JPH01217701A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To suppress skew quantity to the minimum by composing the magnetic head groups of adjoining plural channels which simultaneously execute recording and reproducing and executing recording by driving the respective groups simultaneously. CONSTITUTION:The skew becomes larger as the positions of heads 1 to be used become more separated due to the thermal deformation of medium 2 and an actuator 4 part, the mechanical position deviation of a spindle 3 and the actuator 4 part, etc. Consequently, the skew quantity between parallel channels can be decreased by arranging, for example, five magnetic heads 1 to simultaneously execute recording and reproducing out of fifteen data heads 1 collectively on the surfaces of the magnetic disks 2 closest to the heads 1. Thus, the skew quantity to occur between the channels mutually in a multichannel magnetic disk device can be suppressed to the minimum, and the capacity of a buffer memory used for removing the skew can be suppressed to the minimum.

Description

Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention relates to a magnetic disk device as an external storage device.

(Prior Art) A conventional multi-channel magnetic disk device is shown in FIG. 2, in which 1 is a data head, 2 is a magnetic medium, 3 is a spindle, 4 is an actuator, and 5 is a servo head. Second
In the figure, there are 15 media surfaces (data surfaces) on which data is recorded and reproduced.
(X, shows the channel number and head number in order. - As an example, five heads used when head number "0" is selected are shown in black.

In conventional multi-channel magnetic disk drives.

As shown in FIG. 2, when recording and reproducing data on a certain parallel channel, the magnetic heads that are used at the same time are placed one interval apart with an unused magnetic head sandwiched between them.

In a multi-channel magnetic disk drive, when recording and reproducing data in parallel channels, the relative positional relationship of the magnetic heads used shifts in the circumferential direction of the magnetic disk. A phase shift occurs between channels, resulting in skew.

Possible causes of this skew include thermal deformation of the medium and actuator, mechanical misalignment of the spindle and actuator, etc., but it is thought that the farther the head is used, the greater the skew occurs. .

In conventional multi-channel magnetic disk drives,
In order to eliminate this skew, the above problem was solved by providing a buffer memory or the like to match the phase between each data channel.

(Problems to be Solved by the Invention) In a conventional multi-channel magnetic disk device, the magnetic heads that simultaneously record and reproduce data are arranged at a kneeling position with large intervals, resulting in a large skew.

An object of the present invention is to improve the disadvantages of the conventional multi-channel magnetic disk drive described above and to minimize the amount of skew.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a multi-channel magnetic disk device that includes:
A plurality of magnetic heads for simultaneous recording and reproduction are placed on the surface of the magnetic disk closest to each other.

(Function) The amount of skew is reduced by arranging the magnetic heads that perform recording and reproducing operations at the same time on the disk surface close to each other.
The capacity of the buffer memory for removing this skew can be kept small.

If the amount of skew can be suppressed to a very small certain amount or less, it is possible to remove the buffer memory.

(Example) Hereinafter, details of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of a magnetic disk device according to the present invention. Similar to FIG. 2, FIG. 1 explains the case where the number of data planes is 15 and 5-channel parallel transfer is performed.

Of the 15 data heads 1, five magnetic heads that simultaneously record and reproduce data are placed together on the closest magnetic disk surface to reduce the amount of skew between parallel channels.

- As an example, five heads used when head number "OF+" is selected are shown in black.

FIGS. 3 and 4 are diagrams for explaining the arrangement of heads when two data heads are mounted on one data surface. Both Figures 3 and 4 explain the case where there are 20 data heads 1 and 5-channel parallel transfer is performed. In each case, as an example, head number 410 #j is selected. The five heads that will be used are shown in black.

Figure 3 shows a case in which the magnetic head for simultaneous recording and reproduction is selected from one of the two magnetic heads existing on one data surface, similar to the case in which one magnetic head is mounted on one data surface in Figure 1. Magnetic heads that simultaneously perform recording and reproduction are arranged on the surface of the magnetic disk closest to the magnetic disk.

In FIG. 4, two magnetic heads existing on one data surface are used as magnetic heads for simultaneous recording and reproduction.
A case is shown in which this magnetic head is placed on the closest magnetic disk surface. If the number of parallel channels is odd,
As shown in FIG. 4, channels are assigned to each of the two data heads on one data surface, and the remaining channel is assigned to either one of the two data heads on the adjacent data surface.

Which of the methods shown in FIGS. 3 and 4 is used is determined by selecting the method that minimizes the amount of skew in each magnetic disk device.

〔Effect of the invention〕

According to the present invention, for example, the amount of skew occurring between channels in a multi-channel magnetic disk device can be kept small, and the capacity of the buffer memory used to remove this skew can be kept small.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating an embodiment of the present invention in which one data head is mounted on one data surface. FIG. 2 is a diagram for explaining a conventional example. FIGS. 3 and 4 are diagrams for explaining an embodiment of a magnetic disk device in which two data heads are mounted on one data surface. 1...Data head 2...Magnetic medium 3...
・Spindle 4...Actuator 5...
・Servo head agent Patent attorney Nori Chika Yudo Mitsuyuki Matsuyama N N N NNNN Q N

Claims (1)

[Claims] 1) In a magnetic disk device that records data strings of multiple channels on multiple tracks on a magnetic recording medium using multiple magnetic heads, magnetic head groups of adjacent multiple channels that record and reproduce data simultaneously are configured, and each A magnetic disk device characterized by driving a group of magnetic heads simultaneously to perform recording.