A two-dimensional code for recognizing data in high speed and recording large amount of data in a limited space. The two-dimensional code was designed by locating one solid line that covers four corners of the area for matrix data element in order to obtain information of physical size of the two-dimensional...http://www.google.com.au/patents/US20030029923?utm_source=gb-gplus-sharePatent US20030029923 - Two-dimensional code
