JPH03224105A - Magnetic disk recorder and magnetic disk reproducer - Google Patents

Abstract

PURPOSE:To obtain the magnetic disk recorder having a low error rate by controlling a pulse duration of a recording signal based on a recording data pattern and a head position. CONSTITUTION:This device is provided with a delay 14 up to a delay amt. controller 17, which are functioned to be a pulse duration control means for controlling the pulse duration of a recording signal to be supplied to the head 2 in accordance with head position information from a controller 3 and pattern information from a pattern detector 13. In this case, such a control is performed by the delayer 14 up to the delay amt. controller 17 that the recording signal pulse duration is narrowed in proportion as the head position moves toward the inner circumference based on the head position information from the controller 3 in order to decrease a peak shift amt. of a regenerative signal for a recording data in a pattern of generating a peak shift to be detected by the pattern detector 13. By this method, at the time of reproducing, a peak shift of a regenerative signal is properly suppressed to secure a phase margin satisfactorily, thus obtaining the magnetic disk recorder having a low error rate.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a magnetic disk recording device and a magnetic disk reproducing device.

B1 Summary of the Invention The present invention provides a head for recording signals on a magnetic disk, a head position management means for managing the position of the head in the disk radial direction, and a pattern detection system for detecting a pattern of recorded data in which the peak position of a reproduced signal shifts. and a pulse width control means for controlling the pulse width of the recording signal supplied to the head according to the head position information from the head position management means and the pattern information from the pattern detection means, the pulse width control means , the head position is set to the inner circumference based on the head position information from the head position management means so that the amount of peak shift of the reproduced signal is reduced with respect to the recorded data of the pattern in which the peak shift detected by the pattern detection means occurs. The peak shift of the reproduced signal is suppressed by controlling the pulse width of the recording signal to be narrowed as the pulse width increases.

The present invention also provides a head for recording signals on a magnetic disk, a head position management means for managing the position of the head in the disk radial direction, and a pattern detection means for detecting a pattern of recorded data in which the peak position of a reproduced signal shifts. , the first and second change positions of the pulse of the recording signal supplied to the head are individually controlled according to the head position information from the head position management means and the pattern information from the pattern detection means, and the pulse of the recording signal is pulse width control means for controlling the width, and the pulse width control means is configured to reduce the amount of peak shift of the reproduced signal with respect to the recorded data of the pattern in which the peak shift detected by the pattern detection means occurs. Based on the head position information from the head position management means, as the head position moves toward the inner circumference, the first change position of the pulse of the recording signal is delayed and the second change position is advanced. By controlling the pulse width of the recording signal to be narrow, even if the amount of peak shift of the reproduction signal differs between the first change position of the recording signal pulse and the subsequent change position, the peak shift of the reproduction signal can be reduced. It is designed to appropriately suppress the

The present invention also provides a head for reproducing signals from a magnetic disk, an equalizer with variable equalization characteristics for equalizing the waveform of a reproduced signal from the head, and a head position for managing the position of the head in the disk radial direction. By having a management means and an equalization characteristic control means for controlling an equalizer so that the amount of peak shift of the reproduction signal is reduced according to the head position information from the head position management means, the peak shift of the reproduction signal can be reduced. It is designed to suppress the

C0 Conventional technology The so-called RLL (Run Length
The RLL2,7 code, for example, is a variable word length code with i=2.3.4, which converts i bits of input data into 21 bits of recorded data. The bit information has a minimum of 2 bits and a maximum of 7 consecutive bits (so-called O's minimum run is 2 and maximum run is 7). Then, in the magnetic disk device, this recorded data is processed by so-called N RZ I (Non
Return to Zero Inverted)
A recording signal is generated by performing modulation, and this signal is recorded on a magnetic disk. That is, the magnetization reversal interval formed in the recording medium of the magnetic disk is proportional to the length of consecutive bit information 0 of the recorded data, and as shown in FIG. 5, the pattern of the recorded data after encoding is rlool.
, is the minimum when the pattern is expressed as .

When reproducing a signal recorded as magnetization reversal of the recording medium of a magnetic disk, the peak position of the reproduced signal from the head shifts due to code amount interference (as shown in FIGS. 6 and 7, for example). A so-called peak shift occurs. As a result, as shown in FIG. 5, in adjacent reproduction pulses, the previous pulse is shifted further forward, and the later pulse is shifted further backward, and this shift amount is, as shown in FIG. 7, The narrower the magnetization reversal interval, that is, the pulse interval of recorded data, becomes larger. For example, in a magnetic disk that is rotated at a constant angular velocity, the relative speed of the head to the recording medium becomes slower at the inner periphery of the magnetic disk, and the pulse width of the recording signal becomes narrower, so the head position moves toward the inner periphery of the magnetic disk. The more the peak shift amount increases.

In addition, in order to increase the recording density, the data recording area of the magnetic disk is divided into two, for example, the outer circumferential side and the inner circumferential side, as shown in Figure 8, and the outer circumferential side has a faster relative speed of the head with respect to the recording medium. A magnetic disk device is known in which the recording frequency is made higher on the inner circumferential side and lowered on the inner circumferential side. Even in such a magnetic disk device, as shown in FIG. 8, the pulse width of the recording signal is narrower and the peak shift amount is larger at the inner periphery of each area. Furthermore, as shown in FIG. 8, the peak shift amount at the innermost periphery of the high frequency region where the recording frequency is high is greater than the peak shift amount at the outermost periphery of the low frequency region.

D1 Problems to be Solved by the Invention Conventionally, in order to reduce the peak shift caused by the code amount interference as described above, the following peak shift correction has been performed during recording and reproduction.

During recording, the pattern of the recorded data after RLL2, 7 encoding is determined, and if a pattern that causes a large peak shift is detected, for example a pattern of "1001" as shown in Figure 5, the peak shift amount is determined. The write timing is shifted in the direction of reducing. Furthermore, during reproduction, a so-called cosine equalizer is used, for example, to reduce the tail of the reproduced signal waveform and reduce the amount of peak shift. In other words, the reproduced signal waveform is sharpened to eliminate code amount interference.

In this way, the peak shift correction performed during recording uses only the pattern information of the recorded data to perform appropriate correction, for example, at the innermost circumference of the magnetic disk.
On the outer circumferential side of a magnetic disk where focus density is low and resolution is high, peak shift correction is performed excessively, leading to a decrease in phase margin. In addition, peak shift correction in a magnetic disk device that divides the data area of a magnetic disk into two, an outer circumferential side and an inner circumferential side, and uses two recording frequencies, as shown in FIG. We are making appropriate corrections. For this reason, there is a problem in that excessive peak shift correction is performed on the outer circumferential side of the high frequency region and on the inner circumferential side of the low frequency region, leading to a decrease in the phase margin. In addition, for waveform equalization performed during playback, a method is used in which only the gain of the cosine equalizer is controlled according to the recording frequency. The delay amount of the cosine equalizer was not controlled depending on the frequency, and optimal correction was not performed.

In addition, due to the effect that the magnetization of the preceding recording medium is partially erased by the subsequent reversed magnetization and the mutual interference effect between the magnetization reversals caused by the demagnetizing field, the reproduction from the previous magnetization reversal is caused as shown in Figure 9. Although the peak shift amount P of the reproduced signal is larger than the peak shift amount P7 of the reproduced signal reproduced from the subsequent magnetization reversal, conventional magnetic disk drives have not taken this point into account. That is, the ninth
As shown in the figure, even if the previous peak shift amount P (and the subsequent peak shift amount P) are significantly different, the same amount of correction is performed for the previous peak shift and the subsequent peak shift, The peak shift correction for the previous peak shift was insufficient, the peak shift correction for the subsequent peak shift was excessive, and the effect of reducing the peak shift was not sufficient.

In actual experiments, it has been confirmed that the errors caused by the previous peak shift are overwhelmingly large.

The present invention was made in view of the above circumstances, and suppresses the peak shift of the reproduced signal during reproduction by controlling the pulse width of the recorded signal based on the pattern of recorded data and the head position. An object of the present invention is to provide a magnetic disk recording device that can secure a sufficient phase margin and has a low error rate.

In addition, by controlling the pulse width of the recording signal by individually controlling the first change position and the second change position of the pulse of the recording signal based on the pattern of the recording data and the head position,
It is an object of the present invention to provide a magnetic disk recording device that can more appropriately suppress the peak shift of a reproduced signal during reproduction to ensure a sufficient phase margin and has a low error rate.

In addition, by controlling the isovolume equalization characteristics based on the head position and performing optimal peak shift correction, it is possible to secure a sufficient phase margin during playback, making it possible to use a magnetic disk playback device with a low error rate. For the purpose of providing.

Means for Solving the E0 Problem As shown in FIG. 1, the magnetic disk recording device according to the present invention includes a head 2 for recording signals on a magnetic disk, and a head position for managing the position of the head 2 in the disk radial direction. A controller 3 serving as a management means, a pattern detector 13 serving as a pattern detecting means for detecting a pattern of recorded data in which the peak position of a reproduced signal shifts, and head position information from the controller 3 and information from the pattern detector 13. The delay device 14 to the delay amount controller 17 are provided as pulse width control means for controlling the pulse width of the recording signal supplied to the head 2 according to the pattern information, and the delay device 14 to the delay amount controller 17 The head position is moved to the inner circumference based on the head position information from the controller 3 so that the amount of peak shift of the reproduced signal is reduced with respect to the recorded data of the pattern in which the peak shift detected by the pattern detector 13 occurs. The above problem is solved by controlling the pulse width of the recording signal to be narrowed as the pulse width increases.

Further, as shown in FIG. 4, the magnetic disk recording apparatus according to the present invention includes a head 6 for recording signals on a magnetic disk, and a controller 7 serving as a head position management means for managing the position of the head 6 in the disk radial direction. and a pattern detector 33 serving as a pattern detection means for detecting a pattern of recorded data in which the peak position of the reproduced signal shifts; A delay device 34a to a delay amount controller 37, which serve as pulse width control means for controlling the pulse width of the recording signal by individually controlling the earlier change position and the later change position of the pulse of the recording signal supplied to the head 6; The delay unit 34a to the delay amount controller 37 are configured to reduce the peak shift amount of the reproduced signal with respect to the recorded data of the pattern in which the peak shift detected by the pattern detector 33 occurs. Based on the head position information from the controller 7, as the head position moves toward the inner circumference, the first change position of the pulse of the recording signal is delayed, and the subsequent change position is advanced by individually controlling the recording. The above problem is solved by performing control to narrow the pulse width of the signal.

Further, as shown in FIG. 1, the magnetic disk reproducing apparatus according to the present invention includes a head 2 for reproducing signals from a magnetic disk.
, an equal volume 22 having variable equalization characteristics that equalizes the waveform of the reproduced signal from the head 2, a controller 3 serving as a head position management means for managing the position of the head 2 in the disk radial direction, and By having an equalization characteristic controller 27 serving as an equalization characteristic control means for controlling the equalizer 22 so that the peak shift amount of the reproduced signal is reduced according to the head position information from the controller 3, the above-mentioned Solve problems.

F0 Effect In the magnetic disk recording device according to the present invention, the peak shift of the reproduced signal is suppressed by controlling the pulse width of the recording signal according to the pattern of the recorded data after encoding and the head position.

Further, in the magnetic disk recording device according to the present invention, the first change position and the second change position of the pulse of the recording signal are individually controlled according to the pattern of the recorded data after encoding and the head position. By controlling the pulse width, the peak shift of the reproduced signal is suppressed.

Further, in the magnetic disk reproducing apparatus according to the present invention, by controlling the isovolume equalization characteristic according to the head position,
Suppress the peak shift of the reproduced signal.

G. Embodiments Hereinafter, embodiments of a magnetic disk recording device and a magnetic disk reproducing device according to the present invention will be described with reference to the drawings.

FIG. 1 is a block circuit diagram of a main part of a magnetic disk device of a first embodiment to which a magnetic disk recording device and a magnetic disk reproducing device according to the present invention are applied. That is, FIG. 1 shows both the recording system and the reproducing system of the magnetic disk device.

In FIG. 1, the recording system of the magnetic disk device includes a P/S converter 11 that converts parallel input data input via a data bus 1 into serial data, and a P/S converter 11 that converts the serial data into, for example, an RLL 2.7 code. Encoder 1 to convert
2, a pattern detector 13 that determines the pattern of the recorded data converted into the RLL 2.7 code and controls the MUχ16, and a delay connected in series to delay the recorded data converted into the RLL 2.7 code. Two delay devices 14 and 15 whose amounts are variable, the encoder 12, and the delay device 1
The MUX 16 selects one data from the data from 4.15 and performs NRZI modulation on the selected data to produce a recording signal, the drive amplifier 18 drives the head 2 with the recording signal, and the delay device and a delay amount controller 17 that controls the delay I of 14.15 based on the node position information from the controller 3.

Further, the reproduction system of the magnetic disk device includes a reproduction amplifier 21 for amplifying the signal from the head 2, and a reproduction amplifier 21 for amplifying the signal from the head 2.
22, which has a variable equalization characteristic that equalizes the waveform of the reproduced signal from A discriminator 24 that separately generates a reproduction pulse, and a decoder 2 that decodes the reproduction pulse and generates serial reproduction data.
5, an S/P converter 26 that converts the serial reproduction data into parallel data, and an equalization characteristic controller 27 that controls the equalization characteristic of the equalizer 22 based on the head position information from the controller 3. It consists of

The controller 3 has a function of driving and controlling the actuator to which the head 2 is attached via the actuator servo 4, and driving the head 2 in the radial direction of the magnetic disk.

That is, this controller 3 manages head position information to drive and control the head 2, and also supplies this head position information to the delay amount controller 17 and equalization characteristic controller 27.

Next, the operation will be explained. Parallel input data is supplied to a P/S converter 11 via a data bus 1 . This P/
The S converter 11 converts parallel input data into serial data. The encoder 12 performs, for example, PLL2, 7 code conversion and generates a recording data sequence from an input data sequence. In other words, the pattern of recorded data is based on bit information O
becomes a pattern in which a minimum of 2 to a maximum of 7 are consecutive. This recorded data is supplied to a pattern detector 13 and a delay device 14.

The delay amount controller 17 controls delay units 14 and 15 based on the head position information and recording frequency from the controller 3.
For example, the delay amount of the delay devices 14 and 15 is controlled so as to correct the peak shift amount WC according to the head position as shown in FIG. That is, in the high frequency region and the low frequency region of the recording frequency, the delay amount of the delay devices 14 and 15 is increased as the head position is located closer to the inner circumference side.

The pattern detector 13 determines the pattern of recorded data and controls the MUX 16 . For example, a pattern rlooI with two consecutive zeros that causes the largest peak shift.
When J is detected, the output of the delay device 15 is selected corresponding to the first bit information 1 of the pattern rlooIJ, and the following (
The MUX1 6 is controlled to select the output of the delay device 14 in response to two pieces of bit information 0, and to select the output of the encoder 12 in response to the following bit information 1. Note that when a pattern other than the pattern r1001 with two consecutive zeros is detected, the MU is set to select the output of the delay device 14.
Controls X16.

The MUX 16 performs, for example, NRZI modulation on the data selected as described above to generate a recording signal, and supplies this recording signal to the drive amplifier 18 .

The drive amplifier 18 modulates the direction of the magnetic field of the head 2 based on the recording signal, and records this signal on the magnetic disk. That is, the magnetization of the recording medium of the magnetic disk is reversed in accordance with bit information 1 of the recording data, and information is recorded.

In other words, as the head 2 is located closer to the inner circumference of the magnetic disk, the delay amount of the delay device 14, 15 is increased, and a pattern in which the interval between bit information 1 of the recorded data is narrow, which causes a large peak shift, is detected. By selecting the recorded data from the encoder 12 and the delay device 14 and 15 as described above, the pulse width of the recorded signal is narrowed to reduce the peak shift amount of the reproduced signal caused by code amount interference. Do it like this.

As described above, in the recording system of a magnetic disk device, by controlling the pulse width of the recording signal of the magnetic disk based on the head position information and the pattern of the recorded data, it is possible to suppress the peak shift of the reproduced signal. That is, it becomes possible to perform peak shift correction corresponding to the head position and the pattern of recorded data. As a result, it is possible to significantly reduce the peak shift amount and increase the phase margin, thereby reducing the error rate of the magnetic disk device.

Next, the reproduction system of the magnetic disk device will be explained.

The head 2 reproduces a signal recorded as magnetization reversal of a recording medium of a magnetic disk. The regenerative amplifier 21 amplifies the signal from the head 2 and supplies the amplified reproducing signal to the isovolume 22 .

The equal volume 22 is a equal volume whose equalization characteristic is variable as described above. For example, the equal volume 22 is a cosine filter, which is a type of transversal filter having a waveform equalization characteristic as shown in FIG. It is isoproportional.

Its equalization characteristics are as follows: When the input single pulse is r(t), the output g(t) is expressed as g(t)=f(L)-k[f (t+τ)+r(t-τ)
], and the gain coefficient k and delay time τ are controlled by the head position. That is, the head position information is supplied from the controller 3 to the equalization characteristic controller 27, and the equalization characteristic controller 27 controls the gain coefficient k and the delay time τ based on the head position information. For example, the wider the width of the solitary wave in the reproduced signal, the longer the delay time τ
control to increase. That is, the gain coefficient k and the delay time τ are changed based on the change in the pulse interval due to the head position. Specifically, as shown in FIG. 2, the gain coefficient k and delay time τ of the equal volume 22 are controlled so that the gain and delay time correct the peak shift amount RC corresponding to the head position. .

The shaper 23 shapes the waveform of the equalizer, detects, for example, a peak position, and generates a detection pulse indicating the presence or absence of a signal.

The discriminator 24 reproduces a reproduction pulse from the detected pulse using, for example, a clock from a so-called synchronization signal generator. The decoder 25 decodes the RLL2.7 code and reproduces serial reproduction data. The S/P converter 26 converts the serial reproduction data into parallel data and outputs it to the data bus 1.

As described above, in the reproduction system of a magnetic disk drive, by controlling the isovolume equalization characteristic using the pulse interval, that is, the head position information, it is possible to perform peak shift correction corresponding to the head position. Become. As a result, it is possible to significantly reduce the peak shift amount and increase the phase margin, thereby reducing the error rate of the magnetic disk device.

Next, a second embodiment of the magnetic disk recording device according to the present invention will be described. FIG. 4 is a block circuit diagram of a recording system of a magnetic disk device to which the present invention is applied.

In FIG. 4, the recording system of the magnetic disk device includes a P/S converter 31 that converts parallel input data input via a data bus 5 into serial data, and a P/S converter 31 that converts the serial data into, for example, a PLL2.7 code. Encoder 3 to convert
2, a pattern detector 33 that determines the pattern of the recorded data converted into the PLL2, 7 code and controls the MUX 36, and a series-connected delay that delays the recorded data converted into the PLL2.7 code. two delay units 34a and 35a each having a variable amount, and the encoder 32;
The MUX 36 selects one data from the data from the delay devices 34a and 35a and modulates the selected data by, for example, NRZI to produce a recording signal; the drive amplifier 38 drives the head 6 with the recording signal; delay device 34
A delay amount controller 37 that controls each of the delay amounts of a and 35a based on the head position information from the controller 7, and each set value of the delay amount that is individually set from the delay amount controller 37, Registers 34b and 35 stored to supply to 34a and 35a, respectively
It consists of b.

The controller 7 has a function of driving and controlling the actuator to which the head 6 is attached via the actuator servo 8, and driving the head 6 in the radial direction of the magnetic disk.

That is, this controller 7 manages head position information to drive and control the head 6, and also supplies this head position information to the delay amount controller 37.

Next, the operation will be explained. Parallel input data is supplied to the P/S converter 31 via the data bus 5. This P/
The S converter 31 converts parallel input data into serial data. The encoder 32 performs, for example, PLL2.7 code conversion and generates a recording data sequence from an input data sequence. In other words, the pattern of recorded data is bit information 0.
becomes a pattern in which a minimum of 2 to a maximum of 7 are consecutive. This recorded data is supplied to a pattern detector 33 and a delay device 34a.

The delay amount controller 37 controls the delay units 34a and 3 based on the head position information and recording frequency from the controller 7.
Each delay amount of 5a is controlled via registers 34b and 135b, respectively. For example, the total delay amount of the delay units 34a and 35a is controlled so as to correct the peak shift amount WC corresponding to the hennode position shown in FIG. 2 described above. That is, in the high frequency region and the low frequency region of the recording frequency, control is performed so that the total delay amount of the respective delay amounts of the delay devices 34a and 35a increases as the hennode position is located closer to the inner circumferential side. Specifically, the delay amount of the delay circuit 34a is set to a value that corrects the peak shift amount PL shown in FIG.
The delay amount of a is the peak shift amount P. to a value to be corrected.

The pattern detector 33 determines the pattern of recording data and controls the MUX 36. For example, if the peak shift is the thickest (pattern rlooIJ with two consecutive zeros)
When detecting pattern rloo1. The output of the delay device 35a is selected corresponding to the first bit information 1, the output of the delay device 34a is selected corresponding to the next two bit information Controls MUX 36 to select output. Note that when a pattern other than the pattern rl'001 with two consecutive zeros is detected, the MUX 36 is controlled to select the output of the delay device 34a.

The MUX 36 performs, for example, NRZI modulation on the data selected as described above to generate a recording signal, and supplies this recording signal to the drive amplifier 38.

The drive amplifier 38 modulates the direction of the magnetic field of the head 6 based on the recording signal, and records this signal on the magnetic disk. That is, the magnetization of the recording medium of the magnetic disk is reversed in accordance with bit information 1 of the recording data, and information is recorded.

That is, as the head 6 is positioned closer to the inner circumference of the magnetic disk, the delay amounts of the delay devices 34a and 35a are increased, and the delay amount of the delay device 35a is made larger than the delay amount of the delay device 34a. When a pattern in which the interval between bit information 1 of recording data that causes a large shift is detected, the pulse width of the recording signal can be changed by selecting the recording data from the encoder 32 and the delay devices 34a and 35a as described above. is made narrower to reduce the amount of peak shift of the reproduced signal due to code amount interference, and also to cope with the difference in the amount of peak shift between the earlier change position and the later change position of the pulse of the recording signal.

As described above, in this embodiment, the pulse width of the recording signal of the magnetic disk is controlled by the head position information and the pattern of the recording data, and the amount of peak shift at the earlier change position and the later change position of the pulse of the recording signal By dealing with the difference in , it is possible to more appropriately suppress the peak shift of the reproduced signal. That is, it is possible to perform peak shift correction corresponding to the difference in peak shift amount between the head position, the print data pattern, and the previous and subsequent change positions of the pulse of the print signal. As a result, it is possible to appropriately reduce the peak shift amount and increase the phase margin, thereby further reducing the error rate of the magnetic disk device.

Note that the present invention is not limited to the above embodiments,
Even in a magnetic disk recording device and a magnetic disk reproducing device in which the recording system and the reproducing system of the magnetic disk device are separate devices, the peak shift may be corrected depending on the head position and the like. Furthermore, the encoding rule used in the magnetic disk device is not limited to the above-mentioned RLL2.7 code.

H9 Effects of the Invention As is clear from the above explanation, the magnetic disk recording device according to the present invention can reduce the amount of code by controlling the pulse width of the recording signal of the magnetic disk based on the head position and the pattern of the recorded data. It is possible to reduce the peak shift amount of the reproduced signal due to interference and increase the phase margin.

As a result, a magnetic disk recording device with a low error rate can be provided.

Furthermore, in addition to the above, the magnetic disk recording device according to the present invention can perform more appropriate peak shift correction by dealing with the difference in peak shift amount between the first change position and the second change position of the pulse of the recording signal. It can be done. As a result, a magnetic disk recording device with a lower error rate can be provided.

Furthermore, in the magnetic disk reproducing device according to the present invention, by controlling the equalization characteristic based on the head position, the amount of peak shift of the reproduced signal due to code amount interference is reduced, and the phase margin is increased. It becomes possible to do so.

As a result, a magnetic disk reproducing device with a low error rate can be provided.

[Brief explanation of drawings]

FIG. 1 is a block circuit diagram of a main part of a magnetic disk device of a first embodiment to which a magnetic disk recording device and a magnetic disk reproducing device according to the present invention are applied, and FIG. 2 shows head position and peak shift correction amount. FIG. 3 is a waveform diagram for explaining the principle of the same crime, and FIG. 4 is a diagram showing a magnetic disk of a second embodiment to which the magnetic disk recording device according to the present invention is applied. This is a block circuit diagram of the main part of the recording system of the apparatus, FIG. 5 is a diagram showing the relationship between recorded data and reproduction pulses, and FIGS. 6 and 7 are diagrams showing the relationship between pulse interval and peak shift. 8 is a diagram showing the relationship between the head position and the peak shift, and FIG. 9 is a diagram showing the difference in the amount of peak shift between the earlier change position and the later change position of the pulse of the recording signal. 2, 6 ・ 3, 7 12, 3 13, 3 14, 1 16, 3 17, 3 22 ・ 25 ・ ・ 27 ・ ・ ・ ・ Head Controller 2 Encoder 3 Pattern detector 5 .34a, 35a...Delay device 6...MUX 7...Delay amount controller, equal volume, decoder, equalization characteristic controller

Claims (1)

[Scope of Claims] (1) A head for recording signals on a magnetic disk, head position management means for managing the position of the head in the disk radial direction, and detecting a pattern of recorded data in which a peak position of a reproduced signal shifts. comprising a pattern detection means and a pulse width control means for controlling the pulse width of the recording signal supplied to the head according to the head position information from the head position management means and the pattern information from the pattern detection means, The pulse width control means adjusts the head position information from the head position management means so that the amount of peak shift of the reproduced signal is reduced with respect to the recorded data of the pattern in which the peak shift detected by the pattern detection means occurs. A magnetic disk recording device characterized in that the pulse width of the recording signal is controlled to be narrower as the head position becomes closer to the inner circumference. (2) a head for recording signals on a magnetic disk; a head position management means for managing the position of the head in the disk radial direction; a pattern detection means for detecting a pattern of recorded data in which a peak position of a reproduced signal shifts; The first change position and the second change position of the pulse of the recording signal supplied to the head are individually controlled according to the head position information from the head position management means and the pattern information from the pattern detection means, so that the recording signal is and a pulse width control means for controlling a pulse width, wherein the pulse width control means reduces the amount of peak shift of the reproduced signal with respect to the recorded data of the pattern in which the peak shift detected by the pattern detection means occurs. As the head position becomes closer to the inner circumference, based on the head position information from the head position management means, the first change position of the pulse of the recording signal is delayed and the second change position is advanced. What is claimed is: 1. A magnetic disk recording device that performs control to narrow the pulse width of the recording signal. (3) A head that reproduces signals from a magnetic disk, an equalizer with variable equalization characteristics that equalizes the waveform of the reproduced signal from the head, and head position management that manages the position of the head in the disk radial direction. and head position information from the head position management means,
A magnetic disk reproducing apparatus comprising: equalization characteristic control means for controlling the equalizer so that the amount of peak shift of the reproduced signal is reduced.