Abstract: A multi-function optical reader comprises an photosensor, such as a charge-device (CCD), and signal conditioning and processing circuitry including separate channels for handling data in different formats. A bar code processing channel digitizes the scan signal according to light and dark features using a first-derivative technique, and an OMR processing channel uses an adaptive threshold to adapt to different light conditions and provide a boundary line for digitizing light and dark features of the target scan line. A feature measurement circuit measures the widths of the light and dark regions as derived by the separate processing channels, and provides the feature measurements to a decoding system or host terminal processor. The scan rate of the optical reader can be adjusted according to the data format to be read or the level of ambient light, to avoid saturation. The optical reader can provide multiple depth-of-field zones, both internal and external to an optical reader housing.

Abstract: A system and method for improving the accuracy of edge detection under high Inter-Symbol Interference, or ISI, conditions is disclosed. The amplified and filtered first derivative signal is offset by equal amounts in both directions to generate positive and negative offsets which serve as inputs to negative and positive peak detectors, respectively. The offset is determined by a fast adaptive peak detector provided by attenuating and AC-coupling the first derivative signal to the positive supply to drive a peak detector with a fairly short attack time, such that its output is nearly settled on the first peak of the first derivative signal, but having a decay time long enough to keep the threshold level approximately constant across the label. Peaks are qualified if the peak in question differs in amplitude from the previously qualified peak by the offset amount.

Abstract: An optical code reader for reading optical codes in any orientation with a preferred depth of field (DOF), the optical code reader including imaging sensor arrays arranged at angles to one another and tilted in accordance with the Scheimpflug principle to allow for omni-directional reading and a preferred DOF. In addition, an optical code reader may also include an optical device to rotate an image as it is projected upon a stationary tilted image sensor array. Still further, an optical code reader may include a rotating imaging sensor array tilted in accordance with the Scheimpflug principle to allow for omni-directional reading with a preferred DOF.

Abstract: In a bar code scanning system, information at the leading and trailing ends of a label is corrected to adjust for distortion due to mechanical aspects of the scan line mechanism that might otherwise render information unreadable. The speed of the scanning spot can be characterized over the course of the scan line. With knowledge of the rate of change of the scan mechanism speed at the ends of the scan line, as well as position information in relation to change in speed over the scan line, a measure of the associated time distortion with respect to elements encoded in the scan line information may be established. In turn, a compensation curve may be determined to identify the offset that may be applied to the collected data to compensate for the variation in speed.

Abstract: A system for and a method of optical scanning which provide for focusing a light beam using one or more flex circuits, each flex circuit containing an aperture that is moved into or out of the outgoing optical path of a light beam via an electromagnetic mechanism. The electromagnetic mechanism includes a moving coil or moving magnet attached to each flex circuit for positioning the flex circuit aperture in or out of the outgoing optical path when the electromagnetic mechanism is actuated by an electric current. By positioning a greater or lesser number of apertures in the outgoing optical path, the final aperture size may be modified, thereby adjusting the focal location and depth of field of the light beam. Accordingly, the scanning system provides improved focusing characteristics, as well as an increased read range.

Abstract: Systems (apparatus and methods) for reading bar code data detect light reflected and/or refracted from a target. The detected light is converted into an electrical signal containing width values that are indicative of widths of light areas and dark areas of the target. Systems for pre-screening data read by a bar code reader determine whether sequences of width values are consistent with potential bar code data by comparing the relative widths of subsequences of light areas and dark areas. If the relative widths are consistent with bar code data, the width values of the sequence being pre-screened are output to a decoder, which attempts to read the sequence of width values. If the relative width values are inconsistent with bar code data, the sequence of width values is not output to the decoder, thereby decreasing the amount of processing the decoder would otherwise be required to perform.

Abstract: An improved, rotatably articuable scanner for reading and decoding bar codes in connection with the sale of retail articles is disclosed. An ultra-compact, lightweight, low-cost, self-contained, visible laser diode (VLD) bar code scanner is provided with a great range of functionality and versatility. A scan head housing an optical subsystem is rotatably connected with a tower housing. The heat-generating electronic components are located in the tower housing away from heat-sensitive optical components located in the scan head. The scanner presents an extremely small footprint, and provides for its mounting in virtually any orientation and location. The optical subsystem uses a basket-type mirror array configured around a rotating planar folding mirror, driven by a compact cup (brushed) DC motor. The scanner features a short optical beam path.

Abstract: In a bar code scanning system, correlation and stitching techniques, both at the character and element level are utilized to assemble complete label information from partially scanned label segments. Correlation may require the same characters to be identified a fixed number of times in the same position before acceptance. Alternatively, quality and confidence measures may be implemented to determine the number of times a particular character must be decoded before being accepted. In a preferred implementation, a decoded character that is determined to be of poor quality may be required to be decoded as that same character a greater number of times than if it were of good quality. Identified correlation techniques may be combined with identified stitching techniques to enhance decodability and efficiency of assembling complete label information.

Abstract: An interface selection and configuration system for a computer peripheral in which configuration for the peripheral and/or the host interface is at least in part accomplished by the interface connector cable. In a preferred embodiment, the computer peripheral is equipped with one or more hardware interfaces. The interface connector cable has a first end connector for attaching to the computer peripheral. The first end connector of the interface connector cable is typically a multiple pin connector constructed and arranged to be properly physically and electrically connectable only to a specific computer peripheral or class of computer peripherals, the first end connector including at least one electrical connection between two pins for completing a circuit within the computer peripheral thereby enabling the computer peripheral.

Abstract: A multiple window data reading device and method for reading symbols such as bar codes through each window, including sensing conditions from each window and adjusting optical parameters for controlling data reading control through each of the windows.

Abstract: A self-checkout system for a retail establishment that allows a customer to checkout multiple items having respective identification codes, the system includes a computer having memory with a buffer, an identification code reader coupled to the computer for determining the identifications of the items by the identification codes, a security verification mechanism coupled to the computer for verifying that the items actually being checked out from the retail establishment are the same as those identified by the identification code reader, and whereby the computer is adapted to store identification information of multiple items obtained by the identification code reader in the buffer before verifying that the items actually being checked out from the retail establishment are the same as those identified by the identification code reader.

Abstract: A multiple technology data reader, for reading bar code labels and RFID tags. The multiple technology data reader includes a bar code reader and a radio frequency identification (RFID) reader, connected to a host computer via a computer bus, such as a universal serial bus (USB). The bar code reader and the RFID reader communicate with the host computer through logically independent data pipes and device drivers. Compound, composite, or complex interface implementations are possible. A single electronic interface may be configured to allow a single host computer to logically communicate with the bar code and RFID readers as either separate independent readers, or as a single cooperative multiformat label/tag data reader. Thus, the bar code and RFID readers may be operated independently, or powered and operated simultaneously.

Abstract: A handheld data reader includes a head portion and an attachment device mounted to the head portion for suspending the scanner from an overhead retractor or the like such that the scanner is oriented substantially vertically with its handle directed substantially downward. The attachment device includes an arcuate member that may be configured to pivot away from the head portion. The attachment device may be recessed in the head portion such that the arcuate member is substantially coplanar with the adjacent outer surfaces of the head portion.

Abstract: A scanner or other data reader is equipped with means for determining characteristics of an operator's scanning technique. In a preferred configuration, the scanner is integrated with a weigh scale for obtaining a dynamic weight of an item as the item is moved across the weigh scale. Weight data produced by the scanning/weighing process includes information about the amount of lifting the operator performs on scanned items, the rate of scanning by the operator, and rescanning information. The scanner may be connected to a PC-based training system which uses the scanning technique information to provide feedback to the operator indicating the effectiveness of the operator's scanning technique, and may also provide information to management for analysis. The technique information may be collected by a store controller or other suitable collection device for later analysis and reporting.

Abstract: A scan assembly and method of manufacture in which the dither mechanism comprises a co-molded dither spring, dither mount and mirror mount. The method comprises co-molding a living hinge with a base mount on the fixed end of the living hinge and a mirror mount on the free end of the living hinge. The living hinge may be molded out of the same plastic material as the base mount and mirror mount, or the living hinge may be molded out of a more pliable plastic.

Abstract: A method and apparatus for detecting an object within the field of view of an optical reader, such as bar code scanner. Object detection is determined by a software algorithm that may be embedded in a controller or microprocessor contained within the scanner. The object detection software algorithm uses a current trigger threshold to determine whether there is a change in the amount of reflected light energy sufficient to indicate the presence of motion in the scanner field of view. The system may normalize random noise within a scanner's circuitry and accommodate varying degrees of reflectivity of target materials, without requiring additional circuitry or reflective tape to accurately detect an object.

Abstract: A method and apparatus for determining the transitions between binary levels of an input signal such as a scanned bar code label by detecting zero crossings of an approximated second derivative of the input signal. Samples of the input signal are obtained by using delay lines, sample-and-hold circuits, an analog shift register or similar device. The first derivative of the signal is approximated by the slope of a straight line between two sampled points on the waveform. The second derivative is approximated by the difference between two first derivatives. Zero crossings of the second derivative indicating transitions of the input signal may be determined either by detecting a signal peak on both sides of the zero crossing, or by comparing the second derivative signal to zero when the first derivative exceeds a positive or negative threshold. The amount of shift in the zero crossings may be estimated by measuring relative amplitudes or widths of the surrounding signal lobes.

Abstract: A system for and a method of optical scanning which provide for converting between a multiple beam and a single beam optical scanner. In a preferred configuration, the scanner can be adapted to operate as either a single beam scanning system or a multiple beam scanning system. Light sources, mirrors, detectors, collection lenses, and other scanner components are added, removed, and/or replaced, thereby allowing the user to avoid having to purchase a new scanner when the user's performance requirements and/or cost restrictions vary.

Abstract: A compact scan module including a resonantly driven dithering assembly employing feedback and/or travel stops for scanning an illumination beam of a barcode scanner. In one construction the dithering assembly includes one or more travel stops to limit the motion of the mirror assembly with the two travel stop(s) fabricated from damped resilient material to absorb excess energy imparted on the dithering assembly. A first preferred feedback embodiment employs a Hall effect sensor wherein a feedback magnet is connected to the dithering assembly with a Hall effect sensor positioned to sense the varying magnetic field resulting from the varying position of the feedback magnet. A second feedback embodiment incorporates piezoelectric feedback wherein one or more piezoelectric strain sensors are attached to the bending member to provide the position sensing.