Optical element, vehicle headlight, light source device, and projection device

Patent metadata

Field	Value
Publication number	US-2022170613-A1
Application number	US-202017439766-A
Country	US
Kind code	A1
Filing date	Mar 10, 2020
Priority date	Mar 19, 2019
Publication date	Jun 2, 2022
Grant date	—

Abstract

An optical element includes: a phosphor layer excited by excitation light emitted from a light source, and emitting fluorescence; a translucent thermal-conductive layer formed on a face of the phosphor layer that is irradiated with the excitation light; and a non-translucent thermal-conductive layer formed on a face of the phosphor layer that is across from the face irradiated with the excitation light. The translucent thermal-conductive layer has a thermal conductivity higher than, or equal to, a thermal conductivity of the phosphor layer.

First claim

1 - 12 . (canceled)

13 . An optical element, comprising:
a phosphor layer excited by excitation light emitted from a light source, and configured to emit fluorescence; a translucent thermal-conductive layer formed in direct contact with on a face of the phosphor layer that is irradiated with the excitation light; and a non-translucent thermal-conductive layer formed on a face of the phosphor layer that is across from the face irradiated with the excitation light, the translucent thermal-conductive layer having a thermal conductivity higher than, or equal to, a thermal conductivity of the phosphor layer, and the phosphor layer including at least: a binder; and phosphor particles.

14 . The optical element according to claim 13 , wherein
the translucent thermal-conductive layer is mainly made of a material included in the binder.

15 . The optical element according to claim 13 , wherein
the translucent thermal-conductive layer covers a part of a region irradiated with the excitation light.

16 . The optical element according to claim 13 , wherein
the translucent thermal-conductive layer has a region that is exposed to be irradiated with the excitation light in a surface opposite to a surface facing the phosphor layer of the translucent thermal-conductive layer.

17 . The optical element according to claim 13 , wherein
the translucent thermal-conductive layer exposes a part of a region of the phosphor layer irradiated with the excitation light, and the translucent thermal-conductive layer covers a region except the part of the region of the phosphor layer irradiated with the excitation light.

18 . The optical element according to claim 17 , wherein
the part of the region is a center region of the region of the phosphor layer irradiated with the excitation light.

19 . The optical element according to claim 13 , wherein
in the translucent thermal-conductive layer, an average thickness of a region not irradiated with the excitation light is greater than an average thickness of a region irradiated with the excitation light.

20 . The optical element according to claim 13 , wherein the translucent thermal-conductive layer is further formed on a side face of the phosphor layer.

21 . The optical element according to claim 13 , further comprising
a thermal-conductive layer formed at least: on a portion of a side face of the translucent thermal-conductive layer; and in a portion of a region not irradiated with the excitation light.

22 . The optical element according to claim 13 , wherein
the non-translucent thermal-conductive layer includes a fluorescence obtainment hole for obtaining the fluorescence.

23 . The optical element according to claim 22 , wherein
the fluorescence obtainment hole is provided with a fluorescence obtainment member.

24 . A vehicle headlight, comprising:
the optical element according to claim 13 ; a light source configured to emit excitation light to the optical element; and a reflector including a reflective face reflecting fluorescence exiting from the optical element, the reflective face of the reflector reflecting the fluorescence, exiting from the optical element, to exit parallel in a certain direction.

25 . A vehicle headlight, comprising:
the optical element according to claim 22 ; a light source configured to emit excitation light to the optical element; and a reflector including a reflective face reflecting fluorescence exiting from the optical element, the light source emitting incident light from the translucent thermal-conductive layer, and the reflective face of the reflector reflecting the fluorescence, exiting from the non-translucent thermal-conductive layer, to exit parallel in a certain direction.

26 . A light source device, comprising:
a light source configured to emit excitation light; a fluorescent wheel having at least a circumferential portion through which the excitation light emitted from the light source passes, the circumferential portion being provided with the optical element according to claim 13 ; and a driver configured to rotate the fluorescent wheel.

27 . A projection device, comprising:
the light source device according to claim 26 ; a display element; a light source optical system configured to guide light from the light source device to the display element; and a projector optical system configured to project projection light from the display element on a projection target.

Assignees

• Sharp Kk

Inventors

• UEKI Tomoko
• Aomori Shigeru
• Matsukiyo Hidetsugu

Classifications

• F21V9/32 Primary

  characterised by the arrangement of the photoluminescent material · CPC title

• G03B21/16

  Cooling; Preventing overheating · CPC title

• G03B21/204

  using secondary light emission, e.g. luminescence or fluorescence (using different colours G03B33/00; if related to video signals H04N9/3197) · CPC title

• F21S41/16

  Laser light sources · CPC title

• F21S41/176 Primary

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