Printing apparatus, control method therefor, printhead control circuit, and printhead driving method
AssigneeCanon Kabushiki Kaisha
InventorsTakuji Katsu, Toru Nakayama, Yuji Hamasaki, Norihiro Kawatoko, Atsushi Sakamoto
Life of this patent
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Abstract
A printing apparatus having a printhead for printing by discharging liquid on a printing medium performs a toggle preliminary discharge operation of alternately performing discharge from main nozzles and dummy nozzles in order to establish a good discharge state of the liquid from the main nozzles. The main nozzles and the dummy nozzles communicate with liquid chambers, which in turn communicate with a common liquid chamber. A control circuit for the printhead and a control method are also provided.
Claims14
A printing apparatus which drives and controls a printhead for discharging a liquid from main nozzles and printing on a printing medium, the printhead having a common liquid chamber which receives a liquid, a plurality of main nozzles which are aligned at a predetermined interval along a longitudinal direction of the common liquid chamber and which are used for printing, a plurality of dummy nozzles which are aligned on two sides of the main nozzles along an array direction of the main nozzles and which are not used for printing, and a plurality of liquid chambers which communicate with the common liquid chamber while the main nozzles and the dummy nozzles communicate with the liquid chambers, comprising:
- preliminary discharge means for performing preliminary discharge from the main nozzles and the dummy nozzles in order to establish a good discharge state of the liquid from the main nozzles;
- switching means for alternately switching between the main nozzles and the dummy nozzles;
- and
- control means for executing and controlling, as the preliminary discharge performed by said preliminary discharge means, a toggle preliminary discharge operation of alternately performing discharge from the main nozzles and the dummy nozzles every column for a plurality of successive columns.
A method of controlling a printing apparatus which drives and controls a printhead for discharging a liquid from main nozzles and printing on a printing medium, the printhead having a common liquid chamber which receives a liquid, a plurality of main nozzles which are aligned at a predetermined interval along a longitudinal direction of the common liquid chamber and which are used for printing, a plurality of dummy nozzles which are aligned on two sides of the main nozzles along an away direction of the main nozzles and which are not used for printing, and a plurality of liquid chambers which communicate with the common liquid chamber while the main nozzles and the dummy nozzles communicate with the liquid chambers, comprising:
- a preliminary discharge step of performing preliminary discharge from the main nozzles and the dummy nozzles in order to establish a good discharge state of the liquid from the main nozzles;
- a switching step of alternately switching between the main nozzles and the dummy nozzles;
- and
- a control step of executing and controlling, as the preliminary discharge performed in the preliminary discharge step, a toggle preliminary discharge operation of alternately performing discharge from the main nozzles and the dummy nozzles every column for a plurality of successive columns.
A control circuit for a printhead for discharging a liquid from main nozzles and printing on a printing medium, the printhead having a common liquid chamber which receives a liquid, a plurality of main nozzles which are aligned at a predetermined interval along a longitudinal direction of the common liquid chamber and which are used for printing, a plurality of dummy nozzles which are aligned on two sides of the main nozzles along an array direction of the main nozzles and which are not used for printing, and a plurality of liquid chambers which communicate with the common liquid chamber while the main nozzles and the dummy nozzles communicate with the liquid chambers, comprising:
- switching means for alternately switching between the main nozzles and the dummy nozzles;
- and
- control means for executing and controlling a toggle preliminary discharge operation of alternately performing discharge from the main nozzles and the dummy nozzles every column for a plurality of successive columns, as a preliminary discharge operation of performing preliminary discharge from the main nozzles and the dummy nozzles by using said switching means in order to establish a good discharge state of the liquid from the main nozzles.
A method of driving a printhead for discharging a liquid from main nozzles and printing on a printing medium, the printhead having a common liquid chamber which receives a liquid, a plurality of main nozzles which are aligned at a predetermined interval along a longitudinal direction of the common liquid chamber and which are used for printing, a plurality of dummy nozzles which are aligned on two sides of the main nozzles along an array direction of the main nozzles and which are not used for printing, and a plurality of liquid chambers which communicate with the common liquid chamber while the main nozzles and the dummy nozzles communicate with the liquid chambers, comprising:
- a switching step of alternately switching between the main nozzles and the dummy nozzles;
- and
- a control step of executing and controlling a toggle preliminary discharge operation of alternately performing discharge from the main nozzles and the dummy nozzles every column for a plurality of successive columns, as a preliminary discharge operation of performing preliminary discharge from the main nozzles and the dummy nozzles in the switching step in order to establish a good discharge state of the liquid from the main nozzles.
Dependencies are inferred from the claim text.