MEMS ACTUATOR WITH DISCRETELY CONTROLLED MULTIPLE MOTIONS

• US 20080309190A1
• Filed: 06/13/2007
• Published: 12/18/2008
• Est. Priority Date: 06/13/2007
• Status: Active Grant

• Current Assignee: Stereo D Inc., Stereo Display, Inc.
• Original Assignee: Angstrom, Inc., Stereo Display, Inc.
• Inventors: Seo, Cheong Soo, Cho, Gyoung Il, Sohn, Jin Young
• Granted Patent: US 9,505,606 B2
• Time in Patent Office: Days
• US Class Current: 310/309
• CPC Class Codes: B81B 2201/037 Microtransmissions
• CPC Class Codes: B81B 2201/045 Optical switches
• CPC Class Codes: B81B 3/0062 Devices moving in two or more dimensions, i.e. having special features which allow movement in more than one dimension

Abstract

A MEMS (micro electro mechanical system) actuator with discretely controlled multiple motions comprises bottom layer, stepper plate, support, and motion plate. The multiple motion of the motion plate is generated by the electrostatically actuated stepper plates and geometrically predetermined supports. By introducing the MEMS actuator with discretely controlled multiple motions, simple motion control can be achieved by digital controlling and only single voltage is needed for motion control of the motion plate.

Claims

1. A MEMS (micro electro mechanical system) actuator with discretely controlled multiple motions comprising:

a) a bottom layer having control circuitry;

b) at least one stepper plate, wherein each stepper plate has a plurality of stepper plate electrodes configured to actuate the stepper plate;

c) at least one support, wherein each support is geometrically coupled to the corresponding stepper plate to define motion; and

d) a motion plate having pre-determined multiple motions supported by the stepper plates and the supports;

wherein motions of the motion plate are pre-programmed by the supports and the stepper plates and wherein each of the pre-programmed motions plate is provided by actuating a predetermined set of stepper plates.

2. The MEMS actuator with discretely controlled multiple motions of claim 1, wherein the control circuitry is coupled with the stepper plate electrodes and selectively activates the stepper plate electrodes.

3. The MEMS actuator with discretely controlled multiple motions of claim 2, wherein the control circuitry is wire structure directly connected with the stepper plate electrodes to supply voltages.

4. The MEMS actuator with discretely controlled multiple motions of claim 2, wherein the control circuitry is an electrical addressing circuitry.

5. The MEMS actuator with discretely controlled multiple motions of claim 2, wherein the electrical addressing circuitry comprises a plurality of memory type cell forming a memory addressing array.

6. The MEMS actuator with discretely controlled multiple motions of claim 5, wherein the memory addressing array comprises SRAM circuits to activate the stepper plate electrodes.

7. The MEMS actuator with discretely controlled multiple motions of claim 5, wherein the memory addressing array comprises DRAM circuits to activate the stepper plate electrodes.

8. The MEMS actuator with discretely controlled multiple motions of claim 2, wherein the control circuitry comprises a MOS-type or CMOS-type circuitry on the bottom layer.

9. The MEMS actuator with discretely controlled multiple motions of claim 2, wherein the control circuitry is operated by digital voltage.

10. The MEMS actuator with discretely controlled multiple motions of claim 2, wherein the control circuitry supplies discrete control voltage to the stepper plate electrodes.

11. The MEMS actuator with discretely controlled multiple motions of claim 1, wherein each stepper plate is configured to have pre-programmed rotations about multiple axes by activating predetermined sets of the stepper plate electrodes.

12. The MEMS actuator with discretely controlled multiple motions of claim 1, wherein each support is configured to define a motion of the motion plate when the stepper plate is actuated.

13. The MEMS actuator with discretely controlled multiple motions of claim 12, wherein the support is a motion plate bottom support located under the motion plate.

14. The MEMS actuator with discretely controlled multiple motions of claim 13, wherein each of the motion plate bottom supports is geometrically coupled to the stepper plate and one end is disposed on the bottom side of the motion plate and the other end is configured to contact the stepper plate when the stepper plate is actuated.

15. The MEMS actuator with discretely controlled multiple motions of claim 13, wherein the motion of the motion plate is defined by the contact points of the motion plate bottom support and the stepper plate top side.

16. The MEMS actuator with discretely controlled multiple motions of claim 12, wherein the support is a stepper plate top support located on the stepper plate.

17. The MEMS actuator with discretely controlled multiple motions of claim 16, wherein each of the stepper plate top supports is geometrically coupled to the motion plate and one end is disposed on the top side of the stepper plate and the other end is configured to contact the motion plate bottom side when the stepper plate is actuated.

18. The MEMS actuator with discretely controlled multiple motions of claim 16, wherein the motion of the motion plate is defined by the contact points of the stepper plate top support and the motion plate bottom side.

19. The MEMS actuator with discretely controlled multiple motions of claim 12, wherein the support is a stepper plate bottom support located under the stepper plate.

20. The MEMS actuator with discretely controlled multiple motions of claim 19, wherein each of the stepper plate bottom supports is geometrically coupled to the bottom layer and one end is disposed on the bottom side of the stepper plate and the other end is configured to contact the bottom layer when the stepper plate is actuated.

21. The MEMS actuator with discretely controlled multiple motions of claim 19, wherein the inclination angle of the stepper plate is defined the contact points of the stepper plate bottom support and the bottom layer.

22. The MEMS actuator with discretely controlled multiple motions of claim 19, wherein the motion of the motion plate is defined by the contact points of the stepper plate and the motion plate and the inclination angle of the stepper plate.

23. The MEMS actuator with discretely controlled multiple motions of claim 22, wherein the contact points of the stepper plate and the motion plate are determined by the stepper plate top support.

24. The MEMS actuator with discretely controlled multiple motions of claim 22, wherein the contact points of the stepper plate and the motion plate are determined by the motion plate bottom support.

25. The MEMS actuator with discretely controlled multiple motions of claim 12, wherein the support is a bottom layer support located on the bottom layer.

26. The MEMS actuator with discretely controlled multiple motions of claim 25, wherein each of the bottom layer supports is geometrically coupled to the stepper plate and one end is disposed on the top side of the bottom layer and the other end is configured to contact the bottom side of the stepper plate when the stepper plate is actuated.

27. The MEMS actuator with discretely controlled multiple motions of claim 25, wherein the inclination angle of the stepper plate is defined the contact points of the bottom layer support and the stepper plate.

28. The MEMS actuator with discretely controlled multiple motions of claim 25, wherein the motion of the motion plate is defined by the contact points of the stepper plate and the motion plate and the inclination angle of the stepper plate.

29. The MEMS actuator with discretely controlled multiple motions of claim 25, wherein the contact points of the stepper plate and the motion plate are determined by the stepper plate top support.

30. The MEMS actuator with discretely controlled multiple motions of claim 25, wherein the contact points of the stepper plate and the motion plate are determined by the motion plate bottom support.

31. The MEMS actuator with discretely controlled multiple motions of claim 12, wherein the support is a stepper plate inner support.

32. The MEMS actuator with discretely controlled multiple motions of claim 31, wherein the stepper plate inner support is disposed on the bottom layer and is configured to contact the bottom side of the stepper plate when the stepper plate is actuated.

33. The MEMS actuator with discretely controlled multiple motions of claim 31, wherein the inclination angle of the stepper plate is defined the contact points of the stepper plate and the stepper plate inner support.

34. The MEMS actuator with discretely controlled multiple motions of claim 31, wherein the motion of the motion plate is defined by the contact points of the stepper plate and the motion plate and the inclination angle of the stepper plate.

35. The MEMS actuator with discretely controlled multiple motions of claim 31, wherein the rotation of the stepper plate is pre-programmed by position of the stepper plate inner support.

36. The MEMS actuator with discretely controlled multiple motions of claim 31, wherein the rotation of the stepper plate is pre-programmed by height of the stepper plate inner support, wherein the stepper plate inner support has variation in height.

37. The MEMS actuator with discretely controlled multiple motions of claim 1, wherein the stepper plate has at least one stepper plate tip, configured to contact the bottom layer including landing structures for reducing the contact area of the actuated stepper plate with the bottom layer.

38. The MEMS actuator with discretely controlled multiple motions of claim 12, wherein the motion of the motion plate is defined by the height of the support.

39. The MEMS actuator with discretely controlled multiple motions of claim 1, further comprising at least one motion plate electrode, disposed on the bottom layer, configured to pull the motion plate down toward the bottom layer to make contact between the motion plate and the actuated stepper plate.

40. The MEMS actuator with discretely controlled multiple motions of claim 1, wherein the stepper plate is actuated by electrostatic force induced by the stepper plate electrodes.

41. The MEMS actuator with discretely controlled multiple motions of claim 40, wherein driving voltage of the motion plate is reduced by using multiple stepper plate electrodes to actuate the stepper plate.

42. The MEMS actuator with discretely controlled multiple motions of claim 40, wherein each stepper plate has at least one landing structure, disposed on the bottom layer, configured to stop the rotation of the stepper plate by contacting the actuated stepper plate.

43. The MEMS actuator with discretely controlled multiple motions of claim 1, wherein the motion plate has one rotational degree of freedom motion.

44. The MEMS actuator with discretely controlled multiple motions of claim 1, wherein the motion plate has two rotational degrees of freedom motion.

45. The MEMS actuator with discretely controlled multiple motions of claim 1, wherein the motion plate has two translational degree of freedom motion.

46. The MEMS actuator with discretely controlled multiple motions of claim 1, wherein the motion plate has one rotational degree of freedom motion and one translational degree of freedom motion.

47. The MEMS actuator with discretely controlled multiple motions of claim 1, wherein the motion plate has two rotational degrees of freedom motion and one translational degree of freedom motion.