JPH0323569A - Disk device - Google Patents

Abstract

PURPOSE:To obtain a compact device with high driving torque by juxtaposing plural permanent magnets constituting a voice-coil motor as a head driving means in the direction of driving a head and magnetizing these magnetic poles in the reverse direction to each other. CONSTITUTION:A head supporting means 3 is driven by the driving means 10 and 10' with plural permanent magnets 13, 13', 14 and 14' magnetized in the thicknesswise direction and driving force to be generated between driving coils 11 and 11' arranged in a magnetic circuit formed with magnetic flux 50-52 and 60-62 generated from the magnets 13, 13', 14 and 14'. Then, the plural permanent magnets 13, 13', 14 and 14' are juxtaposed in the direction of moving the head supporting means 3 and also magnetized in the reverse magnetizing direction to each other. Consequently, the magnetic circuit of the driving means 10 and 10' can efficiently be formed. By this method, the compact device with high driving torque can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a disk device, and more particularly to a disk device that drives a head using a voice coil motor. [Conventional Technique 8K] In the field of 4M information devices such as computers, disk devices have been widely used as devices for recording and reproducing information. For example, a voice coil motor is used as a head drive source in an optical disk device because it is affordable and inexpensive. Figure 8 shows the structure of a conventional disk device. In FIG. 8, an optical disk 1 is rotated by a motor (not shown), an optical head 2 is mounted on a carriage 3, and the carriage 3 is connected to a drive coil 5 of a voice coil motor 4. Further, the carriage 3 is capable of linear movement in the radial direction of the optical disc 1 by means of guide shafts 6 and 6'. In FIG. 6, voice coil motors 4 and 4' are arranged on both sides of the optical head 2, but since both have the same structure, only the voice coil motor 4 will be explained here. As shown in Fig. 9, the internal structure of the voice coil motor 4 includes a magnetic circuit composed of a magnetic flux generated by flat permanent magnets 7 and 7' magnetized in the thickness direction and a yoke 9 through which the magnetic flux passes. A drive coil 5 is placed. When current is passed through the drive coil 5, thrust is generated by interaction with the magnetic field of the permanent magnet, and the drive coil 5 moves relative to the yoke 9.
Eventually, the optical head 2 is moved to a predetermined position in the radial force direction of the optical disk l via the carriage to perform recording and reproduction. In FIG. 8, voice coil motors are arranged on both sides of the optical head 2, but there may be a structure in which only the voice coil motor 4 is provided, for example. [Problem that the invention seeks to solve] However,
In recent years, there has been an increasing demand for improved processing speed in information equipment such as computers, and the same is true for optical disk drives. To improve processing speed,
High-speed movement of the optical head, or high-speed access function, is essential. For this reason, the voice coil motor for driving requires higher thrust. To improve thrust,
As shown in Figure 10, it is possible to increase the number of coil turns and increase the size of the permanent magnet to direct the drive torque, but in order to eliminate magnetic saturation, the yoke H has to be enlarged, which results in a particularly thick There was a drawback that there was a large increase in the horizontal direction.

Furthermore, high thrust can be obtained by arranging two conventional voice coil motors in the radial direction of the disk as shown in the figure. Although this did not increase the thickness in the thickness direction, it had the disadvantage that the overall occupied area became extremely large. In addition, the configuration shown in Figure 9 has many serious drawbacks, such as an increase in the number of drive sources for the carriage and a reduction in the resonance frequency due to the relationship between the rigidity of the carriage and the drive coil, which has a significant impact on performance. This caused problems. [Means for Solving the Problems] The present invention has been made with the aim of solving the above-mentioned problems, and is characterized by the fact that a head for recording or reproducing information on a disk-shaped recording medium is connected to one head. ! a head support means arranged to be movable in the radial direction of the disk-shaped recording medium; a drive means for driving the head support means m, the drive means being a drive means arranged in a magnetic circuit formed by a plurality of permanent magnets magnetized in the thickness direction and a magnetic flux generated by the permanent magnets; The head support means is driven by a driving force generated between the permanent magnets and the coil, and the plurality of permanent magnets are juxtaposed in the moving direction of the head support means so that the directions of magnetization thereof are opposite to each other. This is on a disk device configured as follows. [Function] This makes it possible to efficiently form the magnetic circuit of the driving means and realize an ultra-compact, high-performance head feeding device that generates high driving torque.

[Example] The details of the present invention will be described below with reference to the drawings in the case where the disc device of the present invention is applied to an optical disc device.
1 and 2 show a first embodiment of the present invention, and FIG. 1 is a schematic perspective view of a disk device using a voice coil motor consisting of a flat permanent magnet and a drive coil as a head drive means. Figure 2 is a cross-sectional view of the main parts of the voice coil motor. In FIG. 1, the basic configuration of the disk device is the same as that of the conventional example shown in FIG. 6, so a description thereof will be omitted. Also, ffs1
In the figure, the voice coil motors 10 and 10' are arranged on both sides of the optical head, and since both have a rotary structure, the voice coil motors 10 will be explained. 4 heads! The driving coils 11 and If', which are coupled so as to move together with the placed carriage 3, are further coupled and fixed to each other by a highly rigid support member l2.
Permanent magnets 13.13' and 14.14' are fixed to the yoke l5 by well-known means. As shown in the fjSz diagram, a flat permanent magnet 13.13'. 14 and 14' are arranged parallel to each other in the direction of movement of the carriage and magnetized in the thickness direction, and as shown in the figure, the directions of magnetization are opposite to each other between the permanent magnets adjacent to each other in the direction in which the carriage is driven. It is magnetized with a certain polarity. By forming the magnetic poles in this way, the upper permanent magnet 13.
The magnetic fluxes generated from 14 flow in the directions of 50 and 51.52, respectively, and the magnetic fluxes generated from the lower permanent magnets 13' and 14' flow in the directions of 60 and 61.62, respectively. By flowing W currents in different directions through the drive coils 11 and 11' in such a magnetic field, high thrust can be generated by interaction with the magnetic field. And especially permanent magnets l3 and 14 (or 13') in the carriage drive direction.
and 14'), the directions of the magnetic fluxes are in the same direction and do not cancel each other out and weaken each other, making it possible to form an efficient magnetic circuit without unnecessary loss. Therefore, the vertical yokes 9a and 9b as shown in the conventional example of FIG. 11 are not required, and the drive coils 11, 11' can be fixed to the carriage 3 by using the highly rigid support member l2. For this reason, the entire drive system can be lightly oxidized, and operation with good response to high frequency signals (J) is possible, achieving high performance.
Since a and 9b are not required, the drive coil can be integrated and incorporated, resulting in a simple and compact configuration.

Also, as shown in FIG. 3, if the distance between the drive coils 11.11' is d, and the stroke of the drive coil 11.11' is is, then from the relationship between the magnetic poles of the permanent magnets 13 and 14, ld>!
It is preferable that the driving coil length be ls.More specifically, if the length of the drive coil is nc, then the relationship ld>ls+ld may be satisfied.

By doing this, the magnetic field of the permanent magnets 13.14 placed on the drive coil 11.11' acts as a reverse magnetic field at a position between the permanent magnets 13.14, thereby preventing negative effects such as weakening of the magnetic field. can do. In addition, in the present invention, since the drive coils 11 and 11' are supported by the high-rigidity support member l2, it is possible to achieve high rigidity as a whole. Because unnecessary vibrations may occur,
It may also be installed with a vibration absorbing material 70 in between, as in the 61st base. Further, as shown in FIG. 7, the viscoelastic member 7l is attached to the permanent magnet 13, 13'. 14 and 14' and glued to the yoke l5, it is also effective in preventing vibration. In the first embodiment described above, four permanent magnets were used for the drive coil, but in another embodiment, as shown in FIG. 16.
17 and can be used with the left and right polarities reversed. In addition, by placing the permanent magnet on one side as shown in Figure 5, it is possible to create an ultra-thin voice coil motor while maintaining the conventional rotational thrust. Although this embodiment has been described using an optical disk device as an example, it can be widely used not only as a magnetic disk device but also as a linear actuator. That is, according to the present invention, the amount of small e is 41. It is possible to realize a voice coil motor for moving the head that generates a high drive torque. [Effects of Activation 1! 1] As can be seen from the above explanation, according to the disk device based on the IJ1 of the present invention, a plurality of permanent magnets constituting the voice coil motor as a head driving means are arranged side by side in the head driving direction, and By magnetizing the magnetic poles in opposite directions, it is possible to obtain high thrust and high drive torque with a simple configuration, and it is also extremely small and lightweight, making the overall structure compact, making the disk device more compact and high-performance. There is a big effect on In addition, although the above-mentioned embodiment describes the case where the present invention is applied to an optical disk device, the present invention is not limited to this. The present invention can be applied to any device that uses a voice coil motor as a driving means.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a disk device that has implemented unreleased IJ1, Fig. Fig. 4 is a side sectional view showing another embodiment of the present invention, and Fig. 5 is a side sectional view showing another embodiment of the present invention. 6 and 57 are side sectional views showing still other embodiments of the present invention. FIG. 8 is a schematic perspective view of a conventional disk device. FIG. 9 is a schematic perspective view of a conventional disk device. 6th
Figure 10 is an enlarged sectional view of the voice coil motor, Figure 10 is a diagram of a larger voice coil motor, and Figure 1 is a diagram of two voice coil motors arranged side by side. l... Optical disk 2... Optical head 3... Carriage 10.10... Voice coil motor 11.11'.
...Drive coil 12...Support member 13, ■Go, 14.14...Permanent magnet 27//

Claims (3)

[Claims] (1) head support means on which a head for recording or reproduction on a disk-shaped recording medium is mounted and arranged to be movable in the radial direction of the disk-shaped recording medium; and a driving means for driving the head support means. The driving means drives the head by a driving force generated between a plurality of permanent magnets magnetized in the thickness direction and a driving coil disposed in a magnetic circuit formed by magnetic flux generated by the permanent magnets. A disk device configured to drive a support means, wherein the plurality of permanent magnets are arranged in parallel in the moving direction of the head support means, and the magnetization directions thereof are opposite to each other. . (2) A disk according to claim (1), wherein a plurality of the drive coils are arranged in the moving direction of the head support means and are configured to flow current in mutually different directions. Device. (3) The disk device according to claim (1), wherein the plurality of drive coils are connected to each other by a highly rigid member and fixed to the head support means.