CN103854675A - Servo pattern of tape storage medium - Google Patents
Servo pattern of tape storage medium Download PDFInfo
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- CN103854675A CN103854675A CN201310617046.3A CN201310617046A CN103854675A CN 103854675 A CN103854675 A CN 103854675A CN 201310617046 A CN201310617046 A CN 201310617046A CN 103854675 A CN103854675 A CN 103854675A
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/48—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed
- G11B5/58—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
- G11B5/584—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following for track following on tapes
Abstract
A tape storage medium comprises a servo band (SB) along a longitudinal extension (x) of the tape storage medium (TP) for determining positional information. The servo band (SB) comprises a set of servo tracks (STx) which are arranged next to each other and extend along a longitudinal extension (x) of the tape storage medium (TP). Each servo track of the set (STx) contains a servo pattern provided with a pseudo noise sequence (PN_x) of symbols, wherein the pseudo noise sequences (PN_x) of servo patterns of adjacent servo tracks (STx) are different from each other. The set of servo tracks (STx) contains at least three servo tracks (STx) with different pseudo noise sequences (PN_x).
Description
Technical field
The present invention relates to band (tape) storage medium, tape drive and for operating tape drive with from storage medium reading out data and/or to the method with storage medium data writing.
Background technology
Be usually included in pre-recorded servo-information in the dedicated servo band (servo band) that is then used in data band (data band) extension of storing data with storage medium, this servo belt extends in the vertical along band medium.Servo belt is read by the dedicated servo reader of taking the lead of tape drive conventionally, comprises with the box of storage medium and is inserted in this tape drive.The servo-information that reads allows to determine from reference position the lateral runout with storage medium, and this reference position is supposed to for the exclusive data reader by taking the lead and write device correctly from band storage medium reading out data with to band storage medium data writing.For representing that the position error signal of lateral runout will be converted into the control signal for actuator (actuator), this actuator is for controlling the lateral attitude of taking the lead with respect to medium.
Summary of the invention
An embodiment according to a first aspect of the invention, provides a kind of band storage medium, and it comprises along at least one servo belt extending longitudinally with storage medium, for supporting to determine positional information.This servo belt comprises along with the extending longitudinally of storage medium and be positioned to each other one group of servo track immediately.The servo pattern that each servo track of this group comprises the pseudo noise sequence with symbol, wherein, the pseudo noise sequence of the servo pattern of adjacent servo track differs from one another.The servo track of this group comprises at least three servo tracks with different pseudo noise sequence.
In an embodiment, this can comprise the one or more of feature below with storage medium:
-for each servo track of this group, the magnetic transition in such servo track is indication cycle's property waveform in the time being read;
The periodic waveform of-adjacent servo track is orthogonal in time domain;
The maximum length of the pseudo noise sequence in any one of-servo track is less than 100 microns;
The maximum length of the pseudo noise sequence in any one of-servo track is less than 20 microns;
The maximum length of the pseudo noise sequence in any one of-servo track is less than 10 microns;
The maximum length of the pseudo noise sequence in any one of-servo track is less than 2 microns;
-the additional information of encoding in the servo pattern of one or more servo tracks, this additional information is the one or more of following part: longitudinal position information, manufacturing information, servo belt identifier, servo track subset identifier;
-the additional information of encoding in the servo pattern of each servo track of this group;
-all additional informations of as above listing are encoded as the servo pattern of each servo track of this group;
-one or more by amplitude modulation, phase-modulation, polar modulation, on-off keying, in this additional information of one or more middle coding of this servo track;
-by with the one or more other pseudo noise sequence that the individual pseudo noise sequence of servo track is interweaved, in the one or more middle coding additional information of this servo track;
-each pseudo noise sequence comprises the sequence of binit;
-periodicity that each servo track comprises distributed pseudo noise sequence repeats.
An embodiment according to another aspect of the present invention, a kind of tape drive is provided, for from band storage medium reading out data and/or to band storage medium data writing, this with storage medium preferably according to any one band storage medium of previous embodiment.This tape drive comprises takes the lead, this is taken the lead to comprise and is allocated at least one the servo reader reading from servo belt, wherein, when be disposed in this tape drive with the width of this extending longitudinally orthogonal servo reader with storage medium be at least with this this orthogonal servo belt extending longitudinally with storage medium in the width of servo track.
In an embodiment, this tape drive can comprise the one or more of feature below:
The width of-this servo reader equals the width of the servo track in this servo belt;
The width of-this servo reader is greater than the width of the servo track in this servo belt, and is not more than the twice of the width of the servo track in this servo belt.
Embodiment according to another aspect of the present invention, provides a kind of for operating any one with storage medium reading out data and/or to this method with storage medium data writing with from according to previous embodiment of tape drive.The servo reader that this servo belt is preferably taken the lead reads.Determine and comprise the taking the lead with respect to this lateral attitude value with storage medium of this servo reader from the readback signal of this servo reader.Be worth to adjust according to this lateral attitude the lateral attitude that this is taken the lead.
In an embodiment, the method can comprise the one or more of feature below:
-determine that this lateral attitude value is included in the readback signal of this servo reader to identify one or more pseudo noise sequence;
-be used for determining relevant (correlation) operation of this lateral attitude value by application, by this readback signal filtering of this servo reader;
-set up one or more ratios from the energy of different pseudo noise sequences of identification, and draw this lateral attitude value from these one or more ratios;
-by each while determining new lateral attitude value the control signal of renewal adjust this lateral attitude that this is taken the lead.
An embodiment according to another aspect of the present invention, a kind of computer program is provided, this computer program comprises computer-readable medium, this computer-readable medium comprises computer readable program code, this computer readable program code comprise be configured to carry out according to the computer readable program code of any one method of previous embodiment.
Can understand, can be to carry out manner of execution step from the different order of listing in claim to a method.The same with the order of the current step of listing, such different order also should be included in the scope of such claim.
The embodiment describing relatively with the aspect of write head (write head) also should be considered to any disclosed embodiment relatively with other classifications such as method.
Brief description of the drawings
By reference to current preferably but however remain obtain by reference to the accompanying drawings according to the detailed description below illustrative embodiment of the present invention, by comprehend the present invention and embodiment.
Accompanying drawing illustrates:
Fig. 1 is a part of top view of the servo belt with storage medium according to an embodiment of the invention,
Fig. 2 is the top view of the part with storage medium according to an embodiment of the invention,
Fig. 3 is the top view of a part of the servo belt with storage medium according to an embodiment of the invention and relevant figure,
Fig. 4 is the top view of a part of the servo belt with storage medium according to another embodiment of the invention and relevant figure,
Fig. 5 is the top view of the part with storage medium according to another embodiment of the invention,
Fig. 6 be represent according to an embodiment of the invention for operating the process flow diagram of method of tape drive, and
Fig. 7 is the block diagram of the project of the selection of tape drive according to an embodiment of the invention.
Embodiment
As the introduction of the explanation for below, first point to and relate to storage medium, tape drive with for operating the of the present invention general aspect of the method with storage medium.
For storing, the band storage medium of data---is also abbreviated as band (tape)---and specifically tape storage medium can be disposed in box, this box can be inserted in tape drive, with from band storage medium reading out data with to band storage medium data writing.This with storage medium have extending longitudinally and with it orthogonal width extending longitudinally.This band is wound onto on the one or more spools that driven by tape drive, to make this band data reader and write device through taking the lead, for from band storage medium reading out data and/or to band storage medium data writing.Conventionally carry out pre-formatting band storage medium with servo-information.Make with this servo-information of the form of servo pattern the servo reader of taking the lead read and/or data writing during can pick up about the servo-information of taking the lead with respect to the lateral attitude with storage medium, this lateral attitude is and the extending longitudinally orthogonal position of tape storage medium.Such positional information can be converted into the control signal for taking the lead, laterally to readjust in the case of detecting with respect to the departing from of lateral reference position, this lateral reference position is expected to be taken the lead to keep, to pass through exclusive data reader and write device correctly from band reading out data with to band data writing.Also the offset signal that is represented as position error signal (PES) is provided by the servo channel of processing from the readback signal of the dedicated servo reader of taking the lead conventionally, and can be converted into control signal for actuator to control the lateral attitude of taking the lead with respect to band.If servo reader and data reader and write device mechanical couplings and can conventionally be activated by this actuator in one embodiment, can be from realizing the Fast Correction of taking the lead to depart from reading out data and/or during with data writing.Can understand, band head module " taken the lead " also can refer in term, one or more servo readers and data reader and write device are mechanically coupled to wherein, and can there is other band head module simultaneously, this other band head module comprises other servo readers, and data reader and/or write device mechanical couplings, this can be controlled independently on their lateral attitude with head module.
Conventionally, for example by with manufacturer band reserved area on pre-formatting servo pattern, this reserved area be also represented as along band servo belt extending longitudinally.These one or more servo belts are close to the data band of storage data.Each data band can comprise multiple data-tracks, and wherein, each data-track is provided for sequentially stores data.Servo-information can adopt the shape different from data.
In a preferred embodiment, band storage medium comprises at least one servo belt (servo band).The in the situation that of multiple servo belt, preferably, each servo belt comprises the structure with multiple servo tracks, described in more detail as follows.Specifically, each servo belt can be therefore except such as servo belt identifier-if any-servo belt or servo track customizing messages comprise identical servo-information.
Servo belt comprise along servo belt extending longitudinally, along the multiple servo tracks adjacent one another are extending longitudinally with storage medium.Multiple servo tracks like this can comprise different servo patterns, for accurate position control.In one embodiment, servo belt can comprise at least three servo tracks adjacent one another are.Preferably, servo track adjacent one another are comprises different servo patterns.If normally tape storage medium of band storage medium, represents the servo pattern in each servo track by the magnetic conversion (magnetic transition) along servo track.Waveform in the readback signal of the servo reader that such magnetic conversion expression distributes in the time reading separately such servo pattern.In context, emphasize, the waveform that is derived from the servo pattern in independent servo track is encompassed in the expression of the main signal (subject signal) in time domain and frequency domain.
Reading such servo belt by servo reader, and width is at least the width of the single serve track in this servo belt, and be preferably less than in the situation of accumulation of the width of all servo tracks, servo reader so only servo reader be accurately positioned in one of track in the heart, and cover exclusively thus in the situation of this track, and if its width equals the width of servo track, the readback signal with the single waveform starting from single track can be provided, or in the time that servo reader covers two or more servo tracks at least to a certain extent---this can be the situation in the time that its width equals the width of servo track, and be the situation in the time that its width is greater than the width of servo track---the readback signal that comprises two or more different waveforms that start from two or more tracks is provided.Main waveform (subject waveform) is therefore overlapping in the readback signal of servo reader, and in other words, the readback signal of servo reader can be made up of two or more overlapping different wave of magnetic conversion of the adjacent servo track that is derived from the current scanning of servo reader.In order to allow to determine have which waveform in the readback signal of servo reader, preferably, the waveform of adjacent servo track is orthogonal.This means at least two waveforms in adjacent servo track and therefore servo pattern below in the time being arranged at least at the common signal of one of time domain or spectrum domain or channel, be diacritic, make, by apply suitable analysis in any one of these territories, can be identified in the waveform comprising in readback signal.
If use at least three different waveforms of entirety in servo track, preferably, each waveform is each orthogonal with other waveforms that use.
Preferably, if the product of the waveform in the relevant and adjacent orbit of the frequency spectrum of main waveform or the function of time is zero, meet the orthogonality in multi-channel signal transmission.This means, for being employed all different wave that make preferably to use waveform in different servo tracks, crosscorrelation between any two different waveforms is zero in time domain or in spectrum domain, and therefore preferably orthogonal for limiting their basic magnetic conversion plan of different servo patterns.
In one embodiment, the waveform being represented by (underlying) servo pattern below of different servo tracks is characterized in that the different pseudo noise sequence limiting in main servo track in time domain.Specifically, pseudo noise sequence comprises the sequence of binit, and thus, comprises the bit mode (pattern) of the restriction of the binit of given length.Pseudo noise sequence can be defined as the sequence with the similar frequency spectrum of random series, but by determinacy produce.Pseudo noise sequence can for example utilize maximal-length sequence (MLS) generator to produce.Preferably, periodically repeat to the pseudo noise sequence of servo track distribution, the repetition that makes each servo track comprise distributed pseudo noise sequence along servo track.The pseudo noise sequence of different servo track can be alignd or depart from phase place in phase place, that is, the pseudo noise in a servo track can start in the time different from pseudo noise sequence in another servo track.The make an uproar symbol of pattern of the puppet of different servo track can align or depart from phase place in phase place.The waveform of the different bit modes that use is orthogonal in the time domain that is quantified as suitable waveform.Therefore preferably in time domain, analyze the readback signal of servo reader.
At least three pseudo noise sequences that use preferably is characterized in that good cross-correlation properties.Such sequence in one example can be Gold(gold) sequence.
In an alternate embodiment of the present invention, can from having, the single pseudo noise sequence of good auto-correlation attribute is original draws at least three used different pseudo noise sequences.Such pseudo noise sequence can comprise Barker(Bark) code, complementary series or maximal-length sequence.In this embodiment, write the servo pattern of two adjacent servo tracks by pseudo noise sequence identical but that there is phase deviation and/or opposite polarity.If the pseudo-order of different servo tracks can be distinguished their waveform in readback signal, be still considered to different.The advantage of this scheme is that detecting device can only comprise single sequence correlator.The output signal of this correlator can illustrate according to the peak value pair separating in time of the pseudo noise sequence phase deviation between the adjacent orbit being read by servo reader, and/or have the peak value pair of opposite polarity.Amplitude/the range value of use correlator output peak value can be therefore as described below (peak value to).
The servo pattern below of arranging in different servo tracks can preferably belong to a class servo (EBS) pattern based on energy.If this servo pattern of multiple servo tracks is covered the single servo reader of multiple servo tracks and reads in the time reading, provide the different-energy of the different pseudo noise sequences that exist from the readback signal of servo reader in the readback signal of covering of carrying out different servo track.By estimating and/or evaluate the energy of the different pseudo noise sequences in readback signal, and specifically, by set up ratio between various energy, can determine with respect to band the lateral attitude of servo reader.In the case of the data reader for reading out data and data writing device and main servo reader mechanical couplings for data writing, also effective for data reader and write device by reading any lateral excursion of the main servo reader that servo belt detects.Therefore, comprise that any transverse actuating of taking the lead of main servo reader, data reader and write device can be proofreaied and correct detected skew, and take data reader and write device to lateral attitude that they are expected.
Preferably, retain servo belt for servo pattern, to be intended to obtaining lateral attitude information with granular (granular) fast.Servo pattern preferably has the intrinsic high density of magnetic conversion---Here it is why these servo patterns be here also referred to as high density patterns---so as to enable such as the servo channel parameter of lateral attitude frequently and be limited by the estimating very accurately of granularity of the servo track in servo belt, taking the lead of making thus to improve can be with much wide belt speed scope location, and supports the head of larger bandwidth to activate.
Preferably, the high density servo pattern in multiple servo tracks is the unique servo pattern in servo belt, and specifically, any other servo pattern based on frame not providing in same servo belt.
If with traditional with storage system make comparisons can be with thinner yardstick, determine and take the lead or the lateral attitude of its module and may its inclination with respect to band with higher estimation speed and with lower delay, embodiments of the invention can increase the data-track density to following tape drive imagination.High density servo pattern can allow highly must be enough to ensure that the correct track under very low belt speed even follows the repetition rate that lateral attitude of operation is estimated.In addition, support the actuator that take the lead the future with large bandwidth.Therefore, be used for the new servo format of the current introducing with storage medium taking following as target, application as possible: in the situation of abridged (i.a.), BaFe(barium ferrite) band medium, it has 4 or 8 data bands and has 32 or 64 parallel data channels.Therefore, minimized the skew in position error signal (PES), therefore track density can have the band capacity (data) up to 1000G byte.In addition, can improve by supporting wider velocity range, thering is the data transfer rate of principal computer requirement.And high density patterns also can be for generation of reference cycle signal (pilot signal), for helping the timing Recovery processing of Data Detection of data channel.
The servo pattern of current kind can be written into during band is manufactured, or can be written into the operating period with storage medium in tape drive, that is, enter by automatic servo write.In servo writing during band is manufactured, be preferred for to the write head of writing servo pattern in servo belt, to make it possible to writing different servo patterns to different servo tracks simultaneously,, to the multiple adjacent servo track writing servo pattern of spool, that is, need band only by (pass) write head once, write the servo pattern of expectation.In a preferred embodiment, application writes continuously with to band writing servo pattern.Being also represented as in writing continuously that trailing edge writes, write head writes continuously and does not interrupt, that is, change continuously to the electric current of write head application between positive and negative current value.This has enabled, than using pulse to write fashionable much smaller write-in characteristic, in pulse writes, in write head moving belt, to turn on and off electric current.
In automatic servo write enters, with the side by side writing servo pattern that writes of data-track.In this case, preferably hold as automatic servo write and enter another write device of device and special from servo reader with head module.Note, automatic servo write enters any position that the right layout of device/reader can be in taking the lead, for example, and in center.Also note, in principle, can realize more than one automatic servo write in head module at band and enter that device/it is right to read.Note, can in pseudo noise sequence pattern (LPOS, band (band) ID etc.), embed other information by such as following manner: amplitude, phase place or the polarity of modulation pseudo noise sequence, or between the train of impulses of each pseudo noise sequence, leave short gap, and be coded in the existence in gap or do not exist in or information in the length in gap.Even in the case of such gap, also the servo pattern being associated can be regarded as to (frameless) servo pattern continuously without frame.For example, can be for example by sequence not being restricted to the part that binit is regarded gap as pseudo noise sequence.In another embodiment, can by with the one or more other pseudo noise sequence that the individual pseudo noise sequence of servo track is interweaved, in the one or more middle coding additional information of servo track.
According to another aspect of the present invention, provide a kind of tape drive, it comprises takes the lead, and this is taken the lead to comprise and is allocated at least one the servo reader reading from servo belt.In one embodiment, take the lead only to comprise when be disposed in for reading from servo belt tape drive time with extending longitudinally orthogonal dimension with storage medium single servo reader.In another embodiment, be separated from each other but be positioned to adjacent for two servo readers that read from servo belt, with band extending longitudinally orthogonal.
Preferably, with the width of the extending longitudinally orthogonal servo reader with storage medium in the time being disposed in tape drive, be with extending longitudinally orthogonal servo belt with storage medium in the width of servo track.Also contained the multiple servo readers of application by this definition, multiple servo reader lateral excursions and each have the width less than the width of servo track.
The in the situation that of two servo readers, one of servo reader can read in forward direction of belt travel, and the second servo reader can oppositely read in direction of belt travel.
Fig. 1 and data band and the diagram that the cross section that contributes to the servo belt SB with storage medium TP is provided together with servo belt that may be other.Servo belt SB extends along longitudinal axis x, and longitudinal axis x represents the direction of extending with storage medium TP simultaneously, and is with storage medium TP to move along it at run duration, that is, and and direction of belt travel TMD.Preferably, extending longitudinally along with storage medium TP of servo belt SB, the servo pattern shown in making only represents very little cross section, and in fact, shown servo pattern repeats millions of times along band storage medium TP in each servo belt SB.
In order to be illustrated in the sample servo belt/data band structure on storage medium, with reference to figure 2.In top schematic view at this on the cross section with storage medium TP, there is extending longitudinally in x direction and the horizontal expansion in y direction with TP.The direction of belt travel TMD that is parallel to extending longitudinally in x direction, supposes and is not with inclination.Extending longitudinally along with TP of servo belt SB and data band DB.Each data band DB is disposed between two servo belt SB.Each data band DB comprises the multiple data-tracks that are not shown specifically, wherein preferably, if tape drive take the lead provide multiple and write and/or read element, write and/or these data-tracks of reading out data band DB multiple simultaneously.Each servo belt SB comprises along the servo pattern of the layout extending longitudinally with TP, all as shown in FIG. 1.Specifically, the cross section Z of the servo belt SB going up most can be as shown in fig. 1.
In reading and/or write to band from band, band is longitudinally moving with respect to taking the lead on x.In addition, take the lead preferably can be by suitable actuator on horizontal y, vertically move with direction x.But in, because band, with respect to the lateral excursion of taking the lead, may occur that both is unjustified.For by band again with take the lead to align, the position of taking the lead with respect to band from the Signal estimation obtaining by the servo pattern reading in servo belt.
Return to Fig. 1, in multiple parallel servo track STx, organize servo belt SB.In the present embodiment, 6 adjacent servo track ST1 to ST6 are provided, but, be limited by sensitivity in the lateral attitude perception that will obtain, be limited by the width that servo belt SB is provided and be limited by the width wSR of distributed servo reader, any amount of servo track of >2 can be provided.Suppose that each servo track STx is on transverse dimensions y, there is identical width wST with in extending longitudinally orthogonal dimension with TP.Each servo track STx comprises special servo pattern.Servo pattern in the servo track of servo belt SB can preferably it is characterized in that along servo belt and therefore along the continuous servo pattern extending with storage medium TP, and it is characterized in that without frame servo pattern, making can be using servo reader SR draw lateral attitude information from servo pattern continuously in reading, and needn't just as when operate based on frame servo pattern time etc. the completing of whole servo frame FR to be read.
Preferably, the stored pattern of at least adjacent servo track differs from one another, and makes them orthogonal as mentioned above.
In the embodiment shown in Fig. 1, the servo pattern in each servo track STx can comprise pseudo noise sequence PN_x.In this example, use three different pseudo noise sequence PN_A, PN_B and PN_C, wherein, in servo track ST1, pseudo noise sequence PN_A repeats to form servo pattern, and in servo track ST2, pseudo noise sequence PN_B repeats to form servo pattern, and in servo track ST3, pseudo noise sequence PN_C repeats to form servo pattern.In this example, every two servo patterns that adjacent servo track STx comprises the pseudo noise sequence based on different.And identical servo pattern is applied to each the 3rd servo track, makes servo track ST1 and ST4 comprise identical servo pattern.Servo track ST2 and ST5 and ST3 and ST6 are also respectively so.Therefore, the tlv triple of servo track STx is mutually the same.In a preferred embodiment, preferably, this group servo track is organized as the tlv triple of identical servo track, wherein, in each tlv triple, uses and starts from the waveform of three different pseudo noise sequences.
The servo reader SR distributing to the current servo belt SB with TP reading has at least width wSR of the width of each servo track STx,, wSR>=wST, and in the case of the servo track of different in width, there is the width of the servo track at least with minimum widith.The width wSR of servo reader SR reflect its to horizontal direction, with extending longitudinally orthogonal direction with TP in extension.Preferably, the width wSR of servo reader SR is than large such as the width wST of each the servo track STx shown in the embodiment in figure 1.
By in moving through on direction of belt travel TMD with TP and comprising the taking the lead of servo reader SR, servo reader SR provides sensor signal, it is also represented as readback signal, consider that the width wSR of servo reader SR exceedes the width wST of servo track STx, this readback signal at least comprises the component of two of three pseudo noise sequence PN_A, PN_B, PN_C.Be limited by the lateral attitude of servo reader SR, the energy difference of two or three the pseudo noise sequence components in readback signal.From by existence and energy that readback signal and known PN Serial relation are drawn, can show that servo reader SR is with respect to the lateral attitude value with TP.
In a preferred embodiment, additional information can be encoded in servo track.Such additional information can be for example the lengthwise position of the current scanning of band.Can in the servo pattern of all servo tracks, encode and also be represented as such longitudinal position information of LPOS in one embodiment.Therefore, can the LPOS information based on being read by servo reader identify the lengthwise position of band.LPOS information can be for being wound into given lengthwise position with medium, and for example, start to read and/or write in the lengthwise position of specifying like this.Other information such as manufacturing information also can preferably be added to each servo track, and it for example can indicate the information etc. of the manufacturer of tape drum, the date of manufacturing tape drum, the standard that meets about current box.Other additional informations can be servo belt identifier or servo track subset identifier, for example current for example, from which servo track subset-tlv triple-read for identifying servo reader.This information may be due to its characteristic difference in each servo belt or each servo track subset.
Conventionally, new servo format current introduction, that have one group of servo track adjacent one another are can be stated the width wSB of the identical band having with the servo format previously using, with reference to figure 1.In other embodiments, new servo format current introduction, that have one group of servo track adjacent one another are can be stated the width wSB of the band less than the servo format of previous use.
Fig. 3 illustrates the cross section of servo belt SB according to an embodiment of the invention in scheming a), and this servo belt SB is included in multiple high density servo patterns of arranging in several servo track ST1 to ST4 parallel to each other.Four servo track ST1 to ST4 are only exemplary for illustrative object.In this embodiment, by representing high density patterns for the bit mode that represents pseudo noise sequence.Specifically, the circulation pseudo noise sequence with the magnetic conversion of good cross-correlation properties is not only used in adjacent servo track ST1 to ST4, and is used in all servo track ST1 to ST4.Fig. 3 b is the first servo track ST1 of servo belt SB of Fig. 3 a and the cross section of ST2: there is 76 microns of length and comprise 31 symbols-its cause 2.45 microns symbol lengths-servo track ST1 in use the first pseudo noise sequence PN_A.For example, suppose the belt speed of 5.1m/s, pseudo noise sequence recurrence interval equals 14.9 microseconds.Symbol refers to the length of a bit in waveform.In servo track ST2, use the second pseudo noise sequence PN_B, it also has the length of 76 microns and comprises 31 symbols.Other servo tracks ST3 and ST4 can comprise other different pseudo noise sequence PN_C and the PN_D with equal length.Arrow at Fig. 3 in b) only usually reflects different pseudo noise sequence.Fig. 3 b) shown in servo reader SR, it has the width corresponding with the width of servo track STx.
Fig. 3 c) in, in the readback signal for servo reader SR shown in time domain, this servo reader SR b) is positioned according to Fig. 3, and in identical degree, covers the first and second servo track ST1 and ST2.In this example, can preferably provide readback signal to four correlators, at these four correlator places, readback signal and four pseudo noise sequence PN_A, PN_B, PN_C, PN_D are relevant.In the output of correlator shown in Fig. 3 d, wherein, positive peak is derived from the relevant of readback signal and the first pseudo noise sequence PN_A, and negative peak is derived from the relevant of readback signal and the second pseudo noise sequence PN_B, the existence that makes clearly to draw from readback signal these two pseudo noise sequences.And, in the time checking the amplitude/amplitude of the peak value in the accumulation of correlator is exported, can draw if servo reader SR covers two servo track ST1 and ST2 in same degree, two pseudo noise sequences occur with identical energy.In either case, select adjacent servo pattern, make them show very low cross correlation score, and therefore can distinguish with insignificant interference.In this example, suppose that band moves with the speed of 5.1m/s.
The result that good alignment between the phase place of pseudo noise sequence provides above obtaining by supposition.This means at the correlation peak of the output of the correlator of detecting device and occur in the identical moment.If removed the hypothesis of good phases alignment, between pseudo noise sequence, there is limited phase shift range, within the scope of this, the calculating of estimating for PES, the cross correlation score between pseudo noise sequence can be considered to ignore.In a preferred embodiment, the phase shift between the pseudo noise sequence of adjacent servo track symbol lengths ± 12.5% in, to suppose that the crosscorrelation between two pseudo noise sequence is insignificant.If can not be controlled at the phase shift between the pseudo noise sequence of adjacent servo track in writing pseudo noise sequence, preferably, estimate phase shift and application technology for eliminating, deduct crosscorrelation item with the correlation peak of the output from each correlator.
Therefore, conventionally, servo reader provide can by with the readback signal of the correlator filtering of mating for the pseudo noise sequence of determining lateral attitude value.Servo pattern in servo belt also can be for generation of the pilot signal of the timing Recovery processing of the data in supported data track.Can draw the servo reader position with respect to the edge between the adjacent servo pattern of the adjacent servo track servo belt from the readback signal of servo reader, this readback signal is provided to detecting device, and this detecting device detects and distinguish the energy comprising in the different servo pattern by this servo reader sensing.Can be by servo track subset information be encoded to the ambiguity between the servo pattern repeating x the different servo pattern of avoiding for example using in servo track in multiple servo tracks of >x.
In Fig. 4, an embodiment of the servo belt SB that comprises three servo track ST1 to ST3 is shown, the servo pattern that each of servo belt ST1 to ST3 comprises the magnetic conversion for representing different pseudo noise sequence PN_A, PN_B and PN_C.In current example, the first servo track ST1 comprises the servo pattern with the first pseudo noise sequence PN_A, the second servo track ST2 comprises second servo pattern with the second pseudo noise sequence PN_B, and the 3rd servo track ST3 comprises the servo pattern with the 3rd pseudo noise sequence PN_C.Again, the width of servo reader SR is corresponding to the width of each servo track STx.Therefore, by being identified in each pseudo noise sequence in readback signal and their energy of assessment, can be distinguished with the second servo track ST2 by representing as the lateral attitude of the servo reader SR of Fig. 4 as shown in b) and the edge of the 3rd servo track ST3 by the edge between the second servo track ST2 and the first servo track ST1 that represent as the lateral attitude of the servo reader SR of Fig. 4 as shown in a)., except the second pseudo noise sequence PN_B, in the readback signal of servo reader SR, there is the first pseudo noise sequence PN_A, and can detect the first pseudo noise sequence PN_A by correlation analysis a) in the situation that at Fig. 4.Pseudo noise sequence PN_A in readback signal and the energy of PN_B represent the relation that servo reader SR and the first and second servo track ST1 and ST2 are overlapping.If the energy of the first pseudo noise sequence PN_A is less than the energy of the second pseudo noise sequence PN_B, inference thus, servo reader SR covers the second servo track ST2 more than the first servo track ST1.From the ratio of corresponding energy, can draw the fine location of servo reader SR with respect to band., except the second pseudo noise sequence PN_B, in the readback signal of servo reader SR, there is the 3rd pseudo noise sequence PN_C, and can detect this pseudo noise sequence PN_C by spectrum analysis b) in the situation that at Fig. 4.The energy of pseudo noise sequence PN_B and PN_C also represents servo reader SR and second and the 3rd servo track ST2 and the overlapping relation of ST3.If the energy of the 3rd pseudo noise sequence PN_C is less than the energy of the second pseudo noise sequence PN_B, inference thus, servo reader SR covers the second servo track ST2 more than the 3rd servo track ST3.From the ratio of corresponding energy, can draw the fine location of servo reader SR with respect to band.
Fig. 5 illustrates the cross section with storage medium according to another embodiment of the invention.Between servo belt SB, clip data band DB.Servo belt SB comprises the high density servo pattern only schematically being represented by vertical bar (stripe).This high density servo pattern in the distance instruction servo belt SB of the variation between vertical bar also can comprise the additional information of embedding, such as LPOS information, servo belt id information, manufacturing information etc.
Fig. 6 shows process flow diagram according to an embodiment of the invention.In step S1, for example, start the method by following manner: activating belt driver reads and/or data writing with the band storage medium in the tape drum inserting in tape drive.Suppose that band has been positioned in the lengthwise position place of expectation.Then,, although band moves with the belt speed of expecting in step S1, in step S2, read the servo-information from servo belt.
In step S3, analyze the servo-information being read by the servo reader of distributing to servo belt, and determine lateral attitude value from the readback signal of servo reader.Preferably, carry out correlation analysis for readback signal, and bit mode based on identifying is estimated lateral attitude value in readback signal.Therefore, in step S4, be worth control signal for controlling the actuator of taking the lead from lateral attitude, this actuator is for laterally reorientating and take the lead.This processing is continuous by reading the reason of servo-information-herein yes by servo reader in step S2-continues.Provide in without frame servo pattern the speed of lateral attitude value to be not limited to before obtaining about the information of lateral attitude the servo pattern section of scanning first completely at this.On the contrary, the speed of the second lateral attitude value can resemble the length of symbol fast, and certainly, it further depends on belt speed.
Fig. 7 illustrates the block diagram of tape drive according to an embodiment of the invention.Servo reader SR provides its readback signal to control module CU.Receive this readback signal of servo reader SR by related entities CE, and definite lateral attitude value.Then this lateral attitude value is converted to position error signal by determining unit PES.With head actuator controller AC unit, position error signal PES is converted to for the control signal with head actuator THA, then this adjust with head actuator THA the lateral attitude of taking the lead that servo reader SR is attached to.
Note, in the embodiment of all considerations, can be by high density patterns as reference signal, to help the timing Recovery processing for the Data Detection of data channel.
Those skilled in the art can understand, in the situation that not departing from scope of the present invention, can carry out many amendments and displacement.
Person of ordinary skill in the field knows, various aspects of the present invention can be implemented as with storage medium, from and/or to reading with storage medium and/or method or the computer program of data writing.Therefore, various aspects of the present invention, especially controller or control module can specific implementation be following form, that is: hardware implementation mode, implement software mode (comprising firmware, resident software, microcode etc.) completely completely, or the embodiment of hardware and software aspect combination, can be referred to as " circuit ", " module " or " system " here.In addition, in certain embodiments, various aspects of the present invention, for example wiring method, can also be embodied as the form of the computer program in one or more computer-readable mediums, comprises computer-readable program code in this computer-readable medium.
Can adopt the combination in any of one or more computer-readable mediums.Computer-readable medium can be computer-readable signal media or computer-readable recording medium.Computer-readable recording medium can be for example-but be not limited to-electricity, magnetic, optical, electrical magnetic, infrared ray or semi-conductive system, device or device, or above combination arbitrarily.The example more specifically (non exhaustive list) of computer-readable recording medium comprises: have the electrical connection, portable computer diskette, hard disk, random-access memory (ram), ROM (read-only memory) (ROM), erasable type programmable read only memory (EPROM or flash memory), optical fiber, Portable, compact dish ROM (read-only memory) (CD-ROM), light storage device, magnetic memory device of one or more wires or the combination of above-mentioned any appropriate.In presents, computer-readable recording medium can be any comprising or stored program tangible medium, and this program can be used or be combined with it by instruction execution system, device or device.
Computer-readable signal media can be included in the data-signal of propagating in base band or as a carrier wave part, has wherein carried computer-readable program code.The data-signal of this propagation can adopt various ways, comprise-but the combination of be not limited to-electromagnetic signal, light signal or above-mentioned any appropriate.Computer-readable signal media can also be any computer-readable medium beyond computer-readable recording medium, and this computer-readable medium can send, propagates or transmit the program for being used or be combined with it by instruction execution system, device or device.
The program code comprising on computer-readable medium can be with any suitable medium transmission, and comprise-but be not limited to-be wireless, wired, optical cable, RF etc., or the combination of above-mentioned any appropriate.
Can write the computer program code for carrying out the present invention's operation with the combination in any of one or more programming languages, this programming language comprises object-oriented programming language-such as Java, Smalltalk, C++ etc., also comprises conventional process type programming language-such as " C " language or similar programming language.Program code can fully be carried out, partly on subscriber computer, carries out, carry out or on remote computer or server, carry out completely as an independently software package execution, part part on subscriber computer on remote computer on subscriber computer.In the situation that relates to remote computer, remote computer can be by the network of any kind---comprise LAN (Local Area Network) (LAN) or wide area network (WAN)-be connected to subscriber computer, or, can be connected to outer computer (for example utilizing ISP to pass through Internet connection).
Below with reference to describing the present invention according to process flow diagram and/or the block diagram of the method for the embodiment of the present invention, device (system) and computer program.Should be appreciated that the combination of each square frame in each square frame of process flow diagram and/or block diagram and process flow diagram and/or block diagram, can be realized by computer program instructions.These computer program instructions can offer the processor of multi-purpose computer, special purpose computer or other programmable data treating apparatus, thereby produce a kind of machine, make these computer program instructions in the time that the processor by computing machine or other programmable data treating apparatus is carried out, produced the device of the function/action specifying in the one or more square frames in realization flow figure and/or block diagram.
Also these computer program instructions can be stored in computer-readable medium, these instructions make computing machine, other programmable data treating apparatus or other equipment with ad hoc fashion work, thereby the instruction being stored in computer-readable medium just produces the manufacture (article of manufacture) of the instruction of the function/action specifying in the one or more square frames that comprise in realization flow figure and/or block diagram.
Also computer program instructions can be installed to computing machine for making to carry out on computers sequence of operations step, other programmable data processing device or other devices, other programmable devices or other devices for generation of computer implemented processing, the instruction that makes to carry out on computing machine or other programmable devices is provided for the processing of function/behavior that realization specifies in one or more square frames of process flow diagram and/or block diagram.
Claims (15)
1. a band storage medium,
Comprise at least one servo belt (SB) (x) extending longitudinally along this band storage medium (TP), for supporting to determine positional information, this servo belt (SB) comprises along this band storage medium (TP) extending longitudinally and (x) extends and be positioned to the one group of servo track (STx) being closely adjacent to each other
Wherein, the servo pattern that each servo track (STx) of this group comprises the pseudo noise sequence (PN_x) with symbol,
Wherein, the pseudo noise sequence (PN_x) of the servo pattern of adjacent servo track (STx) differs from one another, and
Wherein, the servo track of this group (STx) comprises at least three servo tracks (STx) with different pseudo noise sequence (PN_x).
2. band storage medium according to claim 1,
Wherein, for each servo track (STx) of this group, the indication cycle's property waveform in the time being read of the magnetic transition in such servo track (STx); And
Wherein, this periodic waveform of adjacent servo track (STx) is orthogonal in time domain.
3. band storage medium according to claim 2,
Wherein, the maximum length of the pseudo noise sequence (PN_x) in any one of this servo track (STx) is less than 100 microns, and is preferably less than 20 microns, and is preferably less than 10 microns, and is preferably less than 2 microns.
4. according to the band storage medium described in any one of aforementioned claim,
Wherein, the additional information of encoding in the servo pattern of one or more servo tracks (STx), this additional information is following one or more:
■ longitudinal position information,
■ manufacturing information,
■ servo belt identifier,
■ servo track subset identifier.
5. band storage medium according to claim 4,
Wherein, the additional information of encoding in the servo pattern of each servo track (STx) of this group, and
Preferably, wherein, all additional informations of listing in claim 4 are encoded as the servo pattern of each servo track (STx) of this group.
6. according to the band storage medium described in claim 4 or 5,
Wherein, by following one or more, in these one or more these additional informations of middle coding of this servo track (STx)
■ amplitude modulation,
■ polar modulation,
■ phase-modulation,
■ on-off keying.
7. according to the band storage medium described in any one of aforementioned claim,
Wherein, each pseudo noise sequence (PN_x) comprises the sequence of binit, and
Wherein, the periodicity that each servo track (STx) comprises distributed pseudo noise sequence (PN_x) repeats.
8. tape drive, for from according to the band storage medium reading out data described in any one of aforementioned claim and/or to this band storage medium data writing, this tape drive comprises takes the lead (TH), this is taken the lead to comprise and is allocated at least one the servo reader (SR) reading from servo belt (SB)
Wherein, when be disposed in this tape drive with the width (wSR) of the extending longitudinally (x) orthogonal servo reader (SR) of this band storage medium (TP) be at least with this extending longitudinally (x) orthogonal servo belt (SB) of this band storage medium (TP) in the width of servo track (ST).
9. tape drive according to claim 8,
Wherein, the width of this servo reader (SR) is greater than the width (wSTx) of the servo track (ST) in this servo belt (SB), and is not more than the twice of the width (wSTx) of the servo track (ST) in this servo belt (SB).
For operate tape drive with from according to described in any one of aforementioned claim 1 to 7 with storage medium reading out data and/or to this method with storage medium data writing, comprising:
Read this servo belt (SB) by servo reader (SR),
Determine and comprise the lateral attitude value of the taking the lead of this servo reader (SR) (TH) with respect to this band storage medium (TP) from the readback signal of this servo reader (SR), and be worth to adjust this according to this lateral attitude and take the lead the lateral attitude of (TH).
11. methods according to claim 10,
Wherein, determining that this lateral attitude value is included in this readback signal of this servo reader (SR) identifies one or more pseudo noise sequence (PN_x).
12. according to the method described in claim 10 or 11,
Wherein, the associative operation that is used for determining this lateral attitude value by application is by this readback signal filtering of this servo reader (SR).
13. according to the method described in claim 11 or 12,
Wherein, set up one or more ratios from the energy of different pseudo noise sequences (PN_x) of identification, and,
Wherein, draw this lateral attitude value from these one or more ratios.
14. according to the method described in any one of aforementioned claim 10 to 13,
Wherein, by each while determining new lateral attitude value the control signal of renewal adjust this and take the lead this lateral attitude of (TH).
15. computer programs, this computer program comprises computer-readable medium, this computer-readable medium comprises computer readable program code, this computer readable program code comprise be configured to carry out according to aforementioned according to claim 10 to 14 any one described in the computer readable program code of method.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1221557.0 | 2012-11-30 | ||
| GB1221557.0A GB2508389A (en) | 2012-11-30 | 2012-11-30 | Tape servo band with three different pseudo noise sequences |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103854675A true CN103854675A (en) | 2014-06-11 |
| CN103854675B CN103854675B (en) | 2017-06-06 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310617046.3A Expired - Fee Related CN103854675B (en) | 2012-11-30 | 2013-11-28 | Servo pattern with storage medium |
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| Country | Link |
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| CN (1) | CN103854675B (en) |
| GB (1) | GB2508389A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9047899B1 (en) | 2014-05-15 | 2015-06-02 | International Business Machines Corporation | Servo pattern of a tape storage medium |
| US9058828B1 (en) | 2014-05-15 | 2015-06-16 | International Business Machines Corporation | Servo pattern of a tape storage medium |
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|---|---|---|---|---|
| US6462904B1 (en) * | 1994-06-30 | 2002-10-08 | International Business Machines Corporation | Timing based servo system for magnetic tape systems |
| CN101122888A (en) * | 2006-08-09 | 2008-02-13 | 国际商业机器公司 | Method and system for writing and reading application data |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5253131A (en) * | 1990-03-06 | 1993-10-12 | Maxtor Corporation | Servo pattern for location and positioning of information on a disk drive |
| US7193800B2 (en) * | 2004-05-06 | 2007-03-20 | Hitachi Global Storage Technologies Netherlands B.V. | Data recording medium with servo pattern having pseudo-noise sequences |
| US6975471B2 (en) * | 2004-05-13 | 2005-12-13 | Hitachi Global Storage Technologies Netherlands B.V. | Data recording medium with servo pattern having pseudo-random binary sequences |
| US7342734B1 (en) * | 2004-09-02 | 2008-03-11 | Maxtor Corporation | Disk drives with radially aligned servo burst patterns that generate orthogonal contributions to a read signal and related demodulators and methods |
| US7253986B2 (en) * | 2005-08-30 | 2007-08-07 | International Business Machines Corporation | System and method for deconvolution of multiple data tracks |
| US9311942B2 (en) * | 2009-12-18 | 2016-04-12 | HGST Netherlands B.V. | Information storage device with multiple-use fields in servo pattern |
-
2012
- 2012-11-30 GB GB1221557.0A patent/GB2508389A/en not_active Withdrawn
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2013
- 2013-11-28 CN CN201310617046.3A patent/CN103854675B/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6462904B1 (en) * | 1994-06-30 | 2002-10-08 | International Business Machines Corporation | Timing based servo system for magnetic tape systems |
| CN101122888A (en) * | 2006-08-09 | 2008-02-13 | 国际商业机器公司 | Method and system for writing and reading application data |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9047899B1 (en) | 2014-05-15 | 2015-06-02 | International Business Machines Corporation | Servo pattern of a tape storage medium |
| US9058828B1 (en) | 2014-05-15 | 2015-06-16 | International Business Machines Corporation | Servo pattern of a tape storage medium |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2508389A (en) | 2014-06-04 |
| CN103854675B (en) | 2017-06-06 |
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