Light-emitting device with coated phosphor

• US 7,202,598 B2
• Filed: 10/16/2001
• Issued: 04/10/2007
• Est. Priority Date: 10/17/2000
• Status: Active Grant

• Current Assignee: Lumileds LLC (Apollo Global Management, Inc.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Juestel, Thomas, Ronda, Cornelis Reinder, Schmidt, Peter, Mayr, Walter, Weiler, Volker Ulrich
• Primary Examiner(s): Guharay; Karabi
• Application Number:
  US09/978,995
• Publication Number:
  US 20020105266A1
• Time in Patent Office: 2,002 Days
• Field of Search: 313/498, 313/499, 313/907, 313/502, 313/509, 313/512, 313/501, 313/503, 428/690, 428/917, 428/212, 315/169.3, 359/58, 359/60, 438/26, 438/27, 438/28, 438/29, 438/34, 252/301.4 R
• US Class Current: 313/503
• CPC Class Codes: C09K 11/025 non-luminescent particle coatings or suspension media
• CPC Class Codes: C09K 11/7731 with alkaline earth metals
• CPC Class Codes: C09K 11/7774 Aluminates
• CPC Class Codes: H01L 33/501 characterised by the materials, e.g. binder

Abstract

The invention describes a light-emitting device (1) which comprises a light-emitting diode and a phosphor layer. To prolong the useful life of the light-emitting device (1), a phosphor (4) in the phosphor layer (2) has a water-resistant coating.

Claims

1. A light-emitting device provided with at least one light-emitting diode and a phosphor layer which comprises at least a phosphor comprised of phosphor particles with a coating, characterized in that the coating is a glass material.

2. A light-emitting device as claimed in claim 1, characterized in that the glass material is chosen from the group consisting of borosilicates, phosphosilicates, and alkali silicates.

3. A light-emitting device as claimed in claim 1, characterized in that the phosphor is chosen from the group to consisting of oxidic phosphors, sulfidic phosphors, aluminate phosphors, borate phosphors, vanadate phosphors and silicate phosphors.

4. A light-emitting device as claimed in claim 3, characterized in that the aluminate phosphor is chosen from the group consisting of Y₃Al₅O₁₂:

Ce, (Y, Gd)₃(Al,Ga)₅O₁₂;

Ce and BaMgAl₁₀O₁₇;

Eu, Mn.

5. A light-emitting device as claimed in claim 3, characterized in that the sulfide phosphor is chosen from the group consisting of SrS:

Eu, SrGa₂S₄;

Eu, (Sr,Ca,Ba) (AlGa)₂S₄;

Eu, SrY₂S₄;

Eu, (CaSr)S;

Eu, (Mg,Ca)S;

Eu, SrS;

Ce, CaS;

Ce, CaLa₂S₄;

Ce and CaS;

Ce,Eu.

6. A light-emitting device as claimed in claim 1, characterized in that the phosphor layer comprises SrS;

Eu with a coating of SiO₂ and a silicate glass.

7. A light-emitting device provided with at least one light-emitting diode and a phosphor layer which comprises at least a phosphor comprised of phosphor particles with a coating, characterized in that the coating is an inorganic borate material.

8. A light-emitting device provided with at least one light-emitting diode and a phosphor layer which comprises at least a phosphor comprised of phosphor particles with a coating, characterized in that the phosphor is chosen from the group consisting of aluminate and vandate phosphors, the coating comprises a glass material chosen from the group consisting of borosilicates, phosphosilicates and alkali silicates.