Car number plate lamp

• US 4,868,723 A
• Filed: 11/30/1987
• Issued: 09/19/1989
• Est. Priority Date: 11/28/1986
• Status: Expired due to Fees

• Current Assignee: Koito Manufacturing Company Limited
• Original Assignee: Koito Manufacturing Company Limited
• Inventors: Kobayashi, Syoji
• Primary Examiner(s): Husar, Stephen F.
• Assistant Examiner(s): Hagarman, Sue
• Application Number:
  US07/126,375
• Time in Patent Office: 659 Days
• Field of Search: 40/204, 40/205, 40/208, 40/556, 40/560, 40/582, 362/326, 362/327, 362/328, 362/341, 362/347, 362/308, 362/80
• US Class Current: 362/497
• CPC Class Codes: B60Q 1/56 for illuminating registrations or the like , e.g. for licence plates

Abstract

A car number plate lamp having an improved illuminating efficiency and more uniform illuminating intensity. A light source and lens are provided in a lamp body, and a lens is mounted across an opening in the lamp body. The reflector is three-dimensionally curved in such a manner that the entire surface of the reflector viewed in the longitudinal direction curves circular-arcuately about the light source. The surface perpendicular to the longitudinal direction forms a paraboloid with the light source at the focal point. Concentric steps for refracting the light from the light source to the number plate are formed in the inner surface of the lens.

Claims

1. A car number plate lamp comprising:

a lamp body, a light source provided in said lamp body, a reflector provided in said lamp body, and a lens provided across an opening portion of said lamp body, said reflector being three-dimensionally curved so that the entire surface of said reflector viewed in the longitudinal direction thereof curves circular-arcuately about said light source, and the surface perpendicular to said longitudinal direction forms a paraboloid with said light source at a focal point thereof, concentric steps for refracting light from said light source to a number plate being formed in an inner surface of said lens.

2. The car number plate lamp according to claim 1, wherein a center of said steps is displaced toward said number plate from a shortest line between said front lens and said light source.

3. The car number plate lamp according to claim 1, wherein step angles of said steps decrease in a direction away from said number plate.

4. The number plate lamp according to claim 3, wherein said steps angles decrease in a continuous manner.

5. The number plate lamp according to claim 3, wherein said step angles decrease in a stepwise manner.

6. The car number plate lamp according to claim 1, wherein an incident surface of each of said steps is concave.