

In the present invention, the cutting process is performed in the following manner: the angle between the side A of the workpiece including the cutting starting point of the end milling cutter or the tangent B of the workpiece at the cutting starting point and the absorption axis of the above-mentioned polarizer is 0°~30° or 150°~180°. In addition, in this specification, the angle between the side A or the tangent B and the absorption axis of the polarizer means the angle in the plane viewing angle (horizontal angle). In addition, when the angle is mentioned in this specification, unless otherwise specified, the angle includes the angle in both the clockwise and counterclockwise directions.

A-2-1. Cutting of the peripheral surface Figure 4 is a schematic plan view illustrating the cutting process of the first embodiment of the present invention. In the embodiment shown in Figure 4, the peripheral surface of the workpiece 1 is cut by an end mill. In Figure 4, the workpiece 1 is roughly rectangular, and the cutting start point a is included in the side A of the workpiece 1. The cutting start point a is the position where the end mill first abuts against the workpiece 1, and then the end mill moves relative to the workpiece 1 along the cut surface of the workpiece 1 (the peripheral surface in Figure 4). In the case where the cutting covers the entire circumference of the peripheral surface of the workpiece, the cutting start point a and the cutting end point can be the same position. As mentioned above, the angle between the side A and the absorption axis X of the above-mentioned polarizer is 0°~30° or 150°~180°. In the present invention, the cutting starting point a is set at the side A whose angle with the absorption axis X of the polarizer is 0°~30° or 150°~180°, that is, the cutting starting point a is set at the side parallel to the absorption axis X or the side nearly parallel to the absorption axis X, thereby preventing the polarizer from cracking during the cutting process. The angle between the side A and the absorption axis X of the polarizer is preferably 0°~20° or 160°~180°, more preferably 0°~10° or 170°~180°, and even more preferably 0°~5° or 175°~180°.

The shape of the workpiece (i.e., the optical film) can be any appropriate shape. As the shape of the workpiece, in addition to the roughly rectangular shape as shown in FIG. 4, a slightly polygonal shape, a slightly circular shape, a slightly elliptical shape, etc. can be listed. In addition, the shape of the workpiece can be a shape that is a proper combination of straight lines and curves, or a shape composed of a plurality of curves with different curvatures. In addition, the above-mentioned workpiece is not necessarily a pure rectangular shape, polygonal shape, circular shape, elliptical shape, etc., but can also be a shape in which a deformed part is added to these shapes. In this specification, for example, a rectangular shape with a deformed part added is included in the "roughly rectangular shape". As a deformed part, in addition to the concave part shown in FIG. 4, a convex part, a hole, etc. can be listed. In addition, the above-mentioned workpiece can also be a shape after the corners of the rectangle are curved.

As shown in FIG5 , when the workpiece is in a curved shape, the cutting starting point can be set at the following position: the angle between the tangent B of the workpiece 1 at the cutting starting point a and the absorption axis of the polarizer is 0°~30° or 150°~180°. By setting the cutting starting point in this way, cracks in the polarizer can be prevented during cutting. The angle between the tangent B and the absorption axis X of the polarizer is preferably 0°~20° or 160°~180°, more preferably 0°~10° or 170°~180°, and even more preferably 0°~5° or 175°~180°. In addition, in this specification, "tangent of the workpiece" means the tangent of the outer contour of the plane viewing angle of the workpiece.

When the outer contour of the workpiece has a vertex and/or a connection point between a straight line and a curve, it is preferred not to use the vertex and the connection point as the starting point for cutting, and it is more preferred to use a portion more than 2 mm away from the vertex and the connection point as the starting point for cutting, and it is more preferred to use a portion more than 5 mm away from the vertex and the connection point as the starting point for cutting. In one embodiment, a portion more than 20 mm away from the vertex and the connection point is used as the starting point for cutting. In another embodiment, a portion more than 40 mm away from the vertex and the connection point is used as the starting point for cutting. If the vertex and the connection point are used as the starting point for cutting, there is a risk of burrs.

In the case where the above-mentioned workpiece has a deformed portion, it is preferred to set the starting point of cutting at a position more than 2 mm away from the deformed portion, and more preferably at a position more than 4 mm away. In one embodiment, a position more than 20 mm away from the deformed portion is set as the starting point of cutting. In other embodiments, a position more than 40 mm away from the vertex and the connection point is used as the starting point of cutting. Furthermore, in the case where the shape of the workpiece is slightly rectangular, it is preferred to set the starting point of cutting on a side different from the side where the deformed portion is provided. By not using the deformed portion and the vicinity of the deformed portion as the starting point of cutting, cracks in the polarizer during cutting can be prevented.

In the first embodiment, as shown in FIG6(a), the workpiece 1A is a roughly rectangular shape consisting of a long side and a short side, the absorption axis X of the polarizer is parallel to the long side, and the cutting start point a is set on the long side. In the workpiece 1A, as shown in FIG6(a), the recessed portion can be provided in a part of one of the short sides, and as shown in FIG6(b), a hole portion 11 is provided near one of the short sides.

In other embodiments, as shown in FIG6(c), the workpiece 1B is a roughly rectangular shape consisting of long sides and short sides, the absorption axis X of the polarizer is parallel to the short side, and the cutting starting point a is set on the short side. In the workpiece 1B, the recess can be provided in a part of one of the short sides. In the case where the recess is provided in a part of one of the short sides, it is preferred that the cutting starting point a is provided on the other short side. Furthermore, as shown in FIG6(d), the hole portion 11 of the workpiece 1B can be provided near one of the short sides. In this case, it is preferred that the cutting starting point a is provided on the other short side.

A-2-2. Cutting of the inner circumference Figure 7 is a schematic plan view illustrating the cutting process of the first embodiment of the present invention. In the embodiment shown in Figure 7, the workpiece 1A' (1B') has a hole portion 11', and the inner circumference of the hole portion 11' is cut by an end mill. In this embodiment, the angle between the tangent B' of the workpiece (substantially the outer contour of the hole portion) at the cutting starting point a and the absorption axis X of the polarizer is 0°~30° or 150°~180° (0°~20° or 160°~180° is preferred, 0°~10° or 170°~180° is more preferred, and 0°~5° or 175°~180° is more preferred). In one embodiment, as shown in FIG7(a), the workpiece 1A' is a roughly rectangular shape consisting of a long side and a short side, and the absorption axis X of the polarizer is parallel to the long side. In another embodiment, as shown in FIG7(b), the workpiece 1B' is a roughly rectangular shape consisting of a long side and a short side, and the absorption axis X of the polarizer is parallel to the short side.

A-3. Application of the cut optical film The cut optical film obtained by the manufacturing method of the present invention can be used in liquid crystal image display devices, organic electroluminescent image display devices, etc. In addition, the cut optical film can be appropriately used in the rectangular image display part represented by the above-mentioned personal computer (PC) or tablet computer terminal, and/or the deformed image display part represented by the dashboard of the car or the smart watch.

B. Manufacturing method of optical film set In one embodiment, a manufacturing method of a cutting optical film set is provided. This manufacturing method includes: manufacturing a first optical film that is cut to form a first workpiece (e.g., the above-mentioned workpiece 1A, workpiece 1A'); and manufacturing a second optical film that is cut to form a second workpiece (e.g., the above-mentioned workpiece 1B, workpiece 1B'). The first optical film and the second optical film can be manufactured by the manufacturing method described in the above item A. In one embodiment, the optical films constituting the first workpiece, the second workpiece, and these workpieces are of approximately the same shape.

In one embodiment, in a method for manufacturing a cut optical film assembly, the first optical film and the second optical film are formed in a manner that the absorption axis of the polarizer constituting the first optical film is perpendicular to the absorption axis of the polarizer constituting the second optical film. More specifically, the first optical film and the second optical film are formed into approximately the same shape, and when these films are formed into a laminate of the same shape in a plane viewing angle, the first optical film and the second optical film are formed so that the absorption axis of the polarizer of the first optical film and the absorption axis of the polarizer of the second optical film can be perpendicular. In such an embodiment, the cutting start point when cutting the first workpiece is at a position that does not correspond to the cutting start point when cutting the second workpiece. In addition, in this specification, the so-called "vertical" includes substantially vertical situations, and specifically includes situations where the angle between the two directions is 85° to 95°.

In the first embodiment, in the method for manufacturing the optical film set by cutting, as described above, the first workpiece 1A and the second workpiece 1B are substantially rectangular in shape consisting of long sides and short sides. The first workpiece 1A, the second workpiece 1B, and the optical films constituting these workpieces are preferably substantially the same in shape.

In addition, as shown in Fig. 6 (a) and (b), in the first workpiece 1A, the absorption axis X of the polarizer of the optical film constituting the first workpiece 1A is parallel to the long side. When the first workpiece 1A is cut, the cutting start point is set on the long side of the first workpiece 1A. In one embodiment, a concave portion is provided in a part of one of the short sides of the first workpiece 1A. In addition, a hole portion may be provided near one of the short sides of the first workpiece 1A.

In addition, as shown in Figures 6(c) and (d), in the second workpiece 1B, the absorption axis X of the polarizer possessed by the optical film constituting the second workpiece 1B is parallel to the short side. When the second workpiece 1B is cut, the cutting starting point is set on the short side of the second workpiece 1B. In one embodiment, in the second workpiece 1B, a recess is provided on a portion of one of the short sides. In the case where a recess is provided on a portion of one of the short sides, it is preferred that the cutting starting point is set on the other short side. Furthermore, in the second workpiece 1B, a hole portion may also be provided near one of the short sides. In this case, it is preferred that the cutting starting point is set on the other short side.

The first workpiece may be a first workpiece 1A' having a hole, and the first optical film may be an optical film whose inner circumference of the hole is cut. The second workpiece may be a second workpiece 1B' having a hole, and the second optical film may be an optical film whose inner circumference of the hole is cut. The first workpiece 1A', the second workpiece 1B', and the optical films constituting these workpieces are preferably of approximately the same shape. Furthermore, it is preferred that the holes formed in each workpiece are of approximately the same shape and are formed at the same position (corresponding position) in each workpiece. In one embodiment, as shown in FIG. 7(a), the workpiece 1A' is a roughly rectangular shape consisting of a long side and a short side, and the absorption axis X of the polarizer is parallel to the long side. In other embodiments, as shown in FIG. 7(b), the workpiece 1B' is a roughly rectangular shape consisting of a long side and a short side, and the absorption axis X of the polarizer is parallel to the short side.

The first workpiece and the second workpiece may be in a slightly rectangular shape, a slightly polygonal shape, a slightly circular shape, a slightly elliptical shape, etc. In addition, the shape of the workpiece may be a shape of a proper combination of straight lines and curves, or a shape composed of a plurality of curves with different curvatures. For example, a cut optical film may be manufactured from a first workpiece in the shape shown in FIG. 5(a) and a second workpiece in the shape shown in FIG. 5(b). When the first workpiece and the second workpiece are in such shapes, the first workpiece, the second workpiece, and the optical film constituting these workpieces are preferably in the same shape.

According to the manufacturing method of the optical film by cutting of the present invention, two optical films can be manufactured in which the absorption axes of the polarizers are perpendicular to each other and arranged opposite to each other. The first optical film and the second optical film can be used, for example, in a liquid crystal display device, and can also be used to: configure the first optical film on one side of a liquid crystal display element (cell) of the liquid crystal display device, and configure the second optical film on the other side. Example

The present invention is described in detail below by using embodiments, but the present invention is not limited to these embodiments.

[Example 1] An optical film (polarizing plate) having the following structure in order from the visible side is prepared by conventional methods: surface protection film (48μm)/hard coating (5μm)/cycloolefin protective film (47μm)/polarizer (5μm)/cycloolefin protective film (24μm)/adhesive layer (20μm)/insulator. The adhesive layer is prepared according to [0121] and [0124] of Japanese Patent Publication No. 2016-190996. The obtained optical film is punched into a shape similar to FIG. 4 (approximate size is about 140 mm × about 65 mm). The absorption axis direction of the polarizer of each optical film is made parallel to the long side of the optical film, and then the pressed optical film is overlapped to form a workpiece (total thickness is about 10mm). When the obtained workpiece is clamped by a fixture (jig), the starting point of cutting is set at the long side of the optical film, and the peripheral part is cut by end milling. The number of blades of the end mill is 2, and the twist angle is 0°. In addition, the feed speed of the end mill (the feed speed when cutting the straight line part) is 1000mm/min, and the rotation speed is 25000rpm. During the above cutting, no cracks were generated on the optical film.

[Example 2] The absorption axis of the polarizer of each optical film is made parallel to the short side of the optical film, and then a plurality of punched optical films are overlapped to form a workpiece (total thickness of about 10 mm), and the cutting starting point is set outside the short side of the optical film, and the cutting process is performed in the same manner as in Example 1. During the above cutting, no cracks are generated on the optical film.

[Comparative Example 1] The optical film was cut in the same manner as in Example 1, with the cutting start point set outside the short side of the optical film. In this case, at the start of cutting, when the end milling cutter abutted against the outer peripheral surface of the workpiece, cracks had already occurred in the optical film. Industrial Applicability

The cut optical film of the present invention can be suitably used in the rectangular image display part represented by the above-mentioned personal computer (PC) or tablet computer terminal, and/or the deformed image display part represented by the dashboard of the car or the smart watch.

1,1A,1A’,1B,1B’: Workpiece 1a,1b,1c,1d: Outer circumference (cutting surface) 11,11’: Hole 20: End milling cutter 21: Rotating axis 22: Cutting edge 22a: Blade 22b: Front face 22c: Back face A: Edge a: Cutting start point B,B’: Tangent X: Absorption axis

FIG. 1 is a schematic three-dimensional diagram for illustrating an example of cutting processing of the optical film of the present invention. FIG. 2 is a schematic three-dimensional diagram for illustrating an example of an end mill used for cutting processing in the method for manufacturing the optical film of the present invention. FIG. 3(a) is a schematic cross-sectional diagram viewed from the axial direction for illustrating another example of a cutting mechanism used for cutting processing in the method for manufacturing the optical film of the present invention; FIG. 3(b) is a schematic three-dimensional diagram of the cutting mechanism of FIG. 3(a). FIG. 4 is a schematic plan view for illustrating cutting processing of the first embodiment of the present invention. FIG. 5(a) and FIG. 5(b) are schematic plan views for illustrating cutting processing of the first embodiment of the present invention. FIG. 6(a) to FIG. 6(d) are schematic plan views for illustrating cutting processing of the first embodiment of the present invention. Fig. 7(a) and Fig. 7(b) are schematic plan views illustrating the cutting process of the first embodiment of the present invention.

1: Workpiece

A: Side

a: Cutting starting point

X: Absorption axis

Claims (15)

A method for manufacturing a cut optical film, comprising: overlapping a plurality of optical films including polarizers to form a workpiece; and cutting the workpiece with an end milling cutter, wherein the workpiece is configured such that the absorption axis directions of the polarizers of the plurality of optical films are respectively set to the same direction, and the workpiece is added with a deformed portion, and the angle between the edge A of the workpiece including the cutting starting point of the end milling cutter or the tangent line B of the workpiece at the cutting starting point and the absorption axis of the polarizer is 0°~30° or 150°~180°. The method for manufacturing a cut optical film as claimed in claim 1, wherein the cutting step includes cutting the outer peripheral surface of the workpiece with the end milling cutter. The method for manufacturing an optical film by cutting as in claim 2, wherein the workpiece is a roughly rectangular shape consisting of a long side and a short side, the absorption axis of the polarizer is parallel to the long side, and the cutting starting point is set on the long side. The method for manufacturing an optical film by cutting as in claim 2, wherein the workpiece is a roughly rectangular shape consisting of a long side and a short side, the absorption axis of the polarizer is parallel to the short side, and the cutting starting point is set on the short side. A method for manufacturing a cutting optical film as claimed in claim 4, wherein a concave portion or a hole portion is provided on one side of the aforementioned short side, and the aforementioned cutting starting point is provided on the other short side. The method for manufacturing a cut optical film as claimed in claim 1, wherein the workpiece has a hole, and the cutting step includes cutting the inner circumference of the hole with the end milling cutter, and the angle between the tangent line B' of the workpiece at the starting point of the cutting of the end milling cutter and the absorption axis of the polarizer is 0°~30° or 150°~180°. A method for manufacturing a cut optical film as claimed in claim 6, wherein the workpiece is a roughly rectangular shape consisting of a long side and a short side, and the absorption axis of the polarizer is parallel to the long side. A method for manufacturing a cutting optical film as claimed in claim 6, wherein the workpiece is a roughly rectangular shape consisting of a long side and a short side, and the absorption axis of the polarizer is parallel to the short side. A method for manufacturing a cut optical film set, comprising manufacturing a cut first optical film and a second optical film using the method for manufacturing a cut optical film of claim 1, and forming the first optical film and the second optical film in a manner that can be configured so that the absorption axis of the polarizer constituting the first optical film is perpendicular to the absorption axis of the polarizer constituting the second optical film. The method for manufacturing a cut optical film set as claimed in claim 9 comprises: manufacturing a cut first optical film using the method for manufacturing a cut optical film as claimed in claim 3; and manufacturing a cut second optical film using the method for manufacturing a cut optical film as claimed in claim 4 or 5. The method for manufacturing a cut optical film set as claimed in claim 9 includes: manufacturing a cut first optical film using the method for manufacturing a cut optical film as claimed in claim 7; and manufacturing a cut second optical film using the method for manufacturing a cut optical film as claimed in claim 8. A method for manufacturing an optical film by cutting as claimed in any one of claims 1 to 8, wherein the outer diameter of the end milling cutter is less than 10 mm. A method for manufacturing a cutting optical film assembly as claimed in any one of claims 9 to 11, wherein the outer diameter of the end mill is less than 10 mm. A method for manufacturing a cut optical film as claimed in any one of claims 1 to 8, wherein the twist angle of the end mill is 0°. A method for manufacturing a cut optical film assembly as claimed in any one of claims 9 to 11, wherein the twist angle of the end mill is 0°.