A photosensitive material detecting apparatus having a single or a plurality of optical sensor(s) disposed at a selected location on a transport path of a photosensitive material and (each) including a light emitter and a light receiver for optically detecting the photosensitive material. This apparatus...http://www.google.com.au/patents/US5065178?utm_source=gb-gplus-sharePatent US5065178 - Photosensitive material detecting apparatus
