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:
Jun. 18, 1991
Filed:
Jun. 15, 1990
Nobuo Tsukada, Tokyo, JP;
Seiko Instruments Inc., , JP;
Abstract
An ultrasonic motor adapted to generate a travelling wave by a piezoelectric element and a vibrator to which the piezoelectric element is bonded, the displacement of these parts due to the travelling wave being amplified by a comb-like projection of the vibrator, arranged alternately in the circumferential direction thereof, to frictionally drive a movable member engaged under pressure with the vibrator characterized in that the piezoelectric element is provided on one surface thereof with fan-shaped electrode patterns, the number of which is a multiple of 4, arranged at regular intervals in the circumferential direction thereof, wherein the number of the fan-shaped electrode patterns and that of the vibrator have no common divisor with respect to each other, whereby the scatter of performance of ultrasonic motors, which is caused by a difference in the position in which the piezoelectric element and vibrator are bonded together, is eliminated to enable ultrasonic motors of uniform performance to be obtained.