Abstract: Techniques for using imaging information computed from examining a scanner signal are described. When one or more objects passes within a field of view of a scanner, scan patterns emerging from one or more scanner windows and reflected from the objects back into the scanner windows produce one or more scanner signals. The scanner signals are processed to obtain beam position and beam length information to improve the accuracy of bar code decoding and to compute imaging information for objects within the field of view of the scanner. The imaging information for the objects is compared with bar code information for the objects. The expected number, size and shapes of objects indicated by the bar code information is compared with the actual number, size and shapes of objects in order to determine if valid scans occurred or if missed, double or otherwise erroneous scans occurred.

Abstract: An optical scanner having enhanced item side coverage which scans all six sides of an item and an intermediate side. The optical scanner includes a scanner housing, a first optics assembly within the scanner housing including a horizontal aperture, and a second optics assembly including a second housing within the scanner housing including a substantially vertical aperture. The first and second optics assemblies are capable of scanning six sides of an item. At least one of the first and second optics assemblies additionally generates third scan lines for scanning an intermediate side of the item.

Abstract: Techniques for using imaging information computed from examining a scanner signal are described. When one or more objects passes within a field of view of a scanner, scan patterns emerging from one or more scanner windows and reflected from the objects back into the scanner windows produce one or more scanner signals. The scanner signals are processed to obtain beam position and beam length information to improve the accuracy of bar code decoding and to compute imaging information for objects within the field of view of the scanner. The imaging information for the objects is compared with bar code information for the objects. The expected number, size and shapes of objects indicated by the bar code information is compared with the actual number, size and shapes of objects in order to determine if valid scans occurred or if missed, double or otherwise erroneous scans occurred.

Abstract: Techniques for using imaging information computed from examining a scanner signal are described. When one or more objects passes within a field of view of a scanner, scan patterns emerging from one or more scanner windows and reflected from the objects back into the scanner windows produce one or more scanner signals. The scanner signals are processed to obtain beam position and beam length information to improve the accuracy of bar code decoding and to compute imaging information for objects within the field of view of the scanner. The imaging information for the objects is compared with bar code information for the objects. The expected number, size and shapes of objects indicated by the bar code information is compared with the actual number, size and shapes of objects in order to determine if valid scans occurred or if missed, double or otherwise erroneous scans occurred.

Abstract: A timing and mirror position detector for use in a bar code scanner having a rotating optical assembly. The optical assembly is rotated by a motor which produces a fixed number of pulses per rotation, at least one of the pulses occurring each time the motor passes through a reference position as it rotates. The pulses are continuously monitored and counted. Elapsed time from the time a reference pulse occurs is accurately measured and correlated by a processor with events of interest. When an event of interest, such as a bar code scan, occurs, the timing and pulse count are evaluated and processed to determine the angle of rotation of the motor at the time the scan occurred.

Abstract: A dual aperture optical scanner which employs a single laser beam to produce horizontal and vertical scan patterns. The optical scanner includes a housing having first and second apertures, a laser beam source, a mirrored spinner having a plurality of facets with different elevation angles for reflecting the laser beam in a plurality of directions, and a plurality of pattern mirrors within the housing for reflecting the laser beam from the spinner through the first and second apertures to an article having a bar code label to be scanned. The optical scanner also includes an optical transceiver for passing the laser beam and for collecting reflected light from the scanned article and a photodetector for generating signals representing the intensity of the light reflected from the article.

Abstract: A dual channel video data recovery system for use in a bar code scanner. A first and a second video signal are generated in parallel in response to light reflected from a bar code. The first and second video signals are received and filtered to limit their frequency ranges and produce filtered first and second video signals. The first and second filtered video signals are limited to different and preferably coverlapping frequency ranges. The first and second video signals have differing thresholds which may be dynamically varied. The first and second filtered video signals are converted to first and second digital data strings. If both strings contain useful data, the string containing the higher-quality data is decoded to recover bar code information. If only one string contains useful data, the string containing useful data is decoded.

Abstract: A timing and mirror position detector for use in a bar code scanner having a rotating optical assembly. The optical assembly is rotated by a motor which produces a fixed number of pulses per rotation, at least one of the pulses occurring each time the motor passes through a reference position as it rotates. The pulses are continuously monitored and counted. Elapsed time from the time a reference pulse occurs is accurately measured and correlated by a processor with events of interest. When an event of interest, such as a bar code scan, occurs, the timing and pulse count are evaluated and processed to determine the angle of rotation of the motor at the time the scan occurred.

Abstract: A timing and mirror position detector for use in a bar code scanner having a rotating optical assembly is rotated by a motor which produces a fixed number of pulses per rotation, at least one of the pulses occurring each time the motor passes through a reference position as it rotates. The pulses are continously monitored and counted. Elapsed time from the time a reference pulse occurs in accurately measured and correlated by a processor with events of interest. When an event of interest, such as a bar code scan, occurs, the timing and pulse count are evaluated and processed to determine the angle of rotation of the motor at the time the scan occurred.

Abstract: A system for synchronization of the angular position of a rotating optical assembly in a bar code scanner having a rotating optical assembly. The optical assembly is rotated by a motor which produces a fixed number of pulses per rotation, the pulses occurring at equal intervals such that each pulse indicates a degree of angular rotation of the motor. The pulses are continuously monitored and counted. Timing is simultaneously monitored. A synchronization label is placed in the scanner such that light directed through the rotating optical assembly will strike the synchronization label and be reflected back to the rotating optical assembly when the rotating optical assembly is at a particular angular position, thus establishing an initial angular position of the rotating optical assembly. Once the initial angular position is established, timing is continuously monitored and pulses are continuously monitored and counted.

Abstract: A scanner includes a laser for projecting a laser beam at a facet having a blazed diffractive grating thereon. The facet is rotated relative to the laser to traverse the laser beam across the grating to diffract the laser beam into a scan line. The blazed diffractive grating may be readily manufactured using injection molding or photolithograhic manufacturing techniques.

Abstract: A system for synchronization of the angular position of a rotating optical assembly in a bar code scanner having a rotating optical assembly. The optical assembly is rotated by a motor which produces a fixed number of pulses per rotation, the pulses occurring at equal intervals such that each pulse indicates a degree of angular rotation of the motor. The pulses are continuously monitored and counted. Timing is simultaneously monitored. A synchronization label is placed in the scanner such that light directed through the rotating optical assembly will strike the synchronization label and be reflected back to the rotating optical assembly when the rotating optical assembly is at a particular angular position, thus establishing an initial angular position of the rotating optical assembly. Once the initial angular position is established, timing is continuously monitored and pulses are continuously monitored and counted.

Abstract: A dual aperture optical scanner which employs a single laser beam to produce horizontal and vertical scan patterns. The optical scanner includes a housing having first and second apertures, a laser beam source, a mirrored spinner having a plurality of facets with different elevation angles for reflecting the laser beam in a plurality of directions, and a plurality of pattern mirrors within the housing for reflecting the laser beam from the spinner through the first and second apertures to an article having a bar code label to be scanned. The optical scanner also includes an optical transceiver for passing the laser beam and for collecting reflected light from the scanned article and a photodetector for generating signals representing the intensity of the light reflected from the article.

Abstract: An optical scanner includes a housing having first and second obliquely adjoining windows. Disposed in the housing is a laser for projecting a laser beam against a rotatable spinner having a plurality of mirrored facets for sequentially reflecting the laser beam to effect a scan beam. A plurality of pattern mirrors are optically aligned with the spinner for reflecting the scan beam through the first and second windows to effect a plurality of individual scan lines arranged in first and second patterns corresponding with the first and second windows. The pattern mirrors include a triad set of mirrors optically aligned in series between the spinner and the first window for scanning the first scan pattern to a back edge of the first window for scanning at least the back side of a multisided item.

Abstract: A method and apparatus are disclosed for scanning for a defective bar code having a plurality of alternating bars and spaces of varying widths. A bar code is scanned for providing a bar code signature which is used for measuring the bar and space width as multiples of a minimum width module. By detecting fractional width of adjoining bars and spaces, error in the bar code is correspondingly detected. The measured bar code signature may be corrected by respectively increasing and decreasing the fractional width of an adjoining bar and space for obtaining substantially integer multiple modules thereof. The corrected signature may then be decoded.

Abstract: A dual aperture optical scanner which produces horizontal, vertical, and diagonal scan patterns. The optical scanner includes a housing having a substantially vertical surface containing a first aperture and a substantially horizontal surface containing a second aperture. A laser diode produces a laser beam. A spinner produces first, second, and third groups of scanning beams. A plurality of pattern mirrors reflects the first group of scanning beams in a substantially horizontal direction through the first aperture, the second group of scanning beams in a substantially downward diagonal direction through the first aperture, and the third group of scanning beams in a substantially vertical direction through the second aperture.

Abstract: A dual aperture optical scanner which employs a single laser beam to produce horizontal and vertical scan patterns. The optical scanner includes a housing having first and second apertures, a laser beam source, a mirrored spinner having a plurality of facets with different elevation angles for reflecting the laser beam in a plurality of directions, and a plurality of pattern mirrors within the housing for reflecting the laser beam from the spinner through the first and second apertures to an article having a bar code label to be scanned. The optical scanner also includes an optical transceiver for passing the laser beam and for collecting reflected light from the scanned article and a photodetector for generating signals representing the intensity of the light reflected from the article.

Abstract: There are disclosed a system and method for decoding data read from a plurality of different types of bar code labels which includes circuit means for detecting the occurrence of two equal continuous characters in the data generated by an optical scanner in reading a bar code label and a filter for each of the different bar code labels receiving simultaneously the two equal characters for decoding the character data and inserting locating bits in the data delimiting a valid character in the data.

Abstract: A dual aperture optical scanner which employs a single laser beam to produce horizontal and vertical scan patterns. The optical scanner includes a housing having first and second apertures, a laser beam source, a mirrored spinner having a plurality of facets with different elevation angles for reflecting the laser beam in a plurality of directions, and a plurality of pattern mirrors within the housing for reflecting the laser beam from the spinner through the first and second apertures to an article having a bar code label to be scanned. The optical scanner also includes an optical transceiver for passing the laser beam and for collecting reflected light from the scanned article and a photodetector for generating signals representing the intensity of the light reflected from the article.

Abstract: A dual aperture optical scanner which produces horizontal, vertical, and diagonal scan patterns. The optical scanner includes a housing having a substantially vertical surface containing a first aperture and a substantially horizontal surface containing a second aperture. A laser diode produces a laser beam. A spinner produces first, second, and third groups of scanning beams. A plurality of pattern mirrors reflects the first group of scanning beams in a substantially horizontal direction through the first aperture, the second group of scanning beams in a substantially downward diagonal direction through the first aperture, and the third group of scanning beams in a substantially vertical direction through the second aperture.