JPS63876A - Seek control system - Google Patents

Abstract

PURPOSE:To narrow a guard band area, by detecting the guard band, moving a head in a reverse direction after a prescribed time, and detecting the completion of the guard band. CONSTITUTION:When an inner guard band is detected by moving a head 13 at high speed by a control circuit 1, at the time of performing a re-zero seek operation, the head 13 is switched to low speed movement. And after the lapse of a regulated time, the head 13 is moved in then reverse direction by the circuit 1, and a cylinder 0 is detected by the detection of the completion of the guard band area. Therefore, it is not necessary to provide two pairs of the guard bands, and the guard band area is narrowed, and it is possible to expand a data storage area by a saved share of area.

Description

[Detailed Description of the Invention] [4 Already Required] IJ Ceroseek (System to return the magnetic head to the basic Norinda position?: [II) Narrows the area of the guard band recorded on the servo surface, which is used when Expand the data recording area by making it possible to

C. Field of Industrial Application] The present invention relates to a magnetic disk device, and particularly to a seek control method that makes it possible to widen the data writing area of a magnetic disk.

Among the recording surfaces of multiple magnetic disks, the magnetic disk device uses the - side as a servo surface on which servo information for magnetic positioning is recorded. In some systems, a carriage is moved based on read servo information, and a plurality of data heads for reading/writing data are positioned at a target cylinder.

That is, the seek control method using the servo surface has the feature of being able to perform high-speed and stable seek control, and is therefore widely used in high-performance magnetic disk drives.

By the way, in high-performance magnetic disk devices, the number of tracks per recording is increasing more and more due to the increase in capacity, and there is a need for technology that can utilize as wide an area as possible for data recording.

[Conventional technology]

FIG. 4 is a diagram illustrating an example of a conventional nervo surface, and FIG. 5 is a diagram illustrating the relationship between a magnetic disk and a magnetic head.

As shown in FIG. 5, the magnetic disk has a plurality of data surfaces 15.
and a servo surface 16, and an arm 12 of the carriage 10.
A data controller 13 and a servo head 14 attached to the cylinder are positioned at the target cylinder by a carriage 10 that moves according to servo information t[j read by the servo head 14.

As shown in FIG. 4, for example, the servo surface 16 is provided with an erase zone (2), an outer guard band (2), a data zone (2), an inner guard band A (2), an inner guard band B (2), and an erase zone (2).

When the magnetic disk device is turned on or the servo is
When the servo head 14 fails to be positioned at the target cylinder, in order to clarify the position of the servo head 14, the servo head 14 is returned to cylinder number 0, that is, rezero seek is performed.In this example, cylinder 0 is It is provided on the inner circumferential side of the servo surface 16, that is, within the data zone (2) adjacent to the inner guard band (A).

The current position of the servo controller 14 is detected based on cylinder 0 as dq, the distance to the target cylinder is calculated, and the carriage 10 moves to move within the data zone (2). Therefore, the data destination 13 can access the destination trunk.

When the servo radar 14 sells the outer guard band (2) and reads the inner guard band A2, the magnetic disk device detects that the servo radar 14 has deviated from the data zone (2).

When the magnetic disk device performs rezero seek, the carriage 10 is moved at high speed until the servo head 14 detects the inner guard band A.
When (2) is detected, the carriage 10 is decelerated and the servo head 14 is moved at low speed, and when the inner guard band (2) is detected, the moving direction of the carriage 10 is reversed.

Then, the servo head 1 is moved at low speed within the inner guard band A■, and when the inner guard punt A■ is completed, the speed is decelerated while counting the number of tracks, and the cylinder O
When detected, control '+JII is performed to precisely position the servo head I4.

[Problem that the invention seeks to solve]

As mentioned above, conventionally, inner guard bands A and B cover two areas of 1! ! ! )A, and the area of the data surface 15 corresponding to this area cannot be used for data writing/writing, and there is a problem in that the area available for data recording is narrow.

[Means for solving problems]

FIG. 1 is a block diagram of a circuit showing one embodiment of the present invention.

1 is a control circuit; 2 is a target speed generation circuit that creates the moving speed of the gear ridge 10 according to instructions from the control circuit 1; 3 is a differential amplifier circuit that sends a signal to drive the linear motor 8; 4
is a switch that switches the drive signal for the linear motor 8 between coarse control mode and fine control mode.

5 is an error signal generation circuit that sends out a drive signal for the linear motor 8 in fine control mode; 6 is a speed signal generation circuit that generates a moving speed signal for the carriage 10; 7 is a power amplifier circuit;
1 is a near motor for moving the carriage 10; 9 is a position pulse generation circuit that sends out a pulse indicating the position of the servo head 14; 10 is the carriage; 11 is a position signal generation circuit that generates a signal indicating the position of the servo head X4; is an arm, 13 is a data head, 14 is a servo head, 15
is a data surface, and 16 is a servo surface.

When the control circuit 1 detects the inner guard band, it moves the carriage 10 toward the inner circumference at low speed, reverses the moving direction of the carriage 10 after a predetermined time has elapsed, moves the carriage 10 toward the outer circumference at low speed, and moves the carriage 10 toward the inner circumference at low speed. When the end is detected, the speed is decelerated, the number of tracks is counted, and cylinder 0 is detected.

[Effect]

With the above configuration, the control circuit 1 detects the inner guard band and reverses the moving direction of the servo head 14 within the inner guard band after a predetermined period of time has elapsed. It becomes possible to position the servo head 14 at

Therefore, it is not necessary to provide two inner guard bands on the servo surface 16, the inner guard band B shown in FIG. 4 can be saved, and this area can be expanded as a data recording area.

〔Example〕

FIG. 2 is a diagram for explaining the servo aspect of the present invention, and FIG. 3 is a flowchart for explaining the operation of FIG. 1.

In Figure 1, the system? During normal operation, the I11 circuit 1 controls the carriage 1 in the data zone shown in FIG.
No. 1 to the data head 13 and servo at the tip of the arm I2 attached to the carriage 10.
The distance to be moved is calculated from the position where 4 is placed in a predetermined trunk and the position pulse sent out by the position pulse generation circuit 9, which will be described later, and the remaining distance to be moved is calculated. :', sent to the speed generation circuit 2.

The target speed generation circuit 2 generates a target speed, and sends a high target speed when the moving distance is large, and a slow target speed when the moving distance ^II is small, to the differential amplifier circuit 3. The differential amplifier circuit 3 calculates the difference between the speed signal and the speed signal obtained from the servo head 14, which will be described later, and sends a signal to the switch 4 to drive the linear motor 8. The coarse control mode is sent to this switch 4 from the control circuit 1, and the output of the differential amplifier circuit 3 is sent to the power amplifier circuit 7.

The near motor 8 is supplied with a drive current from the power amplifier circuit 7 and moves the carriage 10 to transport the data head 13 and the servo head 14 near the target track. The servo head 14 reads servo information from the servo surface 16,
It is sent to the position signal generation circuit 11.

The position signal generation circuit 11 generates the servo head 1 from the servo information.
The error signal generation circuit 5 generates a position signal indicating the position of 4.
and is sent to the speed signal generation circuit 6 and the position pulse generation circuit 9.

The control 4ff11 circuit 1 learns the position of the servo head 14 from the position pulse sent out by the position pulse generating circuit 9, and calculates the remaining distance as described above.

The speed signal generation circuit 6 generates the moving speed of the servo head 14 from the position signal, and sends it to the control circuit 1, the error signal generation circuit 5, and the differential amplifier circuit 3.

Based on this speed signal, the control circuit 1 sends the fine control mode to the switch 4 when the moving speed of the throat 14 to the servo becomes less than the specified value, and the switch 4 sends the signal from the differential amplifier circuit 3 side to the error signal generation circuit 5 side. Switch the connection to error signal generation circuit 5.
The output is sent to the power amplifier circuit 7.

The error signal generating circuit 5 detects the deviation of the servo head 14 from the target track using the position signal and velocity (No. 3), and sends out a signal for precise positioning control.

, bll '4111 circuit 1 moves the carriage 10 in the inner circumferential direction at high speed as shown in FIG. Continue operation. Without detecting the inner guard punt (2), the control circuit 1 moves and assists the carriage 1O toward the inner circumference at low speed.

The control circuit 1 moves the carriage 10 in the inner circumferential direction for a specified period of time, and then reverses the moving direction of the carriage 10. Then, the carriage 1O is moved toward the outer circumference at low speed, and the servo is caused to detect the end of the inner guard band (2) using the throat 14.

- When the bohenoto 14 detects the end of the inner guard hand ■, it decelerates the speed of the carriage 10 while counting the number of track crosses, and when it approaches cylinder 0,
Detects the deviation of cylinder 0 from the track and positions it in fine control mode.

Since the control j11 circuit 1 controls the movement of the carriage 10 described above, only one inner guard punt (2) is required, and there is no need to provide two inner guard punts (2) as shown in FIG.

In this example, the case where the cylinder 0 is provided on the inner circumferential side has been described, but when the cylinder 0 is provided on the outer circumferential side, the same operation as described above is performed using the outer guard punt (2).

[Effects of the Invention] As explained above, in the present invention, the guard band area can be narrowed, so that the data recording capacity can be increased by about 5%.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a circuit showing an embodiment of the present invention, and FIG. 2 is a diagram illustrating the navigation aspect of the present invention. Figure 3 is a flowchart explaining the operation of Figure 1;
This figure is a diagram for explaining a conventional servo surface, and FIG. 5 is a diagram for explaining the relationship between a magnetic disk and a magnetic head. In the figure, 1 is a control circuit, 2 is a target speed generation circuit, 3 is a differential amplifier circuit, 4 is a switch, 5 is an error signal generation circuit, 6 is a speed signal generation circuit, 7 is a power amplifier circuit,
8 is a linear motor, 9 is a vertical pulse generation circuit, 10 is a carriage, 11 is a position signal generation circuit, 1
2 is an arm 14, 13 is a data head, 14 is a servo head, 15 is a data surface, and 16 is a servo surface. Let's say it's the 7th one-bo side of January! σ30 per month 2 mouths

Claims (1)

[Claims] In a magnetic disk device that performs seek control using a servo surface (16) on which servo information for detecting the position of the magnetic head (14) is recorded, the magnetic head (14) deviates from a data recording area. This is detected when the magnetic head (14) enters the guard band area of the servo surface, and a control means (1) is provided to reverse the moving direction of the magnetic head (14) after a predetermined period of time. The magnetic head (14) is moved to the reference cylinder position side, the guard band is detected, and after a predetermined period of time, the moving direction of the magnetic head (14) is reversed and the end of the guard band is detected. A seek control method characterized by positioning a magnetic head (14) in a cylinder.