JP2016085356A - Optical element and method for manufacturing optical element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical element which improves the picture quality of the image of an object to be projected that is formed in a space, and a method for manufacturing the optical element.SOLUTION: Provided is an optical element 1, comprising: a member 3 in which mirror surfaces 2B, 2U each perpendicular to a plate surface and the formed angles of which are orthogonal are arranged lengthwise and breadthwise along the plate surface; and a reflectance suppression member 4 covering the edge of at least each of the mirror surfaces of the member. Also provided is a method for manufacturing the optical element, in which applied to a plate member obtained by shearing the laminate of light-transmissive plate members having a thin-film for forming a mirror surface to reflect light formed on one or both sides thereof along a direction perpendicular to the mirror surface is a process for blackening the edge of the thin-film exposed to the surface of the plate member, and two of the plate member with the edge of the thin-film blackened are stacked one on top of another and adhered together in such a way that the angles formed by the thin-films of the plate members are orthogonal.SELECTED DRAWING: Figure 1

Description

  The present application relates to an optical element and a method for manufacturing the optical element.

  In recent years, an optical element that can form an image of a projection object in space has been proposed (see, for example, Patent Document 1-2).

International Publication No. 2011/136200 JP 2011-81300 A JP 2004-287238 A

  A plate-like optical element in which mirror surfaces perpendicular to each other and perpendicular to each other are arranged vertically and horizontally along the plate surface is released from the projection object placed in the space on one side of the optical element. When the incident light beam enters, the mirror surfaces arranged vertically and horizontally reflect the light beam twice, and forms an image of the projection object at a position symmetrical to the projection object with the optical element interposed therebetween. An optical element that forms an image of an object to be projected in a space is, for example, an angle formed by mirror surfaces formed in a stripe shape on each of adjacent plate members by vertically slicing a mirror stack and cutting out a plurality of plate members. Can be realized by stacking and adhering two plate members so that they are orthogonal to each other, or by forming a rectangular hole in a top view that has a mirror surface inside, vertically and horizontally along the plate surface. That is, the optical element that forms an image of the projection object in the space takes a form in which minute mirror surfaces that reflect the light emitted from the projection object a plurality of times are arranged vertically and horizontally on a plate-like member. Therefore, the surface reflectance of the optical element itself increases due to light reflecting off a mirror surface that reflects incident light. As a measure for reducing the possibility that an image of an object other than the projection object is reflected, for example, use of a filter can be mentioned.

  Therefore, the present application provides an optical element that improves the image quality of an image of a projection object that is imaged in space, and a method for manufacturing the optical element.

  The present application discloses the following optical element. That is, the present application relates to a member in which mirror surfaces perpendicular to each other and perpendicular to each other and perpendicular to each other are arranged vertically and horizontally along the plate surface, and reflected light that covers at least the edge of each mirror surface of the members. An optical element comprising a suppressor is disclosed.

  Moreover, this application discloses the manufacturing method of the following optical elements. That is, the present application provides a plate material obtained by shearing a laminated body of light transmissive plate materials formed on one side or both sides of a thin film that forms a mirror surface that reflects light, along a direction perpendicular to the mirror surface. Applying a treatment to blacken the edge of the thin film exposed on the surface of the plate material, the two plate materials blackened at the edge of the thin film are overlapped so that the angle formed by the thin films of each plate material becomes a right angle Disclosed is a method of manufacturing an optical element that is bonded together.

Moreover, this application discloses the manufacturing method of the following optical elements. That is, the present application performs a process of blackening the surface of the plating film in a state in which the plating film is formed on a conductive plate having a non-conductive protrusion group in which cubic protrusions are arranged vertically and horizontally. A method for manufacturing an optical element is disclosed in which the plate material is peeled off from the plated film whose surface is blackened.

  Moreover, this application discloses the manufacturing method of the following optical elements. That is, the present application forms a mirror surface on the wall surface of each hole arranged vertically and horizontally on the surface of a transparent plate material, and black ink is applied to the surface of the plate material on which the mirror surface is formed on the wall surface of each hole. A method for producing an optical element is disclosed in which a flat plate coated with is pressed.

  If the optical element is manufactured by the optical element and the optical element manufacturing method described above, the image quality of the projection object imaged in the space, particularly the contrast ratio of the image is improved.

FIG. 1 is a diagram illustrating an example of an optical element according to the embodiment. FIG. 2 is a diagram illustrating an example of a path of a light beam that passes through the optical element according to the embodiment. FIG. 3 is a diagram illustrating an example of an imaging state of the optical element according to the embodiment. FIG. 4A is a first diagram illustrating an example of a manufacturing process of the optical element according to the embodiment. FIG. 4B is a second diagram illustrating an example of the manufacturing process of the optical element according to the embodiment. FIG. 5 is a diagram showing a manufacturing process of the optical element according to the first modification. FIG. 6 is a diagram illustrating a manufacturing process of the optical element according to the second modification.

  Hereinafter, embodiments will be described. The embodiment described below is merely an example, and the technical scope of the present disclosure is not limited to the following aspect.

  FIG. 1 is a diagram illustrating an example of an optical element according to the embodiment. The optical element 1 is a transparent plate in which minute mirror surfaces (also referred to as “micromirrors”) 2B and 2U that are perpendicular to the plate surface and perpendicular to each other are arranged vertically and horizontally along the plate surface. A shaped member 3 is provided. The member 3 has an angle formed by the mirror surface 2B and the mirror surface 2U formed of a transparent plate material 7B in which the elongated mirror surfaces 2B are embedded in a mutually parallel state and a transparent plate material 7U in which the elongated mirror surfaces 2U are embedded in a mutually parallel state. It has a form that is superimposed so that is perpendicular. Therefore, when the member 3 is observed from the plate surface side, the mirror surface 2B and the mirror surface 2U are embedded in the transparent plate-like member 3 and appear to be orthogonal to each other.

  By the way, when suppressing the surface reflectance of the optical element 1 itself, it is desirable that the mirror surface 2B and the mirror surface 2U be formed as thin as possible. However, if the mirror surface is too thin, the light may pass through the mirror surface, so that the mirror surface 2B and the mirror surface 2U have a certain thickness. A mirror edge having a certain thickness can contribute to diffuse reflection. Therefore, the optical element 1 includes the reflected light suppressing material 4 that covers at least the edges of the mirror surfaces 2B and 2U of the plate-like member 3 as indicated by the thick lines in the overall view of FIG. 1 and the hatching in the enlarged view. . As the reflected light suppressing material 4, any material that absorbs light can be applied. For example, various black materials that absorb light can be applied. The reflected light suppressing material 4 covers at least the edges of the mirror surfaces 2B and 2U of the plate-like member 3, thereby suppressing irregular reflection of light hitting other than the mirror surfaces 2B and 2U.

In the optical element 1, when a light beam emitted from a projection object placed in a space on one side of the optical element 1 is incident, the minute mirror surfaces 2B and 2U arranged vertically and horizontally reflect the light beam twice. An image of the projection object is formed at a position symmetrical to the projection object 1. FIG. 2 is a diagram illustrating an example of a path of a light beam that passes through the optical element 1 according to the embodiment. 2A shows the optical element 1 in FIG.
The figure when seen from the left side is shown as a left side view. FIG. 2B shows a top view of the optical element 1 as viewed from above in FIG. FIG. 2C is a front view of the optical element 1 as viewed from the front side in FIG. For example, when a light beam emitted from a projection object placed in the space below the optical element 1 is incident on the optical element 1, the incident light beam hits the mirror surface 2B and is reflected by a circle surrounded by a broken line in FIG. To do. The light beam reflected by the mirror surface 2B strikes the mirror surface 2U, is reflected again, and is emitted toward the space above the optical element 1. The light beam emitted from the optical element 1 forms an image of the projection object at a position symmetrical to the projection object across the optical element 1.

  FIG. 3 is a diagram illustrating an example of an imaging state of the optical element 1 according to the embodiment. For example, when the optical element 1 is disposed obliquely on the display device 101 with the display surface facing up, an image of the display device 101 is formed at a position symmetrical to the display device 101 with the optical element 1 interposed therebetween. To do. When the inclination of the optical element 1 is 45 °, for example, the image formed by the optical element 1 is vertical. The optical element 1 according to the embodiment is formed such that mirror surfaces 2B and 2U arranged vertically and horizontally are embedded in a plate material forming a plate-like overall structure. In the optical element 1 according to the present embodiment, at least the edges of the mirror surfaces 2B and 2U are covered with the reflected light suppressing material 4, and the irregular reflection of light at the edges of the mirror surfaces 2B and 2U is suppressed. Therefore, in the optical element 1 according to the above embodiment, the surface reflectance of the optical element 1 itself is suppressed as compared with the optical element 1 in which the reflected light suppressing material 4 is omitted. Therefore, in the optical element 1 according to the above-described embodiment, there is a possibility that an image of an object other than the image of the display device 101 that is a kind of the projection object is reflected as compared with the case where the reflected light suppressing material 4 is omitted. Low. That is, with the optical element 1 according to the above-described embodiment, for example, even if light emitted from an object other than the display device 101 enters the optical element 1, the light is irregularly reflected by the optical element 1 and becomes an aerial image. The possibility of reflection is low. Therefore, the optical element 1 according to the above embodiment can obtain a high-quality aerial image with high contrast.

  In addition, the optical element 1 can be manufactured by the following methods, for example. FIG. 4A is a first diagram illustrating an example of a manufacturing process of the optical element 1 according to the embodiment. FIG. 4B is a second diagram showing an example of the manufacturing process of the optical element 1 according to the embodiment.

  When the optical element 1 is manufactured, for example, a plurality of plate materials that are light-transmitting plate materials such as glass plates or acrylic plates and on which a thin film that forms a mirror surface that reflects light is formed on one side or both sides are prepared. For the thin film, for example, aluminum, chromium, or any other material capable of forming a mirror surface can be applied. Then, the prepared plate materials are overlapped while being bonded (FIG. 4A (A)). When the prepared plate materials are stacked while adhering a desired number of sheets, a block of the laminated body is formed (FIG. 4A (B)). Next, the block of the laminate is sheared along a direction perpendicular to the mirror surface, and the block of the laminate is sliced (FIG. 4A (C)).

  After slicing the block of the laminated body, a process of forming a reflected light suppressing material on the edge of the thin film is performed (FIG. 4B (D)). When the thin film is made of aluminum or chrome, the reflected light suppressing material can be formed, for example, by subjecting a plate material obtained by slicing the block of the laminate to an alumite treatment or a chromate treatment for blackening the edges of the thin film. The plate material obtained by slicing the block of the laminate is in a state where the edge of the thin film forming the mirror surface is exposed on the surface, so if blackened alumite treatment or blackened chromate treatment is applied, only the edge of the thin film will be blackened and light will A reflected light suppressing material that prevents reflection is formed. If the edge of the thin film does not blacken or is difficult to blacken even if the blackened alumite treatment or blackened chromate treatment is applied to the plate material, for example, a film that can be blackened on the edge of the thin film is formed by electroless plating, etc. Then, if the plate material is subjected to blackening alumite treatment or blackening chromate treatment, the reflected light suppressing material can be easily formed.

After the reflection light suppressing material is formed on the edge of the thin film, the two plate materials are superposed and bonded so that the angle formed by the thin films becomes a right angle (FIG. 4B (E)). The optical element 1 which is a two-orthogonal reflector (sometimes referred to as a “two-surface corner reflector”) is completed (FIG. 4B (F)).

  Note that the optical element 1 and the method for manufacturing the optical element 1 according to the above embodiment can be modified as follows, for example. Hereinafter, the optical element 1 which concerns on the said embodiment, and the 1st modification of the manufacturing method of the optical element 1 are demonstrated. FIG. 5 is a diagram showing a manufacturing process of the optical element according to the first modification.

  In the first modification, a member in which rectangular holes whose inner walls form a mirror surface is arranged vertically and horizontally along the plate surface is used as an optical element. That is, in the first modification, a non-conductive protrusion group in which cubic protrusions are arranged vertically and horizontally is formed on the surface of the conductive plate (FIG. 5A). The projection group can be produced using, for example, a photosensitive material (resist, dry film, etc.). Next, an electric potential is applied to the plate material and electroplating is performed with a material such as Ni to form a plating film having a desired thickness (FIG. 5B). After the plating film is formed on the plate material, the surface of the plating film is blackened to form the reflected light suppressing material (FIG. 5C). The reflected light suppressing material can be formed, for example, by immersing the plating film formed on the plate material in the black chrome solution without peeling off the plate material, or by forming a chromium oxide thin film on the surface. After the reflection light suppressing material is formed, the plate material is peeled off from the plating film, and the optical element 11 according to the first modification is completed (FIG. 5D).

  Similar to the optical element 1 according to the embodiment, the optical element 11 includes a member 13 having a mirror surface 12 perpendicular to the plate surface and having a right angle with each other in each rectangular hole 15. Since the member 13 has the holes 15 arranged vertically and horizontally along the plate surface, the mirror surface 12 formed on the wall surface in the hole 15 is arranged vertically and horizontally along the plate surface.

  In the optical element 11 according to the first modification, when light rays emitted from the projection object placed in the space on one side of the optical element 11 are incident, the light rays enter the holes 15 arranged in the vertical and horizontal directions. . The light beam that has entered the rectangular hole 15 is reflected twice by adjacent mirror surfaces 12 and 12 that are orthogonal to each other, and forms an image of the projection object at a position symmetrical to the projection object with the optical element 11 interposed therebetween. .

  In the optical element 11 according to the first modified example, the edge of the mirror surface 12 and the portion other than the mirror surface 12 are covered with the reflected light suppressing material 14 to suppress the irregular reflection of light. Therefore, the optical element 11 according to the first modification is, for example, omitted from the process shown in FIG. 5C and the reflected light suppression material 14 is omitted. Surface reflectance is suppressed. Therefore, the optical element 11 according to the first modified example can reduce the possibility that an image of an object other than the projection object is reflected, as compared with the case where the reflected light suppressing material 14 is omitted.

  In addition, the optical element 1 and the method for manufacturing the optical element 1 according to the above-described embodiment can be modified as follows, for example. Hereinafter, a second modification of the optical element 1 and the method for manufacturing the optical element 1 according to the embodiment will be described. FIG. 6 is a diagram illustrating a manufacturing process of the optical element according to the second modification.

In the second modification, a member in which rectangular holes whose inner walls form a mirror surface is arranged vertically and horizontally along the plate surface is used as an optical element. That is, in the second modification, holes are arranged in the surface of the plate material in the vertical and horizontal directions by the nano-imprinting technique in which the original mold in which the cubic protrusions are arranged vertically and horizontally is pressed against the resin plate material (FIG. 6 ( A)). The plate material against which the original mold is pressed is preferably a transparent light transmissive material. After the holes are arranged vertically and horizontally in the plate material, a mirror surface is formed on the wall surface in each hole (FIG. 6B). The mirror surface can be formed, for example, by forming a thin film of a metal material such as aluminum on a plate material in which holes are arranged vertically and horizontally. As a method for forming a metal material thin film on a resin plate, for example, an additive method in which a metal material is deposited to form a thin film can be used. A flat plate coated with black ink is pressed against the surface of the plate material on which the mirror surface is formed, and lithographic pad printing is performed to blacken the periphery of the hole (FIG. 6C). By blackening the periphery of the hole, the optical element 21 according to the second modification is completed (FIG. 6D).

  Like the optical element 1 according to the embodiment and the optical element 11 according to the first modification, the optical element 21 includes mirror surfaces 22 that are perpendicular to the plate surface and perpendicular to each other in the rectangular holes 26. A member 23 is provided. In the member 23, since the holes 26 are arranged vertically and horizontally along the plate surface, the mirror surface 22 formed on the wall surface in the hole 26 is arranged vertically and horizontally along the plate surface.

  In the optical element 21 according to the second modification, when a light beam emitted from a projection object placed in a space on one side of the optical element 21 enters, the light beam enters each hole 26. The light beam that has entered the rectangular hole 26 is reflected twice by the adjacent mirror surfaces 22 and 22 orthogonal to each other, and forms an image of the projection object at a position symmetrical to the projection object with the optical element 21 in between. .

  In the optical element 21 according to the second modified example, the edge of the mirror surface 22 and the periphery of the hole 26 are covered with the reflected light suppressing material 24 to suppress light from being irregularly reflected. Therefore, the optical element 11 according to the second modification example is different from the optical element 21 itself as compared with the optical element 11 that omits the processing shown in FIG. 6C and omits the reflected light suppressing material 24, for example. Surface reflectance is suppressed. Therefore, the optical element 21 according to the second modified example can reduce the possibility that an image of an object other than the projection object is reflected, as compared with the case where the reflected light suppressing material 24 is omitted.

  Note that the optical elements 1, 11, and 21 according to the above-described embodiments and modifications are not limited to those manufactured by the above-described manufacturing method. The optical elements 1, 11, 21 may be manufactured by a method other than the manufacturing method described above. In addition, the optical elements 1, 11 and 21 according to the above-described embodiments and the respective modifications used the reflected incident light twice as the outgoing light. However, as long as the incident light is reflected an even number of times to obtain the outgoing light. The number of reflections may be any value.

1,11,21..Optical element: 2B, 2U, 12, 22, ..Mirror surface: 3, 13, 23..Member: 4, 14, 24..Reflected light suppression material: 15, 26..Hole: 7B , 7U ... Plate material: 101 ... Display device

Claims (7)

A member in which mirror surfaces perpendicular to each other and perpendicular to each other and perpendicular to each other are arranged vertically and horizontally along the plate surface;
A reflected light suppressing material covering at least the edge of each mirror surface among the members,
Optical element. The member is formed by superimposing two transparent plate materials in which elongated mirror surfaces are embedded in a state parallel to each other so that the angles formed by the mirror surfaces of the two plate materials are perpendicular to each other,
The reflected light suppression material covers an edge of the mirror surface exposed on the surface of each of the two plate materials,
The optical element according to claim 1. The member is a rectangular hole whose inner wall forms the mirror surface, arranged vertically and horizontally along the plate surface,
The reflected light suppressing material covers a portion other than the edge of the mirror surface and the mirror surface,
The optical element according to claim 1. The member is a rectangular hole whose inner wall forms the mirror surface, arranged vertically and horizontally along the plate surface,
The reflected light suppression material covers the edge of the mirror surface and the periphery of the hole,
The optical element according to claim 1. On a surface of the plate material obtained by shearing a laminated body of light transmissive plate materials formed on one or both sides with a thin film that forms a mirror surface that reflects light, along a direction perpendicular to the mirror surface. Applying a treatment to blacken the edges of the exposed thin film,
The two plate members blackened at the edges of the thin film are superposed and bonded so that the angle formed by the thin films of each plate member becomes a right angle,
A method for manufacturing an optical element. In a state where the plating film is formed on the conductive plate material provided with the non-conductive protrusion group in which the cubic protrusions are arranged in the vertical and horizontal directions, the surface of the plating film is blackened,
Peeling the plate material from the plated film whose surface is blackened;
A method for manufacturing an optical element. A mirror surface is formed on the wall surface in each hole arranged vertically and horizontally on the surface of a transparent plate,
A flat plate coated with black ink is pressed against the surface of the plate material in which a mirror surface is formed on the wall surface in each hole.
A method for manufacturing an optical element.