WO2019167139A1 - Lightguide and method of manufacture therefor - Google Patents

Lightguide and method of manufacture therefor Download PDF

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Publication number
WO2019167139A1
WO2019167139A1 PCT/JP2018/007330 JP2018007330W WO2019167139A1 WO 2019167139 A1 WO2019167139 A1 WO 2019167139A1 JP 2018007330 W JP2018007330 W JP 2018007330W WO 2019167139 A1 WO2019167139 A1 WO 2019167139A1
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WIPO (PCT)
Prior art keywords
light guide
film layer
manufacturing
substrate
base materials
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PCT/JP2018/007330
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French (fr)
Japanese (ja)
Inventor
田中　真人
琢也 木本
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株式会社島津製作所
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Priority to JP2020503135A priority Critical patent/JP6844742B2/en
Priority to PCT/JP2018/007330 priority patent/WO2019167139A1/en
Publication of WO2019167139A1 publication Critical patent/WO2019167139A1/en

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    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C27/00—Joining pieces of glass to pieces of other inorganic material; Joining glass to glass other than by fusing
    • C03C27/06—Joining glass to glass by processes other than fusing
    • C03C27/10—Joining glass to glass by processes other than fusing with the aid of adhesive specially adapted for that purpose
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/02—Viewing or reading apparatus
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/08—Mirrors

Definitions

  • the present invention relates to a light guide for enlarging a light beam (exit pupil) in an image display device that displays image information as a virtual image in front of a user's eyes, and a manufacturing method thereof.
  • the image display device using the light guide according to the present invention is suitable for an image display device such as a helmet mount display, a head-up display, or a glasses-type display (so-called smart glasses).
  • a head that forms a display image with a virtual image in front of the driver's eyes by projecting an image displayed on a display element such as a liquid crystal display (LCD) onto a windshield or combiner and reflecting the image on the driver's side Up display is used.
  • a helmet-mounted display that projects images onto a combiner provided in a helmet worn by the pilot on the head and forms a display image as a virtual image in front of the pilot is used by a similar mechanism.
  • eyeglass-type or head-mounted head-mounted displays called smart glasses have begun to spread.
  • FIG. 8 is a schematic diagram showing an optical path configuration in an example of a conventional image display device using a light guide, which is disclosed in Patent Document 1 and the like.
  • x, y, and z axes orthogonal to each other are defined as shown in the figure.
  • the image display device 2 includes a light source unit 21, a display element 22, a collimating optical system 23, and a light guide 20.
  • the display element 22 is a transmissive liquid crystal display element
  • the light source unit 21 is a backlight light source for a so-called transmissive liquid crystal display element.
  • the light emitted from the light source unit 21 illuminates the display element 22 from the back side, and light including information formed on the display surface of the display element 22 as information (hereinafter referred to as “image light”) is emitted from the display element 22. Is done.
  • the collimating optical system 23 introduces the image light emitted from each point (pixel) on the display surface of the display element 22 into the light guide 20 as a substantially parallel light beam. Accordingly, the light introduced from the collimating optical system 23 into the light guide 20 includes information on different parts of the image formed on the display surface of the display element 22 and enters the light guide 20 at different angles. Is a set of
  • the light guide 20 has a first surface 200a and a second surface 200b that are both parallel and opposite to the yz plane, and a third surface and a fourth surface (not shown) that are both parallel to the xy plane.
  • a transparent substrate 200 having a flat cubic shape is provided inside the substrate 200. Inside the substrate 200, one incident-side reflecting surface 201 and a plurality (three in this example) of exit-side reflecting surfaces 202a to 202c are formed.
  • the incident-side reflection surface 201 is perpendicular to the third surface and the fourth surface, and is inclined with respect to the first surface 200a and the second surface 200b.
  • the plurality of exit-side reflecting surfaces 202a to 202c are perpendicular to the third surface and the fourth surface, are inclined with respect to the first surface 200a and the second surface 200b, and are parallel to each other.
  • the incident side reflection surface 201 is a reflection surface by a mirror or the like
  • the emission side reflection surfaces 202a to 202c are partial reflection surfaces having a predetermined reflectance (that is, transmittance), that is, a beam splitter or a half mirror.
  • the image light including information on different parts of the image formed on the display surface of the display element 22 is incident on the light guide 20 at different angles as a parallel light flux and is reflected by the incident-side reflection surface 201.
  • This light flux is transmitted through the substrate 200 while being repeatedly reflected by the first surface 200a and the second surface 200b, and reaches the exit-side reflection surface 202a.
  • the exit-side reflecting surface 202a reflects part of the arrived image light and transmits the rest.
  • the transmitted image light reaches the next exit-side reflecting surface 202b, a part of the light is reflected, and the rest is transmitted.
  • the image light that has passed through the inside of the substrate 200 of the light guide 20 is reflected by the plurality of exit-side reflecting surfaces 202a to 202c, and is transmitted through the first surface 200a of the substrate 200 to be emitted to the outside. Then, the image light reflected by each of the exit-side reflecting surfaces 202a to 202c enters the observer's eye E at a predetermined angle.
  • the image formed on the display surface of the display element 22 is displayed as a virtual image in front of the eyes of the observer.
  • the substrate 200 of the light guide 20 is transparent and the exit-side reflecting surfaces 202a to 202c are partially reflecting surfaces, the observer can also visually recognize the scenery in front through the light guide 20.
  • the light guide 20 that is one of the components constituting the image display apparatus has a plurality of partial reflection surfaces inside the substrate 200.
  • Patent Documents 2 and 3 disclose a method for manufacturing such a light guide. 9 is an explanatory diagram of the light guide manufacturing method described in FIG. 32 of Patent Document 2, and FIG. 10 is an explanatory diagram of the light guide manufacturing method described in FIG. In any of these manufacturing methods, a light guide is manufactured by bonding a plurality of transparent substrates such as glass.
  • the optical film layer 211 having the function of partial reflection is formed only on one of the bonding surfaces on both sides of each substrate 210 that is glass. Then, by laminating a plurality of base materials 210 so that the formation surface of the optical film layer 211 of one base material 210 and the glass surface of the other base material 210 are joined together, the plurality of partial reflection surfaces are inside the substrate.
  • the light guide formed in the above is manufactured.
  • a first base material 221 whose both surfaces are glass surfaces and a second base material 222 on which optical film layers having a partial reflection function are formed on both surfaces are prepared, and the first base material is prepared.
  • the light guide formed in the above is manufactured.
  • any manufacturing method it is necessary to join the glass surface of one substrate and the optical film layer forming surface of another substrate.
  • components for adjusting the refractive index are added to the optical glass, and the bonding properties are poor due to these components.
  • a light guide for an image display device requires a high refractive index in order to expand the field of view, but a component added to glass in order to increase the refractive index tends to lower the bondability. If the bonding property between the glass surface and the optical film layer forming surface is poor, the yield of the product (light guide) may be reduced, and the cost of the product itself may be increased. In addition, the reliability of the image display device itself incorporating such a light guide may be reduced.
  • the glass material used as the base material is changed, its bondability changes, so it is necessary to reexamine the appropriate bonding conditions (temperature, pressure, etc.) corresponding to the new glass material. Therefore, changing the glass material lowers the production efficiency, and there is a problem that it is difficult to improve performance, reduce weight, and reduce costs by changing the glass material.
  • the present invention has been made to solve the above-mentioned problems, and improves the light guide manufacturing efficiency and reliability by improving the bonding property when forming the partial reflection surface on the bonding surface of a plurality of base materials. Its main purpose is to make it happen.
  • the light guide manufacturing method which has been made to solve the above-described problems, includes a transparent substrate having a first surface and a second surface facing each other in parallel, and the first surface and the second surface.
  • each film layer is such that the one or two optical film layers and the network-forming oxide film layer are laminated to form predetermined optical characteristics as the partial reflection surface. It is characterized by being defined.
  • a network-forming oxide film is formed on the surface of one of the substrates to be bonded, and an optical film layer is formed on the surface of the other substrate to be bonded. It can be formed.
  • a network-forming oxide film is formed on the surface of one of the substrates to be bonded, and the outermost surface is formed on the surface of the other substrate to be bonded.
  • An optical film layer that is a network-forming oxide film layer may be formed in advance.
  • an optical film layer whose outermost surface is a network-forming oxide film layer is formed on the surface of one base material to be bonded, and the other side to be bonded
  • An optical film layer can be formed on the surface of the substrate.
  • the optical film layer whose outermost surface is a network formation oxide film layer in the surface of one base material joined while forming the optical film layer whose outermost surface is a network formation oxide film layer in the surface of one base material joined, the other joined An optical film layer whose outermost surface is a network-forming oxide film layer can also be formed on the surface of the substrate.
  • a network former is a substance that can form a three-dimensional network structure by itself, and examples thereof include SiO 2 , B 2 O 3 , and Al 2 O 3 .
  • the glass used for the light guide substrate often contains a component that lowers the bondability.
  • the base material itself is exposed.
  • the surface to be bonded is not used for bonding, and at least one surface is a network-forming oxide film layer having relatively good bonding properties. Therefore, two base materials can be joined well and a partial reflection surface can be formed on the joining surface. Further, even when the glass material of the base material is changed, the joining condition is not affected by the change of the glass material. Therefore, once an appropriate joining condition is found, the base materials can be joined under the same joining condition even if the glass material is changed.
  • a plurality of base materials are joined in a single row to form a substrate and a plurality of adjacent partial reflection surfaces are formed.
  • the base material on which the partial reflection surfaces are respectively formed at least on both sides thereof may have different film layers on both sides corresponding to the partial reflection surfaces.
  • each base material there are a plurality of base materials each having a partially reflecting surface formed on both sides thereof, and the film layers formed on both sides of each base material are the same film structure. It is good to be.
  • a substrate having the same film structure can be used as the plurality of substrates on which the partial reflection surfaces are respectively formed on both sides. Therefore, it is not necessary to prepare a plurality of types of base materials having different film structures, and the manufacturing process can be simplified and the manufacturing efficiency can be improved. Moreover, since the order is not ask
  • a plurality of base materials are joined in a single row to form a substrate and to form a plurality of adjacent partial reflection surfaces.
  • a substrate is formed by joining a plurality of base materials in a single row and a plurality of adjacent partial reflection surfaces are formed.
  • the process of forming the optical film layer can be simplified, and the light guide manufacturing efficiency can be improved.
  • the order of the base materials does not matter, and the front and back of the joint surfaces of the base materials are not questioned. Therefore, it is possible to prevent generation of defective products due to erroneous joining.
  • the partial reflection surface which becomes the same film structure after joining becomes the same reflectance.
  • the light guide according to the present invention is a light guide manufactured by the above-described light guide manufacturing method according to the present invention, wherein the first light guide and the second surface facing each other in parallel are disposed inside the transparent substrate.
  • the substrate is composed of a plurality of transparent base materials, and the partial reflection surface is formed on a joint surface between two base materials of the plurality of base materials, and the partial reflection surface is either one sandwiching the joint surface or
  • An optical film layer formed on the surfaces of both base materials and at least one network-forming oxide film layer are formed so as to have predetermined optical characteristics.
  • the light guide according to the present invention has good bondability because two substrates are bonded with a network-forming oxide film layer interposed therebetween, and can ensure high reliability.
  • the light guide manufacturing method it is possible to improve the bonding property between the substrates when forming the partial reflection surfaces on the bonding surfaces of the plurality of substrates. Thereby, the manufacturing efficiency of a light guide can be improved and manufacturing cost can be reduced. Further, the reliability of the light guide itself can be improved.
  • FIG. 1 is a schematic configuration diagram of an optical system in an image display apparatus using a light guide that is an embodiment of the present invention.
  • FIG. 6 is a schematic configuration diagram of an optical system in a conventional image display apparatus.
  • FIG. 1 is a schematic configuration diagram of an optical system in the image display apparatus of this example
  • FIG. 2 is a plan view when the light guide in FIG. 1 is viewed in the y-axis direction.
  • This image display device 1 includes a light source unit 11, a display element 12, a collimating optical system 13, and a light guide 10 as in the conventional image display device 2 shown in FIG.
  • the light source unit 11, the display element 12, and the collimating optical system 13 can be the same as the light source unit 21, the display element 22, and the collimating optical system 23 in the conventional image display apparatus 2, but are not limited thereto.
  • the light guide 10 includes a first surface 100a and a second surface 100b that are both parallel to the yz plane and facing each other, and a third surface 100c and a fourth surface 100d that are both parallel to the xy plane and are facing each other. And a substrate 100 having a flat cubic shape.
  • the substrate 100 is a transparent body such as polycarbonate resin or quartz glass. Inside the substrate 100, one incident-side reflecting surface 101 and a plurality (three in this example) of exit-side reflecting surfaces 102a to 102c are formed.
  • the incident side reflection surface 101 is perpendicular to the third surface 100c and the fourth surface 100d, and is inclined with respect to the first surface 100a.
  • the plurality of exit-side reflecting surfaces 102a to 102c are perpendicular to the third surface 100c and the fourth surface 100d, respectively, and are inclined with respect to the first surface 100a.
  • the plurality of exit-side reflecting surfaces 102a to 102c are parallel to each other.
  • the image light emitted from the display screen of the display element 12 upon receiving the illumination light from the light source unit 11 is made approximately parallel by the collimating optical system 13 and passes through the first surface 100a. Then, the light guide 10 is introduced into the substrate 100.
  • the image light introduced from the collimating optical system 13 into the light guide 10 includes information on different parts of the two-dimensional image formed on the display surface of the display element 12 and is incident on the light guide 10 at different angles. Is a set of parallel luminous fluxes.
  • the image light is reflected by the incident-side reflecting surface 101, then passes through the substrate 100 while being reflected by the first surface 100 a and the second surface 100 b one or more times, and is positioned closest to the incident-side reflecting surface 101. It reaches a certain exit side reflecting surface 102a.
  • the exit-side reflecting surface 102a reflects a part of the reached light beam and transmits the rest.
  • the transmitted light reaches the next exit-side reflecting surface 102b, a part of the light beam is reflected, and the rest is transmitted. The same applies to the exit-side reflecting surface 102c.
  • the light beams that have passed through the inside of the substrate 100 of the light guide 10 are reflected by the plurality of exit-side reflecting surfaces 102a to 102c, respectively, and are transmitted through the second surface 100b of the substrate 100 to be emitted to the outside.
  • the light beam introduced into the substrate 100 of the light guide 10 is enlarged and emitted from the substrate 100, and an image formed on the display surface of the display element 12 is displayed as a virtual image in front of the eyes E of the observer. Is done.
  • the reflectances of the plurality of exit-side reflecting surfaces 102a to 102c are the same, but they are not necessarily the same.
  • FIG. 3 is an explanatory view of a light guide manufacturing method according to an embodiment of the present invention.
  • the substrate 100 is formed by joining a plurality of transparent base materials 110 (110A, 110B) in a single row. Then, the joint surface between the two adjacent base materials 110A and 110B becomes the incident-side reflection surface 101 and the emission-side reflection surfaces 102a to 102c.
  • the base material 110 on which the partial reflection surfaces are formed on both sides specifically, in FIG. 1, the base material constituting the substrate 100 between the emission side reflection surface 102b and the emission side reflection surface 102c, the emission side reflection surface
  • the base material constituting the substrate 100 between 102a and the exit-side reflecting surface 102b is a rod-shaped member having a rhombic cross section on the xy plane and extending in the z-axis direction. .
  • the two opposing surfaces 110a and 110b of one base 110A are surfaces that are part of the first surface 100a and the second surface 100b of the substrate 100.
  • an optical film layer 111 whose outermost layer is a network-forming oxide film layer is formed on the surface of the base material 110A that is bonded to another adjacent base material 110B.
  • a network-forming oxide film layer 112 is formed on the surface of the adjacent base material 110B that is bonded to the base material 110A.
  • the main part of the optical film layer 111 formed on the substrate 110A is a dielectric multilayer film, and its optical characteristics vary depending on the material, thickness (optical thickness) of each film layer, and the configuration (number of sheets, etc.) of the film layers. Determined.
  • the network-forming oxide film having a predetermined thickness is further added to the network-forming oxide film layer on the outermost layer of the optical film layer 111. Since the physical film layer 112 is laminated, the optical film layer 111 and the network formation oxidation are obtained so that predetermined optical characteristics, that is, desired reflection characteristics (or transmission characteristics) as a partial reflection surface can be obtained as a whole.
  • the material film layer 112 is designed.
  • the network-forming oxide is a substance that can form a three-dimensional network structure by itself, and is typically SiO 2 , but may be B 2 O 3 , Al 2 O 3 , or the like.
  • the base materials 110A and 110B are made of glass, various components are added to increase the refractive index in addition to the main component of the glass, and therefore, the bondability is low.
  • the manufacturing method of this example not all of the base materials 110A and 110B but the network-forming oxide film layer is exposed on the bonding surface.
  • the base materials 110A and 110B are bonded to each other satisfactorily, and a partially reflecting surface composed of the optical film layer 111 and the network-forming oxide film layer 112 whose outermost layer is a network-forming oxide film layer is formed on the bonding surface. can do. Further, even when the type of the glass material of the base materials 110A and 110B is changed in order to enlarge the virtual image or reduce the weight, it is not necessary to review the joining conditions. In addition, since the film structures of the optical film layers on both sides of the base material on which the partial reflection surfaces are formed on both sides are the same, when the base material is joined, regardless of the front and back of the joint surface of the base material, Generation of defective products can be prevented.
  • FIGS. 4 to 7 are explanatory views of a light guide manufacturing method according to another embodiment of the present invention.
  • FIG. 3 there is no optical film layer on the bonding surface of the base material 110B, and only the network-forming oxide film layer 112 is formed.
  • FIGS. Optical film layers 113 and 111 whose outermost layers are network-forming oxide film layers are also formed on the bonding surface.
  • the optical film layer 111 having the same film layer structure is formed on the bonding surface between the base material 110B and the base material 110A.
  • the optical film layers 111 and 113 whose outermost layers are network-forming oxide film layers are designed so that the desired reflection characteristics (or transmission characteristics) as a partial reflection surface can be obtained as a whole. Is done.
  • the two base materials 110 ⁇ / b> A and 110 ⁇ / b> B can be bonded satisfactorily as in the example shown in FIG. 3.
  • the bonding surface of the substrate when bonding the substrates Regardless of the front and back it is possible to prevent the occurrence of defective products due to a mistake in the front and back.
  • the optical film layer 111 having the same film structure is formed on all surfaces of each substrate that are bonded to the other substrate, partial reflection surfaces (that is, emission surfaces) are formed on both sides.
  • the same substrate can be used as the base material on which the side reflection surface is formed. Therefore, there is no problem even if the arrangement order of the base materials is changed when the substrate 100 is manufactured by joining a plurality of base materials in a single row, and the productivity is further improved.
  • the surface layers of the opposing surfaces to be bonded are all network-forming oxide film layers. However, if the glass surface of the substrate itself is not exposed, the network-forming oxide is used. The film layer only needs to be formed on one of the surfaces. 6 and 7 show an example in such a case.
  • the optical film layer 114 having no network-forming oxide film layer as the outermost layer is bonded to one side of the substrate 110A.
  • a network forming oxide film layer 112 is formed on the bonding surface on the other side of the substrate 110A.
  • the adjacent base material 110B The same applies to the adjacent base material 110B. Therefore, the film layer structure of the partially reflecting surface formed on the bonding surface in the bonded state as shown in FIG. 6B is almost the same as the example shown in FIG.
  • the same type of base material can be used as the base materials 110 ⁇ / b> A and 110 ⁇ / b> B on which partial reflection surfaces are formed on both sides. Therefore, although the front and back of each base material cannot be interchanged, as in the example shown in FIG. 5, when the substrate 100 is manufactured by joining a plurality of base materials in a single row, the order of the base materials is changed. There is no problem and productivity is improved.
  • the optical film layer 114 having no network forming oxide film layer as the outermost layer is formed on both surfaces of the substrate 110A, and the substrate 110B adjacent to the substrate 110A is formed.
  • a network-forming oxide film layer 112 is formed on the opposite surfaces. Therefore, the film layer structure of the partially reflecting surface formed on the bonding surface in the bonded state as shown in FIG. 7B is the same as the example shown in FIG.
  • the base materials 110A and 110B on which the partial reflection surfaces are formed on both sides have different film structures on the surfaces to be the bonding surfaces. Therefore, in this case, although the arrangement order of the base materials cannot be changed, the front and back of each base material can be changed, and the occurrence of a defective product due to an incorrect front and back can be prevented.
  • the structure when the exit-side reflecting surfaces 102a to 102c, which are partial reflecting surfaces, are formed inside the substrate 100 has been described.
  • the incident-side reflecting surface 101 which is a reflecting surface by a mirror or the like, is formed on the substrate 100. It is obvious that the same method can be adopted when forming the inside. Further, in the example shown in FIG. 1, only three exit-side reflection surfaces are provided, but it is natural that any number of exit-side reflection surfaces can be formed by the same method.
  • the third surface 100c and the fourth surface 100d of the substrate 100 are parallel to each other, but the third surface 100c and the fourth surface 100d are parallel to the xy plane. There is no need. That is, the first surface 100a, the second surface 100b, the incident-side reflecting surface 101, and the exit-side reflecting surfaces 102a to 102c, the third surface 100c, and the fourth surface 100d do not have to be perpendicular to each other.
  • the angles and the shapes of the third surface 100c and the fourth surface 100d can be arbitrarily determined.
  • the types of base materials 110A and 110B are used.
  • the types of base materials are not limited to two types, and all of the light guides that constitute one light guide are used. Different types of substrates may be used.
  • the reflectance of the plurality of partial reflection surfaces in the light guide is the same, but the reflectance may not be the same. Even if the reflectivities of a plurality of partial reflection surfaces are different from each other, if an optical film on the surfaces of two substrates to be bonded is designed so that desired reflection characteristics are obtained when the substrates are bonded, Good. However, in that case, for example, even when the optical film layer 111 whose outermost layer is a network-forming oxide film layer is formed on both surfaces of one base material, the film structure is not necessarily the same. In some cases, the front and back of the material cannot be replaced. Similarly, the arrangement order of the base materials may not be changed.
  • the base 110 is formed in a rhombus shape, and the first surface 110a and the second surface 110b are part of the first surface 100a and the second surface 100b of the light guide 100, respectively.
  • it is configured to form, for example, after joining a plurality of plate-like base materials, external processing such as grinding or polishing the base materials is performed, and the first surface 100a and the first surface of the light guide 100 The two surfaces 100b may be formed.
  • the cross-sectional shape of the base material is not limited to the rhombus shape, and a shape other than the joining surface such as a flat plate shape may be arbitrary.
  • the light guide according to the present invention manufactured by the above manufacturing method is not limited to use for the image display device as described above, but can be used for various applications where it is necessary to change the incident light beam width. .
  • the use mode of the ride guide is not particularly limited, light is incident on the inside of the substrate 100 from the exit side reflection surfaces 102a to 102c (that is, the partial reflection surface) side, and taken out from the incident side reflection surface 101 side to the outside. You may do it.

Abstract

A substrate for a lightguide is formed by bonding, in a single row, rod-like glass base materials (110A, 110B) each having a lozenge-shaped cross-section and extending in the Z axis direction. Before bonding, an optical film layer(111) the outermost layer of which is a network-formation oxide film layer is formed on the bonding surface of the base material (110A) and a network-formation oxide film layer (112) is formed on the bonding surface of the base material (110B) adjacent to the base material (110A). The optical film layer (111) and the network-formation oxide film layer (112) are designed to act as a partially reflective surface when bonded, that is, to extract a portion of light from inside the substrate and emit that light to the outside, to thereby give the substrate as a whole the desired optical characteristics. Since none of the glass containing various components for adjusting the refractive index is exposed on the bonding surface, the base materials can be suitably bonded. This improves production efficiency while increasing the reliability of the lightguide itself.

Description

ライトガイド及びその製造方法Light guide and manufacturing method thereof
　本発明は、画像情報を虚像として使用者の眼前に表示する画像表示装置において光束（射出瞳）を拡大するためのライトガイド、及びその製造方法に関する。本発明に係るライトガイドを用いた画像表示装置は、ヘルメットマウントディスプレイ、ヘッドアップディスプレイ、眼鏡型ディスプレイ（いわゆるスマートグラス）などの画像表示装置に好適である。 The present invention relates to a light guide for enlarging a light beam (exit pupil) in an image display device that displays image information as a virtual image in front of a user's eyes, and a manufacturing method thereof. The image display device using the light guide according to the present invention is suitable for an image display device such as a helmet mount display, a head-up display, or a glasses-type display (so-called smart glasses).
　自動車や電車では、液晶ディスプレイ（ＬＣＤ）などの表示素子に表示された画像をフロントガラスやコンバイナに投影して運転者側に反射させることにより、運転者の眼前に虚像による表示画像を形成するヘッドアップディスプレイが使用されている。また、航空機では、同様の仕組みにより、操縦者が頭部に着用するヘルメットに設けられたコンバイナに画像を投影し、操縦者の眼前に虚像による表示画像を形成するヘルメットマウントディスプレイが使用されている。また最近では、スマートグラス等と呼ばれる眼鏡型、或いは頭部装着型のヘッドマウントディスプレイも普及し始めている。 In automobiles and trains, a head that forms a display image with a virtual image in front of the driver's eyes by projecting an image displayed on a display element such as a liquid crystal display (LCD) onto a windshield or combiner and reflecting the image on the driver's side Up display is used. Also, in aircraft, a helmet-mounted display that projects images onto a combiner provided in a helmet worn by the pilot on the head and forms a display image as a virtual image in front of the pilot is used by a similar mechanism. . Recently, eyeglass-type or head-mounted head-mounted displays called smart glasses have begun to spread.
　こうした画像表示装置には観察者の眼前に虚像を表示する光学系として様々な方式のものが知られているが、その一つとして、ライトガイド（導光板）を用いた方式がある。
　図８は特許文献１等に開示されている、ライトガイドを用いた従来の画像表示装置の一例における光路構成を示す概略図である。説明の便宜上、図中に示すように互いに直交するｘ、ｙ、ｚ軸を定めている。 As such an image display device, various types of optical systems for displaying a virtual image in front of an observer's eyes are known. One of them is a method using a light guide (light guide plate).
FIG. 8 is a schematic diagram showing an optical path configuration in an example of a conventional image display device using a light guide, which is disclosed in Patent Document 1 and the like. For convenience of explanation, x, y, and z axes orthogonal to each other are defined as shown in the figure.
　画像表示装置２は、光源部２１、表示素子２２、コリメート光学系２３、及びライトガイド２０を備える。ここでは表示素子２２は透過型液晶表示素子であり、光源部２１はいわゆる透過型液晶表示素子に対するバックライト光源である。光源部２１から出射した光は表示素子２２を背面側から照明し、表示素子２２の表示面上に形成された画像を情報として含む光（以下「画像光」という）が該表示素子２２から射出される。コリメート光学系２３は、表示素子２２の表示面の各点（画素）から射出された画像光をそれぞれ略平行な光束としてライトガイド２０に導入する。したがって、コリメート光学系２３からライトガイド２０に導入される光は、それぞれが表示素子２２の表示面上に形成される画像の異なる部位の情報を含み、異なる角度でライトガイド２０に入射する平行光束の集合である。 The image display device 2 includes a light source unit 21, a display element 22, a collimating optical system 23, and a light guide 20. Here, the display element 22 is a transmissive liquid crystal display element, and the light source unit 21 is a backlight light source for a so-called transmissive liquid crystal display element. The light emitted from the light source unit 21 illuminates the display element 22 from the back side, and light including information formed on the display surface of the display element 22 as information (hereinafter referred to as “image light”) is emitted from the display element 22. Is done. The collimating optical system 23 introduces the image light emitted from each point (pixel) on the display surface of the display element 22 into the light guide 20 as a substantially parallel light beam. Accordingly, the light introduced from the collimating optical system 23 into the light guide 20 includes information on different parts of the image formed on the display surface of the display element 22 and enters the light guide 20 at different angles. Is a set of
　ライトガイド２０は、共にｙ－ｚ平面に平行で対向している第一面２００ａ及び第二面２００ｂと、共にｘ－ｙ平面に平行である図示しない第三面及び第四面と、を有する偏平立方体形状である透明な基板２００を備える。基板２００の内部に一つの入射側反射面２０１と複数（この例では３枚）の射出側反射面２０２ａ～２０２ｃとが形成されている。入射側反射面２０１は第三面及び第四面に垂直であり、第一面２００ａ及び第二面２００ｂに対して傾斜している。複数の射出側反射面２０２ａ～２０２ｃは同様に第三面及び第四面に垂直であり、第一面２００ａ及び第二面２００ｂに対して傾斜しており、且つそれらは互いに平行である。ここでは、入射側反射面２０１はミラー等による反射面であり、射出側反射面２０２ａ～２０２ｃは所定の反射率（つまりは透過率）を有する部分反射面つまりはビームスプリッタ又はハーフミラーである。 The light guide 20 has a first surface 200a and a second surface 200b that are both parallel and opposite to the yz plane, and a third surface and a fourth surface (not shown) that are both parallel to the xy plane. A transparent substrate 200 having a flat cubic shape is provided. Inside the substrate 200, one incident-side reflecting surface 201 and a plurality (three in this example) of exit-side reflecting surfaces 202a to 202c are formed. The incident-side reflection surface 201 is perpendicular to the third surface and the fourth surface, and is inclined with respect to the first surface 200a and the second surface 200b. Similarly, the plurality of exit-side reflecting surfaces 202a to 202c are perpendicular to the third surface and the fourth surface, are inclined with respect to the first surface 200a and the second surface 200b, and are parallel to each other. Here, the incident side reflection surface 201 is a reflection surface by a mirror or the like, and the emission side reflection surfaces 202a to 202c are partial reflection surfaces having a predetermined reflectance (that is, transmittance), that is, a beam splitter or a half mirror.
　上述したように表示素子２２の表示面上に形成される画像の異なる部位の情報を含む画像光は平行光束として異なる角度でライトガイド２０に入射し、入射側反射面２０１で反射される。この光束が第一面２００ａと第二面２００ｂとで繰り返し反射されつつ基板２００の内部を透過し射出側反射面２０２ａに達する。射出側反射面２０２ａは到達した画像光の一部を反射させ、残りを透過させる。透過した画像光は次の射出側反射面２０２ｂに到達し、その光の一部は反射され、残りは透過する。射出側反射面２０２ｃも同様である。したがって、ライトガイド２０の基板２００の内部を透過してきた画像光の一部は複数の射出側反射面２０２ａ～２０２ｃでそれぞれ反射され、基板２００の第一面２００ａを透過して外部に射出する。そして、各射出側反射面２０２ａ～２０２ｃで反射された画像光はそれぞれ所定の角度で観察者の眼Ｅに入射する。 As described above, the image light including information on different parts of the image formed on the display surface of the display element 22 is incident on the light guide 20 at different angles as a parallel light flux and is reflected by the incident-side reflection surface 201. This light flux is transmitted through the substrate 200 while being repeatedly reflected by the first surface 200a and the second surface 200b, and reaches the exit-side reflection surface 202a. The exit-side reflecting surface 202a reflects part of the arrived image light and transmits the rest. The transmitted image light reaches the next exit-side reflecting surface 202b, a part of the light is reflected, and the rest is transmitted. The same applies to the exit-side reflecting surface 202c. Accordingly, some of the image light that has passed through the inside of the substrate 200 of the light guide 20 is reflected by the plurality of exit-side reflecting surfaces 202a to 202c, and is transmitted through the first surface 200a of the substrate 200 to be emitted to the outside. Then, the image light reflected by each of the exit-side reflecting surfaces 202a to 202c enters the observer's eye E at a predetermined angle.
　このようにしてこの画像表示装置２では、表示素子２２の表示面に形成された画像が虚像として観察者の眼前に表示される。また、ライトガイド２０の基板２００は透明であり、射出側反射面２０２ａ～２０２ｃは部分反射面であるため、観察者はライトガイド２０を通して前方の風景を視認することもできる。 In this way, in this image display device 2, the image formed on the display surface of the display element 22 is displayed as a virtual image in front of the eyes of the observer. Further, since the substrate 200 of the light guide 20 is transparent and the exit-side reflecting surfaces 202a to 202c are partially reflecting surfaces, the observer can also visually recognize the scenery in front through the light guide 20.
　上記画像表示装置を構成する部品の一つであるライトガイド２０は、基板２００の内部に複数の部分反射面を有する。特許文献２、３には、こうしたライトガイドを製造する方法が開示されている。
　図９は特許文献２の図３２に記載されたライトガイドの製造方法の説明図、図１０は特許文献３の図１に記載されたライトガイドの製造方法の説明図である。これら製造方法ではいずれも、ガラス等の透明である複数の基材を接合することによりライトガイドを製造する。 The light guide 20 that is one of the components constituting the image display apparatus has a plurality of partial reflection surfaces inside the substrate 200. Patent Documents 2 and 3 disclose a method for manufacturing such a light guide.
9 is an explanatory diagram of the light guide manufacturing method described in FIG. 32 of Patent Document 2, and FIG. 10 is an explanatory diagram of the light guide manufacturing method described in FIG. In any of these manufacturing methods, a light guide is manufactured by bonding a plurality of transparent substrates such as glass.
　図９に示した製造方法では、ガラスである各基材２１０の両側の接合面の一方にのみ部分反射の作用を有する光学膜層２１１を形成する。そして、 一つの基材２１０の光学膜層２１１の形成面と他の基材２１０のガラス面とを接合するように複数の基材２１０を積層させることで、複数の部分反射面が基板の内部に形成されたライトガイドを製造する。
　図１０に示した製造方法では、両面がガラス面である第１基材２２１と、両面に部分反射の作用を有する光学膜層を形成した第２基材２２２とを用意し、第１基材２２１と第２基材２２２とを交互に配置して第１基材２２１のガラス面と第２基材２２２の光学膜層形成面とを接合することで、複数の部分反射面が基板の内部に形成されたライトガイドを製造する。 In the manufacturing method shown in FIG. 9, the optical film layer 211 having the function of partial reflection is formed only on one of the bonding surfaces on both sides of each substrate 210 that is glass. Then, by laminating a plurality of base materials 210 so that the formation surface of the optical film layer 211 of one base material 210 and the glass surface of the other base material 210 are joined together, the plurality of partial reflection surfaces are inside the substrate. The light guide formed in the above is manufactured.
In the manufacturing method shown in FIG. 10, a first base material 221 whose both surfaces are glass surfaces and a second base material 222 on which optical film layers having a partial reflection function are formed on both surfaces are prepared, and the first base material is prepared. 221 and the second base material 222 are alternately arranged so that the glass surface of the first base material 221 and the optical film layer forming surface of the second base material 222 are joined, so that a plurality of partial reflection surfaces are inside the substrate. The light guide formed in the above is manufactured.
　いずれの製造方法でも、一つの基材のガラス面と他の基材の光学膜層形成面とを接合する必要がある。しかしながら、多くの場合、光学ガラスには屈折率調整用の成分が添加されており、こうした成分のために接合性が悪い。特に、画像表示装置用のライトガイドでは視野を拡大するために高い屈折率が必要とされるが、屈折率を高くするためにガラスに添加される成分は接合性を低下させ易い。ガラス面と光学膜層形成面との接合性が悪いと、製品（ライトガイド）の歩留まりが低下し製品自体のコストが増加するおそれがある。また、こうしたライトガイドを組み込んだ画像表示装置自体の信頼性が低下するおそれもある。 In any manufacturing method, it is necessary to join the glass surface of one substrate and the optical film layer forming surface of another substrate. However, in many cases, components for adjusting the refractive index are added to the optical glass, and the bonding properties are poor due to these components. In particular, a light guide for an image display device requires a high refractive index in order to expand the field of view, but a component added to glass in order to increase the refractive index tends to lower the bondability. If the bonding property between the glass surface and the optical film layer forming surface is poor, the yield of the product (light guide) may be reduced, and the cost of the product itself may be increased. In addition, the reliability of the image display device itself incorporating such a light guide may be reduced.
　また、基材として使用する硝材を変更するとその接合性が変化するため、新たな硝材に対応した適切な接合条件（温度、圧力など）を調べ直す作業が必要になる。そのため、硝材の変更は製造効率を下げることになり、硝材の変更による性能の改善や軽量化、コスト削減などが行いにくいという問題もある。 Also, if the glass material used as the base material is changed, its bondability changes, so it is necessary to reexamine the appropriate bonding conditions (temperature, pressure, etc.) corresponding to the new glass material. Therefore, changing the glass material lowers the production efficiency, and there is a problem that it is difficult to improve performance, reduce weight, and reduce costs by changing the glass material.
特許第４５０８６５５号公報Japanese Patent No. 4508655 特許第５６９８２９７号公報Japanese Patent No. 5698297 米国特許出願公開第２０１３／０１６３０８９号明細書US Patent Application Publication No. 2013/0163089
　本発明は上記課題を解決するために成されたものであり、複数の基材の接合面に部分反射面を形成する際の接合性を改善することでライトガイドの製造効率や信頼性を向上させることをその主たる目的としている。 The present invention has been made to solve the above-mentioned problems, and improves the light guide manufacturing efficiency and reliability by improving the bonding property when forming the partial reflection surface on the bonding surface of a plurality of base materials. Its main purpose is to make it happen.
　上記課題を解決するためになされた本発明に係るライトガイドの製造方法は、互いに平行に対向する第一面及び第二面を有する透明な基板の内部に、前記第一面及び第二面に対して所定角度で以て傾斜している複数の部分反射面を有するライトガイドを製造する方法であって、
　それぞれが前記基板の構成部材である複数の透明な基材同士を接合し、二つの基材の間の接合面に前記部分反射面を形成するものであり、接合前に、接合される一方の基材の面に、網目形成酸化物膜層、又は最表面が網目形成酸化物膜層である光学膜層のいずれかを形成するとともに、接合される他方の基材の面に少なくとも光学膜層を形成しておき、接合によりそれら一又は二の光学膜層と網目形成酸化物膜層とが積層された状態において前記部分反射面としての所定の光学特性となるように各膜層の構造が定められることを特徴としている。 The light guide manufacturing method according to the present invention, which has been made to solve the above-described problems, includes a transparent substrate having a first surface and a second surface facing each other in parallel, and the first surface and the second surface. A method of manufacturing a light guide having a plurality of partially reflecting surfaces that are inclined at a predetermined angle with respect to each other,
A plurality of transparent base materials, each of which is a constituent member of the substrate, are joined together, and the partial reflection surface is formed on the joint surface between the two base materials. Either a network-forming oxide film layer or an optical film layer whose outermost surface is a network-forming oxide film layer is formed on the surface of the base material, and at least the optical film layer is formed on the surface of the other base material to be bonded The structure of each film layer is such that the one or two optical film layers and the network-forming oxide film layer are laminated to form predetermined optical characteristics as the partial reflection surface. It is characterized by being defined.
　本発明に係るライトガイドの製造方法の第１の態様では、接合される一方の基材の面に網目形成酸化物膜を形成するとともに、接合される他方の基材の面に光学膜層を形成しておくものとすることができる。 In the first aspect of the light guide manufacturing method according to the present invention, a network-forming oxide film is formed on the surface of one of the substrates to be bonded, and an optical film layer is formed on the surface of the other substrate to be bonded. It can be formed.
　また本発明に係るライトガイドの製造方法の第２の態様では、接合される一方の基材の面に網目形成酸化物膜を形成するとともに、接合される他方の基材の面に最表面が網目形成酸化物膜層である光学膜層を形成しておくものとすることができる。 In the second aspect of the light guide manufacturing method according to the present invention, a network-forming oxide film is formed on the surface of one of the substrates to be bonded, and the outermost surface is formed on the surface of the other substrate to be bonded. An optical film layer that is a network-forming oxide film layer may be formed in advance.
　また本発明に係るライトガイドの製造方法の第３の態様では、接合される一方の基材の面に最表面が網目形成酸化物膜層である光学膜層を形成するとともに、接合される他方の基材の面に光学膜層を形成しておくものとすることができる。 In the third aspect of the light guide manufacturing method according to the present invention, an optical film layer whose outermost surface is a network-forming oxide film layer is formed on the surface of one base material to be bonded, and the other side to be bonded An optical film layer can be formed on the surface of the substrate.
　また本発明に係るライトガイドの製造方法の第４の態様では、接合される一方の基材の面に最表面が網目形成酸化物膜層である光学膜層を形成するとともに、接合される他方の基材の面にも最表面が網目形成酸化物膜層である光学膜層を形成しておくものとすることができる。 Moreover, in the 4th aspect of the manufacturing method of the light guide which concerns on this invention, while forming the optical film layer whose outermost surface is a network formation oxide film layer in the surface of one base material joined, the other joined An optical film layer whose outermost surface is a network-forming oxide film layer can also be formed on the surface of the substrate.
　即ち、本発明に係るライトガイドの製造方法では、接合される二つの基材の表面の少なくとも一方は網目形成酸化物膜層であり、他方は網目形成酸化物膜層か或いは光学膜層である。一般に知られているように網目形成酸化物（Network former）は単独で３次元網目構造を形成し得る物質であり、ＳｉＯ2、Ｂ2Ｏ3、Ａｌ2Ｏ3などがある。 That is, in the light guide manufacturing method according to the present invention, at least one of the surfaces of the two substrates to be joined is a network-forming oxide film layer, and the other is a network-forming oxide film layer or an optical film layer. . As is generally known, a network former is a substance that can form a three-dimensional network structure by itself, and examples thereof include SiO 2 , B 2 O 3 , and Al 2 O 3 .
　上述したように、ライトガイドの基板に使用されるガラスには接合性を低下させる成分が含まれていることが多いが、本発明に係るライトガイド製造方法では、基材そのもののが露出している面が接合に供されることはなく、少なくとも一方の面は接合性が比較的良好である網目形成酸化物膜層である。そのため、二つの基材を良好に接合して、その接合面に部分反射面を形成することができる。また、基材の硝材が変更された場合でも、接合条件はその硝材の変更の影響を受けない。そのため、一旦、適切な接合条件を見いだせば、硝材が変更されても同じ接合条件で以て基材の接合を行うことができる。 As described above, the glass used for the light guide substrate often contains a component that lowers the bondability. However, in the light guide manufacturing method according to the present invention, the base material itself is exposed. The surface to be bonded is not used for bonding, and at least one surface is a network-forming oxide film layer having relatively good bonding properties. Therefore, two base materials can be joined well and a partial reflection surface can be formed on the joining surface. Further, even when the glass material of the base material is changed, the joining condition is not affected by the change of the glass material. Therefore, once an appropriate joining condition is found, the base materials can be joined under the same joining condition even if the glass material is changed.
　なお、本発明に係るライトガイド製造方法の第１乃至第４の態様において、好ましくは、複数の基材を単列状に接合することで基板を形成するとともに隣接する複数の部分反射面を形成するものであり、少なくともその両側に部分反射面がそれぞれ形成される基材は、その部分反射面に対応する両側の面に互いに異なる膜層を有するものとしてもよい。 In the first to fourth aspects of the light guide manufacturing method according to the present invention, preferably, a plurality of base materials are joined in a single row to form a substrate and a plurality of adjacent partial reflection surfaces are formed. The base material on which the partial reflection surfaces are respectively formed at least on both sides thereof may have different film layers on both sides corresponding to the partial reflection surfaces.
　また、上記製造方法では、その両側に部分反射面がそれぞれ形成される基材が複数あり、該複数の基材同士で各基材の両側の面にそれぞれ形成される膜層は同一の膜構造であるものとするとよい。 Further, in the above manufacturing method, there are a plurality of base materials each having a partially reflecting surface formed on both sides thereof, and the film layers formed on both sides of each base material are the same film structure. It is good to be.
　これによれば、その両側に部分反射面がそれぞれ形成される複数の基材として、膜構造が同一の基材を用いることができる。そのため、膜構造が相違する複数種類の基材を用意する必要がなく、製造工程を簡略化して製造効率を向上させることができる。また、複数の基材を接合する際にその順番を問わないので、誤った接合による不具合品の発生を防止することができる。なお、接合後に同一の膜構造となる部分反射面は、同一の反射率となる。 According to this, a substrate having the same film structure can be used as the plurality of substrates on which the partial reflection surfaces are respectively formed on both sides. Therefore, it is not necessary to prepare a plurality of types of base materials having different film structures, and the manufacturing process can be simplified and the manufacturing efficiency can be improved. Moreover, since the order is not ask | required when joining a some base material, generation | occurrence | production of the malfunctioning goods by incorrect joining can be prevented. In addition, the partial reflection surface which becomes the same film structure after joining becomes the same reflectance.
　また本発明に係るライトガイド製造方法の第１乃至第４の態様において、複数の基材を単列状に接合することで基板を形成するとともに隣接する複数の部分反射面を形成するものであり、その両側に部分反射面がそれぞれ形成される基材が複数あって、該複数の基材はそれぞれ、その両側の面に形成される膜層が同一の膜構造であるものとしてもよい。 In the first to fourth aspects of the light guide manufacturing method according to the present invention, a plurality of base materials are joined in a single row to form a substrate and to form a plurality of adjacent partial reflection surfaces. In addition, there may be a plurality of base materials on which the partial reflection surfaces are formed on both sides, and the plurality of base materials may have the same film structure in the film layers formed on the both side surfaces.
　これによれば、複数の基材を接合する際に基材の接合面の表裏を問わないので、表裏の間違いによる不具合品の発生を防止することができる。 According to this, when joining a plurality of base materials, the front and back surfaces of the joint surfaces of the base materials are not questioned, so that it is possible to prevent the occurrence of a defective product due to an error in the front and back surfaces.
　さらにまた本発明に係るライトガイド製造方法の第４の態様において、複数の基材を単列状に接合することで基板を形成するとともに隣接する複数の部分反射面を形成するものであり、その両側に部分反射面がそれぞれ形成される基材が複数あって、該複数の基材は両側の面にそれぞれ形成される膜層が全て同一の膜構造であるものとしてもよい。 Furthermore, in the fourth aspect of the light guide manufacturing method according to the present invention, a substrate is formed by joining a plurality of base materials in a single row and a plurality of adjacent partial reflection surfaces are formed. There may be a plurality of base materials on which the partial reflection surfaces are formed on both sides, and the plurality of base materials may have the same film structure in all the film layers formed on both sides.
　これによれば、光学膜層を形成する工程を簡略化することができ、ライトガイドの製造効率を向上させることができる。また、複数の基材を接合する際にその順番を問わず、さらにまた基材の接合面の表裏も問わないので、誤った接合による不具合品の発生を防止することができる。なお、接合後に同一の膜構造となる部分反射面は、同一の反射率となる。 According to this, the process of forming the optical film layer can be simplified, and the light guide manufacturing efficiency can be improved. In addition, when joining a plurality of base materials, the order of the base materials does not matter, and the front and back of the joint surfaces of the base materials are not questioned. Therefore, it is possible to prevent generation of defective products due to erroneous joining. In addition, the partial reflection surface which becomes the same film structure after joining becomes the same reflectance.
　また本発明に係るライトガイドは、上記本発明に係るライトガイド製造方法により製造されたライトガイドであり、互いに平行に対向する第一面及び第二面を有する透明な基板の内部に、前記第一面及び第二面に対して所定角度で以て傾斜している複数の部分反射面を有するライトガイドであって、
　前記基板は複数の透明な基材から成り、その複数の基材の中の二つの基材の間の接合面に前記部分反射面が形成され、該部分反射面は接合面を挟んだ一方又は両方の基材の面に形成された光学膜層と少なくとも一つの網目形成酸化物膜層とを含んで所定の光学特性となるように形成されていることを特徴としている。 The light guide according to the present invention is a light guide manufactured by the above-described light guide manufacturing method according to the present invention, wherein the first light guide and the second surface facing each other in parallel are disposed inside the transparent substrate. A light guide having a plurality of partially reflective surfaces inclined at a predetermined angle with respect to the one surface and the second surface,
The substrate is composed of a plurality of transparent base materials, and the partial reflection surface is formed on a joint surface between two base materials of the plurality of base materials, and the partial reflection surface is either one sandwiching the joint surface or An optical film layer formed on the surfaces of both base materials and at least one network-forming oxide film layer are formed so as to have predetermined optical characteristics.
　本発明に係るライトガイドは、網目形成酸化物膜層を挟んで二つの基材が接合されているので接合性が良好であり、高い信頼性を確保することができる。 The light guide according to the present invention has good bondability because two substrates are bonded with a network-forming oxide film layer interposed therebetween, and can ensure high reliability.
　本発明に係るライトガイド製造方法によれば、複数の基材の接合面に部分反射面を形成する際の、基材同士の接合性を改善することができる。それにより、ライトガイドの製造効率を向上させ、製造コストを低減することができる。また、ライトガイド自体の信頼性を向上させることができる。 According to the light guide manufacturing method according to the present invention, it is possible to improve the bonding property between the substrates when forming the partial reflection surfaces on the bonding surfaces of the plurality of substrates. Thereby, the manufacturing efficiency of a light guide can be improved and manufacturing cost can be reduced. Further, the reliability of the light guide itself can be improved.
本発明の一実施例であるライトガイドを用いた画像表示装置における光学系の概略構成図。1 is a schematic configuration diagram of an optical system in an image display apparatus using a light guide that is an embodiment of the present invention. 図１に示した画像表示装置におけるライトガイドをｙ軸方向に見たときの平面図。The top view when the light guide in the image display apparatus shown in FIG. 1 is seen in the y-axis direction. 本発明の一実施例であるライトガイド製造方法の説明図。Explanatory drawing of the light guide manufacturing method which is one Example of this invention. 本発明の他の実施例であるライトガイド製造方法の説明図。Explanatory drawing of the light guide manufacturing method which is the other Example of this invention. 本発明の他の実施例であるライトガイド製造方法の説明図。Explanatory drawing of the light guide manufacturing method which is the other Example of this invention. 本発明の他の実施例であるライトガイド製造方法の説明図。Explanatory drawing of the light guide manufacturing method which is the other Example of this invention. 本発明の他の実施例であるライトガイド製造方法の説明図。Explanatory drawing of the light guide manufacturing method which is the other Example of this invention. 従来の画像表示装置における光学系の概略構成図。FIG. 6 is a schematic configuration diagram of an optical system in a conventional image display apparatus. 従来のライトガイドの製造方法の一例の説明図。Explanatory drawing of an example of the manufacturing method of the conventional light guide. 従来のライトガイドの製造方法の他の例の説明図。Explanatory drawing of the other example of the manufacturing method of the conventional light guide.
　本発明の一実施例であるライトガイド及びその製造方法について、添付図面を参照して説明する。まず、本実施例によるライトガイドを用いた画像表示装置の一例について説明する。
　図１は本例の画像表示装置における光学系の概略構成図、図２は図１中のライトガイドをｙ軸方向に見たときの平面図である。 A light guide and a manufacturing method thereof according to an embodiment of the present invention will be described with reference to the accompanying drawings. First, an example of an image display device using the light guide according to the present embodiment will be described.
FIG. 1 is a schematic configuration diagram of an optical system in the image display apparatus of this example, and FIG. 2 is a plan view when the light guide in FIG. 1 is viewed in the y-axis direction.
　この画像表示装置１は、図８に示した従来の画像表示装置２と同じく、光源部１１、表示素子１２、コリメート光学系１３、及びライトガイド１０を備える。光源部１１、表示素子１２及びコリメート光学系１３は、従来の画像表示装置２における光源部２１、表示素子２２、コリメート光学系２３と同じものを用いることができるが、これに限るものではない。 This image display device 1 includes a light source unit 11, a display element 12, a collimating optical system 13, and a light guide 10 as in the conventional image display device 2 shown in FIG. The light source unit 11, the display element 12, and the collimating optical system 13 can be the same as the light source unit 21, the display element 22, and the collimating optical system 23 in the conventional image display apparatus 2, but are not limited thereto.
　ライトガイド１０は、共にｙ－ｚ平面に平行であって対向する第一面１００ａ及び第二面１００ｂと、共にｘ－ｙ平面に平行であって対向する第三面１００ｃ及び第四面１００ｄとを有する偏平立方体形状である基板１００を備える。基板１００は例えばポリカーボネート樹脂や石英ガラスなどの透明体である。この基板１００の内部に一つの入射側反射面１０１と複数（本例では３枚）の射出側反射面１０２ａ～１０２ｃとが形成されている。 The light guide 10 includes a first surface 100a and a second surface 100b that are both parallel to the yz plane and facing each other, and a third surface 100c and a fourth surface 100d that are both parallel to the xy plane and are facing each other. And a substrate 100 having a flat cubic shape. The substrate 100 is a transparent body such as polycarbonate resin or quartz glass. Inside the substrate 100, one incident-side reflecting surface 101 and a plurality (three in this example) of exit-side reflecting surfaces 102a to 102c are formed.
　入射側反射面１０１は第三面１００ｃ及び第四面１００ｄに垂直であり、第一面１００ａに対し傾斜している。また、複数の射出側反射面１０２ａ～１０２ｃも同様に、それぞれ第三面１００ｃ及び第四面１００ｄに垂直であり、第一面１００ａに対して傾斜している。また、複数の射出側反射面１０２ａ～１０２ｃは互いに平行である。 The incident side reflection surface 101 is perpendicular to the third surface 100c and the fourth surface 100d, and is inclined with respect to the first surface 100a. Similarly, the plurality of exit-side reflecting surfaces 102a to 102c are perpendicular to the third surface 100c and the fourth surface 100d, respectively, and are inclined with respect to the first surface 100a. The plurality of exit-side reflecting surfaces 102a to 102c are parallel to each other.
　本実施例の画像表示装置１において、光源部１１からの照明光を受けて表示素子１２の表示画面から発せられた画像光は、コリメート光学系１３によって略平行光化され第一面１００ａを通過してライトガイド１０の基板１００の内部に導入される。コリメート光学系１３からライトガイド１０に導入される画像光は、それぞれが表示素子１２の表示面上に形成される二次元的な画像の異なる部位の情報を含み、異なる角度でライトガイド１０に入射する平行光束の集合である。 In the image display apparatus 1 of the present embodiment, the image light emitted from the display screen of the display element 12 upon receiving the illumination light from the light source unit 11 is made approximately parallel by the collimating optical system 13 and passes through the first surface 100a. Then, the light guide 10 is introduced into the substrate 100. The image light introduced from the collimating optical system 13 into the light guide 10 includes information on different parts of the two-dimensional image formed on the display surface of the display element 12 and is incident on the light guide 10 at different angles. Is a set of parallel luminous fluxes.
　この画像光は入射側反射面１０１で反射されたあと第一面１００ａと第二面１００ｂとで一又は複数回反射されながら基板１００の内部を透過し、入射側反射面１０１に最も近い位置にある射出側反射面１０２ａに達する。射出側反射面１０２ａは到達した光束の一部を反射させ、残りを透過させる。透過した光は次の射出側反射面１０２ｂに到達し、その光束の一部は反射され、残りは透過する。射出側反射面１０２ｃも同様である。したがって、ライトガイド１０の基板１００の内部を透過してきた光束は複数の射出側反射面１０２ａ～１０２ｃでそれぞれ反射され、基板１００の第二面１００ｂを透過して外部に射出される。これにより、ライトガイド１０の基板１００に導入された光束は拡大されて該基板１００から射出され、観察者の眼Ｅの前には表示素子１２の表示面上に形成された画像が虚像として表示される。なお、一般的に複数の射出側反射面１０２ａ～１０２ｃの反射率は同一であるが、必ずしも同一である必要はない。 The image light is reflected by the incident-side reflecting surface 101, then passes through the substrate 100 while being reflected by the first surface 100 a and the second surface 100 b one or more times, and is positioned closest to the incident-side reflecting surface 101. It reaches a certain exit side reflecting surface 102a. The exit-side reflecting surface 102a reflects a part of the reached light beam and transmits the rest. The transmitted light reaches the next exit-side reflecting surface 102b, a part of the light beam is reflected, and the rest is transmitted. The same applies to the exit-side reflecting surface 102c. Accordingly, the light beams that have passed through the inside of the substrate 100 of the light guide 10 are reflected by the plurality of exit-side reflecting surfaces 102a to 102c, respectively, and are transmitted through the second surface 100b of the substrate 100 to be emitted to the outside. Thereby, the light beam introduced into the substrate 100 of the light guide 10 is enlarged and emitted from the substrate 100, and an image formed on the display surface of the display element 12 is displayed as a virtual image in front of the eyes E of the observer. Is done. In general, the reflectances of the plurality of exit-side reflecting surfaces 102a to 102c are the same, but they are not necessarily the same.
　次に、上記ライトガイド１０の製造方法について説明する。図３は本発明の一実施例であるライトガイド製造方法の説明図である。 Next, a method for manufacturing the light guide 10 will be described. FIG. 3 is an explanatory view of a light guide manufacturing method according to an embodiment of the present invention.
　従来技術である図９と同様に、基板１００は複数の透明な基材１１０（１１０Ａ、１１０Ｂ）を単列状に接合することにより形成される。そして、隣接する二つの基材１１０Ａ、１１０Ｂの間の接合面が入射側反射面１０１や射出側反射面１０２ａ～１０２ｃとなる。その両側に部分反射面が形成される基材１１０、具体的に図１で言えば、射出側反射面１０２ｂと射出側反射面１０２ｃとの間の基板１００を構成する基材、射出側反射面１０２ａと射出側反射面１０２ｂとの間の基板１００を構成する基材、は図３に示すようにｘ－ｙ平面上の断面が菱形形状であり、ｚ軸方向に延伸する棒状の部材である。 Similarly to FIG. 9, which is the prior art, the substrate 100 is formed by joining a plurality of transparent base materials 110 (110A, 110B) in a single row. Then, the joint surface between the two adjacent base materials 110A and 110B becomes the incident-side reflection surface 101 and the emission-side reflection surfaces 102a to 102c. The base material 110 on which the partial reflection surfaces are formed on both sides, specifically, in FIG. 1, the base material constituting the substrate 100 between the emission side reflection surface 102b and the emission side reflection surface 102c, the emission side reflection surface As shown in FIG. 3, the base material constituting the substrate 100 between 102a and the exit-side reflecting surface 102b is a rod-shaped member having a rhombic cross section on the xy plane and extending in the z-axis direction. .
　一つの基材１１０Ａの対向する二つの面１１０ａ、１１０ｂは基板１００の第一面１００ａ、第二面１００ｂの一部となる面である。また、この基材１１０Ａにあって隣接する別の基材１１０Ｂと接合される面にはそれぞれ、最表層が網目形成酸化物膜層である光学膜層１１１が形成されている。一方、隣接する基材１１０Ｂにあって上記基材１１０Ａと接合される面には網目形成酸化物膜層１１２が形成されている。 The two opposing surfaces 110a and 110b of one base 110A are surfaces that are part of the first surface 100a and the second surface 100b of the substrate 100. In addition, an optical film layer 111 whose outermost layer is a network-forming oxide film layer is formed on the surface of the base material 110A that is bonded to another adjacent base material 110B. On the other hand, a network-forming oxide film layer 112 is formed on the surface of the adjacent base material 110B that is bonded to the base material 110A.
　基材１１０Ａに形成されている光学膜層１１１の主体は誘電体多層膜であり、各膜層の材料、厚さ（光学厚さ）、膜層の構成（枚数など）によって、その光学特性が決まる。ただし、ここでは、図３（ｂ）に示すように二つの基材１１０Ａ、１１０Ｂを接合したとき、光学膜層１１１の最表層にある網目形成酸化物膜層にさらに所定厚さの網目形成酸化物膜層１１２が積層される構造となるため、これら全体で所定の光学特性、つまりは部分反射面としての所望の反射特性（又は透過特性）が得られるように光学膜層１１１及び網目形成酸化物膜層１１２が設計される。 The main part of the optical film layer 111 formed on the substrate 110A is a dielectric multilayer film, and its optical characteristics vary depending on the material, thickness (optical thickness) of each film layer, and the configuration (number of sheets, etc.) of the film layers. Determined. However, here, when the two base materials 110A and 110B are bonded as shown in FIG. 3B, the network-forming oxide film having a predetermined thickness is further added to the network-forming oxide film layer on the outermost layer of the optical film layer 111. Since the physical film layer 112 is laminated, the optical film layer 111 and the network formation oxidation are obtained so that predetermined optical characteristics, that is, desired reflection characteristics (or transmission characteristics) as a partial reflection surface can be obtained as a whole. The material film layer 112 is designed.
　一般に知られているように網目形成酸化物はそれのみで３次元網目構造を形成し得る物質であり、典型的にはＳｉＯ2であるが、Ｂ2Ｏ3、Ａｌ2Ｏ3などでもよい。基材１１０Ａ、１１０Ｂはガラス製であるが、ガラスの主成分のほかに屈折率を高くするために様々な成分が添加されており、そのために接合性が低くなっている。これに対し、この実施例の製造方法では、いずれの基材１１０Ａ、１１０Ｂも接合面にはガラスでなく網目形成酸化物膜層が露出している。そのため、基材１１０Ａ、１１０Ｂ同士を良好に接合して、その接合面に最表層が網目形成酸化物膜層である光学膜層１１１と網目形成酸化物膜層１１２とから成る部分反射面を形成することができる。また、虚像の拡大率や軽量化等のために基材１１０Ａ、１１０Ｂの硝材の種類を変更した場合でも、接合条件を見直す必要がない。また、両側に部分反射面が形成される基材の両面の光学膜層の膜構造は同一であるので、基材を接合する際に基材の接合面の表裏を問わず、表裏の間違いによる不具合品の発生を防止することができる。 As is generally known, the network-forming oxide is a substance that can form a three-dimensional network structure by itself, and is typically SiO 2 , but may be B 2 O 3 , Al 2 O 3 , or the like. Although the base materials 110A and 110B are made of glass, various components are added to increase the refractive index in addition to the main component of the glass, and therefore, the bondability is low. On the other hand, in the manufacturing method of this example, not all of the base materials 110A and 110B but the network-forming oxide film layer is exposed on the bonding surface. Therefore, the base materials 110A and 110B are bonded to each other satisfactorily, and a partially reflecting surface composed of the optical film layer 111 and the network-forming oxide film layer 112 whose outermost layer is a network-forming oxide film layer is formed on the bonding surface. can do. Further, even when the type of the glass material of the base materials 110A and 110B is changed in order to enlarge the virtual image or reduce the weight, it is not necessary to review the joining conditions. In addition, since the film structures of the optical film layers on both sides of the base material on which the partial reflection surfaces are formed on both sides are the same, when the base material is joined, regardless of the front and back of the joint surface of the base material, Generation of defective products can be prevented.
　図４～図７はいずれも本発明の他の実施例であるライトガイド製造方法の説明図である。図３に示した例では、基材１１０Ｂの接合面には光学膜層がなく網目形成酸化物膜層１１２のみが形成されていたが、図４、図５に示す例では、基材１１０Ｂの接合面にも最表層が網目形成酸化物膜層である光学膜層１１３、１１１が形成されている。 4 to 7 are explanatory views of a light guide manufacturing method according to another embodiment of the present invention. In the example shown in FIG. 3, there is no optical film layer on the bonding surface of the base material 110B, and only the network-forming oxide film layer 112 is formed. However, in the examples shown in FIGS. Optical film layers 113 and 111 whose outermost layers are network-forming oxide film layers are also formed on the bonding surface.
　図４と図５の相違は、図４では基材１１０Ｂの接合面に形成されている光学膜層１１３と基材Ａの接合面に形成されている光学膜層１１１とは膜層の構造が異なるのに対し、図５では基材１１０Ｂと基材１１０Ａとで膜層の構造が同一の光学膜層１１１が接合面に形成されている点である。
　いずれの場合にも図４（ｂ）、図５（ｂ）に示すように二つの基材１１０Ａ、１１０Ｂを接合したとき、間に網目形成酸化物膜層を挟んで二つの光学膜層が積層される構造となるため、これら全体で部分反射面としての所望の反射特性（又は透過特性）が得られるように、最表層が網目形成酸化物膜層である光学膜層１１１、１１３がそれぞれ設計される。 4 differs from FIG. 5 in that the optical film layer 113 formed on the bonding surface of the base material 110B and the optical film layer 111 formed on the bonding surface of the base material A in FIG. In contrast, in FIG. 5, the optical film layer 111 having the same film layer structure is formed on the bonding surface between the base material 110B and the base material 110A.
In either case, as shown in FIGS. 4B and 5B, when the two substrates 110A and 110B are joined, the two optical film layers are stacked with the network-forming oxide film layer interposed therebetween. Therefore, the optical film layers 111 and 113 whose outermost layers are network-forming oxide film layers are designed so that the desired reflection characteristics (or transmission characteristics) as a partial reflection surface can be obtained as a whole. Is done.
　図４、図５に示した例のいずれにおいても、図３に示した例と同様に、良好に二つの基材１１０Ａ、１１０Ｂを接合することができる。また、図３に示した例と同様に、両側に部分反射面が形成される基材の両面の光学膜層の膜構造は同一であるので、基材を接合する際に基材の接合面の表裏を問わず、表裏の間違いによる不具合品の発生を防止することができる。また特に、図５に示した例では、各基材において他の基材と接合される面には全て同じ膜構造の光学膜層１１１が形成されるので、両側に部分反射面（つまりは射出側反射面）が形成される基材は全て同じものを使用することができる。そのため、複数の基材を単列状に接合して基板１００を製作する際に基材の配列順序を入れ替えても何ら問題がなく、さらに一層製造性が向上する。 4 and 5, the two base materials 110 </ b> A and 110 </ b> B can be bonded satisfactorily as in the example shown in FIG. 3. In addition, as in the example shown in FIG. 3, since the film structures of the optical film layers on both sides of the substrate on which the partial reflection surfaces are formed on both sides are the same, the bonding surface of the substrate when bonding the substrates Regardless of the front and back, it is possible to prevent the occurrence of defective products due to a mistake in the front and back. In particular, in the example shown in FIG. 5, since the optical film layer 111 having the same film structure is formed on all surfaces of each substrate that are bonded to the other substrate, partial reflection surfaces (that is, emission surfaces) are formed on both sides. The same substrate can be used as the base material on which the side reflection surface is formed. Therefore, there is no problem even if the arrangement order of the base materials is changed when the substrate 100 is manufactured by joining a plurality of base materials in a single row, and the productivity is further improved.
　図３～図５に示した例では、接合対象である相対する面の表面層はいずれも網目形成酸化物膜層であるが、基材のガラス面自体が露出していなければ網目形成酸化物膜層はいずれか一方の面にのみ形成されていればよい。図６、図７はこうした場合の実施例であり、図６に示した例では、最表層に網目形成酸化物膜層を有さない光学膜層１１４が基材１１０Ａの一方の側の接合面に形成され、該基材１１０Ａの他方の側の接合面には網目形成酸化物膜層１１２が形成されている。隣接する基材１１０Ｂも同様である。したがって、図６（ｂ）に示すように接合された状態でその接合面に形成される部分反射面の膜層構造は図３に示した例とほぼ同様である。 In the examples shown in FIG. 3 to FIG. 5, the surface layers of the opposing surfaces to be bonded are all network-forming oxide film layers. However, if the glass surface of the substrate itself is not exposed, the network-forming oxide is used. The film layer only needs to be formed on one of the surfaces. 6 and 7 show an example in such a case. In the example shown in FIG. 6, the optical film layer 114 having no network-forming oxide film layer as the outermost layer is bonded to one side of the substrate 110A. A network forming oxide film layer 112 is formed on the bonding surface on the other side of the substrate 110A. The same applies to the adjacent base material 110B. Therefore, the film layer structure of the partially reflecting surface formed on the bonding surface in the bonded state as shown in FIG. 6B is almost the same as the example shown in FIG.
　この図６の例では、両側に部分反射面が形成される基材１１０Ａ、１１０Ｂとして同じ種類の基材を使用することができる。そのため、各基材の表裏の入れ替えはできないものの、図５に示した例と同様に、複数の基材を単列状に接合して基板１００を製作する際に基材の配列順序を入れ替えても何ら問題がなく、製造性が向上する。 In the example of FIG. 6, the same type of base material can be used as the base materials 110 </ b> A and 110 </ b> B on which partial reflection surfaces are formed on both sides. Therefore, although the front and back of each base material cannot be interchanged, as in the example shown in FIG. 5, when the substrate 100 is manufactured by joining a plurality of base materials in a single row, the order of the base materials is changed. There is no problem and productivity is improved.
　一方、図７に示した例では、基材１１０Ａの両方の面に最表層に網目形成酸化物膜層を有さない光学膜層１１４が形成され、該基材１１０Ａに隣接する基材１１０Ｂの相対する面には網目形成酸化物膜層１１２が形成されている。したがって、図７（ｂ）に示すように接合された状態でその接合面に形成される部分反射面の膜層構造は図６に示した例と同様である。ただし、この場合には、両側に部分反射面が形成される基材１１０Ａ、１１０Ｂは接合面となる面の膜構造が異なる。そのため、この場合には基材の配列順序の入れ替えはできないものの、各基材の表裏の入れ替えは可能であり、表裏の間違いによる不具合品の発生を防止することができる。 On the other hand, in the example shown in FIG. 7, the optical film layer 114 having no network forming oxide film layer as the outermost layer is formed on both surfaces of the substrate 110A, and the substrate 110B adjacent to the substrate 110A is formed. A network-forming oxide film layer 112 is formed on the opposite surfaces. Therefore, the film layer structure of the partially reflecting surface formed on the bonding surface in the bonded state as shown in FIG. 7B is the same as the example shown in FIG. However, in this case, the base materials 110A and 110B on which the partial reflection surfaces are formed on both sides have different film structures on the surfaces to be the bonding surfaces. Therefore, in this case, although the arrangement order of the base materials cannot be changed, the front and back of each base material can be changed, and the occurrence of a defective product due to an incorrect front and back can be prevented.
　なお、上記説明では、部分反射面である射出側反射面１０２ａ～１０２ｃを基板１００の内部に形成する際の構造について述べたが、ミラー等による反射面である入射側反射面１０１を基板１００の内部に形成する際にも同様の方法を採ることができることは明らかである。また、図１に示した例では射出側反射面は３枚のみであるが、任意の枚数の射出側反射面を同様の方法で形成できることは当然である。 In the above description, the structure when the exit-side reflecting surfaces 102a to 102c, which are partial reflecting surfaces, are formed inside the substrate 100 has been described. However, the incident-side reflecting surface 101, which is a reflecting surface by a mirror or the like, is formed on the substrate 100. It is obvious that the same method can be adopted when forming the inside. Further, in the example shown in FIG. 1, only three exit-side reflection surfaces are provided, but it is natural that any number of exit-side reflection surfaces can be formed by the same method.
　また、上記実施例におけるライトガイドでは、基板１００の第三面１００ｃと第四面１００ｄとが互いに平行となっているが、第三面１００ｃ及び第四面１００ｄはｘ－ｙ平面に平行である必要はない。即ち、第一面１００ａ、第二面１００ｂ、入射側反射面１０１、及び、射出側反射面１０２ａ～１０２ｃと第三面１００ｃ及び第四面１００ｄとは垂直である必要はなく、それらの間の角度や第三面１００ｃ及び第四面１００ｄの面の形状は任意に定めることができる。 In the light guide in the above embodiment, the third surface 100c and the fourth surface 100d of the substrate 100 are parallel to each other, but the third surface 100c and the fourth surface 100d are parallel to the xy plane. There is no need. That is, the first surface 100a, the second surface 100b, the incident-side reflecting surface 101, and the exit-side reflecting surfaces 102a to 102c, the third surface 100c, and the fourth surface 100d do not have to be perpendicular to each other. The angles and the shapes of the third surface 100c and the fourth surface 100d can be arbitrarily determined.
　また上記実施例におけるライトガイドの製造方法では、二種類の基材１１０Ａ、１１０Ｂを用いているが、基材の種類は二種類に限定されるものではなく、一つのライトガイドを構成する全ての基材が異なる種類であってもよい。 In the light guide manufacturing method in the above embodiment, two types of base materials 110A and 110B are used. However, the types of base materials are not limited to two types, and all of the light guides that constitute one light guide are used. Different types of substrates may be used.
　また上記実施例では、ライトガイドにおける複数の部分反射面の反射率が同一であることを前提としていたが、反射率が同一でない場合もあり得る。複数の部分反射面の反射率が互いに異なる場合であっても、基材を接合したときに所望の反射特性が得られるように接合される二つの基材の面上の光学膜を設計すればよい。ただし、その場合には、例えば一つの基材の両面にそれぞれ最表層が網目形成酸化物膜層である光学膜層１１１を形成する場合でも、その膜構造は同一であるとは限らず、基材の表裏の入れ替えができない場合もあり得る。また同様に、基材の配列順序の入れ替えができない場合もあり得る。 In the above embodiment, it is assumed that the reflectance of the plurality of partial reflection surfaces in the light guide is the same, but the reflectance may not be the same. Even if the reflectivities of a plurality of partial reflection surfaces are different from each other, if an optical film on the surfaces of two substrates to be bonded is designed so that desired reflection characteristics are obtained when the substrates are bonded, Good. However, in that case, for example, even when the optical film layer 111 whose outermost layer is a network-forming oxide film layer is formed on both surfaces of one base material, the film structure is not necessarily the same. In some cases, the front and back of the material cannot be replaced. Similarly, the arrangement order of the base materials may not be changed.
　また上記実施例におけるライトガイドの製造方法では、基材１１０を断面菱形形状とし、その第一面１１０ａ及び第二面１１０ｂがそれぞれライトガイド１００の第一面１００ａ及び第二面１００ｂの一部を形成する構成としているが、例えば複数の板状である基材を接合した後に、該基材を研削したり研磨したりする等の外形加工を施して、ライトガイド１００の第一面１００ａ及び第二面１００ｂを形成してもよい。その場合、基材の断面形状は菱形形状に限らず、平板形状など、接合面以外の形状は任意で構わない。 In the light guide manufacturing method in the above embodiment, the base 110 is formed in a rhombus shape, and the first surface 110a and the second surface 110b are part of the first surface 100a and the second surface 100b of the light guide 100, respectively. Although it is configured to form, for example, after joining a plurality of plate-like base materials, external processing such as grinding or polishing the base materials is performed, and the first surface 100a and the first surface of the light guide 100 The two surfaces 100b may be formed. In that case, the cross-sectional shape of the base material is not limited to the rhombus shape, and a shape other than the joining surface such as a flat plate shape may be arbitrary.
　また、上記の製造方法により製造された本発明に係るライトガイドは上述したような画像表示装置への使用に限らず、入射光束幅を変化させることが必要な様々な用途に使用することができる。また、ライドガイドの使用の態様は特に問わないから、光を射出側反射面１０２ａ～１０２ｃ（つまりは部分反射面）側から基板１００の内部に入射し、入射側反射面１０１側から外部へ取り出すようにしてもよい。 In addition, the light guide according to the present invention manufactured by the above manufacturing method is not limited to use for the image display device as described above, but can be used for various applications where it is necessary to change the incident light beam width. . Further, since the use mode of the ride guide is not particularly limited, light is incident on the inside of the substrate 100 from the exit side reflection surfaces 102a to 102c (that is, the partial reflection surface) side, and taken out from the incident side reflection surface 101 side to the outside. You may do it.
　さらにまた、上記実施例はあくまでも本発明の一例にすぎず、本発明の趣旨の範囲で適宜、変更や修正、追加を行っても本願特許請求の範囲に包含されることは当然である。 Furthermore, the above-described embodiment is merely an example of the present invention, and it is natural that the present invention is encompassed by the scope of the claims of the present application even if changes, modifications, and additions are made as appropriate within the scope of the present invention.
１…画像表示装置
１０…ライトガイド
１００…基板
１００ａ…第一面
１００ｂ…第二面
１００ｃ…第三面
１００ｄ…第四面
１０１…入射側反射面
１０２ａ～１０２ｃ…射出側反射面
１１…光源部
１２…表示素子
１３…コリメート光学系
１１０、１１０Ａ、１１０Ｂ…基材
１１０ａ…第一面
１１０ｂ…第二面
１１１、１１３…最表層が網目形成酸化物膜層である光学膜層
１１２…網目形成酸化物膜層
１１４…最表層に網目形成酸化物膜層を有さない光学膜層 DESCRIPTION OF SYMBOLS 1 ... Image display apparatus 10 ... Light guide 100 ... Board | substrate 100a ... 1st surface 100b ... 2nd surface 100c ... 3rd surface 100d ... 4th surface 101 ... Incident side reflective surface 102a-102c ... Outgoing side reflective surface 11 ... Light source part DESCRIPTION OF SYMBOLS 12 ... Display element 13 ... Collimating optical system 110,110A, 110B ... Base material 110a ... 1st surface 110b ... 2nd surface 111, 113 ... Optical film layer 112 whose outermost layer is a network formation oxide film layer ... Network formation oxidation Material film layer 114: optical film layer having no network-forming oxide film layer as the outermost layer

Claims (10)

  1. 　互いに平行に対向する第一面及び第二面を有する透明な基板の内部に、前記第一面及び第二面に対して所定角度で以て傾斜している複数の部分反射面を有するライトガイドを製造する方法であって、
    　それぞれが前記基板の構成部材である複数の透明な基材同士を接合し、二つの基材の間の接合面に前記部分反射面を形成するものであり、接合前に、接合される一方の基材の面に、網目形成酸化物膜層、又は最表面が網目形成酸化物膜層である光学膜層のいずれかを形成するとともに、接合される他方の基材の面に少なくとも光学膜層を形成しておき、接合によりそれら一又は二の光学膜層と網目形成酸化物膜層とが積層された状態において前記部分反射面としての所定の光学特性となるように各膜層の構造が定められることを特徴とするライトガイドの製造方法。     A light guide having a plurality of partially reflecting surfaces inclined at a predetermined angle with respect to the first surface and the second surface inside a transparent substrate having a first surface and a second surface facing each other in parallel. A method of manufacturing
    A plurality of transparent base materials, each of which is a constituent member of the substrate, are joined together, and the partial reflection surface is formed on the joint surface between the two base materials. Either a network-forming oxide film layer or an optical film layer whose outermost surface is a network-forming oxide film layer is formed on the surface of the base material, and at least the optical film layer is formed on the surface of the other base material to be bonded The structure of each film layer is such that the one or two optical film layers and the network-forming oxide film layer are laminated to form predetermined optical characteristics as the partial reflection surface. A method for manufacturing a light guide, characterized by being defined.
  2. 　請求項１に記載のライトガイドの製造方法であって、
    　接合される一方の基材の面に網目形成酸化物膜を形成するとともに、接合される他方の基材の面に光学膜層を形成しておくことを特徴とするライトガイドの製造方法。     A light guide manufacturing method according to claim 1,
    A method for producing a light guide, wherein a network-forming oxide film is formed on the surface of one base material to be bonded, and an optical film layer is formed on the surface of the other base material to be bonded.
  3. 　請求項１に記載のライトガイドの製造方法であって、
    　接合される一方の基材の面に網目形成酸化物膜を形成するとともに、接合される他方の基材の面に最表面が網目形成酸化物膜層である光学膜層を形成しておくことを特徴とするライトガイドの製造方法。     A light guide manufacturing method according to claim 1,
    A network-forming oxide film is formed on the surface of one substrate to be bonded, and an optical film layer whose outermost surface is a network-forming oxide film layer is formed on the surface of the other substrate to be bonded. A light guide manufacturing method characterized by the above.
  4. 　請求項１に記載のライトガイドの製造方法であって、
    　接合される一方の基材の面に最表面が網目形成酸化物膜層である光学膜層を形成するとともに、接合される他方の基材の面に光学膜層を形成しておくことを特徴とするライトガイドの製造方法。     A light guide manufacturing method according to claim 1,
    An optical film layer whose outermost surface is a network-forming oxide film layer is formed on the surface of one base material to be bonded, and an optical film layer is formed on the surface of the other base material to be bonded A light guide manufacturing method.
  5. 　請求項１に記載のライトガイドの製造方法であって、
    　接合される一方の基材の面に最表面が網目形成酸化物膜層である光学膜層を形成するとともに、接合される他方の基材の面にも最表面が網目形成酸化物膜層である光学膜層を形成しておくことを特徴とするライトガイドの製造方法。     A light guide manufacturing method according to claim 1,
    An optical film layer whose outermost surface is a network-forming oxide film layer is formed on the surface of one base material to be bonded, and the outermost surface is also a network-forming oxide film layer on the surface of the other base material to be bonded A method for producing a light guide, wherein an optical film layer is formed in advance.
  6. 　請求項２～５のいずれか１項に記載のライトガイドの製造方法であって、
    　複数の基材を単列状に接合することで基板を形成するとともに隣接する複数の部分反射面を形成するものであり、少なくともその両側に部分反射面がそれぞれ形成される基材は、その部分反射面に対応する両側の面に互いに異なる膜層を有することを特徴とするライトガイドの製造方法。     A method of manufacturing a light guide according to any one of claims 2 to 5,
    A substrate is formed by joining a plurality of base materials in a single row, and a plurality of adjacent partial reflection surfaces are formed. A method for manufacturing a light guide, comprising different film layers on both sides corresponding to a reflecting surface.
  7. 　請求項６に記載のライトガイドの製造方法であって、
    　その両側に部分反射面がそれぞれ形成される基材が複数あり、該複数の基材同士で各基材の両側の面にそれぞれ形成される膜層は同一の膜構造であることを特徴とするライトガイドの製造方法。     It is a manufacturing method of the light guide according to claim 6,
    There are a plurality of base materials each having a partial reflection surface formed on both sides thereof, and the film layers formed on both sides of each base material have the same film structure. Manufacturing method of light guide.
  8. 　請求項２～５のいずれか１項に記載のライトガイドの製造方法であって、
    　複数の基材を単列状に接合することで基板を形成するとともに隣接する複数の部分反射面を形成するものであり、その両側に部分反射面がそれぞれ形成される基材が複数あって、該複数の基材はそれぞれ、その両側の面に形成される膜層が同一の膜構造であることを特徴とするライトガイドの製造方法。     A method of manufacturing a light guide according to any one of claims 2 to 5,
    Forming a substrate by joining a plurality of base materials in a single row and forming a plurality of adjacent partial reflection surfaces, there are a plurality of base materials on each of which a partial reflection surface is formed, The light guide manufacturing method, wherein the plurality of base materials have the same film structure in the film layers formed on both sides thereof.
  9. 　請求項５に記載のライトガイドの製造方法であって、
    　複数の基材を単列状に接合することで基板を形成するとともに隣接する複数の部分反射面を形成するものであり、その両側に部分反射面がそれぞれ形成される基材が複数あって、該複数の基材は両側の面にそれぞれ形成される膜層が全て同一の膜構造であることを特徴とするライトガイドの製造方法。     It is a manufacturing method of the light guide according to claim 5,
    Forming a substrate by joining a plurality of base materials in a single row and forming a plurality of adjacent partial reflection surfaces, there are a plurality of base materials on each of which a partial reflection surface is formed, The method of manufacturing a light guide, wherein the plurality of base materials have the same film structure on all of the film layers formed on both sides.
  10. 　互いに平行に対向する第一面及び第二面を有する透明な基板の内部に、前記第一面及び第二面に対して所定角度で以て傾斜している複数の部分反射面を有するライトガイドであって、
    　前記基板は複数の透明な基材から成り、その複数の基材の中の二つの基材の間の接合面に前記部分反射面が形成され、該部分反射面は接合面を挟んだ一方又は両方の基材の面に形成された光学膜層と少なくとも一つの網目形成酸化物膜層とを含んで所定の光学特性となるように形成されていることを特徴とするライトガイド。     A light guide having a plurality of partially reflecting surfaces inclined at a predetermined angle with respect to the first surface and the second surface inside a transparent substrate having a first surface and a second surface facing each other in parallel. Because
    The substrate is composed of a plurality of transparent base materials, and the partial reflection surface is formed on a joint surface between two base materials of the plurality of base materials, and the partial reflection surface is either one sandwiching the joint surface or A light guide comprising an optical film layer formed on the surfaces of both base materials and at least one network-forming oxide film layer so as to have predetermined optical characteristics.
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005055860A (en) * 2003-08-04 2005-03-03 Vtec Technologies Llc Transparent plastic optical component and abrasion resistant polymer substrate, and method for making the same
JP2013076847A (en) * 2011-09-30 2013-04-25 Seiko Epson Corp Virtual image displaying device
JP2014222260A (en) * 2013-05-13 2014-11-27 セイコーエプソン株式会社 Optical element, display device, and method for manufacturing optical element
WO2017104402A1 (en) * 2015-12-16 2017-06-22 コニカミノルタ株式会社 Holographic recording material, volume holographic medium, and method for producing volume holographic medium

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6982997B1 (en) * 2003-09-16 2006-01-03 Np Photonics, Inc. Single-frequency narrow linewidth 1μm fiber laser

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005055860A (en) * 2003-08-04 2005-03-03 Vtec Technologies Llc Transparent plastic optical component and abrasion resistant polymer substrate, and method for making the same
JP2013076847A (en) * 2011-09-30 2013-04-25 Seiko Epson Corp Virtual image displaying device
JP2014222260A (en) * 2013-05-13 2014-11-27 セイコーエプソン株式会社 Optical element, display device, and method for manufacturing optical element
WO2017104402A1 (en) * 2015-12-16 2017-06-22 コニカミノルタ株式会社 Holographic recording material, volume holographic medium, and method for producing volume holographic medium

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