JPH02210601A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To increase capacity by extending a data area by utilizing a guard band area as an effective data area. CONSTITUTION:Only a plane on one side of a prescribed disk 11a in a magnetic recording medium 13 of disk package system unified on one shaft 12 is set as a servo plane S, and the guard band area 22 for servo head 16 is provided, and on each plane of another disks, an area corresponding to the area 22 of an area 21 for data only to perform the write and readout of the data is also used as the area 21. Therefore, a magnetic disk device in which the effective data area 23 is extended and the capacity is increased can be obtained.

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a magnetic disk device that can expand the data recording area. (Prior Art) A magnetic disk device is a device that rotates one or more magnetic disks coated or plated with magnetic material at high speed, and records and reproduces information on the disks using a magnetic head.It has a large capacity and high-speed access. It has the feature that it is possible. Such magnetic disks are known to have a data surface on which data is recorded and a servo surface on which positioning information is recorded in advance, and are configured so that the positioning of a magnetic head is performed by a servo signal from the servo surface. Fourth
For example, the diagram shows "Mitsubishi fixed disk device old 865F/M48
70F Maintenance Manual, April 1985, published by Mitsubishi Electric Corporation" is a diagram showing the relationship between the data write area and guard band in a conventional magnetic disk device,
In the figure (1) is the contact start stop (CS
S) A guard band 0 (GBO) area is provided so that the magnetic head comes into contact with the disc surface when the magnetic head is in contact with the disc surface. The data area, which is an area that can be moved, (
3) is a guard punt 1 (Gel) area provided on the outer circumferential side of the data area (2) for the purpose of detecting the reference cylinder (CJ 000) during first seek or return to zero (RTZ). , (4) is a guard band 2 (Ga4) area provided on the outer circumferential side of this guard band 1 area (3) to indicate that it is dangerous if the magnetic head moves further to the outer circumferential side. Next, the operation will be explained based on FIG. In this figure, the horizontal axis shows the range in which the magnetic head moves on the disk, and the vertical axis shows time. When the device is powered off, the magnetic head moves to the contact start/stop area GB.
The guard band retracts to the 0 position (a) in the O area (1) and stops in contact with the disc. When the power is turned on and the disk starts rotating (time T0), the magnetic head flies up, reaches a steady rotation speed (time TI), and begins a first seek operation (101). This first seek (101) is an operation to move the magnetic head toward the outer circumference, and the magnetic head crosses the data area (2) from position (a), enters the GBI area (3), and moves to position (b). (operation 101^), where position (b) is in the GBI area (
3), a track cross counter inside the device starts subtracting, and after seeking for the initial set track, the device enters a positioning mode and stops moving the magnetic head. After a certain time period T2 has passed, this time it begins to seek slowly from position (b) in the opposite direction toward data area (2) (operation 101B), and the positioning fails at position (C) where GBI area (3) is no longer detected. Assume that the time T, ) and this position (C) are the reference cylinders c and x ooo. This location (C) is the data area (2) and the GBI area (
3), and this series of operations between times 71 and 13 is called a first seek operation (101). Note that the GB2 area (4) is not detected by normal seek. Thereafter, a normal seek operation (102) is performed to read and write data between times T and T4, but the range of this operation is limited to the data area (2). After the seek operation (102), the magnetic head is moved from time T4 to T.
Move it for a period of a, and then use the cylinder C, J200 as the reference again.
The return-to-zero (RTZ) operation (103) for positioning the G position (C) is different from the first seek operation (103), except that the position of the magnetic head is initially different.
1), that is, in the first seek operation (101), the first position is position (a) in the GBO area (1), whereas in the RTZ operation (103), the first position is in the data area ( 2) is position (d).

[Problem to be solved by the invention]

Conventional magnetic disk drives are configured as described above, and in addition to the data area (2), three areas are required: GBO area (1), GBI area (3), and GB2 area (4).
There was a problem in that data could not be written to or read from each of these areas (1), (3), and (4), and therefore the data area could not be expanded. The present invention was made to solve such problem,
The object of the present invention is to obtain a magnetic disk device that can expand the data area. [Means for Solving the Problems] A magnetic disk drive according to the present invention has a data area and a guard band area provided for detecting a reference cylinder and used during a first seek or return-to-zero operation. In the magnetic disk device equipped with the above-mentioned magnetic disk drive, the guard band area can also be used as a valid data area. (Function) The magnetic disk device according to the present invention has GB
It has a configuration of G area, data area, GBI area, and GB2 area, and the GBI area is first seek or RT
The data area is expanded because it is used not only during Z but also as an effective data area. (Embodiment) An embodiment of the present invention will be described below. This embodiment is a magnetic disk device that performs servo surface servo. Zero (RTZ
) Use it not only during operation, but also as a valid data area. It is characterized by the fact that it can be done. FIG. 1 is an overall configuration diagram of a magnetic disk device, in which a magnetic head (14) is inserted into a disk-back type magnetic recording medium (13) in which a plurality of magnetic disks (11) are grouped together on one shaft (12). Data is recorded and read out concentrically. Among the magnetic disks (11), only one surface S of a predetermined disk (lla) is a servo-dedicated surface on which positioning information is recorded, and the other surface is a data surface on which data can be recorded and read. D of the magnetic head (14)
The head (15) is a data surface head, and the S head (16)
is a head for performing servo on the servo surface S. Conventionally, the data area was limited to the range A, but in this embodiment, by improving the servo-dedicated surface S, it is now possible to write and read data in the range B as well as the range A. I have to. Figure 2 shows the relationship between the data area and the guard band.
In the figure, (1) is the same guard band O (GBO) area as before, and (21) is this GBO area (1).
A data-only area (22) is provided on the outer circumferential side of the data-only area where data is only written and read.
21) is provided on the outer circumferential side of the cylinder (c, i ooo
) guard band 1 established for the purpose of detecting
In the (GBI) area, a data-only area (21) and a Gel area (22) that also serves as a data area constitute a valid data area (23) in which data can be written and read. Guard band 2 (G
e2) area, which is the same as the conventional one. Next, the operation of this embodiment will be explained based on FIG. This Figure 3 is a diagram equivalent to Figure 5. The horizontal axis indicates the range in which the magnetic head (14) moves on the disk, and the vertical axis indicates time.
Regarding a), after the magnetic head (14) enters the GBI area (22), the data-only area (21) and the G11
The reference track is determined by 0 positioning, which is the same as in the prior art until it is positioned at the boundary position (C) with the Gel area (22).
22), a seek operation (IOIC) is performed by a specified amount to locate the position (e) (time T++), and in this example, the Gel area (22) has 20 tracks. This position (e) is positioned as reference cylinder c, J2ooo, and a series of first seek operations (101
0 normal seek operation (102a (or 1
02b)) is the time T r r ~T I2 (or T1
3 to T, 4), but it can be performed at any time within the valid data area (23). However,
The return-to-zero (RTZ) operation (103a) is as follows. That is, C, fL20 or more (data-only area (
The RTZ operation (103a) from 21)) is performed in the same way as the first seek operation (lola) above, but C,1
20 or less (shared data area (22)) (times are T14 to T8.), - degrees C, f! Seek operation to 20 (103A), then first seek operation (1
Proceed in the same manner as 01a). These judgments are made based on the contents of a current address register in the magnetic disk device that determines the current position. Therefore, in this embodiment, the data area is expanded by the Get area (22) (approximately 20 tracks) compared to the conventional magnetic disk device. In addition, in the above embodiment, the shared area between GBI and data (2
2) is set to 20 tracks, but this number can be set arbitrarily. In addition, the GBO area (1) is placed on the inner circumferential side, and the Gel area (2
2) and the Ge2 region (4) are set on the outer peripheral side, but this positional relationship may be reversed. [Effects of the Invention] As described above, according to the present invention, since the guard band area is used as a part of the data area, there is an effect that the data area can be expanded and the capacity of the magnetic disk device can be increased. .

[Brief explanation of the drawing]

1 to 3 are diagrams showing one embodiment of the present invention, in which FIG. 1 is an explanatory diagram showing the overall configuration of a magnetic disk device, FIG. 2 is an explanatory diagram showing the relationship between a data area and a guard band, and FIG. Fig. 3 is an explanatory diagram showing the seek operation of the magnetic head, Fig. 4 is an explanatory diagram showing the relationship between the data area and guard band of a conventional magnetic disk and is equivalent to Fig. 2, and Fig. 5 is an explanatory diagram showing the seek operation of the conventional device. FIG. 3 is a diagram corresponding to FIG. (22)...Guard band area (Gel area), (2
3)...Valid data area. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] In a magnetic disk drive equipped with a data area and a guard band area provided for detecting a reference cylinder and used during a first seek or return-to-zero operation, the guard band area is also used as an effective data area. A magnetic disk device characterized by making it possible.