3806874 is referenced by 147 patents and cites 2 patents.

The identification unit described in this specification comprises a testing station for identifying each of a plurality of identification units adapted to be carried or worn by authorized personnel. Each unit has data stored therein which is different from the data stored in other units and includes a generator for generating first and second data pulse sequences in accordance with the stored data; the testing station also includes a store for storing data and a generator for generating in response to the contents of its associated store pulse sequences identical to the pulse sequences generated by each unit so that when a unit is coupled to the testing station a comparator in that unit compares the first pulse sequence generated thereby with the first pulse sequence generated by the testing station and if the sequences are found to be identical causes the unit to generate the second pulse sequence which is compared in a comparator in the testing station with the second pulse sequence generated thereby to produce an identification signal if the two second pulse sequences are identical.The circuits of each unit may be encapsulated and mounted in a wrist strap to be worn by an authorized individual and the unit may be inductively coupled or coupled by radio means to the testing station.

Identification system for individuals
Application Number
Publication Number
Application Date
April 10, 1973
Publication Date
April 23, 1974
Ehrat Kurt
Pierce Schleffler & Parker
Gretag Aktiengesellschaft
G11b 09/02
G08b 29/00
G07C 09/00
G06K 07/10
G06K 19/04
G06K 19/77
G06K 19/07
G07F 07/10
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