JP2816033B2 - Optical disk drive - Google Patents

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,
In particular, the present invention relates to an optical disk device having a tracking actuator configured to support a mirror with a leaf spring.

Generally, an optical disk device is provided with a tracking actuator in order to accurately access a target track on a recording medium with a light beam.

[0003] In particular, a mirror is supported on the tip side of a leaf spring,
In a tracking actuator configured to change the direction of the mirror while changing the direction of the mirror while bending the leaf spring by the drive mechanism, the direction in which the gravity of the mirror acts on the leaf spring changes depending on the installation direction of the optical disk device, In some cases, the accuracy of tracking may be reduced, and effective improvement measures for this are desired.

[0004]

2. Description of the Related Art FIG. 7 is a perspective view showing an example of a tracking actuator in which a mirror is supported by a leaf spring.

In FIG. 1, a tracking actuator (hereinafter, simply referred to as an actuator) 1 includes a mirror 2 for reflecting light, a coil 3 for generating a force for driving the mirror 2, a magnet 4, and a plate for supporting the mirror 2. Spring 5
And a leaf spring supporting member 6 for fixing the leaf spring 5 to the optical disk apparatus main body (hereinafter simply referred to as the apparatus main body).

When a predetermined current is applied to the coil 3, the coil 3
By the action of the magnetic force between the coil 3 and the magnet 4, the coil 3
The mirror 2 supported by the leaf spring 5 is displaced in the direction indicated by the arrow A or B in FIG. Since the angle of the reflecting surface 2a changes due to the displacement of the mirror 2, the reflected light beam with respect to the incident light beam 7 changes, for example, from the light beam 8 to a light beam 8 'indicated by a dotted line, thereby performing a tracking operation.

In a conventional optical disk device, as shown in FIG. 8A, the surface of a leaf spring 5 is
The actuator 1 is provided in the apparatus main body in a direction parallel to the disk surface 11a. In this case, the light source 1
2 is reflected by the actuator 1, the tracking-adjusted reflection-side light beam 8 irradiates the disk surface 11 a on the back side of the optical disk 11, and the light source 12
The optical system from the optical disk 11 to the mounted optical disk 11 is simplified.

[0008]

Generally, an optical disk device is installed in a horizontal orientation (direction in which the optical disk 11 is mounted in a horizontal direction) as shown in FIG. ), There is a case where the optical disk 11 is installed in a vertically installed direction (a direction in which the optical disk 11 is mounted in a vertical direction).

As can be seen by comparing FIGS. 8A and 8B, the direction in which gravity is applied to the actuator 1 in the apparatus main body differs depending on the installation direction of the optical disk apparatus 10. That is, in the optical disc device 10 in the horizontal state shown in FIG. 8A, the direction perpendicular to the plane of the leaf spring 5 (Z direction)
8B, and in the optical disc device 10 in the vertically placed state shown in FIG. 8B, the gravity G is applied in a direction parallel to the plane of the leaf spring 5 (Z direction).

Generally, a leaf spring has a structure that is highly elastic and hard to bend with respect to a force in a plane direction, though it is elastically bent with respect to a force in a direction perpendicular to the plane. Therefore, the optical disk device 1
In a state where 0 is set horizontally, even when no driving force is applied to the mirror 2, the leaf spring 5 is bent by the gravity G applied to the mirror 2, and the mirror 2 is inclined. For this reason, the reflected light beam 8 reflected by the mirror 2 is also inclined from the beginning, and an aberration occurs in the optical system, which is not preferable.

On the other hand, in the conventional optical disk apparatus 10, when the apparatus main body is placed horizontally, a DC current as a bias current is always applied to the coil 3 so as to correct the inclination of the mirror 2 due to gravity G. The position of the mirror 2 was kept at the position of the regular zero point.

However, this DC current is applied to the optical disk drive 1
0, which is a disadvantageous factor especially for mounting on a small and portable computer device. Further, when the DC current is always supplied to the coil 3, the coil 3 generates heat and the coil 3 is disconnected. Also, this causes distortion on the reflection surface 2a of the mirror 2.

Further, in the case of a vertical installation, it is not necessary to supply a bias current, so that it is necessary to detect a difference between a horizontal installation and a vertical installation, and the configuration is complicated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides an optical disk device capable of performing a tracking operation with high accuracy irrespective of the installation direction of the optical disk device without employing a method of applying a bias current to a coil. The purpose is to do.

[0015]

The present invention for achieving the above objects resolving means for the] is, in the optical disk apparatus having the configuration of a tracking actuator for supporting the mirror at the tip of the leaf spring, the leaf spring, displaceable surfaces of the optical disk The arrangement is such that it is arranged in a direction perpendicular to the direction of insertion into the optical disk device body.

[0016]

The structure in which the plane of the leaf spring is perpendicular to the direction of insertion of the optical disk into the optical disk apparatus main body is such that the optical disk is mounted horizontally in the horizontal direction or the optical disk is mounted in the vertical direction. In any case of the vertical placement, the direction in which the gravity of the mirror acts on the leaf spring acts so as to be the plane direction of the leaf spring.

The leaf spring is easy to bend in a direction perpendicular to the plane,
It has high rigidity in the plane direction and is hardly bent. Therefore, regardless of whether the optical disk device is placed horizontally or vertically, the leaf spring is prevented from being bent by the action of gravity applied to the mirror.

[0018]

FIG. 1 is a perspective view of a first embodiment of the optical disk apparatus according to the present invention.

In FIG. 1, an optical disk device 20 is in a horizontal position in which an optical disk 11 is mounted in a horizontal direction. The optical disk device 20 is roughly composed of a fixed optical unit 21 serving as a light source and a tracking actuator described with reference to FIG. 1, a movable optical unit 22, a rail 23 on which the movable optical unit 22 moves, a spindle motor 24, and a chassis 25 as an optical disk device main body. The movable optical section 22 is further provided with a focus actuator 26 having an objective lens.

In the optical disk device 20 of the present embodiment, as shown in the figure, the surface of the leaf spring 5 of the actuator 1 is perpendicular to the insertion direction (Y direction in the figure) of the optical disk 11, and The mirror 2 is provided on the chassis 25 so that the mirror 2 is on the horizontal direction (X direction) side of the leaf spring 5, that is, with the actuator 1 shown in FIG. The components have been omitted). In this case, the reflection surface 2a of the mirror 2 is provided vertically.

FIG. 2 is a plan view of an optical system portion of the optical disk device 20.

As shown in FIG. 1, a light beam 30 emitted from the fixed optical section 21 is reflected by the reflecting surface 2a of the mirror 2, travels toward the movable optical section 22, and is provided in the movable optical section 22. The light is reflected by a mirror 27 at a right angle on a plane, and again reflected by a mirror 28 provided in the movable optical section 22.
The light beam 30 is redirected from the horizontal direction to the vertical direction (Z direction in FIG. 1) by being reflected by the last mirror 28, and irradiates the disk surface of an optical disk (not shown).

When the driving force acts on the mirror 2 by the coil and the magnet of the actuator 1, the leaf spring 5 and the mirror 2 supported by the leaf spring supporting member 6 are displaced on the XY plane as indicated by the dotted line. 2 (only the angular displacement of the mirror 2 is shown in FIG. 2, and the displacement of the leaf spring 5 in the bending direction is not shown). In this case, the light beam reflected by the mirror 2 becomes a light beam 30 like a light beam 31 indicated by a dotted line.
Go at an angle to. As a result, the mirror 28 passes through the mirror 27 in a substantially Z direction (a direction substantially perpendicular to the paper surface).
3 reflected toward the disk surface of the optical disk
1 'is a light beam which is inclined with respect to the optical axis of the objective lens 26 provided in the movable optical section 22, whereby the spot position of the light beam on the disk surface is displaced in the radial direction (Y direction) of the optical disk. In the optical disk device 20,
The tracking of the optical disk is performed by the operation of the optical system as described above.

FIG. 3 is a diagram for explaining the effect of the present invention.
3A and 3B are a perspective view showing a state where the optical disk device 20 shown in FIG. 1 is installed horizontally and a perspective view showing a state where the optical disk device 20 is installed vertically.

First, in the horizontal state shown in FIG. 3A, the surface of the leaf spring 5 provided perpendicular to the insertion direction (Y direction) of the optical disk 11 is in the direction of gravity G, which is the Z direction. And a configuration extending in the same direction as Leaf springs are generally
Although the structure is elastically bent with respect to a force in a direction perpendicular to the surface, the structure has high rigidity and is hardly bent with respect to a force in the surface direction. Therefore, in the optical disc device 20 in the horizontal state, even if the gravity G acts on the leaf spring 5 and the mirror 2 at the tip, the leaf spring 5 extending in the same direction as the gravity as described above does not bend downward. , The mirror 2 is securely supported. For this reason, in the optical disk device 20, it is not necessary to flow a bias current as in the related art in order to correct the position of the displacement of the mirror 2 due to the action of gravity.

As can be seen by comparing FIGS. 3A and 3B, the relationship between the horizontal and vertical positions of the optical disk device 20 is as follows.
The axis is the Y direction in the drawing, which is the insertion direction of the optical disk 11.
This is a relationship of a 90-degree rotation displacement. For this reason, the surface of the leaf spring 5, which is set as the XZ plane in the horizontal state, is arranged in the XZ plane direction as it is in the vertical state shown in FIG. As in the case of placing, it extends in the same direction as the direction of gravity G which is the Z direction. The mirror 2 is on the upper side (Z direction) of the leaf spring 5.

Therefore, the leaf spring 5 reliably supports the mirror 2 without bending downward due to the action of the gravity G even in the case of a vertical installation. For this reason, in the optical disk device 20, there is no need to supply a bias current to the coil 3 in the case of the vertical installation as in the case of the horizontal installation.

As described above, the optical disk device 20 of this embodiment
Then, regardless of whether the installation direction of the optical disk device 20 is horizontal or vertical, the surface of the leaf spring 5 of the actuator 1 always extends in the same direction as the direction of gravity G. Since the gravity G does not act on the plane of the leaf spring 5 in the vertical direction, the mirror 2 supported by the leaf spring 5 is not displaced by the action of the gravity G.

Therefore, in the optical disk device 20, the gravity G
, And only the driving force of the coil and the magnet and the elastic force in the direction perpendicular to the plane of the leaf spring 5 act purely on the mirror 2, so that accurate tracking can be performed.

FIG. 4 shows a second embodiment of the optical disk apparatus according to the present invention.
It is a perspective view of an Example.

In the figure, the optical disk device 40 has the same configuration as the optical disk device 20 of the first embodiment except for the configuration of the optical system, and generally includes a fixed optical unit 41 serving as a light source,
7, the tracking actuator 1, the movable optical unit 42, and the rail 43 on which the movable optical unit 42 moves.
, A spindle motor 44, and a chassis 45.

In the optical disk device 40 of this embodiment, similarly to the optical disk device 20, the surface of the leaf spring 5 is
Although the actuator 1 is provided so as to be perpendicular to the insertion direction (Y direction in the drawing) of the
Is provided at one end on the upper side (Z direction) of the leaf spring 5 (in the optical disc device 20, it is provided on the horizontal side of the leaf spring 5).

FIG. 5 is a side view of the optical system of the optical disk device 40.

As shown in FIG. 3, in the optical disk device 40, a mirror 46 is provided in front of the actuator 1, and a light beam 50 emitted from the fixed optical
The movable optical portion 42 is reflected and proceeds in the order of 6, 2, 47, respectively.
Objective lens 4 provided in the focus actuator
The light is irradiated onto the disk surface 11a of the optical disk 11 through the optical disk 8.

When the driving force acts on the mirror 2 by the coil of the actuator 1 and a magnet (not shown), the mirror supported by the leaf spring 5 and the leaf spring supporting member 6 similarly to the optical disc apparatus 20 described above. 2 is displaced on the YZ plane as indicated by the dotted line (only the angular displacement of the mirror 2 is shown in FIG. 5, but the displacement of the leaf spring 5 in the bending direction is not shown). In this case, mirror 2
The light ray reflected at travels at an angle with respect to the light ray 50 like a light ray 51 shown by a dotted line. Therefore, mirror 4
The light beam 51 ′ reflected by 7 becomes a light beam inclined with respect to the optical axis of the objective lens 48, whereby the spot position of the light beam on the disk surface is displaced in the radial direction (Y direction) of the optical disk 11. In the optical disk device 40, tracking of the optical disk is performed by the operation of the optical system as described above.

FIGS. 6A and 6B are a perspective view showing a state where the optical disk device 40 shown in FIG. 4 is installed horizontally and a perspective view showing a state where the optical disk device 40 is installed vertically.

As shown in FIG. 6A, the optical disk device 4
When 0 is set horizontally, the installation direction of the actuator 1 is set to the optical disc device 20 in the vertically set state shown in FIG.
The surface of the leaf spring 5 extends in the same direction as the direction of gravity G, as in the optical disk device 20, in the same direction as the actuator 1 provided therein. Therefore, the leaf spring 5 reliably supports the mirror 2 without bending even when the gravity G acts. Therefore, in the optical disk device 40, similarly to the optical disk device 20, there is no need to supply a bias current as in the related art, in order to correct the position of the displacement of the mirror 2 due to the action of gravity.

As shown in FIG. 6B, when the optical disk device 40 is placed vertically, the same as the actuator 1 provided in the optical disk device 20 shown in FIG. The leaf spring 5 is perpendicular to the insertion direction of the optical disk 11, and the mirror 2 is provided at one end of the leaf spring 5 on the horizontal direction. Accordingly, even in this case, as described above with reference to FIG. 3A, the leaf spring 5 provided with the surface extending in the same direction as the direction of the gravity G supports the mirror 2 without bending downward. Mirror 2 is gravity G
Is prevented from being displaced by the influence of the above, and the conventional bias current is not required.

As described above, the optical disk device 4 of the second embodiment
0, as in the optical disk device 20 of the first embodiment,
The mirror 2 is prevented from being displaced by the action of the gravitational force G, regardless of whether the installation direction is horizontal or vertical, and only the driving force of the coil and the magnet and the elastic force of the leaf spring 5 are reduced. Since the mirror 2 is displaced by acting purely on the mirror 2, accurate tracking can be realized.

In addition to the direction of the actuator 1 in the optical disk devices 20 and 40, if the actuator 1 is mounted on the main body of the device so that the surface of the leaf spring 5 is perpendicular to the insertion direction of the optical disk 11, the influence of gravity can be obtained. Thus, an optical disk device capable of performing accurate tracking without receiving a signal can be realized. Further, according to the optical disk device of the present invention, in addition to the horizontal and vertical installations as described above, even if the optical disk device is installed in an oblique direction between the horizontal and vertical installations, good tracking can be performed without being affected by gravity. It can be carried out.

[0041]

As described above, according to the present invention, the tracking actuator can be affected by gravity regardless of the horizontal or vertical installation direction of the optical disk device with a simple structure that only takes into account the installation direction of the actuator. Can be prevented. As a result, accurate tracking can be performed regardless of whether the optical disk device is placed horizontally or vertically. In addition, since a bias current that has been applied to the coil in order to correct the displacement of the mirror due to gravity becomes unnecessary, the power consumption of the optical disc device can be suppressed, and the tracking actuator caused by the heat generation of the coil is eliminated. Can be prevented from occurring.

Since there is no need to detect the installation state of the apparatus, that is, whether the apparatus is placed vertically or horizontally, the apparatus configuration can be simplified.

[Brief description of the drawings]

FIG. 1 is a perspective view of a first embodiment of an optical disk device according to the present invention.

FIG. 2 is a plan view of an optical system portion in the optical disk device shown in FIG.

FIG. 3 is a diagram for explaining the effect of the present invention, and is a perspective view showing a state where the optical disk device shown in FIG. 1 is installed horizontally or vertically.

FIG. 4 is a perspective view of a second embodiment of the optical disk device according to the present invention.

5 is a side view of an optical system in the optical disk device shown in FIG.

6 is a diagram for explaining the effect of the present invention, and is a perspective view showing a state where the optical disk device shown in FIG. 4 is installed horizontally or vertically.

FIG. 7 is a perspective view of an example of a tracking actuator in which a mirror is supported by a leaf spring.

FIG. 8 is a perspective view of an example of a conventional optical disk device.

[Explanation of symbols]

 Reference Signs List 1 tracking actuator 2, 27, 28, 46, 47 mirror 2a reflecting surface 3 coil 4 magnet 5 leaf spring 11 optical disk 20, 40 optical disk device 21, 41 fixed optical unit 22, 42 movable optical unit 24, 44 spindle motor 25, 45 Chassis 30, 31, 31 ', 50, 51 rays

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G11B 7/08-7/095 G02B 7/00 G02B 7/18-7/24 G02B 26/10-26 / 10 109

Claims (1)

(57) [Claims] 1. An optical disc device having a tracking actuator (1) configured to support a mirror (2) at the tip of a leaf spring (5), wherein a surface on which the leaf spring (5) can be displaced is an optical disc (1).
1) Insertion direction (Y) into the optical disk device main body (25)
An optical disc device characterized by being arranged in a direction perpendicular to the optical disc.