JPH0950636A - Head moving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a behavior resistance of a carriage by reducing leakage magnetic flux at the periphery of a bearing and suppressing magnetic attraction caused by magnetization of the bearing. SOLUTION: An objective lens 1 for recording and reproducing an optical disk 2 is fixed to a focus driving coil 8, and is also installed on a carriage 5. The carriage 5 is movable with the bearings 6, and is guided in a prescribed direction by guide rails 7a and 7b. The guide rails 7a and 7b are provided with radial drive coils 12a and 12b and radial yokes 14a and 14b to be in magnetic contact with the coils. The radial yokes 14a and 14b are fixed with radial drive magnets 13a and 13b. On the other hand, focus drive magnets 10a and 10b magnetized in the reverse direction to the magnetization direction of these radial drive magnets are disposed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head moving device applied to a recording system having an information recording medium such as a disk and a card, and particularly to a head for selectively recording and reproducing information at a desired position. The present invention relates to a head moving device for positioning.

[0002]

2. Description of the Related Art In a device for reading information from an information recording medium such as an optical disk or an optical card, or a device for reading and writing information, a head moving device for positioning a head is used. This head moving device positions a head for reading and / or writing information at a desired position by irradiating the information recording medium with laser light.

For example, when an optical disk is applied to the information recording medium, the head moving device uses the Lorentz force generated by passing an electric current through a predetermined coil to irradiate the irradiated laser beam on the surface of the information recording medium. Move the head so that the position is irradiated. At the same time, this apparatus moves the head in a direction perpendicular to the surface of the information recording medium so that the focus of the laser beam is at the desired position.

Such a head moving device is, for example, a compact disc drive device, a CD-ROM drive device, an MO (Magneto Optical) disc drive, a PC.
(Phase Change) Used for disk drives.

Now, a conventional head moving device will be described with reference to FIG. FIG. 4 is a perspective view of a conventional head moving device. Laser light emitted from a laser emission source (not shown) is guided to the objective lens 1 through optical elements such as a collimator lens, a beam splitter, and a mirror, and is focused on the optical disc 2. The light reflected on the optical disc 2 passes through the objective lens 1, passes through optical elements such as a mirror and a beam splitter, and reaches a light receiving element (not shown). The objective lens 1 is fixed to the objective lens holder 3.

The objective lens holder 3 is connected to the carriage 5 by a parallel leaf spring and is held so as to be movable in a direction perpendicular to the surface of the optical disc 2. The objective lens holder 3 includes focus drive coils 102a and 102a.
b is attached. In this specification,
The components including the carriage 5 and held by the carriage 5 such as the lens holder 3 are collectively referred to as a head.

The first focus drive magnets 100a and 100b attached to the focus yokes 9a and 9b fixed to a base (not shown) and the second focus drive magnets 101a and 101b have opposite magnetization directions. It is arranged to be.

Further, the focus drive magnets 100a and 10
The magnetizing directions of 0b and 101a and 101b are arranged to be parallel to the plane direction of the optical disc 2. Also,
A bearing 6, which is a rolling element made of a ferromagnetic material, is attached to the carriage 5 so as to be in contact with the guide rails 7a and 7b. The carriage 5 is movable in the direction parallel to the surface of the optical disc 2. Radial drive coils 12a and 12b are attached to the carriage 5. Guide rails 7a, 7 made of a ferromagnetic material fixed to the base are provided on the radial drive coils 12a, 12b.
b is passing. Also, the U-shaped radial yoke 14
a, 14b, 14c and 14d are guide rails 7a and 7b
Are arranged so as to be magnetically connected to both ends of.

Also, the radial drive magnets 13a, 13b
Is connected to the radial yokes 14a, 14b, 14c, 14d. Further, the radial yokes 14a and 14
c, 14b and 14d are a set, and fixing screw holes 15
It is attached to the base through.

The operation of the head moving device having such a structure is as follows. Radial drive coils 12a, 1
A Lorentz force is generated by passing a current through the optical disc 2b, and the carriage 5 moves in a direction parallel to the surface of the optical disc 2, whereby the focus of the laser beam is changed.
Is moved to the desired position on the plane.

Further, focus drive coils 102a, 1
By passing a current through 02b, a Lorentz force is generated in the focus drive coil in the direction perpendicular to the surface of the optical disk 2, and the objective lens 1 can be moved in the direction perpendicular to the surface of the optical disk 2. At this time, the objective lens 1 is moved by a control device (not shown) so that the laser beam is focused on a desired track on the optical disc 2.

[0012]

In recent years, various devices such as the above-mentioned compact disk drive device have been desired to be reduced in size and weight. When miniaturizing and reducing the weight of various devices, a small amount of constituent members of the head moving device is required, that is, miniaturization of the head moving device itself and the function of the head moving device are not deteriorated. It becomes important. However, it is very difficult to realize the downsizing of the head moving device without deteriorating the function of the head moving device, particularly without reducing the moving speed of the head.

For example, in the above-described head moving device, the guide rail also serves as a part of the radial magnetic circuit composed of the radial drive magnet and the radial yoke. Therefore, in head movement using a bearing made of a ferromagnetic material that linearly guides the head, the bearing is magnetized by the leakage magnetic field from the radial circuit, which causes a large running resistance, which makes control difficult.

In order to prevent such a defect, a strong magnet cannot be used, and therefore it becomes difficult to move the head at high speed. It should be noted that such a phenomenon occurs when the bearing is placed in the leakage magnetic field from the radial magnetic circuit. Therefore, the similar problem occurs when the distance between the radial magnetic circuit and the bearing is short.

Further, four focus drive magnets and two focus drive coils are used, which causes increase in cost due to increase in the number of parts, deterioration of vibration characteristics due to increase in weight of the movable part, and hindrance to miniaturization.

Further, the friction of the bearing is affected not only by the radial magnetic circuit but also by the focus magnetic circuit composed of the focus driving coil and the focus driving magnet, which is the peripheral magnetic circuit. In order to prevent this, it is necessary to secure a sufficient distance between the radial magnetic circuit and the focus magnetic circuit, or to weaken the magnet to reduce the leakage magnetic field, and therefore the head moving speed decreases.

In view of the above-mentioned circumstances, it is an object of the present invention to provide a head moving device which can realize a downsizing of the head moving device without deteriorating the function of positioning the head.

A further object of the present invention is to provide a head moving device having a structure in which a supporting member for supporting the head is less likely to be magnetized and capable of driving the head at high speed in the radial direction.

[0019]

A first head moving device according to the present invention is a head unit for selectively recording and reproducing data on a recording medium, and a first head unit connected to the head unit.
A guide rail made of a coil and a magnetic body for guiding the head portion in a predetermined direction; a support body made of a magnetic body for movably supporting the head portion while contacting the guide rail; A tubular second coil that is connected and that passes through the guide rail, a yoke that is magnetically connected to the guide rail, and a magnetic circuit that is fixed to the yoke together with the guide rail to form a magnetic circuit. A first permanent magnet that allows the support body to move in the predetermined direction by supplying a magnetic flux, and a first permanent magnet that is arranged on the opposite side of the guide rail from the first permanent magnet and that has the first permanent magnet attached thereto. A second permanent magnet that is magnetized in a direction opposite to the magnetic direction and that is capable of moving the head unit in a direction perpendicular to the recording medium surface.

A second head moving device according to the present invention is
A head unit for selectively recording and reproducing data on a recording medium, a first coil connected to the head unit, a magnetic body, a guide rail for guiding the head unit in a predetermined direction, and a magnetic body. And a support body that movably supports the head portion while contacting the guide rail, a cylindrical second coil that is connected to the head portion and that passes through the guide rail, and a magnetic body that is magnetically connected to the guide rail. A yoke to be connected, and a first permanent magnet fixed to the yoke to form a magnetic circuit together with the guide rail, and supplying magnetic flux to the second coil to move the support in the predetermined direction. And a second permanent magnet that supplies a magnetic flux to the first coil and generates a magnetic flux that cancels a leakage magnetic flux from the magnetic circuit.

In this second head moving device, the first
The permanent magnets and the second permanent magnets are preferably magnetized in opposite directions. Further, in the first and second head moving devices, the support may be a rolling body rolling on the guide rail or a sliding conductor sliding on the guide rail.

With the first and second head moving devices as described above, the magnetic flux in the support is canceled, and the magnetic flux leakage from the magnetic circuit composed of the first permanent magnet, the yoke and the guide rail to the second magnet is reduced. To be done. As a result, the influence of the leakage magnetic flux is suppressed, and a head moving device capable of high driving force and high acceleration can be realized.

That is, by magnetizing the focus driving magnet in the opposite direction to the radial driving magnet,
It is possible to reduce magnetic flux leakage around the bearing and reduce the running resistance of the carriage due to the magnetization of the bearing.

Therefore, since a radial magnetic circuit that gives a stronger magnetic flux to the coil than the conventional one can be manufactured, it is possible to obtain a head moving device that can move in the radial direction at high speed with high acceleration. Further, since the distance between the focus magnetic circuit and the radial magnetic circuit can be reduced, a small head moving device can be obtained.

Further, it is possible to downsize the radial yoke, whereby the rigidity of the head moving device can be ensured and the storage device to which the head moving device is applied can be downsized in the height direction. It becomes possible to do.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First and second embodiments of a head moving device according to the present invention will be described below with reference to the drawings. First, a second embodiment of the head moving device according to the present invention will be described with reference to FIGS. 1 (a) and 1 (b). FIG. 1A is a perspective view showing a first embodiment of the head moving device, and FIG. 1B is shown in the perspective view of FIG.
It is a perspective view which removed the right half in the figure by the line B-1B '.

Laser light emitted from a laser emission source (not shown) is controlled so as to pass through the objective lens 1 (head portion) and be focused on the optical disc 2 (information recording medium). The light reflected on the optical disk 2 passes through the objective lens 1 again, passes through optical elements such as a mirror and a beam splitter, and reaches a light receiving element (not shown). Objective lens 1
Are fixed to the objective lens holder 3.

The objective lens holder 3 includes a parallel plate spring 4a,
The optical disc 2 is connected to the carriage 5 by 4b.
It is movably held in a direction perpendicular to the plane.
The objective lens holder 3 has a focus drive coil (first
The coil 8 is attached in a state of being wound around the optical axis of the objective lens 1.

Focus drive magnet (second permanent magnet) 10
The a and 10b are attached to focus yokes 9a and 9b fixed to a base (not shown), and the focus drive magnets 10a and 10b are arranged such that their magnetizing directions are opposite to each other.

Further, the focus drive magnets 10a, 10b
The magnetization direction of is parallel to the plane of the optical disc 2. A bearing (support) 6 which is a rolling element including at least a ferromagnetic material is attached to the carriage 5 so as to contact the guide rails 7a and 7b.

The carriage 5 is guided so as to be movable in a direction parallel to the surface of the optical disc 2. On the carriage 5, a wound cylindrical radial drive coil (second
Coil) 12a, 12b is attached. Guide rails 7a and 7b made of a ferromagnetic material fixed to the base are inserted into the hollow portions of the radial drive coils 12a and 12b.

Further, the radial yokes 14a, 14b, 14c, 14 are formed by bending the ends of the U-shaped plate made of a ferromagnetic material into a shape substantially along the curved surfaces of the guide rails 7a, 7b.
d so that its curved surface is almost in contact with the guide rails 7a and 7b, and the radial yokes 14a and 14c and 1
4b and 14d are arranged so as to overlap with each other, and the fixing screw hole 1
It is fixed to the base through a screw.

Further, the radial drive magnet (first permanent magnet) 13a is the radial yokes 14a and 14c, and the radial drive magnet (first permanent magnet) 13b is the radial yoke 14.
It is attached to b and 14d. Radial drive magnet 1
The magnetizing directions of 3a and 13b are parallel to the surface of the optical disk 2, and the radial driving magnet 13a and the radial driving magnet 13b have opposite magnetization directions to the focus driving magnet 10b. It is located at.

The operation of the head moving device having such a structure will be described below. First, by passing a current through the focus drive coil 8, a Lorentz force is generated in a direction perpendicular to the surface of the optical disc 2, and the objective lens 1 can be moved in a direction perpendicular to the surface of the optical disc 2. A Lorentz force is generated by passing a current through the radial drive coils 12a and 12b, and the electromagnetic force causes the carriage 5 to move in a direction parallel to the surface of the optical disc 2 so that the laser beam is focused on the optical disc 2. It can be moved to a desired position on the plane.

The guide rails 7a and 7b, the radial yokes 14a and 14b, and the radial drive magnets 13a and 13 are used.
When b, the focus driving magnets 10a, 10b, etc. are made of a material that is easily oxidized, the surface may be plated to form an antioxidant film.

In the head moving device having such a structure, as shown by the arrow in FIG. 2B, the focus drive magnets 10a and 10b are magnetized in the same direction as the radial drive magnets 13a and 13b. The magnetic flux is canceled by making them opposite to each other. Therefore, the radial drive magnet 13
The leakage magnetic flux from the magnetic circuit composed of a and 13b and the guide rails 7a and 7b is not guided to the bearing 6. As a result, the focus drive magnets 10a and 10b and the radial magnetic circuit (the yokes 14a, 14c, or 14).
b, 14d, radial drive magnets 13a, 13b, and guide rails 7a, 7 which are part of the guide rails 7a, 7b).
The magnetic flux leakage of the radial magnetic circuit between b can be reduced.

Incidentally, FIG. 2A shows the flow of the leakage magnetic flux of the radial magnetic circuit in the above-mentioned conventional head moving device by arrows, and FIG. 2C shows the focus in the first embodiment. It is a schematic diagram which shows the flow of the leakage magnetic flux of a radial magnetic circuit when the magnetization directions of the drive magnets 10a and 10b are made mutually the same as the magnetization directions of the radial drive magnets 13a and 13b.

As is clear from FIGS. 2A to 2C, the head is moved so that the magnetizing directions of the focus driving magnets 10a and 10b are opposite to the magnetizing directions of the radial driving magnets 13a and 13b. By configuring the device, magnetic flux leakage at the position of the bearing 6 between the focus drive magnets 10a and 10b and the guide rails 7a and 7b is reduced. Therefore, the rotational resistance of the bearing 6 due to the magnetic attraction between the components inside the bearing 6 can be reduced, the magnetic attraction between the guide rails 7a and 7b and the bearing 6 can be reduced, and the rolling resistance of the bearing 6 can be reduced.

Therefore, since the traveling resistance of the carriage 5 is reduced, the loss of the driving force in the radial direction is suppressed, the head is moved at high speed by high acceleration / deceleration, the head is driven with high efficiency, and the head is moved stably by the low traveling resistance. Control can be realized.

The bearing 6 in the head moving device
Is the focus drive magnet 10a and the radial drive magnet 13
It is desirable to be located between a and a, or between the focus drive magnet 10b and the radial drive magnet 13a. Here, an example of measurement values when the running resistance of the carriage is measured in a carriage having eight bearings is shown below.

[0041]

[Table 1]

The bearings A and B are two types of bearings having different rotation resistances. Further, in this measurement, the polarity shown in the first embodiment (see FIG. 2B) and the opposite polarity (FIG. 2C) are used.
Measurement) for each head moving device. In the polarity shown in FIG. 2B, compared with the polarity shown in FIG.
The friction is reduced by 0.8E-2N and 0.71E-2N, and the friction is reduced by 26% to 40%.

Also, considering that the weight of the entire moving part is about 4 g, and the acceleration of 1 G is generated by the force of 3.92E-2N, the reduction of the frictional force according to the first embodiment is stable. It provides a sufficient effect to the controlled.

Further, it is possible to downsize the radial yoke, so that the rigidity of the head moving device can be secured and the device can be downsized in the height direction.

Next, a second embodiment of the head moving device according to the present invention will be described with reference to FIGS. 3 (a) and 3 (b). FIG. 3A is a perspective view of a third embodiment of the head moving device, and FIG. 3B is a broken line 3B-3B ′ according to the perspective view of FIG. It is the perspective view removed.

In the second embodiment, the two focus driving coils are arranged on both side surfaces of the lens holder 3, and the radial driving magnet and the focus driving magnet are arranged so that their magnetizing directions are opposite to each other. Has been done.

Laser light emitted from a laser emission source (not shown) is guided to the objective lens (head portion) 1 and focused on the optical disc 2 (information recording medium). The light reflected on the optical disc 2 passes through the objective lens 1, passes through optical elements such as a mirror and a beam splitter, and reaches a light receiving element (not shown). The objective lens 1 is fixed to the objective lens holder 3.

The objective lens holder 3 is connected to the carriage 5 by a parallel leaf spring 4 and is held so as to be movable in a direction perpendicular to the surface of the optical disc 2. Focus drive coils (first coils) 11a and 11b wound in a plane are attached to the objective lens holder 3 so as to face each other with the objective lens 1 interposed therebetween.
The focus drive magnets 10a and 10b are attached to focus yokes 9a and 9b fixed to a base (not shown).

Further, the focus drive magnets 10a, 10b
The magnetization direction of is parallel to the plane of the optical disc 2. In addition, the focus drive magnet 10a and the focus drive magnet 1
The magnetization directions of 0b may be opposite to each other or may be the same.

The carriage 5 has guide rails 7a, 7
A bearing (support) 6, which is a rolling element including at least a ferromagnetic material, is attached to be in contact with b. Then, the carriage 5 is guided so as to be movable in a direction parallel to the surface of the optical disc 2. To the carriage 5, cylindrical radial drive coils (second coils) 12a and 12b are attached. Radial drive coils 12a, 12b
Guide rails 7a and 7b made of a ferromagnetic material and fixed to the base pass through.

Further, the radial yokes 14a, 14b, 14c, 14 each having a shape of a U-shaped plate made of a ferromagnetic material and bent in a shape substantially along the curved surfaces of the guide rails 7a, 7b.
d so that the curved surface portion is almost in contact with the guide rails 7a and 7b, and the radial yokes 14a and 14c and 14b.
And 14d are arranged so as to overlap with each other, and screws are fixed through the fixing screw holes 15 to the base.

Further, the radial drive magnet (first permanent magnet) 13a is the radial yokes 14a and 14c, and the radial drive magnet (first permanent magnet) 13b is the radial yoke 14.
It is attached to b and 14d. Radial drive magnet 1
The magnetizing directions of 3a and 13b are parallel to the surface of the optical disc 2, and the radial driving magnet 13a and the radial driving magnet 13b are opposite to the focusing driving magnet 10b and the focusing driving magnet 10b, respectively. Is.

The operation of the head moving device having such a structure will be described below. First, by passing a current through the focus drive coils 11a and 11b, a Lorentz force is generated in a direction perpendicular to the surface of the optical disc 2, and the objective lens 1 can be moved in a direction perpendicular to the surface of the optical disc 2. . Also, the radial drive coils 12a, 12
Lorentz force is generated by applying current to b,
By the electromagnetic force, the carriage 5 can be moved in a direction parallel to the surface of the optical disc 2, and the focus of the laser light can be moved to a desired position on the plane of the optical disc 2.

The guide rails 7a and 7b, the radial yokes 14a and 14b, and the radial drive magnets 13a and 13 are used.
When b, the focus driving magnets 10a, 10b, etc. are made of a material that is easily oxidized, the surface may be plated to form an antioxidant film. Also, the bearing 6 is
Similar to the first embodiment described above, it is desirable to be located between the radial drive magnet and the focus drive magnet.

Also in the head moving device having such a configuration, the magnetizing directions of the focus driving magnets 10a and 10b are set to the radial driving magnet 1 as in the first embodiment.
By reversing the magnetizing directions of 3a and 13b, the focus drive magnets 10a and 10b and the radial magnetic circuit (yoke 1
4a, 14c, or 14b, 14d, the radial drive magnets 13a, 13b, and the guide rails 7a, 7b that are a part of the guide rails 7a, 7b) can reduce the magnetic flux leakage of the radial magnetic circuit.

Therefore, the focus drive magnets 10a,
Bearing 6 between 10b and guide rails 7a, 7b
The magnetic flux leakage at the position of is reduced, the rotational resistance of the bearing 6 due to the magnetic attraction between the parts inside the bearing 6 can be reduced, the magnetic attraction between the guide rails 7a and 7b and the bearing 6 is reduced, and the rolling resistance of the bearing 6 is reduced. It can be reduced.

Therefore, since the traveling resistance of the carriage 5 is reduced, the loss of the driving force in the radial direction is suppressed, the head is moved at high speed by high acceleration / deceleration, the head is driven with high efficiency, and the head is moved stably by the low traveling resistance. Control can be realized.

Further, the focus drive magnets 10a, 10
By making only the magnetizing directions of b and the radial drive magnets 13a and 13b opposite to each other, the periphery of the optical head may be the same as the conventional one, and the size of the focus drive magnets 10a and 10b is reduced. Therefore, the periphery of the head portion can be made smaller and lighter, and the entire head can be easily made smaller and lighter.

It is needless to say that the present invention is not limited to the above-described embodiment, and can be variously modified and implemented without departing from the spirit of the invention. For example, the radial yoke does not have to have a U-shape, as long as a magnetic circuit is formed together with the guide rail and the radial drive magnet.

Further, for example, the guide rail does not have to be made of a magnetic material, and it is possible to reduce the magnetization of the bearing in contact with the guide rail even if the yoke is arranged near the outside of the guide rail. Good.

Further, in the above-described first and second embodiments, the bearing is applied as the member for supporting the head, but it is also possible to apply a roller made of a magnetic material. Alternatively, bushings can be used.

[0062]

As described above in detail, according to the present invention,
Since a radial magnetic circuit that gives a stronger magnetic flux to the coil than the conventional one can be manufactured, a head moving device that can move in the radial direction at high acceleration and high speed can be obtained. Further, since the distance between the focus magnetic circuit and the radial magnetic circuit can be reduced, a small head moving device can be obtained.

Further, it is possible to downsize the radial yoke, whereby the rigidity of the head moving device can be ensured and the storage device to which the head moving device is applied can be downsized in the height direction. It becomes possible to do.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of a first embodiment of a head moving device according to the present invention.

FIG. 2 is a schematic diagram showing a direction of a leakage magnetic flux of the head moving device according to the present invention.

FIG. 3 is a perspective view showing a configuration of a second embodiment of a head moving device according to the present invention.

FIG. 4 is a perspective view showing a configuration of a conventional head moving device.

[Explanation of reference numerals] 1 ... Objective lens (head part), 2 ... Optical disk, 3 ... Objective lens holder, 4a, 4b ... Parallel spring, 5 ... Carriage, 6 ... Bearing (support), 7a, 7b ... Guide rail, 8 ... Focus drive coil (first coil), 9
a, 9b ... Focus yoke, 10a, 10b ... Focus drive magnet (second permanent magnet), 11a, 11b ... Focus drive coil (first coil), 12a, 12b ... Radial drive coil (second coil), 13a, 13b ... Radial drive magnet (first permanent magnet), 14a, 14b, 1
4c, 14d ... Radial yoke (yoke), 15 ... Screw holes for fixing.

Claims (5)

[Claims] 1. A guide rail which comprises a head portion for selectively recording and reproducing data on a recording medium, a first coil connected to the head portion, and a magnetic body, and guides the head portion in a predetermined direction. A support body that is made of a magnetic material and movably supports the head portion while contacting the guide rail; a cylindrical second coil that is connected to the head portion and that passes through the guide rail; A yoke that is magnetically connected to the rail, and is fixed to the yoke to form a magnetic circuit together with the guide rail, and supplies magnetic flux to the second coil to make the support movable in the predetermined direction. A first permanent magnet is disposed on the side opposite to the first permanent magnet with respect to the guide rail, and the head portion is magnetized in a direction opposite to the magnetization direction of the first permanent magnet. Head moving device, characterized by comprising a second permanent magnet movable in a vertical direction with respect to the recording medium surface. 2. A guide rail, which comprises a head section for selectively recording and reproducing data on a recording medium, a first coil connected to the head section, and a magnetic body, and which guides the head section in a predetermined direction. A support body that is made of a magnetic material and movably supports the head portion while contacting the guide rail; a cylindrical second coil that is connected to the head portion and that passes through the guide rail; A yoke that is magnetically connected to the rail, and is fixed to the yoke to form a magnetic circuit together with the guide rail, and supplies magnetic flux to the second coil to make the support movable in the predetermined direction. A first permanent magnet; and a second permanent magnet that supplies a magnetic flux to the first coil and generates a magnetic flux that cancels a leakage magnetic flux from the magnetic circuit. Earthmoving equipment. 3. The head moving device according to claim 2, wherein the first permanent magnet and the second permanent magnet are magnetized in opposite directions. 4. The support body includes a rolling body that rolls on the guide rail.
The head moving device described. 5. The support body includes a slide body that slides on the guide rail.
The head moving device described.