Light-emitting device, illumination device, and vehicle headlamp

Patent metadata

Field	Value
Publication number	US-10514151-B2
Application number	US-201816044969-A
Country	US
Kind code	B2
Filing date	Jul 25, 2018
Priority date	Jan 18, 2012
Publication date	Dec 24, 2019
Grant date	Dec 24, 2019

Abstract

A headlamp includes a light-emitting section which emits fluorescence upon receiving excitation light from a laser element. Energy intensity distribution of the excitation light, which is received by the light-emitting section, is a top-hat distribution.

First claim

The invention claimed is:

1. A light-emitting device, comprising:
a first optical member which transmits excitation light emitted from an excitation light source and has an exit surface through which the excitation light goes out;
a second optical member which receives the excitation light which has come out through the exit surface; and
a light-emitting section
the second optical member controlling a spot size of the excitation light and directing the excitation light of the controlled spot size to the light-emitting section,
the light-emitting section emitting fluorescence upon receiving the excitation light which has come out of the second optical member,
the exit surface and a spot of the excitation light on a light irradiation surface of the light-emitting section being optically conjugate with each other,
the first optical member being a multimode fiber, and
the multimode fiber converting an energy intensity distribution of the excitation light, which has been emitted from the excitation light source, into a top-hat distribution.

2. The light-emitting device of claim 1 , wherein:
a region of the exit surface through which the excitation light passes has at least one linear edge.

3. The light-emitting device of claim 1 , wherein:
the exit surface is a planar surface.

4. An illumination device comprising a light-emitting device of claim 1 .

5. A vehicle headlamp comprising an illumination device of claim 4 .

Assignees

• Sharp Kk

Inventors

• Takahira Yoshiyuki
• Takahashi Koji
• Maemura Yosuke
• Kijima Hiroshi

Classifications

• F21V9/00 Primary

  Elements for modifying spectral properties, polarisation or intensity of the light emitted, e.g. filters (coloured shades F21V1/00; elements characterised by cooling arrangements F21V29/502) · CPC title

• G02B6/4207

  with optical elements reducing the sensitivity to optical feedback (anti-reflection devices specially adapted for lasers, see H01S3/0064) · CPC title

• F21V9/30

  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 title

• G02B27/0994

  Fibers, light pipes (optical fibers per se G02B6/02) · CPC title

• F21S41/176

  Light sources where the light is generated by photoluminescent material spaced from a primary light generating element · CPC title