JPS6391826A - Method for preventing forgery of magnetic recording medium - Google Patents

Abstract

PURPOSE:To reduce the cost of production and to prohibit transfer by encoding the distance information between regions where arrangement is disturbed, comparing and collating the distance information and encoding information at the time of reading out the information, then judging the true ticket when both coincide with each other. CONSTITUTION:The distance between the regions where the arrangement is disturbed is measured by an electrical means. The distance information is encoded and the encoding information is encoded to the region where a magnetic material is arranged horizontally in one direction. The distance information and the encoding information are compared and collated at the time of reading out the information of a magnetic recording medium. More specifically, the distance information l1, l2 read by a reading head 82 are encoded in a signal processing and encoding circuit 85. Whether both of the distance information l1, l2 read by the head 82 and the magnetic recording information L1, L2 read by a reading head 83 coincide or not is checked in a true-false discriminating circuit 88. A signal for 'true' is transmitted to a circuit connected to the main circuit if the information coincide and a signal for 'false' is transmitted to the circuit connected to the main circuit if the information do not coincide with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Application The present invention relates to a method for preventing counterfeiting of magnetic recording media applied to cash cards of toll road t-payment collection systems.

(Prior Art) Conventionally, in order to prevent counterfeiting of magnetic recording media, it is important to prevent magnetic recording contents from being transferred. To solve this problem, the magnetic recording medium has a two-layer structure consisting of a magnetoresistive layer and a high coercive force layer, and the low coercive force layer encodes meaningless noise, while the high coercive force layer encodes normal information. It has been practiced to encode information in the high coercive force layer to erase noise in the low coercive force layer when reading the information, and then read information in the high coercive force layer (Japanese Patent Publication No. 185/1985).

In addition, a method has been implemented in which card-specific information, for example, information encoded with paper fiber patterns, is magnetically recorded on each magnetic card, and the magnetically recorded contents are compared with the card-specific information (Japanese Patent Laid-Open Publication No. 57-97188).

(Problems to be Solved by the Invention) However, the prior art has the following problems. In other words, in a two-layer magnetic recording medium, two
r! 1 magnetic recording layer must be applied. Also, a device that inputs magnetically recorded information into a magnetic recording medium and reads this magnetically recorded information! ! This increases manufacturing costs because an extra head is required to write and read the noise signal.

Furthermore, even if the recorded contents cannot be copied using the above-mentioned magnetic recording medium, it is possible to erase the information that has been written into it and manufacture a new λ card, and it is possible to reliably prevent G4 production. Can not.

Furthermore, the device for encoding card-specific information described in Japanese Unexamined Patent Publication No. 57-97188@ has a problem in that it is generally expensive.

Therefore, the object of the present invention is not to use the two-layer magnetic recording medium that is costly as described above, but to
r! is a magnetic recording medium counterfeit prevention method that uses H magnetic recording media and prevents recorded contents from being copied without hooding the pattern. It's there to serve you.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides III in which the axis of easy magnetization of the magnetic substance is arranged in the plane direction of the base, and the gJ axis of the magnetic substance in 1F to the base! In a magnetic recording medium that has a plurality of regions arranged perpendicularly or at a certain angle to the arrangement direction and in which this arrangement is disturbed, the distance between the regions in which the arrangement is disturbed is determined by electrical means. This distance information is encoded, and this encoded information is encoded in an area arranged horizontally in one direction of the magnetic body, and when reading the information tfi of the magnetic recording medium, the distance information and the encoded information are encoded. The paper is compared and verified, and if the two match, it is determined to be a genuine bill.

(Function) Therefore, in the present invention, since a single layer magnetic recording medium is used, the manufacturing cost is reduced, and furthermore, during manufacturing, it is possible to reduce the thickness of the distribution area that starts from the horizontal direction. ! ! By setting a different distance for each magnetic recording medium when installing the cards over several days, it is possible to encode different distance information on all cards, and the same information can be encoded in a manner specific to the magnetic recording medium. If the magnetic material is erased and issued, it will not be possible to transfer it.

Furthermore, measuring distance information electrically is disclosed in Japanese Patent Application Laid-Open No. 57-97188J, which is described in the conventional example. Since it is different from pattern recognition as in the official bulletin, it is a simple method and
Can accurately read media-specific information.

(Example) Hereinafter, Example-XI of the present invention will be explained with reference to the first to FIG. Here, FIG. 1 shows the shape of a magnetic recording medium, and FIG. 2 shows a detection output waveform from a magnetic head. In FIG. 1, numeral 11 indicates a magnetic reading head, and numeral 12 indicates a detection coil. Further, 13 is a magnetic layer, for example, barium ferrite (Ba0.6Fe203), which has a needle-like F layer at the lli end.
! i! Rather, a magnetic material with relatively high magnetic anisotropy is applied together with a binder and a layer material onto the algal bodies 16 such as plastic.

14, the axis of easy magnetization (C-axis) is [aligned (orientated) parallel to the direction of travel of the n-type write (read) head" L1
5 shows *tit in which the axis of easy EtJ formation is oriented in the vertical direction. Such a magnetic recording medium is realized by simultaneously applying a binder and a layer material to the substrate 16 and applying magnetic lines of force in a desired direction of magnetization using a single-layer magnet or the like in a relatively fluid state.

Further, 21 indicates the detection output level from the magnetic reading head 11, and the detection output signal is the detection output level from the reading head 11.
1g! realized by amplifying the output signal from the detection coil 12 of ! The written signal is modulated at a certain frequency Ia, and the signal output is obtained by WL flow detection of the written signal. Therefore, in the region 15 where the easy axis of magnetization is oriented perpendicularly, the magnetic field lines are perpendicular to the easy axis, so the magnetic field lines are the highest, while the easy axis of magnetization is the read head (11
When the magnetic field is oriented in the direction of travel with respect to the head (containing head), the lines of magnetic force are parallel to the axis of easy boration, making it the easiest to magnetize.

FIG. 3 shows a conductor coded with an anti-counterfeit pattern according to the present invention. ! ! Directly above patternAs shown in the figure, they are arranged at a distance MIQs, β2 apart, and a distance tm21 . /
12 is set, and the magnetic head scans on the Y-Y line.
The distance information is encoded (λr −Lt, Q2→L
2)'Y-Yl! written to the upper track.

FIG. 4 shows a control block diagram of the pattern coding device of the present invention. In the figure, 41 is a DC magnetization head that scans the X-X axis shown in FIG. 3, 42 is a forgery prevention pattern code reading head,
-It is installed along the X axis.

Reference numeral 44 denotes an amplifier circuit that converts the anti-counterfeit pattern signal read by the reading head 42 into layers. 45 is an amplifier circuit 44
a rectifier circuit that passes only positive component signals from 4;
6 is a Schmitt circuit that passes signals above a certain threshold;
47 is a monostable multivibrator, which sends out an on signal in response to a set signal from the Schmitt circuit 46.

This ON signal continues to be sent until an OFF signal is received from the inverter circuit 412. 48 shows the signal waveform of the monostable multivibrator 47 for a certain time τl.
49 is an AND gate circuit,
410 is a rectifier circuit that passes only the negative component signal from the amplifier circuit 44, 411 is a Schmitt circuit that passes signals above a certain threshold, 412 is an inverter circuit that sends a reset signal to the monostable multivibrator 47, and 413 is a A rectifier circuit that passes only the positive component signal from the AND gate circuit 49; 414 is a time delay circuit that delays the signal waveform from the rectifier circuit 413 by a certain time τ2; 415 is set by a signal from the time delay circuit 414; Counter circuit 42 in gate circuit 416
417 is a tarok circuit, 418 is a counter circuit that counts clock pulses from this clock circuit 417, and 419 is a negative component from AND gate 49. A rectifier circuit that passes only the signal of 420 is the monostay blue multivibrator 4
15, an inverter circuit that sends a reset signal to the counter circuits 1423 and 418. Here, the counter circuit 42
3 counts the signal from the time delay circuit 414 and sends a reset signal to the monostable multivibrator 415 when it reaches 3 pulses.

Next, the operation of the pattern coding device shown in FIG. 4 will be explained with reference to the timing chart shown in FIG. 6. The DC magnetization head 41 and the read head 42 are arranged on the X-X axis of the magnetic recording medium.
1, and then pattern information is read by a read head 42.

After being magnetized by the DC magnetization head 41, the read head 42
When the winding reaches the end, a positive pulse (1) is induced in the read head 42, and this signal is amplified by the amplifier circuit 44. Thereafter, since the amplified signal a is a positive signal, it passes through the rectifier circuit 45-2, but the Schmitt circuit 46 shapes only the pulses with a certain peak value and outputs the signal from the monostable multivibrator 47. q
Thereafter, the time delay circuit 48 obtains an output signal c8 delayed by a certain period of time τ1. Therefore, the plus direction pulse (1) output from the end of the winding is removed from the AND gate circuit 49.

Then, read head 4 at the vertically patterned position.
If 1 scans, sequentially (if), (il)
.

Waveforms as shown in (iv) and (v) are output, and a waveform signal d is obtained via a rectifier circuit 413 and a time delay circuit 272414. This waveform signal d sets the monosdible multivibrator 415.

While the main output signal @d is being output, the clock pulse CLK passes through the AND gate 416 to obtain the output signal e. The output signal set due to the positive direction pulse of the pulse waveform 11) is reset by the negative direction pulse of the pulse waveform (Iii). That is, the output signal from the AND gate circuit 49 is rectified by the rectifier circuit 419, allowing only the negative of the signal a to pass, and the signal is reversed by the inverter circuit 420. 423 is reset. When the counter circuit 41B is reset, distance information is sent to the device connected to this circuit at that timing. Ll'.

12' are vertically patterned feeds IPIII, respectively.
.

This is the distance S information of ■, ■, and ■. Also ■, the distance between V! For information, the output pulse d is measured from the counter circuit 423, and based on (2) (when M@ is counted, the counter circuit 423 sends a reset signal to the monostable multivibrator 415 (reset during the set v4). Therefore, the counter circuit 418 does not count.

In the above example, three vertically patterned areas (
L rfl, IV), but is not limited to this.

The above description has been made regarding the case of scanning only on the X-X axis, but next, the case of scanning on the X-X axis and the Y-Y axis will be described with reference to FIG. 5. FIG. 5 is a control block diagram of the pattern coding device of the present invention. In the figure,
51 is a DC magnetization head that scans the X-X axis shown in FIG. 3; 52 is a forgery prevention pattern code reading head;
Like the DC magnetization head 51, it is attached along the X-X axis. 53 is a write head for writing information read by the head 52, and Y shown in FIG.
-It is installed along the Y axis. , 54 is an amplifier circuit that amplifies the anti-counterfeit pattern read by the reading head, 55 is a rectifier circuit that passes only the positive component signal from the amplifier circuit 54, 56 is a Schmitt circuit that passes signals of a certain value or higher, and 57 is a monostable multivibrator which sends an on signal in response to a set signal from the Schmitt circuit 56 and continues to send it until it receives an off signal from the inverter circuit 412. 58 is a time delay circuit that delays the signal waveform from the monostable multivibrator 57 by a certain time τ1, 59 is an AND gate circuit, 510 is a rectifier circuit that passes only the negative component signal from the amplifier circuit 54, and 511 is a certain threshold value. 512 is an inverter circuit that sends a reset signal to monostable multipibrator 57, 513 is a rectifier circuit that passes only the positive component signal from AND gate circuit 59, and 514 is a rectifier circuit that passes the above signals. 515 is a monostable multi-by-break circuit which is set by the signal from the time delay circuit 514 and sends a reset signal from the counter circuit 523 to the AND gate circuit 516; clock circuit, 518
519 is a rectifier circuit that passes only the negative component from the AND gate circuit 59; 520 is a monostable multivibrator 515; counter circuit 52;
an inverter circuit that sends a reset signal to 3°518;
521 is a coding circuit that codes the count signal from the counter circuit 518, and 522 is an amplifier circuit. The counter circuit 523 counts the signal from the time delay circuit 514 and sends a reset signal to the monostable multivibrator 515 when it reaches three pulses.

Next, regarding the operation of the pattern coding device shown in Fig. 5,
This will be explained according to the timing chart shown in FIG. The DC magnetization head 51 and the read head 52 are arranged on x-xm, and the magnetic recording medium is first DC magnetized by the DC magnetization head 51, and then the pattern information is read by the read head 52.

After being DC magnetized by the DC magnetization head 51, the reading head 5
2 reaches the winding end, a positive pulse (1) is induced in the read head 52, and this signal a is transmitted to the amplifier circuit 5.
It is amplified by 4. Thereafter, since this signal is a positive signal, it passes through the rectifier circuit 55. Schmitt circuit 56
obtains a signal output from the monostable multivibrator 57 by waveform shaping only a pulse having a certain peak value, and then obtains an output signal @C delayed by a certain time τ1.

Therefore, the positive pulse (1) output from the end of the winding is removed from the AND gate circuit 59.

Thereafter, the vertically oriented position is transferred to the magnetization head 52.
scans, sequentially (It), (tii).

A waveform signal dJE: shown in (iv) and (v) is output, and the waveform signal dJE: is obtained via the rectifier port 1'g513.times11131!recircuit 514. Sera 515]・Do.

While this output signal is being output, the clock pulse CLK
passes through the AND gate circuit 516 and obtains an output signal 0. The output signal set due to the positive direction pulse of the pulse waveform (11) is reset by the negative direction pulse of the pulse waveform (iii). That is, the output signal from the AND gate circuit 59 is input to the rectifier circuit 519.
HR is applied, only the negative signal a is passed through, the signal is reversed by the inverter circuit 520, and the monostable multivibrator 515, counter circuit 518, and counter circuit 523 are reset. When the counter circuit 518 is reset, the number of pulses counted so far is encoded by the encoding circuit 521, and the encoded signal Ll
, A2 are output. The signals L1 and A2 are coded signals corresponding to the vertically patterned distance information of vAAl1■, ■, and ■, respectively.

Regarding the distance information between the areas (■ and v), the counter circuit 523 counts the waveform signal d, and when the signal based on 1v is counted, the counter circuit 523 sends a reset signal to the monostaple multivibrator 515 (set counter circuit 518 does not count.

The coded signal @Lt mentioned above, A2 is increased vA
It is amplified by the YfA path 522 and written by the marking head 53, which scans on the Y-Y axis shown in FIG. 3 and records the magnetization pattern (Lx, A2).

Next, a circuit for determining authenticity of a magnetic recording medium according to the present invention will be explained with reference to FIG.

In the figure, 81 is a DC magnetization head, 82 is a reading head mounted on the X-X axis in FIG. 3, and 83 is a Y-Y in FIG.
A reading head mounted on the shaft; 84 is an amplifier circuit for amplifying the signal read by the reading head 82; 85 is a signal processing and encoding circuit;
The distance information shown in FIG. 3 read by
(Coding 12. Signal processing and encoding circuit 85
is realized by the circuits shown in the block diagram of FIG. 5, from rectifier circuit 55 to encoding circuit 521. 86 is the reading head 8
3 is an amplifier circuit that amplifies the information read, 87 is the third
Magnetic recording medium Ls written on the Y-Y axis shown in the figure
, A2, and 88 is a coding circuit that reads and codes distance information flx , (A2) read by the reading head 82.
2 and the magnetic record t&information Ls read by the reading head 83
, A2 both match, and if they match, a "true" signal is sent to the circuit connected to this circuit, and if they do not match, a "true" signal is sent to the circuit connected to this circuit. This is a true discrimination circuit that sends out a "false" signal.

As is clear from the above, even if you try to transfer information from a magnetic recording medium as shown in FIG.
．． Since ρ2 can be unique for a magnetic recording medium, it is possible to completely prevent counterfeiting.

[Effect of R-light J According to the present invention described above, f14vA is such that the axis of easy magnetization of the magnetic substance is aligned in the plane direction of the base body, and the axis of easy magnetization of the magnetic body is aligned perpendicularly to the base body or In a magnetic recording medium that has a plurality of seismic areas arranged at a certain angle to the arrangement direction and in which this arrangement is disturbed, the distance of the Snx leap where the arrangement is disturbed is measured by electrical means. , this distance information is encoded in the fR region arranged horizontally in one direction of the magnetic body, and when reading information from the magnetic recording medium, the cost becomes higher than the distance information. Provides a method for preventing the C formation of a magnetic 21111 body, which uses a 1 m magnetic recording n* body instead of using a 2@ magnetic recording medium, and prevents the recorded contents from being copied without further encoding the pattern. can.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the shape of a magnetic recording medium according to one embodiment of the present invention fIvI4, Fig. 2 is a diagram showing the detection output of the magnetic head, and Fig. 3 is a diagram showing the detection output of the magnetic head.
4 and 5 are control block diagrams of the pattern encoding device of the present invention, and FIG. 6 is a diagram showing the coded state of the anti-counterfeit pattern of the present invention. ! 11 is a time chart diagram, and FIG. 7 is a circuit diagram for determining authenticity of the magnetic recording medium of the present invention. 11... Magnetic reading head, 12... Detection coil, 1
3... Magnetic layer, 14.15... Region, 16... Substrate, 41.51... DC magnetization head, 42.52...
・Reading head, 53...Writing head, 44.54...
・Amplifier circuit, 45.55... Rectifier circuit, 46.56・
... Schmitt circuit, 47.57... Monostable multivibrator, 48.58... Time delay circuit,
49°59...AND gate circuit, 410.510.
... Rectifier circuit, 411,511... Schmitt circuit,
412゜512...Inverter circuit, 413.513
... Rectifier circuit, 414.514 ... Time delay circuit,
415゜515... Monostable multivibrator, 417.517... Clock circuit, 418.51
8... Counter circuit, 419.519... Rectifier circuit, 420.520... Inverter circuit, 521...
Encoding circuit, 522...Amplification circuit, 42-3, 52
3...Counter circuit. Applicant Sub-Agent Patent Attorney Takehiko Suzue Figure 2 Figure 3 Figure 7

Claims (1)

[Claims] A region in which the easy axis of magnetization of the magnetic material is arranged in the plane direction of the substrate, and a region in which the easy axis of magnetization of the magnetic material is arranged in a direction perpendicular to the substrate or at a certain angle to this arrangement direction, and In a magnetic recording medium having a plurality of disarranged regions, the distance between the disarranged regions is measured by electrical means, this distance information is encoded, and this encoded information is transferred to the magnetic material. The distance information is encoded in areas arranged in one horizontal direction of the magnetic recording medium, and when information is read from the magnetic recording medium, the distance information and the encoded information are compared and verified, and if both match, the bill is determined to be genuine. A method for preventing counterfeiting of magnetic recording media.