JP2010277628A - Optical pickup device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an "optical pickup device" which can be made thin by shortening a distance between an objective lens and an optical element in an optical axis direction, in a state where a plurality of objective lenses and coils for correction are mounted on the lens holder. <P>SOLUTION: A first objective lens 41 for BD and a second objective lens 42 for DVD are mounted on a top surface of a lens holder 30, and a prism 43 is arranged in an inner space 36 of the lens holder 30, and at a front surface 34 of the lens holder 30, an opening 37 large in width dimension W is formed to give light individually to two objective lenses 41 and 42. The objective lenses 41 and 42 and the opening 37 are arranged while being shifted toward an R1 side, and a front side tracking coil Ct2 is arranged on an R2 side of a front surface 43 not to be overlapped with the opening 37. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an optical pickup device in which a plurality of objective lenses corresponding to different media such as BD and DVD are mounted on a lens holder.

  The following Patent Document 1 discloses an optical pickup device that is commonly used for different media. In this type of optical pickup device, two objective lenses having different optical conditions corresponding to respective media are mounted on one lens holder. The objective lenses are arranged side by side with a space in the radial direction on the lens holder.

  The lens holder is supported by a linear elastic body so as to be movable in the optical axis direction and the radial direction. The lens holder is provided with a focusing coil for driving in the optical axis direction and a tracking coil for driving in the radial direction, and a magnet for applying a magnetic field to the focusing coil and the tracking coil is provided on the fixed side. ing.

JP-A-9-17005

  In the optical pickup device, light given from the outside is reflected by the prism at right angles and given to the objective lens, and this light is condensed on the recording surface of the disk by the objective lens. In order to reduce the thickness of this type of optical pickup device, it is necessary to form an internal space in which the prism can intervene inside the lens holder, and to form an opening in the lens holder that guides light from the outside to the prism. It is.

  However, as described in Patent Document 1, in a lens holder in which two objective lenses are mounted, it is necessary to individually provide light from the outside to the two objective lenses arranged side by side. For this reason, when the opening is provided, it must be formed widely. If a wide opening is to be provided, it is difficult to dispose a focusing coil or a tracking coil in the lens holder. In particular, if an attempt is made to mount a tilt coil that tilts the lens holder in the radial direction, a space for arranging the tilt coil cannot be secured by providing the opening.

  If a focusing coil, a tracking coil, and a tilt coil are arranged in the lens holder and the opening is further formed, the radial width of the lens holder becomes too large for focus correction and tracking correction. It becomes difficult to perform the operation with high accuracy.

  The present invention solves the above-described conventional problems, and an optical pickup device that uses a lens holder equipped with a plurality of objective lenses, can be reduced in thickness, and can be reduced as much as possible. It is intended to provide.

The present invention includes a lens holder on which a plurality of objective lenses corresponding to different media are mounted, a support mechanism that operably supports the lens holder, and a focusing coil that drives the lens holder in the optical axis direction of the objective lens. And an optical pickup device provided with a tracking coil that drives the lens holder in a radial direction intersecting the optical axis direction, and a magnet that applies a magnetic field to the focusing coil and the tracking coil.
The lens holder includes an opening that is opened forward in the tangential direction that intersects both the optical axis direction and the radial direction, and an optical element that reflects light applied through the opening toward the objective lens. An inner space for accommodating the plurality of objective lenses, and an array center of the plurality of objective lenses in the radial direction and a center of the opening are arranged to be offset toward one side in the radial direction from the center of the lens holder,
The tracking coil is attached to each of the front surface of the lens holder facing forward in the tangential direction and the rear surface facing backward, and the center of the tracking coil attached to the front surface is at the center of the lens holder. On the other hand, it is attached to the opposite side of the opening is formed,
The focusing coil is attached at a position deviating from the opening in the optical axis direction.

  In the optical pickup device of the present invention, a plurality of objective lenses corresponding to different media are mounted on the lens holder. A plurality of objective lenses and an opening for supplying light to each objective lens are provided from the center of the lens holder. Also, it is not necessary to increase the width dimension of the lens holder in the radial direction more than necessary by biasing to one side in the radial direction and offset the tracking coil provided on the same side as the opening to the side opposite to the opening. In addition, an optical element such as a prism can be accommodated in the interior and can be configured to be thin.

  In the present invention, the support mechanism includes a support portion fixed to a pickup base, and an elastic support member that extends from the support portion and operably supports the lens holder. A support member is provided on the rear surface side of the lens holder.

Further, the present invention is provided with a pair of tilt coils that operate the lens holder in a direction in which the optical axis of the objective lens is tilted in a radial direction, and a magnet that applies a magnetic field to the tilt coils,
The pair of tilt coils are attached to the rear surface of the lens holder with a gap in the radial direction, and the tracking coil attached to the rear surface is arranged between the pair of tilt coils. Can be configured.

  In the optical pickup device of the present invention, the radial width of the lens holder is such that one tracking coil and two tilt coils provided on the rear surface can be arranged, and the three coils are in the radial direction. The width dimension of the lens holder does not become larger than necessary with respect to the length of the arrangement. On the front side of the lens holder with this limited width, all functions can be efficiently arranged by biasing the multiple objective lenses and openings to one side and the tracking coil to the other side. Therefore, it becomes possible to realize a thin shape.

  In the present invention, the tracking coil attached to the front surface of the lens holder and the tracking coil attached to the rear surface are at the same height position in the optical axis direction, and the driving action of each tracking coil It is preferable that the point and the center of gravity of the lens holder are set at the same height position in the optical axis direction.

  In the optical pickup device of the present invention, on the front side of the lens holder, the tracking coil is arranged to be offset toward one side in the radial direction, and on the rear side of the lens holder, the tracking coil is arranged in the center in the radial direction. The driving action points of the two tracking coils are different in the radial direction between the front side and the rear side of the lens holder. However, the driving action points of the two tracking coils coincide with the optical axis direction, and preferably the driving action point coincides with the center of gravity of the lens holder. It becomes difficult to act.

  In the present invention, it is preferable that one of the plurality of objective lenses is for a Blu-ray disc, and the objective lens for the Blu-ray disc is disposed at a position furthest away in the radial direction from the center of the lens holder, Furthermore, it is preferable that the objective lens for a Blu-ray disc among the plurality of objective lenses is disposed at a position closest to the center of the disc.

  Since the BD (Blu-ray Disc) has a BCA (burst cutting area) closer to the center of the disc than the DVD, the Blu-ray disc objective lens is placed at the end of the lens holder and the center of the disc. The ID information recorded on the BCA of the BD can be easily read by being positioned on the side.

  The optical pickup device of the present invention can reduce the height dimension by allowing an optical element such as a prism to intervene in the internal space of a lens holder on which a plurality of objective lenses are mounted. In addition, a plurality of objective lenses, openings for guiding light to the objective lenses, tracking coils, focusing coils, and tilt coil functional parts can be efficiently arranged in a thin and small width lens holder. Become.

The perspective view which shows the optical pick-up apparatus of embodiment of this invention from the front of a tangential direction, The perspective view which shows the lens holder provided in the optical pick-up apparatus from the front of a tangential direction, A rear view showing the lens holder from the rear in the tangential direction, A side view showing the lens holder from the radial direction, (A) (B) is explanatory drawing which shows the magnetic pole of the magnet facing each coil,

  The optical pickup device of the present invention can reproduce information and record information on a plurality of types of discs. The optical pickup device 10 shown in FIG. 1 is a BD (Blu-ray “Blu-ray” disc) (however, , “Blu-ray” is a registered trademark)) and DVD (digital versatile disc), and information can be reproduced and recorded.

  In each figure, the F1-F2 direction is the optical axis direction of the objective lens, and the F1 side is the side facing the disk. The R1-R2 direction is the radial direction (the radial direction of the disk), the R1 side is the center side and the inner peripheral side of the disk loaded in the rotation drive unit, and the R2 side is the outer peripheral side of the disk. The T1-T2 direction is the tangential direction (the tangential direction of the recording track recorded on the disc). The T1 direction is the front and the T2 direction is the rear.

  The optical pickup device 10 is mounted on a moving base (not shown) that moves in the R1-R2 direction so as to face the disk loaded in the rotation drive unit.

  The moving base includes a light emitting element such as a laser diode, an optical element such as a lens group or a light separator that supplies light emitted from the light emitting element to the objective lens, and a light receiving element that receives reflected light from the disk. It is equipped with the optical system. On this moving base, an optical system for BD and an optical system for DVD are individually mounted.

  As shown in FIG. 1, the optical pickup device 10 has a pickup base 20. The pickup base 20 is configured by being bent with a sheet metal material. Support portions 21, 22, and 23 are provided at three locations on the pickup base 20. The support portion 21 is supported on the moving base, a compression coil spring is interposed between the support portions 22 and 23 and the moving base, and an adjusting screw inserted through the support portions 22 and 23 is screwed to the moving base. Is done. In this structure, the amount of inclination of the pickup base 20 in the radial direction (R1-R2 direction) and the tangential direction (T1-T2 direction) is adjusted on the moving base by adjusting the tightening amounts of the two adjusting screws. The

  A synthetic resin support 25 is fixed on the bottom plate 24 of the pickup base 20. A substrate 26 is attached to the rear portion (T2 side) of the support 25. Fixed to the substrate 26 are base ends of metal wires 27 arranged as elastic support members on the R1 side and the R2 side. The three wires 27 arranged on the R1 side and the R2 side are aligned in the optical axis direction (F1-F2 direction) and extend in parallel toward the front (T1 direction).

  A lens holder 30 made of synthetic resin is supported at the tip of the six wires 27. The lens holder 30 is integrally formed with support pieces 31 projecting on both sides in the radial direction, and the distal ends of the wires 27 are fixed to the support pieces 31. The lens holder 30 is movable on the pickup base 20 in a parallel posture in the optical axis direction (F1-F2 direction) and the radial direction (R1-R2 direction) by the wire 27, and the optical axis is tilted in the radial direction. An operation of tilting in the radial tilt direction is possible.

  As shown in FIG. 2, the lens holder 30 has an upper surface 32 facing in the F1 direction and left and right side surfaces 33, 33 facing in the radial direction, and the support pieces 31, 31 are integrally formed from the left and right side surfaces 33, 33. It protrudes. The lens holder 30 has a front surface 34 facing the T1 direction and a rear surface 35 facing the T2 direction. Inside the lens holder 33, an internal space 36 that opens downward (F2 direction) is formed.

  On the upper surface 32 of the lens holder 30, lens holding holes 32a and 32b penetrating vertically and communicating with the internal space 36 are opened. The first objective lens 41 is held in one lens holding hole 32a, and the other. The second objective lens 42 is held in the lens holding hole 32b. The optical axis O1 of the first objective lens 41 and the optical axis O2 of the second objective lens 42 are parallel to each other, and both extend in a direction orthogonal to the direction in which the wire 27 extends. The optical axis O1 and the optical axis O2 are located on a straight line facing in the radial direction (R1-R2 direction).

  The center points of the first objective lens 41 and the second objective lens 42 in the radial direction, that is, the midpoint between the optical axis O1 and the optical axis O2 on the line extending in the radial direction are both side surfaces of the lens holder 30. The disk is arranged closer to the disk center side (R1 side) in the radial direction than the center of the width dimension between 33 and 33. As a result, the first objective lens 41 is located on the side closest to the center of the disk in the lens holder 30.

  The first objective lens 41 is for BD, and the second objective lens 42 is for DVD. The first objective lens 41 and the second objective lens 42 have different optical conditions, and the numerical aperture of the first objective lens 41 for BD is larger than that of the second objective lens 42 for DVD, The working distance of the first objective lens 41 for BD is shorter than that of the second objective lens 42 for DVD.

  The BD and DVD recording areas have a BCA (burst cutting area) at the center, and a media ID for copyright protection, a unique ID for each disc, and the like are recorded on the BCA. The BCA of the BD is provided in an area closer to the center of the disc than the BCA of the DVD. Since the lens holder 30 is provided with the first objective lens 41 for BD on the R1 side that is the center side of the disk, the optical pickup device 10 is located on the inner peripheral side of the disk loaded in the rotation drive unit. When the first objective lens 41 is moved to, the first objective lens 41 can be easily opposed to the BCA of the BD, and the BCA information can be read accurately.

  On the moving base to which the pickup base 20 is fixed, a prism 43 that functions as a total reflection element, which is one of the optical elements constituting the optical system, is fixed. As shown in FIGS. 1, 2, and 4, the prism 43 enters the internal space 36 formed in the lens holder 30.

  As shown in FIG. 4, the total reflection surface 43a of the prism 43 is arranged at an angle of 45 degrees with respect to both the tangential direction (T1-T2 direction) and the optical axis direction (F1-F2 direction).

  As shown in FIG. 2, the radial dimension (R1-R2 direction) of the prism 43 is such that the effective diameter of the first objective lens 41 and the effective diameter of the second objective lens 42 are both totally reflecting surfaces 43a. It is decided to be able to face. That is, the prism 43 has an elongated shape that is long in the radial direction.

  As shown in FIG. 2, an opening 37 is cut out and formed in the front surface 34 of the lens holder 30. The opening 37 has a predetermined width dimension W in the radial direction (R1-R2 direction), opens with a predetermined height dimension H in the optical axis direction (F1-F2 direction), and downward (F2 direction). ) Is open. The opening 37 is formed such that the center of the radial width W is closer to the R1 side than the center of the lens holder 30 in the radial direction. Further, the opening 37 can face all of the total reflection surface 43a of the prism 43, and the two light beams LB (see FIG. 4) for BD and DVD sent in the T2 direction are transmitted to the total reflection surface 43a. It is formed with a wide width W so that it can pass through.

  As shown in FIG. 1, a vertically bent yoke 28 is integrally formed on the front side (T1 side) of the pickup base 20, and a notch 28 a leading to the opening 37 is formed in the yoke 28. Is formed. The light emitted from the optical system for BD and the optical system for DVD passes through the notch 28 a and the opening 37 and is given to the total reflection surface 43 a of the prism 43.

  As shown in FIG. 2, a coil holding groove 38 is formed on the upper portion of the lens holder 30. The coil holding groove 38 is formed continuously over the entire circumference over the front surface 34, the rear surface 35, and the left and right side surfaces 33, 33. A focusing coil Cf is wound around the coil holding groove 38. The focusing coil Cf is attached to a region that does not overlap with the opening 37 between the upper edge of the opening 37 and the upper surface 32 of the lens holder 30.

  As shown in FIG. 2, on the front surface 34 of the lens holder 30, a coil installation recess 34a is formed between the R2 side edge of the opening 37 and the side surface 33 facing the R2 side. A front tracking coil Ct1 is installed in 34a. The front tracking coil Ct1 is wound in a loop in a vertical plane parallel to a plane including the optical axis direction (F1-F2 direction) and the radial direction (R1-R2 direction), and is bonded to the coil installation recess 34a. It is fixed by means such as.

  On the front surface 34 of the lens holder 30, the opening 37 is formed at a position offset toward the R1 side, so that the tracking coil Ct1 is offset toward the R2 side from the center of the lens holder 30 so as to avoid the opening 37. Placed in position.

  As shown in FIG. 3, a coil installation recess 35a is formed on the rear surface 35 of the lens holder 30 at the center in the radial direction and below the focusing coil Cf, and rear tracking is provided in the coil installation recess 35a. A coil Ct2 is installed. The rear tracking coil Ct2 is wound in a loop shape in the vertical plane, and is fixed inside the coil installation recess 35a by means such as adhesion.

  A pair of coil installation recesses 35b and 35c are formed on the left and right sides of the rear surface 35 of the lens holder 30, and a tilt coil Clt is installed in each of the coil installation recesses 35b and 35c. The respective tilt coils Clt, Clt are wound in a loop shape in the vertical plane, and are fixed inside the respective coil installation recesses 35b, 35c by means such as adhesion.

  The rear tracking coil Ct2 is attached at a position where its winding center coincides with the center of the width dimension of the lens holder 30 in the radial direction (R1-R2 direction). In addition, the winding centers of the pair of tilt coils Clt are arranged at equal distances on the left and right with respect to the center of the width dimension of the lens holder 30 in the radial direction.

  As shown in FIG. 3, the width dimension in the radial direction of the lens holder 30 is slightly larger than the dimension in which the three coils of the rear tracking coil Ct2 and the two tilt coils Clt are arranged. Is not excessively larger than the sum of the width dimensions of the three coils Ct2, Clt, and Clt. In addition, the opening 37 and the front tracking coil Ct1 are also arranged close to each other on the front surface 34 side, and the radial width of the lens holder 30 is equal to the width W of the opening 37 and the width of the front tracking coil Ct1. It is only slightly larger than the sum of the dimensions.

  Therefore, even if the opening 37 is formed in the lens holder 30, and the front tracking coil Ct1, the rear tracking coil Ct2, and the pair of tilt coils Clt and Clt are arranged side by side in the radial direction, the whole is useless. There is no space, and the radial width of the lens holder 30 can be minimized.

  The front tracking coil Ct1 shown in FIG. 2 and the rear tracking coil shown in FIG. 3 have the same shape. The tracking coils Ct1 and Ct2 have a vertically long shape in which the current flowing in the optical axis direction (F1-F2 direction) contributes to tracking correction drive, and the dimension in the optical axis direction is longer than the width dimension in the radial direction.

  The front tracking coil Ct1 and the rear tracking coil Ct2 are arranged at different positions in the radial direction. However, as shown in FIG. 4, the tracking coils Ct1 and Ct2 are in the optical axis direction (F1-F2 direction). They are placed at the same height. Further, the winding center of the front tracking coil Ct 1, that is, the driving action point, and the winding center of the rear tracking coil Ct 2, that is, the driving action point are set to be at the same height as the gravity center G of the lens holder 30. .

  As shown in FIG. 1, a front upper magnet 51 and a front lower magnet 52 are provided inside a front yoke 28 provided on the pickup base 20. As shown in FIG. 5 (A), the front upper magnet 51 has a shape elongated in the radial direction and faces the focusing coil Cf. The front lower magnet 52 has a vertically long shape with a long dimension in the optical axis direction, and faces the front tracking coil Ct1. The front lower magnet 52 is magnetized with magnetic poles whose surfaces facing the coil are different between a portion 52a facing the current A2 in one direction flowing through the front tracking coil Ct1 and a portion 52b facing the current A3 in the other direction. Yes.

  The front upper magnet 51 is disposed so as to be offset toward the upper side (F1 side) in the optical axis direction, and the front lower magnet 52 is disposed so as to be offset toward the outer peripheral side (R2 side) in the radial direction. Is disposed in a region that does not overlap the opening 37 of the front surface 34 of the lens holder 30.

  The pickup base 20 shown in FIG. 1 is integrally formed with a rear yoke that rises rearward from the lens holder 30, and a rear upper magnet 53 and a rear lower magnet 54 are fixed to the rear yoke. .

  As shown in FIG. 5B, the rear upper magnet 53 has an elongated shape in the radial direction, and faces the focusing coil Cf. The front upper magnet 51 and the rear upper magnet 53 are magnetized with the same magnetic poles on the surfaces facing the focusing coil Cf.

  The rear lower magnet 54 has an area that can face the rear tracking coil Ct2 and all of the pair of tilt coils Clt and Clt. As shown in FIG. 5 (B), the rear lower magnet 54 has magnetic poles having different surfaces facing the coil between a portion 54a facing the current A2 flowing through the rear tracking coil Ct2 and a portion 54b facing the current A3. Is magnetized. The rear lower magnet 54 is magnetized with different magnetic poles in a portion 54c facing the current A4 flowing in the tilt coil Clt located on the R1 side and a portion 54d facing the current A5, and is located on the R2 side. The portion 54e facing the current A6 flowing through the tilting coil Clt and the portion 54f facing the current A7 are magnetized with different magnetic poles.

  In FIGS. 5A and 5B, the magnetic poles on the surfaces of the portion 52b of the front lower magnet 52 and the portions 54a, 54c, and 54f of the rear lower magnet 54 facing the lens holder 30 are the same. Further, the magnetic poles on the surfaces of the portion 52a of the front lower magnet 52 and the portions 54b, 54d, 54e of the rear lower magnet 54 facing the lens holder 30 are the same.

  In the optical pickup device 10, when a BD (Blu-ray disc) is loaded in the rotation drive unit, the optical element of the BD optical system provided on the moving base emits light. The BD light passes through the inside of the opening 37 of the lens holder 30, is reflected by the total reflection surface 43 a of the prism 43, and is given to the first objective lens 41, and the BD recording is performed by the first objective lens 41. Detection light is condensed on the surface. Thereby, the writing operation to the recording surface of the BD can be performed. Further, when the detection light is reflected from the recording surface of the BD, the reflected light is reflected by the total reflection surface 43a and received by the light receiving element for BD, whereby information can be read from the recording surface of the BD. .

  When a DVD is loaded in the rotation drive unit, a light emitting element of an optical system for DVD emits light. This light passes through the inside of the opening 37, is reflected by the total reflection surface 43a, and is collected on the recording surface of the DVD by the second objective lens. Information is recorded on the DVD and information is read.

  Further, the lens holder 30 is driven in the optical axis direction (F1-F2 direction) by the current A1 flowing through the focusing coil Cf and the magnetic field generated by the front upper magnet 51 and the rear upper magnet 53, so that the recording surface of the disk Focusing correction for condensing light is performed. Further, the lens holder 30 is moved in the radial direction (R1-R2 direction) by the currents A2 and A3 flowing through the front tracking coil Ct1 and the rear tracking coil Ct2, and the magnetic field generated from the front lower magnet 52 and the rear lower magnet 54. Driven. Thereby, the tracking correction operation is performed so that the light condensed on the recording surface of the disk follows the recording track.

  Further, the optical axes O1, O2 of the objective lenses 41, 42 are generated by the currents A4, A5, A6, A7 flowing through the pair of tilt coils Clt, Clt and the magnetic fields generated from the front lower magnet 52 and the rear lower magnet 54. It is driven to fall in the radial direction (R1-R2 direction). Thereby, even if the recording surface is tilted when the disk rotates, tilt correction is performed so that the optical axes O1 and O2 are directed perpendicular to the recording surface.

  The optical pickup device 10 can perform multi-directional correction operations for performing focusing correction, tracking correction, and tilt correction, and the prism 43 is disposed in the internal space 36 even though the two objective lenses 41 and 42 are mounted. It can be housed in an optical axis, and the dimension in the direction of the optical axis can be shortened to realize a thin shape.

  In addition, since the first objective lens 41 for BD is provided at the end portion on the R1 side that is the inner peripheral side of the disc, it is recorded in the BCA when the optical pickup device 10 moves to the center side of the BD. It becomes easier to read information.

  In the lens holder 30, as shown in FIG. 4, the winding centers (drive action points) of the two tracking coils Ct1 and Ct2 are at the same height position in the optical axis direction, and the center of gravity G of the lens holder 30 is also the same. Since the front tracking coil Ct1 and the rear tracking coil Ct2 are at different positions in the radial direction (R1-R2 direction), the lens holder 30 receives R1- A moment that the lens holder 30 tilts in the T1 direction or the T2 direction with respect to the R2 direction is less likely to act.

  On the lens holder 30, the arrangement center of the objective lenses 41 and 42 is offset toward the R1 side. However, since the front tracking coil Ct1 is offset toward the R2 side, the radial direction of the lens holder 30 is increased. This makes it possible to minimize the deviation of the mass and to achieve a balanced correction drive.

DESCRIPTION OF SYMBOLS 10 Optical pick-up apparatus 20 Pickup base 25 Support body 27 Wire 30 which is elastic support member Lens holder 32 Upper surface 33 Side surface 34 Front surface 35 Rear surface 37 Opening 41 First objective lens 42 Second objective lens 51 Front upper magnet 52 Front lower portion Magnet 53 Rear upper magnet 54 Rear lower magnet Cf Focusing coil Ct1 Front tracking coil Ct2 Rear tracking coil Clt Tilt coil

Claims (6)

A lens holder on which a plurality of objective lenses corresponding to different media are mounted, a support mechanism that operably supports the lens holder, a focusing coil that drives the lens holder in the optical axis direction of the objective lens, and the lens In an optical pickup device provided with a tracking coil that drives a holder in a radial direction that intersects the optical axis direction, and the focusing coil and a magnet that applies a magnetic field to the tracking coil,
The lens holder includes an opening that is opened forward in the tangential direction that intersects both the optical axis direction and the radial direction, and an optical element that reflects light applied through the opening toward the objective lens. An inner space for accommodating the plurality of objective lenses, and an array center of the plurality of objective lenses in the radial direction and a center of the opening are arranged to be offset toward one side in the radial direction from the center of the lens holder,
The tracking coil is attached to each of the front surface of the lens holder facing forward in the tangential direction and the rear surface facing backward, and the center of the tracking coil attached to the front surface is at the center of the lens holder. On the other hand, it is attached to the opposite side of the opening is formed,
The optical pickup device according to claim 1, wherein the focusing coil is attached at a position deviating from the opening in the optical axis direction.   The support mechanism includes a support portion fixed to a pickup base, and an elastic support member that extends from the support portion and operably supports the lens holder, and the support portion and the elastic support member include: The optical pickup device according to claim 1, wherein the optical pickup device is provided on the rear surface side of the lens holder. A pair of tilt coils that operate the lens holder in a direction in which the optical axis of the objective lens tilts in a radial direction, and a magnet that applies a magnetic field to the tilt coil;
The pair of tilt coils are attached to the rear surface of the lens holder with a gap in a radial direction, and a tracking coil attached to the rear surface is disposed between the pair of tilt coils. 3. The optical pickup device according to 1 or 2.   The tracking coil attached to the front surface of the lens holder and the tracking coil attached to the rear surface are at the same height position in the optical axis direction, the driving action point of each tracking coil, 4. The optical pickup device according to claim 1, wherein the center of gravity of the lens holder is set at the same height position in the optical axis direction. 5.   One of the plurality of objective lenses is for a Blu-ray disc, and the objective lens for the Blu-ray disc is arranged at a position furthest away in the radial direction from the center of the lens holder. 2. An optical pickup device according to item 1.   The optical pickup device according to claim 5, wherein the objective lens for a Blu-ray disc among the plurality of objective lenses is disposed at a position closest to the center of the disc.

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