Abstract: A package sorting and/or tracking system or workstation including a high performance data reader or barcode scanner, a real time system control computer, user interface devices, a superstructure to which all hardware is attached providing hands-free scanning operation at each work station, and a real-time communication link with the host computer system for transferring information scanned from the parcels or configuring the scanning system with up-to-the minute routing information. A scale system weighs each parcel to assure compliance to specifications. An optional feedback system to error-proof the sorting operation whereby the scanning system is configured with a sensing device on each of the bins to which a parcel may be sorted. Based on the tracking information read from the barcode label and the routing information provided by the host computer system, the scanning system instructs the operator to place the parcel in a particular bin.

Abstract: A method of and system for generating multiple parallel scan lines, for a thin, narrow height scanner by generating a reading beam, using a suitable scanning mechanism to scan or dither the reading beam, directing the scanned beam onto an optical element, controlling the system such that the beam is alternately transmitted or reflected by the optical element, and directing multiple scan lines into the scan volume. When the optical element is reflective, a scan line is produced directly off the optical element; when the optical element is transmissive, a scan line passes through the optical element and is reflected by a fold mirror and into the scan volume.

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 diffractive collector for an optical scanner includes a wedged-shaped substrate having holographic grating provided on a front surface, a conical-shaped back surface, and at least one detector. Substantially parallel light is made incident upon the front surface of the substrate, and the light is diffracted within the substrate to the back surface. The wedged shaped of the collector and the holographic grating cause the light to reflect back within the substrate at such an angle that the light remains within the substrate as the light propagates to the at least one detector.

Abstract: A scan module and an optical system such as for a bar code scanner wherein the optical system has an axis of outgoing (illumination) light offset from the axis of collected light, arranged to limit the dynamic range of the collected light and thus the dynamic range within which the bar code scanner detector and signal processor must function. Preferably, the outgoing axis and the collection lens axis are substantially parallel.

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.

Abstract: A scanner including a plastic focusing lens and thermal compensation element, integrally formed with the asphere or comprising a separate element, to replace the existing glass laser diode focusing lens. The combined optical system is thereby configured to provide overall temperature compensation for the system with reduced cost and improved performance.

Abstract: A scanning system and method of data reading in which the scanning system is provided with a more rugged scanning mechanism which is "parked" or otherwise locked in position, moved to a protected mechanically position, or into a secured condition thereby protecting more delicate scanning components, such as flexures, from damage due to external mechanical shock.

Abstract: A method and apparatus for improving the accuracy of bar and space measurements in a barcode scanner system utilizing second derivative signal processing is provided wherein edges are more accurately detected under low signal-to-noise conditions, such as when shot noise is the major source of noise in an input signal and the larger noise levels present during the light portions of the input signal may cause premature triggering of a light-to-dark transition in the output signal. In a preferred embodiment, an input capture circuit captures and stores the time of successive assertions of an STV signal corresponding to light-to-dark transitions. Upon detection by a second input capture circuit of a first assertion, following the STV assertions, of an RTV signal corresponding to dark-to-light transitions, the last STV signal time is stored and used with a previously stored RTV time to determine a space width. The new RTV signal time and the last STV signal time are then used to determine a bar width.

Abstract: A scanning system and method of data reading in which the scanning system is provided with a mounting mechanism having the ability to flex and/or rotate when subjected to external mechanical shock for reducing shock experienced by the more delicate scanning components.

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 positioning a dither spring in a mold fixture, closing a mold over both a free end of the dither spring and a fixed end of the dither spring, placing the mold in an injection molding machine, injecting plastic material into the mold and forming a base mount on the fixed end of the dither spring and a mirror mount on the free end to form the spring assembly, allowing the spring assembly to cool, and removing the spring assembly from the mold.

Abstract: An electronic edge detection system for use in a barcode scanning system utilizing second derivative signal processing wherein the temporal offset between the first and second derivative signals is eliminated so as to enable edge detection for signal levels down to the noise level of an input signal. In a preferred embodiment, an overall filter network receives an input signal and comprises two real poles as the last elements of two parallel output channels. The first output channel terminates with a low pass filter and produces the first derivative of the input signal. The second output channel terminates with a high pass filter and produces the second derivative of the input signal. Implementing the second differentiator as one real pole of the overall edge detection system filter polynomial and placing the poles of the two output filters at the same frequency eliminates the temporal offset.

Abstract: An object recognition system comprises a sensing apparatus for collecting light reflected from objects presented at a point-of-sale machine. The sensing apparatus includes a mechanism, such as a holographic disk or diffraction grating, for separating the color components of the light reflected from the object and directing, the color components onto an optical detector such as a two-dimensional imaging array, or a one-dimensional imaging array or single photo-sensitive optical cell used in conjunction with a rotating mirror. A pattern recognizer compares the spectral response, including the locations, amplitudes and widths of energy peaks of the different color components, against premeasured characteristics of known objects in order to classify the object. The weight of the object can be measured with a scale, and the density of the object calculated, with the weight and density being used by the pattern recognizer to further classify the object.

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: A data reading system and method which renders the return signal strength of light reaching the detector more uniform over greater distances and/or positions relative to the collection system and including an optical correction module or corrective optical element(s) is placed in the light collection path to the detector whereby the characteristics of light coming from sources in different locations and/or distances relative to the collection lens may be changed. In one embodiment, an optical element such as a diffusion element or aperture is placed between a collection lens and the detector such that the amount of collected light from a far field target reaching the detector is maximized and the amount of collected light from a near field target reaching the detector is selectively inhibited rendering the total light intensity on the detector more uniform as between the far field signal and the near field signal.

Abstract: A package sorting and/or tracking system or workstation including a high performance data reader or barcode scanner, a real time system control computer, user interface devices, a superstructure to which all hardware is attached providing hands-free scanning operation at each work station, and a real-time communication link with the host computer system for transferring information scanned from the parcels or configuring the scanning system with up-to-the minute routing information. A scale system weighs each parcel to assure compliance to specifications. An optional feedback system to error-proof the sorting operation whereby the scanning system is configured with a sensing device on each of the bins to which a parcel may be sorted. Based on the tracking information read from the barcode label and the routing information provided by the host computer system, the scanning system instructs the operator to place the parcel in a particular bin.

Abstract: A method and apparatus for improving the accuracy of bar and space measurements in a barcode scanner system utilizing second derivative signal processing is provided wherein edges are more accurately detected under low signal-to-noise conditions, such as when shot noise is the major source of noise in an input signal and the larger noise levels present during the light portions of the input signal may cause premature triggering of a light-to-dark transition in the output signal. In a preferred embodiment, an input capture circuit captures and stores the time of successive assertions of an STV signal corresponding to light-to-dark transitions. Upon detection by a second input capture circuit of a first assertion, following the STV assertions, of an RTV signal corresponding to dark-to-light transitions, the last STV signal time is stored and used with a previously stored RTV time to determine a space width. The new RTV signal time and the last STV signal time are then used to determine a bar width.

Abstract: A scanner with multiple modes of operation producing two or more distinct scan patterns, with each scan pattern optimized for different modes of operation with a manually actuated switching mechanism whereby the operator may readily select a desired scan pattern. The switching mechanism may operate by mechanically moving one set of scan pattern generating optics out of the optical path of the scanner and/or moving another set of scan pattern generating optics into the optical path. Alternatively, the different sets of scan pattern generating optics may remain stationary while the optical path of the scanner is moved. In either case the operator may choose from among two or more distinct scan patterns the scan pattern most appropriate to the scanning application at hand.