Low-pressure mercury vapor discharge lamp comprising UV-A phosphor

US7591962B2 · kind B2 · utility

Assignee

• KONINKLIJKE PHILIPS ELECTRONICS NV · NL

Inventors

• Thomas Justel · Witten, DE
• Walter Mayr · Alsdorf, DE
• Helmut Bechtel · Aachen, DE
• Peter Josef Schmidt · Aachen, DE

Key dates

• Filing date: May 17, 2005
• Grant date: Sep 22, 2009
• Expiry date: Mar 24, 2026

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09K11/7777
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

The invention is concerned with a low-pressure mercury vapor discharge lamp comprising a light-transmitting discharge vessel, said discharge vessel enclosing, in a gastight manner, a discharge space provided with a filling of mercury, at least a part of a wall of the discharge vessel being provided with a luminescent composition comprising a first UV-A phosphor of general formula (Gd1-x-y-zYxLuy)PO4:Cez, wherein 0≦x<1.0, 0≦y<1.0, 0<z≦0.2 and x+y+z<1, the low-pressure mercury vapor discharge lamp comprising also discharge means for igniting and maintaining an electric discharge in the discharge vessel.Such lamp is especially useful for tanning purposes as well as cosmetic and medical purposes.The invention is also concerned with an UV-A phosphor of general formula (Gd1-x-y-zYxLuy)PO4:Cez, wherein 0≦x<1.0, 0≦y<z≦0.2 and x+y+z<1.