JP2003227907A - Light guide sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light guide sheet from which a light guide paths patterned in an arbitrary shape can easily be formed and stuck. <P>SOLUTION: A light guide sheet 10 comprises a high refractive index transparent layer 11 and a low refractive index transparent layer 12 disposed on at least one face thereof and the sheet 10 is stuck on a substrate with an adhesive layer 13 via the low refractive index transparent layer 12. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light guide sheet, and more particularly to a light guide sheet having an arbitrary shape that can be bonded to an arbitrary adherend by transfer or the like. is there. Conventionally, as a light guide for an optical circuit or the like, a film such as a core or a clad is formed by vacuum film formation or the like, and a photolithographic method of applying a photoresist, exposing a pattern, or etching is applied. Patterned light guides are known. However, according to such a method of creating a light guide, there are many processing steps, and it is not easy to create a pattern having no defects. The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a light guide capable of easily forming and sticking a light guide patterned in an arbitrary shape. Is to provide a sheet. The light guide sheet of the present invention which achieves the above object comprises a high refractive index transparent layer and a low refractive index transparent layer laminated on at least one side thereof, and the low It is affixed on an adherend by an adhesive layer through a refractive index transparent layer. According to the present invention, since the light guide sheet is composed of a high refractive index transparent layer and a low refractive index transparent layer laminated on at least one surface thereof, a highly accurate sheet can be produced by a simple process. And since it is a uniform sheet shape, it can be easily patterned into an arbitrary light guide shape by a simple cutting means. In addition, since it is not necessary to use a conventional photolithographic method, it can be produced with a high yield. DETAILED DESCRIPTION OF THE INVENTION The light guide sheet of the present invention will be described below based on examples. FIG. 1 shows a plan view (a) and a sectional view (b) of the basic form of the light guide sheet of the present invention. The light guide sheet 10 of the present invention is formed on at least one surface of a high refractive index transparent layer 11 that acts as a core for guiding light, and is guided in the high refractive index transparent layer 11. A low-refractive-index transparent layer 12 that acts as a cladding that totally reflects light and confines it in the high-refractive-index transparent layer 11, and the low-refractive-index transparent layer 12 is provided on the opposite side of the high-refractive-index transparent layer 11. It consists of an adhesive, an adhesive, etc., and consists of an adhesive layer 13 that acts to fix the light guide sheet 10 to the adherend. Such a light guide sheet 10 is provided with a cutting line 14 for determining a light guide pattern in advance, or is it cut along the cutting line 14 with a cutting tool such as scissors before bonding to the adherend? Alternatively, after the entire light guide sheet 10 is attached to the adherend, it is cut along the cutting line 14 and the portions other than the necessary pattern portion are peeled off. Thus, as shown in the cross-sectional view of FIG. 2, the light guide 10 ′ having a desired pattern shape on the adherend 20 is obtained.
Is formed. In addition, in such a light guide path 10 ′, no reflecting member is provided on both side surfaces thereof, so that when the pattern of the light guide path 10 ′ is bent, the light guide light is transmitted from both side surfaces. Since there is a risk of escaping, the light guide path 10 'having a desired pattern shape is formed on the adherend 20, and then a reflective paint layer, a low refractive index paint layer, or a metal reflection is formed on at least both sides. It is desirable to form a layer or the like by coating or the like. Of course, at this time, a similar layer may be formed on the upper surface of the high refractive index transparent layer 11 at the same time. By the way, in the case of the light guide sheet 10 of FIG. 1, the adhesive layer 13 made of an adhesive, a pressure sensitive adhesive or the like remains exposed. In the case where the adhesive layer 13 is made of an adhesive, etc., as shown in a cross-sectional view in FIG. 3, a form in which a release paper 16 provided with a release layer 15 made of wax, silicon resin, or the like is attached to the adhesive layer 13. When the light guide portion composed of the high refractive index transparent layer 11 and the low refractive index transparent layer 12 is attached to the adherend, the release paper 16 is peeled off and attached to the adherend by the adhesive layer 13. It is desirable. 1 to 3, total reflection occurs at the interface with the air on the surface side of the high refractive index transparent layer 11 of the light guide sheet 10 and the light guide path 10 ', and the inside of the high refractive index transparent layer 11 is inside. However, if foreign matter or the like adheres to or contacts the interface, the total reflection condition may be lost and light may leak to the outside. Therefore, as shown in the sectional view of FIG. A low refractive index transparent layer 12 ′ that acts as a clad may also be provided on the surface side of the refractive index transparent layer 11. FIG. 5 shows a light guide sheet 10 according to one embodiment of the present invention.
FIG. In this embodiment, the high refractive index transparent layer 11 is 100 mm × 100 mm in thickness of 100 μm.
On one surface of a polycarbonate film (trade name: Teijin Pure Ace) 21 having a refractive index of about 1.6 mm, a layer 22 having a thickness of 0.2 μm constituting the low refractive index transparent layer 12 (trade name of Asahi Glass Co., Ltd.) : Cytop) is applied by spin coating, and a 30 μm-thick double-sided pressure-sensitive adhesive tape 23 (product name of Scotch: transparent double-sided tape W-12) constituting the adhesive layer 13 is applied thereon, and the light guide sheet 10 Configured. From the light guide sheet 10, as shown in a plan view in FIG. 6A and a cross-sectional view in FIG.
A strip-shaped light guide 10 'having a length of 100 mm is cut out and pasted onto a paper 25 with a double-sided adhesive tape 23, and a light introducing right-angle prism 26 is provided on a high refractive index transparent layer at one end of the light guide 10'. When the red laser beam 27 having a wavelength of 680 nm was irradiated on the inclined surface, light 28 having the same wavelength was emitted from the other end of the high refractive index transparent layer and was clearly guided in the light guide 10 ′. became. The light guide sheet 1 of the present invention as described above.
In the configuration of 0, the total thickness of the high refractive index transparent layer 11 and the low refractive index transparent layer 12 is practically preferably between 0.1 μm and 10 mm, more preferably between 1 μm and 2 mm, Most preferably between 10 μm and 0.4 mm. As the material of the adhesive layer 13, any of known adhesives and pressure-sensitive adhesives can be used, but reactive adhesives or adhesives that can be polymerized by light such as ultraviolet rays may be used. Further, the high refractive index transparent layer 11 may have a one-dimensional refractive index distribution structure in which the refractive index decreases in a gradient from the center of the layer to both surfaces. In this case, the low refractive index transparent layers 12 and 12 ′ are not necessarily required. Further, the adhesive layer 13 may be configured to also serve as the low refractive index transparent layer 12. In that case, naturally the refractive index of the adhesive layer 13 is selected to be lower than the refractive index of the high refractive index transparent layer 11. The adhesive layer 13 is provided not on the light guide sheet 10 side but on the adherend 20 side, so that the high refractive index transparent layer 1 is provided.
1 and the low refractive index transparent layer 12 may be adhered to the adherend 20. The light guide sheet according to the present invention as described above is
It can be used as art means such as a display, or can be used as a means for guiding sunlight. Furthermore, it can also be used as a light guide for an optical circuit or an optical computer. Although the light guide sheet of the present invention has been described based on the embodiments, the present invention is not limited to these embodiments and can be variously modified. The light guide sheet of the present invention described above can be constructed as follows, for example. [1] It consists of a high refractive index transparent layer and a low refractive index transparent layer laminated on at least one surface thereof, and is adhered to an adherend by an adhesive layer through the low refractive index transparent layer. A light guide sheet characterized by the above. [2] The light guide sheet as described in 1 above, wherein the adhesive layer is provided in advance on the low refractive index transparent layer. [3] The light guide sheet as described in 2 above, wherein a peeling member is attached to the adhesive layer through a peeling layer. [4] The light guide sheet as described in 1 above, wherein the adhesive layer is provided in advance on the adherend. [5] The light guide sheet as described in any one of 1 to 4 above, wherein the adhesive layer comprises a photopolymerizable adhesive. [6] The above 1 to 5 characterized in that the high refractive index transparent layer and the low refractive index transparent layer are patterned in a desired pattern before or after being attached to the adherend. The light guide sheet according to any one of the above. [7] The light guide sheet according to any one of the above items 1, 3 to 6, wherein the adhesive layer also serves as the low refractive index transparent layer. [8] A light guide sheet, characterized in that a transparent layer having a one-dimensional refractive index distribution structure in which the refractive index decreases in a gradient from the center of the layer to both surfaces is attached to an adherend by an adhesive layer. As is apparent from the above description, in the light guide sheet of the present invention, a light guide comprising a high refractive index transparent layer and a low refractive index transparent layer laminated on at least one side thereof. Since it is a sheet, it can be produced with high accuracy by a simple process, and since it is a uniform sheet, it can be easily patterned into an arbitrary light guide shape by a simple cutting means. . Further, since it is not necessary to use a conventional photolithographic method, it can be produced with a high yield. Moreover, in the light guide sheet of this invention, there also exists a merit that it is easy to overlap a light guide path.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view and a sectional view of a basic form of a light guide sheet of the present invention. FIG. 2 is a cross-sectional view of a light guide that is patterned and pasted on an adherend. FIG. 3 is a cross-sectional view of an example light guide sheet in which release papers are laminated. FIG. 4 is a cross-sectional view of an example light guide sheet in which a low refractive index transparent layer is also provided on the surface side of a high refractive index transparent layer. FIG. 5 is a cross-sectional view of a light guide sheet according to one embodiment of the present invention. 6A and 6B are a plan view and a cross-sectional view of an arrangement in which the light guide sheet of FIG. DESCRIPTION OF SYMBOLS 10 ... Light guide sheet 10 '... Light guide path 11 ... High refractive index transparent layer 12, 12' ... Low refractive index transparent layer 13 ... Adhesive layer 14 ... Cutting line 16 ... Release paper 20 ... Substrate 21 ... Polycarbonate film 22 ... Layer 23 constituting low refractive index transparent layer ... Double-sided adhesive tape 25 ... Paper 26 ... Right-angle prism 27 ... Laser beam 28 ... Outgoing light

Continued front page    F-term (reference) 2H042 AA02 AA18 AA26 AA30 BA12                       BA15 BA18 DA11 DA17 DA21                       DB07                 4F100 AK01A AK45 AR00A AR00B                       AR00C BA03 BA10A BA10C                       BA26 GB43 JL11C JN01A                       JN01B JN18A JN18B

Claims (1)

What is claimed is: 1. A transparent layer comprising a high refractive index transparent layer and a low refractive index transparent layer laminated on at least one side of the transparent layer. The adhesive layer is interposed on the adherend through the low refractive index transparent layer. A light guide sheet that is affixed to.