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. 21, 2001
Filed:
Jun. 01, 1999
Masatoshi Sakata, Hitachinaka, JP;
Keiji Kunimi, Hitachinaka, JP;
Takashi Sekino, Hitachinaka, JP;
Kazuo Shimizu, Hitachinaka, JP;
Hitachi Koki Co., Ltd., Tokyo, JP;
Abstract
A piezoelectric type ink recording device has piezoelectric elements for ejecting ink droplets. Variation can exist in characteristics of the piezoelectric elements that results in variation in speed at which the piezoelectric elements eject ink droplets. In order to suppress this variation in ejection speed, the ink recording device has a driver shared by all of the piezoelectric elements and a separate discharge control circuit for each piezoelectric element. The driver shared and the separate discharge control circuits output pulses to the piezoelectric elements in synchronization. Each piezoelectric element starts discharging its charge in synchronization with the falling edge of a drive pulse from the driver. As a result, the piezoelectric elements deform during the falling edge of the drive pulse to increase volume of corresponding ink chambers, thereby drawing ink into the ink chambers. However, each piezoelectric element continues discharging for a time determined by the width of the pulse from the corresponding discharge control circuit. In this way, the amount of charge discharged from each piezoelectric element can be individually regulated by changing the pulse waveform applied to each piezoelectric element by the corresponding discharge control circuit.