JP2022026089A - Magnetic recording information processing method and device - Google Patents

Abstract

To provide a magnetic recording information processing method and a device, for making it possible to demodulate well at a high S/N ratio regardless of an amplitude of a magnetic reproduction waveform output from a magnetic head without using automatic gain control and a high-solution AD converter, when reading magnetic information from a magnetic card.SOLUTION: A magnetic recording information processing device includes: an amplifier 11 that outputs a signal obtained by amplifying a magnetic reproduction waveform output from a magnetic head 10 at a first amplification ratio; an amplifier 12 that outputs a signal obtained by amplifying the magnetic reproduction waveform at a second amplification ratio, which is larger than the first amplification ratio; AD converters 21 and 22 that output the signals output from the amplifiers 11 and 12 as a first output value and a second output value, respectively; and a control unit 23 that detects a peak position in the magnetic reproduction waveform by using the second output value if the second output value is within a predetermined saturation determination value, and using the first output value if it is not within the value.SELECTED DRAWING: Figure 1

Description

The present invention relates to a magnetic recording information processing method and an information processing apparatus used when reading data recorded as magnetic information from a magnetic recording medium.

In a magnetic recording medium such as a magnetic card, information is recorded by reversing the direction of magnetization on the magnetic surface. When reading information from the magnetic recording medium, the magnetic recording medium is conveyed to the magnetic head in a fixed direction with the magnetic recording medium close to the magnetic head. Then, an induced voltage is generated in the magnetic head so as to have a peak corresponding to the reversal of the direction of magnetization on the magnetic surface, and the magnetic head outputs a signal of the magnetic reproduction waveform. After amplifying the output signal from the magnetic head, analog / digital conversion (AD conversion) is performed, and peak detection processing is performed on the obtained digital signal to read magnetic information from the magnetic recording medium. can.

By the way, the magnitude of the magnetic reproduction waveform output from the magnetic head also depends on the strength of magnetization in the magnetic recording medium. There is a difference of 10 times or more in the amplitude of the output signal waveform. The amplitude of the magnetic reproduction waveform is also proportional to the moving speed of the card, but in the case of a dip-type magnetic card reader that moves the card relative to the magnetic head by moving the card by hand, the moving speed of the card is slow. In the case of, it is about 50 mm / sec, and in the case of high speed, it is about 2000 mm / sec. When designing an amplifier that is inserted between the magnetic head and the AD converter, set the amplification factor according to the amplitude of the magnetic reproduction waveform when the unmagnetized card is moved at high speed, and the card at low speed. When the is moved or when targeting a demagnetized card, the amplitude of the magnetic reproduction waveform output from the magnetic head becomes too small, which falls below the resolution of the AD converter, or the signal-to-noise ratio. (SN ratio) deteriorates and demodulation becomes difficult. Patent Document 1 compares the output value of a digital signal output by an AD converter with a specified output reference value in a magnetic head device in which an amplifier is provided between the magnetic head and the AD converter, and is based on the comparison result. Discloses that the gain of the amplifier is changed.

Japanese Unexamined Patent Publication No. 2012-216264

The technique described in Patent Document 1 attempts to satisfactorily read information from the card regardless of the amplitude of the magnetic reproduction waveform from the magnetic head by applying automatic gain control (AGC) technique. It is something to do. However, an amplifier whose gain can be controlled from the outside has a complicated configuration, which leads to an increase in cost. A method of dealing with the magnitude of the amplitude of the magnetic reproduction waveform by using a high-resolution AD converter, that is, a wide bit width, can be considered, but the high-resolution AD converter is expensive and has a wide bit width. Signal processing for digital signals has a large computational load, and noise is superimposed, so it is not possible to obtain the intended results.

An object of the present invention is to obtain high S / S / magnetic information regardless of the magnitude of the amplitude of the magnetic reproduction waveform output from the magnetic head, without using an automatic gain control and without requiring a high-resolution AD converter. It is an object of the present invention to provide a magnetic recording information processing apparatus and a method used for satisfactorily demodulating at an N ratio.

The magnetic recording information processing apparatus of the present invention has a magnetic head that acquires magnetic information recorded on a magnetic recording medium and outputs a magnetic reproduction waveform, and a first that outputs a signal obtained by amplifying the magnetic reproduction waveform at a first amplification factor. The first amplification means, the second amplification means for outputting a signal obtained by amplifying the magnetic reproduction waveform with a second amplification factor larger than the first amplification factor, and the first conversion means for converting the signal output from the first amplification means into a digital signal. The first AD conversion unit that outputs as an output value, the second AD conversion unit that converts the signal output from the second amplification means into a digital signal and outputs it as a second output value, and the second output value are predetermined saturation determination values. A control unit that detects the peak position in the magnetic reproduction waveform using the second output value when it is within, and detects the peak position using the first output value when the second output value is not within the saturation determination value. Have.

In the magnetic recording information processing apparatus of the present invention, two amplification means having different amplification factors and two AD conversion units are provided, and the magnetic reproduction waveform is digitized in two ways by these amplification means and the AD conversion unit. .. Then, when there is a risk of saturation in the magnetic reproduction waveform having the larger amplification factor, peak detection is performed using the magnetic reproduction waveform having the smaller amplification factor. As a result, even when the amplitudes of the magnetic reproduction waveforms output from the magnetic head are significantly different, the peak position can be satisfactorily detected with a high S / N ratio without using the automatic gain control technique. If the peak position can be detected satisfactorily, it becomes possible to demodulate the magnetic information satisfactorily with a high S / N ratio. In this magnetic recording information processing apparatus, each of the two AD conversion units does not need to have high resolution. For example, if two sample hold circuits are provided, two AD conversion units can be realized by switching and using a single AD conversion circuit.

In the magnetic recording information processing method of the present invention, the magnetic reproduction waveform obtained by reading the magnetic information recorded on the magnetic recording medium by a magnetic head is amplified by the first amplification factor and converted into a digital signal to obtain the first output value. The magnetic reproduction waveform is amplified by a second amplification factor larger than the first amplification factor and converted into a digital signal to obtain a second output value, and when the second output value is within a predetermined saturation determination value, the second output value is used. The peak position in the magnetic reproduction waveform is detected, and when the second output value is not within the saturation determination value, the peak position is detected using the first output value.

In the magnetic recording information processing method of the present invention, the magnetic reproduction waveform output from the magnetic head is amplified by two amplification factors and then converted into a digital signal, and when there is a risk of saturation, the one with the smaller amplification factor is supported. Peak detection is performed using the digital signal. As a result, even when the amplitude of the magnetic reproduction waveform output from the magnetic head is significantly different, a high S / N ratio is not required without increasing the resolution in analog / digital conversion and without using automatic gain control technology. Peak detection can be performed satisfactorily by the ratio, and by using the detected peak position, magnetic information can be satisfactorily demolished at a high S / N ratio.

The first output value and the second output value include an offset component and noise. In order to eliminate the influence of noise, it is preferable to apply a threshold value to each output value in the detection of the peak position, and in order to cope with the fluctuation of the offset component, the output value at that time is detected every time the peak position is detected. It is preferable to recalculate the threshold using. For example, when a peak position is detected, the first output value at that time is used to determine the threshold value to be used when detecting the next peak position in the magnetic reproduction waveform based on the first output value. Just do it. With this configuration, it is possible to eliminate the influence of the offset on the threshold value used when detecting the peak position using the first output value.

It is necessary to change the method of obtaining the threshold value for the second output value depending on the possibility of saturation of the second output value. For example, when the peak position is detected using the second output value, the threshold value used when the next peak position in the magnetic reproduction waveform is detected based on the second output value is set using the second output value. Can be decided. That is, when there is no possibility of saturation, the threshold value for the second output value can be determined in the same manner as the threshold value for the first output value. On the other hand, when the peak position is detected using the first output value, the threshold value used when detecting the next peak position in the magnetic reproduction waveform based on the second output value can be determined based on the saturation determination value. can. When there is a possibility of saturation, it is not appropriate to determine the threshold value using the second output value at that time, but by using the saturation determination value, the threshold value used for detecting the next peak position can be appropriately used. It will be possible to decide.

In the present invention, magnetic information can be demodulated based on the detected peak position. The magnetic information can be better demodulated based on the peak positions detected as described above.

According to the present invention, high S / S / high magnetic information is obtained regardless of the magnitude of the amplitude of the magnetic reproduction waveform output from the magnetic head, without using an automatic gain control and without requiring a high-resolution AD converter. The N ratio enables good demodulation.

It is a block diagram which shows the structure of the processing apparatus of one Embodiment of this invention. It is a block diagram which shows another example of the structure of a processing apparatus. It is a flowchart explaining the peak detection process.

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a magnetic recording information processing apparatus (hereinafter, simply referred to as “processing apparatus”) according to an embodiment of the present invention. This processing device reads magnetic information recorded on a magnetic recording medium such as a magnetic card and outputs it as data.

The processing device has a magnetic head 10 that reads the magnetic information recorded on the magnetic recording medium and outputs the magnetic reproduction waveform as an analog signal, and performs analog / digital conversion (AD conversion) on the magnetic reproduction waveform to perform the magnetic reproduction waveform. A processor 20, a first amplifier 11, and a second amplifier 12 are provided, which converts a digital signal into a digital signal, performs signal processing on the digital signal, demolishes magnetic information, and outputs the data. The processor 20 is provided with two input terminals IN1 and IN2. The output of the magnetic head 10 is input to the first amplifier 11, and the output of the first amplifier 11 is supplied to the input terminal IN1 of the processor 20 and is also input to the second amplifier 12. The output of the other amplifier 12 is supplied to the input terminal IN2 of the processor 20.

The processor 20 is composed of, for example, an embedded microprocessor or a CPU (central processing unit), and has two AD conversion units, that is, a first AD conversion unit (ADC1) 21 and a second AD conversion unit (ADC2) 22. , A control unit 23 is logically provided. The first AD conversion unit 21 converts the analog signal supplied to the input terminal IN1 into a digital signal, and the second AD conversion unit 22 converts the analog signal supplied to the input terminal IN2 into a digital signal. The two AD conversion units 21 and 22 may actually be composed of two physical AD conversion circuits, and are provided with two sample hold circuits and one for two inputs. It may be configured so that it can be logically handled as two AD conversion units 21 and 22 by periodically switching the switch using a circuit block composed of an input changeover switch and one AD conversion circuit. .. The outputs from the first AD conversion unit 21 and the second AD conversion unit 22 are input to the control unit 23.

By connecting the first amplifier 11, the second amplifier 12, the first AD conversion unit 21, and the second AD conversion unit 22 as described above, the first amplifier 11 produces a magnetic reproduction waveform output from the magnetic head 10. A signal amplified by the first amplification factor is output, and this signal is converted into a digital signal by the first AD conversion unit 21 and input to the control unit 23 as a first output value. The first output value represents the waveform after the magnetic reproduction waveform is amplified by the first amplification factor as a digital value. Similarly, the second amplifier 12 outputs a signal obtained by amplifying the magnetic reproduction waveform at the second amplification factor, and this signal is converted into a digital signal by the second AD conversion unit 22 and is converted into a digital signal by the second output unit 22 to the control unit 23. input. The second amplification factor is larger than the first amplification factor. The second output value represents the waveform after the magnetic reproduction waveform is amplified by the second amplification factor as a digital value, and is larger than the first output value as a waveform. The control unit 23 detects the peak position (that is, the timing at which the peak is reached) in the magnetic reproduction waveform based on the first output value and the second output value, demodulates the magnetic information based on the detection result, and outputs the data. Since the demodulation process after detecting the peak position is the same as the process executed in the conventional magnetic card reader or the like, the description of the specific process contents of the demodulation process will be omitted. The peak detection process performed by the control unit 23 will be described later.

In the processing apparatus based on the present invention, the arrangement of the first amplifier 11 and the second amplifier 12 is not limited to that shown in FIG. FIG. 2 shows the configuration of another example of the processing apparatus of the present embodiment. In this processing device, the magnetic reproduction waveform output by the magnetic head 10 is parallel to the first amplifier 11 having the first amplification factor and the second amplifier 12 having the second amplification factor larger than the first amplification factor. It differs from that shown in FIG. 1 in that it is supplied to. The outputs of the first amplifier 11 and the second amplifier 12 are supplied to the input terminals IN1 and IN2 of the processor 20, respectively. The configuration and operation of the processor 20 in the processing device shown in FIG. 2 is the same as that of the processing device described with reference to FIG. The processing apparatus shown in FIG. 2 requires a larger amplification factor (ie, higher gain) than that shown in FIG. 1 for the second amplifier 12, but instead does not connect the amplifier to the cascade, so that the signal-to-noise ratio is increased. It is advantageous in keeping it in good condition.

Next, the peak detection process in the control unit 23 will be described. The peak detection process itself is the same for both the processing device shown in FIG. 1 and the processing device shown in FIG. The first output value and the second output value obtained by performing AD conversion after amplifying the same magnetic reproduction waveform with different amplification factors are input to the control unit 23. In the processing apparatus of the present embodiment, one of the first output value and the second output value that is more suitable for peak detection is dynamically selected, and peak detection is performed based on the selected output value. FIG. 3 shows a peak detection process performed by the control unit 23. In FIG. 3, the first AD processing unit 21 is described as "ADC1", and the second AD processing unit 22 is described as "ADC2". Further, in the following description, it is assumed that the magnetic recording medium for which the magnetic information is read out is a magnetic card.

First, when the start of movement of the magnetic card is detected by a sensor (not shown), or when the motor (not shown) starts carrying the card, the control unit 23 starts the peak detection process. First, in step 101, the control unit 21 confirms the output values of the first AD conversion unit 21 and the second AD conversion unit 22 when there is no signal. This is because the output value may not be 0 and may have an offset even when there is no signal, and the influence of this offset is eliminated. Next, in step 102, the control unit 23 adds and subtracts the determination reference value to the offset value, that is, the output value when there is no signal, and obtains a pair of initial threshold values. There are two types of initial threshold values, one used for the output of the first AD conversion unit 21 and one used for the output of the second AD conversion unit 22, and therefore there are also two types of determination reference values. The threshold value is used to detect only peaks of a certain size or larger in the magnetic reproduction waveform so that noise is not misidentified as a peak when detecting a peak.

In the magnetic reproduction waveform, positive peaks and negative peaks appear alternately, so it is used to detect the positive threshold and the negative peak used to detect the positive peak in order to determine the peak. A pair of thresholds with the threshold in the negative direction is required. The positive peak was detected when the maximum of the magnetic reproduction waveform was detected after the magnetic reproduction waveform exceeded the positive threshold, and the minimum of the magnetic reproduction waveform was detected after the magnetic reproduction waveform fell below the negative threshold. When it is determined that a peak in the negative direction is detected, the value obtained by adding the judgment reference value to the offset value becomes the initial threshold value in the positive direction, and the value obtained by subtracting the judgment reference value from the offset value is used in the negative direction. It becomes the initial threshold. In the following, it is determined that the peak in the positive direction (negative direction) is detected when the maximum (minimum) of the magnetic reproduction waveform is detected after the magnetic reproduction waveform exceeds (falls below) the threshold value in the positive direction (negative direction). (This is referred to as a first determination method) will be described, but the peak determination method is not limited to this first determination method. For example, the time when the magnetic reproduction waveform becomes maximum (minimum) is memorized, and then when the magnetic reproduction waveform falls below (exceeds) the threshold in the positive direction (negative direction), the previously memorized time becomes positive. There is also a peak detection method (this is the second determination method) for determining that the peak is in the (negative direction). In this case, the value obtained by subtracting the determination reference value from the offset value is the initial threshold value in the positive direction, and the value obtained by adding the determination reference value to the offset value is the initial threshold value in the negative direction. Even when the second determination method is used, the addition and subtraction of the determination reference value are only reversed in the calculation of the threshold value as in the case of the first determination method, and the present invention is applied equally. Can be done. Since the calculation of the threshold value used to detect the peak in the positive direction and the calculation of the threshold value used to detect the peak in the negative direction are substantially the same process except that the sign is different, the threshold value is used here. Regarding the calculation and the like, the case of calculating the threshold value in the positive direction will be described.

After calculating the initial threshold value, the control unit 23 acquires the output value of the second AD conversion unit 22, that is, the second output value in step 103, and determines whether or not the second output value is within the saturation determination value in step 104. The saturation determination value is determined for both positive and negative peaks, and here, it is determined whether the second output value is equal to or less than the saturation determination value on the positive side and equal to or greater than the saturation determination value on the negative side. The saturation determination value is predetermined as a constant. When the second output value is within the saturation determination value, the signal is not saturated even if the magnetic reproduction waveform having the higher amplification factor is used, and it is considered that the peak can be detected appropriately. The unit 23 performs peak detection based on the output of the second AD conversion unit 22, and determines in step 105 whether or not the peak could be detected. In the peak detection, it is assumed that the peak in the positive direction is detected when the output value of the second AD conversion unit 22 exceeds the threshold value in the positive direction and becomes the maximum, and the peak in the negative direction is detected when the output value falls below the threshold value in the negative direction and becomes the minimum. It is assumed that the peak of is detected. If the peak cannot be detected in step 105 yet, the control unit 23 repeats the process from step 103 in order to detect the peak.

When it is determined in step 105 that a peak has been detected, the control unit 23 stores the peak position for demodulation of magnetic information, and in step 106, the next peak is calculated from the output value of the second AD conversion unit 22. The threshold value used for detection is calculated, and in step 107, the threshold value used for detecting the next peak from the output value of the first AD conversion unit 21 is calculated. The next peak is a negative peak if the peak detected in step 105 is a positive peak. Here, it is assumed that the peak in the negative direction is detected in step 105. Then, in step 106 and step 107, the threshold value in the positive direction is calculated. The threshold value calculated in step 106 is, for example, the output value of the second AD conversion unit 22 at the previously detected peak in the direction opposite to the current peak from the output value of the second AD conversion unit 22 at the peak detected this time. Is subtracted, and the subtraction result is multiplied by 1/2, and the determination reference value for the second AD conversion unit 22 described above is added. When the output of the second AD conversion unit 22 is saturated at the time of detecting the previous peak (that is, when the previous peak is detected using the output value of the first AD conversion unit 21), the previous detection is performed. For example, a saturation determination value can be used instead of the output value of the second AD conversion unit 22 at the peak. Further, the control unit 23 stores the output value of the first AD conversion unit 21 when the peak is detected by the output value of the second AD conversion unit 22, and the threshold value calculated in step 107 is, for example, the peak this time. The output value of the 1st AD conversion unit 21 at the time of detection minus the output value of the 1st AD conversion unit 21 at the time of detecting the previous peak is multiplied by 1/2, and further, the determination standard for the 1st AD conversion unit 21. It is the sum of the values. By recalculating the threshold value each time a peak is detected in this way, the peak can be accurately detected even when the offset in the output of each AD conversion unit 21 or 22 changes with time. After the execution of step 107, the process proceeds to step 108. When the second determination method is applied instead of the first determination method for peak detection, in step 106, the positive threshold value is determined by the second AD conversion unit 22 at the peak detected this time. The output value of the second AD conversion unit 22 at the previously detected peak, which is the opposite direction to the current peak, is subtracted from the output value, and the subtraction result is multiplied by 1/2 to obtain the above-mentioned second AD conversion unit. It is calculated by subtracting the determination reference value for 22. Similarly, the threshold value calculated in step 107 is halved by subtracting the output value of the first AD conversion unit 21 when the previous peak is detected from the output value of the first AD conversion unit 21 when the peak is detected this time. Is multiplied by, and the determination reference value for the first AD conversion unit 21 is subtracted from this.

If the second output value is not within the saturation determination value in step 104, that is, if the second output value is greater than the positive saturation determination value or lower than the negative saturation determination value, the second output value is saturated. Since there is a possibility, it is not possible to detect the peak position using the second output value. In this case, the control unit 23 acquires the output value of the first AD conversion unit 21 in step 111, then performs peak detection based on the output value, and determines in step 112 whether or not the peak can be detected. In the peak detection, it is assumed that the positive peak is detected when the output value of the first AD conversion unit 21 exceeds the positive threshold and becomes the maximum, and when the output value falls below the negative threshold and becomes the minimum, it is negative. Suppose that a peak in the direction is detected. If the peak cannot be detected in step 112, the control unit 23 repeats the peak detection process.

When it is determined that the peak has been detected in step 112, the control unit 23 stores the peak position for demodulation of the magnetic information, and in step 113, the same procedure as described for step 107 is followed. The threshold value used when detecting the peak of 1 from the output value of the first AD conversion unit 21 is calculated, and in step 114, the threshold value used when detecting the next peak from the output value of the second AD conversion unit 22 is calculated. In step 114, the threshold value is calculated by the same procedure as that described for step 106, but since the output value of the second AD conversion unit 22 may be saturated when the current peak is detected, this time. A saturation determination value is used instead of the output value of the second AD conversion unit 22. After the execution of step 114, the process proceeds to step 108.

In step 108, the control unit 23 determines whether the movement or transfer of the magnetic card has been completed. When the movement of the magnetic card is not completed, the control unit 23 repeats the process from step 103 in order to detect the next peak. When the movement of the magnetic card is completed, the control unit 23 ends the peak detection process.

In the above description, even if the card reader is a dip type, the start of movement of the card can be detected by the sensor, but some card readers do not have the sensor. When the card reader does not have a magnetic sensor, the output of the magnetic head 10 of the card reader is monitored, and when the output fluctuates by a certain amount or more as compared with the time when there is no signal, it can be determined that the card has started moving. For example, the process shown in FIG. 3 is executed regardless of whether or not the movement of the card is detected, the time of the peak is saved when the peak is detected, and it is determined that the card has started the movement, and demodulation based on the peak is performed. Processing etc. can be started.

According to the processing apparatus of the present embodiment described above, by using the first amplifier 11 and the second amplifier 12 having a fixed amplification factor, and the first AD conversion unit 21 and the second AD conversion unit 22 having relatively low resolution. That is, the peak position in the magnetic reproduction waveform can be satisfactorily obtained with a high S / N ratio without being affected by offset and noise without using automatic gain control or a high-resolution AD converter. By using the peak position thus obtained, the control unit 23 can satisfactorily demodulate the magnetic information recorded on the magnetic recording medium at a high S / N ratio.

10 ... Magnetic head; 11 ... First amplifier; 12 ... Second amplifier; 20 ... Processor; 21 ... First AD conversion unit (ADC1); 22 ... Second AD conversion unit (ADC2); 23 ... Control unit.

Claims (10)

A magnetic head that acquires magnetic information recorded on a magnetic recording medium and outputs a magnetic reproduction waveform,
A first amplification means for outputting a signal obtained by amplifying the magnetically reproduced waveform at the first amplification factor,
A second amplification means that outputs a signal obtained by amplifying the magnetically reproduced waveform with a second amplification factor larger than the first amplification factor.
A first AD conversion unit that converts the signal output from the first amplification means into a digital signal and outputs it as a first output value.
A second AD conversion unit that converts the signal output from the second amplification means into a digital signal and outputs it as a second output value.
When the second output value is within a predetermined saturation determination value, the peak position in the magnetic reproduction waveform is detected using the second output value, and when the second output value is not within the saturation determination value, the second output value is detected. A control unit that detects the peak position using one output value, and
Magnetic recording information processing device with. When the control unit detects the peak position, the control unit uses the first output value at that time to detect the next peak position in the magnetic reproduction waveform based on the first output value. The magnetic recording information processing apparatus according to claim 1, wherein the threshold value is determined. When the control unit detects the peak position using the second output value, the control unit uses the second output value to determine the next peak position in the magnetic reproduction waveform based on the second output value. The magnetic recording information processing apparatus according to claim 1 or 2, which determines a threshold value to be used for detection. When the control unit detects the peak position using the first output value, the control unit sets a threshold value used when detecting the next peak position in the magnetic reproduction waveform based on the second output value. The magnetic recording information processing apparatus according to claim 1 or 2, which is determined based on a determination value. The magnetic recording information processing apparatus according to any one of claims 1 to 4, wherein the control unit demodulates the magnetic information based on the detected peak position. The magnetic reproduction waveform obtained by reading the magnetic information recorded on the magnetic recording medium with a magnetic head is amplified by the first amplification factor and converted into a digital signal to obtain the first output value.
The magnetic reproduction waveform is amplified with a second amplification factor larger than the first amplification factor and converted into a digital signal to obtain a second output value.
When the second output value is within a predetermined saturation determination value, the peak position in the magnetic reproduction waveform is detected using the second output value, and when the second output value is not within the saturation determination value, the second output value is detected. 1 A magnetic recording information processing method for detecting the peak position using an output value. When the peak position is detected, the first output value at that time is used to determine a threshold value to be used when detecting the next peak position in the magnetic reproduction waveform based on the first output value. The magnetic recording information processing method according to claim 6. When the peak position is detected using the second output value, the second output value is used to detect the next peak position in the magnetic reproduction waveform based on the second output value. The magnetic recording information processing method according to claim 6 or 7, wherein the threshold value is determined. When the peak position is detected using the first output value, the threshold value used when detecting the next peak position in the magnetic reproduction waveform based on the second output value is set based on the saturation determination value. The magnetic recording information processing method according to claim 6 or 7, which is determined. The magnetic recording information processing method according to any one of claims 6 to 9, wherein the magnetic information is demodulated based on the detected peak position.

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