Method and apparatus for reading symbols on items moved by conveyor

A method for reading symbols, comprising the steps of:

• moving a symbol across a gap between a first conveyor and a second conveyer, said symbol affixed to a two-dimensional or three-dimensional movable object;
• repeatedly scanning through said gap along a single line to acquire scanned data over two dimensions;
• storing data at only selected points along said single line determined according to said pattern of virtual scan lines, said virtual scan lines covering a two dimensional imaging region defined in one dimension by a field-of-view of each scan along said single line, and in another dimension by a number of repeated scans along said single line;
• and
• decoding said scanned data according to a plurality of virtual scan lines.

An apparatus for reading symbols, comprising:

• a first conveying element;
• a second conveying element separated from said first conveying element by a gap, such that two-dimensional or three-dimensional symbol-bearing objects placed on said first conveying element arc moved from said first conveying element across the gap to said second conveying element;
• a single line scanner positioned to scan through said gap, said single line scanner outputting a serial data stream of predefined length at regular time intervals such that symbol-bearing objects moving from said first conveying element to said second conveying element are scanned by said single line scanner in at least two dimensions;
• a digital memory connected to said serial data stream, said digital memory storing only a portion of data generated from a plurality of scans made by said single line scanner;
• and
• a decoder connected to said digital memory, whereby data stored from said plurality of scans is decoded along virtual scan lines oriented at a plurality of angles with respect to a field-of-view of said single line scanner.

A method of data reading through a gap between a first conveying element and a second conveying element, comprising the steps of:

• moving a two-dimensional or three-dimensional item to be scanned from the first conveying clement to the second conveying element and across the gap;
• scanning through the gap to produce successive scans on the item, said successive scans thereby covering a multi-dimensional scan volume;
• rejecting an amount of scanned data from said successive scans;
• and
• decoding a remaining portion of the scanned data according to a plurality of virtual scan lines oriented at a plurality of angles with respect to one another.

An apparatus for reading symbols, comprising:

• a first conveying clement;
• a second conveying element separated from said first conveying element by a gap, such that two-dimensional or three-dimensional symbol-bearing objects placed on said first conveying element are moved from said first conveying element across the gap to said second conveying element;
• a single line scanner positioned to scan through said gap, said single line scanner outputting a serial data stream of predefined length at regular time intervals such that symbol-bearing objects moving from said first conveying element to said second conveying element are scanned by said single line scanner in at least two dimensions, wherein said single line scanner is positioned at an angle offset from the vertical with respect to said gap, such that said single line scanner may scan a side surface of three-dimensional symbol bearing objects moving from said first conveying element to said second conveying element;
• a digital memory connected to said serial data stream, said digital memory storing only a portion of data generated from a plurality of scans made by said single line scanner;
• and
• a decoder connected to said digital memory, whereby data stored from said plurality of scans is decoded along virtual scan lines oriented at a plurality of angles with respect to a field-of-view of said single line scanner.

Apparatus for reading symbols, comprising:

• first conveyor means;
• second conveyor means located adjacent to said first conveyor means and separated from said first conveyor means by a gap, such that two-dimensional or three-dimensional symbol-bearing objects placed on said first conveyor means are moved from said first conveyor means to said second conveyor means across said gap to said second conveyor means;
• linear scanner means for scanning said symbol-bearing objects through said gap by successive linear scans, thereby covering a multi-dimensional scan volume;
• memory means for storing a reduced portion of scanning data output by said linear scanner means;
• and
• decoder means connected to said memory means for decoding the scanning data stored in said memory means along predefined virtual scan lines.