Spread illuminating apparatus

• US 6,582,095 B1
• Filed: 06/01/2000
• Issued: 06/24/2003
• Est. Priority Date: 07/23/1999
• Status: Active Grant

• Current Assignee: Minebea Company Limited (MinebeaMitsumi Inc.)
• Original Assignee: Minebea Company Limited (MinebeaMitsumi Inc.)
• Inventors: Toyoda, Koichi
• Primary Examiner(s): Cariaso, Alan
• Assistant Examiner(s): Ton, Anabel
• Application Number:
  US09/583,541
• Time in Patent Office: 1,118 Days
• Field of Search: 362/31, 362/555, 362/800, 362/235, 362/311, 362/351, 362/367, 362/361, 362/360, 362/26
• US Class Current: 362/235
• CPC Class Codes: G02B 6/0013 Means for improving the coupling-in of light from the light source into the light guide coupling light into light guides in general G02B6/42
• CPC Class Codes: G02B 6/0038 Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide

Abstract

In the spread illuminating apparatus in which the light emitted from the light emitting diode 4, which is disposed close to the transparent substrate 2, is made to be emitted toward the viewing direction of the transparent substrate 2, the groove 2a is provided on the transparent substrate 2 in such a manner as it crosses orthogonally light emitted in a radial direction from the light emitting diode 4 so that most light beams 5a, 5b, 5c can be emitted toward the viewing direction. Since the light beams 5a, 5b and 5c progress in the viewing direction through the groove 2a, an amount of light turning aside to no purpose can be reduced.

Claims

1. A spread illuminating apparatus in which at least one spot-like light source is disposed at a periphery of a transparent substrate made of light permeable material and has its emitting face facing said transparent substrate, and light from said spot-like light source is made to be emitted toward the viewing direction of said transparent substrate, wherein a plurality of continuously formed band-like light emitting elements formed on a major surface of said transparent substrate and consisting of at least one of groove, recessed portion, convex portion, and curved surface are disposed curvilinearly, each making an arc defining said spot-like light source as its center in such a manner as they cross orthogonally most light beams available emitted in a radial direction from said spot-like light source so that as much light as possible can be emitted toward the viewing direction.

2. A spread illuminating apparatus according to claim 1, wherein said transparent substrate is rectangular, said spot-like light source is disposed at one corner of the transparent substrate so as to face inside said transparent substrate, a plurality of light emitting elements are provided on said transparent substrate and said light emitting elements are disposed linearly in such a manner as they cross orthogonally as many light beams as available emitted in a radial direction from said spot-like light source so that as much light as possible can be emitted toward the viewing direction.

3. A spread illuminating apparatus according to claim 1, wherein said transparent substrate is rectangular and said spot-like light source is disposed at one corner of said transparent substrate so as to face inside said transparent substrate.

4. A spread illuminating apparatus according to claim 1, wherein said transparent substrate is rectangular, and said spot-like light source is disposed at one side of said transparent substrate so as to face inside said transparent substrate.

5. A spread illuminating apparatus according to claim 1, wherein said transparent substrate is rectangular and a plurality of spot-like light sources are disposed at sides of said transparent substrate at a spacing so as to face inside said transparent substrate.

6. A spread illuminating apparatus according to claim 1, wherein said transparent substrate is rectangular and said spot-like light sources are disposed at one or both corners of a diagonal line of said transparent substrate.

7. A spread illuminating apparatus according to claim 1, wherein said transparent substrate is rectangular and said spot-like light sources are disposed slantwise at both corners of one or a plurality of sides of said transparent substrate.