JPH11345470A - Servo data write device for disk storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep a track pitch constant and to realize high track density by providing a means capable of evaluating a track locus when the servo data are recorded. SOLUTION: This servo data write device is a servo writer provided with rotary positioner 17 and arm 18 for recording the servo data on a disk 1 by using a head 7 of an HDD and a servo data observation mechanism having an observing head 52 for observing the recorded servo data. The servo data observation mechanism is provided with a positioner drive circuit 61, an observing rotary positioner 50, the arm 51, a signal processing circuit 54 and a position detective circuit 55.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a servo data writing apparatus for pre-recording data on a magnetic disk device such as a hard disk drive (HDD).

[0002]

2. Description of the Related Art Conventionally, a hard disk drive (HD)
In D), as shown in FIG. 6, a sector servo system in which servo areas 4 arranged at predetermined intervals on the disk 1 are provided. On the disk 1, a number of tracks 2 used as data recording areas are formed concentrically. Each track 2 roughly includes a servo data area 4 and a data sector 5 which is a recording area for user data. The servo data area 4 may be referred to as a servo sector 6 together with an adjacent data sector 5 in some cases. The distance between adjacent tracks is
Called track pitch 3.

As will be described later, servo data necessary for controlling the positioning of the head 7 at a specified position (target track) on the disk 1 is recorded in the servo area 4. The head 7 is mounted on a head actuator 20, moved in a radial direction on the disk 1, and positioned at a designated position. The head positioning control is executed by the microcontroller, which is the main control device of the HDD, based on the servo data read by the head 2. Therefore, the recording accuracy of the servo data greatly affects the head positioning accuracy.

[0004] The servo data is stored in the HDD during the manufacturing process.
Servo track writer (hereinafter simply called servo writer)
The data is recorded by a dedicated servo data writing device referred to as "servo data writing device". Here, in the servo area 4, as shown in FIG.
In addition to the servo data including the address data 10 indicating the track number and the servo burst data 11, an AGC block 8 and an erase block 9 are provided. AG
The C block 8 is used for head sensitivity adjustment. The erase block 9 is an area for detecting an area where the address data 10 is recorded later by two magnetic transitions.

The servo burst data 11 usually has 4
Servo burst patterns A (12), B (13),
C (15) and D (16). Each burst pattern is recorded with a shift of 1/2 track pitch. The microcontroller controls the positioning of the head 7 so that the reproduced output values (amplitude values) of the servo burst patterns A (12) and B (13) from the head 7 become equal, and recognizes the position as the track center 14. I do. Here, the servo burst patterns C (15), D
(16) shows a servo burst pattern A during a seek operation in which the head 7 moves from one track to another track.
It is used when the reproduction output values of (12) and B (13) are saturated (that is, when the head 7 is located on the patterns A and B).

As shown in FIG. 3, the servo writer drives a rotary positioner 17, an arm 18 attached to the rotary positioner 17, a push pin 19 attached near the tip of the arm 18, and the rotary positioner 17. Drive circuit 30 for the operation. FIG. 4 is a conceptual diagram showing the positional relationship between the servo writer, the disk 1 of the HDD, and the head actuator 20 as viewed from the side.

The servo writer records servo data on the disk 1 using the head 7 and head actuator 20 of the HDD for recording servo data. Specifically, when the rotary positioner 17 is rotated by the positioner drive circuit 30, the push pin 19 attached to the arm 18 moves the head actuator 20 so as to press the head actuator 20 in the radial direction of the disk 1. On the other hand, the head actuator 20 also supplies the driving force from the voice coil motor (VCM) 21 to the rotary positioner 17.
Acts in a direction opposite to the rotation direction of the arm 18 and moves integrally with the arm 18.

When the positioner drive circuit 30 sets the rotary positioner 17 at a target position on the disk 1, the head 7 records servo data at a specified position on the disk 1. Hereinafter, the procedure of the servo data recording method will be described with reference to FIG.

First, the head 7 is set at the position A, and servo burst patterns A12 and C15 are recorded. next,
The head 7 is set at the position B, the position of the pattern A12 is erased, and the servo burst patterns B13 and C15 are recorded. The head 7 is set at the position C, and the pattern C1 is set.
5 is erased and the servo burst pattern B1 is erased.
3, Record D16. Next, the head 7 is set at the position D, the position of the pattern B13 is erased, and the servo burst patterns A12 and D16 are recorded. Then, the head 7 is set at the position E, and the servo burst pattern A1 is set.
2 and C15 are recorded, and the position of the pattern D16 is erased. By repeating such a sum of operations, servo burst data can be recorded at a predetermined position in the servo area on the disk 1. The other blocks 8, 9, and 10 in the servo data area are recorded at each head position.

[0010]

By recording servo data (formation of a servo data area) on the disk 1 by the above-described servo writer, a track format is formed. However, the recording method using the conventional servo writer has the following problems.

The servo writer includes a head 7 and a disk 1
There is no means for detecting the positional relationship between the two. The disk 1 is rotated by a spindle motor built in the HDD. The spindle motor has a vibration in the radial direction, and the relative position between the head 7 and the disk 1 is constantly changing. Even if the head 7 is completely stationary, the track trajectory by recording the servo data does not become a perfect circle. Therefore, when a plurality of tracks are formed by recording servo data, as shown in FIG.
A phenomenon occurs in which the track locus does not become concentric, and the track pitch 3 does not become constant. FIG. 5 shows a state of the track center 56 actually formed with respect to the ideal track center 53.

When the track pitch 3 is expanded or contracted, the possibility of overwriting data on an adjacent track when user data is recorded on each track on the disk 1 increases. For this reason, in practice, it is necessary to give the track pitch a certain margin,
This is a factor that hinders an increase in the track density (recording density in the radial direction) of the disk 1. Further, in the conventional servo writer, the evaluation of the recording state of the servo data (the reproduction accuracy of the servo data) cannot be performed at the time of recording, so that the evaluation is performed again after the write operation. However, the write error detection process required for the evaluation requires approximately the same processing time as the servo data write process.

An object of the present invention is to firstly provide a means for evaluating a track locus when recording servo data, thereby realizing a constant track pitch and consequently increasing a track density. It is to realize.
Secondly, by enabling the evaluation of the recording state of servo data at the time of recording, the efficiency of the servo data recording process can be improved as a result.

[0014]

According to the present invention, there is provided a servo data recording means for recording servo data on a disk by using, for example, a head of a disk storage device itself, and an observation device for observing the recorded servo data. This is a servo writer provided with servo data observation means having a head.
The servo data observation means has observation positioning means for controlling the positioning of the observation head on the disk separately from the head positioning means of the servo data recording means.

Further, according to the present apparatus, based on the observation result of the servo data recorded on the disk by the servo data recording means from the servo data observation means, the track trajectories adjacent in the radial direction of the disk coincide with each other. Is provided with control means for controlling the servo data recording means.

With this configuration, when the servo data is recorded on the disk, the track trajectory to be formed is observed, and the recording position of the head is controlled so that the trajectories of the adjacent tracks match. Therefore, the track pitch between the tracks formed on the disk becomes substantially constant, and it is possible to suppress a situation in which an overwrite phenomenon occurs between adjacent tracks. As a result, the margin of the track pitch can be minimized, so that it is easy to increase the track density.

According to another aspect of the present invention, there is provided a servo writer having an evaluation unit for evaluating a recording state when recording servo data. Specifically, the evaluation means evaluates whether the displacement of the track formed by recording the servo data is within an allowable range with respect to a preset reference value. Thus, for example, when the evaluation result is out of the allowable range, the recording of the servo data on the corresponding track can be performed again. Therefore,
After the servo data recording process, it is possible to omit the step of evaluating the recording state again, and as a result, it is possible to realize an efficient servo data recording step.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration of a servo data writer related to the present embodiment, and FIG. 2 is a diagram for explaining a servo data recording method by the servo writer of the embodiment. (Structure of Servo Writer) The servo writer of the present embodiment
As shown in FIG. 1, in addition to a mechanism including a rotary positioner 17, an arm 18, and a push pin 19 for recording servo data, a servo data observation mechanism is provided. This servo data observation mechanism includes an observation rotary positioner 50, an arm 51 attached to the observation rotary positioner 50, and an observation head 52 attached to the tip of the arm 51.

The observation rotary positioner 50 is an HDD.
The observation head 52 does not physically interfere with the head 7, and the heads 7 and 52 are arranged on adjacent tracks, respectively, and the distance between the heads 7 and 52 is minimized. Is configured. In addition, when the servo data is reproduced from a certain track, the rotation direction of the disk 1 is set so that the observation head 52 can reproduce the data ahead of the head 7 of the HDD.

Further, the servo writer of this embodiment has a signal processing circuit 54 for servo data read by the observation head 52, a position detection circuit 55, and a positioner drive circuit 61. The position detection circuit 55 includes the signal processing circuit 5
Based on the servo data processed by step 4, the position (track position) of the observation head 52 is detected. The positioner drive circuit 61 includes a drive function of the observation rotary positioner 50 and a control device that executes a control process (evaluation process) related to the present embodiment, in addition to a positioner drive function for driving the conventional rotary positioner 17. Collectively. Specifically, it is a computer which is a control device of the servo writer. (Servo Data Recording Method of the Present Embodiment) A servo data recording method of the present embodiment will be described below with reference to FIG. 2 together with FIG.

In this embodiment, as shown in FIG. 2, servo data (here, a servo burst pattern A) is continuously recorded on adjacent tracks 57 (track number N) and track 58 (track number N + 1) on the disk 1. ~ D only) is assumed.

First, the positioner drive circuit 61 drives and controls the rotary positioner 17 in the same manner as a conventional servo writer, and moves the head 7 to the target track 57 on the disk 1.
, The servo burst pattern A
12, B13, C15, and D16 are recorded. Here, the positioner driving circuit 61 includes the observation rotary positioner 5.
2, the control is performed such that the observation head 52 is located at the ideal track center 53 assumed in advance as shown in FIG. In FIG. 2, the track center 56
Is composed of a servo burst pattern actually recorded by the head 7.

As described above, when the servo data is being recorded, the servo burst pattern recorded by the rotational vibration of the spindle motor 23 for rotating the disk 1 has the recording position (the ideal track described above) assumed in advance. It is recorded at a position different from the center 53). That is, it is a recording position displaced in the radial direction of the disk 1. Even when the observation head 52 is located at the ideal track center 53, the output values of the servo burst patterns A12 and B13 detected by the head 52 do not become the same.

The positioner drive circuit 61 is connected to an observation head 52 via a signal processing circuit 54 and a position detection circuit 55.
Then, the output values for the servo burst patterns A12 and B13 from the above are input, and the displacement amount (in the radial direction of the disk 1) between the ideal track center 53 and the actual track center 56 is calculated. At this time, the positioner driving circuit 61
Is the servo burst pattern A by the observation head 52
12, the total displacement X is calculated by adding the rotational shaft runout of the spindle motor 23 to the displacement at the time of reproduction of B13.

When the writing of the servo data to the track 57 of the track number N is completed, the positioner drive circuit 61 controls the drive of the rotary positioner 17 to move the head 7 to the adjacent track 58 of the track number N + 1. The head 7 records new servo burst patterns A12 and B13 in the same procedure. At this time, the observation head 52 is located at the ideal track center 53 of the track 57 on which the servo data was recorded immediately before.

The positioner drive circuit 61 observes the total displacement (denoted as Xab 59) of the servo burst patterns A12 and B13 from the observation head 52. Also,
The head 7 is newly provided with servo burst patterns C15 and D1.
When recording No. 6, the observation head 52 is located at a position displaced from the ideal track center 53 by a 1/2 track pitch. Therefore, the positioner driving circuit 6
1 is the total displacement amount (Xc) of the track 57 from the observation head 52 with respect to the servo burst patterns C15 and D16.
d60).

The positioner drive circuit 61 shifts the head 7 from the original operation position with respect to the adjacent track 58 by the displacement amount (distance) Xab 59, Xcd 60 based on the observed total displacement amount (Xab 59, Xcd 60). Position adjustment. By repeating the above procedure for all the tracks on the disk 1, a large number of concentric tracks having servo data areas arranged at predetermined intervals are formed on the disk 1 (FIG. 6).
See).

The positioner drive circuit 61 detects the presence of unreproducible data while the servo data of the track 57 is being observed by the observation head 52, or causes the track locus to change to the ideal track center due to accidental vibration or the like. If it is detected that the value is significantly out of the allowable range from 53, the servo data recording process is executed again. That is, the head 7 is moved to the track 5 of the previous track number N.
7 (of course, the observation head 52 returns to the track of the track number N-1), and the recording operation of the servo data is executed again from the beginning.

As described above, according to the present embodiment, the servo data recorded on the adjacent track is observed, and the amount of displacement from the ideal track position to the actual track position is obtained. The position of the head 7 when recording the servo data of the track is adjusted. Therefore, it is possible to always form adjacent tracks on the same track on the disk 1. In other words, a track format including a large number of concentric tracks having a constant track pitch can be configured. As a result, the margin of the track pitch for preventing overwriting of the adjacent track can be minimized, so that the track density can be increased.

When recording servo data, a function for evaluating the recording state detects an abnormal track locus due to the presence of unreproducible data or accidental vibration, and executes a re-recording operation. It becomes possible to correct the servo data. Moreover, since such an evaluation process can be performed at the time of recording the servo data, it is not necessary to execute the corresponding evaluation process again after the servo data recording process. Accordingly, the efficiency of the servo data recording process can be improved as a result.

[0031]

As described above in detail, according to the present invention, when servo data is recorded on a disk to form a predetermined track format, servo data recorded on an adjacent track is observed, and With the function of controlling the recording position of the servo data based on the observation result, a track format with a constant track pitch can be configured as a result. As a result, the track pitch margin can be minimized, so that the track density can be increased, and it is easy to realize a higher track density. In particular, it is extremely effective when applied to an HDD that achieves high recording density by increasing track density. In addition, since the recording state can be evaluated when the servo data is recorded, the efficiency of the servo data recording process can be improved as a result.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a configuration of a servo writer related to an embodiment of the present invention.

FIG. 2 is an exemplary view showing a method for recording servo data by the servo writer of the embodiment.

FIG. 3 is a conceptual diagram showing a configuration of a conventional servo writer.

FIG. 4 is a conceptual diagram showing a positional relationship between a conventional servo writer, a disk 1 of an HDD, and a head actuator 20 as viewed from a side.

FIG. 5 is a diagram showing a state of a track recorded by a conventional servo writer.

FIG. 6 is a conceptual diagram showing a configuration of a disk used in a conventional HDD.

FIG. 7 is a conceptual diagram showing a configuration of a conventional servo area.

FIG. 8 is a diagram showing a method of recording servo data by a conventional servo writer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Disc 7 ... Head 17 ... Rotary positioner 18 ... Arm 19 ... Push pin 20 ... Head actuator 21 ... Voice coil motor (VCM) 23 ... Spindle motor 30 ... Positioner drive circuit 50 ... Rotary positioner 51 for observation 51 ... Arm 52 ... Observation Head 53: Ideal track center 54: Signal processing circuit 55: Position detection circuit 56: Actual track center

Claims (7)

[Claims] 1. A servo data writing device for recording servo data necessary for head positioning control on a disk of a disk storage device, wherein each of the tracks has a track format based on a track format configured on the disk. Servo data recording means for recording the servo data, an observation head for observing the servo data recorded on the disk, and an observation positioning means for controlling the positioning of the observation head on the disk. Servo data observing means having the servo data based on the observation result from the servo data observing means with respect to the servo data recorded on the disk, so that adjacent track trajectories in the radial direction of the disk match. Control means for controlling the recording means. Body data writing device. 2. The control means calculates a track displacement amount in a radial direction of the disk from the observation result, and sets a recording position of the servo data so that an adjacent track follows the displacement amount. 2. The servo data writing device according to claim 1, further comprising means for controlling said servo data recording means. 3. The servo data recording means has a positioning means for controlling the positioning of a head incorporated in the disk storage device at an arbitrary position on a disk,
3. The servo data writing device according to claim 1, wherein predetermined servo data is recorded on the disk via the head. 4. The servo data observing means, wherein the observing head does not physically interfere with a head incorporated in the disk storage device, and each of the heads mutually adjoins adjacent tracks on the disk. 4. The servo data writing device according to claim 3, wherein said observation positioning means is arranged at a position such that a distance between said heads is minimized. 5. The servo data observation means is arranged such that the observation head can reproduce the servo data recorded on the disk in advance with respect to a head incorporated in the disk storage device. 5. The servo data writing device according to claim 4, wherein: 6. An evaluation means for evaluating whether or not the amount of displacement of the track calculated by the control means is within an allowable range with respect to a preset reference value, and an evaluation result of the evaluation means 3. The apparatus according to claim 2, further comprising re-execution means for controlling the servo data recording means and the servo data observation means so as to re-execute the recording of the servo data on the corresponding track when is out of the allowable range. The servo data writing device according to claim 5. 7. A servo data recording method applied to a servo data writing device for recording servo data necessary for head positioning control on a disk of a disk storage device, wherein the servo data writing device comprises: A servo data observation means having an observation head for observing servo data recorded thereon and an observation positioning means for controlling the positioning of the observation head on a disk; and a track formed on the disk. Positioning the head at a position set based on the format; recording the servo data with the head; and reading the servo data recorded on the disk from the observation result read by the observation head. Calculate the amount of track displacement in the radial direction of the disk Setting the recording position of the servo data so that an adjacent track follows the displacement amount, and recording the servo data by the head so that adjacent track trajectories match in a radial direction of the disk. And a servo data recording method.