A method and apparatus performs the detection of an edge of a tape and further controls the read/write head to position itself relative to the detected edge. An array of photodetectors in an integrated circuit chip senses the intensity of light illuminating the chip with the tape running between the...http://www.google.co.uk/patents/US5294803?utm_source=gb-gplus-sharePatent US5294803 - System and a method for optically detecting an edge of a tape
