Image reader with detection of original accidentally left on platen

摘要

Contact glass platen (13) provides flat bed scan area with automatic document feed (ADF) scan window and area for manually fed original. Sensor detects front edge of ADF sheet before it reaches image sensor and detects opening of cover (21). Detection of opening of cover is used to determine if document is left on platen after scanning. Detector provides signals indicating opening/shutting of ADF and cover which are processed to determine if original document has been left on platen, before allowing use of ADF. If processor determines original has been left on platen, signal is provided to scanner ADF control which blocks use of ADF and provides a warning screen message to user.