An image is optically scanned by projecting the image onto an optical sensor through an optical shutter. In an exemplary embodiment, the image is projected through the optical shutter while the shutter is made substantially opaque except for a selected substantially transparent group of contiguous pixels....http://www.google.es/patents/US6005990?utm_source=gb-gplus-sharePatente US6005990 - System for optically scanning images using optical shutter
System for optically scanning images using optical shutter
