JPS6212970A - Disc device - Google Patents

Abstract

PURPOSE:To attain direct access to an optional location and to attain a high track density by forming a spiral data track in accordance with the spiral servo pattern formed over plural servo sectors provided by dividing a disc recording medium in peripheral direction. CONSTITUTION:With an index mark 1a provided in one location in the disc recording medium for reference, the phase of the spiral servo pattern written in the plural sectors 1b... made by dividing the disc in its peripheral direction is shifted at each one turn of the track. The servo patterns of the same phase are sequentially shifted along the length of one round using the quatient of the division of the track pitch by the number of sectors, and are formed in respective sectors. By reading the servo pattern written in the servo track, the location signal of the disc recording medium of a head is obtained. According to the obtained location signal, the head is made follow the servo track. And, in such way, a data track is formed in a spiral form on the disc recording medium.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a disk device 2 that forms a spiral data track on a disk recording medium and allows direct access to the middle of the data track.

[Risk of invention and its problems]

In the disk Vclt, information is generally recorded and reproduced by forming a plurality of concentric data tracks on the disk recording medium. This is because, unless a track access command is given to the 1 and Je heads that form concentric data tracks in this way, the heads will be on the same data track.

Head positioning system can be performed relatively easily,
It also has the advantage of being easy to achieve high track density.

However, on the other hand, when trying to record or reproduce a large amount of information, such as image information, over multiple data tracks on a disk recording medium, it is necessary to perform track access control many times, and the data (information) becomes discontinuous. becomes. Furthermore, since a large amount of time is spent on accessing the track, there is a problem that the data transfer rate (time required for recording and reproduction) is substantially reduced.

Therefore, it has been considered to form data tracks in a spiral shape. By doing this, the data tracks will be continuous across the entire disk recording medium, so there will be no need to control track access even when recording and reproducing a large amount of information, and there will be no data loss. Continuity will no longer occur. Furthermore, there is no possibility of a decrease in data transfer speed.

However, in a conventional disk drive WE that forms data tracks in a spiral shape on a disk recording medium, the head is simply mechanically controlled in the radial direction of the disk recording medium. For this reason.

It was not possible to record or reproduce data by moving the head to any position on the data track. A friend of mine has a problem where it is not possible to directly access any position on the data track. Moreover, since the head is simply mechanically controlled, it is necessary to allow the head to follow the track with some leeway. For this reason, it has been difficult to increase the track density. [Objective of the Invention] The present invention has been made in consideration of the above circumstances. It is an object of the present invention to provide a highly practical disk device that can form a data track in the form of a disc, directly access any position on the data track, and easily achieve high track density.

[Summary of the invention]

In the present invention, a spiral servo track is formed on a disk recording medium, for example, by dividing the disk recording medium in the circumferential direction based on an index mark provided at one location on the disk recording medium and writing into a plurality of sectors. The phase of the servo pattern is switched every round of the track based on the index mark position, and the servo patterns of the same phase are sequentially shifted over one round of the track by the value obtained by dividing the track pitch by the number of sectors. The servo pattern written on the servo track is read through a head to obtain a position signal of the disk recording medium of the head, and the position signal of the disk recording medium is determined according to this position signal. A spiral data track is formed on the disk recording medium by a head that follows the servo track, and another head provided in association with the head. The servo patterns are placed on both sides of the disk recording medium so that the directions of the phase shifts of the patterns are opposite to each other,
In other words, the direction of rotation of the spiral is reversed, magnetic heads are provided facing each side of the disk medium, and on one side of the disk medium, the heads are arranged continuously from the outer circumference toward the inner circumference. It moves by following the track, and when it reaches the innermost track, it switches to the magnetic head on the other side of the disk medium, and this head continuously follows the track from the inner circumference to the outer circumference of the disk medium. It has been carefully cleaned.

〔Effect of the invention〕

According to the present invention, a spiral data track is easily formed according to a spiral servo pattern formed alternately in a plurality of servo sectors provided by dividing the circumferential direction of a disk recording medium. Therefore, using this spiral data track, a large amount of data such as image information can be continuously and effectively recorded and reproduced. At the same time, it is possible to directly access any intermediate position of the data track using each of the servo patterns described above. Direct access is possible by performing head positioning control on knob and spiral data tracks in much the same way as accessing conventional concentric data tracks.Therefore, head positioning control is performed using servo patterns. This makes it possible to continuously record and reproduce information on the spirally formed data track while accessing any data track position. Furthermore, since the positioning of the head is controlled using the above-mentioned servo pattern, great practical effects can be achieved, such as the ability to easily increase the track density.

Furthermore, since recording and reproduction can be performed continuously on both sides of the disk medium, a large amount of sequential data can be read and written continuously on both sides without the need for access time for each track, and without the loss time when switching heads on both sides. This can significantly reduce data transfer time.

[Implementation sequence of the invention]

Hereinafter, a first embodiment of the present invention will be explained with reference to the drawings.

FIG. 1 is a schematic diagram of the practical apparatus. 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 2.2' in the radial direction of the disk recording medium 1. . The head 2.2' is supported by an actuator 3, and is connected to a head movement controller 1 that is connected to a voice coil, etc.
4, the disk recording medium 1 is integrally moved in the radial direction l and positioning is controlled.

Heads 2 and 2' are switched and selected by switch 5. That is, when the head 2,2' moves from the outer circumference to the inner circumference of the disk recording medium 1, for example, the switch 5 is connected to the head 2 side and the head 2 is selected.

When the head 2.2' reaches the innermost circumference, the switch 5 is switched to the head 2' side, the head 2' is selected, and the head 2' is moved toward the outer circumference of the disk recording medium 1.

As shown in FIG. 2 on both sides, the disk recording medium 1 is equally divided in the circumferential direction using an index mark 1a provided at one location in the circumferential direction as a reference to form a plurality of secondary cells lb, lb. . . , and each servo sector IC is provided in a part of the valley sector 1b. In other words, each sector 1b is composed of the servo sector 1c and the data sectors ld and i, respectively! has been completed. The index mark may be embedded as a pattern signal in a specific sector.

For example, as shown in detail in FIG. 3, the servo sector IC has an erase area 6 used for servo sector detection, and a 7% guard zone detection unit 8 for AGC area for adjusting the reproduction signal level.
1 and a servo pattern area 9 for position detection,
A servo pattern for positioning control of the head 2 is embedded in the servo pattern area 9 in advance.

The servo pattern embedded in this servo sector IC is, for example, disclosed in Japanese Patent Application No. 58-40 by the present inventors.
The first servo signal consists of a two-phase dibit pattern with a period of 4 tracks, as proposed in No. 370, and the second servo signal consists of two dibit patterns with a period of 16 tracks and a shift of 4 tracks. The second servo signal has a period of 8 tracks, and a third servo No. 18 consisting of a dibit pattern having a shift of 2 tracks with respect to the second servo signal. Each of these servo signals is formed with a 1/2 track shift with respect to each data track of the data sector 1d, and the head 2 that traces the data track halves the servo pattern of the two adjacent tracks. It is now played one by one. The fourth part played in this way
The position of the nuclear head 2.2' relative to the disk recording medium 1 is detected from the servo signal as shown in the figure. It should be noted that the signals shown in FIG. 4 show reproduction signals in four states when the position of the head 2#2' is varied in the radial direction of the disk recording medium 1. As shown in these signals, when the signals are sampled at the embedding positions (S, A, B, C, D) of the servo pattern, the reproduction signal level at each sampling time is equal to that of the head 2.
, 2' differs depending on the position with respect to the disk recording medium 1. Based on the relationship between the reproduced signal levels at each sampling time point, the head 2.2' ejects the light to the disk recording medium 11.

Now, the signal reproduced from the disk recording medium 1 via the head 2.2' is adjusted in reproduction level via the AGC circuit 11, and then guided to the sector detection circuit 12 and index zone detection circuit 131 to detect the servo sector. and index zone detection. The sector detection circuit 12 detects that the position of the head 2 with respect to the disk recording medium 1 is on the servo sector IC by the detection by the erasing section 6, and the index zone detection circuit 13 detects that the index mark exists on the servo sector IC. It is detected whether the servo sector is an index zone serving as a reference for position control.

The sample pulse generation circuit 14 receives such a detection signal and generates a timing signal for detecting each of the signals embedded in the servo sector IC.

Upon receiving this timing signal, the AGC circuit 11 adjusts the signal reproduction gain from the reproduction signal level at the AGC signal reproduction timing, and controls the signal reproduction level for the servo signal etc. reproduced thereafter to be constant. There is.

In this way, the reproduced signal level is controlled to be constant, and the reproduced signal is sent to seven sample and hold circuits 15 provided in parallel.
a, 15b, 15c, 15d, 15p, 15qs15r
and extracted according to the timing signal. and sample and hold circuits 15a-15d
The value of the reproduced servo signal at each timing is extracted by a subtracter 16a.

After the difference is determined through the A/D converter 17, the difference is taken into the CPU 18 through the A/D converter 17.

Further, the signals extracted to the sample and hold circuits 15p to 15r are passed through the I10 port 19 to the CP018.
is input.

In this way, according to the input CPUxs#M@servo signal), the CPU 8 detects the position of the head 2 with respect to the disk recording medium 1, and from the change in the detected position, the CPU 8 detects the position of the head 2.2'. A movement control signal for the % nuclear head 2.2' is generated by determining the movement speed and the like. This movement control signal is applied to the head movement control device 4 via the switch circuit 20 to control the positioning of the head 2 with respect to the disk recording medium 1.

Incidentally, during the seek operation of the head 2.2' or in the case of coarse positioning control for the disk recording medium 1 (track), the difference between the servo signals obtained through the subtracters 16a and 16b is output from the compensation circuit 21. The signal is applied to the head movement control device 4 via the switch circuit 20, and its control is performed.

Head positioning control based on such servo signal detection is performed in the same manner as in the conventional apparatus which forms a plurality of concentric tracks.

Now, the feature of this device is that the phase of a servo pattern formed by embedding each of a plurality of sectors L, which are equally divided in the circumferential direction of the disk recording medium 1, is
The index zone (one sector specified in the circumferential direction of the disc recording medium 1) in which the index mark 1a is formed is switched every round as a reference, and the track pitch is divided by the number of sectors set as above. There are points where servo patterns of the same phase are sequentially shifted from each other around one track to form a spiral shape with a value of .

Furthermore, the spiral servo pattern is formed so that the spiral direction is opposite between one surface and the other surface of the disk recording medium 1.

That is, when looking at one side of the disc recording medium 1,
Servo patterns of the same phase are formed in servo sectors 1c formed by dividing the disk recording medium 1 into l pieces in the circumferential direction, and are shifted by l predetermined pitches in the radial direction. When the servo pattern is rotated once, the positions where the servo patterns of the same phase are formed are shifted by exactly one track. Then, the servo signal formation position fi! that caused the deviation by one track! (index zone), the phase of the servo signal is sequentially switched.

Specifically, as shown in FIG. 5, which shows an example of servo patterns in adjacent servo sectors 1c, the total deviation Δp of the servo signal formation position between the servo sector ICs, the number of divided sectors is n, and the track When the pitch is P.

A servo pattern of a predetermined phase is embedded in each of the servo sectors 1c with a determination of Δp s P/n I.

On the other hand, servo patterns are similarly formed on the other surface of the disk recording medium 1 with a deviation of Δp, but the direction of the deviation is reversed as shown in FIG.

In this way, make the phase true every round.

In addition, according to the disk recording medium 1, which has servo patterns formed on both sides of the servo pattern while shifting the positions over a plurality of servo sectors 1c in a spiral manner, on one side of the medium ζ, a follow-up servo is applied every round. Switch pattern phase 1+7!
The head 2 performs disk recording on the disk recording medium 1 by making the head 2 follow a servo pattern of the same phase throughout one rotation while using the index mark 1a as a reference. It is possible to spirally move the medium 1 from the outer circumference to the inner circumference.
J Noh and Nashi.

On the other hand, the head 2' can be moved continuously from the inner circumference to the outer circumference of the disk recording medium.

Therefore, under the positioning control of this head, it is possible to continuously form spiral data tracks on both sides of the disk recording medium 1.

Moreover, when forming this spiral data track, the position of the head 2 can be regulated with high precision according to the servo pattern, so it is possible to improve the track density by controlling the track pitch. Become.

The data track has a spiral shape, and when recording and reproducing on one side is completed, simply by switching the head, recording and reproducing are performed continuously on the other side. 2 can be continuously followed.

Even with large amounts of data such as image signals, it is possible to continuously record and reproduce the information without causing so-called interruptions. Furthermore, the data track may be formed in a spiral shape.

Since the phase of the servo pattern is sequentially switched with the index zone as a reference, the track position of the head 2 can be detected with high precision in each station and sector from the phase of the servo pattern. Therefore, using this position detection information, it is possible to control the movement of the head to any data track position and to directly access any data track position.

Thus, here is a disk that has both the advantages of the conventional device for recording and reproducing information by forming data tracks concentrically on the disk recording medium 1, and the advantages of forming the data tracks in a spiral shape. The device can be realized.

Note that the present invention is not limited to the above-described embodiment. In the embodiment, the two heads 2 and 2' are integrally driven at the same time. , the head 2' is placed on the inner circumferential side, first only the head 2 is moved to the inner circumferential side, and when the innermost circumference is reached, only the head 2' is moved to the outer circumferential side.
It can also be driven independently. Further, in the embodiment, an example applicable to the 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 diagram are separate. Further, the present invention can be similarly applied to a data surface servo method in which servo signals are recorded deep. The rotational driving method of the disk recording medium 1 may also be a constant rotational speed type or a constant linear velocity type. Also, the spiral track pitch, track pitch, etc. may be determined according to the specifications of the apparatus. In short, the present invention.

can be implemented with various modifications without departing from the gist thereof.

[Brief explanation of the drawing]

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, Fig. 3 is a diagram showing the configuration of a servo sector, and Fig. 4 is a diagram showing a configuration of a servo sector. The figure shows an example of a reproduced servo signal. FIG. 5 is a diagram showing the phase relationship of servo signals between adjacent servo sectors on one side of the disk recording medium, and FIG. 6 is a diagram showing the phase relationship of servo signals on the other side of the disk recording medium. 1...Disk recording medium% 2.2'...Head,
3... Actuator, 4... Head movement control mechanism, 5... Switch, 11... AGC circuit, 12...
- Sector detection circuit % 13... Index zone detection circuit, 14... Sample pulse generation circuit, 15a~
15r...Sample fist hold circuit, 16...Subtractor, 17...A/D converter, 18...CPU% 1
9... I10 port, 20... Switch circuit, 21
...Compensation circuit. Agent Patent Attorney Ken Nori Chika Kikuo Takehana Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (4)

[Claims] (1) A spiral servo track is formed on both sides of a disk recording medium in mutually opposite rotational directions, and a servo pattern written on the servo track is read via a head to signal the position of the disk recording medium of the head. 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 using the head or another head provided in association with the head. A disk device featuring: (2) The spiral servo track divides the disk recording medium in the circumferential direction using an index mark provided at one location on the disk recording medium as a reference, and adjusts the phase of the servo pattern written in each of a plurality of sectors. Switching every lap of the track based on the above index mark position,
In addition, servo patterns having the same phase are sequentially shifted over one circumference of the track and formed in each of the sectors at a value obtained by dividing the track pitch by the number of sectors. Disk device as described. (3) The disk device according to claim 2, wherein the index mark is written in a specific sector as part of a servo pattern. (4) The servo pattern consists of a first servo pattern used for coarse positioning of the head with respect to the disk recording medium, and a second servo pattern consisting of a two-phase dibit pattern used for precise positioning. The disk device according to item 1.