JPH0464928A - Optical information recording and reproducing device - Google Patents

Abstract

PURPOSE:To make a mobile part light-weight and simple and to realize the quick access by providing a fixed part with all magnetic circuits required for driving in the focusing direction, the radial direction, and the tracking direction. CONSTITUTION:A focus control coil 101 and a track control coil 102 are stuck to a condenser lens holder 2 as one body and are arranged in the magnetic circuit consisting of a magnet 103 for actuator and a yoke 104 for actuator. The magnet 103 for actuator and the yoke 104 for actuator are attached on a yoke 106 for radial control. Prescribed currents flow to respective coils to move a condenser lens in the focusing direction and the tracking direction. It is controlled in the radial direction in the same manner as conventional.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention focuses a laser beam onto a rotating disk-shaped record carrier using a condensing lens, records information, and reads out the recorded information. The present invention also relates to an optical information recording and reproducing apparatus that can erase recorded information and that can perform recording and reproducing access to any position on a disk, that is, random access, at high speed.

[Prior Art] FIG. 5 is a perspective view of a conventional optical information recording/reproducing device. In the figure, (1) is a condenser lens, (2) is a condenser lens holder, (3) is a focus control coil, (4) is a track control coil, (5) is a balancer, (6) is a bearing, (
7) is an elastic support member that movably supports the condenser lens holder (2) in the focusing direction and the tracking direction, (8) is a support shaft, (9) is a focus control magnet, (10) is a focus control yoke, (11) is a track control magnet, (
12) is the actuator base, (13) is the base, (
14) is a radial control coil, (15) is a reflective mirror, (16) is a radial control magnet, (17) is a radial control yoke, (18) is a fixed optical system, (19)
is a light beam.

Next, the operation will be explained.

Light beam (19) emitted from fixed optical system (18)
The light enters the condenser lens (1) via the reflection mirror (15) and is condensed onto the recording surface (not shown) of the disk. The light beam reflected by the disk travels backwards and passes through the fixed optical system.
(18), the optical path is converted by an optical component (not shown), and the light is received by a photodetector (not shown). This photodetector is configured with two or four divisions and detects defocus, track deviation, and signals.

In such an optical system, a common method for correcting the focal shift and track shift of the detected light spot on the disk is to control the condenser lens (1) in the focusing direction and the tracking direction. A focus control coil (3) and a track control coil (4) are attached to the condenser lens holder (2). Each of these coils has an actuator pace (1
2), a focus control magnet (9), a focus control yoke (10), and a track control magnet (1).
1) is arranged in a magnetic circuit configured by: By energizing each coil in accordance with the defocus and track misalignment signals obtained from the photodetector, the focusing direction of the condenser lens holder (2) and eventually the condenser lens (1) with respect to the axis (8) is determined. (in the direction of arrow A) and
It rotates in the racking direction (direction of arrow B) to control the drive.

On the other hand, the radial control coil (14) is connected to the base (13).
The radial control magnet (1
6) is arranged in a magnetic circuit consisting of a radial control yoke (17). Radial control coil (1
4) by applying the necessary current to the base (13
) Furthermore, by driving the condenser lens (1) in the radial direction (in the direction of arrow C), it is possible to access a desired position on the disk.

[Problems to be Solved by the Invention] As described above, the conventional optical information recording/reproducing device has separate magnetic circuits for radial control, focus control, and track control. It is necessary to install a magnet or yoke on a certain base, which increases the weight of the movable parts, making it difficult to access at high speed, and the structure becomes complicated and large.

The present invention has been made to solve the above-mentioned problems, and aims to provide an optical information recording/reproducing device which can shorten access time, and has a compact and simplified configuration.

[Means for Solving the Problems] An optical information recording and reproducing apparatus according to the present invention includes (1) a mount movable in a radial direction above a disk, and a mount fixed to the mount and having an optical axis direction in the radial direction. a light reflecting means for reflecting a light beam in a substantially perpendicular direction; a condensing lens for condensing the reflected light from the light reflecting means on the disk; and the condensing lens is slidable and rotatable about a support shaft. an elastic support member held in place; two sets of magnetic circuits having a gap;
at least two sets of rectangular coils fixed to the condenser lens, one side facing or inserted into the first gap, and wound approximately perpendicular to each other; fixed to the pedestal, one side facing the first gap; and at least one set of coils inserted into the second gap.

Another feature is that (2) the light reflecting means is provided with a control means configured to be rotatable in the track direction.

Yet another feature is that (3) it has a control means configured to be able to move two relay lenses placed in the optical path in the focal direction.

[Function] The optical information recording/reproducing device according to the present invention allows high-speed access and is suitable for miniaturization, simplification, and thinning.

[Example] Hereinafter, this invention will be explained based on the drawings.

FIG. 1 is a perspective view of an optical information recording/reproducing apparatus according to a first embodiment of the present invention, and the same parts as in FIG.

In the figure, (101) is a focus control coil, (102)
) is a coil for track control, (103) is a magnet for an actuator, (1,04) is a yoke for an actuator, (105) is a radial control magnet l-1 (10
6) is a yoke for radial control.

Next, the operation will be explained.

A focus control coil (101) and a track control coil (
H]2) is integrally attached to the condensing lens holder (2), and the actuator magnet (+-03
) and an actuator yoke (104). The actuator magnet (1, 03) and the actuator yoke (104) are attached to the radial control yoke (106). By applying a desired current to each coil, the condenser lens is moved in the focusing direction and the tracking direction. Control in the radial direction is performed in the same manner as in the conventional method.

FIG. 2 is a block diagram of main parts of a second embodiment of the present invention.

In the figure, (201) is a focus control coil, (202
) is a track control coil, (203) is a coil holder, and (204) is an inner yoke for actuator. The focus control coil (201,) and the tracking control coil (202) are connected to the actuator magnet (103).
) and the actuator inner yoke (204), a larger driving force can be obtained.

FIG. 3 is a block diagram showing the main parts of a third embodiment of the present invention. In the figure, (301) and (302) are laminated piezoelectric elements. By applying a voltage to the laminated piezoelectric elements (301) and (302) to extend one and contract the other, the reflecting mirror (15) rotates in the direction indicated by the arrow in the figure. Accordingly, the light beam (19) is displaced in the track direction. By appropriately sharing the amount of power applied to the coil (102) and the amount of rotation of the mirror depending on the amount of displacement in the radial direction (track direction), higher accuracy and higher bandwidth can be achieved. control can be realized.

FIG. 4 is a diagram showing the main part of a fourth embodiment of the present invention. In the figure, (/101) and (402) are relay lenses, (403) and (404) are relay lens holders,
(405) is a laminated piezoelectric element. These are arranged at the exit of the light beam (19) of the fixed optical system (18). Applying a voltage to the laminated piezoelectric element (405),
The second relay lens (402) is driven in the direction of the arrow to perform focus control. Depending on the amount of drive in the focal direction, the amount of power applied to the coil (], 0 ]) and the amount of driving the relay lens can be divided and controlled appropriately.
Same as above.

In the above example, a laminated piezoelectric element was used to drive the reflective mirror and the lacing, but other methods such as a bimorph piezoelectric element may be used, or an electromagnetic method may be used. It goes without saying that both the focusing direction and the tracking direction may be controlled in a shared manner as described above.

[Effects of the Invention] As described above, according to the present invention, all the magnetic circuits necessary for driving in the focusing direction, radial direction, and tracking direction are provided in the fixed part, so the weight of the movable part is reduced.
It is simplified, high-speed access can be realized, and the entire device can be made smaller and thinner.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an optical information recording and reproducing apparatus according to a first embodiment of the present invention, FIG. 2 is a configuration diagram of main parts of a second embodiment of this invention, and FIG. FIG. 4 is a diagram showing the configuration of the main parts of the fourth embodiment of the present invention,
FIG. 5 is a perspective view of a conventional optical information recording/reproducing device. In the figure, (1) is a condenser lens, (2) is a condenser lens holder, (5) is a balancer, (6) is a bearing, (7) is an elastic support member, (8) is a support shaft, (101) is a focus control coil, (102) is a track control coil, (103)
(104) is an actuator magnet, and (104) is an actuator yoke. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims (3)

[Claims] (1) Accessing any position on the disk, optically detecting the defocus and track deviation of the information surface, and controlling the defocus and track deviation of the optical spot on the disk based on this information; The optical information recording and reproducing device for reproducing or recording information on the disk includes a mount movable in a radial direction on the disk, and a light beam fixed to the mount and having an optical axis direction in the radial direction almost perpendicularly. a light reflecting means for reflecting light in a direction, a condensing lens for condensing the reflected light from the light reflecting means on the disk, and an elastic support for holding the condensing lens slidably and rotatably about a support shaft. a member, two sets of magnetic circuits having a gap, and at least two sets of corners fixed to the condenser lens, one side facing or inserted into the first gap, and wound so as to be substantially perpendicular to each other. An optical information recording/reproducing device comprising: a molded coil; and at least one set of coils fixed to the pedestal and having one side inserted into the second gap. (2) The optical information recording and reproducing apparatus according to claim 1, further comprising a control means configured to allow the light reflection means to rotate in the track direction. (3) The optical information recording/reproducing apparatus according to claim 1 or 2, further comprising a control means configured to enable two relay lenses disposed in the optical path to move in the focal direction.