JPS5926001B2 - Method for manufacturing flexible light guide - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a flexible light guide using a reflection method using air as a medium.

Conventionally, light guides used for interior lighting of automobiles, medical lighting, decorative lighting, etc., generally referred to as light guides, are usually bundles of one or more optical glass fibers. Due to the need for flexibility, the manufacturing method involves winding thin fibers of about 40 to 70 μm in multiple layers back and forth on a suitable drum to form a bundle of a predetermined number of fibers, usually several hundred to several thousand fibers or more. The material is then cut, taken out in a straight line, covered with a vinyl tube or the like, hardened with epoxy resin or the like on both ends, and finished with a fabric finish to make the product.

In this method, since a large number of glass fibers are handled, it is very difficult to collect them, insert them into the covering, etc., and the work is often done manually, resulting in high costs. Considerable care is required in handling to prevent fiber breakage. The light guide obtained by the present invention does not transmit light using materials such as glass or plastic as in the conventional method, but instead forms a metal light-reflecting layer on the inner surface of a hollow plastic structure. However, the light incident from the end face is transmitted by reflection. With this method, in terms of light transmission, there is no loss of light scattering or absorption due to the fiber material itself or foreign matter in the fiber material, which often occurs with optical fibers, and loss due to light escaping outside the fiber. Since the transmittance of light depends only on the reflectance, excellent light guiding properties can be provided by forming a metal film with high reflectance. In addition, due to its excellent flexibility, it is possible to increase the hollow cross-sectional area of the light guide, which reduces the number of individual items handled during manufacturing, and makes focusing and coating operations simple and economical. is obtained.

Furthermore, a method of forming a tubular light guide from a sheet has been known for some time, but the method of the present invention is simpler than this method, and the resulting light guide has excellent shape stability. ing.

To explain this invention based on the drawings, as an example, FIGS. 1 and 2 show the manufacturing method and structure of a light guide using a tube method, and FIG. 1 shows a light guide made by an extrusion method etc. After obtaining a synthetic resin chup 6 made of polyvinyl chloride, polyethylene, etc. with a diameter of approximately 0.5 to 5 mmφ, insert the cutting blade 2 at a point on its periphery and forcibly push it open using a roller die or the like. , while keeping it flat, form a light-reflecting layer on the surface using methods such as adhesion of aluminum foil, aluminum vapor deposition, sputtering, ion plating, etc., remove the external force of pushing open, and make it soft due to elastic recovery. It is shown that the flexible light guide 7 is made by restoring the original shape to a tube body with a reflective layer on the inner surface.

Figure 2 shows the tube body at a predetermined length, usually 50 mm. ~5m
The outer diameter is usually 1 mm to 10 mm.The outer diameter is usually 1 mm to 10 mm. The structure of the light guide is shown.

Compared to conventional methods, the light guide obtained by this method has a light transmittance equal to or higher than that of the conventional method, has good flexibility, and requires less number of focusing beams, making it easier and more economical to manufacture. It has the great advantage of being easy to handle due to its excellent properties and resistance to damage.

It goes without saying that the tube alone can function as a light guide depending on the application. The light guide obtained as described above has many features such as light conductivity, flexibility, light weight, and low cost, and has a wide range of uses such as medical use, lighting, automobile interior equipment lighting, and decorative lighting.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of the method for manufacturing a light guide according to the present invention, and FIG.
The figure is a schematic diagram of the assembly of the light guide. (Explanation of symbols), 1: extruder, cutting blade, 3, 4: holding roll, 5: metal foil, 6: synthetic resin tube, 7: light guide.

Claims (1)

[Claims] 1. Flexibility characterized by cutting a synthetic resin tube open, forming a metallic reflective layer on the inner surface of the tube, and then forming the tube into the original circular cross-section by elastic recovery. Method for manufacturing a light guide. 2. The method for manufacturing a flexible light guide according to claim 1, wherein the metal is aluminum metal. 3. The method of manufacturing a flexible light guide according to claim 1, wherein the tube is elastically recovered to form a circular cross section of the original shape, and the cut-out portion of the tube is joined.