Image reading apparatus, control method, and product for adjusting a correcting value for connected image data from line sensors based on measured skew during document conveyance

A control method of an image reading apparatus comprising:

• a plurality of line image sensors arrayed in a first direction;
• and
• a conveyance unit configured to convey a document in a second direction intersecting with the first direction, the control method comprising:
• a calculation step of calculating a correction value for correcting a deviation at the time of connecting image data obtained by each of the plurality of line image sensors based on read data obtained by reading a chart with the plurality of line image sensors, on which a plurality of dot patterns is printed and which is conveyed by the conveyance unit;
• a measurement step of measuring an amount of conveyance in the first direction in a case where the document is conveyed in the second direction by the conveyance unit;
• and
• an adjusting step of adjusting the correction value based on the amount of conveyance in the first direction in a case where the read data is obtained and the amount of conveyance in the first direction in a case where the image data is obtained.

A non-transitory computer readable storage medium storing a program for causing a computer to perform a control method of an image reading apparatus comprising:

• a plurality of line image sensors arrayed in a first direction;
• and
• a conveyance unit configured to convey a document in a second direction intersecting with the first direction, the control method comprising:
• a calculation step of calculating a correction value for correcting a deviation at the time of connecting image data obtained by each of the plurality of line image sensors based on read data obtained by reading a chart with the plurality of line image sensors, on which a plurality of dot patterns is printed and which is conveyed by the conveyance unit;
• a measurement step of measuring an amount of conveyance in the first direction in a case where the document is conveyed in the second direction by the conveyance unit;
• and
• an adjusting step of adjusting the correction value based on the amount of conveyance in the first direction in a case where the read data is obtained and the amount of conveyance in the first direction in a case where the image data is obtained.