JPS61145772A - Reading system of magnetic stripe - Google Patents

Abstract

PURPOSE:To attain a correct reading even with data having the shift of data by changing the delay amount by the program control for the reproduction waveform of a track 0 or 1 of the magnetic stripe data to which a medium is written obliquely. CONSTITUTION:A programmable timer PTC1 has independent timers 0 and 1 and selects a chip selection CS by a program before a reading mode. Then the PTC1 selects the timers 0 and 1 by addresses A0 and A1 respectively and writes the action mode and the value for counting the clocks CLK supplied to terminals T0 and T1 to the timers 0 and 1 respectively through a data bus. The timer PTC1 counts the pulses of the clocks CLK and obtains the output pulses at output terminals PTCO0 and PTCO1 of the timers 0 and 1 when the count number of pulses reaches a set count level. In other words, the changing point of a track 0 is supplied to the gate G0 of the PTC1 and to the gate G1 of the PTC1 through an inverter INV1. Then the pulses delayed by the count value of set clocks are delivered through terminals PTCO0 and PTCO1.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a magnetic stripe reading method, and more particularly, to a magnetic stripe reading method that is capable of correctly reading magnetic stripe data with a large azimuth that is written at an angle. It is.

[Background of the invention]

For example, passbooks handled by cash handling machines in bank terminals are recorded using the NRZI'@ method on the magnetic stripe. In this case, only data O is recorded on track 0, and data is recorded on track 1. Only 1 is recorded, and 0 and 1 data are written in separate tracks. When written normally, K is written perpendicular to the magnetic stripe, but if the head and the medium such as a passbook are misaligned, K is written obliquely to the magnetic stripe. I end up. When reading data from a magnetic stripe written with the medium running diagonally, the phase of the data on track O and track 1 is shifted, and the data on 11077 and 1'' are exchanged, making it impossible to read the data.

Conventionally, as a measure to prevent the skew of a magnetic stripe medium, there is a method described in Japanese Patent Application Laid-Open No. 58-35776, but this method mechanically detects that the medium is skewed with respect to the head. However, this will be corrected in terms of position.

However, this method requires a large number of structurally unnecessary parts, and care must be taken when inserting the medium. Therefore, it is desirable to be able to read data accurately even when writing is skewed to the medium.

[Purpose of the invention]

An object of the present invention is to solve such problems, and even when the phase of data on track 0 and track 1 of magnetic stripe data written obliquely is out of phase, the data can be read accurately. The purpose of the present invention is to provide a magnetic stripe reading method.

[Summary of the invention]

In order to achieve the above object, the magnetic stripe reading method of the present invention includes a
In a magnetic stripe reading method in which "θ" data and "1" data are written independently, a delay circuit with a variable signal delay amount is provided in one of the reading circuits for each track, and the two tracks are combined. The result of the read check on the read data that was read is either a forward or reverse read operation.

In the event of an error, the read operation can be repeated while changing the delay time of the delay circuit stepwise.

(Embodiments of the invention) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 5 is a block diagram of the entire transport system for a magnetic stripe recording medium to which the present invention is applied.

HO and Hl are reading heads, 1 is a transport mechanism for a medium such as a passbook, 2 is a transport control circuit, and 3 is a reading circuit.

4 is a microprocessor, and 5 is a memory. When the transport mechanism 1 is operated by the transport control circuit 2 and the medium reaches the reading position, the reading circuit 3 detects tracks 0 and 1.
combine the data into one data and write the read data to the memory 5 in chronological order via the microprocessor 4 1
Next, the microprocessor 4 executes a program for checking the data written in the memory 5, and checks whether the data written on the magnetic stripe is correct. By providing a delay circuit or the like in circuit 3, when reading data diagonally written on the magnetic stripe, one of the data on track O or track 1 is delayed, and the data on track 0 and track 1 is Corrects data reading due to phase shift and reads data correctly. FIG. 6 is an explanatory diagram of the data checking method in FIG. 5.

In one data block, as shown in FIG. 6, first a timing bit is written, then a start code, and then information.
Next to the information is BCC (Block CheckChar).
acter (vertical parity), then a termination code, and finally a timing bit. - As an example, the case is shown when written with 5 bits, and since it is an odd parity, the last bit P of each character is set to 0 or 1 and transmitted so that the number of 1s is odd except for the timing code. , When detecting, count the number of ■ character by character, and if it is an odd number, it is good.
If the number is even, it is determined that there is an error.

FIGS. 7 and 8 are diagrams showing the results of read waveforms and discrimination data of magnetic stripes written normally and obliquely, respectively.

As shown in FIG. 7, in the magnetic stripe normally written on track 0 and track 1.

Since the changing points of the reproduced waveform do not change between track 0 and track 1, correct discrimination data can be obtained by combining the changing points of track 0 and track 1. On the other hand, in FIG. 8, since the magnetic stripe is written diagonally, the extension that intersects track 0 intersects track 1 at a different timing position from track 0. As a result, the changing points of the reproduced waveform are swapped between track 0 and track 1, so even if they are combined, the changing points are swapped and correct discrimination data cannot be obtained, resulting in a reading error.

In FIG. 8, two pieces of data indicated by double lines under the discrimination data have been exchanged, resulting in incorrect content. The inventors of the present invention have focused on the fact that in such a case, if the reproduced waveform on the track side whose phase is leading is delayed by an appropriate amount using a delay circuit, the waveform can be read correctly. FIG. 1 is a block diagram of a magnetic stripe reading circuit illustrating one embodiment of the present invention.

In FIG. 1, HO and Hl are reading magnetic heads, AM
PO, AMP 1 is an amplifier, FFO to FF4 are flip-flops, PTCl is a programmable timer, INV
I is an inverter. In the conventional circuit, the regeneration circuit SO
Because the wire was connected between the and flip-prop FFO,
No delays will occur.

In this embodiment, the reproduction circuit SO and the flip-flop FFO
By providing PTCI, FF4, etc. in between, even if a phase delay or phase lead occurs in either track O or track 1, this can be corrected by changing the delay time of the delay circuit PTC. .

The data on track 1 written on the magnetic stripe is read out from the magnetic head H1 by operating the transport system shown in FIG. 5, amplified by the amplifier AMP1, reproduced by the reproduction circuit S1, and then exclusive OR circuit EXORI (
EXORI (hereinafter simply referred to as EXORI or 0) is connected to the D terminal of flip-flop FFI (hereinafter simply referred to as FFO to 4), and a change point in the data of track 1 is detected at the output of EXORI. On the other hand, the data of track 0 is
After being read by the magnetic head HO and reproduced by the amplifier SO, it is connected to the G1 terminal via the GO terminal or inverter INVI of a programmable timer PTCI that controls the data delay time according to program settings. The programmable timer PTC1 used has independent timer 0 and timer 1, and before reading, the chip select C8 is selected in advance by the program, and the address AO,
At, select retimer 0 and timer 1, set the operation mode to timer O and timer l, and set the TO and T1 terminals respectively; write a value for counting the input clock CLK from the data bus. The operating mode (normal mode or 41 diagonal mode) and count number (delay time number) can be determined through.

~Write to D7. Programmable timer PTC1 is
Each gate GO has an independent circuit.

Clock C input to TO and TI terminals from the rising edge of G1
The number of LK pulses is counted, and when the set count number is reached, the output terminal p'rc of timer 0 or timer 1 is
Obtain the output pulses at oo and PTCO. In other words, by inputting the change point of track 0 to G1 through the gates Go and INVI of the programmable timer PTC1, the set clock count number is obtained. The pulses delayed by PTCOo and PTCOt
It is output from

FIG. 2 is a timing chart showing the circuit operation of FIG. 1.

As shown in FIG. 2, the output pulse P T of the programmable timer PTC1 starts from the change point of the reproduced waveform of track O.
Obtain COo and PTCO. NOR gate N0R1
When the pulse that has passed is input to the trigger terminal T of FF4 for frequency division, the reproduced waveform of track 0 will be changed for the time set in the program (Tarlock CLK cycle x number of clocks).
It is obtained from output 1 of FF4 with a delay of . When the output of FF4 is connected to the D terminal of EXORO and FFO, EX
The delayed changing point of the reproduced waveform of track 0 is output as the ORO output (not shown in FIG. 2).

This EXORI output and EXORO output are connected to an OR gate O
RI, the output of ORI is input to the D terminal of FF2, and one output of FF2 is input to the D terminal of FF3.

The 0 output of FF3 and the 1 output of FF2 are input to the NAND gate NANDI.

Here, if track 1 or track 0 changes,
A pulse for determining data is output from NANDI at the rising timing of the clock CLK at the T terminals of FF2 and FF3, and when the output of NANDI is input to the T terminals of FFI and FFO, when there is a change in track 1, the data is sent to EXORI. When a signal of 1117+ is output and there is a change in track 0, the output data (actually, data 110
(No pulse of IT is output) is obtained. NAND
Data is written into the memory 5 in FIG. 5 using the I output (timing of a clock for determining data), and the data is checked by a program.

In the explanation so far, when the phase of the reproduced waveform is ahead on the track O side than on the track 1 side.

Although the phase on the track 0 side is delayed, if the data check is correct, by setting the count number of the programmable timer PTCI to no correction value in the program, u 1 rt and 110 tp of the discrimination data in Fig. 2 can be set.
are replaced and can be read correctly as is.

FIG. 3 is a program control flowchart of a magnetic stripe reading method showing one embodiment of the present invention.

First, after starting reading, set the correction value (0) to timer 0 and timer l.
) is set (Step 31), the transport mechanism 1 is operated in the forward (suction) direction (Step 32), data is read and written into the memory 5, and then the data is checked (Step 33). As a check method, check the 6th
As shown in the figure, the start code, end code, vertical and horizontal parity, etc. are checked, and if the read data check is correct, the reading is completed.If a reading error occurs, the reading is performed in the back (ejection) direction. (Step 34) If a reading error occurs even in the back,
Set the correction value (θ) in timer O and timer I (steps 35 and 36), and repeat forward (intake) and back (exhaust) readings (steps 37 and 38). After reading, check (step 38.40)
If a reading error occurs, the correction values for timers 0 and 1 are changed from θ to 20, and further from 2θ to 30, and the reading is repeated (steps 41 to 50). Each time, a reading check is performed, and if the reading is normal, the reading is finished and the data is processed. If a reading error occurs until the end, it is treated as a reading error.

FIG. 4 is a diagram showing the magnetic stripe reading range under program control according to the present invention.

The vertical axis represents write jitter (instantaneous write fluctuation).

The horizontal axis represents the light azimuth (writing inclination).

(a) shows the reading range when the correction value is 0 for the timer 0.1, and (b), (c), and (d) show the reading range when the correction value is 0, 2θ, and 3θ, respectively. . The downward diagonal line to the left is forward reading, and the downward diagonal line to the right is backward reading.

It can be determined that when written with an inclination of about -1.5θ to 1.50, it can be read with a correction value O. Approximately -2,5θ~2.
When the slope is 50, it can be read with the correction value θ, which is about -3
, 5θ to 3.50 can be read with the correction value 2θ, and when the slope is about -4.5θ to 4.50, the correction value 3 can be read.
It can be read at θ. By changing the correction value in this way, the reading range is gradually expanded.

The reading range of (e) is controlled by the program (,) ~
(d) is the entire reading range.

In this embodiment, since the delay amount of the reproduced waveform on the track 0 side can be changed by program control, it is possible to expand the reading range of the data of the magnetic stripe written obliquely.

In the circuit shown in FIG. 1, the lead and lag of one phase are completely reversed depending on whether the reading direction is forward or backward.

That is, when reading in the forward direction, the delay of track O corresponds to the advance of track 1, and the advance of track 0 corresponds to the delay of track 1. Further, when reading in the reverse direction, the advance of track O corresponds to the delay of track 1, and the delay of track 0 corresponds to the advance of track I. Therefore, if the recorded data on the medium has a phase lead on the track 1 side, the phase can be adjusted by one phase by delaying the track O when reading in the reverse direction.

〔Effect of the invention〕

As explained above, according to the present invention, the reproduction waveform of track 0 or track l of magnetic stripe data written in a skewed manner is changed by program control to read the magnetic stripe. Since the range can be expanded, even data with a phase shift between track 0 and track I can be read correctly.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a magnetic stripe reading device showing an embodiment of the present invention, FIG. 2 is a timing chart showing the circuit operation of FIG. 1, and FIG. 3 is a magnetic stripe reading device showing an embodiment of the present invention. Program control flowchart of the method,
FIG. 4 is a diagram showing the reading range of the magnetic stripe according to the present invention, FIG. 5 is a block diagram of the entire medium transport system of the magnetic stripe reading method to which the present invention can be applied, and FIG. 6 is a diagram showing the data checking method according to FIG. Explanatory drawings, FIG. 7 is a diagram of the read waveform of normally written magnetic stripe data and the result of discrimination data, and FIG. 8 is a diagram of the read waveform of magnetic stripe data written diagonally and the result of discrimination data. It is. HO, Hl: magnetic head, 1: transport mechanism, 2: transport control circuit, 3: reading circuit, 4: microprocessor, 5:
Memory, AMP: Amplifier, SO. SL: Regeneration circuit, FFO~FF4: Flip-flop, RTCI: Programmable timer, EXORO~1:
Exclusive OR circuit. Tsugu 3rd figure 4th figure 5th figure 6th figure

Claims (1)

[Claims] (1) In a magnetic stripe reading method in which "0" data and "1" data are independently written to tracks 0 and 1 of a magnetic recording medium, there is a signal delay in one of the reading circuits of each track. A variable amount delay circuit is provided so that the read check result of the combined read data of the two tracks is determined whether the read operation is forward or reverse.
A magnetic stripe reading method characterized in that when an error occurs, the reading operation can be repeated while changing the delay time of the delay circuit stepwise.