Manufacturing method of a light scattering light guide

• US 5,580,932 A
• Filed: 03/18/1994
• Issued: 12/03/1996
• Est. Priority Date: 09/27/1991
• Status: Expired due to Term

• Current Assignee: Yasuhiro Koike
• Original Assignee: Yasuhiro Koike
• Inventors: Koike, Yasuhiro
• Primary Examiner(s): Clark, W. Robinson H.
• Application Number:
  US08/214,589
• Time in Patent Office: 991 Days
• Field of Search: 525/276, 525/277, 525/185, 525/200, 525/227, 525/242, 385/130, 385/131, 385/143
• US Class Current: 525/276
• CPC Class Codes: G02B 1/045 Light guides
• CPC Class Codes: G02B 5/0247 by means of voids or pores
• CPC Class Codes: G02B 5/0257 creating an anisotropic diffusion characteristic, i.e. distributing output differently in two perpendicular axes
• CPC Class Codes: G02B 5/0263 with positional variation of the diffusing properties, e.g. gradient or patterned diffuser
• CPC Class Codes: G02B 5/0268 characterized by the fabrication or manufacturing method
• CPC Class Codes: G02B 5/0284 used in reflection
• CPC Class Codes: G02B 6/00 Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
• CPC Class Codes: G02B 6/0001 specially adapted for lighting devices or systems lighting or signalling on vehicles using light guides B60Q1/00; lighting devices for vehicle dashboards B60Q3/10; lighting devices for vehicle interior using light guides B60Q3/62; lighting devices mounted on the vehicle rear part using light guides F21S43/235; measuring arrangements having light conducting pointers G01D13/265; illumination of liquid crystal displays G02F1/1336; illuminated signs G09F13/00
• CPC Class Codes: G02B 6/001 the light being emitted along at least a portion of the lateral surface of the fibre
• CPC Class Codes: G02B 6/0041 provided in the bulk of the light guide
• CPC Class Codes: G02B 6/0046 Tapered light guide, e.g. wedge-shaped light guide
• CPC Class Codes: G02B 6/0065 Manufacturing aspects; Material aspects
• CPC Class Codes: G02B 6/02033 Core or cladding made from organic material, e.g. polymeric material G02B1/04 takes precedence
• CPC Class Codes: G02B 6/2808 using a mixing element which evenly distributes an input signal over a number of outputs
• CPC Class Codes: Y10S 385/901 Illuminating or display apparatus

Abstract

A light scattering light guide, which is capable of converting a light flux of a relatively small cross-sectional area into a light flux of a relatively large area with high efficiency and uniformity, manufacturing method thereof, and applied optical apparatuses such as backlight light source apparatuses and light branching/mixing devices which make effective use of the characteristics of said light scattering light guide. Such light scattering light guide is obtained by utilizing various structures with irregular refraction indexes generated in the process of polymerization of organic materials.

Claims

1. A manufacturing method of a light scattering light guide, comprising the steps of:

(a) providing first and second organic substances, the first organic substance being a monomer and the second organic substance being a polymer or oligomer, a polymer of the first organic substance having a different refractive index and a different compatibility than those of the second organic substance;

(b) preparing a mixed transparent solution by substantially completely dissolving the second organic substance in the first organic substance;

(c) starting a polymerization reaction;

(d) allowing the first organic substance in the mixed transparent solution to polymerize so that as polymerization proceeds, compatibility with the second organic substance decreases causing the second organic substance to coagulate; and

(e) obtaining a heterogeneous coagulated structure having heterogeneities with a size corresponding to a correlation distance "a" in the range of 0.07 μ

m≦

a≦

50 μ

m and an effective scattering irradiation parameter E in the range of 0.45 cm^-1 ≦

E ≦

80 cm^-1.

2. A manufacturing method of a light scattering light guide, comprising the steps of:

(a) preparing a uniformly mixed monomer solution by combining first and second monomers, the first monomer being more reactive than the second monomer, the respective polymers of the first and second monomers having different refractive indices;

(b) starting a polymerization reaction;

(c) allowing the monomer mixture to polymerize so that initially the first monomer polymerizes preferentially causing the second monomer to coagulate, and subsequently, as the first monomer is consumed, the second monomer polymerizes preferentially; and

(d) obtaining a heterogeneous coagulated structure having heterogeneities with a size corresponding to a correlation distance "a" in the range of 0.07 μ

m≦

a≦

50 μ

m and an effective scattering irradiation parameter E in the range of 0.45 cm^-1 ≦

E≦

80 cm^-1.