Prism assembly for separating light

• US 7,281,804 B2
• Filed: 02/23/2005
• Issued: 10/16/2007
• Est. Priority Date: 12/16/2004
• Status: Expired due to Fees

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Ring, James W., Gupta, Anurag, Lerner, Scott
• Primary Examiner(s): KOVAL, MELISSA J
• Application Number:
  US11/064,166
• Publication Number:
  US 20060132719A1
• Time in Patent Office: 965 Days
• Field of Search: 353/31, 353/33, 353/81, 359/634, 359/583, 359/838
• US Class Current: 353/33
• CPC Class Codes: G02B 27/1026 for use with reflective spatial light modulators
• CPC Class Codes: G02B 27/149 using crossed beamsplitting surfaces, e.g. cross-dichroic cubes or X-cubes
• CPC Class Codes: H04N 9/315 Modulator illumination systems general applications of lighting devices F21V; general optical systems G02B; lamp houses for projectors not peculiar to the presence of an electronic spatial light modulator G03B21/20

Abstract

A prism assembly is provided. The prism assembly comprises a first prism component having a triangular cross-section along an optical path, a second prism component having a first quadrilateral cross-section along the optical path, a third prism component having a second quadrilateral cross-section along the optical path, a fourth prism component having a pentagon cross-section along the optical path, a first dichroic interface between the first and second prism components and between the third and fourth prism components and configured to reflect a first range of wavelengths of the light, and a second dichroic interface between the first and third prism components and between the second and fourth prism components and configured to reflect a second range of wavelengths of the light.

Claims

1. A prism assembly comprising:

a first prism component having a triangular cross-section along an optical path;

a second prism component having a first quadrilateral cross-section along the optical path;

a third prism component having a second quadrilateral cross-section along the optical path;

a fourth prism component having a pentagon cross-section along the optical path;

a first dichroic interface between the first and second prism components and between the third and fourth prism components and configured to reflect a first range of wavelengths of light; and

a second dichroic interface between the first and third prism components and between the second and fourth prism components and configured to reflect a second range of wavelengths of the light.

2. The prism assembly of claim 1 wherein the optical path comprises an illumination path.

3. The prism assembly of claim 1 wherein the optical path comprises an projection path.

4. The prism assembly of claim 1 wherein the optical path comprises an illumination path and a projection path.

5. The prism assembly of claim 1 wherein the first dichroic interface and the second dichroic interface transmit a third range of wavelengths of the light into the fourth prism component.

6. The prism assembly of claim 1 wherein the first prism component includes a first face for receiving the light from the optical path, wherein the first range of wavelengths of the light totally internally reflects off of the first face into the third prism component, and wherein the second range of wavelengths of the light totally internally reflects off of the first face into the second prism component.

7. The prism assembly of claim 6 wherein the second prism component includes a second face, wherein the third prism component includes a third face, wherein the first range of wavelengths of the light totally internally reflects off of the second face of the second prism component, and wherein the second range of wavelengths of the light totally internally reflects off of the third face of the third prism component.

8. The prism assembly of claim 7 wherein the first range of wavelengths of the light transmit through the third prism component onto a first modulation device, wherein second range of wavelengths of the light transmit through the second prism component onto a second modulation device, and wherein a third range of wavelengths of the light transmit through the fourth prism component onto a third modulation device.

9. The prism assembly of claim 1 wherein the first dichroic interface is between a first face of the first prism component and a first face of the second prism component and between a first face of the third prism component and a first face of the fourth prism component, and wherein the second dichroic interface is between a second face of the first prism component and a second face of the third prism component and between a second face of the second prism component and a second face of the fourth prism component.

10. The prism assembly of claim 9 wherein the first face of the third prism component extends beyond the first face of the fourth prism component, and wherein the second face of the second prism component extends beyond the second face of the fourth prism component.

11. A method for manufacturing a prism assembly, the method comprising:

providing a first prism component having a triangular cross-section along an optical path;

providing a second prism component having a first quadrilateral cross-section along the optical path;

providing a third prism component having a second quadrilateral cross-section along the optical path;

providing a fourth prism component having a pentagon cross-section along the optical path;

providing a first dichroic interface between the first and second prism components and between the third and fourth prism components and configured to reflect a first range of wavelengths of light; and

providing a second dichroic interface between the first and third prism components and between the second and fourth prism components and configured to reflect a second range of wavelengths of the light.

12. The method of claim 11 wherein the first dichroic interface and the second dichroic interface transmit a third range of wavelengths of the light into the fourth prism component.

13. The method of claim 11 wherein the first prism component includes a first face for receiving the light from the optical path, wherein the first range of wavelengths of the light totally internally reflects off of the first face into the third prism component, and wherein the second range of wavelengths of the light totally internally reflects off of the first face into the second prism component.

14. The method of claim 13 wherein the second prism component includes a second face, wherein the third prism component includes a third face, wherein the first range of wavelengths of the light totally internally reflects off of the second face of the second prism component, and wherein the second range of wavelengths of the light totally internally reflects off of the third face of the third prism component.

15. The method of claim 14 wherein the first range of wavelengths of the light transmit through the third prism component onto a first modulation device, wherein the second range of wavelengths of the light transmit through the second prism component onto a second modulation device, and wherein a third range of wavelengths of the light transmit through the fourth prism component onto a third modulation device.

16. The method of claim 11 wherein the first dichroic interface is between a first face of the first prism component and a first face of the second prism component and between a first face of the third prism component and a first face of the fourth prism component, and wherein the second dichroic interface between a second face of the first prism component and a second face of the third prism component and between a second face of the second prism component and a second face of the fourth prism component.

17. The method of claim 16 wherein the first face of the third prism component extends beyond the first face of the fourth prism component, and wherein the second face of the second prism component extends beyond the second face of the fourth prism component.

18. A method comprising:

reflecting a first range of wavelengths of light from a first prism component off of a first dichroic interface;

reflecting a second range of wavelengths of the light from the first prism component off of a second dichroic interface;

totally internally reflecting the first range of wavelengths and the second range of wavelengths off of a first face of the first prism component;

totally internally reflecting the first range of wavelengths off of a second face of a second prism component;

totally internally reflecting the second range of wavelengths off of a third face of a third prism component; and

transmitting a third range of wavelengths of the light from the first prism component through a fourth prism.

19. The method of claim 18 further comprising:

transmitting the second range of wavelengths of the light from the first prism component though the first dichroic interface.

20. The method of claim 18 further comprising:

transmitting the first range of wavelengths of the light from the first prism component through the second dichroic interface.

21. The method of claim 18 further comprising:

transmitting the third range of wavelengths of the light from the first prism component though the first dichroic interface and the second dichroic interface.

22. The method of claim 18 further comprising:

transmitting the first range of wavelengths onto a first modulation device; and

transmitting the second range of wavelengths onto a second modulation device.

23. The method of claim 22 further comprising:

transmitting the third range of wavelengths of the light from the fourth prism component onto a third modulation device.

24. A prism assembly comprising:

a first prism component having at least first and second faces substantially orthogonal to an optical path;

a second prism component having at least third and fourth faces substantially orthogonal to the optical path;

a third prism component having at least fifth and sixth faces substantially orthogonal to the optical path;

a fourth prism component having at least seventh and eighth faces substantially orthogonal to the optical path;

a first dichroic interface between the first and the third faces and between at least a portion of the sixth and the eighth faces and configured to reflect a first color of the light and transmit second and third colors of the light; and

a second dichroic interface between the second and the fifth faces and between at least a portion of the fourth and the seventh faces and configured to reflect the second color and transmit the first and the third colors.

25. The prism assembly of claim 24 wherein the first prism component includes a ninth face configured to totally internally reflect the first color between the first dichroic interface and a first modulator and the second color between the second dichroic interface and a second modulator.

26. The prism assembly of claim 25 wherein the second prism component includes a tenth face configured to totally internally reflect the first color between the first dichroic interface and the first modulator, and wherein the third prism component includes an eleventh face configured to totally internally reflect the second color between the second dichroic interface and the second modulator.

27. The prism assembly of claim 24 wherein the optical path comprises an illumination path.

28. The prism assembly of claim 24 wherein the optical path comprises an projection path.