JPH0440675A - Flexible magnetic disk storage device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a flexible magnetic disk storage device used particularly as an external storage device for a computer.

[Prior art] Figure 5 shows, for example, the book "Latest Magnetic Recording Technology and Apparatus/Apparatus" published by Sogo Gijutsu Publishing Co., Ltd. on December 25, 1984.
1 is a partially cutaway perspective view of the configuration of a flexible magnetic disk storage device using a conventional lead screw and a step motor, disclosed in Chapter 1, ``Flexible Pull Disk Devices and Magnetic Card Devices.'' FIG. In the figure, ■ is a flexible disk, 2 is a cartridge that stores the flexible disk 1, 3 is a head that records and plays back on the flexible disk 1, 4 is a carriage on which the head 3 is mounted,
5 is a kite rod that guides the reciprocating linear motion of the carriage 4; 6 is a reet screw that transmits the reciprocating force to the carriage 4; 7 is a step motor that provides rotational driving force for the reet screw 6; and 8 is a component on which each of the above components is mounted. This is the basis on which it will be done.

Figure 6 is, for example, part 8 of "The History of Floppy Disk Devices" published by CQ Publishing Co., Ltd. on November 15, 1989.
FIG. 8 is a perspective view showing the configuration of a voice coil motor used in a conventional flexible magnetic disk storage device disclosed on pages 8 to 89.

In the figure, 9 is a voice coil attached to the rear end of the carriage 4, 10 is a center yoke surrounded by the voice coil 9, and 11 is located on the left and right sides of the voice coil 9, facing the center yoke 10. A pair of left and right permanent magnets 12 are outer yokes that fix each permanent magnet 10 and are connected to the center yoke 10 to form a magnetic circuit.

Next, the operation of the above conventional flexible magnetic disk storage device will be explained. In the method illustrated in FIG. 5 as an example of operating the head 3 that moves while contacting the upper and lower surfaces of the flexible disk 1, a step motor 7, which is mounted on a boat, is used, and a rotor (not shown) of the step motor 7 is connected to the rotor (not shown). When the connected lead screw 6 is rotated and the rotational force of the lead screw 6 is transmitted to the carriage 4, the rotational force is converted into parallel propulsive force and moves the carriage 4. In such a system, a 3.5-inch flexible disk or a 5.25-inch flexible disk may be used.
Inch flexible disks also have predefined industry standard recording track layout dimensions and number of tracks, and the carriage 4 is fed by the lead screw 6 corresponding to the rotation angle per one pulse of the step motor 7. Quantities are dependent on construction and accuracy to meet these specifications.

In recent years, in order to realize the market demand for accessing large-capacity and high-speed information, a voice coil motor as shown in FIG. There is a technological trend toward replacing the above-mentioned method based on No. 6. The reason for this is that in the above system using the step motor 7 and the lead screw 6, there is a limit to the minimum amount of movement that can be sent per one pulse of the step motor 7 due to processing considerations, and it may not be possible to increase the density of recording tracks.

In addition, in the step motor 7, there is a limit to the maximum torque that can be generated to increase the moving speed of the carriage 4 by the lead screw 6, and if this limit is exceeded, a phenomenon called tax adjustment occurs and the carriage 4 cannot be moved at high speed. Sometimes.

On the other hand, the voice coil motor shown in FIG. 6 has a permanent magnet 11. In the magnetic circuit composed of the outer yoke 12 and the center yoke 10, when a current is applied to the voice coil 9, an electric current is applied to the left and right sides of the voice coil 9 in accordance with Fleming's left hand rule in the direction of the arrow shown in FIG. A force is generated to move the carriage 4. Furthermore, if the direction of the current flowing through the voice coil 9 is changed, the carriage 4 will be moved in the opposite direction to that described above. Also, if you increase the amount of current flowing through the voice coil 9, the carriage 4
The movement speed of will also increase. Further, although a position information source such as an encoder is required, by using this source, it becomes possible to position the carriage 4 at an arbitrary position, and the track density is also increased, thereby increasing the capacity of the device.

[Problems to be Solved by the Invention] Since the above-described conventional flexible magnetic disk storage device is configured as described above, if the device itself is to be made thin and compact, the magnetic circuit It is necessary to reduce the height dimension of the left and right side surfaces of the voice coil 9 that intersect with the magnetic flux of As a result, a sufficient force for moving the carriage 4 cannot be generated in response to a predetermined current flowing through the voice coil 9, and high-speed access becomes impossible. Alternatively, a large current must be passed through the voice coil 9 in order to generate a force for moving the carriage 4, resulting in problems such as increased power consumption.

This invention was made to solve the above-mentioned problems, and in addition to providing large capacity and high-speed access,
An object of the present invention is to obtain a flexible magnetic disk storage device that can be configured into a thin and compact device.

[Means for Solving the Problems] A flexible magnetic disk storage device according to the present invention includes:
A pair of center corks are provided that are surrounded by one voice coil attached to the rear end of the carriage and are divided left and right with the carriage at the center. A voice coil motor is provided, which includes a pair of permanent magnets at opposing positions, a pair of outer yokes to which the permanent magnets are fixed, and a pair of magnetic circuits formed by these.

[Operation] The flexible magnetic disk storage device of the present invention has a voice coil motor that is surrounded by one voice coil attached to the rear end of a carriage, and has a pair of left and right parts divided around the carriage. A pair consisting of a center yoke, a pair of permanent magnets at positions facing each center yoke on either the upper or lower side of the voice coil, and a pair of outer yokes to which each of the permanent magnets is fixed. Since the device is equipped with a magnetic circuit, sufficient force for moving the carriage can be obtained, high-speed access is possible, and the device itself can be made thinner.

[Example 1] An example of the present invention will be described below with reference to the drawings. 1st
2 is a perspective view showing a part of the configuration of a flexible magnetic disk storage device according to an embodiment of the present invention, FIG. 3 is a sectional view showing a magnetic circuit portion of the flexible magnetic disk storage device of FIG. 1. FIG. In the figure, 1 is a flexible disk, 2 is a cartridge that stores the flexible disk 1, 3 is a head that records and plays back on the flexible disk 1, 4 is a carriage on which the head 3 is mounted, and 8 is a base on which each component is mounted. , 9
is a voice coil; 10 is a pair of center yokes that are surrounded by the voice coil 9 and are divided left and right with the carriage 4 at the center; 11 is a position facing each center yoke 10; A pair of permanent magnets 12 arranged on the left and right fix each permanent magnet 11, and a pair of outer yokes 13 each constitute a magnetic circuit together with each permanent magnet 11 and each center yoke lO, and 13 is integrated with the carriage 4. 14 is an optical linear encoder that generates track positioning information depending on the presence or absence of slits on the linear scale 13; 15 is a linear guide that serves as a guide member when the carriage 4 moves;

Next, the operation of the flexible magnetic disk storage device according to the embodiment of the present invention will be described.

When the head 3, which has been positioned on a given recording track, moves to the next recording track, the head 3 reads the recording track information written in advance on the flexible disk 1, and the track set on the linear scale 13 is read by the head 3. Positioning information is generated by the optical linear encoder 14, and each piece of information is sent to a control circuit (not shown).
The control current sent from this control circuit is passed through the voice coil 9. The voice coil 9 has a pair of left and right permanent magnets 1.
1 and each center yoke 10, and as a result, a force based on Fleming's left-hand rule is generated in the voice coil 9.

At this time, the portion of the voice coil 9 that contributes to the generation of the force is the winding of the voice coil 9 that intersects the magnetic flux existing between the permanent magnet 11 and the center yoke 10. That is, in the cross-sectional view of the magnetic circuit portion shown in FIG. 3, the width of the heis coil 9 is a measure of the portion that contributes to the generation of the force. Here, when making the device itself thinner, it goes without saying that the voice coil 9. The center yoke lO, the permanent magnet 11, and the outer yoke 12 must also be made thinner. In this case, as the voice coil 9 is made thinner, its height H becomes smaller, but its width remains unchanged. Therefore, even if the voice coil 9 is made thinner, the width that contributes to the generation of the force does not change. Furthermore, in order to increase the generation of the above-mentioned force, it is advantageous to arrange the permanent magnet 11 and the outer yoke 12 on the lower surface of the voice coil 9 symmetrically with the upper surface to form a common magnetic circuit with the center yoke 10. However, there are restrictions on the required thickness due to the magnetic properties of the permanent magnet 11, and restrictions on the required cross-sectional area of the center yoke lO and the outer yoke 12 in order to prevent saturation of the magnetic flux of the magnetic circuit. For this purpose, the height H of the device itself must be increased by 2
In order to limit the force to 5.4+nm or less and generate a predetermined force, it is preferable to configure the magnetic circuit as shown in FIG.

That is, it is optimal to arrange the permanent magnet 11 and the outer yoke 12 on either the upper surface side or the lower surface side of the voice coil 9.

In the embodiment shown in FIG. 3, the permanent magnet 11 and the outer yoke 12 are arranged on the upper surface side of the voice coil 9.

The force generated by the voice coil 9 is transmitted to the carriage 4 coupled to the voice coil 9, which is held by the linear kite 15.
Therefore, the carriage 4 moves linearly along the linear guide 15. The linear scale 13 and the head 3 attached to an arm (not shown) extending from the side of the carriage 4 feed back information from the linear movement of the carriage 4 to the control circuit, and adjust the information according to the difference from the target track. The control current is adjusted to control the positioning of the head 3.

In addition, when using a conventional flexible disk 1 on which recording track information is not written in advance, in order to control the positioning of the head 3, a linear scale 1
This is performed using track positioning information generated from the optical linear encoder 14 and the optical linear encoder 14.

FIG. 4 is a sectional view showing the main parts of a flexible magnetic disk storage device according to another embodiment of the present invention. In the figure, 1 is a flexible disk, 3 is a head that performs recording/reproduction on the flexible disk 1, 4 is a carriage on which the head 3 is mounted, 8 is a base on which each component is mounted, 1
A magnetic scale 6 is fixed to the bottom surface of the carriage 4 and moves together with the carriage 4, and a magnetic scale 17 is fixed to the base 8 so as to maintain a predetermined gap with the magnetic scale 16 and face the magnetic scale 16. Magnetoresistive element, 18
is a magnetic sensor consisting of a magnetic scale 16 and a magnetoresistive element 17.

Another embodiment of the present invention shown in FIG. 4 includes a magnetic scale 16 and a magnetoresistive element 7 instead of the linear scale 13 and optical linear encoder 14 in the embodiment shown in FIG. A case is shown in which a magnetic sensor 18 is used. In another embodiment of the present invention shown in FIG. 4, the magnetic scale 16 has a structure in which the south pole and the north pole are magnetized at a predetermined pitch to form a large number of poles, and when the carriage 4 moves, The magnetic scale 16 also moves together with the carriage 4, and the change in magnetic flux at this time is detected by the magnetoresistive element 17, thereby generating track positioning information. By using the magnetic sensor 18, there is an effect that the device itself can be made even thinner.

In addition, although the above embodiment shows the case where the linear guide 15 is used, a guide rod, a ball bearing, a sliding bearing, etc. may also be used.

[Effects of the Invention] As described above, the flexible magnetic disk storage device of the present invention is surrounded by one voice coil attached to the rear end of the carriage, and has a pair of center yokes divided left and right around the carriage. A pair of permanent magnets is provided at a position facing each center yoke on either the upper surface side or the lower surface side of the voice coil, and a pair of outer yokes to which each of the permanent magnets is fixed is provided. Since the structure includes a voice coil motor having a pair of magnetic circuits, it is possible to obtain a flexible magnetic disk storage device that can be made thinner and smaller without impairing the performance of the voice coil. be effective.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view of the configuration of a flexible magnetic disk storage device according to an embodiment of the present invention, and FIG.
1 is a cross-sectional view showing a main part of the flexible magnetic disk storage device shown in FIG. 1, FIG. 3 is a cross-sectional view showing a magnetic circuit portion of the flexible magnetic disk storage device shown in FIG. 1, and FIG. FIG. 5 is a cross-sectional view showing the main parts of a flexible magnetic disk storage device according to an embodiment; FIG. 6th
The figure is a perspective view showing the configuration of a voice coil motor used in a conventional flexible magnetic disk storage device. In the figure, 1... flexible disk, 2...
Cartridge, 3...head, 4...carriage,
5...Guide rod, 6...Leat screw, 7
...Step motor, 8...Base, 9...-Voice coil, 10...-Center yoke, 11...Permanent magnet, 12...Outer yoke, 13...Linear scale, 14... - Optical linear encoder, 15... linear guide, 16... magnetic scale, 17... magnetoresistive element, 18... magnetic sensor. In addition, it is shown. In the drawings, the same reference numerals refer to the same or corresponding parts. Fig. 5) L, '+Flexible disk head A, 1 cylinder rod 6°, lead 7791 7'', tenop 7-ri 8-head, 1st flexible disk, M carriage-to-screw 8 4th: 9: 10-11: 12: Key 1] Tight water Izumi coil ink yoke Permanent magnet outer yoke

Claims (1)

[Claims] Recording track information is written in advance on a part of a concentric recording track formed on a flexible disk as a recording medium, and the recording track information is connected to a carriage equipped with a head for recording and reproducing information on the recording track. In a flexible magnetic disk storage device of a type in which a voice coil motor is controlled using track positioning information generated by an encoder to move and position the head, one voice attached to the rear end of the carriage. a coil, a pair of center yokes surrounded by the voice coil and divided left and right around the carriage, and each center yoke on either the upper surface side or the lower surface side of the voice coil. A voice coil motor includes a pair of permanent magnets provided at opposing positions, and a pair of outer yokes that fix each permanent magnet and constitute a magnetic circuit together with the permanent magnets and each center yoke. A flexible magnetic disk storage device characterized by: