Light source and vehicle lamp

• US 7,753,573 B2
• Filed: 07/23/2007
• Issued: 07/13/2010
• Est. Priority Date: 09/17/2003
• Status: Active Grant

• Current Assignee: Stanley Electric Company Limited
• Original Assignee: Stanley Electric Company Limited
• Inventors: Yatsuda, Yasushi, Harada, Mitsunori
• Primary Examiner(s): O'Shea; Sandra L
• Assistant Examiner(s): Dunwiddie; Meghan K
• Application Number:
  US11/781,337
• Publication Number:
  US 20070263403A1
• Time in Patent Office: 1,086 Days
• Field of Search: 362/84, 362298-300, 362/459, 362/539, 362/545, 362/800, 257/98
• US Class Current: 362/539
• CPC Class Codes: F21S 41/143 the main emission direction of the LED being parallel to the optical axis of the illuminating device
• CPC Class Codes: F21S 41/16 Laser light sources
• CPC Class Codes: F21S 41/176 Light sources where the light is generated by photoluminescent material spaced from a primary light generating element
• CPC Class Codes: F21S 41/43 characterised by the shape thereof
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/19107 off-chip wires
• CPC Class Codes: H01L 33/507 the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body
• CPC Class Codes: H01L 33/58 Optical field-shaping elements
• CPC Class Codes: H01L 33/60 Reflective elements
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

A light source for vehicles can include a base having a cavity formed on its upper surface, an LED chip mounted in the cavity of the base, a resin portion for sealing the LED chip in the cavity, an optical member disposed above the base and apart from the LED chip, a light shielding portion disposed on the inner surface of the optical member and which forms a cutoff suited for a light distribution pattern, and a fluorescent substance layer disposed at least in regions other than the light shielding portion on the inner surface of the optical member.

Claims

1. A light source device configured to emit light in a light emitting direction and along an optical axis, comprising:

a base having an upper surface and a cavity located at the upper surface;

an LED chip located adjacent the cavity of the base;

a resin portion located adjacent the LED chip;

an optical member disposed adjacent the upper surface of the base and separate from the LED chip and having an inner surface facing towards the LED chip;

a light shielding portion disposed adjacent the inner surface of the optical member and configured to form a cutoff suited for a light distribution pattern; and

a fluorescent substance layer disposed adjacent the inner surface of the optical member and at least in a region other than the light shielding portion when the device is viewed from the light emitting direction.

2. The light source device according to claim 1, wherein the base is formed from a ceramic material.

3. The light source device according to claim 1, wherein the optical member is a flat cover.

4. The light source device according to claim 1, wherein the light shielding portion is positioned within 2 mm from the LED chip.

5. The light source device according to claim 1, wherein the light shielding portion includes a thin film formed on the inner surface of the optical member.

6. The light source device according to claim 1, wherein the light shielding portion includes a plate member adhered to the inner surface of the optical member.

7. The light source device according to claim 6, wherein the plate member has a given thickness in a direction parallel to the optical axis that is substantially uniform about an entire extent of the plate member.

8. The light source device according to claim 1, further comprising:

a second light shielding portion disposed on an outer surface of the optical member.

9. The light source device according to claim 1, wherein an inner surface of the light shielding portion includes a reflection surface configured to reflect light emitted from the LED chip.

10. The light source device according to claim 9, wherein the reflection surface is disposed at an angle with respect to the optical axis so as to reflect light received from the LED chip at an angle with respect to the optical axis.

11. The light source device according to claim 10, wherein the base cavity includes a second reflection surface that is located and positioned to receive light that is reflected by the reflection surface of the light shielding portion from the LED chip towards the light emitting direction of the device.

12. The light source device according to claim 11, wherein the reflection surface includes a thin metal film formed on the light shielding portion.

13. The light source device according to claim 11, wherein the reflection surface includes a surface of the light shielding portion made of a metallic material.

14. The light source device according to claim 1, wherein the fluorescent substance layer is formed in thin film form.

15. The light source device according to claim 14, wherein the fluorescent substance layer is formed by impregnating silicon film with a fluorescent substance.

16. The light source device according to claim 15, wherein the optical member and an inner surface of the light shielding portion are each at least partially coated with a SiO₂ layer.

17. The light source device according to claim 14, wherein the fluorescent substance layer is thinner in a direction parallel to the optical axis with increasing distance from the optical axis.

18. The light source device according to claim 3, wherein an outer surface of the flat cover is provided with a microtexture structure at least in a region not corresponding to the light shielding portion.

19. The light source device according to claim 18, wherein the microtexture structure is formed on a surface of the flat cover.

20. A vehicle headlight comprising:

the light source device according to claim 1; and

a projection lens disposed adjacent the light source device and having a focus located substantially at the light shielding portion, wherein the projection lens is configured to irradiate emission light forward in a shape defined by the light shielding portion.

21. The light source device according to claim 1, wherein the light source device is configured as a vehicle headlight and the light shielding portion is configured to produce a low-beam vehicle light distribution.

22. A light source device configured to emit light in a light emitting direction and along an optical axis, comprising:

a base having an upper surface and a cavity located at the upper surface;

an LED chip located adjacent the cavity of the base;

a light shielding portion disposed adjacent the LED chip and configured to form a cutoff suited for a light distribution pattern, an inner surface of the light shielding portion including a reflection surface configured to reflect light emitted from the LED chip, wherein

the reflection surface is disposed at an angle with respect to the optical axis so as to reflect light received from the LED chip at an angle with respect to the optical axis, and

the base includes a base reflection portion that is located and positioned to receive light that is reflected by the reflection surface of the light shielding portion from the LED chip towards the light emitting direction of the device.

23. The light source device according to claim 22, wherein the reflection surface includes a thin metal film formed on the light shielding portion.

24. The light source device according to claim 22, wherein the base reflection portion is positioned at an angle with respect to the optical axis.

25. The light source device according to claim 22, further comprising:

a fluorescent substance layer disposed adjacent the LED chip and at least in a region other than the light shielding portion when the device is viewed from the light emitting direction.

26. The light source device according to claim 22, further comprising:

an optical member disposed adjacent the upper surface of the base and separate from the LED chip and having an inner surface facing towards the LED chip.