Illumination unit consisting of discharge lamp, LEDs and conversion phosphors

• US 8,256,920 B2
• Filed: 04/18/2008
• Issued: 09/04/2012
• Est. Priority Date: 05/14/2007
• Status: Expired due to Fees

• Current Assignee: Merck Patent GmbH (Merck & Co., Inc.)
• Original Assignee: Merck Patent GmbH (Merck & Co., Inc.)
• Inventors: Winkler, Holger, Juestel, Thomas
• Primary Examiner(s): CROWE, DAVID R
• Application Number:
  US12/599,889
• Publication Number:
  US 20100309647A1
• Time in Patent Office: 1,600 Days
• Field of Search: 362/84, 362/228, 362/229, 362/230, 362/231
• US Class Current: 362/229
• 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 color 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. An illumination unit (1) having an adjustable colour location, having a housing (2), in which at least one primary light source and secondary light source are arranged, where the colour locations of the two light sources are different and where the primary light source is a sodium vapour discharge lamp, which emits orange-yellow light of a given colour location having a given colour temperature and light colour, while the secondary light source (10) is at least one LED which emits UV or blue light, and where the intensity of the secondary light source can be adjusted steplessly, and where the primary and secondary light sources interact so that the colour location of the radiation emitted by the illumination unit can differ from the primary light source, wherein a deflector (4) located in the housing comprises a phosphor layer (12), comprising one or more conversion phosphors, and which 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. An illumination unit according to claim 1, wherein the secondary light source emits UV light.

3. An illumination unit according to claim 1, wherein the secondary light source emits blue light.

4. An illumination unit according to claim 1, wherein the phosphor layer (12) comprises only homogeneous conversion phosphor particles or resin-dispersed homogeneous conversion phosphor particles.

5. An illumination unit according to claim 1, wherein the phosphor layer (12) comprises additives.

6. An illumination unit according to claim 1, wherein the phosphor layer (12) comprises one or more conversion phosphors which contain 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.

7. An illumination unit according to claim 6, wherein the one or more activator ions are Ce, Eu, Mn, Cr, Tb and/or Bi.

8. An illumination unit according to claim 1, wherein the directly emitted radiation from the light sources passes through a scatterer.

9. A method for lighting an area by an illumination unit (1) according to claim 1, comprising arranging the light sources and the deflector (4) such a way that a multiband lamp having high colour reproduction and colour temperature and a high illumination efficiency results.

10. An illumination unit (1) unit according to claim 1, wherein the colour temperature and the light colour of the radiation emitted by the illumination unit differs from the primary light source.

11. An illumination unit according to claim 1, wherein the phosphor layer (12) comprises one or more conversion phosphors which contain 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, in each case individually or mixtures thereof with one or more activator ions which are Ce, Eu, Mn, Cr, Tb and/or Bi.

12. An illumination unit according to claim 1, wherein the directly emitted radiation from the light sources passes through a scattering or diffuser plate.