Patent ID: 7567012
Filing Date: 2009-07-28
Classification: H02N

Abstract:
1. A drive unit comprising: an electromechanical transducer capable of expanding/contracting by drive signal application, a supporting member that is connected to said electromechanical transducer and displaced together with said electromechanical transducer, a movable object that is slidably supported on said supporting member and moves along said supporting member owing to a vibration of said supporting member by virtue of the expansion/contraction of said electromechanical transducer, a restricting member that restricts a movable range of said movable object, a drive circuit that applies to the electromechanical transducer a first wave drive signal for vibrating said supporting member so that a difference occurs between the expansion and contraction of said electromechanical transducer when said movable object is moved to a position where said movable object makes contact with said restricting member, and applies to the electromechanical transducer a second wave drive signal for vibrating said supporting member so that said movable object is not moved substantially after said movable object makes contact with said restricting member.