Patent ID: 9154055
Filing Date: 2015-10-06
Classification: H02N

Abstract:
1. A drive device comprising: a first vibrator adapted to be vibrated in a predetermined direction as a vibration direction; a second vibrator provided on the side of one end of the first vibrator in the vibration direction and adapted to be displaceably driven in the vibration direction by the first vibrator, and further vibrated in the predetermined direction, independently; a driven member engaged with the second vibrator or a driving member coupled to the second vibrator, with a predetermined frictional force; a drive circuit for giving drive signals to the first and second vibrators, respectively, to vibrate the first and second vibrators; and a coupling member interposed between the first vibrator and the second vibrator, the coupling member having a shank and a head having a diameter greater than that of the shank, the shank having a distal end fixedly attached to the one end of the first vibrator, wherein the second vibrator is formed in a tubular shape to insertingly receive the coupling member, and fixedly attached to the head of the coupling member at a midpoint thereof in the vibration direction, and the engagement section with respect to the driven member is provided on the side of an end of the second vibrator opposite to the first vibrator; wherein: the first and second vibrators are formed to have two resonance modes in a vibration system, respectively, and allow a ratio between respective frequencies of the resonance modes in the first and second vibrators to become approximately 2; and the drive circuit is operable to generate two signals each having a component approximately conforming to a respective one of the frequencies in the first-order and second-order resonance modes having the approximately one-to-two relation, and give the signals to respective ones of the first and second vibrators as the drive signals, thereby producing resonantly-amplified pseudo-sawtooth displacement vibration in an engagement section between the second vibrator or the driving member, and the driven member, to move the driven member in the vibration direction.