DISTURBING MAGNETIC FIELD GENERATOR AND CARD READER
20210406488 · 2021-12-30
Inventors
Cpc classification
International classification
Abstract
Provided are a disturbing magnetic field generator and a card reader capable of suppressing the generation of noise caused by vibration of a core. A disturbing magnetic field generator that generates a disturbing magnetic field for disturbing unauthorized reading of magnetic data recorded on a card includes a coil to generate the disturbing magnetic field, a bobbin including a tubular body part in which the coil is wound on an outer peripheral side, and a core disposed inside the tubular body part. A first gap is provided between the tubular body part and the core.
Claims
1. A disturbing magnetic field generator that generates a disturbing magnetic field for disturbing unauthorized reading of magnetic data recorded on a card, the disturbing magnetic field generator comprising: a coil to generate the disturbing magnetic field; a bobbin comprising a tubular body part in which the coil is wound on an outer peripheral side; and a core disposed inside the tubular body part, wherein a first gap is provided between the tubular body part and the core.
2. The disturbing magnetic field generator according to claim 1, wherein the tubular body part and the core are bonded by a soft adhesive provided in the first gap.
3. The disturbing magnetic field generator according to claim 1, comprising a circuit board disposed so as to overlap the coil, the circuit board comprising a circuit to feed the coil, the bobbin comprising a plurality of projection parts, wherein the circuit board is fixed to the bobbin via the plurality of projection parts.
4. The disturbing magnetic field generator according to claim 3, wherein the circuit board is bonded to the bobbin by a soft adhesive provided between the circuit board and the plurality of projection parts.
5. The disturbing magnetic field generator according to claim 1, comprising a circuit board disposed so as to overlap the coil, the circuit board comprising a circuit to feed the coil, wherein a second gap is provided between the circuit board and the coil.
6. The disturbing magnetic field generator according to claim 5, wherein the circuit board and the coil are bonded by a soft adhesive provided in the second gap.
7. A card reader comprising the disturbing magnetic field generator according to claim 1, the card reader comprising a card insertion part provided with an insertion slot through which the card is inserted, the disturbing magnetic field generator comprising a case in which the coil, the bobbin, and the core are housed inside, the card insertion part comprising a case housing part in which the case is housed inside, wherein the case is housed in the case housing part in such a manner that an outer wall of the case and an inner wall of the case housing part face each other via a third gap in an extending direction of the core.
8. The card reader according to claim 7, wherein the case and the inner wall of the case housing part are bonded by a soft adhesive provided in the third gap.
9. The card reader according to claim 7, the case comprising a case main body formed in a shape of a rectangular box with an openable upper side, wherein the upper side of the case main body is released.
10. The disturbing magnetic field generator according to claim 2, comprising a circuit board disposed so as to overlap the coil, the circuit board comprising a circuit to feed the coil, the bobbin comprising a plurality of projection parts, wherein the circuit board is fixed to the bobbin via the plurality of projection parts.
11. The disturbing magnetic field generator according to claim 10, wherein the circuit board is bonded to the bobbin by a soft adhesive provided between the circuit board and the plurality of projection parts.
12. The disturbing magnetic field generator according to claim 2, comprising a circuit board disposed so as to overlap the coil, the circuit board comprising a circuit to feed the coil, wherein a second gap is provided between the circuit board and the coil.
13. The disturbing magnetic field generator according to claim 12, wherein the circuit board and the coil are bonded by a soft adhesive provided in the second gap.
14. A card reader comprising the disturbing magnetic field generator according to claim 11, the card reader comprising a card insertion part provided with an insertion slot through which the card is inserted, the disturbing magnetic field generator comprising a case in which the coil, the bobbin, and the core are housed inside, the card insertion part comprising a case housing part in which the case is housed inside, wherein the case is housed in the case housing part in such a manner that an outer wall of the case and an inner wall of the case housing part face each other via a third gap in an extending direction of the core.
15. The card reader according to claim 14, wherein the case and the inner wall of the case housing part are bonded by a soft adhesive provided in the third gap.
16. A disturbing magnetic field generator that generates a disturbing magnetic field for disturbing unauthorized reading of magnetic data recorded on a card, the disturbing magnetic field generator comprising: a coil to generate the disturbing magnetic field; a bobbin comprising a tubular body part in which the coil is wound on an outer peripheral side; a core disposed inside the tubular body part; and a circuit board disposed so as to overlap the coil, the circuit board comprising a circuit to feed the coil, wherein a second gap is provided between the circuit board and the coil.
17. The disturbing magnetic field generator according to claim 16, wherein the circuit board and the coil are bonded by a soft adhesive provided in the second gap.
18. A card reader comprising: a card insertion part provided with an insertion slot through which a card is inserted; and a disturbing magnetic field generator that generates a disturbing magnetic field for disturbing unauthorized reading of magnetic data recorded on the card, the disturbing magnetic field generator comprising: a coil to generate the disturbing magnetic field; and a case in which the coil and a core are housed inside, the card insertion part comprising a case housing part in which the case is housed inside, wherein the case is housed in the case housing part in such a manner that an outer wall of the case and an inner wall of the case housing part face each other via a third gap in an extending direction of the core.
19. The card reader according to claim 18, wherein the case and the inner wall of the case housing part are bonded by a soft adhesive provided in the third gap.
20. The card reader according to claim 18, the case comprising a case main body formed in a shape of a rectangular box with an openable upper side, wherein the upper side of the case main body is released.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Embodiments will now be described, by way of example only with reference to the accompanying drawings which are meant to be exemplary not limiting, and wherein like elements are numbered alike in several figures, in which:
[0021]
[0022]
[0023]
[0024]
[0025]
[0026]
[0027]
DETAILED DESCRIPTION
[0028] With reference to the drawings, a card reader and a disturbing magnetic field generator, to which at least an embodiment of the present invention is applied, is described. The soft adhesives and sealing resins described below mean, for example, adhesives and sealing resins having elasticity with a Shore A of 500 or less.
Schematic Configuration of Card Reader
[0029]
[0030] The card reader 1 illustrated in
[0031] The card reader 1 includes a magnetic head 7 that performs at least one of reading magnetic data recorded on the card 2 and recording magnetic data onto the card 2. In addition, the card reader 1 includes a drive roller 8 and a pad roller 9 for conveying the card 2. Moreover, the card reader 1 includes a disturbing magnetic field generator 10 that generates a disturbing magnetic field for disturbing unauthorized reading of magnetic data recorded on the card 2.
[0032] In the card reader 1, the card 2 transfers in the X direction illustrated in
[0033] In the following description, the X direction is referred to as the “front-rear” direction, the Y direction is referred to as the “right-left” direction, and the Z direction is referred to as the “up-down” direction. In addition, one side of the front-rear direction (X1 direction side in
[0034] The card 2 is, for example, a card made of vinyl chloride of a rectangular shape having a thickness of approximately 0.7 to 0.8 mm. On the back side of the card 2, a magnetic stripe is formed in which magnetic data is recorded. The magnetic stripe is formed along the longitudinal direction of the card 2 which is formed in a rectangular shape. The card 2 is inserted into the card reader 1 with the back side of the card 2 facing downward and with the longitudinal direction of the card 2 substantially coinciding with the front-rear direction, and is conveyed in the card transfer path 6. An IC chip may be incorporated in the card 2. In addition, the card 2 may be a card made of polyethylene terephthalate having a thickness of approximately 0.18 to 0.36 mm, or a paper card or the like having a predetermined thickness.
[0035] The card insertion part 4 is attached to the front end face of the main body part 5. The card insertion part 4 is formed in a hollow shape, and the disturbing magnetic field generator 10 is disposed inside the card insertion part 4. The disturbing magnetic field generator 10 of this embodiment is disposed on the upper side of the card transfer path 6. Note that the disturbing magnetic field generator 10 of this embodiment may be disposed on the lower side of the card transfer path 6. The specific configuration of the disturbing magnetic field generator 10 will be described later.
[0036] The magnetic head 7, the drive roller 8, and the pad roller 9 are disposed inside the main body part 5. The magnetic head 7 is disposed so as to face the card transfer path 6 from below. In addition, the magnetic head 7 is disposed in the right-left direction at a position through which the magnetic stripe of the card 2 passes. A motor is connected to the drive roller 8 via a power transmission mechanism such as a belt or pulley. The drive roller 8 and the pad roller 9 face each other in the up-down direction. The pad roller 9 is urged toward the drive roller 8. The card 2 is conveyed in a state of being sandwiched between the drive roller 8 and the pad roller 9.
[0037] As illustrated in
[0038] In the card reader 1 thus configured, when the card 2 is inserted into the card insertion slot 3 and the card 2 is taken into the card reader 1, the disturbing magnetic field generator 10 generates a disturbing magnetic field until, for example, the entire card 2 inserted into the card insertion slot 3 is taken into the card insertion part 4. In addition, in the card reader 1, when the card 2 is ejected from the card insertion slot 3, the disturbing magnetic field generator 10 generates a disturbing magnetic field until, for example, the card 2, which has been conveyed to a position where the card 2 can be withdrawn by a user, is withdrawn by the user. In other words, when reading or recording magnetic data by the magnetic head 7, the disturbing magnetic field generator 10 does not generate any disturbing magnetic field.
[0039] Overall Configuration of Disturbing Magnetic Field Generator 10
[0040] As illustrated in
[0041] The core 11 is a laminated core made of thin magnetic plates. In this embodiment, the core 11 includes a plurality of core dividers 21 to 25 that are formed separately, and five core dividers 21 to 25 are integrated. Since the core 11 is a laminated core formed by laminating thin magnetic plates, the core dividers 21 to 25 are also laminated cores formed by laminating thin magnetic plates.
[0042] The core dividers 21 to 25 are each formed in the shape of a linearly extending rod. More specifically, the core dividers 21 to 25 are formed in the shape of elongated substantially quadrangular prisms. The core dividers 21 to 24 are arranged in such a manner that the longitudinal direction coincides with the front-rear direction. In addition, the core dividers 21 to 24 are arranged parallel to each other with a certain interval in the right-left direction. The core dividers 21 to 24 are arranged in this order from one side to the other in the right-left direction. The thicknesses of the core dividers 21 to 24 in the up-down direction are equal, and the widths of the core dividers 21 to 24 in the right-left direction are equal.
[0043] The core divider 25 is arranged in such a manner that the longitudinal direction coincides with the right-left direction. Rear ends 21a to 24a of the core dividers 21 to 24 are fixed to the core divider 25. More specifically, the thickness of the core divider 25 in the up-down direction is thicker than the thickness of the core dividers 21 to 24, and four recessed parts 25a are formed in the core divider 25, in which the rear ends 21a to 24a are fitted from above. The core dividers 21 to 24 are fixed to the core divider 25 with the rear ends 21a to 24a fitted in the recessed parts 25a. In addition, the core dividers 21 to 24 are fixed to the core divider 25 by, for example, an adhesive applied to the recessed parts 25a, and the five core dividers 21 to 25 are integrated by the adhesive. Here, the width in the right-left direction of the rear ends 21a to 24a of the core dividers 21 to 24 is narrower than the width in the right-left direction of the portions other than the rear ends 21a to 24a of the core dividers 21 to 24. The core divider 21 and the core divider 24 are formed in the same shape, and the core divider 22 and the core divider 23 are formed in the same shape. The length of the core dividers 21 and 24 are longer than the length of the core dividers 22 and 23.
[0044] In the core 11 thus configured, the core dividers 21 to 24 are each disposed inside the tubular body part 150 of the bobbin 15, and the coil 12 is wound on the core 11 through the tubular body part 150 of the bobbin 15. More specifically, the disturbing magnetic field generator 10 includes four coils 12, and each of the four coils 12 is wound on the core dividers 21 to 24 via the bobbin 15. The bobbin 15 includes flange parts 151 and 152 on both ends of the tubular body part 150, and the coil 12 is wound between the flange parts 151 and 152.
[0045] Here, the length of the core dividers 21 and 24 are longer than the length of the core dividers 22 and 23. For this reason, the length of the tubular body part 150 of the bobbin 15 attached to the core dividers 21 and 24 is longer than the length of the tubular body part 150 of the bobbin 15 attached to the core dividers 22 and 23. Accordingly, the length of the coil 12 wound on the core dividers 21 and 24 is longer than the length of the coil 12 wound on the core dividers 22 and 23.
[0046] In this embodiment, among the four tubular body parts 150, in the tubular body part 150 that is attached to the core dividers 22 and 23 at the inner side in the right-left direction, the flange parts 151 and 152 are provided with projection parts 156 and 157 that project upwardly. In this embodiment, the projection parts 156 and 157 are stepped projection parts having upwardly facing stepped parts 156a and 157a at middle positions in the up-down direction.
Internal Configuration of Tubular Body Part 150
[0047] As illustrated in
Configuration of Circuit Board 13
[0048] Again, in
[0049] When alternating current is supplied to the coil 12 from the power feed circuit 14, a disturbing magnetic field in which the direction of the magnetic line of force is directed from either one of a front end face 21b of the core divider 21 and a front end face 23b of the core divider 23 to either other of the front end face 21b and the front end face 23b and a disturbing magnetic field in which the direction of the magnetic line of force is directed from either one of a front end face 22b of the core divider 22 and a front end face 24b of the core divider 24 to either other of the front end face 22b and the front end face 24b are generated.
[0050] Specifically, when alternating current is supplied to the coil 12, a disturbing magnetic field in which the direction of the magnetic line of force varies periodically in the direction from the front end face 21b to the front end face 23b and in the direction from the front end face 23b to the front end face 21b and a disturbing magnetic field in which the direction of the magnetic line of force varies periodically in the direction from the front end face 22b to the front end face 24b and in the direction from the front end face 24b to the front end face 22b are generated.
[0051] The coil 12 may be connected to a power feed circuit that includes a DC power supply to which the coil 12 is connected and a capacitor connected in parallel with the coil 12 with respect to the DC power supply. In this case, the capacitor and the coil 12 constitute a resonance circuit. In addition, the coil 12 may be connected to a DC power supply via a circuit such as an inverter that converts DC to AC. Moreover, in both cases where an AC power supply is connected to the coil 12 and where a DC power supply is connected to the coil 12, the timing for fluctuating the direction of the magnetic line of force need not be periodic.
[0052] As illustrated in
Fixing Structure of Circuit Board 13
[0053] In
[0054] In this embodiment, as illustrated in
[0055] In this state, the circuit board 13 overlaps the coil 12 from above. However, since each of the projection parts 156 and 157 has an upwardly facing stepped parts 156a and 157a in the middle position in the up-down direction, a second gap G2 is formed between the circuit board 13 and the coil 12 as illustrated in
Configuration of Case 16
[0056] In
[0057] As illustrated in
Sealing Structure within Case 16
[0058] In the disturbing magnetic field generator 10 thus configured, the interior of the case 16 is sealed by a soft sealing resin R0 such as a urethane resin, a silicon resin, or a vinyl chloride resin. Such a configuration can be achieved by disposing the core 11, the coil 12, the circuit board 13, and the bobbin 15 inside the case 16, and then filling the inside of the case 16 with the sealing resin R0. In this embodiment, the sealing resin R0 is filled below the circuit board 13 from a nozzle through notches 13e and 13f (see
Fixing Structure of Case 16 in Case Housing Part 40
[0059] As illustrated in
[0060] In this state, as illustrated in
Main Effects of this Embodiment
[0061] As explained above, in this embodiment, since the first gap G1 is provided between the tubular body part 150 of the bobbin 15 and the core 11, transmission of vibration from the core 11 to the bobbin 15 is suppressed. In addition, since the tubular body part 150 and the core 11 are bonded by the soft adhesive R1 provided in the first gap G1, transmission of vibration from the core 11 to the bobbin 15 is suppressed even when the tubular body part 150 of the bobbin 15 and the core 11 are fixed. Accordingly, the generation of noise caused by the vibration of the core 11 can be suppressed.
[0062] In addition, since the coupling points between the bobbin 15 and the circuit board 13 are limited to the projection parts 156 and 157, transmission of vibration from the bobbin 15 to the circuit board 13 is suppressed. Moreover, since the circuit board 13 is bonded to the bobbin 15 by the soft adhesive R4 provided between the circuit board 13 and the plurality of projection parts 156 and 157, transmission of vibration from the bobbin 15 to the circuit board 13 is suppressed even when the bobbin 15 and the circuit board 13 are fixed. Accordingly, the generation of noise caused by the vibration of the core 11 can be suppressed.
[0063] In addition, since the second gap G2 is provided between the coil 12 and the circuit board 13, transmission of vibration from the coil 12 to the circuit board 13 is suppressed. Moreover, since the circuit board 13 and the coil 12 are bonded by the soft adhesive R2 provided in the second gap G2, transmission of vibration from the coil 12 to the circuit board 13 is suppressed even when the coil 12 and the circuit board 13 are fixed. Accordingly, the generation of noise caused by the vibration of the core 11 can be suppressed.
[0064] In addition, in the extending direction (front-rear direction) of the core 11, where vibration is easily transmitted, since the third gaps G31 and G32 are provided between the case 16 and the inner wall 48 of the case housing part 40, transmission of vibration from the case 16 to the inner wall 48 of the case housing part 40 is suppressed. Moreover, since the case 16 and the inner wall 48 of the case housing part 40 are bonded by the soft adhesive R3 provided in the third gaps G31 and G32, transmission of vibration from the case 16 to the inner wall 48 of the case housing part 40 is suppressed even when the case 16 and the inner wall 48 of the case housing part 40 are fixed. Accordingly, the generation of noise caused by the vibration of the core 11 can be suppressed.
[0065] In addition, the core 11, coil 12, and bobbin 15 housed in the case 16 are spaced apart from the inner surface of the case 16 so as not to contact the inner surface of the case 16. Accordingly, vibration of the core 11 can be suppressed from being transmitted to the case 16.
[0066] In addition, the core 11 includes five core dividers 21 to 25 that are formed separately. This makes it possible to raise the natural frequencies of the individual core dividers 21 to 25 and to shift the natural frequencies of the individual core dividers 21 to 25 out of the human audible frequency range. Moreover, in this embodiment, since the core 11 is formed by integrating five core dividers 21 to 25, which makes it possible to shift the natural frequency from the human audible frequency range, it is possible to suppress the noise generated by the disturbing magnetic field generator 10 even if the coil 12 is made smaller.
[0067] In addition, the sealing resin R0 is disposed between the core 11, the coil 12, and the bobbin 15, and the inner surface of the case 16. Therefore, the sealing resin R0 ensures that the core 11, the coil 12 and the bobbin 15 are not in contact with the inner surface of the case 16. Moreover, since the sealing resin R0 is soft, the vibration of the core 11 can be suppressed from being transmitted to the case 16.
Variation of Disturbing Magnetic Field Generator
[0068]
Variation of Core 11
[0069] In the above-described embodiment, the core 11 includes four core dividers 21 to 24 around which the coil 12 is wound. However, the core 11 may have two or three core dividers around which the coil 12 is wound, or five or more core dividers around which the coil 12 is wound. In addition, in the above-described embodiment, the core 11 includes the five core dividers 21 to 25 that are formed separately. However, the core 11 may be formed as a single unit. That is, in the above-described embodiment, the core 11 is divided into the core dividers 21 to 25, but the core 11 need not be divided into core dividers. In the above-described embodiment, the card reader 1 may be a manual card reader in which a user performs reading and recording magnetic data while manually moving the card 2.