Optical system for a digital light projection system including a 3-channel LED array light engine

• US 20090323028A1
• Filed: 08/20/2009
• Published: 12/31/2009
• Est. Priority Date: 12/09/2005
• Status: Active Grant

• Current Assignee: SCRAM Technologies, Inc
• Original Assignee: SCRAM Technologies, Inc
• Inventors: Shanley, James F.
• Granted Patent: US 7,973,996 B2
• Time in Patent Office: Days
• US Class Current: 353/31
• CPC Class Codes: G03B 21/008 using micromirror devices
• CPC Class Codes: G03B 21/14 Details
• CPC Class Codes: G03B 21/208 Homogenising, shaping of the illumination light

Abstract

An optical system for a digital light projection system is provided. The optical system comprises a plurality of LED arrays, wherein each LED array comprises a plurality of LEDs. The optical system also comprises an optical concentrator element positioned substantially adjacent to each of the LED arrays, wherein each concentrator element totally internally reflects light emitted from the plurality of LEDs within the corresponding LED array so as to provide substantially uniform light at an output surface of each concentrator element, and wherein the concentrator element has a complex conic shape. The optical system preferably further comprises an optical combiner element, wherein the output surface of each concentrator element is positioned substantially adjacent to a corresponding side of the combiner element, and wherein the combiner element spatially combines the substantially uniform light provided at the output surface of each concentrator element so as to form substantially white light at an output surface of the combiner element.

Claims

1. An optical system for a digital light projection system, the optical system comprising:

at least one LED array, wherein each LED array comprises a plurality of LEDs; and

an optical concentrator element positioned substantially adjacent to each LED array, wherein each concentrator element totally internally reflects light emitted from the plurality of LEDs within the corresponding LED array so as to provide substantially uniform light at an output surface of each concentrator element, and wherein the concentrator element has a complex conic shape along a direction longitudinally from an input surface of the concentrator element to an output surface of the concentrator element.

2. The optical system of claim 1, wherein the concentrator element is positioned directly in contact with each LED array.

3. The optical system of claim 1 further comprising an optical coupling material positioned between the concentrator element and each LED array, wherein the optical coupling material is in contact with the concentrator element and each LED array.

4. The optical system of claim 3, wherein the optical coupling material comprises a gel having an index of refraction which substantially matches that of the concentrator element.

5. The optical system of claim 1, wherein each LED array comprises LEDs which are less than 0.35 mm in width.

6. The optical system of claim 1, wherein each LED array comprises LEDs which are spaced from adjacent LEDs within the same array by an amount less than 0.025 mm.

7. The optical system of claim 1, wherein the concentrator element has a substantially parabolic cross section.

8. The optical system of claim 1, wherein the optical system is an illumination optical system.

9. The optical system of claim 1 further comprising a digital imaging device.

10. The optical system of claim 9, wherein the output surface of each concentrator element is imaged directly on the digital imaging device.

11. An optical system for a digital light projection system, the optical system comprising:

a plurality of LED arrays, wherein each LED array comprises a plurality of LEDs;

an optical concentrator element positioned substantially adjacent to each of the LED arrays, wherein each concentrator element totally internally reflects light emitted from the plurality of LEDs within the corresponding LED array so as to provide substantially uniform light at an output surface of each concentrator element, and wherein the concentrator element has a complex conic shape along a direction longitudinally from an input surface of the concentrator element to an output surface of the concentrator element; and

an optical combiner element, wherein the output surface of each concentrator element is positioned substantially adjacent to a corresponding side of the combiner element, and wherein the combiner element spatially combines the substantially uniform light provided at the output surface of each concentrator element so as to form substantially white light at an output surface of the combiner element.

12. The optical system of claim 11, wherein the concentrator element is positioned directly in contact with each LED array.

13. The optical system of claim 11 further comprising an optical coupling material positioned between the concentrator element and each LED array, wherein the optical coupling material is in contact with the concentrator element and each LED array.

14. The optical system of claim 13, wherein the optical coupling material comprises a gel having an index of refraction which substantially matches that of the concentrator element.

15. The optical system of claim 11, wherein each LED array comprises LEDs which are less than 0.35 mm in width.

16. The optical system of claim 11, wherein each LED array comprises LEDs which are spaced from adjacent LEDs within the same array by an amount less than 0.025 mm.

17. The optical system of claim 11, wherein the concentrator element has a substantially parabolic cross section.

18. The optical system of claim 11, wherein the plurality of LED arrays consists of 3 LED arrays, wherein the 3 LED arrays consist of 3 single-color LED arrays, and wherein each of the 3 single-color LED arrays is of a different color from one another.

19. The optical system of claim 18, wherein the 3 single-color LED arrays consist of an LED array consisting of only red LEDs, an LED array consisting of only green LEDs, and an LED array consisting of only blue LEDs.

20. The optical system of claim 11, wherein the plurality of LED arrays consists of 3 LED arrays, and wherein the combiner element is a combiner cube.

21. The optical system of claim 11, wherein the plurality of LED arrays consists of 3 LED arrays, wherein the combiner element is a dichroic combiner cube.

22. The optical system of claim 11, wherein the plurality of LED arrays consists of 3 LED arrays, wherein the combiner element is a dichroic combiner cube, and wherein the combiner cube comprises 4 prisms.

23. The optical system of claim 11, wherein the optical system is an illumination optical system.

24. The optical system of claim 11 further comprising a digital imaging device.

25. The optical system of claim 24, wherein the output surface of each concentrator element is imaged directly on the digital imaging device.