Light emitting diode illumination system

• US 8,629,982 B2
• Filed: 08/15/2013
• Issued: 01/14/2014
• Est. Priority Date: 08/06/2007
• Status: Active Grant

• Current Assignee: Lumencor, Inc.
• Original Assignee: Lumencor, Inc.
• Inventors: Brukilacchio, Thomas J.
• Primary Examiner(s): Ton, Tri T
• Application Number:
  US13/968,178
• Publication Number:
  US 20130334440A1
• Time in Patent Office: 152 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, 356402-420, 356/432, 356 43- 50, 356/440, 362227-228, 362216-225, 36221701-21717, 362253-254, 362/260, 362307-310, 362/257, 362/296.01, 362/317, 362326-329, 362 23- 30
• US Class Current: 356/432
• 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

In various embodiments of the invention, a unique construction for Light Emitting Diodes (LEDs) with at least one luminescent rod and extracting optical elements used to generate a variety of high brightness light sources with different emission spectra. In an embodiment of the invention, forced air cooling is used to cool the luminescent rod. In an embodiment of the invention, totally internal reflected light can be redirected outward and refocused. In another embodiment of the invention, light emitted by the luminescent rod is out-coupled for use in a variety of applications.

Claims

1. A light engine for generating white light for endoscopy or microscopy, the light engine comprising:

a first light source, wherein the first light source includes a plurality of first Light Emitting Diodes (LEDs) and a first concentrator, wherein the first light source emits a first light beam of a first color;

wherein said plurality of first Light Emitting Diodes (LEDs) of said first light source emit light of an excitation color different than said first color, and wherein said first light source further comprises a luminescent rod comprising a luminescent material which absorbs said light of said excitation color and, in response, emits light of said first color which passes through said first concentrator to generate said first light beam of said first color;

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

a plurality of reflective optical components positioned so as to combine the first light beam of the first color, the second light beam of the second color, the third light beam of the third color, on a main optical axis of the light engine to generate a beam of white light; and

an output system including one or more lens for focusing the beam of white light into a light guide for transmission to a microscope or endoscope.

2. The light engine of claim 1, wherein the light engine has the ability to control correlated color temperature (CCT) of the beam of white light.

3. The light engine of claim 1, wherein the light engine has the ability to control the color rendering index (CRI) of the beam of white light.

4. The light engine of claim 1, wherein the beam of white light has a color rendering index (CRI) of at least 85.

5. The light engine of claim 1, wherein the light engine has the ability to modulate the light output in synchronization with a camera shutter.

6. The light engine of claim 1, in combination with a light guide positioned to receive said beam of white light from said lens, wherein the light guide is adapted to transport said beam of white light to said microscope or endoscope.

7. The light engine of claim 1, wherein said plurality of reflective elements comprise a plurality of dichroic reflective elements.

8. The light engine of claim 1, wherein air is directed at a surface of the luminescent rod in order to cool the luminescent rod.

9. The light engine of claim 1, wherein the luminescent rod comprises one of a single crystal Ce:

YAG and a sintered ceramic Ce;

YAG.

10. The light engine of claim 1 wherein the output system further comprises a lens stop to prevent color fringe effects.

11. The light engine of claim 1, wherein the first color is green, the second color is blue, the third color is red, and the excitation color is blue.

12. A light engine for generating white light for an optical instrument, the light engine comprising:

a first light source, wherein the first light source includes a plurality of first Light Emitting Diodes (LEDs) and a first concentrator, wherein the first light source emits a first light beam of a first color;

wherein said plurality of first Light Emitting Diodes (LEDs) of said first light source emit light of an excitation color different than said first color, and wherein said first light source further comprises a luminescent rod comprising a luminescent material which absorbs said light of said excitation color and, in response, emits light of said first color which passes through said first concentrator to generate said first light beam of said first color;

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

a plurality of reflective optical components positioned so as to combine the first light beam of the first color, the second light beam of the second color, the third light beam of the third color, on a main optical axis of the light engine to generate a beam of white light; and

an output system including one or more lens for focusing the beam of white light into a light guide for transmission to said optical instrument.

13. The light engine of claim 12, wherein the beam of white light has a color rendering index (CRI) of at least 85.

14. The light engine of claim 13, wherein said plurality of reflective elements comprise a plurality of dichroic reflective elements.

15. The light engine of claim 13, wherein the luminescent rod comprises one of a single crystal Ce:

YAG and a sintered ceramic Ce;

YAG.

16. The light engine of claim 13, wherein the light engine has the ability to modulate the light output in synchronization with a camera shutter.

17. The light engine of claim 13, wherein air is directed at a surface of the luminescent rod in order to cool the luminescent rod.

18. The light engine of claim 12, wherein the light engine has the ability to control correlated color temperature (CCT) of the beam of white light.

19. The light engine of claim 12, wherein the light engine has the ability to control the color rendering index (CRI) of the beam of white light.

27. The light engine of claim 13, in combination with a light guide positioned to receive said beam of white light from said lens, wherein the light guide is adapted to transport said beam of white light to said microscope or endoscope.

20. A light engine for generating white light for endoscopy or microscopy, the light engine comprising:

a first light source, wherein the first light source includes a plurality of first Light Emitting Diodes (LEDs) and a first concentrator, wherein the first light source emits a first light beam of a first color;

wherein said plurality of first Light Emitting Diodes (LEDs) of said first light source emit light of an excitation color different than said first color, and wherein said first light source further comprises a luminescent rod comprising a luminescent material which absorbs said light of said excitation color and, in response, emits light of said first color which passes through said first concentrator to generate said first light beam of said first color;

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

a plurality of reflective optical components positioned so as to combine the first light beam of the first color, the second light beam of the second color, the third light beam of the third color, on a main optical axis of the light engine to generate a beam of white light;

a light guide adapted to couple the light engine to an endoscope or microscope, and

an output system including one or more lens for focusing the beam of white light into said light guide for transmission to said endoscope or microscope.

21. The light engine of claim 20, wherein the beam of white light has a color rendering index (CRI) of at least 85.

22. The light engine of claim 20, wherein said plurality of reflective elements comprise a plurality of dichroic reflective elements.

23. The light engine of claim 20, wherein the luminescent rod comprises one of a single crystal Ce:

YAG and a sintered ceramic Ce;

YAG.

24. The light engine of claim 20, wherein the light engine has the ability to modulate the light output in synchronization with a camera shutter.

25. The light engine of claim 20, wherein the light engine has the ability to control correlated color temperature (CCT) of the beam of white light.

26. The light engine of claim 20, wherein the light engine has the ability to control the color rendering index (CRI) of the beam of white light.