JPH11259886A - Rotary arm of optical disk drive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the rotary arm of the optical disk driven lightweight. SOLUTION: The rotary arm of the optical a disk drive consists of an optical unit equipped with a light source part which emits luminous flux, 1st and 2nd arm tip parts which are a couple of arm tip parts 3a and 3b facing both surfaces of an optical disk 2 respectively and equipped with objectives for converging luminous flux on the surfaces of the optical disk, and a selecting means which guides the luminous flux from the optical unit selectively to one of the 1st and 2nd arm tip parts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk device, and more particularly, to a rotating arm having an optical system for recording and reproducing information.

[0002]

In recent years, the areal recording density has become 1
Optical disk devices exceeding 0 Gbit / (inch) 2 are being developed. In such an optical disk device, a rotating arm equipped with an optical system for recording information on the recording surface of the optical disk (or reproducing the information on the recording surface) includes:
It is configured to move along the recording surface of the optical disc.

[0003] When both sides of the optical disk are recording surfaces, it is necessary to provide two opposing rotating arms on both sides of the optical disk. However, since the light source module that emits the light beam is relatively heavy, there is a problem that if the light source modules are mounted on both the rotating arms, the weight of the entire rotating arm must be increased. When the weight of the rotating arm is increased, it is difficult to improve the access speed, and the manufacturing cost is increased.

The present invention has been made in view of the above circumstances, and has as its object to reduce the weight of a rotating arm in an optical disk device.

[0005]

In order to solve the above-mentioned problems, a rotating arm of an optical disk device according to the present invention is provided with
(1) first and second arm tips, each of which is a pair of arm tips opposed to both sides of the optical disc, respectively, and has an objective lens for condensing a light beam on each face of the optical disc;
(2) an optical unit including a light source unit that emits a light beam; and (3) a selection unit that selectively guides a light beam from the optical unit to one of the first and second arm tips. Have been.

With this configuration, only one optical unit is required for the pair of arm tips. Therefore, the weight of the rotating arm can be reduced as compared with the case where all the optical systems are mounted on both the rotating arms. And, by reducing the weight of the rotating arm, the access speed can be improved and the manufacturing cost can be reduced.

The above-mentioned selection means can be constituted by a movable prism which is configured to be swingable. The movable prism is configured to change the position of the emission surface by swinging, and when the emission surface is at the first position, the light beam from the optical unit is emitted toward the tip of the first arm, When the emission surface is at the second position, the light beam from the optical unit is emitted toward the tip of the second arm.

The optical unit and the distal end of the second arm are arranged so that the light beam from the optical unit is guided to the distal end of the second arm, and the selection means is connected to the optical unit and the distal end of the second arm. It is also possible to use a movable mirror that can be moved to a position that blocks the optical path, and a relay mirror that deflects the light beam from the movable mirror toward the distal end of the first arm.

Further, the selection means may be constituted by a movable housing which accommodates the optical unit and is movable with respect to the distal ends of the first and second arms. In this case, when the movable housing is at the first position, the light beam from the optical unit is guided to the first arm distal end portion, and when the movable housing is at the second position, the light beam from the optical unit is transmitted to the second arm distal end. It can be configured to be guided to a unit. Specifically, a configuration in which the movable housing is moved in parallel in the rotation axis direction of the optical disc and a configuration in which the movable housing is swung about a predetermined swing axis are possible.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an embodiment of the present invention will be described. The optical disk device of the embodiment uses a recording / reproducing method called a near field recording (NFR) technique. FIG. 1 is a perspective view showing a schematic configuration of the optical disc device of the embodiment. The optical disk 2 as a recording medium has upper and lower surfaces serving as recording surfaces, and a rotating shaft 22 of a spindle motor (not shown).
It is attached to. In the following description, the direction (rotation axis direction) perpendicular to the surface of the optical disk 2 is referred to as “vertical direction”.

A rotating arm having a predetermined optical system (described later) for recording / reproducing information on / from the optical disk 2 is mounted on a rotating shaft 4 parallel to the rotating shaft 22 of a spindle motor of the optical disk 2 via a bearing 44. Installed. A drive coil 16 which is a flat coil is fixed to the rotating arm. The drive coil 16 is inserted and arranged in a magnetic circuit (not shown) with a space therebetween, and forms a so-called voice coil motor. When a current is applied to the drive coil 16, the rotation arm rotates around the rotation shaft 4 by the electromagnetic action with the magnetic circuit.

The tip of the rotating arm is bifurcated into upper and lower portions, and includes first and second arm tips 3a and 3b extending along the upper and lower surfaces of the optical disk 2, respectively. An optical disk 2 is provided at each of the distal ends of the first and second arm distal ends 3a and 3b.
The floating optical units 6a and 6b (to be described later) for converging the laser beam are mounted on the upper and lower surfaces. A light source module 7 having a light source unit and a light receiving unit is housed near the rotation shaft 4 of the rotation arm, and is configured to be driven integrally with the rotation arm.

First, the floating optical unit will be described. FIG. 2 is a side view showing the tip of the upper arm tip 3a, and FIG. 3 is an enlarged side view showing the floating optical unit 6a provided on the upper arm tip 3a.
The floating optical unit 6b provided on the lower arm tip 3b is vertically symmetrical with the upper floating optical unit 6a, and a description thereof will be omitted.

As shown in FIG. 2, the floating optical unit 6
a is attached to one end of the flexure beam 8a, and the other end of the flexure beam 8a is
a is fixed to the lower surface. When the optical disk 2 rotates, the floating type optical unit 6a floats a small amount from the surface of the optical disk 2 due to the balance between the airflow due to the rotation of the optical disk 2 and the elastic force of the flexure beam 8a. Follow the etc. This eliminates the need for focus control (focus servo) of the objective lens, which is required in the conventional optical disk device.

As shown in FIG. 3, the floating optical unit 6
a denotes a floating slider 9a, an objective lens 10a, a solid immersion lens (SIL) 11a, and a magnetic coil 12.
a, and converges a parallel laser beam 13 emitted from a light source module described later on the optical disc 2. Also, the laser beam 1 is provided at the arm tip 3a.
Deflecting mirror 3 for guiding the mirror 3 to the floating optical unit 6a
1a is fixed. The laser beam 13 incident on the objective lens 10a by the deflecting mirror 31a is converged by the refraction of the objective lens 10a. A solid immersion lens (SIL) 11a is disposed near the converging point, and irradiates the convergent light onto the optical disc 2 as finer evanescent light 15a.

A magnetic coil 12a for recording by a magneto-optical recording method is formed around a solid immersion lens (SIL) 11a facing the optical disk 2, and a magnetic field necessary for recording is recorded on the optical disk 2. It can be applied on the surface. Evanescent light 15a
And the magnetic coil 12a enable high-density recording and reproduction on the optical disk 2.

Next, the structure of the rotating arm will be described. FIG. 4 is a plan view of the rotating arm, and FIG. 5 is a diagram illustrating only the optical system of the rotating arm. As shown in FIG. 5, the light source module 7 of the rotating arm includes a semiconductor laser 18 that emits a laser beam,
Lens 2 for converting divergent light into parallel light
0, composite prism assay 21, imaging lens 23, data detection / tracking detection sensor 24, and APC
It has a sensor 25.

The cross-sectional shape of the parallel light beam emitted from the collimating lens 20 is an elliptical shape due to the characteristics of the semiconductor laser 18, and it is inconvenient to narrow down the laser light beam onto the optical disk 2. Need to be converted to For this reason, the entrance surface 21a of the composite prism assay 21 has a predetermined inclination with respect to the incident optical axis,
By refracting the incident light, the cross-sectional shape of the parallel light beam is shaped from an oval shape to a substantially circular shape.

FIG. 6 is a view of the optical system of the rotating arm viewed from the direction of arrow A in FIG. FIG. 7 is a side sectional view of the rotating arm. In this embodiment, one light source module 7 is configured to be commonly used for the two arm tip portions 3a and 3b. Therefore, as shown in FIG. 6, the light source module 7 is housed in a mezzanine housing 3c provided vertically vertically between the arm tips 3a and 3b. A laser beam 13 from the light source module 7 is supplied to the portion connecting the mezzanine housing 3c and the arm tips 3a and 3b with the first and second arm tips 3a and 3b.
a movable prism 50 for guiding to any one of a and 3b
Is provided.

The movable prism 50 has an entrance surface and an exit surface 51, 52 parallel to each other, and two reflection surfaces 5 parallel to each other.
3,54. Then, the laser beam incident on the entrance surface 51 from the light source module 7 is reflected by the reflection surfaces 53 and 54.
And is emitted from the emission surface 52 in parallel with the incident light. That is, the movable prism 50 emits incident light in parallel with the incident light and at a shifted position.

The movable prism 50 swings up and down 180 ° about the optical axis of the light incident from the light source module 7. As shown in FIG. 6A, the emission surface 52 of the movable prism 50
Is swung upward, the laser beam 13 from the light source module 7 is emitted toward the galvanomirror 26a provided at the first arm tip 3a. And FIG.
As shown in (a), the laser beam 13 reflected by the galvanomirror 26a passes through a first relay lens 29a and a second relay lens 30a (described later) and is reflected downward by a deflection mirror 31a. Then, the light is condensed on the upper surface of the optical disk 2 via the floating optical unit 6a.

On the other hand, as shown in FIG. 6B, when the emission surface 52 of the movable prism 50 swings downward, the laser beam 13 from the light source module 7 is provided in the second arm tip 3b. The light is emitted toward the galvanomirror 26b. Then, as shown in FIG. 7B, the laser beam reflected by the galvanometer mirror 26b is reflected upward by the deflection mirror 31b via a first relay lens 29b and a second relay lens 30b (described later). Then, the light is condensed on the lower surface of the optical disk 2 via the floating optical unit 6b. The configuration for swinging the movable prism 50 will be described later.

The returning laser beam 13 reflected from the optical disk 2 travels in the opposite direction to the outward route, is reflected by the movable prism 50, returns to the light source module 7, and enters the composite prism assay 21. Complex prism assay 21
Generates a transmitted light and a reflected light directed to the data detection / tracking detection sensor 24,
Separates the laser beam on the return path. The data detection / tracking detection sensor 24 is a composite sensor that reads data information recorded on the optical disc 2 and outputs a data signal and outputs a tracking error signal.
To be precise, the tracking error signal and the data signal are generated by a head amplifier circuit (not shown) and sent to a control circuit or an information processing circuit.

The galvanomirror 26a (26)
b) performs fine tracking control by finely adjusting the incident angle of the laser beam 13 with respect to the objective lens 10a (10b) by swinging about a predetermined swing axis on the mirror surface. That is, in the optical disk device of the embodiment, an access operation is performed over the inner circumference / outer circumference of the optical disk 2 by the rotation of the rotation arm, and the galvanomirror 2
The minute tracking control is performed by the rotation of 6a (26b). The rotation angle of the galvanometer mirror 26a (26b) is detected by an angle detection sensor (not shown) provided near the galvanometer mirror 26a (26b).

The first relay lens 29a (29b)
And the second relay lens 30a (30b) is provided between the reflecting surface of the galvanometer mirror 26a (26b) and the objective lens 10a.
This is for making the pupil plane of (10b) have a conjugate relationship. That is, when the optical distance between the galvanomirror 26a (26b) and the objective lens 10a (10b) is long, the amount of movement of the laser beam 13 incident on the objective lens 10a (10b) increases, and It may not be possible to enter. Therefore, the first and second relay lenses make the reflection surface of the galvanometer mirror 26a (26b) and the pupil surface of the objective lens 10a (10b) have a conjugate relationship, and the galvanometer mirror 26a (26b) rotates. Also, the laser beam incident on the objective lens 10a (10b) does not move so that accurate tracking control can be performed.

Next, a method of driving the movable prism 50 will be described. As shown in FIGS. 8A and 8B, the prism 50 is attached to a drive motor 55 via a prism holder 58. The rotation axis of the drive motor 55 coincides with the optical axis of the laser beam that enters the light incident surface 51 from the light source module 7. The movable prism 50 has a drive motor 55
When the emitting surface 52 swings upward, the laser beam incident on the incident surface 51 is emitted upward with a predetermined displacement, and when the emitting surface 52 swings downward, the incident surface 51 is swung downward. The laser beam incident on 51 is emitted after being displaced downward by a predetermined amount.

As described above, according to the first embodiment, by swinging the movable prism 50,
The laser beam can be selectively guided to one of the first arm tip 3a and the second arm tip 3b. Thus, only one optical module 7 is required for the two arm tip portions 3a and 3b, and the weight of the arm can be reduced.

Next, a modification of the first embodiment will be described. FIG. 9 and FIG. 10 are a plan view and a side sectional view showing a rotation arm according to a modification of the first embodiment. In this modification, not only the light source module 7 but also the galvanometer mirror 26 is shared. Therefore, galvanomirror 26
Are arranged in the same mezzanine housing 3c as the light source module 7, and a movable prism 150 is provided between the mezzanine housing 3c and the first and second arm tips 3a, 3b.

As shown in FIGS. 11A and 11B, the movable prism 150 is attached to a drive motor 155 via a prism holder 158, and the rotation axis of the drive motor 155 is moved from the galvanometer mirror 26 to the movable prism 150. Coincides with the optical axis of incident light.

As shown in FIG.
When the zero emission surface 152 swings upward, the laser beam incident from the galvanomirror 26 is emitted upward after being displaced by a predetermined amount and the first lens 30 of the first arm tip 3a.
a. On the other hand, as shown in FIG. 11B, when the exit surface 152 of the prism 150 swings downward, the laser beam incident from the galvanomirror 26 is displaced downward by a predetermined amount and emitted, and the tip end of the second arm. The light enters the first lens 30b of FIG.

As described above, according to the optical disk device of this modification, only one optical module 7 and one galvanometer mirror 26 are required for the two arm tips, so that the weight of the rotating arm is further reduced. be able to.

Next, a second embodiment of the present invention will be described. FIG. 12 is a plan view showing a rotating arm according to the second embodiment. The rotating arm of the second embodiment has upper and lower forked arm tips 3a and 3b similar to the first embodiment. The optical system from the light source module 7 and the galvanomirrors 26a (26b) in the arm end portions 3a and 3b to the floating optical unit 6a (6b) is configured in the same manner as in the first embodiment.

FIG. 13 is a view of the optical system of the rotating arm viewed from the direction of arrow A in FIG. As shown in FIGS. 13A and 13B, the light source module 7 is arranged in a housing 200 provided at the same height as the second arm tip 3. A movable mirror 250 slidable up and down is provided at a connection portion between the housing 200 and the second arm tip 3b.

As shown in FIG. 13A, the movable mirror 2
When the mirror 50 is located at the lower end, the movable mirror 250 blocks the optical path connecting the light source module 7 and the tip 3b of the second arm, and the laser beam 13 from the light source module 7
Is reflected upward.

A fixed mirror 258 is provided above the movable mirror 250, and deflects the laser beam from the movable mirror 250 horizontally and guides it to the optical system of the first arm tip 3a. That is, the movable mirror 250
Is located at the lower end, the laser beam from the light source module 7 is guided to the first arm tip 3a.

On the other hand, as shown in FIG. 13B, when the movable mirror 250 is located at the upper end,
Since 50 does not block the optical path connecting the light source module 7 and the second arm tip 3b, the laser beam 13 from the light source module 7 is guided to the second arm tip 3b as it is.

The laser beam 13 guided to the first arm tip 3a is reflected by the galvanometer mirror 26a, passes through the first relay lens 29a and the second relay lens 30a, and is reflected downward by the deflection mirror 31a. And
The light is condensed on the upper surface of the optical disc 2 via the floating optical unit 6a. On the other hand, the laser beam 13 guided to the second arm tip 3b is reflected by the galvanomirror 26b, and is reflected by the first relay lens 29b and the second relay lens 3b.
After that, the light is reflected upward by the deflection mirror 31b. Then, the light is condensed on the lower surface of the optical disk 2 via the floating optical unit 6b.

As in the first embodiment, the first relay lens 29a (29b) and the second relay lens 30a (30b)
Accordingly, the reflection surface of the galvanometer mirror 26a (26b) and the pupil surface of the objective lens (not shown) have a conjugate relationship.

Next, a method of driving the movable mirror 250 will be described. As shown in FIG. 14, the movable mirror 250 is mounted on a lift 251. This elevator 251
Are guided vertically by a guide bar 252 extending vertically. Female screw part (not shown) on the lift 251
Are formed, and a drive screw 253 extending in the vertical direction is engaged with the female screw portion. The drive screw 253 is driven to rotate by a drive motor 255. Thus, the driving screw 253 is rotationally driven by the driving motor 255, so that the elevator 251 (and the movable mirror 250 thereon) are driven.
Is driven up and down.

As described above, by moving the movable mirror 250 up and down, the laser beam 1 from the light source module 7 is moved.
3 can be selectively guided to either the first arm tip 3a or the second arm tip 3b, so that only one optical module 7 is required for the two arm tips 3a and 3b. . That is, the weight of the rotating arm can be reduced.

Next, a third embodiment of the present invention will be described. FIG. 15 is a plan view showing a rotating arm according to the third embodiment. The rotating arm of the third embodiment has upper and lower forked arm tips 3a and 3b similar to the first embodiment. The optical system from the light source module 7 and the galvanomirrors 26a (26b) in the arm end portions 3a and 3b to the floating optical unit 6a (6b) is configured in the same manner as in the first embodiment.

FIG. 16 is a diagram showing the arrangement of the optical system of the rotating arm viewed from the direction of arrow A in FIG. FIG. 16 (a)
As shown in (b), the light source module 7 is housed in an elevating housing 300 configured to be able to elevate and lower. When the lift housing 300 is located at the upper end, the lift housing 300 and the first arm tip 3a are at the same height. When the lift housing 300 is located at the lower end, the lift housing 300 and the second arm tip 3a. 3b is at the same height.

That is, as shown in FIG. 16A, when the elevating housing 300 is located at the upper end, the laser beam from the light source module 7 emits the first arm tip 3a.
To the optical system inside. On the other hand, as shown in FIG. 16B, when the elevating housing 300 is located at the lower end, the laser beam from the light source module 7 is guided to the optical system in the second arm tip 3b.

The laser beam 13 guided to the first arm tip 3a is reflected by the galvanometer mirror 26a, passes through the first relay lens 29a and the second relay lens 30a, and is reflected downward by the deflection mirror 31a. And
The light is condensed on the upper surface of the optical disc 2 via the floating optical unit 6a. On the other hand, the laser beam 13 guided to the second arm tip 3b is reflected by the galvanomirror 26b, and is reflected by the first relay lens 29b and the second relay lens 3b.
After that, the light is reflected downward by the deflecting mirror 31b. Then, the light is condensed on the lower surface of the optical disk 2 via the floating optical unit 6b.

As in the first embodiment, the first relay lens 29a (29b) and the second relay lens 30a (30b)
Accordingly, the reflection surface of the galvanometer mirror 26a (26b) and the pupil surface of each objective lens (not shown) are in a conjugate relationship.

Next, a method of driving the lifting housing 300 will be described. As shown in FIG. 17, the lifting housing 300 is guided vertically by a guide bar 302 extending vertically. A female screw portion (not shown) is formed in the lifting housing 300, and a drive screw 303 extending in the vertical direction is engaged with the female screw portion. The drive screw 303 is driven to rotate by a drive motor 305. Thus, by driving the drive screw 303 by the drive motor 305, the lift housing 300 (and the light source unit 7 thereon) is driven to move up and down.

As described above, the laser beam 13 from the light source module 7 can be selectively guided to either the first arm tip 3a or the second arm tip 3b by moving the lifting housing 300 up and down. One optical module 7 can be used for one arm tip 3a, 3b. That is, the weight of the rotating arm can be reduced.

Next, a fourth embodiment of the present invention will be described. FIG. 18 is a plan view showing a rotating arm according to the fourth embodiment. The rotating arm according to the fourth embodiment has upper and lower forked arm tips 3a and 3b similar to the first embodiment. The optical system from the light source module 7 and the galvanomirrors 26a (26b) in the arm end portions 3a and 3b to the floating optical unit 6a (6b) is configured in the same manner as in the first embodiment.

FIG. 19 is a view of the arrangement of the optical system of the rotating arm viewed from the direction of arrow A in FIG. FIG. 19 (a)
As shown in (b), the light source module 7 is housed in a swingable housing (swinging housing 400).
The swing housing 400 is configured so that the complex prism assay 21 side swings about a swing axis 401 on the semiconductor laser 18 side. The swing shaft 401 is
It extends parallel to the longitudinal direction of the first and second arm tips 3a, 3b (in a direction substantially orthogonal to the light flux from the light source module), and is located vertically intermediate between the upper and lower arm tips 3a, 3b.

Then, as shown in FIG. 19A, when the swing housing 400 swings upward, the laser beam 13 from the light source module 7 receives the first arm tip 3
The light is guided to the galvanomirror 26a in FIG. On the other hand, FIG.
As shown in (b), when the movable mirror 250 swings downward, the galvano mirror 2 in the second arm tip 3b is moved.
6b.

FIG. 20 is a side sectional view of the rotating arm. As shown in FIG. 20A, the laser beam 13 incident on the first arm tip 3a is reflected by the galvanomirror 26a, and floats on the upper side via the first and second relay lenses 29a and 30a and the deflecting mirror 31a. The light enters the optical unit 6a. As shown in FIG. 20B, the second arm tip 3
b is incident on the galvanomirror 26
b, the first and second relay lenses 29b, 3
0b and the deflection mirror 31b, and is incident on the lower floating optical unit 6b.

As in the first embodiment, the first relay lens 29a (29b) and the second relay lens 30a (30b)
Accordingly, the reflection surface of the galvanometer mirror 26a (26b) and the pupil surface of each objective lens 10a (10b) have a conjugate relationship.

As shown in FIG. 19, the laser beam from the light source module 7 is supplied to the galvanomirrors 26a and 26b.
b. So, Galvanomirror 2
The swing axes of 6a and 26b are inclined by a predetermined amount so as to be orthogonal to the optical axis of the incident light from the light source module 7. As a result, the galvanomirrors 26a (26b) swing, and the angle of incidence of the laser beam 13 on each objective lens 10a (10b) can be finely adjusted to perform fine tracking control.

Next, a method of driving the swing housing 400 will be described. As shown in FIG. 21, the swing shaft 401 of the swing housing 400 is attached to the distal ends of both arms via a bracket 402. Swing housing 4
A sector gear 403 having a predetermined circular arc shape is attached to the side opposite to the swing shaft 401 of 00. The pinion 406 of the drive motor 405 is engaged with the sector gear 403. The sector angle of the sector gear 403 corresponds to the swing angle of the swing housing 400 in FIGS. Thus, the drive motor 405
, The swing housing 400 can be swung as shown in FIGS. 19A and 19B.

As described above, the swing of the swing housing 400 allows the laser beam 13 from the light source module 7 to be selectively guided to either the first arm tip 3a or the second arm tip 3b. It is possible to use only one optical module 7 for the two arm tips 3a and 3b. That is, the weight of the rotating arm can be reduced.

Next, a fifth embodiment of the present invention will be described. FIG. 22 is a plan view showing a rotating arm according to the fifth embodiment. The rotating arm of the fifth embodiment has upper and lower forked arm tips 3a, 3b similar to the first embodiment. The optical system from the light source module 7 and the galvanomirrors 26a (26b) in the arm end portions 3a and 3b to the floating optical unit 6a (6b) is configured in the same manner as in the first embodiment.

FIGS. 23A and 23B are side sectional views of the rotating arm. As shown in FIGS. 23A and 23B, the light source module 7 includes a swingable housing (a swing housing 50).
0). The swing housing 500 is configured so that the complex prism assay 21 side swings around a swing axis 501 on a side closer to the rotation axis 4. The swing shaft 501 extends in a direction perpendicular to the longitudinal direction of the first and second arm tips 3a and 3b (a direction substantially parallel to the light flux from the light source module), and extends vertically in the upper and lower arm tips 3a and 3b. It is located in the middle.

Then, as shown in FIG. 23A, when the swing housing 500 swings upward, the laser beam 13 from the light source module 7 receives the first arm tip 3a.
It is led to. The laser beam 13 incident on the first arm tip 3a is reflected by the galvanomirror 26a, and the first and second relay lenses 29a and 30a and the deflection mirror 31a.
And enters the upper floating optical unit 6a.

On the other hand, as shown in FIG. 23 (b), when the swing housing 500 swings downward, the laser beam 13 from the light source module 7 is guided to the second arm tip 3b. The laser beam 13 incident on the tip 3b of the second arm is reflected by the galvanometer mirror 26b, and the first and second relay lenses 29b and 30b and the deflection mirror 31b
And enters the lower floating optical unit 6b.

As in the first embodiment, the first relay lens 29a (29b) and the second relay lens 30a (30b)
Accordingly, the reflection surface of the galvanometer mirror 26a (26b) and the pupil surface of each objective lens 10a (10b) have a conjugate relationship.

Next, a method of driving the swing housing 500 will be described. As shown in FIG. 24, both ends of a swing shaft 501 of a swing housing 500 are attached to both arm tip portions 3a and 3b via brackets 502. A sector gear 50 having a predetermined arc shape is provided on the swing shaft 501.
3 is fixed. The pinion 506 of the drive motor 505 is engaged with the sector gear 503.
Thus, by driving the drive motor 505, the swing housing 500 can be swung as shown in FIGS.

As described above, by oscillating the swing housing 500, the laser beam 13 from the light source module 7 is supplied to the first arm tip 3a and the second arm tip 3a.
b can be selectively guided to any one of the two arm tips 3a and 3b, so that only one optical module 7 is required. That is, the weight of the rotating arm can be reduced.

In each of the above embodiments, it is also possible to provide a configuration in which three or more arm tips are provided for one rotating arm so as to correspond to a plurality of optical disks. In this case, three or more arm tips may be configured to share a part of the optical system (for example, a light source module).

[0064]

As described above, according to the rotating arm of the optical disk apparatus of the present invention, the tip of the pair of arms can share the optical unit, so that the weight of the rotating arm can be reduced. And, by reducing the weight of the rotating arm, the access speed can be improved and the manufacturing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an optical disc device according to a first embodiment.

FIG. 2 is a side view showing a distal end portion of a rotating arm.

FIG. 3 is a side view showing a floating optical unit.

FIG. 4 is a plan view showing an optical head.

FIG. 5 is a diagram showing an optical system of the optical head.

FIG. 6 is a diagram of the optical system of the optical head as viewed from the side.

FIG. 7 is a side sectional view of the optical head.

FIG. 8 is a perspective view showing a configuration for swinging a movable mirror.

FIG. 9 is a plan view showing an optical head.

FIG. 10 is a side sectional view of the optical head.

FIG. 11 is a perspective view showing a configuration for swinging a movable mirror.

FIG. 12 is a plan view illustrating an optical head according to a second embodiment.

13 is a diagram of the optical system of the optical head of FIG. 12 as viewed from the side.

FIG. 14 is a perspective view showing a configuration for driving a movable mirror up and down.

FIG. 15 is a plan view illustrating an optical head according to a third embodiment.

16 is a diagram of the optical system of the optical head of FIG. 15 as viewed from the side.

FIG. 17 is a perspective view showing a configuration for driving the lifting housing up and down.

FIG. 18 is a plan view illustrating an optical head according to a fourth embodiment.

19 is a view of the optical system of the optical head of FIG. 18 as viewed from the side.

FIG. 20 is a perspective view showing a configuration for swinging a swing housing.

FIG. 21 is a side sectional view of the optical head of FIG. 18;

FIG. 22 is a plan view showing an optical head according to a fifth embodiment.

FIG. 23 is a side sectional view of the optical head of FIG. 22;

FIG. 24 is a perspective view showing a configuration for swinging the swing housing.

[Explanation of symbols]

 2 Optical disc 3a, 3b Arm tip 6a, 6b Floating optical unit 3c Mezzanine housing 7 Light source module 13 Laser beam 26a, 26b Galvano mirror 29a, 29b First lens 30a, 30b Second lens 50 Movable prism 55 Drive motor 200 Housing 250 Movable mirror 258 Relay mirror 300 Lifting housing 400 Swing housing 500 Swing housing

Claims (21)

[Claims] 1. An optical disk device, comprising: an optical unit having a light source unit for emitting a light beam, the optical unit being a rotating arm that rotates along an optical disk mounted on a predetermined rotation axis, and opposing both surfaces of the optical disk. First and second arm tips respectively provided with an objective lens for converging a light beam on each surface of the optical disc; and a first and second light beam from the optical unit. A selecting means for selectively guiding the arm to one of the arm end portions. 2. The optical unit further comprises a light receiving unit for receiving a light beam reflected from the recording surface.
The rotating arm of the optical disk device for an optical disk according to claim 1, wherein: 3. A deflecting mirror is provided at each of the first and second arm tips, and at the arm tip selected by the selecting means, the deflecting mirror is centered on a predetermined axis on the mirror surface. The rotating arm of the optical disk device according to claim 1, wherein the swinging motion finely adjusts an incident angle of the light beam incident on the objective lens. 4. At least two lenses are provided between the deflecting mirror and the objective lens at each of the first and second arm distal ends, and the two lenses are used to adjust the swing axis of the deflecting mirror. The rotating arm of the optical disk device according to claim 3, wherein the entrance pupil of the objective lens has a conjugate relationship. 5. A deflecting mirror is provided between said light source unit and said selecting means, and said deflecting mirror is oscillated about a predetermined axis on a mirror surface of said deflecting mirror, so that the one selected by said selecting means is obtained. The rotating arm of the optical disk device according to claim 1, wherein an incident angle of the light beam with respect to the objective lens at an arm tip is finely adjusted. 6. The selecting means has a movable prism which can swing, and the movable prism emits light after the light from the optical unit is reflected at least once. With the light emitting surface, the position of the light emitting surface changes due to the swing, and when the light emitting surface is at the first position, the light beam from the optical unit is emitted toward the tip of the first arm,
5. The optical disk device according to claim 1, wherein the light beam from the optical unit is emitted toward the distal end of the second arm when the emission surface is at the second position. 6. Rotating arm. 7. The optical disk according to claim 6, wherein a swing axis of the movable prism coincides with an optical axis of a light beam incident on the entrance surface of the movable prism from the optical unit. The pivot arm of the device. 8. The movable prism has two reflecting surfaces,
The rotating arm according to claim 7, wherein the incident light is reflected twice to emit the incident light in a parallel and shifted position. 9. The optical unit according to claim 8, wherein the optical unit is disposed at an intermediate position between the first and second rotation arms in a direction of a rotation axis of the optical disk.
A rotating arm of the optical disk device according to 1. 10. The optical unit and the distal end of the second arm are arranged such that a light beam from the optical unit is guided to the distal end of the second arm, and the selecting means includes the optical unit and the second arm. 2. The movable mirror according to claim 1, further comprising: a movable mirror movable to a position that blocks an optical path connecting the distal ends, and a relay mirror that deflects a light beam from the movable mirror toward the distal end of the first arm. 5. The rotating arm of the optical disk device according to any one of 4. 11. A rotating arm according to claim 10, wherein said movable mirror deflects a light beam from said optical unit at a right angle when said movable mirror is in said optical path. 12. The relay mirror according to claim 11, wherein said relay mirror deflects a light beam from said movable mirror at a right angle.
A rotating arm of the optical disk device according to 1. 13. The optical disk drive according to claim 10, wherein the housing accommodating the optical unit and the distal end of the second arm are substantially at the same position in the direction of the rotation axis of the optical disk. A rotating arm of the optical disc device according to any one of the above. 14. A rotating arm according to claim 13, wherein said movable mirror is mounted on a movable table which moves in a direction of a rotation axis of said optical disk. 15. The selecting means has a movable housing which accommodates the optical unit and is provided movably with respect to the distal ends of the first and second arms, wherein the movable housing is at a first position. Sometimes, the light flux from the optical unit is guided to the first arm tip, and when the movable housing is at the second position, the light flux from the optical unit is guided to the second arm tip. 5. The rotating arm of the optical disk device according to claim 1, wherein: 16. A rotating arm according to claim 15, wherein said movable housing moves parallel to a direction of a rotation axis of said optical disk. 17. When the movable housing is at the first position, the movable housing and the distal end of the first arm are substantially at the same position in the direction of the rotation axis of the optical disk, and the movable housing is in the second position. 17. The rotating arm of the optical disk device according to claim 16, wherein, when in the position, the movable housing and the distal end of the second arm are substantially at the same position in the direction of the rotation axis of the optical disk. 18. The movable housing swings about a swing shaft provided between the tip ends of the first and second arms in the direction of the rotation axis of the rotation arm.
The rotating arm of the optical disk device according to claim 15, wherein: 19. The light source according to claim 1, wherein a swing axis of said movable housing and a light beam incident from said optical unit to said first and second arm tips are substantially orthogonal to each other.
9. A rotating arm of the optical disc device according to 8. 20. The oscillating axis of the movable housing and a light beam incident on the distal ends of the first and second arms from the optical unit are substantially parallel to each other.
A rotating arm of the optical disk device according to 1. 21. A rotating arm that rotates along a recording surface of at least one optical disk, a plurality of arm tips facing each surface of the at least one optical disk, and a light source that emits a light beam. An optical unit comprising: an optical unit; and a unit for selectively guiding a light beam from the optical unit to any of the plurality of arm tips, the rotating arm of the optical disc device.