IP Library Granted Patent US 11,189,987
Granted Patent B2
US 11,189,987 · App. 16/103,905 · Granted Nov 30, 2021

Light emitting device

Inventor: Soichiro Miura (Tokushima, JP)
Assignee: NICHIA CORPORATION
H01S5/0087H01S5/0071H01S5/024H01S5/028H01S5/02255H01S5/4075H01S5/4081F21S41/16F21S41/176F21S43/16H01S5/0222H01S5/02216H01S5/02257H01S5/32341H01S5/4025H01S2301/206
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Quick Facts
Patent No.
US 11,189,987
App. No.
16/103,905
Granted
Nov 30, 2021
Kind
B2
Abstract

A light emitting device includes: one or more semiconductor laser elements; one or more light-reflecting parts, each having a light-reflecting surface configured to reflect laser light emitted from a corresponding one of the one or more semiconductor laser elements; and a fluorescent part having a light-receiving surface configured to be irradiated with the laser light reflected at the light-reflecting surface of each of the one or more light-reflecting parts. An irradiated region is formed on the light-reflecting surface when the light-reflecting surface is irradiated with the laser light, the irradiated region including a first end and a second end opposite the first end.

Claims (51)

1. A light emitting device comprising:

one or more semiconductor laser elements, each configured to emit laser light;

one or more light-reflecting parts, each having a light-reflecting surface configured to reflect the laser light emitted from a corresponding one of the one or more semiconductor laser elements; and

a fluorescent part having a light-receiving surface configured to be irradiated with the laser light reflected at the light-reflecting surface of each of the one or more light-reflecting parts;

wherein an irradiated region is formed on the light-reflecting surface when the light-reflecting surface is irradiated with the laser light, the irradiated region including a first endmost portion and a second endmost portion opposite the first endmost portion;

wherein the light-reflecting surface of each of the one or more light-reflecting parts is arranged such that the following occur simultaneously when the light-reflecting surface is irradiated with the laser light:

(i) a portion of the laser light reflected at the first endmost portion of the irradiated region and a portion of the laser light reflected at a location other than the first endmost portion of the irradiated region are overlapped with each other on the light-receiving surface,

(ii) a portion of the laser light reflected at the second endmost portion of the irradiated region and a portion of the laser light reflected at a location other than the second endmost portion of the irradiated region are overlapped with each other on the light-receiving surface, and

(iii) a portion of the laser light reflected at the first endmost portion of the irradiated region and a portion of the laser light reflected at the second endmost portion of the irradiated region are not overlapped with each other on the light-receiving surface.

2. The light emitting device according to claim 1 , wherein:

the light-reflecting surface of each of the one or more light-reflecting parts comprises a plurality of regions positioned at different angles with respect to a lower surface of the light-reflecting part;

the laser light from each of the one or more semiconductor laser elements is irradiated on the plurality of regions of a corresponding light-reflecting surface;

an irradiated region is formed on the light-receiving surface when the laser light reflected at each of the one or more light-reflecting parts is irradiated on the light-receiving surface, the irradiated region on the light-receiving surface includes a first endmost portion; and

a portion of the laser light reflected at a location other than the first endmost portion of the irradiated region on the light-reflecting surface of each of the one or more light-reflecting parts is irradiated on at least the first endmost portion of the irradiated region on the light-receiving surface.

3. The light emitting device according to claim 2 , wherein:

each of the one or more semiconductor laser elements is configured to emit laser light with a light intensity distribution higher at a center portion than at a peripheral portion of the irradiated region on the light-reflecting surface;

the irradiated region on the light-reflecting surface of each of the one or more light-reflecting parts comprises a first region including the first endmost portion and configured to reflect a portion of the laser light irradiated at least to the first endmost portion, and a second region including the second endmost portion and configured to reflect a portion of the laser light irradiated to the second endmost portion;

a portion of the laser light reflected at locations closer to the center portion of the first region is irradiated to the light-receiving surface at locations closer to the first endmost portion of the irradiated region on the light-receiving surface; and

the closer the location of a portion of the laser light reflected at locations to the center portion of the second region, the closer the location of the reflected laser light irradiated to a second endmost portion located at an opposite side of the first endmost portion of the irradiated region on the light-receiving surface.

4. The light emitting device according to claim 3 , wherein:

each of the one or more semiconductor laser elements is configured to emit a laser light having a far field pattern of an elliptic shape;

the irradiated region on the light-reflecting surface of each of the one or more light-reflecting parts has an elliptic shape that corresponds to the elliptic shape of the far field pattern irradiated on the light-reflecting surface, the irradiated elliptic shape of the far field pattern comprises two or more regions that include the first region and the second region, in a longitudinal direction of the elliptic shape;

the first region and the second region are arranged such that:

a portion of the laser light reflected at the first region at a location closer to the second region and a portion of the laser light reflected at the second region at a location away from the first region, are overlapped with each other on the light-receiving surface of the fluorescent part, and

a portion of the laser light reflected at the first region at a location away from the second region, and a portion of the laser light reflected at the second region at a location closer to the first region are overlapped with each other on the light-receiving surface of the fluorescent part.

5. The light emitting device according to claim 4 , wherein:

the plurality of regions of the irradiated region on the light-reflecting surface of each of the one or more light-reflecting parts further includes a third region located between the first region and the second region;

the third region is arranged such that:

a portion of the laser light reflected at the third region at a location closer to the first region and a portion of the laser light reflected at the first region at a location away from the second region are overlapped with each other on the light receiving surface of the fluorescent part, and

a portion of the laser light reflected at the third region at a location closer to the second region and a portion of the laser light reflected at the second region at a location away from the first region are overlapped with each other on the light receiving surface of the fluorescent part.

6. The light emitting device according to claim 3 wherein:

each of the one or more semiconductor laser elements is configured to emit a laser light having a far field pattern of an elliptic shape;

the irradiated region on the light-reflecting surface of each of the one or more light-reflecting parts has an elliptic shape that corresponds to the elliptic shape of the far field pattern irradiated on the light-reflecting surface, the irradiated elliptic shape of the far field pattern comprises three regions, including a first region, a second region, and a third region in a longitudinal direction;

the third region is located between the first region and the second region;

the first region is arranged such that a portion of the laser light reflected at the first region and a portion of the laser light reflected at the third region at a location closer to the first region or the second region are overlapped with each other on the light-receiving surface of the fluorescent part; and

the second region is arranged such that a portion of the laser light reflected at the second region and a portion of the laser light reflected at the third region at a location closer to the other of the first region or the second region are overlapped with each other on the light-receiving surface of the fluorescent part.

7. The light emitting device according to claim 6 , wherein the first region is arranged such that a portion of the laser light reflected at the first region and a portion of the laser light reflected at the third region at a location closer to the second region are overlapped with each other on the light-receiving surface of the fluorescent part; and the second region is arranged such that the laser light reflected at the second region and a portion of the laser light reflected at the third region at a location closer to the first region are overlapped with each other on the light-receiving surface of the fluorescent part.

8. The light emitting device according to claim 3 , wherein the first region and the second region are respectively arranged such that a light intensity distribution of the laser light reflected at the first region and a light intensity distribution of the laser light reflected at the second region have line symmetry in a direction corresponding to the longitudinal direction on the light receiving surface of the fluorescent part.

9. The light emitting device according to claim 3 , wherein the first region and the second region are flat surfaces.

10. The light emitting device according to claim 3 , wherein:

compared to the second region, the first region is located closer to corresponding one of the one or more semiconductor laser elements; and

an area of the first region is smaller than an area of the second region.

11. The light emitting device according to claim 1 wherein:

each of the one or more semiconductor laser elements is configured to emit a laser light having a far field pattern of an elliptic shape; and

the light-reflecting surface has a curved surface, and the curved surface is configured such that divergent angles of the laser light reflected at the regions corresponding to both endmost portions in a longitudinal direction of the elliptic shape of the far field pattern are smaller than a divergent angle of the laser light reflected at the region corresponding to a center portion in the longitudinal direction of the elliptic shape of the far field pattern, to obtain a light intensity distribution of the laser light at the light-receiving surface of the fluorescent part approaching uniformity.

12. The light emitting device according to claim 1 , wherein each of the light-reflecting parts is an optical element having at least one light-reflecting surface.

13. The light emitting device according to claim 1 wherein:

the light-receiving surface of the fluorescent part has a rectangular shape that is elongated in one direction;

the laser light is irradiated in a shape that is elongated in one direction on the light-receiving surface of the fluorescent part; and

the fluorescent part and the one or more semiconductor laser elements are disposed such that a longitudinal direction of the light-receiving surface of the fluorescent part and a longitudinal direction of the laser light reflected at the light-reflecting surface of each of the one or more light-reflecting parts are parallel to each other.

14. The light emitting device according to claim 1 , wherein the irradiated region on the light-reflecting surface is irradiated with the laser light having an intensity 1/e2 or greater with respect to a peak intensity value of the laser light.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 14, 2018
From: MIURA, SOICHIRO
To: NICHIA CORPORATION
Reel/Frame 046831/0933 →
Priority Claims (1)
JP JP2017-157063 · Aug 16, 2017 · national
Continuity (1)
Related Publication 20190058303A1 · Feb 21, 2019