WO2007119410A1 - 光学ヘッドおよび光ディスク装置 - Google Patents
光学ヘッドおよび光ディスク装置 Download PDFInfo
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- WO2007119410A1 WO2007119410A1 PCT/JP2007/055462 JP2007055462W WO2007119410A1 WO 2007119410 A1 WO2007119410 A1 WO 2007119410A1 JP 2007055462 W JP2007055462 W JP 2007055462W WO 2007119410 A1 WO2007119410 A1 WO 2007119410A1
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- lens
- optical head
- optical
- objective lens
- light
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Classifications
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
- G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
- G11B7/095—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following specially adapted for discs, e.g. for compensation of eccentricity or wobble
- G11B7/0956—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following specially adapted for discs, e.g. for compensation of eccentricity or wobble to compensate for tilt, skew, warp or inclination of the disc, i.e. maintain the optical axis at right angles to the disc
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
- G11B7/135—Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
- G11B7/1372—Lenses
- G11B7/1378—Separate aberration correction lenses; Cylindrical lenses to generate astigmatism; Beam expanders
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
- G11B7/135—Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
- G11B7/1392—Means for controlling the beam wavefront, e.g. for correction of aberration
- G11B7/13925—Means for controlling the beam wavefront, e.g. for correction of aberration active, e.g. controlled by electrical or mechanical means
- G11B7/13927—Means for controlling the beam wavefront, e.g. for correction of aberration active, e.g. controlled by electrical or mechanical means during transducing, e.g. to correct for variation of the spherical aberration due to disc tilt or irregularities in the cover layer thickness
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
- G11B2007/0003—Recording, reproducing or erasing systems characterised by the structure or type of the carrier
- G11B2007/0006—Recording, reproducing or erasing systems characterised by the structure or type of the carrier adapted for scanning different types of carrier, e.g. CD & DVD
Definitions
- the present invention relates to an optical head used for recording and Z or reproduction on an optical information recording medium such as an optical disc, and an optical disc apparatus equipped with such an optical head.
- Patent Document 1 a collimating lens is mounted on a collimating lens actuator, and the collimating lens arranged between the light source and the objective lens is moved so as to cancel the spherical aberration caused by the thickness error of the light transmission layer.
- the method of the optical disk device is shown. This optical disk device will be described with reference to FIG.
- FIG. 18 shows a configuration of a conventional optical head.
- 101 is a light source
- 102 is a polarization beam splitter
- 103 is a quarter-wave plate
- 104 is a collimating lens
- 106 is an objective lens
- 107 is a multi lens
- 108 is a light receiving element
- 109 is driving an objective lens 106
- the biaxial actuator 110 is a collimating lens actuator that drives the collimating lens 104, and these constitute the optical head 120.
- the laser light emitted from the light source 101 is transmitted through the polarization beam splitter 102 and collimated.
- the light enters the first lens 104.
- the laser light incident on the collimating lens 104 is converted into parallel light by the collimating lens 104 when the thickness of the light transmission layer 131 of the optical disc 130 is as specified.
- the collimating lens 104 is mounted on the collimating lens actuator 110, and can be moved back and forth along the optical axis of the laser beam by the collimating lens actuator 110.
- the laser beam that has passed through the collimator lens 104 becomes a circularly polarized state when it passes through the 1Z4 wavelength plate 103 and enters the objective lens 106.
- the laser light collected by the objective lens 106 and incident on the information recording surface of the optical disk 130 is reflected by the information recording surface and becomes return light.
- the return light follows the original optical path, passes through the objective lens 106, and then enters the 1Z4 wavelength plate 103.
- the return light passes through the 1Z4 wave plate 103 and becomes linearly polarized light rotated by 90 degrees with respect to the polarization direction of the forward path. After that, it is converted into convergent light by the collimator lens 104 and then reflected by the polarization beam splitter 102.
- the return light reflected by the polarization beam splitter 102 enters the light receiving element 108 via the multi lens 107 and is detected.
- the optical head 120 When the optical head 120 is used to collect and reproduce light on the information recording surface of the optical disc 130, the main aberration caused by the thickness error of the light transmission layer 131 of the optical disc 130 is defocused. And spherical aberration. Defocus is corrected by the focus servo. That is, based on the focus servo from the light receiving element 108, the defocus is corrected by moving the objective lens 106 in the optical axis direction by the two-axis actuator 109, and the information recording surface is focused.
- spherical aberration by making the laser light incident on the objective lens 106 into divergent light or convergent light, a spherical aberration having a polarity opposite to that of the spherical aberration that occurs according to the thickness of the light transmission layer 131. Correction is performed by generating aberration. Specifically, the collimating lens actuator 110 moves the collimating lens 104 back and forth in the direction of the optical axis, so that the laser light incident on the objective lens 106 is diverged or convergent, and the objective lens 106 has a reverse polarity. Spherical aberration is generated, and spherical aberration due to the thickness error of the light transmission layer 131 is canceled. Thus, in this optical head 120, when the light passes through the objective lens 106 and is focused on the information recording surface, the spherical aberration is canceled.
- the collimating lens actuator 110 moves the collimating lens 104 back and forth in the direction of the optical axis, so that the laser light incident on
- the method of moving the collimating lens in the optical axis direction and making the laser light incident on the objective lens into divergent light or convergent light is optical for high-density optical discs such as BD (Blu-ray Disc). Used in the head. Note that in a BD having two light transmission layers 131, the distance between the light transmission layers is 30 m at maximum including variations in the thickness of each light transmission layer.
- Patent Document 1 Japanese Patent Laid-Open No. 11-259906
- the information recording surface has a multilayer structure exceeding two layers. In this case, it is not practical to form a new information recording surface between the two conventional information recording surfaces because various problems occur due to the distance between the information recording surfaces becoming too small. Therefore, in a multi-layered optical disc having an information recording surface exceeding two layers, the distance between the information recording surface of the thickest light transmission layer and the information recording surface of the thinnest light transmission layer exceeds 30 m. It will be. When the information recording surface is multi-layered, information is recorded and Z or playback is performed on multiple information recording surfaces.
- the optimal substrate thickness strength is required for information recording surfaces that deviate from the optimum substrate thickness of the objective lens (the light-transmitting layer thickness that minimizes the residual aberration).
- Spherical aberration occurs depending on the thickness of the light transmission layer up to a predetermined information recording surface.
- the spherical aberration increases in proportion to the thickness of the light transmission layer from the optimum base material thickness of the objective lens to a predetermined information recording surface. If the information recording surface is multilayered and the distance between the light transmission layers is changed greatly, the third-order spherical aberration to be corrected also increases. Therefore, in the conventional optical head, when the collimating lens is moved in the optical axis direction to correct the spherical aberration, the moving range of the collimating lens becomes very large.
- optical disc light transmission layer is the minimum) 85.5 ⁇ m, the collimation when recording or playing back an optical disc whose thickness varies from 0 ⁇ m to 125 ⁇ m.
- Figure 19 shows the movement range of the first lens (the direction toward the objective lens is positive (+)).
- the moving range of the collimating lens for correcting the spherical aberration is 8 mm or more.
- the thickness of the light transmission layer is large due to the multi-layered structure. Therefore, it is necessary to increase the size of the optical head in order to secure the movement range of the collimating lens for the optical head used in the optical disk. There is.
- the present invention has been made in view of such problems, and the change in the thickness of the light transmission layer is large, that is, the information recording surface of the thickest light transmission layer and the information of the thinnest light transmission layer.
- the thickness of the light transmission layer differs from that of the light source, the coupling lens that changes the divergence and Z or the convergence of the light beam emitted from the light source, and 3
- the diameter Dl of the light beam incident on the convergence expanding member and the diameter D2 of the light beam emitted from the divergence convergence expanding member satisfy the expression (1).
- the inter-surface distance between the information recording surface of the thickest light transmission layer and the information recording surface of the thinnest light transmission layer among the plurality of information recording surfaces is 30 m. It may be configured beyond.
- the divergence / convergence expanding member may be fixed to a movable portion of an actuator that drives the objective lens, and may be driven integrally with the objective lens.
- the divergence / convergence expanding member is a focal lens in which the emitted light becomes substantially parallel light when the incident light beam is substantially parallel light. Also good.
- the divergent / convergence enlarging member has a positive surface on the surface facing the coupling lens and a negative surface on the objective lens. A refractive lens having power may be used.
- the divergence / convergence expanding member has at least one of a surface facing the coupling lens and a surface facing the objective lens. It may have an aspherical shape.
- the divergence / convergence enlarging member may include a chromatic aberration correction function that corrects chromatic aberration of the objective lens that occurs due to a change in wavelength of the light source. ⁇ ⁇ .
- the divergent / convergence enlarging member is a diffractive surface having a positive power on a surface facing the coupling lens and a surface facing the objective lens. May be a refractive surface having negative power.
- the divergent / convergence enlarging member has a refractive surface in which a surface facing the force coupling lens is a convex surface and a surface facing the objective lens is a concave surface.
- the convex surface or the concave surface may be provided with a chromatic aberration correction function for correcting chromatic aberration of the objective lens that occurs due to wavelength variation of the light source.
- the divergence / convergence expanding member is a lens formed by bonding two lenses, and the side facing the coupling lens has a positive power.
- the first lens is a second lens having a negative power on the side facing the objective lens, and the glass material Abbe number V 1 of the first lens and the glass material Abbe number V of the second lens 2 may be configured to satisfy equation (2).
- the Abbe number V 1 of the glass material of the first lens and the Abbe number V 2 of the glass material of the second lens may be configured to satisfy (4).
- the divergent / convergence expanding member In this case, at least one of the surface facing the coupling lens, the surface facing the objective lens, and the bonding surface of the two lenses may have an aspherical shape.
- the diameter Dl of the light beam incident on the divergence / convergence expanding member and the diameter D2 of the light beam emitted from the divergence / convergence expanding member You may comprise so that 5) may be satisfy
- the optical head further includes drive means for moving the coupling lens in the optical axis direction, and changing the position of the coupling lens in the optical axis direction.
- the divergence and Z or the convergence of the light beam emitted from the light source may be changed.
- a second light source provided separately from the light source, and a light beam disposed adjacent to the objective lens and emitted from the second light source is the optical information recording medium.
- the second objective lens may be configured to be fixed to a movable portion of an actuator that drives the objective lens and to be driven integrally with the objective lens.
- the optical disc device includes an optical head, an optical disc driving unit for rotationally driving the optical disc, and a control unit for controlling the optical head and the optical disc driving unit.
- optical head in the first aspect of the present invention and the optical disc apparatus in the second aspect for example, in an optical head used for an optical disc in which the thickness change of the light transmission layer is large due to the multilayered information recording surface.
- An excellent effect is achieved in that a more compact size can be realized.
- FIG. 1 is a schematic configuration diagram of an optical head according to a first embodiment of the invention
- FIG. 2 is a diagram schematically showing the structure of an optical disc on which information is recorded and reproduced by the optical head shown in FIG.
- FIG. 3A Schematic configuration diagram of a mechanism for driving the collimating lens provided in the optical head shown in FIG. 1 in the optical axis direction.
- FIG. 3B Schematic configuration diagram of a mechanism for driving the collimating lens provided in the optical head shown in FIG. 1 in the optical axis direction.
- FIG. 4A A diagram showing the state of the light beam when the collimating lens provided in the optical head shown in FIG. 1 is driven in the optical axis direction.
- FIG. 4B is a diagram showing the state of the light beam when the collimating lens provided in the optical head shown in FIG. 1 is driven in the optical axis direction.
- FIG. 4C is a diagram showing the state of the light beam when the collimating lens provided in the optical head shown in FIG. 1 is driven in the optical axis direction.
- FIG. 5 is a diagram schematically showing the structure of an incident angle conversion lens provided in the optical head shown in FIG. 1.
- FIG. 6A is a diagram showing a state of light rays emitted from the incident angle conversion lens provided in the optical head shown in FIG.
- FIG. 6B is a diagram showing a state of light rays emitted from the incident angle conversion lens provided in the optical head shown in FIG.
- FIG. 6C is a diagram showing a state of light rays emitted from the incident angle conversion lens provided in the optical head shown in FIG.
- FIG. 7 is a diagram showing the relationship between the thickness of the light transmission layer and the collimating lens movement in the optical head shown in FIG.
- FIG. 8 is a schematic configuration diagram of an optical head according to a second embodiment of the invention.
- FIG. 9 is a diagram schematically showing the structure of an incident angle conversion hologram in the optical head shown in FIG.
- FIG. 10 is a schematic configuration diagram of an optical head according to a third embodiment of the invention.
- FIG. 11 A diagram schematically showing the structure of an incident angle conversion lens in the optical head shown in FIG.
- FIG. 12 shows a member for increasing the divergence and convergence degree provided in the optical head according to the second embodiment of the present invention. Showing a modification of
- FIG. 13 is a diagram showing a two-lens optical head according to a fourth embodiment of the present invention, in which the optical head according to the first to third embodiments of the present invention and the optical head for CDZDVD are configured integrally.
- FIG.14 Diagram of each lens in a two-lens optical head placed along the seek center line of the optical disc
- FIG.15 Diagram of lenses in a two-lens optical head placed in a tangential direction perpendicular to the seek center line of the optical disc
- FIG. 16 is a schematic configuration diagram of an optical disc device according to a fifth embodiment of the present invention.
- FIG. 17 is a diagram showing the configuration of the optical head for CDZDVD shown in FIG.
- FIG. 18 Schematic configuration diagram of a conventional optical head
- FIG. 19 is a diagram showing the relationship between the thickness of a light transmission layer and the amount of movement of a collimating lens in a conventional optical head.
- FIG. 1 is a schematic configuration diagram of an optical head according to an embodiment of the present invention.
- 1 is a semiconductor laser corresponding to an example of a light source
- 2 is a polarizing beam splitter
- 3 is a 1Z4 wave plate
- 4 is a collimating lens corresponding to an example of a coupling lens
- 5 is a reflecting mirror
- 6 is an objective.
- Lens 7 is a detection lens, 8 is a light receiving element, 9 is a 2-axis actuator that drives the objective lens 6, 20 is an incident angle conversion lens corresponding to an example of a divergent / convergence expanding member, and 16 is a collimating lens 4 A stepping motor, 17 is a screw shaft, and 18 is a lens holder for holding a collimating lens 4, which constitute an optical head 10!
- Reference numeral 30 denotes an optical disc having a plurality of transparent substrates (light transmission layers) and corresponding to an optical information recording medium.
- the optical disc 30 is formed with information recording surfaces 31, 32, 33, and 34 from the light incident surface side (objective lens 6 side) to the respective information recording surfaces from the light incident surface.
- the thickness force of the light transmission layer is dl, d2, d3, d4. Since the optical disc 30 corresponds to the optical disc having the multilayer structure described above, the distance between the information recording surface 34 of the thickest light transmission layer and the information recording surface 31 of the thinnest light transmission layer includes variations. And over 30 m.
- the optical disc 30 is an optical disc having three or more information recording surfaces, which is not limited to the force having four information recording surfaces.
- the linearly polarized laser beam emitted from the semiconductor laser 1 passes through the polarization beam splitter 2, is converted to circularly polarized light by the 1Z4 wavelength plate 3, is then converted to substantially parallel light by the collimating lens 4, and the reflecting mirror 5 And is transmitted through the incident angle conversion lens 20 and is condensed by the objective lens 6 as a light spot on any one of the information recording surfaces 31 to 34 of the optical disc 30 through the light transmission layer.
- the laser light reflected by any one of the information recording surfaces 31 to 34 is transmitted again through the objective lens 6 and the incident angle converting lens 20, reflected by the reflecting mirror 5, and transmitted through the collimating lens 4, and 1Z4 wavelength. After being converted into linearly polarized light different from the forward path by the plate 3, it is reflected by the polarization beam splitter 2 and guided to the light receiving element 8 by the detection lens 7.
- the laser beam detected by the light receiving element 8 is calculated after being subjected to photoelectric conversion, and generates a focus error signal for following the surface shake of the optical disc 30 and a tracking error signal for following the eccentricity.
- the biaxial actuator 9 drives the objective lens 6 in the biaxial direction so that the light spot follows the information track of the rotating optical disk 30 by using the focus error signal and the tracking error signal.
- the collimating lens 4 is held by the lens holder 18 and is movable along the optical axis of the laser beam. Depending on the thickness of the light transmission layer on the information recording surface 31 to 34, if the thickness of the light transmission layer deviates from the specified force, the spherical aberration associated with the change in the thickness of the light transmission layer is corrected. As described above, the laser light incident on the objective lens 6 by the collimator lens 4 is made into divergent light or convergent light, and the objective lens 6 generates spherical aberration of opposite polarity to correct the spherical aberration.
- FIGS. 3A and 3B are schematic configuration diagrams of a mechanism for driving the collimating lens 4 in the optical axis direction.
- 16 is a stepping motor
- 17 is a screw shaft
- 18 is a lens Honoreda
- 19 is a guide.
- the stepping motor 16 by driving the stepping motor 16 to rotate the screw shaft 17, the collimating lens 4 and the lens holder 18 holding the collimating lens 4 are moved along the guide 19 to the optical axis of the collimating lens 4. It can move in the direction.
- FIGS. 4A to 4C are diagrams showing the state of the light flux when the collimating lens 4 is driven in the optical axis direction.
- the spherical aberration that occurs due to the difference in the thickness of the light transmission layer of the optical disc 30 changes the divergence and convergence of the laser light incident on the object lens 6, and the spherical aberration that occurs due to the difference in the thickness of the light transmission layer. Correction can be made by generating spherical aberration of opposite polarity.
- the light emitted from the collimating lens 4 is diverged by moving the collimating lens 4 to the light source side as shown in FIG. 4B.
- a spherical surface generated when the optical transmission layer of the optical disc 30 becomes thicker Aberration can be corrected.
- FIG. 4C by moving the collimating lens 4 to the objective lens 6 side, the light emitted from the collimating lens 4 becomes convergent light, and the spherical aberration that occurs when the light transmission layer of the optical disc 30 becomes thin. Can be corrected.
- the means for moving the collimating lens 4 in the optical axis direction is not limited to the method using the stepping motor 16 described above, and may be any means such as an actuator by driving a piezoelectric element such as a magnetic circuit.
- the present invention is not limited to the above method.
- the magnetic circuit drives the piezoelectric element.
- the actuator according to has a small driving part, so it is suitable for miniaturization of the optical head.
- the incident angle conversion lens 20 has a convex power on the collimating lens 4 side (first surface) and a concave power on the objective lens 6 side (second surface). It functions as a so-called focal lens that emits parallel light with different beam diameters when parallel light is incident. Further, when expressing that the incident angle conversion lens 20 functions as the afocal lens by another method, the diameter of the light beam incident on the incident angle conversion lens 20 is D1, and the light beam emitted from the incident angle conversion lens 20 When the diameter of D2 is D2, it can be said that the relationship is D1> D2.
- the incident angle conversion lens 20 has at least one of an incident surface (first surface) and an output surface (second surface) as described above in order to reduce spherical aberration generated in the incident angle conversion lens itself. It is preferable to make the two surfaces aspherical.
- the function of the incident angle conversion lens 20 will be described with reference to FIGS. 6A to 6C.
- FIG. 6A to FIG. 6C are diagrams showing states of emitted light when parallel light, divergent light, and convergent light are incident on the incident angle conversion lens 20, respectively.
- the incident angle conversion lens 20 emits parallel light having different beam diameters as shown in FIG. 6A.
- the inclination angle ⁇ 1 of the emitted divergent light with respect to the optical axis of the marginal ray is the merged incident divergent light.
- the inclination angle of the null ray with respect to the optical axis is larger than ⁇ 2.
- the inclination angle ⁇ 3 of the emitted convergent light with respect to the optical axis of the marginal ray is equal to the optical axis of the incident convergent light with respect to the optical axis.
- the inclination angle is larger than ⁇ 4.
- the incident angle conversion lens 20 emits parallel light with an outgoing light beam diameter different from the incident light beam diameter when parallel light is incident, and more divergently emits divergent light as divergent light. When converged light is emitted, it converges further and emerges as converged light. As described above, the incident angle conversion lens 20 has a function of projecting the divergence / convergence degree of incident light with a larger magnification.
- the objective lens 6 is characterized by focusing on a farther position when divergent light is incident, and conversely focusing on a closer position when convergent light is incident, with reference to the case where parallel light is incident.
- the incident angle conversion lens 20 having the function of further expanding the divergence and convergence of the incident light as described above on the incident side of the objective lens 6, the divergent light and the convergence formed by the movement of the collimating lens 4 can be obtained.
- the light is further diverged or converged and enters the objective lens 6. Therefore, even if the movement amount of the collimating lens 4 is the same as the conventional one, the focal distance of the objective lens 6 can be changed greatly. That is, the distance between the information recording surfaces of the optical disc If the distance is the same as in the conventional case, it will be understood that the amount of movement of the collimating lens 4 can be made smaller than in the conventional case.
- FIG. 7 shows the result of calculation for the relationship between the thickness of the light transmission layer to be corrected and the amount of movement of the collimating lens in the present embodiment.
- the horizontal axis represents the thickness of the light transmission layer to be corrected, and the vertical axis represents the amount of movement of the collimating lens 4.
- the specific values for each parameter used in the calculation are as follows.
- the amount of movement of the collimator lens 4 is based on the case where the optimum base material thickness of the objective lens 6 (the thickness of the optical disk light transmission layer that minimizes the residual aberration) is 85.5 m. (+).
- the collimating lens 4 of the present embodiment requires a movement amount of +3.65 mm to correct the thickness of the light transmission layer of dl of the optical disc 30, and d4 light
- the collimating lens 4 of the present embodiment requires a moving amount of 3.47 mm. That is, the moving range of the collimating lens 4 is about 7.1 mm, which is about 1 mm smaller than the conventional example shown by the wavy line. This shows that the amount of spherical aberration generated per unit movement of the collimating lens 4 is increased because the incident angle conversion lens 20 increases the divergence and convergence of the light incident on the objective lens 6. ! /
- the incident angle conversion lens 20 is mounted on a two-axis actuator 9 that drives the objective lens 6 as shown in FIG. Since the incident angle conversion lens 20 is a focal lens, coma aberration due to the optical axis shift with respect to the objective lens 6 hardly occurs, and when the lens 20 is mounted on the 2-axis actuator 9. In this case, the position adjustment is easy and preferable.
- the optical head 10 in the present embodiment includes the incident angle conversion lens 20, the movable range of the collimating lens 4 can be reduced, and a compact-sized optical head can be realized.
- FIG. 8 is a schematic configuration diagram of an optical head according to another embodiment of the present invention.
- 1 is a semiconductor laser corresponding to an example of a light source
- 2 is a polarization beam splitter
- 3 is a 1 Z4 wave plate
- 4 is a collimating lens corresponding to an example of a coupling lens
- 5 is a reflection mirror
- 7 is a detection lens
- 8 is a light receiving element
- 9 is a 2-axis actuator that drives the objective lens 6
- 21 is an incident angle conversion hologram corresponding to an example of a divergent / convergence expanding member
- 16 is a collimating lens 4
- Reference numeral 30 denotes an optical disk having a plurality of transparent substrates (light transmission layers) and corresponding to an optical information recording medium.
- the optical disk 30 is the thinnest and the information recording surface 34 of the light transmission layer is the thinnest.
- the optical disk has a distance between the recording surface 31 and the recording surface 31 exceeding 30 ⁇ m.
- the operation of the optical head 11 when recording or reproducing information on the optical disc 30 is the same as the operation of the optical head 10 described in the first embodiment, and thus detailed description thereof is omitted. To do.
- the difference between the optical head 10 of the first embodiment and the optical head 11 of the present embodiment is the difference between the incident angle conversion lens 20 and the incident angle conversion hologram 21.
- the incident angle conversion hologram 21 has a diffractive surface 21a having a convex power on the collimating lens 4 side (first surface) and a concave surface (second surface) on the objective lens 6 side.
- Refractive surface 21b with the power of The diffractive surface 21a has a plurality of concentric diffractive structures 21c having an annular force, and is configured to obtain the maximum diffraction efficiency at the wavelength of the semiconductor laser 1.
- This incident angle conversion hologram 21 is also similar to the incident angle conversion lens 20 shown in the first embodiment.
- the inclination angle of the emitted divergent light with respect to the optical axis of the marginal light beam is larger than the inclination angle of the incident divergent light with respect to the optical axis of the marginal light beam.
- the tilt angle of the emitted convergent light with respect to the optical axis of the marginal light beam is larger than the tilt angle of the incident convergent light with respect to the optical axis of the marginal light beam.
- the incident angle conversion hologram 21 has a function of emitting the divergence / convergence of incident light with a larger magnification, and has the effect of increasing the amount of spherical aberration generated per unit movement amount of the collimating lens 4. Therefore, the incident angle conversion hologram 21 also has a relationship of D1> D2, where D1 is the diameter of the light beam incident on the incident angle conversion hologram 21, and D2 is the diameter of the light beam emitted from the incident angle conversion hologram 21.
- the incident angle conversion hologram 21 can reduce the amount of movement of the collimating lens 4 compared to the conventional effect similar to the above-described effect of the incident angle conversion lens 20, which contributes to the miniaturization of the optical head. be able to.
- the wavelength of the laser light source fluctuates due to a change in recording power and reproduction power, a change in ambient temperature, and the like.
- the shorter the wavelength of the laser beam the greater the influence of the fluctuation of the best image point position due to the refractive index fluctuation of the objective lens material due to the fluctuation of the wavelength. Therefore, in particular, in the recording type optical head, it is general to have a chromatic aberration correction function for correcting the fluctuation of the best image point position caused by the fluctuation of the wavelength.
- the incident angle conversion hologram 21 of the present embodiment functions as a focal lens in which the convex diffraction power and the concave refraction power are equal when parallel light with a reference wavelength of 408 nm of the semiconductor laser 1 is incident.
- the diffraction angle at the diffractive surface 21a becomes larger and the convex power becomes stronger, and it functions as a lens that emits convergent light when parallel light is incident.
- the diffraction angle at the diffractive surface 21a is decreased and the concave power is increased, so that it functions as a lens that emits divergent light when parallel light is incident.
- the diffractive structure 21c has a convex power which is a condition for performing a chromatic aberration correction function.
- the convex power amount is an amount necessary to cancel the chromatic aberration generated in the objective lens 6.
- the incident angle conversion hologram 21 has a plane on the collimating lens 4 side and a concave surface on the objective lens 6 side. It should be noted that even if the diffractive structure 21c having a convex surface is formed on the concave surface on the objective lens 6 side, the chromatic aberration correction function by the diffractive structure 2lc can be obtained.
- the diameter D1 of the light beam incident on the incident angle conversion hologram 21 is equal to the diameter D2 of the emitted light beam, the effect of increasing the divergent convergence of the incident light cannot be obtained. Therefore, in the case of the shape of the incident angle conversion hologram 21 having one plane as shown in FIG. 9, it is necessary to form the diffraction structure 21c on the plane on the collimating lens 4 side.
- the shape of the divergence / convergence expanding member having the chromatic aberration correction function is not limited to the shape of the incident angle conversion hologram 21.
- the optical head 11 in the present embodiment includes the incident angle conversion hologram 21, the movable range of the collimating lens 4 can be reduced, and a compact optical head can be realized.
- the incident angle conversion hologram 21 has a function of correcting chromatic aberration, an optical head excellent in recording or reproducing performance can be realized.
- the incident angle conversion hologram 21 in the present embodiment can be configured to be thinner and lighter than the incident angle conversion lens in the first embodiment, the small size of the two-axis actuator 6 can be achieved. And more suitable for high speed driving.
- the collimating lens 4 side surface is a flat surface
- the objective lens 6 side surface is a concave surface. It is formed on the plane on the collimating lens 4 side.
- the divergent / convergence-enhancing member can also have a shape as described below. By adopting such a shape, it has a chromatic aberration correction function and a larger afocal lens as a focal lens. It is possible to obtain a multiplication factor.
- the amount of convex power generated by the diffractive structure 21c for exhibiting the chromatic aberration correction function is determined by the amount of chromatic aberration generated in the objective lens used.
- the amount of chromatic aberration generated in an object lens is 0.5 / z mZnm, and the convex power due to the diffractive structure 21c formed on the divergence / convergence expanding member to make this approximately zero is almost uniquely determined. Determined.
- the divergent / convergence-enlarging member functions as a focal lens. The convex power and the concave power at must be equal.
- the thickness of the incident angle conversion hologram 21 is about lmm. Then, when the diameter of the light beam incident on the incident angle conversion hologram 21 is D1 and the diameter of the light beam emitted from the incident angle conversion hologram 21 is D2, the value of D2ZD1 for canceling the chromatic aberration of the above value is 0. It will be about 95.
- the value of D2ZD1 in the divergence / convergence-enhancing member is considered to be determined by the amount of chromatic aberration to be corrected.
- the value of D2ZD1 can be set appropriately to further reduce the amount of movement of the collimating lens 4 and further reduce the size of the optical head.
- the value of D2ZD1 in order to further reduce the amount of movement of the collimating lens 4 and further reduce the size of the optical head, the value of D2ZD1 must be further reduced.
- the surface on the collimating lens 4 side is formed on the convex surface 23a so as to have a predetermined convex power amount.
- the convex power and the concave power in the divergence / convergence expanding member must be equal to each other. It is formed on the concave surface 23b having a concave power amount that is almost equal in absolute value to the sum of the convex power by the convex surface 23a. In this way, the divergent / convergence expanding member 23 as shown in FIG. 12 is formed.
- the diffractive structure 21c is formed on the convex surface 23a on the collimator lens 4 side.
- the diffractive structure 21c is provided on either the collimator lens 4 side or the objective lens 6 side. It may be formed. For example, in the above example, if the diffractive structure 21c is provided on the surface on the objective lens 6 side, does the surface on the objective lens 6 side have a convex power due to the diffractive structure 21c?
- the surface on the collimating lens 4 side has a convex surface 23a having a convex power amount approximately equal in absolute value to the sum of the convex power due to the diffractive structure 21c and the concave power due to the concave surface 23b.
- the divergence convergence widening member functions as a focal lens. Decide the shape of the divergent convergence expanding member so that the power and the convex power are equal.
- the effective surface area of the convex surface is larger, and the viewpoint power in manufacturing the diffractive structure 21c is that it is easy to form the diffractive structure 21c on the convex surface. And preferred.
- FIG. 10 is a schematic configuration diagram of an optical head according to another embodiment of the present invention.
- 1 is a semiconductor laser corresponding to an example of a light source
- 2 is a polarization beam splitter
- 3 is a 1Z4 wavelength plate
- 4 is a collimating lens corresponding to an example of a coupling lens
- 5 is a reflection mirror
- 6 is an objective lens.
- Reference numeral 30 denotes an optical disk corresponding to an optical information recording medium having a plurality of transparent substrates (light transmission layers).
- the information recording surface 34 has the thickest light transmission layer and the information recording surface 31 has the thinnest light transmission layer. And the distance between the surfaces exceeds 30 ⁇ m.
- the incident angle conversion lens group 22 includes a convex lens 22a (glass material: VC78, Abbe number 55) on the collimating lens 4 side (incident side) and a concave lens 22b (glass material) on the objective lens 6 side (outgoing side). : FD15 and Abbe number 30) are bonded together.
- the inclination angle of the emitted diverging light with respect to the optical axis of the marginal ray is the inclination angle of the incident diverging light with respect to the optical axis of the marginal ray.
- the inclination angle of the emitted convergent light with respect to the optical axis of the marginal ray becomes larger than the inclination angle of the incident convergent light with respect to the optical axis of the marginal ray.
- the incident angle conversion lens group 22 has a function of further expanding the divergence / convergence degree of incident light, and has an effect of increasing the amount of spherical aberration generated per unit movement amount of the collimating lens 4. . Therefore, the incident angle conversion lens group 22 also has a relationship of D1> D2, where D1 is the diameter of the light beam incident on the incident angle conversion lens group 22, and D2 is the diameter of the light beam emitted from the incident angle conversion lens group 22.
- the incident angle conversion lens group 22 can achieve the same effect as the above-described effect of the incident angle conversion lens 20, that is, the amount of movement of the collimating lens 4 can be made smaller than before, and the optical head can be downsized. Can contribute.
- the power of the convex lens 22a is equal to the power of the concave lens 22b.
- Force that functions as a focal lens When the wavelength of the laser beam becomes longer, the power of the concave lens with a large dispersion (small Abbe number) becomes smaller, and a lens that emits convergent light when collimated light is incident Function as.
- the power of the concave lens having a large dispersion Small Abbe number
- the power of the concave lens having a large dispersion small Abbe number
- the dispersion force of the glass material used for the concave lens 22b must be greater than the dispersion of the glass material used for the convex lens 22a. Specifically, it is preferable to use a low dispersion material with an Abbe number of 50 or more for the convex lens 22a and a high dispersion material with an Abbe number of 35 or less for the concave lens 22b.
- the optical head 12 in the present embodiment includes the incident angle conversion lens group 22, the movable range of the collimating lens 4 can be reduced, and light of a compact size can be obtained. Academic head can be realized. Further, since the incident angle conversion lens group 22 also has a function of correcting chromatic aberration, an optical head excellent in recording or reproducing performance can be realized.
- any one of the incident angle conversion lens 20, the incident angle conversion hologram 21, and the incident angle conversion group lens 22 mounted on the movable portion of the biaxial actuator 9 is used.
- the force of the optical head in which the movable range of the collimating lens 4 is reduced V is not limited to these.
- the divergence / convergence increasing member is fixed between the collimating lens and the objective lens, and the inclination angle of the light beam emitted from the collimating lens and incident on the objective lens with respect to the optical axis of the marginal light beam is set.
- Any device having an expanding function can be applied.
- diffractive structures may be provided on both the entrance surface and the exit surface.
- these divergent / convergence-enhancing members should be fixed on the optical head that is not on the 2-axis actuator.
- the condition that the divergence / convergence expanding member has a function of expanding the inclination angle of the light beam emitted from the collimator lens and incident on the objective lens with respect to the optical axis of the marginal ray is incident on the divergence / convergence expanding member. If the diameter of the light beam is Dl and the diameter of the light beam emitted from the divergence convergence expanding member is D2,
- the degree On the other hand, the smaller the outgoing beam diameter D2 with respect to the incident beam diameter D1, the greater the effect of expanding the tilt angle.
- the effective diameter of the objective lens cannot be significantly reduced. That is, if the incident light beam diameter D1 is larger than the outgoing light beam diameter D2 of the divergence / convergence expanding member, the effective diameter and the outer diameter of the collimating lens 4 are increased, so that the entire optical system becomes larger. Therefore, in effect,
- the diameter D1 of the light beam incident on the divergent / convergence expanding member and the diameter D2 of the emitted light beam are
- the coupling lens that is driven to correct the spherical aberration is configured to drive the collimating lens 4 shown in the first to third embodiments in the optical axis direction using the stepping motor 16.
- an optical element such as a so-called beam expander that changes the divergence and Z or convergence of the light beam incident on the objective lens by changing the distance between the two lens groups in the optical axis direction. It is clear that this is also applicable.
- the collimating lens 4 As described in the first to third embodiments, by disposing a divergent / convergence expanding member such as the incident angle conversion lens 20 between the collimating lens 4 and the objective lens 6, the collimating lens 4 The amount of movement can be reduced and the optical head can be miniaturized.
- a divergent / convergence expanding member such as the incident angle conversion lens 20 between the collimating lens 4 and the objective lens 6, the collimating lens 4 The amount of movement can be reduced and the optical head can be miniaturized.
- there is a method of increasing the focal length of the objective lens 6 as a method of reducing the moving amount of the collimating lens 4 without using a member for increasing the divergence convergence degree.
- the objective lens 6 having a large focal length has a large diameter, it is contrary to the miniaturization of the optical head, and the weight of the objective lens increases, which is disadvantageous in terms of the operation performance of the actuator that drives the objective lens and the like. Become. Therefore, providing a divergence / convergence expanding member such as the incident angle conversion lens 20 as described above is also effective from the viewpoint of operating performance of an actuator that drives the objective lens and the like.
- a chromatic aberration correction function such as the incident angle conversion hologram 21 and the incident angle conversion group lens 22
- the two-lens optical head 13 may be configured by integrally configuring the BD optical head 13B in the third embodiment.
- the optical head 13A for CDZDVD and the light for BD The optical head 13B and the optical head 13A for the CD / D VD, and the objective lens 6 for the optical head 13B for the BD,
- the actuator that drives the divergent / convergence-enhancing member may be shared and driven by a single movable part.
- the CDZDVD optical head 13A shown in FIG. 13 can have, for example, the configuration of the optical head 220 shown in FIG.
- the light source 201 corresponds to the second light source
- the objective lens 206 corresponds to the second objective lens
- 202 is a polarization beam splitter
- 203 is a 1Z4 wavelength plate
- 204 is a collimating lens
- 207 is a multi lens.
- 208 is a light receiving element
- 209 is a two-axis actuator that drives the objective lens 206.
- Reference numeral 230 denotes an optical disc
- reference numeral 231 denotes a light transmission layer.
- the optical head 13A is shown on the right side, and the optical head 13B is shown on the left side for the sake of convenience, so that it is not related to the actual arrangement.
- the illustrated shape, size, and the like are also different from actual ones.
- a force that can also constitute a two-lens optical head instead of providing a divergent / convergence expanding member such as an incident angle conversion lens 20, a large diameter is used to reduce the amount of movement of the collimating lens.
- the two-lens optical head 14 shown in FIG. 14 and FIG. 15 provided with the objective lens has the following problems. That is, as described above, because of the weight increase due to the large objective lens, the operation performance of the objective lens driving actuator is degraded.
- center-to-center distance L1 between the objective lens 14A-1 in the CDZDVD optical head 14A and the objective lens 14B-1 in the BD optical head 14B is based on the center-to-center distance L in the two-lens optical head 13 shown in FIG.
- tracking control there arises a problem regarding reading and writing of information with respect to the optical disc such as tracking control.
- the arrangement of the objective lens 14A-1 in the optical head 14A for CDZDVD and the objective lens 14B-1 in the optical head 14B for BD is as shown in FIG.
- the objective lens 14A-1 is placed on the seek centerline 30a of the optical disc 30 and the objective lens 14B-1 is placed on the seek centerline 30a.
- the large center-to-center distance L1 is Therefore, the size of the two-lens optical head 14 is increased.
- the CDZDVD optical head 14A may interfere with the optical disc rotating motor.
- the center-to-center distance L1 since the center-to-center distance L1 is large, the positional deviation of the objective lens 14B-1 from the seek center line 30a becomes large.
- the curvature of the track of the optical disc 30 is relatively gentle on the outer track and tight on the inner track. Therefore, there is a difference in the track angle 30c between when the BD optical head 14B having the objective lens 14B-1 accesses the outer track and when the inner track is accessed. Due to the difference in the track angle 30c, the light flux pattern detected by the photodetector provided in the optical head for BD 14B changes, so that there is a problem that the tracking performance deteriorates.
- the movement amount of the collimating lens 4 can be reduced, the optical head can be reduced in size, and the objective lens 6 can be reduced.
- the center-to-center distance L can be made equal to or less than the conventional distance. Therefore, the problem described with reference to FIGS. 14 and 15 does not occur in the optical head of this embodiment.
- providing a member for increasing the divergence / convergence, such as the incident angle conversion lens 20, is effective from the viewpoint of reading / writing information from / to an optical disk, such as tracking control.
- FIG. 16 is a schematic configuration diagram of an optical disc apparatus according to an embodiment of the present invention.
- reference numeral 50 denotes the entire optical disk device, and the optical disk device 50 includes an optical disk drive unit 35, a control unit 36, and an optical head 40.
- 30 is an optical disk having a transparent substrate.
- the optical disk drive unit 35 has a function of rotationally driving the optical disk 30, and the optical head 40 is any of the optical heads described in the first to fourth embodiments.
- the control unit 36 has a function of driving and controlling the optical disk drive unit 35 and the optical head 40, and
- the optical head 40 has a function of performing signal processing of control signals and information signals and a function of interfacing the information signals with the outside of the optical disc device 50 inside.
- the optical disk device 50 includes any one of the optical heads described in the first to thirty-fourth embodiments, and the moving range of the collimating lens is reduced.
- the optical disc device 50 in the present invention has an excellent effect that it can realize a more compact size even when used for an optical disc in which the thickness change of the light transmission layer is large due to the multilayered information recording surface.
- the movement range of the collimating lens can be reduced! Since the optical disc device 50 according to the present embodiment is also provided with a correction function, a remarkable effect that the recording or reproducing performance is excellent in addition to the compact size can be obtained.
- the optical head of the present invention can be configured compactly and has a chromatic aberration correction function even when used in an optical disc in which the thickness of the light transmission layer is large due to the multilayered information recording surface.
- the optical disk device can be reduced in size, weight and accuracy, and a high-performance optical disk device can be provided at low cost.
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Abstract
Description
Claims
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
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JP2008510808A JP4987856B2 (ja) | 2006-03-20 | 2007-03-19 | 光学ヘッドおよび光ディスク装置 |
CN2007800096943A CN101405800B (zh) | 2006-03-20 | 2007-03-19 | 光学头及光盘装置 |
US12/293,291 US8325581B2 (en) | 2006-03-20 | 2007-03-19 | Optical head and optical disc device |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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JP2006076315 | 2006-03-20 | ||
JP2006-076315 | 2006-03-20 |
Publications (1)
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WO2007119410A1 true WO2007119410A1 (ja) | 2007-10-25 |
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ID=38609202
Family Applications (1)
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PCT/JP2007/055462 WO2007119410A1 (ja) | 2006-03-20 | 2007-03-19 | 光学ヘッドおよび光ディスク装置 |
Country Status (4)
Country | Link |
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US (1) | US8325581B2 (ja) |
JP (1) | JP4987856B2 (ja) |
CN (1) | CN101405800B (ja) |
WO (1) | WO2007119410A1 (ja) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2010047093A1 (ja) * | 2008-10-24 | 2010-04-29 | パナソニック株式会社 | 光学ヘッド、光ディスク装置及び情報処理装置 |
WO2011077647A1 (ja) * | 2009-12-24 | 2011-06-30 | パナソニック株式会社 | 光学ヘッド、光ディスク装置、情報処理装置及び対物レンズ |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7933182B2 (en) * | 2006-12-13 | 2011-04-26 | Canon Kabushiki Kaisha | Optical information recording and reproducing apparatus that sets a movable range of an objective lens based on the type of recording medium |
KR20110090648A (ko) * | 2010-02-04 | 2011-08-10 | 삼성전자주식회사 | 광 픽업장치 |
JP6969459B2 (ja) * | 2018-03-15 | 2021-11-24 | オムロン株式会社 | センサヘッド |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH11126362A (ja) * | 1997-10-24 | 1999-05-11 | Asahi Optical Co Ltd | 光情報記録再生ヘッドの光学系 |
JP2004079146A (ja) * | 2001-10-12 | 2004-03-11 | Konica Minolta Holdings Inc | 光ピックアップ装置、対物レンズ、回折光学素子、光学素子及び記録・再生装置 |
JP2004185797A (ja) * | 2002-11-21 | 2004-07-02 | Konica Minolta Holdings Inc | 光ピックアップ装置用光学系、光ピックアップ装置及び対物レンズ |
JP2004247047A (ja) * | 2004-05-31 | 2004-09-02 | Toshiba Corp | 光ヘッドおよびその光ヘッドを有する光ディスク装置ならびに情報記録再生装置 |
JP2005327394A (ja) * | 2004-05-14 | 2005-11-24 | Sony Corp | 光ピックアップおよび光ディスク装置 |
Family Cites Families (19)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6256283B1 (en) * | 1996-10-01 | 2001-07-03 | Matsushita Electric Industrial Co., Ltd. | Optical pickup having a common light beam path for passing either of a plurality of kinds of light beams |
JPH11259906A (ja) | 1998-01-09 | 1999-09-24 | Sony Corp | 光学ヘッド、記録及び/又は再生装置、記録及び/又は再生方法、並びに厚み検出方法 |
JP4288769B2 (ja) * | 1999-07-09 | 2009-07-01 | コニカミノルタホールディングス株式会社 | 光情報記録媒体の記録および/または再生用集光光学系および光ピックアップ装置 |
JP4070936B2 (ja) | 2000-04-14 | 2008-04-02 | ペンタックス株式会社 | 光ヘッド用対物光学系 |
EP1154417B1 (en) * | 2000-05-12 | 2012-05-09 | Konica Minolta Opto, Inc. | Optical pick-up apparatus |
JP2002197712A (ja) | 2000-12-25 | 2002-07-12 | Konica Corp | 集光光学系、光ピックアップ装置及び再生装置 |
AU2001294248A1 (en) | 2000-10-16 | 2002-04-29 | Konica Corporation | Objective lens, coupling lens, light converging optical system, and optical pick-up apparatus |
US6934226B2 (en) * | 2001-04-12 | 2005-08-23 | Matsushita Electric Industrial Co., Ltd. | Optical disk apparatus |
JP2003045042A (ja) * | 2001-07-31 | 2003-02-14 | Toshiba Corp | 情報記録媒体の厚みムラ補正方法および厚みムラ補正方法を用いた情報記録再生装置 |
JP4373036B2 (ja) * | 2001-08-31 | 2009-11-25 | パイオニア株式会社 | 光ピックアップ |
TWI239520B (en) | 2001-10-12 | 2005-09-11 | Konica Corp | Objective lens, optical element, optical pick-up apparatus and optical information recording and/or reproducing apparatus equipped therewith |
EP1313095B1 (en) * | 2001-11-15 | 2008-10-15 | Samsung Electronics Co. Ltd. | Compatible optical pickup |
JP3716805B2 (ja) * | 2002-03-18 | 2005-11-16 | 日本ビクター株式会社 | 光ピックアップ装置 |
TW200402037A (en) * | 2002-07-31 | 2004-02-01 | Tdk Corp | Method and apparatus for initializing recording films of optical recording medium and optical recording medium |
TW200502670A (en) | 2002-11-21 | 2005-01-16 | Konica Minolta Holdings Inc | Objective lens, optical system and optical pickup apparatus |
KR100509493B1 (ko) * | 2003-02-26 | 2005-08-22 | 삼성전자주식회사 | 호환형 광픽업 |
JP4321217B2 (ja) * | 2003-10-31 | 2009-08-26 | コニカミノルタオプト株式会社 | 光学素子及び光ピックアップ装置 |
JP2005322356A (ja) * | 2004-05-11 | 2005-11-17 | Canon Inc | 光ピックアップ装置 |
JP2006107558A (ja) * | 2004-09-30 | 2006-04-20 | Fujinon Corp | 光記録媒体用対物光学系およびこれを用いた光ピックアップ装置 |
-
2007
- 2007-03-19 JP JP2008510808A patent/JP4987856B2/ja not_active Expired - Fee Related
- 2007-03-19 WO PCT/JP2007/055462 patent/WO2007119410A1/ja active Application Filing
- 2007-03-19 CN CN2007800096943A patent/CN101405800B/zh not_active Expired - Fee Related
- 2007-03-19 US US12/293,291 patent/US8325581B2/en not_active Expired - Fee Related
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH11126362A (ja) * | 1997-10-24 | 1999-05-11 | Asahi Optical Co Ltd | 光情報記録再生ヘッドの光学系 |
JP2004079146A (ja) * | 2001-10-12 | 2004-03-11 | Konica Minolta Holdings Inc | 光ピックアップ装置、対物レンズ、回折光学素子、光学素子及び記録・再生装置 |
JP2004185797A (ja) * | 2002-11-21 | 2004-07-02 | Konica Minolta Holdings Inc | 光ピックアップ装置用光学系、光ピックアップ装置及び対物レンズ |
JP2005327394A (ja) * | 2004-05-14 | 2005-11-24 | Sony Corp | 光ピックアップおよび光ディスク装置 |
JP2004247047A (ja) * | 2004-05-31 | 2004-09-02 | Toshiba Corp | 光ヘッドおよびその光ヘッドを有する光ディスク装置ならびに情報記録再生装置 |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2010047093A1 (ja) * | 2008-10-24 | 2010-04-29 | パナソニック株式会社 | 光学ヘッド、光ディスク装置及び情報処理装置 |
US8391120B2 (en) | 2008-10-24 | 2013-03-05 | Panasonic Corporation | Optical head, optical disc device and information processing device |
WO2011077647A1 (ja) * | 2009-12-24 | 2011-06-30 | パナソニック株式会社 | 光学ヘッド、光ディスク装置、情報処理装置及び対物レンズ |
Also Published As
Publication number | Publication date |
---|---|
US20090046564A1 (en) | 2009-02-19 |
JP4987856B2 (ja) | 2012-07-25 |
CN101405800B (zh) | 2011-04-13 |
CN101405800A (zh) | 2009-04-08 |
US8325581B2 (en) | 2012-12-04 |
JPWO2007119410A1 (ja) | 2009-08-27 |
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