Canon Kabushiki Kaisha

Daisuke Ishii

Shigeyasu Nagoshi

Yoshiaki Murayama

Takeshi Murase

Kenji Kubozono

Satoshi Tada

A printing apparatus includes a printhead having a plurality of chips each including a plurality of nozzle arrays which are arranged in a predetermined nozzle array direction and each of which is formed from a plurality of nozzles and energy generation elements provided in correspondence with the nozzles of each nozzle array and each configured to generate energy used for discharging ink. The apparatus relatively moves the printhead and a print medium in a direction intersecting the nozzle array direction, reads a predetermined test pattern printed on the print medium by driving the printhead, analyzes the read test pattern, calculates a slant of the printhead with respect to a reference based on a result of the analysis, and corrects the calculated slant of the printhead by moving the printhead.

Printing apparatus and correction method therefor

A printing apparatus includes a printhead having a plurality of chips, each including a plurality of nozzle arrays which are arranged in a predetermined nozzle array direction and each of which is formed from a plurality of nozzles and energy generation elements provided in correspondence with the nozzles of each nozzle array and each configured to generate energy used for discharging ink. The apparatus relatively moves the printhead and a print medium in a direction intersecting the nozzle array direction, reads a predetermined test pattern printed on the print medium by driving the printhead, analyzes the read test pattern, calculates a slant of the printhead with respect to a reference based on a result of the analysis, and corrects the calculated slant of the printhead by moving the printhead.

An inkjet printing apparatus obtains data of a second image by correcting, using shading data, signal values of pixels in an image of a read test pattern so that a signal value of a pixel lower than a value of the shading data becomes a value corresponding to a lowest luminance; specifies an area of a pattern of each of the plurality of inks in the image of the test pattern using the data of a first image and the data of the second image; and calculates a position deviation amount of a printhead based on a position of the pattern of the specified area.

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Fuchu, Japan

Daisuke Ishii