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:
Sep. 15, 1992
Filed:
Oct. 26, 1989
Atsuo Sakaida, Gifu, JP;
Yoshiyuki Ikezaki, Nagoya, JP;
Akira Iriguchi, Nagoya, JP;
Takeshi Niikawa, Nagoya, JP;
Masashi Suzuki, Nagoya, JP;
Brother Kogyo Kabushiki Kaisha, Nagoya, JP;
Abstract
A driver circuit for driving a piezoelectric element, including a charging circuit having a DC power source and a coil for charging the piezoelectric element, and a discharging circuit for discharging the piezoelectric element. When the piezoelectric element is charged, a first switching device in the charging circuit is held on until a voltage of the element reaches a predetermined level below a line voltage of the power source. A second switching device provided in the discharging circuit is turned on at the time when the first switching device is turned off or at a predetermined later time, and is turned off by the time when said first switching device is again turned on next activation of the piezoelectric element. A voltage limiter inhibits the voltage of the piezoelectric element element from exceeding the predetermined level. The driver circuit may be used for a dot-matrix printer, which may be adapted to discharge the piezoelectric element for a comparatively long time where a distance between adjacent two dots to be formed is larger than a predetermined value.