Abstract: A statistical basis for use in a self-scanning checkout system determines how many items to check in a shopper's shopping cart for incorrect or missing scans as well as which particular or types of items to check to determine if they were properly scanned, if the shopper is determined to be audited. The present invention does not audit every customer, but rather determines whether a given shopper or customer is to be audited on a given shopping trip based upon obtaining a minimum checkout loss for such customer. The methodology determines how many items to check for a given shopper as well as which particular items to check for that shopper.

Abstract: A method and apparatus for aligning a scan pattern to a two dimensional bar code having parallel rows of codewords. The two dimensional bar code is scanned with a scanning pattern oriented such that a plurality of lines thereof cross the bar code rows. A determination if there is a non-zero angle between at least one of the plurality of lines and the rows by decoding codewords in rows intersected by the at least one line is made and the orientation of the scanning pattern is adjusted to reduce the absolute value of the angle.

Abstract: A statistical basis for use in a self-scanning checkout system determines how many items to check in a shopper's shopping cart for incorrect or missing scans as well as which particular or types of items to check to determine if they were properly scanned, if the shopper is determined to be audited. The present invention does not audit every customer, but rather determines whether a given shopper or customer is to be audited on a given shopping trip based upon obtaining a minimum checkout loss for such customer. The methodology determines how many items to check for a given shopper as well as which particular items to check for that shopper.

Abstract: A portable data input or computer system includes an input/output device such as a keyboard and a display, another data input device such as an optical bar code scanner, and a data processor module. To scan bar code type indicia, the operator points the scanner at the bar code and triggers the scanner to read the indicia. All the system components are distributed on an operator's body and together form a personal area system (PAS). Components may include a scanner or imager, a wrist unit, a headpiece including an eyepiece display, speaker and a microphone. Components within a particular PAS communicate with each other over a personal area network (PAN). Individual PASs may be combined into a network of PASs called a PAS cluster. PASs in a particular PAS cluster can communicate with each other over another wireless communication channel. Individual PAS can gain access to a Local Area Network (LAN) and/or a Wide Area Network (WAN) via an access point.

Abstract: A system and method described for tracking portable devices. The system may include a transmitter which transmits wireless inquiries to a plurality of portable devices and a receiver receiving replies to the inquiries from the portable devices. In addition, the system may include a memory storing identifier data corresponding to the portable devices and a processor coupled to the memory and to the receiver, the processor retrieving from each reply, identifier data uniquely identifying a particular one of the portable devices which generated the reply and comparing the identifier data to the stored identifier data. Furthermore, the system may include an alarm system coupled to the processor and controlled based on the comparison of stored identifier data to the identifier data retrieved from the replies.

Abstract: Wireless data communications using a master/slave protocol are easily established between a master radio module which is part of a POS terminal and a slave radio module which is part of a portable bar code scanning device. A bar code identifying the portable bar code scanning device is provided on the outside of the housing of the portable device. By scanning this bar code with a scanner associated with the POS terminal, such as a fixed scanner built onto a counter, the master/slave radio communications link can be automatically implemented.

Abstract: A data encoding/decoding scheme includes a plurality of bar code symbols each carrying a portion of the data in which improved error correction capabilities are incorporated. According to one aspect, once data codewords have been derived to form the symbols, a first set of data correction elements are derived from a first field, then a second set of error correction elements are derived from the data elements and the first set of error correction elements using a second, wider field.

Abstract: A signaling arrangement and method for use in a wireless local area network managed by a system manager include a reader for electro-optically reading bar code symbols. The system manager verifies that a symbol has been successfully read and sends an acknowledgment signal by wireless, radio frequency transmission to a remote indicator operative for generating an alert signal noticeable to a user.

Abstract: A statistical basis for use in a self-scanning checkout system determines how many items to check in a shopper's shopping cart for incorrect or missing scans as well as which particular or types of items to check to determine if they were properly scanned, if the shopper is determined to be audited. The present invention does not audit every customer, but rather determines whether a given shopper or customer is to be audited on a given shopping trip based upon obtaining a minimum checkout loss for such customer. The methodology determines how many items to check for a given shopper as well as which particular items to check for that shopper.

Abstract: A method and apparatus for decoding a two-dimensional bar code symbol using a charge-coupled device (CCD) camera, charge-modulation device (CMD) camera, or other bar code reading device such as a hand-held reader, light pen or wand, scan mouse, or stationary laser scanner. The CCD/CMD camera or reading device optically images the bar code symbol to obtain digital image data, which is stored in a memory.

Abstract: Disclosed are methods and apparatus for automatically aligning the field of view of a two dimensional bar code reading device with a randomly oriented two-dimensional bar code symbol wherein the symbol comprises a unique pattern located contiguously on at least one side thereof. One method is implemented in a laser based embodiment by scanning the symbol with a laser scan line extending through the border pattern (which is a PDF417 start codeword), measuring the length of the start codeword detected by the scan line, and rotating the laser scan line by a predetermined amount. This is repeated for a predetermined number of times, and the rotation angle at which the codeword length is smallest is determined by performing a least squares fit of the measured codeword lengths and rotation angles. The raster pattern is then rotated to the determined rotation angle so as to be aligned with the symbol for subsequent scanning and decoding.

Abstract: Combining scan fragments of a bar code symbol. Each fragment is represented by a series of values, with each value representing the width of an element in the fragment. The alignment at which the fragments are combined is determined by shifting the alignment of the fragments over a range of positions, and determining for each position an index of the overall degree of similarity between the aligned values of the two fragments at that position. The fragments are combined at an alignment that produces a relatively larger index value (e.g., that maximizes the index). The index of overall similarity may be a correlation factor representing the degree of correlation, at each tested alignment, between the series of values representing each fragment. The index of overall similarity may alternately be the number of consecutive matching elements. At each position, the values in each series are compared and the number of consecutive values that match within a preselected tolerance is determined.

Abstract: A method and apparatus for decoding a two-dimensional bar code symbol using a charge-coupled device (CCD) camera or a charge-modulation device (CMD) camera. The CCD/CMD camera takes pictures of the symbol and the picture is converted into digital data. The location and orientation of the two-dimensional bar code symbol is determined and verified. Defects and damages on the symbol are detected and corrected. The symbol is scanned to read the codewords of the two-dimensional bar code symbol.

Abstract: Two-dimensional information such as a written signature can be captured and subsequently reconstructed by using an electro-optical scanner. A multi-row preamble code and a multi-row postamble code flank the signature, and each code has a row identifier for identifying which row is being scanned by a scan line emitted by the scanner, as well as start/stop data for identifying when each scan line traverses the boundaries of a space containing the signature.