US 4,254,441 AGranted

Digital code reader

OwnerAlan J. Fisherinventor

Life of this patent

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Abstract

A system for reading binary digital data, represented by two possible spacings between abrupt flux reversals appearing on a magnetic track of a credit card, as the credit card is transported by hand by and in engagement with a magnetic head of the system. A read head having an unusually large read aperture is used to translate the two possible encoded lengths into two possible waveform amplitudes which are independent of transport speed. Then, by means of amplitude discrimination, the "0" bits are detected; and by zero slope detection, the "1" bits are detected. Mechanically, the read head is located centrally in an obtusely angled long side of a housing and is opposed by a contoured Teflon pillow that substitutes for one-half of the usual card slot. This unidirectional pillow is shaped and spaced from the head so as to cause the credit card to be slightly bent around the head's face in passing.

Claims4

Dependent claims

A magnetic transducer assembly for detecting a magnetic code recorded on a magnetic track on a thin, rigid, but bendable plastic card as such a card is passed through said assembly along a selected line of direction comprising:

a magnetic detection head having a generally convex curved responsive face surface positioned along said line of direction;
and
a guide member comprising:
separated entrance and exit lengths of bearing surfaces positioned and spaced from said surface of said magnetic detection head, and each said bearing surface lying in a discrete plane, wherein extensions of planes of said bearing surfaces form an obtuse angle at a line in a plane normal to and centrally through said surface of said magnetic detection head;
whereby a card moved along said line of direction is bent by virtue of engagement with the combination of said entrance bearing surfaces, said surface of said head, and said exit bearing surface, causing said card to be maintained in frictional contact with said magnetic detection head.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 06/013,907Filed 22 Feb 1979 · division
Priority: 25 Feb 1977
Granted: 3 Mar 1981
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

G06K 7/084
Inductive: sensing magnetic material by relative movement detecting flux changes without altering its magnetised state
G06K 7/015
Details: aligning or centering of the sensing device with respect to the record carrier
G06K 7/087
Using inductive or magnetic sensors: flux-sensitive, e.g. magnetic, detectors
G11B 20/1419
Code representation depending on a single bit, i.e. where a one is always represented by a first code symbol while a zero is always represented…