Vehicle lamp

• US 20020034081A1
• Filed: 09/18/2001
• Published: 03/21/2002
• Est. Priority Date: 09/18/2000
• Status: Abandoned Application

• Current Assignee: Koito Manufacturing Company Limited
• Original Assignee: Koito Manufacturing Company Limited
• Inventors: Serizawa, Tomoaki
• Application Number:
  US09/953,943
• Publication Number:
  US 20020034081A1
• Time in Patent Office: Days
• US Class Current: 362/540
• CPC Class Codes: B60Q 1/2696 Mounting of devices using LEDs
• CPC Class Codes: B60Q 1/28 for indicating front of vehicle
• CPC Class Codes: F21S 43/14 Light emitting diodes [LED]
• CPC Class Codes: F21S 43/26 Refractors, transparent cover plates, light guides or filters not provided in groups F21S43/235 - F21S43/255
• CPC Class Codes: F21S 43/30 characterised by reflectors
• CPC Class Codes: F21S 43/40 characterised by the combination of reflectors and refractors

Abstract

A vehicle lamp having a light source formed from a plurality of LEDs. The vehicle lamp has a plurality of Fresnel lenses for converting light from the LEDs to parallel light, and are provided in front of the light source. A diffusion lens having a plurality of diffusion lens elements is provided in front of the plurality of Fresnel lenses. The vehicle lamp also has a condenser lens that receives light from the plurality of diffusion lens, and the condenser lens is provided in front of the diffusion lens. Light from each LED is converted to parallel light, diffused by the diffusion lens and then concentrated by the condenser lens before being emitted in the forward direction of the lighting device. The maximum diffusion angle and luminous intensity distribution of the forward emission light of the lighting device can readily be set at target values by properly adjusting the shapes of the respective diffusion lens elements and the condenser lens. Moreover, luminosity of the whole light source can be made substantially uniform over a broad luminescent area.

Claims

1. A vehicle lamp comprising a light source having a plurality of LEDs, and further comprising:

a plurality of Fresnel lenses provided in front of said light source;

a diffusion lens having a plurality of diffusion lens elements, said diffusion lens provided in front of said plurality of Fresnel lenses; and

a condenser lens provided in front of said diffusion lens.

2. The vehicle lamp as claimed in claim 1, wherein said light source, said plurality of Fresnel lenses, said diffusion lens and said condenser lens comprise a single light emitting unit.

3. The vehicle lamp as claimed in claim 2, wherein a plurality of light emitting units are provided at predetermined intervals on the circumference of a circle.

4. The vehicle lamp as claimed in claim 3, wherein a dome-shaped panel having an opening portion is provided in the front portion of each light emitting unit among said plurality of light emitting units.

5. The vehicle lamp as claimed in claim 4, wherein each opening portion in said dome-shaped panel comprises a cylindrical portion extending towards each condenser lens of each light emitting unit while maintaining the outer peripheral shape of said opening portion.

6. The vehicle lamp as claimed in claim 5, wherein the inner peripheral surface of each of the cylindrical portions in said dome-shaped panel is mirror reflection processed.

7. The vehicle lamp as claimed in claim 1, wherein said plurality of LEDs are mounted on a plurality of printed boards, and each of said printed boards has an edge face having an irregular shape.

8. The vehicle lamp as claimed in claim 1, wherein each of said plurality of diffusion lens elements comprises a fish-eye lens.

9. The vehicle lamp as claimed in claim 1, wherein said condenser lens is a planoconvex lens having a convex surface on a side facing away from said diffusion lens.

10. A vehicle lamp comprising a light source having a plurality of LEDs that emit light, and further comprising:

a plurality of Fresnel lenses that convert light from said light source to parallel light;

a diffusion lens having a plurality of diffusion lens elements, said diffusion lens diffusing the parallel light from said plurality of Fresnel lenses; and

a condenser lens that concentrates the diffused light from said diffusion lens.

11. The vehicle lamp as claimed in claim 10, wherein said plurality of Fresnel lenses, said diffusion lens and said condenser lens are provided along an optical axis of said light source.

12. The vehicle lamp as claimed in claim 10, wherein said light source, said plurality of Fresnel lenses, said diffusion lens and said condenser lens comprise a single light emitting unit.

13. The vehicle lamp as claimed in claim 12, wherein a plurality of light emitting units are provided at predetermined intervals on the circumference of a circle.

14. The vehicle lamp as claimed in claim 13, wherein a dome-shaped panel having an opening portion is provided in a front portion of each light emitting unit among said plurality of light emitting units.

15. The vehicle lamp as claimed in claim 14, wherein each opening portion in said dome-shaped panel comprises a cylindrical portion extending towards each condenser lens of each light emitting unit.

16. The vehicle lamp as claimed in claim 15, wherein the inner peripheral surface of each of the cylindrical portions in said dome-shaped panel is mirror reflection processed.

17. The vehicle lamp as claimed in claim 10, wherein each of said plurality of diffusion lens elements comprises a fish-eye lens.

18. The vehicle lamp as claimed in claim 10, wherein said condenser lens is a planoconvex lens having a convex surface on a side facing away from said diffusion lens.

20. The vehicle lamp as claimed in claim 19, wherein said plurality of Fresnel lenses, said diffusion mean and said condenser means are provided along an optical axis of said light source.

19. A vehicle lamp comprising a light source having a plurality of LEDs that emit light, and further comprising:

a plurality of Fresnel lenses that convert light from said light source to parallel light;

a diffusion means for diffusing the parallel light from said plurality of Fresnel lenses; and

a condenser means for condensing the diffused light from said diffusion lens.