Abstract: A system for reading indicia such as bar code symbols having a scanner for generating a scanning light beam directed toward a symbol to be read; a first actuator manually displaceable from a first position to a second position for producing a first light beam for aiming or positioning the reader, and a second actuator manually displaceable from a first position to a second position for initiating a scanning beam pattern for reading the symbol. The actuators are independently operative of each other. A detector receives the reflected light from the symbol and produces electrical signals corresponding to data represented by the symbol. A graphical user interface simplifies system control functions.

Abstract: An optical scanner for reading indicia having part of differing light reflectivity, including an optical element and a mounting bracket. The optical element is mounted for oscillation with respect to the mounting bracket by first and second wires forming a first spring having a relatively high modulus of elasticity, the optical element having a relatively low inertia when oscillating by elastic movement of the first spring. A stationary frame is provided with the mounting bracket mounted for oscillation with respect to the frame by third and fourth wires having a relatively high modulus of elasticity; the optical element, mounting bracket and first and second wires taken together having a relatively high inertia when oscillating by elastic movement of the third and fourth wires. The optical element is oscillated with respect to the mounting bracket at a relatively high frequency, and the mounting bracket oscillated with respect to the frame at a relatively low frequency by an electromagnetic drive.

Abstract: A self-check apparatus is provided for processing a sales transaction of an article having an attached surveillance tag, each attached surveillance tag bearing a coded indicia such as a bar code. The self-checkout apparatus stores an indication of the articles which have been selected for purchase. When the surveillance tag is presented to the apparatus for deactivation, the bar code on the tag is scanned, and a check is made to verify that the surveillance tag is attached to an article which has been selected for purchase, and provided such verification is made, the surveillance tag is deactivated.

Abstract: In a bar code reader, a field of view which includes a symbol to be read is imaged upon a light-responsive array such as a CCD imager device. The output of this array is transferred to a memory array to provide a bit-mapped type of binary representation of the image including the symbol. The memory is scanned (instead of the field of view itself being mechanically scanned) to recognize and decode the symbol. Because the angular orientation of the symbol is variable, this binary representation may be interpreted to determine how the memory array is to be scanned to recognize the bar code symbol. For example, the distinctive patterns of characters used in bar codes may be found by scanning the memory and the relative positions of these patterns interpreted to determine the position, size and shape of the symbol in the memory, thereby defining at what angular displacement the memory array need be addressed to traverse the rows of the bar code symbol.

Abstract: An optical scanning module has a metal base, a first circuit board mounted across one end of the metal base and a second circuit board mounted orthogonal to the first circuit board. The metal base supports a light emitter for producing a scanning beam and serves as a heat sink for the emitter. A flexible support attached to the metal base supports a mirror for oscillating motion. The module includes a drive mechanism, typically in the form of a permanent magnet and electromagnet, for producing reciprocal motion of the mirror. A detector included in the module senses light reflected from an indicia scanned by the beam. A flexible electrical cable connects the circuitry on the first and second circuit boards so that circuitry operates together to produce all signals necessary for operation of the scanner module and to process the electrical signals from the detector. Preferred embodiments include a flexible support consisting of a planar spring located between the mirror and one of the magnets.

Abstract: A portable laser diode scanning head, aimable at each symbol to be read, emits and receives non-readily-visible laser light, and is equipped with a trigger-actuated aiming light arrangement for visually locating and tracking each symbol. A compact laser diode optical train and an optical folded path assembly, as well as an interchangeable component design and an integral window construction for the head also are disclosed. An embodiment that employs a stationary folding mirror mounted in fixed stationary relationship with a curved collecting mirror and a lightweight, movable scanning mirror is disclosed.

Abstract: A scanning arrangement contained in a scanning device which is operative for repetitively scanning indicia having parts of different light reflectivity; for instance, such as a bar code symbol through the intermediary of a scanning light or laser beam projected by the scanning arrangement in the form of a scan line which traverses the indicia at high scanning speeds in order to enable the reading of the information contained therein.

Abstract: In bar code symbol scanning systems employing laser, optical and sensor components, a mirrorless scanner arrangement mounts the laser diode and optical element components on a drive for repetitive reciprocating movement relative to a stationary photodetector component to effect scanning.

Abstract: A louver is mounted adjacent a sensor in a housing of a laser scanning head of a system for electro-optically reading bar code symbols. The louver includes a plurality of mutually parallel, permanently-open slots. The slats are inclined to allow more light from far-out symbols to reach the sensor as compared to close-in symbols.

Abstract: A circuit for digitizing an analog signal generated from a photoelectric conversion of reflected light when scanning indicia having spatially-separated, light-reflective portions bounded by edges includes a differentiator for differentiating the analog signal to generate a first derivative signal of the analog signal. An inverter inverts the first derivative signal to generate an inverted signal and a peak detector detects amplitude peaks of the first derivative signal and the inverted signal and generates a first peak signal corresponding to the first derivative signal and a second peak signal corresponding to the inverted signal. An adder sums the first peak signal and the first derivative signal to generate a first sum signal. The adder also sums the second peak signal and the inverted signal to generate a second sum signal.

Abstract: High speed scanning arrangements in scanners for reading bar code symbols by oscillating a scanner component in single or multi-axis scan patterns.

Abstract: In a system for electro-optically reading coded indicia, such as bar code symbols, a light sensor in a scanning head generates higher amplitude electrical signals for symbols closer to the head, and lower amplitude electrical signals for symbols further from the head. To decrease this amplitude variation, and thereby increase the depth of the field of the system, various optical elements such as a lens, a louver, a filter and a shade, are proposed.

Abstract: A scanner module for use in a bar code reader has a scanning mirror which is mounted to a bracket by way of leaf-spring, allowing the mirror to oscillate in one direction. The bracket is hung from a stationary chassis by means of two strips of mylar film, allowing the entire bracket to oscillate in the perpendicular direction, thereby providing two dimensional oscillation of the mirror and raster scanning of a light beam reflected from the mirror. The mylar sheets are protected against mechanical shock by pins which pass through holes in the bracket. The pins are slightly smaller than the holes, allowing sufficient clearance for movement of the bracket during normal operation, but preventing too much stress being placed upon the mylar films if the module is dropped. The pins also provide accurate alignment of the bracket with respect to the chassis.

Abstract: A system for reading indicia having parts of different light reflectivity, includes a light emitter and optical detector supported by a ring to be worn on a finger of a user. The light emitter generates a scanning light beam which scans the indicia and produces reflected light of variable intensity reflected from the indicia. The optical detector detects the reflected light and produces an electrical signal indicative of the reflected light intensity. The ring is worn in a position such that a light beam emitted by the light emitter is directed away from the user.

Abstract: A method and apparatus for increasing the information density of a bar code symbol by generating multiple constituent bar code symbols, wherein each one is formed in a different color selected from a group of various primary colors, and overlaying each differently colored symbol on top of each other, thus forming an aggregate bar code symbol of various colors. In areas where the differently colored bars overlap each other, colors distinct from those in the original group of colors are formed. The aggregate bar code symbol is scanned by a solid state imaging device, and the scanned image is resolved by image processing techniques into the three constituent bar code symbols of the various colors. Each bar code symbol is then individually processed and decoded in accordance with the particular symbology used to encode the constituent bar code symbols.

Abstract: A system for scanning a symbol that has a plurality of modes including a learning mode and an adaptive mode. When the scanner is in a learning mode, a plurality of scans are generated using a plurality of sets of operating parameters. A decoder decodes the plurality of scans generated by the scanner. A data collector collects readability data indicating whether the generated scan decodes successfully or unsuccessfully for each of the sets of operating parameters. A processor determines whether the readability data is acceptable for each of the sets of operating parameters. An optimal set of operating parameters is selected from the acceptable sets of operating parameters. The optimal set of operating parameters is stored along with data identifying the symbol so that the optimal set of operating parameters may be recalled for use in scanning symbols of a similar type or in a similar environment.

Abstract: A handheld data entry terminal includes a housing and a scanning head mounted to the housing for pivotal movement between at least first and second reading positions. The scanning head, when actuated, optically scans an encoded symbol and detects light reflected from the encoded symbol while in either of the first and second reading positions. As desired, a terminal user can establish either one of first and second trigger switches mounted to the housing as a scanning head actuating switch, leaving the other of the trigger switches to be established as a shift key for determining the type of characters entered by alphanumeric data entry keys of a keypad also mounted to the housing in conjunction with an LCD display.

Abstract: A scanner determines whether a target is a bar code symbol and, if so, whether that symbol is one-dimensional or two-dimensional. For two-dimensional symbols, the scanner aligns a scanning pattern with the symbol and expands the scanning pattern to reach only to the top and bottom edges of the symbol, not beyond. The scanner also has a microprocessor-control scanning engine that uses a coil to drive a scanning element and pick up feed back signals from the scanning element. A pulse-width-modulated regulator also provides fast and efficient operation for driving the coil. The scanning engine can also be designed to generate a pattern that precesses across the target, and a powerful interface to the scanning engine allows decoding and control logic to work efficiently with and independently of the scan engine.

Abstract: A false-transition inhibitor circuit for a bar code reader that produces a detection signal from a scan of a bar code, a first derivative signal related to the first derivative of the detection signal, and a peak signal indicating peaks of the detection signal includes an inhibitor comparator, a latch comparator, and a feedback circuit. The inhibitor comparator compares the first derivative signal to a feedback signal and sets and outputs an inhibition signal in a blocking state when the first derivative signal bears a first relationship to the feedback signal. The latch comparator prevents the transmission of the peak signal when the inhibition signal is in the blocking state. The feedback circuit samples the inhibition signal and the output of the latch comparator and to produce the feedback signal.

Abstract: A holographic grating element is provided which enables tracing different scan lines. The element is divided into a plurality of sectors. A first grating pattern is provided which diffracts a beam in one direction, and a second grating pattern is next to the first and diffracts the scan beam in the reverse direction. Sectors can be produced with different sector sizes to enable scanning at different rates in the reverse direction, or in successive scans in the same direction. Angle relationships are described to produce diffraction patterns for a desired relationship between disc rotation and the angle of the scan line.