JPS619875A - Head speed controlling system - Google Patents

Abstract

PURPOSE:To control the speed of a head by using a speed free from speed detection error due to track vibration by correcting servo information read by the head by track vibration information. CONSTITUTION:When a disk 8 is inserted into a floppy disk device, muCPU38 switches a servo system to speed control, and gives a negative speed control current to a voice coil motor 46 through an IO board 41, D/A converter 43 and a switch 34, and moves a head 7 from the inner periphery to the outer periphery of the disk 8. A carriage 22 comes into contact with a stopper 45, and the head is fixed on the servo information recording area. Servo information is read successively from the servo sector of the disk by the head 7 and stored in a memory 39. Fluctuation of position caused by track vibration is obtained from the data obtained and the moving speed of the head is corrected, and speed control is performed by using a speed that does not include track vibration while comparing with a preset speed table.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a recording medium in which servo information is embedded in a predetermined area of a data surface, and the present invention relates to a recording medium having servo information embedded in a predetermined area of a data surface. Regarding control method.

[Technical background of the launch]

Conventionally, a so-called embedded servo system has been proposed as a tracking servo system for disk recording media. In this method, the data surface is divided into a plurality of sectors, a servo sector for the head position side (e) is provided in the index portion where each sector is detected, and servo information is embedded in the servo sector in advance.

In ancient times, for example, as shown in FIG.
It is composed of a G0 section 4 and a position section 5.

The erase section 3 has a maximum erasing period of one track zero, and is a section that detects the leading portion of each sector. Further, the AGC section 4 is used for signals and the like when adjusting signal levels between tracks and sectors. The position section 5 is a section that detects the position of the recording medium in the radial direction.
A two-phase sabot signal 6, which is usually called a two-phase dibit pattern, is input. Note that writing by the head is prohibited in this servo sector 2.

For such a disk, when the head 7 is currently on-tracking on the 4N+4) rack as shown in FIG. 4, the signal detected on the servo sector 2 becomes the signal shown in FIG. Here, the signals detected by the position section 5 are sequentially referred to as a position signal A.

B, C, and D, head position control is performed as follows.

That is, the difference signal X=A-B Y=C-D between the 8th question and CD of the peak-held values of the position signals A, B, C, and D is defined as a first signal group, and this first The sum signal and difference signal U=X0Y V=X−Y of the signal group are defined as a second signal group. These signals X, Y, U
.

The relationship between the size of (2) and the position of the head is as shown in FIG.

When performing a seek operation, if the maximum moving speed of the head is less than 4 tracks per sector, as is clear from Figure 2, by determining the size of X and Y, the section where the head exists can be . .

It is possible to determine Ll, L, .

In other words, interval. + "1 + Ll! + To judge Ll, first obtain the signals X and Y, Lo;X>0, Y)O Ll;X)O, Y<O5 Ll; , Y〉0, the head existence section L0-L,
can be known.

On the other hand, the position of the head within the track is determined using %Ul■, Do=V/a +0.5; L.

D 1 = o, 5U/a; LID l =
0.5- ■/ a j L2Ds = UZa +〇,
5 ; It can be found in L3 (however, a is X shown in Figure 2,
width value of Y).

Thus, if we record in memory the section LB in which the head was at position 1 in the previous sector and the position gDB within that section Ln, we can record in memory the section Lp where the head is currently located and the position gDB within that section Current position IR by position Dp
pp'E can be obtained. At the same time, the head movement speed V per sector can also be determined by v = pp -1)B.

Therefore, using such information (first, perform rough movement of the head by speed control according to a preset speed table, and then perform position control when the head approaches the target position sufficiently). As mentioned above, when the servo information embedded in the disk is sequentially extracted from adjacent servo sectors according to the rotation and the difference between the created positions is used as the speed, if the head moves due to the head movement, if track wobbling occurs on the disk, Due to variations in the absolute position of the disk in the radial direction as seen from the head, the speed created from the position obtained from the disk includes an error.

In a convertible disk device, especially a floppy disk device, track deviation of one track or more occurs due to eccentricity due to spindle or chucking errors or eccentricity due to expansion and contraction of the disk itself due to changes in temperature and humidity.

Therefore, during speed control, accurate speed cannot be obtained, and in particular, variation occurs in the entry speed when switching to field control when approaching the target track, which in turn causes variation in settling time during position control. caused a problem.

[Purpose of the invention]

The present invention has been made in view of the above problem, and its purpose is to obtain an accurate speed that does not include errors caused by the lack of tracking, and to smoothly move to a target track according to the above speed. Seshime,
Another object of the present invention is to provide a highly practical head speed control system of 7 m.

[Summary of the invention]

The present invention provides a disk recording medium in which servo information is embedded in servo sectors provided at equal angular intervals, in which a head is fixed in advance at an arbitrary position in a servo information recording area, and the servo information is read by the head in each sector. Obtain track runout data from the head, determine the moving speed of the head from servo information sequentially read by the head from adjacent servo sectors according to the rotation, and use the speed to roughly move to the target track. During image production, the servo information read by the head is corrected using the above-mentioned track recording method to correct the speed I! caused by track shake. It is characterized in that speed control vAl is performed using accurate speed without detection errors.

〔Effect of the invention〕

According to this research, even when track runout occurs, an accurate speed is determined from the position corrected using track runout data obtained in advance, and the speed is accurately controlled according to the above speed, allowing the head to move smoothly to the target track. It becomes possible to move the .

Therefore, the variation in entry speed when approaching the target track and switching to position control becomes smaller, and this reduces the variation in entry speed when switching to position control.
The variation in the centering time at If11 is also reduced, making stable seeking possible.

[Actual J-angle example of the invention]

Hereinafter, details of the present invention will be explained based on illustrated embodiments.

Figure g1 shows a schematic diagram of a recording pattern and a detailed diagram of a servo pattern of a floppy disk according to an embodiment of the present invention.

In FIG. 1ζ, one side or both sides of the disk 8 are
The inner circumferential portion l and the data zone 11, which is an area for recording data. A guard zone 12 is formed at the outer periphery.

The guard zone 12 is provided at the outermost portion of the disk with a width of several tens of tracks in order to detect the outermost trunk in the data zone 11, and normally data is not written or read therein.

Furthermore, they are divided into 32 sectors arranged radially, and each sector 9 is composed of servo sectors 13 and 15 in which servo information is embedded and a data sector 14 which is a part for writing/reading zones. There is. The 32 sectors are individually identified, and the sector located in the same radial direction as the 1st digit of the index hole 10 is designated as sector number 0, and from this sector number is increased in order from 0 to 31 according to the rotation direction. Sector numbers are assigned. Furthermore, data sector 1 in guard zone 12
In part 6, a signal with no particular meaning is recorded.

The details of the above servo sectors 3 and 15 are as follows: erase section 17, AGC section 18. It is composed of four parts: a zone part 19 and a position part 20. The zone section 19 is a section provided to distinguish the data zone and the guard zone, and the other sections have the same functions as those shown in FIG. 1.

Next, the process by which track recording information is taken in from the disk 8 in which servo information is embedded as described above will be explained with reference to FIGS. 2 and 3.

In FIG. 3, when a disk is inserted into the floppy disk device, the μCPU 3B switches the servo system to speed control and at the same time switches the analog switch 34 via the Ilo boat 40, the I10 boat 41, the D/A
Converter 43, analog switch 34 and amplifier 37
A negative speed control current is applied to the voice coil motor 46 via the voice coil motor 46 to move the head 7 fixed to the carriage 22 from the inner circumference of the disk 8 to the outer circumference. The carriage 22 eventually comes into contact with the stopper 45, and the head 7 is fixed at that position. However, at this time, the head exists on the servo information recording area.

Thus, the fixed head 7 moves from 32 servo sectors in one revolution of the disk 8. Read la. Then, from the read servo information, as described above, the section Lp in which the head exists and the position iDp within that section are determined and stored in the address of the memory 39 corresponding to the number of each sector. The data obtained in this way becomes track runout data.

When performing a seek operation, the head movement speed Vs per sector is determined by the head position PS-8 in the previous sector (sector number 5-1) and the current sector (sector number 5-1), as described above. S) is determined by the difference from the digit 1ilys.

Vs = Ps-Ps-.

The positional variation Ep caused by track failure during the period from the previous sector to the current sector is calculated from the track runout data as follows: Ep=Rs - Rs.

It can be found by Here, Rs is track runout data obtained in the sector where the head currently exists, and R5-1 is k
This is track runout data obtained in the previous sector.

Therefore, the accurate head movement speed [VA is this variation B
corrected by p.

VA = Vs - Ep It is required as.

Then, the head is moved to the target track using a speed VA that does not include track runout and compared with a preset speed table, and when it gets close enough, it switches to position control. .

[Brief explanation of drawings]

FIG. 1 is a diagram showing an outline and details of a recording pattern of a floppy disk according to an embodiment of the present invention, and FIG. 2 is a diagram showing position signals X, Y, and U according to the same embodiment. Fig. 3 is a block diagram showing the electric circuit configuration of the floppy disk device according to the same embodiment;
This figure is a diagram for explaining a servo sector recording pattern of a conventional embedded servo system, and FIG. 5 is a waveform diagram showing an example of a signal read by a head on the recording pattern. 8... Floppy disk, 2, 13.15... Servo sector, 1.14... Data sector, 11-data zone, 12... Guard zone, 10... Index hole, 8... Head , 9... Sector, 3.
17...Erase section, 4, 18...AGC section, 5,
20...Position section, 19...Zone section, 45.
...Stopper, 32, 33.34...Analog switch, 21°37...Amplifier. Representative Patent Attorney Kensuke Chika (and 1 other person) No. 1
Diagram / γ ZQ 2nd diagram External rotation □ Internal cause 3rd diagram

Claims (1)

[Claims] In a disk recording medium in which servo information is embedded in servo sectors provided at equal angular intervals, the head is fixed in advance at an arbitrary position in the servo information recording area.
Track runout data is obtained from the servo information read by the head in each sector, the moving speed of the head is determined from the servo information sequentially read by the head from adjacent servo sectors according to rotation, and the speed is used to approximate the target track. 1. A head speed control method, characterized in that during speed control to control the movement of the head, a speed determined by correcting servo information read by the head using the track runout information is used for control.