JPH03225680A - magnetic disk device - Google Patents

Abstract

PURPOSE:To obtain a good access means by accessing even an area on the outside of a recording and reproducing area of a usual data on the surface of a magnetic disk. CONSTITUTION:An objective track address for recording and reproducing a data to be sent from a controller 1 is held by an objective track register 3 in the inside of a microprocessor 2. Then, a target speed signal for a seeking operation of magnetic heads 19-26 corresponding to a difference amt. at the seeking time is produced by a digital target speed table 5 and a D/A converter 6. Now, the areas existing on the outside of the usable areas for recording and reproducing usual data on the magnetic disks 15-18 are utilized as well. Then, the recording and reproducing can also be performed on tracks in the outside area so that the storage capacity can moreover be increased. Consequently, when the difference amt. is large, the execution is performed by dividing it into two or more timer, so that the reliability is prevented from lowering due to a shock even when a seeking operation is ended in failure.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention is directed to a magnetic disk device in which data is also transferred to tracks within a guard band area that exists outside the area that can be used for normal data recording and reproduction on a magnetic disk surface. The object is to provide good access means for recording and reproducing.

[Conventional technology]

In conventional devices, the guard band area serves as a reference track, but has functions such as being used for O track positioning operations, and the tracks within the guard band area are not used for general data recording and reproduction. It looks like this.

Also, as described in Japanese Patent Application Laid-Open No. 60-57579,
Although there is a method of providing a reproduction-only track outside the track, it is not for data recording and reproduction.

[Problem to be solved by the invention]

In terms of maximizing the storage capacity of the magnetic disk drive, the above-mentioned conventional technology does not allow the use of tracks in the guard band area outside the normal data recording/reproducing area for data recording/reproducing. However, if the tracks within the guard band area could be used for data recording and reproduction, the storage capacity of the magnetic disk device could be increased a little more.

However, when recording and reproducing data in the guard band area, consideration must be given to the following points. First of all, when the magnetic head performs a high-speed seek operation to the target track for recording and reproducing data, it may not be able to stop on the target track, resulting in an overrun of several tracks or, in the worst case, a runaway, resulting in a collision. However, if a high-speed seek operation is performed to the guard band area, the impact when the actuator goes out of control will be greater.Secondly, the most important This means that the maximum seek time, which is one of the elements, becomes longer due to factors such as the longer maximum movement distance of the actuator due to seeking to the guard band area and recording/reproducing.

An object of the present invention is to provide a good access means for recording and reproducing data even in a guard band area that has not conventionally been used for normal data recording and reproducing, in order to maximize the recording capacity of a magnetic disk device. It's about doing.

[Means to solve the problem]

In order to achieve the above purpose, first, in order to alleviate the impact of colliding with the crash stop due to failure of seek operation,
As a method of performing a seek operation for recording and reproducing data in the guard band area, access is not achieved with a single seek operation, but is divided into at least two or more seek operations, and the guard band is performed at the end. The maximum movement speed of the actuator during a seek operation to a target track within the area is equivalent to the impact caused by a collision with a crash stop that occurs when a seek fails to the same as that caused by a seek operation failure to a target track outside the normal guard band area. Alternatively, it is set to be slower as shown below. In addition, as a measure against the increase in seek time, it is conventional to record the defect information itself on the magnetic disk surface or use it as a spare track to prevent the effective seek time from increasing.

[Effect]

If you perform a seek operation on a track within the guard band area in the same way as a normal seek operation on a track outside the guard band area, the distance between the actuator and the crash stop will be shorter, and the impact when the actuator collides with the crash stop will be reduced. However, the best way to prevent this is to shorten the travel distance when seeking to the target track within the guard band area, which shortens the seek time and reduces the amount of energy given to the actuator mechanism. This can be achieved by keeping the speed low.

In addition, defect information on the magnetic disk surface is accessed only when formatting (initializing) the magnetic disk.
track) and does not affect the maximum seek time. Furthermore, by using a recordable/reproducible track within the guard band area as a backup track, the frequency of access to this area is reduced, making it possible to suppress an increase in effective seek time.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1, 2, and 3. FIG. 1 is a block diagram of a magnetic head positioning system according to an embodiment of the present invention.

The magnetic disks 15, 15, 17 and I8 are mounted on a spindle 14 for rotation by a spindle motor (not shown). Magnetic head 19.20°21
, 22.23.24.25 and 26 are actuator 1
0 on each magnetic disk surface.

The voice coil motor 9 for actuator parking is used for driving the positioning of the magnetic head. Magnetic head positioning servo information is recorded on the magnetic disk 15. Servo information read by the magnetic head 19 is amplified by an amplifier 11, and a speed signal converter 12 creates an actual speed signal when the magnetic head performs a seek operation. In addition, position signal converter 1
3, the signal is converted into a magnetic head position signal. During a seek operation, a current track register 4 in the microprocessor 2 indicating the current position of the magnetic head is updated every time the magnetic head moves, based on the position signal of the magnetic head.

The target track address of the target track on which data sent from the controller 1 is to be recorded and reproduced is held in a target track register 3 within the microprocessor 2. The difference amount, which is the amount of movement of the magnetic head during the seek operation, is obtained from the target track address value and the current track address value, and the target speed signal for the seek operation of the magnetic head corresponding to the difference amount is stored in the digital target speed table 5. and a digital-to-analog converter 6. The speed error between the target speed signal and the actual speed signal is amplified by the speed error amplifier 7, and the actuator 10 is moved to the target track by the voice coil motor 9 via the power amplifier 8.

The explanatory diagram of each area on the magnetic disk surface in FIG. 2 and the flowchart of the method of seeking to the data recording/reproducing track in the guard band area 0GBI in FIG. 3 show the seek operation to the target track in the guard band area oGBI. I will explain how to do this.

The magnetic disk surface is connected to the spindle 14 across the data area.
The 0GBI area is the guard band area used for positioning the 0 track, which is the reference track on the opposite side of the ■a B area, which is the guard band area where the magnetic head is located when the magnetic disk device is started up. and ○GB2 area. Here ○GBI
The area is a track area in which data can be recorded and reproduced within the guard band area. Track addresses range from O to M for tracks within the data area, and M+1 to M+N are assigned for tracks within the OGB area. When receiving a seek operation command from the controller, the magnetic disk device sets the target track address to M in the OGB 1 area.
It is determined whether it is within the range from +1 to M+N, and if it is within the above range, the access method is divided depending on the amount of difference from the current track address where the magnetic head is currently located. If the current track address is in the range from A to M, the difference amount is large and the acceleration time of the actuator during seek operation is long, so in order to reduce the impact caused by collision with the crash stop when seek operation fails. Then, a seek operation is performed to track O. After this is completed, a seek operation is performed to the target track within the 0GB1 area.

After the seek operation is completed, the magnetic disk device sends a seek operation completion signal to the controller. If the target track is outside the range of track addresses M+1 to M1N, or if the target track is outside the range of track addresses M+1 to M+H,
Even if the track address is within the range of
If it is outside the range, access to the target track is completed with one seek operation.

To determine track address A, accelerate the actuator from track address A, and
The impact of the actuator colliding with the crash stop when accelerating to the track and stopping the acceleration due to seek operation overrun detection in OGB2 caused the conventional method to accelerate from the track address M to 0 and stop accelerating in the ○GBI area. It is decided to be equal to or lower than that of the time.

The controller 1 manages and uses the area from track addresses M+1 to M+N as an area for recording defect information on the magnetic disk surface and as a spare trunk area.

According to this embodiment, tracks within the guard band ○GBI area, which were not conventionally used for data recording and reproduction, can also be used for data recording and reproduction without impairing reliability. It has the effect of further increasing the storage capacity, which is one of the elements, and also has the effect of keeping the access time the same as before by using it in combination with a controller.

〔Effect of the invention〕

According to the present invention, tracks in the guard band area that were not used for data recording and reproduction in conventional magnetic disk drives can be used for data recording and reproduction.
This has the effect of further increasing memory capacity.

In addition, by dividing the seek operation to the track within the guard band area into two or more times when the amount of difference is large, there is no reduction in reliability caused by impact etc. when the seek operation fails. There is.

In addition, along with the magnetic disk device controller,
By using the tracks in the guard band area to record defect information on the magnetic disk surface and as spare tracks,
This has the effect of eliminating any reduction in effective access time.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a magnetic head positioning system according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of each area on the magnetic disk surface, and FIG. 3 is a block diagram of a magnetic head positioning system according to an embodiment of the present invention. 3 is a flowchart of a method for performing a seek operation. 1... Controller, 2... Microprocessor. 3...Target track register, 4...Current track register. 5... Digital target speed table, 10... Actuator, 15-18... Magnetic disk, 19-26... Magnetic head. 14...Spindle, 9...Voice coil motor. Mistake? ℃ Spi, Torto Rif 71 Shizuyu/vIt1MfH No.

Claims (1)

[Scope of Claims] 1. A magnetic disk device comprising a magnetic disk, a magnetic head, an actuator mechanism for positioning the magnetic head to a number of concentric tracks on the surface of the magnetic disk, and a control circuit thereof; It is characterized by being equipped with an access means that allows data to be recorded and reproduced even on tracks in an area (hereinafter abbreviated as guard band area) that exists outside the data area that can be used for recording and reproducing normal data on the surface. magnetic disk device. 2. In the magnetic disk device according to claim 1, the moving distance of the magnetic head is determined in advance as a method for moving the magnetic head to a data recording/reproducing track within the guard band area (hereinafter abbreviated as seek operation). A magnetic disk drive that divides the seek operation into at least two or more times when the seek operation is longer than the distance. 3. In the magnetic disk device according to claim 1 or 2, the data recording/reproducing track in the guard band area may be used to record defect information on the magnetic disk surface. , or a magnetic disk device used as a spare track.