JPS6353766A - Head moving device - Google Patents

Abstract

PURPOSE:To finely adjust the position of a head with a high accuracy by mounting the head on a second moving base disposed freely movably with respect to a first moving base, and moving the second carriage base only with a motor for fine adjustment at the time of finely moving the head. CONSTITUTION:If a disk 15 is loaded and the head 13 contacts it, a motor 6 for coarse moving is made rotate, a needle 8 is guided by a leed screw 5 and a groove 7, so that the second moving base 10 is coarsely moved together with the first moving base 4, and thus the coarse adjustment of the position of the head is executed. Thereafter, the motor 19 for fine moving is made rotate in the positive or negative direction in accordance with a servo signal from the disk 15, a lever 17 is rotated in the direction of arrow (b) by the guiding action of a screwed shaft 20, consequently, the protruding part 21 of the moving base 10 is pressed by a base part 17b with a fine stroke and made finely move to the direction of arrow (a) resisting against a tension coil spring 12. But if the lever 17 is rotated in the direction b', the moving stroke of the base part 17b and finely moved in the direction of arrow a', and thus the fine adjustment of the head position is executed.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is most suitable for application to a head moving device of a flow-novy disk device, for example, and is suitable for rough adjustment and fine adjustment of head position. The present invention relates to a head moving device capable of performing the following operations.

[Summary of the invention]

The present invention provides a first head moving device that performs coarse and fine adjustment of the head position by coarsely and finely moving a moving table on which a head is attached using a motor.
The head is attached to a second movable base which is arranged to be movable relative to the movable base, and when coarsely moving the head, the first movable base is moved together with the second movable base by the coarse movement motor, and the head is When making fine movements, the second
By moving only the first movable base with respect to the first movable base, fine adjustment of the head position can be performed with high precision independently of coarse adjustment.

[Conventional technology]

Conventionally, for example, in a head moving device for a floppy disk drive, a stepping motor is used to rotate a lead screw to move a moving base on which the head is attached, and this moves the head in the radial direction of the disk to track the disk. There is one that allows you to adjust the head position.

Incidentally, in recent years, the recording capacity of floppy disk devices has been increasing, and the track pinch of the disk has been narrowed to increase the density. However, in this case, if the disk is eccentric, the narrow trunk pitch tends to cause off-track, in which the head deviates from a predetermined track, and desired recording and reproduction may become impossible. For this reason, it is necessary to finely adjust the head position by moving the head slightly by about ±1 pitch using a servo signal from the disk.

Therefore, in a head moving device that uses a stepping motor to rotate a lead screw to move a moving table, as described above, by changing the balance of the current flowing through each phase of the stepping motor's coil, the rotation of the lead screw can be changed to a normal rotation. There is a method in which the moving table is made to move coarsely and finely by changing the movement of the moving table into small rotations and small rotations.

[Problem that the invention seeks to solve]

However, in the conventional method described above, the rotation of a single stepping motor is changed to coarsely and finely move the moving table, so when making a fine movement of the head, the entire moving table, which has a considerable mass, must be coarsely moved. must be moved in exactly the same way as in the case of .

It is not easy to move the entire moving table with such a large load with extremely high precision, and it has been difficult to finely adjust the head position with high precision.

Furthermore, since the coarse and fine movements of the head are always performed by one stepping motor, the power consumption of that stepping motor increases significantly and heat generation increases. This heat generation causes thermal expansion of various parts including the lead screw, and this also poses a problem that prevents highly accurate fine adjustment of the head position.

Furthermore, in a stepping motor that uses a single stepping motor for both coarse and fine movement of the head, the dynamic range when finely moving the head is ±1 of the pitch of one stepping pulse. /2, making it impossible to freely set the dynamic range of microtremors.

Moreover, since the balance of the current flowing through each phase of the coils of a single stepping motor is changed, the control circuit system of the stepping motor becomes extremely complicated, resulting in extremely high costs and the problem that control malfunctions are likely to occur. Ta.

Therefore, the present invention enables fine adjustment of the head position to be performed with high precision independently of coarse adjustment.

[Means for solving problems]

The present invention provides a first movable base configured to be freely movable, a coarse movement motor for moving the first movable base via a coarse movement mechanism, and a head attached to the first movable base. a second moving table movably disposed, and a fine movement motor provided on the first moving table to move the second moving table via a fine movement mechanism; by moving the first moving table via the coarse movement mechanism, the second moving table is moved together with the first moving table to coarsely move the head, and the fine movement motor is used to move the head. The head is configured to be moved slightly by moving the second moving table relative to the first moving table via a fine movement mechanism.

[Effect]

According to the present invention, when the coarse movement motor is rotated, the first moving table is moved, and the second moving table is also moved together with the first moving table to coarsely move the head. When the fine movement motor is rotated here, only the second moving table is moved relative to the first moving table, and the head is slightly moved. Therefore, the load on the fine movement motor when finely moving the head is reduced to only the small mass of the second moving table to which the head is attached, and this can be finely moved with high precision.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a head moving device of a floppy disk device will be described below with reference to the drawings.

First, FIG. 1 shows a head moving device 1 in a first embodiment. A guide shaft 3 is installed horizontally, and a first movable table 4 is inserted through the guide shaft 3 at its bearing portion 4a so as to be movable in the directions of arrows a and a'.

A lead screw 5 is arranged horizontally on one side of the first moving table 4 along the moving direction of the first moving table 4. This lead screw 5 is constituted by the motor shaft of a coarse movement motor 6 consisting of a stepping motor, and has a spiral groove 7 formed on its outer peripheral surface. A needle 8 attached to the first movable table 4 is engaged with this groove 7. Note that the lead screw 5 constitutes a coarse movement mechanism.

Next, on the front side of the first movable base 4, a second movable base 10 is inserted through the guide shaft 3 at its bearing portion 10a, and is configured to be movable in the directions of arrows a and a'. A projecting piece 11 is provided on one side of the second movable table 10, and this projecting piece 11 abuts on the lead screw 5. Further, a tension coil spring 12 is provided between the protruding piece 11 and the first moving table 4.
is stretched, thereby urging the second movable base 10 to move toward the first movable base 4 side. and a second moving table 10
A head 13 is attached to the upper surface of the disc 13, and the head 13 is configured to come into contact with the disk 15.

Next, a lever 17 is mounted on the upper surface of the first moving table 4.
8 so as to be rotatable in the directions of arrows A and b'. A fine movement motor 19 is horizontally fixed to the first moving table 4, and a screw shaft 20 constituted by the motor shaft of this fine movement motor 19 is screwed onto the tip 17a of the lever 17.

Note that the fine movement motor 19 is optimally a stepping motor, but may also be a general servo motor. The second movable table 10 is provided with a protrusion 21, and this protrusion 21 is connected to the lever 1.
7 is in contact with the base 17b. Note that the lever 17 constitutes a fine movement mechanism.

Next, the operation of the head moving device 1 described above will be explained.

First, when the disk 15 is loaded into a floppy disk device, the head 13 comes into contact with the disk 15. Then, the coarse movement motor 6 is rotated in the forward or reverse direction,
Lead screw 5 is rotated. Then, the needle 8 is guided by the groove 7 of the lead screw 5, and the first moving table 4 is coarsely moved in the direction of arrow a or a'. Here, the second movable base 10 is biased to move toward the first movable base 4 by the tension coil spring 12, so the second movable base 10 as well as the first movable base 4 also moves in the direction of arrow a or a. Being moved roughly. Note that the protruding piece 11 of the second movable table 10 will slide on the lead screw 5.

As a result, the head 13 is roughly moved along the radial direction of the disk 15 while in contact with the disk 15, and the head position is roughly adjusted with respect to the track of the disk 15.

Next, when the head position is roughly adjusted, the disk 15
The fine movement motor 19 is rotated in the forward or reverse direction in response to a servo signal from the servo signal. Then, the lever 17 is rotated in the direction of arrow A or b' by the guiding action of the screw shaft 20 of the fine movement motor 19. When the lever 17 is rotated in the direction indicated by the arrow, the base 17b of the lever 17 presses the protrusion 21 of the second movable base 10 with a slight stroke, so that the second movable base 10 is slightly moved in the direction of arrow a with respect to the first movable table 4 against the tension coil spring 12. Further, when the lever 17 is rotated in the force direction of arrow b', the second movable base 10 is urged by the tension coil spring 12 following the minute stroke escape of the base 17b of the lever 17, and the second movable base 10 is biased by the tension coil spring 12, The second moving table 10 is slightly moved in the direction of arrow a'. As a result, the head 13 is moved slightly along the radial direction while in contact with the disk 15, and the head position is finely adjusted with respect to the track of the disk 15.

According to the head moving device 1 configured as described above, when the head 13 moves slightly, only the second moving table 10 is moved with respect to the first moving table 4 by the fine movement motor 19. Therefore, the load on the fine movement motor 19 is only the small mass of the second moving table 10. Therefore, the second moving table 10 is finely moved with extremely high precision, and thereby the fine adjustment of the head position is extremely easy. Performed with high precision.

Further, since the coarse movement of the head 13 is independently performed by the coarse movement motor 6 and the fine movement by the fine movement motor 19, and the second moving table 10 is mechanically driven by the lever 17, it is a fine movement mechanism. After off-track correction, the fine movement motor 19 can be powered off, thereby reducing power consumption.

Next, FIG. 2 shows a head moving device 31 in a second embodiment.
This shows that. This head moving device 31 has a fine movement mechanism composed of a cam, and is similar to the head moving device 1.
The same parts are given the same reference numerals. That is, the first
A gear 33 is mounted on the upper surface of the moving table 4 by a shaft 34 in the direction of arrow c.
, c' directions so as to be rotatable. A fine movement motor 35 is vertically fixed to the lower surface of the first moving table 4, and a gear 36 fixed to the motor shaft is connected to the gear 33.
is engaged with. In addition, as mentioned above, the fine movement motor 35
A stamping motor is optimal, but a -i-like servo motor may also be used. A cam 37 is formed on the upper surface of the gear 33, and the radius of the cam surface 37a on the outer periphery of this cam is indicated by the arrow a'.
It is formed so that it gradually becomes larger as it reaches the direction. The protrusion 21 of the second movable table 10 is in contact with the cam surface 37a of the cam 37.

In the head moving device 31 described above, when coarse adjustment of the head position is performed as in the head moving device 1 described above, the fine movement motor 35 is rotated in the forward or reverse direction, and the gear 36 is rotated.
The gear 33 is rotated in the direction of arrow C or a'. When the cam 37 is rotated in the direction of arrow C,
By pressing the protrusion 21 of the second movable table 10 with a minute stroke by the cam surface 37a of the cam 37, the second movable table 10 moves in the direction of arrow a with respect to the first movable table 4. trembled slightly. Further, when the cam 37 is rotated in the direction of the arrow a', the second movable base 10 is slightly moved in the direction of the arrow a' following the escape of the cam surface 37a of the cam 37.

, thus fine adjustment of the head position is performed. In this head moving device 31 as well, fine adjustment of the head position is performed with extremely high precision as described above.

Although the embodiments of the present invention have been described above, the present invention is not limited to the embodiments, and various effective changes can be made based on the technical idea of the present invention.

For example, in the embodiment, a lead screw is shown as the coarse movement mechanism, but this coarse movement mechanism may have a structure such as a steel belt driven by a coarse movement motor.

Further, the fine movement mechanism is not limited to the lever and cam of the embodiment, and various effective changes can be made.

Note that the present invention is not limited to head moving devices for floppy disk drives, but can be applied to various head moving devices that perform rough and fine head position adjustment.

〔Effect of the invention〕

In the present invention, the head is attached to a second movable base movably arranged with respect to the first movable base, and when the head is moved slightly, only the second movable base is moved by a fine movement motor. Therefore, when the head is slightly moved, the load on the fine movement motor is reduced to the small mass of the second moving table. Therefore, there is no need to move the entire moving table, which is a large load, and by slightly moving only the second moving table, which has a small load, the head position can be finely adjusted with extremely high precision, and the recording capacity can be reduced. It can reliably handle larger capacity.

Further, since the coarse movement and fine movement of the head are performed by independent motors, the power consumption of these motors can be significantly reduced, and the heat generation of these motors can be suppressed. Therefore, it is possible to prevent various parts including the coarse movement mechanism and the fine movement mechanism from thermally expanding due to heat generation, and from this point of view as well, highly accurate fine adjustment of the head position is possible.

Furthermore, since the coarse and fine movements of the head are independent, the dynamic range when finely moving the head is not limited by the pitch at which the head is coarsely moved. Therefore, the dynamic range of the micro-movement can be freely set, and it is possible to correspond to various trunks of recording media (for example, disks), thereby improving compatibility.

Moreover, since the control circuit systems for the two motors are independent and simple, it is possible to significantly reduce costs, prevent control malfunctions, and significantly improve reliability. .

[Brief explanation of drawings]

The drawings show an embodiment in which the present invention is applied to a head moving device of a floppy disk device, and FIG.
Perspective view of the embodiment, FIG. 2 is a perspective view of the second embodiment. In addition, in the symbols used in the drawings, 1. 1 moving table 5---------lead screw 6---
−・・−・・−−−−Coarse movement motor 10・・−−・
...--1------Second moving table 12--
−・・−・・−・・Tension coil spring 13・−・−・
−−1−−・−・−Head 15−・−・−・−・・−・
−Disk 17−・−1−−−−−−−−・−1−−−
・Lever 19 - - - - - - - Fine movement motor 21 - - - - - - m - - - - - Protrusion 3
Knee・・・・・−・・−・−・・Head moving device 3
5--...-----1----- Fine movement motor 37
− ・−・−−−−−−−−・Cam.

Claims (1)

[Scope of Claims] A first movable base configured to be movable, a coarse movement motor for moving the first movable base via a coarse movement mechanism, and a first movable base to which a head is attached. a second moving table disposed to be movable relative to the first moving table; and a fine movement motor provided on the first moving table to move the second moving table via a fine movement mechanism; A motor moves the first moving table via the coarse movement mechanism to move the second moving table together with the first moving table to coarsely move the head, and the fine movement motor moves the second moving table together with the first moving table. the second through the fine movement mechanism.
A head moving device configured to move the head slightly by moving a movable base relative to the first movable base.