JP6231819B2 - Information medium reading apparatus and information medium reading method - Google Patents

Description

  The present invention relates to an information medium reading apparatus and an information medium reading method for reading magnetic data from a magnetic stripe formed on an information medium such as a card or a passbook.

Data is magnetically recorded on a magnetic stripe formed on an information medium such as a card or a passbook by, for example, F2F modulation.
Patent Document 1 describes a magnetic reproduction circuit as an information medium reading device applied to a card reader or the like that reads F and 2F signals corresponding to “0” and “1” signals magnetically recorded by a frequency modulation method. .

In this magnetic reproduction circuit, F and 2F signals (magnetic data) recorded on a card conveyed on a conveyance path by a conveyance roller or the like are reproduced as analog signals by a magnetic head and amplified by an amplification circuit.
The analog signal amplified by the amplifier circuit has a peak point detected by a peak detection circuit, which is an analog circuit, and the output signal is inverted at the peak point to be shaped into a rectangular wave signal.
This rectangular wave signal is a signal subjected to frequency modulation (F2F modulation), and is input to the F2F demodulation circuit and demodulated.

By the way, in the information medium reading apparatus as described above, for example, the magnetic stripe on the medium side may be worn, and the analog signal of the read magnetic data may be attenuated from a specified value. In this case, magnetic data may not be demodulated quickly and accurately.
Patent Document 2 proposes a magnetic data reader configured so that magnetic data can be demodulated quickly and accurately even when the analog signal of the magnetic data is attenuated below a specified value due to wear of the magnetic stripe or the like. Yes.

In the information medium reading apparatus as described above, for example, the conveyance speed of an information medium such as a card or a passbook may suddenly change or the conveyance may stop. Also in this case, magnetic data may not be demodulated quickly and accurately.
Patent Document 3 proposes a magnetic data reading demodulation method configured so that magnetic data can be demodulated quickly and accurately even when the conveyance speed of the information medium changes suddenly or the conveyance stops.

  According to the proposed apparatus and method, even if a partial loss or error occurs in the read magnetic data, the original magnetic data can be restored by devising the demodulation method.

Utility Kaihei 6-52003 JP 2001-273605 A JP 2003-77231 A

  By the way, it is a useful means in failure analysis to investigate the output waveform (analog signal) of the magnetic head stored in the memory in the information medium reader (magnetic data reader) when magnetic data reading fails.

On the other hand, when the output waveform of the magnetic head is disclosed in the failure analysis, it is possible to analyze specific magnetic data from the output waveform.
However, in the case where important data such as customer personal data is included in a portion other than the portion where the failure actually occurs, this can be demodulated.
Therefore, when disclosing the output waveform of the magnetic head at the time of failure analysis, a method for making it impossible to demodulate the magnetic data by a known demodulation method or data restoration method is required.

  An object of the present invention is to make it difficult to reliably demodulate magnetic data by a known method while outputting an output waveform of a magnetic head in failure analysis or the like while leaving the original output waveform as much as possible for failure analysis. It is an object to provide an information medium reading apparatus and an information medium reading method capable of performing the above.

An information medium reader according to a first aspect of the present invention includes a magnetic head that reads magnetic data recorded on an information medium, and a pseudo data creation unit that creates pseudo data from the magnetic data read by the magnetic head. The pseudo data creation unit includes an analog / digital (A / D) conversion unit that converts magnetic data read by the magnetic head from an analog signal to a digital signal; and the A / D conversion unit performs A / D A storage unit for storing the converted magnetic data as a digital value so as to be readable in time series, and for reading out the magnetic data stored in the storage unit and outputting the output waveform of the magnetic head for failure analysis while leaving only the original output waveform possible, among the number of bits constituting one character, so that the original data is left, the number of bits that can be corrected by the parity bits from the The digital value of a plurality number of bits have, including a pseudo data rewriting processing unit for rewriting the digital value of the pseudo and.
As a result, when outputting the output waveform of the magnetic head in failure analysis, etc., it is difficult to reliably demodulate magnetic data with a known method while leaving the original output waveform (analog signal) as much as possible for failure analysis. It becomes possible to do.

Preferably, the pseudo data rewrite processing unit simulates at least a 2-bit digital value for each bit number obtained by subtracting the number of bits constituting one character from a different position in the scan direction instead of the same position. Rewrite to the digital value of.
As a result, only specific bits are erased, and there are no places where only a number of bits (1 bit) that can be corrected with parity bits can be erased within one character (character). 2 characters or more can be erased. As a result, the original output waveform (analog signal) read by the magnetic head can be left to the extent that failure analysis can be performed, and further, even with a part of the true magnetic data by a known method, it can be demodulated. Can be prevented.

Preferably, the pseudo data rewrite processing unit rewrites a digital value of at least 2 bits into a pseudo digital value for each number of bits obtained by subtracting 1 from the number of bits constituting one character.
In this case as well, only specific bits are erased, and there is no place where only 1 bit can be erased within one character (character). Furthermore, all characters (characters) can be erased by 2 bits or more. Since the original output waveform (analog signal) remains to the extent that failure analysis can be performed, an optimum output waveform (analog signal) can be created.

Preferably, the pseudo data rewrite processing unit includes a rewrite pattern in which only a specific bit is erased in one character and a rewrite pattern in which a portion where only a number of bits that can be corrected with a parity bit can be erased in one character is generated. Rewrite processing is performed with the removed rewrite pattern.
As a result, it is possible to prevent the true magnetic data content read from the magnetic head from being predicted, and to prevent demodulation of even a portion of the true magnetic data.

  The pseudo data rewrite processing unit performs a rewrite process so that the original magnetic data cannot be demodulated as character data.

Preferably, one character is 8 bits, 7 bits, or 5 bits including a parity bit.
It can handle magnetic data in accordance with JIS standards.

  A read processing unit that performs a process of demodulating magnetic data read by the magnetic head; the A / D conversion unit; the storage unit; and the pseudo data rewrite processing unit. A pseudo data creation unit that stores magnetic data as a digital value in the storage unit. When the pseudo data creation unit receives a data provision request, the pseudo data rewrite processing unit corresponds to the storage unit. A part of the stored data can be rewritten to pseudo data and provided to the request destination.

  Moreover, you may comprise so that the said information medium may have a conveyance part which moves relatively with respect to the said magnetic head.

An information medium reading method according to a second aspect of the present invention includes a reading step of reading magnetic data recorded on an information medium by a magnetic head, and a pseudo data generating step of generating pseudo data from the magnetic data read by the magnetic head. The pseudo data creation step includes an analog / digital (A / D) conversion step for converting magnetic data read by the magnetic head from an analog signal to a digital signal, and the A / D conversion step. A step of storing the A / D converted magnetic data in a storage unit so as to be readable in a time series as a digital value, and reading the magnetic data stored in the storage unit and outputting an output waveform of the magnetic head while leaving only the original output waveform possible for failure analysis, among the number of bits constituting one character, the original data As you remain including a plurality of bits of number greater than the number of bits that can be corrected by the parity bit digital value, the pseudo data rewriting processing step for rewriting the digital value of the pseudo and.
As a result, when outputting the output waveform of the magnetic head in failure analysis, etc., it is difficult to reliably demodulate magnetic data with a known method while leaving the original output waveform (analog waveform) as much as possible for failure analysis. An information medium reading device can be realized.

  According to the present invention, when outputting an output waveform of a magnetic head in failure analysis or the like, the known method can reliably demodulate magnetic data while leaving the original output waveform (analog waveform) as much as possible for failure analysis. Can be made difficult.

It is a figure which shows the structural example of the information medium reader which concerns on embodiment of this invention. It is a figure for demonstrating the standard of a card | curd and its specification. It is a figure which shows the signal processing waveform of the principal part of the information-medium reader of FIG. It is a figure which shows the process outline | summary which rewrites 2 bits in 1 character (character) of the pseudo data rewrite process part which concerns on this embodiment with pseudo data. It is a figure which shows the structural example of the pseudo data rewriting process part in the pseudo data preparation part which concerns on this embodiment. It is a flowchart for demonstrating the specific process example in the pseudo data preparation part which concerns on this embodiment. It is a figure for demonstrating the replacement rule of the digital value in the pseudo data creation part which concerns on this embodiment. It is a figure which shows the example of a data sample before and behind rewriting (erasing) in case magnetic data respond | corresponds to a JIS-II specification. It is a figure which shows an example of the reading failure analysis before and behind rewriting (erasing) in case magnetic data respond | corresponds to a JIS standard. It is a figure for considering the erase pattern at the time of 1 character 8 bits of the pseudo data rewrite process part which concerns on this embodiment. It is a figure for considering the erase pattern at the time of 1 character 7 bits of the pseudo data rewrite process part which concerns on this embodiment. It is a figure for considering the erasure pattern at the time of 1 character 5 bits of the pseudo | simulation data rewrite process part which concerns on this embodiment. It is a flowchart for demonstrating the general operation | movement outline | summary of the information medium reading apparatus which concerns on this embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram illustrating a configuration example of an information medium reading device according to an embodiment of the present invention.

In the present embodiment, an information medium reading device (hereinafter referred to as a card reader) that reproduces magnetic data recorded on a card or the like (hereinafter referred to as a card) that is a recording medium will be described as an example.
In this embodiment, an example in which F and 2F signals corresponding to “0” and “1” signals magnetically recorded by the frequency modulation method are read and reproduced will be described.
However, the present technology is not limited to the F2F method, and various methods such as the F3F method, the NRZI method, and the MFM method can be applied.

Card reader 10, as shown in FIG. 1, the card processing unit 20, that having a reading processor 30 and the pseudo data generation unit 40,.

In FIG. 1, a reading processing unit 30 and a pseudo data creation unit 40 are connected to a host device (higher level device) 50 via a communication line, execute processing in accordance with a command from the host device 50, and perform magnetic processing after processing. It is configured to transfer data to the host device 50.
In order to establish communication between the host device 50 and the card reader (lower device), various communication methods such as an RS232C method, a parallel port method, and a USB (Universal Serial Bus) connection method can be employed.

In the present embodiment, the read processing unit 30 basically performs a process of demodulating the F and 2F signals (magnetic data) read by the magnetic head 23.
The pseudo data creation unit 40 accumulates (stores) the F and 2F signals (magnetic data) read by the magnetic head as digital values, and there is a failure or the like in the magnetic data reading process by the read processing unit 30. When it occurs, in response to a request for providing an output waveform (analog signal) from the host device 50 or the like, part of the accumulated magnetic data is rewritten to pseudo data and provided to the host device 50.
The reason why the pseudo data creation unit 40 according to the present embodiment rewrites a part of the accumulated magnetic data to pseudo data and provides it to the host device 50 is that the output waveform (analog signal) of the magnetic head is output in failure analysis or the like. This is because it is possible to make it difficult to reliably demodulate magnetic data by a known method while leaving the original output waveform (analog waveform) as much as possible for failure analysis.
Specific configurations and functions of the reading processing unit 30 and the pseudo data creating unit 40 will be described in detail later.

[Configuration of card processing unit]
The card processing unit 20 includes a card transport path 21 and a card transport section 22 that transports the card MC along the card transport path 21 by a transport roller 22-1 driven by a drive motor (not shown). The magnetic data can be read by moving the card MC relative to the magnetic head 23 by the card transport unit 22 or manually.
The card processing unit 20 is provided with a magnetic head 23 that reads the magnetic data of the magnetic stripe mp of the card MC along the card transport path 21.
In the example of FIG. 1, the magnetic head 23 is arranged on the upper side of the card conveyance path 21, but the magnetic head 23 may be arranged on the lower side of the card conveyance path 21.

  In addition, a plurality of sensors (not shown) that detect the presence / absence of a card MC to be transported and a transport position are arranged in the card transport path 21, and the card MC transport operation (speed, etc.) is determined according to the detection results of these sensors. ) Control and magnetic data reading operation control by the magnetic head 23 are performed by the read processing unit 30 side or the host device 50.

The magnetic head 23 uses, as an analog signal S23, magnetic data (magnetic recording information) MRD recorded on the card MC, which is an information medium (magnetic recording medium), for example, as shown in FIG. read out.
An analog signal S23 of magnetic data read by the magnetic head 23 is supplied to the read processing unit 30.

Here, the standard of the card (magnetic stripe card in this example) MC will be described.
FIG. 2 is a diagram for explaining card standards and specifications.
Cards used in Japan are JIS standard cards.
As standards, there are JIS-I (ISO) track 1, JIS-I (ISO) track 2, JIS-I (ISO) track 3, and JIS-II.
ISO and JIS-I have the same specifications. JIS-II is unique to Japan and is used for cash cards in Japan.

JIS-I (ISO) track 1 has a specification of 7 bits, of which 1 bit is a parity bit, the character type is alphanumeric, the maximum number of characters is 72/79 characters, and the magnetic surface is on the back side of the card MC. It is formed.
JIS-I (ISO) track 2 has a specification of 5 bits, of which 1 bit is a parity bit, the character type is numeric, the maximum number of characters is 40 characters, and the magnetic surface is formed on the back side of the card MC. .
JIS-I (ISO) track 3 has a specification of 5 bits, of which 1 bit is a parity bit, the character type is a number, the maximum number of characters is 107 characters, and the magnetic surface is formed on the back side of the card MC.
JIS-II has a specification of 8 bits, one of which is a parity bit, the character type is alphanumeric, the maximum number of characters is 72, and the magnetic surface is formed on the front side of the card MC.

  For example, a track 1 of JIS-I (ISO), a track 2 of JIS-I (ISO), and a track 3 of JIS-I (ISO) are formed in one magnetic stripe on the back side of the card MC.

[Configuration and Function of Reading Processing Unit 30]
The read processing unit 30 basically performs a process of demodulating the magnetic data read by the magnetic head 23.
The read processing unit 30 amplifies the analog signal S23 of the magnetic data read by the magnetic head 23 and supplies it to the pseudo data creation unit 40.

  1 includes a first amplifier 31, a second amplifier 32, a peak detector 33, a first comparator 34, a second comparator 35, a timing generator 36, and a demodulator 37. It is configured.

  The first amplifier 31 amplifies the analog signal (magnetic data) S23 read and reproduced by the magnetic head 23 to an appropriate level, and outputs the amplified magnetic data to the peak detector 33 as a signal S31.

  The second amplifier 32 amplifies the analog signal (magnetic data) S23 read and reproduced by the magnetic head 23 to an appropriate level, and uses the amplified magnetic data as a signal S32 as the second comparator 35 and the pseudo data. The data is output to the creation unit 40.

  The peak detection unit 33 includes a differentiation circuit, an integration circuit, and the like, detects a peak position generated at the magnetic inversion position of the analog signal S31 of the magnetic data by the first amplifier 31, and uses the detection result as a signal S33. Output to the first comparator 34.

  The first comparator 34 shapes and binarizes the signal S33 from the peak detector 33 and outputs the binarized result to the timing generator 36 as a peak interval (interval) signal S34.

  The second comparator 35 shapes the analog signal S32 of the magnetic data from the second amplifier 32 to obtain binarized data, and outputs this as a signal S35 to the timing generator 36.

  The timing generator 36 generates a timing signal S36 corresponding to the peak output of the analog signal according to the peak interval (interval) signal S34 that has been shaped and binarized by the first comparator 34 and the signal S35 from the second comparator 35. The timing signal S36 is output to the demodulator 37.

  The demodulator 37 measures the time interval between adjacent peak positions according to the timing signal S36 generated by the timing generator 36, and demodulates the magnetic data based on the interval data obtained thereby.

[Operation of Reading Processing Unit 30]
Here, the basic operation of the reading processing unit 30 will be described with reference to FIG.
FIG. 3 is a diagram showing signal processing waveforms of the main part of the information medium reading apparatus of FIG.
3A shows the magnetic signal (magnetic data) MRD recorded on the magnetic card, FIG. 3B shows the analog signal (magnetic data) S31 (S32) read and amplified by the magnetic head, and FIG. 3C. 3 shows the peak position detection signal S33, FIG. 3D shows the peak interval (interval) signal S34 of the first comparator, FIG. 3E shows the output signal S35 of the second comparator 35, and FIG. Shows timing signals S36 by the timing generator 36, respectively.

In the information medium reader 10 of the present embodiment, magnetic data written on a card MC, which is an information medium to be read, consisting of a combination of two types of frequencies (F, 2F) as shown in FIG. Is read (reproduced) as an analog signal S 23 by the magnetic head 23 and supplied to the reading processing unit 30.
In the reading processing unit 30, the analog signal S23 of magnetic data is amplified by the two first amplifiers 31 and the second amplifier 32, and the amplified analog signals are as shown in FIG. It becomes a waveform.
The magnetic data amplified by the first amplifier 31 is supplied as a signal S31 to the peak detector 33, and the magnetic data amplified by the second amplifier 32 is supplied as a signal 32 to the second comparator 35. .
In the peak detector 33, as shown in FIG. 3C, the peak position generated at the magnetic reversal position of the analog signal S31 is detected, and the detection result is supplied to the first comparator 34 as the signal S33.

In the first comparator 34, in response to the signal S33 indicating peak position detection, as shown in FIG. 3D, a waveform-shaped and binarized peak interval (interval) signal S34 is formed to generate timing. Supplied to the unit 36.
In the second comparator 35, as shown in FIG. 3E, the analog signal S32 of the magnetic data by the second amplifier 32 is waveform-shaped to obtain binary data, and the timing is obtained as the signal S35. It is supplied to the generator 36.
The timing generator 36 generates a timing signal S36 corresponding to the peak output of the analog signals S31 and S32 in accordance with the peak interval (interval) signal S34 from the first comparator 34 and the signal S35 from the second comparator 35. S 36 is supplied to the demodulator 37.
In the demodulator 37, the time interval between adjacent peak positions is measured in accordance with the timing signal S36 generated by the timing generator 36, and the magnetic data is demodulated based on the interval data obtained thereby. Is done.

[Configuration and Function of Pseudo Data Creation Unit 40]
The pseudo data creation unit 40 accumulates (stores) the magnetic data read by the magnetic head 23 and amplified by the second amplifier 32 of the read processing unit 30 as a digital value. When a failure or the like occurs in the reading process, a part of the stored magnetic data is rewritten to pseudo data in response to a data provision request from the host device 50 or the like and provided to the requesting host device 50 or the like. .
The reason why the pseudo data creation unit 40 of the present embodiment rewrites a part of the accumulated magnetic data to pseudo data and provides it to the host device 50 is as described above. ), The original output waveform (analog signal) is kept as much as possible for failure analysis, and it is possible to make it difficult to reliably demodulate magnetic data with a known method. is there.

As shown in FIG. 1, the pseudo data creation unit 40 includes an analog / digital (A / D) conversion unit 41, a memory 42 as a storage unit, and a pseudo data rewrite processing unit 43.
In the present embodiment, the rewriting by pseudo data is digital data of a plurality of bits that is larger than the number of bits that can be corrected by the vertical parity bits, out of the number of bits constituting one character (hereinafter also referred to as characters). It means rewriting the value to a pseudo digital value, in other words, replacing or erasing.
In the following description, it may be rewritten, erased, or replaced depending on the description and drawings.

The A / D converter 41 converts the magnetic data amplified by the second amplifier 32 of the reading processor 30 from an analog signal to a digital signal.
The A / D conversion unit 41 samples the analog signal S32 amplified by the amplifier 32 at a predetermined frequency, for example, 300 kHz, converts it to a digital signal, and supplies it to the memory 42 as a signal S41.
In other words, the A / D converter 41 converts the analog signal reproduced by the magnetic head 23 into a digital signal every predetermined time by sampling.
Therefore, the magnetic data after A / D conversion is equally spaced. As a result, when digital data is stored in the memory 42, a fixed address in the memory 42 can be handled as a fixed time, and can be handled as an address, that is, a time.

  The memory 42 can be configured by a nonvolatile memory or the like, and stores magnetic data A / D converted by the A / D conversion unit 41 in a time series as a digital value.

The pseudo data rewrite processing unit 43 accumulates in response to a request for providing an output waveform (analog signal) from the host device 50 or the like when a failure or the like occurs in the magnetic data reading processing by the read processing unit 30, for example. A part of the magnetic data is rewritten to pseudo data and provided to the host device 50.
When the pseudo data rewrite processing unit 43 receives a request to provide an output waveform (analog signal) from the host device 50, the pseudo data rewrite processing unit 43 reads a digital value (magnetic data) stored in the memory 42 and forms one character (one character). Of the number of bits to be processed, the digital value of a number larger than the number of bits that can be corrected by the vertical parity bit is rewritten to a pseudo digital value.

In other words, the pseudo data rewrite processing unit 43 has a number of consecutive or non-consecutive bits (2 bits) larger than the number of bits that can be corrected by the vertical parity bits among the number of bits constituting one character (one character). The above digital value is rewritten to a pseudo digital value that is a value different from the true data value, for example, the value “00h”, and the process of deleting the true data value is performed.
Pseudo data rewrite processing section 43, the magnetic data rewriting pseudo data PSD, sending output waveform to the host device 50 or the like which issued the request for providing (analog signals), are provided.
Magnetic data is DA-converted from digital to analog, and part of the original output waveform (analog signal) remains, but failure analysis is possible, but magnetic data that has been rewritten with pseudo data that cannot be read As an output waveform (analog signal).

The pseudo data rewrite processing unit 43 according to the present embodiment subtracts the number of bits constituting one character (8, 7 or 5) from the number that is not the same position but a different position in the scanning direction (horizontal direction). Each time, a digital value of at least 2 bits is rewritten (erased) to a pseudo digital value, for example, “00h”.
In the present embodiment, the number that is not the same position but different positions in the scanning direction (horizontal direction) is, for example, “1”.
That is, the pseudo data rewrite processing unit 43 rewrites a continuous or non-continuous digital value of at least 2 bits into a pseudo digital value for each bit number obtained by subtracting 1 from the number of bits constituting one character (character).
For example, when the magnetic data is compliant with the JIS-II specification, a continuous or discontinuous 2-bit digital value is rewritten and erased to, for example, “00h” every 7 bits obtained by subtracting 1 from 8 bits.

FIG. 4 is a diagram showing an outline of processing for rewriting two bits in one character of the pseudo data rewrite processing unit according to the present embodiment with pseudo data.
The example of FIG. 4 is an example when the magnetic data corresponds to the JIS-II specification.
As will be described later, the erasure (rewrite) pattern (format) is 7 (8-1) in the scan direction (horizontal direction) when the magnetic data corresponds to the JIS-II specification as a result of examination through simulation. ) If a process of rewriting (erasing) two consecutive bits is performed for each bit, all characters (characters) can be erased by 2 bits or more, and the original output waveform (analog signal) can be most preserved.

  Similarly, as described later, when the magnetic data corresponds to the specification of the track 1 of JIS-I, two consecutive bits are rewritten every 6 (7-1) bits in the scanning direction (horizontal direction). When the (erasing) process is performed, all characters (characters) can be erased by 2 bits or more, and the original output waveform (analog signal) can be left to the extent that failure analysis or the like can be performed.

  Similarly, as described later, when the magnetic data corresponds to the specification of the track 2 or 3 of JIS-I, two consecutive bits for every 4 (5-1) bits in the scanning direction (horizontal direction). When the process of rewriting (erasing) is performed, all characters (characters) can be erased by 2 bits or more, and the original output waveform (analog signal) can be left to the extent that failure analysis can be performed.

This example is the most efficient pattern, but a pattern in which only a specific bit is erased in one character (character) or a number of bits that can be corrected with a parity bit in one character (character) (1 bit in this example) It can be said that a pattern in which a portion that can only be erased is unsuitable for rewriting (erasing) pseudo data in this embodiment.
Therefore, even if the efficiency is not so good, only a specific bit is erased in one character (character), or only a number of bits (1 bit) that can be corrected by parity bits in one character (character). As long as the pattern cannot be generated, a pattern can be selected and applied by appropriately selecting the number of cycles and the number of erased characters.

FIG. 5 is a diagram illustrating a configuration example of the pseudo data rewrite processing unit in the pseudo data creation unit according to the present embodiment.
The pseudo data rewrite processing unit 43 in FIG. 5 includes a rewrite range setting unit 431, a format (pattern) setting unit 432, and a pseudo data rewriting unit 433.

The rewrite range setting unit 431 sets a rewrite range in magnetic data to be rewritten to pseudo data, that is, a region to be rewritten of magnetic data.
The format setting unit 432 sets a rewrite format (pattern) for rewriting the rewrite range set by the rewrite range setting unit 431.
The pseudo data rewriting unit 433 rewrites the magnetic data to be rewritten into pseudo data according to the rewrite format (pattern) set by the format setting unit 432 in the rewrite range set by the rewrite range setting unit 431.

Next, specific functions and processing examples of the pseudo data rewrite processing unit 43 will be described.
In this embodiment, when the pseudo data rewrite processing unit 43 outputs an output waveform read by the magnetic head 23 in failure analysis or the like, the pseudo data is changed to pseudo data that makes it impossible to reliably demodulate magnetic data by a known method. Conversion, that is, rewriting (erasing) a predetermined bit by pseudo data.
The pseudo data rewrite processing unit 43 performs rewrite (erase) by selecting a pattern (format) that retains the original output waveform as much as possible for failure analysis when performing pseudo data rewrite processing. This pattern (format) is set in the format setting unit 432 as described above. In the rewrite range setting unit 431, a range to be rewritten in the magnetic data to be rewritten to the pseudo data, that is, a region in which the magnetic data is to be rewritten is set.

Specifically, for the purpose of making it impossible to demodulate the format defined by the JIS standard, the following features are provided.
Disable character recovery for all characters. Specifically, character recovery using vertical parity bits is disabled for all characters.
Disable bit recovery using horizontal parity bits for all bits of each character.
The original output waveform from the magnetic head 23 is kept as much as possible to the extent that failure analysis is possible.

FIG. 6 is a flowchart for explaining a specific processing example in the pseudo data creation unit according to the present embodiment.
FIG. 7 is a diagram for explaining a digital value replacement rule in the pseudo data creation unit according to the present embodiment.

In order to read the magnetic data recorded on the magnetic card MC, the card MC is transported at a constant speed by a mechanical transport system, and the output value of the analog signal read using the magnetic head 23 in accordance with this is output from the read processing unit 30. After being amplified by the second amplifier 32, it is supplied to the pseudo data creation unit 40.
In the pseudo data creation unit 40, the analog signal (magnetic data) is A / D converted by the A / D conversion unit 41 (step ST1) and stored in the memory 42 as a time-series digital value (step ST2).
When the pseudo data rewrite processing unit 43 receives a request for providing an output waveform (analog signal) from the host device 50 or the like (step ST3), the magnetic data (digital value) stored in the requested memory 42 is received. Is read (step ST4).
Then, the pseudo data rewrite processing unit 43 rewrites and replaces a part of the read digital value with the value “00h” according to “rule RL1” (step ST5).
The pseudo data rewrite processing unit 43 outputs the replaced pseudo data as the output waveform (analog signal) of the magnetic head to the host device 50 or the like that has issued the output waveform (analog signal) provision request (step ST6).

The “rule RL” will be described with reference to FIGS. 7A and 7B.
(1) The storage start time of the magnetic data after A / D conversion in the memory 42 is used as a starting point (step ST51).
That is, the A / D conversion unit 41 converts the analog signal reproduced by the magnetic head 23 into a digital signal every predetermined time by sampling.
Therefore, as described above, the magnetic data after A / D conversion is equally spaced. As a result, when a digital value is stored in the memory 42, a fixed address in the memory 42 can be handled as a fixed time, and can be handled as an address, that is, time.
In the present embodiment, as shown in FIG. 7B, the predetermined address ADDRx of the memory 42 is stored starting from the head of the magnetic data including the notified magnetic data.

(2) A cycle in which the digital value stored in the memory 42 is replaced with the value “00h” is set to a time shorter by one bit than the character (character) length including the odd parity (check) bit (step ST52).
When the magnetic data conforms to the JIS-II specification, a continuous 2-bit digital value (magnetic data) is rewritten and erased to, for example, “00h” every 7 bits obtained by subtracting 1 from 8 bits.

(3) The width replaced with the value “00h” is set to a time corresponding to a 2-bit length (ST53).
The above method makes it impossible to reproduce magnetic data using redundant codes in both the horizontal and vertical directions.
However, the original output waveform (analog signal) remains as much as possible. The original output waveform (analog signal) is left by rewriting processing so that it cannot be demodulated as character data.
In other words, the output waveform of the magnetic head obtained by reading the magnetic data with the magnetic head can be observed by the observer visually, but cannot be demodulated as specific character data (magnetic data).

  FIGS. 8 and 9 show an example in which a part of the digital value is actually rewritten (erased or replaced) with “00h” in accordance with the “rule RL”.

FIG. 8 is a diagram showing an example of magnetic data samples before and after rewriting (erasing) when the magnetic data corresponds to the JIS-II specification.
FIG. 8A shows a magnetic data sample before erasure, and FIG. 8B shows a magnetic data sample after erasure.
In this case, according to the rule RL, the 2-bit magnetic data (digital value) is rewritten (erased or replaced) with “00h” every 7 bits.
After data rewriting (erasing), the output waveform remains the original, but cannot be demodulated as magnetic data (character data).

FIG. 9 is a diagram showing an example of reading failure analysis before and after rewriting (erasing) when the magnetic data corresponds to the JIS standard.
FIG. 9A shows an output waveform before erasure, and FIG. 9B shows an output waveform example after erasure.
In this example, as shown in FIG. 9A, there is a region where a period in which almost no magnetic data is output continues before data rewrite (erase).
After data rewriting (erasing), as shown in FIG. 9B, it can be seen that the reading failure is a decrease in output (demagnetization) of magnetic data.

As described above, according to the pseudo data generation unit 40 of the present embodiment, it is not possible to accurately demodulate one character (one character) from the output waveform, and information can be protected.
The original output waveform (analog signal) can be left to the maximum while preventing accurate demodulation from the output waveform.
Even when specific magnetic data cannot be demodulated, an approximate failure analysis can be performed from the output waveform.
Further, since the 2-bit magnetic data (digital value) is rewritten (erased or replaced) with “00h”, the portion processed this time becomes clear at a glance, and can be ignored in the analysis processing depending on the state.

Next, consider the erase (rewrite) pattern of 8 bits per character, 7 bits per character, and 5 bits per character in the pseudo data rewrite processing unit.
There are three items to be examined (considered): the number of erased characters ECN, the erase cycle ECY, and the erase rate ER (%). The case where it is not (not preferable) is indicated by x.
The case where it is good means that all characters can be erased by 2 bits or more and the original output waveform (analog signal) remains. The case where it is not good means that only a specific bit is erased or within the character. This refers to the case where there are places where only the number of bits (1 bit) that can be corrected by the parity bit can be erased.

[When one character is 8 bits]
FIG. 10 is a diagram for considering an erase pattern for one character of 8 bits in the pseudo data rewrite processing unit according to the present embodiment.
The example of FIG. 10 shows the result of examining an erase pattern for magnetic data in which one character of a JIS-II type magnetic card is 8 bits. In this example, the 21st to 21st patterns were examined. In FIG. 10, the pattern shown at the top is the first pattern, and the pattern shown at the bottom is the twenty-first pattern.
Of the erase patterns shown below, a pattern in which only a specific bit is erased by one character (character) may be able to predict the true magnetic data content of the original output waveform (analog signal). In this embodiment, it is unsuitable.
In addition, a pattern in which a portion where only the number of bits (1 bit) that can be corrected with a parity bit can be erased in one character (character) can be demodulated even if part of the true magnetic data is demodulated. In this embodiment, it is unsuitable.

The first erase pattern in the upper stage is a case where the number of erased characters ECN is 1, the erase cycle ECY is 2, and the erase rate ER (%) is 50%. In the case of this first erase pattern, only a specific bit is erased by one character (character), and therefore, this is not suitable for this embodiment.
The second erase pattern at the next stage is when the number of erased characters ECN is 1, the erase cycle ECY is 3, and the erase rate ER (%) is 33.3%. In the case of the second erasure pattern, only specific bits are erased, and no place where only one bit can be erased in one character (character) is generated. It is possible to do.

The third erase pattern at the next stage is when the number of erased characters ECN is 1, the erase cycle ECY is 4, and the erase rate ER (%) is 25%. In the case of the third erase pattern, only a specific bit is erased, which is not suitable for this embodiment.
The fourth erase pattern in the next stage is when the number of erased characters ECN is 1, the erase cycle ECY is 5, and the erase rate ER (%) is 20%. In the case of the fourth erasure pattern, a place where only one bit can be erased in one character (character) is generated, which is not suitable for the present embodiment.

The fifth erase pattern in the next stage is when the number of erased characters ECN is 2, the erase cycle ECY is 5, and the erase rate ER (%) is 40%. In the case of the fifth erasure pattern, only specific bits are erased and no place where only one bit can be erased in one character (character) is generated. It is possible to do.
The sixth erase pattern in the next stage is when the number of erased characters ECN is 2, the erase cycle ECY is 6, and the erase rate ER (%) is 33.3%. In the case of this sixth erase pattern, only specific bits are erased, and no place where only one bit can be erased in one character (character) is generated. It is possible to do.

  The seventh erase pattern in the next stage is when the number of erased characters ECN is 2, the erase cycle ECY is 7, and the erase rate ER (%) is 28.6%. In the case of the seventh erasure pattern, only specific bits are not erased, and no place where only one bit can be erased in one character (character) is generated, and all characters (characters) are further eliminated. Can be erased by 2 bits or more, and the original data remains the most, which is optimal, and can be applied to this embodiment.

The eighth erase pattern in the next stage is when the number of erased characters ECN is 2, the erase cycle ECY is 9, and the erase rate ER (%) is 22.2%. In the case of the eighth erasure pattern, a place where only one bit can be erased in one character (character) is generated, which is not suitable for this embodiment.
The ninth erase pattern in the next stage is when the number of erased characters ECN is 3, the erase cycle ECY is 9, and the erase rate ER (%) is 33.3%. In the case of the ninth erasure pattern, only specific bits are erased, and no place where only one bit can be erased in one character (character) is generated. It is possible to do.

The tenth erase pattern in the next stage is a case where the number of erased characters ECN is 3, the erase cycle ECY is 10, and the erase rate ER (%) is 30%. In the case of the tenth erase pattern, a portion where only one bit can be erased in one character (character) is generated, which is not suitable for this embodiment.
The eleventh erase pattern in the next stage is when the number of erased characters ECN is 4, the erase cycle ECY is 10, and the erase rate ER (%) is 40%. In the case of the eleventh erasing pattern, only specific bits are erased, and no place where only one bit can be erased in one character (character) is generated. It is possible to do.

The twelfth erase pattern at the next stage is when the number of erased characters ECN is 4, the erase cycle ECY is 11, and the erase rate ER (%) is 36.4%. In the case of the twelfth erasure pattern, a portion where only one bit can be erased in one character (character) is generated, which is not suitable for this embodiment.
The 13th erase pattern in the next stage is when the number of erased characters ECN is 5, the erase cycle ECY is 11, and the erase rate ER (%) is 45.5%. In the case of the thirteenth erase pattern, only specific bits are erased, and no place where only one bit can be erased in one character (character) is generated. It is possible to do.

The 14th erase pattern in the next stage is a case where the number of erased characters ECN is 5, the erase cycle ECY is 12, and the erase rate ER (%) is 41.7%. In the case of the fourteenth erase pattern, a place where only one bit can be erased in one character (character) is generated, which is not suitable for this embodiment.
The fifteenth erase pattern in the next stage is when the number of erased characters ECN is 6, the erase cycle ECY is 12, and the erase rate ER (%) is 50%. In the case of the fifteenth erase pattern, only specific bits are erased, and no place where only one bit can be erased in one character (character) is generated. It is possible to do.

The 16th erase pattern in the next stage is a case where the number of erased characters ECN is 6, the erase cycle ECY is 13, and the erase rate ER (%) is 46.2%. In the case of the sixteenth erasing pattern, a portion where only one bit can be erased in one character (character) is generated, which is not suitable for the present embodiment.
The 17th erase pattern in the next stage is a case where the number of erased characters ECN is 7, the erase cycle ECY is 13, and the erase rate ER (%) is 53.8%. In the case of the seventeenth erase pattern, only specific bits are erased, and no place where only one bit can be erased in one character (character) is generated. It is possible to do.

The 18th erase pattern in the next stage is a case where the number of erased characters ECN is 7, the erase cycle ECY is 14, and the erase rate ER (%) is 50%. In the case of the eighteenth erase pattern, a place where only one bit can be erased in one character (character) is generated, which is not suitable for this embodiment.
The 19th erase pattern in the next stage is a case where the number of erased characters ECN is 8, the erase cycle ECY is 14, and the erase rate ER (%) is 57.1%. In the case of the nineteenth erase pattern, only specific bits are erased, and no place where only one bit can be erased in one character (character) is generated. It is possible to do.

The twentieth erase pattern at the next stage is when the number of erase characters ECN is 8, the erase cycle ECY is 15, and the erase rate ER (%) is 53.3%. In the case of the twentieth erase pattern, a portion where only one bit can be erased in one character (character) is generated, which is not suitable for this embodiment.
The 21st erase pattern in the next stage is a case where the number of erased characters ECN is 9, the erase cycle ECY is 15, and the erase rate ER (%) is 60%. In the case of the 21st erase pattern, only a specific bit is erased or a place where only 1 bit can be erased in one character (character) does not occur. It is possible to do.

[When one character is 7 bits]
FIG. 11 is a diagram for considering an erase pattern for one character of 7 bits in the pseudo data rewrite processing unit according to the present embodiment.
The example of FIG. 11 shows the result of examining an erase pattern for magnetic data in which one character of the magnetic card of the track 1 of JIS-I type is 7 bits. In this example, 18 patterns were examined. In FIG. 11, the pattern shown at the top is the first pattern, and the pattern shown at the bottom is the eighteenth pattern.
Of the erase patterns shown below, a pattern in which only a specific bit is erased or a portion where only the number of bits (one bit) that can be corrected with a parity bit within one character (character) can be erased is true magnetic Since even part of the data can be demodulated, it is not suitable in this embodiment.

The first erase pattern in the upper stage is a case where the number of erased characters ECN is 1, the erase cycle ECY is 2, and the erase rate ER (%) is 50%. In the case of this first erasure pattern, only specific bits are erased, and no place where only one bit can be erased in one character (character) is generated. It is possible to do.
The second erase pattern at the next stage is when the number of erased characters ECN is 1, the erase cycle ECY is 3, and the erase rate ER (%) is 33.3%. In the case of the second erasure pattern, only specific bits are erased, and no place where only one bit can be erased in one character (character) is generated. It is possible to do.

The third erase pattern at the next stage is when the number of erased characters ECN is 1, the erase cycle ECY is 4, and the erase rate ER (%) is 25%. In the case of the third erasure pattern, a place where only one bit can be erased in one character (character) is generated, which is not suitable for this embodiment.
The fourth erase pattern at the next stage is when the number of erased characters ECN is 2, the erase cycle ECY is 4, and the erase rate ER (%) is 50%. In the case of the fourth erasure pattern, only specific bits are erased, and no place where only one bit can be erased in one character (character) is generated. It is possible to do.

  The fifth erase pattern in the next stage is when the number of erased characters ECN is 2, the erase cycle ECY is 5, and the erase rate ER (%) is 40%. In the case of the fifth erasure pattern, only specific bits are erased and no place where only one bit can be erased in one character (character) is generated. It is possible to do.

  The sixth erase pattern in the next stage is when the number of erased characters ECN is 2, the erase cycle ECY is 6, and the erase rate ER (%) is 33.3%. In the case of the sixth erasure pattern, only a specific bit is erased or a place where only one bit can be erased does not occur in one character (character), and all characters (characters) are further eliminated. Can be erased by 2 bits or more, and the original output waveform (analog signal) remains to the extent that a failure analysis or the like can be performed, which is optimal and can be applied to this embodiment.

The seventh erase pattern in the next stage is a case where the number of erased characters ECN is 2, the erase cycle ECY is 8, and the erase rate ER (%) is 25%. In the case of the seventh erasure pattern, a portion where only one bit can be erased in one character (character) is generated, which is not suitable for this embodiment.
The eighth erase pattern in the next stage is when the number of erased characters ECN is 3, the erase cycle ECY is 8, and the erase rate ER (%) is 37.5%. In the case of the eighth erasing pattern, only a specific bit is erased or a portion where only one bit can be erased in one character (character) does not occur. It is possible to do.

The ninth erase pattern in the next stage is when the number of erased characters ECN is 3, the erase cycle ECY is 9, and the erase rate ER (%) is 33.3%. In the case of the ninth erasure pattern, a portion where only one bit can be erased in one character (character) is generated, which is not suitable for this embodiment.
The tenth erase pattern in the next stage is a case where the number of erased characters ECN is 4, the erase cycle ECY is 9, and the erase rate ER (%) is 44.4%. In the case of the tenth erase pattern, only specific bits are erased, and no place where only one bit can be erased in one character (character) is generated. It is possible to do.

The eleventh erase pattern in the next stage is when the number of erased characters ECN is 4, the erase cycle ECY is 10, and the erase rate ER (%) is 40%. In the case of the eleventh erasure pattern, a portion where only one bit can be erased in one character (character) is generated, which is not suitable for this embodiment.
The twelfth erase pattern at the next stage is when the number of erased characters ECN is 5, the erase cycle ECY is 10, and the erase rate ER (%) is 50%. In the case of the twelfth erase pattern, only specific bits are erased, and no place where only one bit can be erased in one character (character) is generated. It is possible to do.

The 13th erase pattern in the next stage is when the number of erased characters ECN is 5, the erase cycle ECY is 11, and the erase rate ER (%) is 45.5%. In the case of the thirteenth erase pattern, a place where only one bit can be erased in one character (character) is generated, which is not suitable for this embodiment.
The 14th erase pattern in the next stage is a case where the number of erased characters ECN is 6, the erase cycle ECY is 11, and the erase rate ER (%) is 54.5%. In the case of the fourteenth erase pattern, only specific bits are erased, and no place where only one bit can be erased in one character (character) is generated. It is possible to do.

The fifteenth erase pattern in the next stage is when the number of erased characters ECN is 6, the erase cycle ECY is 12, and the erase rate ER (%) is 50%. In the case of the fifteenth erasure pattern, a portion where only one bit can be erased in one character (character) is generated, which is not suitable for this embodiment.
The 16th erase pattern in the next stage is a case where the number of erased characters ECN is 7, the erase cycle ECY is 12, and the erase rate ER (%) is 58.3%. In the case of the sixteenth erase pattern, only specific bits are erased, and no place where only one bit can be erased in one character (character) is generated. It is possible to do.

The 17th erase pattern in the next stage is a case where the number of erased characters ECN is 7, the erase cycle ECY is 13, and the erase rate ER (%) is 53.8%. In the case of the seventeenth erasure pattern, a place where only one bit can be erased in one character (character) is generated, which is not suitable for this embodiment.
The 18th erase pattern in the next stage is a case where the number of erased characters ECN is 8, the erase cycle ECY is 13, and the erase rate ER (%) is 61.5%. In the case of the eighteenth erase pattern, only specific bits are erased, and no place where only one bit can be erased in one character (character) is generated. It is possible to do.

FIG. 12 is a diagram for considering an erase pattern for one character of 5 bits in the pseudo data rewrite processing unit according to the present embodiment.
The example of FIG. 12 shows the result of examining an erase pattern for magnetic data in which one character of the magnetic card of the JIS-I type track 2 or 3 is 5 bits. In this example, 12 patterns were examined. In FIG. 12, the pattern shown at the top is the first pattern, and the pattern shown at the bottom is the twelfth pattern.
Of the erasure patterns shown below, a pattern in which only specific bits are erased or a portion where only the number of bits (one bit) that can be corrected with parity bits within one character (character) can be erased is true data. Since it is possible to demodulate a part of the signal, it is not suitable in the present embodiment.

The first erase pattern in the upper stage is a case where the number of erased characters ECN is 1, the erase cycle ECY is 2, and the erase rate ER (%) is 50%. In the case of this first erasure pattern, only specific bits are erased, and no place where only one bit can be erased in one character (character) is generated. It is possible to do.
The second erase pattern at the next stage is when the number of erased characters ECN is 1, the erase cycle ECY is 3, and the erase rate ER (%) is 33.3%. In the case of this second erasure pattern, a place where only one bit can be erased in one character (character) is generated, which is not suitable for this embodiment.

  The third erase pattern at the next stage is when the number of erased characters ECN is 2, the erase cycle ECY is 3, and the erase rate ER (%) is 66.7%. In the case of the third erasure pattern, only specific bits are erased, and no place where only one bit can be erased in one character (character) is generated. It is possible to do.

  The fourth erase pattern at the next stage is when the number of erased characters ECN is 2, the erase cycle ECY is 4, and the erase rate ER (%) is 50%. In the case of the fourth erasure pattern, only specific bits are erased, and no place where only one bit can be erased in one character (character) is generated, and all characters (characters) are further eliminated. Can be erased by 2 bits or more, and the original output waveform (analog signal) remains to the extent that a failure analysis or the like can be performed, which is optimal and can be applied to this embodiment.

The fifth erase pattern in the next stage is when the number of erased characters ECN is 2, the erase cycle ECY is 6, and the erase rate ER (%) is 33.3%. In the case of the fifth erasure pattern, a place where only one bit can be erased in one character (character) is generated, which is not suitable for the present embodiment.
The sixth erase pattern in the next stage is when the number of erased characters ECN is 3, the erase cycle ECY is 6, and the erase rate ER (%) is 50%. In the case of this sixth erase pattern, only specific bits are erased, and no place where only one bit can be erased in one character (character) is generated. It is possible to do.

The seventh erase pattern in the next stage is when the number of erased characters ECN is 3, the erase cycle ECY is 7, and the erase rate ER (%) is 42.9%. In the case of the seventh erasure pattern, a portion where only one bit can be erased in one character (character) is generated, which is not suitable for this embodiment.
The eighth erase pattern in the next stage is when the number of erased characters ECN is 4, the erase cycle ECY is 7, and the erase rate ER (%) is 57.1%. In the case of the eighth erasing pattern, only a specific bit is erased or a portion where only one bit can be erased in one character (character) does not occur. It is possible to do.

The ninth erase pattern in the next stage is when the number of erased characters ECN is 4, the erase cycle ECY is 8, and the erase rate ER (%) is 50%. In the case of the ninth erasure pattern, a portion where only one bit can be erased in one character (character) is generated, which is not suitable for this embodiment.
The tenth erase pattern in the next stage is when the number of erased characters ECN is 5, the erase cycle ECY is 8, and the erase rate ER (%) is 62.5%. In the case of the tenth erase pattern, only specific bits are erased, and no place where only one bit can be erased in one character (character) is generated. It is possible to do.

The eleventh erase pattern at the next stage is when the number of erased characters ECN is 5, the erase cycle ECY is 9, and the erase rate ER (%) is 55.6%. In the case of the eleventh erasure pattern, a portion where only one bit can be erased in one character (character) is generated, which is not suitable for this embodiment.
The twelfth erase pattern at the next stage is when the number of erased characters ECN is 6, the erase cycle ECY is 9, and the erase rate ER (%) is 66.7%. In the case of the twelfth erase pattern, only specific bits are erased, and no place where only one bit can be erased in one character (character) is generated. It is possible to do.

  As discussed in detail above, in the present embodiment, the erase (rewrite) pattern is the result of the simulation and examination. As a result, when the magnetic data corresponds to the JIS-II specification, the seventh erase in FIG. If a process of rewriting (erasing) two consecutive bits every 7 (8-1) bits in the scan direction (horizontal direction) as in a pattern, all characters (characters) can be erased by 2 bits or more. The original output waveform (analog signal) can be left to the extent that failure analysis can be performed.

  Similarly, when the magnetic data corresponds to the specification of the track 1 of JIS-I, as in the sixth erase pattern of FIG. 11, every 6 (7-1) bits in the scan direction (horizontal direction), When a process of rewriting (erasing) two consecutive bits is performed, all characters (characters) can be erased by 2 bits or more, and the original output waveform (analog signal) can be left to the extent that failure analysis can be performed.

  Similarly, when the magnetic data corresponds to the specification of the track 2 or 3 of JIS-I, every 4 (5-1) bits in the scan direction (horizontal direction) as in the fourth erase pattern of FIG. When the process of rewriting (erasing) two consecutive bits is performed, all characters (characters) can be erased by 2 bits or more, and the original output waveform (analog signal) can be left to the extent that failure analysis can be performed.

This example is the most efficient pattern. However, as described above, only a specific bit is erased in one character (character), or the number of bits (1 that can be corrected with a parity bit in one character (character)). It can be said that a pattern in which only a bit) can be erased is not suitable for rewriting (erasing) pseudo data in this embodiment.
Therefore, even if the efficiency is not so good, only a specific bit is erased in one character (character), or only a number of bits (1 bit) that can be corrected by parity bits in one character (character). As long as the pattern cannot be generated, a pattern can be selected and applied by appropriately selecting the number of cycles and the number of erased characters.

[Overall behavior]
FIG. 13 is a flowchart for explaining an overall operation outline of the information medium reading apparatus according to the present embodiment.
Next, the overall operation of the card reader 10 having the above-described configuration will be described with reference to the flowchart of FIG.

The analog signal S23 is output from the magnetic head 23 by moving the card or the like relative to the magnetic head 23 (step ST11), and the analog signal S23 is supplied to the reading processing unit 30.
In the read processing unit 30, the analog signal S23 of magnetic data is amplified by the two systems of the first amplifier 31 and the second amplifier 32 (step ST12).
The magnetic data amplified by the first amplifier 31 is supplied to the peak detector 33 as a signal S31.
The magnetic data amplified by the second amplifier 32 is supplied as a signal 32 to the second comparator 35 and also supplied to the A / D converter 41 of the pseudo data generator 40.

In the peak detector 33, the peak position generated at the magnetic reversal position of the analog signal S31 is detected (step ST13), and the detection result is supplied to the first comparator 34.
In the first comparator 34, a signal S33 indicating peak position detection is waveform-shaped and binarized, and a peak interval (interval) signal S34 is formed and supplied to the timing generator 36.
Further, in the second comparator 35, the analog signal S32 of the magnetic data from the second amplifier 32 is waveform-shaped to obtain binary data.
In the timing generator 36, a timing signal S36 corresponding to the peak output of the analog signals S31 and S32 is generated in accordance with the peak interval (interval) signal S34 from the first comparator 34 and the signal S35 from the second comparator 35 (step ST14). ), And the timing signal S36 is supplied to the demodulator 37.
In the demodulator 37, the time interval between adjacent peak positions is measured in accordance with the timing signal S36 generated by the timing generator 36, and the magnetic data is demodulated based on the interval data obtained thereby. Is performed (step ST15).
The demodulated magnetic data is transferred to the host device 50 or the like.

  On the other hand, in the pseudo data creation unit 40, the amplified analog signal (magnetic data) is A / D converted by the A / D conversion unit 41 (step ST16) and stored in the memory 42 as a time-series digital value (step ST16). Step ST17).

Here, when the pseudo data rewrite processing unit 43 receives a request for providing an output waveform (analog signal) from the host device 50 or the like in order to perform failure analysis or the like (step ST18), the pseudo data rewrite processing unit 43 stores it in the requested memory 42. The magnetic data thus read is read by the pseudo data rewrite processing unit 43 (step ST18).
The pseudo data rewrite processing unit 43 stores the read magnetic data in the memory 42 as a time-series digital value, and a part of the time-series digital value is rewritten and replaced with the value “00h” according to the “rule RL”. (Step ST19).
In the pseudo data rewrite processing unit 43, the replaced pseudo data is output as the output waveform of the magnetic head to the host device 50 or the like that has issued the output waveform (analog signal) provision request (step ST20).

[Effect of the embodiment]
As described above, according to the card reader 10 of the present embodiment, the pseudo data creation unit 40 includes the A / D conversion unit 41, the memory 42, and the pseudo data rewrite processing unit 43.
The A / D converter 41 converts the magnetic data amplified by the second amplifier 32 of the reading processor 30 from an analog signal to a digital signal.
The memory 42 can be configured by a nonvolatile memory or the like, and stores magnetic data A / D converted by the A / D conversion unit 41 in a time series as a digital value.
The pseudo data rewrite processing unit 43 outputs an output waveform (analog signal) from the host device 50 or the like in order to analyze a failure or the like when a failure or the like occurs in the magnetic data reading process by the read processing unit 30, for example. In response to the provision request, a part of the stored magnetic data is rewritten to pseudo data and provided to the host device 50.
When the pseudo data rewrite processing unit 43 receives a request to provide an output waveform (analog signal) from the host device 50, the pseudo data rewrite processing unit 43 reads a digital value (magnetic data) stored in the memory 42 and forms one character (one character). Of the number of bits to be processed, the digital value of a number larger than the number of bits that can be corrected by the vertical parity bit is rewritten to a pseudo digital value.
In other words, the pseudo data rewrite processing unit 43 has a number of consecutive or non-consecutive bits (2 bits or more) larger than the number of bits that can be corrected by the vertical parity bits among the number of bits constituting one character. ) Is rewritten (replaced) with a pseudo digital value (pseudo data) that is different from the true digital value (true magnetic data), for example, the value “00h”, and the true digital value is erased. Perform the process.
The pseudo data rewrite processing unit 43 transmits and provides the magnetic data rewritten with the pseudo data PSD to the host device 50 that has issued the output waveform (analog signal) provision request.
The pseudo data rewrite processing unit 43 of the present embodiment subtracts a number such as 1, for example, that is not the same position but the different position in the scanning direction (horizontal direction) from the number of bits (8, 7 or 5) constituting one character. For each number of bits, a continuous or discontinuous digital value of at least 2 bits is rewritten (erased) to a pseudo digital value, for example, “00h”.

Therefore, according to the present embodiment, the following effects can be obtained.
In the card reader 10 according to the present embodiment, it is useful in failure analysis to investigate the output waveform of the magnetic head stored in the memory 42 in the card reader 10 when reading of magnetic data fails. If the output waveform of the magnetic head is disclosed in FIG. 4, there is an advantage that it is impossible to analyze specific magnetic data from the output waveform.
As with existing technology, when important data such as customer's personal data is included in places other than the part where the fault actually occurred, it can be prevented that it can be demodulated, and fault analysis Sometimes, when an output waveform (analog signal) of a magnetic head is disclosed, it is possible to make it impossible to demodulate magnetic data by a known demodulation method or data restoration method.
That is, according to the card reader 10 according to the present embodiment, when the output waveform (analog signal) of the magnetic head is output in failure analysis or the like, a known method is performed while leaving the original output waveform as much as possible for failure analysis. Then, there is an advantage that it is possible to make it difficult to reliably demodulate magnetic data.

In other words, according to the present embodiment, in order to analyze a failure or the like, it is not possible to accurately demodulate the output waveform output to the host device or the like, so that information can be protected.
In addition, it is possible to leave the original output waveform to the extent that a failure or the like can be analyzed while preventing accurate demodulation from the output waveform.
In other words, even when specific magnetic data cannot be demodulated, an approximate failure analysis can be performed from the output waveform (analog signal) output from the pseudo data creation unit 40.

[Other Embodiments]
In this embodiment, the case where the card MC is transported at a constant speed by the mechanical transport method has been described as an example. However, if the card MC is synchronized with the card speed, it can be applied to a swipe type or a dip type card reader. Moreover, although embodiment mentioned above demonstrated the card | curd as an example as an information medium, this invention is applicable also to the information medium of the card | curd in which other magnetic information was recorded, and a passbook.
Furthermore, the present invention can be applied to other recording systems having redundant codes.

  DESCRIPTION OF SYMBOLS 10 ... Information-medium reader, 20 ... Card processing part, 21 ... Card conveyance path, 22 ... Card conveyance part, 23 ... Magnetic head, 30 ... Reading processing part, 31. First amplifier 32 ... Second amplifier 33 ... Peak detection unit 34 ... First comparator 35 ... Second comparator 36 ... Timing generation unit 37 ... demodulator, 40 ... pseudo data generator, 41 ... A / D converter, 42 ... memory (storage), 43 ... data rewrite processor, 431 ... rewrite Range setting unit, 432... Format (pattern) setting unit, 433... Pseudo data rewriting unit, 50... Host device (higher level device), MC.

Claims (14)

A magnetic head for reading magnetic data recorded on an information medium;
A pseudo data creation unit that creates pseudo data from magnetic data read by the magnetic head,
The pseudo data creation unit
An analog / digital (A / D) converter that converts magnetic data read by the magnetic head from an analog signal to a digital signal;
A storage unit for storing the magnetic data A / D converted by the A / D conversion unit as a digital value so as to be readable in time series;
When reading the magnetic data stored in the storage unit and outputting the output waveform of the magnetic head, while keeping the original output waveform as much as possible for failure analysis, out of the number of bits constituting one character And a pseudo data rewrite processing unit that rewrites a digital value of a plurality of bits larger than the number of bits that can be corrected by the parity bit so that the original data remains, to a pseudo digital value. The pseudo data rewrite processing unit
The information medium according to claim 1, wherein the digital value of at least 2 bits is rewritten to a pseudo digital value for each bit number obtained by subtracting the number of bits constituting one character from a different position in the scanning direction instead of the same position. Reader. The pseudo data rewrite processing unit
The information medium reading device according to claim 1 or 2, wherein a digital value of at least 2 bits is rewritten to a pseudo digital value for each bit number obtained by subtracting 1 from the number of bits constituting one character. The pseudo data rewrite processing unit
The rewrite process is performed using a rewrite pattern that excludes a rewrite pattern in which only a specific bit is erased by one character and a rewrite pattern in which a portion that can be erased only by the number of bits that can be corrected by a parity bit is generated in one character. 4. The information medium reading device according to any one of items 1 to 3. The pseudo data rewrite processing unit
The information medium reading device according to claim 1, wherein rewriting processing is performed so that the original data cannot be demodulated as character data. 6. The information medium reading device according to claim 1, wherein one character is one of 8 bits, 7 bits, and 5 bits including a parity bit. A read processing unit for performing a process of demodulating magnetic data read by the magnetic head;
Including the A / D conversion unit, the storage unit, and the pseudo data rewrite processing unit, and the pseudo data creation unit that accumulates the magnetic data read by the magnetic head in the storage unit as a digital value. ,
The pseudo data creation unit
The information according to any one of claims 1 to 6, wherein when receiving a data provision request, the pseudo data rewrite processing unit rewrites a part of the corresponding stored data in the storage unit to pseudo data and provides the request destination. Media reader. The information medium reading apparatus according to claim 1, further comprising a transport unit that moves the information medium relative to the magnetic head. A step of reading magnetic data recorded on the information medium with a magnetic head;
Creating pseudo data from magnetic data read by the magnetic head, and
The pseudo data creation step includes:
An analog / digital (A / D) conversion step of converting magnetic data read by the magnetic head from an analog signal to a digital signal;
A storage step of storing the magnetic data A / D converted in the A / D conversion step in a storage unit so as to be readable in time series as a digital value;
When reading the magnetic data stored in the storage unit and outputting the output waveform of the magnetic head, while keeping the original output waveform as much as possible for failure analysis, out of the number of bits constituting one character A pseudo data rewriting process step of rewriting a digital value of a plurality of bits larger than the number of bits that can be corrected by the parity bits so that the original data remains, to a pseudo digital value. The pseudo data rewrite processing step includes:
The information medium according to claim 9, wherein a digital value of at least 2 bits is rewritten to a pseudo digital value for each bit number obtained by subtracting the number of bits constituting one character from a different position in the scan direction instead of the same position. Reading method. The pseudo data rewrite processing step includes:
11. The information medium reading method according to claim 9, wherein a digital value of at least 2 bits is rewritten to a pseudo digital value for each bit number obtained by subtracting 1 from the number of bits constituting one character. The pseudo data rewrite processing step includes:
The rewrite process is performed with a rewrite pattern excluding a rewrite pattern in which only a specific bit is erased in one character and a rewrite pattern in which a portion where only a number of bits that can be corrected with a parity bit can be erased is generated in one character. To 11. The information medium reading method according to any one of 11 to 11. The pseudo data rewrite processing step includes:
The information medium reading method according to claim 9, wherein rewriting processing is performed so that the original data cannot be demodulated as character data. The information medium reading method according to any one of claims 9 to 13, wherein one character is one of 8 bits, 7 bits, and 5 bits including a parity bit.

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