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. 23, 2001
Filed:
Nov. 30, 1998
Applicant:
Inventors:
Mizuaki Suzuki, Chiba, JP;
Kazuo Tani, Chiba, JP;
Assignee:
Seiko Instruments Inc., , JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L 4/108 ;
U.S. Cl.
CPC ...
H01L 4/108 ;
Abstract
In a small rotary actuator having a rotor and a plurality of oscillators, each having a piezoelectric element that is excited by application of energy thereto so that the piezoelectric element oscillates at a resonance frequency thereof, the resonance frequency of the respective oscillators varies to some degree. This variation reduces the efficiency of rotation of the rotor. In order to reduce this variation, one or more of the piezoelectric elements of the oscillators is etched so that its resonance frequency is increased to match the resonance frequency of the other oscillators.