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:
Aug. 25, 1987
Filed:
Apr. 17, 1986
You Kondoh, Yokohama, JP;
Chiaki Tanuma, Tokyo, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
In a displacement generating device, a voltage signal generator produces a triangular-wave drive voltage signal so as to drive a piezoelectric element in a desired vibration mode. The voltage signal generator is connected to the piezoelectric element through a differentiator and a constant current supply. The drive voltage signal is differentiated by the differentiator, and is then supplied as a rectangular-wave voltage signal to the constant current supply. Since constant currents having two levels are alternately supplied to the piezoelectric element, an amount of charge accumulated in the piezoelectric element can be controlled linearly during the current supply time. As a result, since displacement of the piezoelectric element is linearly controlled in proportion to the amount of charge, it coincides with the triangular waveform of the drive voltage signal. A vibration mode free from hysteresis can be obtained.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile