Lock mechanism for a movable unit, a position sensor, a method of setting the movable unit, and an image reading apparatus

摘要

An image reading apparatus having a movable image reading unit, a locking mechanism locking the image reading device, and a position sensor. The image reading unit has an engaged portion. The lock mechanism has an engaging portion that engages the engaged portion. A first detected portion changes its position in accordance with the movement of the engaging portion. The position sensor detects the image reading unit when the image reading unit is in a first position, and detects the first detected portion when the engaging portion engages with the engaged portion.