Method and device for corner interferometric modulation

• US 20060077515A1
• Filed: 04/11/2005
• Published: 04/13/2006
• Est. Priority Date: 09/27/2004
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: IDC, LLC
• Inventors: Cummings, William J.
• Granted Patent: US 7,321,456 B2
• Time in Patent Office: Days
• US Class Current: 359/290
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• 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: G02B 5/122 cube corner, trihedral or triple reflector type
• CPC Class Codes: G02B 5/124 plural reflecting elements forming part of a unitary plate or sheet

Abstract

A display is described, wherein the display includes surfaces arranged at a non-zero angle to one another. A least one of the surfaces may include an interferometric modulator. Compensation for color shift can be provided through the use of two or three surfaces arranged at an angle to one another, the surfaces having similar interferometric modulators. Methods of making such a display are also described. A brighter display can be provided through the use of three surfaces arranged orthogonally to one another, where each of the surfaces has an interferometric modulator which reflects a different color of light. Either additive or subtractive methods can be used to generate light of a particular color.

Claims

1. A display, comprising

a substantially transparent substrate, said substrate having at least a first generally planar surface and a second generally planar surface, the second surface at a first non-zero angle to the first surface;

at least a first reflective element on said first surface, wherein said first reflective element has a first reflectivity which changes in response to a first signal; and

at least a second reflective element on said second surface.

2. The display of claim 1, wherein the second reflective element comprises a reflective layer on the substrate.

3. The display of claim 1, wherein the second reflective element has a second reflectivity which changes in response to a second signal.

4. The display of claim 3, wherein the first reflective element is substantially identical to the second reflective element.

5. The display of claim 1, wherein the first non-zero angle is approximately 90 degrees.

6. The display of claim 1, wherein the substrate comprises a third generally planar surface at a second non-zero angle to the first surface, said third surface at a third non-zero angle to the second surface.

7. The display of claim 6, further comprising at least a third reflective element on the third surface of the substrate.

8. The display of claim 6, wherein the second reflective element comprises a reflective layer on the second surface, and wherein the third reflective element comprises a reflective layer on the third surface.

9. The display of claim 6, wherein:

the second reflective element has a second reflectivity which changes in response to a second signal; and

the third reflective element has a third reflectivity which changes in response to a third signal.

10. The display of claim 9, wherein the first reflective element is substantially identical to the second reflective element and is substantially identical to the third reflective element.

11. The display of claim 1, wherein the first reflective element comprises a reflective layer movable between at least a first position and a second position, and a partially reflective layer located between said movable reflective layer and the first surface.

12. The display of claim 11, wherein the first reflectivity of the first reflective element comprises a range of wavelengths reflected from said first reflective element, said range of wavelengths changing in response to the first signal.

13. The display of claim 12, wherein the first reflective element reflects generally white light when the movable reflective layer of the first reflective element is in the first position and white light is incident on said first reflective element.

14. A method of fabricating a display device, comprising:

providing a substrate having at least one positive feature;

forming a first electrode over a first surface of the positive feature of the substrate;

depositing a dielectric layer over the first electrode;

depositing a sacrificial layer over the dielectric layer;

forming a flexible layer over the sacrificial layer;

removing the sacrificial layer to form an interferometric cavity, thereby allowing the flexible layer to move toward the first electrode; and

forming a reflective element on a second surface of the positive feature of the substrate, said second surface at a non-zero angle to the first surface.

15. The method of claim 14, additionally comprising:

removing a portion of the sacrificial layer prior to the formation of the second electrode to form cavities in said sacrificial layer; and

forming support structures in the cavities.

16. The method of claim 15, wherein the flexible layer comprises a second electrode.

17. The method of claim 14, wherein forming a flexible layer over the sacrificial layer comprises:

forming a second electrode above at least a portion of the sacrificial layer; and

forming a mechanical layer above the second electrode, wherein said mechanical layer is in contact with at least a portion of said second electrode.

18. The method of claim 14, wherein the positive feature comprises a third surface, said third surface at a non-zero angle to the first surface, and at a non-zero angle to the second surface, the method further comprising:

forming a reflective element on the third surface of the positive feature of said substrate.

19. A display, wherein said display is manufactured by the process of:

providing a substrate having at least one positive feature;

forming a first electrode over a first surface of the positive feature of the substrate;

depositing a dielectric layer over the first electrode;

depositing a sacrificial layer over the dielectric layer;

forming a flexible layer over the sacrificial layer;

removing the sacrificial layer to form an interferometric cavity, thereby allowing the flexible layer to move toward the first electrode; and

forming a reflective element on a second surface of the positive feature of the substrate, said second surface at a non-zero angle to the first surface.

20. A display, said display comprising:

first means for modulating light;

first means for reflecting light towards the first means for modulating;

first means for supporting the first means for modulating; and

second means for supporting the first reflecting means.

21. The display of claim 20, wherein the first means for reflecting comprises second means for modulating light.

22. The display of claim 20, additionally comprising:

second means for reflecting light toward the first reflecting means; and

third means for supporting the second reflecting means.

23. The display of claim 22, wherein:

the first means for reflecting comprise second means for modulating light; and

said second means for reflecting comprise third means for modulating light.

24. A method of displaying a color, comprising:

reflecting light off of a first surface towards a second surface; and

reflecting the light toward a viewer, wherein the first surface comprises a first optical element which modulates said light and reflects said light towards the second surface.

25. The method of claim 24, wherein the first optical element interferometrically modulates the light and reflects said light towards the second surface.

26. The method of claim 24, wherein reflecting the light toward a viewer comprises reflecting light off the second surface to the viewer

27. The method of claim 26, wherein the second surface comprises a reflective layer.

28. The method of claim 26, wherein the second surface comprises a second optical element configured to reflect a second range of wavelengths of light.

29. The method of claim 27, wherein the first range of wavelengths is substantially similar to said second range of wavelengths.

30. The method of claim 24, wherein said first optical element comprises an interferometric modulator.

31. The method of claim 24, wherein reflecting the light toward a viewer comprises:

reflecting light off the second surface to a third surface; and

reflecting light off the third surface toward a viewer.

32. The method of claim 31, wherein the second surface comprises a second optical element configured to reflect a second range of wavelengths of light, said second range of wavelengths being substantially similar to the first range of wavelengths.

33. The method of claim 31, wherein the second surface comprises:

a second optical element configured to reflect a second range of wavelengths of light; and

a third optical element configured to reflect a third range of wavelengths of light;

wherein the second range of ravelengths is different from the first range of wavelengths, and wherein the third range of wavelengths is different from said first range of wavelengths.

34. The method of claim 33, wherein the first surface comprises a plurality of optical elements, and wherein at least one of of said plurality of optical elements is configured to reflect a fourth range of wavelengths of light, said fourth range of wavelengths being different from said first range of wavelengths.

35. A method of manufacturing a display device, said method comprising:

providing a first substrate having a generally planar surface;

forming a first reflective element on the surface of the first substrate, wherein said first reflective element has a first reflectivity which changes in response to a first signal;

providing a second substrate having a generally planar surface;

forming a second reflective element on the surface of the second substrate; and

positioning the first substrate relative to the second surface such that the surface of said first substrate is at a non-zero angle to the surface of said second substrate.

36. The method of claim 35, wherein said first reflective element comprises an interferometric modulator.

37. The method of claim 35, wherein the surface of said first substrate is oriented substantially orthogonally to the surface of said second substrate.

38. The method of claim 35, wherein positioning the first substrate relative to the second substrate comprises fixing said first substrate relative directly to said second substrate.

39. The method of claim 35, wherein positioning the first substrate relative to the second substrate comprises fixing said first substrate and said second substrate to a frame.

40. The method of claim 35, additionally comprising:

providing a third substrate having a generally planar surface;

forming a third reflective element on the surface of the third substrate; and

positioning the third substrate relative to the first and second substrates such that the surface of said third substrate is at a non-zero angle to the surfaces of said first and second substrates.

41. The method of claim 40, wherein the surfaces of the three substrates are oriented substantially orthogonally to one another.

42. The method of claim 40, wherein said second reflective element comprises an interferometric modulator.

43. The method of claim 42, wherein said third reflective element comprises an interferometric modulator.

44. A display, wherein said display is manufactured by a method comprising:

providing a first substrate having a generally planar surface;

forming a first reflective element on the surface of the first substrate, wherein said first reflective element has a first reflectivity which changes in response to a first signal;

providing a second substrate having a generally planar surface;

forming a second reflective element on the surface of the second substrate; and

positioning the first substrate relative to the second surface such that the surface of said first substrate is at a non-zero angle to the surface of said second substrate.