US 2012/0069067 A1Published application

Printing apparatus and method for controlling printing apparatus

AssigneeCanon Kabushiki Kaisha

InventorsMakoto Torigoe, Shigeyasu Nagoshi, Yoshiaki Murayama, Satoshi Azuma, Kei Kosaka

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Abstract

According to the present invention, each printing head includes chips wherein a plurality of nozzles are prepared. The density of dots formed by ejecting ink from the nozzles is detected for each chip, and when a density difference between the chips is smaller than a predetermined value, print data are corrected, and the number of dots is adjusted so as to reduce the density difference. When the density difference is equal to or greater than the predetermined value, first, a drive pulse for the nozzles is modulated and the volume of ink to be ejected for one dot is adjusted so as to reduce the density difference. Thereafter, the print data is corrected, and the number of dots to be formed is controlled so as to reduce the density difference.

Claims10

Dependent claims

A printing apparatus configured to print an image on a printing medium by using a printing head comprising a plurality of printing elements able to form dots on the printing medium, and by driving the plurality of printing elements in accordance with a drive pulse generated based on print data, the printing apparatus comprising:

a first correction unit configured to be able to correct the print data so as to adjust the number of dots to be formed by the printing elements in a unit print area;
a second correction unit configured to be able to modulate the drive pulse for the printing element so as to adjust densities of dots formed by the printing elements;
and
a density correction control unit configured to, when a difference in print densities among the plurality of printing elements is smaller than a predetermined value, permit the first correction unit to correct the print data for reducing the difference, and, when the difference in the print densities is greater than the predetermined value, permit the second correction unit to modulate the drive pulse for reducing the difference in the print densities, and thereafter permit the first correction unit to correct the print data for reducing the difference in the print densities.

1 more element

Dependencies are inferred from the claim text.