Optical system for a digital light projection system including 3-channel and 4-channel LED array light engines

• US 20070132958A1
• Filed: 03/13/2006
• Published: 06/14/2007
• Est. Priority Date: 12/09/2005
• Status: Active Grant

• Current Assignee: SCRAM Technologies, Inc
• Original Assignee: SCRAM Technologies, Inc
• Inventors: Cotton, Christopher, Shanley, James
• Granted Patent: US 7,508,590 B2
• Time in Patent Office: Days
• US Class Current: 353/31
• CPC Class Codes: G03B 21/2013 Plural light sources
• CPC Class Codes: G03B 21/2033 LED or laser light sources
• CPC Class Codes: G03B 21/208 Homogenising, shaping of the illumination light
• CPC Class Codes: G03B 33/06 by additive-colour projection apparatus
• CPC Class Codes: H04N 9/3152 for shaping the light beam beam shaping per se G02B27/09

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 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. The optical system preferably further comprises an optical combiner element, wherein the output surface of each concentrator element is optically aligned with a corresponding side of the combiner element, and wherein the combiner element chromatically combines the substantially uniform light provided at the output surface of each concentrator element so as to form color-combined light at an output surface of the combiner element. In one embodiment, the combiner element comprises a first dichroic element and a second dichroic element, and wherein the first dichroic element and the second dichroic element are positioned substantially adjacent to each other and are angled with respect to each other so as to form a substantially V-shaped pattern.

Claims

1. 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 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

an optical combiner element, wherein the output surface of each concentrator element is optically aligned with a corresponding side of the combiner element, and wherein the combiner element chromatically combines the substantially uniform light provided at the output surface of each concentrator element so as to form color-combined light at an output surface of the combiner element;

wherein the combiner element comprises a first dichroic element and a second dichroic element, wherein the first dichroic element and the second dichroic element are positioned substantially adjacent to each other and are angled with respect to each other so as to form a substantially V-shaped pattern, wherein each of the first dichroic element and the second dichroic element spatially combines the substantially uniform light provided at the output surface of at most two of the concentrator elements.

2. The optical system of claim 1, wherein the first dichroic element spatially combines the substantially uniform light provided at the output surface of each of a first and a second of the concentrator elements, wherein the second dichroic element spatially combines the substantially uniform light provided at the output surface of each of the second and a third of the concentrator elements.

3. The optical system of claim 2, wherein the first dichroic element reflects the substantially uniform light provided at the output surface of the first concentrator element, and wherein the first dichroic element transmits the substantially uniform light provided at the output surface of the second concentrator element.

4. The optical system of claim 3, wherein the second dichroic element reflects the substantially uniform light provided at the output surface of the third concentrator element, and wherein the second dichroic element transmits the substantially uniform light provided at the output surface of the second concentrator element.

5. The optical system of claim 2, wherein the first concentrator element and the third concentrator element are oriented in substantially opposite directions from each other such that the output surfaces of the first concentrator element and the third concentrator element are optically aligned with opposite sides of the combiner element, wherein the output surface of the second concentrator element is optically aligned with an intermediary side of the combiner element, and wherein the intermediary side of the combiner element joins the opposite sides of the combiner element.

6. The optical system of claim 2, wherein the output surfaces of the first, second, and third concentrator elements are optically aligned with a common side of the combiner element, wherein the combiner element further comprises a first reflector and a second reflector, wherein the first reflector is provided in the optical path between the output surface of the first concentrator element and the first dichroic element, and wherein the second reflector is provided in the optical path between the output surface of the third concentrator element and the second dichroic element.

7. The optical system of claim 2, 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.

8. The optical system of claim 7, 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.

9. The optical system of claim 1, wherein the first dichroic element spatially combines the substantially uniform light provided at the output surface of each of a first and a second of the concentrator elements, wherein the second dichroic element spatially combines the substantially uniform light provided at the output surface of each of a third and a fourth of the concentrator elements, and wherein the second concentrator element and the third concentrator element are positioned substantially adjacent to each other such that the output surfaces of the second concentrator element and third concentrator element are optically aligned with a common side of the combiner element.

10. The optical system of claim 9, wherein the first dichroic element reflects the substantially uniform light provided at the output surface of the first concentrator element, and wherein the first dichroic element transmits the substantially uniform light provided at the output surface of the second concentrator element.

11. The optical system of claim 10, wherein the second dichroic element reflects the substantially uniform light provided at the output surface of the fourth concentrator element, and wherein the second dichroic element transmits the substantially uniform light provided at the output surface of the third concentrator element.

12. The optical system of claim 9, wherein the first concentrator element and the fourth concentrator element are oriented in substantially opposite directions from each other such that the output surfaces of the first concentrator element and the fourth concentrator element are optically aligned with opposite sides of the combiner element, and wherein the common side of the combiner element joins the opposite sides of the combiner element.

13. The optical system of claim 9, wherein the output surfaces of the first, second, third, and fourth concentrator elements are optically aligned with the common side of the combiner element, wherein the combiner element further comprises a first reflector and a second reflector, wherein the first reflector is provided in the optical path between the output surface of the first concentrator element and the first dichroic element, and wherein the second reflector is provided in the optical path between the output surface of the fourth concentrator element and the second dichroic element.

14. The optical system of claim 9, wherein the plurality of LED arrays consists of 4 LED arrays, wherein the 4 LED arrays consist of 4 single-color LED arrays, and wherein 3 of the 4 single-color LED arrays is of a different color from one another.

15. The optical system of claim 14, wherein the 4 single-color LED arrays consist of an LED array consisting of only red LEDs, an LED array consisting of only green LEDs, an LED array consisting of only blue LEDs, and an LED array consisting of only either red, green, or blue LEDs.

16. The optical system of claim 9, wherein the substantially uniform light at the output surface of the second and third concentrator elements is substantially the same color.

17. The optical system of claim 9, wherein the substantially uniform light at the output surface of the second and third concentrator elements is green.

18. The optical system of claim 9 further comprising a common field lens provided between the output surfaces of the second and third concentrator elements, and the common side of the combiner element.

19. The optical system of claim 9 further comprising a digital imaging device, wherein the imaging device has an aspect ratio other than 1:

1, and wherein the substantially uniform light provided at the output surfaces of the second and third concentrator elements are directed towards different portions of the imaging device so as to substantially fill the etendue of the imaging device.

20. The optical system of claim 1 further comprising a field lens provided between the output surface of each concentrator element and the corresponding side of the combiner element.

21. The optical system of claim 1, wherein at least one of the first dichroic element and the second dichroic element is a dichroic plate.

22. The optical system of claim 1, wherein the first dichroic element and the second dichroic element are defined by dichroic coatings on two adjacent facets of a prism.

23. The optical system of claim 1, wherein the reflection of light performed by the concentrator elements is total internal reflection.

24. The optical system of claim 1, wherein the reflection of light performed by the concentrator elements is specular reflection.

25. The optical system of claim 1 further comprising an integrator element, wherein the output surface of the combiner element is optically aligned with an input surface of the integrator element, wherein the integrator element spatially homogenizes the color-combined light provided at the output surface of the combiner element so as to form color-combined light which is substantially homogenized at an output surface of the integrator element.

26. The optical system of claim 25 further comprising at least one field lens provided between the output surface of the combiner element and the input surface of the integrator element.

27. The optical system of claim 1, wherein the concentrator elements have a conic shape.

28. The optical system of claim 1, wherein the concentrator elements have a complex conic shape.

29. The optical system of claim 1, wherein the concentrator elements have a substantially parabolic cross section.

30. The optical system of claim 1, wherein the concentrator elements comprise a material selected from the group consisting of a polymer, plastic, glass, metal, and combinations thereof.

31. The optical system of claim 1, wherein the concentrator elements comprise Zeonex®

.

32. The optical system of claim 1, wherein the concentrator elements comprise metal.

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

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

35. The optical system of claim 34, wherein the output surface of each concentrator element is imaged directly on the digital imaging device.

36. The optical system of claim 34, wherein the imaging device has an aspect ratio other than 1:

1.

37. The optical system of claim 34, wherein the imaging device has an aspect ratio of 16:

9.

38. 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 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

a digital imaging device having an aspect ratio other than 1;

1;

wherein the substantially uniform light provided at the output surface of at least two of the concentrator elements is directed towards different portions of the imaging device so as to substantially fill the etendue of the imaging device.

39. The optical system of claim 38 further comprising an optical combiner element, wherein the combiner element chromatically combines the substantially uniform light provided at the output surface of each concentrator element so as to form color-combined light at an output surface of the combiner element.