JPS62204476A - Disk device - Google Patents

Abstract

PURPOSE:To rapidly restore a head advanced spirally to its original track position of a sector at an index mark position, by forming sectors of several folds or several ten folds of regular number of sectors between the sectors, and writing servo patterns on the sectors. CONSTITUTION:A disk device main body is constituted so that the recording or the reproduction of a bit of information is performed by rotating and driving a disk recording medium 1 at a prescribed rotating speed, and moving a head 2 in the radius direction of the recording medium 1. The head 2 is supported with an actuator 3, and is positioned and controlled with a head movement control mechanism 4 consisting of a voice coil, etc., in the radius direction of the disk recording medium 1. The disk recording medium 1 is constituted so that it is divided equally in a circumferential direction, and plural first - N-th sectors are formed setting the index mark provided at a part in the circumferential direction as a reference, and the first - the N-th servo sectors are provided at a part of respective sector. Furthermore, the N-th sector at the preceding position of the index mark is divided into several tens of sectors, and the N1-th - the Nn-th servo patterns to detect positions are formed on the sectors.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention forms a spiral data track on a disk recording medium, enables continuous recording and reproduction, and provides direct access to the middle of the data track. The present invention relates to a disk device using a head positioning control method that allows for.

[Technical Background of the Invention and Problems Therewith] Generally, a disk device records and reproduces information by forming a plurality of concentric data tracks on a disk recording medium. When data tracks are formed concentrically in this way, the heads remain on the same data track unless a track seek operation is performed, so head positioning control can be performed relatively easily, resulting in a high track It has the advantage that it is easy to achieve high density, and since the heads are positioned on the same data track, it is easy to perform an overlay trial when a data error occurs. Furthermore, during random access, direct positioning to the target track is possible, making it possible to simplify the comparison seek operation sequence when the track has a spiral shape.

However, on the other hand, when trying to record and reproduce a large amount of information over several data tracks on a disk recording medium,
It is necessary to perform track seek control many times, and a lot of time is spent on track seeking, resulting in problems such as a decrease in throughput.

Therefore, it is conceivable to form the data track in a spiral shape. In this way, the data tracks are continuous over the entire disc recording medium, so track seek control is not required when recording and reproducing a large amount of information, and throughput does not deteriorate.

As a specific method for forming a data track in a spiral shape, for example, a spiral servo track is formed on a disk recording medium in the circumferential direction with reference to an index mark provided at one location on the disk recording medium. The phase of the servo pattern written in each divided iti number of sectors is switched every track round with the index mark position as a reference, and the servo pattern has the same phase as the value obtained by dividing the track pitch by the number of sectors. The servo pattern written on this servo track is read through a head and the position of the disk recording medium of the head is determined. A method of determining a signal and causing the head to follow the servo track according to the position signal to form a spiral data track on the disk recording medium by the head or another head provided in association with the head. has been proposed (for example, Japanese Patent Application No. 59-2 [17172)].

This method makes it possible to form data tracks in a spiral shape. By the way, with this method, if the phase of the servo pattern is appropriately switched every track round with the index mark position as a reference, the data track will be followed in a spiral pattern, but if the phase is not changed by -J , the head will be located at the heater of the position signal in the sector where the head has progressed one track in a spiral manner.

Therefore, the head moves toward the center of the position signal, causing a large overshoot and vibration. In other words, even if the head tries to follow position signals of the same phase, the index mark position after one rotation will have moved by one track.
You will move back one track. At that time, the position control is in a state similar to step response, so the head vibrates. This vibration is a damped vibration, but it lasts for several cefts and more than 10 sectors.

Therefore, if you want to record or reproduce the same track, it is necessary to seek again two tracks earlier and advance the tracks in a spiral again until you reach the target track, resulting in wasted time during rotation. Furthermore, if you want to use this disk in the same way as a concentric disk and want to record and reproduce data randomly, there are problems such as a complicated control sequence for seek operations.

[Object of the Invention] The present invention has been made in consideration of the above circumstances, and its purpose is to form a spiral data track on a disk recording medium and to form one concentric data track. To provide a highly practical disk device that can be handled in the same way as a disk device.

[Summary of the Invention] The present invention provides a spiral servo track on a disk recording medium, for example, an index mark is provided at one location on the disk recording medium, and the disk recording medium is divided into Iu numbers in the circumferential direction based on the index mark. The phase of the servo pattern written in each sector is switched to one round of the track iij based on the index 1-, and the servo pattern of the same phase is changed to one round of the track by the value obtained by dividing the track pitch by the number of sectors. The servo pattern is sequentially shifted and formed in each sector, and the head reads the servo pattern written on the servo track to obtain a position signal of the disk recording medium of the head, and according to this position signal, the head is moved to the servo track. by the head, or another head provided in relation to the head, following the track;
In a disk device in which a spiral data track is formed on the disk recording medium, data is recorded between sectors before the phase of the servo pattern is switched, that is, between sectors from the sector position before the index mark to the sector at the index mark position. By forming a sufficiently large number of servo sectors for position detection, that is, by forming sectors between these sectors that are several times to several ten times the size of normal sectors, and by writing servo patterns into these sectors, a head that advances in a spiral shape can be created. can be quickly returned to the original track position of the sector at the index mark position.

[Effects of the Invention] Thus, according to the present invention, a spiral data track is formed according to a spiral servo pattern formed over a plurality of servo sectors provided by dividing the circumferential direction of a disk recording medium, A large amount of data can be continuously recorded and reproduced using this spiral data track, and at the same time, by using a densely formed servo pattern between the sectors in front of the index mark, it is similar to a concentric solid track. It realizes head positioning and allows random data to be recorded and played in the same way as a conventional disk device with concentric data tracks. Therefore, even though it has a spiral data track, it can handle concentric solid data tracks in the same way, so it is easy to perform a retry operation when a data error occurs, and it is possible to directly seek to the target track and record/play back. (In the case of only a spiral upper I/rack, when performing random access, directly seek one track ahead, then hold to the index mark position and start the spiral track advance operation, etc. 1m)
This has advantages such as (requires tilt operation), and has a great practical effect.

[Embodiments of the invention] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram of an embodiment device.

The disk device main body is configured to record and reproduce information while rotating the disk recording medium 1 at a predetermined rotational speed and moving the head 2 in the radial direction of the disk recording medium 1. The head 2 is supported by an actuator 3, and its positioning in the radial direction of the disk recording medium 1 is controlled by a head movement control mechanism 4 consisting of a voice coil or the like.

As shown in FIG.
The disk recording medium 1 is equally divided into a plurality of sectors in the circumferential direction based on index marks provided at locations.
~Nth servo pattern is formed, and servo sectors 1st to Nth are provided in a part of each sector, and furthermore, the Nth sector before the index mark is divided into several tens of sectors, and a servo pattern N1th for position detection is formed. ~ Nnth is formed densely.

It consists of a two-phase dibit pattern with a period of four tracks as shown in the figure. Each servo pattern is formed with a deviation of 1721-rack from each data track of the data sector, and the head 2 that traces the data track reproduces half of the servo pattern of the two adjacent tracks. There is. The position of the head 2 with respect to the disk recording medium 1 is detected from the position signal reproduced in this manner. FIG. 2 shows an example of the configuration of a servo pattern and a servo sector used in the present invention.

The spiral servo pattern is embedded in each of the disk recording medium 1 and the lu number of sectors, 1st sector to Nth sector, which are equally divided in the circumferential direction of the disk recording medium 1, and the servo patterns form index marks. The number N of sectors is switched every round based on the index zone (one sector specified in the circumferential direction of the disk recording medium l, the first sector in this embodiment), and the track pitch is set to be divided as described above. Servo patterns of the same phase are sequentially shifted over one track to form a value obtained by dividing by . Furthermore, the Nth sector is divided into N1 to Nth sectors, and the servo patterns of the same phase do not shift in position from the N1 to the Nnth sectors.
In other words, they are formed in concentric circles.

That is, servo sectors (first to
Nth), the servo patterns with the same phase are formed by shifting them by a predetermined pitch in the radial direction, and when the servo patterns with the same phase have made one revolution around the disk recording medium 1, the formation position of the servo patterns with the same phase is shifted by exactly one track. Do it like this. Then, the Nth sector is further divided into finer sectors (Nt to Nn).
The servo patterns of the same phase are divided into N1 to Nth sectors at the same radius position as the formation position of the N1 sector of the
Form into 11 sectors.

In this way, the servo pattern is formed by changing the phase every round and shifting the position over a plurality of servo sectors in a spiral manner, and furthermore, the servo pattern is formed by changing the phase every round and shifting the position over a plurality of servo sectors in a spiral manner. According to the disk recording medium 1 on which the servo pattern is formed, in the Nth sector, the N1th
Using only the servo pattern of the sector, the head 2 is controlled to follow the servo pattern of the same phase throughout the round using the index mark as a reference while controlling the following servo pattern by switching the phase every round. By doing so, it is possible to move the head 2 in a spiral manner with respect to the disk recording medium 1, and further, in the Nth sector, position detection is performed using the servo patterns of the N1 to Nnth sectors, and speed control is performed. By quickly returning to the head position in the first sector of the track that has been followed, it can be handled in the same way as a disk device that follows concentric tracks.

If you do not use a dense servo pattern in the N-th sector, for example, if you do not switch the Buddhist temple 11 in the first sector while controlling the position, the servo pattern in the N-th sector (N1 sector) and the servo in the first sector Since the patterns have different phases, the head 2 tries to move toward the center of the position signal reproduced from the servo pattern, resulting in a large overshoot and vibration. The behavior of the head at that time is shown in Figure 4a. Therefore, recording/reproduction of the first to several sectors becomes impossible. Also, the Nth sector (
If you try to send the position signal from the N1 sector to the 1st sector by controlling the speed and length, the position signal will be obtained only in the Nth sector, the 1st sector, and will be intermittent, so the speed control will not be able to be performed well and the position signal will be sent from the 1st sector to the 1st sector.
It is not possible to position and settle the head 2 in sectors.

By the way, from the Nth sector to the first sector, the Nlth Seftar is the Nth. For example, the position detection method when transmitting at high speed with speed control using sector servo patterns is disclosed in Japanese Patent Application No. 58-146.
If position detection is performed with sufficient accuracy using the method of No. 058, position signals within the N-th sector can be obtained almost continuously, making it possible to quickly position from the N-th sector to the first sector. .

The behavior of the head at this time is shown in Figure 4.

Based on the relationship between the playback signal levels obtained when the playback signal obtained from the disk recording medium 1 is sampled at the servo pattern embedding positions (A, B, C, D), the disk recording medium 1
The position of the head 2 relative to the position is detected. The signal reproduced from the disk recording medium 1 via the head 2 is AGCu.
After adjusting the ILF raw level through the line 11, it is led to a sector detection circuit 12 and an index mark detection circuit 13, and is used for detecting servo sectors and index zones. The sector detection circuit 12 detects that the position of the spatula 2 with respect to the disk recording medium 1 is at the servo button by the detection by the erasing section 6, and the index mark detection circuit 13 detects the servo sector lc.
It is detected whether or not the index mark is present in the servo sector, and whether or not the servo sector is an index zone that is the basis of position control is detected.

The sample pulse generation circuit 14 generates timing signals for detecting each of the signals embedded in the servo sector by manually inputting such detection signals. Upon receiving this timing signal, the AGC circuit 11
The signal reproduction gain is adjusted from the reproduction signal level at the GC signal reproduction timing, and the signal reproduction level of the servo signal etc. reproduced thereafter is controlled to be constant.

The 111 raw signal whose reproduction signal level is controlled to be constant is guided to seven sample-and-hold circuits 15a, 15b, 15c, and L5d provided in parallel, respectively.
Extracted according to the timing signal. The values of the reproduced servo signals at each timing extracted by the sample and hold circuits 15a and 15d, respectively, are calculated by subtracters 18a and 1[ib, and then the difference between them is determined by A.
The data is taken into the CPU 1B via the /D converter 17.

According to the signal (servo signal) inputted to the CPU 1B in this manner, the CPU 18 controls the head 2. The position of the head 2 relative to the disk recording medium 1 is detected, and the moving speed of the head 2 is determined from the change in the detected position to generate a movement control signal for the head 2.

This movement control signal is applied to the head movement control device 4 via the switch circuit 20 to control the speed of the head 2 relative to the disk recording medium 1. This speed control is used when randomly seeking tracks and when moving from the Nth sector to the first sector back to the original track.
The difference between the servo signals obtained through the tab is applied from the compensation circuit 21 to the head movement control device 4 via the switch circuit 20 to perform position follow-up control. In other words, when performing spiral head position tracking control,
Under position tracking control, the phase of the position signal may be appropriately switched in the first sector based on the index mark. At this time, position signals +Ij are generated from the servo patterns of the first sector to the Nth sector. In addition, if spiral head position tracking control is not performed, switch to speed control in the Nth sector, and use the position signal obtained from the servo pattern of the Nth to Nnth sectors to quickly adjust the head position to the first position.
The head is moved to the same track as the I rack in the Nth sector of the sector, and the head is controlled as if it were following a concentric track.The advantage of a disk device with concentric tracks is that the error retry is a seek operation. Sector interleaving is possible without the need for rotational waiting time, simple control of seek operation,
can have.

FIG. 4 shows another embodiment of the present invention, in which the spiral servo sectors 1 to N and the servo patterns written therein are similar to those in the first embodiment, and are formed densely in the N sector. The servo patterns to be written in the N1 to N0 sectors are formed by sequentially shifting from the Nth sector to the Nth sector so as to smoothly connect to the servo pattern of the first sector.

The direction of this radial shift is opposite to that of the spiral sectors 1 to N1.

Therefore, when following a spiral data track, position tracking control is performed using position signals reproduced from servo patterns from the 1st to the Nl sectors, and the phase of the position signal is adjusted appropriately in the 1st sector. When following the same data track using the conventional method of switching, the N1
Position tracking control is performed using position signals reproduced from servo patterns from the position tracked up to the sector to the N2-th to Nn-th sectors. Therefore, in this embodiment, two modes, spiral data track tracking and same track tracking, are possible by simply selecting the position signal in the N-th sector while maintaining the position tracking control.

Thus, it is possible to realize a disk device that has both the advantages of a conventional disk device with one concentric data track and a disk device with a spiral data track.

Note that the present invention is not limited to the embodiments described above. In the embodiment, an example in which the present invention is applied to a sector servo system has been described, but it is also applicable to a disk device using a servo surface servo system in which the information recording surface and the servo surface are separate. Furthermore, the present invention can be similarly applied to a data surface servo method for deep recording of servo signals. Further, the track pitch of the spiral data track, the sector interval, the dense sector interval of the Nth sector, etc. may be determined according to the specifications of the device and the performance of the actuator. In short, the present invention can be implemented in various modifications without departing from the gist thereof.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram of an apparatus according to an embodiment of the present invention, Fig. 2 is a diagram showing an example of forming a servo pattern according to an embodiment of the present invention, and Fig. 3 is a position tracking using a spiral servo pattern. Figure 4 is a diagram for explaining the difference between the behavior of the head when the phase is not switched in the control state and when the head is smoothly moved from the Nth sector to the first sector using this embodiment. FIG. 7 is a diagram for explaining another embodiment of the invention. 1... Disk recording medium, 2... Head. 3...actuator. 4...Head movement controller tM, 11...AGC circuit. 12... Sector detection circuit. 13... Index zone generation circuit. 14... Sample pulse generation circuit 15a-15d... Sample/hold circuit. 1B...Subtractor, 17...A/D, 18...C
P.U. 19...I10 boat, 20...switch circuit. 21...Compensation Circuit Agent Patent Attorney Nori Chika Ken Yudo Takehana Kikuo Figure 1 17 Portrait and Song Section 2 Figure 2 Sys 70th Kusei N Sewo

Claims (4)

[Claims] (1) A servo pattern written in each of a plurality of sectors obtained by dividing a disk recording medium in the same direction is formed into one servo unit, and the servo unit is sequentially shifted around one track to form a spiral in each sector. In a disk drive having a track of
The sector is further divided into multiple parts and a servo pattern is written in each to form a sector with dense servo units, making it possible to follow tracks in a spiral pattern continuously and to follow the same track smoothly. A disk device characterized by: (2) When following a track in a spiral shape, position tracking control is performed using a position signal reproduced from the servo pattern of the sector formed in a spiral shape, and when following the same track, reproduction is performed in the dense servo unit. 2. The disk device according to claim 1, wherein positioning is performed quickly on the same track by speed control using a position signal. (3) When patterns to be written in dense servo units are sequentially shifted so that they are smoothly connected to the same track, and the track is followed in a spiral shape, the position reproduced from the servo pattern of the spirally formed sector When performing position tracking control using a signal and following the same track, the position signal reproduced by the servo pattern formed in the dense servo unit that smoothly continues to the same track is used, and the position tracking control smoothly follows the same track. 2. The disk device according to claim 1, wherein the disk device is positioned at . (4) The disk device according to claim 1, wherein a plurality of tracks has at least one servo sector having dense servo units.