Printing apparatus and printing method

A printing method in a printing apparatus which prints by discharging ink from a plurality of nozzles onto a print medium while reciprocally scanning a carriage, which mounts a printhead on which the plurality of nozzles are arrayed, in a direction crossing a direction in which the plurality of nozzles are arrayed, comprising the steps of:

• obtaining slant information indicating a slant between the direction in which the nozzles are arrayed, and a moving direction of the carriage, for each position corresponding to a printing column in the moving direction of the carriage by reading a predetermined pattern printed on a print medium by the printhead using an optical sensor;
• detecting a position of the carriage;
• reading image data corresponding to the printing column stored in a print buffer in association with each printing column by separating the image data into image data used for printing by first scanning of the printhead and image data used for printing by second scanning of the printhead in a same region as that in which printing is done by the first scanning, based on the detected position of the carriage and the slant information in the position of the carriage corresponding to the printing column;
• and
• controlling the printhead so as to print by scanning the same region by the first scanning and the second scanning, using the read image data.

A printing apparatus which prints by discharging ink from a plurality of nozzles onto a print medium while reciprocally scanning a carriage, which mounts a printhead on which the plurality of nozzles are arrayed, in a direction crossing a direction in which the plurality of nozzles are arrayed, the apparatus comprising:

• an obtaining unit configured to obtain slant information indicating a slant between the direction in which the nozzles are arrayed, and a moving direction of the carriage, for each position corresponding to a printing column in the moving direction of the carriage by reading a predetermined pattern printed on a print medium by the printhead using an optical sensor, wherein the slant in one printing column in the moving direction of the carriage is different from that in another printing column in the moving direction of the carriage;
• a print buffer configured to store image data in association with the printing column;
• a detection unit configured to detect a position of the carriage;
• a reading unit configured to read image data corresponding to the printing column stored in the print buffer by separating the image data into image data used for printing by first scanning of the printhead and image data used for printing by second scanning of the printhead in a same region as that in which printing is done by the first scanning, based on the position of the carriage detected by said detection unit and the slant information in the position of the carriage corresponding to the printing column obtained by said obtaining unit;
• and
• a control unit configured to control the printhead so as to print by scanning the same region by the first scanning and the second scanning, using the image data read by said reading unit,
• wherein said reading unit reads image data used for printing by first scanning of the printhead and image data used for printing by second scanning of the printhead in a same region as that in which the image data is printed by the first scanning not only so as not to be repeatedly used for printing in the first scanning and the second scanning, but also so as not to be used for printing in either of the first scanning and the second scanning.

A printing method in a printing apparatus which prints by discharging ink from a plurality of nozzles onto a print medium while reciprocally scanning a carriage, which mounts a printhead on which the plurality of nozzles are arrayed, in a direction crossing a direction in which the plurality of nozzles are arrayed, comprising the steps of:

• obtaining slant information indicating a slant between the direction in which the nozzles are arrayed, and a moving direction of the carriage, for each position corresponding to a printing column in the moving direction of the carriage by reading a predetermined pattern printed on a print medium by the printhead using an optical sensor, wherein the slant in one printing column in the moving direction of the carriage is different from that in another printing column in the moving direction of the carriage;
• detecting a position of the carriage;
• reading image data corresponding to the printing column stored in a print buffer in association with each printing column by separating the image data into image data used for printing by first scanning of the printhead and image data used for printing by second scanning of the printhead in a same region as that in which printing is done by the first scanning, based on the detected position of the carriage and the slant information in the position of the carriage;
• and
• controlling the printhead so as to print by scanning the same region by the first scanning and the second scanning, using the read image data,
• wherein at said reading, image data used for printing by first scanning of the printhead and image data used for printing by second scanning of the printhead in a same region as that in which the image data is printed by the first scanning are read not only so as not to be repeatedly used for printing in the first scanning and the second scanning, but also so as not to be used for printing in either of the first scanning and the second scanning.