Punching blade

Abstract

To provide a punching blade capable of punching a film piece with good dimensional accuracy while reducing punching chips.SOLUTION: A punching blade for punching a film piece of a substantially rectangular shape from an original film of a long-sized shape is configured so that all the four sides of one film piece are formed by combining two punching lines formed by a single punching. The punching lines include two or more first cut lines having a first side, a second side opposite the first side, a third side connecting the first side and the second side and a fourth side. Among the four sides, three sides are formed of the first to third sides, and a part of remaining one side is formed of the fourth side. The third side and the fourth side are linear sides. Neighboring two first cut line (1) and first cut line (2) are parallel to each other, and the second side and the third side of the first cut line (1) lie opposite the fourth side of the first cut line (2). A thickness of a blade for forming the second side of the first cut line is larger than a thickness of a blade for forming the side other than the second side of the first cut line.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a punching blade for punching film pieces from an original film, and a manufacturing method and manufacturing apparatus for an optical film using the same. [Background technology]

[0002] In display devices such as liquid crystal display devices and organic EL display devices, optical films such as polarizing films and retardation films are used. Optical films are usually manufactured using film pieces obtained by punching a long original film into a size that takes into account the size of the display area of ​​the display device using a punching blade. When punching out the film pieces, the original film is repeatedly punched out with the punching blade while changing the punching position of the original film, thereby obtaining multiple film pieces. When performing such punching, from the viewpoint of reducing costs and waste, it is required to reduce the portion (punching waste) remaining after punching out the film pieces from the original film and punch out as many film pieces as possible from the original film.

[0003] Patent Document 1 discloses a method for punching out a film piece from an original film, in which punching is performed multiple times, one of the multiple punchings forming a punch line that becomes part of the contour of the film piece, and the remaining punchings forming punch lines that become the remaining part of the contour of the film piece, thereby forming the entire contour of the film piece. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2009-56583 A Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, when punching out a film piece from an original film piece, the entire contour of the film piece may be formed by combining two punch lines formed by two punching operations. In this case, in order to punch out a film piece with high dimensional accuracy, it is necessary to ensure that the contour of the film piece is properly formed by punching with the punching blade, and to properly align the punch line punched earlier with the punch line punched later.

[0006] In addition, when obtaining film pieces to be used for optical films, rectangular film pieces may be punched out so that each side is oblique to the width direction of the original film. In this case, it is necessary to devise an arrangement of the film pieces to be punched on the original film so as to reduce punching waste as much as possible.

[0007] An object of the present invention is to provide a punching blade capable of punching out film pieces with excellent dimensional accuracy while reducing punching waste, and a manufacturing method and manufacturing apparatus for an optical film using the same. [Means for solving the problem]

[0008] The present invention provides the following punching blade, method and apparatus for producing an optical film. [1] A punching blade for punching out a substantially rectangular piece of film from a long raw film, a punching blade is configured to punch out two punching lines in a single punching operation to form all four sides of one of the film pieces; The punching line includes two or more first cutting lines having a first side, a second side opposite to the first side, a third side connecting the first side and the second side, and a fourth side connecting to the first side; the first side, the second side, and the third side constitute three of the four sides, and the fourth side constitutes a part of the remaining side of the four sides; The third side and the fourth side are straight sides, The first cutting line (1) and the first cutting line (2), which are two adjacent first cutting lines, are parallel to each other, and the second side and the third side of the first cutting line (1) face the fourth side of the first cutting line (2); A punching blade, the thickness of the blade for forming the second side of the first cutting line being greater than the thickness of the blade for forming sides of the first cutting line other than the second side. [2] The punching blade according to [1], wherein the third side of the first cutting line (1) and the fourth side of the first cutting line (2) face each other with a gap therebetween. [3] The punching blade according to [1] or [2], wherein the thicknesses of the blades for forming the sides of the first cutting line other than the second side are the same. [4] The punching line further includes two or more second cutting lines that share a portion of the third side of the first cutting line and form an entire outline of one of the film pieces; a fifth side, which is one side of the film piece that constitutes the entire outline of the second cutting line, is configured by combining a part of the third side and a first protruding portion that extends from a side of the third side that is connected to the first side to an opposite side to the second side so as to extend the third side; The punching blade described in any one of [1] to [3], wherein the contour of the film piece formed by the second cutting line is parallel to the contour of the film piece formed by connecting the second side and the fourth side of the first cutting line. [5] The first cutting line has a first vertex connecting the first side and the third side, the second cutting line has a sixth side opposite to the fifth side, a seventh side connecting the sixth side and the first protruding portion side of the fifth side, and a second vertex connecting the sixth side and the seventh side, The punching blade described in [4], wherein an angle between a straight line connecting the first vertices of the first cutting line (1) and the first cutting line (2) and a straight line connecting the first vertex of the first cutting line (1) and a second vertex of a second cutting line that shares a portion of the third side of the first cutting line (1) among the second cutting lines is within a range of 90±5°. [6] The second cutting line has a sixth side opposite to the fifth side, a seventh side connecting the sixth side and the first protruding portion side of the fifth side, and an eighth side opposite to the seventh side, The punching line further includes two or more third cutting lines that share a portion of the sixth side of the second cutting line and that constitute an entire outline of one or more of the film pieces; a side of one of the film pieces whose entire contour is constituted by the third cutting line is formed by combining a part of the sixth side and a second protruding portion that extends from a side of the sixth side connected to the seventh side to an opposite side to the eighth side so as to extend the sixth side; The punching blade according to claim 4 or 5, wherein the contour of the film piece defined by the third cutting line is parallel to the contour of the film piece defined by the second cutting line. [7] The punch blade described in [6], wherein the third cutting line constitutes the entire outline of two or more of the film pieces. [8] A method for producing an optical film, comprising the steps of: punching out a substantially rectangular piece of film from a long raw film using the punching blade according to any one of [1] to [7] to produce an optical film, the punching blade forms the punching line such that an angle between the third side of the first cutting line and the width direction of the original film and an angle between the fourth side of the first cutting line and the width direction are each independently 20° or more and 70° or less; A punching line (m) is formed by punching the m-th shot (m is a natural number) of the original film with the punching blade, A punch line (n) is further formed by punching the n-th shot (n is a natural number greater than m) of the original film with the punching blade, forming the punching line (n) so as to connect the second side and the fourth side of the first cutting line included in the punching line (m). [9] The first cutting line has a first vertex connecting the first side and the third side, The method for producing an optical film according to [8], wherein the punched line is formed such that the first vertex of the first cutting line included in the punched line is positioned on a straight line substantially parallel to the width direction.

[10] The raw film is a stretched film, The method for producing an optical film according to [8] or [9], wherein the stretching axis of the stretched film is parallel to the width direction of the raw film or a direction perpendicular to the width direction.

[11] An optical film manufacturing apparatus for manufacturing an optical film by punching out a substantially rectangular film piece from a long raw film, comprising: A punching blade according to any one of [1] to [7], a drive unit that moves the original film and the punching blade relative to each other so that a different position of the original film is punched for each punching by the punching blade, and two of the punching lines formed for each punching by the punching blade are combined to form four sides of one film piece, The punching blade forms the punching line such that an angle between the third side of the first cutting line and the width direction of the original film, and an angle between the fourth side of the first cutting line and the width direction are each independently 20° or more and 70° or less. Effect of the Invention

[0009] According to the punching blade of the present invention, it is possible to punch out film pieces with excellent dimensional accuracy while reducing punching waste. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a diagram for explaining a punched line formed by one punching operation using a punching blade according to one embodiment of the present invention. [Diagram 2] 2 is a diagram for explaining a punch line formed when punching is performed twice using the punch blade that forms the punch line shown in FIG. 1. FIG. [Diagram 3]13 is a diagram illustrating a punched line formed by one punching operation using a punching blade according to another embodiment of the present invention. FIG. [Figure 4] 3 is a diagram for explaining a punch line formed when punching is performed twice using the punch blade that forms the punch line shown in FIG. 2. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiment. All the drawings are shown to help understand the present invention, and the size and shape of each component shown in the drawings do not necessarily correspond to the size and shape of the actual component.

[0012] [Embodiment 1] Fig. 1 is a diagram for explaining a punched line formed by one punching with a punching blade of this embodiment. Fig. 2 is a diagram for explaining a punched line formed when two punchings are performed using the punching blade that forms the punched line shown in Fig. 1. In the diagram, W represents the width direction of the original film, and L represents the length direction of the original film, which is perpendicular to the width direction W.

[0013] (Punching blade) The punching blade of this embodiment is for punching out an approximately square film piece 85 (FIG. 2) from a long raw film 80. In this specification, the approximately square refers to a square, a rounded square with one or more of the four corners of the square being chamfered, or a square with a notch formed by cutting out a part of the side of the square or the rounded square other than both ends, and the square refers to a rectangle or a square. FIGS. 1 and 2 show a case where a rectangular film piece 85 is punched out. The boundary between two sides that are continuous through the rounded corners of the rounded square film piece is a position that bisects the contour length of the rounded corners. The position of this boundary can be a vertex that is a part that connects sides, which will be described later. In this specification, two or more sides divided by the notch of a square film piece having a notch are considered to be one side that constitutes one side of the square. The side of the film piece 85 is the side of the film piece 85 in a plan view.

[0014] The punching blade is configured so that two punching lines 1 formed by one punching are combined (FIG. 2) to form all four sides of one film piece 85. Therefore, if the punching position of the original film 80 is changed and punching is performed twice with the punching blade, the film piece 85 can be punched out by the two punching lines 1 (FIG. 2) formed by the two punchings. The film pieces 85 punched out by the punching blade usually have the same size and preferably the same shape.

[0015] The punched line 1 formed by one punching with the punching blade includes two or more first cut lines 10 (10a to 10d). Fig. 1 shows a case where the punched line 1 has four first cut lines 10, but is not limited to this. The number of first cut lines 10 included in the punched line 1 may be three or more, six or more, or eight or more, and may be, for example, 20 or less, 15 or less, 12 or less, or 10 or less.

[0016] The number of the first cutting lines 10 that the punching line 1 has may be determined based on the length in the width direction W of the long raw film 80. The ratio of the width direction length of the punching lines 1 to the length in the width direction W of the raw film 80 may be 70% or more, 80% or more, or 90% or more, and is usually 100% or less. The width direction length of the punching line 1 is the length in the width direction W between the endmost part of the first cutting line 10 (for example, the first cutting line 10a shown in FIG. 1) located at one end of the punching lines 10 in the width direction W of the raw film 80 and the endmost part of the first cutting line 10 (for example, the first cutting line 10d shown in FIG. 1) located at the other end of the punching lines 10.

[0017] As shown in FIG. 1, the first cutting line 10 has a first side 11, a second side 12 opposed to the first side 11, a third side 13 connecting the first side 11 and the second side 12, and a fourth side 14 connected to the first side 11. The first side 11, the second side 12, and the third side 13 constitute three of the four sides of the film piece 85. The fourth side 14 constitutes a part of the remaining side of the four sides of the film piece 85. The third side 13 and the fourth side 14 face each other. The third side 13 and the fourth side 14 are straight sides and do not have a notch. In the first cutting line 10, the second side 12 and the fourth side 14 are not directly connected to each other but are separated from each other, and when the fourth side 14 is extended toward the second side 12 on the side opposite to the side of the fourth side 14 connected to the first side 11, the extended portion is configured to be connected to the second side 12.

[0018] When punching the original film 80 with a punching blade, the punching line 1 can be formed so that the angle between the third side 13 of the first cutting line 10 and the width direction W of the original film 80 and the angle between the fourth side 14 of the first cutting line 10 and the width direction W of the original film 80 are each independently 20° or more and 70° or less. The above angles may be 30° or more, 40° or more, 60° or less, or 50° or less. The angle between the third side 13 and the width direction W and the angle between the fourth side 14 and the width direction W each refer to the smaller angle between the angles they form.

[0019] The two adjacent first cutting lines (1) 10a and first cutting lines (2) 10b included in the punching line 10 are parallel to each other, and the second side 12 and the third side 13 of the first cutting line (1) 10a face the fourth side 14 of the second cutting line (2) 10b. As shown in FIG. 1, it is preferable that the second side 12 and the third side 13 of the first cutting line (1) 10a do not face the spaced portion between the second side 12 and the fourth side 14 of the first cutting line (2) 10b (between the end of the second side 12 opposite to the side connected to the third side 13 and the end of the fourth side 14 opposite to the side connected to the first side 11).

[0020] In this specification, the cutting lines being parallel to each other means that when one cutting line is translated in a plane and overlapped with the other cutting line, the shapes match. The second side 12 of the first cutting line (1) 10a and the fourth side 14 of the second cutting line (2) 10b face each other so that the extending directions of each side intersect with each other, and may face each other with a gap therebetween as shown in Fig. 1, or one end of the fourth side 14 of the second cutting line (2) 10b may be in contact with and face the second side 12 of the first cutting line (1) 10a.

[0021] The third side 13 of the first cutting line (1) 10a and the fourth side 14 of the second cutting line (2) may overlap each other, but are preferably opposed to each other with a gap therebetween as shown in FIG. 1. This is because it is easy to arrange them in a way that can reduce punching waste when punching out a plurality of film pieces 85 from the original film 80 so that the third side 13 and the fourth side 14 are at the above-mentioned angle with respect to the width direction W. It is preferable that the third side 13 of the first cutting line (1) 10a is opposed to the fourth side 14 of the second cutting line (2) 10b so as to be substantially parallel. Here, "substantially parallel" means that the smaller angle between the extension directions of the two sides is within 3°, and may be within 2°, may be within 1°, or may be 0.5° or less.

[0022] The relationship between the first cutting line (2) 10b and the first cutting line (3) 10c, and the relationship between the first cutting line (3) 10c and the fourth cutting line (4) 10d are also preferably the relationship described above for the relationship between the first cutting line (1) 10a and the first cutting line (2) 10b. Furthermore, even when five or more first cutting lines 10 are included, it is preferable that any two adjacent first cutting lines 10 have the relationship described above for the relationship between the first cutting line (1) 10a and the first cutting line (2) 10b.

[0023] In the punching blade, the thickness of the blade (hereinafter sometimes referred to as the "second blade") for forming the second side 12 of the first cutting line 10 is greater than the thickness of the blades (hereinafter sometimes referred to as the "first blade", the "third blade", and the "fourth blade", respectively) for forming the first side 11, the third side 13, and the fourth side 14. In this specification, the thickness of the blade refers to the thickness of the base part (main body part) of the blade, which is connected to the cutting edge whose thickness decreases toward the tip and has a constant thickness. It is preferable that the thicknesses of the blades for forming the sides other than the second side 12 (the first side 11, the third side 13, and the fourth side 14) of the punching blade are the same.

[0024] When punching the original film 80 using the punching blade, the punching blade and the original film 80 are moved relative to each other, and different positions of the original film 80 are punched with the punching blade, thereby sequentially forming a plurality of punching lines 1 in the original film 80. At this time, as shown in FIG. 2, the punching line (n) which is the punching line 1 formed by the punching of the nth shot (n is a natural number larger than m) is formed so that the second side 12 and the fourth side 14 of the first cutting line 10 included in the punching line (m) which is the punching line 1 formed by the punching of the mth shot (m is a natural number). In FIG. 2, the punching line (m) is shown by a solid line, and the punching line (n) is shown by a dashed line. It is preferable that n satisfies the relationship of n=m+1.

[0025] As a result, the first cutting line 10 of the punching line (m) and a part of the punching line (n) form the entire contour of the film piece 85. Fig. 2 shows a case where punching is performed such that the second side 12 and the fourth side 14 of the first cutting line 10 of the punching line (m) are connected by a part of the third side 13 of the first cutting line 10 of the punching line (n). As a result, when punching out a plurality of film pieces 85 from the original film 80, the film pieces 85 can be punched out by arranging the punching lines 1 so as to reduce the gaps between the film pieces 85 adjacent to each other in the length direction L of the original film 80.

[0026] The arrangement of the punching line (m) and the punching line (n) is not particularly limited as long as the second side 12 and the fourth side 14 of the first cutting line 10 of the punching line (m) are connected by the punching line (n) as described above. For example, the second side 12 of the first cutting line (1) 10a of the punching line (m) and the first side 11 of the first cutting line (2) 10b of the punching line (n) may be arranged to overlap, or as shown in FIG. 2, the second side 12 of the first cutting line (1) 10a of the punching line (m) and the first side 11 of the first cutting line (2) 10b of the punching line (n) may be arranged to face each other with a gap therebetween.

[0027] As described above, the punching blade forms part of the contour of the film piece 85 by the first cutting line 10, so the second blade for forming the second side 12 and the fourth blade for forming the fourth side 14 are not directly connected and are separated. Therefore, the second blade and the fourth blade, one end of which is a free end not connected to the other blades in a plan view, may cause problems such as distortion and positional deviation due to the pressing force applied to the punching blade when punching the original film 80. Therefore, in the punching blade, the thickness of the second blade is made larger than the thicknesses of the first blade, the third blade, and the fourth blade, and the strength of the second blade is increased, thereby preventing the above-mentioned problems from occurring. By increasing the thickness of the second blade, there is a possibility that the dimensional accuracy of the film piece to be punched out may decrease, but since the second side 12 formed by the second blade forms one side of the film piece 85, it is easy to adjust by processing such as polishing the film piece 85 after punching.

[0028] On the other hand, the fourth blade may be thicker like the second blade, but it is preferable that the fourth blade has the same thickness as the first blade and / or the third blade for the following reason. The portion of the punched line (m) formed by the mth shot of the punching blade formed by the fourth blade forms the entire contour of the film piece 85 in combination with the punched line (n) formed by the nth shot of the punching blade. If the thickness of the fourth blade differs from the thickness of the blade forming the portion connecting the second side 12 and the fourth side 14 of the punched line (m), it becomes difficult to align the punching blade when performing the nth shot, and the dimensional accuracy of the punched film piece 85 is likely to decrease. Therefore, it is preferable that the fourth blade has the same thickness as the first blade and / or the third blade.

[0029] As described above, the punching of the nth shot by the punching blade may be performed so that the punching line (n) is in contact with the fourth side 14 of the punching line (m) and is formed by connecting the fourth side 14 and the second side 12 along the extension direction of the fourth side 14. In FIG. 2, the third side 13 of the first cutting line 10 of the punching line (n) connects the second side 12 and the fourth side 14 of the punching line (m). As described above, the punching line 10 formed by the punching blade can be in contact with the second side 12 and connect the second side 12 and the fourth side 14 by extending the side of the fourth side 14 that is not connected to the first side 11. Therefore, by using the linear fourth side 14 formed by punching in the mth shot as a landmark and adjusting the position of the punching blade when performing the nth shot so as to extend the end of this fourth side 14 on the opposite side to the first side 11, a punching line (n) can be formed to punch out the film piece 85. In this way, by using the punching blade of this embodiment, it is easy to align the position of the punching blade for each shot, and it is easy to obtain a film piece 85 with excellent dimensional accuracy.

[0030] The thickness of the second blade of the punching blade is not particularly limited, and may be, for example, 0.3 mm or more, or may be 0.5 mm or more, or may be 4.0 mm or less, or may be 2.0 mm or less, or may be 1.0 mm or less. The thicknesses of the first blade, third blade, and fourth blade of the punching blade may each independently be, for example, 0.1 mm or more, or may be 0.3 mm or more, or may be 3.0 mm or less, or may be 2.0 mm or less, or may be 1.5 mm or less.

[0031] The shape of the blade of the punching blade is not particularly limited, and may be any of double-edged, single-edged, and multi-stage blades, such as double-stage blades, single-stage blades, double-stage blades, double-stage blades, and single-stage blades. The punching blade preferably has a cutting edge whose thickness decreases toward the tip. The angle of the tip of the cutting edge is not particularly limited, and may be, for example, 10° or more, or 20° or more, or may be, for example, 40° or less, or may be 30° or less.

[0032] The punching blade may be a Thomson blade, an etching blade, an engraving blade, a rotary die cutter, or the like, but is not particularly limited to this. A Thomson blade is preferred.

[0033] (Method of manufacturing optical film) The punching blade described above can be used to manufacture an optical film. The manufacturing method of the optical film of this embodiment is, for example, a method of manufacturing an optical film by punching out a substantially rectangular film piece 85 from a long original film 80 using a punching blade that forms a punching line 1 as shown in Fig. 1. As described above, the punching blade forms the punching line 1 so that the angle between the third side 13 of the first cutting line 10 and the width direction W of the original film 80 and the angle between the fourth side 14 of the first cutting line 10 and the width direction W of the original film 80 are each independently 20° or more and 70° or less.

[0034] In the manufacturing method of the optical film, as described above, a punching line (m) is formed by punching the original film 80 with the punching blade in the mth shot (m is a natural number), and a punching line (n) is further formed by punching the original film 80 with the punching blade in the nth shot (n is a natural number larger than m) (FIG. 2). The punching line (n) is formed so as to connect the second side 12 and the fourth side 14 of the first cutting line 10 included in the punching line (m). After the punching line (n) is formed, the next punching line is formed so as to connect the second side 12 and the fourth side 14 of the first cutting line 10 included in the punching line (n). In other words, by repeating the punching performed in the same procedure as the punching method performed in the nth shot for the punching line (n) formed by the mth shot and the nth shot, a plurality of film pieces 85 can be punched out of the original film 80.

[0035] The optical film is manufactured by moving the original film 80 and the punching blade relative to each other. For example, first, while the conveyance of the original film 80 is stopped, the punching blade is advanced and retreated relative to the original film to perform punching, and then, while the punching by the punching blade is stopped, the original film 80 is conveyed to a position where the punching blade faces the next punching position, and conveyance of the original film 80 is stopped. By repeating this operation, film pieces 85 can be punched out continuously.

[0036] The film piece 85 punched out as described above may be used as an optical film as it is, but the optical film may also be produced by subjecting the end surface formed by punching out the film piece 85 to a polishing process, a hole forming process for forming through holes in the film piece 85, a lamination process for laminating other layers onto the film piece 85, or the like.

[0037] When the vertex of the first cutting line 10 connecting the first side 11 and the third side 13 is defined as the first vertex 19 of the first cutting line 10 formed by punching with the punching blade, it is preferable that the first vertex 19 of the first cutting line 10 included in the punching line 1 is formed so as to be located on a straight line W1 that is substantially parallel to the width direction W, as shown in Figures 1 and 2.

[0038] Here, "substantially parallel" means that the smaller of the angles between the width direction W and the straight line W1 is within 3°, may be within 2°, or may be within 1°. The angle may be 0°. In Fig. 1 and Fig. 2, the straight line W1 is shown by a dashed line.

[0039] By forming the punching line 1 as described above, even when punching out film pieces 85 from the original film 80 so that the third side 13 and the fourth side 14 form the above-mentioned angles with respect to the width direction W, punching can be performed so that multiple film pieces are lined up along a straight line W1 that is substantially parallel to the width direction W of the original film 80, and by using the above-mentioned punching blade, punching waste can be reduced.

[0040] In particular, by forming the punching line 1 so that the third side 13 and the fourth side 14 are at the above-mentioned angle with respect to the width direction W, when the original film 80 is a stretched film having a stretching axis parallel to the width direction W and / or the length direction L, the stretching axis in the film piece 85 to be punched out can be made to be inclined with respect to each side rather than parallel to any of the sides of the film piece 85.

[0041] The number of film pieces 85 punched out by one mth shot and one nth shot shown in Figure 2 depends on the number of first cutting lines 10 that the punching line 1 has, but may be two or more, three or more, three or more, six or more, eight or more, or may be, for example, 20 or less, 15 or less, 12 or less, or 10 or less.

[0042] (Optical film manufacturing equipment) The optical film manufacturing apparatus is an apparatus for manufacturing an optical film by punching out approximately rectangular film pieces from a long raw film 80. The optical film manufacturing apparatus includes a punching blade for forming the punching lines 1 described above, and a drive unit for relatively moving the raw film 80 and the punching blade so that a different position of the raw film 80 is punched out for each punching by the punching blade, and two punching lines 1 formed for each punching by the punching blade are combined to form four sides of one film piece 85.

[0043] When the original film 80 is moved relative to the punching blade, the drive unit is a transport unit for transporting the original film 80. Examples of the transport unit include known film transport devices such as transport rollers and transport belts. When the punching blade is moved relative to the original film 80, examples of the drive unit include a rail that moves the position of the punching blade, a drive source for a roller having a punching blade on its surface, and the like.

[0044] In the optical film manufacturing apparatus, as described above, the punching blade forms the punching line 1 so that the angle between the third side 13 of the first cutting line 10 and the width direction W of the original film 80, and the angle between the fourth side 14 of the first cutting line 10 and the width direction W of the original film 80, are each independently 20° or more and 70° or less. The optical film manufacturing apparatus of this embodiment is capable of carrying out the optical film manufacturing method described above.

[0045] [Embodiment 2] Fig. 3 is a diagram for explaining a punched line formed by one punching with the punching blade of this embodiment. Fig. 4 is a diagram for explaining a punched line formed when two punchings are performed using the punching blade that forms the punched line shown in Fig. 3. In the figure, W represents the width direction of the original film, and L represents the length direction of the original film that is perpendicular to the width direction W. In each embodiment and each drawing, the same or corresponding reference symbols are used for members that are the same as or equivalent to those previously described, and their descriptions may not be repeated.

[0046] (Punching blade) The punching line 2 formed by the punching blade of this embodiment can include, in addition to the first cutting line 10 described in the previous embodiment, a second cutting line 20 that shares a part of the third side 13 of the first cutting line 10 and constitutes the entire outline of one film piece 85, as shown in FIG. 3. The fifth side 25 included in the second cutting line 20 is formed by combining a part of the third side 13 of the first cutting line 10 and a first protruding portion 21 that extends from the side of the third side 13 connected to the first side 11 to the opposite side to the second side 12 side so as to extend the third side 13. The fifth side shares a part of the third side 13 of the first cutting line 10, and the second cutting line 20 becomes one side of the film piece 85 that constitutes the entire outline. The second cutting line 20 further has a sixth side 26 facing the fifth side 25, a seventh side 27 that connects the first protruding portion 21 side of the fifth side 25 to the sixth side 26, and an eighth side 28 facing the seventh side 27. The second cutting line 20 has a second vertex 29 connecting the sixth side 26 and the seventh side 27 .

[0047] In the punching line 2, the contour of the film piece 85 formed by the second cutting line 20 is parallel to the contour of the film piece 85 ( FIG. 4 ) formed by connecting the second side 12 and the fourth side 14 of the first cutting line 10. In this specification, the contour of one film piece 85 being parallel to the contour of the other film piece means that when one film piece is translated in a plane and superimposed on the other film piece, the contour shapes match.

[0048] The number of first cutting lines 10 and second cutting lines 20 included in the punching line 2 is two or more, and is usually the same as the number of first cutting lines 10 included in the punching line 2. Figures 3 and 4 show a case in which the punching line 2 formed by one punching with the punching blade includes four first cutting lines 10 and four second cutting lines 20, and four film pieces 85 are punched out by the second cutting lines 20 by one punching with the punching blade, but this is not limited to the case.

[0049] When punching the original film 80 with the punching blade, the punching lines 2 are formed so that the angle between the third side 13 of the first cutting line 10 and the width direction W of the original film 80 and the angle between the fourth side 14 of the first cutting line 10 and the width direction W of the original film 80 are each independently 20° or more and 70° or less. The above angles may be 30° or more, 40° or more, 60° or less, or 50° or less. The angle between the third side 13 and the width direction W and the angle between the fourth side 14 and the width direction W each refer to the smaller angle between the angles they form.

[0050] The two adjacent second cutting lines (1) 20a and (2) 20b included in the punching line 2 are preferably parallel to each other, and the sixth side 26 and the eighth side 28 of the second cutting line (1) 20a face the fifth side 25 of the second cutting line (2) 20b. The sixth side 26 of the second cutting line (1) and the fifth side 25 of the second cutting line (2) may overlap each other, but are preferably opposed to each other with a gap therebetween as shown in FIG. 3. This is because, as described above, when punching out a plurality of film pieces 85 from the original film 80 so that the third side 13 and the fourth side 14 are at the above-mentioned angles with respect to the width direction W, it is easy to arrange them in a way that can reduce punching waste. It is preferable that the sixth side 26 of the second cutting line (1) 20a faces the fifth side 25 of the second cutting line (2) 20b so as to be substantially parallel to each other. The term "substantially parallel" used here is as described in the previous embodiment.

[0051] When the punched line 2 includes four second cutting lines 20 as shown in Figures 3 and 4, or when the punched line 2 includes five or more second cutting lines 20, it is preferable that any two adjacent second cutting lines 20 have the relationship described above in relation to the second cutting line (1) 20a and the second cutting line (2) 20b.

[0052] When the apex connecting the first side 11 and the third side 13 in the first cutting line 10 is the first apex 19, the angle between [i] the straight line W1 connecting the first apex 19 of the first cutting line (1) and the second cutting line (1) (FIGS. 1 to 3) and [ii] the straight line L2 connecting the first apex 19 of the first cutting line (1) 10a and the second apex 29 of the second cutting line (1) 20a that shares a part of the third side 13 of the first cutting line (1) 10a among the second cutting lines 20 (FIG. 3) is preferably within a range of 90±5°. This is because it is easy to arrange the film pieces 85 so that the third side 13 and the fourth side 14 are at the above-mentioned angle with respect to the width direction W from the original film 80 as described above, so that the punching waste can be reduced. The above angle may be within a range of 90±3°, may be within a range of 90±2°, or may be within a range of 90±1°. The above angle may be 90°.

[0053] The angle between the straight line W1 and the straight line connecting the first vertex 19 of the first cutting line (2) 10b and the second vertex 29 of the second cutting line (2) 20b is also preferably the angle described above for the angle between the straight line W1 and the straight line L2. When the punching line 2 has three or more first cutting lines 10 and three or more second cutting lines 20, the angle between the straight line W1 and the straight line connecting the first vertex 19 of the first cutting line 10 and the second vertex 29 of the second cutting line 20 that shares a part of the third side 13 of the first cutting line 10 is preferably the angle described above for the angle between the straight line W1 and the straight line L2.

[0054] In addition to the second cutting line 20 described above, the punching line 2 may include a third cutting line 30 that shares a part of the sixth side 26 of the second cutting line 20 and constitutes the entire outline of one or more film pieces, as shown in FIG. 3. FIG. 3 shows a case where the outline of the film piece 85 constituted by one third cutting line 30 is two. The third cutting line 30 has a ninth side 33 that is constituted by combining a part of the sixth side 26 and a second protruding portion 31 that extends from the side connected to the seventh side 27 of the sixth side 26 to the opposite side to the eighth side 28. The ninth side 33 constitutes one side of one of the film pieces 85 whose outline is constituted by the third cutting line 30.

[0055] The contour of the film piece 85 defined by the third cutting line 30 is parallel to the contour of the film piece 85 defined by the second cutting line 20. It is preferable that the relationship between the two adjacent third cutting lines 30 included in the punching line 2 is as described above for the relationship between the second cutting line (1) 20a and the second cutting line (2) 20b.

[0056] The number of third cutting lines 30 included in the punching line 2 is two or more, and is usually the same as the number of first cutting lines 10 and / or second cutting lines 20 included in the punching line 2. Figures 3 and 4 show a case in which the punching line 2 formed by one punching with the punching blade includes four third cutting lines 30, and eight film pieces 85 are punched out by the third cutting lines 30 by one punching with the punching blade, but this is not limited to the case.

[0057] The number of contours of the film piece 85 defined by one third cutting line 30 may be one or more, but is preferably two or more. When the number of contours of the film piece 85 defined by the third cutting line 30 is two or more, it is preferable that the contours of adjacent film pieces are all arranged in the relationship described above in relation to the second cutting line 20 and the portion of the third cutting line 30 that forms the contour of the film piece 85 so as to share a part of the sixth side 26 of the second cutting line 20, as shown in FIG.

[0058] It is preferable that the third vertex 39 connecting the side connected to the second protruding portion 31 side of the ninth side 33 and the side opposite to the ninth side 33 of the film piece 85 having an outline including the ninth side 33 of the third cutting line 30 is on the straight line L2. When the punching line 2 has two or more first cutting lines 10, two or more second cutting lines 20, and two or more third cutting lines 30, it is preferable that the third vertex 39 of the film piece 85 having an outline so as to share a part of the sixth side 26 of the second cutting line 20 of the third cutting lines is all on the straight line connecting the second vertex 29 of the second cutting line 20 and the first vertex 19 of the first cutting line 10 sharing a part of the fifth side 25 of the second cutting line 20 (corresponding to the straight line L2 described above).

[0059] When punching the original film 80 using the punching blade, the punching blade and the original film 80 are moved relative to each other, and different positions of the original film 80 are punched with the punching blade, thereby sequentially forming a plurality of punching lines 2 in the original film 80. At this time, as shown in FIG. 4, the punching line (n) which is the punching line 2 formed by the punching of the nth shot (n is a natural number larger than m) is formed so that the second side 12 and the fourth side 14 of the first cutting line 10 included in the punching line (m) which is the punching line 2 formed by the punching of the mth shot (m is a natural number) are connected. In FIG. 4, the punching line (m) is shown by a solid line, and the punching line (n) is shown by a dashed line. It is preferable that n satisfies the relationship of n=m+1.

[0060] As a result, the entire contour of the film piece 85 is formed by the first cutting line 10 of the punching line (m) and a part of the punching line (n). FIG. 4 shows a case where punching is performed so that the second side 12 and the fourth side 14 of the first cutting line 10 of the punching line (m) are connected by a part of the side of the third cutting line 30 of the punching line (n), but this is not limited to this. When the punching line 2 formed by the punching blade does not include the third cutting line 30, punching may be performed so that the second side 12 and the fourth side 14 of the first cutting line 10 of the punching line (m) are connected by a part of the sixth side 26 of the second cutting line 20 of the punching line (n). As a result, when punching a plurality of film pieces 85 from the original film 80, the film pieces 85 can be punched out by arranging them so as to reduce the gap between the film pieces 85 adjacent to each other in the length direction L of the original film 80.

[0061] As described above, the arrangement of the punched line (m) and the punched line (n) is not particularly limited as long as the second side 12 and the fourth side 14 of the first cutting line 10 of the punched line (m) are connected by the punched line (n). For example, the side constituting the third cutting line 30 of the punched line (n) facing the second side 12 of the first cutting line 10 of the punched line (m) may overlap the second side 12, or may face the second side 12 with a gap therebetween, as shown in FIG. 4.

[0062] Since the punching blade of this embodiment includes the second cutting line 20, or the second cutting line 20 and the third cutting line 30, the film piece can be punched out by one punching with the punching blade. Therefore, the film piece 85 can be punched out more efficiently from the original film 80 than the punching blade of the previous embodiment. As described above, the thickness of the second blade forming the first cutting line 10 of the punching blade is greater than the thickness of the other blades, so that defects such as distortion and positional deviation during punching can be suppressed. In addition, the linear fourth side 14 formed by punching the mth shot is used as a guide, and the punching line (n) is formed by adjusting the position of the punching blade when performing the nth shot so as to extend the end of the fourth side 14 opposite to the first side 11 side, and the film piece 85 can be punched out. In this way, by using the punching blade of this embodiment, it is easy to align the punching blade in each shot, and it is easy to obtain a film piece 85 with excellent dimensional accuracy.

[0063] In the punching blade, the thickness of the blade for forming the second cutting line 20 and the third cutting line 30 is preferably smaller than the thickness of the second blade described above, and is preferably the same as the thickness of any one of the first cutting line, the third cutting line, and the fourth cutting line, and is preferably the same as the thickness of the first cutting line, the third cutting line, and the fourth cutting line. Of the blades for forming the second cutting line 20 and the third cutting line 30, the thickness of the blade for forming the cutting line connecting the second side 12 and the fourth side 14 of the first cutting line 10 is preferably the same as the thickness of the fourth blade from the viewpoint of obtaining a film piece 85 with excellent dimensional accuracy. Examples of the shape of the blade of the punching blade and the type of the punching blade include those described above.

[0064] (Method of manufacturing optical film) The punching blade described above can be used to manufacture an optical film. The manufacturing method of the optical film of this embodiment is a method of manufacturing an optical film by punching out a substantially rectangular film piece 85 from a long raw film 80 by a punching blade that forms a punching line 2 shown in FIG. 3, for example. In the manufacturing method of the optical film, as described in the previous embodiment, the film piece 85 can be obtained by forming the punching line (m) by the mth shot and the punching line (n) by the nth shot. As described above, the punching blade forms the punching line 2 so that the angle between the third side 13 of the first cutting line 10 and the width direction W of the raw film 80 and the angle between the fourth side 14 of the first cutting line 10 and the width direction W of the raw film 80 are each independently 20° or more and 70° or less.

[0065] In the method for producing an optical film of this embodiment, a punch blade including the second cutting line 20, or the second cutting line 20 and the third cutting line 30, is used, so that the film piece can be punched out in one punching operation with the punch blade. Therefore, the film piece can be punched out efficiently.

[0066] 3, in the manufacturing method for the optical film of this embodiment, it is preferable that the first vertex 19 of the first cutting line 10 included in the punching line 1 is formed so as to be located on a straight line W1 that is substantially parallel to the width direction W. In particular, when the angle between the straight line W1 and the straight line L2 in the punching line 2 is within a range of 90±5° as described above, punching waste can be further reduced and the film piece 85 can be punched out efficiently.

[0067] The number of film pieces 85 punched out by one mth shot and one nth shot shown in Figure 4 depends on the number of first cutting lines 10, second cutting lines 20, and third cutting lines 30 that the punching line 2 has, and may be, for example, 6 or more, 10 or more, 15 or more, 20 or more, 30 or more, or, for example, 100 or less, 80 or less, or 60 or less.

[0068] (Optical film manufacturing equipment) The optical film manufacturing apparatus of this embodiment includes a punching blade for forming the punching lines 2 described above, and a drive unit for relatively moving the original film 80 and the punching blade so that a different position of the original film 80 is punched for each punching by the punching blade, and two punching lines 2 formed for each punching by the punching blade are combined to form the four sides of one film piece 85. Examples of the drive unit include those described in the previous embodiment.

[0069] In the optical film manufacturing apparatus, as described above, the punching blade forms the punching line 2 such that the angle between the third side 13 of the first cutting line 10 and the width direction W of the original film 80, and the angle between the fourth side 14 of the first cutting line 10 and the width direction W of the original film 80, are each independently 20° or more and 70° or less. The optical film manufacturing apparatus of this embodiment is capable of carrying out the optical film manufacturing method described above.

[0070] The raw film, film piece, and optical film used in each embodiment will be described in detail below. (Original film) The original film may be a long strip-shaped film used to punch out film pieces. The width of the original film may vary depending on the size and number of the film pieces 85 to be punched out, but may be, for example, 800 mm or more, 1000 mm or more, or 1200 mm or more, and may be preferably 2500 mm or less, or may be 2300 mm or less.

[0071] The raw film may have a single layer structure or a multilayer structure. The raw film is preferably a raw film for producing an optical film described later. The raw film may have a pressure-sensitive adhesive layer, and may have a release film for covering and protecting the pressure-sensitive adhesive layer. The raw film is preferably a stretched film. The stretched film may be a uniaxially stretched film or a biaxially stretched film. The stretching axis of the stretched film may be parallel to the width direction of the raw film or a direction perpendicular to the width direction.

[0072] (Film fragment) The film piece is not particularly limited as long as it is approximately square, but is preferably approximately rectangular. The length of one side of the film piece is not particularly limited, but may be, for example, 50 mm or more, 60 mm or more, 70 mm or more, 300 mm or less, 250 mm or less, 200 mm or less, or 160 mm or less. When the film piece is approximately rectangular, the length of the long side may be, for example, 70 mm or more, 100 mm or more, 300 mm or less, or 200 mm or less, and the length of the short side may be, for example, 50 mm or more, 70 mm or more, 200 mm or less, or 150 mm or less.

[0073] When the original film is a uniaxially stretched film, the smaller of the angles between the stretching axis direction and any side of the film piece may be 20° or more, or 30° or more, or 70° or less, or 60° or less.

[0074] (Optical film) The optical film may have a single-layer structure or a multi-layer structure. Examples of the optical film having a single-layer structure include a polarizing film, a retardation film, a brightness-enhancing film, an anti-glare film, an anti-reflection film, a diffusion film, and a light-collecting film. Examples of the polarizing film include a polyvinyl alcohol-based resin film in which a dichroic dye such as iodine is adsorbed and oriented. Examples of the retardation film include a thermoplastic resin film that is uniaxially or biaxially stretched.

[0075] Examples of optical films having a multilayer structure include a polarizing plate in which another layer such as a protective film is laminated on one or both sides of a polarizing film, a retardation plate in which another layer such as a protective film is laminated on one or both sides of a retardation film, etc. The optical film may have a pressure-sensitive adhesive layer, and may have a release film for covering and protecting the pressure-sensitive adhesive layer. [Explanation of symbols]

[0076] 1,2 punched lines, 10 first cutting line, 10a first cutting line (1) (first cutting line), 10b first cutting line (2) (first cutting line), 10c first cutting line (3) (first cutting line), 10d first cutting line (4) (first cutting line), 11 1st side, 12 2nd side, 13 3rd side, 14 4th side, 19 1st vertex, 20 second cutting line, 20a second cutting line (1) (second cutting line), 20b second cutting line (2) (second cutting line), 21 first protrusion, 25 fifth side, 26 sixth side, 27 seventh side, 28 eighth side, 29 second vertex, 30 third cutting line, 31 second protrusion, 33 ninth side, 39 third vertex, 80 Original film, 85 Film piece, L Length direction, W Width direction.

Claims

1. A punching blade for punching a substantially square film piece from a long original film, configured such that by combining two punching lines formed by one punching with the punching blade, the entire four sides of one said film piece are formed, said punching line includes two or more first cutting lines having a first side, a second side facing the first side, a third side connecting the first side and the second side, and a fourth side connected to the first side, said first side, said second side, and said third side constitute three of the four sides, and said fourth side constitutes a part of the remaining one of the four sides, said third side and said fourth side are straight sides, two adjacent first cutting lines, the first cutting line (1) and the first cutting line (2), are parallel to each other, and the second side and the third side of the first cutting line (1) face the fourth side of the first cutting line (2), A punching blade, wherein the thickness of the blade for forming the second side among the first cutting lines is larger than the thickness of the blade for forming the sides other than the second side among the first cutting lines.

2. The punching blade according to Claim 1, wherein the third side of the first cutting line (1) and the fourth side of the first cutting line (2) face each other with a gap therebetween.

3. The punching blade according to Claim 1 or 2, wherein the thicknesses of the blades for forming the sides other than the second side among the first cutting lines are the same as each other.

4. said punching line further includes two or more second cutting lines that share a part of the third side of the first cutting line and constitute the entire contour of one said film piece, a fifth side that becomes one side of the film piece whose entire contour is constituted by the second cutting line is constituted by combining a part of the third side and a first protrusion that extends the third side from the side connected to the first side of the third side to the side opposite to the second side side, The punching blade according to any one of Claims 1 to 3, wherein the contour of the film piece formed by the second cutting line is parallel to the contour of the film piece formed by connecting the second side and the fourth side of the first cutting line.

5. said first cutting line has a first vertex connecting the first side and the third side, said second cutting line has a sixth side facing the fifth side, a seventh side connecting the first protrusion side of the fifth side and the sixth side, and a second vertex connecting the sixth side and the seventh side. [i] The angle formed by the straight line connecting the first vertices of the first cutting line (1) and the first cutting line (2), and [ii] the straight line connecting the first vertex of the first cutting line (1) and the second vertex of the second cutting line that shares a part of the third side of the first cutting line (1) among the second cutting lines is within the range of 90 ± 5°. The punching blade according to claim 4.

6. The second cutting line has a sixth side facing the fifth side, a seventh side connecting the first protrusion side of the fifth side and the sixth side, and an eighth side facing the seventh side. The punching line further includes two or more third cutting lines that share a part of the sixth side of the second cutting line and constitute the entire contour of one or more of the film pieces. The side that becomes one side of a film piece whose entire contour is constituted by the third cutting line is a combination of a part of the sixth side and a second protrusion that extends the sixth side from the side connected to the seventh side of the sixth side to the side opposite to the eighth side. The contour of the film piece constituted by the third cutting line is parallel to the contour of the film piece constituted by the second cutting line. The punching blade according to claim 4 or 5.

7. The third cutting line constitutes the entire contour of two or more of the film pieces. The punching blade according to claim 6.

8. A method for manufacturing an optical film, which punches a substantially square film piece from a long original film using the punching blade according to any one of claims 1 to 7, wherein the punching line is formed such that the angle between the third side of the first cutting line and the width direction of the original film, and the angle between the fourth side of the first cutting line and the width direction are each independently 20° or more and 70° or less. A punching line (m) is formed by punching the original film with the punching blade in the m-th shot [m represents a natural number]. A further punching line (n) is formed by punching the original film with the punching blade in the n-th shot [n represents a natural number greater than m]. A method for manufacturing an optical film, wherein the punching line (n) is formed so as to connect the second side and the fourth side of the first cutting line included in the punching line (m).

9. The first cutting line has a first vertex connecting the first side and the third side. The punching line is formed such that the first vertex of the first cutting line included in the punching line is located on a straight line substantially parallel to the width direction, the method for manufacturing an optical film according to claim 8.

10. The raw film is a stretched film, The stretching axis of the stretched film is parallel to the width direction of the raw film or a direction perpendicular to the width direction, the method for manufacturing an optical film according to claim 8 or 9.

11. An optical film manufacturing apparatus for manufacturing an optical film by punching a substantially square film piece from a long raw film, The punching blade according to any one of claims 1 to 7, A driving unit that relatively moves the raw film and the punching blade such that different positions of the raw film are punched for each punching by the punching blade, and four sides of one film piece are formed by combining two punching lines formed for each punching by the punching blade, The punching blade forms the punching line such that the angle formed by the third side of the first cutting line and the width direction of the raw film, and the angle formed by the fourth side of the first cutting line and the width direction are each independently 20° or more and 70° or less, an optical film manufacturing apparatus.

Images