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. 02, 2009
Filed:
Jul. 24, 2006
Akira Koyabu, Shiojiri, JP;
Satoshi Nakajima, Azumino, JP;
Yuji Takiguchi, Shiojiri, JP;
Seiko Epson Corporation, , JP;
Abstract
High print quality from a thermal printer is maintained while the print speed is decreasing without producing white streaks or uneven print density by controlling the hysteresis coefficient of the thermal print headbased on the energizing history of the thermal print headand print speed control factors used for determining print speed, which is the speed at which the paper is advanced while printing. The thermal printer, comprises a hysteresis coefficient setting unitfor setting a hysteresis coefficient for the print head based on the energizing history of the thermal print headan energizing time calculation unitfor calculating the energizing time during which drive signals are to be applied to the thermal print headfor printing based upon the hysteresis coefficient set by the hysteresis coefficient setting unit; a printing control devicefor generating the drive signals to be applied to the print head in response to the energizing time calculated by the energizing time calculation unit; a print speed determination unitfor determining the change in the print speed and when the print speed is decreasing; and a coefficient changing unitfor changing the hysteresis coefficient when a change in print speed occurs causing the print speed to decrease. Preferably the coefficient changing unit changes the hysteresis coefficient to a value greater than the hysteresis coefficient value used immediately before deceleration.