JPH0869627A - Optical pickup - Google Patents

Abstract

PURPOSE: To make it possible to maintain the optical axis of an objective lens at a specified angle at all times by fixing a fixing part to be coupled to an objective lens holder which is born with spherical surfaces on a carriage freely movable in the radial direction of a disk and to be coupled to an objective holder to this carriage via a flexible substrate. CONSTITUTION: The fixing member 12 coupled by means of a pair of supporting springs to the objective lens holder have spherical surface parts 12c. This member 12 is born on the carriage 2 by the spherical recessed parts 2a of the carriage 2 freely movable in the radial direction of the carriage 2. On the other hand, the member 12 is fixed to the carriage via the first flexible substrate held in pressurized contact with the second flexible substrate 32 having curving parts 24c, 24d. The stresses generated in the flexible substrate at the time of adjusting the inclination of the optical axis of the objective lens by the deformation of the flexible substrates caused by these curving parts 24c, 24d are absorbed away by the curving parts, by which the optical axis of the objective lens is maintained always at the specified angle. A pickup capable of recording and reproducing the information with high accuracy is thus obtd.

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 irradiating a disc with light to record or reproduce predetermined information.

[0002]

2. Description of the Related Art Conventionally, an optical pickup of this type is disclosed in, for example, Japanese Patent Application Laid-Open No. 3-120629 (hereinafter referred to as Conventional Example 1) and Japanese Patent Application Laid-Open No. 4-119530 (hereinafter referred to as Conventional Example 2). It has the configuration as disclosed.

In the optical pickup of the first conventional example, a flexible substrate for supplying a control current to a focus coil and a tracking coil of a bobbin equipped with an objective lens is solder-bridge connected to a substrate fixed at a holder at one end thereof. The other end is fixed to the optical pickup body or the bobbin transfer member. The holder is
It is connected to the bobbin via four metal springs.

In the optical pickup of the second conventional example, one end of a flexible substrate for supplying a control current to a focus coil and a tracking coil of a bobbin equipped with an objective lens is fixed to a relay member and the other end is provided to a moving base. Connected to the connector. The relay member is connected to the bobbin via four leaf springs.

In any of these prior arts 1 and 2, the flexible substrate is pulled out in a direction away from the disk, laid around in a straight line shape and a gentle bend shape, and then connected to a predetermined portion. .

[0006]

Usually, the bobbin, which is one structure of the objective lens actuator, is tilted with respect to an axis orthogonal to the optical axis so that the optical axis of the objective lens is substantially orthogonal to the disc. Adjusted.

At this time, the flexible board is
Forces such as pulling, compressing, bending, and twisting complicately act, but in general, flexible boards have a thin plate structure in which copper foil is sandwiched with high-rigidity polyimide resin. It has strong rigidity against bending force in the direction. Therefore, when the flexible board is bent, the board is bent due to folds.

As described above, since the flexible substrates applied to the conventional examples 1 and 2 have a structure which is difficult to deform,
When a complex force is applied to the flexible substrate, the force is accumulated as a residual stress in the flexible substrate.

In this case, due to the residual stress, a force for tilting the optical axis of the objective lens always acts on the bobbin. Therefore, in long-term use, creep deformation may occur in the resin member, the adhesive, or the like, and the optical axis of the objective lens may be inclined with respect to the disc. For example, the optical axis is 10
When tilted by about a minute, aberration is generated in the light irradiated on the disc, which makes it difficult to record or reproduce information with high accuracy.

The present invention has been made to solve such a problem, and an object thereof is to maintain the optical axis of the objective lens at a constant angle with respect to the disk at all times, thereby highly accurately recording information. Another object of the present invention is to provide an optical pickup capable of recording and reproducing.

[0011]

In order to achieve such an object, the present invention provides an access member which is movable in the radial direction of a disk and an objective lens which can be mounted on the access member and which has an objective lens in a predetermined direction. An optical pickup comprising: an actuator that is displaceably supported on the optical axis; an inclination adjusting unit that can adjust the inclination of the optical axis of the objective lens; and a flexible substrate that electrically connects the access member and the actuator. For flexible boards,
When adjusting the inclination of the optical axis of the objective lens, the bent portion is formed so as to absorb and remove the stress generated in the flexible substrate.

[0012]

When the tilt of the optical axis of the objective lens is adjusted, the stress generated in the flexible substrate is absorbed and removed by the bent portion.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical pickup according to a first embodiment of the present invention will be described below with reference to FIGS.
As shown in FIGS. 1 to 3, the optical pickup of this embodiment includes an access member or carriage 2 which is movable in a radial direction of a disc (not shown) along a pair of guide shafts 28 (see FIG. 3). An actuator 4 configured to be mounted on the carriage 2 and supporting the objective lens 6 so as to be displaceable in a predetermined direction is provided.

FIG. 1 is an exploded perspective view showing the structure of the optical pickup of this embodiment, FIG. 2 is a perspective view showing a state in which the actuator 4 is mounted on the carriage 2, and FIG. Shows a sectional view of the optical pickup of the present embodiment.

That is, the objective lens 6 for condensing the recording and reproducing light on the disc is adhered and fixed to the lens receiving portion 8a provided at one end of the holder 8. Further, the other end of the holder 8 is provided with an opening 8b to which an actuator movable part 10 described later can be fixed by adhesion.

The actuator movable portion 10 has a rectangular focus coil 10a having a winding axis parallel to the optical axis of the objective lens 6 and a first outer surface S1 of the outer peripheral surface of the focus coil 10a facing the objective lens 6. On the second outer surface S2 parallel to the first outer surface S1, among the pair of flat tracking coils 10b adhered and fixed so that their winding axes are orthogonal to the first outer surface S1 and the outer peripheral surface of the focus coil 10a. A printed wiring board 10c that is adhesively fixed is provided.

The holder 8 is provided with a pair of support springs 14 on a fixing member 12 having a convex spherical surface portion 12c (see FIG. 3) which can be seated on a concave spherical surface seat 2a provided on the bottom portion of the carriage 2 which will be described later. It is elastically supported by 18.

Although these support springs 14 and 18 have the same structure, the fixed optical system (not shown) will be described below.
The support spring arranged on the side is referred to as a first support spring 14,
The other support spring is referred to as a second support spring 18.

These first and second support springs 14, 18
Are arranged symmetrically with respect to the center of gravity G of the actuator movable portion 10 (see FIG. 4B). These first
The second support springs 14 and 18 respectively include, for example, a pair of metal thin plate-shaped spring members 15 that have been etched or pressed, and a pair of spring members 15 so that the pair of spring members 15 are parallel to each other. Plastic first and second spacers 16 and 17 integrally connected to both ends of the spacer 15.
And are provided.

The first and second support springs 14 and 18
As a material of, for example, beryllium copper, phosphor bronze, or solderable stainless steel is suitable.

Each of the first spacers 16 has a holder 8
A fitting recess 16a that can be fitted to the positioning projection 8c provided on the outer surface is formed, while the second spacer 1 is provided.
7 are configured so that they can be fitted into the first and second groove portions 12a and 12b formed on both sides of the fixing member 12, respectively.

The first and second support springs 14,
18 fits the fitting concave portions 16a of the first spacer 16 into the positioning convex portions 8c of the holder 8, and the second spacers 17 respectively into the first and second groove portions 12 of the fixing member 12.
It is fitted into a and 12b and is fixed by adhesion.

In this case, the first support spring 14 arranged on the fixed optical system (not shown) side approaches the position avoided from the light beam, that is, the disk so as not to interfere with the light beam output from the fixed optical system. It is placed in the position In addition,
On the contrary, the second support spring 18 is arranged at a position separated from the disc. Therefore, the first and second groove portions 12a,
The formation position of 12b is relatively displaced so that the first and second support springs 14 and 18 satisfy the above arrangement relationship.

Also, the first and second support springs 14 and 18
In the portion near the fixing member 12, the spring effective portion 15
a is provided, and specifically, the spring effective portion 15a
Are formed on the pair of spring members 15, respectively. That is,
The spring effective portion 15a is configured such that the protruding portion of the spring member 15 and the protruding portion extending from the second spacer 17 face each other.

Further, the fixing member 12 is provided on both sides with
A spring effective portion accommodating opening 12d is formed which is continuous with the first and second groove portions 12a and 12b and has a dimension larger than the inner dimension of the groove portions 12a and 12b. For convenience of layout in FIG. 1, only the spring effective portion accommodating opening 12d continuously provided in the first groove portion 12a is shown, but the spring effective portion accommodating opening 12d is similarly formed in the second groove portion 12b. It is lined up.

Therefore, as described above, the fitting concave portion 16a of the first spacer 16 is fitted into the positioning convex portion 8c of the holder 8, and the second spacer 17 is fitted to the first and first fixing members 12, respectively. When the spring effective portion 15a is fitted into the groove portions 12a and 12b of the second groove,
It will be located within 2d.

In such a state, the spring effective portion accommodating opening 12d is filled with a damping material such as silicon gel, urethane gel or butyl rubber. As a result, since the vibration absorption of the spring effective portion 15a is enhanced, the vibrations of the first and second support springs 14 and 18 are efficiently absorbed.

Such first and second support springs 14,
18 is provided with L-shaped soldering portions 20a and 20b protruding from the first and second spacers 16 and 17, respectively.

The soldering portion 20a is the focus coil 1
0a is soldered to the printed wiring board 10c that is adhesively fixed on the second outer peripheral surface S2, while the soldering portion 20b is provided.
Is an end surface of the fixing member 12 (that is, the first and second groove portions 1
It is soldered to the first land portion 24a of the first flexible substrate 24 which is fastened to the surface 12e on the side where 2a and 12b are formed) 12e with the screw 22.

As a result, it becomes possible to supply a predetermined control current to the focus coil 10a and the tracking coil 10b. Further, the optical pickup of the present embodiment is provided with a magnetic circuit 26 which is set on a magnetic circuit supporting surface 2b provided on the bottom portion of the carriage 2 which will be described later, and the magnetic circuit 26 includes the magnetic circuit supporting surface 2b. A low-carbon steel plate yoke 26a that is adhesively fixed onto the yoke 26a,
a, a back yoke 26b and a center yoke 26c, which face each other from a, along the winding axis direction of the focus coil 10a, an Nd-Fe-B magnet 26d adhered to the back yoke 26b, and a back yoke 26.
b and an auxiliary yoke 26e that connects the upper portions of the center yoke 26c to each other (see particularly FIG. 4A).

The Nd-Fe-B magnet 26d is bonded with one magnetic pole (for example, the S pole as shown in FIG. 4B) facing the back yoke 26b. The width dimensions of the back yoke 26b, the center yoke 26c, and the auxiliary yoke 26e are Nd-Fe-B, respectively.
It is larger than the magnet 26d. As described above, by making the width dimensions of the back yoke 26b, the center yoke 26c, and the auxiliary yoke 26e different, magnetic saturation of the yoke 26a is prevented, and the leakage magnetic field from the magnetic circuit 26 is suppressed.

When the actuator 4 as described above is mounted on the carriage 2, as shown in FIG.
The back yoke 26b and the Nd-Fe-B magnet 26d are
The center yoke 26c is positioned in the inner area of the focus coil 10a, and is positioned in the area between the lens receiving portion 8a of the holder 8 (see FIGS. 1 and 3) and the tracking coil 10b. As a result, the focus coil 10a and a part of the tracking coil 10b are positioned in the magnetic gap formed by the Nd-Fe-B magnet 26d and the center yoke 26c.

Here, the positional relationship between the magnetic circuit 26 and the focus coil 10a and the tracking coil 10b will be described in detail with reference to FIG. In the optical pickup of the present embodiment, the gap h between the center yoke 26c and the tracking coil 10b, the focus coil 10
Of the gap i between the a and the Nd-Fe-B magnet 26d and the gap j between the back yoke 26b and the focus coil 10a,
The gap j is the largest and the gap i is the smallest.

The reason why the gap j is maximized is to reduce the influence of the leakage magnetic field from the back yoke 26b during focus driving as much as possible. The reason why the gap i is minimized is that the magnetic field of the Nd-Fe-B magnet 26d acting on the focus coil 10a is increased as much as possible to enhance the driving sensitivity.

Further, since the actuator movable portion 10 moves only in the direction in which the gap i increases, the focus coil 10a and the Nd-Fe-B magnet 26d do not come into contact with each other.

Furthermore, when the actuator movable portion 10 is driven by one magnetic circuit 26 as in this embodiment, the focus coil 10a and the tracking coil 1 are used.
It is necessary to reduce the moment around the center of gravity G generated at 0b. If the moment becomes large, the driving characteristics will be disturbed due to higher-order resonance such as pitching and yawing, so that accurate control becomes difficult.

Therefore, the optical pickup of this embodiment is constructed as follows in order to reduce the moment. The center of gravity G of the actuator movable portion 10 is set near the first outer surface S1 of the focus coil 10a to which the tracking coil 10b is adhesively fixed.

Since the leakage magnetic field from the back yoke 26b acts on the second outer surface S2 of the focus coil 10a, the direction of the force generated when the control current flows is opposite to that of the first outer surface S1. Therefore, the magnitude of the force generated on the second outer surface S2 may be appropriately set to minimize the moment around the center of gravity G. Specifically, by appropriately setting the gap j between the back yoke 26b and the second outer surface S2, the moments about the center of gravity G can be mutually canceled.

Next, in order to cancel the moment generated in the tracking coil 10b, the moment of the tracking coil 10b generated on the side outside the magnetic gap and
The moments generated on the sides in the magnetic gap may be the same.

The outward magnetic flux density Bl acts on the side outside the magnetic gap. At this time, of the force Fl generated when the control current flows, if the component force acting as a moment around the center of gravity G is Flm and the distance between the action point P of the resultant force and the center of gravity G is b, the moment is Flm × b.

On the other hand, since the width of the center yoke 26c is larger than that of the Nd-Fe-B magnet 26d, the outward magnetic flux density Bg acts on the side in the magnetic gap. At this time, of the force Fg generated when the control current flows, if the component force acting as a moment around the center of gravity G is Fgm and the distance between the action point T of the resultant force and the center of gravity G is a, the moment is Fgm × a.

Therefore, in order to cancel the moment generated in the tracking coil 10b, it is sufficient that these two moments satisfy the relationship of Flm × b = Fgm × a. Specifically, the position of the tracking coil 10b is appropriately set so that the size of Fgm increases in a state where the width d of the side in the magnetic gap is larger than the width c of the Nd-Fe-B magnet 26d. do it.

Next, the structure of the carriage 2 on which the actuator 4 having such a structure is mounted is shown in FIG.
Or, it demonstrates with reference to FIG. The carriage 2 is provided with a main bearing 2c having a circular cross section and a driven bearing 2d having an elliptical cross section, through which a pair of guide shafts 28 (see FIG. 3) extending in the radial direction of a disk (not shown) can be inserted. There is.

Magnets 30 are arranged on the upper sides of the main bearing 2c and the driven bearing 2d, respectively, and the magnetic action thereof attracts the guide shaft 28 inserted into the main bearing 2c and the driven bearing 2d. , There is no play.

On the upper surface of the carriage 2 on the main bearing 2c side, a second end whose tip is connected to an electric board (not shown)
The base end of the flexible substrate 32, that is, the land portion 32a is fixed. Access coils 34 are adhered and fixed to both sides of the carriage 2, and a second flexible substrate 32 is sandwiched between the access coil 34 on the main bearing 2c side and the carriage 2. Thus, the second
By sandwiching the flexible substrate 32, the reaction force of the second flexible substrate 32 which affects the optical pickup during access driving is reduced.

A hole 2f is formed in the center of the side wall 2e of the carriage 2 on the side of the fixed optical system (not shown) for passing the light beam output from the fixed optical system. A recess 2g is formed in the center of the bottom of the carriage 2, and a mirror 36 that reflects the light beam guided from the fixed optical system through the hole 2f toward the objective lens 6 is bonded to the recess 2g. It is fixed.

The side wall 2e of the carriage 2 and the side wall 2h facing the side wall 2e have a higher central portion than the other portions, which increases the bending rigidity of the carriage 2 to increase the bending mode. The resonance frequency is increased.

A through hole 2i penetrating to the back surface of the carriage 2 is formed in the center of the concave spherical seat 2a of the carriage 2 on which the convex spherical surface portion 12c of the fixing member 12 (see FIG. 3) is seated. There is. The center of curvature (not shown) of the concave spherical seat 2a is positioned in a plane parallel to the disc (not shown) including the principal point of the objective lens 6 and near the upper surface of the fixing member 12. There is.

In such a structure, the fixing member 12 seated on the concave spherical seat 2a is moved by the plate-like pressing member 40 (see FIG. 3) provided in the cover 38 covering the upper surface of the carriage 2. It is kept pressed in the 2a direction. As a result, the convex spherical surface portion 12c of the fixing member 12 and the concave spherical seat 2a of the carriage 2 are always maintained in contact with each other with a constant pressure.

The convex spherical surface portion 12c of the fixing member 12 has a central portion facing the through hole 2i.
The adjustment hole 12f (see FIG. 3) is formed. According to such a structure, a kind of inclination adjusting means is formed, and an adjusting pin (not shown) is inserted into the adjusting hole 12f through the through hole 2i of the carriage 2 to form the concave spherical seat 2a and the convex spherical surface portion 12.
By sliding c relatively, the optical axis of the objective lens 6 can be adjusted so as to be substantially orthogonal to the disc.

After that, the gap between the fixing member 12 and the carriage 2 is filled with an adhesive, and the fixing member 12 is adhesively fixed onto the carriage 2. Further, in particular, as shown in FIG. 3, the first land portion 24 a is the end surface 12 of the fixing member 12.
First flexible substrate 2 fastened to e (see FIG. 1)
Reference numeral 4 denotes a first bent portion 24c that is bent in a substantially U shape near the bottom surface of the carriage 2 and a second bent portion 24d that is bent in a substantially U shape near the cover 38 that covers the upper surface of the carriage 2. After the formation, the second land portion 24b is overlaid and fixed on the land portion 32a of the second flexible substrate 32. The land portions 24b and 32a are electrically connected to each other by soldering.

Hereinafter, referring to FIGS. 5 and 6, the first flexible substrate 24 when adjusting the optical axis of the objective lens 6 is described.
The deformed state of will be described. 5A and 5B show a state in which the fixing member 12 is slid on the concave spherical seat 2a so as to rotate the objective lens 6 (see FIGS. 1 to 3) around the tracking axis. Has been done.

At this time, the first land portion 24a of the first flexible substrate 24 fastened to the fixing member 12
Moves up and down with the movement of the fixing member 12, and the stress generated in the first flexible substrate 24 by this up and down movement is due to the stress of the first and second bent portions 24c and 24d of the first flexible substrate 24. It is absorbed and removed by the change of curvature and the change of position.

On the other hand, FIGS. 6A and 6B show a state in which the fixing member 12 is slid on the concave spherical seat 2a so as to rotate the objective lens 6 around the tangential axis. There is. In the figure, the first flexible substrate 24
Other configurations have been removed to expose the.

At this time, the first land portion 24a of the first flexible substrate 24 rolls along with the operation of the fixing member 12, and the stress generated in the first flexible substrate 24 by this rolling is the first. The second bent portions 24c and 24d are relatively deformed so as to correct the kinking of the first flexible substrate 24, and are absorbed and removed.

As described above, according to this embodiment, when adjusting the optical axis of the objective lens 6 in both cases of FIG. 5 and FIG.
Since the first flexible substrate 24 is not unduly deformed such as twisted, it is possible to prevent inappropriate stress from remaining on the first flexible substrate 24. That is, after the optical axis adjustment, the force for returning the objective lens 6 to the state before the optical axis adjustment does not act, so that highly accurate information recording and reproduction can be performed.

Next, an optical pickup according to the second embodiment of the present invention will be described with reference to FIGS. 7 and 8.
In the description of this embodiment, the same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

As shown in FIGS. 7 and 8, the optical pickup of the present embodiment relates to the improvement of the arrangement state of the first flexible substrate 24, and the other structure is the same as that of the first embodiment. In the same figure, only the configuration around the first flexible substrate 24 is shown enlarged.

As shown in FIG. 7A, the first flexible substrate 24 applied to this embodiment is located above the end surface 12e (see FIG. 1) of the fixing member 12 (that is, the carriage 2).
Of the concave spherical seat 2a is formed in the vicinity of a plane parallel to a disk (not shown) including the center of curvature X of the concave spherical seat 2a, and a bent portion 24e bent in a substantially U shape is formed. The second land portion 24b is the second flexible substrate 32.
And is firmly fixed on the land portion 32a.

Specifically, the second land portion 24b is fixed to the land portion 32a of the second flexible substrate 32 in a folded state so that the conductor surface is exposed. The land portions 24b and 32a are electrically connected to each other by soldering.

The center of curvature X of the concave spherical seat 2a is located in a plane parallel to the disk (not shown) including the principal point of the objective lens 6. In such a configuration, as shown in FIGS. 7B and 7C, the objective lens 6
When the fixing member 12 is slid on the concave spherical seat 2a so as to rotate (see FIGS. 1 to 3) around the tracking axis, the first flexible substrate 24 of the first flexible substrate 24 fastened to the fixing member 12 is moved. The land portion 24a of No. 1 is the fixing member 12
It moves up and down with the movement of the
The stress generated in the flexible board 24 is absorbed and removed by the change in the curvature and the change in the position of the bent portion 24e of the first flexible board 24.

On the other hand, FIGS. 8A and 8B show a state in which the fixing member 12 is slid on the concave spherical seat 2a so as to rotate the objective lens 6 around the tangential axis. There is. In the figure, the first flexible substrate 24
Other configurations have been removed to expose the.

At this time, the first land portion 24a of the first flexible substrate 24 rolls as the fixing member 12 moves. However, since the bent portion 24e applied to the present embodiment is positioned at substantially the same height as the center of curvature X of the concave spherical seat 2a (see FIG. 7), it is generated on the first flexible substrate 24 by the rolling. The stress to be absorbed is absorbed and removed by the bent portion 25e being deformed without the first flexible substrate 24 being twisted.

As described above, according to this embodiment, when adjusting the optical axis of the objective lens 6 in both cases of FIG. 7 and FIG.
Since the first flexible substrate 24 is not unduly deformed such as twisted, it is possible to prevent inappropriate stress from remaining on the first flexible substrate 24. Therefore, after the optical axis adjustment, the force for returning the objective lens 6 to the state before the optical axis adjustment does not act, so that highly accurate information recording and reproduction can be performed.

The present invention is not limited to the configuration of each of the above-described embodiments, and the same applies to an actuator having a tilt adjusting means other than the concave spherical seat and a supporting mechanism other than the spring support. Produces the effect of. The present invention can also be applied to an optical system driving device other than the objective lens actuator. Further, the bending directions of the first and second bent portions applied to the first embodiment are not limited to those shown in the drawings, and can be variously changed according to the usage state. Is.

[0066]

According to the optical pickup of the present invention, the stress generated in the flexible substrate can be absorbed and removed by the bent portion when the optical axis of the objective lens is adjusted.
After the optical axis adjustment, the action of the force to return the objective lens to the state before the optical axis adjustment does not occur. As a result, the optical axis of the objective lens can always be maintained at a constant angle with respect to the disc, so that information can be recorded and reproduced with high accuracy.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a configuration of an optical pickup according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a state where an actuator is mounted on a carriage.

FIG. 3 is a sectional view of the optical pickup according to the first embodiment of the present invention.

FIG. 4A is a perspective view showing the configuration of a magnetic circuit applied to the optical pickup of the present invention, and FIG. 4B is a plan view showing the positional relationship between the actuator movable portion and the magnetic circuit.

5A and 5B are enlarged views showing only the configuration around a first flexible substrate applied to the optical pickup according to the first embodiment of the present invention, in which an objective lens is shown. The figure which shows the state which made the fixed member slide on a concave spherical surface seat so that it may rotate around a tracking axis.

6 (A) and 6 (B) are enlarged views showing only the configuration around the first flexible substrate applied to the optical pickup according to the first embodiment of the present invention, and FIG. The figure which shows the state which made the fixed member slide on a concave spherical seat so that it may rotate around a tangential axis.

FIG. 7A is an enlarged view showing only the configuration around a first flexible substrate applied to an optical pickup according to a second embodiment of the present invention, and FIGS. The figure which shows the state which made the fixed member slide on a concave spherical seat so that an objective lens may be rotated around a tracking axis.

8A and 8B are enlarged views showing only the configuration around the first flexible substrate applied to the optical pickup according to the second embodiment of the present invention, in which the objective lens is shown. The figure which shows the state which made the fixed member slide on a concave spherical seat so that it may rotate around a tangential axis.

[Explanation of symbols]

2 ... Carriage, 4 ... Actuator, 6 ... Objective lens, 24 ... 1st flexible substrate, 24c ... 1st bending part, 24d ... 2nd bending part, 32 ... 2nd flexible substrate.

Claims (3)

[Claims] 1. An access member movable in a radial direction of a disk, an actuator mountable on the access member and supporting an objective lens so as to be displaceable in a predetermined direction, and an inclination of an optical axis of the objective lens. In an optical pickup including an adjustable tilt adjusting means and a flexible substrate electrically connecting the access member and the actuator, the flexible substrate is configured to adjust the tilt of an optical axis of the objective lens, An optical pickup, wherein a bent portion is formed so as to absorb and remove stress generated in the flexible substrate. 2. The bent portion is a first bent portion that is bent in a substantially U shape near the bottom surface of the access member, and a second bent portion that is bent in a substantially U shape near the upper surface of the access member. The optical pickup according to claim 1, further comprising: 3. The optical pickup according to claim 1, wherein the bent portion is bent in a substantially U shape near a plane parallel to the disk including a principal point of the objective lens.