Spatial light modulator with integrated optical compensation structure

• US 7,342,705 B2
• Filed: 01/14/2005
• Issued: 03/11/2008
• Est. Priority Date: 02/03/2004
• Status: Expired due to Fees

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: IDC, LLC
• Inventors: Chui, Clarence, Sampsell, Jeffrey B., Cummings, William J., Tung, Ming-Hau
• Primary Examiner(s): Mack; Ricky
• Assistant Examiner(s): TRA, TUYEN Q
• Application Number:
  US11/036,965
• Publication Number:
  US 20050179977A1
• Time in Patent Office: 1,152 Days
• Field of Search: 359/290, 359/291, 359/292, 359/298, 359/223, 359/224, 359/320, 359/322
• US Class Current: 359/237
• CPC Class Codes: G02B 26/001 based on interference in an adjustable optical cavity interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26
• CPC Class Codes: G02F 1/1335 Structural association of cells with optical devices, e.g. polarisers or reflectors
• CPC Class Codes: G02F 1/13356 characterised by the placement of the optical elements
• CPC Class Codes: G02F 1/21 by interference

Abstract

A spatial light modulator comprises an integrated optical compensation structure, e.g., an optical compensation structure arranged between a substrate and a plurality of individually addressable light-modulating elements, or an optical compensation structure located on the opposite side of the light-modulating elements from the substrate. The individually addressable light-modulating elements are configured to modulate light transmitted through or reflected from the transparent substrate. Methods for making such spatial light modulators involve fabricating an optical compensation structure over a substrate and fabricating a plurality of individually addressable light-modulating elements over the optical compensation structure. The optical compensation structure may be a passive optical compensation structure. The optical compensation structure may include one or more of a supplemental frontlighting source, a diffuser, a black mask, a diffractive optical element, a color filter, an anti-reflective layer, a structure that scatters light, a microlens array, and a holographic film.

Claims

1. A spatial light modulator comprising:

a substrate;

a plurality of individually addressable light-modulating elements arranged over the substrate and configured to interferometrically modulate light transmitted through the substrate;

a diffuser; and

an optical compensation structure, the optical compensation structure different from the diffuser;

wherein the diffuser and the optical compensation structure are arranged between the substrate and the plurality of individually addressable light-modulating elements.

2. The spatial light modulator of claim 1 in which the interferometric modulator comprises a movable element and a cavity.

3. The spatial light modulator of claim 1 in which the optical compensation structure comprises a black mask.

4. The spatial light modulator of claim 1 in which the optical compensation structure comprises a color filter.

5. The spatial light modulator of claim 1 in which the optical compensation structure comprises an anti-reflective layer.

6. The spatial light modulator of claim 1 in which the optical compensation structure comprises a plurality of scattering elements.

7. The spatial light modulator of claim 1 in which the optical compensation structure comprises a microlens array.

8. The spatial light modulator of claim 1 in which the optical compensation structure comprises a holographic film that mitigates a shift in reflected color with respect to an angle of incidence of the light transmitted through the substrate.

9. The spatial light modulator of claim 1 in which the optical compensation structure comprises a diffractive optical element.

10. The spatial light modulator of claim 1 in which the optical compensation structure comprises a planarization layer that comprises a scattering element.

11. The spatial light modulator of claim 1 in which the individually addressable light-modulating elements comprise an interferometric modulator and in which the optical compensation structure is selected from the group consisting of black mask and color filter.

12. The spatial light modulator of claim 1 in which the optical compensation structure comprises a black mask and a color filter.

13. The spatial light modulator of claim 1 in which the optical compensation structure is a passive optical compensation structure.

14. The spatial light modulator of claim 1 further comprising a planarization layer.

15. The spatial light modulator of claim 1 in which the substrate is partially reflective.

16. The spatial light modulator of claim 1 in which the optical compensation structure is arranged between the diffuser and the plurality of individually addressable light-modulating elements.

17. A spatial light modulator comprising:

a transparent substrate;

a plurality of individually addressable interferometric light-modulating elements arranged over the transparent substrate and configured to modulate light transmitted through the transparent substrate, the interferometric light-modulating elements comprising a cavity and a movable wall; and

a plurality of different optical compensation structures arranged between the transparent substrate and the plurality of individually addressable interferometric light-modulating elements, at least one of the optical compensation structures comprising a diffuser.

18. A spatial light modulator comprising:

a substrate;

a means for interferometrically modulating light transmitted through or reflected from the substrate;

a means for diffusing the light transmitted through or reflected from the substrate; and

a means for compensating the light transmitted through or reflected from the substrate, the means for compensating the light being different from the means for diffusing the light;

wherein the means for diffusing the light and the means for compensating the light are operatively arranged between the substrate and the means for modulating light transmitted through or reflected from the substrate.

19. The spatial light modulator of claim 18 in which the means for modulating light transmitted through or reflected from the substrate comprises a plurality of interferometric modulators.

20. The spatial light modulator of claim 18 in which the means for compensating the light transmitted through or reflected from the substrate comprises a structure selected from the group consisting of a black mask, a diffractive optical element, a color filter, an anti-reflective layer, a plurality of scattering elements, a microlens array, and a holographic film.

21. The spatial light modulator of claim 18 in which the means for compensating the light transmitted through or reflected from the substrate comprises a structure selected from the group consisting of a black mask and a color filter.

22. A spatial light modulator comprising:

a substrate;

a plurality of individually addressable light-modulating elements arranged over the substrate and configured to interferometrically modulate light transmitted through the substrate;

a first optical compensation structure; and

a second optical compensation structure, the second optical compensation structure different from the first optical compensation structure, the second optical compensation structure selected from the group consisting of an anti-reflective layer, a plurality of scattering elements, a microlens array, a holographic film that mitigates a shift in reflected color with respect to an angle of incidence of the light transmitted through the substrate, and a diffractive optical element;

wherein the first and second optical compensation structures are arranged between the substrate and the plurality of individually addressable light-modulating elements.

23. The spatial light modulator of claim 22 in which the interferometric modulator comprises a movable element and a cavity.

24. The spatial light modulator of claim 22 in which the first optical compensation structure comprises a black mask.

25. The spatial light modulator of claim 22 in which the first optical compensation structure comprises a color filter.

26. The spatial light modulator of claim 22 in which the individually addressable light-modulating elements comprise an interferometric modulator and in which the first optical compensation structure is selected from the group consisting of black mask and color filter.

27. The spatial light modulator of claim 22 in which the first optical compensation structure comprises a black mask and a color filter.

28. The spatial light modulator of claim 22 in which the first optical compensation structure is a passive optical compensation structure.

29. The spatial light modulator of claim 22 in which a planarization layer comprises the second optical compensation structure.

30. The spatial light modulator of claim 22 in which the substrate is partially reflective.

31. The spatial light modulator of claim 22 in which the second optical compensation structure is an anti-reflective layer.

32. The spatial light modulator of claim 22 in which the second optical compensation structure is a plurality of scattering elements.

33. The spatial light modulator of claim 22 in which the second optical compensation structure is a microlens array.

34. The spatial light modulator of claim 22 in which the second optical compensation structure is a holographic film that mitigates a shift in reflected color with respect to an angle of incidence of the light transmitted through the substrate.

35. The spatial light modulator of claim 22 in which the second optical compensation structure is a diffractive optical element.

36. The spatial light modulator of claim 22 in which the first optical compensation structure is arranged between the second optical compensation structure and the plurality of individually addressable light-modulating elements.