JPS6356630B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic stripe reading device in which self-clocking magnetic recording is performed including a data signal and a clock signal in the same channel.

Recently, financial institutions such as banks have been using magnetic cards and passbooks with magnetic stripes attached for the purpose of saving labor and improving customer service.
Information necessary for transactions at financial institutions is recorded on the magnetic stripes on the magnetic cards and bankbooks using the above-mentioned magnetic recording method, and is read by a reading device as shown in FIG.

FIG. 1 schematically shows the configuration of a magnetic card reading device, in which 1 is a magnetic card having a magnetic stripe 1a having the format shown in detail in FIG. A feed roller and a pressure roller for drawing in the magnetic card 1; 3a to 3d are rollers; 4;
Numerals a and 4b are feed belts that are wound around the rollers to sandwich and convey the magnetic card 1, 5 is a magnetic head that reads the magnetic stripe 1a, 6 is a pressure roller that presses the magnetic card 1 against the magnetic head 5, and 7 is a feed belt that is used during suction. A first sensor 8 detects that the leading edge of the magnetic card 1 has passed, and a second sensor 8 detects that the leading edge of the magnetic card 1 has passed during reverse feeding.

The recording format of the magnetic stripe 1a first has a synchronization pull-in area 9 in which only clock information is written, and then a start code 10 and an end code 11 in which a predetermined number of consecutive bits of "1" are written.
There is a data area 12 between which transaction information such as an ID number, bank code, account number, and deposit balance is recorded. Finally, a check code 13 is written.

Feed roller 2a and feed belts 4a, 4
When the magnetic card 1 is drawn in by the rotation of b, the synchronous pull-in area 9 first passes the magnetic head 5. The vicinity of the front edge of the magnetic stripe 1a is often touched by hands when inserting or removing a card, and is easily damaged. For this purpose, the first sensor 7 is provided at a distance _l0 from the reading position of the magnetic head 5 so as to skip signals within a distance _l0 from the front edge of the card, and based on the detection signal of this sensor, the reading gate is I'm trying to open it. When the lead gate opens,
A reproduced signal from the magnetic head 5 is supplied to a data signal demodulation circuit.

As mentioned above, the magnetic stripe 1a on a magnetic card or passbook is recorded using a magnetic recording method that includes data signals and clock signals, and is generally FM.
It is done in a method. In the FM method, if there is a magnetization reversal at the center of a bit cell, which is a unit information recording area, the data information is "1", otherwise the data information is "0", and magnetization reversal always occurs at the boundary of each bit cell. , this is the clock information. Then, based on the clock information, a data window of, for example, 3/4 of the time of bit cell synchronization is created, and whether the data information is "1" or "0" is determined based on whether or not a reproduced signal exists within this data window. ing.

FIG. 3 is a waveform diagram illustrating information reproduction using such an FM recording method. a indicates information recorded on the magnetic stripe 1a, A indicates magnetization reversal, and a section T delimited by A corresponds to a bit cell. b is a reproduction signal of this recorded information, and section T
The signal that always occurs at the boundary of is the clock signal,
The signal generated at the center of section T is the data signal.
c indicates a data window created based on the clock signal, and its time is set to 3/4 of the interval T, for example. Conventionally, the time of this data window was not constant so that the data information could be reproduced correctly even if the relative speed between the magnetic stripe 1a and the magnetic head 5 fluctuated, but was set to 3/4 of the synchronization of the preceding bit, and the time of the bit period was set to 3/4. I try to follow the changes.

By the way, the above data window is attached to the magnetic card 1 in the synchronization pull-in area 9 of the magnetic stripe 1a.
Since the data information is generated in synchronization with the traveling speed of the clock, all "0"s are continuously written in the data information, and when this area passes through the magnetic head 5, only the clock signal is reproduced. After that, there is a starting code 10 in which a predetermined number of consecutive bits of "1" are written, and when this area passes through the magnetic head 5, a clock signal and a data signal are alternately reproduced.
Then, the magnetic stripe reader determines that the data signal is a starting code when a predetermined number of bits of "1" continue, and takes in the subsequent reproduced data as transaction information. Therefore, the starting code is 1
Detection of 0 is important for capturing transaction information, and if the initial code 10 is detected incorrectly, the subsequent reproduced data will be unreliable as transaction information.

FIG. 4 is a waveform diagram illustrating information reproduction when an abnormal bit exists in the synchronization pull-in area 9, where a, b, and c show the same waveforms as in FIG. 3, and d
indicates data information to be reproduced. B is an abnormal bit cell that exists among consecutive normal bit cells,
If there is such a long bit cell in the middle,
The time of the data window corresponding to the next bit cell becomes longer as shown in b, and the clock information is read as data information "1", which is erroneously determined to be the first code. Once the synchronization is broken in this way, all incorrect data information will be read thereafter.

The occurrence of such abnormal bit cells is caused by various causes such as sudden fluctuations in the card speed during writing, noise, abnormalities in the writing circuit, etc. In addition, since the synchronization pull-in area 9 is located at the edge of the card, it is often touched by hand. It may also be caused by dirt or scratches.

Conventionally, reading errors due to out-of-synchronization as described above are detected by checking the number of digits of the read transaction information, and the reading operation is repeated several times. If the magnetic card 1 cannot be read correctly as a result, the magnetic card 1 is ejected as being unreadable and the card handler is notified of this fact. Therefore, if an abnormal bit cell exists in the synchronization pull-in area 9,
The card handler is forced to wait while the read operation is retried several times, and then the card is returned without being able to complete the transaction. This is not good from a customer service standpoint.

The present invention aims to solve the above-mentioned problems of conventional magnetic stripe reading devices, and aims to improve the reading ability when abnormal bits are present in the synchronization pull-in area.

The present invention will be explained in detail below with reference to the drawings.

FIG. 5 is a block diagram schematically showing the configuration of a read control circuit according to an embodiment of the present invention, and FIG. 6 is a flowchart illustrating the operating procedure of an embodiment of the present invention.

In FIG. 5, 14 is an amplification and shaping circuit that amplifies and shapes the read signal of the magnetic head 5, 15 is a read gate that controls the sending of the read signal, and 16 is a
17 is a data reproducing circuit which separates the read signal into a data signal and a clock signal and reproduces the data using the above-described reproduction method; 17 is a read gate control flip-flop whose set side output is connected to one input of the read gate; 18 is a card feed control device that controls the feeding of the magnetic card 1; 19 receives signals S ₁ to _{S 3} that control the read gate 15; This is an OR gate connected to the set side input of the control F/F17.

Next, the operation of the present invention will be described with reference to FIG. 6. First, a card feed command FW is given to the card feed control device 18, and the magnetic card 1 is sucked. The read gate 15 has the front edge of the magnetic card 1 connected to the first sensor 7.
(hereinafter referred to as _P1 ), and no read signal is supplied to the data reproducing circuit 16 during _l0 shown in FIG. The front edge of magnetic card 1
When passing _P1 , the signal _S1 is supplied based on the detection signal of the first sensor 7, and the read gate control F/F17 is set to "1" via the OR gate 19. As a result, the read gate 15 is opened and a read signal is thereafter supplied to the data reproducing circuit 16.

Read the end code 11 of the magnetic stripe 1a,
If the read end is divided in half, the read end signal RE
is supplied to the card feeding control device 18, and the feeding of the magnetic card 1 is stopped and this read end signal is supplied to the card feeding control device 18.
RE resets the read gate control F/F17 and closes the read gate 15. Based on the generation of this read end signal RE, the number of digits of the read data is checked by a digit number checking means (not shown).
As a result, if the number of digits of the read data matches the predetermined number of digits, it is assumed that the data has been read correctly and the transaction process is continued; if they do not match, it is assumed that there is a synchronization error and a card reverse sending command RV is issued to the card sending control device 18.
As a result, the card feed control device 18 issues a normal rotation command to a drive source (not shown), and returns the magnetic card 1 toward the insertion slot. When the leading edge of the magnetic card 1 passes the position of the second sensor 8 (hereinafter referred to as P ₂ ), a signal S ₄ is supplied to the card feed control device 18 based on the detection signal, and the magnetic card 1 is fed back at the same time. At the same time, the card feeding command FW is supplied and the magnetic card 1 is stopped.
is sent in the positive direction again.

Even if the leading edge of the magnetic card 1 passes through _P1 , the signal _S1 is not output because this is the second reading operation.
Then, the signal _S2 is sent out after further feeding _l1 shown in FIG. That is, read gate control F・F1
7, the front edge of the magnetic card 1 is separated from the magnetic head 5 (l ₀
+l ₁ ), and the read gate 15 is opened at this point. After this, the same operation as the first read operation is repeated, the read gate 15 is closed upon detection of the end code 11, and the number of digits of the read data is checked. As a result, if it is determined that the reading has been performed correctly, the transaction processing is continued, and if not, the card reverse transfer command RV is sent again. If the transaction processing continues at this time, information indicating that the card reading operation has been retried may be recorded on the magnetic card, slip, or archival recording paper, or may be recorded by the person handling or operating the device. The information may be notified by display or the like. By doing this, it is possible to encourage the reissuance of a magnetic card without defects, and it is also possible to skip reading l ₁ in advance when reading this magnetic card again.

The magnetic card 1 is returned again by the card reverse transport command RV, and when its leading edge passes _P2 , the magnetic card 1 is sent in the forward direction again in order to enter the third reading operation. In the case of the third reading operation, after the leading edge of the magnetic card 1 passes _P1 , it is further fed by _l2 shown in FIG. 2, and then the signal _S3 is supplied, and the read gate control F.
Set F17 and open read gate 15. If the result of checking the number of digits after reading is good, the transaction is processed in the same way as in the case of the second reading above, and if it is abnormal, it is assumed to be out of synchronization, and an alarm is issued when the number of out of sync readings reaches 3 times. . In the case of an alarm, the magnetic card 1 is returned as unreadable, and the magnetic card handler, operator, etc. are informed of this fact and urged to issue a new card.

FIG. 7 shows signals S ₁ - applied to the OR gate 19 of FIG. 5 above to turn on and off the read gate 15.
This shows an example of a readout control circuit for generating S ₃ , in which the signals S ₁ to _{S 3} are connected to the AND gate 20.
~22 outputs. Said and gate 2
0 to 22 use the output of each decoder 23 as one input, and this decoder 23 outputs output a when the reading counter 24 is "1", output b when it is "2", and output b when it is "3". The output c is sent to the husband. The reading counter 24 reads the magnetic card 1
The count is incremented by "1" by the card feed command FW sent when reading. On the other hand, the other inputs of the AND gates 20 to 22 are given based on the leading edge detection signal of the magnetic card 1 by the first sensor 7. That is, the detection signal is applied to the AND gate 20 and the card feed monitoring circuit 26 via the amplification and shaping circuit 25. When the card feed monitoring circuit 26 is supplied with the detection signal, it counts the feed command pulses FP given to the drive source of the card feeding means, and after the leading edge of the magnetic card 1 passes P1, the card feed monitoring circuit 26 counts the feed command pulses FP given to the drive source of the card feeding means, and then continues to count the feed command pulses _FP given to the drive source of the card feeding means. When the signal has advanced by l ₁ and l ₂ shown in FIG. Therefore, in the first reading operation, since the reading number counter 24 is "1", the signal S ₁ is sent out as soon as the leading edge of the magnetic card 1 passes P ₁ , and in the second and third reading operations, the signal S 1 is sent out. Signals S ₂ and S ₃ are emitted when the leading edge of the magnetic card 1 has advanced l ₁ and l ₂ after passing P ₁ .

As explained in detail above, in the present invention,
When an out-of-synchronization read error occurs due to abnormal writing, scratches, or dust on the magnetic stripe, it not only allows the read operation to be retried.
Since the reading start position is shifted at any time, the reading ability is improved, and it is possible to avoid a situation where a magnetic card or the like cannot be read and the transaction is returned without completion, thereby further improving customer service.

Although the above embodiment describes the case of a magnetic card, it goes without saying that the same method can be applied to reading the magnetic stripe on a bankbook. Further, the configuration for shifting the reading start position toward the starting code each time a retry is performed is not limited to the above embodiment, and various design changes are possible, and the number of retry attempts is also arbitrary.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of a magnetic card reader;
The figure shows the recording format of the magnetic stripe of a magnetic card. Figure 3 is a waveform diagram explaining information reproduction in the FM recording method. Figure 4 is a waveform diagram explaining information reproduction when an abnormal bit cell exists. FIG. 5 is a block diagram showing one embodiment of the present invention, FIG. 6 is a flowchart explaining the operating procedure of one embodiment of the present invention, and FIG. 7 is a block diagram of a read-discard control circuit in one embodiment of the present invention. It is a diagram. 1...magnetic card, 1a...magnetic stripe,
5... Magnetic head, 7... First sensor, 8... Second sensor, 15... Read gate, 16... Data reproducing circuit, 17... Read gate control FF, 2
3...Decoder, 24...Reading number counter,
26... Card feed monitoring circuit.

Claims (1)

[Scope of Claims] 1. When the sensor detects the leading edge of the medium, the read gate is opened, and the read operation is started by reading the synchronization pull-in area recorded on the magnetic stripe on the medium, and the start code and data are read. In a magnetic stripe reader that performs a read operation in the order of area, end code, and check code, and retries the read operation when a read error due to loss of synchronization occurs, the read count counter counts the number of times the read operation is performed; and a medium feed monitoring circuit that sends a signal to open the read gate when a certain period of time according to the count value of the reading counter has elapsed since the sensor detected the leading edge of the medium, and the medium feeding monitoring circuit is configured to restart the reading operation. During the trial, the read gate opening timing is changed depending on the number of read operations, so that the reading start position of the synchronization pull-in area recorded on the magnetic stripe is initially brought closer to the code side. Magnetic stripe reader.