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. 11, 2019
Filed:
Sep. 06, 2017
Seiko Epson Corporation, Tokyo, JP;
Hiroyuki Yoshino, Suwa, JP;
SEIKO EPSON CORPORATION, Tokyo, JP;
Abstract
A drive circuit includes a signal generating circuit that generates drive waveform signal, an arithmetic circuit that generates difference signal representing a difference between the drive waveform signal and a feedback signal, a modulation circuit that modulates the difference signal pulse to generate modulated signal, a digital power amplifier circuit that amplifies the modulated signal to generate amplified signal, a smoothing circuit that smoothes the amplified signal to generate drive signal, a compensation circuit that generates the feedback signal based on the drive signal, and a voltage generating circuit that is connected to wiring between the digital power amplifier circuit and the capacitive load and generates a first voltage that exceeds a voltage range in which a pulse frequency of the modulated signal does not vary with respect to voltage variation of the drive signal, the drive signal being supplied to the capacitive load after the first voltage.