Registers – Coded record sensors – Particular sensor structure
Patent
1990-10-05
1993-01-05
LaRoche, Eugene R.
Registers
Coded record sensors
Particular sensor structure
235450, 235493, 380 3, 380 22, G06K 708, G06K 1906
Patent
active
051773449
ABSTRACT:
A randomly varying modulated current is generated and used to drive a magnetic write head in an apparatus for enhancing a randomly varying magnetic security characteristic of a medium. The write head can be positioned adjacent a fluid magnetic slurry for the purpose of altering the location of the various magnetic particles therein in a random fashion. The slurry can then be hardened thermally or using ultraviolet dryers. A circuit which can generate the randomly variable current for the read head includes a modulator which receives a first randomly variable signal and a second, different randomly varying signal which modulates the first signal.
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LaRoche Eugene R.
Nguyen Tan
Rand McNally & Company
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