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 quick release weigh plate for a weighing device includes a support member to which is secured a pair of cantilever load beam cells for generating electrical signals representing the weight of an object placed on the load beam cells. The load beam cells each include a support portion which extends through an aperture in the support member on which is removably mounted a cover for supporting the object to be weighed. One of the support portions has a truncated slotted end on which is removably mounted a U-shaped saddle member secured to the cover preventing any unnecessary movement of the cover when mounted on the load beam cells while allowing the cover to be easily removed when necessary. The other support portion has its end removably positioned within an aperture in the cover.

Abstract: An overhead bar code scanning system is supported by a checkout counter and includes an overhanging portion to which is secured a plurality of scanning units orientated towards the counter to scan a coded label on a merchandise item moved under the scanning units. Mounted in the overhanging portion are a pair of display members, a pair of keyboard members, a printer and a magnetic stripe reader for use by the operator and the customer to process the purchased merchandise items.

Abstract: A digital phase lock loop decoder for use in decoding Manchester encoded data operates at an internal clock speed having a speed equal to the data rate of the encoded data. The decoder includes a first sampling circuit for providing signals based on the clock speed of the encoded data, a delay circuit for generating delayed clock signals relative to the clock speed of the encoded data, a second sampling circuit for sampling the encoded data based on the delayed clock signals, a feedback circuit for generating clock signals whose phase corresponds with the phase of the delayed clock signals and a storage for outputting decoded data signals corresponding to the encoded data utilizing the delayed clock signals.

Abstract: A quick release weigh plate for a weighing device includes a support member to which is secured a pair of cantilever load beam cells for generating electrical signals representing the weight of an object placed on the load beam cells. The load beam cells each include a support portion which extends through an aperture in the support member on which is removably mounted a cover for supporting the object to be weighed. One of the support portions has a truncated slotted end on which is removably mounted a U-shaped saddle member secured to the cover preventing any unnecessary movement of the cover when mounted on the load beam cells while allowing the cover to be easily removed when necessary. The other support portion has its end removably positioned within an aperture in the cover.

Abstract: A self-contained optical scanning unit for use in a bar code scanner includes a motor driven hollow drive shaft through which is projected a laser light beam from a laser source positioned adjacent one end of the drive shaft. Mounted on the other end of the drive shaft is an optical transceiver which includes a deflecting portion which deflects the laser light beam outwardly towards a ring of mirrors which forms a scanning pattern for scanning a coded indicia and a collection portion which collects the reflected light beams from the coded indicia and directs the light beams at a detecting member. The collection portion of the transceiver is orientated obliquely across the spin axis of the drive shaft while the deflection portion is oriented obliquely to the spin axis and to the face of the collection portion. The detection member is located on the spin axis between the transceiver and the coded indicia.

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: There is disclosed a mounting structure for a CRT display which includes a pair of tubular support members with the first one secured to a ceiling surface and the second one slidably mounted within the first one. Knobs are included to lock the second support member in an adjusted position within the first support member. A yoke assembly secured to one end of the second tubular support member includes a yoke member secured to the support member, a tray member rotatably secured to the yoke member for supporting the display and adapted to be rotated to an adjusted position, a strap member secured to the yoke member for holding the display on the tray member and a locking knob for locking the tray member in the adjusted position.

Abstract: An apparatus for controlling the transfer of data between a first remote processor constructed to process data words of a first length and a second remote processor constructed to process data words of a second length and which includes a storage member constructed to store data words of a third length. A DMA controller controls the transmission of data words between the storage member and the first remote processor. A first control processor controls the operation of a second processor and the DMA controller for transferring data from the second remote processor to the storage member. In response to instructions transmitted from the second remote processor, the first control processor will enable the second control processor to transfer data words of a third length to the storage member and will enable the DMA controller to transfer data words of the second length from the storage member to the second remote processor.

Abstract: A hand-held bar code reader includes a source of scanning laser beams for scanning a coded label, a detector for detecting the light reflected from the coded label and a single piece composite optical lens structure. The lens structure has a first portion receiving the laser beams for reversing the direction of the laser beams. A second portion for focusing the laser beams on a rotating member which generates scanning beams for use in the scanning of the coded label and a third portion for collecting the light reflected from the coded label for focusing the reflected light on the detector.

Abstract: A portable optical bar code reader is adapted to be attached to the underside of the wrist of the user for reading coded labels on a purchased merchandise item. A ring member mounted on one of the fingers of the user has an actuating member mounted therein which is actuated by another finger of the user to enable the bar code reader to read a coded label. Scanning device mounted within the bar code reader provide a compact arrangement for generating a scanning light beam which scans the coded label. The bar code reader is attached to the wrist of the user by an easily removable strap member.

Abstract: A data entry keyboard apparatus includes a key switch array (18) in a keyboard unit (12) connected via a cable (14) to a tamper-resistant module (28) which contains control circuitry (16). The control circuitry (16) includes a random pattern generator (30) which generates successive random patterns, causing the selection of a single column and a random pattern of rows, thereby effecting the simulation of key actuations. An EXCLUSIVE-OR gating network (56a-56d) is effective to distinguish a genuine key actuation from simulated key actuations. The invention prevents the ascertainment of actuated keys by unauthorized tapping connections applied to the keyboard unit (12) or the cable (14).

Abstract: A semiconductor memory controller chip associated with a remote DMA device, a multispeed microprocessor and a DRAM memory requiring refreshing periodically includes refresh circuits for generating refresh signals for controlling refreshing of the memory during transparent and contention refresh operations. When a conflict occurs between the DMA device requesting access to the memory and the occurrence of a transparent refresh operation, control signals are generated to allow the memory to be refreshed prior to the time the DMA device is given access to the memory, thereby eliminating the need for a contention refresh operation. Control signals are also generated in accordance with the speed of the microprocessor for synchronizing the operation of the microprocessor with the operation of the DMA device.