Method of adjusting image reading position, method of reading image and image reading apparatus

A method of adjusting an image reading position structured such that a plurality of line image sensors having CCDs arranged as a photo-electric conversion element are arranged in a main scanning direction of a paper, and end portions in respective reading areas of said line image sensors adjacent to each other in an arrangement direction are overlapped with each other, thereby adjusting an image reading position of said line image sensor at a time of reading a whole image on said paper by a combination of said line image sensors, comprising the steps of:

• irradiating light from light sources to an image surface on said paper so as to read reflected light thereof, said light sources arranged in a zigzag manner with overlapping end portions thereof with each other with respect to a reading position;
• forming an image on an area included in the overlapping portion between a pair of adjacent line image sensors so as to form a marker;
• respectively reading said marker by said pair of line image sensors;
• inspecting a relative position of each of said pair of line image sensors with respect to said marker on the basis of each of output values of said pair of line image sensors at a time of reading said marker;
• and
• coinciding each of the overlapping portions of said pair of line image sensors with a sub scanning direction on the basis of the inspected result of said relative position.