Angular light guide with fringed portion

• US 7,500,774 B2
• Filed: 06/15/2006
• Issued: 03/10/2009
• Est. Priority Date: 06/23/2005
• Status: Active Grant

• Current Assignee: Alps Alpine Co., Ltd.
• Original Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Inventors: Kobayashi, Ayumu, Nishiyama, Yoshinori
• Primary Examiner(s): Lee; Jong-Suk (James)
• Assistant Examiner(s): SPINELLA, KEVIN
• Application Number:
  US11/424,476
• Publication Number:
  US 20060291183A1
• Time in Patent Office: 999 Days
• Field of Search: 362/628, 362/602, 362/26, 362/551, 362/555, 362/610, 362/611, 362/104, 362/108, 362/216, 362/570, 362/23, 362/100, 362/326, 362/327, 362/331, 362/333, 362/334, 362/336, 362/337, 362/338, 362/88, 362/511, 362/16, 362 27- 30, 362/615, 362/488, 359/247, 359/737, 359/387, 359/711, 385/146, 385/901, 396/267
• US Class Current: 362/551
• CPC Class Codes: G02B 6/0016 Grooves, prisms, gratings, scattering particles or rough surfaces
• CPC Class Codes: G02B 6/0018 Redirecting means on the surface of the light guide
• CPC Class Codes: G02B 6/0021 for housing at least a part of the light source, e.g. by forming holes or recesses
• CPC Class Codes: G05G 1/105 comprising arrangements for illumination

Abstract

An annular light guide is provided. The annular light guide is made of optically transparent material, and is provided with an annular body that is an integrated combination of a light inlet and a light outlet. A light source is disposed in a cavity formed in the light inlet. Illumination light is emitted from the front surface 16c of the light outlet.

Claims

1. An annular light guide that is a molded product made of optically transparent material, comprising:

a light inlet that includes a cavity defined by an inner wall surface in which a light source is disposable;

a toric light outlet having an outer circumferential side extending in a horizontal direction that is continuous with a circumferential side in a horizontal direction of the light inlet, the toric light outlet having an inner wall surface defining a hole through the toric light outlet; and

fringes formed in an exterior wall surface of the light inlet and extending in a vertical direction, the exterior wall surface of the light inlet being substantially parallel to the inner wall surface of the light inlet,

wherein a front surface of the toric light outlet forms an illumination area that circumnavigates the hole through the toric light outlet, and light traveling from the light source is reflected at the fringes in a horizontal direction toward the toric light outlet for emission from the illumination area.

2. The annular light guide according to claim 1, wherein the cavity is a through-hole passing through the light inlet in the through-thickness direction.

3. The annular light guide according to claim 1, wherein collective lenses that have a convex lens shape and refract light from the light source to guide the light to the toric light outlet are formed in part of the inner wall surface of the light inlet in which the first inner wall demarcates the cavity.

4. The annular light guide according to claim 1, wherein the fringes along one part of the exterior wall surface are closer to a symmetry line passing through a center of the light inlet than fringes along a further part of the exterior wall surface, and wherein the toric light outlet is broader than the further part of the exterior wall surface farther from the symmetry line.

5. The annular light guide according to claim 1, further comprising inward projected fringes on a region of the inner wall surface of the light inlet that extend in the vertical direction.

6. The annular light guide according to claim 5 wherein light from the light source is refracted by the inward projected fringes to travel in predetermined directions.

7. The annular light guide according to claim 1, wherein the fringes have a triangle pole shape.