Light emitting device, illumination device, and vehicle headlamp

• US 9,366,399 B2
• Filed: 01/14/2015
• Issued: 06/14/2016
• Est. Priority Date: 03/03/2011
• Status: Active Grant

• Current Assignee: Sharp Fukuyama Laser Co., Ltd. (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Takahira, Yoshiyuki, Maemura, Yosuke, Fukai, Yasuo, Takahashi, Koji
• Primary Examiner(s): Lee, Y M
• Application Number:
  US14/596,808
• Publication Number:
  US 20150124432A1
• Time in Patent Office: 517 Days
• US Class Current: 1/1
• CPC Class Codes: B60Q 1/28 for indicating front of vehicle
• CPC Class Codes: F21K 9/64 using wavelength conversion means distinct or spaced from the light-generating element, e.g. a remote phosphor layer
• 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 13/14 the elements being filters or photoluminescent elements, reflectors and refractors
• CPC Class Codes: F21V 29/74 with fins or blades
• 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: F21V 9/35 at focal points, e.g. of refractors, lenses, reflectors or arrays of light sources
• CPC Class Codes: F21V 9/38 Combination of two or more photoluminescent elements of different materials
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: F21Y 2115/30 Semiconductor lasers

Abstract

An illumination device 1 which is a light emitting device capable of emitting white light, includes: a laser element 2 for emitting a blue laser beam; a light emitting section 4 for generating fluorescence by be being irradiated with the blue laser beam emitted from the laser element 2; and a parabolic mirror 5 for reflecting the fluorescence generated from the light emitting section 4, the parabolic mirror 5 being disposed on an irradiated surface side which irradiated surface is a surface of the light emitting section 4 which surface is irradiated with the blue laser beam. This allows the illumination device 1 to efficiently project the white illumination light.

Claims

1. A light emitting device capable of emitting white light, comprising:

an excitation light source for emitting blue excitation light and comprising a plurality of semiconductor lasers; and

a light emitting section containing a fluorescent material that emits fluorescence in an irradiated surface of the light emitting section when irradiated with the blue excitation light source, the irradiated surface being a surface to be irradiated with the blue excitation light,

the light emitting section further containing an excitation light scatterer in a form of particles in the irradiated surface, the excitation light scatterer being different from the fluorescent material and scattering the blue excitation light with which the irradiated surface is irradiated,

particles of the fluorescent material and the excitation light scatterer being irradiated with the blue excitation light in the irradiated surface, and

the plurality of semiconductor lasers being configured so that excitation blue laser beams from the semiconductor lasers are superposed on each other at a portion of the irradiated surface of the light emitting section.

2. The light emitting device as set forth in claim 1, wherein:

chromaticity of light outputted from the light emitting device is controlled by a ratio between an area of a region containing the fluorescent material and an area of a region containing the excitation light scatterer in the irradiated surface.