Patent ID: 8351094

Claim:
An image reading apparatus which detects the presence of a sheet reads an image in said sheet, comprising: a transparent plate for mounting the sheet thereon; a sheet cover having a light reflecting plate mounted thereunder, the light reflecting plate for reflecting light which passes through said transparent plate; a storage means for storing first profile information which involves plural darkness data of reflection light from said light reflecting plate which are detected by an image sensor in advance when a speed of closing said sheet cover is changed variously without said sheet mounted on said transparent plate, and for storing second profile information which involves plural darkness data of reflection light which are detected by said image sensor when said sheet is mounted on said transparent plate and said sheet cover is closed; and a control means for comparing said first profile information with said second profile information stored in said storage means, and for determining that a sheet is mounted on said transparent plate when there is a predetermined difference therebetween.