WO2008065800A1 - Optical pickup device - Google Patents

Optical pickup device Download PDF

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Publication number
WO2008065800A1
WO2008065800A1 PCT/JP2007/068232 JP2007068232W WO2008065800A1 WO 2008065800 A1 WO2008065800 A1 WO 2008065800A1 JP 2007068232 W JP2007068232 W JP 2007068232W WO 2008065800 A1 WO2008065800 A1 WO 2008065800A1
Authority
WO
WIPO (PCT)
Prior art keywords
light beam
correction lens
light
pickup device
optical pickup
Prior art date
Application number
PCT/JP2007/068232
Other languages
French (fr)
Japanese (ja)
Inventor
Takeshi Inatani
Original Assignee
Mitsubishi Electric Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsubishi Electric Corporation filed Critical Mitsubishi Electric Corporation
Publication of WO2008065800A1 publication Critical patent/WO2008065800A1/en

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Classifications

    • 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
    • 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
    • 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
    • G11B7/0948—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 detection and avoidance or compensation of imperfections on the carrier, e.g. dust, scratches, dropouts
    • 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
    • G11B7/22—Apparatus or processes for the manufacture of optical heads, e.g. assembly

Definitions

  • the present invention relates to an optical pickup device capable of correcting spherical aberration by correcting the spherical aberration of a beam spot caused by the difference in the thickness of a light transmission layer of an optical disc by adjusting the lens position.
  • the difference in the thickness of the light transmission layer of the optical disk is caused by the type of optical disk and the structure of the recording layer.
  • the difference in the type of optical discs such as DVD (Digital Versatile Disc) and BD (Blu-ray Disc)
  • the information recording surface has a two-layer structure. Because of this difference, the thickness of the transmission layer differs, so that spherical aberration correction is required each time the optical disk is replaced.
  • the conventional optical pickup device includes a position detection sensor for detecting the current position of the lens, for example, an LED and a photodetector, and the lens position becomes the reference of the optical system. Once moved to the origin position, the lens is moved to a predetermined position that can suppress the influence of spherical aberration according to the thickness of the light transmitting layer of the optical disc that performs recording and reproduction! /, (For example, see Patent Document 1).
  • Patent Document 1 Japanese Patent Application Laid-Open No. 2003-131113 (page 4, FIG. 1) Disclosure of the invention
  • the present invention has been made to solve the above-described problems. It is easy to assemble, and can be reduced in size and weight, and further, light that does not cause an increase in cost.
  • the purpose is to provide a pickup device.
  • An optical pickup device includes a laser light source that outputs a first light beam, and the first light beam is different from the second light beam and the third light beam at a predetermined ratio.
  • a beam splitter that separates in the direction, a correction lens provided on the optical axis of the third light beam, and a moving mechanism that supports the correction lens so as to be movable in the optical axis direction of the third light beam.
  • a correction plate that is interlocked with the correction lens and that moves the correction lens by the moving mechanism, thereby changing the ratio of blocking the first light beam, and controlling the moving mechanism to control the correction lens.
  • a movement control unit that moves the light beam, a light power measurement unit that receives the second light beam and measures a power value of the second light beam, the power value measured by the light power measurement unit, and the power value Moved by the movement control unit To the moving position of the positive lens Motodzure Te, and is characterized that you and a position measuring unit for measuring the position of the origin of the correction lens.
  • FIG. 1 is a perspective view showing a configuration of an optical pickup device according to a first embodiment of the present invention.
  • FIG. 2 is a perspective view for explaining an optical system according to the first embodiment of the optical pickup device according to the present invention.
  • FIG. 3 is an operation explanatory diagram for explaining the position and operation of the light shielding plate 19 with respect to the optical system of Embodiment 1 of the optical pickup device according to the present invention.
  • FIG. 4 is an operation explanatory diagram for explaining the position and operation of the light shielding plate 19 with respect to the optical system of Embodiment 1 of the optical pickup device according to the present invention.
  • FIG. 5 is an assembly diagram illustrating the assembly procedure of the first embodiment of the optical pickup device according to the present invention.
  • FIG. 6 is an explanatory diagram for explaining in detail the structure of the movable holder 13 of the first embodiment of the optical pickup device according to the present invention.
  • FIG. 7 is an explanatory diagram for explaining the position of the light shielding plate when the optical pickup device according to the first embodiment of the present invention is in a recording / reproducing state of a DVD.
  • FIG. 8 In the optical pickup device according to the first embodiment of the present invention! /, The light shielding plate when the moving mechanism of the correction lens 9 is moved to the origin position when the optical disk is changed from DV D to BD. It is explanatory drawing for demonstrating an example of a position.
  • FIG. 9 shows an output voltage corresponding to the laser light power value detected by the optical power detector 8 with respect to the position of the correction lens 9 held by the movable holder 13 in the first embodiment of the optical pickup device according to the present invention. It is a correction lens position output voltage characteristic view showing the relationship between
  • FIG. 10 is a perspective view showing the configuration of Embodiment 2 of the optical pickup device according to the present invention.
  • an example of the optical pickup device is a case where the optical disks to be reproduced and recorded are DVD and BD, and the optical power is changed to DVD with different light transmission layer thicknesses.
  • FIG. 1 is a perspective view showing the configuration of the first embodiment of the optical pickup device according to the present invention.
  • the approximately horizontal direction is called the X direction
  • the diagonally upward direction from the front to the rear is called the Y direction
  • the diagonally downward direction from the front to the rear is called the Z direction.
  • a positive or negative sign is attached. For example, if the direction is approximately the left side, it is called the + X direction.
  • a laser light source 2 is fixed to a pickup base 1 of the optical pickup device via a laser holding plate 3.
  • the transmitted light beam 6 is reflected and the traveling direction is changed by approximately 90 °, and is separated into a reflected light beam 7 which is a third light beam traveling in the X direction at a predetermined ratio.
  • the transmitted light beam 6 is incident on an optical power detector 8 which is an optical power measuring unit.
  • the transmitted light beam 6 is output based on the received laser light power value. Is controlled from time to time.
  • the reflected light beam 7 is transmitted through the correction lens unit 9 and turned up by approximately 90 ° in the + Z direction where a DVD (not shown) is set by the launch mirror 10.
  • the DVD reflected light beam including the recording information reflected on the information recording surface of the DVD follows the reverse path so far and enters the beam splitter 5 again.
  • the light transmitted through the beam splitter 5 passes through the cylindrical lens 11 and then enters the light detector 12.
  • the photodetector 12 converts the DVD recording information into an electrical signal.
  • the correction lens 9 is held by a movable holder 13, and the movable holder 13 is a guide.
  • the shaft 14 and the guide shaft 15 are restricted so as to be movable only in one axial direction.
  • the movable holder 13 has a protruding needle portion 13a, and the needle portion 13a is engaged with a groove portion 17a of a lead screw 17 driven by a stepping motor 16! /.
  • the movable holder 13 is movable in the X direction, which is the optical axis direction of the reflected light beam 7, as the stepping motor 16 rotates.
  • a light shielding plate 19 is fixed to the movable holder 13 via a set screw 18.
  • the incident light beam 4 can continuously change the light shielding ratio by moving the light shielding plate 19 in the X direction in conjunction with the movable holder 13.
  • the size and shape of the light shielding plate 19 such as the length in the X direction and the width in the Z direction are set to sizes and shapes that can completely block the outgoing light beam 4.
  • FIG. 2 is a perspective view for explaining in detail the optical system according to the first embodiment of the optical pickup device according to the present invention. Also, the same reference numerals as those in FIG.
  • the outgoing light beam 4 emitted from the laser light source 2 in the + Y direction is changed by a substantially 90 ° direction from the transmitted light beam 6 that goes straight in the + Y direction by the beam splitter 5. And is reflected at a predetermined ratio to the reflected light beam 7 traveling in the X direction.
  • the straight transmitted beam 6 enters the optical power detector 8 and the laser beam power value of the laser light source 2 is detected.
  • the reflected light beam 7 passes through a correction lens 9 for correcting spherical aberration due to a difference in thickness of a light transmission layer of a DVD (not shown), and the DVD is launched by a launch mirror 10. Change the direction by approximately 90 ° to the set + Z direction. Furthermore, after being converted into circularly polarized light by the ⁇ / 4 wavelength plate 20, it is condensed by an objective lens (not shown) and irradiated to the information recording surface of the DVD.
  • FIG. 3 and FIG. 4 are operation explanatory views for explaining the position and operation of the shielding plate 19 with respect to the optical system of the first embodiment described above with reference to FIG. 1 and FIG. The same reference numerals as those in FIG. 1 and FIG.
  • the light shielding plate 19 is a light beam emitted from the laser light source 2 toward the beam splitter 5.
  • the light shielding ratio of the outgoing light beam 4 by the light shielding plate 19 is 0%, and the outgoing light beam 4 emitted from the laser light source 2 toward the beam splitter 5 is not shielded by the light shielding plate 19. Pass 100%.
  • the shielding ratio of the emitted light beam 4 gradually increases from 0%, and finally, as shown in FIG.
  • the light shielding ratio of the outgoing light beam 4 by the light shielding plate 19 is 100%, and the outgoing light beam 4 emitted from the laser light source 2 toward the beam splitter 5 is completely shielded by the light shielding plate 19. That is, the outgoing light beam 4 is not incident on the optical system downstream of the beam splitter 5 in the propagation of the light beam, including the beam splitter 5 described above.
  • FIG. 5 is an assembly diagram illustrating the assembly procedure of Embodiment 1 of the optical pickup device according to the present invention.
  • the same reference numerals as those in FIGS. 1, 2, 3, and 4 denote the same or corresponding parts, and thus the description thereof is omitted.
  • the laser holding plate 3 is provided with a hole 3a for inserting and holding the laser light source 2, and the cylindrical portion 2a of the laser light source 2 is engaged with the hole 3a so that the laser light source 2 Is press-fitted and held in the laser holding plate 3.
  • the laser holding plate 3 is subjected to in-plane adjustment for optical axis positioning adjustment in a state where the mounting surface 3b on the side facing the pickup base 1 is in surface contact with the mounting surface la of the pickup base 1, and then the pickup base 1 Bonded and fixed to 1.
  • the emitted light beam 4 emitted from the laser light source 2 is introduced into the pickup base 1 through a hole lb provided on the side surface of the pickup base 1.
  • the beam splitter 5 has a cubic shape, and its three surfaces are positioned so as to press against the corresponding three mounting surfaces provided on the pickup base 1, respectively. , Glued and fixed.
  • the optical power detector 8 is attached and fixed to the power detector holding plate 21, and is positioned and fixed in such a manner that the three surfaces are pressed against the corresponding attachment surfaces provided on the pickup base 1.
  • the cylindrical lens 11 has a configuration in which the lens portion 1 la is held by the outer peripheral holder 1 lb, and is positioned and bonded and fixed in such a manner that three surfaces are pressed against corresponding mounting surfaces provided on the pickup base 1.
  • the light detector 12 is attached and fixed to the light detector holding plate 22, and has a shape that closes the hole lc through which the light beam provided in the pickup base 1 passes, and the direction of the optical axis and the light of the light detector 12. After performing optical axis positioning adjustment in three directions consisting of the in-plane direction of the detection surface, the adhesive 23 is bonded and fixed to the positioned position.
  • the laser light source 2, the optical power detector 8, and the photodetector 12 are each electrically connected by a flexible printed circuit board (FPC) or the like.
  • the movable holder 13 has the correction lens 9 bonded and fixed, the guide shaft 14 and the guide shaft 15 are engaged, and the light shielding plate 19 is fixed with screws using the set screw 18. Positioned and mounted on the corresponding mounting surface of 1.
  • the stepping motor 16 for enabling the movable holder 13 to move in the optical axis direction has a lead screw 17 integrated with the rotor, and is held by the motor holding plate 24.
  • the motor holding plate 24 is precisely positioned with respect to the pickup base 1 by engaging two positions of the positioning hole 24a and the positioning hole 24b with a boss provided with a corresponding mounting surface of the pickup base 1.
  • the mounting screw 25 passes through the screw hole 24c and is fixed to the pickup base 1.
  • FIG. 6 is an explanatory diagram for explaining in detail the structure of the movable holder 13 of the first embodiment of the optical pickup device according to the present invention. 1, 2, 3, 4, and 5 indicate the same or corresponding parts, and the description thereof is omitted.
  • the correction lens 9 is a positioning portion provided in the hole 13 b of the movable holder 13.
  • the outer peripheral portion 9b which is the outer periphery of the lens portion 9a is engaged with and fixed to the movable holder 13 in 13c.
  • the guide shaft 14 and the guide shaft 15 are engaged with the bearing portion 13d and the bearing portion 13e of the movable holder 13, respectively, and the movable holder 13 is in the X direction which is the optical axis direction of the reflected light beam. It is possible to move to.
  • the needle portion 13a provided in the movable holder 13 is engaged with the groove portion 17a of the lead screw 17 so as to be movable in the X direction which is the optical axis direction as the lead screw 17 rotates. It is.
  • the movable holder 13 has a light shielding plate 19 composed of a screw hole portion 19a and a light shielding portion 19b.
  • the set screw 18 passes through the screw hole portion 19a and is screwed with the screw portion 13f of the movable holder 13. It is fixed.
  • FIG. 7 is an explanatory diagram for explaining the position of the light shielding plate in the DVD recording / reproducing state in the first embodiment of the optical pickup device according to the present invention.
  • 1, 2, 3, 4, 5, and 6 denote the same or corresponding parts and will not be described.
  • the correction lens 9 causes the light spot when the reflected light beam 7 is applied to the information recording surface of the DVD (not shown). Spherical aberration due to the difference in thickness of DVD and BD light transmission layers is suppressed so that the spot diameter is sufficiently small. It is set at an appropriate position in the X direction corresponding to the DVD light transmission layer thickness. .
  • the light shielding plate 19 is fixed to the movable holder 13 that holds the correction lens 9. Therefore, when the movable holder 13 moves in the X direction, the light shielding plate 19 moves in the X direction in conjunction with the movable holder 13, thereby changing the ratio of shielding the emitted light beam 4 emitted from the laser light source 2. It is possible.
  • the correction lens 9 is set to an appropriate position capable of suppressing spherical aberration.
  • the light shielding plate 19 is emitted from the laser light source 2. Do not block the outgoing light beam 4!
  • the movement control unit includes the movable holder 13 including the needle unit 13a and the needle.
  • the moving mechanism which includes a lead screw 17 with which the screw portion 13a is fitted and a stepping motor 16 that rotates the lead screw 17, is controlled so that the correction lens 9 moves to a predetermined position.
  • FIG. 8 shows the position of the light shielding plate when the moving mechanism of the correction lens 9 is moved to the origin position when the optical disk is exchanged from DVD to BD in Embodiment 1 of the optical pickup device according to the present invention. It is explanatory drawing for demonstrating an example. The same reference numerals as those in FIG. 7 denote the same or corresponding parts, and the description thereof will be omitted.
  • the light shielding plate 19 is moved in the direction of + ⁇ compared to the case of FIG. 7 so as to shield a part of the outgoing light beam 4.
  • the outgoing light beam 4 partially shielded by the light shielding plate 19 enters the beam splitter 5, and the transmitted light beam 6 transmitted through the beam splitter 5 enters the optical power detector 8.
  • the laser light power value corresponding to the ratio of light shielded by the light shielding plate 19 is detected.
  • FIG. 9 corresponds to the position of the correction lens 9 held by the movable holder 13 and the laser light power value detected by the optical power detector 8 in Embodiment 1 of the optical pickup device according to the present invention. It is a correction
  • the laser is adjusted so that the output of the laser light source 2 becomes a constant value based on the laser light power value detected by the optical power detector 8.
  • the output of light source 2 is controlled.
  • the movement control unit controls the drive power source (not shown) of the laser light source 2 so as not to control the output of the laser light source 2 based on the laser light power value. Instruct.
  • the type of optical disc to be recorded / reproduced for example, DVD and BD, or a multi-layer optical disc in which the optical disc has a plurality of information recording layers, such as a two-layer structure.
  • the thickness of the light transmission layer of the optical disk is different, and when the optical disk is replaced, the thickness of the light transmission layer changes.
  • the movement of the correction lens 9 is controlled by the movement controller.
  • the movement control unit electrically inputs a drive pulse to the stepping motor 16 to rotate the lead screw 17, and the direction of the optical axis of the reflected light beam 7 is applied to the needle portion 13a of the movable holder 13 engaged with the groove portion 17a of the lead screw 17.
  • the driving force in the X direction is applied, the movable holder 13 is driven in the X direction.
  • the position of the correction lens 9 is set to an appropriate position where the spherical aberration corresponding to the thickness of the light transmission layer of the DVD can be suppressed. Yes.
  • the position of the correction lens 9 is temporarily returned to the origin position of the moving mechanism as shown in FIG. 8, and then the thickness of the light transmission layer of the BD is set. It will be moved to an appropriate position where the corresponding spherical aberration can be suppressed.
  • the origin position in the X direction of the correction lens 9 with respect to the pickup base 1 is set, and the movement control unit of the movement mechanism holds the movement amount from the origin position to each appropriate position of the DVD or BD as data. Therefore, when replacing the optical disk, the correction lens 9 once moves to the origin position. This is because the stepping motor 16 electrically controls the rotation of the lead screw 17 according to the number of drive pulses. In the unlikely event of a temporary drive mechanism failure, the number of drive pulses and the actual position of the correction lens 9 Even if a so-called out-of-step occurs that makes it impossible to deal with This is to make the estimated position coincide with the actual position of the correction lens 9.
  • the movement control unit After recognizing that the optical disk has been exchanged from DVD to BD, the movement control unit starts control to move the correction lens 9 to the origin position.
  • the correction lens 9 starts to move from the appropriate position corresponding to DVD recording / reproduction, controlled by the movement control unit in the + X direction.
  • the outgoing light beam 4 emitted from the light source 2 is not shielded by the light shielding plate 19.
  • the unshielded outgoing light beam 4 is incident on the beam splitter 5, and the transmitted transmitted light beam 6 is incident on the optical power detector 8.
  • the output voltage in Fig. 9 corresponds to the laser light power value of the transmitted light beam 6 received by the optical power detector 8. That is, the output voltage V in FIG. 9 is an output voltage corresponding to the laser light power value of the outgoing light beam 4 when not shielded by the light shielding plate 19.
  • the position of the correction lens 9 corresponding to the output voltage that is the output voltage V is the original position.
  • the movement control unit makes a correction level to the movement mechanism.
  • the light shielding plate 19 In conjunction with the correction lens 9, the light shielding plate 19 also moves in the + X direction, and when the light shielding plate 19 reaches a position where it partially blocks the outgoing light beam 4, the output voltage gradually decreases. .
  • the movement control unit stops at a position where the output voltage of the optical power detector 8 becomes the output voltage V with respect to the movement mechanism.
  • the movement control unit can detect the origin position of the correction lens 9 by detecting the output voltage of the optical power detector 8.
  • the correction lens 9 may first be positioned on the + X direction side of the origin position. In that case, the output voltage of the optical power detector 8 is smaller than the output voltage V. The length of the light shielding plate 19 in the X direction and
  • the position of the correction lens 9 is moved from the origin position to the + X direction due to a defect or the like.
  • the output voltage of the optical power detector 8 is 0V. Therefore, when the output voltage of the optical power detector 8 is smaller than the output voltage V, the movement control unit
  • the light shielding plate 19 When the correction lens 9 moves in the -X direction, the light shielding plate 19 also moves in the X direction in conjunction with the correction lens 9, and the light shielding plate 19 emits the emitted light beam 4 emitted from the laser light source 2.
  • the ratio of light shielding decreases, and as a result, the output voltage of the optical power detector 8 increases.
  • the movement control unit determines that the output voltage of the optical power detector 8 is equal to the output voltage V with respect to the movement mechanism. To stop at a certain position. That is, also in this case, the movement control unit can detect the origin position of the correction lens 9 by detecting the output voltage of the optical power detector 8.
  • the outgoing light beam 4 emitted from the laser light source 2 and the reflected light beam 7 separated by the beam splitter 5 form an angle of approximately 90 ° has been described.
  • the light shielding plate 19 interlocked with the correction lens 9 can block the outgoing light beam 4, so this angle is limited to approximately 90 °. Do not mean.
  • the output voltage of the optical power detector 8 becomes the output voltage V that is a predetermined value.
  • the detection accuracy of the origin position of the compensation lens 9 may be lowered.
  • the correction lens 9 When the correction lens 9 is returned to the original position after the force is also exchanged with the BD, the value obtained by multiplying the output voltage V, which is the output voltage at the time of recording / playback of the DVD before replacement, by the ratio value p obtained in advance Is the output voltage V corresponding to the origin position.
  • the movement control unit
  • the output voltage of the optical power detector 8 becomes equal to the output voltage V calculated in this way.
  • the origin position of the correction lens 9 can be detected more stably and accurately.
  • Embodiment 1 of the optical pickup device moves in conjunction with the correction lens 9 that can be moved by the moving mechanism and emits the emitted light beam emitted from the laser light source 2.
  • a light shielding plate 19 that can change the ratio of shielding the light beam 4, and detecting the origin position of the correction lens 9 based on the output voltage corresponding to the laser light power value of the emitted light beam 4 shielded by the light shielding plate 19. I did it. Therefore, it is not necessary to newly install a position detection sensor for detecting the position of the correction lens 9, and wiring to the position detection sensor itself or the attached control board is unnecessary, so that the assembly work becomes easy. Since the number of parts is small, it is possible to reduce the size and weight, and to prevent the cost from increasing.
  • the size and shape of the light shielding plate 19 such as the length in the X direction and the width in the Z direction, are set to sizes and shapes that can completely block the outgoing light beam 4! /
  • the size and shape of the light shielding plate 19 are not limited to the case where the outgoing light beam 4 is set to be completely shielded. That is, even when the light shielding plate 19 is set so as to block only a part of the outgoing light beam 4, the output voltage of the optical power detector 8 in that case is the output voltage V corresponding to the origin position. If it is smaller, the movement control unit
  • the correction lens 9 is instructed to move in the X direction, so that the V is based on the output voltage corresponding to the laser light power value of the outgoing light beam 4 partially shielded by the light shielding plate 19. Needless to say, the origin position of the correction lens 9 can be detected!
  • the light shielding plate 19 shields the outgoing light beam 4 as the first light beam, and the power value of the transmitted light beam 6 as the second light beam is the optical power measuring unit.
  • the force S indicates that the detector 8 is configured to measure, and the light shielding plate shields the transmitted light beam, which is the second light beam, and the light shielding ratio of the light shielding plate is changed. Needless to say, the same effect can be obtained even if the optical power detector 8 is used to measure the power value of the transmitted light beam, which is the second light beam.
  • the optical pickup device is described as an example in which the optical disc is exchanged from DVD to BD.
  • the optical disc has, for example, an information recording surface having a two-layer structure. It is also effective when it is BD.
  • the first embodiment of the optical pickup device according to the present invention is effective even when the correction lens 9 is once returned to the origin and then moved to the proper position.
  • the stepping motor 16 is used as a drive source, and after the initial position of the correction lens 9 held by the movable holder 13 is initially detected by the method described above, a predetermined number of pulses set in advance is stepped.
  • Embodiment 1 of the optical pickup device according to the present invention is configured to position the correction lens 9 at a predetermined position by inputting to the motor 16. Therefore, for example, the positioning movement can be executed without waiting time regardless of other operation states such as a state in which a reproduction signal from the optical disk cannot be obtained. There is an effect that the replacement time can be shortened.
  • the force S is such that the light shielding plate 19 is fixed to the screw portion 13f of the movable holder 13 with the set screw 18, and the light shielding plate 19 is connected to the movable holder 13. It may be an integral part.
  • FIG. 10 is a perspective view showing the configuration of the optical pickup apparatus according to Embodiment 2 of the present invention.
  • an integral movable holder 13g that holds the correction lens 9 includes an integrally formed light shielding portion 13h, and the positional relationship between the correction lens 9 and the light shielding portion 13h is a process of performing integral molding. The accuracy is determined, and the accuracy cannot be lowered by fixing with screws.
  • Embodiment 2 of the optical pickup device according to the present invention can further improve the detection accuracy of the origin position.
  • the assembly work can be reduced and work costs can be reduced.

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  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Moving Of The Head For Recording And Reproducing By Optical Means (AREA)
  • Optical Head (AREA)

Abstract

[PROBLEMS] To provide an optical pickup device which can be assembled easily because a sensor for detecting the position of a correction lens is not required and can reduce the size and the weight without increasing the cost. [MEANS FOR SOLVING PROBLEMS] The optical pickup device comprises a shading plate (19) interlinked with a correction lens (9) movable through a moving mechanism and moves to vary the shading ratio of a light beam (4) emitted from a laser light source (2), and detects the origin position of the correction lens (9) based on the output voltage corresponding to the laser light power value of the emitted light beam (4) shaded by the shading plate (19).

Description

明 細 書  Specification
光ピックアップ装置  Optical pickup device
技術分野  Technical field
[0001] この発明は、光ディスクの光透過層の厚みが異なることにより発生するビームスポッ トの球面収差を、レンズ位置を調整することで補正する球面収差補正可能な光ピック アップ装置に関する。  TECHNICAL FIELD [0001] The present invention relates to an optical pickup device capable of correcting spherical aberration by correcting the spherical aberration of a beam spot caused by the difference in the thickness of a light transmission layer of an optical disc by adjusting the lens position.
背景技術  Background art
[0002] 光ディスクの記録再生に使用する高開口数の対物レンズを備えた光ピックアップ装 置では、光透過層の厚みが異なると、光透過層の厚みの違いに起因する球面収差 の発生が著しレ、ことが従来より知られて!/、る。  [0002] In an optical pickup device equipped with an objective lens with a high numerical aperture used for recording and reproduction of an optical disc, if the thickness of the light transmission layer is different, the occurrence of spherical aberration due to the difference in the thickness of the light transmission layer is significant. Shire, it has been known for a long time!
[0003] 球面収差が大きいと、光ディスクの情報記録面上に集光される光スポットのスポット 径が大きくなり、光スポットの光強度分布のピーク強度が低下する。その結果、情報 の読取り時では、再生信号レベルが低下してジッターが増大し、隣接トラック力、らのク ロストークが増加し、エラーレートが大きくなる。また、情報の書込み時では、マークサ ィズが増大して、記録感度が低下する。このような現象は、狭トラックピッチ、短ピット 長となる高密度記録では一層顕著となる。  [0003] When the spherical aberration is large, the spot diameter of the light spot collected on the information recording surface of the optical disc increases, and the peak intensity of the light intensity distribution of the light spot decreases. As a result, at the time of reading information, the reproduction signal level decreases and jitter increases, adjacent track force and other crosstalk increase, and the error rate increases. Also, when writing information, the mark size increases and the recording sensitivity decreases. Such a phenomenon becomes more prominent in high-density recording with a narrow track pitch and a short pit length.
[0004] なお、光ディスクの光透過層の厚みが異なる要因としては、光ディスクの種類や記録 層の構造の違いによって発生する。例えば、 DVD (Digital Versatile Disc)や B D (Blu-ray Disc)というような光ディスクの種類の違いや情報記録面が 2層構造を 有する BDの 1層目と 2層目というような記録層の構造の違いによって、透過層の厚み が異なることとなるので、光ディスクを交換する毎に、球面収差補正が必要となる。  [0004] Note that the difference in the thickness of the light transmission layer of the optical disk is caused by the type of optical disk and the structure of the recording layer. For example, the difference in the type of optical discs such as DVD (Digital Versatile Disc) and BD (Blu-ray Disc), and the information recording surface has a two-layer structure. Because of this difference, the thickness of the transmission layer differs, so that spherical aberration correction is required each time the optical disk is replaced.
[0005] そこで、従来の光ピックアップ装置では、レンズの現在位置を検出するための、例え ば、 LEDと光検出器とからなる位置検出センサを備え、レンズの位置を光学系の基 準となる原点位置に一旦移動させてから、記録再生をこれ力 行う光ディスクの光透 過層の厚みに対応して、球面収差の影響を抑制できる所定の位置にレンズを移動さ せるようにして!/、た (例えば、特許文献 1参照）。  [0005] Therefore, the conventional optical pickup device includes a position detection sensor for detecting the current position of the lens, for example, an LED and a photodetector, and the lens position becomes the reference of the optical system. Once moved to the origin position, the lens is moved to a predetermined position that can suppress the influence of spherical aberration according to the thickness of the light transmitting layer of the optical disc that performs recording and reproduction! /, (For example, see Patent Document 1).
[0006] 特許文献 1 :特開 2003— 131113号公報（第 4頁、第 1図） 発明の開示 [0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2003-131113 (page 4, FIG. 1) Disclosure of the invention
発明が解決しょうとする課題  Problems to be solved by the invention
[0007] ところ力 上記のような従来の光ピックアップ装置にあっては、レンズの位置を検出 するための位置検出センサを新たに搭載する必要があり、位置検出センサ自体や付 属する制御基板等への配線が必要となって組立て作業が複雑となったり、部品数が 増えることで小型化や軽量化を阻害したり、さらには、製造コストの増大を招くという問 題があった。 However, in the conventional optical pickup device as described above, it is necessary to newly install a position detection sensor for detecting the position of the lens, and the position detection sensor itself, an attached control board, etc. There is a problem that the assembly work becomes complicated due to the necessity of wiring, the increase in the number of parts hinders miniaturization and weight reduction, and further increases the manufacturing cost.
[0008] この発明は、上記のような課題を解決するために為されたもので、組立てが容易で あるとともに、小型化や軽量化が図れ、さらには、コストの増大を招くことの無い光ピッ クアップ装置を提供することを目的とする。  [0008] The present invention has been made to solve the above-described problems. It is easy to assemble, and can be reduced in size and weight, and further, light that does not cause an increase in cost. The purpose is to provide a pickup device.
課題を解決するための手段  Means for solving the problem
[0009] この発明に係る光ピックアップ装置は、第 1の光ビームを出力するレーザ光源と、前 記第 1の光ビームを第 2の光ビームと第 3の光ビームに所定の割合で互いに異なる向 きに分離するビームスプリッタと、前記第 3の光ビームの光軸上に設けられた補正レン ズと、前記補正レンズを前記第 3の光ビームの光軸方向に移動可能に支持する移動 機構と、前記補正レンズに連動され、前記移動機構により前記補正レンズが移動す ることで、前記第 1の光ビームを遮光する割合を可変する遮光板と、前記移動機構を 制御して前記補正レンズを移動させる移動制御部と、前記第 2の光ビームを受光して 前記第 2の光ビームのパワー値を測定する光パワー測定部と、前記光パワー測定部 で測定された前記パワー値と前記移動制御部により移動した前記補正レンズの移動 位置とに基づレ、て、前記補正レンズの原点位置を測定する位置測定部とを備えるこ とを特徴とするものである。 [0009] An optical pickup device according to the present invention includes a laser light source that outputs a first light beam, and the first light beam is different from the second light beam and the third light beam at a predetermined ratio. A beam splitter that separates in the direction, a correction lens provided on the optical axis of the third light beam, and a moving mechanism that supports the correction lens so as to be movable in the optical axis direction of the third light beam. And a correction plate that is interlocked with the correction lens and that moves the correction lens by the moving mechanism, thereby changing the ratio of blocking the first light beam, and controlling the moving mechanism to control the correction lens. A movement control unit that moves the light beam, a light power measurement unit that receives the second light beam and measures a power value of the second light beam, the power value measured by the light power measurement unit, and the power value Moved by the movement control unit To the moving position of the positive lens Motodzure Te, and is characterized that you and a position measuring unit for measuring the position of the origin of the correction lens.
発明の効果  The invention's effect
[0010] この発明によれば、位置検出センサを新たに搭載する必要が無!/、ので、位置検出 センサ自体や付属する制御基板等への配線が不要なことから組立て作業が容易とな るとともに、部品数が少なくて良いので、小型化や軽量化が図れ、さらには、コストの 増大を招かなレ、と!/、う効果がある。 図面の簡単な説明 [0010] According to the present invention, since it is not necessary to newly install a position detection sensor !, wiring to the position detection sensor itself or an attached control board is not necessary, and therefore assembly work is facilitated. At the same time, since the number of parts can be small, it is possible to reduce the size and weight, and to increase the cost! Brief Description of Drawings
[0011] [図 1]この発明に係る光ピックアップ装置の実施の形態 1の構成を示す斜視図である  FIG. 1 is a perspective view showing a configuration of an optical pickup device according to a first embodiment of the present invention.
[図 2]この発明に係る光ピックアップ装置の実施の形態 1の光学系を説明するための 斜視図である。 FIG. 2 is a perspective view for explaining an optical system according to the first embodiment of the optical pickup device according to the present invention.
[図 3]この発明に係る光ピックアップ装置の実施の形態 1の光学系に対する遮光板 19 の位置、及び動作を説明するための動作説明図である。  FIG. 3 is an operation explanatory diagram for explaining the position and operation of the light shielding plate 19 with respect to the optical system of Embodiment 1 of the optical pickup device according to the present invention.
[図 4]この発明に係る光ピックアップ装置の実施の形態 1の光学系に対する遮光板 19 の位置、及び動作を説明するための動作説明図である。  FIG. 4 is an operation explanatory diagram for explaining the position and operation of the light shielding plate 19 with respect to the optical system of Embodiment 1 of the optical pickup device according to the present invention.
[図 5]この発明に係る光ピックアップ装置の実施の形態 1の組み立て手順を説明する 組立て図である。  FIG. 5 is an assembly diagram illustrating the assembly procedure of the first embodiment of the optical pickup device according to the present invention.
[図 6]この発明に係る光ピックアップ装置の実施の形態 1の可動ホルダ 13の構造を詳 細に説明するための説明図である。  FIG. 6 is an explanatory diagram for explaining in detail the structure of the movable holder 13 of the first embodiment of the optical pickup device according to the present invention.
[図 7]この発明に係る光ピックアップ装置の実施の形態 1にお!/、て、 DVDの記録再生 状態にある場合の遮光板の位置を説明するための説明図である。  FIG. 7 is an explanatory diagram for explaining the position of the light shielding plate when the optical pickup device according to the first embodiment of the present invention is in a recording / reproducing state of a DVD.
[図 8]この発明に係る光ピックアップ装置の実施の形態 1にお!/、て、光ディスクを DV Dから BDに交換した際に補正レンズ 9の移動機構が原点位置に移動した場合の遮 光板の位置の一例を説明するための説明図である。  [FIG. 8] In the optical pickup device according to the first embodiment of the present invention! /, The light shielding plate when the moving mechanism of the correction lens 9 is moved to the origin position when the optical disk is changed from DV D to BD. It is explanatory drawing for demonstrating an example of a position.
[図 9]この発明に係る光ピックアップ装置の実施の形態 1において、可動ホルダ 13に 保持された補正レンズ 9の位置に対する光パワー検知器 8で検知されたレーザ光パ ヮー値に対応する出力電圧との関係を示す補正レンズ位置出力電圧特性図である。  FIG. 9 shows an output voltage corresponding to the laser light power value detected by the optical power detector 8 with respect to the position of the correction lens 9 held by the movable holder 13 in the first embodiment of the optical pickup device according to the present invention. It is a correction lens position output voltage characteristic view showing the relationship between
[図 10]この発明に係る光ピックアップ装置の実施の形態 2の構成を示す斜視図である 符号の説明  FIG. 10 is a perspective view showing the configuration of Embodiment 2 of the optical pickup device according to the present invention.
[0012] 2 レーザ光源、 2a 円筒部、 4 出射光ビーム、 5 ビームスプリッタ、 6 透過 光ビーム、 7 反射光ビーム、 8 光パワー検知器、 9 補正レンズ、 9a レンズ 部、 9b 外周部、 13 可動ホルダ、 13a ニードル部、 13b 穴部、 13c 位 置決め部、 13d 軸受部、 13e 軸受部、 13f ネジ部、 13g —体型可動ホル ダ、 13h 遮光部、 14 ガイドシャフト、 15 ガイドシャフト、 16 ステッピングモ ータ、 17 リードスクリュー、 17a 溝部、 19 遮光板。 [0012] 2 laser light source, 2a cylindrical part, 4 outgoing light beam, 5 beam splitter, 6 transmitted light beam, 7 reflected light beam, 8 optical power detector, 9 correction lens, 9a lens part, 9b outer peripheral part, 13 movable Holder, 13a Needle part, 13b Hole part, 13c Positioning part, 13d Bearing part, 13e Bearing part, 13f Screw part, 13g 13h Shading part, 14 Guide shaft, 15 Guide shaft, 16 Stepping motor, 17 Lead screw, 17a Groove part, 19 Shading plate.
発明を実施するための最良の形態  BEST MODE FOR CARRYING OUT THE INVENTION
[0013] 以下、この発明の実施の形態による光ピックアップ装置を、再生記録する光ディスク が DVDと BDであり、光透過層の厚みが互いに異なる DVD力、ら BDに光ディスクを交 換する場合を一例に説明する。  [0013] In the following, an example of the optical pickup device according to the embodiment of the present invention is a case where the optical disks to be reproduced and recorded are DVD and BD, and the optical power is changed to DVD with different light transmission layer thicknesses. Explained.
[0014] 実施の形態 1.  [0014] Embodiment 1.
図 1は、この発明に係る光ピックアップ装置の実施の形態 1の構成を示す斜視図で ある。なお、図 1に記載されている直交座標系が示すように、略横方向を X方向、手 前から後方へに向かう斜め上方を Y方向、手前から後方へ向かう斜め下方を Z方向と 呼ぶこととする。さらに、向きを指定する場合は、正負の符号を付けて、例えば、略左 横の向きであれば +Xの向きと呼ぶものとする。  FIG. 1 is a perspective view showing the configuration of the first embodiment of the optical pickup device according to the present invention. As shown by the Cartesian coordinate system shown in Fig. 1, the approximately horizontal direction is called the X direction, the diagonally upward direction from the front to the rear is called the Y direction, and the diagonally downward direction from the front to the rear is called the Z direction. And Furthermore, when designating the direction, a positive or negative sign is attached. For example, if the direction is approximately the left side, it is called the + X direction.
[0015] 光ピックアップ装置のピックアップベース 1には、レーザ光源 2がレーザ保持板 3を 介して固定されている。レーザ光源 2から + Yの向きへ出射された第 1の光ビームで ある出射光ビーム 4はビームスプリッタ 5に入射し、ビームスプリッタ 5によってそのまま + Yの向きへ直進する第 2の光ビームである透過光ビーム 6と、反射されて略 90° 進 行方向が変わり、 Xの向きに進む第 3の光ビームである反射光ビーム 7とに所定の 割合で分離される。  A laser light source 2 is fixed to a pickup base 1 of the optical pickup device via a laser holding plate 3. The outgoing light beam 4, which is the first light beam emitted from the laser light source 2 in the + Y direction, enters the beam splitter 5, and is a second light beam that goes straight in the + Y direction by the beam splitter 5. The transmitted light beam 6 is reflected and the traveling direction is changed by approximately 90 °, and is separated into a reflected light beam 7 which is a third light beam traveling in the X direction at a predetermined ratio.
[0016] 透過光ビーム 6は、光パワー測定部である光パワー検知器 8に入射し、光ディスク の記録再生時には、そこで受光されたレーザ光パワー値に基づ!/、てレーザ光源 2の 出力が随時制御される。一方、反射光ビーム 7は、補正レンズ部 9を透過して打上げ ミラー 10で DVD (図示せず）がセットされている + Zの向きに略 90° 方向転換される  [0016] The transmitted light beam 6 is incident on an optical power detector 8 which is an optical power measuring unit. When recording / reproducing an optical disc, the transmitted light beam 6 is output based on the received laser light power value. Is controlled from time to time. On the other hand, the reflected light beam 7 is transmitted through the correction lens unit 9 and turned up by approximately 90 ° in the + Z direction where a DVD (not shown) is set by the launch mirror 10.
[0017] 次に、 DVDの情報記録面で反射された記録情報を含む DVD反射光ビームは、こ れまでと逆の経路をたどり、再びビームスプリッタ 5に入射する。次に、ビームスプリツ タ 5を透過した光はシリンドリカルレンズ 11を透過した後、光検知器 12に入射する。 光検知器 12では、 DVDの記録情報が電気信号に変換される。 Next, the DVD reflected light beam including the recording information reflected on the information recording surface of the DVD follows the reverse path so far and enters the beam splitter 5 again. Next, the light transmitted through the beam splitter 5 passes through the cylindrical lens 11 and then enters the light detector 12. The photodetector 12 converts the DVD recording information into an electrical signal.
[0018] なお、補正レンズ 9は、可動ホルダ 13にて保持されており、可動ホルダ 13は、ガイド シャフト 14とガイドシャフト 15とで一軸方向にのみ移動可能に規制されている。この 可動ホルダ 13は突き出したニードル部 13aを有し、ニードル部 13aがステッピングモ ータ 16で駆動されるリードスクリュー 17の溝部 17aと嚙み合わされて!/、る。可動ホル ダ 13は、ステッピングモータ 16が回転することで、反射光ビーム 7の光軸方向である X方向に移動可能となっている。 Note that the correction lens 9 is held by a movable holder 13, and the movable holder 13 is a guide. The shaft 14 and the guide shaft 15 are restricted so as to be movable only in one axial direction. The movable holder 13 has a protruding needle portion 13a, and the needle portion 13a is engaged with a groove portion 17a of a lead screw 17 driven by a stepping motor 16! /. The movable holder 13 is movable in the X direction, which is the optical axis direction of the reflected light beam 7, as the stepping motor 16 rotates.
[0019] さらに、可動ホルダ 13には、止めネジ 18を介して遮光板 19が固定されている。出 射光ビーム 4は、遮光板 19が可動ホルダ 13に連動して X方向に移動することで、連 続的に遮光割合を可変できる。遮光板 19の X方向の長さ及び Z方向の幅等のサイズ 及び形状は、出射光ビーム 4を完全に遮ることが可能なサイズ及び形状に設定され ている。 Furthermore, a light shielding plate 19 is fixed to the movable holder 13 via a set screw 18. The incident light beam 4 can continuously change the light shielding ratio by moving the light shielding plate 19 in the X direction in conjunction with the movable holder 13. The size and shape of the light shielding plate 19 such as the length in the X direction and the width in the Z direction are set to sizes and shapes that can completely block the outgoing light beam 4.
[0020] 図 2は、この発明に係る光ピックアップ装置の実施の形態 1の光学系を詳細に説明 するための斜視図である。また、図 1と同一符号は同一又は相当部分を示すので説 明を省略する。  FIG. 2 is a perspective view for explaining in detail the optical system according to the first embodiment of the optical pickup device according to the present invention. Also, the same reference numerals as those in FIG.
[0021] 図 2において、レーザ光源 2から + Yの向きに出射された出射光ビーム 4は、ビーム スプリッタ 5でそのまま + Yの向きに直進する透過光ビーム 6と、略 90° 向きを変える ように反射され、 Xの向きに進む反射光ビーム 7とに所定の割合で分離される。直 進する透過ビーム 6は光パワー検知器 8に入射して、レーザ光源 2のレーザ光パワー 値が検知される。  In FIG. 2, the outgoing light beam 4 emitted from the laser light source 2 in the + Y direction is changed by a substantially 90 ° direction from the transmitted light beam 6 that goes straight in the + Y direction by the beam splitter 5. And is reflected at a predetermined ratio to the reflected light beam 7 traveling in the X direction. The straight transmitted beam 6 enters the optical power detector 8 and the laser beam power value of the laser light source 2 is detected.
[0022] また、反射光ビーム 7は、 DVD (図示せず）の光透過層の厚みの違いに起因する球 面収差を補正するための補正レンズ 9を通過して、打上げミラー 10で DVDがセットさ れている + Zの向きに略 90° 向きを変える。さらに、 λ /4波長板 20で円偏光に変 換された上で、対物レンズ（図示せず）で集光されて DVDの情報記録面に照射され  [0022] The reflected light beam 7 passes through a correction lens 9 for correcting spherical aberration due to a difference in thickness of a light transmission layer of a DVD (not shown), and the DVD is launched by a launch mirror 10. Change the direction by approximately 90 ° to the set + Z direction. Furthermore, after being converted into circularly polarized light by the λ / 4 wavelength plate 20, it is condensed by an objective lens (not shown) and irradiated to the information recording surface of the DVD.
[0023] DVDで反射された DVD反射光ビームは、逆の経路で、対物レンズ、 λ /4波長板 20、打上げミラー 10、及び、補正レンズ 9を経て、ビームスプリッタ 5に入射する。さら に、ビームスプリッタ 5を直進して通過した DVD反射光ビームは、シリンドリカルレンズ 11を通過して集光された後、光検知器 12に入射し、 DVDの記録情報に対応した電 気信号に変換される。 [0024] 図 3及び図 4は、先に図 1及び図 2で説明した実施の形態 1の光学系に対する遮蔽 板 19の位置、及び動作を説明するための動作説明図である。図 1及び図 2と同一符 号は同一又は相当部分を示すので説明を省略する。 The DVD reflected light beam reflected by the DVD enters the beam splitter 5 through the objective lens, the λ / 4 wavelength plate 20, the launch mirror 10, and the correction lens 9 in the reverse path. Further, the DVD reflected light beam that has passed straight through the beam splitter 5 passes through the cylindrical lens 11 and is collected, and then enters the light detector 12 to generate an electric signal corresponding to the recorded information on the DVD. Converted. FIG. 3 and FIG. 4 are operation explanatory views for explaining the position and operation of the shielding plate 19 with respect to the optical system of the first embodiment described above with reference to FIG. 1 and FIG. The same reference numerals as those in FIG. 1 and FIG.
[0025] 遮光板 19は、レーザ光源 2からビームスプリッタ 5に向けて出射される出射光ビーム  The light shielding plate 19 is a light beam emitted from the laser light source 2 toward the beam splitter 5.
4を可動ホルダ 13の X方向の移動に伴って遮光割合を連続的に変化させながら遮 光することが可能な位置に、配置される。図 3においては、出射光ビーム 4の遮光板 1 9による遮光割合は 0%で、レーザ光源 2からビームスプリッタ 5に向けて出射された 出射光ビーム 4は、遮光板 19によって遮光されることなく 100%通過する。この図 3に 示された可動ホルダ 13の位置から、可動ホルダ 13を + Xの向きに移動させると、出 射光ビーム 4の遮光割合は 0%から徐々に増加し、ついには図 4に示すように出射光 ビーム 4の遮光板 19による遮光割合は 100%となり、レーザ光源 2からビームスプリツ タ 5に向けて出射された出射光ビーム 4は完全にこの遮光板 19で遮光されることとな る。すなわち、先に示したビームスプリッタ 5を含めて、光ビームの伝搬におけるビー ムスプリッタ 5よりも下流側の光学系には、出射光ビーム 4が入射されない状態となる 4 is arranged at a position where light can be shielded while continuously changing the light shielding ratio as the movable holder 13 moves in the X direction. In FIG. 3, the light shielding ratio of the outgoing light beam 4 by the light shielding plate 19 is 0%, and the outgoing light beam 4 emitted from the laser light source 2 toward the beam splitter 5 is not shielded by the light shielding plate 19. Pass 100%. When the movable holder 13 is moved in the + X direction from the position of the movable holder 13 shown in FIG. 3, the shielding ratio of the emitted light beam 4 gradually increases from 0%, and finally, as shown in FIG. In addition, the light shielding ratio of the outgoing light beam 4 by the light shielding plate 19 is 100%, and the outgoing light beam 4 emitted from the laser light source 2 toward the beam splitter 5 is completely shielded by the light shielding plate 19. That is, the outgoing light beam 4 is not incident on the optical system downstream of the beam splitter 5 in the propagation of the light beam, including the beam splitter 5 described above.
〇 Yes
[0026] 次に、図 5は、この発明に係る光ピックアップ装置の実施の形態 1の組み立て手順 を説明する組立て図である。図 1、図 2、図 3、及び図 4と同一符号は同一又は相当部 分を示すので説明を省略する。  Next, FIG. 5 is an assembly diagram illustrating the assembly procedure of Embodiment 1 of the optical pickup device according to the present invention. The same reference numerals as those in FIGS. 1, 2, 3, and 4 denote the same or corresponding parts, and thus the description thereof is omitted.
[0027] 図 5において、まずは、レーザ光源 2の取り付けについて説明する。レーザ保持板 3 には、レーザ光源 2を揷入して保持するための穴部 3aが設けられ、この穴部 3aにレ 一ザ光源 2の円筒部 2aが係合する形で、レーザ光源 2はレーザ保持板 3に圧入保持 されている。なお、レーザ保持板 3は、ピックアップベース 1と対向する側の取り付け 面 3bを、ピックアップベース 1の取り付け面 laに面接触させた状態で光軸位置決め 調整の面内調整を行った後、ピックアップベース 1に接着固定される。レーザ光源 2 力、ら出射された出射ビーム光 4は、ピックアップベース 1の側面に設けられた穴部 lb を通して、ピックアップベース 1の内部に導入される。  In FIG. 5, first, attachment of the laser light source 2 will be described. The laser holding plate 3 is provided with a hole 3a for inserting and holding the laser light source 2, and the cylindrical portion 2a of the laser light source 2 is engaged with the hole 3a so that the laser light source 2 Is press-fitted and held in the laser holding plate 3. The laser holding plate 3 is subjected to in-plane adjustment for optical axis positioning adjustment in a state where the mounting surface 3b on the side facing the pickup base 1 is in surface contact with the mounting surface la of the pickup base 1, and then the pickup base 1 Bonded and fixed to 1. The emitted light beam 4 emitted from the laser light source 2 is introduced into the pickup base 1 through a hole lb provided on the side surface of the pickup base 1.
[0028] 次に、ビームスプリッタ 5は立方体形状をしており、その 3つの面をピックアップべ一 ス 1に設けられたそれぞれ対応する 3つの取り付け面に押し当てる形で位置決めされ 、接着固定される。 [0028] Next, the beam splitter 5 has a cubic shape, and its three surfaces are positioned so as to press against the corresponding three mounting surfaces provided on the pickup base 1, respectively. , Glued and fixed.
[0029] 次に、光パワー検知器 8は、パワー検知器保持板 21に取り付け固定され、ピックァ ップベース 1に設けられた対応する取り付け面に 3面を押し当てる形で位置決め接着 固定される。  Next, the optical power detector 8 is attached and fixed to the power detector holding plate 21, and is positioned and fixed in such a manner that the three surfaces are pressed against the corresponding attachment surfaces provided on the pickup base 1.
[0030] シリンドリカルレンズ 11は、レンズ部 1 laが外周ホルダ 1 lbで保持された構成となつ ており、ピックアップベース 1に設けられた対応する取り付け面に 3面を押し当てる形 で位置決め接着固定される。  [0030] The cylindrical lens 11 has a configuration in which the lens portion 1 la is held by the outer peripheral holder 1 lb, and is positioned and bonded and fixed in such a manner that three surfaces are pressed against corresponding mounting surfaces provided on the pickup base 1. The
[0031] 光検知器 12は、光検知器保持板 22に取り付け固定され、ピックアップベース 1に 設けられた光ビームが通過する穴部 lcをふさぐ形で、光軸方向及び光検知器 12の 光検知面の面内方向からなる 3方向での光軸位置決め調整を行った後、接着材 23 で、位置決めされた位置に接着固定される。なお、図示していないが、レーザ光源 2 、光パワー検知器 8、及び、光検知器 12には、それぞれフレキシブルプリント配線板（ FPC)等で電気的な結線が施される。  [0031] The light detector 12 is attached and fixed to the light detector holding plate 22, and has a shape that closes the hole lc through which the light beam provided in the pickup base 1 passes, and the direction of the optical axis and the light of the light detector 12. After performing optical axis positioning adjustment in three directions consisting of the in-plane direction of the detection surface, the adhesive 23 is bonded and fixed to the positioned position. Although not shown, the laser light source 2, the optical power detector 8, and the photodetector 12 are each electrically connected by a flexible printed circuit board (FPC) or the like.
[0032] さらに、可動ホルダ 13は、補正レンズ 9が接着固定され、ガイドシャフト 14、ガイドシ ャフト 15が係合するとともに、止めネジ 18を用いて遮光板 19がネジ固定された上で 、ピックアップベース 1の対応する取り付け面に位置決めが為されて取り付けられる。  Further, the movable holder 13 has the correction lens 9 bonded and fixed, the guide shaft 14 and the guide shaft 15 are engaged, and the light shielding plate 19 is fixed with screws using the set screw 18. Positioned and mounted on the corresponding mounting surface of 1.
[0033] さらに、可動ホルダ 13を光軸方向に移動可能とするためのステッピングモータ 16は 、ロータと一体となったリードスクリュー 17を有し、モータ保持板 24に保持されている 。モータ保持板 24は、位置決め穴 24aと位置決め穴 24bの 2箇所がピックアップべ一 ス 1の対応する取り付け面の設けられたボスと係合することにより、ピックアップベース 1に対する精密な位置決めが為され、ネジ穴 24cに取り付けネジ 25が揷通してピック アップベース 1にネジ固定される。  Furthermore, the stepping motor 16 for enabling the movable holder 13 to move in the optical axis direction has a lead screw 17 integrated with the rotor, and is held by the motor holding plate 24. The motor holding plate 24 is precisely positioned with respect to the pickup base 1 by engaging two positions of the positioning hole 24a and the positioning hole 24b with a boss provided with a corresponding mounting surface of the pickup base 1. The mounting screw 25 passes through the screw hole 24c and is fixed to the pickup base 1.
[0034] 図 6は、この発明に係る光ピックアップ装置の実施の形態 1の可動ホルダ 13の構造 を詳細に説明するための説明図である。図 1、図 2、図 3、図 4、及び、図 5と同一符号 は同一又は相当部分を示すので説明を省略する。  FIG. 6 is an explanatory diagram for explaining in detail the structure of the movable holder 13 of the first embodiment of the optical pickup device according to the present invention. 1, 2, 3, 4, and 5 indicate the same or corresponding parts, and the description thereof is omitted.
[0035] 図 6において、補正レンズ 9は、可動ホルダ 13の穴部 13bに設けられた位置決め部  In FIG. 6, the correction lens 9 is a positioning portion provided in the hole 13 b of the movable holder 13.
13cにレンズ部 9aの外周である外周部 9bが係合する形で、可動ホルダ 13に接着固 定されている。 [0036] また、可動ホルダ 13の軸受部 13d及び軸受部 13eには、それぞれガイドシャフト 14 及びガイドシャフト 15が係合しており、可動ホルダ 13は、反射光ビームの光軸方向で ある X方向に移動可能となっている。 The outer peripheral portion 9b which is the outer periphery of the lens portion 9a is engaged with and fixed to the movable holder 13 in 13c. [0036] Further, the guide shaft 14 and the guide shaft 15 are engaged with the bearing portion 13d and the bearing portion 13e of the movable holder 13, respectively, and the movable holder 13 is in the X direction which is the optical axis direction of the reflected light beam. It is possible to move to.
[0037] また、可動ホルダ 13に設けられたニードル部 13aは、リードスクリュー 17の溝部 17a と係合し、リードスクリュー 17の回転に伴い光軸方向である X方向に移動可能とする ためのものである。 [0037] Further, the needle portion 13a provided in the movable holder 13 is engaged with the groove portion 17a of the lead screw 17 so as to be movable in the X direction which is the optical axis direction as the lead screw 17 rotates. It is.
[0038] さらに、可動ホルダ 13には、ネジ穴部 19aと遮光部 19bからなる遮光板 19が、止め ネジ 18がネジ穴部 19aを揷通し可動ホルダ 13のネジ部 13fと螺合することにより、固 定されている。  [0038] Further, the movable holder 13 has a light shielding plate 19 composed of a screw hole portion 19a and a light shielding portion 19b. The set screw 18 passes through the screw hole portion 19a and is screwed with the screw portion 13f of the movable holder 13. It is fixed.
[0039] 図 7は、この発明に係る光ピックアップ装置の実施の形態 1において、 DVDの記録 再生状態にある場合の遮光板の位置を説明するための説明図である。図 1、図 2、図 3、図 4、図 5、及び、図 6と同一符号は同一又は相当部分を示すので説明を省略す  FIG. 7 is an explanatory diagram for explaining the position of the light shielding plate in the DVD recording / reproducing state in the first embodiment of the optical pickup device according to the present invention. 1, 2, 3, 4, 5, and 6 denote the same or corresponding parts and will not be described.
[0040] 図 7において、光ピックアップ装置が DVDの記録再生状態にある時は、補正レンズ 9は、反射光ビーム 7が DVD (図示せず）の情報記録面に照射される際の光スポット のスポット径が十分に小さくなるように、 DVDと BDの光透過層の厚みの違いに起因 する球面収差が抑制される DVDの光透過層の厚みに対応した X方向の適正位置に 設定されている。 In FIG. 7, when the optical pickup device is in the DVD recording / reproducing state, the correction lens 9 causes the light spot when the reflected light beam 7 is applied to the information recording surface of the DVD (not shown). Spherical aberration due to the difference in thickness of DVD and BD light transmission layers is suppressed so that the spot diameter is sufficiently small. It is set at an appropriate position in the X direction corresponding to the DVD light transmission layer thickness. .
[0041] さらに、補正レンズ 9を保持する可動ホルダ 13には、既に説明したように、遮光板 1 9が固定されている。従って、可動ホルダ 13が X方向に移動すると、遮光板 19が可 動ホルダ 13に連動して X方向に移動することにより、レーザ光源 2から出射された出 射光ビーム 4を遮光する割合を可変することが可能となっている。  Furthermore, as already described, the light shielding plate 19 is fixed to the movable holder 13 that holds the correction lens 9. Therefore, when the movable holder 13 moves in the X direction, the light shielding plate 19 moves in the X direction in conjunction with the movable holder 13, thereby changing the ratio of shielding the emitted light beam 4 emitted from the laser light source 2. It is possible.
[0042] 図 7に示す DVDの記録再生状態にある時には、補正レンズ 9は、球面収差を抑制 できる適正位置に設定されているが、この時、遮光板 19は、レーザ光源 2から出射さ れた出射光ビーム 4を遮光しな!/、ように取り付けられて!/、る。  In the DVD recording / reproducing state shown in FIG. 7, the correction lens 9 is set to an appropriate position capable of suppressing spherical aberration. At this time, the light shielding plate 19 is emitted from the laser light source 2. Do not block the outgoing light beam 4!
[0043] また、光ディスクが DVDから BDに交換された場合は、一旦、補正レンズ 9の位置を 原点位置に復帰させるため、可動ホルダ 13の移動機構を駆動する必要がある。そこ で、移動制御部（図示せず）は、ニードル部 13aを備える可動ホルダ 13とこのニード ル部 13aが嚙み合わされるリードスクリュー 17とこのリードスクリュー 17を回転させるス テツビングモータ 16とからなるこの移動機構を、補正レンズ 9が所定の位置に移動す るように制卸している。 [0043] Further, when the optical disk is changed from DVD to BD, it is necessary to drive the moving mechanism of the movable holder 13 in order to return the position of the correction lens 9 to the original position. Therefore, the movement control unit (not shown) includes the movable holder 13 including the needle unit 13a and the needle. The moving mechanism, which includes a lead screw 17 with which the screw portion 13a is fitted and a stepping motor 16 that rotates the lead screw 17, is controlled so that the correction lens 9 moves to a predetermined position.
[0044] 図 8は、この発明に係る光ピックアップ装置の実施の形態 1において、光ディスクを DVDから BDに交換した際に補正レンズ 9の移動機構が原点位置に移動した場合の 遮光板の位置の一例を説明するための説明図である。図 7と同一符号は同一又は相 当部分を示すので説明を省略する。  FIG. 8 shows the position of the light shielding plate when the moving mechanism of the correction lens 9 is moved to the origin position when the optical disk is exchanged from DVD to BD in Embodiment 1 of the optical pickup device according to the present invention. It is explanatory drawing for demonstrating an example. The same reference numerals as those in FIG. 7 denote the same or corresponding parts, and the description thereof will be omitted.
[0045] 図 8において、遮光板 19は、出射光ビーム 4の一部を遮光するように、図 7の場合 に比べて、 +Χの向きに移動させられている。遮光板 19によって一部を遮光された 出射光ビーム 4は、ビームスプリッタ 5に入射し、ビームスプリッタ 5を透過した透過光 ビーム 6は、光パワー検知器 8に入射して、光パワー検知器 8では、遮光板 19で遮光 された割合に応じたレーザ光パワー値が検知される。  In FIG. 8, the light shielding plate 19 is moved in the direction of + Χ compared to the case of FIG. 7 so as to shield a part of the outgoing light beam 4. The outgoing light beam 4 partially shielded by the light shielding plate 19 enters the beam splitter 5, and the transmitted light beam 6 transmitted through the beam splitter 5 enters the optical power detector 8. In this case, the laser light power value corresponding to the ratio of light shielded by the light shielding plate 19 is detected.
[0046] 図 9は、この発明に係る光ピックアップ装置の実施の形態 1において、可動ホルダ 1 3に保持された補正レンズ 9の位置と光パワー検知器 8で検知されたレーザ光パワー 値に対応する出力電圧との関係を示す補正レンズ位置出力電圧特性図である。  FIG. 9 corresponds to the position of the correction lens 9 held by the movable holder 13 and the laser light power value detected by the optical power detector 8 in Embodiment 1 of the optical pickup device according to the present invention. It is a correction | amendment lens position output voltage characteristic view which shows the relationship with the output voltage to perform.
[0047] 光ピックアップ装置が DVDの記録再生中である場合は、光パワー検知器 8で検知 されたレーザ光パワー値に基づいて、レーザ光源 2の出力が一定値となるように、レ 一ザ光源 2は出力制御されている。一方、補正レンズ 9を原点位置に復帰させる場合 には、移動制御部は、レーザ光パワー値に基づくレーザ光源 2の出力制御を行なわ ないように、レーザ光源 2の駆動電源（図示せず）に指示する。  [0047] When the optical pickup device is recording / reproducing a DVD, the laser is adjusted so that the output of the laser light source 2 becomes a constant value based on the laser light power value detected by the optical power detector 8. The output of light source 2 is controlled. On the other hand, when the correction lens 9 is returned to the origin position, the movement control unit controls the drive power source (not shown) of the laser light source 2 so as not to control the output of the laser light source 2 based on the laser light power value. Instruct.
[0048] 以下に、図 7、図 8、及び、図 9を用いて、この発明に係る光ピックアップ装置の実施 の形態 1の動作を説明する。  [0048] The operation of the first embodiment of the optical pickup device according to the present invention will be described below with reference to FIGS. 7, 8, and 9. FIG.
[0049] 一般に記録再生する光ディスクの種別、例えば、 DVDと BDの場合や、光ディスク が複数の情報記録層を有する多層光ディスク、具体例としては、 2層構造を有する Β Dの 1層目と 2層目においては、光ディスクの光透過層の厚みが異なり、光ディスクを 交換すると光透過層の厚みが変化することとなる。ここでは、図 7に示すように DVD の記録再生を行っていた後、光ディスクを BDに交換する際に、補正レンズ 9の位置 を移動機構の原点位置に復帰させる場合を一例に説明する。 [0050] 補正レンズ 9の移動は、移動制御部で制御されて!/、る。移動制御部がステッピング モータ 16に電気的に駆動パルスを入力してリードスクリュー 17を回転させ、リードスク リュー 17の溝部 17aに係合した可動ホルダ 13のニードル部 13aに反射光ビーム 7の 光軸方向である X方向の駆動力が作用することにより、可動ホルダ 13は X方向に駆 動される。 [0049] Generally, the type of optical disc to be recorded / reproduced, for example, DVD and BD, or a multi-layer optical disc in which the optical disc has a plurality of information recording layers, such as a two-layer structure. In the layer, the thickness of the light transmission layer of the optical disk is different, and when the optical disk is replaced, the thickness of the light transmission layer changes. Here, an example will be described in which the position of the correction lens 9 is returned to the origin position of the moving mechanism when the optical disk is replaced with the BD after the DVD is recorded and reproduced as shown in FIG. [0050] The movement of the correction lens 9 is controlled by the movement controller. The movement control unit electrically inputs a drive pulse to the stepping motor 16 to rotate the lead screw 17, and the direction of the optical axis of the reflected light beam 7 is applied to the needle portion 13a of the movable holder 13 engaged with the groove portion 17a of the lead screw 17. When the driving force in the X direction is applied, the movable holder 13 is driven in the X direction.
[0051] ところで、 DVDの記録再生状態においては、図 7に示すように、補正レンズ 9の位 置は、 DVDの光透過層の厚みに対応した球面収差が抑制できる適正位置に設定さ れている。その状態で、光ディスクを DVDから BDに交換した場合、補正レンズ 9の位 置を、一旦、図 8に示すように移動機構の原点位置まで復帰させ、その後に、 BDの 光透過層の厚みに対応した球面収差が抑制できる適正位置に移動させることとなる  By the way, in the DVD recording / reproducing state, as shown in FIG. 7, the position of the correction lens 9 is set to an appropriate position where the spherical aberration corresponding to the thickness of the light transmission layer of the DVD can be suppressed. Yes. In this state, when the optical disk is changed from DVD to BD, the position of the correction lens 9 is temporarily returned to the origin position of the moving mechanism as shown in FIG. 8, and then the thickness of the light transmission layer of the BD is set. It will be moved to an appropriate position where the corresponding spherical aberration can be suppressed.
[0052] なお、 DVDや BDの光透過層の厚みに対応した球面収差が抑制できる適正位置 は、それぞれ、光学系全体の仕様値から事前に机上計算で求めることが可能である [0052] It should be noted that the appropriate position where the spherical aberration corresponding to the thickness of the light transmission layer of DVD or BD can be suppressed can be obtained in advance by desktop calculation from the specification values of the entire optical system.
[0053] ピックアップベース 1に対する補正レンズ 9の X方向の原点位置が設定されており、 移動機構の移動制御部は、原点位置から DVDや BDのそれぞれの適正位置までの 移動量をデータとして保持しているので、光ディスクを交換する場合は、一旦、補正 レンズ 9は原点位置まで移動する。これは、ステッピングモータ 16は駆動パルスの数 によって電気的にリードスクリュー 17の回転を制御しており、万が一、一時的な駆動 機構の不具合によって駆動ノ ルスの数と実際の補正レンズ 9の位置との対応が取れ なくなるような、いわゆる脱調が発生したとしても、光ディスクの交換毎に原点復帰を 行うことで、駆動ノ ルスの数力 移動制御部が認識して!/、る補正レンズ 9の推定位置 と、実際の補正レンズ 9の位置とを一致させるためである。 [0053] The origin position in the X direction of the correction lens 9 with respect to the pickup base 1 is set, and the movement control unit of the movement mechanism holds the movement amount from the origin position to each appropriate position of the DVD or BD as data. Therefore, when replacing the optical disk, the correction lens 9 once moves to the origin position. This is because the stepping motor 16 electrically controls the rotation of the lead screw 17 according to the number of drive pulses. In the unlikely event of a temporary drive mechanism failure, the number of drive pulses and the actual position of the correction lens 9 Even if a so-called out-of-step occurs that makes it impossible to deal with This is to make the estimated position coincide with the actual position of the correction lens 9.
[0054] 次に、補正レンズ 9を原点位置に復帰させる際の原点位置の検出方法について説 明する。移動制御部は、光ディスクが DVDから BDに交換されたことを認識した後に 、補正レンズ 9を原点位置に移動させるように制御を開始する。  Next, a method for detecting the origin position when the correction lens 9 is returned to the origin position will be described. After recognizing that the optical disk has been exchanged from DVD to BD, the movement control unit starts control to move the correction lens 9 to the origin position.
[0055] 図 9において、補正レンズ 9は、 DVDの記録再生に対応した適正位置から、 +Xの 向きに移動制御部に制御されて移動を開始する。その際、図 7に示すように、レーザ 光源 2から出射された出射光ビーム 4は遮光板 19によって遮光されていない。遮光さ れていない出射光ビーム 4はビームスプリッタ 5に入射し、透過した透過光ビーム 6は 光パワー検知器 8に入射する。図 9の出力電圧は光パワー検知器 8で受光された透 過光ビーム 6のレーザ光パワー値に対応している。すなわち、図 9の出力電圧 Vは 遮光板 19で遮光されていない場合の出射光ビーム 4のレーザ光パワー値に対応し た出力電圧である。 In FIG. 9, the correction lens 9 starts to move from the appropriate position corresponding to DVD recording / reproduction, controlled by the movement control unit in the + X direction. At that time, as shown in FIG. The outgoing light beam 4 emitted from the light source 2 is not shielded by the light shielding plate 19. The unshielded outgoing light beam 4 is incident on the beam splitter 5, and the transmitted transmitted light beam 6 is incident on the optical power detector 8. The output voltage in Fig. 9 corresponds to the laser light power value of the transmitted light beam 6 received by the optical power detector 8. That is, the output voltage V in FIG. 9 is an output voltage corresponding to the laser light power value of the outgoing light beam 4 when not shielded by the light shielding plate 19.
[0056] 移動制御部では、出力電圧 Vとなる出力電圧に対応した補正レンズ 9の位置が原  [0056] In the movement control unit, the position of the correction lens 9 corresponding to the output voltage that is the output voltage V is the original position.
2  2
点位置であると設定されている。従って、移動制御部は、光パワー検知器 8の出力電 圧が原点位置に対応する出力電圧 Vよりも大きい場合、移動機構に対して、補正レ  It is set to be a point position. Therefore, when the output voltage of the optical power detector 8 is larger than the output voltage V corresponding to the origin position, the movement control unit makes a correction level to the movement mechanism.
2  2
ンズ 9を +Xの向きへ移動するように指示する。  Instructs 9 to move in the + X direction.
[0057] 補正レンズ 9に連動して、遮光板 19も + Xの向きに移動し、遮光板 19が出射光ビ ーム 4の一部を遮る位置まで達すると、出力電圧は徐々に低下する。移動制御部は 、移動機構に対して、光パワー検知器 8の出力電圧が出力電圧 Vとなる位置で停止 [0057] In conjunction with the correction lens 9, the light shielding plate 19 also moves in the + X direction, and when the light shielding plate 19 reaches a position where it partially blocks the outgoing light beam 4, the output voltage gradually decreases. . The movement control unit stops at a position where the output voltage of the optical power detector 8 becomes the output voltage V with respect to the movement mechanism.
2  2
するように指示する。すなわち、移動制御部が、光パワー検知器 8の出力電圧を検知 することで、補正レンズ 9の原点位置を検出することが可能である。  To instruct. That is, the movement control unit can detect the origin position of the correction lens 9 by detecting the output voltage of the optical power detector 8.
[0058] なお、移動機構の一時的な不具合等があると、補正レンズ 9が原点位置よりも + X の向き側に最初に位置することが起こり得る。その場合には、光パワー検知器 8の出 力電圧は出力電圧 Vよりも小さい値となっている。なお、遮光板 19の X方向の長さ及 [0058] If there is a temporary malfunction or the like of the moving mechanism, the correction lens 9 may first be positioned on the + X direction side of the origin position. In that case, the output voltage of the optical power detector 8 is smaller than the output voltage V. The length of the light shielding plate 19 in the X direction and
2  2
び Z方向の幅等の形状は、出射光ビーム 4を完全に遮ることが可能なサイズ及び形 状に設定されているので、補正レンズ 9の位置が不具合等により原点位置から + Xの 向きに大きくはずれている場合は、光パワー検知器 8の出力電圧は 0Vとなる。そこで 、光パワー検知器 8の出力電圧が出力電圧 Vよりも小さい場合は、移動制御部は、  Since the shape such as the width in the Z direction is set to a size and shape that can completely block the outgoing light beam 4, the position of the correction lens 9 is moved from the origin position to the + X direction due to a defect or the like. In the case of large deviation, the output voltage of the optical power detector 8 is 0V. Therefore, when the output voltage of the optical power detector 8 is smaller than the output voltage V, the movement control unit
2  2
補正レンズ 9が原点位置よりも + Xの向き側に位置すると認識し、移動機構に対して Recognizing that the correction lens 9 is located on the + X side of the origin position,
、補正レンズ 9を Xの向きへ移動するように指示する。 Instructs the correction lens 9 to move in the X direction.
[0059] 補正レンズ 9がー Xの向きに移動すると、補正レンズ 9に連動して、遮光板 19も X の向きに移動し、遮光板 19がレーザ光源 2から出射された出射光ビーム 4を遮光す る割合が減少し、その結果、光パワー検知器 8の出力電圧が増加する。 [0059] When the correction lens 9 moves in the -X direction, the light shielding plate 19 also moves in the X direction in conjunction with the correction lens 9, and the light shielding plate 19 emits the emitted light beam 4 emitted from the laser light source 2. The ratio of light shielding decreases, and as a result, the output voltage of the optical power detector 8 increases.
[0060] 移動制御部は、移動機構に対して、光パワー検知器 8の出力電圧が出力電圧 Vと なる位置で停止するように指示する。すなわち、この場合も、移動制御部が、光パヮ 一検知器 8の出力電圧を検知することで、補正レンズ 9の原点位置を検出することが 可能である。 [0060] The movement control unit determines that the output voltage of the optical power detector 8 is equal to the output voltage V with respect to the movement mechanism. To stop at a certain position. That is, also in this case, the movement control unit can detect the origin position of the correction lens 9 by detecting the output voltage of the optical power detector 8.
[0061] なお、以上では、レーザ光源 2から出射された出射光ビーム 4とビームスプリッタ 5で 分離された反射光ビーム 7が略 90° の角度を為す場合について説明した。ただし、 出射光ビーム 4と反射光ビーム 7が異なる方向であれば、補正レンズ 9と連動する遮 光板 19が出射光ビーム 4を遮光することが可能なので、この角度が略 90° に限られ るわけではない。  In the above description, the case where the outgoing light beam 4 emitted from the laser light source 2 and the reflected light beam 7 separated by the beam splitter 5 form an angle of approximately 90 ° has been described. However, if the outgoing light beam 4 and the reflected light beam 7 are in different directions, the light shielding plate 19 interlocked with the correction lens 9 can block the outgoing light beam 4, so this angle is limited to approximately 90 °. Do not mean.
[0062] また、以上では、光パワー検知器 8の出力電圧が所定の値である出力電圧 Vとな  Further, in the above, the output voltage of the optical power detector 8 becomes the output voltage V that is a predetermined value.
2 る補正レンズ 9の位置を原点位置であると設定したが、レーザ光源 2の出力が一時的 に変動した場合、補正レンズ 9の原点位置の検出精度の低下の恐れが生じる。  However, if the output of the laser light source 2 fluctuates temporarily, the detection accuracy of the origin position of the compensation lens 9 may be lowered.
[0063] そこで、予め、補正レンズ 9が原点位置に正確に位置する状態で、出力電圧 Vと出 [0063] Therefore, in advance, the output voltage V and the output voltage V with the correction lens 9 accurately positioned at the origin position.
2 力電圧 Vの比のィ直 p (=V /V )を求めておく。そして、例えば、光ディスクが DVD  2 Find the direct ratio p (= V / V) of the ratio of force voltage V. And for example, if the optical disc is a DVD
1 2 1  1 2 1
力も BDに交換されて補正レンズ 9を原点位置に復帰させる際には、交換前の DVD の記録再生時の出力電圧である出力電圧 Vに、予め求めておいた比の値 pを乗算 した値を、原点位置に対応した出力電圧 Vとする。移動制御部が、移動機構に対し  When the correction lens 9 is returned to the original position after the force is also exchanged with the BD, the value obtained by multiplying the output voltage V, which is the output voltage at the time of recording / playback of the DVD before replacement, by the ratio value p obtained in advance Is the output voltage V corresponding to the origin position. The movement control unit
2  2
て、光パワー検知器 8の出力電圧がこのようにして算出した出力電圧 Vに等しくなる  Therefore, the output voltage of the optical power detector 8 becomes equal to the output voltage V calculated in this way.
2  2
位置で停止するように指示すれば、補正レンズ 9の原点位置をさらに安定して精度良 く検出することが可能である。  If an instruction is given to stop at the position, the origin position of the correction lens 9 can be detected more stably and accurately.
[0064] 以上のように、この発明に係る光ピックアップ装置の実施の形態 1は、移動機構によ り移動可能な補正レンズ 9に連動して移動し、レーザ光源 2から出射される出射光ビ ーム 4を遮光する割合を可変する遮光板 19を備え、遮光板 19によって遮光された出 射光ビーム 4のレーザ光パワー値に対応する出力電圧に基づいて補正レンズ 9の原 点位置を検出するようにした。従って、補正レンズ 9の位置を検出するための位置検 出センサを新たに搭載する必要が無ぐ位置検出センサ自体や付属する制御基板 等への配線が不要なことから組立て作業が容易となるとともに、部品数が少なくて良 いので、小型化や軽量化が図れ、さらには、コストの増大を招かないという効果があるAs described above, Embodiment 1 of the optical pickup device according to the present invention moves in conjunction with the correction lens 9 that can be moved by the moving mechanism and emits the emitted light beam emitted from the laser light source 2. A light shielding plate 19 that can change the ratio of shielding the light beam 4, and detecting the origin position of the correction lens 9 based on the output voltage corresponding to the laser light power value of the emitted light beam 4 shielded by the light shielding plate 19. I did it. Therefore, it is not necessary to newly install a position detection sensor for detecting the position of the correction lens 9, and wiring to the position detection sensor itself or the attached control board is unnecessary, so that the assembly work becomes easy. Since the number of parts is small, it is possible to reduce the size and weight, and to prevent the cost from increasing.
〇 [0065] なお、以上では、遮光板 19の X方向の長さ及び Z方向の幅等のサイズ及び形状は 、出射光ビーム 4を完全に遮ることが可能なサイズ及び形状に設定されて!/、る場合に ついて説明したが、遮光板 19のサイズ及び形状は、出射光ビーム 4を完全に遮るよう に設定される場合に限られない。すなわち、遮光板 19が出射光ビーム 4の一部のみ を遮るように設定されている場合であっても、その場合の光パワー検知器 8の出力電 圧が、原点位置に対応する出力電圧 Vより小さければ、移動制御部は、移動機構に Yes [0065] In the above, the size and shape of the light shielding plate 19, such as the length in the X direction and the width in the Z direction, are set to sizes and shapes that can completely block the outgoing light beam 4! / However, the size and shape of the light shielding plate 19 are not limited to the case where the outgoing light beam 4 is set to be completely shielded. That is, even when the light shielding plate 19 is set so as to block only a part of the outgoing light beam 4, the output voltage of the optical power detector 8 in that case is the output voltage V corresponding to the origin position. If it is smaller, the movement control unit
2  2
対して、補正レンズ 9を Xの向きへ移動するように指示するので、遮光板 19によつ て一部を遮光された出射光ビーム 4のレーザ光パワー値に対応する出力電圧に基づ V、て、補正レンズ 9の原点位置を検出することができるのは言うまでも無!/、。  On the other hand, the correction lens 9 is instructed to move in the X direction, so that the V is based on the output voltage corresponding to the laser light power value of the outgoing light beam 4 partially shielded by the light shielding plate 19. Needless to say, the origin position of the correction lens 9 can be detected!
[0066] また、以上では、遮光板 19が第 1の光ビームである出射光ビーム 4を遮光し、第 2の 光ビームである透過光ビーム 6のパワー値を光パワー測定部である光パワー検知器 8で測定するように構成されている場合を示した力 S、遮光板が第 2の光ビームである 透過光ビームを遮光するようにし、当該遮光板で遮光する割合を可変された第 2の光 ビームである透過光ビームのパワー値を光パワー検知器 8で測定するように構成して も、同様の効果が得られることは言うまでも無い。  Also, in the above, the light shielding plate 19 shields the outgoing light beam 4 as the first light beam, and the power value of the transmitted light beam 6 as the second light beam is the optical power measuring unit. The force S indicates that the detector 8 is configured to measure, and the light shielding plate shields the transmitted light beam, which is the second light beam, and the light shielding ratio of the light shielding plate is changed. Needless to say, the same effect can be obtained even if the optical power detector 8 is used to measure the power value of the transmitted light beam, which is the second light beam.
[0067] なお、以上では、光ディスクを DVDから BDに交換する場合を一例に実施の形態 1 の光ピックアップ装置につ!/、て説明したが、光ディスクが例えば 2層構造の情報記録 面を有する BDである場合にも効果がある。すなわち、 BDの 1層目と 2層目の光透過 層が異なることにより発生する球面収差を抑制するために、 1層目の記録再生を行つ た後、 2層目の記録再生を行う前に、一旦、補正レンズ 9を原点復帰させてから、適 正位置に移動させる場合にも、この発明に係る光ピックアップ装置の実施の形態 1が 有効であることは言うまでも無レ、。  In the above description, the optical pickup device according to the first embodiment is described as an example in which the optical disc is exchanged from DVD to BD. However, the optical disc has, for example, an information recording surface having a two-layer structure. It is also effective when it is BD. In other words, in order to suppress spherical aberration caused by the difference between the first and second light transmission layers of the BD, after recording / reproducing the first layer, before recording / reproducing the second layer In addition, it goes without saying that the first embodiment of the optical pickup device according to the present invention is effective even when the correction lens 9 is once returned to the origin and then moved to the proper position.
[0068] また、ステッピングモータ 16を駆動源とし、上記に示した方法で可動ホルダ 13で保 持された補正レンズ 9の原点位置を初期に検知した後に、予め設定した所定のパル ス数をステッピングモータ 16に入力することで、補正レンズ 9を所定の位置に位置決 めするように、この発明に係る光ピックアップ装置の実施の形態 1は構成されて!/、る。 従って、例えば、光ディスクからの再生信号が得られない状態等、その他の動作状態 とは関係無しに待ち時間無しで位置決め移動を実行することが可能となるので、切 替時間の短縮を図ることができるという効果がある。 [0068] Further, the stepping motor 16 is used as a drive source, and after the initial position of the correction lens 9 held by the movable holder 13 is initially detected by the method described above, a predetermined number of pulses set in advance is stepped. Embodiment 1 of the optical pickup device according to the present invention is configured to position the correction lens 9 at a predetermined position by inputting to the motor 16. Therefore, for example, the positioning movement can be executed without waiting time regardless of other operation states such as a state in which a reproduction signal from the optical disk cannot be obtained. There is an effect that the replacement time can be shortened.
[0069] 実施の形態 2. [0069] Embodiment 2.
この発明に係る光ピックアップ装置の実施の形態 1では、可動ホルダ 13のネジ部 1 3fに止めネジ 18で遮光板 19をネジ止め固定するようにした力 S、遮光板 19を可動ホ ルダ 13と一体の部品としても良い。このようにすることで、出射光ビーム 4を遮光する 位置と補正レンズ 9との位置関係に関する寸法精度が向上するので、原点位置の検 出精度がさらに向上するとともに、部品点数が減ることから、組立て作業の削減が可 能となる。  In the first embodiment of the optical pickup device according to the present invention, the force S is such that the light shielding plate 19 is fixed to the screw portion 13f of the movable holder 13 with the set screw 18, and the light shielding plate 19 is connected to the movable holder 13. It may be an integral part. By doing so, the dimensional accuracy regarding the positional relationship between the position where the outgoing light beam 4 is shielded and the correction lens 9 is improved, so that the detection accuracy of the origin position is further improved and the number of parts is reduced. Assembly work can be reduced.
[0070] 図 10は、この発明に係る光ピックアップ装置の実施の形態 2の構成を示す斜視図 である。図 1、図 7、及び、図 8と同一符号は同一又は相当部分を示すので説明を省 略する。  FIG. 10 is a perspective view showing the configuration of the optical pickup apparatus according to Embodiment 2 of the present invention. The same reference numerals as those in FIG. 1, FIG. 7, and FIG.
[0071] 図 10において、補正レンズ 9を保持する一体型可動ホルダ 13gは、一体成形され た遮光部 13hを備えており、補正レンズ 9と遮光部 13hとの位置関係は、一体成形を する加工精度で決まっており、ネジ止め固定による精度の低下が起こり得ない。  In FIG. 10, an integral movable holder 13g that holds the correction lens 9 includes an integrally formed light shielding portion 13h, and the positional relationship between the correction lens 9 and the light shielding portion 13h is a process of performing integral molding. The accuracy is determined, and the accuracy cannot be lowered by fixing with screws.
[0072] 従って、この発明に係る光ピックアップ装置の実施の形態 2は、原点位置の検出精 度をさらに向上させることが可能となる。また、組立ての必要な部品点数が減ることか ら、組立て作業の削減が図れ、作業コストを抑制できるという効果がある。  Therefore, Embodiment 2 of the optical pickup device according to the present invention can further improve the detection accuracy of the origin position. In addition, since the number of parts that need to be assembled is reduced, the assembly work can be reduced and work costs can be reduced.

Claims

請求の範囲 The scope of the claims
[1] 第 1の光ビームを出力するレーザ光源と、 [1] a laser light source that outputs a first light beam;
前記第 1の光ビームを第 2の光ビームと第 3の光ビームに所定の割合で互いに異な る向きに分離するビームスプリッタと、  A beam splitter for separating the first light beam into a second light beam and a third light beam in different directions at a predetermined ratio;
前記第 3の光ビームの光軸上に設けられた補正レンズと、  A correction lens provided on the optical axis of the third light beam;
前記補正レンズを前記第 3の光ビームの光軸方向に移動可能に保持する移動機 構と、  A moving mechanism for holding the correction lens movably in the optical axis direction of the third light beam;
前記補正レンズに連動され、前記移動機構により前記補正レンズが移動することで The correction lens is moved by the movement mechanism in conjunction with the correction lens.
、前記第 1の光ビームを遮光する割合を可変する遮光板と、 A light shielding plate that varies a ratio of shielding the first light beam;
前記移動機構を制御して前記補正レンズを移動させる移動制御部と、 前記第 2の光ビームを受光して前記第 2の光ビームのパワー値を測定する光パワー 測定部と、  A movement control unit that controls the movement mechanism to move the correction lens; a light power measurement unit that receives the second light beam and measures a power value of the second light beam;
前記光パワー測定部で測定された前記パワー値と前記移動制御部により移動した 前記補正レンズの移動位置とに基づ!/、て、前記補正レンズの原点位置を測定する位 置測定部と、  A position measuring unit that measures the origin position of the correction lens based on the power value measured by the optical power measurement unit and the movement position of the correction lens moved by the movement control unit;
を備えることを特徴とする光ピックアップ装置。  An optical pickup device comprising:
[2] 第 2の光ビームのパワー値力 S、所定の値となった補正レンズの移動位置を、前記補 正レンズの原点位置とすること [2] The power value S of the second light beam S, and the movement position of the correction lens that has reached a predetermined value shall be the origin position of the correction lens.
を特徴とする請求項 1に記載の光ピックアップ装置。  The optical pickup device according to claim 1, wherein:
[3] 所定の値は、遮光板が第 1の光ビームを遮光しない場合の第 2の光ビームのパワー 値に基づレ、て設定されること [3] The predetermined value is set based on the power value of the second light beam when the light shielding plate does not block the first light beam.
を特徴とする請求項 2に記載の光ピックアップ装置。  The optical pickup device according to claim 2, wherein:
[4] 第 1の光ビームを出力するレーザ光源と、 [4] a laser light source that outputs a first light beam;
前記第 1の光ビームを第 2の光ビームと第 3の光ビームに所定の割合で互いに異な る向きに分離するビームスプリッタと、  A beam splitter for separating the first light beam into a second light beam and a third light beam in different directions at a predetermined ratio;
前記第 3の光ビームの光軸上に設けられた補正レンズと、  A correction lens provided on the optical axis of the third light beam;
前記補正レンズを前記第 3の光ビームの光軸方向に移動可能に保持する移動機 構と、 前記補正レンズに連動され、前記移動機構により前記補正レンズが移動することで 、前記第 2の光ビームを遮光する割合を可変する遮光板と、 A moving mechanism for holding the correction lens movably in the optical axis direction of the third light beam; A light-shielding plate that is interlocked with the correction lens and that moves the correction lens by the moving mechanism to change a ratio of shielding the second light beam;
前記移動機構を制御して前記補正レンズを移動させる移動制御部と、 前記遮光板で遮光する割合を可変された第 2の光ビームを受光して当該第 2の光 ビームのパワー値を測定する光パワー測定部と、  A movement control unit that moves the correction lens by controlling the movement mechanism, and a second light beam that has a variable ratio of light shielding by the light shielding plate, and receives a power value of the second light beam. An optical power measurement unit;
前記光パワー測定部で測定された前記パワー値と前記移動制御部により移動した 前記補正レンズの移動位置とに基づ!/、て、前記補正レンズの原点位置を測定する位 置測定部と、  A position measuring unit that measures the origin position of the correction lens based on the power value measured by the optical power measurement unit and the movement position of the correction lens moved by the movement control unit;
を備えることを特徴とする光ピックアップ装置。  An optical pickup device comprising:
[5] 遮光板で遮光する割合を可変された第 2の光ビームのパワー値が、所定の値となつ た補正レンズの移動位置を、前記補正レンズの原点位置とすること [5] The movement position of the correction lens where the power value of the second light beam, the ratio of which is shielded by the light shielding plate, has become a predetermined value is the origin position of the correction lens.
を特徴とする請求項 4に記載の光ピックアップ装置。  The optical pickup device according to claim 4, wherein:
[6] 所定の値は、遮光板が第 2の光ビームを遮光しない場合の前記第 2の光ビームの ノ ヮ一値に基づ!/、て設定されること [6] The predetermined value is set based on the first value of the second light beam when the light shielding plate does not shield the second light beam!
を特徴とする請求項 5に記載の光ピックアップ装置。  The optical pickup device according to claim 5, wherein:
[7] 移動機構は、ステッピングモータを駆動源とし、 [7] The moving mechanism uses a stepping motor as the drive source,
移動制御部は、原点位置を測定した後、所定のノ ルス数を前記ステッピングモータ に入力し、補正レンズを移動させて所定の位置に位置決めすること  The movement control unit measures the origin position, inputs a predetermined number of noises to the stepping motor, moves the correction lens, and positions it at the predetermined position.
を特徴とする請求項 1に記載の光ピックアップ装置。  The optical pickup device according to claim 1, wherein:
[8] 移動機構は、ステッピングモータを駆動源とし、 [8] The moving mechanism uses a stepping motor as the drive source,
移動制御部は、原点位置を測定した後、所定のノ ルス数を前記ステッピングモータ に入力し、補正レンズを移動させて所定の位置に位置決めすること  The movement control unit measures the origin position, inputs a predetermined number of noises to the stepping motor, moves the correction lens, and positions it at the predetermined position.
を特徴とする請求項 4に記載の光ピックアップ装置。  The optical pickup device according to claim 4, wherein:
[9] 補正レンズはホルダで保持され、前記ホルダと遮光板は一体に形成されていること を特徴とする請求項 1に記載の光ピックアップ装置。 9. The optical pickup device according to claim 1, wherein the correction lens is held by a holder, and the holder and the light shielding plate are integrally formed.
[10] 補正レンズはホルダで保持され、前記ホルダと遮光板は一体に形成されていること を特徴とする請求項 4に記載の光ピックアップ装置。 10. The optical pickup device according to claim 4, wherein the correction lens is held by a holder, and the holder and the light shielding plate are integrally formed.
PCT/JP2007/068232 2006-11-27 2007-09-20 Optical pickup device WO2008065800A1 (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP2006318550 2006-11-27
JP2006-318550 2006-11-27
JP2007184292 2007-07-13
JP2007-184292 2007-07-13

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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006127693A (en) * 2004-11-01 2006-05-18 Canon Inc Optical information recording/reproducing device
JP2006155839A (en) * 2004-12-01 2006-06-15 Canon Inc Optical pickup driving device, optical component, and object driving mechanism

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006127693A (en) * 2004-11-01 2006-05-18 Canon Inc Optical information recording/reproducing device
JP2006155839A (en) * 2004-12-01 2006-06-15 Canon Inc Optical pickup driving device, optical component, and object driving mechanism

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