JPH0254479A - Optical head travel guiding mechanism - Google Patents

Abstract

PURPOSE:To prevent play from being generated between a roller and a travel rail by applying repulsion or an attractive force between a linear motor magnet fixed on the main body device side of an optical disk device and a magnet or a magnetic material on an optical head side as a force to press the optical head downward, and pressing the roller to the travel rail side. CONSTITUTION:When an optical head travel control current flows on a linear motor coil 11, a travel driving force in a travel direction (direction of arrow head A) is generated by an electromagnetic force applied between the linear motor coil 11 and a linear magnet 13, and the optical head 3 is supported and guided accurately along the travel rail 1 on one side by a bearing 4, and simultaneously, the roller 5 is moved rotatably on the travel rail 2 on the other side, then, the head is traveled between the inner periphery and the outer periphery of a disk. At the time of traveling the optical head, the magnet 14 on the optical head 3 side and the linear motor magnet 13 are repulsed with each other since their N poles are neighbored to each other, and the optical head 3 receives a downward force by the repulsion, then, the roller 5 is pressed on the rail 2. Therefore, the roller 5 is moved rotatably keeping contact with the travel rail 2 even when the optical disk device is used perpendicularly, which prevents the optical head 3 from being inclined against the plane of the disk.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical head feeding guide mechanism in an optical disc device such as a CD player.

[Prior Art] FIG. 5 is a front view of a conventional optical head feed guide mechanism, and FIG. 6 is a side view of the same.

In this optical head feeding guide mechanism, two feeding rails 1 and 2 which are parallel to each other in the optical head feeding direction are provided on the base side, that is, on the main body housing side, and are mounted on the optical head 3 side. Said one feed rail 1
A bearing 4 that is slidably fitted into the feed rail 2 and a roller 5 that moves by riding on the other feed rail 2 under its own weight are provided.
In this structure, a leaf spring 6 that contacts the lower surface of the feed rail 2 for pressing the optical head against the feed rail 2 is attached to a side projecting portion 7a of the optical head housing 7 with a screw. This leaf spring 6 prevents the backlash h that occurs between the roller 5 and the feed rail 2 when the optical disc device is used in a vertical position, causing the optical head 3 to tilt with respect to the disc surface by this backlash. It was established for the purpose of In this way, the optical head 3
is accurately supported and guided along the feed rail 1 by the bearing 4, and at the same time, the roller 5 moves on the other feed rail 2 and is fed between the inner and outer circumferences of the disk.

[Problems to be Solved by the Invention] In the conventional feed guide mechanism described above, the roller 5 and the feed rail 2
However, since the leaf spring 6 and the feed rail 2 slide when the optical head is fed, the sliding friction is large and the load for feeding the optical head increases. . If the load is large, it is difficult to feed the optical head at high speed.

In addition, as another structure for eliminating play between the roller 5 and the feed rail 2, there is also a structure in which a presser plate that presses the roller 5 from above against the feed rail 2 side is attached to the optical disk device main body side along the feed rail 2. However, in this case roller 5
The disadvantage is that the load increases further because the holder does not rotate, or that load fluctuations occur with respect to the optical head feed due to variations in the flatness of the presser plate.

In addition, without using rollers, bearings are provided on both sides of the optical head (usually one bearing is a long hole bearing), and both sides of the optical head are connected to the feed rail via the bearings. There is also a WI-built feed guide mechanism that is supported.
Since this feed guide mechanism uses bearings on both sides, the load on the optical head feed is still large.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned conventional drawbacks and to obtain an optical head transport guide mechanism that imposes a small load on optical head transport.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides the following on the optical head side:
A magnet is provided opposite to the linear motor magnet provided on the main body housing side.

Alternatively, a mere magnetic body may be provided instead of the magnet.

[Function] In the above configuration, the repulsion or attraction force between the linear motor magnet fixed to the optical disk device main body side and the magnet or magnetic material on the optical head side acts as a force to push the optical head downward, causing the rollers to move. Press it against the feed rail side. This prevents play from occurring between the roller and the feed rail. In this case, the force used to press the roller against the feed rail is due to non-contact magnetic force and there are no sliding parts, so unnecessary frictional force is not generated when moving the optical head, reducing the load on moving the optical head. be done.

[Example] Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 4.

The same parts as before are given the same reference numerals and explained as follows:
In FIGS. 1 and 2, the rail mounting of the optical disk device shown in the drawings involves two feed rails 1.2 parallel to each other forming the optical head feeding direction shown by the arrow (A) on the base side, that is, on the main body housing side. The structure in which a bearing 4 that is slidably fitted on one of the feed rails 1 and a roller 5 that moves on the other feed rail 2 on the optical head 3 side is provided in the conventional structure shown in FIGS. 5 and 6. Similar to the example. In addition, 3a
indicates the objective lens.

The present invention is applied to an optical disk device that employs a linear motor system as an optical head feed drive mechanism. Reference numeral 10 indicates a linear motor, reference numeral 11 indicates a cylindrical linear motor coil fixed to the side projecting portion 7a of the optical gutter housing 7, and reference numeral 12 indicates a linear motor yoke fixed to the main body of the optical disk device. The linear motor yoke 12 has a portion 12a outside the linear motor coil 11 and a portion 12b that passes through the inside of the linear motor coil 11.
A linear motor magnet 13 is fixed to 2a facing the near motor coil 11. In this embodiment, the linear motor magnet 13 is placed on the projecting portion 7a of the optical head housing 7, as shown in FIG.
Magnet 1 is placed diagonally downward near the motor coil 11.
4 is fixed. As shown in the figure, the magnetic poles of this magnet 14 are oriented vertically, and the polarity is such that the north pole is on top so as to repel the north pole of the linear motor magnet 13 whose magnetic poles are oriented horizontally. It is. The arrows in FIG. 3 indicate the directions of some lines of magnetic force, and both 13 and 141?
The direction of the repulsive force of J is not shown.

Next, the operation will be explained.

When the optical head feed control current flows through the linear motor coil 11, the electromagnetic force acting between the linear motor coil 11 and the linear motor magnet 13 causes the optical head to move in the feeding direction as shown by the arrow (A).
direction) is generated, and the optical head 3 is moved by the bearing 4.
While the rollers 5 are accurately supported and guided along one feed rail 1, the rollers 5 are transferred on the other feed rail 2.
It is sent between the inner and outer circumferences of the disk. During this optical head feeding, the magnet 14 on the optical head 3 side and the linear motor magnet 13 repel each other because their N poles are close to each other, and the optical head 3 receives a downward force due to this repulsive force, causing the roller 5 is pressed against the feed rail 2. Therefore, even when the optical disc device is used vertically, the rollers 5 are prevented from rolling while contacting the feed rail 2, and the optical head 3 is prevented from tilting with respect to the disc surface. Furthermore, even when the optical disk device is used horizontally (as shown in the figure), an upward inertial force acts on the optical head 3 due to external vibrations, starting or stopping of the optical head 3, etc. Also, the roller 5 is prevented from floating off the feed rail 2 due to the repulsive force.

In the above-mentioned feeding operation, the force used to press the roller 5 against the feeding rail 2 is due to non-contact magnetic force and there are no sliding parts, so unnecessary frictional force is not generated and the load on the optical head feeding is reduced. Ru. Further, since it is based on magnetic force, it is possible to obtain a force for pressing the optical head uniformly and without strain over the entire length in the direction in which the optical head is moved.

Although the magnet 14 in the above embodiment is a permanent magnet, an electromagnet may also be used.

FIG. 4 shows another embodiment. In this embodiment, an iron plate 15, that is, a mere magnetic body that is not a magnet, is arranged diagonally above the linear motor magnet 13 near the linear motor coil 11. In the illustrated example, the iron plate 15 is fixed to the upper surface of the linear motor coil 11.

In this embodiment, the iron plate Y5 is the linear motor magnet 1
3, so a downward force acts on the optical head 3.
The 0-rail 5 is pressed against the feed rail 2 and performs the same function as in the previous embodiment.

Furthermore, instead of the iron plate 15 in FIG. 4, a magnet may be arranged with a polarity that attracts the linear motor magnet 13.

Note that the arrangement of the linear motor magnet in the present invention is not limited to that shown in the drawings; for example, it may be arranged on the side or below the optical head housing 7; The magnets or iron plates should be arranged appropriately, that is, the roller 5 should be moved to the feed rail 2.
Set it so that a force is generated in the direction of pressing against it. For example, when the magnetic poles of a linear motor magnet are oriented in the vertical direction, a magnet or iron plate is placed directly above or below the linear motor magnet.

[Effects of the Invention] As explained above, according to the present invention, a magnet or a magnetic body is provided on the optical head side, which faces the linear motor magnet provided on the main body housing side of the optical disk device. It became possible to eliminate looseness by constantly pressing the roller against the feed rail by the repulsive force or attractive force between the magnet or the magnetic material, and it was possible to prevent the optical head from tilting with respect to the disk surface.

Further, since the pressing force is caused by magnetic force and there is no sliding part, unnecessary frictional force is not generated, and the load of moving the optical head can be reduced. In addition, since it is based on magnetic force, it is possible to obtain a force that is reasonably uniform over the entire length in the feeding direction, and there is little variation in the load for feeding the optical head. These enable high-speed optical head feeding control. In addition, with conventional leaf springs, the accuracy of mounting the leaf spring and the pressing force greatly affect the force, so sufficient care must be taken when assembling, but with the present invention, this is not the case, so assembly is easy6.

[Brief explanation of the drawing]

Fig. 1 is a front view of an optical head feed guide mechanism showing one embodiment of the present invention, Fig. 2 is a plan view of the same, Fig. 3 is an enlarged view of the main parts in Fig. 1, and Fig. 4 is another embodiment. Front view showing example, 5th
The figure is a front view of a conventional optical head feed guide mechanism, and FIG. 6 is a side view of the same.

Claims (1)

[Claims] 1. Two feeding rails parallel to each other in the optical head feeding direction are provided on the main body housing side of an optical disk device equipped with a linear motor for feeding the optical head, and one of the feeding rails is provided on the optical head side. In the optical head feeding guide mechanism, the optical head feeding guide mechanism is provided with a bearing that is slidably fitted to one feeding rail and a roller that moves by riding on the other feeding rail under its own weight. An optical head feed guide mechanism characterized by having a magnet facing the magnet. 2. The optical head transport guide mechanism according to claim 1, characterized in that a mere magnetic body is provided in place of the magnet. 3. The optical head feed guide mechanism according to claim 1, wherein the magnets are arranged obliquely below the linear motor magnet whose magnetic poles are oriented in a horizontal direction, with polarities that repel each other with respect to the linear motor magnet. . 4. The optical head feed guide mechanism according to claim 1, wherein the magnets are arranged diagonally above the linear motor magnet whose magnetic poles are oriented in a horizontal direction and have polarities that attract each other to the linear motor magnet. .