JPH02230572A - Head positioning control method - Google Patents

Abstract

PURPOSE:To prevent a readout/write error occurring by controlling a method in such a way that no seek complete signal is outputted until an on-track state set in advance is set at the next seek when a magnetic head is located at a position near the margin of an off-track machine. CONSTITUTION:In the case of detecting a state where servo information is read out and the magnetic head is located at the position in an area near the margin of the off-track machine and with high possibility to generate the off- track of the head, the positioning of the magnetic head is performed so that a prescribed on-track state can be set necessarily on a cylinder (recording track) until the seek complete signal is outputted based on servo information when the next seek command arrives and seek on another cylinder is performed. And after tracking is confirmed, the seek complete signal is outputted to a host computer. Thereby, it is possible to prevent an error occurring by prohibiting readout/write at an off-track state where the magnetic head is positioned in a range near to the margin of the off-track machine.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention is a method for recording and recording information by rotationally driving an information recording medium.
The present invention relates to a method for controlling the positioning of a head device with respect to a recording trunk in an information recording medium drive device that performs reproduction.

[Conventional technology]

Various types of disk drives are known for recording and/or reproducing information by rotationally driving an information recording medium, for example, a disk-shaped magnetic recording medium (hereinafter referred to as a magnetic disk). However, especially for small-sized devices that require a large amount of information, disk drive devices, also called hard disk devices, are often used.

This hard disk drive rotates a magnetic disk, which has a magnetic recording layer formed on the surface of a hard disc, at high speed, and makes a magnetic head levitate above the surface of the magnetic disk to perform recording/reproduction.

An example of this type of disk drive is shown in FIG. In the figure, the disk drive device includes a magnetic disk 1 for recording information, a magnetic head 2 for recording/reproducing information on the magnetic disk 1, and a direct drive motor (not shown) for rotationally driving the magnetic disk 1. Below, D
D motor) and the magnetic head 2 are connected to the magnetic disk 1.
2. A head drive mechanism 4 for moving to a predetermined trunk, a head plate 5 that serves as a head for a housing that houses the magnetic disk 1, magnetic head 2, etc. and holds it in a sealed shape, and a motor drive circuit and a control circuit. It mainly consists of a printed circuit board (not shown) on which are formed, etc., and a frame (not shown) for mounting this printed circuit board in the hairsprays 1 to 5.

The magnetic disk 1 is 1 in this disk drive device.
2. Magnetic Hesode 2
are provided on each side, two in total, and are attached to the swing arm 8 of the head drive mechanism 4 via a cantilevered support spring 6. The head drive mechanism 4 is attached to this swing arm 8 and a part of the swing arm 8.
The steel heel l- Pulley 1 with 9 wound around it
0 is inserted and fixed, and by driving the stamping motor 11, the swing arm 8 can be swung about the concave shaft 8a.

The casing that accommodates the magnetic disk 1, magnetic henode 2, swing am 8, steel hell 1-9, pulley 10, etc.
It consists of the hair plate 5 and a 1-sopkahar (not shown), and in order to maintain airtightness, hair plates 1, 5 and 1, are used.
Gasket is used for the contact part with the sobcacher and the part of the stenoping motor 1, and the shaft part of the DD motor is filled with magnetic fluid.

In the drawing of the stenobing motor 11, a filter 13 is provided on the top surface and is used to remove dust inside the housing.

Further, a signal line is extended from the magnetic helix 2 via the flexible printed circuit 1 and the wiring board 14 to the hemisphere amplifier 21.

By the way, when moving the magnetic hemlock 2 using the stethoping motor 11 as described in Section 2, the positioning of the magnetic hemlock F'2 becomes more difficult as the density increases. That is,
In hard disk drives, since the coefficient of expansion of each material inside the drive is different, there is a problem called thermal off I-rank in which the position of the magnetic head 2 relative to the recording head deviates due to temperature changes. Inch-type hard disk drives generally have 400 TP.
Beyond I, it is difficult to position the magnetic head 2 without using a servo.

Therefore, it is necessary to introduce some kind of servo means.The servo information is read out by reading out the servo information from the magnetic disk 1, and based on the read servo information, the magnetic head 2 is positioned at the recording 1 rank fine trunk position. Various positioning control methods have been proposed.

For example, patent application No. 62-19922 filed by the present applicant.
In 4, the positional shift is detected by moving the magnetic head from the recording l rank to a predetermined zarbo track. Obtaining two signals of the second index signal generated by the wear timer within the circuit,
These two signals are used as the window timing of the servo data access control circuit and as an interrupt signal to notify the microcomputer of the arrival of the servo pattern.

The servo data pinoch amplifier circuit generates two windows (UP, DOWN) in response to the above servo information, performs V/F conversion during each window period, and performs UP/DOWN.
Perform N count 1. This will be explained with reference to FIGS. 4 to 6. FIG. 4 is a block diagram showing a control system of a conventional disk drive device, FIG. 5 is a configuration diagram of a positional deviation detection circuit, and FIG. 6 is a timing chart of the positional deviation detection circuit.

In FIG. 4, the drive system of the disk drive device controls a DD motor 3 that rotates the magnetic disk 1 and a stethoping motor 11 that swings the swing arm 8.
A drive circuit 22 sends and receives signals to and from the hesode amplifier 21, and processes servo information read by the magnetic hesode 2 and amplified by the hesode amplifier 21, and sends an electric signal related to servo control to the drive circuit 22. The servo circuit 23 and the drive circuit 22 are connected to the interface 2
It is mainly composed of a controller 25 which is controlled via a controller 4. The controller 1/roller 25 and the post computer 26 are connected by a lotus 27, and are capable of processing signals detected by the magnetic hesode 2 or signals sent to the magnetic hesode 2. Further, the drive circuit 22 is equipped with a RAM table 4a that records excitation currents to be supplied to each excitation phase of the stevening motor 11.

On the other hand, in this conventional example, known staggered servo information is written in advance over all the trunks on the magnetic disk 1 at one preset location on each trunk and at a position 180 degrees shifted from this location.

When processing servo information, first, as shown in FIG. 5, position data consisting of known staggered servo information written in advance in the recording trunk of the servo area is read out by the magnetic head 2. Amplifier 4 of head amplifier 21
．． The signal is amplified by 0.41, passes through the low-pass filter 42, and then is input to the IC 43. The servo readout signal shown in FIG. 6 (2) differentiated by the IC 43 is detected and amplified by a detector 44 and an amplifier 45 to become a detected and amplified signal shown in FIG. 6 (2). This detection signal is V/F
Voltage/frequency conversion is performed by the converter 46, and the sixth
The V/F converter output will be as shown in Figure ■. This V
The /F converter output is further applied to the basic window shown in FIG. 6 (■) and the real window [phase] shown in FIG. It is input to the boat as 8 bits. Regarding the second servo area, the first internal index signal IN. When the disk 1 rotates approximately 180 degrees based on the output of the timer, the second internal index signal generating circuit 49
The second internal index signal IN2 is outputted to the V/F converter 46, and the same operation is performed.

The microcomputer 48 which pink-amplified the data contents output as the above 8-bit data determines the current servo zone type from the trunk counter number, switches the range from ON 1 to rank according to the type, and switches the ON trunk based on the content. or judge the degree and direction of off-track and, if necessary, drive the stamping motor 11 via the drive circuit.
is driven by the microstep described below.

On the other hand, the stamping motor 11 used is, for example, 0
．． It is a 4-phase uni-bolar type with 9 degrees/steps. By exciting this motor in two phases and unbalancing the winding currents of each phase of A and B, a step angle of 0.9 degrees can be changed to a maximum of 12 degrees.
Microstamp with a resolution of 8 stop points, and then 0.
The 9 degrees/stethop is divided into two, and each trunk is driven to correspond to 0.45 degrees. Also, since the trunk density of the magnetic disk 1 is 880 TP I, the trunk pinch is approximately 28.9 μm, and this 1 piso and the above 0.45 degrees correspond to 1 step. 0.9 degrees is 128 microtemps, so 0.45
The degree is half that, 64 microsteps. Therefore, the resolution of microstep drive is 28.9/64=
This is 0.45 μm/microstep, and naturally the servo correction possible range for each trunk is 28.9 μm at maximum.

In FIG. 6, ■ is the first internal index signal IN obtained by taking the index from the rotor 3a of the DD motor 3, and ■ is the second internal index signal IN!
, ■ is the waveform after the first internal index signal/second internal index signal waveform shaping, ■ is the external index E
I N, ■ is write protect, ■ is servo read signal, ■ is servo signal detection amplification signal, ■ is base isolation window, ■ is V/F converter output, [phase] is real window, ■ is count pulse, @ is The U/D counter and [phase] each indicate head selection.

The criteria for determining whether on-trunk or off-track is as shown in the explanatory diagram of the relationship between the U/D counter output and on-trunk/off-track in Figure 7. Two wide range on-trunk ranges WR are set on both sides of this narrow range on-track range NR.

That is, the center value (O
OH) is taken as the fine track position, and ±n (n is a natural number) count based on the center value is treated as onl/rack. In the conventional example shown in FIG. 7, ±8 counts 1. are on-l-rasok, and among these, ±6 to 8 counts are wide range on-track range WR.
, ±0 to 5 counts is narrow range on trunk range N
It is R.

Then, the output value of the U/D counter 47 and the microstep are made to correspond to each other to determine the output to the stooping motor 11, and the stomping motor 11 is driven in microsteps based on the determined output. In this case, for example, the center value of the U/D counter 47 (OOT{>) is set as the fine trunk position, and the relation between the above output and the U/D counter 11 is established in advance, and the stamping motor 11 is adjusted according to the U/D counter output. In this way, the narrow range on-track range NR
and wide range on-track range WR is set,
For example, when the magnetic head nod 2 is located in the narrow range on 1 and the rasok range NR, read/write is performed at that position without microstep driving, and the magnetic head 2 is placed in the wide range on I and the rasok range WR. When it is located, the read/write is performed by moving to the center of the 1-rank by 1 or 2 microsteps.

[Problem to be solved by the invention]

Incidentally, a disk drive device has an off-track limit called an off-track margin, and if this limit is exceeded, an error will occur and reproducibility of writing/reading cannot be ensured. Therefore, even if the on-track range of narrow range and wide range is set as described above to efficiently control on-track, if the magnetic head exceeds the off-1-rank margin due to some disturbance, an error may occur eventually. , and the meaning of on-1 rank control is lost.

This invention was made in view of the above technical background, and its purpose is to propose a positioning control method for a magnetic head of a disk drive device that does not cause errors even if some disturbance is applied. There is a particular thing.

[Means to solve the problem]

The above purpose is to read out a pair of staggered servo information written in correspondence with the recording track, and based on the read servo information, record information on the information recording medium of the head device.
- In a head positioning control method that performs positioning with respect to a rack, there is an off-track margin between a preset off-track margin limit and an allowable on-trunk range limit.
An area with a high risk of slipping is set in advance, and when it is detected that a magnetic head is located in that area,
After positioning the magnetic head so that it is on track when the next seek operation is completed, read/write
This is achieved by making it writable.

[Effect]

According to the above means, when the servo information is read and it is detected that the magnetic henode is located in an area where there is a high risk of off-tracking near the off-track margin limit, the next seek command comes and other When seeking to a cylinder, the magnetic head is positioned based on the servo information so that the cylinder (recording track) is in the predetermined on-trunk state before outputting the seek combined signal, and the on-track position is confirmed. After confirming, please
Outputs seek combine signal to computer. This allows read/write in off-track conditions where the magnetic head is located close to the off-track margin limit.
Writing is not performed, and errors can be prevented from occurring.

〔Example〕

Hereinafter, an example of implementation of the present invention will be described with reference to the drawings.

FIG. 1 shows OFF 1 in the positioning control method according to the embodiment.
~ It is an explanatory diagram of an area set within the rack margin.

Note that the disk drive device, the hardware configuration for detecting servo information, the processing method for each servo information, etc. are the same as in the conventional example, so components that are the same or can be considered to be the same as those in the conventional example are given the same reference numerals. , and omit explanations about them.

In FIG. 1, the count value of the U/D counter 47 and each area correspond as follows.

That is, ±10 counts 1 of the center value (OOH) are the on-track range, of which ±6 to 10 counts are the wide range on-track range WR, and ±0 to 5 counts are the narrow range on-track range NR. Also, ±11
~15 counts are set as the yellow zone YZ, and ±16 to 20 counts outside of that are set as the resodo zone RZ. The counter values in this case are similar to the values of the U/D counter 47 shown in FIG. 5, and the 5 counts correspond to 05H, the 10 counts correspond to AH, and the 15 counts correspond to FH. This count number and the actual amount of movement of the magnetic hesode 2 are set so that 5 counts indicates a difference of about 0.45 μm. In the disk drive device according to this embodiment, the trunk density of the magnetic disk 1 is 880 TPI as in the conventional example described above, so the track pinch between each recording track is about 28.9 μm, and the off-track margin limit OFTL is 40 counts, approximately 3.67
It is 17m. Therefore, in this embodiment, the resodo zone R is close to the off-track margin limit OFTL.
For Z, the amount of deviation detected in the same manner as in the conventional example described above is 30.
This means that it is set in a range that exceeds approximately 2.7 μm. Then, when reading the servo information, if it is found that the deviation is greater than the range setting value of the red zone RZ, it is determined that the magnetic head 2 is located in the red zone RZ. When located in this raid zone RZ, all separately prepared flags are turned on.

After that, when a seek command is received from the host computer 26, the host computer 26 positions itself on the target trunk in the completely on-trunk mode, and after confirming that the position has been positioned, sends a seek complete signal to the host computer. It is output to the computer 26 side and read/written.

This will be explained in detail with reference to the flowchart in FIG.

First, when the power is turned on (step S1), the disk drive device is started up (step S2), a ready signal is output (step S3), and the system waits for a step signal to be input from the host computer 26 (step S34). and,
If a step signal is input in step S4, a seek operation is performed (step S5), the corresponding flag of the target cylinder is checked (step S6), and it is determined whether the corresponding flag is turned on (step S6).
Step S7). In this step S7, the corresponding flag is turned ON.
When it is determined that the magnetic head 2 is located in the resodo zone RZ as described above, the on-track operation is performed so that the magnetic head 2 is in the on-track state in the complete on-track mode (step S8). Then, after clearing one flag corresponding to the sought stop cylinder (step S9), a seek complete signal is output (step 310), and the process returns to before step S4 to execute the same procedure.

Further, when the corresponding flag is not turned on in step S7, the magnetic heel 2 is not located in the resodo zone RZ, so it is assumed that it is on track, and a seek combine signal is output in step S10, and the The process returns to before step S4 and the procedure from step S4 is repeated.

On the other hand, when the step signal is not output in step S4, the every servo information detection/correction interrupt routine is executed. In this routine, first, servo information is detected (step S11) and the U/
The on-trunk status is determined from the value of the D counter (step S12). When it is determined in the next step 313 that the narrow range on-track NR state is present, the servo (RAM) table storing the positioning information of the magnetic head 2 with respect to the recording track is updated (step 314), and the Go back to Stepsop S4
Repeat the following steps.

Further, when it is determined in step S13 that the narrow range on 1/rasok NR state is not reached, the step step 315 determines whether or not the wide range on track state is reached. If it is determined in step S15 that the recording trunk is located in the wide range on-track WR range, move it one microstep to the center of the recording trunk and adjust the spread (step S16), and then perform the same procedure as above. After updating the servo table (step S17), the process returns to step S4.

Furthermore, if it is determined in step S15 that the vehicle is not located in the wide range on trunk WR range, the step 3 determines whether the vehicle is located in the yellow zone YZ.
Judging by 18. When it is determined by this step SI8 that it is located in the yellow zone YZ, the ROM is
Using the calculation formula set in the code, for example, substitute the U/D count value into the calculation formula, correct the required correction value for Off 1st and Rank world at once (Stenop S19), and update the servo table in the same way as above (Stenop S20) After L, return to the front of Step S4.

On the other hand, if it is determined in Step S18 that the vehicle is not located in Yellow Zone YZ, it means that the vehicle is located in Red Dune RZ.
In the same way as when it is located at
). After that, all 64 flags are turned ON (step S
23) to return to before step S4 and execute the steps from step 84 onwards. In the above flowchart, reading/writing is not possible from step S5 to step S9, and from step S11 to step S2.
Up to step 3, the magnetic head 2 stops on the recording 1/ranok and performs servo correction, so reading/writing is disabled even in these steps. Then, reading/writing becomes possible only after executing any one of steps S]4, 17, 20, and 23 above. In addition, in the above flowchart 1, steps from step S6 to step S9 surrounded by dotted lines, and steps from step S21 to step 323 indicating processing in the resodo zone.
The processing up to this point is a procedure related to the gist of the present invention.

Thus, according to the above embodiment, narrow range ion I
・Rank range NR, white range on L ・Rasoku range W
Since the method of positioning control of the magnetic head 2 is changed depending on the four regions of R, yellow zone YZ, and recording zone RZ, the average seek time can be shortened. In addition, when it is detected that the magnetic hesode 2 is located in the resodo zone RZ close to the off-track margin limit ○F T L, servo control is performed in full on-track mode, and the magnetic hesode 2 is located at the off-track margin limit ○F T L. ○F T L is prevented from exceeding, so when the magnetic head 2 is located in the resodo zone RZ,
Although the seek time is longer, there is no risk of read/write errors occurring.

In addition, if the boundary of the setting range of Resodo Zone RZ is too close to the off-1 rank margin limit OFTL, there is a risk of actual off-tracking, and if it is too close to the wide range on-trunk WR side, the average seek time will decrease. Therefore, the Lesotho Zone RZ is set within the above range in consideration of these circumstances. However, the above range is appropriately selected depending on the 1-Ranok density of the magnetic disk 1 used, the accuracy of drive control of the magnetic head 2, etc. Also, depending on the inner circumferential side and outer circumferential side of the magnetic disk 1, narrow range on I/
It goes without saying that the setting areas for the rank NR range and the wide range on trunk WR range may be changed, and the setting areas for the yellow zone YZ and the red zone RZ may be changed accordingly.

In addition, the servo control of the completely on 1 laser motor is performed by checking a separately prepared flag. For example, the magnetic disk surface is divided in advance into four areas as track groups in the radial direction, and each track group is multiplied by eight possible excitation phase numbers of the four-phase univollar stenoping motor 11. Total 3
Two flags are prepared for transferring to the inner circumferential side and for transferring to the outer circumferential side. Then, when it is detected that the magnetic hesode 1 is located in the lend zone RZ, all 64 flags are set to be set unconditionally, and when the next seek command is output from the host computer 26, the seek operation is performed. After completion, before outputting the seek complete signal, the appropriate flag is calculated from among all flags corresponding to the area of the stopped trunk, the excitation phase of the four-phase unipolar stamping motor 11, and the moving direction of the magnetic head, and the flag is Check to see if it is standing. When all flags are set, the system is in complete on-track mode, and after positioning to the trunk center, a seek complete signal is output.

〔Effect of the invention〕

As is clear from the previous explanation, an area where there is a high risk of off-tracking is set in advance between a preset off-track margin limit and an allowable on-trunk range limit, and the magnetic head is positioned in that area. When it is detected that the magnetic head is on track for the next seek operation, the magnetic head is positioned so that it is on track, and then a seek complete signal is output to enable reading/writing. According to this invention, when the magnetic head is located close to the off-track margin limit, the seek complete signal is not output unless the on-trunk state is set in advance during the next seek. There is no risk of read/write errors when seeking.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the relationship between counter values and on-trunk/off-I/rank areas in an embodiment of the present invention;
FIG. 2 is a flowchart showing the processing procedure of servo correction by area according to the embodiment, FIGS. 3 to 7 are for explaining the conventional example, and FIG. 3 shows the internal structure of the disk drive device. 4 is a block diagram showing the entire control system of the disk drive device; FIG. 5 is a block diagram showing the positional deviation detection circuit; FIG. 6 is a timing chart showing the operation of the positional deviation detection circuit; FIG. 7 is an explanatory diagram showing the relationship between the value of the UZD counter and on-track/off-track. l...Magnetic disk, 2...Magnetic head, 11...Stessoving motor, 26...
...Post computer, 47...U/D counter, 48. Old...Microcomputer. 1561- ＼ school

Claims (1)

[Claims] A head positioning control method that reads a pair of staggered servo information written corresponding to a recording track, and positions a head device with respect to a recording track on an information recording medium based on the read servo information,
An area where there is a high risk of off-tracking is set in advance between a preset off-track margin limit and a permissible on-track range limit, and when it is detected that the magnetic head is located in that area, A head positioning control method characterized by positioning a magnetic head so that it is in an on-track state when the next seek operation is completed, and then enabling reading or writing.