Illumination Unit Consisting of Discharge Lamp, LEDs and Conversion Phosphors

• US 20100309647A1
• Filed: 04/18/2008
• Published: 12/09/2010
• Est. Priority Date: 05/14/2007
• Status: Active Grant

• Current Assignee: Merck Patent GmbH (Merck & Co., Inc.)
• Original Assignee: Merck Patent GmbH (Merck & Co., Inc.)
• Inventors: Juestel, Thomas, Winkler, Holger
• Granted Patent: US 8,256,920 B2
• Time in Patent Office: Days
• US Class Current: 362/84
• CPC Class Codes: C09K 11/7774 Aluminates
• CPC Class Codes: F21V 7/30 the coatings comprising photoluminescent substances
• CPC Class Codes: F21Y 2113/00 Combination of light sources
• CPC Class Codes: F21Y 2113/20 of different form
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H05B 35/00 Electric light sources using a combination of different types of light generation

Abstract

The invention relates to an illumination unit having an adjustable colour location consisting of a discharge lamp as primary light source and LEDs as secondary light source and additionally a phosphor layer in the form of a phosphor screen comprising conversion phosphors. Furthermore, the present invention relates to a method for lighting usable areas by the illumination unit according to the invention.

Claims

1. Illumination unit (1) having an adjustable colour location, having a housing (2), in which at least one primary light source and secondary light source is arranged, where the colour location of the two light sources is different and where the primary light source emits orange-yellow light of a given colour location having a given colour temperature and light colour, while the secondary light source (10) emits light of a different colour location, in particular having a different light colour or coloured light, and where the intensity of the secondary light source can be adjusted steplessly, and where the primary and secondary light source interact so that the colour location, in particular also the colour temperature and the light colour, of the radiation emitted by the illumination unit can differ from the primary light source, characterised in that the deflection means (4) located in the housing comprise a phosphor layer (12), comprising one or more conversion phosphors, and in that this phosphor layer can be excited by the secondary light source to the emission of radiation whose colour location differs from the colour locations of the primary and secondary light sources.

2. Illumination unit according to claim 1, characterised in that the primary light source is a discharge lamp (6), in particular a sodium vapour discharge lamp.

3. Illumination unit according to claim 1, characterised in that the secondary light source is at least one LED (10) which emits UV or blue light.

4. Illumination unit according to claim 1, characterised in that the phosphor layer (12) comprises only homogeneous conversion phosphor particles or resin-dispersed homogeneous conversion phosphor particles.

5. Illumination unit according to claim 1, characterised in that the phosphor layer (12) comprises additives.

6. Illumination unit according to claim 1, characterised in that the phosphor layer (12) comprises one or more conversion phosphors which consist of at least one of the following phosphor materials:

(Y, Gd, Lu, Sc, Sm, Tb)₃ (Al, Ga)₅O₁₂;

Ce (with or without Pr), (Ca, Sr, Ba)₂SiO₄;

Eu, YSiO₂N;

Ce, Y₂Si₃O₃N₄;

Ce, Gd₂Si₃O₃N₄;

Ce, (Y,Gd,Tb,Lu)₃Al_5-xSi_xO_12-xN_x;

Ce, BaMgAl₁₀O₁₇;

Eu (with or without Mn), SrAl₂O₄;

Eu, Sr₄Al₁₄O₂₅;

Eu, (Ca,Sr,Ba)Si₂N₂O₂;

Eu, SrSiAl₂O₃N₂;

Eu, (Ca,Sr,Ba)₂Si₅N₈;

Eu, CaAlSiN₃;

Eu, (Ca,Sr,Ba)₂SiO₅;

Eu, (Ca,Sr)AlSiN₃;

Eu, LaEuSi₂N₃O₂;

Eu, LaSi₃N₅;

Eu, (Ca,Sr,Ba)Si₂N₂O₄;

Eu, CaSiN₂;

Eu, molybdates, tungstates, vanadates, group III nitrides, oxides, in each case individually or mixtures thereof with one or more activator ions, such as Ce, Eu, Mn, Cr, Tb and/or Bi.

7. Illumination unit according to claim 1, characterised in that the directly emitted radiation from the light sources passes through a scattering means (8).

8. Method for lighting usable areas by an illumination unit (1) according to claim 1, characterised in that the light sources and the deflection means (4) are arranged in such a way that a multiband lamp having high colour reproduction and colour temperature and a high useful illumination efficiency results.