Hitachi Maxell, Limited

Keisuke Taguchi

Hitoshi Kawamura

Manabu Tani

Susumu Aoki

Ikuo Shinta

Takashi Hasuda

A drive device in which the frequency of a drive waveform applied to a piezoelectric element is easily settable with less obligation to consider resonance in a stationary member. The device includes a piezo element that expands and contracts according to a drive voltage, a transmission shaft that receives vibration produced by the piezo element, a stationary member that holds the transmission shaft in a slidable state along the longitudinal direction of the transmission shaft, and a lens holder that is displaced together with the piezo element and transmission shaft relative to the stationary member according to drive of the piezo element. The piezo element and the transmission shaft move in the moving direction of the lens holder in synchronization with the lens holder according to drive of the piezo element in the state where the piezo element is spaced from the stationary member. By employing this structure, the frequency of the drive waveform applied to the piezo element can be set easily without considering resonance in the stationary member.

Drive device, image acquisition device, and electronic apparatus

An ultrasonic actuator according to an embodiment of the present invention includes: a stator generating a rotational driving force in accordance with a driving signal having a train pulse, which is used, for example, an AF mechanism; and a rotor converting the rotational driving force into actual movement. In the thus-structured ultrasonic actuator of the present invention, the driving signal is obtained by removing a predetermined number of pulses from the pulse train upon deceleration, and the remaining number of consecutive pulses is set to at least 2 or 4 or more.

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Ibaraki, Japan

Keisuke Taguchi