The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 05, 2011
Filed:
Apr. 22, 2008
Richard Topliss, Trumpington, GB;
Richard Topliss, Trumpington, GB;
Cambridge Mechatronics Limited, Cambridge, GB;
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.