Light emitting device

• US 20040207998A1
• Filed: 03/10/2004
• Published: 10/21/2004
• Est. Priority Date: 03/10/2003
• Status: Active Grant

• Current Assignee: Sumita Optical Glass, Inc., Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Original Assignee: Sumita Optical Glass, Inc., Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Inventors: Kato, Hideaki, Suehiro, Yoshinobu, Inoue, Mitsuhiro, Terajima, Tohru, Aida, Kazuya, Sawanobori, Naruhito
• Granted Patent: US 7,319,289 B2
• Time in Patent Office: Days
• US Class Current: 362/84
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48257 connecting the wire to a die pad of the item
• CPC Class Codes: H01L 2224/8592 Applying permanent coating, e.g. protective coating
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 33/501 characterised by the materials, e.g. binder
• CPC Class Codes: H01L 33/56 Materials, e.g. epoxy or silicone resin

Abstract

A light emitting device has a light emitting element, and a phosphor layer of phosphor glass to generate fluorescence while being excited by light emitted from the light emitting element. The light emitting element emits ultraviolet light, and the phosphor glass generates visible fluorescence while being excited by the ultraviolet light.

Claims

1. A light emitting device, comprising:

a light emitting element; and

a phosphor layer that is composed of phosphor glass to generate fluorescence while being excited by light emitted from the light emitting element;

wherein the light emitting element emits ultraviolet light, and the phosphor glass generates visible fluorescence while being excited by the ultraviolet light.

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

the phosphor glass contains, as glass component, at least one of Tb³⁻

(terbium), Eu²⁺ (divalent europium) and Eu³⁻

(trivalent europium).

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

the phosphor layer is composed of a plurality of layers that are of different kinds of the phosphor glasses.

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

the phosphor glass is particle-shaped, and the phosphor layer is composed of a transparent material and the particle-shaped phosphor glass that is dispersed in the transparent material.

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

the particle-shaped phosphor glass is composed of different kinds of the particle-shaped phosphor glasses.

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

the phosphor layer is further composed of a phosphor material other than the phosphor glass, the phosphor material being dispersed in the transparent material.

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

the transparent material is low-melting glass or synthetic resin.

8. A light emitting device, comprising:

a light emitting element;

an optical system that converges light emitted from the light emitting element;

wherein the optical system is composed of phosphor glass.