Dynamic card reader

• US 4,213,039 A
• Filed: 10/16/1978
• Issued: 07/15/1980
• Est. Priority Date: 10/16/1978
• Status: Expired due to Term

• Current Assignee: APD Security Systems Incorporated
• Original Assignee: Automatic Parking Devices Incorporated
• Inventors: Schasser, Donald S.
• Primary Examiner(s): Cook, Daryl W.
• Application Number:
  US05/951,760
• Time in Patent Office: 638 Days
• Field of Search: 235/449, 235/450, 360/112, 360/2
• US Class Current: 235/449
• CPC Class Codes: G06K 7/0163 by means of additional timing marks on the record-carrier
• CPC Class Codes: G06K 7/087 flux-sensitive, e.g. magnetic, detectors G06K7/10336 takes precedence

Abstract

A dynamic card reader adapted for use in reading information magnetically recorded on a card in two rows or tracks parallel to the longer dimension of the card. The information is read as the card is being inserted into the slot by two Hall effect sensors disposed in side-by-side relation at the entrance to the card slot. One row of magnet information generates a data signal and the other row generates a clock signal which is used to strobe the data signal into a shift register. The Hall sensors are connected to the detection circuitry through differentiating capacitors, such that the detection circuitry is responsive to transition of magnetic polarities as the card is inserted into the slot.

Claims

1. In a Hall effect magnetic card reader which includes first and second Hall effect sensors each having a pair of bias electrodes for connection to a source of electrical power and a pair of signal electrodes for generation of a voltage signal in response to proximity of a magnetic field, the improvement comprising a source of dc potential and means connecting said bias electrodes of said first and second Hall effect sensors in series with each other across said source of dc potential.

2. The improvement set forth in claim 1 wherein said means includes current limiting resistance means.

3. In a Hall effect magnetic card reader for use with a card carrying magnetic indicia at preselected locations thereon, and including means providing a slot for receiving a card in a planar orientation such that said indicia is disposed in at least one track parallel to the direction of card insertion into said slot, at least one Hall effect sensor disposed adjacent said slot for providing a signal as a function of indicia on a card inserted into said slot and output means for providing a reader output signal as a function of said indicia, the improvement wherein said means for providing said slot includes means constructed of magnetically permeable material disposed adjacent said slot on a side thereof opposite said Hall effect sensor means for amplifying the effect of magnetic indicia on a said card inserted into said slot on said Hall effect sensor means.

4. The improvement set forth in claim 3 for use with a card carrying magnetic indicia selectively disposed in any one or more of a plurality of parallel tracks disposed laterally of each other wherein said reader includes a plurality of Hall effect sensors at locations corresponding to selected ones of said tracks, and wherein said means constructed of magnetically permeable material extends laterally across said slot so as to amplify the effect of magnetic indicia carried in any one of said tracks.

5. In a card reader for use with a card carrying indicia comprising magnetic zones in said card readable in the form of a binary code at preselected parallel track locations thereon and including means for providing a slot for receiving a card such that said track locations are parallel to the direction of card insertion into said slot and means disposed at preselected locations adjacent said slot and responsive to magnetic indicia on a card inserted into said slot for providing a binary coded signal as a function of said indicia, the improvement wherein said means comprises a plurality of magnetic sensor means disposed laterally of said slot one adjacent each said preselected parallel track location for providing sensor signals in response to proximity of magnetic indicia adjacent the corresponding said sensor means, output means for providing a reader output signal in response to said sensor signals and including input means for receiving signals from each said sensor means, said sensor means comprising Hall effect sensor each having a pair of signal electrodes for connection to said input means for providing said binary coded signal to said input means, and differentiating means comprising a pair of capacitors connected in series one between each of said electrodes and said input means such that said output means is responsive to dynamic changes in magnetic polarity adjacent each said sensor means as a card is inserted into said slot.

6. In a card reader for use with card carrying magnetic zones for defining indicia readable in the form of a binary code at preselected locations thereon and including means for providing a slot for receiving a card in an orientation such that said indicia is disposed in at least one track parallel to the direction of card insertion into said slot, at least one sensor means disposed at a preselected lateral position adjacent said slot corresponding to the preselected location of the said at least one track on a card inserted into said slot for providing a binary coded signal as a function of said indicia, said sensor means comprising Hall effect sensor means having a pair of signal electrodes for providing said binary coded signal, and output means including input means for receiving signals from each said sensor means to provide a reader output signal as a function of said indicia, the improvement comprising a pair of capacitors connected in series one between each of said electrodes and said input means such that said output means is responsive to transition of said indicia from one state to another as a card is inserted into said slot.

7. A card reader for use with a card carrying indicia readable in the form of a binary code at first and second parallel preselected track locations thereon and including means for providing a slot for receiving a card in an orientation such that said tracks are parallel to the direction of card insertion into said slot, sensor means disposed at preselected lateral positions adjacent said slot corresponding to the preselected location of the said tracks on a card inserted into said slot for providing binary coded signals as functions of said indicia, output means for providing a reader output signal as a function of said indicia, and differentiating means connecting said sensor means to said output means such that said output means is responsive to transition of said indicia from one state to another as a card is inserted into said slot, said reader output means comprising serial binary data storage means connected to receive an input data signal from a first of said sensor means as indicia in a first of said tracks pass adjacent said first sensor means, clock means connected to a second of said sensor means for generating a clock signal to strobe data signals from said first sensor means into said storage means as indicia in the second of said tracks pass adjacent said second sensor means, counter means connected to said second sensor means for counting said clock signals up to a level corresponding to a selected number of data signals to be stored in said storage means, comparator means for comparing binary data signals stored in said storage means with a preselected code, and first gate means having a first input connected to said counting means and a second input connected to said comparator means for providing said reader output signal when both said count equals said selected number and said stored data equals said preselected code.

9. The improvement set forth in claim, 8 or 7 further comprising first means disposed adjacent said slot and responsive to initial insertion of a card into said slot for enabling said storage means, and second means disposed adjacent said slot and connected to a third input of said first gate means, said second means being responsive to full insertion of a card into said slot for enabling generation of said output signal.

10. The improvement set forth in claim 9 wherein said output means further comprises master card sensor means including programmable means adapted for selective connection to said storage means and responsive only to selected data bits in said storage means, and second gate means connected to said second means and to said programmable means for generating said output signal independently of said first gate means when both a card is fully inserted into said slot and said selected data bits in said storage means are at a preselected level.

8. In a card reader for use with a card carrying magnetic indicia readable in the form of a binary code at first and second preselected parallel track locations thereon, and including means for providing a slot for receiving a card such that said track locations are parallel to the direction of card insertion into said slot and means disposed at preselected locations adjacent said slot and responsive to magnetic indicia on a card inserted into said slot for providing a binary coded signal as a function of said indicia, the improvement wherein said means comprises a plurality of magnetic sensor means disposed laterally of said slot one adjacent each said preselected parallel track location for providing sensor signals in response to proximity of magnetic indicia adjacent the corresponding said sensor means, output means for providing a reader output signal in response to said sensor signals and differentiating means connecting each said sensor means to said output means such that said output means is responsive to dynamic changes in magnetic polarity adjacent each said sensor means as a card is inserted into said slot, said reader output means comprising serial binary data storage means connected to receive an input data signal from a first of said sensor means as indicia in a first of said tracks pass adjacent said first sensor means, clock means connected to a second of said sensor means for generating a clock signal to strobe data signals from said first sensor means into said storage means as indicia in the second of said tracks pass adjacent said second sensor means, counter means connected to said second sensor means for counting said clock signals up to a level corresponding to a selected number of data signals to be stored in said storage means, comparator means for comparing binary data signals stored in said storage means with a preselected code, and first gate means having a first input connected to said counting means and a second input connected to said comparator means for providing said reader output signal when both said count equals said selected number and said stored data equals said preselected code.

11. A card reader for use with a card carrying indicia readable in the form of a binary code at preselected locations thereon comprising means for providing a slot for receiving a said card, a number of sensor means selectively disposed at preselected locations laterally spaced from each other with respect to said slot so as to define a selected number of indicia reading tracks corresponding to said number of sensor means, serial binary data storage means connected to receive an input data signal from a first of said sensor means as indicia in a first of said tracks pass adjacent said first sensor means, clock means connected to a second of said sensor means for generating a clock signal to strobe data signals from said first sensor means into said storage means as indicia in the second of said tracks pass adjacent said second sensor means, counter means connected to said second sensor means for counting said clock signals up to a level corresponding to a selected number of data signals to be stored in said storage means, comparator means for comparing binary data signals stored in said storage means with a preselected code, first gate means having a first input connected to said counting means and a second input connected to said comparing means for providing a reader output signal when both said count equals said selected number and said stored data equals said preselected code, first means disposed adjacent said slot and responsive to initial insertion of a card into said slot for enabling said storage means, second means disposed adjacent said slot and connected to a third input of said first gate means, said second means being responsive to full insertion of a card into said slot for enabling generation of said output signal, and master card sensor means including programmable means adapted for selective connection to said storage means and responsive only to selected data bits in said storage means and second gate means connected to said second means and to said programmable means for generating said output signal independently of said first gate means when both a card is fully inserted into said slot and said selected data bits in said storage means are at preselected levels.

16. The improvement set forth in claim 12 or 11 wherein said indicia includes magnetized zones on said card, and wherein said sensor means comprises Hall effect sensor elements.

12. A card reader for use with a card carrying indicia readable in the form of a binary code at preselected locations thereon and including means for providing a slot for receiving a card in an orientation such that said indicia is disposed in at least two tracks parallel to the direction of card insertion into said slot, first and second sensor means disposed at preselected lateral positions adjacent said slot corresponding to lateral positions of the said tracks on a card inserted into said slot for providing binary coded signals as functions of said indicia, output means for providing a reader output signal as a function of said indicia and including input means for receiving separate input signals from said first and second sensor means, and differentiating capacitor means including first and second capacitors each connected in series between a corresponding one of said first and second sensor means and said input means for providing said input signals as independent functions of said indicia in said parallel tracks and responsively to transition of said indicia in each said track from one state to another as a card is inserted into said slot.

13. The improvement set forth in claim 12 wherein said indicia comprises magnetic zones in said card, wherein said sensor means comprise Hall effect sensors each having a pair of signal electrodes for connection to said input means for providing said binary coded signal to said input means, and wherein said capacitor means comprises a pair of capacitors connected in series one between each of said electrodes and said input means.

14. The improvement set forth in claim 12 wherein said reader output means comprises serial binary data storage means connected to receive an input data signal from a first of said sensor means as indicia in a first of said tracks pass adjacent said first sensor means and clock means connected to a second of said sensor means for generating a clock signal to strobe data signals from said first sensor means into said storage means as indicia in the second of said tracks pass adjacent said second sensor means.

15. The improvement set forth in claim 14 wherein said output means further comprises counter means connected to said second sensor means for counting said clock signals up to a level corresponding to a selected number of data signals to be stored in said storage means, comparator means for comparing binary data signals stored in said storage means with a preselected code, and first gate means having a first input connected to said counting means and a second input connected to said comparing means for providing said reader output signal when both said count equals said selected number and said stored data equals said preselected code.

17. For use in the combination of a card reader and a plurality of key cards, a method of programming the card reader to be selectively responsive to coded combinations of indicia recorded on key cards comprising the steps of (a) providing said card reader with a slot adapted to receive said key cards one at a time in a selected direction, (b) constructing said key cards to have a plurality of available laterally spaced recording tracks parallel to the direction of insertion into said slot, (c) recording coded indicia in at least some of said recording in each of said key card tracks, and (d) locating sensor means in said reader at preselected laterally spaced locations adjacent to said slot and corresponding in lateral position to selected ones less than the total of said plurality of recording tracks such that said sensor means are responsive only to ones of said key cards having a said coded combination of indicia recorded in said selected ones of said recording tracks.