JPH0630954U - Optical head drive - Google Patents

Abstract

(57) [Summary] [Purpose] To reduce the moving time of the optical head. [Structure] The drive coils 31 and 32 are wound while being inclined toward the recording medium to generate a thrust component FX and a vertical force component FZ, and at the same time, have a function of pressing the optical head 8 and the movable portion 7 downward by the magnet 12. By controlling the force, frictional force can be used to shorten the travel time.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an optical head driving device used in, for example, an optical disk device.

[0002]

[Prior art]

 Conventionally, as shown in FIG. 3, for example, a linear motor is used to drive an optical head 8 incorporated in an optical disk device. The linear motor guides a movable portion 7 on which the optical head 8 is mounted, a guide 6, 10 and guide parts 1 and 4 are provided in parallel with the guide part 10, and the movable part is moved by the driving force by the electromagnetic force between the drive part yokes 1 and 4 and the coils 31 and 32 of the movable part. I am trying to let you.

[0003]

[Problems to be solved by the device]

 In the above linear motor, the movable portion 7 is supported and guided by the guide 6 and the guide 10, and the frictional resistance when moving in the radial direction of the optical disc is small, and when the movable portion 7 is stopped at the target stop position, The inertial force of the head 8 greatly influences the movable portion 7 so that the movable portion 7 goes over or over the target stop point and vibrates to reach the target stop point. Further, if the optical head 8 and the movable portion 7 are further miniaturized, the frictional resistance is lowered and the moving acceleration of the movable portion 7 is increased, but it takes time to control the movable portion 7 when stopped.

[0004]

[Means for Solving the Problems]

 The present invention was made in view of such a point, and includes a permanent magnet arranged in the radial direction of the optical disk and a driving coil wound around a magnetic yoke installed in parallel with the permanent magnet. In the linear motor type optical head driving device having the above, the driving coil is wound while being inclined toward the recording medium side, and a permanent magnet is attached so as to repel the magnetic yoke.

[0005]

Embodiments The present invention will be described in detail below with reference to illustrated embodiments.

FIG. 1 is a sectional view of an essential part of an optical head driving device according to the present invention, in which a fixed-side magnetic yoke 1 is provided with a permanent magnet 2 inside, and drive coils 31 and 32 are provided. It faces the magnetic yoke 4 which penetrates and is fixed.

Drive coils 31 and 32 for moving the movable portion 7 in the radial direction of the recording medium are attached to the movable portion 7 together with the optical head 8.

The two parallel guide shafts 6 and 10 are fixed to the main body of the optical disk device, the guide shaft 10 penetrates a bearing 11 attached to the movable portion 7, and the guide shaft 6 is movable. A supporting roller 5 rotatably provided on the optical head 7 is supported from below, and the optical head 8 and the movable portion 7 are movable.

The drive coils 31 and 32 are sandwiched between a pair of yokes 1 and a permanent magnet 2 on the outside with a gap therebetween, and a magnetic yoke 4 penetrates the inside, and the magnetic flux generated by the permanent magnet 2 is generated by the coil 31. , 32, so that when a drive current flows through the coil, an electromagnetic force is generated in the coil in a direction perpendicular to the cross section of the coil.

In the optical head driving device according to the present invention, as shown in FIG. 2, the repulsive permanent magnet 12 repels the permanent magnet 2 of the magnetic yoke, and a downward repulsive force P is generated. However, the permanent magnet 12 is attached to the coil 32 on the instruction roller 5 side so as to repel, but the permanent magnet 12 is attached to the drive coil 31 on the bearing 11 side so as to be attracted. As a result, the movable portion 7 can be pressed against the guide shafts 6 and 10.

Since the drive coil 32 of FIG. 2 is wound while being inclined toward the recording medium, an obliquely upward electromagnetic force F is generated, and this electromagnetic force F is decomposed into a thrust component FX and an upward force component FZ. can do.

The upward force FZ has a function of lifting the optical head 8 and the movable portion 7 upward with the guide shaft 10 as a fulcrum, and presses the optical head 8 and the movable portion 7 generated by the repulsive permanent magnet 12. The force P cancels out to some extent and acts as a force for pressing the optical head 8 and the movable part 7 against the guide shafts 6 and 10, and moves the movable part by the thrust component FX.

When the optical head 8 approaches the target stop point, a reverse current is applied to the drive coil 32 to generate a reverse −FX and a downward force component −FZ.

As a result, the downward force P of the permanent magnet 12 and the downward component −FX due to the electromagnetic force of the coil 32 are combined so that the force pressing the movable portion 7 against the guide shafts 6 and 10 is maximized, and a large frictional force is generated. It will be.

With this frictional resistance, the vibration of the movable portion 7 at the time of stop can be suppressed, and the moving time of the optical head 8 can be shortened as compared with the conventional device.

In the above description, the currents to be passed through the left and right drive coils are switched according to the moving direction of the optical head. However, coils inclined in both directions as shown in FIG. The current may be passed through the coil in any of the tilt directions depending on the moving direction of the optical head. Also, magnets are being attached to both the left and right drive coils, but depending on the balance of forces, either one may be used.

[0017]

[Effect of device]

 As described above, in the optical head driving device according to the present invention, the permanent magnet 12 holds the optical head 8 and the movable portion 7 on the rail, and the driving coils 31 and 32 are wound while being inclined toward the recording medium side, and the thrust is applied. Component and vertical force component are generated to control the force that presses the optical head 8 and the movable part 7 downward, so the vibration when the optical head moves and stops can be controlled. The head moving time can be shortened.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of an optical head driving device according to the present invention.

FIG. 2 is an explanatory view of a winding direction of an optical head drive coil according to the present invention.

FIG. 3 is a sectional view of a main part of a conventional optical head driving device.

[Explanation of symbols]

 1 External Magnetic Yoke 2 Permanent Magnets 31, 32 Drive Coil 4 Inner Magnetic Yoke 5 Support Roller 6, 10 Guide Axis 7 Movable Part 8 Optical Head 9 Optical Head Objective Lens 11 Bearing 12 Permanent Magnet

Claims (2)

[Scope of utility model registration request] 1. A movable body disposed near an optical recording medium, around which a drive coil is wound, a magnetic yoke penetrating the coil of the movable body and disposed in the radial direction of the optical recording medium, and a magnetic yoke. In a linear motor type optical head drive device having a permanent magnet arranged in the vicinity of the yoke along its length direction, the drive coil is wound while being inclined to the recording medium side, and the permanent magnet is An optical head driving device, which is mounted so as to repel a magnetic yoke. 2. An optical head drive according to claim 1, wherein at least two sets of said movable part driving coils are provided, and each coil is wound on the optical recording medium side while being inclined in opposite directions. apparatus.