IP Library Granted Patent US 8,476,657
Granted Patent B2
US 8,476,657 · App. 12/625,993 · Granted Jul 2, 2013

Light-emitting device

Inventors: Osamu Kawasaki (Osaka, JP); Toshio Hata (Osaka, JP)
Assignee: Sharp Kabushiki Kaisha
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Quick Facts
Patent No.
US 8,476,657
App. No.
12/625,993
Granted
Jul 2, 2013
Kind
B2
Abstract

To provide a light emitting device easy to produce and extracting light to its outside with high efficiency, the light-emitting device 70 of the present invention includes an insulating base 10 ; a light-emitting element 1 mounted on a side of the base 10 ; and a protection element 2 mounted on the side and protecting the light-emitting element 1 . The element 2 is covered with a light-reflecting filler-containing resin 5 , which is prepared by causing a flexible silicone resin to contain, before being cured, light-reflecting or light-scattering fillers 5 a having a particle diameter larger than the wavelength of light emitted by the element 1 . This causes light emitted from the element 1 to be reflected by the resin 5 , instead of being absorbed by the element 2 , so that such light is released to the outside of the light-emitting device 70 . This allows the device 70 to extract light to the outside with high efficiency, and also allows for easy formation of the resin 5 having a desired pattern and position.

Claims (35)

1. A light-emitting device comprising:

a base which is electrically insulating;

a light-emitting element mounted on one side with respect to the base;

a protection element mounted on the side and protecting the light-emitting element;

a light-reflecting member which reflects light and which covers the protection element, the light-reflecting member including a flexible transparent member and a filler, wherein the filler is added in the transparent member before the transparent member is cured, the filler reflecting or scattering the light and having a particle diameter larger than a wavelength of light emitted by the light-emitting element; and

a light-reflecting wall provided on the side, the light-reflecting wall being light-reflective and surrounding the light-emitting element;

wherein:

the light-reflecting wall has a recess at a portion thereof, and the protection element is disposed in the recess;

the light-reflecting member has a surface continuous with the light-reflecting wall;

the surface of the light-reflecting member and the light-reflecting wall form a light-reflecting surface together, the light-reflecting surface reflecting the light from the light-emitting element toward an outside of the light-emitting device;

the light-reflecting surface is a continuous surface surrounding the light-emitting element; and,

the light-emitting element is not covered with the light-reflecting member.

2. A light-emitting device comprising:

a base which is electrically insulating;

a light-emitting element mounted on one side with respect to the base;

a protection element mounted on the side and protecting the light-emitting element;

a light-reflecting member which reflects light and which covers the protection element,

the light-reflecting member including a flexible transparent member and a filler, wherein the filler is added in the transparent member before the transparent member is cured, the filler reflecting or scattering the light and having a particle diameter larger than a wavelength of light emitted by the light-emitting element; and

a light-reflecting wall provided on the side, the light-reflecting wall being light-reflective and surrounding the light-emitting element,

wherein:

the light-reflecting member has a surface continuous with the light-reflecting wall;

the surface of the light-reflecting member and the light-reflecting wall form a light-reflecting surface together, the light-reflecting surface reflecting the light from the light-emitting element toward an outside of the light-emitting device; and

the light-emitting element is not covered with the light-reflecting member.

3. The light-emitting device according to claim 1 , wherein: a first portion of the light-reflecting surface is identical in shape to a second portion thereof, where the first portion is formed with the light-reflecting member, and the second portion is formed with the light-reflecting wall.

4. The light-emitting device according to claim 1 , further comprising:

two electrodes formed on the base; and

a light-reflecting member in at least part of a gap between the electrodes.

5. The light-emitting device according to claim 1 , wherein the light-emitting element is covered with a light-transmitting member.

6. The light-emitting device according to claim 5 , wherein the light-transmitting member contains a fluorescent material which absorbs light from the light-emitting element and which emits light having a wavelength longer than a wavelength of the light thus absorbed.

7. The light-emitting device according to claim 1 , wherein a plurality of the protection elements are provided and covered with the light-reflecting member.

8. The light-emitting device according to claim 1 , wherein the protection element protects the light-emitting element against an overheat, an overvoltage, or an overcurrent.

9. The light-emitting device according to claim 1 , wherein the protection element comprises a Zener diode which protects the light-emitting element against a reverse voltage applied to the light-emitting element or a forward overvoltage applied thereto.

10. The light-emitting device according to claim 1 , wherein the transparent member comprises a transparent resin or glass.

11. The light-emitting device according to claim 10 , wherein the filler comprises TiO 2 , SiO 2 , alumina, aluminum nitride, or mullite.

12. The light-emitting device according to claim 10 , wherein the transparent resin comprises an epoxy resin, a urea resin, silicone, a modified epoxy resin, a modified silicone resin, or polyamide.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 26, 2018
From: SHARP KABUSHIKI KAISHA
To: XIAMEN SAN'AN OPTOELECTRONICS CO., LTD.
Reel/Frame 047331/0728 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Nov 25, 2009
From: KAWASAKI, OSAMU; HATA, TOSHIO
To: SHARP KABUSHIKI KAISHA
Reel/Frame 023571/0230 →
Priority Claims (1)
JP 2008-304733 · Nov 28, 2008 · national
Continuity (1)
Related Publication 20100133571A1 · Jun 3, 2010