KR100505582B1 - Head actuator of hard disk drive - Google Patents

Abstract

A voice coil motor having an upper yoke and a lower yoke installed so as to correspond to a pair of magnets, and a coil wound around the bobbin and its bobbins so as to form a magnetic field by a current applied between the magnets and the bobbins are formed. Disclosed is a magnetic head actuator of a hard disk drive provided with a swing arm supported by a head and a shield plate stacked on upper and lower surfaces of the bobbin to cover a coil so as to restrict a magnetic field forming pattern to form a uniform magnetic field.

Description

Magnetic Actuator for Hard Disk Drives {Head actuator of hard disk drive}

The present invention relates to a magnetic head actuator of a hard disk drive used as an auxiliary memory device of a computer. More particularly, a coil is wound around a magnet provided in a yoke of a voice coil motor to form a magnetic field. It's about bobbins.

In general, a hard disk drive (HDD), which enables recording and reproducing of information by a user, is mainly used as a secondary storage device of a personal computer. As a result of recent advances in technology, storage capacity is rapidly increased. On the other hand, the standard is becoming more and more compact. As shown in FIG. 1, a magnetic disk 110 is rotatably mounted on a spindle motor (not shown) installed in the base frame 100, and the magnetic head h is mounted on the disk 110. In order to protect the disk 110 and the magnetic head actuator 200, although not shown, the magnetic head actuator 200 is driven to pivot about the pivot axis P to fly the same. It is configured to include a cover frame coupled to the base frame 100 to. Reference numeral 120 denotes, for example, a circuit driver for signal transmission between a main circuit board (not shown) interfaced with a device body such as a computer and the magnetic head h, and driving control of the magnetic head actuator 200.

The magnetic head actuator 200 includes a voice coil motor (VCM) 210 having a lower yoke 211 and an upper yoke 212 to which a pair of magnets M are attached to face each other as shown in FIG. 2. , A swing arm 220 which is pivoted about the pivot axis P by the voice coil motor 210 as a head stack assembly (HSA), supported by the swing arm 220 and magnetically at the tip end thereof. The suspension 230 includes a head h, and a bobbin 230 in which a coil 231 is wound so as to be branched to correspond to the swing arm 220 and positioned between the magnet M. .

The voice coil motor 210 is a kind of driving motor that rotates the swing arm 220 to move the magnetic head h to a desired position on the disk. When the force is applied to the force generated by using the principle, by applying a current to the coil 231 located between the magnet (M) by applying a force to the bobbin 230 is rotated. Accordingly, the swing arm 220 branched to correspond to the bobbin 230 is rotated so that the track can be accessed while flying in the radial direction on the disk 110 on which the magnetic head h supported at its end is rotated. Then, the accessed information is signal-processed by the circuit driver 120 to be recorded or output to, for example, a computer.

On the other hand, the coil 231 is wound on the bobbin 230 in the form of a bundle as shown in Figure 3 by the so-called, inserting injection molding, etc., so that the upper surface and the lower surface of the bobbin 230 is exposed When a current is applied to the coil 231, there is a problem in that actuator driving precision is degraded due to non-uniform magnetic field formation due to the generation of a stray field. Therefore, in order to control the voice coil motor more effectively, it is necessary to form a uniform magnetic field.

The technical problem to be solved by the present invention is to solve the problems of the magnetic head actuator of the conventional hard disk drive, and to form a more uniform magnetic field between the magnet to increase the driving precision of the voice coil motor Its purpose is to provide a magnetic head actuator.

In order to achieve the above object, a magnetic head actuator of a hard disk drive according to the present invention includes a voice coil motor having an upper yoke and a lower yoke in which a pair of magnets are installed to face each other, and a coil wound so as to be located between the magnets. A magnetic head actuator of a hard disk drive, comprising: a bobbin, and a swing arm installed to rotate about a pivot axis by the voice coil motor with a magnetic head supported by a suspension opposite thereto, wherein the bobbin includes the coil. The shield plate is provided to cover the coil in order to restrain the magnetic field formed by the current applied to the.

According to the present invention, the shield plate is preferably any one selected from a metal plate or a conductive polymer material.

Hereinafter, a magnetic head actuator of a hard disk drive according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

4 and 5, the magnetic head actuator according to the present invention has a voice coil motor having a lower yoke 211 and an upper yoke 212 to which a pair of magnets M are attached to face each other as shown. (VCM; 210), the swing arm 220 is rotated about the pivot axis (P) by the voice coil motor 210, and is supported by the swing arm 220, the magnetic head (not shown) at the tip A bobbin in which a coil 231 is wound so that a magnetic field can be formed by a suspension (not shown) in which is installed and branched to correspond to the swing arm 220 and being applied between the magnets M and applied thereto. 230 and shield plates 310 and 320 stacked on the upper and lower surfaces of the bobbin 230 so as to cover the coil 231 to restrain the formation pattern of the magnetic field, thereby preventing the coil 231 from being exposed. It is configured to include). Here, the same reference numerals as the reference numerals of the drawings shown above represent the same components.

According to the present invention, the shield plates 310 and 320 may be, for example, a metal plate having excellent electrical conductivity, or a conductive polymer material such as polyacetylene or polyparaphenylone, for example.

The magnetic head actuator according to the present invention having the above configuration has the same driving principle as that of the conventional magnetic head actuator as described above, and the voice coil motor 210 moves the magnetic head to a desired position on a disk. A drive motor that rotates the arm 220, and uses the principle of Fleming's left hand, that is, a force generated when a current flows through a conductor in the magnetic field, and the coil 231 located between the magnets M. The magnetic field is formed by applying an electric current to the bobbin, and a force is applied to the bobbin 230 by the action of the magnetic force to rotate.

According to the present invention, when the shield plate 310, 320 is applied to the coil 231, the magnetic field is prevented from constraining the lines of magnetic force to extend to the outside, thereby enabling uniform magnetic field formation. .

Then, as the bobbin 230 rotates, the swing arm 220 branched to correspond to the bobbin 230 rotates to search for a track while flying in a radial direction on a disk (not shown) in which a magnetic head supported at its end is rotated. Access is performed, and the accessed information is signal-processed by a circuit driver (not shown), for example, to be recorded or output to a computer.

Meanwhile, according to the present invention, the shield plates 310 and 320 are not limited to the metal plate or the conductive polymer material as described above, and any material capable of restricting the magnetic lines of force may be used to form a uniform magnetic field. Do.

As described above, according to the magnetic head actuator of the hard disk drive according to the present invention, the magnetic field formed between the magnets of the voice coil motor is constrained by the shield plate installed in the bobbin to form the magnetic field more uniformly, thereby improving driving accuracy. It can increase.

1 is a schematic perspective view showing an open state of a cover frame of a conventional hard disk drive;

FIG. 2 is a schematic exploded perspective view showing the magnetic head actuator in FIG. 1;

3 is a schematic cross-sectional view taken along the line III-III of FIG. 2,

4 is a schematic exploded perspective view showing an extract of the magnetic head actuator according to the present invention;

5 is a schematic cross-sectional view taken along the line IV-IV of FIG. 4.

<Description of the symbols for the main parts of the drawings>

100 ... base frame 110 ... disc

200 ... magnetic head actuator 210 ... boy coil motor

211 Lower York 212 Upper York

220 ... swing arm 230 ... bobbin

231 ... coil 310, 320 ... shield

M ... magnet

Claims (3)

The voice coil motor having an upper yoke and a lower yoke having a pair of magnets installed to face each other, a bobbin wound with a coil wound so as to be located between the magnets, and a magnetic head supported by a suspension opposed thereto. In the magnetic head actuator of a hard disk drive including a swing arm installed to rotate about a pivot axis by The bobbin is electrically stacked on the upper and lower surfaces of the bobbin to prevent the exposure of the coil to restrain the magnetic field formed by the current applied to the coil to cover the coil to form a uniform magnetic field between the magnets. Magnetic head actuator of a hard disk drive, characterized in that the conductive shield plate is provided. The method of claim 1, And the shield plate is a metal plate. The method of claim 1, The shield plate is a magnetic head actuator of a hard disk drive, characterized in that the conductive polymer material.

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