Micromachined device with stretchable restoring force member

• US 6,594,057 B1
• Filed: 06/05/2000
• Issued: 07/15/2003
• Est. Priority Date: 03/24/1997
• Status: Expired due to Fees

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: Jerman, John H., Grade, John D., Drake, Joseph D.
• Primary Examiner(s): Phan, James
• Application Number:
  US09/587,675
• Time in Patent Office: 1,135 Days
• Field of Search: 359/198, 359/199, 359/209-214, 359/220, 359/223, 359/224, 359/838, 359/848, 359/871, 359/872, 359/896, 735/70, 735/74, 735/75, 736/49, 736/70
• US Class Current: 359/224.1
• CPC Class Codes: G02B 26/0816 by means of one or more reflecting elements
• 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: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 26/085 the reflecting means being moved or deformed by electromagnetic means
• CPC Class Codes: G02B 6/3518 the reflective optical element being an intrinsic part of a MEMS device, i.e. fabricated together with the MEMS device MEMS devices in general B81B; manufacture of MEM devices in general B81C; micromechanical devices controlling the direction of light G02B26/0833
• CPC Class Codes: G02B 6/357 Electrostatic force electrostatic forces controlling reflecting elements in general G02B26/0841
• CPC Class Codes: G02B 6/3584 constructional details of an associated actuator having a MEMS construction, i.e. constructed using semiconductor technology such as etching MEMS per se B81B, B81C
• CPC Class Codes: G02B 7/1821 for rotating or oscillating mirrors
• CPC Class Codes: G11B 11/10532 Heads
• CPC Class Codes: G11B 11/10543 using optical beam of radiation
• CPC Class Codes: G11B 11/10563 Access of indexed parts
• CPC Class Codes: G11B 11/1058 Flying heads
• CPC Class Codes: G11B 7/08564 using galvanomirrors
• CPC Class Codes: G11B 7/08576 Swinging-arm positioners
• CPC Class Codes: G11B 7/122 Flying-type heads, e.g. analogous to Winchester type in magnetic recording
• CPC Class Codes: G11B 7/1362 Mirrors
• CPC Class Codes: G11B 7/1372 Lenses
• CPC Class Codes: G11B 7/1384 Fibre optics
• CPC Class Codes: H02N 1/006 of the gap-closing type H02N1/004 takes precedence
• CPC Class Codes: H02N 1/008 Laterally driven motors, e.g. of the comb-drive type

Abstract

A micromachined device of micron dimensions comprising a base and a movable member spaced apart from the base. The movable member has first and second end portions and an axis extending between the first and second end portions. First and second torsional members extend along the axis and are connected to the respective first and second end portions for permitting the movable member to rock between first and second positions about the axis relative to the base. The first and second torsional members are secured to the base. At least a portion of the movable member is of a conductive material. First and second spaced-apart electrodes are carried by the base for driving the movable member between the first and second positions. A tether member extends transversely of the axis and is secured to the first torsional member and to the base whereby the tether member regulates the rocking of the movable member.

Claims

1. A micromachined device of micron dimensions comprising a base, a movable member spaced apart from the base, the movable member having first and second end portions and an axis extending between the first and second end portions, first and second torsional members extending along the axis and connected to the respective first and second end portions for permitting the movable member to rock between first and second positions about the axis relative to the base, means for securing the first and second torsional members to the base, at least a portion of the movable member being of a conductive material, first and second spaced-apart electrodes carried by the base for driving the movable member between the first and second positions, a tether member extending transversely of the axis and being secured to the first torsional member and means for securing the tether member to the base whereby the tether member regulates the rocking of the movable member.

2. The micromachined device of claim 1 wherein the means for securing the first and second torsional members to the base and the means for securing the tether member to the base include a frame member extending around the movable member, the first and second torsional members and the tether member being secured to the frame member and the frame member being spaced apart from and secured to the base.

3. The micromachined device of claim 1 wherein the tether member has a length and at least a portion of the tether member is elastic along the length and wherein the first torsional member includes an elongate portion extending along the axis and a substantially rigid flange portion extending transversely of the elongate portion and having an end spaced outwardly from the elongate portion, the tether member being secured to the end of the flange portion whereby the flange portion enhances stretching of the tether member during rocking of the movable member between the first and second positions.

4. A micromachined device of micron dimensions comprising a planar base, a planar movable member spaced apart from the base and disposed generally parallel to the base, the movable member having first and second end portions and an axis extending between the first and second end portions, first and second torsional members extending along the axis and connected to the respective first and second end portions for permitting the movable member to rock between first and second positions about the axis relative to the base, means for securing the first and second torsional members to the base, at least a portion of the movable member being of a conductive material, first and second spaced-apart electrodes carried by the base for driving the movable member between the first and second positions, first and second tether members extending transversely of the axis and being secured to at least one of the first and second torsional members and means for securing the first and second tether members to the base whereby the first and second tether members regulate the rocking of the movable member.

5. The micromachined device of claim 4 wherein each of the first and second tether members has a length and wherein at least a portion of each of the first and second tether members is elastic along the length.

6. The micromachined device of claim 4 wherein the at least one of the first and second torsional members includes an elongate portion extending along the axis and a substantially rigid flange portion extending transversely of the elongate portion and having a first end spaced outwardly from the elongate portion, the first tether member being secured to the first end of the flange portion whereby the flange portion enhances stretching of the first tether member during rocking of the movable member between the first and second positions.

7. The micromachined device of claim 6 wherein the flange portion has a second end spaced outwardly from the elongate portion opposite of the first end, the second tether member being secured to the second end of the flange portion.

8. The micromachined device of claim 6 wherein the flange portion extends perpendicularly of the elongate portion.

9. The micromachined device of claim 4 wherein the at least one of the first and second torsional members includes an elongate portion extending along the axis and a substantially rigid flange portion extending perpendicularly of the elongate portion and having first and second opposite ends spaced outwardly from the elongate portion, the first tether member being secured to the first end of the flange portion and the second tether member being secured to the second end of the flange portion whereby the flange portion enhances stretching of the first and second tether members during rocking of the movable member between the first and second positions.

10. The micromachined device of claim 4 wherein the first and second tether members are secured to the first torsional member.

11. The micromachined device of claim 10 wherein the first and second tether members extend along an axis extending transversely of the axis.

12. The micromachined device of claim 11 wherein the first and second tether members extend along an axis extending perpendicularly of the axis.

13. The micromachined device of claim 10 further comprising an additional set of first and second tether members, the additional set of first and second tether members being secured to the second torsional member.

14. A micromachined device of micron dimensions comprising a base, a movable member spaced apart from the base, the movable member having first and second end portions and an axis extending between the first and second end portions, at least a portion of the movable member being of a conductive material, at least one stretchable member extending transversely of the axis and being coupled to the movable member and means for securing the stretchable member to the base whereby the movable member is rockable between first and second positions about the axis and the stretchable member provides a nonlinear restoring force to the movable member during rocking of the movable member.

15. The micromachined device of claim 14 further comprising at least one electrode carried by the base for rocking the movable member about the axis.

16. The micromachined device of claim 14 further comprising first and second torsional members extending along the axis and connected to the respective first and second end portions and means for securing the first and second torsional members to the base.

17. The micromachined device of claim 16 wherein the stretchable member is coupled to the movable member by mean of one of the torsional members.

18. The micromachined device of claim 14 wherein the base is planar.

19. The micromachined device of claim 18 wherein the movable member is planar and is disposed generally parallel to the base.