Red-deficiency compensating phosphor light emitting device

US6680569B2 · kind B2 · utility

Assignee

• Lumileds Lighting US, LLC · US

Inventors

• Regina B. Mueller-Mach · San Jose, US
• Gerd O. Mueller · San Jose, US
• Tomas Jüestel · Aachen, DE
• Peter Josef Schmidt · Aachen, DE

Key dates

• Filing date: Feb 25, 2002
• Grant date: Jan 20, 2004
• Expiry date: Feb 25, 2022

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10H20/8512

Abstract

A light emitting device includes a light source that emits first light in response to an electrical signal, and a fluorescent layer positioned over the light source. The fluorescent layer includes a first fluorescent material which radiates second light and a second fluorescent material which radiates third light. In one embodiment, the second fluorescent material contains europium activated calcium sulfide. In another embodiment, the second fluorescent material contains europium activated nitrido-silicate. In some embodiments, the device includes a light propagation medium which transmits the first, second, and third light as composite output.