Abstract: A bar code scanner having a housing in which a laser diode and optics forming the beam which scans the code and a photodetector are assembled as a unitary structure upon a printed circuit board so that the entire structure can be located in the housing.

Abstract: An optical device for detecting bar codes (markings or patterns which symbolize data such as the name and vendor of a product) are detected by an optical device which serves as a bar code scanner. A laser diode and associated optics provides an invisible beam. A visible marker beam coincident with the laser beam is generated by a lamp and associated optics and directed coaxial with the laser beam so as to enable the laser beam to be scanned across the bar code by moving a housing in which the laser and the lamp and their associated optics are disposed. Also contained in the housing is a photodetector on which scattered light from the code is incident after passing through a collection lens located at an outlet port for the beams. An aperture is positioned between the collection lens and the detector.