Light emitting device, vehicle headlamp, illumination device, and laser element

• US 10,465,873 B2
• Filed: 03/12/2019
• Issued: 11/05/2019
• Est. Priority Date: 10/29/2010
• 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: Takahashi, Koji, Takahira, Yoshiyuki
• Primary Examiner(s): Gramling, Sean P
• Application Number:
  US16/299,995
• Publication Number:
  US 20190211989A1
• Time in Patent Office: 238 Days
• Field of Search: 362 84, 362257, 362259, 36231107-31109
• CPC Class Codes: B60Q 1/0035 relative to the 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: F21S 43/16 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 9/35 at focal points, e.g. of refractors, lenses, reflectors or arrays of light sources
• CPC Class Codes: F21V 9/40 with provision for controlling spectral properties, e.g. colour, or intensity
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: F21Y 2115/30 Semiconductor lasers
• 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

Abstract

A light emitting device of the present invention includes a light-emitting section for generating fluorescence by receiving a laser beam, and a light irradiation unit for irradiating a light irradiated surface of the light emitting section with a laser beam that increases regularly in beam diameter in a direction in which the laser beam travels.

Claims

1. A light emitting device comprising:

at least one excitation light source for emitting excitation light, each of the at least one excitation light source being a semiconductor laser;

at least one concave mirror for converging the excitation light emitted from the at least one excitation light source;

a light emitting section for emitting fluorescence by receiving the excitation light converged by the at least one concave mirror, the light emitting section having a first surface which receives the excitation light and a second surface which faces away from the first surface;

a heat sink which is in contact with the second surface of the light emitting section; and

another concave mirror for reflecting the fluorescence emitted from the light emitting section,

wherein the light emitting section and the another concave mirror are away from each other without contacting each other.

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

the at least one excitation light source includes a plurality of excitation light sources; and

the at least one concave mirror converges excitation light emitted from the plurality of excitation light sources.

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

the plurality of excitation light sources are bundled together in one position; and

excitation light emitted from each of the plurality of excitation lasers is converged by a single concave mirror.

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

the at least one concave mirror includes a plurality of concave mirrors;

the at least one excitation light source includes a plurality of excitation light sources; and

at least one excitation light source among the plurality of excitation light sources is provided for each of the plurality of concave mirrors.

5. The light-emitting device as set forth in claim 4, wherein:

the plurality of concave mirrors are formed integral with each other.

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

at least a part of the another concave mirror is positioned above an upper surface of the light emitting section, the upper surface having a larger area than that of a side surface of the light emitting section, and

the light emitting section (i) has a small thickness or (ii) has an excitation light irradiated surface which has a larger area than that of a spot of the excitation light on the excitation light irradiated surface of the light emitting section.

7. A vehicle headlamp comprising:

a light emitting device recited in claim 1.

8. An illumination device comprising:

a light emitting device recited in claim 1.