JPH0317870A - Magnetic disk device - Google Patents

Magnetic disk device

Info

Publication number
JPH0317870A
JPH0317870A JP14953089A JP14953089A JPH0317870A JP H0317870 A JPH0317870 A JP H0317870A JP 14953089 A JP14953089 A JP 14953089A JP 14953089 A JP14953089 A JP 14953089A JP H0317870 A JPH0317870 A JP H0317870A
Authority
JP
Japan
Prior art keywords
signal
target speed
voltage
magnetic head
speed voltage
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.)
Pending
Application number
JP14953089A
Other languages
Japanese (ja)
Inventor
Akihiko Fujisawa
藤沢 昭彦
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Electric Corp
Original Assignee
Mitsubishi Electric Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Mitsubishi Electric Corp filed Critical Mitsubishi Electric Corp
Priority to JP14953089A priority Critical patent/JPH0317870A/en
Publication of JPH0317870A publication Critical patent/JPH0317870A/en
Pending legal-status Critical Current

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  • Moving Of Head For Track Selection And Changing (AREA)
  • Moving Of The Head To Find And Align With The Track (AREA)

Abstract

PURPOSE:To promote the following property of the control and to shorten the positioning time as well by changing multistepwise and controlling a voltage just prior to positioning a head at a new target speed voltage. CONSTITUTION:A position signal 3a which is an output from a position detector 3 is impressed upon one pair of nonlinear detectors 21 and 22, and a nonlinear signal (NL signal) 14 is detected out of each of the nonlinear detectors 21 and 22. Furthermore, the NL signal 14 is inputted to a CPU 9, and the new target speed voltage 10aA having a different waveform from an old target speed voltage is outputted from a D/A converter 10 being as a target speed voltage generating means. Components more than fixed reference voltages b1 and b2 are detected to be outputted as the NL signal 14 by the nonlinear detectors 21 and 22. Changes of E pulse of TZC signal 7a and the NL signal are detected and calculated by the CPU 9 to change multistepwise and control the voltage just prior to positioning the head at the new target speed voltage 10aA, so that the following property is promoted while the positioning time is shortened.

Description

【発明の詳細な説明】 [産業上の利用分野] この発明は、磁気ディスク装置に関し、特に、磁気ヘッ
ド目標停止位置直前の電圧を多段階状に切り替え、制御
の追従性を向上させることに関する。
DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a magnetic disk drive, and more particularly to improving control followability by switching the voltage immediately before a magnetic head target stop position in multiple stages.

[従来の技術] 第6図は特開昭62−262283号公報に示された従
来の磁気ディスク装置を示すブロック図である.図中の
(1)は磁気ディスク、(2)は磁気ヘッド、(3)は
この磁気ヘッド(2)に接続された位置検出器、(4)
はこの位置検出器(3)からの位置信号(3a)をとり
込む速度検出器、(5),(6)はそれぞれ位置情報の
奇数トラック成分(以下ODD成分と略す)と偶数トラ
ック成分(以下EVENt分と略す)から基準電圧以上
の戒分を検出するコンパレータ、(7)は各コンバレー
タ(5.6)に接続されたトラック通過検出器、(8)
は計時手段、(9)はCI’U、(10)はD/^コン
バータ、(11)は減算器、〈12)はパワーアンプ、
(13)はアクチュエー夕である. 従来の磁気ディスク装置は、前述したように構成されて
おり、以下に、その動作について説明する。第6図にお
いて、磁気ディスク(1)上に記録された位置情報を磁
気ヘッド〈2)が検出し、位置検出器(3〉によって位
置検出を行う.次いで、位置検出器(3)からの位置信
号(3a)に基づいて速度検出器(4)により磁気ヘッ
ド(2)の実速度電圧(4a)を得る.また、磁気へッ
ド(2)が移動した場合、位置検出器(3)の出カは第
5図の信号(a)に示すように、正弦波状の位置信号(
3a)となる.前記正弦波状の位置信号(3a)は、コ
ンバレータ(5) . (6)によりある一定の基準電
圧al,a2以上のODD成分のコンハレータ出力(5
a)、EVEN成分のコンパレータ出力(6a)として
取り出され、第5図における信号(b) . (c)の
如く出力される.次に、前記コンパレタ(5) . (
6)の出力の論理和を取ることにより、トラック通過検
出器(7)は第5図における信号(d)の如きトラック
通過信号(7a) (以下TZC信号と略す〉を出力す
る。このTZC信号(7a)のパルス間隔を計時手段〈
8〉により計時し、目標速度が一定値をとっている間に
前記磁気ヘッド(2)が通過したトラック数と所定時間
がら前記磁気ヘッド(2)の実速度をCPU(9)によ
り計算し、計算結果にもとづき前記目標速度を補正し、
D/^コンバータ(1o)により目標速度電圧(10a
)を出力する。
[Prior Art] FIG. 6 is a block diagram showing a conventional magnetic disk device disclosed in Japanese Unexamined Patent Publication No. 62-262283. In the figure, (1) is a magnetic disk, (2) is a magnetic head, (3) is a position detector connected to this magnetic head (2), and (4)
is a speed detector that takes in the position signal (3a) from this position detector (3), and (5) and (6) are the odd track components (hereinafter abbreviated as ODD components) and even track components (hereinafter abbreviated as ODD components) of the position information, respectively. (abbreviated as EVENt minute), (7) is a track passing detector connected to each comparator (5.6), (8)
is a clock means, (9) is CI'U, (10) is a D/^ converter, (11) is a subtracter, <12) is a power amplifier,
(13) is the actuator. A conventional magnetic disk device is configured as described above, and its operation will be explained below. In Fig. 6, the magnetic head <2> detects the position information recorded on the magnetic disk (1), and the position is detected by the position detector (3).Then, the position information from the position detector (3) is detected. Based on the signal (3a), the speed detector (4) obtains the actual speed voltage (4a) of the magnetic head (2).Also, when the magnetic head (2) moves, the position detector (3) The output is a sinusoidal position signal (as shown in signal (a) in Figure 5).
3a). The sinusoidal position signal (3a) is sent to a converter (5). (6), the conhalator output (5
a), the EVEN component is taken out as the comparator output (6a), and the signal (b) in FIG. The output is as shown in (c). Next, the comparator (5). (
By taking the logical sum of the outputs of 6), the track passing detector (7) outputs a track passing signal (7a) (hereinafter abbreviated as TZC signal) such as signal (d) in Fig. 5.This TZC signal (7a) A means for measuring the pulse interval
8), and the CPU (9) calculates the actual speed of the magnetic head (2) from the number of tracks that the magnetic head (2) has passed while the target speed is constant and a predetermined time; Correcting the target speed based on the calculation result,
The target speed voltage (10a) is set by the D/^ converter (1o).
) is output.

次に、減算器(11)は前記実速度電圧(4a)と前記
目標速度電圧(10a)との差電圧(ll&)を出力し
、前記差電圧(lla)に比例した電流をパワーアンプ
(l2〉を通じてアクチュエータ(13〉の駆動部(図
示せず)へ流し、磁気ヘッド(2)のヘッド速度制御を
行う.[発明が解決しようとする課題] 従来の磁気ディスク装置は以上のように構成されている
ので、減速時において、D/^コンバータ(10)より
出力される第7図の階段状の目標速度電圧(10a)の
最終段から目標位置に磁気ヘッド(2)が停止する間の
差電圧が大幅であるため、第7図に示す如く、磁気ヘッ
ドが完全に停止するまでに時間tsだけ磁気ヘッドに揺
れが生じる.又前記時間tsは磁気ヘッド移動距離及び
磁気ディスク装置個々によりバラッキが生じるという課
題があった.この発明は以上のような課題を解決するた
めになされたもので、特に、磁気ヘッドが完全に停止す
るまでの揺れによる時間tsの発生を最小限におさえる
ことができるとともに、磁気ヘッドの移動距離及び磁気
ディスク装置個々の前記時間Lsのバラツキの少ない磁
気ディスク装置を得ることを目的とする. 「課題を解決するための手段] 磁気ヘッドの移動速度を検出する速度検出手段と目標速
度を発生する目標速度発生手段を有し、前記磁気ヘッド
の実速度を前記目標速度に追従させて制御することによ
り、ヘッド位置決めを行う磁気ディスク装置において、
前記目標速度を発生する目標速度電圧発生手段から出力
する階段状の新目標速度電圧のヘッド位置決め寸前の電
圧を多段階状に切り替えて制御するようにした楕戒であ
る。
Next, the subtracter (11) outputs a voltage difference (ll&) between the actual speed voltage (4a) and the target speed voltage (10a), and supplies a current proportional to the voltage difference (lla) to the power amplifier (l2). ) to the drive unit (not shown) of the actuator (13) to control the head speed of the magnetic head (2). [Problem to be Solved by the Invention] A conventional magnetic disk device is configured as described above. Therefore, during deceleration, the difference between the final step of the stepped target speed voltage (10a) in FIG. 7 outputted from the D/^ converter (10) and the time when the magnetic head (2) stops at the target position is Since the voltage is large, the magnetic head oscillates for a time ts until it completely stops, as shown in Fig. 7.The time ts varies depending on the distance the magnetic head moves and the individual magnetic disk devices. This invention was made to solve the above-mentioned problems, and in particular, it is possible to minimize the time ts required for the magnetic head to completely stop due to shaking. In addition, it is an object of the present invention to obtain a magnetic disk device with less variation in the moving distance of the magnetic head and the time Ls of each magnetic disk device. ``Means for Solving the Problems'' Speed detection for detecting the moving speed of the magnetic head and a target speed generating means for generating a target speed, and performs head positioning by controlling the actual speed of the magnetic head to follow the target speed,
This is an elliptical control in which the stepwise new target speed voltage outputted from the target speed voltage generating means for generating the target speed is controlled by switching in a multi-step manner the voltage just before head positioning.

[作 用] この発明に係る磁気ヘッド装置においては、目標速度電
圧発生手段から出力される新目標速度電圧のヘッド位置
決め寸前の電圧すなわち最終段の電圧と目標位置に磁気
ヘッドが停止する間の差電圧が多段階に分割されている
ため,従来より速度検出器の出力である実速度電圧の前
記新目標速度電圧に対する追従性が良くなり、磁気ヘッ
ドが完全に停止するに要する時間tsが第7図の状態が
ら第2図の状態の如く短くな.り、磁気ヘッドの位置決
め時間の動作を迅速化できる. [実施例] 以下、この発明による磁気ディスク装置の一実施例を図
について説明する。
[Function] In the magnetic head device according to the present invention, the difference between the new target speed voltage output from the target speed voltage generating means, the voltage just before head positioning, that is, the voltage at the final stage, and the time when the magnetic head stops at the target position. Since the voltage is divided into multiple stages, the ability of the actual speed voltage, which is the output of the speed detector, to follow the new target speed voltage is better than before, and the time ts required for the magnetic head to completely stop is reduced to 7th. The state shown in the figure is shorter like the state shown in Figure 2. This makes it possible to speed up the positioning time of the magnetic head. [Embodiment] Hereinafter, an embodiment of a magnetic disk device according to the present invention will be described with reference to the drawings.

尚、構成は第5図に示す従来のブロック図とほぼ同一で
あるので、同一部分には同一符号を付し、その説明は重
複を避けるために省略するものとし、第5図とは異なる
部分について説明する.第1図において■対のノンリニ
ア検出器(21)(22)に位置検出器(3)からの出
力である位置信号(3a)が印加され、各ノンリニア検
出器(21).(22)からノンリニア信号(以下ML
信号と略す) (14)を検出する。さらに、前記NL
信号(14〉はCPU(9)に入力され、目標速度電圧
発生手段であるD/^コンバタ(10〉から従来の目標
速度電圧とは異なる波形の新目標速度電圧(10a^)
を出力する.すなわち、前記ノンリニア検出器(21)
,(22)は次の様な機能を有しており、第2図のある
一定の基準電圧bl,b2以上の成分を前記ノンリニア
検出器(21),(22)が検出し、NL信号(14)
として出力する.なお、前記基1s電圧bl,b2と第
5図の従来例における前記基準電圧al,a2のrIA
係はIbll>fail ,tb21>a21である. 本発明による磁気ディスク装置は、前述したように楕成
されており、以下に、その動作について説明する.第1
図において、磁気ディスク(1)上に記録された位置情
報を磁気ヘッド(2)が検出し、位置検出器(3)によ
って位置検出を行う.次いで、位置検出器(3〉からの
位置信号(3a〉に基づいて速度検出器(4)により磁
気ヘッド(Z)の実速度電圧(4a^)を得る.また、
前記磁気ヘッド(2)が移動した場合、位置検出器〈3
)の出力は第5図の信号(a)に示すようにOTID成
分, EVEN或分から成る正弦波状の位置信号(3a
)となる。このOD[l成分, EVEN成分はコンパ
レータ(5).(6)により基準電圧以上のODD成分
, EVENt分がコンバレータ出力(5a) , (
6a)として取り出され、第5図の信号(b) , (
e)の如く出力される.次に、前記コンパレータ(5)
 , (6)の出力の論理和を取ることにより、トラッ
ク通過検出器(ア)は第5図の信号(d)のトラック通
過信号(7a) (以下TZC信号と略す)を出力する
。このTZC信号(7a)のパルス間隔を計時手段(8
)により計時し、目標速度が一定値をとっている間に前
記磁気ヘッド(2)が通過したトラック数と所要時間か
ら前記磁気ヘッド〈2)の実速度をCPU(9)により
計算し,計算結果にもとづき、前記目標速度を補正し、
D/^コンバータ(10)により新目標速度電圧(10
a^)を出力する。
The configuration is almost the same as the conventional block diagram shown in FIG. 5, so the same parts are given the same reference numerals and their explanation will be omitted to avoid duplication. I will explain about it. In FIG. 1, a position signal (3a) which is an output from a position detector (3) is applied to a pair of non-linear detectors (21) and (22), and each non-linear detector (21). (22) from the nonlinear signal (hereinafter ML
(abbreviated as signal) (14) is detected. Furthermore, the N.L.
The signal (14>) is input to the CPU (9), and a new target speed voltage (10a^) with a waveform different from the conventional target speed voltage is generated from the D/^ converter (10>) which is a target speed voltage generating means.
Outputs . That is, the nonlinear detector (21)
, (22) have the following functions, the non-linear detectors (21), (22) detect components higher than a certain reference voltage bl, b2 in Fig. 2, and the NL signal ( 14)
Output as . Note that rIA of the base 1s voltages bl, b2 and the reference voltages al, a2 in the conventional example of FIG.
The relationships are Ibll>fail and tb21>a21. The magnetic disk device according to the present invention has an elliptical structure as described above, and its operation will be explained below. 1st
In the figure, a magnetic head (2) detects position information recorded on a magnetic disk (1), and a position detector (3) detects the position. Then, based on the position signal (3a) from the position detector (3), the speed detector (4) obtains the actual speed voltage (4a^) of the magnetic head (Z).
When the magnetic head (2) moves, the position detector <3
) is a sinusoidal position signal (3a) consisting of an OTID component and an EVEN component, as shown in signal (a) in Figure 5.
). This OD[l component and EVEN component are the comparator (5). According to (6), the ODD component, EVENt, which is higher than the reference voltage becomes the converter output (5a), (
6a), and the signals (b), (
The output is as shown in e). Next, the comparator (5)
, (6), the track passing detector (a) outputs the track passing signal (7a) (hereinafter abbreviated as TZC signal) of the signal (d) in FIG. The pulse interval of this TZC signal (7a) is measured by a clocking means (8).
), and while the target speed is constant, the CPU (9) calculates the actual speed of the magnetic head (2) from the number of tracks passed by the magnetic head (2) and the required time. Based on the result, correct the target speed,
The new target speed voltage (10
a^) is output.

次に、iIi!iX器(11)は前記実速度電圧(4a
^)と前記新目標速度電圧(10a^)との差電圧を出
力し、前記差電圧に比例した電流をパワーアンプ(l2
)を通じてアクチュエータ(13)の駆動部へ流し、ヘ
ッド(2)に対するヘッド速度制御を行う.ここで目標
停止位置まで残りlトラックになった場合、第4図のヘ
ッド速度制御に移るが,残り1トラック以上の場合は同
じシーケンスをくり返し行う。
Next, iIi! The iX device (11) receives the actual speed voltage (4a
^) and the new target speed voltage (10a^), and outputs a current proportional to the difference voltage to the power amplifier (l2
) to the drive section of the actuator (13) to control the head speed of the head (2). If there is one track left to reach the target stop position, the process moves to the head speed control shown in FIG. 4, but if there is one track or more remaining, the same sequence is repeated.

前述の状態で、前記新目標速度電圧(10a八)を得る
場合について説明する.まず、第2図のTZC信号(7
a)のEパルス(磁気ヘッドの目標停止位置まで残り1
トラックを示すTZC信号)をCPII(9)で検知す
るとヘッド速度制御は第4図のサブルーチンに移行する
.すなわち、第4図の第1ステップs1で第2図の新目
標速度電圧(10a^)における第l段電圧(^)を計
算し、D/^コンバータ(10)へ出力する.このD/
^コンバータ(10)がら、前述と同様のシーゲンスを
たどり、次に、第4図の第3ステップS3で第2図のN
L信号(14)の立ち上がり(F)を検知し、速度電圧
(10a^〉の第2段電圧(B)を計算し(第4ステッ
プS4L出力する(第5ステップS5)。また、同様の
シーケンスをたどり、第4図の第6ステップS6で第2
図のNL信号(l4)の立ち下がり(G)を検知し、新
巨標速度電圧(10a^)の第3段電圧(C)を計算し
(第7ステップS7)、出力する(第8ステップS8)
.次に、再度、同様のシーケンスを実行後、第4図の第
9ステップS9で、第2図のTZC信号(7a)のHパ
ルスを検知し、第10ステップSIOで0■の第4段電
圧(D)を出力して磁気ヘッドは目標停止位置に停止す
る. なお上記実施例では、目標速度切り換えにディジタル信
号を用いた場合について説明したが、時間的要素による
目標速度切り換え方式を用いてもよい. また、本実施例においては、新目標速度電圧の最終段の
電圧を三段階からなる多段階に切換えるようにした場合
を開示したが、図示しない他のパルス信号によって三段
階以上の多段階に設定するようにした場合も、前述と同
様の作用効果を得ることができることは、述べるまでも
ないことである. [発明の効果] 以上のように、この発明によれば、階段状に出力される
新目標速度電圧における磁気ヘッド目標停止位置直前の
電圧を従来の一段階からデイジタル信号により多段階状
に切り換えるように構戒したので、目標速度の分解能が
向上して制御の追従性が改善でき、磁気ヘッド停止動作
における時間tsが短かくなり、磁気ヘッドの位置決め
時間が速くなる.また、磁気ヘッド移動距離、磁気ディ
スク装置個々による前記時間Lsのバラッキの少ない磁
気ディスク装置が得られるなどの効果があり、動作精度
を向上させることができる.
The case where the new target speed voltage (10a8) is obtained in the above state will be explained. First, the TZC signal (7
a) E pulse (1 remaining until the target stop position of the magnetic head)
When the CPII (9) detects the TZC signal indicating the track, the head speed control shifts to the subroutine shown in FIG. 4. That is, in the first step s1 of FIG. 4, the l-stage voltage (^) at the new target speed voltage (10a^) of FIG. 2 is calculated and output to the D/^ converter (10). This D/
^ With the converter (10), follow the sequence similar to the above, and then in the third step S3 of Fig. 4, N of Fig. 2
The rising edge (F) of the L signal (14) is detected, the second stage voltage (B) of the speed voltage (10a^) is calculated (fourth step S4L is output (fifth step S5)). , and in the sixth step S6 of Fig. 4, the second
Detect the fall (G) of the NL signal (l4) in the figure, calculate the third stage voltage (C) of the new giant speed voltage (10a^) (seventh step S7), and output it (eighth step S8)
.. Next, after executing the same sequence again, the H pulse of the TZC signal (7a) in FIG. 2 is detected in the ninth step S9 in FIG. 4, and the fourth stage voltage of 0■ is detected in the tenth step SIO. (D) is output and the magnetic head stops at the target stop position. In the above embodiment, a case was explained in which a digital signal was used for switching the target speed, but a method for switching the target speed based on a time element may also be used. Furthermore, in this embodiment, a case has been disclosed in which the voltage at the final stage of the new target speed voltage is switched to a multi-stage of three stages, but it is set to a multi-stage of three or more by another pulse signal (not shown). It goes without saying that even if you do this, you can obtain the same effects as mentioned above. [Effects of the Invention] As described above, according to the present invention, the voltage immediately before the magnetic head target stop position in the new target speed voltage that is output in a stepwise manner is switched from the conventional single step to multistep by digital signals. As a result, the resolution of the target speed is improved, the followability of the control is improved, the time ts for the magnetic head stopping operation is shortened, and the time for positioning the magnetic head is shortened. In addition, there is an effect that a magnetic disk device with less variation in the magnetic head movement distance and the time Ls between individual magnetic disk devices can be obtained, and operational accuracy can be improved.

【図面の簡単な説明】[Brief explanation of the drawing]

第1図はこの発明による磁気ヘッド装置の一実施例を示
すブロック図、第2図は新目潔速度電圧と位置信号, 
TZC信号およびNL信号の関係を示す波形図、第3図
は新目標速度電圧と従来の目標速度電圧の比較特性図、
第4図は新目標速度電圧を生戒するプログラムのフロー
チャート、第5図は従来および本発明におけるとTZC
信号とTZC信号生成要素て;あるODD成分コンパレ
ート出力とEVEN成分コンパレート出力の関係を示す
波形図、第6図は従来の磁気ヘッド装置を示すブロック
図、第7図は従来の位置信号, TZC信号および目標
速度電圧を示す波形図である. (1)は磁気ディスク、(2)は磁気ヘッド、(3)は
位置検出器、(4〉は速度検出器、(9)はCPl.I
、(10)はD/^コンバータ(目標速度電圧発生手段
)、(10a^)は新目標速度電圧である.なお、各図
中、同一符号は同一又は相当部分を示す. PIF)2図 昂3図 昂1図 lja償テ”イスク 2:職繁ヘッド 10 : Q/A :I>n−−ク(日憚iLftF−
発恒予搾)10aA : !ft @ Il’l jl
度電反帛4図 昂5図 帛6図
FIG. 1 is a block diagram showing an embodiment of the magnetic head device according to the present invention, and FIG. 2 shows the new speed voltage and position signals,
A waveform diagram showing the relationship between the TZC signal and the NL signal, Figure 3 is a comparative characteristic diagram of the new target speed voltage and the conventional target speed voltage,
Fig. 4 is a flowchart of a program to monitor the new target speed voltage, and Fig. 5 is a flowchart of a program to monitor the new target speed voltage.
Signals and TZC signal generation elements: A waveform diagram showing the relationship between a certain ODD component comparator output and an EVEN component comparator output, FIG. 6 is a block diagram showing a conventional magnetic head device, FIG. 7 is a conventional position signal, It is a waveform diagram showing a TZC signal and target speed voltage. (1) is a magnetic disk, (2) is a magnetic head, (3) is a position detector, (4> is a speed detector, (9) is a CPl.I
, (10) is a D/^ converter (target speed voltage generation means), and (10a^) is a new target speed voltage. In each figure, the same reference numerals indicate the same or equivalent parts. PIF) 2 Figures 3 Figures 1 Figure lja redemption
10aA: ! ft @ Il'l jl
Denden paper 4, 5, 6

Claims (1)

【特許請求の範囲】[Claims] 磁気ヘッドの移動速度を検出する速度検出手段と目標速
度を発生する目標速度電圧発生手段を有し、前記磁気ヘ
ッドの実速度を前記目標速度に追従させて制御すること
により、ヘッド位置決めを行う磁気ディスク装置におい
て、前記目標速度を発生する目標速度電圧発生手段から
出力する階段状の新目標速度電圧のヘッド位置決め寸前
の電圧を多段階状に切り替えて制御するように構成した
ことを特徴とする磁気ディスク装置。
The magnetic head has a speed detecting means for detecting the moving speed of the magnetic head and a target speed voltage generating means for generating a target speed, and performs head positioning by controlling the actual speed of the magnetic head to follow the target speed. In the disk device, the magnetism is characterized in that the step-like new target speed voltage output from the target speed voltage generating means for generating the target speed is controlled by switching in a multi-step manner a voltage just before head positioning. disk device.
JP14953089A 1989-06-14 1989-06-14 Magnetic disk device Pending JPH0317870A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP14953089A JPH0317870A (en) 1989-06-14 1989-06-14 Magnetic disk device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP14953089A JPH0317870A (en) 1989-06-14 1989-06-14 Magnetic disk device

Publications (1)

Publication Number Publication Date
JPH0317870A true JPH0317870A (en) 1991-01-25

Family

ID=15477154

Family Applications (1)

Application Number Title Priority Date Filing Date
JP14953089A Pending JPH0317870A (en) 1989-06-14 1989-06-14 Magnetic disk device

Country Status (1)

Country Link
JP (1) JPH0317870A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4960883A (en) * 1988-02-16 1990-10-02 Kowa Company, Ltd. Piperazines and homopiperazines

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4960883A (en) * 1988-02-16 1990-10-02 Kowa Company, Ltd. Piperazines and homopiperazines

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