A unitary hand-held bar code scanner and reader produces an elliptical beam, oriented with its major axis along the direction of the bars, utilizing optics employing far field diffraction effects to shape the beam and maintain its elliptical aspect (length to width ratio) constant over a distance...http://www.google.ca/patents/US5786581?utm_source=gb-gplus-sharePatent US5786581 - Optical system for scanning and recording bar codes which is adapted to be configured in a hand held unit 
