erate corresponding dataUS6354506 *Apr 28, 1999Mar 12, 2002Wenyu HanMethod and apparatus for impeding the counterfeiting of cards, instruments and documentsUS6533174Oct 20, 1998Mar 18, 2003Symbol Technologies, Inc.Method and apparatus for reading and writing indicia such as bar codes using a scanned laser beamUS6616041Feb 28, 2000Sep 9, 2003General Electric CompanyPart marking method applicable to