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:
Apr. 22, 2008
Filed:
Dec. 07, 2005
Takashi Ochiai, Tokyo, JP;
Tsuyoshi Shibata, Yokohama, JP;
Hiromitsu Yamaguchi, Yokohama, JP;
Eri Goto, Yokohama, JP;
Takashi Ochiai, Tokyo, JP;
Tsuyoshi Shibata, Yokohama, JP;
Hiromitsu Yamaguchi, Yokohama, JP;
Eri Goto, Yokohama, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An inkjet printing apparatus which performs time-divisional driving poses the following problem for at least some gray levels when halftoning control by the unit matrix is performed. More specifically, the shape of a dot cluster in each unit matrix periodically changes due to the mismatch between the unit matrix size and the unit section size of time-divisional driving. For this reason, periodical density unevenness is generated and appears as degradation of the image quality. In order to prevent degradation of the image quality, according to this invention, image data is shifted in accordance with the unit section of time-divisional driving, or the discharge timing of ink from a printhead is shifted.