METHOD AND DEVICE FOR CHECKING DOCUMENTS, WHICH ARE PROTECTION AGAINST FAKING Russian patent published in 2000 - IPC

FIELD: security equipment. SUBSTANCE: device may be used for checking documents, which use current-conducting strip as protection element. Said current-conducting strip is designed as ribbon or filament, which conducts current along its complete length, or as strips with several current-conducting pieces, which are insulated from each other. Corresponding method uses known capacitance coupling for transmission of electric signals from transmitting antennas to receiving antennas through current- conducting protection strips. Method involves detection of temporal and amplitude characteristics of such signals, and their comparison to target characteristics, so that converting into signal characteristics ensures easy comparison of parameters. Specific selectivity of checking device is achieved by means of connection of additional selective amplifier to decoding electronic circuit. Identification which is specific for particular type of bank notes is achieved using analytic electronic circuit, so that temporal limit of amplitude of test signal, which differs from duration of amplitude characteristics of all other types of bank notes can be set using, for example, controller. EFFECT: increased reliability of protection against faking. 21 cl, 10 dwg