ILLUMINATION DEVICE WITH LED AND A TRANSMISSIVE SUPPORT COMPRISING A LUMINESCENT MATERIAL

• US 20100328925A1
• Filed: 01/19/2009
• Published: 12/30/2010
• Est. Priority Date: 01/22/2008
• Status: Abandoned Application

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Hoelen, Christoph Gerard August, Ansems, Johannes Petrus Maria, Waumans, Lars Rene Christian, Wegh, Rene Theodorus
• Application Number:
  US12/812,976
• Publication Number:
  US 20100328925A1
• Time in Patent Office: Days
• US Class Current: 362/84
• CPC Class Codes: F21K 9/232 specially adapted for generating an essentially omnidirectional light distribution, e.g. with a glass bulb
• CPC Class Codes: F21K 9/62 using mixing chambers, e.g. housings with reflective walls
• CPC Class Codes: F21K 9/64 using wavelength conversion means distinct or spaced from the light-generating element, e.g. a remote phosphor layer
• CPC Class Codes: F21K 9/65 specially adapted for changing the characteristics or the distribution of the light, e.g. by adjustment of parts
• CPC Class Codes: F21V 13/14 the elements being filters or photoluminescent elements, reflectors and refractors
• CPC Class Codes: F21V 14/08 by movement of the screens or filters
• CPC Class Codes: F21V 3/08 the material comprising photoluminescent substances
• CPC Class Codes: F21V 9/32 characterised by the arrangement of the photoluminescent material
• CPC Class Codes: F21V 9/38 Combination of two or more photoluminescent elements of different materials
• CPC Class Codes: F21V 9/45 by adjustment of photoluminescent elements
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H01L 33/507 the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body
• CPC Class Codes: H01L 33/58 Optical field-shaping elements

Abstract

The invention provides an illumination device (10) with a light emitting diode (20), a transmissive support (50) comprising a luminescent material (51), and a translucent exit window (60). The luminescent material (51) LED (20) distance dLL is larger than 0 mm, and the luminescent material (51) exit window (60) distance dLW is also larger than 0 mm. With the pro-posed illumination device (10) the lamp may especially look white when it is in the off-state and illuminated with white light. Other advantages are that an intrinsically efficient system may be provided and that a warm white option may be provided.

Claims

1. An illumination device comprising a light emitting diode (LED) arranged to emit LED emission, a transmissive support comprising a luminescent material, wherein the luminescent material is arranged to absorb at least part of the LED emission and emit luminescent material emission, wherein the LED and the luminescent material are arranged to generate light of a predetermined colour, wherein the illumination device further comprises a translucent exit window arranged to transmit at least part of the light, wherein, relative to the LED, the transmissive support is downstream from the LED, thereby providing a luminescent material LED distance (dLL), and the translucent exit window is downstream from the transmissive support, thereby providing a luminescent material exit window distance (dLW), wherein the translucent exit window has an upstream face with an exit window upstream face area (AEW1) and that the transmissive support has an upstream face with an transmissive support upstream face area (AS1), wherein exit window and transmissive support have a surface area ratio AEW1/A51 in the range of 2-20.

2. The illumination device according to claim 1, wherein between at least part of the luminescent material and the exit window, a material is arranged having an index of refraction equal to or smaller than 1.2.

3. The illumination device according to claim 1, wherein the transmissive support comprises an organic material selected from the group consisting of:

PET (polyethylene terephthalate), PE (polyethylene), PP (polypropylene), PC (polycarbonate), P(M)MA (poly(methyl)metacrylate), PEN (polyethylene napthalate) and PDMS (polydimethylsiloxane).

4. The illumination device according to claim 1, wherein the transmissive support comprises an inorganic material selected from the group consisting of glasses, fused quartz, ceramics, and silicones.

5. The illumination device according to claim 1, wherein at least part of the luminescent material comprises a transmissive ceramic luminescent material, and wherein the transmissive support comprises the transmissive ceramic luminescent material.

6. The illumination device according to claim 1, wherein the luminescent material LED distance (dLL) is adjustable.

7. The illumination device according to claim 1, wherein the luminescent material LED distance (dLL) is in the range of 0.5-50 mm.

8. The illumination device according to claim 1, wherein the luminescent material exit window distance (dLW) is in the range of 0.01-100 mm.

9. The illumination device according to claim 1, wherein the transmissive support has an upstream face comprising a coating, wherein the coating comprises at least part of the luminescent material.

11. The illumination device according to claim 1, wherein the transmissive support has an upstream face with an effective transmissive support upstream face diameter (DS1), wherein the ratio dLL/DS1 is in the range of 0.01-1.

12. The illumination device according to claim 1, wherein the transmissive support has an upstream face with an effective transmissive support upstream face diameter (DS1), wherein the ratio dLW/DS1 is in the range of 0.01-1.

13. The illumination device according to claim 1, wherein the translucent exit window has a substantially convex shape.

14. The illumination device according to claim 1, wherein the transmissive support has a substantially convex shape.

15. The illumination device according to claim 1, wherein the translucent exit window has a substantially flat shape.

16. The illumination device according to claim 1, wherein the transmissive support has a substantially flat shape.

17. The illumination device according to claim 1, wherein the illumination device comprises a plurality of light emitting diodes (LEDs arranged to emit LED emission.

18. A method for tuning the colour point of the light of an illumination device according to claim 1, wherein the luminescent material LED distance (dLL) is adjustable, and wherein, during operation of the light emitting diode (LED) and optionally in the absence of the translucent exit window, the luminescent material LED distance (dLL) is adjusted until a predetermined colour point is sensed by a sensor arranged to sense the light generated by the LED and the luminescent material.

19. A method for tuning the colour point of the light of an illumination device according to claim 1, wherein the transmissive support comprises a non-uniform distribution of the luminescent material, wherein the transmissive support is movable, and wherein, during operation of the light emitting diode (LED) and optionally in the absence of the translucent exit window, the position of the transmissive support relative to the LED is adjusted until a predetermined colour point is sensed by a sensor arranged to sense the light generated by the LED and the luminescent material.

10. (canceled)