JP2020134582A - Method for manufacturing optical film - Google Patents

Abstract

To provide a method for manufacturing an optical film cut by end mill machining performed two or more times, capable of easily determining the existence of finish-machining.SOLUTION: The method for manufacturing an optical film includes the step of stacking a plurality of optical films to form a work piece and the end mill machining step of cutting the outer peripheral surface of the work piece by an end mill. The end mill machining step includes roughly cutting the outer peripheral surface of the work piece by the end mill and finish-machining the roughly cut outer peripheral surface of the work piece by the end mill; the roughly cutting step includes providing an uncut portion in the outer peripheral surface of the work piece; and the finish-machining includes cutting the uncut portion.SELECTED DRAWING: Figure 5

Description

The present invention relates to a method for producing an optical film.

Various optical films (for example, polarizing plates) are used in image display devices such as mobile phones and notebook personal computers in order to realize image display and / or enhance the performance of the image display. In recent years, it has been desired to use an optical laminate for an automobile instrument panel, a smart watch, and the like, and it is desired to process the shape of the optical laminate into a desired shape. During such processing, the end face may be cut by an end mill. In such a case, the surface to be ground is subjected to a plurality of times of end milling, such as rough cutting and then finishing.

In the above-mentioned end mill processing, it is assumed that there is a process error that the product is made into a product or flows out to the next process without being finished after rough cutting. It is difficult to judge whether or not finish processing is performed by visual quality inspection, and if a predetermined inspection device is introduced, the process becomes complicated and it is disadvantageous in terms of cost.

JP-A-2007-187781 Japanese Unexamined Patent Publication No. 2018-022140

The present invention has been made to solve the above-mentioned conventional problems, and a main object thereof is a method for manufacturing an optical film cut by a plurality of end milling processes, and it is easy to determine whether or not there is a finishing process. The purpose is to provide a manufacturing method that can be used.

The method for producing an optical film of the present invention includes forming a work by stacking a plurality of optical films and an end milling step of cutting the outer peripheral surface of the work with an end mill, and the end milling step is the work. A roughing step of roughing the outer peripheral surface with an end mill and finishing of the outer peripheral surface of the roughed work with an end mill are included, and the roughing step includes providing an uncut portion on the outer peripheral surface of the work. The finishing process includes cutting the uncut portion.
In one embodiment, in the method for manufacturing an optical film, in the rough cutting step, at the start of cutting, the end mill is brought into contact with the work while running the end mill from an oblique direction with respect to the work in a plan view. This includes forming the uncut portion by setting a portion where cutting starts and a portion where cutting ends on the work at different positions.
In one embodiment, the method for manufacturing an optical film is to separate the end mill from the work while running the end mill diagonally with respect to the work in a plan view at the end of cutting in the rough cutting step. Including that.

According to the present invention, it is possible to provide a method for manufacturing an optical film cut by a plurality of end milling processes, and a manufacturing method capable of easily determining the presence or absence of finish processing.

It is the schematic perspective view for demonstrating an example of the cutting process of the optical film of this invention. It is a schematic perspective view for demonstrating an example of an end mill used for cutting in the method of manufacturing an optical film of this invention. FIG. 3 (a) is a schematic cross-sectional view seen from the axial direction for explaining another example of the cutting means used for cutting in the method for manufacturing an optical film of the present invention; FIG. 3 (b) is a schematic cross-sectional view. It is a schematic perspective view of the cutting means of FIG. 3A. 4 (a) to 4 (c) are schematic partial plan views of a work for explaining an uncut portion in the method for manufacturing an optical film of the present invention. 5 (a) and 5 (b) are schematic plan views illustrating a rough cutting step in the method for manufacturing an optical film according to one embodiment of the present invention. 6 (a) and 6 (b) are schematic plan views illustrating the cutting process according to one embodiment of the present invention. 7 (a) and 7 (b) are schematic plan views illustrating the cutting process according to one embodiment of the present invention. It is a schematic plan view explaining the work in one Embodiment of this invention. 9 (a) and 9 (b) are schematic plan views illustrating the cutting process according to one embodiment of the present invention. 10 (a) and 10 (b) are schematic plan views illustrating the cutting process according to one embodiment of the present invention.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments. The drawings are schematically shown for easy viewing, and the ratios of length, width, thickness, etc., angles, etc. in the drawings are different from the actual ones.

The method for producing a machined optical film of the present invention includes stacking a plurality of optical films to form a work, and an end milling step of cutting the outer peripheral surface of the work with an end mill.

<< Work formation >>
FIG. 1 is a schematic perspective view for explaining a cutting process, and the work 1 is shown in this figure. As shown in FIG. 1, a work 1 in which a plurality of optical films are stacked is formed. The optical film is typically cut into any suitable shape when the work is formed. Specifically, the optical film may be cut into a rectangular shape, may be cut into a shape similar to a rectangular shape, or may be cut into an appropriate shape (for example, a circle) according to the purpose. Good. In the illustrated example, the optical film is cut into a rectangular shape, and the work 1 has outer peripheral surfaces (cutting surfaces) 1a and 1b facing each other and outer peripheral surfaces (cutting surfaces) 1c and 1d orthogonal to them. .. The work 1 is preferably clamped from above and below by clamping means (not shown). The total thickness of the work is, for example, 8 mm to 100 mm, preferably 8 mm to 50 mm, more preferably 8 mm to 20 mm, further preferably 9 mm to 15 mm, still more preferably about 10 mm. With such a thickness, damage due to pressing by the clamping means or impact during cutting can be prevented. The optical films are stacked so that the workpieces have such a total thickness. The number of optical films constituting the work can be, for example, 10 to 500 (in one embodiment, 10 to 300; in another embodiment, 10 to 50). The clamping means (for example, a jig) may be made of a soft material or a hard material. When composed of a soft material, its hardness (JIS A) is preferably 20 ° to 80 °, more preferably 60 ° to 80 °, and its thickness is, for example, 0.3 mm to 5 mm. If the hardness is too high, imprints may remain due to the clamping means. If the hardness is too low or too thick, the jig may be deformed and misaligned, resulting in insufficient cutting accuracy.

<< End mill processing process >>
Next, in the end mill processing step, the outer peripheral surface of the work 1 is cut by the end mill 20. Cutting is performed by bringing the cutting blade of the end mill into contact with the outer peripheral surface of the work 1. The cutting may be performed over the entire circumference of the outer peripheral surface of the work, or may be performed only at a predetermined position. Further, for a work having a hole, the cutting blade of the end mill may be brought into contact with the inner peripheral surface of the hole to cut the inner peripheral surface. As the end mill 20, a straight end mill can be typically used. In the cutting process, only the end mill may be moved, only the work may be moved, or both the end mill and the work may be moved.

As shown in FIGS. 2 and 3, the end mill 20 includes a rotating shaft 21 extending in the stacking direction (vertical direction) of the work 1 and a cutting blade 22 formed as the outermost diameter of a main body rotating around the rotating shaft 21. And have. The cutting blade 22 may be configured as the outermost diameter twisted along the rotation shaft 21 as shown in FIG. 2 (may have a predetermined twist angle), or may have a rotation shaft as shown in FIG. It may be configured to extend in a direction substantially parallel to 21 (the twist angle may be 0 °). In addition, "0 °" means that it is substantially 0 °, and includes the case where the angle is slightly twisted due to a processing error or the like. When the cutting blade has a predetermined twist angle, the twist angle is preferably 70 ° or less, more preferably 65 ° or less, still more preferably 45 ° or less. The cutting blade 22 includes a cutting edge 22a, a rake surface 22b, and a relief surface 22c. The number of cutting blades 22 can be appropriately set as long as the desired number of contacts described later can be obtained. The number of blades in FIG. 2 is three and the number of blades in FIG. 3 is two, but the number of blades may be one, four, or five or more. Preferably, the number of blades is two. With such a configuration, the rigidity of the blade is ensured, the pocket is secured, and the shavings can be discharged satisfactorily. In one embodiment, an end mill with a twist angle of 0 ° is used.

In the end mill processing step, a rough cutting step of rough cutting the outer peripheral surface of the work with an end mill is performed, and further, the outer peripheral surface of the roughed work is finished with an end mill. The rough cutting process and the finishing process are performed to improve the cutting accuracy. In the rough cutting process, for example, the outer peripheral surface of the work is cut to a thickness of 0.1 mm to 0.5 mm, and in the finishing process, after the rough cutting. The outer peripheral surface of the work is cut to a thickness of, for example, 0.01 mm to 0.2 mm. In the rough cutting process and the finishing process, the surface to be ground may be cut by the end mill a plurality of times.

<Roughing process>
In the present invention, in the rough cutting process, an uncut portion is provided on the outer peripheral surface of the work. 4 (a) to 4 (c) are schematic partial plan views of a work for explaining an uncut portion. The uncut portion 11 is a portion that has not been cut by an end mill. Typically, the uncut portion 11 is formed as a convex portion formed on the outer peripheral surface of the work 1 as shown in FIGS. 4A to 4C.

The uncut portion is cut in a finishing process which is a subsequent process. According to the present invention, by providing the uncut portion in the rough cutting process, it is possible to easily determine whether or not the product (or semi-finished product) is obtained through the finishing process depending on the presence or absence of the uncut portion. .. That is, a work or optical film having no uncut portion can be judged to be a normal product obtained through finishing, while a work or optical film having an uncut portion is a defective product not finished. Alternatively, it may be judged that the semi-finished product should be finished.

The shape of the uncut portion 11 can be defined by the running locus of the end mill. In one embodiment, an uncut portion is formed by setting a portion on the work where cutting starts and a portion where cutting ends at different positions. More specifically, as shown in the running locus t of the end mill shown in FIG. 5A, cutting is started by the end mill, cutting is finished and the end mill is released from the work before the end mill reaches the cutting start point a. By running in this way, the uncut portion 11 shown in FIG. 5B is formed.

The shape of the uncut portion 11 is not particularly limited, and the shapes shown in FIGS. 4A to 4C are exemplified. The width of the uncut portion (width w in FIG. 4) is preferably 0.1 mm to 30 mm, more preferably 0.5 mm to 10 mm, and further preferably 1 mm to 2 mm. The height of the uncut portion (height h in FIG. 4) is preferably 0.05 mm to 1 mm, more preferably 0.1 mm to 0.5 mm.

In one embodiment, the outer diameter of the end mill used in the rough cutting step is 10 mm or less, preferably 3 mm to 9 mm, and more preferably 4 mm to 6 mm. In the present specification, the "outer diameter of the end mill" means that the distance from the rotating shaft to one cutting edge is doubled.

The cutting conditions in the rough cutting process can be appropriately set according to the desired shape. For example, the end mill rotation speed is preferably 1000 rpm to 60,000 rpm, more preferably 10000 rpm to 40,000 rpm. The feed rate of the end mill is preferably 500 mm / min to 10000 mm / min, and more preferably 500 mm / min to 2500 mm / min. In this specification, the speed of the end mill is a relative speed with respect to the work.

In one embodiment, at the start of cutting, the end mill is brought into contact with the work while running the end mill from an oblique direction with respect to the work in a plan view. In the present specification, the "diagonal direction with respect to the work" at the start of cutting means the side A of the work including the start point a of the work behind the running direction of the end mill after the start of cutting with reference to the start point a of cutting. Alternatively, it means a direction in which the angle x (angle x in FIG. 6) formed by the tangent line B of the work at the cutting start point a is 60 ° or less. Further, the “oblique direction with respect to the work” means a direction not including a direction perpendicular to the work or a direction close to vertical, that is, a direction in which the angle x is 0 ° is also included. In this specification, the angle x is referred to as a running angle x of the end mill at the start of cutting. When the cutting start point a is on a straight line, the running angle x of the end mill at the start of cutting is defined from the side A of the work including the cutting start point a and the running locus of the end mill (FIG. 6), and the cutting start is started. When the point a is on the curve, the running angle x of the end mill at the start of cutting is defined from the tangent line B of the work at the cutting start point a and the running locus of the end mill (FIG. 7). In the present specification, the “cutting start point a” means a point where the end mill starts running so as to scrape the outer periphery of the work having a predetermined thickness.

In one embodiment, in the rough cutting step, at the start of cutting, a portion where the end mill is brought into contact with the work and cutting is started on the work while the end mill is running from an oblique direction with respect to the work in a plan view. An uncut portion is formed by setting the position where the cutting is finished and the position where the cutting is finished at different positions.

6 (a) and 6 (b) are schematic plan views illustrating the cutting process according to one embodiment of the present invention. 7 (a) and 7 (b) are schematic plan views illustrating a cutting process according to another embodiment of the present invention. In FIGS. 6 (a) and 6 (b), and in FIGS. 7 (a) and 7 (b), the movement of the end mill (movement relative to the work 1) at the start of cutting is the traveling locus in a plan view. It is shown as ts. In FIGS. 6A and 6B, the work 1 has a substantially rectangular shape. In FIGS. 7A and 7B, the outer shell of the work 1 includes a curved line. The running locus ts of the end mill at the start of cutting may be curved as shown in FIGS. 6 (a) and 7 (a), and may be a straight line as shown in FIGS. 6 (b) and 7 (b). It may be in the shape. The traveling angle x of the end mill at the start of cutting is 60 ° or less, preferably 0 ° or more and 60 ° or less, more preferably 0 ° or more and 45 ° or less, and further preferably 0 ° or more and 40 ° or less as described above. ° or less, particularly preferably 0 ° or more and 35 ° or less. As described above, the traveling angle x may be 0 °. For example, when the outer shell of the work 1 includes a curve, the traveling angle x can be set to 0 °. In one embodiment, when the work 1 has a substantially rectangular shape, the traveling angle x can be set to an angle larger than 0 °. By bringing the end mill into contact with the work while running the end mill from an oblique direction with respect to the work, it is possible to prevent the occurrence of unnecessary recesses at the cutting start point. The traveling angle x of the end mill at the start of cutting is preferably closer to 0 °, and in one embodiment, the traveling angle x is 5 ° or less (preferably 3 ° or less, more preferably 1 ° or less, still more preferably 0). .5 ° or less).

In one embodiment, the running locus ts of the end mill at the start of cutting is curved. By making the traveling locus ts of the end mill at the start of cutting curved, the effect of the present invention becomes more remarkable. When the traveling locus ts is curved, the traveling angle x of the end mill at the start of cutting depends on the tangent us of the traveling locus ts at the cutting start point a and the tangent line B at the side A of the work or the cutting start point a. Is regulated. In one embodiment, the end mill and the work are brought into close contact with each other while rotating the work in an in-plane manner, so that the end mill runs relative to the work on a curved running locus ts. When bringing the end mill and the work closer to each other, the work may be brought closer to the fixed end mill, the end mill may be moved linearly to bring the end mill and the work closer to each other, and both the end mill and the work may be brought closer to each other linearly. It may be moved so that the end mill and the work are brought closer to each other.

When the running locus ts of the end mill at the start of cutting is curved, the radius of curvature of the running locus ts is preferably ½ or more of the outer diameter of the end mill, and more preferably larger than the outer diameter of the end mill. It is more preferably 110% or more with respect to the outer diameter of the end mill, particularly preferably 130% or more with respect to the outer diameter of the end mill, and 150% or more with respect to the outer diameter of the end mill. Most preferred. By setting the range to such a range, it is possible to prevent the occurrence of unnecessary recesses at the cutting start point a. When the traveling locus ts of the end mill at the start of cutting is curved, the radius of curvature of the traveling locus ts is preferably 4 mm or more, more preferably 6 mm or more, still more preferably 7.5 mm or more. is there.

The speed of the end mill when the end mill is brought into contact with the work is preferably slower than the feed speed of the end mill during cutting (when the surface to be cut of the work is cut by the end mill). By slowing the speed of the end mill at the start of cutting, rattling of the work can be suppressed. In one embodiment, the speed of the end mill when it comes into contact with the work is preferably 400 mm / min to 1200 mm / min, more preferably 500 mm / min to 900 mm / min. In one embodiment, for example, when cutting the inner peripheral surface of a work having a hole, the speed of the end mill when the end mill is brought into contact with the work is preferably 30 mm / min to 1200 mm / min. It is more preferably 50 mm / min to 1000 mm / min.

The shape of the work (that is, the optical film) can be any suitable shape. Examples of the shape of the work include a substantially rectangular shape as shown in FIG. 6, a substantially polygonal shape, a substantially circular shape, a substantially elliptical shape, and the like. Further, the shape of the work may be a shape in which a straight line and a curved line are appropriately combined, or a shape composed of a plurality of curves having different curvatures. The work may not be a pure rectangular shape, a polygonal shape, a circular shape, an elliptical shape, or the like, and may be a shape in which a deformed portion is added to these shapes. In the present specification, for example, a rectangular shape to which a deformed portion is added is included in the "substantially rectangular shape". Examples of the deformed portion include a concave portion as shown in FIG. 6, a convex portion, a hole, and the like. Further, the work may have a shape in which the corners of the rectangle are curved.

Further, the cutting method (specifically, the running locus of the end mill at the start of cutting and the running locus of the end mill at the end of cutting described later) is a work 1 having a hole 11 as shown in FIG. With respect to', it can also be applied when cutting the inner peripheral surface of the hole portion 11.

In one embodiment, at the end of cutting, the end mill is separated from the work while running the end mill diagonally with respect to the work in a plan view. In the present specification, the "diagonal direction with respect to the work" at the end of cutting means the side A of the work including the end point b in front of the running direction of the end mill before the end of cutting with reference to the end point b of cutting. Alternatively, it means a direction in which the angle y (angle y in FIG. 9) formed by the tangent line B'of the work at the cutting end point b is 60 ° or less. As described above, the "oblique direction with respect to the work" means a direction not including a direction perpendicular to the work or a direction close to vertical, that is, a direction in which the angle y is 0 ° is also included. In this specification, the angle y is referred to as a running angle y of the end mill at the end of cutting. When the cutting end point b is on a straight line, the running angle y of the end mill at the end of cutting is defined from the side A of the work including the cutting end point b and the running locus of the end mill (FIG. 9), and the cutting ends. When the point b is on the curve, the running angle y of the end mill at the end of cutting is defined from the tangent line B'of the work at the cutting end point b and the running locus of the end mill (FIG. 10).

9 (a) and 9 (b) are schematic plan views illustrating the cutting process according to one embodiment of the present invention. 10 (a) and 10 (b) are schematic plan views illustrating a cutting process according to another embodiment of the present invention. In FIGS. 9 (a) and 9 (b), and in FIGS. 10 (a) and 10 (b), the movement of the end mill (movement relative to the work 1) at the end of cutting is the traveling locus te in a plan view. It is shown as. In FIGS. 9A and 9B, the work 1 has a substantially rectangular shape. Further, in FIGS. 10A and 10B, the outer shell of the work 1 includes a curved line. The running locus te of the end mill at the end of cutting may be curved as shown in FIGS. 9 (a) and 10 (a), and may be a straight line as shown in FIGS. 9 (b) and 10 (b). It may be in the shape. The running angle y of the end mill at the end of cutting is 60 ° or less, preferably 0 ° or more and 60 ° or less, more preferably 0 ° or more and 45 ° or less, and further preferably 0 ° or more and 40 ° or less as described above. ° or less, particularly preferably 0 ° or more and 35 ° or less. As described above, the traveling angle y may be 0 °. For example, when the outer shell of the work 1 includes a curve, the traveling angle y may be set to 0 °. In one embodiment, when the work 1 has a substantially rectangular shape, the traveling angle y can be set to an angle larger than 0 °. In the present specification, the "cutting end point b" means a point where an end mill that has been running so as to scrape the outer circumference of a work having a predetermined thickness changes its running direction in a direction away from the work and ends cutting. To do. In one embodiment, the distance between the "cutting start point a" and the "cutting end point b" corresponds to the width w of the uncut portion.

Preferably, the running locus te of the end mill at the end of cutting is curved. The above effect becomes more remarkable by making the traveling locus te of the end mill at the end of cutting curved. When the traveling locus te is curved, the traveling angle y of the end mill at the end of cutting is the tangent line ue of the traveling locus te at the cutting end point b and the tangent line B'at the side A of the work or the cutting end point a. Specified by. In one embodiment, the end mill and the work are separated from each other while rotating the work in-plane, so that the end mill runs relative to the work on a curved running locus te. When separating the end mill and the work, the work may be separated from the fixed end mill, the end mill may be moved linearly to separate the end mill from the work, and both the end mill and the work may be linearly separated. It may be moved to separate the end mill from the work.

When the running locus te of the end mill at the end of cutting is curved, the radius of curvature of the running locus te is preferably ½ or more of the outer diameter of the end mill, and more preferably larger than the outer diameter of the end mill. It is more preferably 110% or more with respect to the outer diameter of the end mill, particularly preferably 130% or more with respect to the outer diameter of the end mill, and 150% or more with respect to the outer diameter of the end mill. Most preferred. By setting it in such a range, it is possible to prevent the occurrence of unnecessary steps and fluff at the cutting end point b. When the traveling locus te of the end mill at the end of cutting is curved, the radius of curvature of the traveling locus te is preferably 4 mm or more, more preferably 6 mm or more, and further preferably 7.5 mm or more. is there.

The speed of the end mill when the end mill is separated from the work is preferably slower than the feed speed of the end mill during cutting (when the surface to be cut of the work is cut by the end mill). By slowing the speed of the end mill at the end of cutting, rattling of the work can be suppressed. In one embodiment, the speed of the end mill when separating it from the work is preferably 400 mm / min to 1200 mm / min, more preferably 500 mm / min to 900 mm / min. In one embodiment, for example, when cutting the inner peripheral surface of a work having a hole, the speed of the end mill when separating the end mill from the work is preferably 30 mm / min to 1200 mm / min. It is more preferably 50 mm / min to 1000 mm / min.

<Finishing>
After the rough cutting step, the outer peripheral surface of the roughed work is finished by cutting with an end mill. In the finishing process, the outer peripheral surface of the work including the uncut portion is cut.

In one embodiment, the outer diameter of the end mill used in the finishing process is 10 mm or less, preferably 3 mm to 9 mm, and more preferably 4 mm to 6 mm.

The cutting conditions in the finishing process can be appropriately set according to the desired shape. For example, the end mill rotation speed is preferably 1000 rpm to 60,000 rpm, more preferably 10000 rpm to 40,000 rpm. The feed rate of the end mill is preferably 500 mm / min to 10000 mm / min, and more preferably 500 mm / min to 2500 mm / min.

Also in the finishing process, as described above, at the start of cutting, the end mill may be brought into contact with the work while running the end mill from an oblique direction with respect to the work in a plan view. Further, at the end of cutting, the end mill may be separated from the work while running the end mill in a diagonal direction with respect to the work in a plan view. In the finishing process, the cutting start point and the cutting end point may be at the same position, the cutting start point and the cutting end point are set to different positions, and the cutting end point is ahead of the cutting start point in the traveling direction of the end mill. May be good. Preferably, the cutting start point and the cutting end point are set to different positions, and the cutting end point b is set ahead of the cutting start point in the traveling direction of the end mill. In this way, if the cutting is completed so that the traveling trajectories of the end mills at the time of cutting partially overlap each other, it is possible to preferably prevent unnecessary steps and fluff from occurring at the end of cutting.

<< Optical film >>
In one embodiment, the optical film comprises a polarizer.

The optical film containing the polarizer may be a single polarizer or a film containing the polarizer and other layers. Other layers include a protective layer that protects the polarizer, a layer composed of any suitable optical functional layer, and the like. In one embodiment, a polarizing plate is used as an optical film containing a polarizer. The polarizing plate may include a polarizing element and a protective layer arranged on at least one side of the polarizer. Further, as the film containing the polarizer, a laminate of a polarizing plate and a surface protective film and / or a separator may be used. The surface protective film or separator is detachably laminated on the polarizing plate via any suitable adhesive. In the present specification, the "surface protective film" is a film that temporarily protects the polarizing plate, and is different from the protective layer (layer that protects the polarizer) included in the polarizing plate.

The polarizer is typically a resin film (for example, a polyvinyl alcohol-based resin film) that is swelled, stretched, dyed with a dichroic substance (for example, iodine, an organic dye, etc.), crosslinked, or washed. It is obtained by performing various treatments such as drying treatment. Generally, the polarizer obtained through the stretching treatment has a characteristic that cracks are likely to occur, but according to the present invention, it is possible to cut an optical film containing a polarizer while preventing cracks.

The thickness of the optical film containing the polarizer is not particularly limited, and an appropriate thickness can be adopted depending on the intended purpose, for example, 20 μm to 200 μm. The thickness of the polarizer is also not particularly limited, and an appropriate thickness can be adopted depending on the intended purpose. The thickness of the polarizer is typically about 1 μm to 80 μm, preferably 3 μm to 40 μm.

The size of the optical film including the polarizer is not particularly limited, and may be an appropriate size depending on the purpose. In one embodiment, the optical film containing the polarizer has a rectangular shape including 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. Yes, the length of the other side is 10 mm to 500 mm. As used herein, the term "parallel" includes the case of being substantially parallel, and specifically includes the case where the angle formed by the two directions is 0 ° to 5 °.

The machined optical film obtained by the production method of the present invention can be used in a liquid crystal image display device, an organic EL image display device, or the like. In addition, the machined optical film is a rectangular image display unit represented by the personal computer (PC) or tablet terminal, and / or a deformed image display represented by an automobile instrument panel or smart watch. It can be suitably used for a part.

1 work 20 end mill

Claims (3)

It includes forming a work by stacking a plurality of optical films and an end milling step of cutting the outer peripheral surface of the work with an end mill.
The end milling step includes a roughing step of roughing the outer peripheral surface of the work with an end mill and finishing of the outer peripheral surface of the roughed work with an end mill.
The rough cutting step includes providing an uncut portion on the outer peripheral surface of the work.
The finishing process involves cutting the uncut portion.
A method for manufacturing a machined optical film. In the rough cutting step, at the start of cutting, the end mill is brought into contact with the work while running the end mill from an oblique direction with respect to the work in a plan view.
The uncut portion is formed by setting a portion where cutting starts and a portion where cutting ends on the work at different positions.
The method for producing a machined optical film according to claim 1. At the end of cutting, the end mill is separated from the work while the end mill is run in a diagonal direction with respect to the work in a plan view.
The method for producing a machined optical film according to claim 1 or 2.

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