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:
Feb. 22, 2005
Filed:
Jul. 23, 2002
Satoru Hosono, Nagano, JP;
Hirofumi Teramae, Nagano, JP;
Hironori Endo, Nagano, JP;
Seiko Epson Corporation, Tokyo, JP;
Abstract
In an apparatus for measuring a natural period of liquid in a pressure chamber formed in a head device which is provided with a nozzle orifice communicated with the pressure chamber and an actuator which varies pressure of the liquid contained in the pressure chamber, a driver generates a plurality of drive signals, each of which drives the actuator to eject a liquid droplet from the nozzle orifice under a condition different from the conditions established by the other drive signals. A light emitter emits a light beam so as to intersect a space through which the liquid droplet passes. A light receiver receives the light beam which has been passed through the space. A first calculator calculates an ejection velocity of the liquid droplet based on a timing at which the actuator is driven and a change in a photo-receiving state of the light receiver, with regard to every drive signal. A second calculator calculates a natural period of the liquid based on a change in the ejection velocity which is obtained from the plural drive signals.