Printing apparatus in which registration adjustment between a plurality of print heads is performed
AssigneeCanon Kabushiki Kaisha
InventorsMasashi Kamada, Takayuki Ninomiya, Kazuhiko Morimura
Life of this patent
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Abstract
When a position deviation of more than 1/2 pitch of ejection port pitch is generated by a difference in thermal expansion between ejection ports of a low temperature line head and ejection ports of high temperature line head, a dummy data is inserted in part of ejection data arrangement, so that ejection data inherent in the arrangement is shifted by one ejection port unit to be assigned to other ejection ports This reduces position deviation between dots formed by individual heads according to the data to less than 1/2 pitch.
Claims13
A printing apparatus in which a plurality of print heads, each having a plurality of printing elements arranged in a predetermined direction, are arranged in a direction along which a relative movement between the print heads and a printing medium is performed, and which performs printing of an image on the printing medium, by using the plurality of print heads so that each of the plurality of print heads scans on a same area of the printing medium while performing the relative movement, said apparatus comprising:
- head temperature data obtaining means for obtaining temperature data from each of the plurality of print heads;
- driving data supply means for supplying driving data, for driving the plurality of printing elements of each of the plurality of print heads, to each of the plurality of print heads in accordance with an arrangement of the plurality of printing elements;
- judging means for judging thermal expansion of respective print heads based on the temperature data obtained by said head temperature data obtaining means;
- and
- dummy data insertion means for inserting dummy data into the driving data supplied by said driving data supply means based on a judging result from said judging means as to whether respective differences in thermal expansion between the print heads are greater than a predetermined value.
A position deviation adjusting method for use with a printing apparatus using a plurality of print heads to record an image, each print head having a plurality of printing elements arranged in a predetermined direction, and performing printing on a printing medium, said method comprising the steps of:
- obtaining a temperature data corresponding to each of the plurality of print heads;
- judging thermal expansion of respective print heads based on the temperature data obtained in said obtaining step;
- judging as to whether respective differences in thermal expansion between the print heads are greater than a predetermined value;
- and
- inserting dummy data into driving data supplied to a print head, which has a smaller thermal expansion than that of a print head having a greatest thermal expansion of the plurality of print heads, when a plurality of differences in thermal expansion become greater than the predetermined value.
Dependencies are inferred from the claim text.