THERMOELECTRIC COOLING FOR INCREASED BRIGHTNESS IN A WHITE LIGHT L.E.D. ILLUMINATOR

• US 20110148304A1
• Filed: 11/17/2010
• Published: 06/23/2011
• Est. Priority Date: 12/22/2009
• Status: Abandoned Application

• Current Assignee: Alcon Research Limited (Nestle SA)
• Original Assignee: Alcon Research Limited (Nestle SA)
• Inventors: Artsyukhovich, Alexander N., Gordon, Raphael, Boukhny, Mikhail, Yadlowsky, Michael J.
• Application Number:
  US12/947,985
• Publication Number:
  US 20110148304A1
• Time in Patent Office: Days
• US Class Current: 315/112
• CPC Class Codes: F21V 9/30 Elements containing photoluminescent material distinct from or spaced from the light source shades F21V1/17; globes, bowls or cover glasses F21V3/08, F21V3/12; refractors F21V5/10; reflectors F21V7/26, F21V7/30; elements with provision for controlling the spectral properties or intensity F21V9/40
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil

Abstract

A white light source includes a light-emitting diode configured to emit light of a characteristic wavelength. The white light source also includes at least one phosphor. The phosphor is configured to emit light in response to the light emitted by the light-emitting diode so that the white light source emits white light. The white light source further includes a thermally conductive base in thermal contact with the light-emitting diode and a thermo-electric cooler in thermal contact with the thermally conductive base.

Claims

1. A white light source, comprising:

a light-emitting diode configured to emit radiation of a characteristic wavelength;

at least one phosphor, the phosphor configured to emit light in response to the light emitted by the light-emitting diode so that the white light source emits white light;

a thermally conductive base in thermal contact with the light-emitting diode; and

a thermo-electric cooler in thermal contact with the thermally conductive base.

2. The white light source of claim 1, further comprising a cooling fan configured to direct air at the thermo-electric cooler.

3. The white light source of claim 1, further comprising a heat sink in thermal contact with the thermo-electric cooler.

4. The white light source of claim 1, further comprising a proportional-integral-derivative (PID) controller configured to regulate a temperature of the thermo-electric cooler.

5. The white light source of claim 4, further comprising a thermistor in contact with the thermo-electric cooler providing feedback to the PID controller.

6. The white light source of claim 1, wherein the thermally conductive base is formed from copper.

7. The white light source of claim 1, wherein an operating temperature of the light-emitting diode is greater than 130 degrees Celsius when the light-emitting diode is passively cooled by the thermally conductive base and less than 25 degrees Celsius when the thermo-electric cooler is actively cooling the thermally conductive base.

8. A method of providing white light illumination, comprising:

providing a white light source comprising a light-emitting diode configured to emit radiation of a characteristic wavelength, at least one phosphor, the phosphor configured to emit light in response to the light emitted by the light-emitting diode so that the white light source emits white light, and a thermally conductive base;

powering the light-emitting diode with a current sufficient to heat the light-emitting diode to a temperature significantly above an ambient temperature when the light-emitting diode is passively cooled by thermal contact with the thermally conductive base; and

cooling the thermally conductive base with a thermo-electric cooler during the step of powering the light-emitting diode with the current to maintain the temperature of the light-emitting diode near the ambient temperature.

9. The method of claim 8, further comprising cooling the thermo-electric cooler to prevent heat in the thermo-electric cooler from raising the temperature of the light-emitting diode above the ambient temperature.

10. The method of claim 8, further comprising placing the thermally conductive base in contact with a heat sink.

11. The method of claim 8, wherein the current is higher than 1.5 A.

12. The method of claim 8, wherein the temperature of the light-emitting diode when passively cooled is at least 130 degrees Celsius and the temperature of the light-emitting diode when cooled by the thermo-electric cooler is less than 25 degrees Celsius.

13. The method of claim 8, wherein the temperature of the light-emitting diode when cooled is 5 degrees Celsius or less.