LED-BASED ILLUMINATION SYSTEM FOR HEAT-SENSITIVE OBJECTS

• US 20110002114A1
• Filed: 07/07/2008
• Published: 01/06/2011
• Est. Priority Date: 07/17/2007
• 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: Koerner, Brad Eric
• Application Number:
  US12/667,943
• Publication Number:
  US 20110002114A1
• Time in Patent Office: Days
• US Class Current: 362/126
• CPC Class Codes: A47F 3/001 Devices for lighting, humidifying, heating, ventilation
• CPC Class Codes: F21S 8/00 Lighting devices intended for fixed installation F21S9/00, F21S10/00 take precedence; using a string or strip of light sources F21S4/00
• CPC Class Codes: F21S 8/02 of recess-mounted type, e.g. downlighters specially adapted for vehicle exteriors F21S41/00-F21S45/00
• CPC Class Codes: F21V 21/30 Pivoted housings or frames
• CPC Class Codes: F21V 23/04 the elements being switches safety devices F21V25/00
• CPC Class Codes: F21V 29/15 Thermal insulation
• CPC Class Codes: F21V 29/67 characterised by the arrangement of fans
• CPC Class Codes: F21V 29/75 with fins or blades having different shapes, thicknesses or spacing
• CPC Class Codes: F21V 29/76 with essentially identical parallel planar fins or blades, e.g. with comb-like cross-section
• CPC Class Codes: F21V 29/763 the planes containing the fins or blades having the direction of the light emitting axis
• CPC Class Codes: F21V 29/89 Metals
• CPC Class Codes: F21W 2131/405 for shop-windows or displays

Abstract

Disclosed herein are illumination systems (300) employing LED-based light sources that are suitable for illuminating display cases (310) containing museum-quality artifacts or other heat-sensitive objects. Taking advantage of compact size and unique thermal properties of LED light sources, these illumination systems are configured to direct focused and/or diffuse illumination into a hermetically-sealed enclosure without introducing undesirable heat. These illumination systems may also include a transparent insulative barrier (400) and forced-air convection-cooling system (480).

Claims

1. An illumination system (300) for illuminating one or more heat-sensitive objects disposed in a display case, the illumination system comprising:

a thermally insulated housing (400) comprising a partition (470) at least partially defining a proximal chamber (420) and a distal chamber (430) of the housing;

a first lighting unit (440) attached to the partition and disposed within the housing, the first lighting unit comprising a first plurality of LED light sources disposed within the proximal chamber and configured to generate a first radiation having a first spectrum for illuminating the one or more objects;

a control module (490) for controlling at least the first plurality of LED light sources;

a first heat-dissipating member (460) at least partially disposed within the distal chamber in thermal communication with the first plurality of LED light sources; and

a cooling system (480) configured to cause an airflow through the distal chamber (430).

2. The illumination system of claim 1, wherein the first lighting unit further comprises a second plurality of LED light sources adapted to generate a second radiation having a second spectrum different from the first spectrum.

3. The illumination system of claim 1, further comprising a second lighting unit (450) attached to the partition and disposed within the housing, the second lighting unit comprising a third plurality of LED light sources configured to generate a third radiation having a third spectrum for illuminating the one or more objects.

4. The illumination system of claim 3, wherein the second lighting unit is configured to generate a light beam having a beam angle within a range of 40 to 70 degrees for providing ambient illumination within the display case.

5. The illumination system of claim 3, wherein the control module (490) further controls the third plurality of LED light sources.

6. The illumination system of claim 5, wherein the third spectrum is equal to the first spectrum.

7. The illumination system of claim 1, wherein the first lighting unit is attached to the partition with an adjustable orientation so as to direct a light beam at a desired limited area within the case.

8. The illumination system of claim 7, wherein the light beam has a beam angle within a range of 5 to 20 degrees.

9. The illumination system of claim 8, wherein the light beam has a beam angle of about 10 degrees.

10. The illumination system of claim 1, wherein the partition is thermally conductive and defines a second heat-dissipating member comprising a plurality of fins.

11. The illumination system of claim 1, further comprising a thermally insulating light-transmissive panel (495) attached to the housing for transmitting at least the first radiation.

12. The illumination system of claim 11, wherein the light-transmissive panel is at least partially removable for providing access at least to the first lighting unit and the control module.

13. The illumination system of claim 11, wherein the cooling system comprises a fan.

14. A housing for securing at least one lighting unit and at least one control module for illuminating at least one heat-sensitive object, the housing comprising:

opposing side walls;

a top wall connected to the side walls;

a partition extending between the side walls and opposing the top wall, the partition being adapted to receive the at least one lighting unit and the at least one control module;

wherein the opposing side walls, the top wall, and a first surface of the partition define a distal chamber and a first pair of opposing openings for allowing air flow through the distal chamber;

wherein the opposing side walls and a second surface of the partition define a proximal chamber and a second pair of opposing openings; and

a pair of opposing end walls covering only the second pair of opposing openings for preventing airflow through the proximal chamber.

15. A method for illuminating a heat-sensitive object within a display case, the method comprising:

(a) providing a housing defining a proximal chamber proximate to the heat-sensitive object and a distal chamber distal from the heat-sensitive object;

(b) disposing within the housing at least one lighting unit having a plurality of LED light sources and a heat-dissipating member in thermal communication with the plurality of LED light sources, such that the heat-dissipating member is disposed within the distal chamber;

(c) causing the plurality of LED light sources to direct a light beam towards the heat-sensitive object;

(d) creating an airflow through the distal chamber but not through the proximal chamber, thereby enhancing conductive heat transfer from the LED light sources to the heat-dissipating member and enhancing convective heat transfer from the heat-dissipating member to the ambient; and

(e) thereafter, exhausting the heated air away from the heat-sensitive object.

16. The method of claim 15, wherein the plurality of LED light sources are configured to generate radiation having a variable spectrum.

17. The method of claim 16, wherein step (c) further comprises controlling the radiation generated by the plurality of LED light sources to select a desirable spectrum.

18. The method of claim 15, further comprising providing diffuse illumination within the case.