Two dimensional data encoding structure and symbology for use with optical readers
First Claim
1. An optically readable two dimensional bar code symbol, comprising:
- a finder structure including a center and a plurality of squares which have centers that approximately coincide with said center and which are disposed in nested relationship to one another, each of said squares having first and second major axes which are substantially perpendicular to one another and which pass approximately through said center;
a symbol descriptor structure encoding data indicating at least the overall symbol size and the length of the message encoded in said bar code symbol, said descriptor structure being located adjacent to said finder structure;
a reference structure comprising at least two linear arrays of reference elements, said linear arrays having respective longitudinal axes that are oriented parallel to at least one of said first and second major axes;
a data structure including a plurality of data blocks, said data blocks being concatenated to form layers that surround said finder structure;
whereby the data blocks of said layers may be read sequentially within each layer and said layers may be read sequentially until all data has been read from said symbol.
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Accused Products
Abstract
A two dimensional (2D) matrix symbology for use with bar code and other optical readers. A finder structure includes a center square and a plurality of nested squares having centers that approximately coincide with the center square. A symbol descriptor located adjacent to the finder structure encodes data indicating the size of the symbol and the length of the message encoded therein. A reference grid extends throughout the symbol to facilitate the location of individual data elements with respect to the finder structure thereof. The data structure of the symbol is filled with data blocks which are organized into layers which surround the finder structure. Data encoded in the data blocks may be read sequentially within layers and between layers. The symbology is a versatile symbology in that the number of check data blocks is user selectable to provide the desired level of error correction.
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Citations
20 Claims
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1. An optically readable two dimensional bar code symbol, comprising:
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a finder structure including a center and a plurality of squares which have centers that approximately coincide with said center and which are disposed in nested relationship to one another, each of said squares having first and second major axes which are substantially perpendicular to one another and which pass approximately through said center; a symbol descriptor structure encoding data indicating at least the overall symbol size and the length of the message encoded in said bar code symbol, said descriptor structure being located adjacent to said finder structure; a reference structure comprising at least two linear arrays of reference elements, said linear arrays having respective longitudinal axes that are oriented parallel to at least one of said first and second major axes; a data structure including a plurality of data blocks, said data blocks being concatenated to form layers that surround said finder structure; whereby the data blocks of said layers may be read sequentially within each layer and said layers may be read sequentially until all data has been read from said symbol. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An optically readable two dimensional bar code label comprising:
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finder cell including a plurality of rectilinear line segments which form a plurality of closed nested squares, said squares having centers which substantially coincide with one another and having sides which are perpendicular with one another; a symbol descriptor containing data indicating at least the overall symbol size and the length of a message printed on said label, said symbol descriptor including optically readable marks which are organized into a descriptor field which is located adjacent to said finder; a reference grid including a plurality of linear segments, each grid segment having a longitudinal axis that is parallel to a side of one of said squares; a plurality of data blocks for encoding data for printing on said label, said data blocks being organized into a string of data blocks which are in turn organized into at least one layer that surrounds said symbol descriptor; whereby said data blocks may be read sequentially within each layer and said layers may be read sequentially until all of the data encoded within said symbol has been read. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19)
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20. An optically readable two dimensional bar code symbol comprising:
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a finder for use in determining the center of said symbol; a symbol descriptor for use in determining the maximum data capacity of said symbol and the quantity of message data encoded therein; a reference grid for use in determining the position of any part of said symbol with reference to said center; a linear array of data blocks including a plurality of message data blocks and a plurality of check data blocks, the number of message data blocks being just sufficient to encode said quantity of message data, and the number of check data blocks being fixed by the difference between said maximum data capacity and said just sufficient number of message data blocks; a data field within which said linear array of data blocks may be densely packed without overlapping any of said finder, said symbol descriptor and said reference grid.
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Specification