Display devices manufactured utilizing mems technology

• US 20040080484A1
• Filed: 12/01/2003
• Published: 04/29/2004
• Est. Priority Date: 11/22/2000
• Status: Abandoned Application

• Current Assignee: Flixel Ltd.
• Original Assignee: Flixel Ltd.
• Inventors: Shappir, Joseph, Karty, Adiel, Cohen, Allon, Heines, Amichai
• Application Number:
  US10/432,174
• Publication Number:
  US 20040080484A1
• Time in Patent Office: Days
• US Class Current: 345/108
• CPC Class Codes: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B
• CPC Class Codes: G09F 9/372 the positions of the elements being controlled by the application of an electric field

Abstract

Apparatus including a substrate, having a substrate surface; an object having a maximum dimension smaller than 1 mm; an axle, having an axis, attached to the object body; and an axle support attached to the substrate and having a support surface. The axle has a rounded cross-section, as manufactured and forms a non-zero angle with a perpendicular to the surface. The object is capable of rotating about the axle.

Claims

1. Apparatus comprising:

a substrate, having a substrate surface;

an object having a maximum dimension smaller than 1 mm;

an axle, having an axis, attached to the object body; and

an axle support attached to the substrate and having a support surface, wherein;

the axle has a rounded cross-section, as manufactured;

the axle forms a non-zero angle with a perpendicular to the surface; and

the object is capable of rotating about the axle.

2. Apparatus according to claim 1 wherein the axle rolls along the axle support surface as the object rotates.

3. Apparatus according to claim 1 or claim 2 and including at least one socket within which the axle rotates.

4. Apparatus according to claim 3 wherein the socket overlays the axle support surface and wherein the axle is held between the support surface, edge constraints and a top constraint.

5. Apparatus according to claim 4 wherein the distance between the side constraints is larger than a diameter of the axle, and the axle is not constrained by the socket between the side support surfaces.

6. Apparatus according to any of the preceding claims wherein the axle is comprised in two axially separated parts and the object is attached to the axle between the two parts.

7. Apparatus according to claim 6 wherein the object extends on both sides of the axle in a direction perpendicular to the axis of the axle.

8. Apparatus according to any of the preceding claims wherein the maximum extent of the object is less than 200 micrometers.

9. Apparatus according to any of the preceding claims wherein the maximum extent of the object is under 90 micrometers.

10. Apparatus according to any of the preceding claims wherein the maximum extent of the object is under 50 micrometers.

11. Apparatus according to any of the preceding claims wherein the maximum extent of the object is under 20 micrometers.

12. Apparatus according to any of the preceding claims wherein the maximum extent of the object is 10 micrometers.

13. Apparatus according to any of the preceding claims wherein the axle support surface is generally parallel to the substrate surface.

14. Apparatus according to any of the preceding claims wherein the axis of the axle is substantially parallel to the substrate surface.

15. Apparatus according to claim 14 wherein the object is a planar object whose planar surface is parallel to the axle.

16. Apparatus according to claim 15 wherein the planar object is adapted to be rotated from a first position at which one side of the object is visible to a second position at which a second side of the planar object is visible.

17. Micro-mechanical display apparatus comprising:

a plurality of pixels, each comprising an object according to claim 16.

18. Apparatus according to claim 17, wherein the planar object extends to a first extent on one side of the axis and extends to a lesser extent on a second side.

19. Apparatus according to claim 18 and including an electrifyable surface area on or in the substrate under at least a portion of the lesser extent.

20. Apparatus according claim 18 or claim 19 wherein the planar object is electrically conducting over at least a portion of its extent.

21. Apparatus according to claim 20 wherein the planar object is conducting over at least a portion of the lesser extent.

24. Apparatus according to any of claims 18-23 and including a source of electrical voltage that provides a non-zero voltage to said electrifyable surface area, to attract the lesser extent thereto, initiating rotation of the surface area.

25. Apparatus according to any of claims 18-24 and including at least one levitation electrode situated past the greater extent and above a resting position of the planar object, the at least one levitation electrode being electrifyable.

26. Apparatus according to claim 25 and including a controller that controls selective electrification of the electrifyable surface area and the levitation electrode to cause the planar element to flip from the first position to the second position;

27. Apparatus according to any of claims 18-26 and wherein at least a portion of the planar object near the axis on the portion of greater extent is either missing or non-conducting.

28. Apparatus according to any of claims 18-27 wherein the first face of the planar object is finished in a first manner and the second face of the panel is finished in a second manner.

29. Apparatus according to claim 28 wherein when the planar object is in the first position or the second position, a visible area on the far side of the axis is finished in a manner similar to the visible face of the planar object.

30. Apparatus according to claim 28 or claim 29 wherein the different finishes comprise different colors.

31. Apparatus according to any of the preceding claims wherein the object is comprised of polysilcon.

32. Apparatus according to claim 31 wherein the object is coated at least partially with another material

33. Apparatus according to any of the preceding claims wherein the axle is comprised of polysilicon.

34. Apparatus according to any of claims 1-29 wherein the object is comprised of a metal.

35. Apparatus according to claim 34 wherein the object is coated at least partially with another material

36. Apparatus according to any of claims 1-29, 34 or 35 wherein the axle is comprised of a metal.

37. Apparatus according to any of the preceding claims wherein the substrate is silicon.

38. Apparatus according to any of claims 1-36 wherein the substrate is glass.

39. Apparatus according to any of claims 1-36 wherein the substrate is flexible.

52. A method according to any of the preceding claims wherein the object is a generally planar object and wherein one face of the planar object is visible in the first position and a second face of the object is visible in a second position.

53. A method according to claim 52 wherein the object is a generally rectangular panel.

54. A method according to claim 52 or claim 53 wherein the additional electrode is an electrode situated in a plane different from that of the planar object in the first position or the second position.

55. A method according to claim 54 wherein the additional electrode is situated below the plane of the first position.

56. A method according to claim 54 wherein the additional electrode is situated above the plane of the first position and to the side of the object when it is in the first position.

22. Micro-mechanical display apparatus, comprising:

a substrate;

a plurality of pixels on the substrate, each comprising;

a planar object; and

an axle, about which the planar object is rotatable, the planar object being adapted to be rotated from a first position at which one side of the object is visible to a second position at which a second side of the planar object is visible;

wherein;

the planar object extends past an axis of the axle, to a greater extent on one side and to a lesser extent on a second side thereof;

the planar object is conducting at least over a portion of the lesser extent, further comprising;

an electrifyable surface area on or in the substrate under at least a portion of the lesser extent.

23. Apparatus according to claim 22 and including at least one socket that at least partially constrains movement of the axle.

40. A method of forming a rounded cylindrical element, comprising:

(a) providing a rectangular cylindrical element of a first material that can be etched with a first etchant;

(b) coating at least some of the surfaces of the rectangular cylindrical element with a layer of a second material etchable with a second etchant and resistant to the first etchant;

(c) overcoating the second material with a third material, resistant to the first and second etchants, the third material being discontinuous at at least some corners of the cylindrical element;

(d) etching the second material with the second etchant, at the corners to remove a portion of the layer of second material adjacent the corners;

(e) etching the first material with the first etchant to remove a portion of the first material at the corner and under a portion of the remaining second material layer.

41. A method according to claim 40 including repeating (d) and (e) at least once.

42. A method according to claim 41 including repeating (d) and (e) a plurality of times.

43. A method according to any of claims 40-42 and including removing any remaining first and second materials.

44. A method according to any of claims 40-43 wherein the first material is polysilicon.

45. A method according to any of claims 40-44 wherein the second material is an oxide or glass layer.

46. A method according to any of claims 40-45 wherein the third material is silicon nitride.

47. A method according to any of claims 40-43 wherein the first material is a metal.

48. A method of flipping an object having an axle about which the object is generally rotatable, from a first position at which one area of the object is visible to a second position at which a second area of the object is visible, the object extending radially past an axis of the axle, to a greater extent on one side and to a lesser extent on a second side thereof, the method comprising:

constraining the panel from flipping;

providing an electric field to at least a portion of the lesser extent, in a direction that tends to move the panel from the first toward the second positions

49. A method according to claim 48 and including removing the constraint against flipping, such that the object flips from the first position to the second position.

50. A method according to claim 49 wherein constraining comprises electrifying an additional electrode and where removing the constraint comprises removing the electrification.

51. A method according to any of claims 48-50 wherein the object is conducting at least over a portion of the lesser extent.

57. A method according to any of claims 48-56 wherein the object is comprised of polysilicon.

58. A method according to any of claims 48-56 wherein the object is comprised of a metal.

59. A method according to any of claims 48-58 wherein the object has a maximum dimension of less than 1 mm.