VEHICLE LAMP

• US 20090257240A1
• Filed: 02/23/2009
• Published: 10/15/2009
• Est. Priority Date: 02/22/2008
• Status: Active Grant

• Current Assignee: Stanley Electric Company Limited
• Original Assignee: Stanley Electric Company Limited
• Inventors: KOIKE, Teruo
• Granted Patent: US 8,070,339 B2
• Time in Patent Office: Days
• US Class Current: 362/538
• CPC Class Codes: F21S 41/147 the main emission direction of the LED being angled to the optical axis of the illuminating device
• CPC Class Codes: F21S 41/275 Lens surfaces, e.g. coatings or surface structures
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]

Abstract

A vehicle lamp including a projector headlight using an LED light source for a low beam can include a shade, an LED light source, an ellipsoidal reflector and a projector lens. Both a focus of the projector lens and a top edge of the shade can be located near a second focus of the reflector. The LED light source can be located near a first focus located below the second focus of the reflector. Therefore, light emitted from the LED light source can be effectively gathered near the focus of the projector lens via the reflector and can be projected via the projector lens with high light use-efficiency. The projector lens can include light dispersing portions or structures on an upside and downside thereof for reducing chromatic aberration. Thus, the lamp can project a favorable light distribution that can conform to light distribution standards for vehicle headlights and the like.

Claims

1. A projector headlight, comprising:

a shade having a top edge;

a circuit board having a mounting surface and a virtual substantially co-planar extension of the mounting surface substantially intersecting with the top edge of the shade;

an LED light source mounted on the mounting surface of the circuit board and having an optical axis extending substantially perpendicular to the mounting surface of the circuit board;

at least one ellipsoidal reflector having a first focus and a second focus, the first focus located substantially at the LED light source, and the second focus located substantially at the top edge of the shade; and

a projector lens configured as a convex lens having both a lens optical axis and a focus located on the lens optical axis, the lens optical axis substantially intersecting with the second focus of the at least one ellipsoidal reflector at the focus of the projector lens and substantially intersecting with both the optical axis of the LED light source and the virtual substantially co-planar extension of the mounting surface of the circuit board located below the lens optical axis, wherein the projector lens includes a first light dispersing surface portion structure located above the lens optical axis and a second light dispersing surface portion structure located below the lens optical axis and a light transmission surface located between the first light dispersing surface portion structure and the second light dispersing surface portion structure, wherein the first light dispersing surface portion structure and second light dispersing surface portion structure disperse light to a different degree as compared to the light transmission surface when light from the LED light source transmits therethrough.

2. The projector headlight according to claim 1, wherein an intersecting angle between the lens optical axis and the virtual substantially co-planar extension of the mounting surface of the circuit board is 45 degrees or less.

3. The projector headlight according to claim 1, wherein the LED light source includes at least one blue LED chip and a yellow phosphor.

4. The projector headlight according to claim 2, wherein the LED light source includes at least one blue LED chip and a yellow phosphor.

5. The projector headlight according to claim 1, wherein a total area of the second light dispersing surface portion structure formed below the lens optical axis is larger than a total area of the first light dispersing surface portion structure formed above the lens optical axis.

6. The projector headlight according to claim 4, wherein a total area of the second light dispersing surface portion structure formed below the lens optical axis is larger than a total area of the first light dispersing surface portion structure formed above the lens optical axis.

7. The projector headlight according to claim 1, wherein both the first and second light dispersing surface portion structures are integrally cast into the projector lens and the projector lens includes a transparent thermoplastic material.

8. The projector headlight according to claim 2, wherein both the first and second light dispersing surface portion structures are integrally cast into the projector lens and the projector lens includes a transparent thermoplastic material.

9. The projector headlight according to claim 3, wherein both the first and second light dispersing surface portion structures are integrally cast into the projector lens and the projector lens includes a transparent thermoplastic material.

10. The projector headlight according to claim 4, wherein both the first and second light dispersing surface portion structures are integrally cast into the projector lens and the projector lens includes a transparent thermoplastic material.

11. The projector headlight according to claim 5, wherein both the first and second light dispersing surface portion structures are integrally cast into the projector lens and the projector lens includes a transparent thermoplastic material.

12. The projector headlight according to claim 6, wherein both the first and second light dispersing surface portion structures are integrally cast into the projector lens and the projector lens includes a transparent thermoplastic material.

16. A vehicle lamp including the projector headlight according to claim 2, further comprising:

a housing;

a headlight for a high beam attached to the housing; and

an outer lens located adjacent the housing.

17. A vehicle lamp including the projector headlight according to claim 6, further comprising:

a housing;

a headlight for a high beam attached to the housing; and

an outer lens located adjacent the housing.

19. The vehicle lamp according to claim 16, wherein the headlight for a high beam includes a projector headlight using an LED light source.

20. The vehicle lamp according to claim 17, wherein the headlight for a high beam includes a projector headlight using an LED light source.

13. A projector headlight, comprising:

a casing including a shade having a top edge;

a heat sink;

a circuit board having a mounting surface located adjacent the heat sink, wherein a virtual substantially co-planar extension of the mounting surface substantially intersects with the top edge of the shade;

an LED light source located adjacent the mounting surface of the circuit board, the LED light source includes an optical axis extending substantially perpendicularly with respect to the mounting surface of the circuit board;

at least one ellipsoidal reflector having a first focus and a second focus, one end of the reflector attached to the casing and another end of the reflector located adjacent the circuit board, the first focus of the reflector being located substantially at the LED light source, and the second focus of the reflector being located substantially at the top edge of the shade; and

a projector lens configured as a convex lens having a lens optical axis and a focus located on the lens optical axis, the lens optical axis substantially intersecting with both the second focus of the at least one ellipsoidal reflector at the focus of the projector lens and the optical axis of the LED light source, the lens optical axis intersecting at an angle of substantially 45 degrees or less with the virtual substantially co-planar extension of the mounting surface of the circuit board located below the lens optical axis, wherein the projector lens includes both a smaller light dispersing portion located above the lens optical axis and a relatively larger light dispersing portion located below the lens optical axis, the larger light dispersion portion being larger in total area than a total area of the smaller light dispersing portion located above the lens optical axis.

14. The projector headlight according to claim 13, wherein the smaller and larger light dispersing portions are integrally cast into the projector lens with a transparent thermoplastic and the projector lens is attached to the casing.

15. A vehicle lamp including the projector headlight according to claim 14, further comprising:

a housing;

a headlight for a high beam attached to the housing; and

an outer lens located adjacent the housing.

18. The vehicle lamp according to claim 15, wherein the headlight for a high beam includes a projector headlight using an LED light source.