Card reader and control method of card reader
The present invention is to provide a card reader that can prevent the illegal acquisition of magnetic information recorded on a magnetic stripe, based on an output signal from a pre-head. More specifically described, in a card reader having a card insertion slot for guiding a magnetic card having a magnetic stripe to a transport passage and a pre-head arranged in the vicinity of the card insertion slot for detecting the presence of the magnetic stripe, the pre-head is equipped with a head portion having at least one pair of magnetic cores arranged to be opposite from each other having a magnetic gap between them and coils wound around a pair of the magnetic cores; and a signal different from that of the magnetic information recorded on the magnetic stripe is output from the pre-head.
1. A card reader for reading magnetic data recorded on cards, comprising:
a magnetic head including:
a reading core for reading said magnetic data; and
a reading-side coil which is wound around said reading core; and
a non-reading current-generating means for generating, to said reading-side coil, a non-reading current other than a reading current flowing through said reading-side coil when said magnetic data is read;
wherein a period of the wave of said non-reading current is a period determined by a recording density of said magnetic data recorded on said card and a moving speed of said card in said card reader.
2. The card reader according to claim 1 ;
wherein said non-reading current-generating means is connected to a reading-side signal wire to which said reading-side coil is connected.
3. The card reader according to claim 1 ;
wherein said magnetic head is a read-write integral type magnetic head which is equipped with a writing core for writing said magnetic data on said card and a writing-side coil wound around said writing core and in which said reading core and said writing core are integrated;
wherein said non-reading current-generating means is connected to a writing-side signal wire to which said writing-side coil is connected; and
wherein an amplitude of a wave of said non-reading current is smaller than that of a wave of a writing current for writing said magnetic data on said card.
4. The card reader according to claim 3 ;
wherein said non-reading current-generating means is a writing current-generating means which generates said writing current to said writing-side coil.
5. The card reader according to claim 1 ;
wherein an amplitude of the wave of said non-reading current is equal to that of a wave of said reading current.
6. The card reader according to claim 1 ;
wherein the period of the wave of said non-reading current varies irregularly within a range of periods determined by the recording density of said magnetic data and the moving speed of said card in said card reader.
7. The card reader according to claim 1 ;
wherein an intensity of a magnetic field generated by said magnetic head when said non-reading current is applied to said reading-side coil is weaker than a coercivity of a magnetic stripe formed on said card.
8. The card reader according to claim 1 , further comprising:
a reading status-detecting means for detecting that the reading of said magnetic data is performed by said magnetic head;
wherein said non-reading current-generating means is configured to suspend said non-reading current, which has been generated to said reading-side coil, right before said magnetic head starts reading said magnetic data, based on the detection result of said reading-status detecting means; and
wherein said non-reading current-generating means is configured to start generating said non-reading current to said reading-side coil after said magnetic head finishes reading said magnetic data.
9. The card reader according to claim 1 , further comprising:
a circuit board on which said non-reading current-generating means is mounted;
wherein a non-reading current component-cancelling means is mounted on said circuit board for cancelling out the component of said non-reading current of the current flowing through said reading-side coil.
10. The card reader according to claim 1 , further comprising:
a reading status-detecting means for detecting that said magnetic head is performing the reading of said magnetic data; and
a circuit board on which said non-reading current-generating means is mounted;
wherein a non-reading current component-cancelling means is mounted on said circuit board for cancelling out the component of said non-reading current of the current flowing through said reading-side coil; and
wherein, based on the detection result of said reading-status detecting means, said non-reading current-generating means generates said non-reading current to said reading-side coil before said magnetic head starts reading said magnetic data and stops generating said non-reading current to said reading-side coil after said magnetic head finishes reading said magnetic data.
11. The card reader according to claim 1 ;
wherein a non-reading current-detecting means is equipped for detecting that said non-reading current is generated to said reading-side coil.
12. A control method of a card reader equipped with a magnetic head which has a reading core for reading magnetic data recorded on a card and a reading-side coil wound around said reading core, comprising:
a non-reading current-generating step which generates a non-reading current, other than a reading current that flows through said reading-side coil at the time of the reading of said magnetic data, to said reading-side coil before said card is inserted to said card reader;
a non-reading current-halting step which stops generating said non-reading current which has been generated to said reading-side coil before said magnetic head starts reading said magnetic data; and
a non-reading current re-generating step which resumes generating said non-reading current to said reading-side coil after said magnetic head finishes reading said magnetic data;
wherein a period of the wave of said non-reading current is a period determined by a recording density of said magnetic data recorded on said card and a moving speed of said card in said card reader.
13. A control method of a card reader equipped with a magnetic head which has a reading core for reading magnetic data recorded on a card and a reading-side coil wound around said reading core, comprising:
a non-reading current-generating step which generates to said reading-side coil a non-reading current, other than a reading current that flows through said reading-side coil at the time of the reading of said magnetic data, before said magnetic head starts reading said magnetic data; and
a non-reading current-halting step which stops generating said non-reading current to said reading-side coil after said magnetic head finishes reading said magnetic data;
wherein, in said non-reading current-generating step, a component of said non-reading current is cancelled out of the current flowing through said reading-side coil at a circuit board of said card reader; and
wherein a period of the wave of said non-reading current is a period determined by a recording density of said magnetic data recorded on said card and a moving speed of said card in said card reader.