System and method for display device with reinforcing substance

• US 20060066600A1
• Filed: 06/03/2005
• Published: 03/30/2006
• Est. Priority Date: 09/27/2004
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Palmateer, Lauren
• Granted Patent: US 7,710,629 B2
• Time in Patent Office: Days
• US Class Current: 345/204
• CPC Class Codes: B81B 2201/047 Optical MEMS not provided for in B81B2201/042 - B81B2201/045
• CPC Class Codes: B81B 3/007 For controlling stiffness, e.g. ribs
• CPC Class Codes: B81B 7/0038 using materials for controlling the level of pressure, contaminants or moisture inside of the package, e.g. getters
• CPC Class Codes: B81C 2203/0163 Reinforcing a cap, e.g. with ribs
• 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

A package structure and method of packaging an interferometric modulator with a reinforcing substance to help support the integrity of the package. In some embodiments the reinforcing substance is a desiccant integrated into the backplate or the transparent substrate.

Claims

1. A display device, comprising:

a transparent substrate;

an interferometric modulator configured to modulate light transmitted through the transparent substrate;

a backplate cover sealed to said transparent substrate to form a package, wherein said interferometric modulator is inside said package; and

a reinforcing substance in contact with said backplate cover, wherein said reinforcing substance is configured to provide structural support to the backplate cover.

2. The display device of claim 1 where said reinforcing substance is a desiccant.

3. The display device of claim 2, wherein the desiccant is located on the backplate at a weak point of the backplate.

4. The display device of claim 2, wherein the weak point of the backplate is a corner of a recess of the backplate.

5. The display device of claim 3, wherein the desiccant is located primarily at a weak point of the backplate.

6. The display device of claim 3, wherein the desiccant is located exclusively in a corner of a recess of the backplate.

7. The display device of claim 2, wherein the desiccant is selected from a group consisting of zeolites, calcium sulfate, calcium oxide, silica gel, molecular sieves, surface adsorbents, bulk adsorbents, chemical reactants, and indicating silica gel.

8. The display device of claim 1, wherein a coefficient of thermal expansion of the reinforcing substance and a coefficient of thermal expansion of the backplate cover are approximately the same.

9. The display device of claim 8, wherein the backplate cover has an internal surface and an external surface, and the reinforcing substance substantially covers said interior surface.

10. The display device of claim 1, wherein the coefficient of thermal expansion of the reinforcing substance and a coefficient of thermal expansion of the backplate cover are not equal.

11. The display device of claim 10, wherein the backplate cover has an internal surface and an external surface, and the reinforcing substance covers only a portion of said interior surface.

12. The display device claim 1, wherein the reinforcing substance is distributed in a pattern so that any corners of the pattern are rounded.

13. The display device claim 1, wherein the reinforcing substance is distributed in a spiral pattern on the backplate cover.

14. The display device claim 1, wherein the reinforcing substance is distributed in a checkered pattern on the backplate cover.

15. The display device of claim 1, wherein the reinforcing substance is distributed across the backplate to optimize the filling of imperfections in the backplate, thereby providing structural support to the backplate.

16. The display device of claim 1, wherein the reinforcing substance is distributed across the backplate to minimize a stress caused by a difference in a coefficient of thermal expansion of the backplate and of the reinforcing substance.

17. The display device of claim 1, wherein said display device is a display system comprising:

an electronic display comprising said interferometric modulator;

a processor that is in electrical communication with said interferometric modulator, wherein said processor is configured to process image data; and

a memory device in electrical communication with said processor.

18. The display device as recited in claim 17, further comprising:

a first controller configured to send at least one signal to said display; and

a second controller configured to send at least a portion of said image data to said first controller.

19. The display device as recited in claim 17, further comprising:

an image source module configured to send said image data to said processor.

20. The display device as recited in claim 19, wherein said image source module comprises at least one of a receiver, transceiver, and transmitter.

21. The display device as recited in claim 17, further comprising an input device configured to receive input data and to communicate said input data to said processor.

22. The device of claim 2, wherein the desiccant has a vapor barrier protecting said desiccant.

23. The device of claim 22, wherein the vapor barrier is a hydrophobic polymer coating that reduces water absorption of the desiccant by at least 50 percent.

24. The display device of claim 2, wherein a coefficient of thermal expansion of the reinforcing substance and a coefficient of thermal expansion of the backplate cover are significantly the same, and wherein said reinforcing substance covers approximately an entire surface of the backplate cover that is within the package.

25. The display device of claim 2, wherein a coefficient of thermal expansion of the reinforcing substance and a coefficient of thermal expansion of the backplate cover are different and wherein the reinforcing substance is positioned over a part of the backplate cover so as to fill in imperfections in the substrate but is also positioned to reduce stresses caused from differences in the coefficient of thermal expansion.

26. The display device of claim 25, wherein said reinforcing substance is distributed in a spiral pattern on the backplate.

27. A method of manufacturing a display device, comprising:

providing a transparent substrate comprising an interferometric modulator configured to modulate light transmitted through the transparent substrate;

providing a backplate cover configured to mount to said transparent substrate;

applying a reinforcing substance to said backplate cover, wherein said reinforcing substance is configured to provide structural support to said backplate, and wherein said reinforcing substance is also a desiccant; and

sealing said backplate cover to said transparent substrate.

28. A display device comprising:

a transparent substrate comprising an interferometric modulator configured to modulate light transmitted through the transparent substrate;

a backplate cover sealed to said transparent substrate to form a package, wherein said interferometric modulator is inside said package; and

a prolonged-acting desiccant associated with said backplate cover, wherein said prolonged-acting desiccant has a half-life for absorbing water of not less than 10 hours.

29. The display device of claim 28, wherein the prolonged acting desiccant comprises calcium oxide and wherein the half-life of the prolonged acting desiccant is not less than about 40 hours.

30. The display device of claim 28 wherein said prolonged acting desiccant comprises a polymer containing zeolites.

31. The display device of claim 30, wherein said prolonged acting desiccant absorbs water at no more than about a rate of 0.2 mg/hour.

32. The display device of claim 31, wherein said prolonged acting desiccant absorbs water at a rate of between about 0.2 mg/hour and 0.01 mg/hour.

33. A display device package, comprising:

a transparent substrate;

an interferometric modulator configured to modulate light transmitted through the transparent substrate;

a backplate cover sealed to said transparent substrate to form a package, wherein said interferometric modulator is inside said package; and

a means for reinforcing the backplate cover.

34. The display device of claim 33 wherein the means for reinforcing the backplate is an adhesive and a solid sheet of desiccant, wherein said adhesive keeps the solid desiccant located next to the backplate cover.

35. A display device manufactured by a process comprising:

applying a reinforcing substance to a backplate cover, wherein said reinforcing substance is a desiccant;

allowing the reinforcing substance to dry; and

sealing a transparent substrate comprising an interferometric modulator to the backplate cover.

36. The display device of claim 35, wherein the applying of a reinforcing substance to the backplate cover comprises applying a majority of the desiccant in a corner of a recess of the backplate.