JPH0376523B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic card data recording state measuring method for measuring the recording state of data recorded on a magnetic card, and particularly to a magnetic card data recording state measuring method that can measure the peak value of data recorded on a magnetic card. The present invention relates to a data recording state measuring method.

In general, many magnetic cards are JIS-
Necessary data is recorded based on the B9561 standard. According to the standard, the interval between recorded data on the magnetic card is defined as 8.268 bit/mm±4%. Specifically, the interval between the recorded data is 0.12 mm, and the tolerance is ±4.
%, so it is about ±5 μm. 5 μm like this
It has become necessary to measure the peak value of recorded data in such minute magnetic recording states.

The present invention has been made in view of the above, and it reproduces various data recorded on a magnetic card, converts the peak value of the reproduced signal into a digital signal, and also converts the time interval between the peak values. Measure and store the stored time interval, read out the stored time interval, and compare it with the time interval from one measurement before, and when the compared time interval is determined to be one of the logics based on the comparison result, the peak value during that time is It is an object of the present invention to provide a method for measuring the recording state of a magnetic card, which outputs a peak value that is the average of the peak value between them and the peak value after one measurement when the other logic is determined.

Embodiments of the present invention will be described below based on the drawings.

FIG. 1A is a plan view showing a magnetic card, and FIG. 1B is an explanatory diagram showing the recording state of data recorded on a magnetic stripe provided on the magnetic card.

In FIG. 1A, reference numeral 1 indicates a magnetic card, and this magnetic card 1 is provided with a magnetic stripe 2, as well as the name 3 of the issuer of the magnetic card 1,
A predetermined code number 4, individual name 5, expiration date 6, etc. are written.

On the magnetic stripe 2 provided on the magnetic card 1, necessary data is recorded as logic "1" and "0", as shown in FIG. 1B. In the magnetic stripe 2, both "0" and "1" are basically recorded at the same interval, and "0" has no change in magnetization within that interval, and "1" has no change in magnetization within that interval. There is a change in magnetization within. The arrow shown in Figure B indicates the direction of magnetism; "0" means that there is no change in magnetization during that interval even if the direction of magnetism changes, and "1" means that there is always a change in magnetization during that interval. I can understand that.

FIG. 2 is a perspective view showing a measuring device that implements an embodiment of the method for measuring the data recording state of a magnetic card according to the present invention. In FIG. 2, the same components as those in FIG. 1 are given the same reference numerals and their explanations will be omitted.

In FIG. 2, reference numeral 7 is a reading device, and this reading device 7 includes a power switch 8, a power indicator light 9 that lights up when the power switch 8 is turned on, and a magnetic card 1 inserted into the card insertion slot 10. A reader 11 that inserts and reads data recorded on the magnetic stripe 2 of the magnetic card 1, and a master key 1.
2. OK indicator light 13 or NG indicator light 14 lights up when the data recording status of magnetic card 1 is normal or abnormal, and magnetic card 1 is detected by reader 11.
A plug 15 is provided from which a reproduced signal read from the stripe 2 can be taken out.

This reading device 7 is connected to a processing device 17 via a cable 16.

The processing device 17 is provided with a keyboard 18 . This processing device 17 includes a CRT display device 19 that displays various information, a floppy disk device 20 that stores programs and various data for operating the processing device 17, and various print data from the processing device. A printer 21 for printing is connected.

FIG. 3 is a block diagram showing a signal system of a measuring device to which an embodiment of the present invention is applied.

In FIG. 3, the signal system in the reading device 7 includes a magnetic head 2 that can reproduce data recorded on the magnetic stripe 2 of the magnetic card 1 inserted into the card insertion slot 10 of the reader 11 into electrical signals.
2, an amplifier 23 that amplifies the reproduced signal from the magnetic head 22 at a constant level, and this amplifier 2.
a sample-and-hold circuit 24 that holds the peak value (upper and lower peak values) of the output signal from the sample-and-hold circuit 24; and an analog-digital (AD) converter 25 that converts the peak value of the output signal from the sample-and-hold circuit 24 into a digital signal. , a comparison circuit 26 that forms a time interval measurement signal (also referred to as a time interval measurement signal) based on the output signal from the amplifier 23 and outputs a sampling command to the sample hold circuit 24; and an output from the comparison circuit 26. A time interval measuring circuit 27 capable of measuring the time interval between the upper and lower peaks of the data recorded on the magnetic stripe 2 of the magnetic card 1 based on a signal and forming a timing signal for AD conversion of the AD converter 25.
and a control circuit 28 which instructs the data acquisition timing to the processing device 17, sets the amplification degree of the amplifier 23 based on commands from the processing device 17, and controls the measurement timing. Thus, the signals output from the AD converter 25 and the time interval measurement circuit 27 are supplied to the processing device 17.

Next, the signal system of the processing device 17 will be explained.

The processing device 17 includes a central processing unit (CPU) 29 that performs various arithmetic processing and control;
a read-only memory (ROM) 30 that stores programs for executing basic operations, etc., and a random access memory (RAM) 31 that can store programs for executing the measurement method, predetermined constants, data imported from the outside, etc. , a digital input port 32 for taking in data from the AD converter 25, and a digital input port 3 for taking in data from the time interval measuring circuit 27.
3, an input/output port 34 for inputting and outputting various commands between the reading device 7, and a keyboard 1.
8. Connect the CRT display device 19, floppy disk device 20 and printer 21 to the CPU 29.
Input/output control devices 35, 36, 3 for connecting to
7 and 38, each port 32 to 34, RAM3
1, a bus 39 that connects input/output control devices 35 to 38 and a CPU 29.

The operation of the measuring device configured as described above will be explained below.

FIGS. 4 to 4 are time charts shown to explain the operation of the reading device 7, and FIGS.
is a flowchart shown to explain the operation of the measuring device.

In FIG. 4, indicates the recording state of data recorded on the magnetic stripe 2, indicates the output signal from the amplifier 23, indicates the digital signal obtained from the digital signal, indicates the differential signal obtained from the digital signal, and indicates the signal based on the signal. The bit interval measurement signal obtained in , is the time interval (T ₁ , T ₂ ,...) measured by the bit interval signal,
Each horizontal axis represents time. Incidentally, the signals in the figures are generated within the comparator circuit 26, and are outputted as its output signals.

Now, the operation will be explained with reference to FIGS. 1 to 5.

First, reading of data from the magnetic card 1 will be explained with reference to FIG.

The magnetic card is inserted into the card insertion slot 10 of the reader 11 of the reading device 7 (step S41). Then, the reader 11 detects that the magnetic card 1 has been inserted and reads out the data (see FIG. 4) recorded on the magnetic stripe 2 of the magnetic card 1 using the magnetic head 22 (step S42). The read reproduction signal is amplified by the amplifier 23 and supplied to the sample and hold circuit 24 and the comparison circuit 26 (step S43). The sample hold circuit 24 holds the upper peak value or the lower peak value according to the command signal from the comparison circuit 26 (step
S44). The peak value held by the sample hold circuit 24 is converted into a digital signal by the AD converter 25 and sent to the RAM 31 via the input/output port 32.
The digital signal is stored in a predetermined first area (step S45).

On the other hand, the signal output from the amplifier 23 (see FIG. 4) is first converted into the signal shown in FIG. 4 in the comparison circuit 26 (step S46). Next, the signal shown in FIG.
At step S47, the signal is differentiated into a differential signal shown in the same figure, thereby obtaining a bit interval measurement signal as shown in the same figure. This bit interval measurement signal is supplied to the time interval measurement circuit 27, and the time from fall to fall of the bit interval measurement signal is measured (step S48). Note that the time interval measurement circuit 27 does not actually measure the measurement signal from one fall to the other, but drives, for example, a one-shot multivibrator with the measurement signal, and measures the signal output from this element. A circuit configuration is adopted in which the time T _T until the next fall of the measurement signal is measured, and this time T _S is used in addition to the operating time T _S of the one-shot multivibrator. Therefore, the operating time T _S of the one-shot multivibrator is
The period between is used to transfer the measurement time T _T to the processing device 17. Time interval data T ₁ , T ₂ , T ₃ ,...T _N measured in this way
(See the figure)
is stored in the area (step S49). That is, all output data from the AD converter 25 and the time interval measurement circuit 27 are stored in a predetermined area of the RAM 31. The above is the operation of reading data from the magnetic card 1.

Next, processing of bit interval data will be explained with reference to FIG.

At step 50, the time interval data T ₁ ,
T ₂ , T ₃ . . . are read out, these are added together, and the average of the added values is taken, and the first reference width is obtained based on this. That is, the following calculation is performed.

Tmean=T ₁ +T ₂ +T ₃ +...T _N /N (1) However, N is the number from T ₁ to T _N. Based on the calculation result, the first standard width T _S1 {= (1±α)Tmean} is obtained. Note that α is, for example, 4% as described above.

Also, bit interval data _TM is stored in RAM
31 (step S51), and it is determined in step S52 whether the logic is "1" or "0".
In this step S52, if the logic is determined to be "0", the process moves to step S53. In step S53,
The bit interval data _TM is compared with the first reference width T _S1 (e.g., equivalent to 0.12 m ± 5 μm), and it is determined whether the bit interval data _TM is within the first reference width T _S1 . Determine whether

In this step S53, the data _TM is set to a predetermined first value.
If it is determined that the value is within the standard value range T _S1 , the process moves to step S54, and the determination result (“OK”) is stored in the RAM.
The information is stored in the third area of No. 31.

On the other hand, if it is determined in step S53 that the data _TM is not within the first reference width T _S1 , the process moves to step S55, and the determination result ("NG") is stored in the RAM 3.
1 in the fourth area.

After the above-mentioned steps S54 and S55, a step is performed to determine whether all of the bit interval data _TM stored in the second area of the RAM 31 has been completed.
Determine with S56. If the comparison of all bit interval data is not completed in this step S56, the process returns to step S51, and when the comparison of all bit interval data is completed, the next step is started.
Move on to S57.

Further, if it is determined in step S52 that the bit interval data from the second area of the RAM 31 is logic "1", the process moves to step S58, where
The next bit interval data ( _TM+1 ) is read from the second area of the RAM 31. Next, in step S59, the previous bit interval data (T _M ) and the bit interval data (T _M+1 ) just read out are added (T _M +T _M+1 ), and
This addition result can be used as bit interval data in step S53, and the process moves to step S53.

Next, in step S57, the first bit interval data _T1 is read from the second area of the RAM 31, T _A (1 + α) is calculated, this is set as a temporary second reference value T _S2 , and the process proceeds to step S60. Move.
In step S60, the next bit interval data _TM is read from the second area of the RAM 31, and
It is determined whether this is logic "1" or "0". If it is determined that the bit interval data _TM is "0", the process moves to step S61, and in step S61, this data _TM is compared with the second reference width T _S2 . If the data T _M is within the second standard width T _S2 in step S61, the judgment result is determined as "OK".
It is stored in the third area of the RAM 31 (step S62).

On the other hand, in this step S61, the data _TM is
If it is not within the standard width T _S2 , the judgment result is determined as "NG" and is stored in the third area of the RAM 31 (step S63).

From steps S62 and S63, the process moves to step S64.
In this step S64, the second reference value T _S2 is calculated from this data T _M using the following equation (2), T _S2 = (1±α) T _M ... (2) This calculation result is used as the next 2 standard value T _S2 .

Next, the process moves to step S65, where it is determined whether the comparison of all bit interval data T _N has been completed. If the comparison has not been completed, the process returns to step S60, and if it has completed, the process moves to step S66.

On the other hand, if the data _TM is determined to be "1" in step S60, the process moves to step S67. step
In S67, the next bit interval data T _M+1 is
Read from the second area of RAM31. Next, in step S68, the third reference value is calculated from the previous data T _M.
T _S3 {=(1±α) T _M } is calculated and compared with the next data T _M+1 (step S69). If the comparison result is "NG", the process moves to step S70, and if the comparison result is "OK", the process moves to step S71. In step S70, the comparison result is stored in the fourth area of the RAM 31.
In step S71, the comparison result is stored in the third area of the RAM 31. These steps S70,
After passing S71, the previous data T _M and the subsequent data
T _M+1 is added in step S72 (T _M + T _M+1 )
Then, the addition result is used as the data in step S61.
It is made to be used as _TM , and the process moves to step S61.

In step S66, the third and fourth RAM 31
Search the area, and if there is no "NG", turn on the OK indicator light 13, and if there is "NG", turn on the NG indicator light 14.
Turn it on. Incidentally, it is also possible to adjust whether or not the NG indicator light 14 is turned on depending on the number of "NG" or the like.

In this way, according to the measuring device, the AD converter 25 converts the peak value into a digital signal, measures the time interval from the peak value to the peak value, and compares this with a predetermined reference value width to determine the accuracy. It is possible to determine whether data is recorded on the magnetic stripe of a magnetic card based on the interval.

Furthermore, the operation of outputting the peak value in bit interval data will be explained with reference to FIG.

Assume that an instruction to output a peak value is input (step S80).

Then, the digital data V _1F and V _1B at the front and rear edges of the bit interval T ₁ are read out from the RAM 31, and the calculation of V ₁ = V _1F - _{V 1B} is performed (step S81). This peak value V ₁ is the bit interval data. It is used as the peak value at T ₁ , which is
It is temporarily stored in the buffer of CPU29.

Next, this bit interval data _T1 is
It is compared with a constant reference width {T _S =(1±α)T ₀ } obtained from the bit interval data T ₀ of the previous measurement (step S82). Here, since this bit interval data T ₁ is within a constant reference width T _S ,
The peak value _V1 in the buffer of the CPU 29 is outputted as logic "0" (step S83). Then, it is determined whether all the data has been completed, and since it has not been completed, the process moves to the next operation (step S84).

Next, the digital V _2B at the trailing edge of the bit interval data T ₂ is read out from the RAM 31,
V ₂ ′=V _2F −V _2B =V _1B −V _2B (V _2F =V _1B ) is calculated (step S81). This peak value V ₂ ' is used as the peak value of the bit interval data T ₂ and is temporarily stored in the buffer of the CPU 29.

Next, this bit interval data _T2 is
It is compared with a constant reference width {T _S =(1±α)T ₁ } obtained from the bit interval data T ₁ of the previous measurement (step S82). Here, since the bit interval data _T2 is not within a certain standard width,
The logic is set to "1" and the process moves to the next step S85.

Here, the peak value V _3B of the trailing edge of the bit interval data T ₃ is read out from the RAM 31, and V ₂ ″=
V _3F −V _3B =V _2B −V _3B (V _3F =V _2B ) is calculated (step S85).

This wave height V ₂ '' is used as the wave height value of the bit interval data T ₃ and is stored in the buffer of the CPU 29 in the same manner as the wave height value V ₂ '.

Therefore, the reference width obtained from the bit interval data T ₃ and the bit interval data T ₂ { _TS ′=
(1±α)T ₂ } (step S86). Here, if the bit interval data _T3 is within the standard width T _S ', the following calculation is performed, and
The peak value _V2 is output (step S87).

V ₂ = V ₂ ′ + V ₂ ″/2 T ₂ ′ = T ₂ + T ₃ If it does not fit within the standard width T _S ′, error data is output without performing the above calculation (step S88). In both steps S87 and S88, it is determined whether all data has been completed (step S84), and since it has not been completed, the process moves to the following operation.

Furthermore, the digital data _T4B at the trailing edge of the bit interval data _T4 is read out from the RAM 31, and _V3 = _V4F - _V4B = _V3B - _V4B is calculated (step S81). Here, it is determined whether the bit interval data T ₄ falls within the reference width {T _S (1±α) T ₂ '} (step S82). in this case,
Since it is within the standard width T _S , the peak value V ₃ is output as logic "0". (Step S83) In this way, the peak values of each bit interval data are output one after another until all data are completed.

That is, some bit interval data T _M
Find the peak value V _M of the bit interval data T _M from the peak values of the leading and trailing edges of the bit interval data T M (step
S81), the bit interval data _TM at this peak value _VM is compared with the reference width _TS obtained from the bit interval data _TM-1 of the previous measurement (step S82), and the comparison result is a logic "0". If so, the peak value V _M is output (step S83), and if the comparison result is logic "1", the peak value and the peak value V _{M+1 of the bit interval data T M+1} after one measurement _{are output.}
The wave height value V _MM =(V _M +V _M+1 /2) which is the average of the two is output (steps S85 to S88).

Therefore, the peak value V _M obtained as above
will be displayed on the CRT display device 19 or printed out from the printer 21.

Although one example of operation has been described above, it goes without saying that the peak value _VM may be determined after comparing the bit interval data _TM .

As described above, according to the present invention, there is an advantage that magnetic recording wave height value data of a magnetic card can be measured.

[Brief explanation of drawings]

Figure 1A is a plan view showing the magnetic card, Figure 1B
is an explanatory diagram shown to explain the state of data recorded on a magnetic stripe, and FIG. 2 is a perspective view showing a measuring device for realizing an embodiment of the present invention.
Figure 3 is a block diagram showing the signal system of the measuring device.
4 is a time chart shown for explaining the operation of the reading device, and FIG. 5 is a flow chart shown for explaining the operation of the measuring device. 1...Magnetic card, 2...Magnetic stripe, 7
...Reading device, 11...Reader, 16...Cable, 17...Processing device, 19...CRT display device, 20...Floppy disk device,
21...Printer.

Claims (1)

[Claims] 1. Reproducing various data recorded on a magnetic card, converting the peak value of the reproduced signal into a digital signal, measuring and storing the time interval between the peak values, and reading out the stored time interval. If the above-mentioned time interval is determined to be one logic based on the comparison result, then the peak value of that logic is determined, and if it is determined to be the other logic, that peak value and the peak value after one measurement are compared. A method for measuring the data recording state of a magnetic card, characterized by outputting a peak value obtained by taking the average of .