White light emitting diode

US6084250A · kind A · utility

Assignee

• U.S. Philips Corporation · US

Inventors

• Thomas Justel · Witten, DE
• Hans Nikol · Aachen, DE
• Cees RONDA · Aachen, DE

Key dates

• Filing date: Nov 3, 1998
• Grant date: Jul 4, 2000
• Expiry date: Nov 3, 2018

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10H20/8513

Abstract

A light-emitting device comprising a UV-diode with a primary emission of 300 nm.ltoreq..lambda..ltoreq.370 nm and a phosphor layer including a combination of a blue-emitting phosphor having an emission band, with 430 nm.ltoreq..lambda..ltoreq.490 nm, a green-emitting phosphor having an emission band, with 520 nm.ltoreq..lambda..ltoreq.570 nm and a red-emitting phosphor having an emission band, with 590 nm.ltoreq..lambda..ltoreq.630 nm, emits high-quality white light. The color-rendering index CRI is approximately 90 at a color temperature of 4000 K. The color rendition depends only on the composition of the three phosphors, not on the relation between converted and non-converted light, and hence can be readily controlled and regulated.