JP2016177140A - Method of manufacturing optical element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing an optical element with high productivity.SOLUTION: A method of manufacturing an optical element comprises the steps of; preparing a plurality of wire rods 1, each comprising a core 2 and a cover 3; planarly arranging the plurality of wire rods 1 such that the covers 3 sit next to each other and pressing the plurality of wire rods 1 in a direction crossing a direction of a plane of the plurality of planarly arranged wire rods to deform the plurality of wire rods; and, while the covers 3 of the plurality of wire rods 1 are joined with each other, removing portions of the covers 3 positioned on one side and on the other side in the direction crossing the plane to expose the cores 2 on the one side and on the other side.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a method for manufacturing an optical element in which a number of band-like surfaces having a reflecting function are arranged inside.

  There is known an optical element in which a number of band-like surfaces having a reflecting function are arranged inside. As disclosed in International Publication No. 2009/131128 (Patent Document 1), by using two such optical elements, for example, a three-dimensional image is formed in the air on the side of an observer viewing an object. Is possible.

International Publication No. 2009/131128

  In the method of manufacturing an optical element disclosed in International Publication No. 2009/131128 (Patent Document 1), first, a plurality of transparent plates (acrylic resin plates or glass plates) having a metal reflecting surface formed on one side are prepared. To do. A laminated body is formed by laminating a plurality of transparent plates so that the metal reflecting surface is arranged on one side. An optical element (light control panel) is produced by cutting out the laminate so that a cut surface perpendicular to each metal reflecting surface is formed. This manufacturing method includes a process of laminating a transparent plate and a somewhat complicated process of cutting the laminate in a direction perpendicular to each metal reflecting surface, leaving room for improvement in terms of productivity. Yes.

  An object of this invention is to provide the manufacturing method of the optical element which can manufacture an optical element with high productivity compared with the former.

  The method for manufacturing an optical element according to the present invention includes a step of preparing a plurality of wires having a light-transmitting core material and a covering portion provided so as to cover the periphery of the core material, and the covering portions. A plurality of the wire rods are arranged in a plane shape so that the adjacent wire rods are adjacent to each other, and the plurality of wire rods are pressed by pressing the plurality of wire rods in a direction intersecting with the surface direction arranged in the plane shape of the plurality of wire rods. By removing the portions located on one side and the other side of the intersecting direction of the covering portions in a state where the covering portions of the plurality of wires are joined to each other, Exposing the core material on the one side and the other side.

Preferably, the wire is made of a plastic optical fiber.
Preferably, the plurality of wires are bonded to each other by thermally welding the covering portions of the plastic optical fiber.

Preferably, the core material is made of a plastic fiber.
Preferably, the coating portion is a reflective film that is formed on the surface of the plastic fiber and reflects light inside.

Preferably, the material of the reflective film includes a dielectric or a metal.
Preferably, the plurality of wires are joined to each other by an adhesive.

  Preferably, when pressurizing the wire, the wire is heated so as to have a temperature equal to or higher than a temperature at which the core softens or melts.

  Since the above manufacturing method does not include a step of laminating a transparent plate or cutting out a laminated body, it is easy to improve productivity.

5 is a perspective view showing a first step of the method of manufacturing an optical element in Embodiment 1. FIG. 2 is a cross-sectional view showing a wire used in the method for manufacturing an optical element in Embodiment 1. FIG. It is arrow sectional drawing along the III-III line in FIG. It is sectional drawing (wire material before a deformation | transformation) for demonstrating the characteristic of the wire used for the manufacturing method of the optical element in Embodiment 1. FIG. FIG. 6 is a cross-sectional view (deformed wire rod) for describing the characteristics of the wire rod used in the method for manufacturing an optical element in the first embodiment. 6 is a cross-sectional view showing a second step of the method of manufacturing an optical element in Embodiment 1. FIG. 6 is a cross-sectional view showing a third step of the method of manufacturing an optical element in Embodiment 1. FIG. 10 is a cross-sectional view showing a fourth step of the method of manufacturing an optical element in Embodiment 1. FIG. 10 is a cross-sectional view showing a fifth step of the method of manufacturing an optical element in Embodiment 1. FIG. 4 is a cross-sectional view showing a fiber array sheet obtained by the method for manufacturing an optical element in Embodiment 1. FIG. FIG. 3 is a perspective view showing a micromirror array obtained by the method for manufacturing an optical element in the first embodiment. 6 is a cross-sectional view showing a core material used in the method for manufacturing an optical element in Embodiment 2. FIG. 10 is a cross-sectional view showing a wire used in the method for manufacturing an optical element in Embodiment 2. FIG. FIG. 10 is a cross-sectional view showing a certain step in the method for manufacturing an optical element in the second embodiment.

  Hereinafter, embodiments will be described with reference to the drawings. The same parts and corresponding parts are denoted by the same reference numerals, and redundant description may not be repeated.

[Embodiment 1]
With reference to FIGS. 1-9, the manufacturing method of the optical element in Embodiment 1 is demonstrated. Although details will be described later, a fiber array sheet 10A (see FIGS. 9 and 10) as an optical element is manufactured by performing the manufacturing method. The fiber array sheet 10A causes light incident from one side surface 2M (see FIGS. 9 and 10) to be emitted from the other side surface 2N (the same figure). Furthermore, the micromirror array 100 as shown in FIG. 11 can also be produced by using two fiber array sheets 10A.

  With reference to FIG. 1, in the manufacturing method of Embodiment 1, the some wire 1 is prepared first. FIG. 2 is a cross-sectional view showing the wire 1 used in the manufacturing method of the present embodiment. FIG. 3 is a cross-sectional view taken along line III-III in FIG. The wire 1 has a core material (2) having light permeability and a covering portion (3) provided so as to cover the periphery of the core material, and can propagate light inside (in FIG. 3). See the black arrow). The wire 1 of this Embodiment is comprised from a plastic optical fiber.

  As shown in FIGS. 2 and 3, a wire 1 as a plastic optical fiber includes a core layer 2 (core material) having optical transparency and a clad layer 3 (covering portion) provided so as to cover the periphery of the core layer 2. ). The wire 1 of the present embodiment has a wire diameter of φ1 mm. Both the core layer 2 and the clad layer 3 are formed from a thermoplastic resin. For example, the core layer 2 has a higher refractive index than the cladding layer 3, the core layer 2 is formed from a polymethyl methacrylate resin, and the cladding layer 3 is formed from a fluorine-based polymer. The thickness of the cladding layer 3 is, for example, 10 μm.

  With reference to FIG. 4, the wire 1 has the following characteristics. That is, it is assumed that the wire 1 is disposed inside the pressurizing tool 4A as shown in FIG. The pressing tool 4A has a flat pressing surface 4S and a pair of pressing surfaces 4T and 4U perpendicular to the pressing surface 4S. The pressing tool 5A also has a flat pressing surface 5S. The wire 1 is pressurized using the pressurizing tools 4A and 5A while heating the wire 1 so that the temperature of the wire 1 becomes 160 ° C., for example. The wire 1 (core layer 2 and clad layer 3) is softened and deformed by pressurization. The wire 1 is deformed so as to follow the shapes of the pressure surfaces 4S, 4T, 4U and the pressure surface 5S to form a wire 1A (see FIG. 5).

  As shown in FIG. 5, the wire 1 </ b> A has a substantially rectangular cross-sectional shape in which four corners are rounded in a state where heating and pressurization are released. The wire 1A obtained by deformation maintains the cross-sectional configuration of the core layer 2 and the clad layer 3 of the wire 1 before deformation (configuration in which the clad layer 3 is positioned so as to cover the periphery of the core layer 2). Yes. The wire 1A also has a function of propagating light inside, similarly to the wire 1 (FIG. 4). In this Embodiment, the characteristic that the wire 1A can form the wire 1A which has such a shape by deformation | transformation is used.

  Referring again to FIG. 1, the plurality of wires 1 having the above-described characteristics are arranged on the pressing surface 4 </ b> S of the pressing tool 4 so that the clad layers 3 (coating portions) are adjacent to each other. Are lined up. In the present embodiment, the plurality of wires 1 are arranged in an XY plane. Assuming that the plurality of wires 1 extend linearly along the arrow Y direction, the plurality of wires 1 are in the direction of the arrow X intersecting the arrow Y (in this embodiment, orthogonal to the arrow Y). In the direction of arrow X). A pressurizing tool 5 having a pressurizing surface 5S is arranged so as to face the pressurizing tool 4. The pressing surfaces 4S and 5S are parallel to each other (see FIG. 6).

  With reference to FIG. 1 and FIG. 6, the plurality of wire rods 1 are in the direction of an arrow Z that intersects the plane direction in which the plurality of wire rods 1 are arranged in a plane (in the present embodiment, the XY plane direction). Is pressurized. In this Embodiment, the some wire 1 is pressurized in the arrow Z direction orthogonal to an XY plane. In order to restrict the movement of the wire 1 in the direction of the arrow X and in the opposite direction, the restricting tools 6 and 7 (FIG. 6) may be used as necessary. The inner surfaces 6S and 7S of the restrictors 6 and 7 are orthogonal to the pressure surfaces 4S and 5S. The inner surfaces 6S and 7S can also function as pressure surfaces.

  In the present embodiment, a heater or the like is incorporated in the pressurizing tools 4 and 5 and pressurizes a plurality of wire rods 1 while heating. The plurality of wires 1 are heated so as to be equal to or higher than the temperature at which the core layer 2 (core material) softens or melts. The plurality of wires 1 are heated so that the temperature of each of the wires 1 is, for example, 160 ° C. Although it depends on the material and purity of the wire 1, it is preferable to heat the plurality of wires 1 so that the temperature is within a range of 110 ° C. or higher and 270 ° C. or lower. Each of the plurality of wire rods 1 (core layer 2 and clad layer 3) is softened and deformed by pressurization in a state where movement to the periphery (movement in the direction of arrow X and the opposite direction) is restricted. Each of the plurality of wire rods 1 is deformed so as to follow the shape of the pressurizing surfaces 4S and 5S (and the inner surfaces 6S and 7S), and adjacent surfaces of the wire rod 1 are formed to be orthogonal to the pressurizing surfaces 4S and 5S. (See FIG. 7).

  7 and 8, in the present embodiment, when the clad layer 3 is softened or melted by heating, the clad layers 3 (coating portions) of the adjacent wire 1A are integrated by thermal welding, and a plurality of Wires 1A are joined together. Thereby, the fiber array 10 shown in FIG. 8 is obtained. The fiber array 10 has a thin plate shape (sheet shape) in a state where heating and pressurization are released. The fiber array 10 maintains the state in which the clad layers 3 are bonded to each other. After releasing the heating and pressurization, a cooling step may be performed as necessary.

  Referring to FIG. 9, the fiber array 10 formed by bonding the clad layers 3 to each other is subjected to a grinding process and / or a polishing process. Of the clad layer 3 (covering portion), a portion 3A located on one side in the arrow Z direction and a portion 3B located on the other side in the arrow Z direction are removed. Thereby, a part of core layer 2 can be exposed in the one side and the other side in the arrow Z direction. The arrow Z direction here is a direction (in this embodiment, a direction orthogonal to the XY plane direction) that intersects the plane direction in which the plurality of wire rods 1A are arranged in a plane.

  In the present embodiment, a part of the core layer 2 (core material) is also removed. Specifically, a portion 2A located on one side in the arrow Z direction and a portion 2B located on the other side in the arrow Z direction are removed from the core layer 2. Thereby, a part of core layer 2 can be further exposed on one side and the other side in the arrow Z direction. The exposed surface 2M and the other surface 2N of the core layer 2 are preferably subjected to a mirror surface treatment. The surfaces 2M and 2N are preferably parallel to each other.

  With reference to FIG. 10, the fiber array sheet 10 </ b> A (optical element) is obtained through the above steps. The clad layer 3 of the fiber array sheet 10A is removed from the portions 3A and 3B (FIG. 9) in the arrow Z direction, and thus has no reflection function, but remains between the adjacent wire 1A. The strip-shaped portion that is present can exert a reflection function. The fiber array sheet 10A has a configuration in which the remaining portions of the core layer 2 and the cladding layer 3 are arranged at an equal pitch, and reflects the light incident from the surface 2M on one side, The light can be emitted from the side surface 2N (see the black arrow in FIG. 10).

  Referring to FIG. 11, micromirror array 100 as shown in FIG. 11 can be manufactured by using two fiber array sheets 10 </ b> A. In the micromirror array 100, a plurality of core layers 2 provided in each of the fiber array sheets 10A intersect with each other at an angle of 90 ° (right angle). Light incident from one surface 2M of the fiber array sheet 10A (10A1) is guided through the core layer 2 of the fiber array sheets 10A (10A1) and 10A (10A2), and the core layer 2 and the cladding layer 3 And is emitted from the other surface 2N of the fiber array sheet 10A (10A2).

  In such a micromirror array 100, a mirror image of a projection object arranged on one surface of the micromirror array 100 is connected to a spatial position on the other surface that is plane-symmetric with respect to the micromirror array 100. Can be imaged. The micromirror array 100 can function as an imaging optical element for imaging a three-dimensional or two-dimensional object and image in space. In the present embodiment, the wire 1 (plastic optical fiber) having a wire diameter of φ1 mm is used, but the wire diameter may be optimized according to the desired image quality.

(Function and effect)
In the method of manufacturing an optical element in the present embodiment, a fiber array 10 (FIG. 8) is formed by deforming and joining a plurality of wires 1 by pressurization, and a part of the core layer 2 is exposed to expose the fiber array. A sheet 10A (FIGS. 9 and 10) can be obtained. As explained at the beginning, the method of manufacturing an optical element disclosed in International Publication No. 2009/131128 (Patent Document 1) includes a step of laminating transparent plates and laminating in a direction perpendicular to each metal reflecting surface. It includes the process of cutting out the body.

  The manufacturing method of the present embodiment does not include a step of laminating a transparent plate or cutting out a laminated body. Equipment for preparing the transparent plate is also unnecessary, and equipment for cutting is also unnecessary. The manufacturing method according to the present embodiment can not only suppress an increase in material costs and costs for production equipment compared to Patent Document 1, but also can manufacture optical elements in a simple process, thereby improving productivity. It can be said that it is easy to plan. If a plastic optical fiber is used as the wire 1, it is possible to further reduce the material cost.

  In the above-described embodiment, the clad layers 3 (coating portions) of the adjacent wire rods 1A are integrated by thermal welding to join the plurality of wire rods 1A. Not limited to heat welding, adjacent wires 1A (cladding layer 3) may be joined together by an adhesive (for example, an epoxy adhesive). A combination of heat welding and an adhesive may be performed. Alternatively, the plurality of wires 1 </ b> A use the minute cracks generated in the cladding layer 3 at the time of thermal deformation to bond the cladding layers 3 of the adjacent wires 1 </ b> A with a solvent that partially dissolves the cladding layer 3. You may join.

[Embodiment 2]
With reference to FIGS. 12-14, the manufacturing method of the optical element in Embodiment 2 is demonstrated. The second embodiment is mainly different from the first embodiment in that a plastic optical fiber is not used and an adhesive 9 is used.

  As shown in FIG. 12, in the present embodiment, first, a core material 2C having optical transparency is prepared. The core material 2C is made of plastic fiber. The core material 2C does not have a member corresponding to the cladding layer 3 (Embodiment 1), and is made of, for example, an acrylic resin. As the core material 2C, polymethacrylstyrene (MS) resin, methacrylbutadiene styrene (MBS) resin, transparent acrylonitrile / butadiene / styrene copolymer (transparent ABS) resin, styrene / butadiene copolymer (SBC) resin, etc. It may be formed.

  Referring to FIG. 13, next, a reflective film 3C as a covering portion is formed so as to cover the periphery of the core material 2C. The reflective film 3C is formed on the surface of the core material 2C (plastic fiber) and can reflect light inside (contain light inside) (see the black arrow in FIG. 13). As shown in FIG. 13, a wire 1C including a core material 2C and a reflective film 3C is obtained.

  The material of the reflective film 3C preferably contains a dielectric or metal. As a specific example, an aluminum film having a film thickness of 0.5 μm can be provided as the reflective film 3C on the surface of the core material 2C made of acrylic resin and having a diameter of φ1 mm by vacuum deposition.

  Referring to FIG. 14, similarly to the case of the first embodiment, the plurality of wires 1 </ b> C are arranged on the pressing surface 4 </ b> S of the pressing tool 4 and are arranged in a planar shape so that the reflective films 3 </ b> C are adjacent to each other. It is done. In the present embodiment, a small amount of the adhesive 9 is supplied or applied between the adjacent wires 1C (reflective film 3C) by a spray or a dispenser. For example, an epoxy adhesive is used as the adhesive 9. The plurality of wires 1C are pressurized from the direction of the arrow Z that intersects the surface direction in which the plurality of wires 1C are arranged in a plane (in this embodiment, the XY plane direction).

  At this time, the plurality of wires 1C are heated so as to be equal to or higher than the temperature at which the core 2C is softened or melted. The plurality of wire rods 1C are deformed in the same manner as in the first embodiment to form a thin plate (sheet shape) fiber array (see FIG. 8). The fiber array formed by bonding the reflective films 3C to each other is subjected to a grinding process and / or a polishing process. Of the reflective film 3C (covering portion), a portion located on one side in the arrow Z direction and a portion located on the other side in the arrow Z direction are removed.

  If necessary, a portion located on one side in the arrow Z direction and a portion located on the other side in the arrow Z direction are removed from the core material 2C. The exposed surface of the core material 2C is preferably subjected to a mirror surface treatment on the one side surface and the other side surface. These planes are preferably parallel to each other.

(Function and effect)
In the present embodiment, the reflective films 3 </ b> C of the adjacent wire 1 </ b> C are firmly bonded by the adhesive 9. When the adhesive 9 is used, it is easy to obtain a stronger bonding strength than the heat welding in the first embodiment. When a dielectric or metal (aluminum film) is used as the material of the reflective film 3C, various adhesives can be used, and when an aluminum film is used, the choice of adhesive is wide.

  In the case of the thermal welding according to the first embodiment, it is necessary to heat the clad layer 3 so that the clad layer 3 can be welded. In the present embodiment, when pressurizing the wire 1C, the wire 1C may be heated so that the temperature becomes higher than a temperature at which the core 2C can be softened or melted and deformed. The temperature at which the core material 2C can be deformed by being softened or melted is lower than the temperature required for heat welding. Therefore, the thermal influence on the core material 2C can be reduced as compared with the case of the first embodiment.

  Although the embodiment has been described above, the above disclosure is illustrative in all respects and is not restrictive. The technical scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  1, 1A, 1C wire, 2 core layer (core material), 2A, 2B, 3A, 3B part, 2C core material, 2M, 2N surface, 3 cladding layer (coating layer), 3C reflective film (coating layer), 4 , 4A, 5, 5A Pressure tool, 4S, 4T, 4U, 5S Pressure surface, 6, 7 Regulator, 6S, 7S Inner surface, 9 Adhesive, 10 Fiber array, 10A Fiber array sheet, 100 Micromirror array.

Claims (8)

A step of preparing a plurality of wires having a core material having optical transparency and a covering portion provided so as to cover the periphery of the core material;
A plurality of the wire rods are arranged in a plane shape so that the covering portions are adjacent to each other, and a plurality of the wire rods are pressed in a direction intersecting a plane direction in which the plurality of wire rods are arranged in a plane shape A step of deforming the wire of
In a state where the covering portions of the plurality of wires are joined to each other, by removing the portions located on one side and the other side of the crossing direction of the covering portions, the core material is Exposing on one side and the other side,
A method for manufacturing an optical element. The wire is composed of a plastic optical fiber,
The manufacturing method of the optical element of Claim 1. The plurality of wires are joined together by thermally welding the covering portions of the plastic optical fiber,
The manufacturing method of the optical element of Claim 2. The core material is composed of plastic fiber,
The manufacturing method of the optical element of Claim 1. The covering portion is a reflective film that is formed on the surface of the plastic fiber and reflects light inside.
The manufacturing method of the optical element of Claim 4. The material of the reflective film includes a dielectric or a metal,
The method for manufacturing an optical element according to claim 5. The plurality of wires are joined together by an adhesive,
The manufacturing method of the optical element in any one of Claim 1 to 6. When pressurizing the wire, the wire is heated so that the core material is at or above the temperature at which it softens or melts.
The manufacturing method of the optical element in any one of Claim 1 to 7.