ELECTRONIC READER MEANS FOR MAGNETIC CREDIT CARDS AND THE LIKE

• US 3,634,657 A
• Filed: 07/16/1969
• Issued: 01/11/1972
• Est. Priority Date: 07/16/1969
• Status: Expired due to Term

• Current Assignee: Casi-Rusco Incorporated
• Original Assignee: Louis M. Ballard, Waldo I. Rogers
• Inventors: Ballard, Louis M., Rogers, Waldo I.
• Primary Examiner(s): Cook, Daryl W.
• Application Number:
  US04/842,190
• Time in Patent Office: 909 Days
• Field of Search: 235/61.11,61.114 340/174.1F,174.1H 307/309 310/8.6
• US Class Current: 235/449
• CPC Class Codes: G06K 7/087 flux-sensitive, e.g. magnetic, detectors G06K7/10336 takes precedence

Abstract

A nonconductive substrate supports resistive elements with a plurality of parallel current paths, and a magnetic card is adapted to be positioned with a plurality of magnet portions thereof aligned with said elements. The resistive elements may be respective elements or different parts of a strip of resistive material. Embodiments are shown in which the elements are connected to a DC voltage source, and a respective DC amplifier is coupled to each element to develop a positive or negative output voltage depending upon the polarity of the end of the card magnet portion adjacent the element. In another embodiment, the elements are connected to an AC reference voltage source, and a respective AC amplifier is coupled to each element to develop an output that is in phase or out of phase with the reference voltage depending upon the polarity of the end of the card magnet portion adjacent the element. In the latter embodiment, phase detectors coupled to the AC amplifiers develop positive or negative outputs depending upon the phase relations of the amplifier outputs to the AC reference voltage.

Claims

1. A housing having a slot to receive and hold stationary a card having a plurality of magnet portions poled along lines at right angles to the card faces, the ends of the magnet portions at the card faces having a predetermined polarity distribution;

a stationary nonconductive element having a flat surface parallel to and at one side of said slot;

resistance means on said surface said resistance means having a plurality of portions positioned to be confronted by respective poles of magnet portions of a card placed in the slot;

means for connecting said resistance means to an external current souRce to establish a current path through said resistance means at each portion thereof, said resistance means being characterized in that at each said portion thereof a potential of predetermined magnitude is developed between points on either side of the current path in the presence of a pole of a card magnet portion aligned therewith, and in that the potential between such points in the presence of a south pole is opposite to that in the presence of a north pole; and

a network means responsive to the potentials to develop signal information identifiable with the card.

2. The combination of claim 1, including means to connect said resistance means to the external current source to establish current paths through said portions thereof in a predetermined sequence.

3. The combination of claim 1, wherein said resistance means includes a plurality of resistance elements connected in parallel;

and switch means for connecting said parallel-connected resistance elements to an external current source; and

a pair of connections to said network means from points on each resistance element along a line at right angles to the current path through it.

4. The combination of claim 1, wherein said resistance means includes a plurality of resistance elements connected in series for connection across an external current source;

and a pair of connections to said network means from points on each resistance element along a line at right angles to the current path through it.

5. The combination of claim 1, wherein said resistance means includes a strip of resistance material of such length that a plurality of magnet portions of a card in said slot are aligned with spaced portions thereof;

and pairs of connections to said network means from the edges of said spaced portions of said strip.

6. The combination of claim 1, including a DC source for the external current source;

and wherein said network means includes a respective DC amplifier for the potential developed at each portion of said resistance means.

7. The combination of claim 1, including an AC reference voltage source for the external current source, and wherein said network means includes means for developing a respective DC voltage representing the phase relation of such potential with respect to the AC reference voltage.