JPH04146529A - Optical head shift support mechanism - Google Patents

Abstract

PURPOSE:To house a support mechanism in a drive coil and to attain a thin and compact structure of a device by supporting the shift of an optical head carried out toward the radius of a disk with use of two inner guide rails, an inner yoke or a V-shaped guide part provided opposite to the guide rails, and the steel balls set between both guide rails. CONSTITUTION:When a current is supplied to a drive coil 25, the electromagnetic drive force is generated at the coil 25 by the operation of a magnetic field produced between an inner yoke 28 and a magnet 31. Thus a carriage 23 tries to move toward the radius of an optical disk 21. As a result, the steel balls 33 roll relatively on a V groove part formed between the rail 24 and the yoke 28. Thus the carriage 23 moves to the yoke 28 and records, reproduces or erases the information to the revolving disk 21. These operations are carried out with the relative rolls of the balls 33 and therefore the frictional resistance is reduced compared with a sliding action, etc. Thus the actuating force can be reduced. Then a compact and thin structure is attained for a device.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an optical recording/reproducing device for recording/reproducing or erasing information on an optical disc.

[Background Art] In recent years, the capacity of information recording and reproducing devices has increased, and optical disk memories have attracted attention as high-density recording media.

Recording or reproducing information on an optical disk is performed by moving the optical head in the radial direction of the optical disk, but in order to process large amounts of information at high speed, the optical head drive mechanism is required to have high-speed access. Voice coil type linear motors are used for boat fishing.

An example of the above-mentioned conventional optical disc device will be described below with reference to the drawings.

FIGS. 5 and 6 are a perspective view and a sectional view showing the structure of a conventional optical disc device.

In FIGS. 5 and 6, 1 is an optical disk, 2
3 is an objective lens actuator for forming a light spot on the optical disk 1; 3 is a carriage to which the objective lens actuator 2 is fixed; a semiconductor laser serving as a light source, a sensor for signal detection, optical components, etc. (not shown) are arranged. The objective lens actuator 2 and the carriage 3 constitute an optical head 6.

4 is a ball bearing that contacts the guide shaft 7, supports the carriage 3, and moves the carriage 3 in the radial direction of the optical disk 2; 5 is a drive coil; 8 is an inner yoke disposed to penetrate inside the drive coil 5; , 9 is an outer yoke with a magnet 11 fixed to the surface facing the inner yoke 8;
O is a relay yoke that secures an operating space for the drive coil 5 between the inner yoke 8 and the outer yoke 9, and 11 is the drive coil 5.
It is a magnet for generating electromagnetic force.

The operation of the optical disc device configured as described above will be described below.

First, by passing a current through the drive coil 5, an electromagnetic driving force is generated in the drive coil 5 due to the action of the magnetic field generated between the inner yoke 8 and the magnet 11. Due to this electromagnetic driving force, the carriage 3 attached to the guide shaft 7 via a ball bearing 4 and the objective lens actuator 2 fixed to the carriage 3, that is, the optical head 6, are moved parallel to the guide shaft 7 and rotationally driven. To record/reproduce or erase optical information on an optical disc l that is not loaded.

[Problems to be Solved by the Invention] However, in the above conventional example, when trying to arrange the ball bearing and the drive coil in the same space in order to downsize the device, the drive coil and the ball bearing or the guide shaft interfere with each other. This actually led to an increase in the size of the drive coil.

It is also possible to make the device thinner by downsizing the ball bearing, but there is a limit to this, and it has been impossible to make the device thinner by a certain amount.

[Means for Solving the Problems] The present invention has been made in view of the above-mentioned problems. The purpose of this invention is to provide an optical head movement support mechanism for an optical disk device that does not use ball bearings that limit miniaturization, and the purpose is to record and/or reproduce information on an information recording medium using an optical head. In an optical head movement support mechanism in an optical disk device, an optical head for recording and/or reproducing information and a magnetic coil provided on the optical head cooperate to move the optical head in the radial direction of the recording medium. A yoke and a magnet provided along the radial direction to generate a driving force, and a V-groove provided on one side of the surface of the yoke that is provided along the radial direction and the surface that is provided with the yoke of the optical head. two guide members provided on either a side surface of the yoke opposing the V-groove of the optical head or a side surface of the optical head opposing the V-groove of the yoke; and the groove and the two guide members; This is achieved by comprising a plurality of rigid balls arranged between the guide members and capable of rolling within the length of the guide member.

[Embodiment] Hereinafter, an optical disc device according to a first embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a partially cutaway perspective view showing the configuration of an optical disc device according to a first embodiment of the present invention, and FIG. 2 is a sectional view of FIG. 1.

1 and 2, 21 is an optical disk, 22 is an objective lens actuator for forming a light spot on the optical disk 21, 23 is a carriage to which the objective lens actuator 22 is fixed, a semiconductor laser serving as a light source (not shown), and a signal Sensors, optical components, etc. that perform detection are arranged. (In the case of a separate optical head, the semiconductor laser and sensor are not included.) Then, the optical head 2
6 is composed.

Reference numeral 24 indicates inner guide rails fixed to both side surfaces of the carriage 23 along the moving direction, and two inner guide rails are arranged on each surface, for a total of four guide rails. Note that the inner guide rails are fixed to each corner of a U-shaped recess provided on both sides of the carriage 23 along the moving direction so as to facilitate positioning. Reference numeral 25 denotes a drive coil fixed to the same surface as the inner guide rail 24, and is disposed in a recess provided in the carriage 23, over which the inner guide rail 24 passes. 26 is an optical head, and 28 is an inner yoke having a V-groove formed on its surface facing the inner guide rail 24, which is disposed so as to pass through the drive coil 25. 2
9 is an outer yoke to which a magnet 31 is fixed on the surface facing the inner yoke 28; 30 is a relay yoke that secures an operating space for the drive coil 25 between the inner yoke 28 and the outer yoke 29; 31 is the drive coil 25; Magnet 33 for generating electromagnetic force, inner guide rail 24 and inner yoke 28
A plurality of rolling members are arranged between the yoke and the V-groove, and are preferably made of a non-magnetic material in order to be unaffected by the magnetic force from the yoke. In this case, steel balls are used. By rolling on the V-groove portions of the inner guide rail 24 and the inner yoke 28, the steel balls support the carriage 23 so as to be operable with a very small force. 3
4 is a stopper that prevents the steel balls 33 from coming off the inner guide rail 24, and 35 is a holding member that maintains the distance between a plurality of steel balls at a certain level or more, and has a function of stabilizing the support of the carriage 23 by the steel balls 33. have.

The operation of the optical disc device configured as described above will be described below with reference to FIGS. 1 and 2.

First, by passing a current through the drive coil 25, an electromagnetic driving force is generated in the drive coil 25 due to the action of the magnetic field generated between the inner yoke 28 and the magnet 31. This electromagnetic driving force causes the carriage 23 to move in the radial direction of the optical disk l. For this reason, steel ball 3
3 relatively rolls on the inner guide rail 24 and the V-groove portion of the inner yoke 28, and the carriage 23 moves relative to the inner yoke 28, recording/reproducing information on the rotating optical disk 21 or recording/reproducing information. to erase. Since this operation is performed by the relative rolling of the steel balls 33, the frictional resistance can be made much lower than when sliding, etc., so that only a small operating force is required.

As described above, according to this embodiment, the inner guide rail 24 and steel ball 33 that constitute the movement support mechanism can be arranged inside the drive coil 25 fixed to the carriage 23, and the movement support mechanism Since a part of the drive coil 25 is integrally formed with the inner yoke 28, the number of parts can be reduced. Also, by using the steel balls 33, the drive coil 25 does not become larger.

Further, in the first embodiment, vIll is provided on the inner yoke,
Although the configuration has a guide rail placed on the carriage side,
The above-mentioned moving support mechanism may be constructed by arranging a guide rail on the inner yoke and providing a V-groove on the carriage side.

[Other Embodiments] Next, an optical disc device according to a second embodiment of the present invention will be described with reference to the drawings.

FIG. 3 is a partially cutaway perspective view showing the configuration of an optical disc device according to a second embodiment of the present invention, and FIG. 4 is a sectional view of FIG. 3.

In FIGS. 3 and 4, functional members that are the same as those in the first embodiment are given the same numbers and their explanations will be omitted.

In both figures, 36 is an inner yoke having a groove formed on the surface facing the inner guide rail 24 and is disposed to pass through the drive coil 25, and 37 is an inner yoke 36 on the surface facing the inner guide rail 24. The guide plate has a V-shaped cross section and is fixed to the groove, and in this embodiment, the steel ball 33 is arranged between the inner guide rail 24 and the guide plate 37.

In this embodiment, high precision is required for the rolling surface of the steel balls 33, and a V-groove that is difficult to machine is formed on the inner yoke 33.
(The shape can be any shape as long as the guide plate 37 can be attached, and sheet metal has good workability and accuracy. In addition, the yoke material is generally a soft material such as electromagnetic soft iron. However, according to this embodiment, the guide plate 37 can be made of a durable material such as stainless steel to improve durability.

[Effects of the Invention] As described above, according to the present invention, the movement of the optical head in the disk radial direction is supported by two inner guide rails each fixed to the optical head or the inner yoke and opposing thereto. By using a V-shaped guide part formed on the inner yoke or optical head and a steel ball placed between the two, these support mechanisms can be housed inside the drive coil, making the device more compact. It can be made thinner.

Furthermore, since the optical head is moved by the relative rolling of a plurality of steel balls between the guide rails, only a small operating force is required, and it is also possible to save power by lowering the current flowing through the drive coil. Furthermore, since the configuration of the guide shaft, steel balls, inner yoke, or guide plate can be made cheaper than ball bearings, it is also possible to reduce costs.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view of an optical disk device according to a first embodiment of the present invention, FIG. 2 is a sectional view of FIG. 1, and FIG. 3 is an optical disk according to a second embodiment of the present invention. FIG. 4 is a partially cutaway perspective view of the device; FIG. 4 is a cross-sectional view of FIG. 3; FIG. 5 is a partially cutaway perspective view of a conventional optical disc device; FIG. 6 is a cross-sectional view of FIG. 5. 21 is an optical disk, 22 is an objective lens actuator,
23 is a carriage, 24 is an inner guide rail, 25 is a drive coil, 26 is an optical head, 28 is an inner yoke, 29 is an outer yoke, 30 is a relay yoke, 31 is a magneto-soto, 33 is a steel pole, and 34 is a striker. 35 is a holding member, 36 is an inner yoke, and 37 is a guide plate.

Claims (1)

[Claims] 1. An optical head movement support mechanism in an optical disk device that records and/or reproduces information using an optical head on an information recording medium, comprising: an optical head that records and/or reproduces information; a yoke and a magnet provided along the radial direction that generate a driving force in cooperation with a magnetic coil provided on the optical head in order to move the recording medium in the radial direction; a V-groove provided on either one of the surfaces along with the yoke of the optical head, the side surface of the yoke opposing the V-groove of the optical head, or the side surface of the optical head opposing the V-groove of the yoke; two guide members provided on either side; and a plurality of rigid balls arranged between the V-groove and the two guide members and capable of rolling within the length of the guide member. An optical head movement support mechanism featuring: