JPH0352155B2 - - Google Patents
Info
- Publication number
- JPH0352155B2 JPH0352155B2 JP58075371A JP7537183A JPH0352155B2 JP H0352155 B2 JPH0352155 B2 JP H0352155B2 JP 58075371 A JP58075371 A JP 58075371A JP 7537183 A JP7537183 A JP 7537183A JP H0352155 B2 JPH0352155 B2 JP H0352155B2
- Authority
- JP
- Japan
- Prior art keywords
- servo
- magnetization reversal
- tracks
- head
- track
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 230000005415 magnetization Effects 0.000 claims description 36
- 238000010586 diagram Methods 0.000 description 6
- 238000001514 detection method Methods 0.000 description 4
- 238000006073 displacement reaction Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 101000860173 Myxococcus xanthus C-factor Proteins 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
Classifications
-
- 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
- G11B5/596—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 disks
Landscapes
- Adjustment Of The Magnetic Head Position Track Following On Tapes (AREA)
- Moving Of The Head To Find And Align With The Track (AREA)
Description
【発明の詳細な説明】
この発明は、磁気デイスク装置において、ヘツ
ド位置決めのための基準信号を作成するために使
用されるサーボデイスクに関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a servo disk used for creating a reference signal for head positioning in a magnetic disk device.
一般に磁気デイスク装置では、情報記録面上に
多数のデータトラツクを形成しており、情報の書
込み、読出しの際には所定のデータトラツク上に
磁気ヘツドを高速でかつ正確に位置決めする必要
がある。そのための磁気ヘツド駆動方式として複
数の情報記録面のうちの一面をサーボ面として利
用するいわゆるトラツク・サーボ・システム
（track servo system）がある。 Generally, in a magnetic disk device, a large number of data tracks are formed on the information recording surface, and when writing or reading information, it is necessary to position the magnetic head quickly and accurately on a predetermined data track. As a magnetic head drive method for this purpose, there is a so-called track servo system, which uses one of a plurality of information recording surfaces as a servo surface.
第１図はトラツク・サーボ・システムの構成を
示すブロツク図であつて、１は磁気円板でその両
面に記録媒体としての磁性膜を備えている。第１
図に示す例では磁気円板１を２個備えしたがつて
４記録面を有しているが、そのうち下側磁気円板
の下面がサーボ面として利用される。このサーボ
面以外の記録面はデータ面である。２と３は磁気
ヘツドで２をサーボヘツド、３をデータヘツドと
いう。４はヘツドホルダ、５はヘツド保持機構、
６はモータ、７は位置検出器、８は速度検出器、
９は駆動器、１０は速度指示器であり、２０は総
合的に磁気デイスク・ヘツドアセンブリを示す。
モータ６はヘツド保持機構５を磁気円板１の半径
方向に駆動するが、各ヘツドホルダ４はヘツド保
持機構５に固定されており、サーボヘツド２もデ
ータヘツド３もそれぞれヘツドホルダ４に固定さ
れているので、サーボヘツド２と各データヘツド
３とは連動して移動し、したがつてサーボヘツド
２を正しく位置決めすればデータヘツド３も同じ
正しさで位置決めができる。 FIG. 1 is a block diagram showing the structure of a track servo system, in which numeral 1 denotes a magnetic disk, both sides of which are provided with magnetic films as recording media. 1st
In the example shown in the figure, two magnetic discs 1 are provided, so there are four recording surfaces, of which the lower surface of the lower magnetic disc is used as a servo surface. The recording surface other than this servo surface is a data surface. 2 and 3 are magnetic heads, 2 is called a servo head, and 3 is called a data head. 4 is a head holder, 5 is a head holding mechanism,
6 is a motor, 7 is a position detector, 8 is a speed detector,
9 is a driver, 10 is a speed indicator, and 20 generally indicates a magnetic disk head assembly.
The motor 6 drives the head holding mechanism 5 in the radial direction of the magnetic disk 1, but each head holder 4 is fixed to the head holding mechanism 5, and the servo head 2 and data head 3 are each fixed to the head holder 4. , the servo head 2 and each data head 3 move in conjunction with each other. Therefore, if the servo head 2 is positioned correctly, the data head 3 can also be positioned with the same accuracy.
サーボヘツド２により読出された信号は、位置
検出器７によりサーボヘツド２の存在する場所を
あらわす位置信号に変換される。この位置信号
は、駆動器９より得られる電流信号とともに速度
検出器８へ送られ、速度検出器８では両者の信号
を変換合成して速度信号を得る。上述の位置信号
および速度信号はともに駆動器９へ入力され、モ
ータ６を駆動するための制御信号として用いられ
る。駆動器９へは速度指示器１０から目標信号が
入力される。この目標信号は、磁気ヘツドが移動
する際の速度の目標値を指示する。 The signal read out by the servo head 2 is converted by the position detector 7 into a position signal representing the location where the servo head 2 is present. This position signal is sent to the speed detector 8 together with the current signal obtained from the driver 9, and the speed detector 8 converts and combines both signals to obtain a speed signal. Both the position signal and speed signal described above are input to the driver 9 and used as control signals for driving the motor 6. A target signal is input to the driver 9 from a speed indicator 10 . This target signal indicates the target value of the speed at which the magnetic head moves.
従来用いられているサーボデイスクについて、
第２図を参照して説明する。サーボ面にはあらか
じめ位置決めに必要な情報がサーボ情報として書
込まれている。これは第１サーボトラツク１１、
第２サーボトラツク１２、第３サーボトラツク１
３および第４サーボトラツク１４のそれぞれを順
次隣接させて書込むもので、この結果サーボ面に
は多数のサーボトラツクが同心円状に形成され
る。なお、第２図では便宜上サーボトラツクを直
線で表示してある。サーボヘツド２のコア幅は、
上記サーボトラツク幅の概ね２倍程度である。そ
れぞれのサーボトラツクには第１サーボトラツク
１１と第２サーボトラツクとまたがる磁化反転
Ａ、第３サーボトラツクと第４サーボトラツクに
またがる磁化反転Ｂ、第４サーボトラツクと第１
サーボトラツクにまたがる磁化反転Ｃ、第２サー
ボトラツクと第３サーボトラツクにまたがる磁化
反転Ｄおよび全トラツクにわたる磁化反転Ｔが形
成されている。磁化反転Ａ，Ｂ，Ｃ，Ｄはヘツド
のトラツク幅方向位置を知るための情報であり、
磁化反転Ｔはトラツク長さ方向位置を知るための
情報である。第４サーボトラツクと第１サーボト
ラツクの境界点にヘツド位置原点をとり、トラツ
ク幅方向のヘツドの位置変位をｘで表わす。ｘの
変化に対する読出し信号の変動は、磁化反転Ａか
らの成分がEa、磁化反転Ｂからの成分がEb、磁
化反転Ｃからの成分がEc、磁化反転Ｄからの成
分がEdのようになる。なおここでは読出しの最
大レベルを１として表示してある。これより、Ａ
信号とＢ信号の差（Ea−Eb）を取り位置信号
Ey、Ｃ信号とＤ信号の差（Ec−Ed）を取り位置
信号Ezとする。サーボトラツク幅をｗとすると、
上記位置信号Eyはｘが±ｗ、±３、…、±mw（ｍ
は奇数）のときに正又は負のピークとなり、ｘが
０、±2w、…、±nw（ｎは偶数）のときにゼロと
なる。また、位置信号Ezはｘが０、±2w、…、±
nw（ｎは偶数）のときにピークとなり、ｘが±
ｗ、±3w、…、±mw（ｍは奇数）のときにゼロと
なる。したがつて、上記位置信号Ey又はEzがゼ
ロとなるように駆動器を制御すれば、サーボヘツ
ドは各サーボトラツクの境界点で静止し、これに
対応してデータトラツク（図示せず）が定まる。
以上の説明にて明らかなように、ヘツドのトラツ
ク幅方向変位は、４つの磁化反転Ａ，Ｂ，Ｃ，Ｄ
より読み出される信号から得ている。したがつ
て、近年の高速かつ高密度なヘツド位置決めを実
現するためには、サーボトラツク１回転内に含ま
れる磁化反転の数ができるだけ多いことが望まし
く、またそれぞれの磁化反転より読み出される信
号波形には歪のない高品質なものが要求される。 Regarding conventionally used servo disks,
This will be explained with reference to FIG. Information necessary for positioning is written in advance on the servo surface as servo information. This is the first servo track 11,
Second servo track 12, third servo track 1
The third and fourth servo tracks 14 are sequentially written adjacent to each other, and as a result, a large number of servo tracks are formed concentrically on the servo surface. In FIG. 2, the servo tracks are shown as straight lines for convenience. The core width of servo head 2 is
It is approximately twice the width of the servo track mentioned above. Each servo track has a magnetization reversal A spanning the first servo track 11 and the second servo track, a magnetization reversal B spanning the third servo track and the fourth servo track, and a magnetization reversal B spanning the fourth servo track and the first servo track.
A magnetization reversal C spanning the servo tracks, a magnetization reversal D spanning the second and third servo tracks, and a magnetization reversal T spanning all the tracks are formed. Magnetization reversals A, B, C, and D are information for knowing the position of the head in the track width direction.
The magnetization reversal T is information for knowing the position in the track length direction. The head position origin is set at the boundary point between the fourth servo track and the first servo track, and the positional displacement of the head in the track width direction is expressed by x. The fluctuation of the read signal with respect to the change in x is such that the component from magnetization reversal A is Ea, the component from magnetization reversal B is Eb, the component from magnetization reversal C is Ec, and the component from magnetization reversal D is Ed. Note that the maximum reading level is shown here as 1. From now on, A
Take the difference between the signal and B signal (Ea-Eb) and get the position signal
The difference (Ec - Ed) between Ey, C signal and D signal is taken as the position signal Ez. If the servo track width is w, then
The above position signal Ey has x ±w, ±3, ..., ±mw (m
is an odd number), it becomes a positive or negative peak, and becomes zero when x is 0, ±2w, ..., ±nw (n is an even number). Also, the position signal Ez is x is 0, ±2w, ..., ±
The peak occurs when nw (n is an even number), and x is ±
It becomes zero when w, ±3w, ..., ±mw (m is an odd number). Therefore, if the driver is controlled so that the position signal Ey or Ez becomes zero, the servo head will come to rest at the boundary point of each servo track, and a data track (not shown) will be determined accordingly.
As is clear from the above explanation, the displacement of the head in the track width direction is determined by the four magnetization reversals A, B, C, and D.
It is obtained from the signal read out from the Therefore, in order to realize high-speed and high-density head positioning in recent years, it is desirable that the number of magnetization reversals included in one rotation of the servo track be as large as possible, and the signal waveform read from each magnetization reversal should be requires high quality without distortion.
この発明は上記の要求を満たすべくなされたも
ので、高品質のヘツド位置信号を得ることができ
るサーボデイスクを提供するものである。 The present invention has been made to meet the above requirements and provides a servo disk from which high quality head position signals can be obtained.
第３図はこの発明の実施例を示す図である。本
発明においては４種のサーボトラツクを用いた位
置決めを行う点では従来例と同様であるが、この
サーボトラツク上に配置する磁化反転の配置方法
が異なつている。この実施例では、サーボ面のう
ちの１カ所に時間検出用のタイミングセルＴを設
定する。さらに、このタイミングセルＴを起点と
して全周にわたりサーボセルＹとサーボセルＺを
交互に配置する。サーボセルＹには、第１サーボ
トラツク１１と第２サーボトラツク１２にまたが
る磁化反転Ａおよび第３サーボトラツク１３と第
４サーボトラツク１４にまたがる磁化反転対Ｂを
含んでいる。サーボセルＺには第４サーボトラツ
ク１４と第１サーボトラツク１１にまたがる磁化
反転対Ｃおよび第２サーボトラツク１２と第３サ
ーボトラツク１３にまたがる磁化反転対Ｄを含ん
でいる。ここに示したそれぞれの磁化反転対は、
個々の磁化反転より読み出される信号波形が互い
に干渉し合う程度に近接させて配置してあり、そ
の間隔は、記憶すべきデータビツト長の１〜２倍
程度である。高精度ヘツド位置決めのためには、
磁化反転対の間隔が大なることは位置決め性能の
阻害要因となるため、サーボトラツク内にはでき
るだけ多くの磁化反転対を形成することが望まれ
る。第３図に示した実施例はこの要求を満たすも
のであり、１回転中のうち、１カ所のタイミング
セルＴを除いてはすべての位置検出用の情報であ
るサーボセルＹおよびサーボセルＺで構成されて
いる。 FIG. 3 is a diagram showing an embodiment of the present invention. The present invention is similar to the conventional example in that positioning is performed using four types of servo tracks, but the method of arranging magnetization reversals on these servo tracks is different. In this embodiment, a timing cell T for time detection is set at one location on the servo surface. Furthermore, servo cells Y and servo cells Z are alternately arranged over the entire circumference with this timing cell T as a starting point. The servo cell Y includes a magnetization reversal pair A spanning the first servo track 11 and the second servo track 12 and a magnetization reversal pair B spanning the third servo track 13 and the fourth servo track 14. The servo cell Z includes a magnetization reversal pair C spanning the fourth servo track 14 and the first servo track 11, and a magnetization reversal pair D spanning the second servo track 12 and the third servo track 13. Each magnetization reversal pair shown here is
The signal waveforms read out from the individual magnetization reversals are arranged close enough to interfere with each other, and the spacing between them is about 1 to 2 times the data bit length to be stored. For high precision head positioning,
Since a large interval between magnetization reversal pairs impedes positioning performance, it is desirable to form as many magnetization reversal pairs as possible in the servo track. The embodiment shown in FIG. 3 satisfies this requirement, and is composed of servo cells Y and Z, which are all position detection information during one rotation, except for one timing cell T. ing.
第４図はこの発明の他の実施例を示す図であ
る。磁気デイスク装置はその種類も用途も実に広
範囲にわたつており、それに応じて装置に要求さ
れる各種性能の重要度も異なる。第４図に示した
例は、サーボトラツク円周方向の位置検出に重き
を置いた装置におけるサーボデイスクを示してい
る。タイミングセルＴは２個の連続した磁化反転
対で構成されており、トラツク円周方向に等間隔
で設置する。タイミングセルＴの間にはサーボセ
ルＹとサーボセルＺを交互に配置する。位置信号
品質を確保するため、上記タイミングセル間のサ
ーボセルＹおよびサーボセルＺはいずれも２個以
上を配置する。 FIG. 4 is a diagram showing another embodiment of the present invention. Magnetic disk devices have a wide range of types and uses, and the importance of various performances required of the device varies accordingly. The example shown in FIG. 4 shows a servo disk in a device that emphasizes position detection in the circumferential direction of the servo track. The timing cells T are composed of two consecutive magnetization reversal pairs, and are arranged at equal intervals in the circumferential direction of the track. Between timing cells T, servo cells Y and servo cells Z are arranged alternately. In order to ensure position signal quality, two or more servo cells Y and Z are arranged between the timing cells.
なお、上記実施例では位置検出用情報を、互に
干渉を及ぼす程度に近接させた正負１組の磁化反
転対で構成した例につき説明したが、従来例のよ
うに単一の磁化反転を用いた場合においても同様
の効果が得られる。 In the above embodiment, the position detection information is composed of a pair of positive and negative magnetization reversals that are close enough to each other to cause interference, but it is also possible to use a single magnetization reversal as in the conventional example. Similar effects can be obtained even when
以上説明したように、この発明のサーボデイス
クでは位置情報検出用のサーボセルの組を、連続
するタイミングセル間に２組以上配置したため位
置信号品等を上げることができ、磁気ヘツドの高
速、高精度の位置決めが可能となる。 As explained above, in the servo disk of the present invention, two or more sets of servo cells for detecting position information are arranged between consecutive timing cells, so position signal products, etc. can be improved, and the magnetic head can be operated at high speed and with high precision. positioning becomes possible.
第１図はトラツク・サーボ・システムの一例を
示すブロツク図、第２図は従来のサーボデイスク
におけるサーボトラツクの説明図、第３図はこの
発明の一実施例を示す説明図、第４図はこの発明
の他の実施例を示す説明図である。
図において１は磁気円板、２はサーボヘツド、
１１，１２，１３，１４はそれぞれ第１、第２、
第３、第４のサーボトラツク、Ｙは第１のサーボ
セル、Ｚは第２のサーボセルである。なお図中同
一符号は同一または相当部分を示す。
FIG. 1 is a block diagram showing an example of a track servo system, FIG. 2 is an explanatory diagram of a servo track in a conventional servo disk, FIG. 3 is an explanatory diagram showing an embodiment of the present invention, and FIG. It is an explanatory view showing other examples of this invention. In the figure, 1 is a magnetic disk, 2 is a servo head,
11, 12, 13, 14 are the first, second, and
In the third and fourth servo tracks, Y is the first servo cell and Z is the second servo cell. Note that the same reference numerals in the figures indicate the same or corresponding parts.
Claims (1)
サーボデイスクであつて、このデイスクの一面
に、異なる４種類のサーボトラツクを順次隣接さ
せて書込み、上記４種類のサーボトラツクに対し
て、第１、第２サーボトラツクにまたがる第１の
磁化反転と、第３、第４サーボトラツクにまたが
る第２の磁化反転と、第４、第１サーボトラツク
にまたがる第３の磁化反転と、第２、第３サーボ
トラツクにまたがる第４の磁化反転とにより位置
情報を構成するサーボデイスクにおいて、サーボ
面上の１カ所又は複数個等間隔に、全トラツクに
またがつて情報の起終点となるクロツクセルを設
定し、上記第１の磁化反転と第２の磁化反転との
組合せによる第１のサーボセルと、上記第３の磁
化反転と第４の磁化反転との組合せによる第２の
サーボセルとを、上記起終点となるクロツクセル
間に交互に２組以上等間隔で配置したことを特徴
とする磁気デイスク装置のサーボデイスク。1 A servo disk used for head positioning of a magnetic disk device, in which four different types of servo tracks are sequentially written adjacent to each other on one side of the disk, and the first and second servo tracks are A first magnetization reversal spanning the tracks, a second magnetization reversal spanning the third and fourth servo tracks, a third magnetization reversal spanning the fourth and first servo tracks, and a third magnetization reversal spanning the second and third servo tracks. In the servo disk that constitutes position information by the fourth magnetization reversal that spans, clock cells that serve as the starting and ending points of information across all tracks are set at one or more equal intervals on the servo surface, and A first servo cell with a combination of magnetization reversal and a second magnetization reversal, and a second servo cell with a combination of the third magnetization reversal and fourth magnetization reversal, are connected between the clock cells serving as the starting and ending points. A servo disk of a magnetic disk device, characterized in that two or more sets of servo disks are alternately arranged at equal intervals.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7537183A JPS59201215A (en) | 1983-04-28 | 1983-04-28 | Servo disk of magnetic disk device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7537183A JPS59201215A (en) | 1983-04-28 | 1983-04-28 | Servo disk of magnetic disk device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59201215A JPS59201215A (en) | 1984-11-14 |
| JPH0352155B2 true JPH0352155B2 (en) | 1991-08-09 |
Family
ID=13574282
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7537183A Granted JPS59201215A (en) | 1983-04-28 | 1983-04-28 | Servo disk of magnetic disk device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59201215A (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54119215A (en) * | 1978-03-09 | 1979-09-17 | Toshiba Corp | Magnetic disc apparatus |
-
1983
- 1983-04-28 JP JP7537183A patent/JPS59201215A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54119215A (en) * | 1978-03-09 | 1979-09-17 | Toshiba Corp | Magnetic disc apparatus |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59201215A (en) | 1984-11-14 |
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