JP3455245B2 - Objective lens tilt adjustment method and positioning device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION 1. Field of the Invention
Records and reproduces information on recording media such as magnetic disks.
The manufacturing process of optical information recording / reproducing devices
Of the objective lens of the optical system of the optical information recording / reproducing device
On how to adjust. [0002] 2. Description of the Related Art In an optical information recording / reproducing apparatus, a recording medium is used.
To write and read information to and from
Focus the laser beam onto the recording medium as small as possible.
Need to be done. However, the optical axis of the objective lens
If it is tilted, coma occurs, and it
In this case, the laser beam spot is too small to be focused.
That is, for example, the amplitude of the read signal decreases,
Or the jitter will increase and the signal will not be reproduced correctly
The problem occurs. [0003] Therefore, a manufacturing process of an optical information recording / reproducing apparatus.
In this case, the optical axis of the objective lens
It is necessary to adjust the orientation of the objective lens so that
You. The tolerance of the optical axis of the objective lens and the tilt of the recording medium is
With the recent increase in recording information density, large NA (aperture
Number) is more strictly defined.
There must be. [0004] For this reason, conventionally, the moving object in the radial direction of the recording medium has been used.
Tilt the supporting member of the objective lens to the moving member
Attachment is possible, and these moving members and support
Are connected using a screw or other member, and the screw is rotated.
The tilt of the objective lens and the support member is adjusted by
Have been used. [0005] On the other hand, recording on a recording medium
It is desired to speed up the recording and playback operations.
Therefore, the tracking operation of the optical pickup, that is,
Movement of the moving member in the radial direction and positioning movement of the recording medium
The need to speed up the work is increasing. However,
Connect the moving member and the support member with screws, etc.
Optical pick-up due to the large number of parts
The weight of the
There are certain limits. Therefore, the number of parts of the optical pickup was reduced.
To reduce the inclination between the moving member and the support member.
And tilt the objective lens with respect to the support member.
It is conceivable to adopt a configuration for adjusting. The present invention relates to a support member for an objective lens.
How to adjust the tilt when adopting the configuration to adjust the tilt
It is intended to provide law. [0007] SUMMARY OF THE INVENTION The objective lens according to the present invention
To adjust the tilt,An adsorption tube for adsorbing the objective lens and this
The suction tube can be inserted and matches the external shape of the objective lens
A circular hole and a tapered surface that continues to this circular hole
And a suction member inserted into the guide member.
The objective lens has a tapered outer peripheral surface
Is guided by the circular hole to the suction tube of the objective lens.
Positioning is performedIt is characterized by: [0008] BRIEF DESCRIPTION OF THE DRAWINGS FIG. Figure
1 is used in the tilt adjustment method according to one embodiment of the present invention.
The objective lens tilt detector 200
Of the tilt of the objective lens 150 of the optical disk device 100
It shows a state in which Structure of optical system of magneto-optical disk drive 100
Will be described. Output from semiconductor laser (LD) light source 101
The divergent laser beam (coherent light) is
It is converted into a parallel light beam by the collimating lens 102,
The cross-sectional shape of this light beam is a beam shaping prism (anamopri
) 103 to form a circle. This beam alignment
The prism 103 has light splitting prisms 104 and 105.
Has been fixed. Transmission through beam shaping prism 103
And a beam splitter between the light splitting prisms 104 and 105.
The laser beam reflected by the
Incident on the antenna 107. Thereby, the semiconductor laser light source 10
1 detects the amount of laser beam output from the
The light intensity of the beam is automatically adjusted to a predetermined value.
You. Laser transmitted through beam splitter 106
After the beam is reflected by the mirror 110, the objective lens
Insertion prism (light splitting means) 2 of the tilt detection device 200
01, is reflected by the mirror 112, and
To 150. When the tilt of the objective lens 150 is adjusted,
As shown, cover glass A (a magneto-optical
Optically equivalent to glass)
When recording / reproducing a magnetic disc,
Facing the disc. Here, the magneto-optical disk
For explanation of the configuration of the signal detection system of the device 100, a magneto-optical
It is assumed that a disc is recorded and reproduced. That is, in this state
Therefore, the objective lens tilt detection device 200 is not provided.
Instead of a cover glass A, a magneto-optical disk was provided.
Have been. Now, the light reflected on the magneto-optical disk
The bundle includes the objective lens 150, the mirror 112, and the mirror 1
10 and is guided to the light splitting prisms 104 and 105.
You. Beam split between light splitting prisms 104 and 105
The light flux reflected by the
3, the polarization direction is rotated by 45 degrees, and the prism 1 is rotated.
Polarization constituted by 14 and wedge prism 115
The light enters the beam splitter. This polarized beam split
The P-polarized light component and the S-polarized light component of the light beam
Beam splitter at the beam splitter
Signal detector consisting of two data sensors transmitted through 16
117, a magneto-optical signal or the like is obtained. On the other hand, light transmitted through the beam splitter 106
The bundle is formed by the beam shaping prism 103 and the light splitting prism 10.
4, the beam splitter 108 formed between
And enters the condenser lens 121. And this luminous flux
Is reflected by the prism 122 and
The light passes through the lens 123 and enters the error detector 124.
That is, this light beam is condensed with the condenser lens 121 and the cylindrical lens.
Is given an astigmatic difference by the
The light is condensed on the output device 124, and the
Focusing by racking error signal and astigmatism method
Error signal is obtained. Next, the light of the objective lens tilt detector 200
Explain the composition of the academic system. The hemispherical lens 202 is
It is provided at a position close to the lath A and faces the cover glass A.
Then, it is disposed on the side opposite to the objective lens 150. Insertion plug
The rhythm 201 corresponds to the mirror 110 of the magneto-optical disk device.
It is inserted between the mirrors 112, that is, in a parallel light beam.
The insertion prism 201 is manufactured with high precision (ie,
There is no new wavefront aberration generated by this insertion prism)
Polarizing beam splitter (PBS) 201a and this
1/1 provided on the objective lens 150 side of the PBS 201a
It comprises a four-wavelength plate 201b. Insertion prism 201
Is transmitted through the quarter-wave plate 201b.
Is converted into circularly polarized light by the
The light beam reflected by the
Objective lens tilt detection as polarization orthogonal to linear polarization
Guided into device 200. From this insertion prism 201
There is no return light to the semiconductor laser light source 101 side,
The generation of noise due to noise is suppressed. Note that half of the polarization beam splitter 201a is
A half-wave plate 201c is provided on the side of the conductor laser light source 101.
You may. １ ／ wavelength plate 201c to PBS 201a
By selecting the mounting state, the semiconductor laser light source
Since the polarization direction of the light from 101 is freely selected,
When the installation location of the output device 200 is different from
That is, the incident polarization direction is the same as the normal of the insertion prism reflection surface.
), The reflected light flux from the hemispherical lens 202 is
It can be taken out to the detection device 200. Part of the light beam reflected by the insertion prism 201
Is transmitted through the half mirror 203 and the imaging lens 204
Through the interference fringe observation unit 205. Interference fringe observation unit 2
Reference numeral 05 denotes, for example, a CCD camera and a monitor (not shown).
Have. In this observation unit 205, the objective lens 150
Through the cover glass A and the flat surface of the hemispherical lens 202.
The light beam reflected by the surface portion 202a and the light beam reflected by the spherical portion 202b
Interference fringes B caused by superposition with the
It is. The distortion of the interference fringe B is
-Coma caused by the relative inclination of glass A
Cause. On the other hand, the light reflected by the half mirror 203
The luminous flux is guided to the condenser lens 211. Condensing lens 2
The light beam emitted from 11 is transmitted to a beam splitter 212.
And one of the light beams is enlarged by a magnifying lens 213.
Through the point image observation unit 214, and the other light beam
It is led to the moment detection unit 215. Point image observation unit 214
Each of the alignment detection units 215 is, for example, a CCD camera.
Camera and a monitor not shown. In the point image observation unit 214, the hemispherical lens 202
Image (point image) and spherical surface reflected from the flat portion 202a
The reflected image (point image) C reflected from the unit 202b is
Observed in enlarged form. The point image by the plane 202a is
Coma is a component that is asymmetric in the direction of 180 degrees with respect to the optical axis.
Component, but a point image C by the spherical portion 202b
Contains a coma aberration component. On the other hand, the alignment detecting section 215
And for observing point images well.
Focus point formed by light flux incident on zero and hemispherical lens
In the curvature of the plane portion 202a and the spherical portion 202b of 202
With the heart (located on the plane portion 202a of the hemispherical lens 202)
It is provided to adjust the positional relationship. This Arai
As will be described later, for example, the objective detection unit 215
When the tilt adjustment of the lens 150 is started, the light
Position setting relative to the magnetic disk device 100
Also, it is used when adjusting the tilt of the objective lens 150. Referring to FIG. 2, the wavefront yield in this embodiment is shown.
Detection of coma aberration component (hereinafter simply referred to as coma aberration) in the difference
The output sensitivity will be described. In this figure, the objective lens 150 and
Part of the light beam L1 transmitted through the cover glass A is a hemisphere.
The objective lens 15 is formed by the flat portion 202a of the lens 202.
Light reflected and reflected 180 degrees symmetrically with respect to the optical axis of 0
This is the line L2. On the other hand, the light transmitted through the flat portion 202a
Some of them are reflected by the spherical portion 202b of the hemispherical lens 202.
Into the ray L3, following the same path as the incident ray,
The light exits from the objective lens 150. The objective lens 150 and the cover glass A
Of the transmitted wavefront, the plane portion 202 of the hemispherical lens 202
The wavefront reflected by a and transmitted through the objective lens 150 has light
Coma, which is an asymmetric component in the direction of 180 degrees with respect to the axis, is
Not included. On the other hand, the spherical portion 20 of the hemispherical lens 202
2b, the wavefront transmitted through the objective lens 150 is
Reciprocating through the object lens 150 and the cover glass A
The objective lens 150 and the cover glass A
It contains a coma that is twice the coma when transmitted.
The two wavefronts are superimposed on each other,
Interference fringes occur, and the interference fringe observation unit 205
50 and cover glass A
Coma is observed with twice the sensitivity. In other words, the view
In the measuring unit 205, the objective lens is
The amount of coma caused by tilting the lens 150 is λ / 2
(Λ indicates the wavelength of light transmitted through the objective lens)
One interference fringe is observed. Next, referring to FIG. 1 and FIG.
A schematic description of the tilt adjustment of the objective lens by the device
You. First, the objective lens 150 is attached to a predetermined supporting member (not shown).
)) And place the cover glass A on the disc
It is arranged at a predetermined position with reference to a mounting surface (not shown).
Then, the alignment detection unit 215 and the point image observation unit 2
14 and collected by the objective lens 150.
Point due to reflection from flat portion 202a of hemispherical lens 202
The hemispherical lens 202 is used so that the image becomes a clear spot.
Performs relative positioning of the objective lens 150 in the optical axis direction.
U. Next, the counter displayed on the alignment detection unit 215 is displayed.
The sphere of the hemispherical lens 202 collected by the object lens 150
The point image due to the reflection from the surface portion 202b is
2 so as to be at the position of the reflection point image from the flat portion 202a.
And the optical axis of the objective lens 150 and the hemispherical lens 202
Perform relative positioning in the vertical direction. The monitor of the interference fringe observing section 205 has the configuration shown in FIG.
The interference fringe B shown in FIG.
The monitor of the output unit 215 and the point image observation unit 214 includes
Point images C and D as shown in (b) are displayed. interference
The distortion of fringe B is caused by coma aberration,
50 and cover glass A have a larger relative inclination.
How big it is. The point image C is a spherical part 2 of the hemispherical lens 202.
It is a reflection image from 02b, and coma appears. one
The direction point image D is obtained from the plane portion 202a of the hemispherical lens 202.
This is a reflection image and does not include a coma aberration component. Araime
The observation magnification differs between the point detection unit 215 and the point image observation unit 214.
Each of the point images C and D is a point image observation unit 214.
Is displayed at a high magnification,
You. The magnitude of the distortion of the interference fringes B is a predetermined amount.
(For example, λ / 4, that is, 本),
By adjusting the tilt of the objective lens 150, this distortion is substantially reduced.
It disappears so that the interference fringes B become linear. This inclination
Adjust the focus point of the objective lens 150 to the hemispherical lens.
From the center of curvature of the spherical portion 202b of the lens 202
And the number of tilt fringes of the interference fringe B increases too much,
It becomes difficult to determine the magnitude of the distortion of B. In this case
In order to reduce the number of interference fringes B,
50, ie, the entire magneto-optical disk device 100 or a hemisphere
Lens 202 in the direction perpendicular to the optical axis of objective lens 150
To make the number of tilt stripes an appropriate value (usually 3
~ 4). Here again, the phase of the objective lens and cover glass
Observation of coma caused by opposite tilt, interference again
Adjust the inclination of the objective lens 150 so that the stripe B is linear.
Adjust. By repeating the above operation, the objective lens
The inclination of 150 is adjusted with high precision. As described above, in this embodiment, the objective lens 1
A hemispherical lens 202 is provided on the cover glass A side for 50.
And the light reflected by the hemispherical lens 202
Based on the generated interference fringes B, the objective lens 150 and the cover
The relative inclination of the glass A is detected. Therefore hippo
-On the glass A side, as an optical system for obtaining interference fringes B
Has substantially only a hemispherical lens 202,
Space is secured. For this reason, in this embodiment,
The tilt of the objective lens 150 can be adjusted from the lens 202 side.
And a support member (not shown) for the objective lens 150
The degree of freedom of the mounting structure is not impaired. sand
In other words, the focusing track of the magneto-optical disk drive
Focusing track to reduce the weight of the
Example of mounting structure of objective lens 150 to King mechanism
For example, the case where the one shown in FIGS.
Also, the inclination of the objective lens 150 can be adjusted. In this embodiment, the hemispherical lens 202 is used.
When the light beam guided from the objective lens 150 is reflected,
Both split into multiple beams and these multiple beams
Rotate about 180 degrees relatively around the optical axis and
The interference fringes are generated by overlapping each other. That is,
Reflection, separation, rotation and superposition of light flux as one member
Has been achieved. Therefore, the concave mirror and the mirror
Compared to the configuration using a prism,
Stable interference because different disturbances hardly enter the number of light beams
Stripes B are obtained, and the tilt adjustment operation can be easily performed. Further, in this embodiment, the hemispherical lens 202 is
Used, the hemispherical lens 202 and the objective lens 150
Position adjustment, that is, alignment adjustment is easy.
You. That is, the hemispherical lens 202 has a spherical surface on the flat portion 202a.
Since there is a center of curvature of the portion 202b,
The hemispherical lens 2 can be obtained simply by adjusting the focal point to the plane portion 202a.
02, the position adjustment in the optical axis direction is completed.
The focal point of the lens 150 is the spherical portion 202b of the hemispherical lens 202.
Hemispherical lens 202 or
Is the objective lens 150 (ie, the magneto-optical disk drive 10).
0) may be adjusted in the direction perpendicular to the optical axis. The tilt adjustment of the objective lens 150 as described above
Is completed, this magneto-optical disk drive is carried to the next process.
It is sent and undergoes a predetermined assembly or inspection. Next, referring to FIG. 4 to FIG.
To the focusing / tracking mechanism of the
The mounting structure of the objective lens 150 will be described. As shown in FIG. 4, the objective lens 150 is
Supported by the support surface 152 of the lens support member 151.
I have. The support surface 152 is an annular inclined surface, and is one of conical surfaces.
Department. The objective lens 150 is, for example, a double-sided non-spherical
The surface is a single glass molded lens, the outer periphery of which
Flange 15 in contact with support surface 152 over the entire circumference
3 are formed. Now, the center line CL of the support surface 152 and the objective lens CL
The optical axis of the lens 150 matches, and the objective lens 150 and
Assume that bar glass A is parallel to each other. This state
From the state, the objective lens 150 receives the lateral force in the figure and is δ.
Displacement, the flange 153 moves along the support surface 152.
Due to the displacement, the objective lens 150 is indicated by a two-dot chain line.
As shown, the straight line M perpendicular to the support surface 152 and the center line CL
Rotate about the intersection C1 of. That is, the objective lens
The inclination 150 of the optical axis of the laser beam 150
Is displaced, and an image point shift ε occurs. This inclination θ occurs
As a result, coma aberration occurs, and interference fringes B (see FIG.
)). In addition, the tee
The number of interference fringes B, which are tilt fringes, increases,
The magnitude of the fringe distortion may be difficult to observe. did
Therefore, when adjusting the tilt of the objective lens 150, the tilt θ
It is desirable that the image point shift ε does not occur. Image point shift due to the inclination of the objective lens 150
In order for ε not to occur, the objective lens 150
In the case of parallel light, the rear principal point (image-side principal point) N2
All you have to do is rotate. However, as shown in FIG.
0 is displaced with respect to the support surface 152,
In order for the lens 150 to rotate around the rear principal point N2,
The support surface 1 passes through the contact point between the support surface 152 and the flange 153.
The intersection C1 between the straight line perpendicular to 52 and the optical axis is the rear principal point N
Must match 2. In this state, the objective lens
It is difficult to support the nozzle 150. So the above implementation
In the example, the image point shift ε occurred in the tilt adjustment process.
As a result, the number of interference fringes increases and the degree of coma
If it becomes difficult, the direction perpendicular to the optical axis of the objective lens
To displace the entire objective lens tilt detection device 200,
Or, change the hemispherical lens 202 (or the concave mirror 240).
Image point shift ε, that is, the number of interference fringes
Is reduced and coma is measured. Objective lens 15
The zero inclination adjustment step will be described later in detail. FIG. 5 shows a focusing and tracking machine.
Schematic of the mounting structure of the objective lens 150 to the structure 160
It is shown. Focusing and tracking mechanism (co
Actuator 160 is located below the magneto-optical disk K.
And the objective lens 150 is
The laser beam S is irradiated from below the hole K. Lens support member
(Fine actuator) 151 is formed by a spring 154
Is fixedly connected to the fixing member 155.
Is fixed to the moving member 157 by the screw 156.
You. That is, the lens support member 151 is attached to the fixing member 155.
On the other hand, the spring 154 can be displaced by bending,
The fixed member 155 and the moving member 157 are integrally connected.
I have. Thus, the objective lens 150 is a lens supporting member.
In addition to the configuration in which the inclination is adjusted with respect to 151,
The fixed member 155 and the moving member 157 are integrally connected.
Therefore, the fixing member 155 and the moving member 157 are
There is no need for a structure for inclining in the opposite direction.
Parts for connecting the moving member 157 and the moving member 157 in a tiltable manner
Can be deleted. Therefore, focusing
・ The tracking mechanism 160 can be significantly reduced in weight.
Speeds up tracking operation for magneto-optical disks
It is possible to do. FIG. 6 is a perspective view of a separated type magneto-optical disk drive.
Specific configuration of focusing / tracking mechanism 160
Is shown. The moving member 157 is, for example, a ball bearing.
Movably supported by rails 161 via
By displacing along this rail 161, light
It is positioned on a predetermined track of the magnetic disk. Move
The member 112 is provided with the mirror 112 (see FIG. 1).
The laser beam is directed through the mirror 112
Guided by the lens 150 and emitted from the objective lens 150
The emitted laser light is guided to a detection system (not shown). Fixed part
The material 155 is fixed to the moving member 157 via the connecting member 158.
Is defined. In FIG. 5, the connecting member 158 is omitted.
Have been. The spring 154 is perpendicular to the paper of FIG.
It extends in the direction. The lens support member 151 is fixed to the fixing member 1.
55 and the connecting member 158,
4 only. Lens support member 151
Has a hole 162 extending below the objective lens 150
Around the hole 162, a plurality of solenoids are provided.
A coil 163 is provided. The connecting member 158 includes
A magnet (not shown) corresponding to the solenoid coil 163
Z) is provided. As is well known in the art,
In the recording or reproducing operation of
Error signal and focusing error signal,
A predetermined one of the plurality of solenoid coils 163 is energized
Then, the lens support member 151 is slightly displaced and the objective lens is displaced.
150 and the focus position and track of the magneto-optical disk K.
The relative positional relationship with the lock position is adjusted. FIG. 7 shows the structure of the lens support member 151.
And a support surface 152 on which the objective lens 150 is mounted, and
The configuration in the vicinity is exaggerated. The annular support surface 152 is provided at the center axis of the hole 162.
Part of a conical surface with a vertex at the top, the lower the inner
Has been established. Projecting upward on the outer periphery of the support surface 152
Four projections 164 are formed. These protrusions
164 are provided at equal intervals, and are concave curves formed on the inner peripheral surface.
The surface is an adhesive reservoir 165. These adhesive reservoirs
165 is used for bonding the objective lens 150 and the support surface 152.
Extra adhesive that is not used is retained. Ie bonding
If the amount of the agent is large, it will expand due to the cured adhesive
However, the expanded portion is absorbed by the adhesive reservoir 165.
As a result, the adhesive enters the surface of the objective lens 150
Is prevented. Next, referring to FIG. 8 to FIG.
150 is placed on the support member 151 and
Apparatus and process for adjusting inclination of object lens 150
Will be described. FIG. 8 shows an optical disk device mounting device 500.
It is a top view which shows the schematic structure of. Mounting device 500
Has a pair of guide members 501 and 502 extending in parallel.
The guide members 501 and 502 are provided with a pallet 503.
Are provided movably. Magneto-optical disk drive 10
0 is placed on the pallet 503 in the first stage ST1
Is placed. Next, the pallet 503 is moved rightward in the figure.
Then, the operation stops at the second stage ST2. 2nd stage
The positioning device 300 as shown in FIG.
Is provided. This positioning device 300 is a rail
Positioning of lens support member 151 with respect to 161 (FIG. 6)
Is performed. The rail 161 is on the left in FIG.
The lens support member 151 extends in the right direction.
To stop at a predetermined position with respect to the
0 is provided with a stopper 301. This stopper
The connecting member 158 comes into contact with 301, thereby
The positioning support member 151 is roughly positioned. Next
The lock mechanism (not shown) is operated by
The tracking mechanism 160 (FIG. 6)
6) and the stopper 301 is turned upward.
It rolls and is released from the connecting member 158. In order to confirm the positioning state,
The microscope objective lens 30 is located above the tip of the
2 are provided. This microscope objective lens 302
Under the cylindrical holder 304 attached to the fixing plate 303
It is fixed to the end. On the other hand, at the upper end of the holder 304
Is provided with a CCD camera 305,
Is connected to a monitor 306. On the monitor 306
And the image of the lens support member 151 represents a predetermined position.
When the index does not match, the video and the index match
As shown, the position of the magneto-optical disk device 100 is adjusted horizontally.
Fine adjustment in the horizontal plane by the mechanism 505 (FIG. 8)
The position of the lens support member 151 is corrected. The horizontal position adjusting mechanism 505 includes a pallet 503.
And the magneto-optical disk drive 100
With respect to the pallet 503, the guide members 501 and 502 are flat.
In the X-axis direction and the Y-axis direction perpendicular to the X-axis.
Can be That is, the X-axis adjustment knob 506 is
By rotating it around, the magneto-optical disk drive 10
0 is finely adjusted in the X-axis direction, and the Y-axis adjustment knob 5
07 by rotating it around the axis,
The Y-axis direction position of the device 100 is finely adjusted. Next, the pallet 503, ie, the magneto-optical
Disk device 100 is shown along guide members 501 and 502.
8 and left at the third stage ST3
Stop. In the third stage ST3, as described below,
Then, the objective lens 150 is moved by the lens supply device 310.
Mounted on the lens support member 151, and
An adhesive is supplied between the object 151 and the objective lens 150. FIG. 10 is provided on the third stage ST3.
The lens supply device 310 is shown. The fixed plate 311
The cylindrical bearing member 312 is fixed, and the bearing member 312
The outer surface of the protruding portion from the fixing plate 311 has a conical cylindrical guide.
The part 313 is fitted. A circle inside the guide 313
A conical tapered surface 314 is formed.
13 are guided by four adhesive coating members 315
Provided at equal intervals around the axis of the part 313.
You. The application member 315 is an elongated tubular member,
The tube 316 is connected to the adhesive supply section 317.
Have been. Adhesive supply unit 317 supplies a fixed amount of adhesive
Is controlled. Insertion tube with suction tube 322 attached to the tip
321 is slidable on the inner wall surface 318 of the bearing member 312
Is fitted to. The insertion tube 321 is connected to the negative pressure source 325.
Due to this negative pressure, the objective lens
Lens 150 is held. Base 321a of insertion tube 321
Is slidably supported by a support tube 323.
The guide groove 323 a formed in the holding tube 323 has a base 32.
The bolt 324 fixed to 1a is engaged. Sand
The bolt 324 is guided by the guide groove 323a.
The insertion tube 321 is aligned with the support tube 323 in the axial direction.
It is movable with respect to. Support tube 323, insertion tube 321 and suction tube
322 is initially removed from bearing member 312
In this state, an unillustrated pair is attached to the tip of the suction tube 322.
The objective lens 150 is supplied from the object lens installation unit. So
Then, the objective lens 150 is held at the tip of the suction tube 322.
The insertion tube 321 and the suction tube 322
It is inserted into the material 312 and the guide 313. This insert
In operation, as shown in FIG.
The outer peripheral surface 154 is formed by the tapered surface 314 of the guide portion 313 and the
Guided by a circular hole 319 formed at the tip
, The diameter of the objective lens 150 with respect to the circular hole 319
Directional positioning, ie, centering, is performed. Insertion tube 3
21 and the adsorption tube 322 are further inserted, and the support tube 323 is inserted.
When the lower end contacts the upper end of the bearing member 312, the suction tube
The tip 322 or objective lens 150 is shown in FIG.
Project downward from the circular hole 319 of the guide portion 313
You. Next, the insertion tube 321 and the adsorption tube 322
Are the support tube 323, the bearing member 312, and the guide portion 313.
, And as shown in FIG.
Is placed on the support surface 152 of the support member 151. Soshi
Supply of negative pressure to the insertion tube 321 and the suction tube 322
At the same time, the suction tube 322 is
A little away from you. In this state, four adhesive coatings
The tip of the cloth member 315 is protruded from each support member 151.
This adhesive is applied to the center of the upper surface of
A predetermined amount of the adhesive G is supplied from the member 315 to the adhesive reservoir 165.
Supplied within. At this time, the adhesives G are arranged at regular intervals.
The adhesive G is supplied to the adhesive reservoir 165, so that the adhesive G is supported.
The entire outer peripheral edge of the objective lens 150 placed on the holding surface 152
Applied evenly over the body. In this example,
The adhesive G is an ultraviolet curing type. After the adhesive G is applied, the insertion tube 321 and the
The suction tube 322 is raised by a spring (not shown).
Away from the objective lens 150 to the position shown in FIG.
And stop. Thereafter, in the fourth stage ST4,
The tilt of the object lens 150 is adjusted, and the adhesive
G is cured and the objective lens 150 is placed on the support member 151.
Fixed. FIG. 13 and FIG.
It is a flowchart which shows. In step S10, the third stage ends.
And the magneto-optical disk transferred to the first stage ST1 again.
Into the locking device 100 as shown in FIGS.
The member 330 is attached. (See FIGS. 17 and 18)
See) The insertion member 330 is provided with a disc-shaped main body 331.
And a spindle motor in the center of the main body 331.
A hole 333 to be fitted to the output shaft 131 is formed.
You. The first arm 334 extends radially from the main body 331.
A cover glass A is attached to the tip of this arm 334.
Have been killed. That is, the cover glass A is a spindle
Installed parallel to the motor's disk contact surface
You. The second arm 335 has a first arm when viewed from above.
The arm 334 has a rectangular shape.
A support portion 336 extending downward is formed at the tip of 35.
The insertion prism 201 is attached to the support portion 336.
ing. That is, the insertion prism 201 is a cover glass
It is located below A. Note that the second arm 335
The tip and the support portion 336 are
Holes 337 and 338 for transmitting light are formed,
In addition, the inclination adjusting claw 401 is passed through the first arm 334.
339 are formed. In step S11, a magneto-optical disk drive
100 is transferred to the fourth stage ST4. 4th stay
The tilt ST4 is provided with a tilt adjustment device 400. Inclination
The adjustment device 400 is provided with an objective lens for the cover glass A.
For adjusting the inclination of the lens 400, and the hemispherical lens 2
02 and an inclination adjusting claw 401 are provided.
The flat part 202a of the hemispherical lens 202 is a cover glass.
Is parallel to the surface A. Note that the configuration of the tilt adjustment device 400
This will be described later. The magneto-optical disk drive 100 is tilted.
Fixed at a predetermined position below the adjusting device 400.
You. First, as shown in FIG.
Above the objective lens 150 and from the objective lens 150
Although it is at a relatively high position,
And moved close to the objective lens 150 as shown in FIG.
It is determined at a predetermined height position. At this time, the hemispherical lens 20
2. Positioning in the optical axis direction is performed.
401 is also set at a position close to the objective lens 150. In step S13, the alignment detecting section
215 (FIG. 1) and the point image (FIG. 3)
The point image D displayed on the measuring unit 214 becomes a clear spot
In other words, the focusing point of the objective lens 150 is
The objective lens so as to be on the flat portion 202a of the lens 202.
The position of the optical axis 150 (Z axis) is finely adjusted. This fine
The adjustment is performed by the alignment detection unit 215 and the point image observation unit 2
While observing each monitor of 14, the solenoid coil 16
3 (FIG. 7) is controlled, and only the objective lens 150 is
Move or show the entire magneto-optical disk drive 100
This is done by moving by no drive. In addition,
Instead of the fine adjustment of the objective lens 150, the hemispherical lens 2
02 may be finely adjusted in the optical axis direction. In step S14, the interference fringe observation unit 20
5. Point image observation unit 214 and alignment detection unit 215
The interference fringes B and the point images C and D (FIG. 3) displayed on the monitor
By observing, the focusing point of the objective lens 150 and the hemisphere
The center of curvature of the spherical portion 202b of the lens 202 matches.
Fine adjustment of the objective lens 150 in the direction perpendicular to the optical axis.
You. That is, fine adjustment is performed so that the point image C approaches the point image D.
You. This adjusts the horizontal position of the magneto-optical disk drive 100.
Small displacement in X-axis direction and Y-axis direction by mechanism 505
This is done by letting As a result, the interference fringe B
In addition to ma aberration, the appropriate number of tilt stripes (for example, 3)
In addition, the distortion of the interference fringes B, that is, the coma aberration becomes easy to see.
You. In addition, instead of fine adjustment of the objective lens 150,
Fine adjustment of the spherical lens 202 in the X-axis direction and the Y-axis direction
You may do so. In step S15, a tilt in an appropriate direction
Is selected and displayed on the monitor of the interference fringe observation unit 205.
Observing the interference fringes B, the objective lens 150
The magnitude of the coma aberration of the light beam emitted from is determined. This
Is not within the allowable value, that is, the interference fringe B
When the magnitude of the distortion is larger than the specified amount, the cover glass
If the degree of inclination of the objective lens 150 with respect to A is large,
Judgment and tilt as shown in the work after step S20
The tilt of the objective lens 150 is adjusted by the adjusting device 400
I do. In addition, the magnitude of the observed coma is smaller than a predetermined value.
Adjustment, the inclination of the objective lens 150 is not adjusted.
The operation after step S26 is performed. Here, the structure of the tilt adjusting device 400 is shown in FIG.
This will be described with reference to FIGS. Of the tilt adjustment device 400
A hemispherical lens holding member 404 is mounted on the lower surface of the main body 402.
It is attached. At the tip of the hemispherical lens holding member 404
A hole 403 extending in the vertical direction is formed.
A hemispherical lens 202 is fixed to the lower end. The four inclination adjusting pawls 401 are shown in FIG.
As you can see, hollow out the center of the disk 409 and mold
And extends toward the center of the disk 409. Disk 4
09 is attached to the lower surface of the hemispherical rotating member 410.
The center of the circular plate 409 is located inside the hemispherical lens 202.
are doing. The inclination adjusting claws 401 are provided at intervals of 90 degrees.
And its tip is bent below the hemispherical lens 202.
It is located in. Also, the tip of each tilt adjusting claw 401 is
The vicinity of the center of curvature of the hemispherical outer peripheral surface 411 of the moving member 410
And the state shown in FIG.
When adjusting the tilt, lower than the lower surface of the cover glass A
It is located in. In addition, one of the four inclination adjusting claws 401
The book is located in the opening 339 of the first arm 334.
You. The rotating member 410 includes a hemispherical lens holding member 40.
Notch 419 is formed to avoid interference with
You. The hemispherical outer peripheral surface 411 of the rotating member 410 is
Sliding into hemispherical recess 412 formed on the lower surface of main body 402
It is freely supported. The outer peripheral surface 411 and the concave
The center of curvature of the section 412 is located on the optical axis of the objective lens 150.
Near the center of rotation C1 of the objective lens 150 (see FIG. 4).
Beside. A connection extending in the up-down direction is connected to the rotation member 410.
A hole 413 is formed, and a cylindrical operation hole is formed in the connection hole 413.
Shaft 414 has been inserted. Set at the lower end of the operation shaft 414
The diameter of the flange 417 is larger than that of the connection hole 413.
And is engaged with the lower surface of the rotating member 410. Operation axis
414 projects upward from the connection hole 413,
Penetrates, and at the upper end of the operation shaft 414,
An annular pressing member 415 is fitted. This pressing member
A spring 416 is provided between the main body 415 and the main body 402.
The spring 416 is rotated by a rotating member via a pressing member 415.
The member 410 is constantly urged upward. The operation shaft 414 has a tilt adjusting claw 401
A parallel plane (transparent glass) 431 is provided in parallel with the reference plane.
Have been. This parallel plane 431 is
In step S12 of the tilt adjusting process, the tilt adjusting claw 4
It is used to confirm the initial position of the inclination of 01. The cylindrical wall 41 formed on the upper part of the main body 411
8, four handles 421 are screwed. Tubular
The wall 418 surrounds the pressing member 415, and each handle 418
The tip 422 of 421 projects into the inside of the cylindrical wall 418
It is in contact with the outer peripheral surface of the pressing member 415. Handle 42
1 about the axis, the handle 421 is rotated.
The amount of protrusion from the cylindrical wall 418 changes. That is, 2
While increasing the amount of protrusion of the two handles 421,
By reducing the amount of protrusion of the two handles 421
As a result, the pressing member 415 can be displaced in the horizontal direction.
As a result, the operating shaft 414 is tilted to rotate the rotating member 410.
Is rotationally displaced. Tilt due to the rotation of this rotating member 410
The tilt of the adjusting claw 401 changes, and the objective lens
The tilt of the nozzle 150 is adjusted. From the center of rotation of the rotating member 410, the handle 4
The distance between the contact portion 21 and the contact portion T between the pressing member 415 depends on the objective.
From the rotation center C1 of the lens 150 to the support surface 152 (FIG. 4)
, For example, about 10 times. did
Accordingly, the handle 421 is rotated to move in the axial direction.
When moved, the moving amount of the objective lens 150 is
1 is about 1/10 of the moving distance, and the handle 421 is operated.
Makes it possible to finely adjust the tilt of the objective lens 150 with high accuracy.
Can be. Note that, as shown in FIG.
Therefore, at the part corresponding to the position of each handle 421,
Each spring 423 is provided. These springs 423
Is locked to the outer periphery of the disk 409, for example, and
Is locked on the upper part of the main body 402. These four springs
The rotating member 410 is always urged upward by the lever 423.
As a result, the rotating member 410 stably stops in an inclined state.
Can be Referring again to FIG. 13 and FIG.
The step of adjusting the inclination of the lens 150 will be described. In step S20, first, the inclination adjusting claw 40
Tilt until 1 contacts the outer peripheral edge of objective lens 150
The adjusting device 400 is lowered by a very small amount. In step S21
Is turned by rotating the handle 421.
10 is turned, and the four tilt adjusting claws 401 are tilted. This
The direction and size of the inclination of the inclination adjusting claw 401
Determined based on interference fringes B observed in step S20
Is done. That is, for example, coma aberration
It appears that it appears in a direction inclined 45 degrees from the X-axis direction.
When it is determined from the interference fringe B, the tilt adjusting claw 401 is
Tilt along the direction. Thereby, the objective lens 150 is supported.
Displaced along the holding surface 152, the objective lens 150 and the support surface
The position of contact with the object 152 changes and the inclination of the objective lens 150 changes.
Changes. In step S22, the tilt adjustment device 400
Is raised by a very small amount, and the tilt adjusting claw 401 is attached to the objective lens.
Separated from 150. In step S21, the objective lens 150
As a result of tilting the objective lens as described with reference to FIG.
The condensing point C2 of 150 is displaced, and thereby the
To determine the magnitude of coma due to the increase in the number of tilt stripes
It may be difficult. Therefore, in step S23,
The number of tilt stripes of stripe B determines the magnitude of coma.
To determine if there is too much, if so, the horizontal position
By operating the adjusting mechanism 505, the magneto-optical disk
The apparatus 100, that is, the objective lens 150 is
The direction in which the number of tilt stripes decreases, that is, step S21
In the direction opposite to the direction in which the tilt adjusting claw 401 is tilted.
Move. Instead of this, the hemispherical lens 202 is
You may move it. In step S24, horizontal position adjustment
By adjusting the mechanism 505 by a very small amount, the coma aberration can be minimized.
Find the direction of greatness and see if coma is still present
Check. Step 25 is the same as step S15
In addition, the magnitude of coma is determined and the coma is within the allowable value.
If not, steps S20 to S24 are executed again. As a result of such processing, the coma aberration has an allowable value.
If it is reduced within the range, the process proceeds to step S26, and the parallel plane 4
Irradiates ultraviolet rays around the objective lens 150 through
Then, the adhesive G is cured. This allows the objective lens 15
0 is adhered to the support surface 152 of the lens support member 151
You. Next, at step S27, the inclination adjusting device
400 and the hemispherical lens holding member 404
The adjustment claw 401 is retracted from the objective lens 150. You
That is, the tilt adjusting device 400 is moved to the initial position shown in FIG.
Return. In step S28, the four handles 421
By rotating the tilt angle, the tilt angle of the tilt adjusting
Return to the initial horizontal position. This operation is not shown.
The light beam from the light source is applied to the parallel plane 431, and the reflected light beam
Done by adjusting so that it reaches the predetermined position
It is. Next, in step S29, the magneto-optical disk drive 1
00 is returned to the original position, that is, the first stage ST1. S
In step S30, the disk is inserted from the magneto-optical disk device 100.
Member 330, ie cover glass A and insertion prism 20
1 and remove. In step S31, the optical disk device
Remove the magneto-optical disk device 100 from the mounting device 500
remove. Thereby, the objective laser of the magneto-optical disk device 100 is
The adjustment of the inclination of the lens 150 ends. As described above, FIG. 13 and FIG.
According to the tilt adjustment method, the objective with respect to the support
Easily adjust the tilt of the lens 150 in real time with high accuracy
can do. In this tilt adjustment method, the first
Used by the objective lens inclination detecting device 200 (FIG. 1) of the embodiment.
However, the objective lens inclination detecting devices of the second to sixth embodiments
In the case of, the tilt adjustment is performed in the same manner. FIG. 21 shows another example of the tilt adjusting device 400.
It is something. In this example, unlike the example of FIG.
A stick 440 is provided instead of the dollar 421
You. The stick 440 extends in the radial direction of the rotating member 410.
And the lower end of the stick 440 is a half of the rotating member 410.
Fixed to the hole 441 formed on the spherical outer peripheral surface 411 side
I have. The main body 402 has a stick 440 inserted therethrough.
A path 442 is formed and the upper end of the stick 402
Project from the main body 402. The diameter of the passage 442 is
The stick 442 is larger than the
Swing around the center of curvature of the material 410
ing. Other configurations are the same as those in the example of FIG. In the example shown in FIG. 18, the handle 421 is
By rotating the tip 422 to change the amount of projection,
The rotation member 410 is configured to rotate.
You. Therefore, in order to remove coma, the objective lens 1
The direction of tilting 50 is different from the axial direction of handle 421
Operating all four handles 421
As a result, the rotating member 410 is tilted in a direction matching the coma.
Must be turned on. According to such an operation, the rotating portion
It is difficult to determine the rotation direction of the material 410 with high accuracy.
You. On the other hand, according to the configuration of FIG.
Tilt the stick 440 in the direction to rotate the member 410
The rotation direction of the rotation member 410 to the desired direction.
Direction can be matched exactly. FIG. 22 shows another example of the inclination adjusting claw 401.
The shape of the tip of the inclination adjusting claw 401 is shown in FIG.
18 and FIG. FIG. 17 and FIG.
In the example shown in FIG. 8, the tip of the tilt adjusting claw 401 is flat.
According to such a configuration, the inclination of the objective lens 150 is
In the adjustment (step S21 in FIG. 13), the objective lens
By pressing the upper surface of 150 downward, the spring 154 is pressed.
(FIG. 7) is bent, and the support member 151 (FIG. 7) moves downward.
Then, the objective lens 150 slides in the horizontal direction and smoothly
May not lean. On the other hand, in the configuration of FIG.
A notch 451 is formed at the tip of the claw 401, and
The notch 451 is located at the upper corner 159 of the outer peripheral portion of the objective lens 150.
Engages. Therefore, the tilt of the objective lens 150 is adjusted.
The support member 151 is moved downward by the claw 401.
When the objective lens 150 tries to slide sideways,
Since the corner 159 is engaged with the notch 451, the objective lens 1
Fifty lateral movements are restricted. Therefore, objective lens
And the support member 151 is a spring.
It returns to the original position by the restoring force of 154. FIGS. 23 to 25 show the objective lens 150 and
14 shows a modification of the lens support member 151. I mentioned earlier
As shown in FIG. 4, the objective lens 150 is
It is placed on a tapered support surface 152 of a member 151.
Therefore, during the tilt adjustment, during rotation of the objective lens 150,
The heart is above the objective lens 150,
Due to the tilt of the object lens 150, the focal point C2 is displaced.
As a result, an image point shift ε occurs, and the number of interference fringes B increases. This
In order to prevent the occurrence of the image point shift as shown in FIG.
Lower the support surface 152 (the focal point of the objective lens 150).
On the opposite side). That is,
With this configuration, the center of rotation of the objective lens 150 is
Can be set near the rear principal point N2 of the lens 150.
You. However, in this example, negative pressure or the like
The objective lens 150 must be constantly attracted from above
It is necessary. The objective lens 1 can also be constructed by the configuration shown in FIG.
The center of rotation of 50 can be set near the rear principal point N2.
Wear. In this example, the support surface 15 of the lens support member 151 is
2 is similar to the configuration of FIG.
The objective lens 150 is a tapered surface where the light spot side) spreads.
Around the optical axis of the objective lens 150
The holding ring 150a is formed in the shape of a circle.
The lower end is supported by the support surface 152. like this
The objective lens 150 is formed by, for example, injection molding.
Plastic lens. FIG. 25 shows the lower surface 150 of the objective lens 150.
b is supported by the tapered portion 151a of the lens support member 151.
Have been. According to this configuration, the objective lens 150 is
Can not tilt around the principal point N2, but during rotation
The center C3 is closer to the posterior principal point than in the example of FIG. [0080] As described above, according to the present invention, the objective lens
Can be easily adjusted with respect to the support member.
You.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing an objective lens tilt detecting device used in a tilt adjusting method according to one embodiment of the present invention. FIG. 2 is a diagram illustrating an optical path in an optical system including an objective lens, a cover glass, and a hemispherical lens. FIG. 3 is a diagram showing interference fringes and a point image displayed on each monitor of an interference fringe observation unit and a point image observation unit. FIG. 4 is a diagram showing occurrence of image point shift when an objective lens is tilted on a lens support member. FIG. 5 is a view schematically showing a structure for attaching an objective lens to a tracking mechanism. FIG. 6 is a sectional view showing a tracking mechanism. FIG. 7 is a perspective view showing a lens support member. FIG. 8 is a plan view showing a schematic configuration of an objective lens mounting device. FIG. 9 is a sectional view showing a positioning device. FIG. 10 is a sectional view showing a lens supply device. FIG. 11 is a diagram illustrating a guide action of an objective lens by a tapered surface of a guide unit. FIG. 12 is a diagram illustrating an operation of supplying an adhesive into an adhesive reservoir by an adhesive applying member. FIG. 13 is a flowchart showing a tilt adjustment step included in the tilt adjustment method according to one embodiment of the present invention. FIG. 14 is a flowchart showing a tilt adjustment step included in the tilt adjustment method according to one embodiment of the present invention. FIG. 15 is a plan view showing an insertion member. FIG. 16 is a sectional view showing an insertion member. FIG. 17 is a cross-sectional view showing a state where the tilt adjustment device is at an initial position. FIG. 18 is a cross-sectional view showing a state where the tilt of the objective lens is being adjusted by the tilt adjusting device. FIG. 19 is a sectional view showing the inclination adjusting claw, taken along the line PP of FIG. 18; FIG. 20 is a view of the tilt adjustment device as viewed from above. FIG. 21 is a cross-sectional view showing another example of the tilt adjusting device. FIG. 22 is a diagram showing another example of the inclination adjusting claw. FIG. 23 is a diagram showing a first modification of the objective lens. FIG. 24 is a diagram showing a second modification of the objective lens. FIG. 25 is a diagram showing a third modification of the objective lens. [Description of Signs] 150 Objective lens 151 Support member 300 Positioning device 310 Lens supply device 400 Tilt adjusting device B Interference fringe G Adhesive

──────────────────────────────────────────────────続 き Continuation of the front page (72) Katsuyoshi Hayashi 2-36-9 Maeno-cho, Itabashi-ku, Tokyo Asahi Optical Industry Co., Ltd. (56) References JP-A-4-50147 (JP, A) JP-A-64-46241 (JP, A) JP-A-3-119524 (JP, A) JP-A-4-501191 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B 7 / 08-7/22 G02B 7/00-7/02 B25J 15/00-15/12

Claims (1)

(57) [Claims] 1. An adsorption tube for adsorbing an objective lens, a circular hole into which the adsorption tube can be inserted, and a circular hole conforming to the outer shape of the objective lens, and a tapered surface continuous with the circular hole. But the inner wall
A guide member formed on the surface , wherein the suction tube is inserted into the guide member,
The outer circumferential surface of the objective lens is guided by the circular hole and the tapered surface, the positioning device of the objective lens, wherein the positioning with respect to the suction pipe of the objective lens is performed.