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. 04, 2015
Filed:
Aug. 27, 2012
Takahiro Matsuzaki, Shiojiri, JP;
Takeshi Seto, Chofu, JP;
Kunio Tabata, Shoijiri, JP;
Shinichi Miyazaki, Suwa, JP;
Takahiro Matsuzaki, Shiojiri, JP;
Takeshi Seto, Chofu, JP;
Kunio Tabata, Shoijiri, JP;
Shinichi Miyazaki, Suwa, JP;
Seiko Epson Corporation, Tokyo, JP;
Abstract
A fluid feeding pump which varies a volume of a pump chamber and thus feeds a fluid out of the pump chamber, includes: a piezoelectric element which accumulates electric charges inside when a voltage is applied, and which deforms according to an amount of accumulated electric charges and thus increases or decreases the volume of the pump chamber; a drive unit which applies a drive signal with a waveform increasing to a predetermined maximum voltage and then decreasing, and thus drives the piezoelectric element; and an air bubble determining unit which detects a current flowing through the piezoelectric element within a predetermined period after the drive signal is applied to the piezoelectric element, and thus determines whether there are air bubbles in the pump chamber or not.