JP2857500B2 - Servo write start position detection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a servo write start position detecting method for detecting a write start position of a servo pattern on a magnetic disk.

[0002]

2. Description of the Related Art A disk-shaped magnetic recording medium includes a flexible floppy disk and a hard disk formed of a hard metal material. The hard disk is used for recording / reproducing with a high storage capacity. I have. In this hard disk, closed loop control is employed for performing fine tracking, and a servo pattern is written on the hard disk in order to perform this closed loop control. That is, the hard disk is provided with one or several write protect areas in which the user cannot write information per turn of each track, and a staggered servo pattern is written in this write protect area at the time of shipment from the factory. Then, at the time of storage / reproduction or at the time of servo correction performed at a preset timing, this servo pattern is read from the magnetic disk, and servo correction is performed to realize fine tracking.

[0003] The write start position of the servo pattern on the magnetic disk is highly accurate (20 to 50 µm) on the magnetic disk.
In step m), it is necessary to start writing, and a closed-loop system is generally used in which a reflection mirror is attached to a head arm and a writing start position is detected using a laser interferometer. However, the closed-loop system has a complicated configuration of the apparatus, and the detection operation is not easy, and there is a problem in terms of the cost of equipment.

Then, using a stepper and a rotary encoder, the position detection pin is moved by the stepper,
A semi-closed loop system has been proposed in which a write start position is detected by pressing the position detection pin against an arm of a magnetic head. In this case, it is necessary to start writing the servo pattern from the end position where the arm comes into contact with the stopper, but it is required to detect that the position detection pin has come into contact with the arm of the magnetic head.

Therefore, in the semi-closed loop system, the following detection method has been proposed. (1) The arm is made of a conductive material to detect electrical continuity when the position detection pin contacts the arm. (2) A signal is written from the magnetic head to the magnetic disk at the contact position between the arm and the stopper, Next, a position detection pin is sent while reading the written signal, and the arm is moved by the sent position detection pin to be in an off-track state, and a position where the signal is no longer read is detected. (3) The principle of the above (2) The signal written by the magnetic head is read out based on the above, and the position detecting pin is manually sent to monitor the waveform by displaying the signal on an oscilloscope to monitor the position where the waveform changes.

[0006]

The method of the above (1) is as follows.
It cannot be applied to currently used arms in which the arm must be conductive and does not conduct when the position detection pin contacts. In addition, if the arm is made of a conductive material as described above in the disk drive device, the mounting jig must be entirely made of an insulating material, which requires a significant remodeling of the device. It has been confirmed by the present inventors that an accident is likely to occur.

According to the method (2), since the stopper portion is made of rubber for preventing impact, the magnetic head is displaced by the elastic deformation force of the rubber a few seconds after the contact, and the written signal is read. In some cases, and the position detection is unstable. The method (3) has the problem of the method (2), and also has a drawback that it takes a long time to detect the position and automatic operation cannot be performed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned current situation of the servo write method, and an object of the present invention is to stably and accurately detect a write start position of a servo pattern on a magnetic disk. An object of the present invention is to provide a servo write start position detecting method.

[0009]

In order to achieve the above object, the present invention detects a write start position of a servo pattern written on a magnetic disk and read out at the time of servo correction of the magnetic disk. In the servo write start position detecting method, a swing arm having a magnetic head is urged against a stopper for restricting a rotation range, and a position detection pin is moved by one track in a direction for rotating the swing arm in a direction opposite to the urging direction. After moving forward, a confirmation signal is written from the magnetic head to the magnetic disk, the position detection pin is moved forward by one track, an erase signal is output from the magnetic head, and after the position detection pin is moved backward by one track, When a confirmation signal is detected, the position detection pin moves in contact with the swing arm and detects that the writing start position has been reached. Are you on the configuration that.

[0010]

By the action wherein said means, Sui by moving the position detection pins
When ring arm is moved, written confirmation signal is not erased even emit an erase signal. On the other hand, if the position detecting pin does not touch the swing arm even if it moves by one track, the magnetic head of the swing arm does not move to the next track, and the magnetic head is placed on the track where the confirmation signal is written. In this state, the erase signal is issued and the written confirmation signal is erased.
Thus, it is determined whether or not the servo pattern is at a write start position on the magnetic disk.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
explain. FIG. 1 is a flowchart illustrating an embodiment of the present invention.
FIGS. 2 to 4 illustrate a detection apparatus to which the present invention is applied.
FIG. 5 is an explanatory view showing an example of a hard disk drive.
It is. First, as an example of the hard disk drive 100,
explain about. In FIG. 5, 100 is a hard disk.
The hard disk drive 100 includes a magnetic disk drive.
At a position where the air disk 1 is shifted to one side of the housing 2,
A spin (not shown) attached to the back of the housing 2
Directly connected to the rotary shaft 3 of the dollar motor and rotatably disposed
ing. In the position near the other side of the housing 2,
The arm 4 is swingably supported by a support shaft 19.
You. At the tip of the swing arm 4 on the magnetic disk 1 side,
A floating magnetic head 5 is attached via a support spring 6.
The other end has a moving coil motor,
The coil 8 of the chair coil motor 7 is attached.
Below the coil 8, there is a magnet for forming a magnetic field.
9 and 10 are provided with different magnetic poles, respectively.
The lower yoke 11 contacts the support poles 12 and 13 in contact with these magnetic poles.
Therefore, it is attached to the housing 2 side. Also,
Although not shown in FIG.
The upper yoke formed in a size to cover these support shafts 12,
13 and the magnets 9 and 10
Are provided opposite to each other. Elastic on the outer circumference of the support shafts 12 and 13
Stoppers 14 and 15 consisting of bodies are externally
The swing range of the swing arm 4 is regulated. Also,
In the figure of the chair coil motor 7, the head
16 are provided, the magnetic head 5 and the flexible print
Input / output via the board 17 and the lead wire 18
ing. The swing arm 4 is a spring (not shown).
In the outer peripheral direction of the magnetic disk 1 (the direction A in FIG. 5).
It is being rushed. Next, a detection device to which the present invention is applied will be described.
This will be described with reference to FIGS. As shown in FIG.
With built-in encoder (not shown)
The stepping motor 20 has a rotating shaft 21.
Of the rotating shaft 21 is fitted into the hole 23 of the rotating plate 22 . Ma
The rotating plate 22 includes a hard disk drive 10.
0 swing arm 4
Position detecting pin 24 for moving the air disk 1 in the radial direction
Is provided. Note that the encoder is a stepping
This is for detecting the rotation angle of the motor 20. Shown in FIG.
So that the rotating plate 22 is
The motor 20 is supported with the rotating plate 22 down.
It is attached to the support 25. And hard disk drive
The moving device 100 is moved in the direction of arrow B, and the swing arm
4 and the stepping motor (support shaft 19 shown in FIG. 5).
The rotation axis 21 of the motor 20 is located coaxially as shown in FIG.
To be placed. As shown in FIG.
When the motor 20 is rotated, the rotating plate 22 also moves in the direction of arrow C.
Rotates, and the position detection pin 24 comes into contact with the swing arm 4
The swing arm 4 against the urging force (in the direction of arrow D).
The magnetic disk 1 is moved in the radial direction. Stepping
Rotation angle of motor (hereinafter referred to as stepper) 20
Is detected by a built-in encoder.

Next, an embodiment of the present invention will be described with reference to FIG.
This will be described in detail with reference to FIG. FIG. 1 is a flowchart showing the write start position detecting operation. Step S1 in FIG.
In order to start writing the servo pattern from the end position of the write protection area, the swing arm 4 is moved to contact the stoppers 14, 15, and the step S2 is executed.
Then, a confirmation signal is written to the magnetic disk 1 by the magnetic head 5 . The position detection pin 24 is first moved to a position not in contact with the swing arm 4 . Next, in step S3, it is confirmed by reading the magnetic head 5 whether the confirmation signal has been reliably written to the magnetic disk 1, and if it has been written (YES in S3), the flow proceeds to step S4. In step S4, the position detecting pin 24 is advanced by one track by the stepper 20 , and in step S5, an erase signal is sent to the magnetic head 5 to perform erasing. Then I connexion position detection pin 24 to Sutetsupa 20 in step S6
Is retracted by one track, the signal is read out in step S7, and it is determined in step S8 whether the confirmation signal has been erased. In this case, if the swing arm 4 is sent to the next track by the position detection pin 24 in step S4, the magnetic head 5 is positioned on the track where the confirmation signal is written by the erase in step S5. Since it has not been done, the confirmation signal is not erased. Therefore, if the determination in step S8 is YES, it can be detected that the servo pattern is at the write start position.

On the other hand, if the determination in step S8 is NO, the magnetic head 5 (swing arm 4 ) moves to step S4.
Since the position detecting pin 24 does not move due to the forward movement of the position detecting pin 24 , the magnetic head 5 and the position detecting pin 24 are not in contact with each other. Therefore, in step S9, the position detecting pin 24 is advanced by two tracks and returned to step S2. The operations of steps S2 to S9 are repeated until the determination in step S8 becomes YES. Since the operations of steps S2 to S9 are completed in 0.5 seconds or less, the detection can be performed without being affected by the elastic deformation of the stoppers 14 and 15 as in the conventional method, and the detection accuracy is one track. Is 19 microns, so that detection with sufficient accuracy is possible.

As described above, according to the above-described embodiment, troubles due to poor electrical contact and stoppages as in the conventional method can be avoided.
There is no erroneous operation due to the elastic deformation of the servo patterns 14 and 15 , and the write start position of the servo pattern on the magnetic disk 1 can be detected and set at a stable position with high accuracy at the end position of the write protect area.

[0015]

As described above, according to the present invention,
The write start position of the servo pattern on the magnetic disk can be detected stably and with high accuracy.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating an embodiment of the present invention.

FIG. 2 It is an explanatory view of a detecting device to which the present invention is applied.

FIG. 3 It is an explanatory view of a detecting device to which the present invention is applied.

FIG. 4 It is an explanatory view of a detecting device to which the present invention is applied.

FIG. 5 FIG. 3 is an explanatory diagram showing an example of a hard disk drive.
is there.

[Explanation of symbols] 1 Magnetic disk 4 Swing arm 5 Magnetic head 14,15 Stopper

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G11B 21/10

Claims (1)

(57) [Claims] In a servo write start position detecting method for detecting a write start position of a servo pattern written on a magnetic disk and read at the time of servo correction of the magnetic disk, the swing arm having a magnetic head is rotated. The stopper is urged against the stopper for regulating the movement range, the position detection pin is advanced by one track in a direction for rotating the swing arm in a direction opposite to the urging direction, and a confirmation signal is written from the magnetic head to the magnetic disk. After the position detection pin is advanced by one track and an erase signal is output from the magnetic head, and the position detection pin is retracted by one track, when the confirmation signal is detected, the position detection pin contacts the swing arm. A servo write start position detecting method, wherein the servo write start position is detected.