JP2003099966A - Optical disk apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such problems that an optical disk apparatus itself is made too large because the mechanism for correcting the tilt of an optical disk is made large, in a conventional optical disk apparatus, and that high accuracy is required for the tilt correcting mechanism. SOLUTION: In the optical disk apparatus, a guide rail inclining axis member which is the inclined axis with respect to guide rail axes passing through the centers of both end surfaces of guide rails 52a and 52b and which is for rotating the guide rails 52a and 52b around the inclined axis is provided, and the guide rails 52a and 52b provided with the guide rail inclining axis member are rotated, according to a detected tilt amount.

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 for recording or reproducing information on an information recording medium such as an optical disk.

[0002]

2. Description of the Related Art As is well known, compact discs (C
As represented by D) and a laser disk (LD), an optical disk device that reproduces information by using laser light is widely used. Recently, optical disk devices have come to be used as storage devices for computers.

When information is recorded / reproduced on / from an optical disk, a laser beam is focused on the surface of the optical disk using an objective lens to form a spot. The smaller the size of this spot, the higher the recording density for the optical disc.

In order to increase the recording density of information that can be recorded on an optical disk, it is effective to shorten the wavelength of the laser beam used and increase the numerical aperture (hereinafter referred to as NA) of the objective lens. It is also important to make the optical axis of the objective lens as vertical as possible with respect to the optical disc and suppress coma aberration caused by tilting the objective lens. The angle at which coma is generated is proportional to the wavelength and inversely proportional to the cube of NA. Therefore, as the recording density is increased, the allowable angle deviation becomes smaller and the component accuracy and the assembly accuracy must be improved. However, an optical disc is generally manufactured by injection molding, and distortion such as warping is inevitably generated, and the optical disc surface is inclined. In addition, the weight of the optical disc itself warps. When the tilt of the optical disk surface is divided into two components, the circumferential direction and the radial direction of the disk, the tilt due to the circumferential disk is the rotation synchronization component of the optical disk, and this correction requires a high-speed drive device. On the other hand, the tilt caused by the disk in the radial direction has a component that is a function of the radial position of the disk in addition to the rotation synchronization component of the optical disk, and the component that is a function of the radial position of the disk is corrected. Even by itself, the amount of coma generated is considerably improved.

Therefore, conventionally, an optical disk device having an actuator capable of tilt correction in the radial direction as shown in FIG. 9 having a drive device for correcting the tilt in the disk radial direction has been devised. FIG. 9 is a schematic diagram showing a configuration of main components of an optical disc device including a conventional tilt correction device.

In FIG. 9, an optical disk 101 is a turntable 104 mounted on a spindle motor 103.
It is mounted on and rotates. The spindle motor 103 is attached to the base 102. Objective lens 116
Is smaller than the disc 101 in the tolerance of the tilt of the optical axis of the objective lens 116. The objective lens 116 is mounted on the objective lens holder 114 of the objective lens driving device 112.
The shaft 115 in the objective lens driving device is inserted into the hole provided in the objective lens holder 114, and the objective lens holder 114 moves in the direction of the shaft 115, so that the objective lens 116
The focus position can be adjusted to a desired track position on the optical disc 101 by adjusting the focus of the optical disc 101 to the optical disc 101 and rotating the optical disc 101 about the axis 116. The base 113 of the objective lens holder 114 is coupled to the carriage 105. An optical element such as a laser diode or a light receiving element (not shown) and a sensor for detecting the inclination of the optical disk 101 with respect to the carriage 105 (not shown) are also mounted on the carriage 105. The carriage 105 includes guide rails 106a and 106b fixed on the sub base 109.
Is supported by the optical disc 101 so as to be movable in the radial direction. By driving the feed screw motor 108 that drives the feed screw 107, the carriage 105
Moves. The objective lens driving device is positioned on the carriage 105 so that the extension of the locus of the center of the objective lens 116 passes through the rotation center of the turntable 104. The sub base 109 includes the shafts 111a and 111b.
It is rotatably attached to the base 102 by and is parallel to the circumferential direction of the sub-base rotation motor 110. Based on the signal from the tilt sensor, the sub-base rotation motor 110 is controlled so that the optical axis of the objective lens 116 corrects the tilt of the optical disc 101.

As described above, in the conventional optical disk device, the base has a double structure of the base 102 and the sub base 109, and when they are arranged horizontally as shown in FIG. 9, a space is required in the width direction. Further, it is possible to make it double in the vertical direction of the paper surface, but in this case as well, a space is required. Furthermore, since this large sub-base rotates, a space for moving the sub-base is required above and below. Generally, various components such as an electronic circuit board, a base support mechanism, a housing, and a loading mechanism, which are not shown, must be inserted in the optical disc device. There was a problem that the whole thing had to be enlarged.

Further, since a large moving part is moved, a large driving force is required, and there is a problem that responsiveness and power consumption increase due to an increase in energy required for driving.

In addition, as described in Japanese Patent Application Laid-Open No. 2000-149278, tilt correction is performed by moving a guide rail. However, tilt correction in the tangential direction (circumferential direction) is described. 2 spacing adjustment mechanism for
Since it is installed side by side with the guide rail of the book, it is necessary to widen the width of the optical disk device. Furthermore, when the mechanism automatically performs tilt correction during operation, it is necessary to further provide a driving unit such as a motor, and thus it is necessary to further widen the lateral width of the optical disc device, which results in a larger optical disc device. There was a problem that was invited.

Further, if the precision or rigidity of the gap adjusting mechanism for moving the guide rail itself is low, the height of the guide rail changes in inclination, so that the gap adjusting mechanism requires high precision. However, since the guide rail is supported by the large swing mechanism, it is difficult to manufacture the guide rail with sufficient accuracy and large rigidity.

[0011]

As described above, the conventional optical disc device has a problem that the optical disc device itself becomes large because the mechanism for correcting the tilt of the optical disc becomes large. .

Further, there is a problem that the tilt correction mechanism requires high accuracy.

An object of the present invention is to solve the above-mentioned problems, to downsize the tilt mechanism, and to provide an optical disk device which does not require high precision for the tilt mechanism.

[0014]

In order to achieve the above object, in an optical disc apparatus of the present invention, two guide rails for moving an optical head in the radial direction of the optical disc and the two guide rails are provided. A guide rail rotating unit that rotates in synchronization with the inclined axis and a tilt detecting unit that detects tilt of the optical disc are provided, and the guide rail has a guide rail shaft extending in a radial direction of the optical disc. The guide rail is rotatably supported by an axis tilted with respect to the guide rail axis, and the guide rail rotating means rotates the guide rail in accordance with the tilt amount detected by the tilt detecting means. Characterize.

Since the tilt of the optical disk can be corrected only by rotating the guide rail which is rotatably supported by the shaft tilted with respect to the guide rail axis extending in the radial direction of the optical disk, the apparatus for tilt correction can be used. It is possible to reduce the size of the device without increasing the size.

Further, the optical head includes two objective lenses, and the axes of the guide rails inclined with respect to the guide rail axes of the respective guide rails intersect the respective guide rail axes. It is characterized in that the intersecting positions are provided at different positions on the two guide rails.

Then, the amount of inclination of the two objective lenses in the circumferential direction of the optical disc is reduced, and the coma aberration is thereby reduced, so that recording or reproduction on a higher density optical disc becomes possible.

Further, two guide rails for moving the optical head in the radial direction of the optical disk and a guide rail axis provided on both end faces of the guide rail and passing through the center of both end faces of the guide rail are inclined. A guide rail tilting shaft member for rotating the guide rail around the tilted shaft, and the two guide rails provided with the guide rail tilting shaft member in synchronization with each other around the tilted shaft. A guide rail rotating means for rotating the guide rail and a tilt detecting means for detecting the tilt of the optical disc, and the guide rail rotating means rotates the guide rail according to the tilt amount detected by the tilt detecting means. Is characterized by.

Since the tilt of the optical disk can be corrected only by rotating the guide rail provided with the guide rail tilt axis member, the apparatus does not become large for tilt correction, and the apparatus can be made compact. You can

Further, the optical head includes two objective lenses, each of the tilted axes of the two guide rails intersects with each of the guide rail axes, and the intersecting position is the above-mentioned position. The feature is that the two guide rails are provided at different positions.

Then, the amount of inclination of the two objective lenses in the circumferential direction of the optical disc is reduced, and the coma aberration is reduced by this, so that recording or reproduction on a higher density optical disc becomes possible.

Further, the guide rail rotating means is
It is characterized in that a cam mechanism for rotating the two guide rails around the inclined axis at a predetermined angle is provided.

Then, the cam mechanism enables tilt correction only by rotating the cam, and power consumption can be reduced as compared with the case where a magnetic circuit is used.

Further, two guide rails for moving the optical head in the radial direction of the optical disk and one of the two guide rails are provided on both end surfaces of the guide rail, and the center of the both end surfaces of the guide rail is provided. A guide rail tilting shaft member which is tilted with respect to a guide rail shaft passing therethrough and which rotates the guide rail around the tilted shaft;
The guide rail is provided on both end surfaces of the other guide rail of the two guide rails, has an axis eccentric with respect to the guide rail axis, and rotates the guide rail around the eccentric axis. A core member and a first rail for rotating the guide rail tilt axis member around the tilt axis.
The guide rail rotating means, the second guide rail rotating means for rotating the guide rail eccentric member around the eccentric axis, and the tilt detecting means for detecting the tilt of the optical disc. The guide rails are rotated by the first guide rail rotating means and the second guide rail rotating means according to the tilt amount detected by.

Then, the radial (radial) direction tilt and the tangential (circumferential) direction tilt of the optical disc are guided by a guide rail having a guide rail tilt axis member and a guide rail having a guide rail eccentric member. Since the corrections can be made independently, more accurate tilt correction is possible.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing the structure of the main parts of the optical disk device according to the first embodiment of the present invention, and FIG. 2 is a plan view showing only the main parts for explaining the principle of the tilt mechanism. .

In FIG. 1, the optical head 8 provided with the objective lenses 14 and 15, the objective lens actuator 55 for driving the optical head 8 in the focusing direction and the tracking direction, and the carriage 7 are shown separately. There is. Note that, of the objective lenses 14 and 15, for example, the objective lens 14 is an objective lens that does not require tilt correction in the disk radial direction, and the wavelength of the laser light passing through the objective lens 14 is
780 nm (for CD-ROM disc reproduction), the objective lens 15 is an objective lens that requires tilt correction in the disc radial direction, and the wavelength of the laser light passing through the objective lens 15 is 650 nm.
(For DVD disc playback).

The optical head 8 is arranged on the turntable 5 and is for recording or reproducing information on or from an optical disk (not shown) rotated by the spindle motor 3, and is mounted on the carriage 7. The feed mechanism for moving the carriage 7 in the radial direction of the optical disc is a carriage feed screw drive motor 53 fixed to the base 2 to which the spindle motor 3 is fixed, and a carriage feed screw rotated by the carriage feed screw drive motor 53. 5
4, the carriage feed screw 54 is engaged with teeth (not shown) provided on the carriage 7, and the carriage feed screw drive motor 53 rotates to move the carriage 7 freely in the disc radial direction. it can.

A light beam emitted from a semiconductor laser (not shown) of the optical head 8 is reflected by an optical disk (not shown), returns to the optical head 8 again, and is detected by a photodetector (not shown). However, if the optical disc has a tilt, the light beam from the optical head 8 is detected at a position deviated from the desired detection position. By detecting this deviation with the optical head 8, the tilt amount of the optical disc can be detected. The optical head 8 includes a light emitting unit 2010 and a light receiving unit 20 as a tilt detecting unit for detecting tilt.
Equipped with 20. The tilt detecting unit is configured to irradiate the optical disc with a light beam from the light emitting unit 2010 and receive and detect the reflected light from the optical disc by the light receiving unit 2020. Light receiving section
In 2020, the tilt signal obtained from the light beam reflected by the optical disc is averaged by the low-pass filter to obtain the average tilt amount on the radius of the optical disc irradiated with the light beams from the objective lenses 14 and 15. To be
This tilt amount is 0 when the light beam emitted from the optical head 8 is perpendicularly incident on the optical disc, is substantially proportional to the tilt amount of the optical disc, and is a signal whose sign is determined by the tilt direction. The drive current supplied to the tilt motor 12 is determined by a control circuit (not shown) based on this tilt amount. Rotation of the tilt motor 12 causes a tilt mechanism described later to operate.

The light emitting unit 2 for obtaining the tilt amount shown in FIG.
Although the example in which the optical head 8 is provided with the 010 and the light receiving unit 2020 is shown,
The present invention is not limited to this, and may be provided on the carriage 7, for example, and the mounting position is not limited as long as the tilt amount can be detected.

Furthermore, it is not necessary to directly detect the tilt amount, and it suffices to have drive signal generating means for rotating the tilt motor 12. This is because, for example, when the tilt amount changes with respect to the optical disc, coma aberration occurs,
As a result, the jitter of the detection signal increases and the error rate deteriorates. Utilizing this, the tilt motor 12 may be rotated by a certain amount, a change in the jitter or the error rate may be detected, and a tilt detecting means may be used that finds a rotational position where the jitter or the error rate is minimized.

Here, the characteristic portion of FIG. 1 will be described in detail with reference to FIG.

In FIG. 1, tilt correction is performed by tilting the carriage 7. For that purpose, the tilted guide rails 52a and 52b are used. For convenience of explanation, FIG. 2 (a) shows the carriage 7 and the tilted guide rail 5 in FIG.
2a and 52b only are shown, and FIG. 2 (b) shows only the guide rails 52a and 52b with tilt axes.

The tilted guide rails 52a and 52b include guide rail portions 520a and 520b having large cylindrical surfaces and a tilted shaft member 521.
a, 522a, 521b, 522b, which are integrally formed.

Here, as shown in FIG. 1, the tilted guide rail 52a is a main shaft and fits into a circular sliding hole provided in the carriage 7, and the tilted guide rail 52b is a sub shaft. , Fits into the groove provided in the carriage 7. Therefore, the tilted guide rail 52a, which is the main shaft, restrains the degree of freedom of the posture of the carriage 7 except the rotational freedom about the axis of the cylindrical surface of the guide rail portion 520a of the tilted guide rail 52a. A certain tilted guide rail 5
The remaining rotational degree of freedom is constrained by 2b, and the posture is uniquely determined.

2A, the tilt correction angle when viewed from the axial direction of the spindle motor 3 is zero, that is, the optical axes of the objective lenses 14 and 15 are oriented in the direction perpendicular to the paper surface of FIG. 2A. The state of the guide rails 52a and 52b with the tilt axis is shown when the tilt axis is attached. The guide rails 52a and 52b with the tilt axis are guide rail portions having a cylindrical guide surface for guiding the carriage 7.
It has 520a and 520b and a guide rail rotation axis that is tilted around the axis perpendicular to the paper surface of Fig. 2 (a) with respect to the axis of the guide surface. This is a guide rail axis that passes through the center of both end surfaces of the guide rail portions 520a and 520b and becomes the center of the guide surface (shown by the dotted line in FIG. 2).
And tilt shaft members 521a, 522a, 521b, 522b are provided in order to make the shaft tilted with respect to the guide rail shaft, and the rotary shaft by the tilt shaft members 521a, 522a and 521b, 522b is a guide rail rotary shaft. (Indicated by a chain line in FIG. 2).

In FIGS. 1 and 2, the guide rail rotating shafts are tilted in the same direction as the two guide rails 52a and 52b with tilt axes. Further, in FIG. 1, the tilted guide rails 52a and 52b are supported rotatably around the axis of the guide rail rotation axis with respect to the base 2.

The tilted guide rails 52a and 52b may be hollow or both end surfaces may be conical. Further, the columnar guide rails may be simply tilted with respect to the guide rail rotation axis without providing the tilt shaft members 521a, 522a and 521b, 522b.

Here, the carriage 7 by the rotation of the tilted guide rails 52a and 52b around the guide rail rotation axis.
The movement of will be described with reference to FIG.

FIG. 3 is a schematic view of the carriage 7 as seen from the direction A (side surface of the carriage 7) of FIG. The carriage
7 rotates about the guide rail rotation axis (the one-dot chain line in the drawing).

FIG. 3B shows a state where the inclination of the carriage 7 is zero. As shown in Fig. 3 (a), when the guide rail rotation axis is rotated in the α direction from the state of Fig. 3 (b), the carriage
The arrow portion of 7 moves to the upper side of the paper surface, so that the arrow portion of the carriage 7 moves toward the optical disc 1,
The outer peripheral side of the carriage 7 in the radial direction of the optical disc 1 is in a state of approaching the optical disc 1.

Contrary to FIG. 3A, as shown in FIG. 3C, when the carriage 7 is rotated around the guide rail rotation axis in the β direction from the state shown in FIG. 3B, the carriage 7 moves. The arrowed portion moves upward in the plane of the drawing, whereby the arrowed portion of the carriage 7 moves in a direction approaching the optical disc 1, and the inner circumferential side of the carriage 7 in the radial direction of the optical disc 1 approaches the optical disc 1.

Then, the guide rails 52a, 52 with the tilt axis are provided.
When b is rotated in the same direction, as shown in FIG. 2 (a), the carriage 7 moves around the line connecting the intersections of the guide rail shafts and the guide rail rotation shafts of the guide rails 52a and 52b with tilt shafts. Rotate.

Therefore, the position and direction of the radial tilt rotary shaft can be designed with great freedom by changing the position of the intersection between the guide rail rotary shaft and the guide rail rotary shaft. Therefore, in extreme terms, the intersection may be located outside the tilted guide rails 52a and 52b. As a result, the amount of tilt of the two objective lenses 14 and 15 in the circumferential direction of the optical disc is reduced, and the coma aberration is reduced, so that recording or reproduction on a higher density optical disc can be performed with a thinner and smaller tilt correction. It can be realized by a mechanism. It should be noted that, for details of the reduction of the inclination in the circumferential direction due to the arrangement of the two objective lenses, see JP-A-2001-184688
A detailed description is given in the publication, so the description thereof will be omitted.

Although the radial tilt rotation axis is tilted with respect to the guide rail axis about the axis perpendicular to the plane of the drawing as shown in FIG.
It is also possible to orient the Y-axis direction (perpendicular to the guide rail axis and perpendicular to the spindle motor axis) in the figure (a) and simply incline to the guide rail axis direction.

Returning to FIG. 1 again, the guide rail 52 with the tilt axis is provided.
The tilt correction operation by a and 52b will be described.

In FIG. 1, the guide rails 52a, 5 with tilt axis are provided.
2b as a tilt mechanism, the two flat cams 50a, 5a
It is rotated in synchronization by the mechanism using 0b. A tilt motor 12 is fixed to the base 2,
Thereby, the tilt mechanism described later is operated. A worm gear 60 (tooth is omitted in the figure) is attached to the rotation shaft of the tilt motor 12. The worm gear 60 is fitted to the wheel gear portion (tooth is omitted in the figure) on the upper surface of the gear 59 rotatably attached to the base 2, and
The lower spur gear (tooth is omitted in the drawing) meshes with the spur gear above the gear 58 (tooth is omitted in the drawing) rotatably attached to the base 2, and the spur gear below the gear 58 (tooth is omitted). The tooth is omitted in the figure) meshes with a spur gear (the tooth is omitted in the figure) below the plane cam 50a rotatably attached to the base 2. Furthermore, the lower spur gear of the flat cam 50a meshes with the lower spur gear (tooth is omitted in the figure) of the flat cam 51a rotatably attached to the base 2. On the other hand, cam levers 56a and 56b are attached to the ends of the tilted guide rails 52a and 52b, respectively, and cam followers 51a and 51b are attached to the cam levers 56a and 56b by screwing them from the upper surface of FIG. Has been. The lower surfaces of the cam followers 51a and 51b are in contact with the cam surfaces of the flat cams 50a and 50b. Cam lever 5
Since springs (not shown) are attached to the bases 6a and 56b, the cam followers 51a and 51b
b is pressed against the flat cams 50a and 50b. The cam followers 51a and 51b are cam levers 56a and 56b.
Since the cam followers 51a and 51b are rotated, the guide rails 52a and
Adjustment can be performed during assembly so that there is no tilt angle in the initial state of 2b.

As described above, according to the configuration of FIG. 1, when the tilt motor 12 is rotated, the power is transmitted by the gears and the flat cams 50a and 50b rotate, whereby the guide rail 52a with the tilt axis is rotated. , 52b rotate to realize the tilting operation.

The advantage of this structure is that there is a large degree of freedom in the design of the position and orientation of the radial tilt rotation shaft, the optimum rotation shaft can be set, and the size of the components of the radial tilt correction mechanism is small, which is extremely saved. It is a space. As a result, the radial tilt rotation axis can be set in the vicinity of the center of the optical disc, so that the amount of expansion by the tilting operation of the focus movable range of the objective lens actuator 55 can be small. In the present embodiment,
The guide rails 52a and 52b with tilt axes have a guide rail rotation axis that is physically tilted. It goes without saying that the same effect can be obtained if possible. This may for example be supported by torsion springs instead of bearings. Alternatively, the guide rail itself may have a columnar structure, and a hole having a substantially hemispherical surface may be provided at a position displaced from the center of both end faces thereof, and a point pin having a spherical tip fixed to the base side may be fitted into the hole to provide a point support structure. I do not care. Further, the two guide rails 52a and 52 with tilt axes are provided.
The synchronous rotation means of b is not limited to that shown in FIG. Further, the flat cams 50a and 50b are cams having three flat portions, but continuously changing cams without flat portions may be used.

The guide rails 52a, 52b with tilt axis are provided.
With the use of, the carriage 7 rotates about an axis parallel to the rotation axis of the spindle motor 12, and the carriage 7 slightly moves in the Y direction in the figure. If this amount is too large, the carriage feed gear 54 and the fitting portion of the carriage 7 may be overloaded. Further, depending on the configuration of the optical head, such movement may prevent proper recording / reproduction of information. For this reason, the tilted guide rails 52a, 52
For b, the angle between the guide rail shaft and the guide rail rotation shaft may be designed so that the rotation angle from the state where the tilt correction amount is 0 is within approximately ± 30 degrees. In this range, the rotation angle of the guide rail and the tilt correction angle are substantially proportional to each other, and the control becomes easy. Also, the amount of movement in the Y direction is smaller than the amount of tilt.

FIG. 4 shows the guide rails 52a with tilt axis of FIG.
FIG. 32 is a perspective view showing a schematic configuration of an optical disc device realized without using the flat cams 50a and 50b as a synchronous rotation mechanism of 52b.

In FIG. 4, a guide rail 52 with a tilt axis is provided.
Guide rail rotation shafts 521a and 521b are provided at the ends of a and 52b.
Wheel gears 82a, 82b centered around (tooth omitted in the figure)
Is installed. A tilt motor 12 is fixed to the base 2, and a rotation shaft of the tilt motor 12 is a worm gear 81 (tooth is omitted in the drawing).
It meshes with 2a and 82b. As a result, when the tilt motor 12 rotates, the two guide rails 5 with tilt axes are provided.
2a and 52b rotate synchronously around the guide rail rotation axis.

Next, an optical disc device according to the second embodiment of the present invention will be described with reference to FIGS.

FIG. 5 is a plan view showing the main structure in the state where the tilt correction angle is 0, and FIG. 6 is a perspective view showing the synchronous rotation mechanism portion of the guide rails 52a and 52b with tilt axes. It should be noted that, except for the synchronous rotation mechanism part of the guide rails 52a and 52b with tilt axis located on the right side of the paper surface of FIG.
This corresponds to the plan view of the optical disk device shown in 1. Therefore, the same parts as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted.

In FIGS. 5 and 6, a big difference from FIG. 1 is that the lift lever 70 is used and the guide rail 5 with the tilt axis is used.
2a and 52b are synchronously rotated. Base 2
A worm gear (tooth is omitted in the figure) 60 is attached to the tilt motor 12 fixed to the gear, and meshes with a wheel gear (tooth is omitted in the figure) below the plane cam 72 rotatably supported by the base 2. ing. On the other hand, base 2
A rotary shaft 71 is attached to the lift lever 70, and the lift lever 70 is rotatably supported by this shaft. A cam follower 51c is screwed into the lift lever 71, and the lower end of the cam follower 51c contacts the upper surface of the flat cam 72. The cam levers 56a and 56b are the cam followers 51.
a and 51b are pressed by a spring (not shown) in the direction of pressing the lift lever 70. By this power,
A force for pressing the cam follower 51c against the upper surface of the flat cam 72 is generated in the lift lever 70. With the above mechanism, the cam followers 51a, 51b, 51c are all in stable contact. Then, when the tilt motor 12 rotates, the lift lever 70 is rotated by the flat cam 72, whereby the cam levers 56a and 56b are lifted. In the component arrangement of this embodiment, the tilted guide rails 52a and 52b rotate in opposite directions. Therefore, the directions of the guide rail rotating shafts of the tilted guide rails 52a and 52b are the same as those of the tilted shaft members 521a, 522a, 521b, and 5 in FIG.
Not parallel like 22b. In FIG. 5, the guide rail rotation axis of the tilt-axis guide rail 52a rotates counterclockwise with respect to the axis perpendicular to the paper surface, but the guide rail rotation axis of the tilt-axis guide rail 52b rotates with respect to the paper surface vertical axis. It is rotating clockwise. The tilted guide rails 52a and 52b are fixed by the guide rail rotating shaft, and by rotating around the guide rail rotating shaft,
Carriage 7 provided on guide rails 52a, 52b with tilt axis
Performs the tilt correction by performing the movement shown in FIG.

An optical disk device according to the third embodiment of the present invention will be described with reference to FIGS. 7 and 8.

FIG. 7 is a plan view showing a guide rail for explaining the principle of the tilt mechanism of this embodiment.
Further, FIG. 8 is a perspective view showing a schematic configuration of an optical disk device using the guide rail of FIG. Note that the major difference between FIG. 7 of the present embodiment and FIG. 2 of the first embodiment is that the guide rails 52a, 5a with tilt axis shown in FIG. 2 (b) are provided.
In 2b, the tilted guide rail 52b is changed to an eccentric guide rail 1000b.

The eccentric guide rail 1000b is a guide rail shaft (dotted line in the drawing), similar to the tilted guide rail 52b.
And the guide rail rotating shaft (indicated by a dashed-dotted line in the drawing) at a position eccentric to the guide rail shaft, the eccentric member 1 is provided on both end surfaces of the guide rail portion 1003b.
001b and 1002b are formed integrally with the guide rail portion 1003b. FIG. 8 shows an optical disk device incorporating the eccentric guide rail 1000b of FIG. Note that FIG. 8 is basically the same as FIG.
Corresponding to the plan view of the optical disk device shown in FIG.

8 is different from FIG. 4 in that a tilt motor 1200 is newly provided and the worm gear 81 is replaced by a worm gear 81.
It is divided into 81a and 81b, and the rotation of the tilt motor 1200 is transmitted to the wheel gear 82b via the worm gear 81b. As a result, the eccentric guide rail 1000b drives the carriage 7 in the direction perpendicular to the paper surface of FIG. Then, the drive current to the tilt motor 1200 is controlled according to the tilt amount in the tangential direction (circumferential direction) of the optical disc obtained by the light receiving unit of the tilt detecting unit. In addition to the tilt motor 1200, tilt correction of the tilt axis guide rail 52a by the tilt motor 12 can be performed at the same time.

Therefore, the tilt correction in the radial direction and
Since tilt correction in the tangential direction can be performed independently, more accurate tilt correction can be performed.

In the above-described embodiment of the invention, the mechanism that requires precision is only the portion that holds the guide rail rotating shaft, and this portion simply rotates the guide rail rotating shaft relative to the base. Since it is only held, a simple mechanism is sufficient, and therefore accuracy and rigidity can be easily ensured. The accuracy of the mechanism that rotates the other guide rails only affects the accuracy of the tilt fluctuation amount, but a tilt correction range of about ± 0.5 degrees is sufficient. If the angle is ± 30 degrees, 1/60 of the guide rail rotation angle becomes a tilt variation amount, and the error of the guide rail rotation angle also becomes 1/60.
Therefore, high precision is not required for the guide rail rotating mechanism. In this way, in this mechanism, the location where accuracy is required can be a local and simple structure,
There is also an advantage that the manufacturing cost is low.

[0063]

As described above, according to the present invention,
It is possible to reduce the size of the tilt mechanism and realize an optical disk device that does not require high precision for the tilt mechanism.

[Brief description of drawings]

FIG. 1 is a perspective view showing a schematic configuration of an optical disc device according to a first embodiment of the present invention.

FIG. 2 is a plan view showing only main parts for showing the principle of the tilt mechanism of FIG.

FIG. 3 is a diagram showing the movement of the carriage due to the rotation of the tilted guide rails 52a and 52b around the guide rail rotation axis.

FIG. 4 is a perspective view showing a schematic configuration of an optical disc device showing another configuration of the synchronous rotation means of the guide rails 52a and 52b with tilt axes in FIG.

FIG. 5 is a plan view showing a schematic configuration of an optical disc device according to a second embodiment of the present invention.

6 is a perspective view showing a synchronous rotation mechanism portion of the tilted guide rails 52a, 52b of FIG.

FIG. 7 is a plan view showing a guide rail for illustrating the principle of the tilt mechanism of the optical disc device according to the third embodiment of the present invention.

8 is a perspective view showing a schematic configuration of an optical disc device using the guide rail of FIG.

FIG. 9 is a schematic diagram showing a configuration of main components of a conventional optical disc device.

[Explanation of symbols]

3 ... Spindle motor 5 ... turntable 8 ... Optical head 12,1200 ... Tilt motor 14, 15 ... Objective lens 50a, 50b, 72 ... Flat cam 51a, 51b, 51c ... Cam follower 52a, 52b ... Guide rail with tilt axis 53 ... Motor for driving carriage feed screw 54 ... Carriage feed screw 55 ... Objective lens actuator 56a, 56b ... Cam lever 58, 59 ... Gear 60, 81, 81a, 81b ... Worm gear 70 ... Lift lever 82a, 82b ... Wheel gear 520a, 520b, 1003b ... Guide rail section 521a, 522a ... Tilt member 1000b ... Guide rail with eccentricity 1001b, 1002b ... Eccentric member 2010 ... Light emitting part (tilt detection part) 2020 ... Light receiving part (tilt detecting part)

Claims (6)

[Claims] 1. A guide rail for moving an optical head in a radial direction of an optical disc, a guide rail rotating means for rotating the two guide rails in synchronization with each other around the inclined axis, and Tilt guide means for detecting tilt, wherein the guide rail has a guide rail shaft extending in a radial direction of the optical disc, and is rotatably supported by a shaft inclined with respect to the guide rail shaft. An optical disk device characterized in that the guide rail rotating means rotates the guide rail in accordance with a tilt amount detected by the tilt detecting means. 2. The optical head comprises two objective lenses, wherein the guide rails have axes that are inclined with respect to the guide rail axes of the respective guide rails and intersect with the respective guide rail axes. The optical disk device according to claim 1, wherein the intersecting positions are provided at different positions on the two guide rails. 3. Two guide rails for moving an optical head in a radial direction of an optical disc, and tilts with respect to a guide rail axis provided on both end faces of the guide rail and passing through the center of both end faces of the guide rail. A guide rail tilting shaft member for rotating the guide rail around the tilted shaft, and the two guide rails provided with the guide rail tilting shaft member in synchronization with each other around the tilted shaft. A guide rail rotating means for rotating the guide rail and a tilt detecting means for detecting the tilt of the optical disc, and the guide rail rotating means rotates the guide rail according to the tilt amount detected by the tilt detecting means. Optical disc device characterized by. 4. The optical head comprises two objective lenses, wherein the tilted axes of each of the two guide rails are:
4. The optical disc device according to claim 3, wherein the guide rail axes are provided so as to intersect with each other, and the intersecting positions are different between the two guide rails. 5. The guide rail rotating means is provided with a cam mechanism for rotating the two guide rails at predetermined angles around the inclined shafts. Optical disc device according to the item. 6. Two guide rails for moving an optical head in a radial direction of an optical disk, and one guide rail of the two guide rails, the guide rails being provided on both end surfaces of the guide rail. A guide rail tilt axis member that is an axis that is tilted with respect to the guide rail axis that passes and that rotates the guide rail around the tilt axis, and on both end surfaces of the other guide rail of the other of the two guide rails. A guide rail eccentric member which is provided and has an eccentric shaft with respect to the guide rail shaft, and which rotates the guide rail around the eccentric shaft; First guide rail rotating means for rotating the guide rail eccentric member, second guide rail rotating means for rotating the guide rail eccentric member around the eccentric axis, and the optical disc. A tilt detecting means for detecting the tilt of the disc, and the guide rail is rotated by the first guide rail rotating means and the second guide rail rotating means in accordance with the tilt amount detected by the tilt detecting means. An optical disk device characterized in that