EM SHIELDING FOR DISPLAY DEVICES

• US 20100245370A1
• Filed: 03/23/2010
• Published: 09/30/2010
• Est. Priority Date: 03/25/2009
• Status: Abandoned Application

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Gally, Brian J., Bita, Ion, Sampsell, Jeffrey B., Narayanan, Kollengode S.
• Application Number:
  US12/730,142
• Publication Number:
  US 20100245370A1
• Time in Patent Office: Days
• US Class Current: 345/522
• 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 5/208 for use with infrared or ultraviolet radiation, e.g. for separating visible light from infrared and/or ultraviolet radiation
• CPC Class Codes: H04N 9/29 using demagnetisation or compensation of external magnetic fields
• CPC Class Codes: Y10T 29/49002 Electrical device making

Abstract

A shielding material that can be arranged with respect to display elements to reduce potential damage or degraded performance caused by incident EM, such as UV and/or IR. The shielding material can be configured to be substantially transparent in visible light wavelengths. The shielding material can include inorganic materials, such as oxides including zinc oxide and titanium dioxide. Display elements can include a shielding material and an outer coating to reduce undesirable optical characteristics of an air/shielding material interface. The shielding material can be electrically conductive and function as a conductive layer in a microelectromechanical system (MEMS) device. In some embodiments, the shielding material can be disposed forward (closer to the viewer) of the electrodes of the display elements to prevent the high energy UV light from building up electrical charge in the electrodes. In some embodiments, the shielding material can also block certain wavelengths of light in the visible spectrum to darken the dark state of the display elements to improve the contrast ratio of the display.

Claims

1. A display device comprising:

a substrate;

a plurality of display elements arranged on a first side of the substrate; and

a nonconductive UV shielding layer comprising substantially no organic material, the UV shielding layer disposed forward of the plurality of display elements such that visible light passes through the UV shielding layer to the plurality of display elements and such that the UV shielding layer blocks 95% or more of UV light below 350 nm in wavelength that is incident on the UV shielding layer from reaching the plurality of display elements.

2. The display device of claim 1, wherein the UV shielding layer comprises an oxide.

3. The display device of claim 2, wherein the UV shielding layer comprises zinc oxide.

4. The display device of claim 1, wherein the UV shielding layer comprises only inorganic material.

5. The display device of claim 1, wherein the plurality of display elements comprise MEMS devices.

6. The display device of claim 1, wherein the plurality of display elements comprise interferometric modulators.

7. The display device of claim 1, wherein the UV shielding layer is disposed between the substrate and the plurality of display elements.

8. The display device of claim 7, wherein the UV shielding layer is formed on the first side of the substrate.

9. The display device of claim 1, wherein the substrate is disposed between the UV shielding layer and the plurality of display elements.

10. The display device of claim 9, wherein the UV shielding layer is formed on a second side of the substrate that is opposite the first side.

11. The display device of claim 9, further comprising an outer coating overlying the UV shielding layer, wherein the outer coating comprises at least one of an anti-reflective coating, an anti-scratch coating, and a filter coating.

12. The display device of claim 1, wherein the UV shielding layer comprises a plurality of UV shielding particles dispersed in a matrix material.

13. The display device of claim 12, wherein the matrix material is glass.

14. The display device of claim 12, wherein the UV shielding layer comprises molecular precursors for the UV shielding particles.

15. The display device of claim 12, wherein the UV shielding layer comprises a heterogeneous layer of inorganic materials.

16. The display device of claim 12, wherein the UV shielding particles are configured to reflect IR light.

17. The display device of claim 16, wherein the UV shielding particles are transparent conductor particles.

18. The display device of claim 12, wherein the UV shielding layer further comprises inorganic blue absorbing particles configured to absorb visible light near the UV spectrum dispersed in the matrix material.

19. The display device of claim 16, wherein the UV shielding layer further comprises inorganic blue absorbing particles configured to absorb visible light near the UV spectrum dispersed in the matrix material.

20. The display device of claim 18, wherein the blue absorbing particles comprise semiconductor nanocrystals.

21. The display device of claim 1, wherein the UV shielding layer comprises a substantially homogenous layer of inorganic material.

22. The display device of claim 1, wherein the UV shielding layer blocks 99% or more of UV light below 350 nm in wavelength that is incident on the UV shielding layer.

23. The display device of claim 1, wherein the UV shielding layer absorbs no more than 1% of visible light that is incident on the UV shielding layer.

24. The display device of claim 1, wherein at least one of the plurality of display elements comprises an optical stack and wherein the optical stack comprises the UV shielding layer.

25. The display device of claim 1, further comprising:

a processor that is configured to communicate with said display device, said processor being configured to process image data; and

a memory device that is configured to communicate with said processor.

26. The display device of claim 25, further comprising a driver circuit configured to send at least one signal from the processor to said display device.

27. The display device of claim 26, further comprising a controller configured to send at least a portion of said image data to said driver circuit.

28. The display device of claim 25, further comprising an image source module configured to send said image data to said processor.

29. The display device of claim 28, wherein said image source module comprises at least one of a receiver, transceiver, and transmitter.

30. The display device of claim 25, further comprising an input device configured to receive input data and to communicate said input data to said processor.

31. The display device of claim 1, further comprising a light assembly arranged to direct light towards the plurality of display elements.

32. The display device of claim 31, wherein the light assembly comprises a light guide.

33. The display device of claim 1, wherein the UV shielding layer comprises titanium dioxide particles suspended in a matrix, wherein the matrix is selected to have an index of refraction such that the UV shielding layer transmits 95% or more of visible light.

34. The display device of claim 1, wherein at least one of the plurality of display elements comprises one or more electrodes for facilitating the actuation of the at least one display element, and wherein the UV shielding layer is disposed forward of the one or more electrodes such that the UV shielding layer blocks 95% or more of UV light below 350 nm in wavelength that is incident on the UV shielding layer from reaching the one or more electrodes.

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

providing a substrate;

arranging a plurality of display elements on a first side of the substrate; and

disposing a nonconductive UV shielding layer comprising substantially no organic material forward of the plurality of display elements such that visible light passes through the UV shielding layer to the plurality of display elements and such that 95% or more of UV light below 350 nm in wavelength that is incident on the UV shielding layer is blocked from reaching the plurality of display elements.

36. A display device, comprising:

means for supporting;

means for displaying an image arranged on a first side of the supporting means; and

means for UV shielding disposed forward of the displaying means such that visible light passes through the UV shielding means to the displaying means, and such that the UV shielding means blocks 95% or more of UV light that is incident on the UV shielding means from reaching the displaying means, and wherein the UV shielding means comprises substantially only inorganic material.

37. The display device of claim 36, wherein the supporting means comprises a transparent substrate, or the displaying means comprises a plurality of display elements, or the UV shielding means comprises a UV shielding layer.

38. A display device comprising:

at least one display element having a dark state and a light state, wherein the at least one display element emits visible light near the UV spectrum when in the dark state; and

an optical shielding layer disposed forward of the at least one display element such that visible light passes through the optical shielding layer to the at least one display element and such that the optical shielding layer blocks UV light that is incident on the optical shielding layer from reaching the at least one display element, and wherein the optical shielding layer blocks visible light near the UV spectrum so as to darken the dark state of the at least one display element.

39. The display device of claim 38, wherein the optical shielding layer absorbs an average of at least about 50% of visible light below 400 nm in wavelength that is incident on the UV shielding layer.

40. The display device of claim 38, wherein the optical shielding layer comprises substantially only inorganic material.

41. The display device of claim 40, wherein the optical shielding layer comprises zinc oxide.

42. The display device of claim 38, wherein the optical shielding layer comprises multiple layers, wherein a first layer is configured to block the UV light and a second layer is configured to block the visible light near the UV spectrum.

43. The display device of claim 38, wherein the optical shielding layer comprises a single layer configured to block both the UV light and the visible light near the UV spectrum.