JPH09180221A - Optical pickup - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize unwanted resonance by bringing an image side principal point position and a center of gravity position of a movable part of an objective lens, a driving center position in a focus direction, and a driving center position in a tracking direction near to each other. SOLUTION: The optical pickup to read and reproduce recording signal of an optical disk consists of an objective lens 20 which converges laser beam made to exit from a laser beam source onto the signal recording surface of an optical disk, a lens holder 30 on which the objective lens 20 is engaged with a recessed part formed thereon, a focus adjusting coil 12 to move the objective lens 20 in the focus direction, a tracking adjusting coil 16 to move the objective lens 20 in the tracking direction, and a supporting part to elastically support a movable part comprising a lens holder 30 holding the objective lens 20, the focus adjusting coil 12, and the tracking adjusting coil 16. In this case, the focus direction driving center of the objective lens 20 and the center of gravity position of the movable part are made to roughly coincide with each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup for reading and reproducing a recording signal of an optical disc, and more specifically, for controlling a position of an objective lens for following a laser spot to a surface wobbling or eccentricity of the optical disc. The present invention relates to a mechanical section (actuator of an optical pickup).

[0002]

2. Description of the Related Art In an optical disk player using an optical disk as a recording medium, an optical pickup is used as means for reading and reproducing information signals recorded on the disk. The optical pickup converges a laser beam emitted from a laser light source as a beam spot on a signal recording surface of an optical disc into a pit row, which is a minute irregularity, as a beam spot through an objective lens, and is reflected from the pit row. An information signal is read and reproduced by detecting the state of the reflected beam with a photodetector.

When a laser beam is focused on the pit row of an optical disk as a beam spot via an objective lens, the optical axis of the objective lens is maintained exactly perpendicular to the signal recording surface of the optical disk. If not, aberration occurs in the beam spot focused on the pit row,
A noise component may be superimposed on an information signal to be read and reproduced, and the reproduction characteristics may be degraded, or the information signal may not be read and reproduced depending on the degree. Therefore, in an optical pickup used in an optical disc player or an optical recording / reproducing apparatus, the laser beam is applied to the signal recording surface of the optical disc so that the laser beam always enters the signal recording surface of the optical disc perpendicularly. There are various types of devices that are equipped with a mechanism for adjusting the inclination of the optical axis of the objective lens that focuses the light on.

An example of a conventional optical pickup will be described with reference to FIGS. 3 and 4. FIG. 3 is a front view showing the configuration of a conventional optical pickup, and FIG. 4 is a view showing setting positions of an image-side principal point of a conventional objective lens and a fulcrum of an adjusting mechanism. ) Is a top view. An optical pickup 100 includes a movable portion 110, a yoke 120, a base 130,
The adjusting screw 140 and the wire 150 are included.

In the movable part 110, an objective lens 111 for condensing a laser beam on a signal recording surface of an optical disk and a magnetic coil (not shown) are fixed to a resin member. The movable part 110 is made up of four elastic body (for example, phosphor bronze) ultra-small diameter wires 150, two fixed on each side.
It is elastically held by the yoke 120. York 120 is L
The fixed portion 121 of the wire 150 that elastically holds the movable portion 110 in the vertical direction, and the tangential skew of the objective lens 111 (the tilt angle in the tangential direction of the disc) in the horizontal direction are formed. A screw hole 123 into which the adjusting screw 140 to be adjusted is screwed, and a V-shaped fulcrum 122 that is a fulcrum of the seesaw operation when adjusting the tangential skew are formed. York 12
0 is engaged with the coil of the movable portion 110 to form a magnetic circuit (not shown).

The base 130 is a base portion of the optical pickup 100, and has a screw hole 131 and the like into which an adjusting screw 140 for adjusting the tangential skew is screwed.
Next, the operation of adjusting the tangential skew will be described.
The image point side principal point 112 of the objective lens 111 and the disk 170
When adjusting the tangential skew with respect to the plane of, for example, the direction E, the V-shaped fulcrum 12 of the yoke 120 is used.
2 to the adjustment screw 140 on the left side of the screw hole 12 of the yoke 120.
At the same time as turning it in the direction of coming out of 3, adjust screw 14 on the right side
When 0 is turned in the direction of screwing into the screw hole 123 of the yoke 120, the yoke 120 tilts in the F direction with the V-shaped fulcrum 122 of the yoke 120 as a fulcrum, and the wire 15 is attached to the yoke 120.
The objective lens 111 of the movable part 110 held at 0 tilts in the E direction and the tangential skew is adjusted. still,
When adjusting in the direction opposite to the E direction, the left adjustment screw 140
The operation of the adjusting screw 140 on the right side may be reversed from that in the E direction.

[0007]

However, in the above-described optical pickup 100, the position of the center of gravity of the movable part including the focus direction drive center and the objective lens, and the position of the center of gravity of the movable part including the tracking direction drive center and the objective lens are separated. In addition, the position of the center of gravity of the movable portion and the position of the image-side principal point of the objective lens are apart from each other in the focus direction and the tangential direction. Therefore, when the actuator is tilted and is away from the focus direction, the displacement of the optical axis occurs due to the displacement in the tracking direction, the oscillation of the tracking servo, and the increase in the jitter amount due to the displacement in the tangential direction and the CLV (constant line). Speed rotation) Servo oscillation occurs. Also, if they are separated in the tangential direction,
Due to the offset in the focus direction caused by the displacement in the focus direction and the oscillation of the focus servo, the servo such as focus, tracking, and CLV is hard to be applied, or the servo is easily disengaged, and finally the reading performance is deteriorated. May occur.

Therefore, the present invention solves the above-described problem by bringing the position of the image-side principal point of the objective lens, the position of the center of gravity of the movable portion, the focus direction drive center position, and the tracking direction drive center position close to each other, and unnecessary resonance ( The object is to provide an optical pickup that minimizes pitching, rolling, and yawing.

[0009]

The present invention achieves the above-mentioned object, and in an optical pickup for reading and reproducing a recording signal of an optical disc, a laser beam emitted from a laser light source is converged on a signal recording surface of the optical disc. Objective lens, a lens holder in which a concave portion for engaging the objective lens is formed, a focus adjustment coil for moving the objective lens in the focus direction, a tracking adjustment coil for moving the objective lens in the tracking direction, and the objective lens And a holding portion that elastically holds a movable portion including the focus adjustment coil and the tracking adjustment coil, the driving center of the objective lens in the focus direction substantially coincides with the position of the center of gravity of the movable portion. The feature is that it is made to do.

Further, in the optical pickup for reading and reproducing the recording signal of the optical disc, an objective lens for converging the laser light emitted from the laser light source to the signal recording surface of the optical disc and a concave portion for engaging the objective lens are formed. A lens holder, a focus adjustment coil that moves the objective lens in the focus direction, a tracking adjustment coil that moves the objective lens in the tracking direction, a lens holder that holds the objective lens, the focus adjustment coil, and the tracking adjustment coil. The movable portion is elastically held, and the position of the image-side principal point of the objective lens and the position of the center of gravity of the movable portion with respect to the focus direction are substantially matched.

Further, in the optical pickup for reading and reproducing the recording signal of the optical disc, the objective lens for converging the laser light emitted from the laser light source to the signal recording surface of the optical disc and the concave portion for engaging the objective lens are formed. A lens holder, a focus adjustment coil that moves the objective lens in the focus direction, a tracking adjustment coil that moves the objective lens in the tracking direction, a lens holder that holds the objective lens, the focus adjustment coil, and the tracking adjustment coil. The movable portion is elastically held, and the position of the image-side principal point of the objective lens, the focus direction drive center of the objective lens, and the center of gravity of the movable portion are substantially aligned. Is characterized by.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIG. 1A and 1B are views showing the configuration of an optical pickup, wherein FIG. 1A is a plan view and FIG. 1B is a sectional view taken along line PP. An optical pickup 1 is composed of a movable portion 10, a yoke 40, a wire 50 and the like.

The movable part 10 is composed of an objective lens 20, a lens holder 30, a focus adjustment coil 12, a tracking adjustment coil 16 and the like. The movable part 10 is elastically held on the side of the erected part (right side in the drawing) of the yoke 40 by four wires 50 of four elastic bodies (for example, phosphor bronze) having extremely small diameters, two fixed on each side. ing. The objective lens 20 is a lens that converges the laser light emitted from the laser light source onto the signal recording surface of the optical disc.

The lens holder 30 includes an objective lens 20, a focus adjusting coil 12 and a tracking adjusting coil 16.
Is a cylindrical member, and a rectangular flange 34 is formed on the end surface of the cylinder. The flange 34 serves as a positioning portion that determines the winding width of the focus adjustment coil 12 that is wound around the outer circumference of the cylinder.
Positioning portions 35 for positioning and fixing the tracking adjustment coil 16 are formed on the upper and lower surfaces in the direction (two directions in the figure, left and right). A stepped hole 31 for positioning and fixing the objective lens 20 is formed inside the cylinder, and a hole 3 through which laser light passes is formed at the bottom.
2 are formed.

The yoke 40 is U-shaped, and a hole 41 through which a laser beam passes is formed at the bottom. Also,
Plate-shaped magnets 45 are adhered and fixed to the insides of both sides of the yoke 40 which are erected, and constitute a magnetic circuit for moving the focus adjustment coil 12 and the tracking adjustment coil 16 of the movable portion. Next, the assembly of the movable part will be described.

A wire is wound around the cylindrical outer peripheral portion 33 of the lens holder 30 by a winding machine or the like to form the focus adjustment coil 12. Next, two tracking adjustment coils 16 formed in another process are placed on the upper and lower surfaces of the flange 34 of the lens holder 30 on the upper and lower surfaces in the two outer peripheral directions (two directions in the right and left in the figure). The spaces between the flanges 34 are positioned in a bridging state and fixed by adhesion with an adhesive or the like. Next, the objective lens 20 is fitted into the stepped hole 31 inside the lens holder 30, and the objective lens 20 is adhesively fixed to the stepped hole 31 with an adhesive or the like. Next, one end of the wire 50 having a predetermined length is moved up and down on the side surface of the flange 34 of the lens holder 30 (an attachment hole or the like is formed on the side surface where the tracking adjustment coil 16 is not fixed). Adhesively fix a total of four, two for each.

Next, in another process, the yoke 40 is fixed in two directions in which the tracking adjustment coil 16 of the movable portion 10 is fixed to the inside of the yoke 40 to which the magnets 45 are adhered and fixed inside the left and right standing portions of the yoke 40. Of the four wires 50 that have been bonded and fixed to the side surface of the flange 34 of the lens holder 30 of the movable portion 10 at a position where the spacing between the tracking adjustment coil 16 and the magnet 45 is substantially equal. One end is adhered and fixed to the side surface of the standing portion of the yoke 40 (a mounting hole or the like is formed if necessary). Therefore, the movable part 10 has four wires 50.
Thus, a magnetic circuit is formed while being elastically held by the yoke 40.

In this state, when an adjustment signal in the focus direction is input to the focus adjustment coil 12, the objective lens 2
When 0 is moved and adjusted in the focus direction, and when an adjustment signal in the tracking direction is input to the tracking adjustment coil 16, the objective lens 20 is moved and adjusted in the tracking direction. In this embodiment, the position 21 of the image-side principal point of the objective lens 20, the focus-direction drive center 22 and the tracking-direction drive center 23 are arranged to coincide with each other. Specifically, the position 2 of the image-side principal point of the objective lens 20 with the objective lens 20 adhered and fixed to the lens holder 30 is used.
The position of the flange 34 is set so that 1 and the center of the winding width (focus direction driving center 22) of the focus adjustment coil 12 wound around the outer circumference 33 of the cylinder of the lens holder 30 coincide with each other. 2 in each of the two outer circumferences
Tracking adjustment coil 1 with a total of 4 glued and fixed
The positioning unit 35 for positioning and fixing 6 is set so that the center of the vertical length of the tracking adjustment coil 16 (tracking direction drive center 23) coincides.
Further, in order to improve the followability of the movable portion 10 and prevent unnecessary resonance (pitching, rolling, yawing), the shape and material are selected so as to reduce the weight of the entire movable portion 10, as described above. In addition, according to the present embodiment, the objective lens 2
The outer circumference 33 of the lens holder 30 of 0 is also used as the bobbin of the focus adjustment coil 12, and the tracking adjustment coil 16 is fixed to the flange 34, whereby the position of the image-side principal point 21 of the objective lens is adjusted. Since the focus-direction drive center position 22, the tracking-direction drive center position 23, and the position of the movable portion center of gravity 24 come close to each other, an optical axis shift occurs, tracking servo oscillation occurs, and the amount of jitter increases due to tangential displacement. CLV
The oscillation of the servo is reduced, and unnecessary resonance of the movable portion 10 can be minimized. Therefore, the reading performance can be improved.

Although the objective lens 20 and the lens holder 30 are constructed as separate parts in this embodiment, the objective lens 20
The lens holder 30 and the lens holder 30 may be integrally formed by, for example, resin molding. Next, a second embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. 2A and 2B are views showing the configuration of the optical pickup, wherein FIG. 2A is a plan view and FIG. 2B is a QQ sectional view.
In the second embodiment, a part of the lens holder of the first embodiment is modified, and other parts are shown in FIG.
Is substantially the same as that of FIG. 1, and the same components as those in FIG.

The lens holder 60 includes an objective lens 20, a focus adjusting coil 12 and a tracking adjusting coil 16.
Is a cylindrical member, and a square flange 64 is formed on one end surface of the cylinder. The flange 64 serves as a positioning portion that determines the winding width of the focus adjustment coil 12 wound around the cylindrical outer peripheral portion 63, and the flange 6
Positioning portions 65 for positioning and fixing the tracking adjustment coil 16 are formed on the surface of the outer peripheral surface 4 of the recording medium 4 in two directions (two directions in the left and right in the drawing), and the tracking adjustment coil 16 is fixed. A stepped hole 61 for sandwiching and fixing the objective lens 20 is formed inside the cylinder, and a hole 62 through which laser light passes is formed at the bottom.

Next, the assembly of the movable part will be described. First, the objective lens 20 is sandwiched between the stepped holes 61 inside the two upper and lower lens holders 60, and the contact surfaces 66 of the upper and lower two lens holders 60 are bonded and fixed with an adhesive or the like (the objective lens 20 and the lens The holder 60 is not bonded and fixed). Next, a wire is wound around the cylindrical outer peripheral portions 63 of the upper and lower two lens holders 60 by a winding machine or the like, and the focus adjustment coil 1
Form 2 Next, the flange 64 of the lens holder 60
Positioning portions 65 formed on the upper and lower surfaces in the two outer peripheral directions (two directions on the right and left in the drawing) are positioned in a bridging state between two upper and lower flanges 64 of tracking adjustment coils 16 formed in a separate process. Then, fix them with an adhesive.
Next, one end of the wire 50 having a predetermined length is bonded and fixed to the side surface of the flange 64 of the lens holder 60 (the side surface where the tracking adjustment coil 16 is not fixed), two wires in each of the upper and lower sides, a total of four wires.

Next, in another process, the yoke 40 is fixed in two directions, in which the tracking adjustment coil 16 of the movable portion 10 is fixed to the inside of the yoke 40 to which the magnets 45 are adhered and fixed inside the left and right standing portions of the yoke 40. Of the four wires 50 that have been bonded and fixed to the side surface of the flange 64 of the lens holder 60 of the movable portion 10 at a position where the spacing between the tracking adjustment coil 16 and the magnet 45 is substantially equal. One end is adhesively fixed to the side surface of the standing portion of the yoke 40. Therefore, the movable portion 10 constitutes a magnetic circuit while being elastically held by the yoke 40 by the four wires 50.

In this state, when an adjustment signal in the focus direction is input to the focus adjustment coil 12, the objective lens 2
When 0 is moved and adjusted in the focus direction, and when an adjustment signal in the tracking direction is input to the tracking adjustment coil 16, the objective lens 20 is moved and adjusted in the tracking direction. In this embodiment, the position 21 of the image-side principal point of the objective lens 20, the focus-direction drive center 22 and the tracking-direction drive center 23 are arranged to coincide with each other. Specifically, the position 2 of the image-side principal point of the objective lens 20 with the objective lens 20 adhered and fixed to the lens holder 60
The position of the flange 64 is set so that 1 and the center of the winding width (focus direction drive center 22) of the focus adjustment coil 12 wound around the outer circumference 63 of the cylinder of the lens holder 60 coincide with each other. 2 in each of the two outer circumferences
Tracking adjustment coil 1 with a total of 4 glued and fixed
The positioning unit 65 that positions and fixes 6 is set so that the center of the vertical length of the tracking adjustment coil 16 (the tracking direction drive center 23) coincides.
Further, in order to improve the followability of the movable portion 10 and prevent unnecessary resonance, the shape and the material are selected so as to reduce the weight of the entire movable portion 10, as described above, also in this embodiment. Since the unnecessary resonance of the movable part 10 can be minimized as in the first embodiment, the reading performance can be improved. In addition, since the objective lens 20 and the lens holder 60 are not fixed with an adhesive, it is possible to reduce the influence of distortion of the lens holder 60 on the objective lens 20 due to a temperature change or the like.

[0024]

As described above, according to the present invention, the position of the image-side principal point of the objective lens of the optical pickup is close to the focus-direction drive center position, the tracking-direction drive center position, and the position of the movable portion center of gravity. Therefore, unnecessary resonance (pitching, rolling, yawing) of the movable part can be minimized. Therefore, the reading performance can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an optical pickup according to a first embodiment of the present invention, in which (a) is a plan view and (b) is a sectional view taken along line PP.

2A and 2B are views showing the configuration of the optical pickup of the first embodiment of the present invention, FIG. 2A being a plan view and FIG. 2B being a QQ sectional view.

FIG. 3 is a front view showing a configuration of a conventional optical pickup.

4A and 4B are diagrams showing a setting position of an image-side principal point of a conventional objective lens and a fulcrum of an adjusting mechanism, in which FIG. 4A is a front view and FIG. 4B is a top view.

[Explanation of symbols]

 1-Optical pickup 10-movable part 12-focus adjustment coil 16-tracking adjustment coil 20-objective lens 21-objective Lens image side principal point 22 ... Focus direction drive center 23 ... Tracking direction drive center 24 ... Movable part center of gravity 30, 60 ... Lens holder 31, 61 ... Stepped hole 32 , 62 ... Holes 33, 63 ... Cylindrical outer circumference 34, 64 ... Flange 35, 65 ... Positioning section 40 ... Yoke 45 ... Magnet 55 ... Wire 66 ... .... Mating surface

Claims (20)

[Claims] 1. An optical pickup for reading and reproducing a recording signal of an optical disc, wherein an objective lens for converging laser light emitted from a laser light source onto a signal recording surface of the optical disc, and a concave portion for engaging the objective lens are formed. A lens holder, a focus adjustment coil that moves the objective lens in the focus direction, a tracking adjustment coil that moves the objective lens in the tracking direction, a lens holder that holds the objective lens, the focus adjustment coil, and the tracking adjustment coil. An optical pickup comprising a holding part that elastically holds a movable part, wherein a focus direction drive center of the objective lens and a position of a center of gravity of the movable part are substantially aligned with each other. 2. The optical pickup according to claim 1, wherein the center of driving of the objective lens in the tracking direction and the position of the center of gravity of the movable portion are made to substantially coincide with each other. 3. The optical pickup according to claim 1, wherein the objective lens is sandwiched between the lens holder A and the lens holder B from both sides. 4. An overhanging portion for positioning the focus adjusting coil is formed in an outer peripheral direction on one or both surfaces of the lens holder in the focus direction, and the focus adjusting coil is wound around the outer periphery of the lens holder. The optical pickup according to claim 1 or 2, characterized in that. 5. The projection of the lens holder is formed in a substantially rectangular shape, and the tracking adjustment coil is positioned and fixed to the projection.
Optical pickup as described. 6. The objective lens is sandwiched from both sides by a lens holder C and a lens holder D, and an overhanging portion for positioning the focus adjustment coil is provided on one or both surfaces in the focusing direction of the lens holder in the outer peripheral direction. The optical pickup according to claim 1, wherein the focus adjusting coil is formed around the lens holder and wound around the lens holder. 7. The lens holder C and the lens holder D
7. The optical pickup according to claim 6, wherein the overhanging portion is formed in a substantially rectangular shape, and the tracking adjustment coil is positioned and fixed to the overhanging portion. 8. A lens holder having a concave portion for engaging the objective lens is formed with an overhanging portion for positioning the focus adjusting coil in an outer peripheral direction on one or both surfaces of the lens holder in the focusing direction. The focus adjustment coil is wound around the outer periphery of the lens, the positioning portion of the tracking adjustment coil is formed on the overhang portion, the position of the center of gravity of the movable portion to which the tracking adjustment coil is fixed, and the objective lens. 2. The optical pickup according to claim 1, wherein the position of the drive center of the focus direction and the position of the drive center of the objective lens in the tracking direction are made to substantially coincide with each other. 9. The objective lens is sandwiched from both sides by a lens holder E and a lens holder F, and an overhanging portion for positioning the focus adjusting coil is provided on one or both surfaces in the focusing direction of the lens holder in the outer peripheral direction. The focus adjustment coil is wound around the outer periphery of the lens holder, and the positioning portion of the tracking adjustment coil is formed on the overhang portion, and the center of gravity of the movable portion to which the tracking adjustment coil is fixed is fixed. 2. The optical pickup according to claim 1, wherein the position, the focus direction drive center of the objective lens, and the tracking direction drive center of the objective lens are made to substantially coincide with each other. 10. An optical pickup for reading and reproducing a recording signal of an optical disc, wherein an objective lens for converging laser light emitted from a laser light source onto a signal recording surface of the optical disc, and a concave portion for engaging the objective lens are formed. A lens holder, a focus adjustment coil that moves the objective lens in the focus direction, a tracking adjustment coil that moves the objective lens in the tracking direction, a lens holder that holds the objective lens, the focus adjustment coil, and the tracking adjustment coil. An optical pickup comprising a holding portion for elastically holding the movable portion, wherein the position of the image-side principal point of the objective lens and the position of the center of gravity of the movable portion in the focusing direction are substantially aligned with each other. . 11. The optical pickup according to claim 1, wherein the position of the image-side principal point of the objective lens and the position of the center of gravity of the movable portion are made to substantially coincide with each other in the tangential direction. . 12. The optical pickup according to claim 10 or 11, wherein the objective lens is sandwiched between a lens holder G and a lens holder H from both sides. 13. A protrusion for positioning the focus adjustment coil is formed in the outer peripheral direction on one or both surfaces of the lens holder in the focus direction, and the focus adjustment coil is wound around the outer periphery of the lens holder. The optical pickup according to claim 10 or 11, characterized in that. 14. The optical pickup according to claim 13, wherein the overhanging portion of the lens holder is formed into a substantially rectangular shape, and the tracking adjustment coil is positioned and fixed to the overhanging portion. 15. The objective lens is sandwiched between both sides by a lens holder I and a lens holder J, and an overhanging portion for positioning the focus adjustment coil is provided on one or both surfaces in the focusing direction of the lens holder in the outer peripheral direction. Formed,
11. The optical pickup according to claim 10, wherein the focus adjustment coil is wound around the outer circumference of the lens holder. 16. The lens holder I and the lens holder J are formed in a substantially rectangular shape, and the tracking adjustment coil is positioned and fixed to the protruding portion. The optical pickup described. 17. A lens holder having a concave portion for engaging the objective lens is formed with an overhanging portion for positioning the focus adjustment coil in an outer peripheral direction on one or both surfaces in the focusing direction of the lens holder. The focus adjustment coil is wound around the outer periphery of the lens, the positioning portion of the tracking adjustment coil is formed on the overhang portion, the position of the center of gravity of the movable portion to which the tracking adjustment coil is fixed, and the objective lens. 11. The optical pickup according to claim 10, wherein the position of the image-side principal point is substantially the same as that of the image-side principal point. 18. A position of a position of the tracking adjustment coil is formed on the protrusion, and a position of a center of gravity of the movable part to which the tracking adjustment coil is fixed and a position of an image-side principal point of the objective lens. 16. The optical pickup according to claim 15, characterized in that 19. An optical pickup for reading and reproducing a recording signal of an optical disc, wherein an objective lens for converging laser light emitted from a laser light source onto a signal recording surface of the optical disc, and a concave portion for engaging the objective lens are formed. A lens holder, a focus adjustment coil that moves the objective lens in the focus direction, a tracking adjustment coil that moves the objective lens in the tracking direction, a lens holder that holds the objective lens, the focus adjustment coil, and the tracking adjustment coil. The movable portion is elastically held, and the position of the image-side principal point of the objective lens, the focus direction drive center of the objective lens, and the center of gravity of the movable portion are substantially aligned. An optical pickup featuring. 20. The optical pickup according to claim 1, wherein the lens holder is provided with both the focus adjustment coil and the tracking adjustment coil.