JPH11203799A - Magnetic disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten time required for read and write and to reduce work time required for initialization by individually moving respective magnetic heads provided for plural pieces for one storage medium surface for reading and writing information to the storage medium surface. SOLUTION: At the time of initializing a magnetic disk, a first magnetic head 2 performs an initialization processing from the track Ta of an outermost periphery, a second magnetic head 3 simultaneously performs the initialization processing from the track Tb of an innermost periphery and the initialization processing is ended at the track Tc at the center of the storage medium surface 6. Since this magnetic disk device 1 is provided with the magnetic head for reading and writing the two pieces of the information of the first magnetic head 2 connected to a first control circuit 4 and the second magnetic head 3 connected to a second control circuit 5, rotation standby time, seek time and the transfer time of data, etc., are all halved, write time per track is shortened and acceleration is made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a magnetic disk drive, and more particularly to a magnetic disk drive having a plurality of magnetic heads on each storage medium surface.

[0002]

2. Description of the Related Art Conventionally, a magnetic disk drive is provided with a magnetic head for reading and writing information at a rate of one on each storage medium surface. Some magnetic disk devices having high-speed performance include a plurality of magnetic heads on each storage medium surface.

In a conventional magnetic disk drive having a plurality of magnetic heads on each storage medium surface, all of these magnetic heads are used only in the same cylinder, and all magnetic heads are mounted on the same storage medium surface. Initialization (a work of erasing all write information and writing a fixed value) is performed while positioning on a circumference (hereinafter referred to as "track").

For example, as shown in FIG. 4, a conventional magnetic disk drive 31 stores two pieces of information of a first magnetic head 32 and a second magnetic head 33 connected to a control circuit 34 on a storage medium surface 36. It has a magnetic head for reading and writing.
When the magnetic disk device 31 is initialized, the initialization process is performed with both the first magnetic head 32 and the second magnetic head 33 positioned on the same track T.

Here, in the above magnetic disk drive,
The time required to read and write information is the rotation waiting time (the time required for the magnetic head to reach the portion of the track to be read / written), the seek time (the time the magnetic head moves to another track), and the data transfer time. It is roughly determined by the three major factors.

[0006]

However, in the conventional magnetic disk drive, the work time required for initialization increases in proportion to the increase in the capacity. This is because the number of tracks existing on one storage medium surface increases as the capacity of the magnetic disk device increases.

For example, in a conventional magnetic disk drive, the rotation waiting time is 4 ms, the seek time is 10 ms,
Assuming that the data transfer time (time required to write one track) is 8 ms and that two magnetic heads are provided, the time required for writing per track is 4 ÷ 2 + 10 + 8 ÷ 2 = 16 ms Is calculated.

Therefore, the present invention has been made in view of the above problems in the conventional magnetic disk drive,
It is an object of the present invention to provide a magnetic disk drive that can reduce the time required for reading and writing information and reduce the time required for initialization.

[0009]

According to the first aspect of the present invention,
A magnetic disk drive that reads and writes information,
A plurality of magnetic heads are provided for one storage medium surface, and a drive unit for individually moving each of the plurality of magnetic heads with respect to the storage medium surface. .

According to a second aspect of the present invention, two magnetic heads are provided for one storage medium surface, and the first magnetic head performs initialization processing from the outermost track on the storage medium surface.
At the same time, the second magnetic head performs initialization processing from the innermost track of the storage medium surface, and the initialization processing ends at the center track of the storage medium surface.

According to a third aspect of the present invention, n (n is an integer of 2 or more) magnetic heads are provided for one storage medium surface, and the first magnetic head is provided from the outermost track of the storage medium surface. Initialization processing is performed, and at the same time, the second magnetic head performs initialization processing from the second track adjacent to the outermost track, and similarly, the n-th magnetic head performs n-th After performing the initialization processing of the track, each magnetic head completes the initialization processing,
It moves to an inner track on which initialization processing has not been performed yet, and sequentially performs initialization processing in the same manner as described above.

According to a fourth aspect of the present invention, n (n is an integer of 2 or more) magnetic heads are provided for one storage medium surface, and the storage medium surface is divided into n regions divided by concentric circles. The first magnetic head performs an initialization process on a track existing in the outermost peripheral area of the storage medium surface, and at the same time, the second magnetic head performs a second magnetic head adjacent to the outermost peripheral area.
It is characterized in that the initialization processing of the track existing in the n-th area is performed, and similarly, the n-th magnetic head performs the initialization processing of the track existing in the n-th area from the outermost track.

According to the present invention, when the magnetic disk drive is initialized, each magnetic head has a function of separately processing different tracks on one storage medium surface. Of the three major elements of the time required for reading and writing, the seek time can be reduced, and the time required for reading and writing information can be reduced.

[0014]

Next, a specific example of an embodiment of a magnetic disk drive according to the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram showing a first embodiment of a magnetic disk drive according to the present invention. The magnetic disk drive 1 includes a first magnetic head 2 connected to a first control circuit 4 and a second magnetic head 2 connected to a second control circuit 5 on a storage medium surface 6.
The magnetic head 3 includes a magnetic head for reading and writing two pieces of information. Each of the magnetic heads 2 and 3 has a head arm as a driving unit (not shown), and is configured to be able to individually perform an initialization process.

When the magnetic disk drive is initialized, the first magnetic head 2 performs an initialization process from the outermost track Ta, and at the same time, the second magnetic head 3 initializes from the innermost track Tb. Then, the initialization process ends at the center track Tc of the storage medium surface 6.

Here, in the magnetic disk drive in which the magnetic disk drive 1 is used, the rotation waiting time when one head is used is 4 m, as in the above-mentioned conventional example.
Assuming that s, the seek time is 10 ms, and the data transfer time (the time required to write all data on one track) is 8 ms, in this embodiment, two magnetic heads are used in the above-described manner. Rotation wait time, seek time, and data transfer time are all halved.
The write time per track is (4 + 10 + 8) / 2 = 11 ms, and the seek time is shortened.
It is possible to increase the speed by about 50% compared to 6 ms.

FIG. 2 is a schematic diagram showing a second embodiment of the magnetic disk drive according to the present invention. In this embodiment, the magnetic disk drive 11 includes a magnetic head for reading and writing n pieces of information on the storage medium surface 16. The first magnetic head 12, the second magnetic head 13, and the n-th magnetic head n of the first control circuit 1
7, connected to the second control circuit 18 and the n-th control circuit 19, and has a head arm (not shown), and is configured to be able to individually perform initialization processing of the magnetic disk drive.

When the magnetic disk drive is initialized, the first magnetic head 12 processes the first track T1 counted from the outside, and at the same time, the second magnetic head 13 processes the second track T2. Is performed by the n-th magnetic head n
The processing of the track Tn is performed. When these processes are completed, the first magnetic head 12 moves to the (n + 1) th track Tn + 1, and the second magnetic head 13 moves to (n +
2) The n-th magnetic head n moves to the (n + n) -th track Tn + n to the second track Tn + 2, and the initialization of the magnetic disk device is completed when the processing of the last track is completed.

Here, as an example, in a magnetic disk drive in which three magnetic heads are provided on each storage medium surface, information is read / written per track in a conventional case and in the above-described embodiment. And compare the time required.

For example, in a conventional magnetic disk drive, the rotation waiting time is 4 ms, the seek time is 10 ms,
Assuming that the data transfer time (the time required to write one track) is 8 ms and that three magnetic heads are provided, the time required for writing per track is 4 ト ラ ッ ク 3 + 10 + 8 ÷ 3 = 14 ms Is calculated.

On the other hand, in this embodiment, since three magnetic heads are used in the above manner, all of the rotation waiting time, the seek time, and the data transfer time are reduced to one third, and one track is used. The write time per hit is (4 + 10 + 8) ÷ 3 = 7.33 ms, and the seek time is shortened. As a result, the speed can be approximately doubled compared to 14 ms in the conventional magnetic disk device.

FIG. 3 is a schematic diagram showing a third embodiment of the magnetic disk drive according to the present invention. As in the second embodiment, the magnetic disk device 21 includes a magnetic head for reading and writing n pieces of information (not shown) on the storage medium surface 26. Each magnetic head is individually provided with a control circuit and a head. It has an arm part and is configured so that initialization processing can be performed individually.

When the magnetic disk drive is initialized, the surface of the storage medium is equally divided into n regions divided by concentric circles, and each magnetic head initializes the respective ranges A1 to An. As a result, similarly to the second embodiment, the seek time can be reduced as compared with the conventional magnetic disk drive, and the time required for reading and writing information can be reduced accordingly.

[0025]

According to the present invention, it is possible to shorten the seek time among the three major factors of the time required for reading and writing information in the magnetic disk drive, and to shorten the time required for reading and writing information. A magnetic disk device that can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a first embodiment of a magnetic disk drive according to the present invention.

FIG. 2 is a schematic diagram showing a second embodiment of the magnetic disk drive according to the present invention.

FIG. 3 is a schematic diagram showing a third embodiment of the magnetic disk drive according to the present invention.

FIG. 4 is a schematic view showing a conventional magnetic disk drive.

[Explanation of symbols]

 1, 11, 21 Magnetic disk drive 2, 12 First magnetic head 3, 13 Second magnetic head 4, 17 First control circuit 5, 18 Second control circuit 6, 16, 26 Storage medium surface 19 Nth control circuit n N-th magnetic head

Claims (4)

[Claims] A plurality of magnetic heads provided for one storage medium surface for reading and writing information; and a plurality of magnetic heads for individually moving the plurality of magnetic heads with respect to the storage medium surface. A magnetic disk drive comprising: 2. A method according to claim 1, wherein two magnetic heads are provided for one storage medium surface, and the first magnetic head performs an initialization process from an outermost track on the storage medium surface. 2. The magnetic disk drive according to claim 1, wherein the initialization process is performed from the innermost track of the storage medium surface, and the initialization process ends at the center track of the storage medium surface. 3. The number n (n is 2) for one storage medium surface
The first magnetic head performs initialization processing from the outermost track on the storage medium surface,
At the same time, the second magnetic head performs an initialization process from a second track adjacent to the outermost track,
Similarly, the n-th magnetic head performs initialization processing of the n-th track from the outermost track, and after completion of each initialization processing, the respective magnetic heads perform initialization processing on the inner circumference track that has not yet been initialized. 2. The magnetic disk drive according to claim 1, wherein the magnetic disk drive moves to a next track and sequentially performs initialization processing in the same manner as described above. 4. A storage medium surface having n (n is 2)
The above-mentioned integer) magnetic head is provided, the storage medium surface is equally divided into n regions divided by concentric circles, and the first magnetic head is an initial part of a track existing in an outermost region on the storage medium surface. At the same time, the second magnetic head performs an initialization process on a track existing in the second area adjacent to the outermost area, and similarly, the n-th magnetic head sets the track on the outermost area. 2. The magnetic disk drive according to claim 1, wherein an initialization process is performed on tracks existing in the nth to nth areas.