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:
Oct. 14, 1997
Filed:
Oct. 04, 1994
Tetsuro Goto, Funabashi, JP;
Akira Katayama, Koganei, JP;
Yoshiaki Tanabe, Kawasaki, JP;
Masanori Hasuda, Yokohama, JP;
Nikon Corporation, Tokyo, JP;
Abstract
A driving device for a piezoelectric actuator, in which a voltage is applied to a piezoelectric actuator to generate a mechanical deformation therein, thus actuating a mechanical system. In an aspect, the piezoelectric actuator is at first given a voltage of inverse polarity, for generating a displacement in an opposite direction, and then given a voltage of forward polarity, for generating a displacement in the normal functioning direction, thereby actuating the mechanical system. Displacement and acceleration become larger, as the displacement of the actuator takes place from a position in the inverse direction. In another aspect, the electrical insulation state of the piezoelectric actuator is detected and, if deteriorated, the destruction of insulation is prevented by an alarm generation and/or inhibition of voltage application in an embodiment, the insulation state is identified from the ambient humidity of the actuator. In another embodiment, if the detected humidity is at a high level that may induce destruction of insulation, the piezoelectric actuator is driven with a low voltage, in order to dehumidify by heat generation. The piezoelectric actuator may be used in a shutter control device for a camera.