Light-distributing lens of head lamp for vehicles

• US 5,921,671 A
• Filed: 10/18/1996
• Issued: 07/13/1999
• Est. Priority Date: 10/18/1995
• Status: Expired due to Term

• Current Assignee: DENSO Corporation, Stanley Electric Company Limited
• Original Assignee: DENSO Corporation, Stanley Electric Company Limited
• Inventors: Sato, Takashi, Okuchi, Hiroaki
• Primary Examiner(s): TSO, LAURA K
• Application Number:
  US08/733,793
• Time in Patent Office: 998 Days
• Field of Search: 362/31, 362/32, 362/61, 362/327, 362/511, 362/558
• US Class Current: 362/511
• CPC Class Codes: F21S 41/24 Light guides
• CPC Class Codes: G02B 6/0008 the light being emitted at the end of the fibre

Abstract

A light-distributing lens which may be employed in head lamps for vehicles is provided. The light-distributing lens includes an entrance surface, a pair of reflecting side surfaces, and an exit surface. The pair of reflecting side surfaces include a plurality of reflecting side portions arranged vertically of the light-distributing lens so as to form vertically compressed light-distributed zones, respectively. Each of the light-distributed zones includes a direct light-distributed portion formed by a portion of the light transmitted directly from the entrance surface without undergoing the total reflection on the reflecting side surfaces and reflected light-distributed zones formed on both sides of the direct light-distributed zone by a portion of the light transmitted from the entrance surface which has undergone the total reflection on the reflecting side surfaces. An angle which the reflecting side portions of one of the pairs make with each other in the horizontal direction is different from that which the reflecting side portions of the other(s) of the pairs make with each other so that each of dark areas formed between the direct light-distributed portion and the reflected light-distributed portions of the light-distributed zone formed by one of the pairs are brightened by one of the direct light-distributed portion and the reflected light-distributed portions of the light-distributed zone of the other(s) of the pairs.

Claims

1. A wide-spread zone-forming lens for a head lamp of a vehicle, comprising:

an entrance surface receiving light from a light source;

an exit surface emitting light entering said entrance surface, said exit surface formed opposite said entrance surface along a horizontal line extending in a lengthwise direction of said wide-spread zone-forming lens; and

a pair of reflecting side surfaces directing a portion of light entering said entrance surface to said exit surface by total reflection, said pair of reflecting side surfaces formed between said entrance surface and said exit surface and include at least a first and second pair of reflecting side portions arranged in a vertical direction substantially perpendicular to the horizontal line of said wide-spread zone-forming lens, said first and second pair of reflecting side portions forming a first and second light-distributed zone disposed ahead of said exit surface, wherein each said first and second light distributed zone includes,

a direct light-distributed zone, defined by a portion of light transmitted directly from said entrance surface without being totally reflected by the reflecting side surfaces;

a plurality of reflected light-distributed zones, formed on both sides of the direct light-distributed zone and defined by a portion of light transmitted from said entrance surface being totally reflected by the reflecting side surfaces; and

a first reflecting side portion angle, formed by the respective first pair reflecting side portions along the horizontal direction of said wide-spread zone-forming lens, differing in degree from a second reflecting side portion angle, formed by the respective second pair reflecting side portions, wherein each of a plurality of dark areas formed outside and between said direct light-distributed and reflected light-distributed zones of said first light-distributed zone are brightened by one of said direct light-distributed and reflected light-distributed zones of said second light-distributed zone.

2. The wide-spread zone-forming lens set forth in claim 1, wherein said exit surface includes a first and second curved surface emitting light transmitted from said first and second pairs of reflecting side portions, respectively, each of said curved surfaces having curvatures which differ in degree from each other.

3. The wide-spread zone-forming lens set forth in claim 2, wherein said first and second curved surfaces are curved in the vertical direction of said wide-spread zone-forming lens, and the curvatures of said first and second curved surfaces differ in degree from each other, wherein the light respectively emitted from said first and second curved surfaces have different focal lengths.

4. A wide-spread zone-forming lens for a head lamp of a vehicle, comprising:

an entrance surface receiving light from a light source;

an exit surface emitting light entering said entrance surface, said exit surface formed opposite said entrance surface along a horizontal line extending in a lengthwise direction of said wide-spread zone-forming lens; and

a pair of reflecting side surfaces directing a portion of light entering said entrance surface to said exit surface by total reflection, said pair of reflecting side surfaces formed between said entrance surface and said exit surface and include a first, second, and third pair of reflecting side portions arranged in a vertical direction substantially perpendicular to the horizontal line of said wide-spread zone-forming lens, said first, second, and third pair of reflecting side portions forming a first, second, and third light-distributed zone disposed ahead of said exit surface, wherein each of said first, second, and third light-distributed zone includes,

a direct light-distributed zone, defined by a portion of light transmitted directly from said entrance surface without being totally reflected by the reflecting side surfaces;

a plurality of reflected light-distributed zones, formed on both sides of the direct light-distributed zone and defined by a portion of light transmitted from said entrance surface being totally reflected by the reflecting side surfaces; and

a first reflecting side portion angle, formed by the respective first pair reflecting side portions along the horizontal direction of the light-distributing lens, differing in degree from a second reflecting side portion angle, formed by the respective second pair reflecting side portions, wherein each of a plurality of dark areas formed outside and between said direct light-distributed and reflected light-distributed zones of said first light-distributed zone are brightened by one of said direct light-distributed and reflected light-distributed zones of said second light-distributed zone.

5. The wide-spread zone-forming lens set forth in claim 4, wherein said exit surface includes first, second, and third curved surfaces emitting light transmitted from said first, second, and third pairs of reflecting side portions, respectively, each of said curved surfaces having curvatures which differ in degree from each other along the vertical direction of said wide-spread zone-forming lens.

6. A light-distributing lens for a head lamp of a vehicle, comprising:

an entrance surface receiving light from a light source;

an exit surface emitting light entering said entrance surface, said exit surface formed opposite said entrance surface along a horizontal line extending in a lengthwise direction of said wide-spread zone-forming lens; and

a pair of reflecting side surfaces directing a portion of light entering said entrance surface to said exit surface by total reflection, said pair of reflecting side surfaces formed between said entrance surface and said exit surface and include at least a first and second pair of reflecting side portions arranged in a vertical direction substantially perpendicular to the horizontal line of said wide-spread zone-forming lens, said first and second pair of reflecting side portions forming a first and second light-distributed zone disposed ahead of said exit surface, and wherein said exit surface includes a first and second curved surface emitting light transmitted from said first and second pair of reflecting side portions, respectively, each of the curved surfaces having a horizontal curvature which differ in degree from each other and the light respectively emitted from said first and second curved surfaces having different focal lengths along the horizontal direction of said wide-spread zone-forming lens, and wherein each of said first and second light distributed zone includes,

a direct light-distributed zone, defined by a portion of light transmitted directly from said entrance surface without being totally reflected by the reflecting side surfaces;

a plurality of reflected light-distributed zones, formed on both sides of the direct light-distributed zone and defined by a portion of light transmitted from said entrance surface being totally reflected by the reflecting side surfaces; and

a first reflecting side portion angle, formed by the respective first pair reflecting side portions along the horizontal direction of said wide-spread zone-forming lens, differing in degree from a second reflecting side portion angle, formed by the respective second pair reflecting side portions, wherein each of a plurality of dark areas formed outside and between said direct light-distributed and reflected light-distributed zones of said first light-distributed zone are brightened by one of said direct light-distributed and reflected light-distributed zones of said second light-distributed zone.