The image sensor according to the present invention comprises a light emitting diode which irradiates light onto a document image, a phototransistor which receives the reflected light and executes photoelectric conversion, an amplifier which amplifies an analog signal from the phototransistor, a time...http://www.google.ca/patents/US5523575?utm_source=gb-gplus-sharePatent US5523575 - Image identifying apparatus using an image sensor to extract false image data from a document image and discriminate the image by comparing the false image data to a predetermined pattern
