JP2002352455A - Optical pickup device and optical disk recording-and- reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correspond to optical disks having different kinds of substrates in thickness by differently using light sources and also to automatically correct a coma aberration caused by the difference in incident angle to an objective lens formed by a different light source in synchronization with the control of focusing. SOLUTION: The objective lens 3 is brought near to the optical disk 1b, since the optical disk 1b of thick substrate is different in position of a data- bearing surface in the z-direction from the optical disk 1a of thin substrate. So, an objective lens-driving means 9 moves the objective lens 3 toward the optical disk 1b and tilts the objective lens 3 in the direction of an arrow mark A. As shown in Figure 2, the optical axis 8b of the luminous flux heading for the objective lens 3 and the optical axis 31 of the objective lens 3 are oppositely inclined to each other to the perpendicular line on the face of the optical disk 1b, and for this reason a light spot with reduced aberration converges to the optical disk 1b by the actuation of the objective lens-driving means 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup device applied to an optical disk drive for recording and / or reproducing data on and from an optical disk such as a CD and a DVD, and an optical disk recording / reproducing apparatus using the optical pickup device.
It relates to a playback device.

[0002]

2. Description of the Related Art In an optical pickup that supports two types of wavelengths, two light sources are housed in a single package, and light emitted from each light source is guided to a substantially common optical path, so that optical components can be shared. A configuration in which the number of parts is reduced has been proposed.

[0003] Although the two light sources are arranged close to each other, the light emission points cannot be matched, so that the light emitted from at least one of the light sources deviates from the optimal optical path, causing coma aberration.

In order to solve this problem, there has been proposed a technique for matching the optical axes of two light sources. For example, in an apparatus described in Japanese Patent Application Laid-Open No. 2000-99983, a reflection film that reflects a light beam of a first wavelength and transmits a light beam of a second wavelength is coated on a first surface, and a light beam of a second wavelength is coated. Light from two light sources disposed close to each other is combined into a common light path by a parallel plate in which a reflection film for reflecting the light is coated on the second surface.

In the apparatus described in Japanese Patent Application Laid-Open No. H10-149559, a small polarizing beam splitter is provided in a light source module, and light paths from two light sources are combined.

[0006]

However, Japanese Patent Laid-Open Publication
In the apparatus described in Japanese Patent Application Laid-Open No. 99983/1999, the light beam of the second wavelength passes through the inside of the parallel flat plate, but when the divergent light passes through the parallel flat plate, astigmatism occurs and the quality of the condensed spot on the optical disk surface is reduced. There is a problem of deterioration.

In addition, the apparatus described in Japanese Patent Application Laid-Open No. 10-149559 has a problem that the optical precision or positional precision of a small polarizing beam splitter is severe, and it is difficult to manufacture the polarizing beam splitter.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned conventional problems and to cope with an optical disk having a plurality of types of substrate thicknesses by selectively using a plurality of light sources. An optical pickup device that enables automatic correction in conjunction with alignment control, and that can increase the allowable value of the light emitting point interval in a light source module in which a plurality of light sources are housed in a single package. Furthermore, using this optical pickup device, the optical pickup device can cope with an optical disk having a plurality of types of substrate thicknesses having different wavelengths used, and can reproduce / write an optical disk having a different substrate thickness with a good light spot with little coma aberration. An object of the present invention is to provide an optical disk recording / reproducing apparatus capable of recording.

[0009]

According to a first aspect of the present invention, there is provided an objective lens for converging a light beam emitted from a light source to an optical disk, wherein a plurality of light sources are selectively provided. In an optical pickup device capable of coping with an optical disk having a plurality of types of substrate thicknesses by emitting light, objective lens driving means for displacing the objective lens in the lens optical axis direction and tilting the objective lens in conjunction with the displacement. The objective lens driving means makes it possible to make the tilt axis of the objective lens parallel to the tilt axis of the light beam emitted from the selected light source and traveling toward the objective lens. Focuses coma caused by fluctuations in the angle of incidence on the objective lens when switching between light sources to accommodate optical discs with different substrate thicknesses. It can be automatically corrected in conjunction with the grayed control.

According to a second aspect of the present invention, in the optical pickup device according to the first aspect, when the direction in which the objective lens is inclined as approaching the optical disk is the A direction, the thickness of the substrate is reduced among a plurality of light sources. The light flux emitted from a light source used for a thick optical disc and traveling
It is characterized by tilting in the direction opposite to the direction, and by switching the light source by making the direction of tilt with the displacement of the objective lens in the optical axis direction opposite to the fluctuation direction of the objective lens incident angle caused by switching the light source. When coping with optical discs having different substrate thicknesses, coma aberration caused by a change in the angle of incidence on the objective lens can be automatically corrected during focusing.

According to a third aspect of the present invention, in the optical pickup device according to the first or second aspect, the direction in which the objective lens is tilted is the circumferential direction of the optical disk, and the tilt direction and the displacement of the objective lens are changed. The directions match, and the focusing operation and the tilting operation can be easily linked.

According to a fourth aspect of the present invention, in the optical pickup device according to the first or second aspect, the direction in which the objective lens is tilted is a radial direction of the optical disk, and the incident angle of the objective lens generated by switching the light source. Becomes a radial direction, and the light condensing points of the respective light sources on the optical disk can be located at the same radius, so that a good signal can be obtained.

According to a fifth aspect of the present invention, in the optical pickup device of the first, second, or third aspect, the objective lens driving means includes a rod-shaped or plate-shaped elastic member extending in the circumferential direction of the optical disk. Thrust generating means for elastically supporting the objective lens and for applying a thrust parallel to the lens optical axis direction of the objective lens to the objective lens is provided, and the thrust action center position in the longitudinal direction of the elastic member moves the objective lens in the lens optical axis direction. Characterized in that the bending moment generated in the elastic member when displaced in parallel is located at a position deviated from a point where the bending moment becomes zero, the inclination direction and the bending direction of the elastic member match, and the focus operation and The tilting operation can be easily linked, and by appropriately setting the positions of both ends of the elastic member with respect to the thrust generating position, the focus displacement amount can be reduced. It is possible to arbitrarily set the proportion of inclination amount.

According to a sixth aspect of the present invention, in the optical pickup device according to the first, second, or fourth aspect, the objective lens driving means includes a rod-shaped or plate-shaped elastic member extending in the radial direction of the optical disk. Thrust generating means for elastically supporting the lens and applying a thrust parallel to the lens optical axis direction of the objective lens to the objective lens is provided, and a thrust action center position in the longitudinal direction of the elastic member parallels the objective lens to the lens optical axis direction. Wherein the bending moment generated in the elastic member when it is displaced to a position deviated from a point at which the bending moment becomes zero, the variation direction of the incident angle of the objective lens caused by the light source switching becomes the radial direction, and each light source Focus point on the optical disk can be located at the same radius, a good signal can be obtained, and the elastic member By setting the end position as appropriate,
The ratio of the tilt amount to the focus displacement amount can be set arbitrarily.

According to a seventh aspect of the present invention, in the optical pickup device of the first, second, or third aspect, the objective lens driving means includes a rod-shaped or plate-shaped elastic member extending in a circumferential direction of the optical disk in a longitudinal direction. Thrust generating means for elastically supporting the objective lens and for applying a thrust parallel to the lens optical axis direction of the objective lens to the objective lens is provided. The thrust generating means is arranged on both sides of the objective lens in a circumferential direction of the optical disc. Characterized in that one thrust generating means is configured to generate a larger thrust than the other thrust generating means. By tilting the lens in conjunction with the focusing operation, the center of gravity of the movable part can be easily aligned with the drive center, and the focus can be adjusted without changing the movable part support mechanism. It is possible to change the setting of the inclination of ratio scum displacement.

According to an eighth aspect of the present invention, in the optical pickup device according to the first, second, or fourth aspect, the objective lens driving means includes a rod-shaped or plate-shaped elastic member extending in the radial direction of the optical disk. Thrust generating means for elastically supporting the lens and applying a thrust parallel to the lens optical axis direction of the objective lens to the objective lens is provided. The thrust generating means is arranged on both sides of the objective lens in the radial direction of the optical disk. Focusing the objective lens by disturbing the thrust balance of the thrust generating means provided on both sides of the objective lens, characterized in that one of the thrust generating means is configured to generate a larger thrust than the other thrust generating means. By tilting in conjunction with the operation, it is easy to match the center of gravity of the movable part with the drive center, and the forehead can be moved without changing the movable part support mechanism. It is possible to change the setting of the inclination of ratio scum displacement.

According to a ninth aspect of the present invention, in the optical pickup device according to the first, second, or third aspect, the objective lens driving means includes a plurality of rod-shaped or plate-shaped elongated longitudinally extending in the circumferential direction of the optical disk. The fixed portion and the objective lens are connected by an elastic member, and the fixed portion is configured to be capable of elastically deforming the elastic member in a longitudinal direction. The elastic modulus of the fixed portion is operated. As a result, the ratio of the tilt amount to the focus displacement amount can be changed, and the degree of freedom or ease of setting is improved.

The invention according to claim 10 is the first or second invention.
Or the optical pickup device according to 4, wherein the objective lens driving means is connected to the fixed part and the objective lens by a plurality of rod-shaped or plate-shaped elastic members extending longitudinally in the radial direction of the optical disc, and the fixed part is The elastic member can be elastically deformed in the longitudinal direction. The tilt ratio with respect to the focus displacement can be changed by manipulating the elasticity of the fixed portion, and the setting can be freely performed. The degree or ease is improved.

The invention described in claim 11 is the first and second inventions.
Or the optical pickup device according to 3, wherein the objective lens driving means is connected to the fixed part and the objective lens by a plurality of rod-shaped or plate-shaped elastic members extending in the circumferential direction of the optical disk, and the lens of the objective lens The distance between the elastic members in the optical axis direction is different between the objective lens side and the fixed part side. The objective lens is tilted in conjunction with the focusing operation by breaking the parallelism between the elastic members. Therefore, it is easy to make the center of gravity of the movable part coincide with the drive center, and the ratio of the tilt amount to the focus displacement amount can be changed without changing the configuration of the movable part or the thrust generating means, so that the setting can be easily changed. .

The invention described in claim 12 is the first or second invention.
In the optical pickup device described in Item 4, the objective lens driving means is connected to the fixed portion and the objective lens by a plurality of rod-shaped or plate-shaped elastic members extending in the radial direction of the optical disk, and the lens light of the objective lens is It is characterized in that the distance between the elastic members in the axial direction is different between the objective lens side and the fixed part side, and the objective lens is tilted in conjunction with the focusing operation by breaking the parallelism between the elastic members. Therefore, it is easy to make the center of gravity of the movable portion coincide with the drive center, and the ratio of the tilt amount to the focus displacement amount can be changed without changing the configuration of the movable portion or the thrust generating means.

According to a thirteenth aspect of the present invention,
5. The optical pickup device according to 2, 3, or 4, wherein the objective lens driving means connects the fixed portion and the objective lens with a rod-shaped or plate-shaped elastic member, and emits the light from a light source used for an optical disk having a thin substrate. It is characterized in that the light flux toward the objective lens is inclined toward the connection side of the elastic member and the fixed portion as the light beam travels toward the objective lens, and the direction in which the objective lens is inclined and the direction of the bending angle of the elastic member are matched. The focus operation and the tilt operation can be easily linked.

The invention according to claim 14 is the invention according to claims 1 and 2.
Or the optical pickup device according to 4, wherein the objective lens driving means is provided with a plurality of elastic members for connecting the fixed portion and the objective lens, the elastic members are formed in a rod-like or plate-like shape, and the longitudinal direction of the elastic members is set to the optical disk. Are arranged in the circumferential direction of the optical disc, and the elastic members are separately arranged at a distance in the radial direction of the optical disc, and the elastic member installed on the inner peripheral side of the optical disc and the elastic member installed on the outer peripheral side of the optical disc are The objective lens is tilted around an axis parallel to the elastic member with the focusing operation, so that the light-condensing points of the respective light sources on the optical disk are located at the same radius. And a good signal can be obtained.

The invention described in claim 15 is the first and second inventions.
Or the optical pickup device according to 4, wherein the objective lens driving means has a rod-like or plate-like shape whose longitudinal direction extends in the circumferential direction of the optical disk, and a plurality of elastic members for connecting the fixed portion and the objective lens; A thrust generating means for applying a thrust parallel to the lens optical axis direction to the objective lens, wherein the thrust acting center and the support center of the elastic member do not coincide with each other in the radial direction of the optical disc; Is tilted around an axis parallel to the elastic member with the focusing operation, so that the condensing points of the light sources on the optical disk can be located at the same radius, and a good signal can be obtained.

[0024] The invention described in claim 16 is the invention according to claims 1-1.
5. In the optical pickup device according to any one of the items 5,
The feature is that a plurality of light sources are housed in a single package close to each other, and the coma aberration correction function is incorporated in the focusing mechanism.Therefore, a coma aberration correction mechanism or an optical axis interval correction mechanism is separately provided. In addition, the allowable value of the light emitting point interval of the light source module can be expanded.

The invention according to claim 17 is an optical disk recording / reproducing apparatus for optically recording and / or reproducing information on / from an optical disk.
By adopting an optical pickup device with a configuration that incorporates a coma aberration correction function into the focusing mechanism, it is not necessary to separately provide a coma aberration correction mechanism, and it is inexpensive. An optical disk recording / reproducing device can be provided.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 5 are views for explaining the principle of coma aberration correction in an optical pickup device for explaining an embodiment of the present invention. A laser module 6, a coupling lens 5, and a rising mirror 4 are fixed to the housing 2, and the objective lens 3 is supported movably in the lens optical axis direction (z direction). Inside the laser module 6, two laser diodes 7a and 7b are housed.

The laser light L emitted from the laser diodes 7a and 7b passes through the coupling lens 5, is reflected by the rising mirror 4, passes through the objective lens 3, and is mounted on a turntable (not shown). The optical disks 1a and 1b having different thicknesses are irradiated. Optical disks 1a, 1
b is transmitted through the substrates of the optical discs 1a and 1b, and the disc surface opposite to the facing surface of the objective lens 3 (hereinafter, referred to as “the objective lens 3”).
The focusing control unit (not shown) controls the position of the objective lens 3 in the z direction so that the light is focused on the recording surface.

When recording / reproducing is performed on the optical disk 1a having a small substrate thickness, the first laser diode 7a emits light as shown in FIG. In this state, the optical axis 8a of the light beam of the laser beam L traveling toward the objective lens 3 and the lens optical axis 31 of the objective lens 3 are perpendicular to the disk surface, and the recording surface of the optical disk 1a is as shown in FIG. Such a good light spot with little coma aberration is converged.

On the other hand, when recording / reproducing the optical disk 1b having a large substrate thickness, as shown in FIG. 2, the second laser diode 7b emits light. Second laser diode 7
b has a light emitting point different from that of the first laser diode 7a, so that the optical axis 8b of the light beam of the laser light L traveling toward the objective lens 3
Does not become perpendicular to the disk surface, but tilts in the opposite direction to the arrow A shown in the state shown in FIG. At this time, when the lens optical axis 31 of the objective lens 3 is perpendicular to the disk surface (not shown), a light spot having a coma aberration as shown in FIG. 4 is focused on the recording surface of the optical disk 1b.

Since the thick optical disk 1b is different from the thin optical disk 1a in the position of the recording surface in the z direction, the objective lens 3 is moved toward the optical disk 1b with respect to the state shown in FIG. Can be Then, the objective lens 3 is moved in the direction of the arrow A while the objective lens 3 is moved in the direction of the optical disk 1b by the objective lens driving means 9. At this time, when the optical axis 8b of the light beam traveling toward the objective lens 3 is perpendicular to the surface of the optical disk 1b (not shown), a light spot having a coma aberration as shown in FIG. I do.

In the state shown in FIG. 2, the optical axis 8b of the luminous flux toward the objective lens 3 and the optical axis 31 of the objective lens 3 are inclined in directions opposite to each other with respect to a perpendicular to the surface of the optical disk 1b. By the operation of the driving means 9,
The axis of the tilt between the objective lens and the light beam becomes parallel, and FIG.
The aberration shown in FIG. 5 and the aberration shown in FIG. 5 cancel each other, and a light spot with reduced aberration as shown in FIG. 6 is collected.

The spot shown in FIG. 6 is better than the spot shown in FIG. 4 or FIG. 5, but does not reach the spot shown in FIG. Therefore, as shown in FIG. 1, a perpendicular line of the optical disk 1a, the optical axis 31 of the objective lens 3, and the objective lens 3
It is preferable to set a state in which the optical axis 8a of the light beam traveling toward the center is made to coincide. The relationship between the thicknesses of the optical disks 1a and 1b may be reversed.

For simplicity of explanation, in the state shown in FIG. 1, the optical axis 8a of the light beam toward the objective lens 3 and the optical axis 31 of the objective lens 3 have been described as being perpendicular to the disk surface of the optical disk 1a. It does not matter.

The optical axis 8a of the light beam emitted from the first laser diode 7a and traveling toward the objective lens 3 and the optical axis 8b of the light beam emitted from the second laser diode 7b and traveling toward the objective lens 3 are positioned with respect to the perpendicular to the disk. If it is set to be inclined in the opposite direction, the spot quality when using the first laser diode 7a is degraded, but the spot quality when using the second laser diode 7b is improved.

FIG. 7 is a perspective view of the first embodiment showing a specific example of the objective lens driving means for coma aberration correction described above. The lens holder 11 has an objective lens 3 and a focusing control and a tracking control. The coil 12 and the relay board 13 are fixed (hereinafter, this lens holder unit is referred to as a movable part). A magnet 15 is fixed to the base 14 so as to face the coil 12, and a fixed substrate 16 is fixed by screws 17. Relay board 1
3 and the fixed substrate 16 are connected by four bar springs (which may be plate-like springs) 18 which are elastic members arranged substantially in parallel. The base 14 is fixed to the housing 2 shown in FIGS.

When a current is applied to the coil 12, a thrust parallel to the z-direction is generated in the coil 12 by an electromagnetic action with the magnet 15, and the rod spring 18 is bent to move the lens holder 11 with respect to the base 14. Move in the direction.

FIGS. 8 to 10 are structural views showing a specific example of the structure and operation of the objective lens driving means 9 of the first embodiment.

When the movable portion is moved in the z direction in parallel, the position in the x direction where the bending moment acting on the cross section of the bar spring 18 becomes zero coincides with the thrust generating position 12a where the thrust F generated by the coil 12 is generated. The movable part is driven in parallel. That is, when they do not match, the movable portion is not driven in parallel in the z direction and tilts with the drive in the z direction. When the cross-sectional shape of the bar spring 18 is uniform, the position in the x direction where the bending moment becomes zero is a point at which the bar spring 18 is bisected.

When the thrust generating position 12a of the coil 12 is closer to the movable part connection side than the x direction position where the moment becomes zero, as shown in FIG. 8, the movable part is driven upward by the arrow in the z direction. Tilt to a side. This is the upper bar spring 1
8, a compressive stress acts on the lower bar spring 16, and a tensile stress acts on the lower bar spring 16, so that the deformation curves of the upper and lower bar springs 18 are different,
This is because the fixed substrate 16 is deformed by being pulled or pushed in the axial direction of the bar spring 18. The ratio of the amount of inclination to the amount of displacement in the z direction can be freely set by manipulating the amount of displacement of the thrust generating position of the coil 12 or the elastic modulus of the fixed substrate 16 in the x direction. In the configuration of FIG. 9, when the movable unit is driven downward in the z direction, the movable unit tilts in the direction opposite to the arrow a.

The thrust generating position 12a of the coil 12 is higher than the fixed substrate 16 in the x direction where the moment becomes zero.
As shown in FIG. 10, when the movable portion is driven to the upper side in the z direction, the movable portion tilts in the direction opposite to the arrow a side as shown in FIG. This is because a tensile stress acts on the upper bar spring 18 and a compressive stress acts on the lower bar spring 18, so that the deformation curves of the upper and lower bar springs 18 are different, or the fixed substrate 16 is This is because they are deformed by being pulled or pushed in the direction. The ratio of the amount of inclination to the amount of displacement in the z direction can be arbitrarily set by appropriately setting the amount of displacement of the thrust generating position 12a of the coil 12 or the elastic modulus of the fixed substrate 16 in the x direction. When the movable section is driven downward in the z direction in the configuration shown in FIG.
The movable part tilts toward the arrow a side.

In order to prevent the rotation of the movable part due to the inertial force, the thrust generating position 12a of the coil 12 is set at x of the center of gravity of the movable part.
It is desirable that they also coincide with the direction position. 9 and 1
As is clear from comparison with 0, the configuration shown in FIG. 9 is easier to match with the center of gravity of the movable part because the thrust generating position 12a of the coil 12 is closer to the center of the movable part. In the configuration shown in FIG. 9, the light flux for an optical disk having a thin substrate is
The setting is such that the light flux for the thick optical disk is inclined toward the arrow a side toward the objective lens 3.

FIGS. 11 to 13 are diagrams showing the configuration and operation of the second embodiment of the objective lens driving means. Unlike the first embodiment, the coil 12 and the magnet 15 are provided on both outer sides with the objective lens 3 interposed therebetween. Fixed substrate 16
The thrust F2 generated in the coil 12 on the side
When the thrust force F1 is smaller than the thrust force F1, the movable portion is driven upward in the z direction and tilted toward the arrow a as shown in FIG. Conversely, the thrust F2 generated in the coil 12 on the fixed substrate 16 side is changed to the thrust F2 generated in the other coil 12.
When it is set to be larger than 1, as shown in FIG. 13, the movable portion is driven upward in the z direction and tilted in the direction opposite to the arrow a.

In the second embodiment, since the parts arrangement of the movable part is almost symmetrical, the center of thrust generation can be easily made coincident with the center of gravity of the movable part, regardless of which setting the inclination is made. The ratio of the amount of inclination to the amount of displacement in the z direction can be arbitrarily set by changing the coil 12 or the magnet 15 as appropriate to change the balance of the thrust generated in both coils 12. Since the parts arrangement of the movable part is close to symmetrical, the center of thrust generation can be easily made coincident with the center of gravity of the movable part regardless of the setting of the inclination.

FIGS. 14 to 17 are configuration diagrams showing the configuration and operation of the third embodiment of the objective lens driving means 9. FIG. The movable part has the same configuration as that of the first embodiment or the second embodiment, and the lens holder 11 is connected to the fixed substrate 16 by four bar springs 18. Bar spring 18 in z direction
Are different between the movable part connection side and the fixed substrate 16 connection side.

FIG. 14 shows a configuration example in which the opposing interval of the bar spring 18 is wider on the connection side of the movable portion than on the connection side of the fixed substrate 16. In this case, as shown in FIG. When the movable part is displaced upward in the z direction by the thrust F generated in 12a, the movable part tilts in the arrow a direction. FIG.
Reference numeral 6 denotes a configuration example in which the opposing interval of the bar spring 18 is wider on the connection side of the fixed substrate 16 than on the connection side of the movable portion. In this case, as shown in FIG. When displaced upward in the direction, the movable portion tilts in the direction opposite to the arrow a. By adjusting the opposing interval of the bar spring 18 between the movable portion connection side and the fixed substrate 16 connection side in this manner,
The inclination direction and the amount with respect to the z-direction displacement can be arbitrarily set.

In the third embodiment, since the inclination direction and the amount can be set irrespective of the configuration of the movable portion, the thrust generating position 12a can be easily made coincident with the center of gravity of the movable portion, as in the second embodiment. Unlike the embodiment, there is no restriction on the configuration of the movable part.

The first embodiment, the second embodiment, and the third embodiment may be implemented by combining any two or more.

The objective lens driving means for supporting the movable portion with the four bar springs 18 shown in the first to third embodiments shown in FIGS. It is possible to displace in the vertical direction, and for example, as shown in FIG. 7, it is possible to displace in the y direction in addition to the z direction.

FIGS. 18 and 19 are configuration diagrams showing the configuration and operation of the fourth embodiment of the objective lens driving means 9. FIG. The movable part is, like the first to third embodiments, a lens holder 11,
It is composed of a unit composed of the objective lens 3, a coil and a relay board (not shown), and is connected to the fixed board 16 by four rod springs 18. The four bar springs 18 are installed at a distance from each other with the object lens 3 interposed therebetween. In this example, the bar spring 18b on one side (the right side in the figure) is replaced with the bar spring on the other side (the left side in the figure). The diameter is smaller than 18a. In the yz plane, the bar springs 18a, 18b
The center of gravity of the rectangle connecting the four movable point support points, the center of gravity of the movable part, and the thrust generating position 12a where the thrust F is generated coincide with each other.

As shown in FIG. 19, when the movable portion is displaced upward in the z direction by the thrust F generated by the coil 12, the right-side bar spring 18b having a smaller diameter is replaced with the left-side bar spring 1 having a larger diameter.
8a, the movable portion is inclined toward the arrow b.

FIG. 20 and FIG. 21 are configuration diagrams showing the configuration and operation of the fifth embodiment of the objective lens driving means 9. The movable part in the fifth embodiment is composed of a unit including a lens holder 11, an objective lens 3, a coil (not shown), a relay board, and the like, as in the first to fourth embodiments, and includes four bar springs. 18 connects to the fixed substrate 16. The four bar springs 18 are offset in the y direction, and in the yz plane, a rectangular centroid connecting the four movable portion support points of the bar springs 18, the center of gravity of the movable portion, and the thrust generating position 12a at which the thrust F is generated. Does not match. All four rod springs 18 have the same diameter.

As shown in FIG. 21, when the movable portion is displaced upward in the z direction by the thrust, the rod spring 18 closer to the thrust generating position 12a bends more than the farther bar spring 18, so that the movable portion has an arrow. Tilt to b side.

Note that the fourth embodiment and the fifth embodiment may be implemented in combination.

FIG. 22 is a plan view showing an embodiment of an optical disk recording / reproducing apparatus according to the present invention equipped with an optical pickup apparatus provided with any one of the objective lens driving means 9 of the first to third embodiments. The objective lens 3 is the optical disc 1
The housing 2 of the optical pickup device is supported by a pair of opposing rails 20 so as to be movable along a radius R of the optical disk 1a (1b). The objective lens driving means 9 is provided in a direction orthogonal to the radius R.

In FIG. 22, the housing 2 is moved by a coarse movement mechanism (not shown) to move the objective lens 3 over a long distance with low precision. 2 can be handled by moving the objective lens 3 in the radius R direction.

Here, since the shift of the light beam toward the objective lens 3 by the light source is in the disk circumferential direction T on the objective lens 3, the condensing points on the optical disk are arranged in a direction perpendicular to the radius R. One of the converging points will be off the radius R of the optical disk.

FIG. 23 shows a modification of the optical disk recording / reproducing apparatus shown in FIG. 22, which is different from FIG.
The objective lens driving means 9 is mounted with the longitudinal direction of the optical disk parallel to the radius R of the optical disk.

In the configuration shown in FIG. 23, the shift of the light beam toward the objective lens 3 by the light source is in the disk radial direction R on the objective lens. Both converging points have the same radius R
When positioned above, a good signal can be obtained from either of the focal points.

In order to cope with high-precision and high-frequency movement of the objective lens 3, it is necessary to separately provide a drive mechanism on the housing 2 or to enhance the responsiveness or accuracy of the coarse movement mechanism.

FIG. 24 is a plan view showing an optical disk recording / reproducing apparatus equipped with the objective lens driving means 9 of the fourth embodiment shown in FIGS. 18 and 19. Are mounted in a direction orthogonal to the radius R of the optical disk. The objective lens 3 can be precisely moved in the direction of the radius R of the disk with respect to the housing 2 by bending the rod spring 18 similarly to the optical disk device shown in FIG. By locating the focal points on the same radius (R), a good signal can be obtained from either focal point.

The tilt axis (tilt direction) of the movable portion of the fifth embodiment shown in FIGS. 20 and 21 is the same as that of the fourth embodiment, and the optical disk recording / reproducing apparatus shown in FIG.
Instead of the objective lens driving means of the fourth embodiment, the objective lens driving means of the fifth embodiment can be mounted.

[0063]

As described above, according to the optical pickup device of the present invention, it is possible to automatically correct the coma caused by the difference in the incident angle of the objective lens due to the different light sources in conjunction with the focusing control. Moreover, the use of a plurality of light sources can be used to properly handle optical discs with multiple types of substrate thicknesses, such as the allowable value of the light emitting point interval in a light source module containing a plurality of light sources in a single package. Will be able to

Further, according to the optical disk recording / reproducing apparatus of the present invention, by using the optical pickup device, it is possible to cope with an optical disk having a plurality of types of substrate thicknesses having different wavelengths to be used, and to cope with an optical disk having a different substrate thickness. In addition, accurate reproduction / recording becomes possible with a good light spot having little coma.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a configuration and an operation of an optical pickup device for describing an embodiment of the present invention.

FIG. 2 is an explanatory diagram illustrating the configuration and operation of an optical pickup device for describing an embodiment of the present invention.

FIG. 3 is a diagram illustrating a relationship between a lens aberration and a spot radius in the present embodiment.

FIG. 4 is a diagram illustrating a relationship between a lens aberration and a spot radius in the present embodiment.

FIG. 5 is a diagram illustrating a relationship between a lens aberration and a spot radius in the present embodiment.

FIG. 6 is a diagram illustrating a relationship between a lens aberration and a spot radius in the present embodiment.

FIG. 7 is a perspective view of a first example showing a specific example of an objective lens driving unit in the present embodiment.

FIG. 8 is a configuration diagram showing the configuration and operation of the first embodiment of the objective lens driving means.

FIG. 9 is a configuration diagram showing the configuration and operation of the first embodiment of the objective lens driving means.

FIG. 10 is a configuration diagram showing the configuration and operation of a first embodiment of an objective lens driving unit.

FIG. 11 is a configuration diagram showing the configuration and operation of a second embodiment of the objective lens driving means.

FIG. 12 is a configuration diagram showing the configuration and operation of a second embodiment of the objective lens driving means.

FIG. 13 is a configuration diagram showing the configuration and operation of a second embodiment of the objective lens driving means.

FIG. 14 is a configuration diagram showing the configuration and operation of a third embodiment of the objective lens driving means.

FIG. 15 is a configuration diagram showing the configuration and operation of a third embodiment of the objective lens driving means.

FIG. 16 is a configuration diagram showing the configuration and operation of a third embodiment of the objective lens driving means.

FIG. 17 is a configuration diagram showing the configuration and operation of a third embodiment of the objective lens driving means.

FIG. 18 is a configuration diagram showing the configuration and operation of the fourth embodiment of the objective lens driving means.

FIG. 19 is a configuration diagram showing the configuration and operation of a fourth embodiment of the objective lens driving means.

FIG. 20 is a configuration diagram showing the configuration and operation of a fifth embodiment of the objective lens driving means.

FIG. 21 is a configuration diagram showing the configuration and operation of a fifth embodiment of the objective lens driving means.

FIG. 22 is a plan view showing an embodiment of an optical disk recording / reproducing apparatus according to the present invention equipped with an optical pickup apparatus provided with any one of the objective lens driving units of the first to third embodiments.

FIG. 23 is a plan view showing a modification of the embodiment of the optical disc recording / reproducing apparatus shown in FIG. 22;

FIG. 24 is a plan view showing an optical disc recording / reproducing apparatus equipped with an objective lens driving unit according to a fourth embodiment.

[Explanation of symbols]

 1a, 1b Optical disk 3 Objective lens 4 Start-up mirror 5 Coupling lens 6 Laser module 7a, 7b Laser diode 8a, 8b Optical axis of laser beam (light flux) 9 Objective lens driving means 11 Laser holder 12 Coil 12a Thrust generating position 13 Relay Substrate 15 Magnet 16 Fixed substrate 18 Bar spring

Claims (17)

[Claims] 1. An optical pickup device comprising an objective lens for condensing a light beam emitted from a light source on an optical disk, and selectively emitting light from a plurality of light sources, thereby being capable of supporting an optical disk having a plurality of types of substrate thicknesses. In the above, while displacing the objective lens in the lens optical axis direction,
An objective lens driving means for tilting the objective lens in conjunction with the displacement, whereby the tilt axis of the objective lens and the tilt axis of the light flux emitted from the selected light source and traveling toward the objective lens are provided. An optical pickup device characterized in that it can be made parallel. 2. A light beam emitted from a light source used for an optical disk having a large substrate thickness and directed to the objective lens among a plurality of light sources, where the direction in which the objective lens is inclined as approaching the optical disk is defined as an A direction. 2. The optical pickup device according to claim 1, wherein the angle is inclined more in the direction opposite to the direction A. 3. The optical pickup device according to claim 1, wherein the direction in which the objective lens is tilted is the circumferential direction of the optical disk. 4. The optical pickup device according to claim 1, wherein a direction in which the objective lens is tilted is a radial direction of the optical disk. 5. The objective lens driving means elastically supports the objective lens by a rod-shaped or plate-shaped elastic member extending longitudinally in the circumferential direction of the optical disc, and applies a thrust parallel to the lens optical axis direction of the objective lens to the objective lens. A thrust generating means for acting on the lens is provided, and the thrust acting center position in the longitudinal direction of the elastic member is such that a bending moment generated in the elastic member becomes zero when the objective lens is displaced parallel to the lens optical axis direction. 4. The optical pickup device according to claim 1, wherein the optical pickup device is configured to be located at a deviated position. 6. The objective lens driving means elastically supports the objective lens by a rod-shaped or plate-shaped elastic member extending in the radial direction of the optical disk, and applies a thrust parallel to the lens optical axis direction of the objective lens to the objective lens. Is provided, and the center of the thrust action in the longitudinal direction of the elastic member deviates from the point where the bending moment generated in the elastic member becomes zero when the objective lens is displaced in parallel in the lens optical axis direction. 5. The optical pickup device according to claim 1, wherein the optical pickup device is configured to be located at a position. 7. The objective lens driving means elastically supports the objective lens by a rod-shaped or plate-shaped elastic member extending in the circumferential direction of the optical disk, and applies a thrust parallel to the lens optical axis direction of the objective lens. Thrust generating means for acting on the lens is provided, and the thrust generating means are arranged on both sides of the objective lens in the circumferential direction of the optical disk, and one of the thrust generating means has a generated thrust more than the other thrust generating means. 3. The method according to claim 1, wherein the first and second parts are configured to be large.
Or the optical pickup device according to 3. 8. The objective lens driving means elastically supports the objective lens by a rod-shaped or plate-shaped elastic member extending in the radial direction of the optical disk, and applies a thrust parallel to the lens optical axis direction of the objective lens. The thrust generating means is disposed on both sides of the objective lens in the radial direction of the optical disc, and one of the thrust generating means has a larger thrust than the other thrust generating means. 3. The structure according to claim 1, wherein
Or the optical pickup device according to 4. 9. The objective lens driving means, wherein a fixed portion and the objective lens are connected by a plurality of rod-shaped or plate-shaped elastic members extending longitudinally in a circumferential direction of the optical disk, and the fixed portion is provided with the elastic member. 4. The optical pickup device according to claim 1, wherein the member is configured to be elastically deformable in a longitudinal direction. 10. The objective lens driving means, wherein a fixed portion and the objective lens are connected by a plurality of rod-shaped or plate-shaped elastic members extending longitudinally in the radial direction of the optical disc;
5. The optical pickup device according to claim 1, wherein the fixing portion is configured to be elastically deformable in a longitudinal direction of the elastic member. 11. The objective lens driving means, wherein a fixed portion and the objective lens are connected by a plurality of rod-shaped or plate-shaped elastic members extending longitudinally in a circumferential direction of the optical disc,
4. The optical pickup device according to claim 1, wherein the distance between the elastic members in the lens optical axis direction of the objective lens is different between the objective lens side and the fixed portion side. 12. The objective lens driving means, wherein a fixed portion and the objective lens are connected to each other by a plurality of rod-shaped or plate-shaped elastic members extending in the radial direction of the optical disk,
5. The optical pickup device according to claim 1, wherein the distance between the elastic members in the lens optical axis direction of the objective lens is different between the objective lens side and the fixed part side. 13. A light beam emitted from a light source used for an optical disk having a small substrate thickness and directed toward the objective lens, wherein the objective lens driving means connects the fixed portion and the objective lens by a rod-shaped or plate-shaped elastic member. 5. The optical pickup device according to claim 1, wherein the optical pickup device is configured to incline toward a connection side between the elastic member and the fixing portion. 14. The objective lens driving means is provided with a plurality of elastic members for connecting the fixed part and the objective lens, the elastic members being rod-shaped or plate-shaped, and the longitudinal direction of the elastic members is set at the circumference of the optical disk. And the elastic members are separated and arranged at a distance in the radial direction of the optical disc,
The elastic member provided on the inner peripheral side of the optical disk and the elastic member provided on the outer peripheral side of the optical disk have different bending elastic coefficients.
Or the optical pickup device according to 4. 15. A plurality of elastic members, each of which has a rod-like or plate-like shape whose longitudinal direction extends in the circumferential direction of the optical disk, connects the fixed portion and the objective lens, and a lens optical axis of the objective lens. A thrust generating means for applying a thrust parallel to the direction to the objective lens, wherein a thrust acting center and a support center of the elastic member do not coincide with each other in a radial direction of the optical disk. Or the optical pickup device according to 4. 16. The optical pickup device according to claim 1, wherein a plurality of light sources are housed close to each other in a single package. 17. An optical disk recording / reproducing apparatus for optically recording and / or reproducing information on and from an optical disk, wherein the optical pickup device according to claim 1 is mounted. Recording / playback device.