Abstract: A bar code scanning system for a conveyor system in which a first conveyor and a second conveyor are disposed apart from each other by a small gap region. A light emitting device is positioned in the gap underneath a top surface of the first and second conveyors, and the light emitting device shines light onto bar code labels on a bottom side of objects as the objects traverse from the first conveyor to the second conveyor. A light receiving device is also positioned in the gap, and the light receiving device receives reflected light from the bottom side of the objects due to the light being shined on the objects by the light emitting device. The gap is covered by a glass or plastic plate, so as to allow light to pass substantially therethrough.

Abstract: A bar code scanning system for a conveyor system in which a first conveyor and a second conveyor are disposed apart from each other by a small gap region. A light emitting device is positioned in the gap underneath a top surface of the first and second conveyors, and the light emitting device shines light onto bar code labels on a bottom side of objects as the objects traverse from the first conveyor to the second conveyor. A light receiving device is also positioned in the gap, and the light receiving device receives reflected light from the bottom side of the objects due to the light being shined on the objects by the light emitting device. The gap is covered by a glass or plastic plate, so as to allow light to pass substantially therethrough.

Abstract: Random partial scans of a bar code label are utilized to re-create the entire symbol. The symbol is reconstructed by a re-match operation which places partial scanned data into memory and allows the data to be examined so that it is properly loaded whether data is acquired from scanning either the left or right side of the label first. Re-match allows labels having very small aspect ratios at extreme scanning angles to be readily captured.

Abstract: A system apparatus for altering the depth of field of a lens mechanism for use with a bar code. The altering of the mechanism allows different focal points and increased depths of field to be selected to accommodate different container sizes. The system is also designed to provide a variable threshold which adjusts the receiving circuitry based upon the amplitude of the signal received from the scanned label. Additionally, the system may be operated in a mode which introduces alternate threshold switching for allowing labels of low contrast bar and space elements to be successfully scanned along with elements of high contrast. Incorporated into the apparatus is a technique for adjusting the circuitry when there is a reduction of the power output of the beam generating laser.

Abstract: An optical code reader employs a flying spot scanner which traces a plurality of forward scan patterns wherein each is off-set from one another, and a plurality of reverse scans wherein each is off-set from one another and the generation of each forward scan is followed by the generation of a reverse scan. Furthermore, the forward and reverse scans are randomly positioned with respect to one another and other reverse and forward scans.