JP2008065888A - Optical pickup device and optical disk device - Google Patents

Abstract

An inexpensive and compact compatible optical pickup capable of recording or reproducing with respect to optical discs having different specifications is provided.
An optical pickup device includes: an optical path switching unit that switches a light beam emitted from a laser light source 101 to two optical paths; a first spherical aberration correction element corresponding to a first optical disk and a first objective lens; And a second spherical aberration correction element 24 corresponding to the second optical disk and the second objective lens. The spherical aberration correction elements 14 and 24 are arranged in a common lens holder 32. The lens holder 32 can be moved in the lens optical axis direction by a drive element 33.
[Selection] Figure 2

Description

  The present invention relates to a compatible optical pickup device capable of recording or reproducing a plurality of multilayer optical discs having different substrate thicknesses, and an optical disc device including the same.

  CD and DVD have different transparent substrate thicknesses. In order to be able to reproduce optical disks having different transparent substrate thicknesses with a single optical pickup device, it is necessary to correct spherical aberration caused by the difference in transparent substrate thickness. For example, Patent Document 1 discloses an information pickup device having a divergence degree changing unit that changes the divergence degree of a light beam incident on an objective lens according to the thickness of a transparent substrate.

  Further, Patent Document 2 includes a spherical aberration correction device that performs correction of spherical aberration caused by the thickness of the surface resin layer of the optical disc in accordance with a plurality of standards, and such a spherical aberration correction device. An invention relating to an optical pickup device is disclosed.

  Patent Document 3 discloses a first and second optical system having at least a light source that emits laser light having one or more wavelengths, a collimator lens or an expander lens, and an objective lens, and a first and second optical system. An optical pickup device is disclosed that includes a moving unit that moves the collimator lens or the expander lens in the optical axis direction.

JP-A-9-17023 JP 2006-18948 A JP 2006-172611 A

  2. Description of the Related Art In recent years, as a next-generation DVD, a substrate thickness of an optical disc called HD DVD (hereinafter abbreviated as HD) as a first next-generation DVD and Blu-ray Disc (hereinafter abbreviated as BD) as a second next-generation DVD. Two types with different specifications have been proposed, and the required numerical aperture of the objective lens is also increased. Furthermore, for the purpose of expanding the storage capacity, an optical disc having a plurality of recording surfaces (hereinafter also referred to as a multilayer optical disc) has been proposed.

  In a multilayer optical disc, the distance from the light incident surface to each recording surface is different. That is, the thickness of the transparent substrate to each recording surface (hereinafter simply referred to as the transparent substrate thickness) is substantially different. For this reason, spherical aberration occurs in proportion to the error from the transparent substrate thickness in the design specifications of the objective lens focused on the recording surface. This spherical aberration increases in proportion to the fourth power of the numerical aperture (NA) of the objective lens and inversely proportional to the wavelength. In an optical pickup device for recording / reproducing a recordable DVD that requires a high numerical aperture and an optical pickup device for recording / reproducing a next-generation DVD for a blue-violet laser diode, this occurs due to the difference in the thickness of the transparent substrate. Spherical aberration is serious.

  In addition, in order to support not only HD and BD but also standards such as CD or DVD with a single optical pickup device in the above situation, a plurality of elements for correcting spherical aberration are required. It becomes. This increases the size of the optical pickup device body and increases the price.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a small and low-priced optical pickup device that can handle optical discs having a plurality of recording layers and different specifications, and an optical disc device including the same. And

  In order to achieve the above object, an optical pickup device of the present invention uses two objective lenses, two spherical aberration correction elements respectively corresponding to the two objective lenses, and a light beam emitted from a laser light source for each objective. And an optical path switching means for switching the optical path so as to face each lens.

  According to the present invention, it is possible to provide a small and low-priced optical pickup device that can handle optical discs having a plurality of recording layers and different specifications, and an optical disc device including the same.

  Embodiments of an optical pickup device according to the present invention and an optical disk device including the same will be described below.

  FIG. 1 is a diagram schematically showing a spherical aberration correction element unit 31 used in the optical pickup device of the first embodiment. The spherical aberration correction element unit 31 includes a spherical aberration correction element (lens 14) corresponding to the first optical disk 10 having two recording surfaces and a spherical aberration corresponding to the second optical disk 20 having two recording surfaces. And a correction element (lens 24). The lens 14 is designed so that divergent light or convergent light is incident on the first objective lens 13 for condensing light on the first optical disk, and the lens 24 condenses light on the second optical disk 20. It is designed so that divergent light or convergent light is incident on the second objective lens 23.

  In the spherical aberration correction element unit 31, the lens 14 and the lens 24 are arranged side by side with a single lens holder 32, and the two lenses are moved by moving the lens holder 32 with the power of the single drive element 33. It translates in the direction of the optical axis.

  The optical disk 10 is an optical disk having a first recording surface 11 and a second recording surface 12. A transparent resin layer is formed between the first recording surface 11 and the second recording surface 12, so that the transparent substrate thickness with respect to the first recording surface 11 and the transparent substrate thickness with respect to the second recording surface 12 are substantially equal. Is different. In the example shown in FIG. 1, a light beam is condensed on the optical disk 10 by an optical system including an objective lens 13 and a lens 14 corresponding to the objective lens 13.

  Here, the operation of the spherical aberration correction element unit 31 at the time of recording or reproduction of the optical disk 10 having two recording surfaces will be described.

  In the case of recording or reproduction on the first recording surface 11 of the optical disc 10, the light that is focused on the first recording surface 11 by driving the spherical aberration correction element unit 31 has the best aberration on the first recording surface 11. Thus, the lens 14 is moved to an arbitrary position 17. Thereby, the light beam emitted from the lens 14 changes from the light beam 16 shown by the solid line to the light beam 15 shown by the broken line. The light beam 15 is partially limited by the aperture 19 and then enters the objective lens 13.

  When the light beam 15 is incident on the objective lens 13, an aberration is generated. By using this aberration, an aberration caused by a difference between the transparent substrate thickness with respect to the first recording surface 11 and the transparent substrate thickness with respect to the second recording surface 12 is generated. It is corrected.

  On the other hand, in the case of recording or reproducing on the second recording surface 12 located at a predetermined distance from the first recording surface 11, the spherical aberration correction element unit 31 is driven and the light condensed on the second recording surface 12 is condensed. The lens 14 is moved to an arbitrary position 18 so as to obtain the best aberration on the second recording surface 12. As a result, the light beam emitted from the lens 14 changes from the light beam 15 indicated by the broken line to the light beam 16 indicated by the solid line. The light beam 16 is partially limited by the aperture 19 and then enters the objective lens 13. When the light beam 16 is incident on the objective lens 13, an aberration is generated. By using this aberration, an aberration caused by a difference between the transparent substrate thickness with respect to the first recording surface 11 and the transparent substrate thickness with respect to the second recording surface 12 is generated. It is corrected.

  Next, the operation of the spherical aberration correction element unit 31 when recording or reproducing the optical disk 20 having different specifications from the optical disk 10 will be described.

  The optical disc 20 has two recording surfaces, a first recording surface 21 and a second recording surface 22. The thickness of the transparent substrate of the optical disc 20 is different from the thickness of the transparent substrate of the optical disc 10. When recording or reproducing the optical disk 20, a light beam is condensed on the optical disk 20 by an optical system including the objective lens 23 and a lens 24 corresponding to the objective lens 23.

  When recording or reproducing the first recording surface 21 of the optical disc 20, the spherical aberration correction element unit 31 is driven so that the light condensed on the recording surface 21 has the best aberration on the recording surface 21. The lens 24 is moved to the position 27. As a result, the light beam emitted from the lens 24 changes from the light beam 26 shown by the solid line to the light beam 25 shown by the broken line. The light beam 26 is partially limited by the aperture 29 and then enters the objective lens 23.

  When the light beam 25 is incident on the objective lens 23, an aberration is generated. By using this aberration, an aberration caused by a difference between the transparent substrate thickness with respect to the first recording surface 21 and the transparent substrate thickness with respect to the second recording surface 22 is generated. It is corrected.

  Further, during recording or reproduction on the second recording surface 22 of the optical disc 20, the spherical aberration correction element unit has an arbitrary position at which the light condensed on the second recording surface 22 becomes the best aberration on the second recording surface 22. 28 is driven so that the lens 24 is moved. As a result, the luminous flux emitted from the lens 14 changes from the luminous flux 25 indicated by the broken line to the luminous flux 26 indicated by the solid line. The light beam 26 is partially limited by the aperture 29 and then enters the objective lens 23. When the light beam 26 is incident on the objective lens 23, an aberration is generated. By using this aberration, an aberration caused by a difference between the transparent substrate thickness with respect to the first recording surface 21 and the transparent substrate thickness with respect to the second recording surface 22 is generated. It is corrected.

  By configuring the spherical aberration correction element unit in the above-described configuration, even in an optical pickup having a high NA objective lens, it is possible to effectively record and reproduce a double-layer disc having different specifications.

  Here, the description has been made using an optical disc having two recording surfaces. However, the present invention is not limited to this, and an optical disc having three or more recording surfaces may be used.

  Next, a configuration example different from the spherical aberration correction element unit shown in FIG. 1 will be described. FIG. 2 shows a configuration example different from that of FIG. 1 of the spherical aberration correction element unit 31.

  In the spherical aberration correction element unit 31 shown in FIG. 2, the lens 14 and the lens 24 are arranged so that a portion outside the effective light beam diameter of each lens overlaps a single lens holder 32. The lens 14 and the lens 24 are displaced from each other in the optical axis direction. The spherical aberration correction element unit 31 can also translate the two lenses in the optical axis direction by the power of a single drive element 33, similarly to the spherical aberration correction element unit shown in FIG. For example, a motor can be used as the drive element 33, and the lens holder 32 is moved in the optical axis direction by using the rotational force of the motor. The drive element is not limited to a motor, and various actuators that can move the lens holder back and forth can be used.

  In the example shown in FIG. 2, it is preferable that the focal length f1 of the lens 14 and the focal length f2 of the lens 24 are set to be different. Thereby, the position of each lens can be freely arranged in the optical axis direction.

  Further, by shifting the lens 14 and the lens 24 from each other in the optical axis direction, it is possible to overlap the portions of the lens 14 and the lens 24 outside the effective luminous flux of each other.

  As a result, the distance 40 between the objective lenses can be shortened, and in addition to the reduction in the size of the spherical aberration correction unit 31, it is possible to achieve a reduction in the size of the actuator on which the objective lens is mounted.

  Further, by reducing the objective lens interval 40, the center of gravity of the actuator on which the objective lens is mounted can be brought closer to the center, and the performance of the actuator can be improved.

  In the case of a configuration in which lenses for correcting spherical aberration are partially overlapped as shown in FIG. 2, the lens is preferably circular. As a result, even if the lens is rotated in the direction in which the aberration is best while checking the direction of the aberration, the positional relationship between the lenses is not limited. Installation can be performed. Further, since the circular shape is an isotropic shape, there is an effect that a lens in which the generation of aberration is prevented or suppressed can be manufactured relatively easily.

  Further, when taking the configuration of the present embodiment, the configuration of the lens mounting portion of the lens holder 32 on which the lens 14 and the lens 24 are mounted is configured such that one of the lenses can be fixed, and the mounting portion of the other lens is mounted. It is desirable that the lens has a margin with respect to the lens outer diameter so that the lens mounting position can be adjusted.

  By adopting such a configuration, it is possible to absorb the variation due to the tolerance of the lens mounting position of the lens holder and the variation due to the tolerance of the outer diameters of the two lenses to be mounted.

  In the description of the present embodiment, the spherical aberration correction element shown in FIGS. 1 and 2 has been described with a configuration using a convex lens. However, the present invention is not limited to this, and the spherical aberration correction element itself has a lens effect and the optical axis. Any element that can change the degree of divergence and focusing of the light beam incident on the objective lens by moving its position in the direction is acceptable. For example, elements such as a biconcave lens, a biconvex lens, a planoconcave lens, a Fresnel lens, and a liquid crystal lens can be used.

  By employing the spherical aberration correcting element unit having the above-described configuration, the first spherical aberration correcting element (for example, an HD / DVD / CD compatible objective lens) is used for the first objective lens (for example, an HD / DVD / CD compatible objective lens) by a single driving unit 33. By driving the second spherical aberration correction element (for BD) to the second objective lens (for BD) and the second objective lens (for BD), and correcting to the best aberration state suitable for the disk in the disk of different specifications Good recording and reproduction can be performed on all discs.

  Further, since the spherical aberration correcting elements are arranged substantially in parallel, one driving means can be provided, and no separate driving means is required. Therefore, there is an effect that it is possible to reduce the cost and to reduce the space.

  Next, an optical pickup device equipped with the above-described spherical aberration correction element unit 31 will be described.

  FIG. 3 shows, as an example, a schematic diagram of an optical system of an optical pickup device equipped with the spherical aberration correction element unit shown in FIG. FIG. 4 is a schematic view of the optical system of the optical pickup device shown in FIG. 3 as viewed from the left side of the drawing. The optical pickup device is an optical pickup device that supports four types of media, CD, DVD, BD, and HD DVD.

  First, a CD optical system of such an optical pickup device will be described.

  The CD laser 301 is an infrared laser having a wavelength of 785 nm for CD. The oscillation wavelength of the laser may be around 785 nm, and is not limited to 785 nm. CD light 302 emitted from the CD laser 301 passes through the half-wave plate 310, the lens 303, and the diffraction grating 304 and is reflected by the polarization beam splitter 305. Then, the CD light 302 passes through the lens 306, is reflected by the composite upright prism 307, passes through the lens 308 and the quarter wavelength plate 309, and enters the HD / DVD / CD compatible objective lens 13. To do. Then, the CD light emitted from the HD / DVD / CD compatible objective lens 13 is condensed on the CD disk 100. The quarter wavelength plate 309 is a broadband quarter wavelength plate with an aperture limiting element.

  The CD light reflected by the CD disk 100 sequentially passes through the HD / DVD / CD compatible objective lens 13, the quarter wavelength plate 309, and the lens 308, and is reflected by the composite upright prism 307.

  Then, the light passes through the lens 306, the polarizing beam splitter 305, and the wavelength selective half-wave plate 311, is reflected by the polarizing beam splitter 312, passes through the lens 313, and enters the photodetector 314.

  Next, the DVD optical system will be described.

  The DVD laser 201 is a red laser having a wavelength of 660 nm. The laser oscillation wavelength may be around 660 nm, and is not limited to 660 nm. The DVD light 202 emitted from the DVD laser 201 passes through the half-wave plate 203 and the diffraction grating 204 and is reflected by the polarization beam splitter 205. Next, the DVD light 202 is transmitted through the polarizing beam splitter 312, the wavelength selective half-wave plate 311, the polarizing beam splitter 305, and the lens 306, reflected by the composite upright prism 307, and then the lenses 308, 1. The light passes through the / 4 wavelength plate 309 and enters the HD / DVD / CD compatible objective lens 13. Then, the DVD light emitted from the HD / DVD / CD compatible objective lens 13 is condensed on the DVD disk 200.

  The DVD light 202 reflected by the DVD disk 200 passes through the HD / DVD / CD compatible objective lens 13, the quarter-wave plate 309 and the lens 308, and is reflected by the composite upright prism 307.

  Then, the light passes through the lens 306, the polarizing beam splitter 307, the wavelength selective half-wave plate 311, the polarizing beam splitter 312, the polarizing beam splitter 205, and the lens 206, and enters the photodetector 207.

  Next, the HD / BD optical system will be described.

  The HD / BD laser 101 is a blue-violet laser having a wavelength of 405 nm. Of course, the laser oscillation wavelength may be in the vicinity of 405 nm, and is not limited to 405 nm. The HD / BD light 102 emitted from the HD / BD laser 101 passes through the beam shaping element 103 and the variable polarization switching element 104 with a diffraction grating, and the HD beam 120 and the BD light are changed by the polarization beam splitter 105 according to the direction of polarization. It is divided into 130. In the present embodiment, the light beam emitted from one laser light source (HD / BD laser 101) is switched to two optical paths by the optical path switching means 401.

  Here, the optical path switching means 401 for BD light and HD light will be described in more detail.

  In the example illustrated in FIG. 3, the optical path switching unit 401 includes a variable polarization switching element 104, a polarization beam splitter 105, and a triangular prism 121.

  The variable polarization switching element 104 is an element that switches the polarization of an incident light beam, and for example, a liquid crystal element can be used. The polarization beam splitter 105 is an optical element that transmits or reflects light according to the deflection direction. Here, the polarization beam splitter 105 is configured to reflect S-polarized light and transmit P-polarized light. The variable polarization switching element 104 switches the incident light beam to S-polarized light when recording or reproducing BD, and switches to P-polarized light when recording or reproducing HD. Thereby, at the time of recording or reproducing the BD, since the light beam emitted from the variable polarization switching element 104 is S-polarized light, it is reflected by the polarization beam splitter 105. On the other hand, at the time of HD recording or reproduction, the light beam emitted from the variable polarization switching element 104 is P-polarized light and is transmitted through the polarization beam splitter 105. The light beam that has passed through the polarization beam splitter 105 is reflected by the triangular prism 121 and enters the lens 14. Here, the triangular prism is used, but it is sufficient that the light beam transmitted through the polarization beam splitter can be reflected toward the lens 14, and for example, a mirror may be used. In this way, BD light and HD light are switched.

  Here, the incident light beam is switched to S-polarized light by the variable polarization switching element 104 during BD recording or reproduction, and is switched to P-polarization during HD recording or reproduction. In this case, the polarization beam splitter 105 may be configured to transmit S-polarized light and reflect P-polarized light.

  Further, here, a liquid crystal element is used as the variable polarization switching element 104 for switching the deflection direction. However, the liquid crystal element is not limited to this. For example, one half-wave plate can be used as a means for switching the deflection direction. It is good also as a structure which replaces mechanically using 1 sheet of transparent glass.

  Specifically, a half-wave plate and a transparent glass are attached to a predetermined position of a rotor that is rotated by electromagnetic force, and the half-wave plate and the transparent glass are replaced in the optical path by rotating the half-wave plate and the transparent glass. Can also realize a polarization switching function. Moreover, it can also comprise using the mechanism by linear motion instead of rotation operation.

  Returning to the description of the HD / BD optical system.

  The HD light 120 transmitted through the polarization beam splitter 104 is reflected by the triangular prism 121, transmitted through the lens 14, reflected by the composite upright prism 307, transmitted through the lens 308 and the quarter wavelength plate 309, and HD. The light enters the objective lens 13 compatible with DVD / CD. Then, the HD light 120 emitted from the HD / DVD / CD compatible objective lens 13 is condensed on the HD disk 10.

  The HD light 120 reflected by the HD disk 10 passes through the HD / DVD / CD compatible objective lens 13, the quarter wavelength plate 309 and the lens 308 and is reflected by the composite upright prism 307.

  Then, the light passes through the lens 14, is reflected by the triangular prism 121, is reflected by the polarization beam splitter 105, passes through the lens 106, and enters the photodetector 107.

  On the other hand, the BD light 130 reflected by the polarization beam splitter 104 passes through the lens 24, is reflected by the mirror 132, and enters the quarter-wave plate 133 and the BD objective lens 23. The BD light 130 emitted from the BD objective lens 23 is condensed on the BD disc 20.

  The BD light 130 reflected by the BD disc 20 passes through the BD objective lens 23 and the quarter-wave plate 133, is reflected by the mirror 132, passes through the lens 24, the polarization beam splitter 105, and the lens 106, and is a photodetector. 107 is incident.

  Signals obtained by the light receiving element for CD 38, the light receiving element for DVD 44, or the light receiving element 30 are subjected to signal processing by the signal processing unit of the optical disc apparatus shown in FIG. During reproduction, a reproduction signal is obtained, and a signal for controlling the focus and tracking of the objective lens is created by a servo signal creation unit. These control signals are input to an AF-TR control circuit, and AF (autofocus) control and TR (tracking) control are performed. Further, a tilt drive signal is created by the tilt signal creation unit, a tilt current is applied to the tilt coil via the tilt drive circuit, and the movable unit including the objective lens performs a tilt operation.

  These system controls are performed by the signal processing unit and controlled so as to obtain the best optical characteristics.

  Such an optical pickup device is used by being mounted on an optical disk device. The optical disk device processes a signal obtained by the optical pickup device to obtain a reproduction signal, and reproduces information recorded on an information recording / reproducing medium rotated by a rotation driving mechanism such as a motor. In addition, the optical disc apparatus can record information on various information recording / reproducing media such as CD, DVD, BD, and HD DVD by irradiating the information recording / reproducing medium with recording light from the optical pickup device.

  As described above, in the optical pickup device according to the present invention, the first spherical aberration correction element (for HD) is arranged with respect to the first objective lens (HD / DVD / CD objective lens), and the second By disposing the second spherical aberration correcting element (for BD) with respect to the objective lens (for BD), it is possible to perform optimal spherical aberration correction for a disc having a multilayer structure and different substrate thickness. As a result, it is possible to provide four types of disc compatible optical pickup devices capable of good recording / reproduction with respect to the four types of optical discs of CD, DVD, first next generation DVD, and second next generation DVD. .

  Further, since the spherical aberration correcting elements are arranged substantially in parallel, one driving means can be provided, and no separate driving means is required. Therefore, there is an effect that it is possible to reduce the cost and to reduce the space.

  The optical pickup device according to the present invention and the optical disk device including the same have been described above, but the present invention is not limited to this, and various improvements can be made without departing from the spirit of the present invention.

  For example, in the above embodiment, the operation of the spherical aberration correction element unit for a multilayer optical disk has been described. However, aberration correction using the spherical aberration correction element unit can also be performed for optical disks having different substrate thicknesses.

FIG. 1 is an explanatory diagram showing the configuration of a spherical aberration correction element unit used in the optical pickup of the first embodiment. It is a schematic block diagram of the spherical aberration correction element unit in which the light beam effective diameter outside portions of the first and second spherical aberration correction elements are overlapped. FIG. 3 is a schematic front view of an optical pickup optical system using a spherical aberration correction element unit. It is a typical side view of the optical pick-up optical system using a spherical aberration correction element unit. It is a conceptual diagram of system control.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... HD disc, 11 ... Recording surface with thick transparent substrate thickness, 12 ... Recording surface with thin transparent substrate thickness, 13 ... Objective lens, 14 ... Lens, 15 ... Light flux, 16 ... Light flux, 17 ... Arbitrary with the best aberration 18 ... Arbitrary position that gives the best aberration, 20 ... BD disc, 21 ... Recording surface with thick transparent substrate, 22 ... Recording surface with thin transparent substrate, 23 ... Objective lens, 24 ... Lens, 25 ... Light beam, 26... Light beam, 27... Arbitrary position for best aberration, 28... Arbitrary position for best aberration, 31... Spherical aberration correction element unit, 32. Interval 100 ... CD disc, 101 ... BD / HD laser, 102 ... BD / HD light, 103 ... beam shaping element, 104 ... variable polarization switching element with diffraction grating, 105 ... polarizing beam splitter, 106 ... , 107 ... photodetector, 120 ... HD light, 121 ... triangular prism, 130 ... BD light, 132 ... mirror, 133 ... 1/4 wavelength plate, 200 ... DVD disc, 201 ... DVD laser, 202 ... DVD light, 203 ... 1/2 wavelength plate, 204 ... diffraction grating, 205 ... polarization beam splitter, 206 ... lens, 207 ... photodetector, 301 ... CD laser, 302 ... CD light, 303 ... lens, 304 ... diffraction grating, 305 ... Polarizing beam splitter, 306 ... lens, 307 ... composite upright prism, 308 ... lens, 309 ... broadband quarter wave plate with aperture limiting element, 310 ... half wave plate, 311 ... wavelength selective half wave plate , 312 ... polarization beam splitter, 313 ... lens, 314 ... photodetector

Claims (9)

In an optical pickup device capable of supporting a first optical disc having a plurality of recording surfaces and a second optical disc having a plurality of recording surfaces and having different specifications from the first optical disc,
A laser light source;
A first objective lens for focusing a light beam emitted from the laser light source on each recording surface of the first optical disc;
A second objective lens for focusing the light beam emitted from the laser light source on each recording surface of the second optical disc;
Optical path switching means for switching a light beam emitted from the laser light source to a first optical path toward the first objective lens and a second optical path toward the second objective lens;
A first spherical aberration correction element disposed on the first optical path and corresponding to the first optical disk and the first objective lens;
An optical pickup device comprising a second spherical aberration correction element disposed on the second optical path and corresponding to the second optical disk and the second objective lens.   2. The optical pickup device according to claim 1, wherein the first spherical aberration correction element and the second spherical aberration correction element are moved using a single driving unit. And a lens holder for holding the first spherical aberration correction element and the second spherical aberration correction element in a state of being arranged in a direction perpendicular to the optical axis,
The optical pickup device according to claim 1, wherein the driving unit moves the lens holder in an optical axis direction.   4. The optical pickup device according to claim 1, wherein a focal length f <b> 1 of the first spherical aberration correction element and a focal length f <b> 2 of the second spherical aberration correction element are different from each other. .   The first spherical aberration correction element and the second spherical aberration correction element are arranged so that portions other than the effective light beam diameter of each optical element overlap each other. An optical pickup device according to claim 1.   6. The optical pickup device according to claim 1, wherein the first optical disc is a Blu-ray Disc and the second optical disc is an HD DVD.   The optical pickup device according to any one of claims 1 to 6, wherein the specification is a thickness of a substrate of an optical disc. The first spherical aberration correction element is designed such that diverging light or convergent light is incident on the first objective lens,
The light according to any one of claims 1 to 7, wherein the second spherical aberration correction element is designed so that divergent light or convergent light is incident on the second objective lens. Pickup device. An optical disc device comprising the optical pickup device according to any one of claims 1 to 8.

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