JPS61153884A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To reduce readout errors originating from an electromagnetic conversion part between a head and a disk by making a pulley which drives a head out of roundness or eccentric so that arrangement intervals of data tracks on a disk vary between the inner peripheral part and inner peripheral part of the disk. CONSTITUTION:A pulley 12 which is made out of roundness or eccentric pulley 13 is used as a pulley fitted on the rotating shaft of a stepping motor so as to drive the head on the disk radially. The pulleys 12 and 13 which increase in radius at the inner periphery of the disk are used to make intervals of data tracks larger at the outer periphery than at the inner periphery to equalize the intervals of the data tracks at any position, thereby reducing readout errors originating from the electromagnetic conversion part between the head and disk.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic disk device, and in particular, by changing the arrangement interval of data tracks on the disk between the outer circumference and the inner circumference of the disk, the head and disk The present invention relates to a magnetic disk device that reduces read errors caused by electromagnetic conversion parts between the disks.

A magnetic disk drive plays a role as a computer peripheral storage device, and is a device that holds a head with a small gap on a high-speed rotating magnetic disk and records information on a large number of concentric tracks.

The spacing between the multiple concentric tracks is the same at every position on the disk. Therefore, in the arrangement of equally spaced data tracks, the data capacity on one circumference is the same on both the outer and inner circumferences, so the tracks on the inner circumference are packed with data bits.

In recent years, as the density of disks has increased, track spacing has become narrower, and evenly spaced data tracks as described above can cause crosstalk with adjacent tracks due to electromagnetic conversion characteristics between the head and the disk, leading to read errors. The problem is that it is easy to cause Therefore, there is a need for a magnetic disk device that does not cause read errors due to electromagnetic conversion between the head and the disk.

[Conventional technology]

FIG. 4 is a plan view illustrating a conventional magnetic disk device including a stepping motor in a head drive mechanism. In the figure, there is a pulley 2 on the rotating shaft of the stepping motor 1.
is attached, and a steel belt 3 is wound around the pulley 2.

Both ends of the steel belt 3 are connected to a flex arm 4 and a tension arm 5.

Rotation of the shaft of the stepping motor 1 is transmitted to the flex arm 4 via the pulley 2 and steel belt 3, and moves the head 7 about the shaft 6.

The head 7 is in contact with the disk 8, and the rotation of the stepping motor 1 is transmitted to the head 7 to move the disk 8 in the radial direction. Note that 9 is the spindle, 10 is the case, and 11
indicates a spring that pushes open the tension arm 5 and applies tension to the steel belt 3.

When the magnetic disk device reads/writes, the disk 8 rotates at high speed, and as a result of this rotation, the magnetic head is held with a small gap above the disk, and information is recorded in a large number of concentric trunks.

[Problem that the invention seeks to solve]

In the conventional magnetic disk drive shown in FIG. 4, a pulley 2 that converts the rotation of the stepping motor 1 into movement of the head has a perfect circular shape. Therefore, the spacing between adjacent data trunks is the same at any location on the disk.

FIG. 5 shows the arrangement of heads on the outer and inner circumferences of the disk 8. As shown in FIG.

The spacing between data tracks on the outer circumference of the disk is d, and on the inner circumference it is d'. However, the rotation angle of the stepping motor 1 for each track is constant, and the rotation angle of the stepping motor 1 for each track is constant.
Since both are perfect circles, the rotation angles θ1 and θ2 of the arm 4 are equal in magnitude. However, since the trajectory of the head 7 over the disk 8 is an arc centered on the shaft 6, the head 7 moves at an angle α with respect to the radial direction of the disk 8 in FIG. Therefore, the spacing d' of data tracks on the inner circumference is d''=dco
Since sα becomes smaller than d, there are problems in that crosstalk with adjacent tracks occurs and S/N characteristics tend to deteriorate.

[Means for solving problems]

The above conventional problems can be solved by the magnetic disk device of the present invention in which the pulley is made out of roundness or eccentric in order to change the spacing between the data tracks on the disk between the outer and inner peripheries of the disk. resolved.

[Effect]

In other words, the distance between the data tracks on the inner and outer peripheries of the disk in a mechanism that moves in an arc shape is slightly irregular, but the roundness of the pulley that converts the rotation of the stepping motor into the movement of the head is broken. or by making it eccentric, so that it is the same at every position on the disk. Therefore, since the track spacing is the same at any location on the disk, reading errors due to electromagnetic transduction between the head and the disk are reduced.

〔Example〕

Hereinafter, the gist of the present invention will be specifically explained with reference to the drawings.

FIGS. 1A and 1B are diagrams for explaining an embodiment of the pulley shape of the present invention, and FIG. 2 is a schematic diagram of the spacing between data tracks on the inner and outer peripheries of the disk.

As an example of the present invention, a pulley 12 with out-of-roundness (elliptical shape, etc.) as shown in FIG. 1(a) or a pulley 12 shown in FIG. 1(b)
An eccentric circle 13 is made as shown in FIG. 4, and it is attached to the shaft of the stepping motor 1 instead of the pulley 2 of the conventional magnetic disk device shown in FIG.

The rest of the configuration is the same as the conventional one, and a description thereof will be omitted.

FIG. 2 schematically shows the spacing between the data trunks on the inner and outer peripheries of the disk.
are using.

As a result, the rotation angle of arm A is θ1 at the outer circumference, but the rotation angle θ2 at the inner circumference is θ2>θ1. Therefore, the interval between data tracks can be such that d' at the inner circumference is larger than d at the outer circumference.

In a conventional mechanism in which the head moves in an arc, the track pitch at the inner circumference of the disk was slightly smaller than the track pitch at the outer circumference, but as mentioned above, d', which sets the interval between data tracks at the inner circumference, is equal to d at the outer circumference. By making the distance larger than , the spacing between data tracks becomes the same at every position on the disk, and reading errors caused by electromagnetic conversion between the head and the disk can be reduced.

Furthermore, even in a disk device having a mechanism in which the head 7 moves straight in the radial direction of the disk 8 as shown in FIG.
The present invention can be applied.

In the figure, a steel belt 14 is wound around a pulley 12 attached to the shaft of a stepping motor 1, and an arm 1 on a carriage 15 is rotated by the rotation of the Boo+J-12.
The head 7 held by the disk 80 moves straight in the radial direction of the disk 80. Note that 17 is a case, and the other parts are the same as in FIG. 4, so the explanation will be omitted.

The roundness of a pulley 12 attached to the shaft of a stepping motor 1 is broken so that the spacing between data tracks is larger on the outer periphery of the disk than on the inner periphery.

This is because when writing data on the outer periphery of the disk, the write current is generally set higher than on the inner periphery (due to the thicker magnetic film on the outer periphery due to manufacturing reasons), so crosstalk between adjacent tracks occurs during reading. This is because it is easy to occur.

Therefore, by applying the present invention and increasing the data track spacing at the outer periphery, the influence of crosstalk can be suppressed.

〔Effect of the invention〕

As explained above, according to the present invention, by destroying the roundness of the pulley that converts the rotation of the stepping motor into head motion, the spacing on the disk can be changed between the outer and inner circumferences of the disk. This makes it possible to reduce read errors caused by electromagnetic conversion between the head and the disk.

[Brief explanation of drawings]

Figures 1 (a) and (b) are front views illustrating an embodiment of the pulley shape of the present invention, Figure 2 is a schematic diagram of the spacing between data tracks on the inner and outer peripheries on the disk according to the present invention, and Figure 3 4 is a plan view illustrating another embodiment of the present invention, FIG. 4 is a plan view illustrating a conventional magnetic disk device, and FIG. 5 is a schematic diagram of the spacing between data tracks on the inner and outer peripheries on a conventional disk. It is. In medicine, 1 is a stepping motor, 7 is a head, 8 is a disk, 9 is a spindle, 12 is a pulley, 13 is an eccentric circle, 14 is a steel belt, 15 is a carriage, 16 is an arm, 1f-3

Claims (1)

[Claims] In a magnetic disk drive equipped with a mechanism in which a pulley is attached to the rotating shaft of a stepping motor and a belt wound around the pulley drives the head in the radial direction of the disk, the spacing between the data tracks on the disk is determined by the outer periphery of the disk. 1. A magnetic disk drive characterized in that the roundness of the pulley is broken or eccentric so as to vary between a central portion and an inner circumferential portion.