Binary system for magnetic card actuation for laundry machines

• US 4,024,379 A
• Filed: 05/19/1975
• Issued: 05/17/1977
• Est. Priority Date: 05/19/1975
• Status: Expired due to Term

• Current Assignee: Eugene S. Elkus Jr
• Original Assignee: Service Distributors Incorporated
• Inventors: Pfost, R. Fred, Breeze, Eric G.
• Primary Examiner(s): Cook, Daryl W.
• Application Number:
  US05/578,652
• Time in Patent Office: 729 Days
• Field of Search: 235/61.11 D, 235/61.12 M, 235/61.7 B, 360/2, 360/39, 360/40, 360/51, 360/53, 340/149 A
• US Class Current: 235/380
• CPC Class Codes: G06K 19/12 the marking being sensed by magnetic means
• CPC Class Codes: G06K 7/0166 by means of clock-signals derived from the code marks, e.g. self-clocking code
• CPC Class Codes: G06K 7/084 sensing magnetic material by relative movement detecting flux changes without altering its magnetised state
• CPC Class Codes: G06Q 20/3433 the counter having monetary units
• CPC Class Codes: G07F 17/20 for washing or drying articles, e.g. clothes, motor cars
• CPC Class Codes: G07F 7/02 by keys or other credit registering devices

Abstract

A control system is described for activating a machine using magnetic signals encoded on a magnetic card, tape or equivalent member. The magnetic signals are pulse-width-modulated and, in one embodiment, also sawtooth-modulated. A means is provided which is responsive to the magnetic signals for generating a first and a second number. The first number corresponds to the number of times the magnetic card is usable for activating a machine. The second number is provided for identification and validation purposes. Means are also provided for reducing the number of times the card can be used each time it is used to activate a machine and for visually displaying that number on a visual display device. The use of skewed recording and reproduction heads is also described for improving signal discrimination and security against the usability of fraudulently produced magnetic cards.

Claims

1. An apparatus for activating a machine with a magnetic member bearing magnetic signals representing one'"'"'s and zero'"'"'s, said magnetic signals having leading and trailing edges, a first predetermined duration when representing a one, a second predetermined duration when representing a zero, and leading edges which are equidistantly spaced, comprising:

means responsive to said magnetic signals for generating pulses of a first polarity corresponding to each of said leading edges and pulses of an opposite polarity corresponding to each of said trailing edges;

means responsive to said pulses of said first polarity for generating clock pulses, said clock pulses having a duration between that of said magnetic signals representing one'"'"'s and said magnetic signals representing zero'"'"'s;

means responsive to said clock pulses and said pulses of opposite polarity for generating data pulses; and

a first registering means responsive to said data pulses and said clock pulses for registering said data pulses, said data pulses representing a data number and an identification number;

means coupled to said first registering means for validating said data number and said identification number and providing an enabling signal when acceptable data and identification numbers are present;

means coupled to said first registering means and responsive to said data number for reducing said data number and providing an output corresponding to said reduced data number;

means coupled to said reducing means and said validating means and responsive to said enabling signal for displaying said reduced data number;

means responsive to said enabling signal for activating a machine;

a second registering means coupled to said first registering means and said reducing means and responsive to said enabling signal for registering said reduced data number and said identification number; and

means coupled to said second registering means for recording on said magnetic member, in place of the original magnetic signals, new magnetic signals corresponding to said identification number and said reduced data number, said magnetic signals having a first predetermined duration when representing a one, a second predetermined duration when representing a zero, and leading edges which are equidistantly spaced.

2. An apparatus according to claim 1 wherein each of said magnetic signals have leading edges and trailing edges, said data pulses are generated in response to said trailing edges and said trailing edges trail associated leading edges by a first amount when said signals represent a number "one" and by a second amount when said signals represent a number zero.

3. An apparatus according to claim 2 wherein said means for activating a machine comprises:

means responsive to said data pulses for registering said first and said second numbers; and

means for comparing said first and said second numbers with said predetermined criteria, said predetermined criteria being a valid and acceptable number corresponding to said identification number and a first number corresponding to at least one remaining use of said magnetic member for activating a machine.

4. An apparatus according to claim 3 further comprising:

means for reducing said first number each time a machine is activated using said magnetic member;

means for displaying said reduced first number whereby a user thereof is able to determine the number of times said magnetic member may still be used for activating a machine; and

means for recording pulse-width-modulated magnetic signals corresponding to said identification number and said reduced first number on said magnetic member in place of the original magnetic signals corresponding to said first and said second numbers.

5. An apparatus according to claim 4 wherein said recording means comprises:

means for registering said identification number and said reduced first member;

a pulse-width modulator; and

a clock means for clocking said identification number and said reduced first number through said modulator and outputting corresponding pulse-width-modulated pulses.

6. An apparatus according to claim 5 further comprising a sawtooth modulator for sawtooth modulating said pulse-width-modulated pulses.

7. The apparatus of claim 1 wherein said magnetic member has a longitudinal axis, and said magnetic signals are skewed relative to said axis at an angle alpha, and wherein said apparatus further comprises means for transporting said magnetic member in a direction parallel to said axis, and wherein said means responsive to said magnetic signals comprises a reader having a reader head skewed relative to said longitudinal axis at angle alpha for discriminating against any magnetic signal on said magnetic member except those signals skewed relative to said axis at angle alpha.

8. In an apparatus according to claim 7, the improvement further comprising a card and wherein said medium comprises a magnetic strip affixed to said card.

9. In an apparatus according to claim 8, the improvement wherein said medium on said card comprises magnetic dipoles having a longitudinal axis parallel to said longitudinal axis of said head when said medium is transported past said head.

10. In an apparatus according to claim 9, the improvement wherein said pre-encoded magnetic signals comprise a predetermined number of credits, said number being proportioned to a predetermined number of times said card is usable for activating a machine.

11. An apparatus for use with a magnetic member bearing pulse-width-modulated magnetic signals comprising:

means responsive to said magnetic signals for generating data pulses representing a first number corresponding to the number of times said magnetic member may be used to activate a machine and a second number corresponding to an identification number; and

means responsive to said first and said second numbers for activating a machine when said first and said second number satisfy predetermined criteria,

wherein said magnetic signals have leading and trailing edges and further wherein said means responsive to said magnetic signals for generating said data pulses comprises;

capacitive means;

means responsive to a first one of said leading edges for changing the potential on said capacitive means from a first predetermined reference potential to a second potential;

means responsive to a first one of said trailing edges following said first leading edge for changing the potential on said capacitive means from said second potential to a third potential;

means sensitive to the polarity of said third potential relative to said reference potential for providing a corresponding predetermined output; and

means responsive to a second one of said leading edges following said first trailing edge for changing the potential on said capacitive means from said third potential to said reference potential.

12. An apparatus according to claim 11 wherein said output of said polarity-sensitive means corresponds to a one when said third potential is of one polarity and to a zero when said third potential is of the opposite polarity.

13. An apparatus according to claim 12 wherein said output of said polarity-sensitive means corresponds to said first and second numbers.

14. An apparatus according to claim 11 wherein said potential-changing means comprises:

a flip-flop having a set and reset input and an output;

a resistor and a capacitor coupled in series between said output and ground;

a grounded-emitter transistor having an input and an output;

means for coupling said transistor output between said resistor and said capacitor;

a one shot coupled to said transistor input;

a differential amplifier coupled to said transistor output in parallel with said capacitor;

means for coupling said set input of said flip-flop and said one shot;

means responsive to said leading edges coupled to said set input; and

means responsive to said trailing edges coupled to said reset input.

15. The apparatus of claim 11 wherein said magnetic member has a longitudinal axis, and said magnetic signals are skewed relative to said axis at an angle alpha, and wherein said apparatus further comprises means for transporting said member in a direction parallel to said axis, and wherein said means responsive to said magnetic signals comprises a reader having a reader head skewed relative to said longitudinal axis at angle alpha for discriminating against any magnetic signal on said magnetic member except those signals skewed relative to said axis at angle alpha.