Optical waveguide plate of surface light emitting apparatus

• US 20020197051A1
• Filed: 05/21/2002
• Published: 12/26/2002
• Est. Priority Date: 05/22/2001
• Status: Active Grant

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Corporation
• Inventors: Shiota, Nobutoshi, Nakanishi, Eiji, Tamura, Yuuki, Kunikata, Koichi
• Granted Patent: US 6,904,225 B2
• Time in Patent Office: Days
• US Class Current: 385/146
• CPC Class Codes: G02B 6/0036 2-D arrangement of prisms, protrusions, indentations or roughened surfaces
• CPC Class Codes: G02B 6/0061 to provide homogeneous light output intensity
• CPC Class Codes: G02B 6/0091 of the light source relative to the light guide G02B6/0021 takes precedence
• CPC Class Codes: Y10S 385/901 Illuminating or display apparatus

Abstract

To provide an optical waveguide that can emit light of which intensity is uniformly distributed over the light emitting surface and can suppress the occurrence of the bright line, the optical waveguide of surface light emitting apparatus has a light emitting plane and a reflecting plane that oppose each other, the reflecting surface having a plurality of dots formed thereon so that light entering from a light source that is provided on one end face or two opposing end faces is output through the light emitting surface with uniform intensity, wherein the dots are arranged so as to form band regions each being defined as a region that has a constant density of distribution, a plurality of vertical lines of the dots are formed at substantially equal intervals in each of the band regions in the direction toward adjacent bands, and the interval between the vertical lines of dots is made different in different bands.

Claims

1. An optical waveguide plate of a surface light emitting apparatus comprising a light emitting plane and a reflecting plane that oppose each other, said reflecting surface having a plurality of dots so that a light inputted from a light source that is provided on one end face or two opposing end faces is output through said light emitting surface with uniform intensity,

wherein said dots are arranged so as to form a plurality of band regions each of which is defined as a region that has a constant distribution density, said each band region having a plurality of vertical lines which are formed by the dots and are formed at substantially equal intervals in the direction toward adjacent band regions, said intervals between the vertical lines of dots is set so as to be different between the adjacent band regions.

3. The optical waveguide plates of a surface emitting apparatus according to claims 1 or 2;

wherein said dots are arranged so that a plurality of horizontal lines are formed perpendicular to said vertical lines in said each band regions, the intervals between said vertical lines and the intervals between said horizontal lines are determined in accordance to the density distribution of dots in each band region.

5. The optical waveguide plate as in one of claims 1, 2, 4;

wherein the density of said dots in each band region is changed according to the attenuation of light transmitted from the light source.

6. The optical waveguide plate as in one of claims 1, 2, 4;

wherein said dots are arranged randomly in a density that is set according to the attenuation of light, in part of the reflector surface located on both sides of the end face where the light source is mounted.

7. The optical waveguide plates as in one of claims 1, 2, 4;

wherein said dots are arranged randomly in a density that is set according to the attenuation of light, in part of the reflector surface adjacent to said light source.

8. The optical waveguide plates as in one of claims 1, 2, 4;

wherein the dot has a concave portion and a convex portion.

9. The optical waveguide plate according to claim 8;

wherein each dot is constituted from a convex portion and a concave portion that surrounds said convex portion.

10. The optical waveguide plate according to claim 8;

wherein each dot is constituted from a concave portion and a convex portion that surrounds said concave portion.

2. An optical waveguide plate of a surface light emitting apparatus comprising a light emitting plane and a reflecting plane that oppose each other, said reflecting surface having a plurality of dots so that a light inputted from a light source that is provided on one end face or two opposing end faces is output through said light emitting surface with uniform intensity,

wherein said dots are arranged so as to form a plurality of band regions each of which is defined as a region that has a constant distribution density and has a plurality of vertical lines of the dots that are formed at equal intervals in the direction toward adjacent band regions,

wherein said dots are arranged in adjacent band regions so that the vertical lines of dots in one band region and the vertical lines of dots in the other band region do not lie in the same straight lines.

4. An optical waveguide plate of a surface light emitting apparatus comprising a light emitting plane and a reflecting plane that oppose each other, said reflecting surface having a plurality of dots so that a light inputted from a light source that is provided on one end face or two opposing end faces is output through said light emitting surface with uniform intensity,

wherein said dots are arranged so as to form a plurality of band regions each of which is defined as a region that has a constant distribution density and has a concentration of dots being different between adjacent band regions, said dots being disposed at lattice points of a lattice consisting of square cells in each of the band regions.