Invention Grant
US07974025B2 Shape memory alloy actuation apparatus 有权
形状记忆合金致动装置

  • Patent Title: Shape memory alloy actuation apparatus
  • Patent Title (中): 形状记忆合金致动装置
  • Application No.: US12596925
    Application Date: 2008-04-22
  • Publication No.: US07974025B2
    Publication Date: 2011-07-05
  • Inventor: Richard Topliss
  • Applicant: Richard Topliss
  • Applicant Address: GB Cambridge
  • Assignee: Cambridge Mechatronics Limited
  • Current Assignee: Cambridge Mechatronics Limited
  • Current Assignee Address: GB Cambridge
  • Agency: Nixon & Vanderhye P.C.
  • Priority: GB0707788.6 20070423; GB0709311.5 20070515; GB0714718.4 20070727
  • International Application: PCT/GB2008/001402 WO 20080422
  • International Announcement: WO2008/129291 WO 20081030
  • Main IPC: G02B7/02
  • IPC: G02B7/02
Shape memory alloy actuation apparatus
Abstract:
A miniature camera lens actuation apparatus employs an SMA actuator comprising SMA wire to move a camera lens element. To provide autofocus, the SMA actuator is heated across its range of contraction and the resistance at which the focus is at an acceptable level is stored. To combat hysteresis, there is performed a flyback in which the SMA actuator is cooled, before heating the SMA actuator to the stored resistance. The stored resistance is adjusted to combat creep caused by non-linear heating of the SMA actuator. The SMA wire has conductive material extending along on a portion of the SMA wire which extends from a member connected to the SMA wire and being in electrical connection with the SMA wire in order to short out that portion of the SMA wire to reduce creep. Additional material is applied over the SMA wire and the member to reduce fatigue.
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