Light emitting device

• US 20110316025A1
• Filed: 06/22/2011
• Published: 12/29/2011
• Est. Priority Date: 06/25/2010
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Electric Works Company Limited (Panasonic Holdings Corporation)
• Inventors: Kuzuhara, Ikko, Nishioka, Kouji
• Granted Patent: US 8,598,608 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: H01L 33/507 the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body

Abstract

A light emitting device includes a light emitting element, a first phosphor which emits a light by being excited by a light emitted from the light emitting element and a second phosphor which emits a light by being excited by the light emitted from the light emitting element and/or the light emitted from the first phosphor. The light emitted from the light emitting element, the light emitted from the first phosphor and the light emitted from the second phosphor are mixed to make an inclination angle of a line, on a chromaticity diagram, connecting a chromaticity coordinate of the light emitted from the first phosphor and a chromaticity coordinate of the light emitted from the light emitting element equal to an inclination angle of an isotemperature line of light of a predetermined color temperature.

Claims

1. A light emitting device comprising:

a light emitting element;

a first phosphor which emits a light by being excited by a light emitted from the light emitting element; and

a second phosphor which emits a light by being excited by the light emitted from the light emitting element and/or the light emitted from the first phosphor,

wherein the light emitted from the light emitting element, the light emitted from the first phosphor and the light emitted from the second phosphor are mixed to make an inclination angle of a line, on a chromaticity diagram, connecting a chromaticity coordinate of the light emitted from the first phosphor and a chromaticity coordinate of the light emitted from the light emitting element equal to an inclination angle of an isotemperature line of light of a predetermined color temperature.

2. The light emitting device of claim 1, wherein the chromaticity coordinate of the light emitted from the second phosphor is higher in an x coordinate value than the line, on the chromaticity diagram, connecting the chromaticity coordinate of the light emitted from the light emitting element and the chromaticity coordinate of the light emitted from the first phosphor.

3. The light emitting device of claim 1, wherein the first phosphor or the second phosphor is a combination of plural kinds of phosphor particles and is adjusted to emit a light of a desired chromaticity coordinate.

4. The light emitting device of claim 1, further comprising a sealing member made of a resin material which seals the light emitting element, wherein the first phosphor is dispersed in the resin material of the sealing member.

5. The light emitting device of claim 4, further comprising a covering member made of a resin material or glass, the covering member being provided in a light emitting direction of the sealing member, wherein the second phosphor is dispersed in the resin material or glass of the covering member.

6. The light emitting device of claim 5, wherein a gap is formed between the sealing member and the covering member.