公开(公告)号：US3636318A

公开(公告)日：1972-01-18

申请号：US3636318D

申请日：1969-06-24

Applicant: SAAB AB

Inventor： LINDSTROM GUNNAR ,  SCHULLSTROM GUNDE

IPC: B42D15/10 ,  G06K19/10 ,  G07C9/00 ,  G07F7/08 ,  G07F7/10 ,  G06K7/08

CPC classification number: B42D25/369 ,  B42D25/00 ,  B42D25/20 ,  B42D25/21 ,  B42D25/23 ,  B42D25/309 ,  B42D25/318 ,  B42D25/47 ,  B42D2033/04 ,  B42D2033/16 ,  B42D2033/24 ,  B42D2033/32 ,  B42D2035/02 ,  B42D2035/06 ,  B42D2035/08 ,  B42D2035/34 ,  G06K19/10 ,  G07C9/00039 ,  G07F7/086 ,  G07F7/10 ,  G07F7/1066

Abstract: A document used to assert a personal right has a randomized unique pattern of normally invisible but mechanically detectable material (e.g., finely divided ferromagnetic material) in a zone overlapping any visible indicia identifying the owner. The document is presented to a mechanical reader which scans the pattern along predetermined lines and records resultant output signals, along with an identifying record. Upon subsequent presentation, it is similarly scanned, for comparison with the recording to confirm its authenticity. Methods of producing appropriate patterns are disclosed.