Inventor
GREENAWAY DAVID L
11 patents
Patents
11 patentsUS4184700AJan 22, 1980
Documents embossed with optical markings representing genuineness information
LANDIS & GYR AG261 citations98
US4662653AMay 5, 1987
Optically diffracting security element
LANDIS & GYR AG82 citations95
US4250393AFeb 10, 1981
Photoelectric apparatus for detecting altered markings
LANDIS & GYR AG86 citations95
US4250217AFeb 10, 1981
Documents embossed with machine-readable information by means of an embossing foil
LANDIS & GYR AG112 citations95
US4223050ASep 16, 1980
Process for embossing a relief pattern into a thermoplastic information carrier
LANDIS & GYR AG96 citations95
US4211918AJul 8, 1980
Method and device for identifying documents
LANDIS & GYR AG138 citations95
US4163570AAug 7, 1979
Optically coded document and method of making same
LANDIS & GYR AG119 citations95
US4376887AMar 15, 1983
Device for the thermal erasure of mechanically readable optical markings
LANDIS & GYR AG92 citations92
US4143810AMar 13, 1979
Documents coded by means of machine-readable optical markings
LANDIS & GYR AG38 citations92
US4129382ADec 12, 1978
Method and apparatus for storing and reading authenticating information
LANDIS & GYR AG46 citations92
US4297001AOct 27, 1981
Projection screen and method for making same
LANDIS & GYR AG18 citations73