Roll die manufacturing method, roll die manufacturing apparatus, and program

Abstract

To manufacture a roll mold in which a predetermined cut place is precisely cut a plurality of times, and a cut hole having a predetermined depth is formed.SOLUTION: A roll mold manufacturing apparatus 10 includes: a signal generation part 15 for generating a control waveform reciprocating a cutting blade 12 in a radial direction of a roll 1 at a position corresponding to a predetermined cut place on the surface of the roll 1, on the basis of a signal output from a rotary encoder 11a; and a control part 16 for reciprocating the cutting blade 12 in the radial direction of the roll according to the control waveform, and moving a stage 14 for a cutting tool in the radial direction of the roll 1 so that a cutting step of cutting the cut place at a predetermined cut depth one or a plurality of times is performed a plurality of times. The control part 16 moves the stage 14 for the cutting tool in the radial direction of the roll 1 so that the cut depth in the cutting step is smaller than the cut depth in a last cutting step. The signal generation part 15 generates a control waveform so that at least one of arrangement and a depth of the plurality of cutting holes becomes random.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a roll mold manufacturing method, a roll mold manufacturing apparatus, a program, and a microlens array.

Background Art

[0002] A microlens array in which a large number of minute lenses (microlenses) are two-dimensionally arranged is used in various applications such as a diffusion plate, a diffusion sheet, or a screen of a head-up display. As a method for manufacturing a microlens array with high mass productivity, a pattern having an inverted shape of a reference pattern of the microlens array (hereinafter referred to as a "transfer pattern") is formed on the surface of a mold, and the transfer pattern formed on the surface of the mold is transferred to a resin coated on a substrate, and the resin after transfer is cured. By cutting the cured resin as needed, a desired microlens array can be manufactured.

[0003] In the method described above, by using a roll mold in which a transfer pattern is formed on the surface of a cylindrical or columnar roll and using a Roll to Roll method, a microlens array with high mass productivity and high quality uniformity can be manufactured.

[0004] As a method for manufacturing the above-described roll mold, there is a method of cutting the surface of a cylindrical or columnar roll with a cutting edge to form a transfer pattern on the roll (see, for example, Patent Document 1). When a roll is cut to form a transfer pattern, protrusions called burrs may be generated on the surface of the roll due to cutting. Transfer using a transfer pattern with burrs results in the transfer of a shape including burrs, which is different from the desired microlens array pattern, and it is known that this causes deterioration in the quality of the manufactured microlens array. In particular, when the height difference between the unevenness of the transfer pattern exceeds 20 μm, it is known that the generated burrs have an adverse effect on the optical performance of the microlens array.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-13748 [Summary of the Invention] [Problems to be Solved by the Invention]

[0006] In order to suppress the generation of burrs as described above, there is a method of forming a cutting hole with a desired depth by repeating the cutting of a roll a plurality of times. In this method, the generation of burrs can be suppressed by gradually reducing the cutting depth of cutting the roll. However, in this method, it is necessary to accurately cut the same cutting portion a plurality of times, but conventionally, sufficient consideration has not been given to the technique of accurately cutting the same cutting portion a plurality of times. In addition, in a microlens array in which a plurality of microlenses having the same height are regularly arranged, a stripe pattern corresponding to the regularity may occur in the light diffused by the microlens array. Therefore, there is a particular demand for a microlens array in which the arrangement or height of a plurality of microlenses is random and a roll mold capable of manufacturing such a microlens array.

[0007] An object of the present invention made in view of the above problems is to provide a roll mold manufacturing method, a roll mold manufacturing apparatus, and a program for manufacturing a roll mold in which a plurality of cutting holes having at least one of a random arrangement and depth are formed by accurately cutting a predetermined cutting portion a plurality of times, and a microlens array including a plurality of microlenses having at least one of a random arrangement and height. [Means for Solving the Problems]

[0008] A roll mold manufacturing method according to an embodiment is A rotary device comprising a rotary encoder that rotates a cylindrical or columnar roll in the circumferential direction and outputs a signal corresponding to the rotational position of the roll, and a roll die manufacturing apparatus comprising a cutting tool stage that holds a cutting edge that can reciprocate in the radial direction of the roll and is movable in the radial direction of the roll, the method for manufacturing a roll die in the roll die manufacturing apparatus being: A generation step of generating a control waveform indicating a movement pattern of the cutting edge that reciprocates the cutting edge in the radial direction of the roll at a position corresponding to a predetermined cutting location on the surface of the roll based on a signal output from the rotary encoder; A cutting step of moving the cutting tool stage in the radial direction of the roll so that the cutting edge reciprocates in the radial direction of the roll according to the control waveform, and a plurality of cutting steps of cutting the predetermined cutting location one or more times at a predetermined cutting depth by the reciprocating cutting edge are performed, including: In the cutting step: The cutting tool stage is moved in the radial direction of the roll so that the cutting depth in the cutting step is smaller than the cutting depth in the cutting step immediately before the cutting step; In the generation step: The control waveform is generated such that at least one of the circumferential and axial arrangements of the plurality of cutting holes on the roll and the depths of the plurality of cutting holes are random.

[0009] A roll die manufacturing apparatus according to an embodiment includes: A rotary device comprising a rotary encoder that rotates a cylindrical or columnar roll in the circumferential direction and outputs a signal corresponding to the rotational position of the roll, and a roll die manufacturing apparatus comprising a cutting tool stage that holds a cutting edge that can reciprocate in the radial direction of the roll and is movable in the radial direction of the roll, A signal generation unit that generates a control waveform indicating a movement pattern of the cutting edge that reciprocates the cutting edge in the radial direction of the roll at a position corresponding to a predetermined cutting location on the surface of the roll based on a signal output from the rotary encoder; A control unit is provided to move the cutting tool stage in the radial direction of the roll so that the cutting edge is reciprocated in the radial direction of the roll according to the control waveform, and a cutting process of cutting the predetermined cutting location one or more times at a predetermined cutting depth with the reciprocating cutting edge is performed a plurality of times. The control unit moves the cutting tool stage in the radial direction of the roll so that the cutting depth in the cutting process is smaller than the cutting depth in the cutting process immediately before the current cutting process. The signal generation unit generates the control waveform such that at least one of the circumferential and axial arrangements of the plurality of cutting holes on the roll and the depths of the plurality of cutting holes are random.

[0010] A program according to an embodiment is provided to a computer of a roll die manufacturing apparatus including a rotary device having a rotary encoder that rotates a cylindrical or columnar roll in the circumferential direction and outputs a signal corresponding to the rotational position of the roll, and a cutting tool stage that holds a cutting edge reciprocable in the radial direction of the roll and is movable in the radial direction of the roll. a generation process of generating a control waveform indicating a movement pattern of the cutting edge that reciprocates the cutting edge in the radial direction of the roll at a position corresponding to a predetermined cutting location on the surface of the roll based on the signal output from the rotary encoder; a cutting process of reciprocating the cutting edge in the radial direction of the roll according to the control waveform and moving the cutting tool stage in the radial direction of the roll so that the predetermined cutting location is cut one or more times at a predetermined cutting depth with the reciprocating cutting edge is performed a plurality of times; In the cutting process the cutting tool stage is moved in the radial direction of the roll so that the cutting depth in the cutting process is smaller than the cutting depth in the cutting process immediately before the current cutting process. In the generation process Generate the control waveform such that at least one of the circumferential and axial arrangements of the plurality of cutting holes on the roll and the depths of the plurality of cutting holes are random.

[0011] A microlens array according to an embodiment is A microlens array in which a plurality of microlenses are two-dimensionally arranged, manufactured using a roll mold manufactured by the above roll mold manufacturing method, wherein at least one of the arrangements of the plurality of microlenses and the heights of the plurality of microlenses is random.

Advantages of the Invention

[0012] According to the present invention, it is possible to provide a roll mold manufacturing method, a roll mold manufacturing apparatus, and a program for manufacturing a roll mold in which a predetermined cutting location is accurately cut a plurality of times to form a plurality of cutting holes in which at least one of the arrangement and depth is random, and a microlens array including a plurality of microlenses in which at least one of the arrangement and height is random.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2A

Figure 2B

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8A

Figure 8B

Figure 9A

Figure 9B

Figure 10A

Figure 10B

Figure 11

Mode for Carrying Out the Invention

[0014] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In each figure, the same reference numerals indicate the same or equivalent components.

[0015] FIG. 1 is a diagram showing a configuration example of a roll mold manufacturing apparatus 10 according to an embodiment of the present invention. The roll mold manufacturing apparatus 10 according to the present embodiment is a manufacturing apparatus that cuts a cylindrical or columnar roll 1 to manufacture a roll mold in which at least one of the arrangement and the depth has a plurality of cutting holes formed randomly.

[0016] The roll mold manufacturing apparatus 10 shown in FIG. 1 includes a rotating device 11, a cutting edge 12, a PZT stage 13, a cutting tool stage 14, a signal generation unit 15, a control unit 16, and an amplification unit 17.

[0017] The rotating device 11 supports the cylindrical or columnar roll 1 from the axial direction and rotates the roll 1 in the circumferential direction. The roll 1 is made of a metal such as SUS (Steel Use Stainless) as the base material, for example. The surface of the roll 1 is plated with a free-cutting plating such as Ni-P or Cu. The roll 1 is not limited to plating and may be a free-cutting material such as pure copper or aluminum. The rotating device 11 includes a rotary encoder 11a.

[0018] The rotary encoder 11a outputs a signal corresponding to the rotational position of the roll 1 to the signal generation unit 15. The signal corresponding to the rotational position of the roll 1 includes a trigger signal output each time the rotational position of the roll 1 reaches a predetermined reference position in one rotation and a pulse signal output each time the roll 1 rotates by a predetermined amount.

[0019] The cutting edge 12 is a cutting tool for cutting the roll 1. The cutting edge 12 is made of a hard material such as a ceramic chip, a diamond chip, or a carbide chip, for example.

[0020] The PZT stage 13 holds the cutting edge 12. The PZT stage 13 includes a PZT (lead zirconate titanate) piezoelectric element, and the PZT piezoelectric element expands and contracts according to the voltage level of the drive signal, thereby reciprocating the cutting edge 12 in the radial direction of the roll 1. Therefore, the cutting edge 12 can reciprocate in the radial direction of the roll 1 by the PZT stage 13. Note that the driving means for driving the cutting edge 12 is not limited to the PZT piezoelectric element.

[0021] FIG. 2A is a view of the cutting edge 12 seen from the front. FIG. 2B is a view of the cutting edge 12 seen from the side.

[0022] As shown in FIG. 2A, the cutting edge 12 has a circular shape. The cutting edge 12 is arranged such that the front of the cutting edge 12 faces the circumferential direction of the roll 1. As described above, the roll 1 rotates in the circumferential direction. By reciprocally moving the cutting edge 12 in the radial direction of the roll 1 toward the roll 1, the cutting edge 12 apparently moves in a semi-circular shape as shown by the dashed arrow in FIG. 2B and cuts the roll 1. By the cutting by the cutting edge 12, a circular bottom surface portion having the same curvature as the curvature of the circular portion of the cutting edge 12 is formed in the cutting hole.

[0023] Referring to FIG. 1 again, the stage 14 for the cutting tool holds the PZT stage 13 and moves in the cutting axis direction (radial direction of the roll 1) and the feed axis direction (axial direction of the roll 1). When the stage 14 for the cutting tool moves, the PZT stage 13 and the cutting edge 12 held by the stage 14 for the cutting tool also move in the cutting axis direction and the feed axis direction. While rotating the roll 1, the cutting edge 12 is reciprocally moved in the radial direction of the roll 1 by the PZT stage 13 to cut the roll 1, and by moving the PZT stage 13 in the axial direction of the roll 1, a cutting hole can be formed over the entire surface of the roll 1.

[0024] Based on the signal output from the rotary encoder 11a, the signal generation unit 15 generates a control waveform indicating the movement pattern of the cutting edge 12 that reciprocally moves the cutting edge 12 at a position corresponding to a predetermined cutting location on the surface of the roll 1. The generation of the control waveform by the signal generation unit 15 will be described with reference to FIG. 3.

[0025] As described above, the rotary encoder 11a outputs a trigger signal each time the rotational position of the roll 1 reaches a predetermined reference position in one rotation. Specifically, for example, as shown in FIG. 3, the rotary encoder 11a outputs a pulse-shaped signal that rises each time the rotational position of the roll 1 reaches a predetermined reference position in one rotation as a trigger signal. Further, as shown in FIG. 3, the rotary encoder 11a outputs a pulse-shaped signal that rises each time the roll 1 rotates by a predetermined amount as a pulse signal. The rotary encoder 11a outputs, for example, a pulse-shaped signal that rises for each rotation amount obtained by dividing one rotation of the roll 1 into 1,440,000 parts as a pulse signal.

[0026] The signal generation unit 15 counts the pulse signal based on the output timing of the trigger signal (the timing at which the trigger signal rises). Then, the signal generation unit 15 generates a control waveform according to the count number of the pulse signal. By counting the pulse signal based on the output timing of the trigger signal, the rotational position of the roll 1 from a predetermined reference position can be specified. Therefore, by generating a control waveform according to the count number of the pulse signal based on the output timing of the trigger signal, a predetermined cutting portion of the roll 1 can be accurately and repeatedly cut.

[0027] Explaining in more detail the generation of the control waveform by the signal generation unit 15, the signal generation unit 15 generates a control waveform such that at least one of the circumferential direction and the axial direction arrangement (two-dimensional arrangement) of the plurality of cutting holes of the roll 1 and the depths of the plurality of cutting holes are random.

[0028] FIG. 4 is a diagram showing an example of an arrangement pattern of cutting holes in a general roll die in which a plurality of cutting holes having the same depth are regularly arranged.

[0029] As shown in FIG. 4, consider a pattern in which a rhombus with one side and another opposite side parallel in the axial direction and the other two sides inclined by about 30 degrees in the circumferential direction is continuously arranged in the axial direction and the circumferential direction. In a general roll mold, for example, the cutting holes are arranged around the four vertices of each rhombus. The two cutting holes centered on both ends of the side parallel to the axial direction partially overlap. Also, the two cutting holes centered on both ends of the side inclined in the circumferential direction partially overlap. If the axial distance between the centers of the two cutting holes centered on both ends of the side inclined in the circumferential direction is A μm, the distance between the centers of two adjacent cutting holes in the circumferential direction is, for example, 2√3 * A μm. Also, the distance between the centers of two adjacent cutting holes in the axial direction is, for example, 2 * A μm. Also, the distance between the centers of the two cutting holes centered on both ends of the side inclined in the circumferential direction is, for example, 2 * A μm. Also, the depth of each cutting hole is, for example, 20 μm.

[0030] On the other hand, in the present embodiment, as described above, the signal generation unit 15 generates a control waveform such that at least one of the circumferential and axial arrangements of the plurality of cutting holes of the roll 1 and the depths of the plurality of cutting holes are random. For example, the signal generation unit 15 may generate a control waveform such that cutting holes are formed centered on points obtained by randomly moving the centers of the respective cutting holes in the basic pattern indicated by the white dots in FIG. 5 in the circumferential and axial directions indicated by the black dots in FIG. 5. The signal generation unit 15 may generate a control waveform such that the arrangement of each cutting hole remains in the basic pattern and the depths of the respective cutting holes are random. The signal generation unit 15 may also generate a control waveform such that the circumferential and axial arrangements of the plurality of cutting holes of the roll 1 and the depths of the plurality of cutting holes are random.

[0031] When the signal generation unit 15 randomly moves the positions of the respective cutting holes in the circumferential and axial directions of the roll 1 from the reference pattern, the amounts of movement in the circumferential and axial directions may be determined based on, for example, a random number table. Also, when the signal generation unit 15 makes the depths of the respective cutting holes random, the depths of the respective cutting holes may be determined based on a random number table.

[0032] The signal generation unit 15 generates a control waveform such that cutting holes are formed in the roll 1 according to the cutting hole arrangement pattern described with reference to FIG. 5. For example, when forming a plurality of cutting holes randomly arranged in the circumferential direction and the axial direction, the signal generation unit 15 generates a control waveform such that the roll 1 is cut by the reciprocating cutting edge 12 at positions corresponding to each cutting hole in the random arrangement. Also, for example, when forming a plurality of cutting holes with random depths, the signal generation unit 15 generates a control waveform such that the reciprocating distance of the cutting edge 12 at each cutting position is random.

[0033] Referring again to FIG. 1, the control unit 16 reciprocates the cutting edge 12 in the radial direction of the roll 1 to cut the roll 1 according to the control waveform generated by the signal generation unit 15. Specifically, the control unit 16 reciprocates the cutting edge 12 in the radial direction of the roll 1 based on the control waveform. Further, the control unit 16 moves the cutting tool stage 14 in the radial direction of the roll 1 so that a cutting process of cutting one or more times at a predetermined cutting depth by the reciprocating cutting edge 12 at a predetermined cutting location of the roll 1 is performed a plurality of times. By doing so, the roll 1 is cut at a predetermined depth by the reciprocating cutting edge 12. The cutting depth and the number of cutting times in each cutting process are, for example, input to the control unit 16 in advance. The control unit 16 generates a drive signal for driving the PZT stage 13 and outputs it to the amplifier unit 17.

[0034] Taking as an example the case of forming cutting holes by a cutting process of cutting x times at a cutting depth d1 and a cutting process of cutting y times at a cutting depth d2. In this case, the control unit 16 drives the PZT stage 13 according to the control waveform to reciprocate the cutting edge 12 in the radial direction of the roll 1. Then, the control unit 16 sequentially moves the cutting tool stage 14 so that the roll 1 is cut x times at the cutting depth d1 by the reciprocating cutting edge 12. Next, the control unit 16 sequentially moves the cutting tool stage 14 so that the roll 1 is cut y times at the cutting depth d2 by the reciprocating cutting edge 12.

[0035] As described above, for example, when forming a plurality of cutting holes randomly arranged in the circumferential direction and the axial direction, the signal generation unit 15 generates a control waveform such that the roll 1 is cut by the reciprocating cutting edge 12 at positions corresponding to the randomly arranged cutting holes. The control unit 16 drives the PZT stage 13 according to the control waveform to reciprocate the cutting edge 12 in the radial direction of the roll 1. Further, the control unit 16 moves the cutting tool stage 14 in the radial direction of the roll 1 so that the cutting edge 12 reciprocatingly cuts by the cutting depth determined in the cutting process. By doing so, a plurality of cutting holes randomly arranged in the circumferential direction and the axial direction of the roll 1 can be formed.

[0036] Also, for example, when forming a plurality of cutting holes with random depths, the signal generation unit 15 generates a control waveform such that the reciprocating distance of the cutting edge 12 at each cutting position is random. The control unit 16 drives the PZT stage 13 according to the control waveform to reciprocate the cutting edge 12 in the radial direction of the roll 1 by a random distance. Further, the control unit 16 moves the cutting tool stage 14 in the radial direction of the roll 1 so that the cutting edge 12 reciprocatingly cuts, for example, at a predetermined reference position, by the cutting depth determined in the cutting process. By doing so, a plurality of cutting holes with random depths can be formed.

[0037] The amplification unit 17 amplifies the drive signal output from the control unit 16 and outputs it to the PZT stage 13. The PZT stage 13 is driven by the amplified drive signal, the cutting edge 12 reciprocates in the radial direction of the roll 1, and the roll 1 is cut.

[0038] FIG. 6 is a flowchart showing an example of the operation of the roll die manufacturing apparatus 10 according to the present embodiment.

[0039] First, the roll 1 is placed on the rotating device 11 (step S101).

[0040] Next, planar processing for flattening the plating layer on the surface of the roll 1 is performed on the roll 1 (step S102).

[0041] Next, the PZT stage 13 is set on the cutting tool stage 14 (step S103).

[0042] Next, the cutting edge 12 is set on the PZT stage 13 (step S104).

[0043] Next, the rotational speed of the rotating device 11 is set (step S105), and the rotating device 11 starts the rotation of the roll 1 at the set rotational speed (step S106).

[0044] Next, the position of the cutting tool stage 14 is set to the start position in the feed axis direction and the start position in the cutting depth axis direction (steps S107, S108), and the cutting tool stage 14 starts driving (step S109).

[0045] According to the control waveform generated by the signal generation unit 15, the cutting edge 12 reciprocates in the radial direction of the roll 1, and thus the roll 1 is cut (step S110).

[0046] The cutting of the cutting hole is completed by repeating a plurality of times the cutting process in which the cutting tool stage 14 moves to the end position in the feed axis direction and cuts a predetermined cutting portion at a predetermined cutting depth (step S111).

[0047] When wear occurs on the cutting edge 12 and it is necessary to replace the cutting edge 12, the replacement of the cutting edge 12 (step S112) and the positioning of the cutting edge 12 (step S113) are performed, and then the processes from step S107 to step S111 are repeated.

[0048] Next, the roll die manufacturing method in the roll die manufacturing apparatus 10 according to the present embodiment will be described with reference to the flowchart shown in FIG. 7. In FIG. 7, the generation of the control waveform indicating the movement pattern of the cutting edge 12 and the cutting by the cutting edge 12 according to the control waveform will be particularly described.

[0049] Based on the signal output from the rotary encoder 11a and corresponding to the rotational position of roll 1, the signal generation unit 15 generates a control waveform for reciprocally moving the cutting edge 12 in the radial direction of roll 1 at a position corresponding to a predetermined cutting location on the surface of roll 1 (step S201). Here, the signal generation unit 15 generates a control waveform such that at least one of the circumferential and axial arrangements of the plurality of cutting holes on roll 1 and the depths of the plurality of cutting holes are random.

[0050] The control unit 16 reciprocally moves the cutting edge 12 in the radial direction of roll 1 according to the control waveform generated by the signal generation unit 15. Further, the control unit 16 moves the cutting tool stage 14 in the radial direction of roll 1 so that a cutting process of cutting one or more times at a predetermined cutting depth by the cutting edge 12 reciprocally moving at a predetermined cutting location on roll 1 is performed a plurality of times (step S202). Specifically, the control unit 16 generates a drive signal for the PZT stage 13 such that the cutting edge 12 moves in the radial direction of roll 1 according to the control waveform and outputs it to the amplifier unit 17. Also, the control unit 16 moves the cutting tool stage 14 in the radial direction of roll 1 so that roll 1 is cut at a predetermined cutting depth and number of times in a predetermined cutting process.

[0051] Thus, the roll die manufacturing method according to this embodiment includes a generation step of generating a control waveform indicating a movement pattern of the cutting edge 12 that reciprocally moves the cutting edge 12 in the radial direction of roll 1 at a position corresponding to a predetermined cutting location on the surface of roll 1 based on the signal output from the rotary encoder 11a, and a cutting step of reciprocally moving the cutting edge 12 in the radial direction of roll 1 according to the control waveform and moving the cutting tool stage 14 in the radial direction of roll 1 so that a cutting process of cutting one or more times at a predetermined cutting depth by the cutting edge 12 reciprocally moving at a predetermined cutting location is performed a plurality of times. In the cutting step, the cutting tool stage is moved in the radial direction of roll 1 such that the cutting depth in the cutting process is smaller than the cutting depth in the cutting process immediately preceding the current cutting process. In the generation step, a control waveform is generated such that at least one of the circumferential and axial arrangements of the plurality of cutting holes on roll 1 and the depths of the plurality of cutting holes are random.

[0052] Based on the signal output from the rotary encoder 11a, a control waveform is generated, and based on the control waveform, the reciprocating movement of the cutting edge 12 is controlled to cut the roll 1, so that a predetermined cutting position can be accurately cut. Therefore, even if the cutting process of cutting one or more times at a predetermined cutting depth is repeated a plurality of times, the same cutting position can be accurately cut. Thus, a roll mold with a cutting hole of a predetermined depth formed by accurately cutting a predetermined cutting position a plurality of times can be manufactured. Also, by making the cutting depth smaller in later cutting processes, the generation of burrs due to cutting can be suppressed. Further, by generating a control waveform such that at least one of the circumferential direction and the axial direction arrangement of the plurality of cutting holes in the roll 1 and the depth of the plurality of cutting holes becomes random, a roll mold with a plurality of cutting holes with at least one of the arrangement and the depth being random can be manufactured.

Example

[0053] Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the following examples.

[0054] (Example 1) A roll with Ni-P plating on the surface of SUS304 was prepared. The diameter of the roll was 130 mm, and the length of the roll was 250 mm.

[0055] Next, the prepared roll was placed on the roll die apparatus according to the present embodiment, and surface machining was performed on the Ni-P plating layer on the roll surface. After the surface machining, the roll was cut to form cutting holes. As the cutting edge, a cutting edge made of a diamond chip with a tip radius of 0.1 mm and a circular shape when viewed from the front was used. The rotational speed of the roll was set to 0.5 min-1. The roll was cut three times at a cutting depth of 5 μm, once at a cutting depth of 3 μm, and three times at a cutting depth of 1 μm. That is, after the cutting process (the first cutting process) of cutting three times at a cutting depth of 5 μm, a cutting process (the second cutting process) of cutting once at a cutting depth of 3 μm, which is smaller than the cutting depth (5 μm) in the first cutting process, was performed. Further, after the second cutting process, a cutting process (the third cutting process) of cutting three times at a cutting depth of 1 μm, which is smaller than the cutting depth (3 μm) in the second cutting process, was performed. By the first to third cutting processes, a roll die was manufactured by forming cutting holes of 21 μm (= 5 μm × 3 + 3 μm × 1 + 1 μm × 3) in the roll. Also, as the control waveform, a control waveform was used such that the depths of a plurality of cutting holes were random. Specifically, as the control waveform, a control waveform was used such that the depth of the cutting holes was random within the range of 21 μm ± 0.75 μm.

[0056] (Example 2) In this example, as the control waveform, a control waveform was used such that the arrangement and depth of a plurality of cutting holes were random. Specifically, as the control waveform, the arrangement of a plurality of cutting holes was random within the range of ±5 μm from the reference pattern (pitch 250 μm) shown in FIG. 4, and the depth of a plurality of cutting holes was random within the range of 21 μm ± 3 μm. Other conditions were the same as in Example 1.

[0057] Next, a microlens array was manufactured using the roll molds according to Examples 1 and 2. The microlens array was manufactured as follows. That is, an uncured acrylic-based UV-curable resin was dropped onto a substrate made of PET (Polyethyleneterephthalate) to form a curable resin layer. Next, the manufactured roll mold was pressed against the formed curable resin layer, and in this state, the curable resin layer was irradiated with UV light to cure the curable resin layer. After the curable resin layer was cured, the cured curable resin layer was peeled off from the roll mold to manufacture a microlens array.

[0058] Next, the surfaces of the roll molds according to Examples 1 and 2 were observed with a microscope. Also, the surface of the microlens array manufactured using these roll molds was observed with an SEM (Scanning Electron Microscope). Further, the height of the microlenses formed on the microlens array manufactured using the roll mold according to Example 1 was measured with a laser microscope.

[0059] Fig. 8A is a diagram of the surface of the roll photographed with a microscope after cutting a predetermined cutting portion a predetermined number of times. Fig. 8B is a diagram of the surface of the roll photographed with a microscope after further cutting the roll shown in Fig. 8A once. The magnification in Figs. 8A and 8B is the same.

[0060] As shown in Figs. 8A and 8B, it was found that by repeating the cutting, cutting holes with large diameters and depths were formed.

[0061] Figs. 9A and 10A are diagrams of the surfaces of the roll molds according to Examples 1 and 2 photographed with a microscope, respectively. Figs. 9B and 10B are diagrams of the surfaces of the microlens arrays manufactured using the roll molds according to Examples 1 and 2 photographed with an SEM, respectively. Fig. 11 is a diagram of the height of the microlenses of the microlens array manufactured using the roll mold according to Example 1 measured with a laser microscope.

[0062] As shown in Fig. 9A, in the roll mold according to Example 1, a plurality of cutting holes having a so-called honeycomb structure in which hexagonal cutting holes were arranged without gaps in a plan view were formed. Further, as shown in Fig. 10A, in the roll mold according to Example 2, a plurality of randomly arranged cutting holes were formed. As shown in Figs. 9A and 10A, no burrs were generated in either the roll mold according to Example 1 or the roll mold according to Example 2.

[0063] As shown in Fig. 9B, in the microlens array manufactured using the roll mold according to Example 1, a plurality of microlenses having a honeycomb structure were formed. However, as shown in Fig. 11, the heights of the respective microlenses were not uniform but random. As shown in Fig. 10B, in the microlens array manufactured using the roll mold according to Example 2, a plurality of randomly arranged microlenses were formed. Also in the microlens array according to Example 2, the heights of the respective microlenses were not uniform but random. As shown in Figs. 9B and 10B, in either the microlens array manufactured using the roll mold according to Example 1 or the microlens array manufactured using the roll mold according to Example 2, a configuration corresponding to burrs was not formed.

[0064] The signal generation unit 15 and the control unit 16 are constituted by, for example, a computer including a memory and a processor. When the signal generation unit 15 and the control unit 16 are constituted by a computer, the signal generation unit 15 and the control unit 16 are realized by the processor reading and executing the program according to the present embodiment stored in the memory.

[0065] In addition, a program that describes the processing content for realizing each function of the signal generation unit 15 and the control unit 16 may be recorded on a computer-readable recording medium. By using such a recording medium, it is possible to install the program in a computer. Here, the recording medium on which the program is recorded may be a non-transitory recording medium. The non-transitory recording medium is not particularly limited, and may be, for example, a recording medium such as a CD-ROM or a DVD-ROM.

[0066] The present invention is not limited to the configurations specified in the above-described embodiments, and various modifications are possible without departing from the gist of the invention described in the claims. For example, the functions included in each component and the like can be rearranged so as not to be logically contradictory, and a plurality of components and the like can be combined into one or divided.

Explanation of Reference Numerals

[0067] 10 Roll Die Manufacturing Apparatus 11 Rotation Device 11a Rotary Encoder 12 Cutting Edge 13 PZT Stage 14 Stage for Cutting Tool 15 Signal Generation Unit 16 Control Unit 17 Amplification Unit

Claims

1. A roll mold manufacturing method in a roll mold manufacturing apparatus including a rotating device that rotates a cylindrical or columnar roll in a circumferential direction and includes a rotary encoder that outputs a signal corresponding to a rotational position of the roll, and a cutting tool stage that holds a cutting edge that can reciprocate in a radial direction of the roll and is movable in both the radial direction and an axial direction of the roll, comprising: a generating step of generating a control waveform indicating a movement pattern of the cutting edge that reciprocates the cutting edge in the radial direction of the roll at a position corresponding to a predetermined cutting location on the surface of the roll based on a signal output from the rotary encoder; a cutting step of moving the cutting tool stage in the radial direction and the axial direction of the roll so that the cutting step of reciprocating the cutting edge in the radial direction of the roll and cutting the predetermined cutting location one or more times at a predetermined cutting depth by the reciprocating cutting edge is performed a plurality of times, wherein in the generating step, a roll mold manufacturing method of generating the control waveform such that at least one of an arrangement in a circumferential direction and an axial direction of the roll of a plurality of cutting holes and a depth of the plurality of cutting holes becomes random.

2. In the roll mold manufacturing method according to claim 1, the signal corresponding to the rotational position of the roll includes a trigger signal output each time the rotational position of the roll reaches a predetermined reference position in one rotation, and a pulse signal output each time the roll rotates a predetermined amount, and in the generating step, the pulse signal is counted based on an output timing of the trigger signal, and the control waveform is generated according to a count number of the pulse signal.

3. In the roll mold manufacturing method according to claim 1, in the generating step, the control waveform is generated such that cutting holes are formed centered on points obtained by randomly moving centers of the plurality of cutting holes when the plurality of cutting holes are regularly arranged in the circumferential direction and the axial direction of the roll.

4. In the roll mold manufacturing method according to claim 1, in the generating step, the control waveform is generated such that a distance of reciprocation of the cutting edge in the radial direction of the roll at a cutting position of each of the plurality of cutting holes becomes random.

5. In the roll mold manufacturing method according to claim 1, wherein in the cutting step, A method for manufacturing a roll mold, wherein the cutting tool stage is moved in the radial direction of the roll so that the cutting depth in the cutting process is smaller than the cutting depth in the cutting process immediately before the cutting process.

6. A rotary device including a cylindrical or columnar roll rotated in the circumferential direction and a rotary encoder that outputs a signal corresponding to the rotational position of the roll, and a cutting tool stage that holds a cutting edge reciprocally movable in the radial direction of the roll and is movable in the radial direction and the axial direction of the roll. A roll mold manufacturing apparatus, A signal generation unit that generates a control waveform indicating a movement pattern of the cutting edge that reciprocates the cutting edge in the radial direction of the roll at a position corresponding to a predetermined cutting location on the surface of the roll based on a signal output from the rotary encoder; A control unit that moves the cutting tool stage in the radial direction and the axial direction of the roll so that a cutting process in which the cutting edge is reciprocated in the radial direction of the roll and the predetermined cutting location is cut one or more times at a predetermined cutting depth by the reciprocating cutting edge is performed a plurality of times. with, The signal generation unit A roll mold manufacturing apparatus that generates the control waveform such that at least one of the circumferential and axial arrangements of the plurality of cutting holes of the roll and the depths of the plurality of cutting holes are random.

7. On a computer of a roll mold manufacturing apparatus including a rotary device including a cylindrical or columnar roll rotated in the circumferential direction and a rotary encoder that outputs a signal corresponding to the rotational position of the roll, and a cutting tool stage that holds a cutting edge reciprocally movable in the radial direction of the roll and is movable in the radial direction and the axial direction of the roll, A generation process for generating a control waveform indicating a movement pattern of the cutting edge that reciprocates the cutting edge in the radial direction of the roll at a position corresponding to a predetermined cutting location on the surface of the roll based on a signal output from the rotary encoder; A cutting process for moving the cutting tool stage in the radial direction and the axial direction of the roll so that a cutting process in which the cutting edge is reciprocated in the radial direction of the roll and the predetermined cutting location is cut one or more times at a predetermined cutting depth by the reciprocating cutting edge is performed a plurality of times is executed, In the generation process, A program that generates the control waveform such that at least one of the circumferential and axial arrangements of the plurality of cutting holes on the roll and the depths of the plurality of cutting holes are random.

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