JP2739049B2 - Optical disk drive - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk device for recording, reproducing and erasing information on an information recording medium using a light beam, and more particularly to an optical disk device. The present invention relates to a structure of an optical head device mounted on a disk device. 2. Description of the Related Art FIG. 12 is a perspective view showing an objective lens driving device of a conventional optical head device, and FIG. 13 is a perspective view showing a conventional optical head device having the objective lens driving device shown in FIG. 1 is a schematic configuration diagram of the optical disc device of FIG. In the figure, 1 is an objective lens, 2 is a holder for holding the objective lens 1, 3 is a fixed base, 4a and 4b are elastic support members having one end connected to the holder 2 and the other end connected to the fixed base 3. ,
5 is a focus direction control coil wound around the holder 2,
Reference numerals 6a and 6b denote permanent magnets, and reference numerals 7a and 7b denote yokes. These objective lens 1, holder 2, fixed base 3, elastic support members 4, 4b, focal direction control coil 5, and permanent magnets 6a, 6
b and the objective lenses driving device 8 by the yokes 7a and 7b
Is configured. Reference numeral 9 denotes a light beam emitted from a light source unit (not shown), 10 denotes a light spot formed by condensing the light beam 9 by the objective lens 1, and 11 denotes an objective lens driving device 8.
12a and 12b are track direction control coils provided on the optical head device 11 to perform radial feed and track direction control; 13 is a base;
Reference numerals a and 14b denote track direction control magnetic circuits fixedly provided to the base 13, and reference numerals 15a and 15b denote base 1
A shaft fixedly provided with respect to 3 and constituting a moving axis of the optical head device 11, 16 is a disk as an information recording medium, and 17a and 17b are permanent magnets for giving opposite magnetic fields to the disk 16. is there. Next, the operation will be described. By passing a desired current through the focus direction control coil 5, the holder 2 is driven in the direction of arrow A to control the focus direction. Further, by supplying a desired current to the track direction control coils 12a and 12b, the optical head device 11 is driven in the direction of arrow B to perform radial feed and track direction control. [0004] Conventional optical head device 1
1 is configured as described above, and in the optical disk device, a plurality of objective lenses are provided on the information recording medium.
Different light spots are formed, in the case of performing the focus control or tracking control independently, pairs respectively
A plurality of optical head devices 11 having object lenses are required, and as shown in FIG. 13, there is a problem that the optical disk device has a large and complicated configuration. In addition, there is also a problem that the number of parts is increased, and the cost is significantly increased. In addition, there is also a problem that the number of parts is increased, and the cost is significantly increased. SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a small number of parts, is small, and has an increased tolerance of assembling accuracy of an apparatus, thereby improving an assembling workability. It is an object of the present invention to obtain a disk drive. An optical disk device according to the present invention focuses independently incident light beams as different light spots on an information recording medium, and uses the light spots to separate the light beams. Independent recording, playback,
A plurality of objective lenses for erasing, a holder for integrally holding the plurality of objective lenses, and a focus position of at least one light spot among different light spots formed by the plurality of objective lenses are set to other light spots. An optical head device includes a focus control device that controls the focus position independently of the focus position, and a tracking control device that controls the tracking direction position of at least one light spot independently of the tracking direction position of another light spot. , Which are mounted so as to be movable in the radial direction of the information recording medium. DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a reference example relating to the present invention
Will be described with reference to the drawings . FIG. 1 relates to the present invention.
Schematic configuration diagram showing an optical disk device according to a reference example ,
FIG. 2 is a perspective view showing an objective lens driving device portion of the optical head device mounted on the optical disk device of FIG. 1, and FIG. 3 is a diagram showing an overwrite of tracks on the disk using the optical head device shown in FIG. FIG. 4 is a cross-sectional view taken along the line IV-IV of FIG. 3, and FIG. 5 is a situation in which overwriting and real-time monitoring are performed simultaneously using the optical head device shown in FIG. FIG. 2 is a cross-sectional view schematically illustrating the structure of FIG. In the drawings, components denoted by the same reference numerals as those of the conventional device shown in FIGS. 12 and 13 indicate the same or corresponding members. 1 to 5, 1a and 1b are objective lenses, 9a to 9c are light beams, 10a to 10c are light beams 9a to 9c are objective lenses 1.
a, a light spot formed by condensing by 1b, 26
Reference numerals a to 26c denote tracks on the disk 16, reference numeral 27 denotes a recording portion whose upper side is magnetized to the N pole, reference numeral 28 denotes a non-recording portion whose upper side is magnetized to the S pole, and reference numerals 29a and 29b denote magnetic fields with respect to the disk 16. Permanent magnet for giving
30b is a magnetic flux emitted from the permanent magnets 29a and 29b. Next, the operation of this embodiment will be described. For a shift in the focus direction, a desired current is applied to the focus direction control coil 5 to drive the holder 2 in the direction of arrow A to control the focus direction. When the feed in the radial direction or the control in the track direction is required, the optical head device 11 is driven in the direction of arrow B by supplying a desired current to the track direction control coils 12a and 12b.
Performs radial feed and track direction control. Next,
A case in which information is overwritten will be described with reference to FIGS. For example, when overwriting the track 26b traveling in the direction of arrow C, the permanent magnet 29a is arranged in a direction in which the direction of magnetization is reversed in the region 27 whose upper side is perpendicularly magnetized to the N pole. .
In this state, the light beam 9a is transferred to the track 2 by the objective
The light is condensed on 9b and the coercive force of the desired portion is lowered by raising the temperature of the desired portion, and erasing is performed by interaction with the magnetic flux 30a emitted from the permanent magnet 29a. Further, in order to perform recording, the permanent magnet 29b is replaced with the permanent magnet 29a.
The direction of magnetization is reversed, and recording is performed in the same manner as in the case of erasing. FIG. 5 shows an embodiment in which overwriting is performed and real-time monitoring is performed.
b, 9c are incident, recording is performed by one light spot 10b, and reproduction is performed by the other light spot 10c. Here, the plurality of light spots are spaced apart by a distance that allows the applied magnetic field to be easily applied in the opposite direction in the case of a magneto-optical recording method or the like. The optical head device 11 according to the above reference example
In the above, the spring support structure supported by the elastic supports 4a and 4b has been described, but is not limited thereto.
For example, as shown in FIG. 6, a voice coil type objective lens driving device may be used. That is, in FIG. 6 showing the optical head device according to the second embodiment, 42a and 42b are support shafts,
44 is a coil holder for winding the focus direction control coil 5; 45 is a magnetic circuit for applying a magnetic field to the focus direction control coil 5; 46 is a radially magnetized permanent magnet;
Reference numeral 7 denotes a yoke, and 48a and 48b denote bearing portions formed on the yoke 47 and supporting the support shafts 42a and 42b. The optical head device 11 according to the above reference example
In FIG. 7, the holder 2 is provided with two objective lenses 1, but as shown in FIGS.
More than two may be provided. In the optical head device according to the third embodiment shown in FIG. 7 and FIG.
Of objective lenses 1a, 1b and 1c are arranged along tracks of a disc (not shown). In this case, the first, second and third objective lenses 1a, 1b, 1c
As shown in FIG. 8, these are used for erasing, recording, and reproducing desired tracks on the disk 16, respectively. Next, an embodiment of the present invention will be described with reference to the drawings.
It will be described using FIG. In the above reference example , the control of the focal direction is
Had done by passing a current through the focus direction control coil 5, according to the present invention, it is possible to correct such focus direction of relative displacement of more light spots 2 pcs. That is, FIGS. 9 and 10 show an optical head device capable of correcting a relative displacement of two or more light spots in the focal direction.
FIG. 10 is a cross-sectional view illustrating a part, and the optical head device illustrated in FIG.
One objective lens 1b is held in a holder 2 via a piezo element 51 as a focus control device. The focus of the objective lens 1b is controlled by a piezo element 51,
The focus of the other objective lens 1a is controlled by the focus direction control coil 5 so that the two light spots 10a, 1a
0b can be controlled separately. In the optical head device shown in FIG. 10, an optical element 52 as a focus control device is driven by using a driving device 53, and the light spots 10a and 10b are similarly controlled separately. . In addition, it is also possible to control by moving a light source unit (not shown) in the direction of the emitted light. The piezo element 51
A focus control device, such as a focus control device such as the optical element 52 and the like, is not shown, but is obtained by processing an output signal of a photodetector that receives reflected light from the disk 16 and converts it into an electric signal. Is servo controlled. Further, the focus control devices such as the piezo element 51 and the optical element 52 may be provided at any one or more of the plurality of objective lenses. According to each of the above configuration examples , the objective lens 1a,
After holding the lens 1b integrally with the holder 2, the objective lenses 1a,
The light spots 10a and 10b of 1b can be controlled independently. As a result, the light spots 10a and 10b are completely adjusted when the objective lens 1 is mounted on the holder 2.
Since there is no need to attach a and 1b, it is possible to greatly increase the arrangement accuracy of the objective lens and the like and the tolerance of the assembly accuracy of the apparatus. FIG. 11 shows the tracking directions of two or more light spots mounted on the optical disk device of the present invention.
FIG. 3 is a perspective view showing a main part of an optical head device capable of correcting a relative displacement of the optical head device . In the figure, reference numerals 40a and 40b denote first and second galvanomirrors disposed in the optical paths indicated by the light rays 9a and 9b, respectively. Other configurations are the same as those shown in FIGS. These galvanomirrors 40a and 40b are individually tilted and adjusted in the direction of arrow E by a control device including a servo circuit (not shown) to swing the light spots 10a and 10b independently in the direction of arrow F, respectively. Tracking control. 1 to 8 for overwriting, real-time monitoring, and the like.
Can be implemented in the same manner as shown in FIG. In the optical head device according to the above configuration example , the same number of galvano mirrors are used in correspondence with the objective lenses. Tracking control for one of the objective lenses is performed by the track direction control coils 12a and 12b shown in FIG.
Therefore, any one of them can be omitted. According to this configuration example , there is an advantage that the allowable value of the arrangement accuracy of the objective lens and the like and the assembling accuracy of the device can be greatly increased. Optical disc device according to the present invention
The device can be configured to include a focus direction control coil 5 as a focus control device shown in FIG. 9, a piezo element 51, and galvano mirrors 40a and 40b as a tracking control device shown in FIG. For this reason, two or more
After holding the objective lens integrally with the holder 2, each objective lens
Light spot can be controlled independently, and
Tracking direction position of at least one light spot
Is independent of the position of other light spots in the tracking direction.
Can be controlled. As a result , assembling is further facilitated, and an optical head device that sufficiently satisfies the required performance can be obtained. It is to be noted that each of the above configuration examples is merely an example of some embodiments of the present invention, and that various modifications, changes, and combinations are possible within the spirit of the present invention. Of course. As described above, according to the present invention, light beams that are independently incident are condensed as different light spots on the information recording medium, and the recording, reproduction, and reproduction of information are independently performed by the light spots. A plurality of objective lenses for erasing, a holder for integrally holding the plurality of objective lenses, and a focus position of at least one light spot among different light spots formed by the plurality of objective lenses are set to other light spots. An optical head device includes a focus control device that controls the focus position independently of a focus position, and a tracking control device that controls the tracking direction position of at least one light spot independently of the tracking direction position of another light spot. Since the information recording medium is mounted so as to be movable in the radial direction, the permissible value of the member mounting and assembly accuracy can be increased, Business property, an optical disk device capable of improving the productivity there is an effect that is obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram showing an optical disk device according to a reference example relating to the present invention. FIG. 2 is a perspective view showing an objective lens driving device portion in the optical head device mounted on the optical disk device of FIG. 1; FIG. 3 is an explanatory diagram showing a state in which tracks on a disk are overwritten using the optical head device shown in FIG. 2; FIG. 4 is a sectional view taken along line IV-IV in FIG. FIG. 5 is a cross-sectional view schematically illustrating a situation in which overwriting and real-time monitoring are performed simultaneously using the optical head device shown in FIG. FIG. 6 is an exploded perspective view of a main part showing another example of an optical head device mounted on an optical disk device as a reference example related to the present invention. FIG. 7 is a perspective view of an essential part showing another example of an optical head device mounted on an optical disk device as a reference example related to the present invention. 8 is a schematic cross-sectional view showing a situation where overwriting and real-time monitoring are performed simultaneously using the optical head device shown in FIG. FIG. 9 is a cross-sectional view of a main part showing a configuration example of an optical head device mounted on the optical disk device of the present invention. FIG. 10 is a cross-sectional view of a main part showing a configuration example of an optical head device mounted on the optical disk device of the present invention. FIG. 11 is a perspective view of an essential part showing a configuration example of an optical head device mounted on the optical disk device of the present invention. FIG. 12 is a perspective view showing an objective lens driving unit of a conventional optical head device. 13 is a schematic configuration diagram showing a conventional optical disk device equipped with an optical head device having the objective lens driving device shown in FIG. [Description of Signs] 1a, 1b objective lens, 2 holder, 8 objective lens driving device, 10a, 10b light spot, 11 optical head device, 16 disk (information recording medium), 40a, 4
0b Galvano mirror (tracking control device), 51
Piezo element (focus control device), 52 optical element (focus control device).

Claims (1)

(57) [Claims] Condenses a light beam incident independently as different light spot on the information recording medium, the light spot
A plurality of objective lenses for independently recording, reproducing, and erasing information, a holder for integrally holding the plurality of objective lenses, and different light spots formed by the plurality of objective lenses. A focus control device for controlling a focus position of at least one light spot independently of a focus position of another light spot, and a tracking direction position of at least one light spot being a tracking position of another light spot. An optical disc device, comprising: an optical head device having a tracking control device that is independently controlled so as to be movable in a radial direction of the information recording medium.