JP2015172986A - Magnetic card reading device, magnetic noise detection method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an MSR(Magnetic Stripe Reader) having a function capable of knowing the actual influence of a magnetic noise and a method for determining the influence of the magnetic noise.SOLUTION: An MSR head part 21 in an MSR 1 is used for both the reading of magnetic data and the detection of a magnetic noise waveform, and configured to calculate a magnetic noise level from the detected magnetic noise waveform, and to compare the magnetic noise level with a predetermined threshold to determine the influence of a magnetic noise on the reading of the magnetic data. Thus, it is possible to detect the actual influence of the magnetic noise on the MSR without using any expensive or complicate magnetic field distribution measurement device.

Description

  The present invention relates to a magnetic card reader having a magnetic noise detection function, a magnetic noise detection method using the magnetic card reader, and a program for executing the method.

  A magnetic card reader (hereinafter referred to as “MSR”) detects the magnetic noise as data if there is a device that generates magnetic noise nearby due to its structure. there is a possibility. There is a magnetic field distribution measuring device as a device for specifying a source of magnetic noise that affects the MSR.

  Patent Document 1 proposes an MSR with good operability that can be read stably and easily by reducing the influence of fluctuations in the reading speed of the magnetic card and lowering of the magnetization level of the magnetic card. Patent Document 2 describes a magnetic field distribution measuring apparatus that measures the influence of electromagnetic field noise on electronic equipment and the magnetic field strength distribution.

JP 2001-236604 A JP 2008-111741 A

  However, the conventional method of identifying magnetic noise with a magnetic field distribution measuring device is to identify magnetic noise using an antenna such as a near magnetic field probe dedicated to the magnetic field distribution measuring device, and apply the identified magnetic noise to the MSR head unit to affect the magnetic noise. It is necessary to investigate. For this reason, the method of identifying magnetic noise by the magnetic field distribution measuring apparatus has been difficult to reproduce the actual influence of magnetic noise on the MSR, although it requires a complicated investigation using an expensive measuring instrument.

  Accordingly, an object of the present invention is to provide an MSR having a function capable of knowing an actual influence of the magnetic noise on the MSR and a magnetic field noise influence determination method using the MSR.

  The MSR according to the first aspect of the present invention reads magnetic data from a magnetic card and outputs a read data waveform, and also outputs a magnetic head portion that outputs induced magnetic noise as a noise waveform, and magnetically outputs the output data waveform. A decoder that converts the data into data and outputs the magnetic noise level that represents the magnitude of the magnetic noise from the output noise waveform, and calculates the magnetic noise level that is acceptable for reading the magnetic data. And a magnetic noise determination unit that determines that the magnetic data reading has an influence of magnetic noise when the magnetic noise level exceeds the threshold.

  The magnetic field noise detection method according to the second aspect is a magnetic field noise detection method using the MSR, and includes a first process for shifting to a mode for determining the influence of magnetic noise, and a noise waveform output from the magnetic head unit. A second process for calculating a magnetic noise level representing the magnitude of the magnetic noise from the second stage, and comparing the calculated magnetic noise level with a threshold value representing the magnitude of the magnetic noise that can be tolerated for reading magnetic data, And a third process for determining that the reading of magnetic data is affected by magnetic noise when the noise level exceeds the threshold value.

  A program according to a third aspect causes a computer to execute the first process, the second process, and the third process.

  According to the present invention, the magnetic head portion in the MSR is used both for reading magnetic data and detecting a magnetic noise waveform, calculating a magnetic noise level from the detected magnetic noise waveform, and calculating the magnetic noise level and a predetermined threshold value. Are compared to determine the influence of magnetic noise on the reading of magnetic data. Thereby, it is possible to know the actual influence of the magnetic noise on the MSR without using an expensive and complicated magnetic field distribution measuring apparatus.

It is a block diagram which shows the outline of MSR of embodiment of this invention. It is a figure explaining the detection method of the present magnetic noise. It is a figure explaining the detection method of the magnetic noise of the embodiment of the present invention. It is a wave form diagram of a MSR head reading part. It is a figure explaining determination of the presence or absence of interference of magnetic noise. It is a flowchart which shows the detection process of the magnetic noise of embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(Configuration of the embodiment)
FIG. 1 is a block diagram showing an outline of an MSR according to an embodiment of the present invention.
The MSR 1 includes an MSR equipped terminal 10 and an MSR unit 20. The MSR-equipped terminal 10 has a central processing unit (MCPU) 11 that controls the entire MSR1. The MCPU 11 communicates with the SCPU 23 of the MSR unit and has a function of setting the SCPU 23 to a state of reading data from the magnetic card. Further, it has a function of receiving data processed by the SCPU 23, and has a function of determining conditions and notifying the user from the data.

  The MSR unit 20 reads magnetic data written on the magnetic strap 31 in the magnetic card 30 in the reading mode, and detects disturbing magnetic noise in the test mode for determining the influence of the magnetic noise. The MSR head unit 21 A decoder 22, an SCPU 23 that controls the MSR unit 20, and an analog / digital (A / D) conversion unit 24.

  In the reading mode, the MSR head unit 21 outputs a voltage waveform obtained by reading magnetic data to the decoder 22 when the magnetic card 30 is scanned along the groove in the direction of the arrow. On the other hand, in the test mode, the MSR head unit 21 converts magnetic noise into a voltage waveform and outputs the voltage waveform to the A / D conversion unit 24.

  The decoder 22 outputs a digital signal of “1” and “0” from the analog signal of the voltage waveform read by the MSR head unit 21 and inputted by the route 1 in the reading mode. The decoder 22 outputs “1” when the peak value of the input voltage waveform exceeds a predetermined “1” reading threshold, and outputs “0” when it falls below the “0” reading threshold. To do.

  The SCPU 23 is a central processing unit that controls the MSR unit 20 and operates in cooperation with the MCPU 11. The SCPU 23 outputs a digital signal input from the decoder 22 to the MCPU 11 in the reading mode.

  The A / D conversion unit 24 converts the analog amplitude value of the voltage waveform read by the MSR head unit 21 and input through the route 5 into a digital value. For example, when a voltage waveform of 1 mV to 30 mV is input to the A / D conversion unit 24 through the route 5, it is converted into a 5-bit digital value. If the resolution per bit is 1 mV, the peak value 20 mV of the voltage waveform is converted to a digital value “010100”.

  Further, the SCPU 23 compares the magnetic noise level (digital value) representing the magnitude of the magnetic noise converted by the A / D conversion unit 24 with the determination threshold value of the disturbing magnetic noise, and the magnetic noise is detected by the magnetic data of the magnetic card 30. It is determined whether reading is affected. Here, the interference magnetic noise determination threshold is an allowable value of magnetic noise that does not cause interference when the MSR 1 reads magnetic data, and is a value obtained experimentally.

  The SCPU 23 constitutes a magnetic noise determination unit, and further includes notifying means (not shown) for notifying that when the magnetic noise level exceeds the determination threshold.

(Operation of the embodiment)
About magnetic field noise detection processing using MSR of the embodiment of the present invention, (I) current magnetic noise detection method, (II) magnetic noise detection method of the present invention, and (III) magnetic noise detection processing of the present invention The explanation will be divided into two.

(I) Magnetic Field Noise Detection Method Using Current MSR FIG. 2 is a diagram for explaining a current magnetic noise detection method. Elements common to FIG. 1 are denoted by common reference numerals.

  The current MSR 1A does not have the A / D converter 24 and the route 5 that were in the MSR 1 shown in FIG. Therefore, in order to investigate whether or not the magnetic noise radiated from the magnetic field generation source affects the magnetic data reading of the magnetic card 30, it is necessary to use the magnetic field strength measuring device 40.

  The magnetic field strength measuring device 40 measures magnetic field strength (A / m) by receiving magnetic noise from the magnetic field generation source via the attached antenna 41. The magnetic field strength measuring device 40 is generally covered with a solid magnetic shield and has a weight that is difficult to carry. The magnetic field strength measuring device 40 is generally expensive. Therefore, in the current magnetic noise detection method, it is necessary to bring the magnetic field strength measuring device 40 that is expensive and difficult to carry and measure the magnetic field strength (A / m) around the MSR 1A.

  Further, even if the magnetic field strength measuring device 40 having a weight that is expensive and difficult to carry is brought and the magnetic field strength is measured, in the current magnetic noise detection method, the magnetic field strength measuring device 40 and the MSR 1A are separated. Since the attached antenna 41 for taking in magnetic noise and the MSR head unit 21 for reading out magnetic data are also separate, it is difficult to reproduce the actual influence of the magnetic noise on the MSR.

(II) Magnetic Noise Detection Method of the Present Invention FIG. 3 is a diagram for explaining the magnetic noise detection method of the embodiment of the present invention, and FIGS. 4 (a) to 4 (c) are output waveforms of the MSR head reading unit. It is a figure which shows the example of.

  With reference to FIG. 3 and FIGS. 4A to 4C, the reading process of magnetic information from the magnetic card by the MSR and the misreading in the presence of disturbing magnetic noise will be described.

  First, when MSR is read, when the magnetic card 30 is scanned on the MSR head unit 21 in the direction of the arrow, a voltage waveform corresponding to the magnetic data written in the magnetic stripe 31 is input to the decoder 22 through the route 1. FIG. 4A shows an example of a voltage waveform at the time of MSR reading.

  In the example shown in FIG. 4A, a significant voltage waveform is shown only during the period from time t2 to t4 and during the period from time t6 to t8. In FIG. 4A, the decoder 22 outputs “1” when the peak value of the voltage waveform exceeds the “1” reading threshold (first threshold), and the peak value of the voltage waveform is “0”. When the value falls below the first threshold value, “0” is output. As a result, in FIG. 4A, the output of the decoder 22 during the period of time t2 to t4 is “10101010101010”, and the output of the decoder 22 during the period of time t6 to t8 is also “10101010101010”.

  Next, FIG. 4B shows a voltage waveform in the case where disturbing magnetic noise enters MSR1 when not reading MSR. Also in FIG. 4B, the decoder 22 outputs “1” when the peak value of the voltage waveform exceeds the “1” reading threshold (first threshold), and the peak value of the voltage waveform is “0”. When it falls below (first threshold), “0” is output. As a result, in FIG. 4B, the output of the decoder 22 during the period of time t1 to t3 is “101”, and the output of the decoder 22 during the period of time t5 to t7 is also “101”.

  Finally, FIG. 4C shows an example of a voltage waveform in the case of being affected by disturbing magnetic noise during MSR reading. FIG. 4C shows a voltage waveform in which the voltage waveform of FIG. 4A and the voltage waveform of FIG. 4B are superimposed. Also in the voltage waveform shown in FIG. 4C, the decoder 22 outputs “1” when the crest value of the voltage waveform exceeds the “1” reading threshold (first threshold), and the crest value of the voltage waveform. When “0” falls below the “0” reading threshold (first threshold), “0” is output. As a result, in FIG. 4C, the output of the decoder 22 during the period from time t1 to t4 is “101110”, and the output from the decoder 22 during the period from time t5 to t8 is “10110101010”.

  When the output “10101010101010” of the decoder 22 corresponding to the read magnetic data when there is no disturbing magnetic noise shown in FIG. 4A is inputted with the magnetic noise of the voltage waveform shown in FIG. It turns out that it changes to "10110101010".

  4A to 4C, the period from time t1 to t3 and the period from time t5 to t7 are caused by disturbing magnetic noise that outputs the voltage waveform shown in FIG. 4B. The output of the decoder 22 is affected. On the other hand, during the period from time t7 to t8, the output of the decoder 22 is not affected by magnetic noise. That is, when a certain level of magnetic noise enters the MSR head unit 21 of MSR1 at the same time of MSR reading, it can be seen that the output of the decoder 22 is affected.

  FIG. 5 shows the same voltage waveform as that in FIG. 4B, but the interference magnetic noise determination threshold value (the first threshold value) is set inside the “1” reading threshold value and the “0” reading threshold value (first threshold value). 2 thresholds). For example, the influence test of the magnetic noise with respect to the MSR reading is performed on the MSR1, and the second threshold value is set in advance on the apparatus side so that the MCPU 11 can determine.

  In FIG. 3, when the magnetic noise is input when the MSR reading is not performed, the MSR head unit 21 outputs a voltage waveform as shown in FIG. 5, passes through the route 5, and the A / D conversion unit 24. A voltage waveform is input to The A / D conversion unit 24 converts the peak value (analog value) of the input time-series voltage waveform into a time-series digital value and passes it to the SCPU 23. The SCPU 23 compares the input time-series digital value with the set second threshold digital value, and determines that there is interference magnetic noise if it is not within the second threshold range.

(III) Magnetic Noise Detection Processing of the Present Invention FIG. 5 is a diagram for explaining determination of presence / absence of magnetic noise interference, and FIG. 6 is a flowchart showing magnetic noise detection processing of the embodiment of the present invention.

  The magnetic noise detection process according to the embodiment of the present invention will be described along the flowchart of FIG. 6 with reference to FIGS. 1, 3, 4A to 4C, and FIG.

  In FIG. 6, when the process is started, the process proceeds to step S1. In step S1, the SCPU 23 determines whether or not it is in the MSR reading mode. If it is in the reading mode (Yes), the process proceeds to step S2, and if it is not in the reading mode (No), the process proceeds to step S3.

  In step S2, the SCPU 23 reads the magnetic data written in the magnetic strap 31 of the magnetic card 30 along the route 1 → decoder 22 → SCPU 23, and ends the magnetic data reading process. For example, when a voltage waveform as shown in FIG. 4A is input, the decoder 22 outputs “10101010101010” as magnetic data to the SCPU 23 during the period of time t2 to t4.

  In step S3, the SCPU 23 takes the voltage waveform obtained by converting the disturbing magnetic noise by the MSR head unit 21 into the A / D conversion unit 24 through the route 5 and converts the voltage waveform into a time-series digital value by the A / D conversion unit 24. After that, it is determined whether or not it is within the range of the determined threshold value of the digital value (for example, the second threshold value). If it is within the determination threshold range (Yes), the process proceeds to step S4. If not (No), the process proceeds to step S5.

  In step S4, the SCPU 23 notifies that the magnetic noise is not at a level that interferes with MSR reading, and returns to step S1. In the case of Yes in step S3, when the MSR reading mode is set in step S1 (Yes), the magnetic data reading process is correctly performed in step S2.

  In step S5, the MCPU 11 notifies that there is magnetic noise at a level that interferes with MSR reading, and ends the interference magnetic noise detection process.

(Effect of embodiment)
According to the present invention, when not in the MSR reading mode, the voltage waveform obtained by converting the magnetic noise by the MSR head unit 21 is taken into the A / D conversion unit 24 through the route 5 and the A / D conversion unit 24 performs time-series digital. After the conversion to the value, the interference magnetic noise is detected depending on whether or not it is within the range of the determination threshold value of the digital value (for example, the second threshold value). Therefore, it is easy to reproduce the actual effect of magnetic noise on the MSR without using the expensive magnetic field strength measuring device 40 that is difficult to carry.

(Modification)
As mentioned above, although embodiment of this invention was described, this invention is not limited to embodiment described above, In the range which does not deviate from the summary of this invention, various structures or embodiment can be taken. it can.

  The present invention is not limited to the above embodiment, and various usage forms and modifications are possible. As such usage forms and modifications, for example, there are the following (a) to (c).

  (A) The magnetic noise detection method described in the operation of the above embodiment is executed by controlling the MSR unit 20 in FIG. 1 or 3 by the SCPU 23 by reading the program into the SCPU 23 in FIG. 1 or FIG. You may do it.

  (B) In the description of the above embodiment, the voltage waveform taken into the A / D converter 24 via the route 5 is converted into a time-series digital value by the A / D converter 24, and then the second threshold value of the digital value is obtained. Although it has been described that the interference magnetic noise is detected depending on whether or not it falls within the range, the second threshold value is obtained using the analog voltage waveform captured by the route 5 without using the A / D converter 24 as the determination voltage. The disturbance magnetic noise may be detected by inputting to the window comparator set to.

  (C) In the description of the above embodiment, it has been described that the influence test of the magnetic noise on the MSR reading is performed and the second threshold value is set in advance, but the second threshold value is read as the peak value of the magnetic data. You may set suitably to the value according to the magnitude of the margin with respect to a threshold value.

1,1A MSR
10 MSR terminal 11 MCPU
20 MSR part 21 MSR head part 22 Decoder 23 SCPU
24 A / D converter 30 Magnetic card 31 Magnetic stripe 40 Magnetic field strength measuring instrument 41 Antenna

Claims (7)

A magnetic head unit that reads magnetic data from a magnetic card and outputs a read data waveform, and outputs induced magnetic noise as a noise waveform;
A decoder that converts the output data waveform into magnetic data and outputs it;
A magnetic noise level representing the magnitude of magnetic noise is calculated from the output noise waveform, and the magnetic noise level is compared with a threshold value representing the magnitude of magnetic noise that can be tolerated for reading magnetic data. Magnetic noise determination unit for determining that there is an influence of magnetic noise in reading magnetic data when the threshold exceeds
A magnetic card reader comprising:   The magnetic card reader according to claim 1, wherein a reading mode for reading magnetic data from the magnetic card and a test mode for determining the influence of magnetic noise can be selected. The threshold is
A first threshold that significantly affects magnetic noise reading of magnetic data;
A second threshold having a smaller influence on the magnetic data reading by the magnetic noise than the first threshold;
The magnetic card reader according to claim 1, further comprising: The magnetic noise determination unit
4. The method according to claim 1, wherein when a period in which a peak value of the voltage waveform exceeds the second threshold exceeds a predetermined value, it is determined that the magnetic data is influenced by reading magnetic data. The magnetic card reader according to item.   The said magnetic noise determination part has an alerting | reporting means which alert | reports that when it determines that there exists influence of magnetic noise in reading of magnetic data, The any one of Claims 1-4 characterized by the above-mentioned. Magnetic card reader. A magnetic field noise detection method using the magnetic card reader according to any one of claims 1 to 5,
A first process for shifting to a test mode for determining the influence of magnetic noise;
A second process of calculating a magnetic noise level representing the magnitude of the magnetic noise from the noise waveform output from the magnetic head unit;
The calculated magnetic noise level is compared with a threshold value indicating the magnitude of magnetic noise that can be tolerated for reading magnetic data, and when the magnetic noise level exceeds the threshold value, the influence of magnetic noise on the reading of magnetic data. A third process for determining that there is,
A magnetic field noise detection method using a magnetic card reader. A first process for shifting to a test mode for determining the influence of magnetic noise;
A second process of calculating a magnetic noise level representing the magnitude of the magnetic noise from the noise waveform output from the magnetic head unit;
The calculated magnetic noise level is compared with a threshold value indicating the magnitude of magnetic noise that can be tolerated for reading magnetic data, and when the magnetic noise level exceeds the threshold value, the influence of magnetic noise on the reading of magnetic data. A third process for determining that there is,
A program that causes a computer to execute.

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