JPH09198704A - Lens changeover mechanism for optical head device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize a lens changeover mechanism and to make the device light in weight by selectively moving a reflection mirror to positions corresponding to plural objective lenses to reduce the number of magnets without exerting an adverse influence on a moving part at the time of changing over the objective lenses. SOLUTION: In the mode by an objective lens 26a, the reflection mirror 31 is slidingly moved in an E1 direction. Then, after the laser beam from a light source 30 progresses parallel with the signal recording surface of an optical disk to pass an optical member, the laser beam is reflected to a right angel direction on the reflection mirror 31 to be cast on the optical disk via the lens 26a. Moreover, in the mode by an objective lens 26b, the reflection mirror 31 is slidingly moved in an E2 direction and the laser beam is cast on the optical disk via the lens 26b. As a result, the recording or the reproducing of optical disks having different recording densities is performed by one head.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a lens switching mechanism of an optical head device for switching a plurality of objective lenses according to a plurality of types of optical disks.

[0002]

As is well known, an optical disk is used as a recording medium, such as a write-once optical disk drive device.
A system for recording and reproducing information is provided with an optical head device for irradiating an optical disk with laser light. This optical head device is arranged so as to face the signal recording surface of the rotationally driven optical disc,
Information is recorded by irradiating an optical disk with laser light, or information is read by receiving reflected light from the optical disk.

Here, in the recent optical head device,
An optical head device has been developed which has a function of switching a plurality of objective lenses, for example, according to optical discs having different recording densities when recording / reproducing on / from the optical disc.

FIG. 11 shows a conventional optical head device having a function of switching a plurality of objective lenses corresponding to such optical disks having different recording densities. In FIG. 11, reference numeral 11 in the drawing is an optical head main body. The optical head main body 11 is provided with a plate body 12 formed in a substantially disc shape on the upper surface in the figure. The plate body 12 has magnet holders 12a and 12b extending from the peripheral edge thereof at a substantially right angle.
Magnets 13a, 14a and magnets 13b, 14b are attached to the. Then, between the magnets 13a and 13b and the magnets 14a and 14b, a substantially cylindrical holder 15 that is a movable portion is arranged. Objective lenses 15a and 15b for exposing and receiving a laser beam to an optical disk (not shown) are exposed on the holder 15.

Further, the holding body 15 has focus actuator coils 16a and 16b on its peripheral side surfaces, respectively.
And tracking actuator coils 17a and 17b are installed. Further, a flexure 18 for applying a drive current to a focus actuator coil 16a, 16b and a tracking actuator coil 17a, 17b from a drive device (not shown) is attached to the upper surface of the holder 15. These focus actuator coils 16a and 16b and tracking actuator coils 17a and 17b are magnets 13a and 13b, respectively.
b and the magnets 14a and 14b are interposed in the magnetic path formed by the magnet b.

Therefore, by energizing the focus actuator coils 16a and 16b and the tracking actuator coils 17a and 17b via the flex 18, the holder 15 is focused in the focus direction (direction perpendicular to the signal recording surface of the optical disk). In the figure, arrow F1-
It can be moved in the tracking direction (direction shown by arrow T1-T2 in the drawing) which is the radial direction of the optical disk and the direction indicated by F2).

Here, the holding body 15 is movably supported in the focusing direction and the tracking direction by attaching the substantially center thereof to the optical head main body 11 by the shaft supporter 19.

FIG. 12 shows a state where the optical head device shown in FIG. 11 is disassembled into its constituent parts. That is, the optical head main body 11 accommodates therein the light source 20, which is composed of a semiconductor laser element and the like, the reflecting mirror 21 and the like. Then, the optical head main body 11 has the plate body 12 arranged on the upper surface thereof.

At this time, magnet holders 12a and 12b are extended from the peripheral edge of the plate member 12 at a substantially right angle so as to face each other. The magnets 13a, 14a and 1 are attached to the magnet holders 12a, 12b.
3b and 14b are attached respectively. Also, plate 1
2, a shaft supporter 19 is provided at a substantially central portion so as to project upward, and a through hole 12c is formed in the vicinity of the shaft supporter 19 to allow a laser beam generated from the light source 20 to pass therethrough. There is. Then, the holding body 15 is arranged between the magnets 13a, 14a and 13b, 14b attached to the magnet holders 12a, 12b. In this state, the holding hole 15c of the holder 15 has the shaft support 19
It is fitted to.

At this time, the focus actuator coils 16a, 16a,
16b (in the figure, the focus actuator coil 1
6a) and a pair of tracking actuator coils 17a, 17a and 17b, 17b, respectively. The holder 15 is the shaft support 1
The focus actuator coils 16a and 16b and the tracking actuator coils 17a and 17b are supported by the plate body 12 via the magnet 1 respectively.
3a, 13b and the magnets 14a, 14b are interposed in the magnetic path formed by the magnets.

Magnetic pieces 22a and 22b are attached to the focus actuator coils 16a and 16b and the tracking actuator coils 17a and 17b, respectively. These magnetic pieces 22a and 22b perform magnetic levitation with respect to the focus direction (direction shown by arrows F1-F2 in the drawing) of the holder 15 and neutral holding with respect to a tracking direction (direction shown by arrows T1-T2 in the drawing). Is.

The holder 15 has a flexible member 18 attached to the upper surface thereof. That is, when the holder 15 detects the recording density of the optical disc by a detection device (not shown), a drive current corresponding to the detection result is applied to the focus actuator coils 16a and 16b and the tracking actuator coils 17a and 17b via the flexure 18. By being given, the objective lenses 15a and 15b are selectively rotated by being rotated in the tracking direction.

On the other hand, FIG. 13 shows how the laser light is emitted in the mode of the objective lens 15a. At this time, the focus actuator coils 16a and 16b and the tracking actuator coils 17a and 17b
Are opposed to the magnets 13a and 13b, respectively. That is, the laser light emitted from the light source 20 travels in a direction parallel to the signal recording surface of the optical disc, that is, a direction indicated by an arrow A in the figure, passes through an optical component (not shown) built in the optical head main body 11, and then is reflected. The light is reflected by the mirror 21 at a right angle, that is, in the direction shown by the arrow B in the figure, and is irradiated onto the optical disk through the objective lens 15a. That is, the laser light passes through the optical paths C and D, respectively. Further, the laser beam applied to the optical disc strikes the signal recording surface of the optical disc, is reflected, and follows a path opposite to the above to be received by a photodetector (not shown) incorporated in the optical head main body 11.

Further, FIG. 14 shows a state of laser light irradiation in the mode of the objective lens 15b. At this time, the focus actuator coils 16a and 16b and the tracking actuator coils 17a and 17b
Face the magnets 14a and 14b, respectively. That is, as in the case of FIG. 13, the laser light emitted from the light source 20 travels in the direction parallel to the signal recording surface of the optical disc, that is, in the direction indicated by the arrow A in the figure, passes through the optical component, and then is reflected by the reflecting mirror 21 at right angles. That is, the light is reflected in the direction indicated by arrow B in the figure and is irradiated onto the optical disc through the objective lens 15b. Further, the laser light applied to the optical disk strikes the signal recording surface of the optical disk, is reflected, and follows the path opposite to the above to be received by the photodetector.

By the way, in the lens switching mechanism of the optical head device configured as described above, the objective lens 15a,
When switching 15b, the holding body 15 is moved in the tracking direction (direction shown by arrows T1-T2 in FIG. 12).
The optical axis of either of the objective lenses 15a and 15b and the optical path D of the laser light generated from the light source 20 are made to coincide with each other by the magnetic action of the magnetic pieces 22a and 22b. Therefore, the magnets 13a, 13b, 14
If a magnetization error occurs in a and 14b, the objective lens 15a,
A deviation will occur between any of the axes of 15b and the optical path D of the laser light generated from the light source 20. Further, since the holder 15 rotates largely with respect to the shaft support 19, a clearance between the shaft support 19 and the joint hole 15c of the holder 15 causes the axes of the objective lenses 15a and 15b to move with respect to the signal recording surface of the optical disc. The problem of tilting has arisen. Since these problems cause optical aberrations, they are not suitable for recording or reproducing particularly high density information.

The holding body 15 has an objective lens 15
When the flex 18 is pulled when switching between a and 15b, the residual vibration remains due to the pulling force of the flex 18 even if the rotation is stopped. further,
In the above optical head device, since the magnets 13a and 13b and the magnets 14a and 14b are selected and used for switching the objective lenses 15a and 15b, the cost of the magnets increases, and further, when a large number of objective lenses are used. Since a large number of magnets must be prepared, the size and weight of the magnets are increased accordingly.

[0017]

As described above, in the conventional switching mechanism of the optical head device, due to the magnetizing error of the magnet and the clearance between the shaft support and the joint hole of the holder, the axis of the objective lens and the light source are There is a problem that there is a deviation from the optical path of the irradiated laser light and an inclination of the axis of the objective lens with respect to the signal recording surface of the optical disc. Also, when the objective lens is switched, the flex is pulled,
Even if the rotation of the holding body is stopped, there is a disadvantage that residual vibration remains in the holding body due to the tension force of the flex. Furthermore, when switching a plurality of objective lenses, a plurality of magnets are selected and used, which increases the cost of the magnets, resulting in an increase in size and weight.

An object of the present invention is suitable for recording or reproducing high-density information without adversely affecting a movable part when switching a plurality of objective lenses, and further reducing the number of magnets for cost reduction. Another object of the present invention is to provide a lens switching mechanism of an optical head device which can be made compact and lightweight.

[0019]

A lens switching mechanism of an optical head device according to the present invention includes an optical head main body and a plurality of optical heads arranged on the optical head main body and adapted to accommodate a plurality of types of optical disks. Objective lens support for supporting the objective lens, drive means for driving the objective lens support in at least one of the focus direction and the tracking direction of the optical disk, a light source built in the optical head body, and an optical head body. A built-in reflector that guides the laser light emitted from the light source to the objective lens, and a reflector
A moving means for moving in a predetermined direction is provided so as to correspond to a desired objective lens.

According to this structure, since the reflecting mirror is selectively moved to the position corresponding to the plurality of objective lenses, it is possible to perform recording or reproduction on the optical discs having different recording densities with one head, and at the same time, to objective. It is possible to prevent unnecessary vibration due to the disturbance applied to the lens support. Further, since the configuration is such that the plurality of objective lenses are switched by moving the reflecting mirror in a predetermined direction, the optical axis of the light source and the axis of the objective lens do not deviate due to the magnetization error of the magnet. Therefore, the number of magnets is reduced, and the cost, size and weight of the optical head device can be reduced.

[0021]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an embodiment of the present invention. In FIG. 1, reference numeral 23 in the drawing is an optical head main body. This optical head body 23 is
A magnet holder 24 formed in a substantially U shape is provided on the upper surface in the figure. The magnet holder 24 is arranged so that its opening side faces a signal recording surface of an optical disk (not shown). Further, magnets 25a and 25b are attached to both side surface portions 24a and 24b of the magnet holder 24. The objective lens support 26 is disposed between the magnets 25a and 25b. The objective lens support 26 has objective lenses 26a and 26b for irradiating and receiving laser light on the optical disc.
Is exposed.

The objective lens support 26 has focus actuator coils 27a and 27b (only one focus actuator coil 27a is shown in the figure) and a tracking actuator coil on both side surfaces facing the magnets 25a and 25b. 28a, 2
8b. The focus actuator coils 27a and 27b and the tracking actuator coils 28a and 28b are magnets 25a and 2b, respectively.
It is interposed in the magnetic path formed by 5b.

Therefore, by energizing the focus actuator coils 27a and 27b and the tracking actuator coils 28a and 28b, the objective lens support 26 is in the focus direction (in the drawing, the direction perpendicular to the signal recording surface of the optical disk). It can be moved in the tracking direction (direction shown by arrow T1-T2 in the drawing) which is the radial direction of the optical disk and the direction shown by arrow F1-F2.

Here, the objective lens support 26 has its tracking direction (direction shown by arrows T1-T2 in the drawing).
Both ends of the magnet are attached to one side surface 24a of the magnet holder 24 through the supports 29a and 29b, so that the magnet holder 24 is movably supported in the focus direction and the tracking direction.

FIG. 2 shows a state in which the optical head device shown in FIG. 1 is disassembled into its constituent parts. That is, the optical head main body 23 accommodates therein the light source 30, the reflecting mirror 31 and the like, which are composed of semiconductor laser elements and the like.
The magnet holder 24 is arranged on the upper surface of the optical head body 23.

The bottom portion 24c of the magnet holder 24
Through holes 24d and 24e corresponding to the objective lenses 26a and 26b are opened in the. In addition, the bottom surface portion 24c of the magnet holder 24 has a pair of side surface portions 2 bent at substantially right angles from both ends thereof so as to face each other.
4a and 24b are extended. Magnets 25a and 25b are attached to the side surface portions 24a and 24b, respectively. The objective lens support 26 is arranged between the magnets 25a and 25b.

At this time, the objective lens support 26 is provided with focus actuator coils 27a and 27b (only one focus actuator coil 27a is shown in the figure) on both side surfaces facing the magnets 25a and 25b, respectively. A pair of tracking actuator coils 28a, 28a and 28b, 28b are attached. Then, with the objective lens support 26 being supported by the magnet holder 24 via the supports 29a and 29b, the focus actuator coil 27
a, 27b and tracking actuator coil 28
a and 28b are respectively interposed in the magnetic paths formed by the magnets 25a and 25b.

The supports 29a and 29b are provided with flexures 32a and 32b (only one flexure 32a is shown in the figure) for supplying a drive current to the focus actuator coils 27a and 27b and the tracking actuator coils 28a and 28b. ) Has been placed. The flexures 32a and 32b are connected to a photodetector (not shown) built in the optical head main body 23. Therefore, the objective lens supporter 26 energizes the focus actuator coils 27a and 27b and the tracking actuator coils 28a and 28b based on the detection result of the photodetector when recording or reproducing to or from the optical disc, The control is performed so as to reduce the shift in the focus direction and the shift in the tracking direction.

Further, the optical head main body 23 is attached with a frame 33 formed in a substantially U shape on a plane 23a on which the reflecting mirror 31 is arranged. The reflecting mirror 31 is engaged with the inner circumference of the frame 33. The reflecting mirror 31 is arranged along the inner circumference of the frame 33 by an arrow E in the figure.
It is slidable in the direction indicated by 1-E2.
The size of the frame 33 is set so that the reflection position of the reflecting mirror 31 coincides with the axes of the objective lenses 26a and 26b.

First, in the mode of the objective lens 26a, as shown in FIG. 3, the reflecting mirror 31 slides in the direction indicated by arrow E1 in the figure by a moving mechanism (not shown). Therefore, the laser light emitted from the light source 30 travels in a direction parallel to the signal recording surface of the optical disc, that is, a direction indicated by an arrow A in the drawing, passes through an optical component (not shown), and then is reflected by the reflecting mirror 31 at a right angle, that is, The light is reflected in the direction indicated by the arrow B and is irradiated onto the optical disc through the objective lens 26a.

Further, in the mode of the objective lens 26b, as shown in FIG. 4, the reflecting mirror 31 is slid by the moving mechanism in the direction indicated by the arrow E2. Therefore, the laser light emitted from the light source 30 advances in a direction parallel to the signal recording surface of the optical disc, that is, a direction indicated by an arrow A in the figure, passes through the optical component, and then is reflected by the reflecting mirror 31 at a right angle, that is, an arrow B in the figure. The objective lens 2 is reflected in the direction shown by
It is irradiated onto the optical disk via 6b.

The moving mechanism detects the recording density of the optical disk when the optical disk is stored in a tray (not shown), and moves the reflecting mirror 31 based on the detection result. Further, the moving mechanism may control the movement of the reflecting mirror 31 so that good recording or reproducing is performed on the optical disc.

Therefore, according to the above-described embodiment, since the reflecting mirror 31 is selectively slid to the position corresponding to the objective lenses 26a and 26b, one head can record or reproduce the optical discs having different recording densities. In addition, it is possible to prevent unnecessary vibration due to the disturbance applied to the objective lens support 26. Further, in this embodiment, since the reflecting mirror 31 can be positioned by pressing the reflecting mirror 31 against the frame 33 provided on the flat surface 23a of the optical head main body 23, the optical paths 34b and 34c and the objective lenses 26a and 26b are respectively arranged. Highly accurate positioning with the axis of is possible.

FIG. 5 shows a second embodiment of the present invention. In FIG. 5, the same parts as those in FIG. 2 is different from FIG. 2 in that the reflecting mirror 31 is fixed to the flat surface 23a of the optical head main body 23,
The difference is that a retractable mirror 35 is provided on the light source 30 side. One end of the tiltable mirror 35 is the optical head body 2
It is fitted to the shaft support 36 provided on the flat surface 23a of the No. 3 plane and interlocks with the shaft support 36. That is, in the tiltable mirror 35, the shaft support 36 has an arrow Z1 in the drawing.
-By rotating in the direction indicated by Z2, the arrow Z
It rotates in the direction indicated by 1-Z2.

Then, in the mode of the objective lens 26a,
The tiltable mirror 35 is rotated in the direction indicated by the arrow Z2 in the figure by a moving mechanism (not shown), and the flat surface of the tiltable mirror 35 comes into contact with the flat surface 23a of the optical head body 23. Therefore, the laser light emitted from the light source 30 travels in the direction indicated by the arrow A in the figure to pass through the optical component, and then the reflecting mirror 3
It is reflected by 1 at a right angle, that is, in the direction indicated by arrow B in the figure, and is irradiated onto the optical disk through the objective lens 26a. At this time, the reflecting mirror 31 is prepositioned so that the optical path 34b of the laser light coincides with the axis of the objective lens 26a.

In the mode of the objective lens 26b, as shown in FIG. 6, the tiltable mirror 35 is rotated by the moving mechanism in the direction indicated by arrow Z1. At this time, the tiltable mirror 35 is rotationally controlled so that the optical path 34c of the laser light coincides with the axis of the objective lens 26b. Therefore, the laser light emitted from the light source 30 travels in the direction indicated by arrow A in the figure and passes through the optical component, and is then reflected by the tiltable mirror 35 at a right angle, that is, in the direction indicated by arrow B in the figure, and the objective lens. It is irradiated onto the optical disk via 26b.

Therefore, according to the second embodiment, since the objective lenses 26a and 26b are selected by rotating the tiltable mirror 35 in a predetermined direction, the objective lenses 26a and 26b are selected as in the previous embodiment. It is possible to prevent unnecessary vibration due to the disturbance applied to the lens support 26.

FIG. 7 shows a third embodiment of the present invention. In FIG. 7, the same parts as those in FIG. 2 is different from FIG. 2 in that, instead of the reflecting mirror 31, a switching mirror 37 having two symmetrical reflecting surfaces is provided on the flat surface 23a of the optical head main body 23. The switching mirror 37 is provided with a rotation hole on a surface parallel to the signal recording surface of the optical disc, penetrates the rotation shaft 38, and is attached to the flat surface 23 a of the optical head body 23. Therefore, the switching mirror 37 can be rotated clockwise or counterclockwise in the drawing. The rotation hole is provided at a position deviated from the symmetry axis formed by the reflection surfaces 37a and 37b of the switching mirror 37, that is, on the light source 30 side.

On the other hand, the switching mirror 37 includes the objective lens 26.
In the mode a, the reflecting surface 37a is rotated clockwise by a moving mechanism (not shown) so that the reflecting surface 37a faces the light source 30, and thereafter, the side surface thereof is flat surface 2 of the optical head main body 23.
It comes into contact with the stopper 39a provided on 3a. Therefore, the laser light emitted from the light source 30 travels in the direction indicated by arrow A in the figure, passes through the optical component, and is then reflected by the reflecting surface 37a of the switching mirror 37 at a right angle, that is, in the direction indicated by arrow B in the figure. , Is irradiated onto the optical disc through the objective lens 26a.

Further, the switching mirror 37 includes the objective lens 26.
In the case of mode b, as shown in FIG.
The moving mechanism is rotated counterclockwise in the figure so that b faces the light source 30, and thereafter, the side surface of the optical head main body 2
3 will come into contact with the stopper 39b provided on the plane 23a. Therefore, the laser light emitted from the light source 30 travels in the direction indicated by the arrow A in the figure, passes through the optical component, and is then reflected by the reflecting surface 37b of the switching mirror 37 at a right angle, that is, in the direction indicated by the arrow B in the figure. , Objective lens 26
The optical disc is irradiated via b.

The switching mirror 37 and the stopper 39
The a and 39b are pre-positioned so that the optical paths 34b and 34c of the laser light coincide with the axes of the objective lenses 26a and 26b, respectively.

Therefore, according to the third embodiment, since the objective lenses 26a and 26b are selected by rotating the switching mirror 37 in a predetermined direction, like the second embodiment. It is possible to prevent unnecessary vibration due to the disturbance applied to the objective lens support 26.

FIG. 9 shows a fourth embodiment of the present invention. In FIG. 9, the same parts as those in FIG. The difference from FIG. 2 is that instead of the reflecting mirror 31, the rotating mirror 4 having a substantially triangular prism shape having two reflecting surfaces.
The difference is that 0 is set. The side of the side surface of the rotary mirror 40 in the height direction is rotatably supported by a rotary shaft 41 provided on the flat surface 23 a of the optical head body 23. That is, when the rotating shaft 41 is rotated in the direction indicated by the arrow G1 or G2 in the figure by the moving mechanism (not shown), the rotating mirror 40 is interlocked in the direction indicated by the arrow G1 or G2 in the figure.

Then, in the mode of the objective lens 26a,
The rotating mirror 40 is rotated by the moving mechanism in the direction indicated by an arrow G1 in the figure, and the reflecting surface 40a of the rotating mirror 40 faces the light source 30. Therefore, the light source 30
The laser light emitted from the laser beam advances in the direction indicated by the arrow A in the figure and passes through the optical component, and then the reflecting surface 4 of the rotating mirror 40.
0a reflects the light at a right angle, that is, in the direction indicated by arrow B in the figure, and irradiates the optical disk through the objective lens 26a.

Further, in the mode of the objective lens 26b, as shown in FIG. 10, the rotating mirror 40 is rotated by the moving mechanism in the direction shown by an arrow G2 in the figure, and the rotating mirror 40 is rotated.
The reflective surface 40b of the light source 30 faces the light source 30.
At this time, the reflecting surface 40a is the flat surface 2 of the optical head body 23.
It is in contact with 3a. Therefore, the laser light emitted from the light source 30 travels in the direction indicated by the arrow A in the figure, passes through the optical component, and is then reflected by the reflecting surface 40b of the rotating mirror 40 at a right angle, that is, in the direction indicated by the arrow B in the figure. , Is irradiated onto the optical disc through the objective lens 26a.

The rotary mirror 40 is preliminarily adjusted in position on the plane 23a of the optical head main body 23 so that the optical paths 34b and 34c of the laser light coincide with the axes of the objective lenses 26a and 26b, respectively.

Therefore, according to the fourth embodiment, since the objective lenses 26a and 26b are selected by rotating the rotary mirror 40 in a predetermined direction, as in the third embodiment. It is possible to prevent unnecessary vibration due to the disturbance applied to the objective lens support 26.

As described above, according to the above-described embodiments, the objective lenses 26a and 26b are switched by moving the reflecting mirror in a predetermined direction.
Optical path of laser beam and objective lens 26 due to magnetizing error of magnet
There is no deviation from the axes of a and 26b, the number of magnets is reduced, and the cost and size and weight of the optical head device having a plurality of objective lenses can be reduced. Therefore, it becomes suitable for an apparatus that requires recording or reproduction of high-density information.

[0049]

As described in detail above, according to the present invention,
An optical head that is suitable for recording or reproducing high-density information without adversely affecting the movable part when switching a plurality of objective lenses, and can reduce the number of magnets to reduce cost and size and weight. A lens switching mechanism for the device can be provided.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a lens switching mechanism of an optical head device according to the present invention.

FIG. 2 is an exploded perspective view showing a specific configuration of the same embodiment.

FIG. 3 is a perspective view shown for explaining a mode of a first objective lens in the same embodiment.

FIG. 4 is a perspective view shown to explain a mode of a second objective lens in the same embodiment.

FIG. 5 is a perspective view shown for explaining modes of the first objective lens according to the second embodiment of the present invention.

FIG. 6 is a perspective view shown for explaining a mode of a second objective lens in the second embodiment.

FIG. 7 is a perspective view shown for explaining a mode of a first objective lens according to a third embodiment of the present invention.

FIG. 8 is a perspective view shown for explaining a mode of a second objective lens in the third embodiment.

FIG. 9 is a perspective view shown for explaining modes of a first objective lens according to a fourth embodiment of the present invention.

FIG. 10 is a perspective view shown for explaining a mode of a second objective lens in the fourth embodiment.

FIG. 11 is a perspective view showing a lens switching mechanism of a conventional optical head device.

FIG. 12 is an exploded perspective view showing a specific configuration of the conventional mechanism.

FIG. 13 is a perspective view shown for explaining a mode of a first objective lens in the conventional mechanism.

FIG. 14 is a perspective view shown for explaining a mode of a second objective lens in the conventional mechanism.

[Explanation of symbols]

 11 ... Optical head main body, 12a ... Magnet holder, 12b ... Magnet holder, 13a ... Magnet, 13b ... Magnet, 14a ... Magnet, 14b ... Magnet, 15 ... Holder, 15a ... Objective lens, 15b ... Objective lens, 16a ... Focus. Actuator coil, 16b ... Focus actuator coil, 17a ... Tracking actuator coil, 17b ... Tracking actuator coil, 20 ... Light source, 21 ... Reflector, 23 ... Optical head main body, 23a ... Plane, 24 ... Magnet holder, 25a ... Magnet, 25b ... magnet, 26 ... objective lens support, 26a ... objective lens, 26b ... objective lens, 27a ... focus actuator coil, 27b ... focus actuator coil, 28a ... tracking actuator coil, 28 Tracking actuator coil, 29a ... Support, 29b ... Support, 30 ... Light source, 31 ... Reflector, 33 ... Frame, 34b ... Optical path, 34c ... Optical path, 35 ... Reversible mirror, 36 ... Shaft support, 37 ... Switching mirror, 37a ... Reflecting surface, 37b ... Reflecting surface, 38 ... Rotating shaft, 40 ... Rotating mirror, 40a ... Reflecting surface, 40b ... Reflecting surface, 41 ... Rotating shaft.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuo Kokubun 8 Shinsita-cho, Isogo-ku, Yokohama, Kanagawa Prefecture Multimedia Technology Research Laboratories, Toshiba Corp. (72) Hideaki Karahara 3-3-9 Shinbashi, Minato-ku, Tokyo No. Within Toshiba Abu E Co., Ltd.

Claims (5)

[Claims] 1. An optical head main body, an objective lens support for supporting a plurality of objective lenses arranged on the optical head main body and adapted to respectively correspond to a plurality of types of optical disks, and the objective lens support. Driving means for driving the body in at least one of the focus direction and the tracking direction of the optical disc; a light source built in the optical head body; and a laser beam built in the optical head body and emitted from the light source. A lens switching mechanism for an optical head device, comprising: a reflecting mirror for guiding the objective lens; and a moving means for moving the reflecting mirror in a predetermined direction so as to correspond to the desired objective lens. . 2. The moving means is means for moving the reflecting mirror in a plane direction of the optical head main body in a direction in which each of the plurality of objective lenses is axially spaced. Lens switching mechanism of optical head device. 3. The reflecting mirror has first and second reflecting mirrors which are parallel to each other on the plane of the optical head main body and are configured to correspond to at least two objective lenses. By tilting the first reflecting mirror on the light source side toward the plane of the optical head body, the laser light emitted from the light source is reflected by the second reflecting mirror and guided to the objective lens. The lens switching mechanism of the optical head device according to claim 1. 4. The reflecting mirror has first and second reflecting surfaces which are symmetric to each other and are configured to correspond to at least two of the objective lenses, and the moving means comprises: By the rotating shaft provided at a position displaced from the symmetry axis of the first and second reflecting surfaces,
The lens switching mechanism of the optical head device according to claim 1, wherein the lens mirror is a unit that rotates the reflecting mirror. 5. The reflecting mirror has first and second reflecting surfaces configured to have a predetermined angle with respect to the optical axis of the light source and the objective lens axis, and the moving means includes A means for rotating the reflecting mirror by a rotating shaft provided on the plane of the optical head main body so as to be perpendicular to the optical axis of the light source and the objective lens axis. The lens switching mechanism of the optical head device according to claim 1.