JP2001202649A - Optical lens, optical device and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To constitute an optical lens in such a manner that sufficient strength of adhesion to a lens holder may be obtained in a sufficiently small region. SOLUTION: The optical lens arranged to face a recording medium is constituted by forming a sand texture rough surface region 9 in part of a circumferential direction on the outer periphery on the surface side of an objective lens 2 facing the recording medium. The strength of adhesion of the optical lens to the lens holder is enhanced by the presence of this sand texture rough surface region 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical lens, an optical device and a method of manufacturing the same, and more particularly, to an optical lens disposed to face a recording medium, and an optical lens having the optical lens and capable of optical recording or An optical device that performs at least one of optical reproduction, a so-called optical pickup device,
The present invention relates to these manufacturing methods.

[0002]

2. Description of the Related Art In recent years, in an optical apparatus having an optical lens for performing optical recording and reproduction on a recording medium such as an optical disk, that is, an optical pickup, the optical lens or a slider mounted with the optical lens is mounted on the recording medium at 200 nm or less. A so-called near-field optical disk device has been proposed in which the distance is reduced to 100 nm or less.

As described above, as the distance between the optical disk, ie, the recording medium, and the optical lens is reduced,
In the control of the focal position, it is required that the unremaining amount of the control be a small numerical value. In addition, in order to reduce the remaining amount of the focus position control and to prevent collision between the recording medium and the optical lens, the servo band of the servo position is higher than the servo band of the focus position in the conventional ordinary optical pickup device. Bandwidth is being requested. As described above, in order to reduce the remaining amount of the focus position control and to increase the servo band as compared with the related art, it is necessary to reduce the size of the optical lens, that is, to reduce the diameter.

On the other hand, for example, an optical lens in an optical pickup device often adopts a mode in which the optical lens is fixed to a lens holding member, that is, a lens holder via an adhesive disposed on an outer periphery thereof. In this case, as described above, when a small-diameter optical lens is used, the area of adhesion to the lens holder is reduced. In particular, the small-diameter optical lens has a spherical surface such as a SIL (Solid Immersion Lens), and in the case of a high-precision optical lens manufactured by a polishing process or an optical lens formed by a glass mold, the outer peripheral surface is an optical lens. It is not easy to sufficiently increase the bonding strength here because the surface is finished to a smooth surface.

Further, the numerical aperture N.sub. A. Is greater than or equal to 1, since almost the entire outer peripheral surface of the small diameter SIL becomes an optical path portion,
The area that can be used for bonding becomes smaller, resulting in a further decrease in bonding strength. In addition, the adhesive is not allowed to protrude from the adhesive area on the outer periphery of the optical lens to both the surface facing the front recording medium and the rear.
In other words, the distance between the recording medium and the front is extremely small, so that the adhesive hinders the setting of the distance between the recording medium and the rear, which hinders the optical path of the spherical surface of the optical lens. Therefore, it is necessary to avoid the protrusion of the adhesive to the front and the rear.

[0006] For example, specifically, the N.D. A. Is 1.5, the refractive index is 1.83, and the diameter φ is 1 mm.
Using a Supersphere (super hemisphere) type SIL, N.I. A. When a lens having a value of 0.45 is used, the area to which the adhesive is applied is actually about 250 mm.
Only a region having a width of about μm can be obtained. Moreover,
As described above, since this adhesive is not allowed to protrude on either of the front and rear sides of this region, 50 μm on each of the front and rear sides as an allowable position margin.
As a result, only a portion having a width of about 150 μm is obtained as the bonding area, and a problem occurs in the bonding strength.

A method for obtaining information on a focal position in an optical pickup is a method for detecting a capacitance between an electrode formed on a main surface of an optical lens on a side facing a recording medium and a recording medium. In this case, it is possible to increase the area of the electrode material formed on the main surface of the optical lens facing the recording medium as much as possible, so that the value of the capacitance can be increased and more accurate information can be obtained. Therefore, there is a demand to increase the electrode area as much as possible.

[0008]

According to the present invention, even when an optical lens miniaturized as described above is used, it is possible to obtain a sufficient adhesive strength to a lens holder in a sufficiently narrow region. It can be so.

[0009]

SUMMARY OF THE INVENTION An optical lens according to the present invention is an optical lens arranged to face a recording medium.
A configuration in which a sandy ground surface region is formed in a part of the circumferential direction.

An optical device according to the present invention has an optical lens disposed to face a recording medium, and performs at least one of optical recording and optical reproduction on the recording medium. A configuration in which a rough sand surface region is formed on a part of the outer periphery on which the adhesive of the optical lens is disposed at a part in the circumferential direction, which is fixed to the lens holder via an adhesive on the outer periphery on the side facing the recording medium. And

The method of manufacturing an optical lens according to the present invention is the above-described method of manufacturing an optical lens, wherein a part of the outer periphery of the optical lens on the side facing the recording medium in the circumferential direction includes:
The objective optical lens is manufactured by adopting a process of forming a rough surface region by selectively performing a sand treatment.

The method of manufacturing an optical device according to the present invention is the method of manufacturing an optical device according to the above-described configuration of the present invention, wherein a part of the outer periphery of the optical lens facing the recording medium in the circumferential direction is partially covered with sand. A step of selectively performing a process to form a rough surface area, and fixing an outer periphery of the optical lens facing the recording medium to the lens holder holding the optical lens via an adhesive over the rough surface area. And obtaining the desired optical device.

According to the above-described optical lens of the present invention, a rough sand surface region is provided at a part of the outer peripheral portion thereof. Adhesive bonding between the partially present outer peripheral portion and the lens holder with an adhesive increases the bonding surface area in the rough sandy surface region, and increases the bonding strength due to the penetration of the adhesive. The effect can be obtained.

[0014]

FIG. 1 is a schematic cross-sectional view of an essential part of an embodiment of an optical device according to the present invention using an optical lens 2 according to the present invention, and FIGS. It is the side view and front view of the lens 2. FIG. However, the invention is not limited to this embodiment and example.

In this embodiment, optical recording and / or optical reproduction is performed by condensing and irradiating a recording medium 1 such as an optical disk or a phase-change optical disk with a light or a laser beam L. This is a case where an optical device is configured as a pickup device for performing the operation. The optical lens 2 has one flat surface, that is, a surface 2a facing the recording medium 1, and a flat surface, and the other main surface, that is, a light source (not shown) side of the laser beam L, has a spherical surface 2b. The facing surface 2 and the spherical surface 2b are formed as, for example, an optically polished surface.

The optical lens system in this example is, for example, A. 1.5, refractive index 1.83, diameter 1mm
A hemispherical optical lens 2 of Supersphere type SIL,
N. A. Is a so-called two-group lens configuration in combination with the objective lens 3 of 0.45.

The optical lens system is mechanically held by a lens holder 4, and minute position control is performed by an electromagnetic actuator 5 having, for example, a focus actuator 5a for performing focusing control and a tracking actuator 5b for performing tracking control. You.

The laser beam L is condensed on the recording medium 1 through this two-unit lens system, and optical recording and / or reproduction is performed.

In this case, the interval between the optical lens 2 and the recording medium 1 facing the optical lens 2 is selected to be a small interval of 200 nm or less. With this two-group lens configuration, the numerical aperture N.D. A. > 1 enables near-field (near-field) optical recording and reproduction.

In the example shown in FIG. 1, the portion of the surface 2a facing the recording medium 1 serving as an optical path, that is, the optical lens 2
Is formed as a convex portion 6, and the top surface of the convex portion 6 and the recording medium 1 are selected at the above-mentioned required narrow interval.

For fixing the optical lens 2 to the lens holder 4, for example, the optical lens 2 is disposed in a center hole formed in the lens holder 4, and an adhesive 8 is provided between the periphery of the optical lens 2 and the lens holder 4. Is performed by intervening. The substantial bonding area of the optical lens 2 with the lens holder 4 is small. This is the optical lens 2 and the surface 2a facing the recording medium 1.
As described above, the interval between the recording medium 1 and the recording medium 1 is set to be extremely small, so that the adhesive 8
In addition, it is necessary to prevent the spherical surface 2b from protruding from the rear surface 2a, and the spherical surface 2b on the rear side actually has an optical path in almost all areas particularly when the size is reduced. The area provided for the bonding in the above becomes a very small part around the surface facing the recording medium 1.

In the present invention, the optical lens 2
On the outer periphery on the side facing the recording medium 1 on the side facing the recording medium 1, a part in the circumferential direction, for example, as shown in FIG. To
Alternatively, for example, a surface roughness R formed by sand blasting by sandblasting, powder beam etching, or the like.
a (the center average roughness defined by JISB060) is about 24 μm to 100 μm, and the sandy ground surface area 9 in the sandy ground state is formed.

The fixing of the optical lens 2 to the lens holder 4 by the adhesive 8 is performed by disposing the adhesive 8 over the rough sand surface region 9. That is, on the outer peripheral portion of the optical lens 2 where the adhesive 8 is attached,
For example, by forming a rough sand surface region 9 at four locations in the illustrated example at a plurality of locations while maintaining a required interval, the adhesive strength by the adhesive 8 can be increased.

The pickup device according to the present invention constituted by the optical lens 2 having the above-described rough sand surface region 9 according to the present invention, that is, the optical device has the rough sand region 9.
In this configuration, the adhesive 8 is fixed to the lens holder 4 over the entire surface of the lens holder 4. Thus, an effect of increasing the adhesion area of the adhesive due to the sand and increasing the adhesive strength due to the penetration of the adhesive is obtained. be able to.

Therefore, the adhesive 8 does not protrude from the recording medium 1 to the opposing surface 2a set at a small interval, and is formed in a limited area without protruding to a portion of the spherical surface 2b which becomes an optical path. Further, the peripheral surface of the optical lens to which the adhesive 8 is applied is a front part of the spherical surface 2b, and this part also has an optically polished surface, so that the adhesive strength is low, but this is hindered. In order to prevent this, the adhesive strength of the optical lens 2 to the lens holder 4 can be ensured in spite of the area limited to a very small part around the surface 2a facing the recording medium 1. . Specifically, in the above-described configuration, by providing four sand ground rough surface regions 9, the position margin of the application region of the adhesive 8 is set to 50 μm on both sides and the width of the adhesive region is set to approximately 150 μm. And sufficient adhesive strength could be obtained.

Therefore, as a result, the size of the optical lens 2 can be reduced, so that the remaining amount of the focus position control can be reduced to a small value, and the servo band can be extended as compared with the conventional case. In addition, since a sufficient coating margin can be secured, the risk of the adhesive 8 protruding into the optical path on the surface 2a facing the recording medium 1 and the spherical surface 2b described above is reduced, and the manufacturing stability is thereby reduced. The yield is improved. In addition, the optical lens 2 can be prevented from being misaligned or falling off, and a highly reliable optical device can be configured.

Further, in the present invention, the rough sand surface region 9 is not formed annularly over the entire circumferential direction of the optical lens 2 but is formed at, for example, four circumferential portions. The rough sand surface region 9 can be used as a mark for positioning. In particular, the facing surface 2a
And the spherical surface 2b and the ridge line 2c at the boundary, the sandy rough surface region 9
There is a part where there is no, and this ridge line is located on the facing surface 2
Since the observation can be performed from the side a, the center position of the optical lens 2 can be observed in a state where the optical lens 2 is fixed to the lens holder 4. Therefore, in particular, in the vicinity of the center of the opposing surface 2a serving as an optical path, inspection for a flaw or the like that impairs the function and characteristics of the optical lens can be easily and reliably performed.

In particular, as in the above-described configuration, the condensing lens of the optical system is formed by combining the objective lens and the SIL.
In the case of a group lens, since optical energy is concentrated on the above-described main surface of the SIL on the recording medium side, the influence of scratches on the surface of the optical lens becomes important. Therefore, in a general optical lens, it is only necessary to judge whether or not there is a defective portion such as a scratch having a problematic size by an appearance inspection. However, two groups combining the objective lens and the SIL are required. Since the main surface of the SIL in the case of a lens, particularly the SIL in the near-field optical system, which faces the recording medium, has a narrow optical path, the presence of a scratch in this optical path is a serious problem. Therefore, it is necessary to perform a focused inspection in this optical path portion. According to the present invention, this inspection is facilitated for the above-described reason.

FIG. 3 is a schematic sectional view of a main part of another example of the optical apparatus of the present invention, FIG. 4 is a front view thereof, and FIGS. 5A and 5B are side and front views of the optical lens 2, respectively. It is. In this case, a convex portion 6 is formed in a central portion of the main surface of the optical lens 2 on the side facing the recording medium 1 and substantially serving as an optical path.
Is formed, and the top surface 6a is a smooth optical surface. According to this configuration, the distance between the recording medium 1 and the optical lens 2 can be reduced. Further, in this example, a case is proposed in which the distance between the optical lens and the recording medium is detected by detecting the capacitance, which is proposed in Japanese Patent Application No. 10-199956 by the present applicant. That is, in this case, an electrode 7 is formed on the surface of the optical lens 2 facing the recording medium 1 at a position receding from the convex portion 6 so as to surround the convex portion 6 and adhere around the convex portion 6. This is performed by detecting the capacitance between the recording medium 1 facing the recording medium 1 such as the phase-change recording layer 1A or the reflection film 1B made of Al, for example.

Further, in this configuration, the terminals can be led out from the electrode 7 by forming the lens holder 4 from a conductive material. In this case, the electrical connection between the electrode 7 and the lens holder 4 can be made by covering the connection electrode 17 across the electrode 7 and the lens holder 4.

The electrode 7 and its connection electrode 17 are, for example, a metal material mainly containing molybdenum (Mo), a metal material mainly containing chromium (Cr), and an electrode mainly containing indium tin oxide (ITO). It can be composed of materials. 3 to 5, parts corresponding to those in FIGS. 1 and 2 are denoted by the same reference numerals, and redundant description is omitted.

According to this configuration, the facing surface 2a is
Since the adhesive 8 is allowed to protrude at the retracted position at the retracted position, the detection accuracy by the capacitance can be increased as the area of the electrode 7 increases, so that the electrode area is increased as much as possible. It is desired that the bonding area be reduced even in this configuration. Therefore, also in this configuration, by providing the rough sand surface region 9, the adhesive strength can be improved in the same manner as described above, and the same effect as described above can be obtained.

Next, an example of a method for manufacturing an optical lens and an optical device according to the present invention will be described. FIG. 6 is a flowchart of the manufacturing method. First, as shown in FIG. 7 to FIG. 10, which are schematic cross-sectional views in each step, the convex portions 6 in the optical lens 2 are manufactured.

For this purpose, as shown in FIG. 7, a carrier 21 is prepared, and a lens (SIL) body 22 is mounted thereon. This element body 22 is polished to a required spherical surface of high precision, for example, 1 mm in diameter, with a high optical polishing surface, and forms a flat surface 6a of the above-mentioned convex portion 6 in the optical lens 2 finally obtained. Surface 22a
And a hemisphere having a spherical surface 2b, in this example, a hemisphere larger than a regular hemisphere.

The carrier 21 has, for example, a plate shape, and has an opening in one main surface 21a, and an insertion hole 23 for inserting and holding the lens body 22 is formed. The insertion hole 23 is formed, for example, in a conical shape, and is inserted while protecting the spherical surface 2b of the lens body 22 from the large-diameter side opening end. At this time, the lens element body 22 is disposed and fixed and held so that the smooth flat surface 22a thereof is substantially parallel to the main surface 21a of the carrier 21 or slightly protrudes from the main surface 21a. This fixing is performed by developing the resist, which will be described later, or by using the lens body 22.
The insertion hole 23 is filled with a fixing agent 24 made of, for example, a novolak resin having resistance to an etching solution or the like,
It can be performed by performing a degree of curing heat treatment.

Next, the projections 6 are formed by polishing and cutting such as a photosensitive resist forming step, a developing step, and ion milling. That is, first, as shown in FIG.
A resist 25 is formed on the main surface 21a of the carrier 21 so as to cover the entire flat surface 22a of the lens body 22. The resist 25 is formed, for example, by coating a negative photosensitive dry film (for example, dry film N-815 manufactured by Hitachi Chemical Co., Ltd.) having a thickness of 15 μm on the main surface 21 of the carrier 21.
A can be formed by laminating the entire surface of the lens body 22 over the smooth plane 22a of the lens body 22, that is, by laminating. By using a dry film having such a thickness, a gap can be formed even when a slight step, for example, a step of several μm occurs between the main surface 21a of the carrier 21 and the smooth plane 22a of the lens body 22. The resist 25 can be formed in close contact with each surface without performing.

The resist 25 is subjected to pattern exposure, that is, exposure hardening only to the portion where the convex portion 6 is finally formed, and then to development processing using, for example, a 0.5% aqueous sodium carbonate solution. As shown in FIG. 9, a mask 26 having a diameter of, for example, about 20 μm to 50 μm is accurately formed. At this time, the fixing agent 24 made of the novolak resin subjected to the curing treatment at 120 ° C.
To the developer described above.

Using the mask 26 thus formed as a mask for ion milling, as shown in FIG. 10, the smooth plane 22a of the lens body 22 is not covered with the mask 26 by ion milling according to a known technique. Is physically etched to form a concave portion 22c, and a portion surrounded by the concave portion 22c has a height of, for example, 2 μm.
The above-mentioned convex portions 6 can be formed. In this case, as described above, by forming the mask 26 from a photosensitive film as thick as 15 μm, the function holding thickness as a mask can be sufficiently maintained by this ion milling. As described above, the protrusion 6 having a height of about 2 μm or more can be formed.

Thereafter, the mask 26 is peeled off. The stripping of the mask 26 can be performed using, for example, a stripping solution of 2.38% tetramethylammonium hydroxide. In this case, the mask 26 made of the dry film described above can be removed without dissolving the cured novolak resin of the fixing agent 24.

Next, a sand ground processing is performed to form a sand ground rough surface area 9. In this sand treatment, for example, as shown in FIG.
A mask 27 that can withstand the next sand processing is formed so as to cover portions other than the portion where the electrode 7 is formed.

Thereafter, for example, through the opening of the mask 27,
Powder using SiC powder of about # 600 to # 2000
-Etching or Al of about # 100- # 800
_TwoO _ThreeFIG. 12 shows the results of sandblasting using powder or the like.
As shown, a rough sandy region 9 is formed, and then the mask 2
7 is removed.

Thereafter, an electrode material layer constituting the electrode 7, M
o A single metal layer is entirely formed by sputtering, vapor deposition or the like, patterned by photolithography to form an electrode 7, the optical lens 2 is removed from the carrier 21, and the optical lens 2 is bonded to the lens holder 4. . The optical lens 2 can be removed from the carrier 21 by dissolving the fixing agent 24 with a solvent of the fixing agent 24, for example, a solvent of a novolak resin, for example, acetone, without damaging the optical lens 2 at all. The optical lens 2 is fixed to the central hole of the lens holder 4 with an epoxy-based adhesive 8, for example.

Thereafter, the lens holder 4 and
A connection electrode 17 for connection to the electrode 7 is formed. As shown in FIG. 13, the connection electrode 17 is formed by, for example, holding the lens holder 4 on a holding jig 41 having an open front, and forming, at the opening end, a portion facing the convex portion 6 of the optical lens 2. A shield 42 having, for example, a pair of through-holes 42b facing the lens holder 4 across the lens holder 4 is disposed on both sides of the shield 102a. Through, the electrode material is formed into a film by flying such as sputtering or vacuum evaporation. The electrode material forming the connection electrode 17 can also be formed of the same material as the electrode 7.

By doing so, as shown in FIG.
The connection electrode 1 is formed by an electrode material flying through the through hole 42.
7 is formed. Thereafter, the lens holder 4 is removed from the holding jig 41, and as shown in FIG. 3, the objective lens 3 is aligned with the optical lens 2 in a predetermined positional relationship, and the objective lens 3 is bonded to the lens holder 4.

Then, the lens holder 4 is incorporated in the electromagnetic actuator 5 described with reference to FIG. Thus, the optical device according to the present invention, that is, the optical pickup device can be configured.

In the above-described example, the electrode 7 and the connection electrode 17 are made of Mo alone. However, for example, Cr alone or these elements are made of, for example, S for preventing crystallization.
For example, the electrode material may be formed by adding i, Ti, Ta, W, etc. to, for example, 1% by weight or less.

In addition, ITO can be used as an electrode material for forming the electrode 7 and the connection electrode 17. In this case, if an etching solution dedicated to ITO is used as the etching solution, the glass material of the optical lens 2 may be damaged. Can be done without.

Actually, after the step of forming the projections 6, the step of forming the electrodes 7, and the step of forming the rough sandy surface area 9, the optical lens 2 is further mounted on the lens holder 4. After the fixing step, after the step of forming the connection electrode 17, after the step of incorporating the objective lens 3, and after the step of incorporating the actuator 5, each inspection operation is performed.

In the above-described optical device, the driving means of the optical lens has a configuration using an electromagnetic actuator, but the present invention is not limited to this embodiment.

The optical apparatus according to the present invention is not limited to the case where the lens system has a two-group lens structure by combining the objective lens 3 and the optical lens 2, and the electrode system is provided on the surface facing the recording medium. May be formed by another optical lens system configuration in which is formed.

Further, in the above-described example, the distance between the recording medium 1 and the optical lens 2 is set to 200 nm or less. However, even in the configuration where the distance exceeds 200 nm, a reduction in the bonding area is required. In this case, the same effect can be obtained by applying the present invention.

In the above example, the optical lens 2 is
Although the case of the SIL configuration made up of a hemispherical lens is illustrated, other various lens configurations can be used, and the present invention is not limited to the case where the lens surface is formed by a polished surface. The same effect can be obtained when providing the optical lens formed by

[0053]

As described above, according to the present invention, the optical lens 2 is formed with the rough sand surface region 9 and the optical lens 2 having the rough sand region 9 constitutes an optical device. The fixing of the optical lens to the lens holder 4 is performed by bonding the lens to the lens holder 4 with the adhesive 8 over the rough sand surface region 9. The effect of increasing the adhesive strength can be obtained by increasing the contact area and inserting the adhesive.

Therefore, the recording is performed so that it does not protrude from the opposing surface 2a and that the adhesive strength is low due to the optically polished surface of the spherical surface 2b and the optical path is not hindered. The adhesive strength of the optical lens 2 to the lens holder 4 can be ensured, despite the fact that a very limited area around the opposing surface 2a with the medium 1 is used as the adhesive surface.

Therefore, as a result, the size of the optical lens 2 can be further reduced, so that the remaining amount of the focus position control can be reduced to a small value, and the servo band can be extended as compared with the conventional case. . In addition, since a sufficient coating margin can be secured, the risk of the adhesive 8 protruding into the optical path of the lens is reduced, thereby improving the manufacturing stability and the yield. In addition, the optical lens 2 can be prevented from being misaligned or falling off, and a highly reliable optical device can be configured.

The sandy rough surface area 9 is formed by the optical lens 2.
Is not formed in an annular shape over the entire area in the circumferential direction.
Since it is formed in a part of the location in the circumferential direction, the rough sand surface area 9 can be used as a mark for alignment. In particular, in the ridge line 2c at the boundary between the facing surface 2a and the spherical surface 2b, there is a portion where the rough sand surface region 9 does not exist, and the position of the ridge line can be observed from the facing surface 2a side. In the state
The center position of the optical lens 2 can be observed. Therefore, especially in the vicinity of the center of the opposing surface 2a which is an optical path, inspection for a flaw or the like which impairs the function and characteristics of the optical lens can be easily and reliably performed. Therefore, many industrially important effects such as a high yield and a highly reliable optical device can be achieved.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an example of an optical device according to the present invention using an optical lens according to the present invention.

FIGS. 2A and 2B are a side view and a bottom view, respectively, showing a part of an example of an optical lens according to the present invention in cross section.

FIG. 3 is a schematic sectional view of another example of the optical device according to the present invention using the optical lens according to the present invention.

FIG. 4 is a front view of another example of the optical device according to the present invention using the optical lens according to the present invention.

FIGS. 5A and 5B are a side view and a bottom view, respectively, showing a part of an example of the optical lens according to the present invention in cross section.

FIG. 6 is a process flowchart of an example of a method for manufacturing an optical lens and a method for manufacturing an optical device according to the present invention.

FIG. 7 is a cross-sectional view in one step of an example of a method for manufacturing an optical lens according to the present invention.

FIG. 8 is a cross-sectional view illustrating one step of an example of a method for manufacturing an optical lens according to the present invention.

FIG. 9 is a cross-sectional view illustrating one step of an example of a method for manufacturing an optical lens according to the present invention.

FIG. 10 is a cross-sectional view illustrating one step of an example of a method for manufacturing an optical lens according to the present invention.

FIG. 11 is a cross-sectional view illustrating one step of an example of a method for manufacturing an optical lens according to the present invention.

FIG. 12 is a cross-sectional view in one step of an example of the method for manufacturing an optical lens according to the present invention.

FIG. 13 is a cross-sectional view illustrating one step of an example of the method for manufacturing an optical device according to the present invention.

FIG. 14 is a cross-sectional view illustrating one step of an example of the method for manufacturing an optical device according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Optical recording medium, 2 ... Optical lens, 2a ...
Opposite surface, 2b ... spherical surface, 3 ... objective lens, 4 ...
.Lens holder, 5 ... electromagnetic actuator, 5a
..Focus actuators, 5b ... tracking actuators, 6 ... projections, 6a ... top surfaces, 7
... Electrode, 8 ... Adhesive, 9 ... Rough surface (sand) area, 17 ... Connection electrode, 21 ... Carrier, 22
..Lens element body, 22c recess, 23 insertion hole, 24 fixing agent, 25 resist, 26, 2
7 ... Mask

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kiyoshi Osato F-term (reference) 2H044 AA02 AB02 5D119 AA01 AA35 AA38 JA44 NA05 6-35 Kita Shinagawa, Shinagawa-ku, Tokyo

Claims (20)

[Claims] 1. An optical lens disposed to face a recording medium, wherein a rough sand area is formed in a part of an outer periphery of the optical lens on a side facing the recording medium in a circumferential direction. An optical lens characterized in that: 2. The optical lens according to claim 1, wherein a convex portion is formed on a main surface of the optical lens facing the recording medium.
An optical lens according to claim 1. 3. The optical lens according to claim 1, wherein the optical lens is a hemispherical lens. 4. The optical lens according to claim 1, wherein said optical lens is one of condensing lenses constituting a second group lens. 5. The optical lens according to claim 1, wherein an electrode is formed on a main surface of the optical lens facing the recording medium.
An optical lens according to claim 1. 6. An optical device having an optical lens disposed to face a recording medium and performing at least one of optical recording and optical reproduction on the recording medium, wherein the optical lens is an optical lens. Is fixed to the lens holder via an adhesive at the outer periphery on the side facing the recording medium, and a rough sand surface region is formed on a part of the outer periphery of the optical lens where the adhesive is disposed in the circumferential direction. An optical device, comprising: 7. The optical lens according to claim 6, wherein a convex portion is formed on a main surface of the optical lens facing the recording medium.
An optical device according to claim 1. 8. The optical device according to claim 6, wherein the optical lens is a hemispherical lens. 9. The optical device according to claim 6, wherein the optical lens is one of condensing lenses constituting a second group lens. 10. The optical device according to claim 6, wherein an electrode is formed on a main surface of the optical lens facing the recording medium. 11. A method of manufacturing an optical lens arranged to face a recording medium, wherein a sandy area treatment is selectively applied to a part of the outer periphery of the optical lens on the side facing the recording medium in the circumferential direction. Performing a step of forming a rough sandy surface region by performing the method. 12. The method of manufacturing an optical lens according to claim 11, wherein a convex portion is formed on a main surface of the optical lens facing a recording medium. 13. The method according to claim 11, wherein the optical lens is a hemispherical lens. 14. The optical system according to claim 1, wherein the optical lens is one of condensing lenses constituting a second group lens.
2. The method for manufacturing an optical lens according to item 1. 15. The method of manufacturing an optical lens according to claim 11, wherein an electrode is formed on a main surface of the optical lens facing the recording medium. 16. A method for manufacturing an optical device having an optical lens arranged to face a recording medium and performing at least one of optical recording and optical reproduction on the recording medium, the method comprising: Of the outer periphery on the side facing the recording medium,
Forming a rough surface region by selectively performing sand processing on a part of the optical lens in a circumferential direction; and forming an optical lens on the opposing surface side of the optical lens through an adhesive over the rough surface region. Fixing the lens to a lens holder for holding the optical device. 17. The method according to claim 16, wherein a convex portion is formed on a main surface of the optical lens facing the recording medium. 18. The method according to claim 16, wherein the optical lens is a hemispherical lens. 19. The optical system according to claim 1, wherein the optical lens is one of condensing lenses constituting a second group lens.
7. The method for manufacturing an optical device according to item 6. 20. The method according to claim 16, wherein an electrode is formed on a main surface of the optical lens facing the recording medium.