Mems electrostatically actuated optical display device and associated arrays

• US 20040001033A1
• Filed: 06/27/2002
• Published: 01/01/2004
• Est. Priority Date: 06/27/2002
• Status: Active Grant

• Current Assignee: Micross Advanced Interconnect Technology LLC
• Original Assignee: MCNC, Inc.
• Inventors: Augustine, Brian H., Yadon, Lindsey N., Goodwin-Johansson, Scott H.
• Granted Patent: US 6,972,889 B2
• Time in Patent Office: Days
• US Class Current: 345/31
• CPC Class Codes: G02B 26/02 for controlling the intensity of light G02B26/004 takes precedence
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 26/0866 the reflecting means being moved or deformed by thermal means
• CPC Class Codes: G09G 2300/0456 with a reflective area and a transmissive area combined in one pixel, such as in transflectance pixels
• CPC Class Codes: G09G 3/3433 using light modulating elements actuated by an electric field and being other than liquid crystal devices and electrochromic devices using liquid crystal devices G09G3/36; using electrochromic devices G09G3/38

Abstract

A simplified MEMS optical display device driven by electrostatic forces and associated arrays are provided for. The optical display device includes an optically transparent substrate, an optically transparent fixed electrode disposed on the substrate and a pigmented translucent film disposed on the substrate. A moveable optical shutter is affixed to the substrate and is generally aligned with the fixed electrode and the pigmented translucent film. The moveable optical shutter comprises an electrode element and a biasing element. In addition, a fixed portion attached to the substrate and a distal portion adjacent to the fixed portion defines the optical shutter. When an electrostatic voltage differential is established between the fixed electrode and the optical shutter electrode element the distal portion of the optical shutter will move to controllably regulate the pigmentation of an optical signal.

Claims

1. An optical display device driven by electrostatic forces, comprising:

an optically transparent substrate;

an optically transparent fixed electrode disposed on the substrate;

a pigmented translucent film disposed on the substrate;

a moveable opaque optical shutter generally aligned with the fixed electrode and the pigmented translucent film, the moveable optical shutter comprising an electrode element and a biasing element, wherein the moveable optical shutter includes a fixed portion attached to the substrate and a distal portion adjacent to the fixed portion, the distal portion being moveable with respect to the fixed electrode; and

a dielectric element disposed between the fixed electrode and the optical shutter electrode element,

wherein a voltage differential established between the fixed electrode and the optical shutter electrode element moves the optical shutter relative to the fixed electrode to thereby controllably regulate the amount of pigmentation of an optical signal.

2. The optical display device according to claim 1, wherein the device is capable of providing reflective transmission of an optical signal and transmissive transmission of an optical signal

3. The optical display device according to claim 1, wherein the optically transparent substrate further comprises glass.

4. The optical display device according to claim 1, wherein the optically transparent fixed electrode further comprises an indium tin oxide material.

5. The optical display device according to claim 1, wherein the optically transparent substrate further comprises opposing first and second planar surfaces and the pigmented translucent film is disposed on the first planar surface and the optically transparent fixed electrode is disposed on the second planar surface.

6. The optical display device according to claim 1, wherein the pigmented translucent film is disposed between the optically transparent substrate and the optically transparent fixed electrode.

7. The optical display device according to claim 1, wherein the optically transparent fixed electrode is disposed between the optically transparent substrate and the pigmented translucent film.

8. The optical display device according to claim 1, wherein the biasing element comprises at least one polymer film layer.

9. The optical display device according to claim 1, wherein the electrode element comprises an electrode layer and the biasing element comprises two polymer film layers deposited on opposite sides of the electrode layer.

10. The optical display device according to claim 1, wherein the electrode element and the biasing element have different thermal coefficients of expansion.

11. The optical display device according to claim 1, wherein the biasing element comprises at least two polymer films of different thickness.

12. The optical display device according to claim 10, wherein the at least two polymer films comprise a first polymer film of first thickness deposited on a surface of the electrode element nearest the substrate and a second polymer of second thickness deposited on a surface of the electrode element furthest from the substrate, the second thickness being greater than the first thickness.

13. The optical display device according to claim 1, wherein the biasing element comprises at least two polymer films of different coefficients of expansion.

14. The optical display device according to claim 1, further comprising a source of electrostatic energy electrically connected to at least one of the substrate electrode and the electrode element.

15. The optical display device according to claim 1, further comprising a supporting enclosure that supports the optical display device by elevating the optically transparent substrate.

16. The optical display device according to claim 15, further comprising an illumination source provided for within the supporting enclosure.

17. The optical display device according to claim 15, wherein the supporting enclosure further comprises light absorbing interior surfaces.

18. The optical display device according to claim 14, wherein the supporting enclosure further comprises interior surfaces having at least one interior surface electrode disposed on an interior surface and at least one moveable film generally overlying the interior surface electrode, the at least one moveable film comprising an electrode element and a biasing element, wherein the at least one moveable film includes a fixed portion attached to an interior surface and a distal portion adjacent to the fixed portion, the distal portion being moveable with respect to the interior surface electrode.

19. The optical display device according to claim 18, wherein the at least one movable film generally unrolls to close when a voltage differential is established between the interior surface electrode and the electrode element in the moveable film to provide light-absorbing and reflective capabilities to an enclosed area of the support enclosure.

20. An optical display array driven by electrostatic forces, comprising:

an optically transparent substrate;

an optically transparent fixed electrode disposed on the substrate;

a plurality of pigmented translucent films disposed on the substrate;

a plurality of moveable optical shutters generally overlying the fixed electrode and one of the plurality of pigmented translucent films, the moveable optical shutters comprising an electrode element and a biasing element, wherein the moveable optical shutters include a fixed portion attached to the substrate and a distal portion adjacent to the fixed portion, the distal portion being moveable with respect to the fixed electrode; and

a dielectric element disposed between the fixed electrode and the optical shutter electrode elements,

wherein a voltage differential established between the fixed electrode and the electrode element of at least one of the plurality of moveable optical shutters moves the optical shutter relative to the fixed electrode to thereby electrode to thereby controllably regulate the amount of pigmentation of an optical signal.

21. The optical display array according to claim 20, wherein the array is capable of providing reflective transmission of an optical signal and transmissive transmission of an optical signal

22. The optical display array according to claim 20, wherein the plurality of optical shutters are configured in an array pattern such that a non-attached end of the distal portion of a first optical shutter is generally adjacent to the fixed portion of a second optical shutter when the first optical shutter is electrostatically activated.

23. The optical display array according to claim 20, wherein the plurality of optical shutters are configured in a pattern such that the fixed portion and the distal portion of a first optical shutter are generally adjacent to the fixed portion and the distal portion of a second optical shutter.

24. The optical display array according to claim 20, wherein the plurality of optical shutters are configured in a column and row array pattern.

25. The optical display array according to claim 20, wherein the optically transparent fixed electrode further comprises an indium tin oxide material.

26. The optical display array according to claim 20, wherein the optically transparent substrate further comprises opposing first and second planar surfaces and the plurality of pigmented translucent films are disposed on the first planar surface and the optically transparent fixed electrode is disposed on the second planar surface.

27. The optical display array according to claim 20, wherein the plurality of pigmented translucent films are disposed between the optically transparent substrate and the optically transparent fixed electrode.

28. The optical display array according to claim 20, wherein the optically transparent fixed electrode is disposed between the optically transparent substrate and the plurality of pigmented translucent films.

29. The optical display array according to claim 20, further comprising a source of electrostatic energy electrically connected to at least one of the substrate electrode and the plurality of optical shutter electrode elements.

30. The optical display array according to claim 20, further comprising a supporting enclosure that supports the optical display array.

31. The optical display array according to claim 30, further comprising an illumination source provided for within the supporting enclosure.

32. The optical display array according to claim 30, wherein the supporting device further comprises light absorbing interior surfaces.

33. The optical display array according to claim 30, wherein the supporting device further comprises interior surfaces having at least one interior surface electrode disposed on an interior surface and at least one moveable film generally aligned with the interior surface electrode, the moveable film comprising an electrode element and a biasing element, wherein the moveable film includes a fixed portion attached to an interior surface and a distal portion adjacent to the fixed portion, the distal portion being moveable with respect to the interior surface electrode.

34. The optical display array according to claim 33, wherein the at least one moveable film generally unrolls to lie generally parallel to the interior surface when a voltage differential is established between the interior surface electrode and the electrode element of the moveable opaque film to provide light-absorbing and reflective capabilities to an enclosed area of the support enclosure.

35. A method for reflective mode and transmissive mode optical display of an optical signal, the method comprising the steps of:

providing for an optical device having an optically transparent substrate, an optically transparent fixed electrode disposed on the substrate;

a pigmented translucent film disposed on the substrate;

a moveable opaque optical shutter comprising an electrode element and a biasing element, the moveable opaque shutter having a fixed portion attached to the substrate and a distal portion unattached to the substrate that is biased in a curled state absent an electrostatic force, and a dielectric element disposed between the fixed electrode and the optical shutter electrode element;

transmitting an optical signal from a first optical source disposed adjacent to the optical shutter, the signal propagating through the optically transparent substrate, the optically transparent fixed electrode and the pigmented translucent film;

providing voltage to the fixed electrode and electrode element to create an electrostatic force that moves the optical shutter to a position generally parallel with the second surface of the substrate; and

transmitting an optical signal from a second optical source disposed adjacent to a surface of the substrate that is opposite the first optical source, the signal propagating through the pigmented translucent film, the optically transparent fixed electrode and the transparent substrate, reflecting the optical signal off of the optical shutter and propagating the signal back through the optically transparent substrate, the optically transparent fixed electrode and the pigmented translucent film.