JPH0643851Y2 - Objective lens drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is directed to driving an objective lens of an optical recording / reproducing apparatus for recording or reproducing information by condensing a light beam as a light spot on a recording medium by an objective lens. Regarding the device.

[Outline of device]

The focus slide base that drives the objective lens in the optical axis direction slides and slides on the parallel guide of the optical base, but the tracking arm that drives the objective lens in the direction perpendicular to the optical axis is a hinge that is provided in the center of the focus slide base. Since it is configured to rotate without "rattle" through the, fine tracking control is possible, and a tracking crash stopper is provided on the focus sliding base.
An objective lens driving device that is strong against disturbance in the tracking direction and does not hinder the operation in the focus direction by restricting the tracking arm from vibrating by a predetermined width or more by the tracking crash stopper.

[Conventional technology]

A conventional objective lens driving device found in Japanese Patent Laid-Open No. 61-198439 will be described with reference to FIG. In FIG. 3, reference numeral 1 denotes an objective lens which is an optical system, and the objective lens 1 is fixedly supported by a lens barrel 23. The lens barrel 23 is fixedly supported by the focus mover 21. The tracking mover 22 slidably supports the focus mover 21 in the optical axis direction (focus direction) of the optical system including the objective lens 1. The frame 24 supports the tracking mover 22 slidably in a direction (tracking direction) perpendicular to the optical axis of the optical system including the objective lens 1.

In the frame 24, facing the focus mover 21 and the tracking mover 22, permanent magnets 25 and 26 are provided, respectively.
The focus mover 21 and the tracking mover 22 have magnetic flux generating means 27, 28a, 28b having a, 26b, 26c, 26d.
A current is passed through the coils 29, 30a, 30b respectively, and the coils 29, 30a, 30b interlink with the magnetic fluxes of the magnetic flux generating means 27, 28a, 28b, and the optical systems including the objective lens 1 are respectively provided as optical axes. Direction and the direction perpendicular to the optical axis. By controlling the amount of current flowing through the coils 29, 30a, 30b respectively provided in the focus mover 21 and the tracking mover 22, the movement amount in the optical axis direction and the direction perpendicular to the optical axis is controlled, and focusing control and tracking are performed. Control can be performed.

The focus mover 21 and the tracking mover described above
The 22 can be supported opposite each other. That is, the tracking mover 22 supports the focus mover 21 slidably in the direction perpendicular to the optical axis of the optical system, and the focus mover 21 allows the frame 24 to slide in the optical axis direction of the optical system. In some cases they support it.

[Problems to be solved by the device]

However, in such a conventional objective lens driving device, the focus mover 21 is supported slidably in the optical axis direction of the optical system including the objective lens 1, and the tracking mover 22 is The frame 24 is slidably supported in a direction perpendicular to the optical axis of the optical system. In particular, the tracking mover 22 is slidably supported by the frame 24, so that there is “rattle” in the sliding portion in the slidable and slidable support, and the slidable and slidable support makes it possible to perform fine movement in correspondence with the eccentricity of the disk as the recording medium. However, there is a problem that it is impossible to follow up even if a precise tracking control is required. Also, since no crash stopper is provided in the tracking direction, the tracking mover 22 vibrates significantly against external disturbances, and it takes time to return to its original state, and in some cases it also interferes with the operation in the focus direction. As a result, poor control in the focus direction occurs due to poor tracking, which is vulnerable to disturbance.

The present invention has been made in order to solve such a conventional problem, and enables fine tracking control corresponding to the eccentricity of a disk as a recording medium, and a tracking arm for disturbance. Does not vibrate significantly, and does not interfere with the movement in the focus direction,
It is an object to obtain an objective lens driving device that can easily return to the range of tracking control and that is strong against disturbance in the tracking direction.

[Means for Solving the Problems]

The objective lens driving device of the present invention comprises a first magnetic circuit and a second magnetic circuit.
Optical base having a magnetic circuit and a parallel guide, and a tracking crash stopper slidably mounted on the parallel guide of the optical base and having a magnetic flux of the first magnetic circuit. A focus slide base having a first coil that interlocks with and drives the objective lens in the optical axis direction, and a focus slide base is rotatably mounted via a hinge at the center of the focus slide base and has the objective lens at one end. A tracking arm provided on the focus slide base, the tracking arm having a second coil at the other end that links the magnetic flux of the second magnetic circuit to drive the objective lens in a direction perpendicular to the optical axis. The tracking stopper regulates the tracking arm so that it does not vibrate more than a specified width, and is arranged so as not to interfere with the movement in the focus direction. .

[Action]

In the present invention, the focus slide base that drives the objective lens in the optical axis direction is slid and slid on the parallel guide of the optical base, while the tracking arm that drives the objective lens in the direction perpendicular to the optical axis is the focus slide base. It is configured so that it can rotate without "rattle" via a hinge in the center, and an objective lens is attached to one end of the tracking arm.
Since only the second coil is arranged on the other end and the first coil is arranged on the focus sliding base, the weight balance of the tracking arm is good and the weight is light.
Fine tracking control is possible according to the eccentricity of the disk as the recording medium. Further, a tracking crash stopper is provided on the focus sliding base, and the tracking arm prevents the tracking arm from vibrating by a predetermined width or more, so that the tracking arm vibrates greatly against external disturbance. It is possible to easily return to the range of the tracking control without any trouble, and it is strong against the disturbance in the tracking direction. In addition, since the tracking arm is a member separate from the movement in the focus direction with respect to the focus slide base, even if the movement in the tracking direction is restricted by the crash stopper, the tracking arm does not interfere with the movement in the focus direction, Since a defective operation in the focus direction, which is secondary to the defective operation, does not occur, the control system can be easily restored.

〔Example〕

The functions and embodiments of the objective lens driving device of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view illustrating the function of the objective lens driving device of the present invention. FIG. 2 is a partially cutaway perspective view of an embodiment of the objective lens driving device of the present invention.

1 and 2, the objective lens 1 driving device of the present invention comprises a pair of first magnetic circuits 4a and 4b including permanent magnets 3a and 3b and a second permanent magnet 5 on an optical base 2. The magnetic circuit 6 of FIG. The first magnetic circuits 4a and 4b are for driving the optical system including the objective lens 1 in the optical axis direction (focusing direction), and the second magnetic circuit 6 includes the optical system including the objective lens 1. Direction perpendicular to the optical axis (tracking direction)
It is for driving to. Further, the optical base 2
Two parallel guides 8a and 8b on which the focus slide base 7 is slidably mounted are vertically provided on the upper side. The focus slide base 7 has a pair of slide bearings 9a and 9b which slide on two parallel guides 8a and 8b provided on the optical base 2 and magnetic fluxes and chains of the first magnetic circuits 4a and 4b. The first coils 10a and 10b are provided so as to drive the optical system including the objective lens 1 in the optical axis direction.

A hinge 11 is provided at the center of the focus slide base 7, and a tracking arm 12 is rotatably attached to the hinge 11. At one end of the tracking arm 12, the objective lens 1 is provided, and at the other end, an optical system interlinking with the magnetic flux of the second magnetic circuit 6 and including the objective lens 1 is formed in a direction perpendicular to the optical axis. It has a second coil 13 that is driven to.
In this way, the tracking arm 12 can rotate without "rattle" through the hinge 11 provided at the center of the focus slide base 7, and the objective lens 1 is provided at one end of the tracking arm 12 and the first lens is provided at the other end thereof. Only the coil 13 of 2 is arranged,
Since the first coils 10a and 10b are arranged on the focus slide base 7, the weight balance of the tracking arm 12 is good and the weight is light.

A pair of tracking crash stoppers 14a and 14b (14 in FIG. 2) made of rubber, for example, are provided on the focus slide base 7 so as to sandwich the tracking arm 12.
Only a is shown). The tracking crash stoppers 14a and 14b regulate the tracking arm so that it does not vibrate more than a predetermined width. Reference numeral 15 shown in FIG. 2 is a 45 ° mirror for bending the optical path.

As described above, in the objective lens driving device of the present invention, current is passed through the first coil 10a, 10b and the second coil 13 which are respectively provided on the focus slide base 7 and the tracking arm 12, and the first coil 10a, 10b The second coil 13 is the optical base 2
The optical systems including the objective lens 1 are respectively driven in the optical axis direction and in the direction perpendicular to the optical axis by interlinking with the magnetic fluxes of the pair of first magnetic circuits 4a and 4b and the second magnetic circuit 6 which are provided above. . By controlling the amount of current flowing through the first coils 10a, 10b and the second coil 13, the movement amount in the optical axis direction and the movement amount in the direction perpendicular to the optical axis are controlled, and focusing control and tracking control are performed.

[Effect of device]

As described above, in the present invention, the focus slide base that drives the objective lens in the optical axis direction is slid and slid on the parallel guide of the optical base, but the tracking arm that drives the objective lens in the direction perpendicular to the optical axis is focused. It is constructed so that it can be rotated without rattling through a hinge provided at the center of the sliding base, and an objective lens is arranged at one end of the tracking arm and a second coil is arranged at the other end. so,
Since the first coil is arranged on the focus slide base, the weight balance of the tracking arm is good and the weight is light, and fine tracking control can be performed according to the eccentricity of the disk as the recording medium. is there. Furthermore, a tracking crash stopper is provided on the focus sliding base, and by restricting the tracking arm from vibrating by a predetermined width or more by the tracking crash stopper, the tracking arm does not vibrate significantly against disturbance, It can easily return to the range of tracking control and is strong against disturbance in the tracking direction. In addition, since the tracking direction does not hinder the operation in the focus direction, the focus direction can be controlled even when tracking is defective.

[Brief description of drawings]

FIG. 1 is a perspective view illustrating the function of the objective lens driving device of the present invention. FIG. 2 is a partially cutaway perspective view of an embodiment of the objective lens driving device of the present invention. FIG. 3 is a partially cutaway perspective view of a conventional objective lens driving device. 1 ... Objective lens 2 ... Optical bases 3a, 3b, 5 ... Permanent magnets 3a, 4b ... First magnetic circuit 6 ... Second magnetic circuit 7 ... Focus sliding bases 8a, 8b ... Parallel Guides 9a, 9b …… Slide bearings 10a, 10b …… First coil 11 …… Hinge 12 …… Tracking arm 13 …… Second coil 14a, 14b …… Tracking crash stopper 15 …… 45 ° mirror

Claims (1)

[Scope of utility model registration request] 1. An objective lens driving device for causing a light beam to follow an information track on a recording medium as a light spot, which has a first magnetic circuit and a second porcelain circuit and is provided with a parallel guide. An optical base and a parallel guide of the optical base are slidably mounted and provided with a tracking crash stopper, and the objective lens is driven in the optical axis direction by interlinking with the magnetic flux of the first magnetic circuit. A focus slide base having a first coil, a focus slide base rotatably attached to the center of the focus slide base via a hinge, an objective lens at one end, and a magnetic flux of the second magnetic circuit at the other end. A tracking arm having a second coil that interlinks to drive the objective lens in a direction perpendicular to the optical axis is provided. An objective lens driving device in which the tracking arm is restricted from vibrating by a predetermined width or more by a stopper to prevent the operation in the focus direction from being disturbed.