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:
Apr. 17, 2001
Filed:
May. 26, 1999
Koutaro Kawabe, Sakai, JP;
Minolta Co., Ltd., Osaka, JP;
Abstract
Signals from a control device are supplied to terminals so as to adequately turn on/off five switches respectively configured by transistors FET,to FET,, and two constant-current circuits I,and I,, whereby a pulse voltage of a saw-tooth waveform is applied to a piezoelectric element A. The transistors FET,and FET,are turned on, so that the piezoelectric element A is charged gently, thereby preventing the generation of a sound at a start of a driving operation from occurring. Thereafter, the constant-current circuit I,and the transistor FET,are alternatingly turned on so that a slow discharge and a fast discharge of the piezoelectric element A are repeated. When the driving operation is to be stopped, the transistors FET,and FET,are turned off, and charges of the piezoelectric element A are dissipated through a closed circuit including resistors R,and R