A digital information recording carrier has a planar recording surface having an information recording area in which meshes corresponding to bits are virtually set in a matrix form, each mesh being provided with an optically recognizable mark corresponding to digital information so that the digital information...http://www.google.com/patents/US6302329?utm_source=gb-gplus-sharePatent US6302329 - Method and apparatus for recording digital information in two-dimensional pattern, carrier of digital information recorded thereby, and a method and apparatus for decoding such digital information
