Abstract: A diffractive-based laser scanning system that monitors portions of the laser light beams generated by a laser light source (e.g., VLD) employed therein to generate a mode switching signal indicative of a shift in the characteristic wavelength of the laser light beams emitted from the laser light source. In response thereto, a temperature controller selectively heats or cools the laser light source to minimize and avoid such wavelength changes. Mode switching is detected by monitoring a zeroth diffractive order beam produced by a diffractive element of the system. Temperature control of the laser light source is accomplished using active heating elements and passive cooling elements in thermal contact with the laser light source. In addition, temperature control of the laser light source is preferably accomplished over a heating range, whereby temperature within this range is approximated by a look-up table.

Abstract: A bioptical holographic laser scanning system employing a plurality of laser scanning stations about a holographic scanning disc having scanning facets with high and low elevation angle characteristics, as well as positive, negative and zero skew angle characteristics which strategically cooperate with groups of beam folding mirrors having optimized surface geometry characteristics. The system has an ultra-compact construction, ideally suited for space-constrained retail scanning environments, and generate a 3-D omnidirectional laser scanning pattern between the bottom and side scanning windows during system operation. The laser scanning pattern of the present invention comprises a complex of pairs of quasi-orthogonal laser scanning planes, which include a plurality of substantially-vertical laser scanning planes for reading bar code symbols having bar code elements (i.e.

Abstract: A holographic laser scanner of ultra-compact design capable of reading bar and other types of graphical indicia within a large scanning volume using holographic optical elements and visible laser diodes. The holographic optical elements are arranged on the scanning disc in such a manner so that none of the laser scanning planes generated within the 3-D scanning volume of the system are spatially and temporally coincident with any other laser scanning plane within the 3-D scanning volume. This novel feature of the present invention ensures that there is substantially zero cross-talk at the plurality of photodetectors provided within the system, significantly improving the performance of the system.

Abstract: The improved diffractive-based laser scanning system of the present invention monitors portions of the laser light beams generated by a laser light source (e.g., VLD) employed therein to generate a mode switching signal indicative of a shift in the characteristic wavelength of the laser light beams emitted from the laser light source. In response thereto, a temperature controller selectively heats (or cool) the laser light source to minimize and avoid such wavelength changes, thereby mitigating any potential problems caused by such wavelength changes (for example, unwanted beam distortion and signal processing errors as described above). Preferably, mode switching (e.g., change in characteristic wavelength of light emitted from the laser light source) is detected by monitoring a zeroth diffractive order beam produced by a diffractive element of the system. Moreover, temperature control of the laser light source is preferably accomplished using active heating elements (e.g.

Abstract: A holographic laser scanner of ultra-compact design capable of reading bar and other types of graphical indicia within a large scanning volume using holographic optical elements and visible laser diodes. The holographic optical elements are arranged on the scanning disc in such a manner so that none of the laser scanning planes generated within the 3-D scanning volume of the system are spatially and temporally coincident with any other laser scanning plane within the 3-D scanning volume. This novel feature of the present invention ensures that there is substantially zero cross-talk at the plurality of photodetectors provided within the system, significantly improving the performance of the system.

Abstract: A diffractive-based laser scanning system of the present invention monitors portions of the laser light beams generated by a laser light source (e.g., VLD) employed therein to generate a mode switching signal indicative of a shift in the characteristic wavelength of the laser light beams emitted from the laser light source. In response thereto, a temperature controller selectively heats (or cool) the laser light source to minimize and avoid such wavelength changes, thereby mitigating any potential problems caused by such wavelength changes. Preferably, mode switching (e.g., change in characteristic wavelength of light emitted from the laser light source) is detected by monitoring a zeroth diffractive order beam produced by a diffractive element of the system. Moreover, temperature control of the laser light source is preferably accomplished using active heating elements (e.g., a heating resistor) and passive cooling elements (e.g., a heat sink) in thermal contact with the laser light source.

Abstract: The effects of paper/substrate noise are significantly reduced in multi-focal zone laser scanning systems by processing analog scan data signals with a scan data signal processor having a plurality of pass-band filters and amplifiers that are automatically selected for passing only the spectral components of an analog scan data signal produced when a bar code symbol is scanned at a particular focal zone in the laser scanning system. Two or more different pass-band filter structures can be provided for use in the scan data signal processor, wherein each pass-band filter structure is tuned to the spectral band associated with a particular focal zone in the laser scanning system. When a bar code symbol is scanned by a laser beam focused within the first focal zone or scanning range of the system, the pass-band filter structure associated with this focal zone or scanning range is automatically switched into operation.

Abstract: A bioptical holographic laser scanning system employing a plurality of laser scanning stations about a holographic scanning disc having scanning facets with high and low elevation angle characteristics, as well as positive, negative and zero skew angle characteristics which strategically cooperate with groups of beam folding mirrors having optimized surface geometry characteristics. The system has an ultra-compact construction, ideally suited for space-constrained retail scanning environments, and generate a 3-D omnidirectional laser scanning pattern between the bottom and side scanning windows during system operation. The laser scanning pattern of the present invention comprises a complex of pairs of quasi-orthogonal laser scanning planes, which include a plurality of substantially-vertical laser scanning planes for reading bar code symbols having bar code elements (i.e.

Abstract: A holographic laser scanner of ultra-compact design capable of reading bar and other types of graphical indicia within a large scanning volume using holographic optical elements and visible laser diodes. The holographic optical elements are arranged on the scanning disc in such a manner so that none of the laser scanning planes generated within the 3-D scanning volume of the system are spatially and temporally coincident with any other laser scanning plane within the 3-D scanning volume. This novel feature of the present invention ensures that there is substantially zero cross-talk at the plurality of photodetectors provided within the system, significantly improving the performance of the system.

Abstract: A bioptical holographic laser scanning system employing a plurality of laser scanning stations about a holographic scanning disc having scanning facets with high and low elevation angle characteristics, as well as positive, negative and zero skew angle characteristics which strategically cooperate with groups of beam folding mirrors having optimized surface geometry characteristics. The system has an ultra-compact construction, ideally suited for space-constrained retail scanning environments, and generate a 3-D omnidirectional laser scanning pattern between the bottom and side scanning windows during system operation. The laser scanning pattern of the present invention comprises a complex of pairs of quasi-orthogonal laser scanning planes, which include a plurality of substantially-vertical laser scanning planes for reading bar code symbols having bar code elements (i.e.

Abstract: Disclosed is a bioptical laser scanning system that provides 360° of omnidirectional bar code symbol scanning coverage at a point of sale (POS) station. The system generates a 3-D omnidirectional laser scanning pattern between the horizontal and vertical scanning windows during system operation. The laser scanning pattern of the present invention comprises a complex of pairs of quasi-orthogonal laser scanning planes, each composed by a plurality of substantially-vertical laser scanning planes for reading bar code symbols having bar code elements (i.e. ladder-type bar code symbols) that are oriented substantially horizontal with respect to the horizontal scanning window, and a plurality of substantially-horizontal laser scanning planes for reading bar code symbols having bar code elements (i.e. picket-fence type bar code symbols) that are oriented substantially vertical with respect to the horizontal scanning window.

Abstract: A holographic laser scanner of ultra-compact design capable of reading bar and other types of graphical indicia within a large scanning volume using holographic optical elements and visible laser diodes. The holographic optical elements are arranged on the scanning disc in such a manner so that none of the laser scanning planes generated within the 3-D scanning volume of the system are spatially and temporally coincident with any other laser scanning plane within the 3-D scanning volume. This novel feature of the present invention ensures that there is substantially zero cross-talk at the plurality of photodetectors provided within the system, significantly improving the performance of the system.

Abstract: The improved diffractive-based laser scanning system of the present invention monitors portions of the laser light beams generated by a laser light source (e.g., VLD) employed therein to generate a mode switching signal indicative of a shift in the characteristic wavelength of the laser light beams emitted from the laser light source. In response thereto, a temperature controller selectively heats (or cool) the laser light source to minimize and avoid such wavelength changes, thereby mitigating any potential problems caused by such wavelength changes (for example, unwanted beam distortion and signal processing errors as described above). Preferably, mode switching (e.g., change in characteristic wavelength of light emitted from the laser light source) is detected by monitoring a zeroth diffractive order beam produced by a diffractive element of the system. Moreover, temperature control of the laser light source is preferably accomplished using active heating elements (e.g.

Abstract: A holographic laser scanner of ultra-compact design capable of reading bar and other types of graphical indicia within a large scanning volume using holographic optical elements and visable laser diodes. The holographic optical elements are arranged on the scanning disc in such a manner so that none of the laser scanning planes generated within the 3-D scanning volume of the system are spatially and temporally coincident with any other laser scanning plane within the 3-D scanning volume. This novel feature of the present invention ensures that there is substantially zero cross-talk at the plurality of photodetectors provided within the system, significantly improving the performance of the system.

Abstract: A bioptical holographic laser scanning system employing a plurality of laser scanning stations about a holographic scanning disc having scanning facets with high and low elevation angle characteristics, as well as positive, negative and zero skew angle characteristics which strategically cooperate with groups of beam folding mirrors having optimized surface geometry characteristics. The system has an ultra-compact construction, ideally suited for space-constrained retail scanning environments, and generate a 3-D omnidirectional laser scanning pattern between the bottom and side scanning windows during system operation. The laser scanning pattern of the present invention comprises a complex of pairs of quasi-orthogonal laser scanning planes, each composed by a plurality of substantially-vertical laser scanning planes for reading bar code symbols having bar code elements (i.e.

Abstract: A bioptical holographic laser scanning system employing a plurality of laser scanning stations about a holographic scanning disc having scanning facets with high and low elevation angle characteristics, as well as positive, negative and zero skew angle characteristics which strategically cooperate with groups of beam folding mirrors having optimized surface geometry characteristics. The system has an ultra-compact construction, ideally suited for space-constrained retail scanning environments, and, generate a 3-D omnidirectional laser scanning pattern between the bottom and side scanning windows during system operation. The laser scanning pattern of the present invention comprises a complex of pairs of quasi-orthogonal laser scanning planes, each composed by a plurality of substantially-vertical laser scanning planes for reading bar code symbols having bar code elements (i.e.

Abstract: The effects of paper/substrate noise are significantly reduced in multi-focal zone laser scanning systems by processing analog scan data signals with a scan data signal processor having a plurality of pass-band filters and amplifiers that are automatically selected for passing only the spectral components of an analog scan data signal produced when a bar code symbol is scanned at a particular focal zone in the laser scanning system. Two or more different pass-band filter structures can be provided for use in the scan data signal processor, wherein each pass-band filter structure is tuned to the spectral band associated with a particular focal zone in the laser scanning system. When a bar code symbol is scanned by a laser beam focused within the first focal zone or scanning range of the system, the pass-band filter structure associated with this focal zone or scanning range is automatically switched into operation.

Abstract: The improved diffractive-based laser scanning system of the present invention monitors portions of the laser light beams generated by a laser light source (e.g., VLD) employed therein to generate a mode switching signal indicative of a shift in the characteristic wavelength of the laser light beams emitted from the laser light source. In response thereto, a temperature controller selectively heats (or cool) the laser light source to minimize and avoid such wavelength changes, thereby mitigating any potential problems caused by such wavelength changes (for example, unwanted beam distortion and signal processing errors as described above). Preferably, mode switching (e.g., change in characteristic wavelength of light emitted from the laser light source) is detected by monitoring a zeroth diffractive order beam produced by a diffractive element of the system. Moreover, temperature control of the laser light source is preferably accomplished using active heating elements (e.g.

Abstract: A holographic laser scanner of ultra-compact design capable of reading bar and other types of graphical indicia within a large scanning volume using holographic optical elements and visible laser diodes. The holographic optical elements are arranged on the scanning disc in such a manner so that none of the laser scanning planes generated within the 3-D scanning volume of the system are spatially and temporally coincident with any other laser scanning plane within the 3-D scanning volume. This novel feature of the present invention ensures that there is substantially zero cross-talk at the plurality of photodetectors provided within the system, significantly improving the performance of the system.

Abstract: An analog scan data signal processor is disclosed, in which a time-domain non-linear substrate noise filter is provided before a first derivative signal generation stage so as to produce, as output, a substantially fixed zero-reference signal level whenever a signal level indicative of a bar code substrate is detected, and the signal level analog scan data signal, whenever a signal level indicative of a bar code element is detected. By virtue of the present invention, it is now possible to reduce the level of substrate noise signals within input analog scan data signals, prior to deriving first derivative signals for subsequent signal processing. Consequently, the accuracy of binary signal level detection within such analog scan data signal processors can be significantly improved, thereby improving the performance of bar code symbol reading systems within which such analog scan data signal processors are employed.