JPH06139385A - Magnetic card reader - Google Patents

Abstract

PURPOSE:To provide the magnetic card reader improving the probability of accurate reading when an error is occurred in a reading of magnetic card. CONSTITUTION:The magnetic card reader is provided with a mechanism section 1, control section 7, motor driving circuit 8 which controls a carrier motor 10, signal detection circuit 4, generating an f2f signal by detecting the peak of the reading signal of a magnetic stripe read by a magnetic head 3, regular reading circuit 5 reading bit information recorded on the magnetic card 2 based on the presence or absence of the signal from the signal detection circuit 4 and sending it to the control section 7, and bit followup reading circuit 6 sending the bit information recorded on the magnetic card 2 to the reading control section 7 based on the presence or absence of the signal from the signal detection circuit 4. The control section 7 controls the motor driving circuit 8, selecting either bit information from the regular reading circuit 5 or the bit followup circuit 6. Based on the selected bit information, the data recorded on the magnetic card 2 are reproduced and the error of the reproduction data is discriminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic card reader used in an automatic teller machine used in financial institutions.

[0002]

2. Description of the Related Art Conventionally, there are magnetic card readers used in automatic teller machines and the like which change the writing direction and the reading direction as in Japanese Patent Laid-Open No. 59-114481. Later rereads are not considered. In general, a 1-bit time is set on the assumption that the reading method (timed reading) based on the constant speed reading based on the f2f signal and a change in the reading speed have a small difference between adjacent 1 bits. A reading method (bit following reading) that counts and uses as a reference for reading the next 1 bit is used. In addition, JP-A-6
After writing to a magnetic card like 0-258691,
In some cases, the method of reading in the reverse direction is adopted.

[0003]

As described above, in the prior art, when reading the recorded information on the magnetic stripe of the magnetic card, when the read recorded information is not correctly read, the read operation is retried. However, since the conveyance speed, the reading method, the reading direction, and the like are all the same, the probability of correct reading by rereading is not high. For example, when the magnetic card is deformed, slippage occurs at the deformed portion even if the transport speed is constant, and the 1-bit interval during reading varies. In addition, there is a preamble with "0" recorded at both ends of the magnetic stripe of the magnetic card. When reading the magnetic stripe, the preamble is read to measure the reference value of 1 bit, and the original data portion is read. I am trying to read it correctly,
Both ends of the magnetic card are easily scratched and the preamble may not be read properly. Further, if the frequency of use of the magnetic card increases, the magnetic stripe surface is also scratched, and the reproduction signal from the magnetic head becomes smaller. Even if re-reading is performed under the same conditions with respect to the magnetic card that causes the reading failure, it is unlikely that the reading can be correctly performed. An object of the present invention is to solve the above-mentioned problems, and when re-reading based on various data obtained at the time of reading,
It is an object of the present invention to provide a magnetic card reader which improves the probability of correct reading by rereading by changing the reading method and changing the reading conditions such as the card transportation speed and the amplification factor.

[0004]

According to the present invention, there is provided a mechanism section including a magnetic card transport path, a card passage sensor, a magnetic head and a transport motor, a control section, and a motor drive circuit for controlling the transport motor. In a magnetic card reader having a signal detection circuit and a reading circuit, a time reading circuit and a bit following reading circuit are provided as reading circuits, and the control unit reads the bit information read by the time reading circuit and the bit following reading circuit. Any one of the bit information thus obtained is selected to reproduce the magnetic card data and determine the error of the reproduced data. Further, when the result of the error determination is an error, the control unit switches one bit information from the selected fixed-time reading circuit or bit-following reading circuit to the other bit information and selects and reads again. I have to. Further, the signal detection circuit sends the peak value of the read signal to the control unit, the bit tracking read circuit sends the measured 1-bit time to the control unit, and the control unit specifies the reproduction signal amplification degree and detects the signal. Sent to the circuit,
When the reference time width is specified and sent to the fixed-time reading circuit, and when the ratio is specified and sent to the bit-following reading circuit, when the result of the error judgment is an error, the error factor is based on the reproduction data, the peak value and the 1-bit time. Is determined. Also,
When it is determined that the error factor is that the fluctuation of the 1-bit time length is large and the fluctuation of the magnetic card transport speed is large, the control unit determines the magnetic card transport speed and the amplification factor of the signal detection circuit based on the error factor. The rereading is performed by changing the reference time width of the regular reading circuit and the ratio of the bit following reading circuit. When it is determined that the peak value is too large or too small as an error factor, the controller determines the magnetic card carrier speed, the reference time width of the regular reading circuit and the bit tracking when the peak value is too large. Rereading is performed by changing the ratio of the reading circuit, and when the peak value is too small, the amplification of the signal detecting circuit is changed to perform rereading. When it is determined that the start code in the reproduction data is incorrect, the control unit changes the transport direction to the opposite direction so that the magnetic card is read from the side opposite to the magnetic stripe, and re-reads. I am trying.

[0005]

The fixed-time reading method is vulnerable to speed changes, and the bit-following reading method may affect read-back reading with respect to signal loss, particularly f2f signal loss in the preamble portion other than the original data. According to the present invention, since the regular reading circuit and the bit following reading circuit are provided and the bit information which is the output of one reading circuit is selected to read the data recorded in the magnetic stripe, there is no error in the read data. If there is, the bit information of the other reading circuit can be selected and re-reading can be performed. Therefore, the probability of correct reading at the time of re-reading can be increased. Also, the factors that could not be read correctly are analyzed, and depending on the factors, the reading speed is changed, the amplification factor is changed, the reference time width is changed, the ratio to the bit time is changed, and the reading direction is changed according to the factors. Therefore, for example, when reading a deformed card or a magnetic card that has been used frequently and has become old, there is a large change in the reading speed at the deformed portion and a low-level output of the reproduction signal from the magnetic head, , The reproduction signal amplification factor, the reference time width, and the ratio to the 1-bit time can be increased to increase the probability of correct reading, and the preamble portion of the leading portion required at the start of reading. For the loss of the f2f signal due to scratches on the magnetic stripe, read from the opposite side of the magnetic stripe by reversing the transport direction and using the preamble part at the rear end. It is possible to increase the probability that the read correctly by the Migihitsuji.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.
Will be described in more detail. FIG. 1 is a block diagram showing a configuration of a magnetic card reader according to an embodiment of the present invention, FIG. 2 is a time chart of a regular reading method and a bit following reading method, and FIG.
3 is a flow chart showing an example of processing in the magnetic card reader of the present invention. FIG. 4 shows a format of recording information of a magnetic stripe on a general magnetic card.
FIG. 5 is a flow chart showing the processing when reading from the opposite direction of the magnetic stripe.

In FIG. 1, when the magnetic card 2 is inserted through the card insertion slot 9 of the mechanical section 1 of the magnetic card reader, the transport motor 10 is rotated, the transport rollers 31 to 34 are driven, and the magnetic card 2 is moved. It is absorbed by the magnetic head 3. The rollers 21 to 24 are pressing rollers of the magnetic card and sandwich the driving rollers 31 to 34 to convey the magnetic card 2.
The control unit 7 detects that the magnetic card 2 has been absorbed and has passed through the passage sensor 11 via the motor drive circuit 8, and starts reading the magnetic stripe. When the magnetic card 2 is further conveyed and passes under the magnetic head 2, the magnetic head 2
The reproduction signal a is output from the output terminal and is input to the peak detection circuit 4. In the peak detection circuit 4 which is a signal detection circuit, the reproduction signal a is amplified by the control unit 7 in advance at the amplification rate set by the signal h, and the pulse signal b of f2f is generated. This pulse signal b is input to the constant-time reading circuit 5 and the bit following reading circuit 6 and is changed to a signal of 1,0.

FIG. 2A shows a time chart of the operations of the fixed-time reading circuit 5 and the bit-following reading circuit. Pulse signal b
The 1-bit time T1 is determined by the carrying speed of the magnetic card 2 and the recording density of the magnetic stripe. However, if the carrying speed varies, the 1-bit time during reading changes. Figure 2
1-bit times T2 and T3 of the pulse signal b of (1) indicate the case where the transport speed becomes slow, and T1 <T2 <
There is a relationship of T3. In the constant-time reading circuit 5, a reference time width obtained by multiplying a 1-bit time T1 at a constant speed determined by the conveyance speed and recording density by a predetermined ratio, for example, a reference time width t of 75%.
The detection pulse tt of t1 is generated for each 1-bit pulse, and is set to "1" when the pulse signal b appears during this reference time width tt1.
Is converted to. Here, since the reference time width of the detection pulse tt is constant even if it becomes longer than T1 as in the case of 1-bit time T2, T3, in the case of 1-bit time T3, a pulse indicating "1" at the center of 1-bit. Cannot be detected within the reference time width tt1, and the pulse indicating the central "1" of 1 bit is
The detection pulse tt is generated by recognizing the bit boundary pulse of the bit, and "1" and "0" are erroneously converted (conversion signal c). However, if the 1-bit time is returned to T1, correct conversion can be performed from the point where it returns.

On the other hand, in the bit following reading circuit 6, normally,
Since a "0" bit appears at the beginning of reading the magnetic stripe, the pulse signal b measures 1-bit time T1 as a signal indicating a bit boundary. This measuring method is performed by counting clock signals having a cycle sufficiently shorter than the 1-bit time T1. Measured 1-bit time T1
Is generated as a detection pulse tb having a reference time width of, for example, 75% of the reference time width tb1, and when the pulse signal b appears during the generation of the detection pulse tb, it is set to "1", and when it does not appear, it is set to "0". ″ Is the same as in the regular reading circuit 5. In the bit-following reading circuit 6, when the transport speed is constant, a detection pulse tb having a time width tb1 is generated with respect to the 1-bit time T1, but if the transport speed slows down for some reason, the 1-bit times T2 and T3 are generated. become longer. 1
With respect to the bit times T2 and T3, the reference time width tb1 is based on the preceding one-bit time T1 and T2, respectively.
A detection pulse tb of tb2 is generated and converted into a conversion signal d of "1" or "0". Therefore, since the time of the preceding 1 bit is always measured and the detection pulse tb is generated by following the change even if the transport speed, that is, the read speed changes, the change in the read speed is less than that in the regular reading circuit 5. It will be strong. However, as shown in (2) of FIG. 2, the output of a part of the reproduction signal a from the magnetic head 3 is small, peak detection cannot be performed, and a signal loss occurs in the pulse signal b of f2f. The detection pulse tb in the detection of "" and "0" has an error that the one-bit time T1 is Tbw, and the time width of the detection pulse tb is large as tbw. Therefore, there is a drawback that "0" is continuously detected as "1". On the other hand, in the scheduled reading circuit 5, one error does not affect the succeeding ones.

The conversion signals c and d generated by the above-described fixed-time reading circuit 5 and bit-following reading circuit 6 and the detection pulses tt and tb as clock signals are input to the control section 7. The control unit 7 reproduces the recorded information of the magnetic stripe from the "1" and "0" signal strings of the conversion signals c and d, and checks the reproduced information.

FIG. 4 shows a general recording information format of a magnetic stripe. The recorded contents of the magnetic stripe 40 on the magnetic card 2 are the preambles 41 and 46 in which “0” is recorded at both ends of the magnetic card 2 and the start code 42.
And data 43 such as an account number, an end code 44 and a check digit 45. When the magnetic card 2 is conveyed through the insertion slot 9 and read, the recorded information on the magnetic stripe 40 starts from the preamble 41 and is denoted by reference numeral 42.
The following 43, 44, 45 and the preamble 46 are read in this order. The control unit 7 sequentially puts the converted signal c or d into the shift register bit by bit, and continues to input the converted signal c or d bit by bit until the bit number of the starting code 42 and the bit pattern match. When the start code 42 can be detected, the data 43 is taken in as one digit of the record information for each specified number of bits.
When the data 43 of the recording information is fetched and the end code 44 is matched, the next check digit 45
Then, the reading of the recorded information is completed. Normally, these data 43 are subjected to vertical parity check for each digit. Also, a check digit 45 is used to perform a horizontal check between the start code 41 and the end code 44 (normal horizontal parity check). If all these checks are correct, it means that the recorded information on the magnetic stripe 40 has been correctly read.

In FIG. 1, the control unit sends a detection pulse for a 1-bit time length corresponding to the conveying speed (reading speed) to the constant-time reading circuit 5 and the bit-following reading circuit 6 by a signal g. Reference time width (for example, the fixed time reading circuit 5 has a reference time width tt1 (for example, 75 of T1).
%)) To the bit-following reading circuit, and the ratio to the one-bit time length (for example, 75%). Furthermore, the control unit 7
Makes it possible to read the 1-bit time length measured by the bit following reading circuit by the signal m. The measurement of the 1-bit time length operates even if the control unit 7 selects the regular reading method. The controller 7 also controls the carry motor 10 and the carry path sensors 11 and 12. The carry motor 10 is composed of a stepping motor, and operates by the drive signal k by sending a control signal f to the motor drive circuit 8. The number of rotations and the direction of rotation can be changed by changing the control signal f. The output signal j of the sensors 11 and 12 is converted into a digital signal by the motor drive circuit 8 and output to the control unit 7 as a signal i. The control unit 7 detects the passage of the magnetic card by the signal i. In addition, the control unit 7 can change the amplification factor of the reproduction signal a by the signal h with respect to the peak detection circuit 4, and can know the magnitude of the peak value of the reproduction signal from the signal e. As described above, the converted signals c and d and the detection pulses tt and tb are input to the control unit 7, and the control unit 7 controls so as to selectively switch which signal is used.

The process of the present invention will be described below with reference to the flowchart of FIG. Before the operation starts, initial setting 101 is performed. In the initial setting, in addition to the designation of the reading method, the carrier speed, the reference time width of the detection pulse to the time length of 1 bit, the ratio to the time length of 1 bit, and the amplification factor are set. It is sent to the reading circuit 6 and the peak detection circuit 4. The designation of the reading method in the control unit 7 is
Generally, the bit-following reading method is initially selected in consideration of fluctuations in the transport speed and fluctuations in the reading speed due to slip of the magnetic card during reading. In this state, when the magnetic card 2 is inserted from the card insertion slot 9 (102), the carry motor 10 drives the carry path to carry the magnetic card 2 in the forward direction (103) in the suction direction. It is checked (104) whether the magnetic card 2 is conveyed and reaches the sensor 11. Sensor 11
When it reaches, the reading starts. The reading (105) is performed by selecting the conversion signal d and the detection pulse tb output from the bit following reading circuit 6 by the control unit 7. Each time 1 bit is read, a 1-bit time length reading (106) sent as a signal m and a peak value of a reproduction signal a sent as a signal e are read (107), and a memory (not shown) in the control unit 7 is read. Sequentially store in. While the magnetic card 2 is passing the magnetic head 3, the magnetic card 2 is read bit by bit, the sensor 12 is checked (108), and the operation is repeated until the rear end of the magnetic card 2 passes the sensor 12. The control unit 7 detects "1" and "0" for each bit in the reading of 105 and inputs them to a shift register (not shown) in the control unit 7,
When the start code is detected, the read data is sequentially stored in the memory with the specified number of bits as one digit. At the same time, a flag for starting code detection is set.

When the passage of the rear end of the magnetic card 2 is detected by the check (108) of the sensor 12, the conveyance motor 10
Then, the conveyance of the magnetic card 2 is stopped (109).
At this point, either all the recorded information on the magnetic stripe has been read, or there is no data because the beginning symbol cannot be detected, and the read data stored in the control unit 7 is checked (110). . This data check is typified by a vertical parity check for each digit and a horizontal parity check by a check digit after the end code. If there is an error in any of the checks, the necessity of rereading is checked (11
1) If necessary, an error factor analysis G is performed. Usually 1
Read again ~ 2 times. After the re-reading is performed a prescribed number of times, a magnetic card return process described later is performed. When there is no data, the beginning code has not been detected.

Checking the start code by factor analysis (112)
Is performed by checking the detection flag. Start code 42
2 is not detected, there is a possibility that the preamble 41 of the reading start portion of the magnetic stripe 40 may lack the pulse shown in (2) of FIG. 2, and it is considered that the reading could not be performed correctly until the end. Switching to the regular reading method (130). Since the magnetic card 2 is stopped behind the sensor 12 (on the side of the rollers 24, 34), the magnetic card 2 is conveyed in the reverse direction toward the insertion slot 9 (117) and moved to the front of the sensor 11 (118). After that, carry in the forward direction (1
03), the same processing as described above is performed.

Start code check (112) to start code 4
When 2 is detected, the data 43 is stored in the memory, but it means that there is a reading error of "1" / "0". Therefore, the time length of 1 bit is read and the change in the time length of adjacent 1 bits is checked (113).
If the transport speed changes abruptly, the magnetic card 2 may be deformed and cannot be transported smoothly, or the surface state of the magnetic card 2 may be in a unique state and slip may have occurred. Is lowered (141) and the carrying force is increased so that rereading is performed. It should be noted that if the transport speed is lowered, the output signal of the reproduction signal a becomes smaller, so that the amplification factor is increased in advance (140). If the change in the transport speed is small, the peak value of the reproduction signal a is read and it is checked whether there is an extremely large value or a small value (114). If it is extremely large, the conveyance speed is lowered (141) to optimize the peak value of the reproduction signal a. In this case, there is a method of instructing the peak detection circuit 4 to reduce the amplification factor, but in this embodiment, the conveyance speed is changed. When the transport speed is changed, the 1-bit time length becomes different. Therefore, the reference time width and ratio are also instructed to be changed to the fixed-time reading circuit 5 and the bit-following reading circuit 6 (14
2). The subsequent processing is the same as the processing in the reading method change (130). On the other hand, when the peak value of the reproduced signal is extremely small, the peak detection circuit 4 is instructed to change the amplification factor (115). The subsequent processing is the same as the processing in the reading method change (130). When the peak value of the reproduced signal is a proper value, the reading is performed again under the same conditions. Also in this case, the subsequent processing is the same as the processing in the reading method change (130).

In addition to this, the process (B ') of reading the magnetic card 2 from the opposite direction will be described with reference to FIG.

When the start code check (112) in FIG. 3 reads the start code 41 when the magnetic stripe 40 is transported in the forward direction, and there is a reproduction signal defect as shown in (2) of FIG. 2 due to a scratch or the like. By reading the preamble 46 of the magnetic stripe 40 by reversing the transport direction, the recorded information may be correctly read regardless of the trouble at the start code 41. Therefore, as processing B ', reading from the opposite direction is shown in FIG.

The control unit 7 specifies the backward reading (15).
0), the carry motor 10 rotates in the opposite direction to carry the magnetic card 2 in the opposite direction (151). In the state up to that time, the magnetic card 2 is behind the sensor 12 (on the side of the rollers 24, 34) and passes through the sensor 12 by the backward conveyance.
This passage start is checked (152), and reading is started (153). Read (153), 1-bit time length read (154), read signal peak value read (155)
Is the same processing as 105, 106 and 107 in FIG. This reading is continued until it passes the sensor 11 (15
6). When the magnetic card 2 passes the sensor 11, the transportation is stopped (157) and the read data is rearranged (158). In this case, the pattern check of the starting code cannot be performed at the same time as reading, as in the case of reading in the forward direction.
The bits are input in the order in which they are read, the bit string is reversed, and the starting code 41 is searched on the memory. Based on the searched start code 41, the data is organized as one digit for each specified number of bits, and then vertical and horizontal parity checks are performed (159). Magnetic card 2 if read correctly
Will be returned. On the other hand, if the data cannot be read correctly, the necessity of re-reading is checked (160), and if it is necessary, the same process as G in FIG. 3 is performed and the condition is read again to read. In the case of no, the magnetic card 2 is returned.

The embodiment of the present invention has been described above, but an example of the factor analysis of the read error and the process based on the factor is shown. By changing the combination of these processes, more correct reading can be made. In addition,
If it is necessary to shorten the reading processing time, stop reading 1-bit time length, read the peak value of the playback signal,
It is also effective to change the reading method when reading again.

[0021]

According to the present invention, when reading the magnetic stripe of the magnetic card, one of different reading circuits can be selected for reading, and when a reading error occurs, another reading circuit can be used for reading again. Therefore, the probability of correct reading by rereading can be increased. In addition, grasp the situation when reading the magnetic stripe, analyze the cause when a read error occurs, and set the optimum conditions when reading again, so increase the probability of correct reading by rereading. You can Also, depending on the cause of the read error,
Since the magnetic stripe can be read from the opposite direction at the time of rereading, the probability of correct reading by rereading can be increased.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a magnetic card reader according to an embodiment of the present invention.

FIG. 2 is a diagram showing a time chart of a regular reading method and a bit following reading method.

FIG. 3 is a flowchart showing an example of processing in the magnetic card reader of the present invention.

FIG. 4 is a diagram showing a format of recording information of a magnetic stripe on a general magnetic card.

FIG. 5 is a flowchart showing a process when reading from the opposite direction of the magnetic stripe.

[Explanation of symbols]

 1 Mechanism 2 Magnetic Card 3 Magnetic Head 4 Peak Detection Circuit 5 Periodic Reading Circuit 6 Bit Follow-up Reading Circuit 7 Controller 10 Transport Motors 11 and 12 Passage Sensor

Claims (6)

[Claims] 1. A mechanism unit including a magnetic card transport path, a card passage sensor, a magnetic head and a transport motor, a control unit, and information detected by the card passage sensor and sent to the control unit. A motor drive circuit for controlling the carrying motor under the control of the control section, and a signal detection circuit for performing peak detection of a read signal of a magnetic stripe read by a magnetic head and generating a signal f2f. , A signal from a signal detection circuit generated within a period of a detection pulse having a reference time width obtained by multiplying a 1-bit time determined by the magnetic card transport speed when passing through the magnetic head and the recording density of the magnetic stripe by a predetermined ratio. The timed reading circuit for reading the bit information recorded on the magnetic card based on the presence / absence of the above, and sending it to the control section, and measuring the time of 1 bit, and reading the next 1 bit. The bit information recorded on the magnetic card is read based on the presence / absence of a signal from the signal detection circuit generated within the period of the detection pulse having the reference time width obtained by multiplying the previously measured 1 bit time by a predetermined ratio. A bit following reading circuit for sending to the control unit, wherein the control unit controls the motor drive circuit;
Means for selecting bit information from either the fixed-time reading circuit or the bit-following reading circuit, and reproducing the data recorded in the magnetic card based on the selected bit information and making an error in the reproduced data. A magnetic card reader comprising means for making a determination. 2. The magnetic card reading device according to claim 1, wherein the control unit selects one of the selected fixed-time reading circuit or bit-following reading circuit when the result of the error determination is an error. A magnetic card reader comprising means for switching and selecting the bit information of the other bit information to the other bit information and reading again. 3. The magnetic card reader according to claim 1, wherein the signal detection circuit is connected to the control unit and sends the peak value of the read signal to the control unit, and the bit tracking read circuit measures. 1-bit time is sent to the control unit, and the control unit specifies a reproduction signal amplification degree and sends it to the signal detection circuit; and means that specifies the reference time width and sends it to the scheduled reading circuit. Means for designating the ratio and sending it to the bit following reading circuit; and error factor determining means for determining an error factor based on the reproduction data, the peak value and the 1 bit time when the result of the error determination is an error. A magnetic card reading device comprising: 4. The magnetic card reading apparatus according to claim 3, wherein the error factor determining means determines that a large variation in the 1-bit time length and a large variation in the magnetic card transport speed are the error factors. Then, the control unit changes the magnetic card carrier speed, the amplification factor of the signal detection circuit, the reference time width of the timed reading circuit, and the ratio of the bit following reading circuit based on the error factor and re-executes. A magnetic card reader comprising a reading means. 5. The magnetic card reader according to claim 3, wherein when the error factor determination means determines that the peak value is excessive or excessively small, the control unit is based on the error factor. When the peak value is too large, the magnetic card carrier speed, the reference time width of the regular reading circuit and the ratio of the bit following reading circuit are changed to read again, and when the peak value is too small, the signal A magnetic card reader comprising a means for re-reading by changing the amplification degree of a detection circuit. 6. The magnetic card reader according to claim 3, wherein when the error factor determining means determines that the start code in the reproduced data is incorrect, it is the error factor. A magnetic card reading device comprising means for changing the transport direction to the opposite direction so that the magnetic card is read from the side opposite to the magnetic stripe and performing re-reading.