JP2003257003A - Device and method for reading magnetic data - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve data reading efficiency, and to carry out highly accurate data reading. <P>SOLUTION: The upper and lower peaks of a magnetic signal read by a magnetic head 1 are detected by a peak detecting means 4, and a processing section 8 is provided with a time interval determining means for measuring a time interval between a peak detection and a next peak detection to determine time intervals TA, TB, TC, and TD, and a data determining means for determining the combination of the TA and TB as data 1 when the times intervals TA and TB are in a first reference range, and the total of the time intervals TA and TB is in a range which is twice as large as a second reference range narrower than the first reference range, and determining the TC and the TD as data 0 when the time intervals TC and TD are in a preset third reference range, and the total of the times intervals TC and TD is in a range which is twice as large as a fourth reference range narrower than the third reference range. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic data reading device and a magnetic data reading method for reading data from a magnetic medium such as a magnetic stripe to determine data.

[0002]

2. Description of the Related Art "1" and "0" of data are recorded on a magnetic stripe provided in a passbook or the like. To judge this data, the upper and lower peaks of a magnetic signal read from the magnetic stripe are determined. The data is detected and the data is determined from the time interval between the upper peak and the lower peak and the time interval between the lower peak and the upper peak.

[0003]

By the way, the magnetic signal read from the magnetic stripe is an analog waveform, and this analog waveform has rising and falling edges. This analog waveform is input to the peak detection circuit to detect the upper and lower peaks, but the circuit has different response times for the rising and falling edges of the analog waveform, so the time interval between the upper and lower peaks and When measuring the time interval between the lower peak and the upper peak, time variations occur.
For example, originally, the time interval between the upper peak and the lower peak and the time interval between the lower peak and the upper peak should be equal to each other, but they are not equal to each other.

However, conventionally, since the data determination is performed under the condition that the time interval between the upper peak and the lower peak and the time interval between the lower peak and the upper peak are almost equal, a judgment error frequently occurs and the data is detected. However, there is a problem that the reading efficiency of the device decreases. The present invention provides a magnetic data reading device and a magnetic data reading method capable of improving data reading efficiency and reading data with high accuracy.

[0005]

According to the present invention, the peak detecting means detects the upper and lower peaks of a magnetic signal read from a magnetic medium by a magnetic head, and the time interval determining means detects the peak and the next peak. A relatively short time interval TA that falls from the upper peak to the lower peak by measuring the time interval between
A relatively short time interval TB that rises from the lower peak to the upper peak, a relatively long time interval TC that falls from the upper peak to the lower peak, and a relatively long time interval TD that rises from the lower peak to the upper peak are determined and determined by the data determination means. , The time intervals TA and TB are respectively within preset first reference ranges, and the total of the time intervals TA and TB is within twice the second reference range narrower than the first reference range. At some point, the combination of TA and TB is determined as data 1,
The time intervals TC and TD are each within a preset third reference range, and the total of the time intervals TC and TD is the third.
When it is within the range twice as large as the fourth reference range, which is narrower than the reference range of, each of TC and TD is determined as data 0.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a magnetic head. The magnetic head 1 is adapted to read a magnetic signal written in the magnetic stripe 2 while conveying the magnetic stripe 2 as a magnetic medium at a constant speed. There is.

The magnetic signal read by the magnetic head 1 is amplified by the amplifier 3 and then supplied to the peak detecting means 4. The peak detecting means 4 comprises a + peak detecting section 5, a −peak detecting section 6 and an OR gate circuit 7, and inputs the magnetic signal from the amplifier 3 to the peak detecting sections 5 and 6, respectively.

The + peak detection unit 5 detects the upper peak from the analog waveform of the input magnetic signal, and outputs the interrupt signal INT due to the detection of the upper peak to the processing unit 8 and the capture register 9 via the OR gate circuit 7. The −peak detector 6 detects the lower peak from the analog waveform of the input magnetic signal and supplies the interrupt signal I by the lower peak detection.
NT is supplied to the processing unit 8 and the capture register 9 via the OR gate circuit 7.

The capture register 9 has an interrupt signal INT.
Is input, the time data measured by the timer 10 is captured as a capture value, and the captured value is supplied to the processing unit 8.

The processing section 8 includes a CPU, a ROM and a RAM.
And a time determination unit and a data determination unit. The time interval determination means is an interrupt signal IN from the peak detection means 4.
The time data from the capture register 9 is fetched by T and stored in the RAM, and by repeating this continuously, the time interval between peak detection and the next peak detection is sequentially measured. ) And (b), a relatively short time interval TA from the upper peak to the lower peak, and a relatively short time interval T from the lower peak to the upper peak.
B is determined. In addition, as shown in FIG. 2 (c), a relatively long time interval TC falling from the upper peak to the lower peak and as shown in FIG. 2 (d) a relatively long time interval TD rising from the lower peak to the upper peak. Is determined.

That is, the time interval determination means is shown in FIG.
As shown in FIG. 3, when the interrupt signal INT from the peak detecting means 4 is fetched in S1, the current capture value captured by the capture register 9 is read in S2 and RA
Store in M. Then, in S3, the time interval is calculated by comparing with the immediately preceding capture value. Further, it is determined from the peak information whether the falling is from the upper peak to the lower peak or the rising is from the lower peak to the upper peak.

If the time interval from the upper peak to the lower peak is relatively short, the time interval is determined to be TA in S4, and if the time interval from the lower peak to the upper peak is relatively short, the process proceeds to S5. Then, the time interval is determined to be TB. If it is a relatively long time interval from the upper peak to the lower peak, the time interval is determined as TC in S6, and if it is a relatively long time interval from the lower peak to the upper peak in S7. , The time interval is determined to be TD.

As shown in FIG. 2, the relationship between the time interval and the data is the combination of the time interval TA and TB, the time interval T.
The combination of B and TA indicates data 1 and time interval TC
And TD indicate data 0, respectively. Therefore,
As shown in FIG. 3, when the data is “0, 1, 0”, the time intervals TC, TB, TA and TD are sequentially measured.

However, the time intervals TA, TB, TC, TD
Even if it is determined that the data 1 and 0 cannot be correctly determined unless the time interval conforms to the standard. Moreover, the time intervals TA, TB, TC, TD
Variation occurs.

Therefore, the data determination means of the processing section 8 is adapted to perform the data determination processing shown in FIGS. When the time interval determination means determines the time interval TA, as shown in FIG. 5, it is checked in S11 whether the time interval TB has already been determined. If the time interval TB has not yet been determined, this process ends.

If the time interval TB has already been determined, then in step S12, T1-α1≤TA≤T1 +
Check if it is α1 or not. TA> T1 + α1, or
If TA <T1−α1, the determination of the time interval TA is an error. If T1−α1 ≦ TA ≦ T1 + α1, then in S13, it is checked whether or not T1−α1 ≦ TB ≦ T1 + α1. TB> T1 + α1 or TB <T
If it is 1-α1, the determination of the time interval TB is made an error.

If T1−α1 ≦ TB ≦ T1 + α1,
Then, in S14, 2 (T1-B1) ≤TA + TB≤
It is checked whether it is 2 (T1 + B1). TA + TB>
2 (T1 + B1) or TA + TB <2 (T1-B
In the case of 1), the determination based on the time intervals TA and TB is set as an error. 2 (T1-B1) ≦ TA + TB ≦ 2 (T1 + B
If 1), the data 1 is determined in S15, and this processing ends.

In this determination, T1 is an ideal reference value for data 1, and ideally TA = TB = T1. α1 and B1 are numerical values for adjusting the judgment standard, and α1>
It is B1. Therefore, T1 + α1 and T1−α1 are determined by comparing TA and TB with a relatively gentle determination criterion, and 2 (T
1 + B1) and 2 (T1-B1) are determined based on a relatively strict criterion of TA + TB.

When the time interval determination means determines the time interval TB, as shown in FIG. 6, it is checked in S21 whether the time interval TA has already been determined. If the time interval TA has not yet been determined, this process ends.

If the time interval TA has already been determined, then in step S22, T1-α1≤TA≤T1 +
Check if it is α1 or not. TA> T1 + α1, or
If TA <T1−α1, the determination of the time interval TA is an error. If T1−α1 ≦ TA ≦ T1 + α1, then in S23, it is checked whether or not T1−α1 ≦ TB ≦ T1 + α1. TB> T1 + α1 or TB <T
If it is 1-α1, the determination of the time interval TB is made an error.

If T1−α1 ≦ TB ≦ T1 + α1,
Then, in S24, 2 (T1-B1) ≤TA + TB≤
It is checked whether it is 2 (T1 + B1). TA + TB>
2 (T1 + B1) or TA + TB <2 (T1-B
In the case of 1), the determination based on the time intervals TA and TB is set as an error. 2 (T1-B1) ≦ TA + TB ≦ 2 (T1 + B
If 1), the data 1 is determined in S25, and this processing ends.

When the time interval determination means determines the time interval TC, as shown in FIG. 7, it is checked in S31 whether the time interval TD has already been determined. If the time interval TD has not yet been determined, this process ends.

If the time interval TD has already been determined, then in step S32, T0-α0≤TC≤T0 +.
Check whether it is α0. TC> T0 + α0, or
If TC <T0-α0, the determination of the time interval TC is made an error. If T0-α0≤TC≤T0 + α0, then in S33, it is checked whether T0-α0≤TD≤T0 + α0. TD> T0 + α0 or TD <T
If it is 0-α0, the determination of the time interval TD is made an error.

If T0-α0≤TD≤T0 + α0,
Succeedingly, in S34, 2 (T0−B0) ≦ TC + TD ≦
Check if it is 2 (T0 + B0). TC + TD>
2 (T0 + B0) or TC + TD <2 (T0-B
If it is 0), the determination based on the time intervals TC and TD is set as an error. 2 (T0-B0) ≤ TC + TD ≤ 2 (T0 + B
If it is 0), in S35, it is determined that TC and TD are data 0, respectively, and this processing ends.

In this determination, T0 is an ideal reference value for data 0, and ideally TC = TD = T0. α0 and B0 are numerical values for adjusting the judgment standard, and α0>
It is B0. Therefore, for T0 + α0 and T0−α0, TC and TD are determined by a relatively gentle determination criterion, and 2 (T
0 + B0) and 2 (T0-B0) are judged by TC + TD by a relatively strict judgment standard.

When the time interval determination means determines the time interval TD, as shown in FIG. 8, it is checked in S41 whether the time interval TC has already been determined. If the time interval TC has not yet been determined, this process ends.

If the time interval TC has already been determined, then in S42, T0-α0≤TC≤T0 +.
Check whether it is α0. TC> T0 + α0, or
If TC <T0-α0, the determination of the time interval TC is made an error. If T0-α0≤TC≤T0 + α0, then in S43, it is checked whether T0-α0≤TD≤T0 + α0. TD> T0 + α0 or TD <T
If it is 0-α0, the determination of the time interval TD is made an error.

If T0-α0≤TD≤T0 + α0,
Succeedingly, in S44, 2 (T0−B0) ≦ TC + TD ≦
Check if it is 2 (T0 + B0). TC + TD>
2 (T0 + B0) or TC + TD <2 (T0-B
If it is 0), the determination based on the time intervals TC and TD is set as an error. 2 (T0-B0) ≤ TC + TD ≤ 2 (T0 + B
If it is 0), in S45, TC and TD are determined to be data 0, respectively, and this processing ends.

In such a configuration, the magnetic head 1
When the magnetic signal is read from the magnetic stripe 2, the peak at that time is detected by the peak detecting means 4.
That is, if the peak is a + peak, the + peak detection unit 5
In the case of -peak, the peak is detected by the peak detector 6. Then, the interrupt signal INT is input to the processing unit 8 and the capture register 9 each time the + peak and the −peak are detected.

When the interrupt signal INT is input, the capture register 9 captures the count time of the timer 10 at that time as a capture value. When the interrupt signal INT is input, the time interval determination means of the processing unit 8 fetches the capture value from the capture register 9 and stores it in the RAM. And
This captured value is compared with the captured value immediately before to obtain the time interval, and it is determined from the peak information whether the falling is from the upper peak to the lower peak or the rising from the lower peak to the upper peak. To do.

In this way, the time interval determination means determines the time interval T from the obtained time interval and the information on the rising and falling edges.
Determine A, TB, TC, TD. Time interval TA, T
When B, TC, and TD are determined, the data determination means performs data determination.

The data judgment is performed by, for example, the time intervals TA and T.
When B is determined, T1-α1 ≦ TA ≦ T1 + α1, T
1-α1 ≦ TB ≦ T1 + α1, 2 (T1-B1) ≦ TA
The determination is made for three conditions of + TB ≦ 2 (T1 + B1), and when all the conditions are satisfied, the combination of the time interval TA and TB is determined as data 1. Also, the time interval T
When C and TD are determined, T0−α0 ≦ TC ≦ T0 + α
0, T0-α0 ≦ TD ≦ T0 + α0, 2 (T0-B0)
When three conditions of ≦ TC + TD ≦ 2 (T0 + B0) are determined and all the conditions are satisfied, the time intervals TC and T
Each D is determined to be data 0.

As described above, when the data is judged, the time intervals TA and TB are set to the comparatively gentle judgment criterion T1 + α.
1 and T1-α1 are used for the determination, the time interval T
Even if there are some variations in A and TB, they are not excluded as errors. And finally, (TA + TB)
Are relatively strict criteria 2 (T1 + B1), 2 (T1-
Since the determination is made using B1), the determination accuracy can be improved.

Even if (TA + TB) is judged using the relatively strict criteria 2 (T1 + B1) and 2 (T1-B1), the variations in the falling time interval TA and the rising time interval TB are mutually different. Since they occur so as to cancel each other, the variation is canceled by adding (TA + TB) and (TA + TB) becomes close to 2T1,
Even if there is some variation in the time intervals TA and TB, they are not excluded as an error.

Further, since the time intervals TC and TD are judged using the relatively gentle judgment criteria T0 + α0 and T0-α0, even if there are some variations in the time intervals TC and TD, they will not be excluded as errors. Absent. Then, finally, (TC + TD) is a relatively strict criterion 2 (T0 +
Since B0) and 2 (T0-B0) are used for the determination, the determination accuracy can be improved.

Even if (TC + TD) is judged using the relatively strict criteria 2 (T0 + B0) and 2 (T0-B0), the variations in the falling time interval TC and the rising time interval TD are mutually different. Since they occur so as to cancel each other, the variation is canceled by adding (TC + TD), and (TC + TD) becomes close to 2T0.
Even if the time intervals TC and TD have some variations, they are not excluded as errors. Therefore, it is possible to improve the data reading efficiency as a whole and to perform highly accurate data reading.

[0037]

As described in detail above, according to the present invention,
It is possible to provide a magnetic data reading device and a magnetic data reading method capable of improving data reading efficiency and reading data with high accuracy.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between a peak change and a time interval between interrupt signals and data in the embodiment.

FIG. 3 is a diagram showing a relationship between an example of data in the embodiment, a peak change at that time, and a time interval between interrupt signals.

FIG. 4 is a flowchart showing a time interval determination process by the time interval determination means in the same embodiment.

FIG. 5 is a flowchart showing a determination process of data 1 by the data determination means in the same embodiment.

FIG. 6 is a flowchart showing a determination process of data 1 by the data determination means in the embodiment.

FIG. 7 is a flowchart showing a process of determining data 0 by the data determining means in the embodiment.

FIG. 8 is a flowchart showing a process of determining data 0 by the data determining means in the embodiment.

[Explanation of symbols]

1 ... Magnetic head 2 ... Magnetic stripe 4. Peak detection means 8 ... Processing unit 9 ... Capture register 10 ... Timer

Claims (2)

[Claims] 1. A magnetic head for reading a magnetic signal written on a magnetic medium, peak detecting means for detecting upper and lower peaks of the magnetic signal read by the magnetic head, and peak detection by the peak detecting means. The time interval between the peak detection and the next peak detection is measured, and the relatively short time interval TA from the upper peak to the lower peak, the relatively short time interval TB from the lower peak to the upper peak, and the upper peak to the lower peak. Relatively long time interval TC falling to the peak, relatively long time interval TD rising from the lower peak to the upper peak
And a data determination unit that determines a combination of TA and TB as data 1 and that determines TC and TD as data 0 according to the time interval determined by the time interval determination unit. The data determination means has a second interval in which the time intervals TA and TB are within a preset first reference range, and the total of the time intervals TA and TB is narrower than the first reference range.
When it is in the range twice as large as the reference range, the combination of TA and TB is determined as data 1, and the time intervals TC and TD are respectively in the preset third reference range and the time interval TC, When the sum of TD is within twice the fourth reference range narrower than the third reference range, TC and T
A magnetic data reader characterized in that each of D and D is determined as data 0. 2. The upper and lower peaks of a magnetic signal read from a magnetic medium are continuously detected, the time interval between the peak and the next peak is measured, and this measurement is sequentially performed, and the upper peak to the lower peak are measured. Relatively short time interval TA for falling to, and relatively short time interval T for rising from lower peak to upper peak
B, a relatively long time interval TC that falls from the upper peak to the lower peak, and a relatively long time interval TD that rises from the lower peak to the upper peak are determined, and the time intervals TA and TB are within the preset first reference range. And the total of the time intervals TA and TB is within the range of twice the second reference range narrower than the first reference range, the combination of TA and TB is determined as data 1 and The intervals TC and TD are each within a preset third reference range, and
Magnetic data characterized in that TC and TD are each determined to be data 0 when the sum of the time intervals TC and TD is within a range twice as large as the fourth reference range narrower than the third reference range. How to read.