Abstract: A detector assembly for use in an optical reader comprises a hollow housing in which is mounted on the central axis of the housing a collection lens, a routing mirror, a light filter and a photodetector. A routing lens mounted in the side of the housing and on an axis which is perpendicular to the central axis of the housing directs the scanning light at the routing mirror which in turn reflects the light in a scanning direction.

Abstract: A portable bar code scanner includes a base member and a overhanging scanning housing secured to the base member. A laser power supply mounted in the housing outputs a laser beam along a first light path directed to a compact optical system in the housing which reflects the laser beam along a second light path which intersects the first light path at approximately ninety degress to scan a coded label positioned below the scaning housing. A collection lens mounted in the housing collects and directs the reflected light from the coded label to a detector which generates electrical signals for transmission over a cable to a processor.

Abstract: A laser power supply includes a support member in which is mounted a laser tube for outputting a laser light beam and a printed circuit board containing the power supply circuits. A slidably mounted cover member encloses the support member and the laser tube and includes a pair of lens members for diverging and attenuating the laser light beam. A pair of spring clip members mounted on the support member releasable secure the laser tube to the support member while electrically connecting the laser tube to the printed circuit board.

Abstract: An optical reader control system includes a source of radiant energy mounted above a checkout counter and detecting means mounted adjacent an aperture in the supporting surface of the counter receives the radiant energy to control the operation of the optical reader mounted within the counter for projecting scanning beams through the aperture. One embodiment of the detecting means includes a pair of photodetectors mounted in the supporting surface of the counter on both sides of the aperture for turning the optical reader on and off. A second embodiment includes a single photodetector mounted in the supporting surface upstream of the aperture for turning on the optical reader and a timer operable upon the positioning of a merchandise item over the photodetector for turning off the optical reader after the expiration of a predetermined time period.

Abstract: A check-out counter having an optical scanning system mounted therein includes, a cover member located on the top surface of the check-out counter. The cover member contains a plurality of apertures through which the optical scanning system will scan a coded label on a merchandise item. A raised housing member having an inclined top surface in which is located a display is secured to the top surface of the counter. The display is orientated to allow the customer to observe, simultaneously, the display, which displays the price of the item being scanned, and the item itself as it moves past the aperture during a scanning operation.

Abstract: A digital timing recovery circuit is disclosed for synchronously transmitting digitally encoded data in a multiterminal configuration between a data processor and a plurality of data terminals associated therewith. Phase shifted synchronous data from the data processor is continuously compared with a newly generated synchronous clock generated at a repeater interposed along the communication line for minimization of the time differential between the retiming clock and the transmitted data. The data transitions enable a digitally implemented one-shot, which generates pulses, the leading edges of which pulses enable a difference counter, while the leading edges of the retiming clock pulses disable the counter. The difference counter output is sampled in a digital phase locked loop to derive the number of cycles of a stable oscillator which occur between the two aforementioned leading edges of the generated pulses.

Abstract: A data communication system for asynchronously transmitting intermittently generated digitally encoded data between a data processor and a plurality of data terminals associated therewith is disclosed wherein the allowable communications line distance between the data processor and the terminals is substantially increased. Asynchronous data from the terminals is intercepted by a novel repeater, retimed in accordance with a newly generated retiming clock to eliminate bit-shift or other errors from the data, and retransmitted to the central processor over an extended length transmission line, with the repeater being substantially transparent to the flow of data. Decoding of an appropriate code by the repeater which is indicative of the receipt of a data character causes the switching from a data derived clock to a retiming clock for reencoding and retransmission of the data.