Light emitting diode illumination system

• US 7,898,665 B2
• Filed: 08/06/2008
• Issued: 03/01/2011
• 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): Toatley; Gregory J
• Assistant Examiner(s): Ton; Tri T
• Application Number:
  US12/187,356
• Publication Number:
  US 20090040754A1
• Time in Patent Office: 937 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
• 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 is selected from one of a first Light Emitting Diode (LED) and a laser, wherein the first light source emits a first light of a first color; and

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

a second LED light source, wherein the second LED light source emits a second light of a second color; and

a luminescent rod that is positioned to receive the second light, wherein the second light is absorbed by the luminescent rod which then emits a third light of a third color;

an outlet aperture wherein the third light exits at the outlet aperture;

an optical element to increase the light emitted at the outlet aperture; and

associated optics, wherein the associated optics combine the light of the first light source and the light of the third light source on the same optical axis.

2. The illumination system of claim 1, further comprising a fourth light source, wherein when the fourth light source is selected from a LED and a laser, wherein the fourth light source emits a fourth light of a fourth color, wherein the associated optics combines the light of the first light source, the light of the third light source and the light of the fourth light source on the same optical axis.

3. The illumination system of claim 1, further comprising one or more additional light source, wherein the additional light source is selected from a LED, a laser and a luminescent rod light source wherein the one or more additional light source emits one or more light of one or more color, wherein the associated optics combines the light of the first light source, the light of the third light source and the light of the one or more additional light source on the same optical axis.

4. The illumination system of claim 1, further comprising an optical element to couple the third light emitted from the luminescent rod at the outlet aperture to a system that uses one or both the first light and third light of the illumination system.

5. The illumination system of claim 1, further comprising an optical element to couple the third light emitted from the luminescent rod into air within a 45 degree half-angle cone.

6. The illumination system of claim 1, wherein the luminescent rod has a proximal and a distal end, wherein the second LED light is adjacent the proximal end of the luminescent rod, wherein the third light is emitted in a forward direction and in a backward direction within the luminescent rod, further comprising an optical element positioned at the proximal end of the luminescent rod, wherein the first optical element reflects the fluorescent light toward the distal end.

7. The illumination system of claim 1, wherein a plurality of LED light sources emit one or both the first light and the second light.

8. The illumination system of claim 1, wherein the second LED light passes through a plurality of luminescent rods arranged in series or in parallel.

9. The illumination system of claim 1, wherein the third second selected 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 second LED light passes through a plurality of luminescent rods.

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

applying a first potential to a first light source, wherein the first light source is selected from one of a first Light Emitting Diode (LED) and a laser, wherein the first light source emits a first light of a first color;

applying a second potential to a second LED to generate second light in a second color;

positioning a luminescent rod to receive the second LED light, wherein the second light is absorbed by the luminescent rod which then emits a third light of a third color, wherein the third light exits at a outlet aperture;

using an optical element to increase the light emitted at the outlet aperture; and

combining the first light and the third light on the same optical axis.

12. The method of claim 11, further comprising one or more light source, wherein the additional light source is selected from a LED, a laser and a luminescent rod light source wherein the one or more additional light source emits one or more light of one or more color, wherein the associated optics combines the light of the first light source, the light of the third light source and the light of the one or more additional light source on the same optical axis.

13. The method of claim 11, wherein the luminescent rod has an outlet aperture, further comprising an optical element to increase the light emitted at the outlet aperture.

14. The method of claim 11, wherein the luminescent rod has an outlet aperture, further comprising an optical element to couple the third light emitted from the luminescent rod at the outlet aperture to a system that uses one or both the first light and third light of the illumination system.

15. The method of claim 11, further comprising an optical element to couple the third light emitted from the luminescent rod into air within a 45 degree half-angle cone.

16. The method of claim 11, wherein the luminescent rod has a proximal and a distal end, wherein the second LED light is adjacent the proximal end of the luminescent rod, wherein the third light is emitted in a forward direction and in a backward direction within the luminescent rod, further comprising an optical element positioned at the proximal end of the luminescent rod, wherein the first optical element reflects the fluorescent light toward the distal end.