A plurality of index members are arranged at desired positions on an end portion of a platen glass, the members being movable in a scanning direction of a scanner. A black mark is provided on a rear surface of each index member, and the mark as well as the original are read by an image reader, so that...http://www.google.com.hk/patents/US5033102?utm_source=gb-gplus-share專利 US5033102 - Image reading apparatus capable of reading desired image areas
