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:
May. 03, 2005
Filed:
Nov. 27, 2002
Yoshiaki Kojoh, Sakurai, JP;
Hiroshi Ishii, Osaka, JP;
Yoshiaki Kojoh, Sakurai, JP;
Hiroshi Ishii, Osaka, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
A rise time and/or a fall time of a driving voltage are set to be not less than {fraction (1/20)} of a period of natural oscillation of an ink-jet head. This suppresses a driving voltage, an amount of generated heat, and dissipated power, which increase when there is a loss due to a resistor component of a charge/discharge system, such as wiring or switching elements, caused by a large current that is flown when the driving voltage rises or falls sharply. The rise time and/or fall time may be made not more than ⅓ of the period of natural oscillation. In this way, 80% or higher efficiency can be ensured for the oscillation energy of piezoelectric elements, which increases as the rise or fall of the driving voltage becomes sharper. Further, the rise time and/or fall time may be set in the vicinity of {fraction (1/20)} of the period of natural oscillation. In this way, the ejection energy of the piezoelectric elements can be saturated almost completely. As a result, less driving voltage, less heat, and less power are required to drive piezoelectric elements, which are used in ink-jet recording apparatuses and other types of apparatuses.