JP3508005B2 - Optical disc apparatus and method for adjusting tilt of objective lens thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for adjusting an inclination of an objective lens in an optical disk device and a method thereof, and is particularly applicable to an optical disk device having a plurality of objective lenses in the same movable part. Is.

[0002]

2. Description of the Related Art In recent years, an optical disk device is often used as a large-capacity recording / reproducing device. In particular, an objective lens driving device is provided with two objective lenses, and the objective lens is selectively used according to the type of the disc. There is an optical disk device having such a configuration (disclosed in Japanese Patent Laid-Open No. 6-333255).

[0003]

In the configuration in which the movable portion is provided with the two objective lenses as described above, the optical axis of each objective lens must be perpendicular to the optical disk, but at present, a suitable adjustment is made. No configuration or adjustment method has been proposed.

For example, in the case where the respective objective lenses are mounted by adjusting the inclination in the movable part of the objective lens driving device by using a jig, the movable part is often supported elastically, so that the mounting is completed after the mounting. If the jig is removed, the movable part will be slightly displaced and returned, and the optical axes of the objective lenses will be tilted.

The present invention has been made in view of the above circumstances, and in an optical disk device equipped with a plurality of types of objective lenses for accommodating a plurality of types of optical desks, the inclination of the plurality of objective lenses can be easily adjusted. The purpose is to be able to adjust accurately.

[0006]

According to a first aspect of the invention, a plurality of objective lenses having different specifications are used as a common lens holder.
In an optical disk device having an objective lens driving device mounted on a rudder, the objective lens driving device uses another objective lens as a reference with respect to one of the plurality of objective lenses.
The lens holder is provided with a first adjusting mechanism for adjusting the tilt of another objective lens so that the optical axis of the lens and the optical axis of the reference objective lens are parallel to each other, and the tilt of the objective lens driving device is provided. Is provided with a second adjusting mechanism for adjusting each optical axis of the objective lenses to be perpendicular to the disc.

The above objective lens driving device includes an objective lens,
It is composed of a lens holder for holding it, a movable part side substrate, a focusing coil and a tracking coil fixed to the lens holder, and is provided so as to be movable with respect to the housing of the optical disk device.

According to the above arrangement, the optical axes of the objective lenses in the objective lens driving device are made parallel by the first adjusting mechanism, and the tilt of the objective lens driving device is adjusted so that the optical axes of the objective lenses are adjusted. By making it perpendicular to the disc, the optical axis of each objective lens is accurately perpendicular to the disc.

[0009]

[0010]

In particular, the holding body for pressing and holding the objective lens on the tilting holder, and the adjusting body which pushes the tilting holder surface through the holding body are integrally provided (the third aspect of the present invention). (Invention), the tilt of the objective lens can be adjusted by operating the adjusting body while pressing and holding the objective lens with the tilt holder. That is, the inclination of the objective lens can be adjusted without using a jig.

[0012]

[0013]

In the invention according to claim 5 , a plurality of different
The objective lens with the specifications
Objective lens of optical disk device having objective lens driving device
Is a method of adjusting the tilt of the objective lens.
Adjust the optical axis of the evaluation optical system based on one of
And the other objective lens with respect to the optical axis of the evaluation optical system.
Adjusting the optical axis of the lens, and the plurality of objective lenses
And a step of adjusting the inclination of the whole with respect to the disc.
And

According to the above arrangement, the optical axes of the objective lenses in the objective lens driving device are made parallel, and the tilt adjustment of the objective lens driving device is performed so that the optical axes of the objective lenses become perpendicular to the disc. The optical axis of each objective lens is perpendicular to the disc with high precision.

[0016]

[0017]

DETAILED DESCRIPTION OF THE INVENTION

(First Embodiment) The method of adjusting the inclination of the objective lens in the optical disk device of the present embodiment is such that the optical axes of a plurality of objective lenses mounted on the same movable part are substantially parallel to each other on a jig in advance. Is adjusted and then the entire tilt is adjusted to adjust the optical disc. Therefore, the tilt adjusting mechanism (first adjusting mechanism) of the objective lens with respect to the lens holder and the objective lens driving device are used. The entire tilt adjusting mechanism (second adjusting mechanism) is provided. The description will be given for the case of two objective lenses, but it is also applicable to the case of three or more objective lenses.

The structure and adjusting method of the optical pickup of this embodiment will be described below with reference to the drawings.

FIG. 1 is a plan view showing a structural example of the optical disk device of this embodiment, and FIG. 2 is a side view thereof. FIG. 3 is a plan view showing the structure of the optical pickup in FIG. 1, and FIG. 4 is a sectional view taken along line AA of FIG. FIG. 5 is a perspective view showing the arrangement of the optical system in FIG. FIG. 6 is a perspective view showing the structure of the hologram laser, and FIG. 7 is a view for explaining the positional relationship between the hologram and the photodiode.
(A) shows the hologram pattern, and (b) shows the photodiode pattern. FIG. 8 is a plan view for explaining a split state of a light beam when recording / reproducing is performed on a magneto-optical disk using one objective lens.
FIG. 6 is a plan view for explaining a split state of a light beam when recording / reproducing on an optical disc other than a magneto-optical disc using the other objective lens. 10 is a plan view showing the structure of the objective lens driving device in FIG. 3, FIG. 11 is a sectional view taken along line AA in FIG. 10, and FIG. 12 is a sectional view taken along line BB in FIG. FIG. 13 is a plan view showing a connection pattern of coils to the movable unit side substrate in FIG.
(A) shows the connection of the focus coil, and (b) shows the connection of the tracking coil. FIG. 14 is a side view showing the pattern of the fixed part side substrate viewed from the direction C in FIG. FIG. 15 is a cross-sectional view showing a configuration and an adjusting method of an adjusting mechanism for making the optical axes of the two objective lenses parallel to each other on the lens holder, and FIG.
It is a D sectional view. 17 is a plan view showing a state in which the tilting holder is fixed by an adhesive in FIG. 16, and FIG. 18 shows a state in which the adjusting mechanism is removed after the state of FIG. 17 and two objective lenses are fixed by the adhesive. It is a top view.

1 to 4, an optical disk device 1 is an optical disk 2, a turntable 3 for mounting the optical disk 2, an optical disk 2 and a spindle motor 4 for rotating the turntable 3, an optical system 6 for a housing 5, an objective lens driving device. The optical pickup 8 is equipped with the optical pickup 7. The spindle motor 4 is mounted on a mechanical chassis (not shown), and the optical pickup 8 is configured to be movable in the Ra direction of FIG. 1 by a guide shaft (not shown) also mounted on the mechanical chassis.

The configuration of the optical system will be described with reference to FIG. The two objective lenses 9 and 10 have different specifications so that they can correspond to different types of optical disks. Here, the thickness of the magneto-optical disk is 1.2m.
The objective lens 9 corresponding to a disc having a thick substrate thickness of about m and the objective lens 10 corresponding to a disc having a thin substrate thickness of about 0.6 mm will be described. However, the objective lens 9 has a thin substrate thickness. Compatible with discs, objective lens 10
May correspond to a disk having a large substrate thickness, and the reverse combination may be used. Further, the objective lens 9 for a disc having a thick substrate may be used for reproducing a CD other than the magneto-optical disc.

Reflecting mirrors 11 and 12 are arranged below the objective lenses 9 and 10, respectively. The light beam emitted from the hologram laser 13 serving as the light source is converted into parallel light by the collimator lens 14 and enters the polarization beam splitter 15. A part of the light beam reflected by the polarization beam splitter 15 enters the objective lens 10 through the reflection mirror 12, and the polarization beam splitter 1
The remaining light beam not reflected by 5 is reflected by mirror 1.
6, the light enters the objective lens 9 through the reflection mirror 11.
On the other hand, the light beam reflected by the optical disc through the objective lens 9 and the light beam reflected by the optical disc through the objective lens 10 again return to the polarization beam splitter 15 and return to the hologram laser 13. It is divided into a light beam toward the Wollaston prism 17,
The light beam heading toward the Wollaston prism 17
Reflecting mirror 18, spot lens 19, reflecting mirror 20
Then, the light enters the photodetector 21 for detecting the magneto-optical signal.

As shown in FIG. 6, the hologram laser 13 includes a semiconductor laser 22 and a photodiode 23 in one package 24, and a hologram 25 and a diffraction grating 26 are provided on both surfaces of the package 24. The formed glass substrate 27 is fixed. The light beam emitted from the semiconductor laser 22 is divided into three main beams and two sub beams by the diffraction grating 26, passes through the bologram 25 as zero-order light, and travels toward the optical disc 2. A part of the light beam reflected by the optical disc 2 returns to the hologram 25 through the same route, and the first-order diffracted light diffracted here is guided to the five-division photodiode 23. The hologram 25 is composed of two regions having different grating periods. Of the reflected light of the main beam, the one that is incident on one region 28 is the one that is incident on the other region 29 on the dividing line of the photodetectors D2 and D3. Is condensed on the photodetector D4. Further, the reflected light of the sub-beams is condensed on the photodetectors D1 and D5, respectively. Therefore, the output of each segment of the five-division photodiode 23 is set to S ₁ , S ₂ ,
If S ₃ , S ₄ , and S ₅ are set, the focus error signal FES
Is given by FES = S ₂ −S ₃ , and the tracking error signal TES is the so-called 3
Detected by the beam method and given by TES = S ₁ -S ₅ . As described above, the servo signal can be detected. For optical discs other than magneto-optical discs that detect the intensity of reflected light, the reproduction signal RF is given by RF = S ₂ + S ₃ + S ₄ .

Next, the operation of injecting a light beam into the two objective lenses 9 and 10 and the detection of the magneto-optical signal will be described with reference to FIG.
And it demonstrates using FIG. Polarizing beam splitter 1
5 is designed to transmit about 80% of the p-polarized light component and reflect the remaining 20% and reflect almost 100% of the s-polarized light component, and the p-polarized light beam emitted from the hologram laser 13 is , Polarization beam splitter 15
As a result, 20% of the light is reflected and enters the objective lens 10, and the remaining 80% passes through the polarization beam splitter 15 and enters the objective lens 9.

FIG. 8 shows a case where the objective lens 9 is used to perform recording and reproduction on a magneto-optical disk. The light beam emitted to the medium surface of the magneto-optical disk is subjected to the Kerr effect by the objective lens 9 and its polarization direction slightly changes (that is, slightly s-polarized component) and returns to the polarization beam splitter 15. come. At this time, the reflectance of the p-polarized component in the polarization beam splitter 15 is about 20%.
Since the reflectance of the s-polarized component is almost 100%, the light beam reflected by the polarization beam splitter 15 has only the p-polarized component reduced, resulting in an increase in the rotation angle of the polarization direction. Become.

The light beam having the increased rotation angle is split into two light beams having respective polarization components by the Wollaston prism 17, and the reflection mirror 18 and the spot lens 1 are provided.
The magneto-optical signal is detected by the photo-detector 21 for detecting the magneto-optical signal through the reflection mirror 20 and the reflection mirror 20.

On the other hand, of the light beam reflected by the disk, the component (p-polarized light) transmitted through the polarization beam splitter 15 returns to the hologram laser 13 and the built-in photodiode 23 detects a servo signal. In addition,
At the same time when the light beam enters the objective lens 9, the remaining 20% of the light beam also enters the objective lens 10, and the light beam reflected by the optical disk is the photodetector 21 for detecting the magneto-optical signal and the hologram laser. The light beam is incident on the photodiode 23 built in the device 13. However, since the specifications of the objective lens 10 are different from those of the objective lens 9, the light beam is not sufficiently condensed on the medium surface and is blurred on the photodetector. And has almost no effect. Also, if the optical disc is other than the magneto-optical disc, the same objective lens 9 may be used if the substrate has the same thickness and refractive index (for example, CD). In this case, the photodetector 21 for detecting the magneto-optical signal may not be used, and the photodiode 23 built in the hologram laser 13 may detect both the servo signal and the RF signal.

FIG. 9 shows a case where the objective lens 10 is used to perform recording and reproduction on a disk having a thin substrate other than the magneto-optical disk. A disc with a thin substrate may be a read-only disc, or may be recorded like a phase change disc.
It may be a playable disc. The light beam (20% p-polarized light component) incident on the objective lens 10 is reflected by the optical disc, and the polarization direction is left unchanged.
Returning to 5, 20% is reflected and enters the hologram laser 13, and the servo signal and the RF signal are detected. The 80% light beam that has passed through the polarization beam splitter 15 is incident on the photodetector 21, but servo detection or RF detection may be performed using this detection signal. Although the light beam is incident on the objective lens 10 at the same time as the light beam is incident on the objective lens 10, there is almost no influence because the specifications of the objective lens are different as in the previous case.

Next, the structure of the objective lens driving device will be described with reference to FIGS. The objective lens driving device 7 includes two objective lenses 9 and 10 having different specifications.
And a lens holder 30 for holding the objective lenses 9, 10.
The movable portion side substrate 31 attached to the upper and lower surfaces of the lens holder 30, and the focusing coil 32 and the tracking coil 33 fixed to the concave portions on both side surfaces of the lens holder 30 form a movable portion. The lens holder 30 is provided on the upper and lower sides of the movable unit side substrate 31 as a base 34
Two elastic bodies 35 for supporting the movable portion in the focusing direction and the tracking direction are arranged, and these are arranged in a substantially V shape having an intersection in the extension line near the center of gravity of the movable portion. There is. Elastic body 35
One end 35a of the elastic body 35 is fixed to the movable portion side substrate 31 by the solder 36, and the other end 35b of the elastic body 35 is fixed to the fixed portion side substrate 38 by the solder 37. Each elastic body 35 includes two linear flexible portions 35c and 35d that are substantially parallel and are not on the same straight line, and a bent portion 35e that connects them.
And a branched arm portion 35f branched from the linear flexible portion. Then, the tip of the branch arm portion 35f and the other end 35b
The damper material 39 is fixed so as to bridge between and, and has a function of suppressing resonance of the elastic body 35 in the three directions of the thickness direction, the width direction, and the longitudinal direction. The fixed portion side substrate 38 is the base 34.
Is fixed to the upright portion 34a. The other standing portions 34b and 34c from the base 34 form a substantially U-shaped yoke, and the permanent magnet 40 is fixed to the wall surface of one of the yokes 34b. A part of the focusing coil 32 and the tracking coil 33 is arranged in the magnetic gearup 41a of the magnetic circuit 41 formed by the yokes 34b and 34c and the permanent magnet 40, and the terminals of the focusing coil 32 and the tracking coil 33 are movable parts. Side board 3
1, electrically connected to the fixed part side substrate 38 via the elastic body 35.

FIG. 1 shows a method of connecting the terminals of each coil to the movable-part-side substrate and the circuit pattern of the movable-part-side substrate.
This will be described in more detail using 3. 13A is a plan view showing a connection state between the focusing coil 32 and the upper movable portion side substrate 31, and FIG. 13B is a connection state between the tracking coil 33 and the lower movable portion side substrate 31. FIG. In FIG. 13B, the circuit pattern of the movable-portion-side substrate 31 is on the back side of the paper surface and is therefore indicated by a broken line. The movable part side substrate 31 includes four coil land parts 31a to 31d and two elastic land parts 31e to 31d.
31f, 31a and 31f, 31b and 31d, 31
c and 31e are electrically connected to each other. The same substrate is used for the upper and lower movable part side substrates 31. The terminal of each focusing coil 32 is connected to the upper coil lands 31a to 31d, and each tracking coil 3 is connected.
The terminal 3 is connected to the lower coil land portions 31a to 31d. As for the connection between the two tracking coils 33 arranged side by side, the terminals are directly connected to each other, but a series of coils connected from the beginning may be used.

The fixed portion side substrate 38 will be described in more detail with reference to FIG. The fixed portion side substrate 38 is divided into two, which are the flexible printed circuit 4
Connected by two. Each fixed part side substrate 38
Has two land portions (four in total) 38a to 38d,
The other end 35b of the elastic body 35 is connected. Each land part 38
a-38d, by the flexible printed circuit 42,
It is connected to an external drive circuit (not shown), and current can be supplied.

In the above structure, when a current is passed through the focusing coil 32 and the tracking coil 33, the movable portion can be driven independently in the focusing direction and the tracking direction. In addition,
Driving in the tracking direction is performed by applying a couple force by the left and right tracking coils 33 to rotate the elastic body 35 around the intersection on the extension line, and to arrange the two objective lenses 9 arranged at positions decentered from the center. A displacement in the tracking direction is given to 10. The two objective lenses 9 and 10 move in opposite directions with respect to the same tracking driving force.

Next, the tilt adjusting mechanism of the objective lens used in this embodiment will be described. The method of adjusting the inclination of the objective lens according to the present invention is performed by previously using the lens holder 30.
In the above, the optical axes of the two objective lenses 9 and 10 are adjusted in parallel, and after the objective lens driving device is assembled, the tilt between the optical disk and the objective lens is adjusted.

As shown in FIG. 12, one of the two objective lenses is directly mounted on the lens holder 30, and tilt adjustment with respect to the lens holder 30 is not possible, whereas the other objective lens 9 is tilted. Holder 4
It is mounted on the lens holder 30 via the lens 3 and the tilt of the lens holder 30 can be adjusted. A part of the bottom surface of the tilt holder 43 is spherical, and the center thereof is near the principal point position of the objective lens 9. A concave portion having a spherical surface or a conical surface is provided on the lens holder 30 side, and slidably holds the tilt holder 43. Therefore, by adjusting the inclination of the objective lens 9 with the objective lens 10 as a reference, it becomes possible to make the optical axes of the both parallel. A method for adjusting the inclination of the objective lens on the lens holder 30 will be specifically described with reference to FIGS. The tilt adjustment on the lens holder 30 is performed using a jig for tilt adjustment. The structure of the jig is not limited, but adjustment is possible with the configuration shown in FIGS. 15 and 16, for example. The lens holder 30 is fixed to the jig, and the tilting holder 43 provided on the one objective lens 9 side is tiltable with respect to the lens holder 30. The tips of three adjusting screws 47 fixed to the jig are in contact with the tilt holder 43, and the tilt can be adjusted by individually tightening or loosening them.

For the adjustment, first, the optical axis of the measuring system is aligned with the objective lens 10 (for example, the table on which the lens holder 30 is mounted is adjusted). Specifically, a light beam is made incident on the objective lens 10 from below, and the focused light is observed by a television camera 49 via a microscope lens 48 and adjusted to an optimum state. The optimum state is judged from the symmetry of the strength of the primary ring (the portion 50 in the strength distribution in a certain cross section shown in the figure). As a result, the objective lens 10 serves as a reference. Next, the measurement system is moved in parallel on the objective lens 9, and the inclination of the objective lens 9 is adjusted so that the optimum state is obtained. With this, the optical axes of the two objective lenses 9 and 10 are set to be substantially parallel. Both objective lenses 9, 10
When the optical axes of are parallel, the tilt holder 43 is bonded to the lens boulder 30. Placing the adhesive 51 between the three adjusting screws 47 facilitates the work.

Once the tilt holder 43 is fixed, the three adjusting screws 47 may be removed. Then, the two objective lenses 9 and 10 are bonded to the tilt holder 43 and the lens holder 30, respectively. If the adhesive 52 is arranged between the adhesives to which the tilting holder 43 is fixed, the work is easy.

Instead of using the tilt holder 43 as described above, the objective lens may be directly mounted on the lens holder by sliding. However, in this case, the objective lens cannot be removed because it is adhered after the adjustment. When the tilt holder is used, if the tilt holder is adhered to the lens holder after tilt adjustment, the accuracy of the mounting surface of the objective lens is fixed, so the objective lens may be removed once. In order to obtain more reproducibility, it is advisable to add a mark so that the direction in which the objective lens is mounted is the same.

If the objective lens can be removed as described above, it becomes possible to assemble the objective lens driving device with high precision based on the position of the light passage hole of the objective lens. That is, the objective lens driving device is assembled by mounting the lens holder on the movable part side to the housing on the fixed part side, and at that time, the optical axis of the lens mounted on the lens holder is accurately set to the set position. Need to be attached to the housing. At that time, if the lens is removed, the lens holder can be easily mounted with the lens mounting opening of the lens holder as a reference. Similarly, the assembly of the optical system for the objective lens driving device also has an advantage that it can be easily performed with the opening of the lens holder as a reference. Further, instead of using the tilting holder, there is also a method of placing a spacer on the objective lens mounting surface of the lens holder to determine the accuracy of the mounting surface, and the objective lens can also be removed once. However, it is good when the necessary adjustment amount is known in advance, but when it is necessary to make adjustments by trial and error many times, the adjustment becomes troublesome. Further, both the objective lenses may be tilt-adjusted with respect to the lens holder, and both objective lenses may be moved to adjust the optical axes of the both in parallel. However, since the number of parts increases, it is preferable to adjust the tilt of only one objective lens with respect to the other.

With the above construction, the optical axes of the two objective lenses can only be made parallel, and tilt adjustment with respect to the optical disk is difficult. The tilt adjusting mechanism for the optical disc will be described below with reference to FIGS. 3 and 4.

On the back surface of the base 34 of the objective lens driving device 7, there is provided a spherical seat 44 having a spherical surface part, and the spherical seat 4 is provided.
4 is fitted into the recess 5a provided in the housing 5,
It is supported so that it can tilt. The center of the sphere of the spherical portion is set between the two objective lenses 9 and 10 and near the height of the principal point of the objective lens. The adjustment spring 45 is provided at the minus end of the base 34.
The two adjusting screws 46 are urged downward by the and are located on the side opposite to the adjusting spring 45 with respect to the spherical seat 44, so that the inclination can be adjusted in two directions. In this configuration, the two objective lenses 9 and 10 are tilted together, but since the optical axes of the two objective lenses 9 and 10 are adjusted in parallel in advance, the optical axes of both objective lenses are relative to the optical disc. Will be adjusted at the same time. In the above description, the method of adjusting the inclination by sliding the spherical seat 44 with respect to the concave portion 5a has been described, but the present invention is not limited to this, and tilting is performed with one point of the substantially spherical convex portion as a fulcrum. A method of freely supporting it may be used.

In this way, the objective lens driving device 7 having the objective lenses 9 and 10 whose optical axes are adjusted is tilt-adjusted and assembled into the housing 5 to assemble the optical pickup 8. The tilt adjustment at this time is performed so that the optical axes of the objective lenses 9 and 10 are perpendicular to the disc surface of the optical disc 2. The adjustment may be performed on the jig for assembling the optical pickup or in a state where it is incorporated in the optical disk device. However, if the adjustment is made on the jig for assembling the optical pickup, the tilt error of the mechanical system remains. On the other hand, if it is carried out in the state where it is incorporated in the optical disk device, the error of the mechanical system can be absorbed.

(Second Embodiment) In the first embodiment, as means for simultaneously adjusting both objective lenses,
Although the description has been made by adjusting the objective lens driving device with respect to the housing, the present invention is not limited to this. As an example in which the adjustment mechanism is provided on the objective lens side, the inclination of the guide shaft guiding the optical pickup may be adjusted. Since the optical disc and the objective lens are adjusted, the adjustment may be performed on the optical disc side. For example, the inclination of the mounting surface of the spindle motor with respect to the mechanical chassis may be adjusted, or the inclination of the optical disk mounting surface of the turntable may be adjusted. Specifically, a method of placing a spacer on the mounting surface or the mounting surface can be considered.

In this embodiment, the structure of the optical pickup in that case will be described assuming that the tilt is adjusted on the optical disk side.

FIG. 19 is a plan view of the optical pickup.
20 is a sectional view taken along line AA of FIG. The difference from the first embodiment is that there is no tilt adjusting mechanism for the entire objective lens driving device 7, and the objective lens driving device 7 is directly fixed to the housing 5. Of course, as in the first embodiment, a tilt adjusting mechanism may be further provided, but if the tilt of the optical disk can be adjusted, the number of adjusting points should be small. In addition, it is desirable to adjust the tilt on the optical disk side in that the tilt error of the mechanical system can be absorbed.

(Third Embodiment) The tilt adjusting mechanism of the objective lens in the optical disk device of the present embodiment is a tilt adjusting mechanism with respect to the lens holder, and includes a tiltable mechanism and a screw and spring mechanism for adjustment as a movable part. It is possible to adjust the tilt of all the objective lenses only within the movable part, or the optical axes of the multiple objective lenses mounted on the same movable part are almost parallel to each other on the jig in advance. By adjusting so that, and then adjusting the overall tilt,
An adjustment method for adjusting the optical disc may be used. The description will be given for the case of two objective lenses, but it can be applied to the case of one objective lens and the case of three or more objective lenses.

The structure and adjusting method of the optical pickup of this embodiment will be described below with reference to the drawings.

FIG. 21 is a plan view showing the structure of the third embodiment of the objective lens driving device according to the present invention.
21 is a sectional view taken along the line BB in FIG. 21, FIG. 23 is a side view showing the shape of the tilt adjusting spring seen from the direction E in FIG. 21, and FIG. 24 is a sectional view taken along the line FF in FIG.

The basic structure is the same as that of the first embodiment, and the description thereof is omitted. However, the difference is that the upper movable portion side substrate 31 is large and one objective lens 9 is moved to the lens holder 30 or tilted. It is arranged so as to be sandwiched between it and the holder 43, and that the movable part has a screw and spring mechanism for tilt adjustment.

As shown in FIGS. 21 and 22, the upper movable part side substrate 31 is enlarged and arranged above the objective lens 9, and a hole is formed right above the objective lens 9 for light passing.
Between the upper movable unit side substrate 31 and the tilt holder 43-
An adjustment spring 53 is inserted at the end to urge a downward force on the tilt holder 43. On the other hand, two adjusting screws 54 are arranged on the side opposite to the adjusting spring 53 with respect to the optical axis, the movable part side substrate 31 is threaded, and the tip end of the adjusting screw 54 contacts the tilt holder 43 ( See FIG. 24). As shown in FIG. 23, the adjusting spring 53 is a leaf spring bent into a substantially V shape.

With the above construction, the two adjusting screws 54
By tightening or loosening the
Is adjustable with respect to the lens holder 30.

A feature of this embodiment is that a screw and a spring mechanism for adjusting the inclination of the objective lens are also mounted on the movable portion. Then, by using the movable part side substrate as a part of the adjusting mechanism, extra parts are reduced, and the size and weight are reduced in spite of having the adjusting mechanism in the movable part. Therefore, unlike the case where the adjustment is performed on the jig as in the first embodiment, the inclination can be adjusted even after the objective lens driving device is assembled, and it is convenient in that a separate axis is not required. Taking only this configuration, it can be applied to an optical pickup having a single objective lens.
Further, even when it is applied to an optical pickup having a plurality of objective lenses, such an adjusting mechanism may be provided for all of the plurality of objective lenses, or one objective lens may be provided as in the first embodiment. It is also possible to provide an inclination adjusting mechanism for the entire objective lens driving device without providing the adjusting mechanism. Post-processing is difficult if a screw hole for adjustment is provided in the resin-molded lens holder, but since the screw is cut on the movable part side substrate, the length to cut the screw is short and the strength is easy to process. Is.

[0052]

As described above, the first aspect of the present invention or
According to the invention described in 6, the optical axes of the objective lenses in the objective lens driving device are made parallel, and the tilt adjustment of the objective lens driving device is made such that the optical axes of the objective lenses become perpendicular to the disc. As a result, the optical axis of each objective lens is perpendicular to the disc with high accuracy, so that the condensing characteristic of the objective lens in the optical disc device is improved, and the recording / reproducing operation is favorably performed.

[0053]

[0054]

Further, according to the invention of claim 3 ,
The tilt of the objective lens can be adjusted by operating the adjusting body while pressing and holding the objective lens with the tilting holder, whereby the tilt of the objective lens can be adjusted without using a jig.

[Brief description of drawings]

FIG. 1 is a plan view showing a configuration example of an optical disc device according to a first embodiment.

FIG. 2 is a side view of the example of FIG.

FIG. 3 is a plan view showing the configuration of the optical pickup in FIG.

4 is a sectional view taken along line AA in FIG.

5 is a perspective view showing the arrangement of the optical system in FIG.

FIG. 6 is a perspective view showing the structure of the hologram laser according to the first embodiment.

7A and 7B are diagrams illustrating the positional relationship between the hologram and the photodiode in the first embodiment, where FIG. 7A shows a hologram pattern and FIG. 7B shows a photodiode pattern.

FIG. 8 is a plan view illustrating a split state of a light beam when recording / reproducing is performed on a magneto-optical disk using the one objective lens in the first embodiment.

FIG. 9 is a plan view illustrating a split state of a light beam when recording / reproducing is performed on an optical disc other than a magneto-optical disc by using the other objective lens in the first embodiment.

10 is a plan view showing the structure of the objective lens driving device in FIG.

11 is a sectional view taken along the line AA in FIG.

12 is a sectional view taken along line BB in FIG.

13A and 13B are plan views showing connection patterns of coils to the movable unit side substrate in FIG. 10, wherein FIG. 13A shows connection of focus coils and FIG. 13B shows connection of tracking coils.

FIG. 14 is a side view showing a pacoon of the fixed part side substrate as viewed from the direction C in FIG.

FIG. 15 is a cross-sectional view showing a configuration and an adjusting method of an adjusting mechanism for making the optical axes of two objective lenses parallel to each other on the lens holder of the first embodiment.

16 is a cross-sectional view taken along the line DD in FIG.

FIG. 17 is a plan view showing a state in which the tilting holder is fixed by an adhesive in FIG.

FIG. 18: After the state of FIG. 17, the adjusting mechanism is removed, and 2
Plan view showing two objective lenses fixed with adhesive

FIG. 19 is a plan view of an optical pickup showing a second embodiment of the present invention.

20 is a cross-sectional view taken along the line AA of FIG.

FIG. 21 is a plan view showing an objective lens driving device according to a third embodiment of the present invention.

22 is a sectional view taken along line BB in FIG.

23 is a side view showing the shape of the tilt adjusting spring as viewed from the direction E in FIG. 21.

24 is a sectional view of an essential part of FF in FIG. 21.

[Explanation of symbols]

2: Optical disc 7: Objective lens driving device 8: Optical pickup 9: Objective lens 10: Objective lens 30: Lens holder 31: Movable part side substrate 43: Tilt holder 44: Spherical seat 45: Adjustment spring 46: Adjustment screw 53: Adjustment spring 54: Adjustment screw

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Claims (5)

(57) [Claims] 1. A common objective lens having a plurality of different specifications is used.
In an optical disc device having an objective lens driving device mounted on a lens holder, the objective lens driving device includes a plurality of objective lenses.
With one of them as a reference, the optical axis of the other objective lens and the reference
The way the optical axis of the objective lens is parallel, the first adjusting mechanism for adjusting the inclination of the other objective lens is the Renzuhoru
The optical disc device, further comprising a second adjusting mechanism that is provided in the optical disc drive and that adjusts the tilt of the objective lens driving device so that the optical axis of each objective lens is perpendicular to the disc. 2. The first adjusting mechanism is attached to a lens holder.
The objective lens is mounted via the tilt holder.
The optical disk apparatus according to claim 1, wherein that. 3. An objective lens on the tilt holder is kept pressed.
A holding body to be held, and the tilting holder inserted through the holding body
3. The optical disk device according to claim 2 , further comprising an adjusting body that presses the negative surface . 4. The holding body is an end portion of a circuit board.
3. The optical disk device described in 3 . 5. A plurality of objective lenses having different specifications are commonly used.
Has an objective lens driving device mounted on the lens holder
A method for adjusting the tilt of an objective lens of an optical disk device, which is evaluated using one of the plurality of objective lenses as a reference.
Adjusting the optical axis of the evaluation optical system, and the optical axis of another objective lens with respect to the optical axis of the evaluation optical system.
And the tilt adjustment of the entire plurality of objective lenses with respect to the disc.
And a step of adjusting the optical disc.
Method for adjusting the tilt of the objective lens in the camera.