Signal lamp for vehicles

• US 6,224,246 B1
• Filed: 08/20/1998
• Issued: 05/01/2001
• Est. Priority Date: 03/18/1998
• Status: Expired due to Fees

• Current Assignee: Koito Manufacturing Company Limited
• Original Assignee: Koito Manufacturing Company Limited
• Inventors: Natsume, Kazunori, Satsukawa, Hideaki
• Primary Examiner(s): O'Shea, Sandra
• Assistant Examiner(s): TON, ANABEL
• Application Number:
  US09/136,963
• Time in Patent Office: 985 Days
• Field of Search: 362/518, 362/346, 362/348, 362/517, 362/297
• US Class Current: 362/518
• CPC Class Codes: F21S 43/30 characterised by reflectors

Abstract

A signal lamp for vehicles has a reflector that acts to diffuse light from a light source within the lamp. The reflector is made up of multiple diffusing reflective elements having a reflecting region that reflects light emitted from the light source in a direction of an optical axis of the lamp. A lens is positioned in front of the reflector. The reflecting region of each diffusing reflective element is varied, such that an area ratio of the reflecting region for portions of the reflector with a high reflective illuminance is less than other portions having lower illuminance.

Claims

1. A signal lamp for vehicles comprising:

a light source;

a reflector having a reflective surface for reflecting forward light emitted from the light source, the reflective surface being composed of a plurality of diffusing reflection elements, each reflection element comprising a reflecting region which reflects light emitted from the light source in an optical axis direction of the reflector, where an area ratio of the reflecting region, for a particular reflection element, to a total area of said particular reflection element is based on the illuminance of said particular reflection element of said plurality of diffusing reflection elements, with respect to the incident light emitting from the light source, such that the area ratio of the reflecting region to the reflection element is lower for reflection elements with a high illuminance than for reflection elements with a low illuminance; and

a lens arranged in the front of the reflector.

2. A signal lamp for vehicles according to claim 1, wherein each of the diffusing reflection elements further comprises an optical axis direction non-reflecting region in which light emitting from the light source is not reflected in the optical axis direction.

3. A signal lamp for vehicles according to claim 2, wherein a part of the optical axis direction non-reflecting region is formed into a light non-reflecting region.

4. A signal lamp for vehicles according to claim 2, wherein a part of the optical axis direction non-reflecting region is formed into a deflection diffusion reflecting region in which light emitting from the light source is diffused and reflected in a direction different from that of another region in the optical axis direction non-reflecting region.

5. A signal lamp for vehicles according to claim 3, wherein the optical axis direction reflecting region of each diffusion reflection element is composed of the same curved surface as that of the optical axis direction non-reflecting region.

6. A signal lamp for vehicles according to claim 1, wherein the diffusion reflection elements are arranged at substantially regular intervals.

7. A signal lamp for vehicles according to claim 1, wherein each of the diffusing reflection elements comprises an end region, the end region being a perpendicular section of which is formed by extending the reflection region thereof.

8. A signal lamp for vehicles according to claim 7, wherein a non-reflecting coating film is disposed on a surface of the end region of the diffusing reflection element.

9. A signal lamp for vehicles according to claim 1, wherein the diffusing reflection elements are sector-shaped and arranged radially and concentrically at regular intervals with respect to the optical axis, forming at least one paraboloid of revolution.

10. A signal lamp for vehicles according to claim 9, wherein each diffusing reflection element has a cross-section in the circumferential direction is formed into a convex curve.

11. A signal lamp for vehicles according to claim 10, wherein the radius of curvature of the convex curve of the reflection element is set at a substantially constant value between the diffusing reflection elements.

12. A signal lamp for vehicles according to claim 9, wherein each diffusing reflection element has a cross-section in the radial direction which is determined in such a manner that a first region is set to have a common curve as that of the cross-section in the radial direction of each paraboloid of revolution, and a second region located on the opposite side to the first region with respect to the optical axis which is set to be a convex curve which smoothly continues to the curve of the first region.

13. A vehicle signal lamp comprising:

a reflector having a reflective surface;

a light source which emits light on the reflective surface creating an illuminance;

a plurality of diffusing reflection elements formed on the reflective surface, each diffusing reflection element including a reflection region operative to reflect the emitted light in an optical axis direction, wherein an area of the reflection region and an area of diffusing reflection element form a ratio, which is increased as the illuminance is decreased; and

a lens arranged in a front portion of the reflector.