DISPLAY ELEMENT HAVING FILTER MATERIAL DIFFUSED IN A SUBSTRATE OF THE DISPLAY ELEMENT

• US 20090086301A1
• Filed: 11/05/2008
• Published: 04/02/2009
• Est. Priority Date: 09/27/2004
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: IDC, LLC
• Inventors: Gally, Brian J., Cummings, William J.
• Granted Patent: US 8,344,377 B2
• Time in Patent Office: Days
• US Class Current: 359/223.100
• 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

Abstract

Optical filter functionality is incorporated into a substrate of a display element thereby decreasing the need for a separate thin film filter and, accordingly, reducing a total thickness of a filtered display element. Filter functionality may be provided by any filter material, such as pigment materials, photoluminescent materials, and opaque material, for example. The filter material may be incorporated in the substrate at the time of creating the substrate or may be selectively diffused in the substrate through a process of masking the substrate, exposing the substrate to the filter material, and heating the substrate in order to diffuse the filter material in the substrate.

Claims

1. A display device comprising:

at least one light modulating element comprising first and second reflective surfaces, said second surface being movable with respect to said first surface; and

a substrate, said light modulating element disposed over said substrate,

wherein said substrate comprises a color filter that transmits color light.

2. The display device of claim 1, wherein the substrate comprises a plurality of color filters that transmit different color light when illuminated by white light.

3. The display of claim 1 wherein said plurality of color filters include red, green, and blue color filters that transmits red, green, or blue light, respectively, when illuminated by white light.

4. The display device of claim 1, wherein said color filter comprises a magenta color filter that transmits magenta light when illuminated with white light.

5. The display device of claim 1, wherein the color filter is substantially optically transmissive to visible light in a first wavelength region and substantially absorptive to visible light in a second wavelength region.

6. The display device of claim 5, wherein the first wavelength region includes red wavelengths and said second wavelength regions includes other wavelengths such that said color filter is substantially optically transmissive to red light when illuminated with white light.

7. The display device of claim 5, wherein the first wavelength region includes green wavelengths and said second wavelength regions includes other wavelengths such that said color filter is substantially optically transmissive to green light when illuminated with white light.

8. The display device of claim 5, wherein the first wavelength region includes blue wavelengths and said second wavelength regions includes other wavelengths such that said color filter is substantially optically transmissive to blue light when illuminated with white light.

9. The display device of claim 5, wherein the light modulating element is configured to reflect light in said first wavelength region.

10. The display device of claim 1, wherein the light modulating element is configured to reflect second order red and third order blue and the color filter is substantially optically transmissive to second order red and absorbs third order blue.

11. The display device of claim 1, wherein the light modulating element is configured to substantially reflect green light and the color filter is substantially optically transmissive to magenta light when illuminated with visible light.

12. The display device of claim 1, wherein the color filter comprises one or more photoluminescent materials.

13. The display device of claim 1, wherein as an angle between a direction of light reflected normal to a surface of the substrate increases, filtering performed by the color filter increases.

14. A display device comprising:

a plurality of light-modulating elements each comprising first and second reflective surfaces, said second surface being movable with respect to said first surface; and

a substrate, said plurality of light-modulating elements disposed over said substrate,

wherein said substrate includes therein first and second absorptive regions, said first and second absorptive regions having different optical transmission properties.

15. The display device of claim 14, wherein said first regions comprise color filters that transmit a color when illuminated by white light.

16. The display device of claim 14, wherein said first regions are below said light modulating elements and said second regions are below areas between said light-modulating elements.

17. The display device of claim 14, wherein said first regions comprise material diffused into said substrate.

18. The display device of claim 17, wherein said second regions are substantially devoid of said material diffused in said first regions.

19. A display device comprising:

at least one plurality of light modulating elements each comprising first and second reflective surfaces, said second surfaces being movable with respect to said first surfaces; and

a substrate, said at least one plurality of light modulating elements disposed over said substrate,

wherein said substrate comprises a plurality of elements configured to limit a field-of-view of the display device.

20. The display of claim 19, wherein the plurality of elements configured to limit a field-of-view of the display comprises a plurality of baffles.

21. The display of claim 20, wherein the substrate is in a horizontal plane and the plurality of baffles comprise substantially planar surfaces substantially parallel to a vertical plane.

22. The display of claim 20, wherein the plurality of baffles comprise spacings between individual baffles, said spacing having a dimension that provides a view angle of not more than about 40 degrees from a plane normal to said substrate, wherein the angle is measured as a half-angle with respect to the normal plane.

23. The display of claim 20, wherein the plurality of baffles comprise spacings between individual baffles, said spacing having a dimension that provides a view angle of not more than about 20 degrees from a plane normal to the substrate, wherein the angle is measured as a half-angle with respect to the normal plane.

24. The display of claim 20, wherein the plurality of baffles are substantially opaque.

25. The display of claim 20, wherein the plurality of baffles comprises absorbing material.

26. A display device comprising:

means for modulating light; and

means for supporting said light modulating means; and

means for filtering light disposed in said supporting means.

27. The apparatus of claim 26, wherein said modulating means comprises first and second reflective surfaces, said second reflective surfaces being movable with respect to said first reflective surface.

28. The apparatus of claim 27, wherein said supporting means comprises a substrate.

29. The apparatus of claim 28, wherein said filtering means comprises a color filter, photoluminescent material, or a mask.

30. A display device comprising:

means for modulating light; and

means for supporting said light modulating means; and

means for limiting a field-of-view.

31. The apparatus of claim 30, wherein said modulating means comprises first and second reflective surfaces, said second reflective surfaces being movable with respect to said first reflective surface.

32. The apparatus of claim 31, wherein said supporting means comprises a substrate.

33. The apparatus of claim 32, wherein said field-of-view limiting means comprises baffles.

34. A display device comprising:

at least one light-modulating element comprising first and second reflective surfaces, said second surface being movable with respect to said first surface; and

a substrate, said light-modulating element disposed over said substrate,

wherein said substrate incorporates at least one photoluminescent material.

35. The display device of claim 34, wherein the at least one photoluminescent material comprises at least one of:

phosphorescent and fluorescent materials.

36. The display device of claim 34, wherein illumination from the photoluminescent material comprises light having a wavelength larger than a wavelength of the light source.

37. A display device formed by the process of:

diffusing a material into a substrate, said material having a different optical property than said substrate; and

forming at least one light modulating element over the substrate, the light modulating element comprising a partially reflective surface and a substantially reflective surface that form an optical cavity, at least one of said reflective surfaces movable with respect to the other to modulate said optical cavity.