A hand-held dual reading head including a hand-held housing having a light transmissive window at one end thereof; and containing an actuatable bar-code reader, which produces a light beam which exits the housing via the window and detects light from the beam reflected from a bar code tag to generate...http://www.google.com.tw/patents/US5382784?utm_source=gb-gplus-share專利 US5382784 - Hand-held dual technology identification tag reading head
