Lamp

• US 20050105301A1
• Filed: 11/10/2004
• Published: 05/19/2005
• Est. Priority Date: 11/19/2003
• Status: Active Grant

• Current Assignee: Koito Manufacturing Company Limited
• Original Assignee: Koito Manufacturing Company Limited
• Inventors: Tokida, Tsukasa, Takeda, Hitoshi
• Granted Patent: US 7,165,871 B2
• Time in Patent Office: Days
• US Class Current: 362/545
• 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 41/147 the main emission direction of the LED being angled to the optical axis of the illuminating device
• CPC Class Codes: F21S 41/153 arranged in a matrix
• CPC Class Codes: F21S 41/155 Surface emitters, e.g. organic light emitting diodes [OLED]
• 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: F21V 9/30 Elements containing photoluminescent material distinct from or spaced from the light source shades F21V1/17; globes, bowls or cover glasses F21V3/08, F21V3/12; refractors F21V5/10; reflectors F21V7/26, F21V7/30; elements with provision for controlling the spectral properties or intensity F21V9/40
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: F21Y 2115/30 Semiconductor lasers
• CPC Class Codes: H01S 5/0087 for illuminating phosphorescent or fluorescent materials, e.g. using optical arrangements specifically adapted for guiding or shaping laser beams illuminating these materials
• CPC Class Codes: H01S 5/02 Structural details or components not essential to laser action
• CPC Class Codes: H01S 5/02251 using optical fibres
• CPC Class Codes: H01S 5/4025 Array arrangements, e.g. constituted by discrete laser diodes or laser bar H01S5/42 takes precedence

Abstract

The lamp for generating light, comprises a semiconductor light emitting element for emitting light, a fluorescent material, provided away from the semiconductor light emitting element, a first optical member operable to focus the light generated by the semiconductor light emitting element on the fluorescent material; and a second optical member having an optical center at a position where the fluorescent material is provided, operable to emit light generated by the fluorescent material based on the light focused by the first optical member to an outside of the lamp. The lamp is used as a headlamp in a vehicle, and the second optical member emits the light generated by the fluorescent material to the outside of the lamp, so that the second optical member form sat least one of a part of a cut line that defines a boundary between a bright region and a dark region of the headlamp.

Claims

1. A lamp for generating light, comprising:

a semiconductor light emitting element for emitting light;

a fluorescent material, provided away from said semiconductor light emitting element;

a first optical member operable to focus the light generated by said semiconductor light emitting element on said fluorescent material; and

a second optical member having an optical center at a position where said fluorescent material is provided, operable to emit light generated by said fluorescent material based on the light focused by said first optical member to an outside of the lamp.

2. The lamp as claimed in claim 1, wherein

the lamp is used as a headlamp in a vehicle, and

said second optical member emits the light generated by said fluorescent material to the outside of the lamp, so that said second optical member forms at least one of a part of a cut line that defines a boundary between a bright region and a dark region of the headlamp.

3. The lamp as claimed in claim 2, wherein

said fluorescent material is provided in a forward direction of said semiconductor light emitting element,

said second optical member is a reflector that is provided between said semiconductor light emitting element and said fluorescent material, and reflects the light entered from said fluorescent material forward, wherein said reflector includes:

a light transmitting part operable to transmit light along a direction from said semiconductor light emitting element to said fluorescent material and, wherein

said first optical member is a lens operable to focus the light transmitted through said light transmitting part on said fluorescent material.

4. The lamp as claimed in claim 3, wherein

said light transmitting part is a hole, provided at a part of said second optical member, and

at least a part of said lens is fitted to said hole, so that said lens is fixed to said second optical member.

5. The lamp as claimed in claim 3, wherein

said semiconductor light emitting element generates ultraviolet light,

said lamp generates white light based on the ultraviolet light, and the lamp further comprises:

a transparent member made of material that transmits white light but obscures ultraviolet light, in a forward direction of said fluorescent material, operable to transmit an incident light entered from said fluorescent material via said second optical member to a front of the vehicle.

6. The lamp as claimed in claim 5, wherein said lamp further comprises:

a second reflector formed on a part on a rear plane in said transparent member, operable to reflect the light generated from said fluorescent material in a backward direction, wherein

said fluorescent material is coated to at least a part of said second reflector so that said fluorescent material is opposed to said transparent member across said second reflector, and

said second optical member reflects the light reflected by said second reflector forward, so that the reflected light is transmitted through said transparent member and said second optical member emits the reflected light to the outside of the lamp.

7. The lamp as claimed in claim 1, further comprising a plurality of said semiconductor light emitting elements, wherein

said first optical member focuses the light from the plurality of said semiconductor light emitting elements on said same fluorescent material.

8. The lamp as claimed in claim 3, further comprising

a light transmitting member made of material which transmits a light generated by said fluorescent material, to be extended along a direction from said second optical member to said fluorescent material, and wherein

said second optical member is formed on a part on a surface of said light transmitting member,

said lens is formed integrally with said light transmitting part, having the same material of said light transmitting member, and

said fluorescent material is coated on a part of a plane that is opposed to said second optical member in said light transmitting member.

9. The lamp as claimed in claim 3, further comprising

an optical fiber, wherein said optical fiber receives the light generated by said semiconductor light emitting element at one end, and emits the light from the other end, wherein

said first optical member focuses the light emitted from said optical fiber on said fluorescent material.

10. The lamp as claimed in claim 1, wherein said semiconductor light emitting element is a laser diode.