Light emitting diode illumination system

• US 8,493,564 B2
• Filed: 08/13/2012
• Issued: 07/23/2013
• 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:
  US13/584,390
• Publication Number:
  US 20120307514A1
• Time in Patent Office: 344 Days
• Field of Search: 362227-228, 362216-225, 36221701-21717, 362253-254, 362/260, 362307-310, 362/257, 362/296.01, 362/317, 362326-329, 362 23- 30, 356402-420, 356/432, 356 43- 50, 385141-142, 385/144
• US Class Current: 356/417
• 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 is 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. In various embodiments of the invention, a plurality of independent narrow band colors can be coaxially combined.

Claims

1. An illumination system, comprising:

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

wherein the fourth light source includes a luminescent rod and an array of Light Emitting Diodes (LEDs), wherein the luminescent rod is adapted to emit the light of a fourth color in response to absorbing excitation light received from the array of Light Emitting Diodes (LEDs), the excitation light having a different color than the fourth color; and

associated optics, wherein the associated optics direct the first collimated beam of light of the first color, the second collimated beam of light of the second color, the third collimated beam of light of the third color, and the fourth collimated beam of light of the fourth color onto a main optical axis.

2. The illumination system of claim 1, further comprising a laser diode, wherein the laser diode emits a laser light beam, and wherein the associated optics also direct the laser light beam onto the main optical axis.

3. The illumination system of claim 1, further comprising a first laser diode which emits a first laser light beam and a second laser diode which emits a second laser light beam, and wherein the associated optics also direct the first laser light beam and second laser light beam onto the main optical axis.

4. The illumination system of claim 1, further comprising a light guide adapted to be coupled to a microscope, wherein the light guide is positioned to receive light beams directed along the main optical axis.

5. The illumination system of claim 1, wherein the illumination system is computer controllable.

6. The illumination system of claim 1, wherein the illumination system is adapted to provide output light of one or more of the first color, second color, third color and fourth color.

7. The illumination system of claim 6, wherein the output light is spectrally tunable.

8. The illumination system of claim 1,

the first light source includes a first bandpass filter which filters the first collimated beam of light of the first color;

the second light source includes a second bandpass filter which filters the second collimated beam of light of the second color; and

the third light source includes a third bandpass filter which filters the third collimated beam of light of the third color.

9. The illumination system of claim 1, wherein the fourth color is between:

an upper limit of 650 nm; and

a lower limit of 450 nm.

10. The illumination system of claim 1, wherein the fourth light source includes a fourth bandpass filter which filters the fourth collimated beam of light of the fourth color.

11. A method of generating light, comprising the steps of:

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

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

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

applying a fourth potential to a fourth light source, wherein the fourth light source includes a fourth collimator, wherein the fourth light source emits a fourth collimated beam of light of a fourth color different than the first color, second color and third color, and wherein the fourth light source includes

a luminescent rod which receives excitation light of an excitation color different than the fourth color from an array of LEDs and,

directing the first beam of collimated light, second beam of collimated light, third beam of collimated light, and the fourth beam of collimated light onto a main optical axis.

12. The method of claim 11, further comprising applying a fifth potential to a laser light source which emits a beam of laser light;

and wherein the directing step further comprises directing the beam of laser light onto the main optical axis.

13. The method of claim 11, further comprising:

filtering the first collimated beam of light with a first bandpass filter;

filtering the second collimated beam of light with a second bandpass filter; and

filtering the third collimated beam of light with a third bandpass filter.

14. The method of claim 11, further comprising:

filtering the fourth collimated beam of light with a fourth bandpass filter.

15. The method of claim 11, further comprising coupling light on the main optical axis to an instrument using a light guide.

16. A fiber optic illumination system, comprising:

a first LED light source including a first collimator, wherein the first LED light source emits a first collimated beam of light of a first color wherein the first color is a color other than green;

a second LED light source including a second collimator, wherein the second LED light source emits a second collimated beam of light of a second color wherein the first color is a color other than green and different than the first color;

a third LED light source including a third collimator, wherein the third LED light source emits a third collimated beam of light of a third color wherein the third color is a color other than green and different than the first color and second color; and

a luminescent rod light source, wherein the luminescent rod light source includes

an array of LEDs, wherein the array of LEDs emits blue light, and

a luminescent rod having a straight longitudinal surface parallel to said array of LEDs such that the luminescent rod is positioned to receive the blue light, wherein the blue light is absorbed by the luminescent rod which then generates by luminescence and emits green light; and

associated optics that directs the first collimated beam of light, the second collimated beam of light, and the third collimated beam of light with the green light generated by the luminescent rod into a fiber optic light guide.

17. The fiber optic illumination system of claim 16, wherein the luminescent rod light source includes a bandpass filter which filters the green light.

18. 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 having a first collimator, wherein the first LED light source emits a first collimated beam of light of the first color;

a second LED light source having a second collimator, wherein the second LED light source emits a second collimated beam of light of the second color;

a third LED light source having a third collimator, wherein the third LED light source emits a third collimated beam of light of the third color;

a fourth light source having a fourth collimator, wherein the fourth LED light source emits a fourth collimated beam of light of the fourth color; and

associated optics that directs each of the first collimated beam of light, second collimated beam of light, third collimated beam of light, and fourth collimated beam of light into a light guide;

wherein the fourth light source includes an array of LEDs and a luminescent rod, wherein the luminescent rod light receives excitation light of an excitation color different than the fourth color from the array of LEDs and, in response, emits light of the fourth color.

19. The light engine of claim 18, wherein:

the first light source includes a first bandpass filter which filters the first collimated beam of light of the first color;

the second light source includes a second bandpass filter which filters the second collimated beam of light of the second color; and

the third light source includes a third bandpass filter which filters the third collimated beam of light of the third color.

20. The light engine of claim 18, wherein the fourth light source includes a fourth bandpass filter which filters the fourth collimated beam of light of the fourth color.