CODING PATTERN COMPRISING REPLICATED AND NON-REPLICATED COORDINATE DATA

摘要

A method of imaging a coding pattern disposed on a surface of a substrate. The method comprises the steps of: (a) operatively positioning an optical reader relative to the surface and capturing an image of a portion of the coding pattern; (b) sampling and decoding x-coordinate data and y-coordinate data within the imaged portion; and (c) determining a position of the pen. The coding is specially adapted to minimize space occupied by coordinate data. The imaged portion has a diameter of at least (l+q)√2 and less than (2 l)√2, where l is the length of a square tag in the coding pattern and q is the width of a central column or row of data within each tag.