Image reading apparatus, image forming apparatus, document sheet width detecting method

摘要

In image reading apparatus, reading control portion causes image reading portion to read at least line of image data when pivoting angle of cover member with respect to document sheet table has changed from angle exceeding predetermined detection angle to angle equal to or less than detection angle. Photoelectric conversion portion is disposed in area that is out of predetermined maximum readable size area in image reading portion, and is covered by cover member when cover member is closed. Data correcting portion corrects image data read by reading control portion, based on output of photoelectric conversion portion output when pivoting angle has changed from angle exceeding detection angle to angle that is equal to or less than detection angle. Document sheet width detecting portion detects width, in main scanning direction, of document sheet placed on document sheet mounting surface, based on image data corrected by data correcting portion.

主权项

1. An image reading apparatus comprising:
a document sheet table including a document sheet mounting surface; a cover member pivotably supported with respect to the document sheet table; an image reading portion configured to read image data from a document sheet placed on the document sheet mounting surface; a reading control portion configured to cause the image reading portion to read at least a line of the image data when a pivoting angle of the cover member with respect to the document sheet table has changed from an angle exceeding a predetermined detection angle to an angle that is equal to or less than the detection angle; a photoelectric conversion portion disposed in an area that is out of a predetermined maximum readable size area in the image reading portion, and is covered by the cover member when the cover member is closed; a data correcting portion configured to correct the image data read by the reading control portion, based on an output of the photoelectric conversion portion which is output when the pivoting angle has changed from an angle exceeding the detection angle to an angle that is equal to or less than the detection angle; and a document sheet width detecting portion configured to detect a width, in a main scanning direction, of the document sheet placed on the document sheet mounting surface, based on the image data corrected by the data correcting portion.