JP3903684B2 - Magnetic storage - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a magnetic storage device that magnetically records and reproduces information such as a hard disk.
[0002]
[Prior art]
In recent years, the recording density of magnetic storage devices has risen remarkably, and research on increasing the recording capacity, increasing the density, and increasing the speed of transfer has been conducted in all fields constituting magnetic storage devices such as recording / reproducing heads, recording media, and mechanisms. Has been done. With respect to the recording medium, when high density recording is performed, the pitch is narrowed, so the thermal reliability of the recording bit is a problem. This is a problem in which the recorded signal is attenuated due to a change with time. When the temperature is increased, the attenuation factor increases. This is called “thermal fluctuation” of the recording medium. Since this thermal fluctuation problem is a physical problem of the recording medium, it can be delayed but cannot be eliminated. Recognizing that this problem may occur, a method of rewriting is used to retain information before recording demagnetization occurs.
[0003]
For example, by pre-recording reference information having a standard output characteristic on a recording medium, it is determined whether re-recording is performed based on whether the output characteristic of reproduction of the reference information shows a predetermined value or less due to a change over time. It is a method.
[0004]
FIG. 4 shows a configuration diagram of a conventional magnetic storage device 1.
[0005]
The magnetic storage device 1 includes an input / output interface unit 2, a recording / reproducing control unit 9, and a magnetic recording / reproducing mechanism unit 4.
[0006]
The recording / reproducing control unit 9 includes a recording / reproducing processing unit 3, a nonvolatile memory 5, an elapsed time measuring unit 11, a reference information quality determining unit 12, and a reference information monitoring unit 13.
[0007]
First, reference recording information serving as a reference is recorded in a predetermined recording area of the recording medium at the time when recording and accumulation of information is started in the magnetic storage device 1, and at the same time, the recording time and recording position of the reference information are stored in the nonvolatile memory 5. To do.
[0008]
The reference information monitor unit 13 periodically monitors reference information at a time interval previously defined by the elapsed time measuring unit 11 and stores the reference information in the nonvolatile memory 5.
[0009]
The reference information quality determination unit 12 determines whether or not the deterioration is below a predetermined value based on the reference information stored by the monitor. When it falls below, it is determined that the signal quality has deteriorated, and all the information recorded on the recording medium is reproduced at the same time as the reference information, temporarily stored in the buffer, and then re-recorded in the same recording area.
[0010]
[Problems to be solved by the invention]
However, in the conventional example, since the deterioration is monitored by providing the reference information in a specific area, it is determined that the deterioration in the monitor area is the deterioration of the information recorded at the same time. Since the recording method of the magnetic recording medium has a constant angular velocity, the recording density is highest in the track adjacent to the inner periphery of the recording medium, and the recording density is lowest in the track adjacent to the outer periphery. The higher the density of changes, the different. That is, when the recording density is increased, the magnetic particles forming one bit are decreased, so that the magnetization intensity is also lowered and the deterioration due to aging is accelerated.
[0011]
For this reason, the output signal characteristics at the time of reproduction differ depending on the recording density, so the determination of deterioration in the monitor area does not deteriorate all the information recorded at the same time, and the deterioration of the area with high recording density proceeds. May be unable to be played.
[0012]
Further, when the area on the recording medium is occupied, the usage efficiency of the recording medium is deteriorated.
[0013]
An object of the present invention is to provide a magnetic storage device that prevents information deterioration due to thermal fluctuation of a recording medium recorded at high density.
[0014]
[Means for Solving the Problems]
A recording medium in which the recording area from the inner periphery to the outer periphery is divided into a plurality of zones, an input / output interface unit that receives recording and playback commands from the host, and information is recorded on the recording medium by the received recording and playback commands, A recording / reproducing control unit for reproducing, wherein the recording / reproducing control unit records and reproduces predetermined information in each zone in advance, and stores the reproduced output characteristics in a memory as reference information; An information deterioration zone detecting means for detecting an information deterioration zone larger than a predetermined attenuation rate by comparing the reference information of each zone and the output characteristics of the reproduction information of each zone when receiving a reproduction command from the host; And a re-recording execution means for re-recording the detected information deterioration zone.
[0015]
With this configuration, reference information for confirming deterioration is acquired for each zone in advance and stored in a memory, and the reference information for each zone and the reproduction information for each zone are obtained based on a reproduction command from the host. Since the comparison is made, information deterioration can be confirmed and re-recorded in each zone having different recording densities in real time.
[0016]
Further, the information deterioration zone detecting means compares the output characteristics when the information designated by the reproduction command from the host is reproduced and the reference information of the zone to which the reproduction information belongs, and when the attenuation rate is larger than a predetermined value, An information deterioration zone search means for comparing the output characteristics of reproduction information of each zone from the zone to the outer periphery with the reference information of each zone and further searching for a zone having an attenuation rate larger than a predetermined value, and based on the search result A zone having an attenuation rate larger than a predetermined value is selected from the zones closest to the outer periphery, and a re-recording range determining means for setting each zone from the zone to the inner periphery as a re-recording range.
[0017]
With this configuration, when the reproduced information has deteriorated due to a reproduction command from the host, information on the predetermined position in each zone is reproduced and confirmed further toward the outer periphery, and there is a deterioration greater than a predetermined attenuation rate. Search for the existence of a zone.
[0018]
This is because the higher the recording density zone, the faster the deterioration progresses, so the zone from the zone where the reproduced information was confirmed to the inner circumference is considered to be deteriorated and the confirmation of information deterioration is omitted. Re-recording range. Therefore, the deterioration is confirmed only toward the outer periphery. Based on the confirmation result, each zone from the deterioration zone closest to the outer periphery to the inner periphery is re-recorded. Thereby, the deterioration of information can be prevented in advance by checking a small number of locations.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a configuration diagram of a magnetic storage device according to an embodiment.
[0020]
FIG. 2 is an explanatory diagram of zone division of the recording medium.
[0021]
The magnetic storage device 1 includes an input / output interface unit 2, a recording / reproducing control unit 9, and a magnetic recording / reproducing mechanism unit 4.
[0022]
The recording / reproduction control unit 9 includes a recording / reproduction processing unit 3, a nonvolatile memory 5, a reproduction information detection unit 6, and an information deterioration zone detection unit 7.
[0023]
Recently, for the purpose of increasing the storage capacity, a zone bit recording (ZBR) system has been adopted as a recording system for recording media. In this ZBR, the recording medium is divided into a plurality of zones, the transfer speed of each zone is changed, and the recording density of the outer peripheral zone is improved as compared with the prior art, and the recording density from the inner peripheral zone to the outer peripheral zone is increased. As shown in Fig. 2 (b), the curve of the decrease is made gentle.
[0024]
In the example shown in FIG. 2, the recording area is divided into five zones, and the recording density is sequentially changed from the inner peripheral zone 5 to the outer peripheral zone 1.
[0025]
The magnetic storage device 1 records predetermined data at the head sector of a track at a predetermined position in each zone during an assembly test at a manufacturing factory, and reproduces the output characteristics, for example, the output voltage of reproduction information for one sector. An average value of the amplitude values is calculated and recorded in the nonvolatile memory 5 as reference information. This is done in all zones.
[0026]
In the zone, since the recording density changes gradually, it is considered that the recording density is almost the same. In the case of almost the same recording density, the deterioration of magnetism is almost the same, so that the reference information is obtained from one predetermined track of the zone representing the zone. By adopting this method, the number of inspections when inspecting deterioration is reduced.
[0027]
When the acquisition of the reference information is completed, the information recorded on the recording medium is erased.
[0028]
Next, the operation when connected to the host 21 will be described.
[0029]
Here, the zone at the current recording medium position is called Px, the zone adjacent to the inner periphery of the recording medium is called PMin, and the zone adjacent to the outer periphery of the recording medium is called PMout.
[0030]
In the example of FIG. 2, the fifth zone is PMin, and the first zone is PMout.
[0031]
First, when the input / output interface unit 2 receives a reproduction instruction command for a specified file from the host 21, the magnetic storage device 1 instructs the recording / reproduction processing unit 3 to reproduce information.
[0032]
FIG. 3 shows a flowchart of the processing of the recording / playback control unit.
[0033]
It is assumed that information has already been recorded by the recording / playback processing unit 3 upon receipt of a recording command from the host.
[0034]
When the recording / reproduction processing unit 3 receives the reproduction instruction, the recording / reproduction processing unit 3 calculates the designated sector of the designated track from the content and reproduces information from the magnetic recording / reproducing mechanism unit 4. (Step S31) The reproduction information detection unit 6 acquires information on the output characteristics of one sector of the first track of the first zone of the reproduction start and stores it in the nonvolatile memory 5. The reproduced information itself is transmitted to the host via the input / output interface unit 2.
[0035]
When the reproduction instruction is over several zones, the same processing is performed for each sector of the track to be reproduced first in each zone. In the following description, the playback instruction is described as a plurality of zones.
[0036]
When the information is reproduced and transmission to the host 21 is completed, the reproduction information detection unit 6 reads the reproduction output information of each zone from the nonvolatile memory 5. Then, the average value of the output characteristic values is calculated for each zone and stored in the nonvolatile memory 5 as the output characteristics for each zone.
[0037]
Then, the information deterioration zone detection unit 7 is notified of the completion of processing. The information deterioration zone detection unit 7 reads the reference information of each zone stored in the nonvolatile memory 5 and the reproduced output characteristics, and compares them with each zone. (S32 step)
Then, with respect to the output characteristic indicated by the reference information, the presence / absence of a zone where the attenuation factor of the output characteristic due to reproduction is equal to or greater than a predetermined value is checked.
[0038]
If there is a zone whose attenuation rate is greater than or equal to a predetermined value, that zone is defined as Px.
When there are a plurality of zones whose attenuation factors are equal to or greater than a predetermined value, the zone closest to the outer periphery is defined as Px.
Next, it is first determined whether Px = PMout. (Step S33)
When Px = PMout, the recording / reproducing processor 3 performs re-recording with information of all zones. (Step S34) In the case of re-recording, first, information on the target area is sequentially stored in the nonvolatile memory, and then the information is sequentially re-recorded in the same place. This is repeated until all information on the target area is completed.
[0039]
When Px = PMout is not satisfied, one track for quality confirmation is further selected in each zone from Px to PMout.
[0040]
As a selection method, the history information of the track in the corresponding zone is acquired from the nonvolatile memory 5, and the track having the oldest history information is selected.
[0041]
If there are multiple selected tracks, select one of the tracks closest to the inner circumference.
[0042]
Next, with respect to the tracks selected in each zone, the reproduction information detection unit 6 sequentially acquires the output characteristics by reproduction from Px to PMout, and stores them in the nonvolatile memory.
[0043]
As for the history information, when the information recording command is received from the host, the recording / playback processing unit 3 updates the history information of the rewritten track from the accessed zone and track.
[0044]
Next, the information deterioration zone detection unit 7 reads out the reference information of the zone and the output characteristics due to the reproduction, and checks whether or not there is a zone whose attenuation rate is a predetermined value or more. (Step S35)
When the information deterioration zone detecting unit 7 detects a zone having an attenuation rate equal to or greater than a predetermined value, the information deterioration zone detecting unit 7 sets the zone closest to the outer periphery to the PMin as the re-recording range. When a zone having an attenuation rate equal to or greater than a predetermined value continues to PMout, all zones are set as a re-recording range. When the range is determined, the recording / playback processing unit performs re-recording. (Step S36)
If there is no zone having an attenuation rate equal to or greater than a predetermined value, re-recording of information in the range from Px to PMin is determined, and information is re-recorded by the recording / playback processing unit. (Step S37)
In addition, when the reproduction of information by the read command from the host is completed, the reference information corresponding to the zone to which the reproduced track belongs is compared with the output characteristics by reproduction, and as a result, the attenuation rate is determined to be within a predetermined value range. If this happens, one track for quality confirmation is selected from PMout to all zones of PMin.
[0045]
Next, with respect to the selected track of each zone, the reproduction characteristic detection unit 6 sequentially obtains the output characteristic by reproduction from the PMout to the PMin direction, calculates the average value of the output characteristic for each zone, and is non-volatile. Store in the memory 5.
[0046]
Then, the information deterioration zone detection unit 7 reads out the reference information of the zone and the output characteristics due to reproduction from the nonvolatile memory 5 and inspects whether or not there is a zone whose attenuation rate is a predetermined value or more. (Step S38)
When there is a zone whose attenuation factor is equal to or greater than a predetermined value, in the detected zone, information re-recording in the range from the zone closest to the outer periphery to PMin is determined, and the recording / playback processing unit Re-record. (Step S39)
At this time, only a zone having an attenuation rate of a predetermined value or more may be selected and re-recorded.
[0047]
If there is no zone with an attenuation rate equal to or greater than a predetermined value, the process ends without doing anything.
[0048]
【The invention's effect】
As described above, according to the present invention, in a high-density magnetic storage device in which recording demagnetization due to thermal fluctuation cannot be ignored, deterioration of information output characteristics is confirmed on a zone basis based on information that is actually reproduced. Therefore, there is an effect that the deterioration of the information on the entire recording medium can be confirmed in real time with few detection points. In addition, since basic information for determining deterioration is stored in the memory, the use efficiency of the recording medium is improved.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a magnetic storage device according to an embodiment. FIG. 2 is an explanatory diagram of zone division of a recording medium. FIG. 3 is a flowchart of processing of a recording / playback control unit. [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Magnetic storage device 2 Input / output interface part 3 Recording / reproducing process part 4 Magnetic recording / reproducing mechanism part 5 Non-volatile memory 6 Reproduction information detection part 7 Information degradation zone detection part 9 Recording / reproduction control part 11 Elapsed time measurement part 12 Reference information quality judgment Part 13 Reference information monitor part 21 Host

Claims (2)

A recording medium in which a recording area from the inner periphery to the outer periphery is divided into a plurality of zones having different recording densities, an input / output interface unit that receives recording and reproduction commands from the host, and a recording medium that records information by the received recording and reproduction commands A magnetic storage device having a recording / reproducing control unit for recording and reproducing on the recording medium;
The recording / reproducing control unit includes reference information acquisition means for recording and reproducing predetermined information in each zone in advance and storing the reproduced output characteristics in the memory as reference information, and when the acquisition of the reference information is completed, the information is erased,
The reproduction control unit further includes
An information deterioration zone detection means for detecting an information deterioration zone larger than a predetermined attenuation rate by comparing output characteristics of reproduction information of an area designated by a reproduction command from the host and reference information of a zone to which the designated area belongs When,
A magnetic recording device comprising: rerecording execution means for performing rerecording on the detected information deterioration zone. The information deterioration zone detection means compares the output characteristics when the information designated by the reproduction command from the host is reproduced and the reference information of the zone to which the reproduction information belongs, and when the attenuation rate is larger than a predetermined value, Information deterioration zone search means for comparing the output characteristics of the reproduction information of each zone from the outer circumference to the outer circumference and the reference information of each zone, and further searching for a zone having an attenuation rate greater than a predetermined value;
Based on the result of the search, a zone closest to the outer periphery is selected from the zones having an attenuation rate larger than a predetermined value, and a re-recording range determining means for setting each zone from the zone to the inner periphery as a re-recording range is provided. The magnetic storage device according to claim 1, wherein:

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