Image reading apparatus having multiple reading operations

An image reading apparatus comprising:

• a reading portion that reads an image on a target object;
• a driving source that causes the reading portion to move;
• and
• a control portion that controls the reading portion and the driving source,
• wherein:
• when a first reading operation is instructed thereby causing the reading portion to move at a first moving speed by the driving source and causing the reading portion to read the image, in a case where the driving source does not enter a step-out state, the control portion causes the driving source and the reading portion to execute the first reading operation,
• when the first reading operation is instructed, in a case where the driving source enters the step-out state, the control portion executes a second operation thereby causing the reading portion to move at a second moving speed slower than the moving speed by the driving source and causing the reading portion to read the image,
• when a third reading operation is instructed thereby causing the reading portion to move at the second moving speed by the driving source and causing the reading portion to read the image, the control portion causes the driving source and the reading portion to execute the third reading operation, and
• a resolution of image data of the image read by the second reading operation is lower than a resolution of image data of the image read by the third reading operation.