JP2009043305A - Optical pickup and disk drive unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure good operation characteristics of an objective lens drive unit. <P>SOLUTION: The disk drive unit is provided with fixed block 9 fixed to a moving base, a movable block 10 having two objective lenses 12 and 13 and a lens holder 11 for holding the objective lens, a plurality of support springs 19 for connecting the fixed block and the movable block together, a focus adjustment magnetic circuit 12 for operating and the movable block in a focus direction, and a tracking adjustment magnetic circuit 22 for operating the movable block in a tracking direction. An optical path notch 14 to be an optical path for laser beams reflected on a rising mirror 41 to enter the two objective lenses, respectively, is formed on the lens holder. An optical path P1 for a laser beam made incident on one of the objective lenses and an optical path P2 for a laser beam made incident on the other objective lens are made to intersect each other at the optical patch notch or in its vicinity. The focus adjustment magnetic circuit and the tracking adjustment magnetic circuit are disposed in both sides of the movable block in a tangential direction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical pickup and a disk drive device. Specifically, the optical paths of the laser beams incident on the two objective lenses are crossed at or near the notch for the optical path, and the focus adjustment magnetic circuit and the tracking adjustment magnetic circuit are arranged on both sides of the movable block in the tangential direction. The present invention relates to a technical field for ensuring good operating characteristics of an objective lens driving device.

  2. Description of the Related Art There is a disk drive device that records and reproduces information signals on and from a disk-shaped recording medium such as an optical disk and a magneto-optical disk. Such a disk drive apparatus is moved in the radial direction of the disk-shaped recording medium and is An optical pickup for irradiating the recording medium with laser light is provided.

  The optical pickup includes a moving base that is moved in the radial direction of a disk-shaped recording medium, and an objective lens driving device that is disposed on the moving base, and the objective lens driving device includes a fixed block and a metal wire on the fixed block. And a movable block supported via a support spring such as a movable spring.

  In an optical pickup, a movable block having an objective lens is moved in a focusing direction, which is a direction in which the movable block is moved away from or in contact with the recording surface of the disk-shaped recording medium. The tracking adjustment is performed by moving the disk-shaped recording medium in the tracking direction, which is approximately the radial direction of the disk-shaped recording medium, and the spot of the laser beam irradiated to the disk-shaped recording medium through the objective lens is condensed on the recording track of the disk-shaped recording medium. To be.

  Some of such optical pickups are provided with two objective lenses in an objective lens driving device corresponding to different types of disc-shaped recording media. For example, one objective lens is provided corresponding to DVD (Digital Versatile Disc) and CD (Compact Disc), and the other objective lens is provided corresponding to BD (Blu-ray Disc).

  There is a type in which two objective lenses are arranged in the tangential direction (tangential direction) of a recording track of a disk-shaped recording medium and separated from each other in an objective lens driving device including two objective lenses (for example, Patent Documents). 1).

  In such an objective lens driving device in which two objective lenses are arranged apart from each other in the tangential direction, a cube mirror that reflects or transmits laser light is arranged below one objective lens, and the other objective lens is arranged. A rising mirror that reflects the laser light is disposed below the lens. Laser light emitted from the first semiconductor laser passes through the notch for the optical path of the movable block, is reflected by the cube mirror, is launched, is incident on one objective lens, and is emitted from the second semiconductor laser. The light passes through the notch for the optical path of the movable block, passes through the cube mirror, is reflected by the rising mirror, is raised, and is incident on the other objective lens.

  In this way, in the objective lens driving device in which the two objective lenses are spaced apart in the tangential direction, the laser light incident on the other objective lens passes through the cube mirror, but the light transmittance in the cube mirror Therefore, there is a problem that the intensity of the laser light incident on the other objective lens may be insufficient.

  Therefore, as an objective lens driving device having two objective lenses, there is a type in which the two objective lenses are arranged separately in the radial direction (radial direction) of the disc-shaped recording medium (see, for example, Patent Document 2). .

JP 2007-102912 A Japanese Patent Laid-Open No. 11-120572

  However, as in the objective lens driving device described in Patent Document 2, when two objective lenses are spaced apart in the radial direction, they are incident on one objective lens and the other objective lens, respectively. Since the optical path of the laser beam is spaced apart and parallel in the radial direction at the position where it passes through the optical path cutout of the movable block, the opening width of the optical path cutout is large in the radial direction, and the rigidity of the movable block is reduced accordingly. There is a problem to say.

  Therefore, resonance is likely to occur particularly when the movable block is moved in the focus direction, which may hinder the focus adjustment operation.

  Also, in order to improve the driving force for the movable block, it is desirable to arrange a focus adjustment magnetic circuit and a tracking adjustment magnetic circuit on both sides of the movable block in the tangential direction. Therefore, there is a risk that the notch for the optical path may be blocked by the coil or magnet to be placed on the surface side where the notch for the optical path of the movable block is formed. It is difficult to arrange on the surface side where the optical path cutout is formed.

  In this case, if the magnetic circuit for focus adjustment and the magnetic circuit for tracking adjustment are arranged on the surface side where the optical path cutout of the movable block is formed without closing the optical path cutout, a space for arranging the coil and the magnet is secured. Therefore, it is necessary to increase the width of the movable block in the radial direction, which causes a problem that the objective lens driving device is increased in size.

  Therefore, the magnetic circuit for focus adjustment and the magnetic circuit for tracking adjustment must be arranged only at a position between the movable block and the fixed block, and when the movable block is operated in the focusing direction, the movable block It tends to be in a tilted state, which also hinders the focus adjustment operation.

  Accordingly, an object of the optical pickup and the disk drive device of the present invention is to overcome the above-described problems and to ensure good operating characteristics of the objective lens driving device.

  In order to solve the above-described problems, the optical pickup and the disk drive device include an objective lens driving device that includes a fixed block fixed to the moving base and two disks that are spaced apart in a substantially radial direction of the disk-shaped recording medium. A focus direction which is a direction in which the objective lens and a lens holder for holding the two objective lenses are separated from and contacting the recording surface of the disc-shaped recording medium with respect to the fixed block, and a tracking direction which is a substantially radial direction of the disc-shaped recording medium Moveable block, multiple support springs connecting the fixed block and the movable block, a focus adjustment magnetic circuit having a magnet and a focus coil by moving the movable block in the focus direction, and moving the movable block in the tracking direction Trackin with magnet and tracking coil A magnetic circuit for adjustment is provided, and a notch for the optical path is formed in the lens holder of the movable block, which becomes the optical path of the laser beam reflected by the standing mirror and incident on each of the two objective lenses, and incident on one objective lens The optical path of the laser light to be incident and the optical path of the laser light incident on the other objective lens are crossed at or near the optical path notch, and the focus adjustment magnetic circuit and the tracking adjustment magnetic circuit are connected to the recording track of the disk-shaped recording medium. Are arranged on both sides of the movable block in the tangential direction, which is the tangential direction.

  Accordingly, in the optical pickup and the disk drive device, thrust for operating the movable block is generated on both sides of the movable block in the tangential direction.

  The optical pickup of the present invention includes a moving base that is moved in the radial direction of a disk-shaped recording medium that is mounted on the disk table, and an objective lens driving device that is disposed on the moving base, and a disk-shaped recording that is mounted on the disk table. An optical pickup that irradiates a medium with laser light, and an objective lens driving device includes a fixed block fixed to a moving base, and two objective lenses that are spaced apart in a substantially radial direction of a disk-shaped recording medium And a lens holder that holds the two objective lenses, and operates in a focusing direction, which is a direction in which the fixed block is separated from and contacting the recording surface of the disk-shaped recording medium, and a tracking direction, which is a substantially radial direction of the disk-shaped recording medium Movable block, a plurality of support springs connecting the fixed block and the movable block, and A focus adjustment magnetic circuit having a magnet and a focus coil that moves the block in the focus direction, and a tracking adjustment magnetic circuit that moves the movable block in the tracking direction and has a magnet and a tracking coil. An optical path notch is formed as an optical path of laser light reflected by the rising mirror and incident on each of the two objective lenses, and is incident on the optical path of the laser light incident on one objective lens and the other objective lens. Cross the optical path of the laser beam at or near the notch for the optical path, and connect the magnetic circuit for focus adjustment and the magnetic circuit for tracking adjustment to both sides of the movable block in the tangential direction that is the tangential direction of the recording track of the disk-shaped recording medium. It is arranged.

  Accordingly, the notch for the optical path can be reduced, and accordingly, the rigidity of the movable block can be increased. Resonance does not easily occur when the movable block is operated, and the objective lens driving device operates well. Characteristics can be secured.

  In addition, since the magnetic circuit for focus adjustment and the magnetic circuit for tracking adjustment are respectively arranged on both sides of the movable block in the tangential direction, driving force for operating the movable block on both sides of the objective lens in the tangential direction can be generated. Therefore, it is difficult to be tilted when the movable block is operated, it is possible to prevent the occurrence of resonance, and it is possible to ensure good operating characteristics of the objective lens driving device.

  In the invention described in claim 2, since the focus adjustment magnetic circuit and the tracking adjustment magnetic circuit are arranged on both sides of the notch for the optical path in the radial direction of the disk-shaped recording medium, the generation point of the driving force is good. Balance is ensured, and good operating characteristics of the objective lens driving device can be secured.

  The disk drive device of the present invention comprises a disk table on which a disk-shaped recording medium is mounted and rotated, and an optical pickup for irradiating a laser beam to the disk-shaped recording medium mounted on the disk table. A disk drive device having a moving base moved in a radial direction of a disk-shaped recording medium mounted on a disk table, and an objective lens driving device arranged on the moving base, the objective lens driving device being a moving base A disk-shaped recording medium having a fixed block that is fixed, two objective lenses that are spaced apart in a substantially radial direction of the disk-shaped recording medium, and a lens holder that holds the two objective lenses. Focus direction, which is the direction of moving away from or touching the recording surface, and the substantially radial direction of the disk-shaped recording medium A movable block operated in the tracking direction, a plurality of support springs connecting the fixed block and the movable block, a focus adjustment magnetic circuit having a magnet and a focus coil by moving the movable block in the focus direction, and a movable block. A magnetic circuit for tracking adjustment that has a magnet and a tracking coil operated in the tracking direction, and is an optical path that becomes the optical path of laser light that is reflected by the rising mirror and incident on the two objective lenses, respectively, on the lens holder of the movable block Forming a notch, crossing the optical path of the laser beam incident on one objective lens and the optical path of the laser beam incident on the other objective lens at or near the optical path notch, and the focus adjustment magnetic circuit and tracking Adjusting magnetic circuit for recording on a disk-shaped recording medium Respectively, characterized in that arranged on both sides of the movable block in the tangential direction which is tangential direction of the rack.

  Accordingly, the notch for the optical path can be reduced, and accordingly, the rigidity of the movable block can be increased. Resonance does not easily occur when the movable block is operated, and the objective lens driving device operates well. Characteristics can be secured.

  In addition, since the magnetic circuit for focus adjustment and the magnetic circuit for tracking adjustment are respectively arranged on both sides of the movable block in the tangential direction, driving force for operating the movable block on both sides of the objective lens in the tangential direction can be generated. Therefore, it is difficult to be tilted when the movable block is operated, it is possible to prevent the occurrence of resonance, and it is possible to ensure good operating characteristics of the objective lens driving device.

  The best mode of an optical pickup and a disk drive device according to the present invention will be described below with reference to the accompanying drawings.

  The disk drive device 1 is configured by arranging required members and mechanisms inside an outer casing 2 (see FIG. 1), and a disk insertion slot (not shown) is formed in the outer casing 2.

  A chassis (not shown) is disposed inside the outer casing 2, and the disk table 3 is fixed to the motor shaft of a spindle motor attached to the chassis.

  Parallel guide shafts 4 and 4 are attached to the chassis, and a lead screw 5 that is rotated by a feed motor (not shown) is supported.

  The optical pickup 6 includes a moving base 7, required optical components provided on the moving base 7, and an objective lens driving device 8 disposed on the moving base 7, and is provided at both ends of the moving base 7. The bearing portions 7a and 7b are slidably supported by the guide shafts 4 and 4, respectively.

  When a nut member (not shown) provided on the moving base 7 is screwed into the lead screw 5 and the lead screw 5 is rotated by the feed motor, the nut member is sent in a direction corresponding to the rotation direction of the lead screw 5, The pickup 6 is moved in the radial direction (radial direction) of the disc-shaped recording medium 100 mounted on the disc table 3.

  As the disc-shaped recording medium 100, for example, a BD (Blu-ray Disc) is used in addition to a DVD (Digital Versatile Disc) and a CD (Compact Disc). The wavelength of the laser beam used in each of these disk-shaped recording media 100 is about 660 nm for DVD, about 780 nm for CD, and about 405 nm for BD.

  The objective lens driving device 8 has a fixed block 9 and a movable block 10 operated with respect to the fixed block 9 (see FIGS. 2 to 4).

  The fixed block 9 and the movable block 10 are arranged apart from each other in the tangential direction (tangential direction) of the recording track of the disc-shaped recording medium 100.

  The movable block 10 includes a lens holder 11 and objective lenses 12 and 13 held by the lens holder 11.

  A front surface 11a of the lens holder 11, that is, a surface opposite to the side facing the fixed block 10, is formed with a transmission notch 14 penetrating back and forth and opening downward. First focus coils 15 and 15 and first tracking coils 16 and 16 are attached to the left and right sides of the transmission notch 14 on the front surface 11a of the lens holder 11, respectively. The first tracking coils 16 and 16 are disposed on the upper ends of the first focus coils 15 and 15, respectively.

  Second focus coils 17 and 17 and a second tracking coil 18 are attached to the rear surface 11 b of the lens holder 11, that is, the surface facing the fixed block 10. The second focus coils 17 and 17 are arranged on the left and right of the second tracking coil 18.

  The objective lenses 12 and 13 are spaced apart from each other in the radial direction (radial direction) of the disc-shaped recording medium 100, and the objective lens 12 has a function of condensing laser light having a working wavelength of BD, for example. For example, 13 has a function of condensing laser light having wavelengths used for DVD and CD.

  Three ends of each of the support springs 19, 19,... Are connected to the left and right ends of the fixed block 9 and the movable block 10, respectively. Therefore, the movable block 10 is connected to the fixed block 9 by the support springs 19, 19,. The support springs 19, 19,... Are made of, for example, a wire shape with a conductive metal material.

  First magnets 20 and 20 are respectively disposed at positions facing the first focus coils 15 and 15 and the first tracking coils 16 and 16 (see FIG. 2). The first magnet 20 is formed by coupling a large main magnet 20a and a small sub magnet 20b, and the sub magnet 20b is coupled to the outer side surface of the upper half of the main magnet 20a.

  The main magnet 20a is vertically magnetized with different polarities, and the sub magnet 20b is magnetized with a pole different from the upper pole of the main magnet 20a.

  The main magnets 20a and 20a are arranged to face the first focus coils 15 and 15, respectively, and the main magnets 20a and 20a and the first focus coils 15 and 15 form first focus adjustment magnetic circuits 21 and 21, respectively. Composed.

  The upper half of the main magnets 20a, 20a and the submagnets 20b, 20b are arranged to face the first tracking coils 16, 16, respectively. The upper half of the main magnets 20a, 20a and the first tracking coils 16, 16 are arranged. The first tracking adjustment magnetic circuits 22 and 22 are respectively configured.

  A second magnet 23 is disposed at a position facing the second focus coils 17 and 17 and the second tracking coil 18 (see FIGS. 2 and 4). The second magnet 23 includes first portions 23a and 23a magnetized to have different polarities on the left and right sides, and second portions 23b and 23b magnetized to different polarities on the respective upper ends at both left and right end portions. .

  The second magnet 23 is positioned so that the outer portions of the first portions 23a and 23a and the second portions 23b and 23b face the second focus coils 17 and 17 respectively, and the first portions 23a and 23a The outer focus portion, the second portions 23b and 23b, and the second focus coils 17 and 17 constitute second focus adjustment magnetic circuits 24 and 24, respectively.

  The second magnet 23 is positioned so that the inner portion of the first portions 23 a and 23 a faces the second tracking coil 18, and the second portion is formed by the inner portion of the first portion 23 a and the second tracking coil 18. The tracking adjustment magnetic circuit 25 is configured.

  In addition, the 1st magnets 20 and 20 and the 2nd magnet 23 may be attached to the yoke, and may be arrange | positioned independently in the state without a yoke.

  When a drive current is supplied from a power supply circuit (not shown) to the first focus coils 15, 15, the second focus coils 17, 17, or the first tracking coils 16, 16, the second tracking coil 18, these drive A force having a direction corresponding to the direction of the current and the direction of the magnetic flux generated by the first magnet 20, 20, or the second magnet 23 is generated, and the movable block 10 is moved in the focus direction or the tracking direction.

  The focus direction is the direction in which the disc-shaped recording medium 100 is moved away from and coming into contact (the F direction shown in FIG. 2), that is, the vertical direction, and the tracking direction is the radial direction of the disc-shaped recording medium 100 (the TR direction shown in FIG. 2). Left and right direction. The direction perpendicular to both the focus direction and the tracking direction is the tangential direction (TAN direction shown in FIG. 2), which is the tangential direction of the recording track of the disc-shaped recording medium 100, that is, the front-rear direction.

  When the movable block 10 is moved in the focus direction or the tracking direction, the support springs 19, 19,... Are elastically deformed.

  Necessary optical components are arranged on the moving base 7 (see FIGS. 5 and 6). The optical components include a first semiconductor laser 26, a second semiconductor laser 27, a first grating lens 28, a second grating lens 29, a dichroic prism 30, a monitor light receiving element 31, a liquid crystal element 32, and a beam splitter 33. The first collimator lens 34, the reflection mirror 35, the polarizing plate 36, the second collimator lens 37, the condenser lens 38, the light receiving element 39, the first rising mirror 40, and the second rising mirror 41 are provided. Is provided.

  The first semiconductor laser 26 emits a first laser light having a working wavelength of BD, and the second semiconductor laser 27 emits a second laser light having a working wavelength of CD or DVD.

  When the first laser light is emitted from the first semiconductor laser 26, the light is diffracted by the first grating lens 28 and is incident on the dichroic prism 30. The incident first laser light is incident on the dichroic prism 30. It is separated in two directions by the functional surface 30a.

  One of the first laser beams separated by the functional surface 30a of the dichroic prism 30 is incident on the monitor light receiving element 31, and the intensity is detected. When the intensity of the first laser beam is detected by the monitor light receiving element 31, the intensity of the first laser beam emitted from the first semiconductor laser 26 is controlled based on the detection result.

  The other first laser beam separated by the functional surface 30a of the dichroic prism 30 is incident on the liquid crystal element 32 to correct coma and astigmatism. The first laser light enters the beam splitter 33 from the liquid crystal element 32, passes through the functional surface 33 a of the beam splitter 33, and enters the first collimator lens 34.

  The first laser light incident on the first collimator lens 34 is converted into parallel light and reflected by the reflection mirror 35 to change the traveling direction, and the transmission cutout 14 formed in the lens holder 11 of the movable block 10. Is passed through the first rising mirror 40 in the vertical direction and irradiated onto the recording surface of the disk-shaped recording medium 100 via the objective lens 12.

  The first laser light applied to the recording surface of the disc-shaped recording medium 100 is reflected by the recording surface of the disc-shaped recording medium 100 and returned as the first rising mirror 40, the reflecting mirror 35, and the first The light is again incident on the beam splitter 33 through the collimator lens 34, reflected by the functional surface 33 a of the beam splitter 33, condensed by the condenser lens 38, and incident on the light receiving element 39.

  When the first laser light is incident on the light receiving element 39, an RF (Radio Frequency) signal and a servo signal are detected.

  On the other hand, when the second laser light is emitted from the second semiconductor laser 27, the light is diffracted by the second grating lens 29 and is incident on the dichroic prism 30, and the incident second laser light is the dichroic prism. It is separated in two directions by 30 functional surfaces 30a.

  One second laser beam separated by the functional surface 30a of the dichroic prism 30 is incident on the light receiving element 31 for monitoring, and the intensity is detected. When the intensity of the second laser beam is detected by the monitor light receiving element 31, the intensity of the second laser beam emitted from the second semiconductor laser 27 is controlled based on the detection result.

  The other second laser beam separated by the functional surface 30a of the dichroic prism 30 is incident on the liquid crystal element 32 to correct coma and astigmatism. The second laser light is incident on the beam splitter 33 from the liquid crystal element 32, is continuously reflected by the functional surface 33 a and the reflecting surface 33 b of the beam splitter 33, is transmitted through the polarizing plate 36, and is second collimator lens 37. Is incident on. The polarization direction of the second laser light is converted by the polarizing plate 36.

  The second laser light incident on the second collimator lens 37 is converted into parallel light, passes through the transmission notch 14 formed in the lens holder 11 of the movable block 10, and is vertically reflected by the second rising mirror 41. The recording surface of the disc-shaped recording medium 100 is irradiated through the objective lens 13.

  The second laser light applied to the recording surface of the disk-shaped recording medium 100 is reflected by the recording surface of the disk-shaped recording medium 100 and returned as second light to the second rising mirror 41 and the second collimator lens 37. Then, the light is again incident on the beam splitter 33 through the polarizing plate 36, reflected by the reflecting surface 33 b of the beam splitter 33, transmitted through the functional surface 33 a, condensed by the condenser lens 38, and incident on the light receiving element 39.

  When the second laser light is incident on the light receiving element 39, an RF signal and a servo signal are detected.

  The optical path P1 of the first laser beam emitted from the first semiconductor laser 26 and the optical path P2 of the second laser beam emitted from the second semiconductor laser 27 are as shown in FIGS. The lens holder 11 intersects at the transmission notch 14 or in the vicinity thereof.

  In the disk drive device 1 configured as described above, when the disk table 3 is rotated in accordance with the rotation of the spindle motor, the disk-shaped recording medium 100 mounted on the disk table 3 is rotated, and at the same time, the light The pickup 6 is moved in the radial direction of the disc-shaped recording medium 100, and a recording operation or a reproducing operation is performed on the disc-shaped recording medium 100.

  In this recording operation and reproduction operation, when a driving current is supplied to the first focus coils 15 and 15 and the second focus coils 17 and 17, the movable block 10 of the objective lens driving device 8 is fixed as described above. The block 9 is operated in the focus direction FF shown in FIG. 2 and emitted from the first semiconductor laser 26 or the second semiconductor laser 27 provided on the moving base 7 and irradiated through the objective lenses 12 and 13. Focus adjustment is performed so that the spot of the first laser beam or the second laser beam to be focused on the recording surface of the disc-shaped recording medium 100.

  Further, when a driving current is supplied to the first tracking coils 16 and 16 and the second tracking coil 18, the movable block 10 of the objective lens driving device 8 is shown in FIG. The spot of the first laser beam or the second laser beam which is operated in the tracking direction TR-TR shown and is emitted from the first semiconductor laser 26 or the second semiconductor laser 27 and irradiated through the objective lenses 12 and 13. Is adjusted so that the light is condensed on the recording track of the disk-shaped recording medium 100.

  These focus adjustment and tracking adjustment are performed when the first laser light or the second laser light as return light reflected by the recording surface of the disk-shaped recording medium 100 is incident on the light receiving element 39 and detected. This is done based on the signal.

  As described above, in the optical pickup 6, the disc-shaped recording is performed via the optical path P <b> 1 of the first laser light irradiated onto the recording surface of the disc-shaped recording medium 100 via the objective lens 12 and the objective lens 13. Since the optical path P2 of the second laser light applied to the recording surface of the medium 100 intersects at or near the optical path cutout 14 of the lens holder 11, the optical path cutout 14 can be made smaller. It becomes possible to increase the rigidity of the movable block 10, and it is difficult for the movable block 10 to resonate particularly when operated in the focus direction, and to ensure good operating characteristics of the objective lens driving device 8. Can do.

  Further, in addition to the second focus adjustment magnetic circuits 24 and 24 and the second tracking adjustment magnetic circuit 25, the first optical path is formed in the space generated on the front surface 11a side of the lens holder 11 by reducing the optical path cutout 14. The focus adjustment magnetic circuits 21 and 21 and the first tracking adjustment magnetic circuits 22 and 22 can be arranged to generate a driving force for operating the movable block 10 on both sides of the objective lenses 12 and 13 in the tangential direction. be able to. Accordingly, it is difficult for the movable block 10 to be inclined particularly when operated in the focus direction, and it is possible to prevent the occurrence of resonance, and to ensure good operating characteristics of the objective lens driving device 8. .

  Further, in addition to the second focus adjustment magnetic circuits 24 and 24 and the second tracking adjustment magnetic circuit 25, the first focus adjustment magnetic circuits 21 and 21 and the first tracking adjustment magnetic circuits 22 and 22 are provided. By arranging it, it is possible to improve the sensitivity during the operation of the movable block 10 by increasing the driving force.

  In addition, the two first focus adjustment magnetic circuits 21 and 21 are arranged on both sides of the optical path cutout 14 in the radial direction of the disc-shaped recording medium 100, and the two first tracking adjustment magnetic circuits 22 and 22 are provided. Since the disc-shaped recording medium 100 is arranged on both sides of the optical path cutout 14 in the radial direction, a good balance of driving force generation points can be secured, and good operating characteristics of the objective lens driving device 8 can be secured. it can.

  In the above description, the first focus coils 15 and 15, the first tracking coils 16 and 16, the second focus coils 17 and 17, and the second focus coil 15 are respectively attached to the lens holder 11 that is movable with respect to the fixed block 9. The so-called moving coil type objective lens driving device 8 with the tracking coil 18 attached is shown as an example, but conversely, a so-called moving magnet type objective lens driving device with a magnet attached to the lens holder 11 can also be used. is there.

  In the above description, the focus direction is described as the vertical direction, the tracking direction is defined as the left-right direction, and the tangential direction is defined as the front-rear direction. However, these directions are shown as examples for convenience of explanation, and are particularly limited to these directions. Never happen.

  The specific shapes and structures of the respective parts shown in the best mode for carrying out the invention described above are merely examples of the implementation of the present invention, and the present invention is thereby limited. This technical scope should not be interpreted in a limited way.

FIG. 2 to FIG. 6 show the best mode for carrying out the optical pickup and the disk drive apparatus of the present invention, and this figure is a schematic perspective view of the disk drive apparatus. It is an expansion perspective view of an objective lens drive device. It is an expansion perspective view which shows an objective lens drive device in the state which abbreviate | omitted the magnet. FIG. 3 is an enlarged perspective view showing the objective lens driving device in a state in which some magnets are omitted and viewed from the opposite direction to FIG. 2. It is an expansion perspective view which shows an objective lens drive device with each optical component. It is an expansion perspective view which shows each optical component and the optical path of a laser beam.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Disk drive apparatus, 3 ... Spindle motor, 3a ... Disk table, 6 ... Optical pick-up, 7 ... Moving base, 8 ... Objective lens drive device, 9 ... Fixed block, 10 ... Movable block, 11 ... Lens holder, 12 ... Objective lens, 13 ... Objective lens, 14 ... Transmission notch, 15 ... First focus coil, 16 ... First tracking coil, 17 ... Second focus coil, 18 ... Second tracking coil, 19 ... Support spring 21... First focus adjustment magnetic circuit 22... First tracking adjustment magnetic circuit 24... Second focus adjustment magnetic circuit 25. Second tracking adjustment magnetic circuit 40. Rising mirror 41 ... second rising mirror 100 ... disc-shaped recording medium

Claims (3)

A laser beam for a disk-shaped recording medium mounted on the disk table, comprising a moving base moved in the radial direction of the disk-shaped recording medium mounted on the disk table and an objective lens driving device disposed on the moving base. An optical pickup that irradiates
The objective lens drive is
A fixed block fixed to the moving base;
A direction having two objective lenses spaced apart in a substantially radial direction of the disc-shaped recording medium and a lens holder for holding the two objective lenses, and being in contact with the recording surface of the disc-shaped recording medium with respect to the fixed block A movable block that is operated in a focusing direction that is and a tracking direction that is a substantially radial direction of the disk-shaped recording medium;
A plurality of support springs connecting the fixed block and the movable block;
A magnetic circuit for focus adjustment having a magnet and a focus coil by moving the movable block in the focus direction;
The movable block is moved in the tracking direction and includes a magnet and a tracking adjustment magnetic circuit having a tracking coil.
In the lens holder of the movable block, a notch for the optical path that becomes the optical path of the laser light reflected by the rising mirror and incident on each of the two objective lenses is formed.
Crossing the optical path of the laser light incident on one objective lens and the optical path of the laser light incident on the other objective lens at or near the optical path notch,
An optical pickup comprising a magnetic circuit for focus adjustment and a magnetic circuit for tracking adjustment arranged on both sides of a movable block in a tangential direction that is a tangential direction of a recording track of a disk-shaped recording medium. The optical pickup according to claim 1, wherein the focus adjustment magnetic circuit and the tracking adjustment magnetic circuit are arranged on both sides of the optical path notch in the radial direction of the disk-shaped recording medium. A disk having a disk table mounted thereon and rotated, and an optical pickup for irradiating the disk-shaped recording medium mounted on the disk table with laser light, the disk having the optical pickup mounted on the disk table A disk drive device having a moving base moved in the radial direction of the recording medium and an objective lens driving device arranged on the moving base,
The objective lens drive is
A fixed block fixed to the moving base;
A direction having two objective lenses spaced apart in a substantially radial direction of the disc-shaped recording medium and a lens holder for holding the two objective lenses, and being in contact with the recording surface of the disc-shaped recording medium with respect to the fixed block A movable block that is operated in a focusing direction that is and a tracking direction that is a substantially radial direction of the disk-shaped recording medium;
A plurality of support springs connecting the fixed block and the movable block;
A magnetic circuit for focus adjustment having a magnet and a focus coil by moving the movable block in the focus direction;
The movable block is moved in the tracking direction and includes a magnet and a tracking adjustment magnetic circuit having a tracking coil.
In the lens holder of the movable block, a notch for the optical path that becomes the optical path of the laser light reflected by the rising mirror and incident on each of the two objective lenses is formed.
Crossing the optical path of the laser light incident on one objective lens and the optical path of the laser light incident on the other objective lens at or near the optical path notch,
A disk drive device characterized in that a focus adjustment magnetic circuit and a tracking adjustment magnetic circuit are arranged on both sides of a movable block in a tangential direction which is a tangential direction of a recording track of a disk-shaped recording medium.

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