Metrologic Instruments, Inc.

Joseph Ralph

Mark Lucera

Timothy A Good

A laser scanning system that employs synchronous time-division-multiplexed laser scanning operations and signal processing operations (for bar code detection). A plurality of successive non-overlapping time slots are defined and logically assigned to a unique laser scanning beam and corresponding photosensor. During a given time slot, the laser scanning beam logically assigned thereto is selectively generated (or selectively projected) into the scanning volume while generation (or projection) of the other laser scanning beam is disabled. Moreover, during the given time slot, the photosensor logically assigned thereto is operably coupled to signal processing circuitry that performs bar code detection operations on the data signals derived therefrom while the other photosensor is operably decoupled from such signal processing circuitry. The frequency of time slots logically assigned to a given laser scanning beam and corresponding photosensor is preferably greater than at least two times the highest frequency component expected in the scan data signal received at the photosensor. In other embodiments, the time slots logically assigned to a given laser scanning beam and corresponding photosensor correspond to scanning planes (or scanning plane groups) generated by the given laser scanning beam during revolution of at least one rotating polygonal mirror. In the preferred embodiment, such synchronous time-division-multiplexed laser scanning operations and signal processing operations (for bar code detection) are embodied in a bioptical laser scanning system comprising a plurality of laser scanning stations, each of which produces a plurality of groups of quasi-orthogonal laser scanning planes that are projected within predetermined regions of space contained within a 3-D scanning volume defined between the bottom and side-scanning windows of the system.

Bar code symbol scanning system employing time-division multiplexed laser scanning and signal processing to avoid optical cross-talk and other unwanted light interference

A bioptical laser scanning system employing a plurality of laser scanning stations about a two independently controlled rotating polygonal mirrors. The system has an ultra -compact construction, ideally suited for space-constrained retail scanning environments, and generates 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 quasi-orthogonal laser scanning planes, including 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 bottom-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 bottom-scanning window.

Bioptical laser scanner for six-sided 360&#xb0; POS-based scanning

A bioptical laser scanning system employing a plurality of laser scanning stations about a two independently controlled rotating polygonal mirrors. The system has an ultra-compact construction, ideally suited for space-constrained retail scanning environments, and generates 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 quasi-orthogonal laser scanning planes, including 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 bottom-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 bottom-scanning window.

Bioptical laser scanner for six-sided 360&#xb0; Pos-based scanning

A laser scanning system that employs synchronous time-division-multiplexed laser scanning operations and signal processing operations. A plurality of successive non-overlapping time slots are defined and logically assigned to a unique laser scanning beam and corresponding photosensor. During a given time slot, the laser scanning beam logically assigned thereto is selectively generated (or selectively projected) into the scanning volume while generation (or projection) of the other laser scanning beam is disabled. During the given time slot, the photosensor logically assigned thereto is operably coupled to signal processing circuitry that performs bar code detection operations on the data signals derived therefrom while the other photosensor is operably decoupled from such signal processing circuitry. The frequency of time slots logically assigned to a given laser scanning beam and corresponding photosensor is preferably greater than at least two times the highest frequency component expected in the scan data signal received at the photosensor.

A laser scanning system including a multi-path scan data signal processor having multiple signal processing paths. Each signal processing path processes the same data signal (which is derived from the output of a photodetector) to detect bar code symbols therein and generate data representing the bar code symbols. And each signal processing path has different operational characteristics (such as low-pass filter cutoff frequencies, amplifier gain characteristics, and/or positive and negative signal thresholds). The varying operational characteristics of the signal processing paths are optimized to provide different signal processing functions (e.g., minimize paper noise, or maximize the scan resolution of the system). The data signal derived from laser scanning is supplied to each path of the multi-path scan data processor, where it is processed (preferably in parallel) to identify signal level transitions therein. A digital scan data signal that encodes such signal level transitions is provided to digitizing circuitry, which converts the digital scan data signal into a corresponding sequence of digital words (i.e., a sequence of digital count values) suitable for bar code symbol decoding.

Multipath scan data signal processor having multiple signal processing paths with different operational characteristics to enable processing of signals having increased dynamic range

Growing community of inventors

Los Angeles, CA, United States of America

Joseph Ralph