Light emitting diode illumination system

• US 9,395,055 B2
• Filed: 05/28/2015
• Issued: 07/19/2016
• Est. Priority Date: 08/06/2007
• Status: Active Grant

• Current Assignee: Lumencor, Inc.
• Original Assignee: Lumencor, Inc.
• Inventors: Brukilacchio, Thomas J., Conner, Arlie R.
• Primary Examiner(s): Ton, Tri T
• Application Number:
  US14/724,297
• Publication Number:
  US 20150267897A1
• Time in Patent Office: 418 Days
• Field of Search: 356/239.2, 356/239.4, 356/239.6, 356/240.1, 356/241.1, 356/241.3, 356/241.5, 356/241.6, 356/44, 356402-420, 356/432, 356 43- 50, 356/440, 362227-228, 362216-225, 362253-254, 362/260, 362307-310, 362/257, 362/296.01, 362/317, 362326-329, 362 23- 30
• US Class Current: 1/1
• CPC Class Codes: A61B 1/00163 Optical arrangements A61B1/002, A61B1/06 take precedence
• CPC Class Codes: A61B 1/0653 with wavelength conversion
• CPC Class Codes: A61B 1/0669 at proximal end of an endoscope
• CPC Class Codes: A61B 1/0684 using light emitting diodes [LED]
• CPC Class Codes: A61N 2005/005 for cooling the radiator
• CPC Class Codes: A61N 2005/0652 Arrays of diodes
• CPC Class Codes: A61N 5/062 Photodynamic therapy, i.e. excitation of an agent
• CPC Class Codes: F21K 9/60 Optical arrangements integrated in the light source, e.g. for improving the colour rendering index or the light extraction
• CPC Class Codes: F21K 9/61 using light guides
• 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: F21V 13/04 the elements being reflectors and refractors for vehicle rear lights F21S43/40
• CPC Class Codes: F21V 13/08 the elements being filters or photoluminescent elements and reflectors
• CPC Class Codes: F21V 13/14 the elements being filters or photoluminescent elements, reflectors and refractors
• CPC Class Codes: F21V 29/60 characterised by the use of a forced flow of gas, e.g. air
• CPC Class Codes: F21V 29/70 characterised by passive heat-dissipating elements, e.g. heat-sinks
• CPC Class Codes: F21V 5/008 Combination of two or more successive refractors along an optical axis
• CPC Class Codes: F21V 7/0066 specially adapted to cooperate with point like light sources; specially adapted to cooperate with light sources the shape of which is unspecified F21V7/16 - F21V7/30 take precedence
• 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: F21W 2131/205 for operating theatres
• CPC Class Codes: F21W 2131/40 Lighting for industrial, commercial, recreational or military use
• CPC Class Codes: F21Y 2105/00 : Planar light sources
• CPC Class Codes: F21Y 2113/00 : Combination of light sources
• CPC Class Codes: F21Y 2113/13 : comprising an assembly of point-like light sources
• CPC Class Codes: F21Y 2115/10 : Light-emitting diodes [LED]
• CPC Class Codes: F21Y 2115/30 : Semiconductor lasers
• CPC Class Codes: G01N 2021/6419 : Excitation at two or more wavelengths
• CPC Class Codes: G01N 2021/6482 : Sample cells, cuvettes
• CPC Class Codes: G01N 21/64 : Fluorescence; Phosphorescence
• CPC Class Codes: G01N 2201/0627 : Use of several LED's for spectral resolution
• CPC Class Codes: G02B 23/2469 : using optical fibres
• CPC Class Codes: G02B 27/0994 : Fibers, light pipes optical fibers per se G02B6/02
• CPC Class Codes: G02B 27/1006 : for splitting or combining different wavelengths G02B27/1086, G02B27/141 take precedence
• CPC Class Codes: G02B 27/143 : using macroscopically faceted or segmented reflective surfaces
• CPC Class Codes: G02B 27/145 : having sequential partially reflecting surfaces
• CPC Class Codes: G02B 6/0006 : Coupling light into the fibre in general G02B6/4298

Abstract

The present invention provides a light engine having four light sources. A combination of collimators, bandpass filters, dichroic mirrors, and other elements is operative to direct light from the light sources onto a main optical axis from where it may be focused into a light guide for transport to an instrument or device. Particular embodiments of the invention provide for computer control, intensity control, color control, and light source modulation. Additional embodiments include particular light sources including light pipes and lasers. The light engine provides white light having a high color rendering index and suitable for applications in microscopy, endoscopy, and/or bioanalytical instrumentation.

Claims

1. An illumination system, comprising:

a first light source, wherein the first light source includes a first Light Emitting Diode (LED) wherein the first light source emits a first collimated beam of light of a first color;

a second light source, wherein the second light source includes a second Light Emitting Diode (LED), wherein the second light source emits a second collimated beam of light of a second color different than the first color;

a third light source, wherein the third light source includes a third Light Emitting Diode (LED), wherein the third light source emits a third collimated beam of light of a third color different than the first color and second color;

a fourth light source, wherein the fourth light source comprises a plurality of emitters of excitation light of an excitation color and a luminescent material positioned to receive the excitation light from all of the plurality of emitters of excitation light and emit light of a fourth color different than the excitation color, the first color, the second color, and the third color, whereby the fourth light source emits a fourth collimated beam of light of the fourth color;

a plurality of reflective optical components positioned to direct the first collimated beam of light, second collimated beam of light, third collimated beam of light and fourth collimated beam of light onto a main optical axis of the illumination system; and

an output system positioned to receive light from said main optical axis of the illumination system and configured to focus said light from said main optical axis into an output beam configured to fill an input aperture of a fiber optic or liquid light guide.

2. The illumination system of claim 1, wherein the plurality of emitters of excitation light comprise more than 20 emitters of excitation light.

3. The illumination system of claim 2 wherein the luminescent material emits said light of the fourth color from an optical output surface at an optical power density of at least 5 watts per square millimeter.

4. The illumination system of claim 2, wherein said luminescent material has an optical output surface of approximately 1 mm squared and emits 5 Watts of light of the fourth color.

5. The illumination system of claim 2, wherein said luminescent material emits said light of a fourth color at an optical output power at least ten times greater an optical power of each of the plurality of emitters of excitation light individually.

6. The illumination system of claim 2, wherein said luminescent material emits said light of a fourth color at an optical power of at least 2000 Lumens.

7. The illumination system of claim 1, further comprising:

a first heatsink in thermal contact with the luminescent material and adapted to dissipate heat from the luminescent material; and

a second heatsink in thermal contact with the plurality of emitters of excitation light and adapted to dissipate heat from the plurality of emitters of excitation light.

8. The illumination system of claim 1, wherein the illumination system is computer controllable and wherein the illumination system is configurable to provide output light of the first color, second color, third color, fourth color, and a mixture of said first color, second color second color, third color, and fourth color.

9. The illumination system of claim 1, further comprising a collection optic in contact with the luminescent material, wherein the collection optic transmits the light of the fourth color from the luminescent material to a collimating lens.

10. The illumination system of claim 1, comprising at least two emitters of coherent light.

11. A light engine for producing output light including one or more of a first color, second color, third color and fourth color wherein the first color, second color, third color, and fourth color are different colors, the light engine comprising:

a first LED light source which emits a first collimated beam of light of the first color;

a second LED light source which emits a second collimated beam of light of the second color;

a third LED light source which emits a third collimated beam of light of the third color;

a fourth light source, wherein the fourth light source comprises a plurality of emitters of excitation light of an excitation color of shorter wavelength than the fourth color and a luminescent material positioned to receive the excitation light from all of the plurality of emitters of excitation light and emit light of the fourth color whereby the fourth light source emits a fourth collimated beam of light of the fourth color;

a plurality of reflective optical components positioned to direct the first collimated beam of light, second collimated beam of light, third collimated beam of light and fourth collimated beam of light onto a main optical axis of the light engine; and

an output system positioned to receive light from said main optical axis of the light engine and configured to focus output light from said main optical axis into an output beam configured to fill an input aperture of a fiber optic or liquid light guide.

12. The light engine of claim 11, wherein the plurality of emitters of excitation light comprise more than 20 emitters of excitation light.

13. The light engine of claim 11 wherein the luminescent material emits said light of the fourth color from an optical output surface at an optical power density of at least 5 watts per square millimeter.

14. The light engine of claim 11, wherein said luminescent material has an optical output surface of approximately 1 mm squared and emits 5 Watts of light of the fourth color.

15. The light engine of claim 11, wherein said luminescent material emits said light of a fourth color at an optical output power at least ten times greater an optical power of each of the plurality of emitters of excitation light individually.

16. The light engine of claim 11, wherein said luminescent material emits said light of a fourth color at an optical power of at least 2000 Lumens.

17. The light engine of claim 11, further comprising:

a first heatsink in thermal contact with the luminescent material and adapted to dissipate heat from the luminescent material; and

a second heatsink in thermal contact with the plurality of emitters of excitation light and adapted to dissipate heat from the plurality of emitters of excitation light.

18. The light engine of claim 11, wherein the light engine is computer controllable and wherein the light engine is configurable to provide output light of the first color, second color, third color, fourth color, and a mixture of said first color, second color second color, third color, and fourth color.

19. The light engine of claim 11, comprising at least two emitters of coherent light.

20. A light engine for producing output light including one or more of a first color, second color, third color and fourth color wherein the first color, second color, third color, and fourth color are different colors, the light engine comprising:

a first LED light source which emits a first collimated beam of light of the first color;

a second LED light source which emits a second collimated beam of light of the second color;

a third LED light source which emits a third collimated beam of light of the third color;

a fourth light source, wherein the fourth light source comprises more than twenty emitters of excitation light of an excitation color of shorter wavelength than the fourth color and a luminescent material positioned to receive the excitation light from all of the more than twenty emitters of excitation light and emit light of the fourth color whereby the fourth light source emits a fourth collimated beam of light of the fourth color having an optical power of at least 5 Watts;

a plurality of reflective optical components positioned to direct the first collimated beam of light, second collimated beam of light, third collimated beam of light and fourth collimated beam of light onto a main optical axis of the light engine; and

an output system positioned to receive light from said main optical axis of the light engine and configured to focus output light from said main optical axis into an output beam configured to fill an input aperture of a fiber optic or liquid light guide;

wherein the light engine is computer controllable and wherein the light engine is controllable to provide output light of the first color, second color, third color, fourth color individually or a mixture of said first color, second color second color, third color, and fourth color.