JPH08203111A - Optical pickup device - Google Patents

Abstract

PURPOSE: To obtain an optical pickup device capable of shutting out the oxygen and moisture from the outside world and preventing the moisture absorption and oxidation deterioration of the photodetectors in an internal space. CONSTITUTION: This optical pickup device includes an objective lens which focuses the luminous flux from a light source 1 onto a disk, the photodetectors 4 which detect the reflected light from this disk, diffraction gratings 5, 6 which are disposed in the luminous flux from the light source 1 to the disk, a holder which holds this objective lens, a substrate 11 which supports the light source 1 and the photodetectors 4 and a holding member 8 which holds the substrate 11 and the diffraction gratings 5, 6. The light source 1 and the photodetectors 4 as well as the substrate 11 for supporting the light source 1 and the photodetectors 4 are housed in the inside space formed out of the diffraction gratings 5, 6, the holding member 8 and an adhesive 9 for joining the diffraction gratings 5, 6 to this holding member 8. A part of the diffraction gratings 5, 6 facing the inside space and/or a part of the holding member 8 is coated with a resin film 10 having a gas barrier property.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup device used for recording and reproducing information on an optical disc (hereinafter referred to as "disc").

[0002]

2. Description of the Related Art In recent years, various techniques of an optical pickup have been disclosed, for example, an optical pickup device is disclosed in Japanese Patent Laid-Open No. 1-237935. This optical pickup device is as shown in FIG.
Objective lens 3 for focusing the light flux from the laser beam on the disk 2
And a light receiving element 4 for detecting the reflected light from the disk 2.
And a light beam from the light source 1, which is provided in the light beam from the light source 1 to the disc 2, is divided into a 0th-order light beam for reading a pit signal on the disc 2 and a 1st-order light beam for reading a tracking shift. A cylindrical holding body 7 for holding the objective lens 3; and a second diffraction grating 6 for branching the reflected light from the disc 2 and guiding it to the light receiving element 4. A cylindrical holding member 8 for holding the substrate 11 to which the light source 1 and the light receiving element 4 are fixed and the diffraction gratings 5 and 6 is provided, and the holding member 8 is placed in the holding body 7 and the luminous flux emitted from the light source 1 is provided. It is rotatably held around the optical axis of the.

[0003]

However, in recent years, while plastic materials have been used more and more due to miniaturization and weight reduction, in the above-mentioned prior art, the light receiving element 4 for detecting reflected light detects moisture and oxygen. Since it is not a preventive structure and the structure is almost sealed, it has the following problems under high humidity.

First, since the diffraction gratings 5 and 6 and the adhesive and the holding member 8 absorb moisture, the light receiving element 4, the light source 1, and the silicon substrate 11 supporting the light receiving element 4 and the light source 1 are absorbed.
The surface is exposed to moisture, and a minute current flows on these surfaces, or a minute current is generated, and the carbon is gradually carbonized, and the detection function of the tracking error signal and the focusing error signal deteriorates. Further, the dimensional accuracy changes due to the moisture absorption of the diffraction gratings 5 and 6.

Secondly, the light receiving element 4 is weak to oxygen, and gradually oxidizes and deteriorates in an oxygen atmosphere and in the presence of absorbed moisture and oxygen, so that a signal which should be received originally cannot be obtained, and the light receiving element 4 is long-term. Will cause an error.

The present invention has been made in view of the above conventional problems, and an object of the inventions according to claims 1 to 3 is to provide an adhesive for bonding (bonding) a diffraction grating to a holding member and the holding member itself. It is an object of the present invention to provide an optical pickup device in which a resin coating prevents the deterioration of the detection function due to the absorption of moisture and the oxidation deterioration of the light receiving element due to coexisting oxygen.

Further, the object of the inventions according to claims 4 and 5 is to improve the detection function due to the fact that the adhesive or the holding member for bonding the diffraction grating to the holding member absorbs moisture and the coexisting oxygen causes the deterioration of the light receiving element due to the oxidation deterioration. An object of the present invention is to provide an optical pickup device which is prevented by the adoption of the activating member.

Further, the object of the invention according to claim 6 is to reduce the deterioration of the detection function due to the fact that the adhesive or the holding member for adhering the diffraction grating and the holding member absorbs moisture, and the coexisting oxygen causes oxidative deterioration of the light receiving element. Another object of the present invention is to provide an optical pickup device which is prevented by adopting various members.

[0009]

In order to solve the above-mentioned problems, the invention according to claim 1 proposes an objective lens for converging a light beam from a light source onto a disc, and a light-receiving element for detecting the reflected light from the disc. A diffraction grating provided in the light flux from the light source to the disc; a holder for holding the objective lens; a substrate for supporting the light source and the light receiving element; and a holding member for holding the substrate and the diffraction grating. In the optical pickup device comprising: a light source, a light receiving element, a substrate supporting the light source and the light receiving element, the diffraction grating, the holding member, and an adhesive for bonding the diffraction grating to the holding member. Stored in the formed internal space,
A part of the diffraction grating and / or a part of the holding member facing the inner space is covered with a resin having a gas barrier property.

According to a second aspect of the present invention, the resin having the diffraction grating and the gas barrier property contains a low hygroscopic material. Further, the invention according to claim 3 is such that the resin having the gas barrier property contains an oxygen scavenger.

Here, as the gas barrier resin,
Materials that do not allow water vapor or air to pass through, such as polyamide resin, ethylene / vinyl alcohol resin, ethylene / vinyl oxide resin, polyarylate resin, acrylonitrile resin, polyethylene resin, polypropylene resin, amorphous polyolefin resin, etc. The above is used by stacking. As the low hygroscopic material, a material having no polar group in the molecule, for example, polyethylene resin, polypropylene resin, amorphous polyolefin resin, fluororesin or the like is used. As a coating method, a resin dissolved in a solvent is applied, dried, melted, baked, or a method such as two-color molding is used at the time of molding.

On the other hand, examples of the oxygen scavenger include:
(1) containing at least iron powder and a metal halide, (2) chain hydrocarbon polymer having at least unsaturated fatty acid compound and / or unsaturated group, oxidation-promoting catalyst, basic substance and adsorbing substance (3) at least a compound having a skeletal structure represented by the following chemical formula 1 and / or a derivative thereof, a transition metal compound and a phosphorus compound, and the like are used.

[0013]

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As the iron powder of the above (1), powdery metallic iron which itself is oxidized and absorbs oxygen is used.
As such iron powder, for example, electrolytic iron powder, reduced iron powder, atomized iron powder, iron powder such as atomized iron powder alloy, cast iron, steel, iron products such as iron alloys are pulverized into powder form. And partial oxides thereof. Of course, the iron powder may contain impurities.

Examples of metal halides include chlorides of alkali metals such as sodium chloride and potassium chloride, chlorides of alkaline earth metals such as magnesium chloride and calcium chloride, aluminum chloride and ferrous chloride.
Various chlorides such as ferric chloride, alkali metal bromides such as sodium bromide and potassium bromide, alkaline earth metal bromides such as magnesium bromide and calcium bromide, iron bromide,
Various bromides such as nickel bromide, alkali metal iodides such as sodium iodide and potassium iodide, alkaline earth metal iodides such as magnesium iodide and calcium iodide, and various iodides such as iron iodide. Can be mentioned. Among these, metal chlorides are preferable from the viewpoint of safety and health to the human body, and sodium chloride, magnesium chloride, calcium chloride, ferrous chloride, ferric chloride and the like are particularly preferable.
The amount of the metal halide used depends on the amount of water and the diffusion rate, but an effective amount is 0.01 to 20 parts by weight, preferably 0.2 to 5 parts by weight with respect to 100 parts by weight of the iron powder. Used in part range. In addition to this, a powder filler may be mixed.

As the powder filler, a substance which is hardly soluble or insoluble in water is used. The particle size is 60 mesh or less, preferably 100 mesh or less. When the particle size of the powder filler exceeds 60 mesh, the iron powder enters the gaps between the powder fillers and the iron powder is not sufficiently dispersed.

The unsaturated fatty acid compound (2) mentioned above is
It has 10 or more carbon atoms and one or more double bonds between carbon atoms, that is, unsaturated fatty acids, unsaturated fatty acid esters and unsaturated fatty acid salts. Examples of unsaturated fatty acid compounds, oleic acid, linoleic acid, linolenic acid, arachidonic acid, parinaric acid, dimer acid, ritinoleic acid or unsaturated fatty acids such as ricinoleic acid, and esters of these unsaturated fatty acids and these esters Examples thereof include oils and fats contained therein, metal salts of the above unsaturated fatty acids, and the like.

The chain hydrocarbon polymer having an unsaturated group is a chain hydrocarbon polymer having 10 or more carbon atoms and at least one double bond between carbon atoms, and derivatives thereof. As a substituent of the derivative, for example, a hydroxyl group or a formyl group may be present. Examples of chain hydrocarbon polymers having an unsaturated group include polymers of butadiene, isoprene, piperylene, and 1,3-pentadiene. These compounds do not necessarily have to be pure substances, and may be a mixture of two or more kinds of unsaturated fatty acids and salts thereof, hydrocarbon polymers having unsaturated groups and derivatives thereof. Preferably, it is a transition metal salt of an unsaturated fatty acid, a mixture of a transition metal salt of an unsaturated fatty acid and an unsaturated fatty acid, or a mixture of these and a hydrocarbon polymer having an unsaturated group.

As the oxidation accelerating catalyst, Fe, Ni, C
Examples thereof include transition metals such as o, V, and Pt, compounds thereof, radical polymerization initiators, and the like. Preferably as the basic substance,
Examples thereof include alkali metal or alkaline earth metal oxides, hydroxides, carbonates, organic acid salts and organic amines. Preferred examples of the adsorbing substance include paper made of natural pulp and synthetic pulp, synthetic paper, silica gel, activated carbon, zeolite, activated clay and the like.

The ratio of each component in the composition is not particularly limited, but 0.01 to 10 parts by weight of the catalyst and 1 to 10 parts by weight of the basic substance are used with respect to 100 parts by weight of the main agent such as unsaturated fatty acid compound.
It is preferable that 1,000 parts by weight and the adsorbing substance are 10 to 1,000 parts by weight.

The compound and / or derivative thereof having the skeleton structure of the chemical formula 1 of the above (3) is a compound having at least one skeleton structure in the molecule, and specifically, benzylamine, 3- Methylbenzylamine, metaxylylenediamine, paraxylylenediamine, N, N'-dimethylmetaxylylenediamine, N, N, N ', N'-tetramethylmethaxylylenediamine, N, N'-dimethylparaxylyl Diamine, N, N, N ', N'-Tetramethylparameter xylylenediamine, N, N'-Dimethylmetaxylylenediamine, N, N, N', N'-Tetraethylmethaxylylenediamine, N, N '-Diethylparaxylylenediamine, N, N, N',
N'-tetraethylparaxylylenediamine, 1,3
5-tris (aminomethyl) benzene, meta-xylylenediamine or para-xylylenediamine and organic carboxylic acids such as stearic acid, oleic acid, lauric acid,
Salts and amides of monocarboxylic acids such as tall oil fatty acids and dicarboxylic acids such as adipic acid, sebacic acid and dimer acid, and metaxylylenediamine or paraxylylenediamine and formaldehyde and phenol widely used as epoxy resin curing agents. Mannich base, adduct of metaxylylenediamine or paraxylylenediamine and vinyl compound such as acrylonitrile and methylmethacrylate, obtained by reaction with, metaxylylenediamine or paraxylylenediamine and epoxy compound, for example, bisphenol A epoxy Resin, bisphenol F-based epoxy resin, adduct with butyl glycidyl ether, etc., cured epoxy resin with these curing agents, amino group represented by tetraglycidyl metaxylylenediamine Yes epoxy compounds, m-xylylene diisocyanate, but the polyurethane are derived from each with an isocyanate compound represented by para-xylylene diisocyanate and the like can be exemplified, can be used by multiple blending these things. Among the above, metaxylylenediamine and the following chemical formula 2 are preferable.
A compound represented by, a polyamide, and tetraglycidyl metaxylylenediamine.

[0022]

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As the transition metal compound, Co, Mn, C
Examples thereof include acetates of transition metals such as u, Fe, Ni and Rh, monocarboxylates such as stearates and naphthenates, dicarboxylates and chelate compounds. Among the above, particularly preferable transition metal compounds are cobalt acetate, cobalt stearate, acetylacetone cobalt, acetylacetone iron, and manganese acetate. These compounds are 1
One kind or two or more kinds can be used in combination, and it is added as a metal component in the range of 1 to 10,000 ppm, preferably 10 to 1,000 ppm with respect to the entire composition.

Examples of the phosphorus compound include phosphate, phosphite and hypophosphite. Specific examples include trisodium phosphate, tripotassium phosphate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, sodium phosphite, potassium phosphite, and Examples thereof include sodium phosphite, potassium hypophosphite, iron phosphate and the like. These phosphorus compounds are
Each of them can be used alone or in combination of two or more, and as a phosphorus component relative to the total composition, 1 to 10,000 ppm
Is added, preferably in the range of 10 to 1,000 ppm.

According to a fourth aspect of the present invention, an objective lens for focusing the light flux from the light source on the disc, a light receiving element for detecting the reflected light from the disc, and a light flux from the light source to the disc are provided. In the optical pickup device, a diffraction grating, a holder for holding the objective lens, a substrate for supporting the light source and the light receiving element, and a holding member for holding the substrate and the diffraction grating are provided. An element and a substrate that supports the light source and the light receiving element are housed in an internal space formed by the diffraction grating, the holding member, and an adhesive that bonds the diffraction grating to the holding member. Alternatively, the oxygen scavenger is included in the holding member.

Here, in order to include an oxygen scavenger in the adhesive, the above-mentioned various oxygen scavengers are mixed and stirred in various uncured liquid adhesives, and then applied to the adhesive portion and dried. Curing etc. As the adhesive used here, commercially available various polymeric materials are used, but from the viewpoint of avoiding the above problems, the invention according to claim 5 uses a low hygroscopic material as a base material. did. In order to contain the oxygen scavenger in the holding member, the low hygroscopic molding material and various oxygen scavengers are dissolved or melted before the holding member is molded, or the powders are kneaded and mixed to be added. To do.

According to a sixth aspect of the present invention, an objective lens for focusing the light flux from the light source on the disc, a light receiving element for detecting the reflected light from the disc, and a light flux from the light source to the disc are provided. An optical pickup device comprising: a diffraction grating; a holder for holding the objective lens; a substrate for supporting the light source and the light receiving element; and a holding member for holding the substrate and the diffraction grating. The light receiving element, the light source, and the substrate supporting the light receiving element are housed in an internal space formed by the diffraction grating, the holding member, and an adhesive that bonds the diffraction grating to the holding member. Then, an oxygen scavenger package containing the oxygen scavenger was installed.

Here, as the oxygen scavenger package, the various oxygen scavengers described above are used by being packaged in a breathable packaging material, or by adding a resin binder or the like to pressurizing, dissolving or melting. It is used after being molded into various shapes such as granules, tablets and sheets. The breathable packaging material is, for example, a bag made by laminating and adhering a polyester film and a polyethylene film to the outside of a bag in which Japanese paper and a perforated polyethylene film are laminated and adhered, and the sealing is usually a heat seal. Done by. As an installation method, for example, the package is fixed to the outside of the optically effective diameter in the space via a double-sided adhesive tape.

[0029]

The action of the invention according to claim 1 is that a part of the diffraction grating facing the internal space formed by the diffraction grating, the holding member, and an adhesive for joining the diffraction grating to the holding member. And / or since a part of the holding member is covered with a gas barrier resin, oxygen and water that enter the material of the diffraction grating or the holding member from outside the internal space are shut out by the covered resin layer. It is possible to prevent moisture absorption and oxidative deterioration of the light receiving element in the internal space.

With the operation of the invention according to claim 2, since the low hygroscopic material is adopted as the material of the gas barrier resin and the diffraction grating in claim 1, the diffraction grating itself becomes hydrophobic as a whole, and the external environment is improved. The water from can be easily shut out.

Since the gas barrier resin according to claim 1 contains the oxygen scavenger, the function of the invention according to claim 3 is to allow oxygen and water to pass through the resin, and further, to collect oxygen in the internal space. Since even oxygen and water are absorbed and removed, the light receiving element can be reliably protected from moisture absorption and oxidative deterioration.

The action of this oxygen scavenger is the same as in the above-mentioned means.
In the case of the combination of iron powder and metal halide as in (1), when the iron powder is oxidized by oxygen in the atmosphere, the moisture in the atmosphere is also transferred to the iron powder by the metal halide and contributes to the oxidation. . In addition, the metal halide also acts as a catalyst for oxidation. At this time, if powder filler is added,
The powder filler enters between the iron powder particles to disperse the iron powder,
The heat generated by the oxidation reaction is quickly released to the outside, and the iron powder is prevented from aggregating to prevent the iron powder agglomerating part from becoming hot. However, when the internal space is a small space, it is not necessary to add this powder filler.

In the case of the combination of the unsaturated fatty acid compound and / or the chain hydrocarbon polymer having an unsaturated group, the oxidation accelerating catalyst, the basic compound and the adsorbing substance as described in (2) in the above-mentioned means, In addition to using the unsaturated fatty acid compound and / or the chain hydrocarbon polymer having an unsaturated group alone, in order to maintain the shape of the composition and increase the contact area with oxygen and water, paper, nonwoven fabric, pearlite It is adsorbed by being impregnated with, mixed with, or coated with an adsorbent such as activated carbon or zeolite. In the unsaturated fatty acid compound and / or the chain hydrocarbon polymer having an unsaturated group, the unsaturated group is oxidized by an addition reaction with oxygen and water in the presence of an oxidation accelerating catalyst. The basic substance absorbs an acidic by-product generated by the oxidation of the unsaturated fatty acid compound and / or the chain hydrocarbon polymer having an unsaturated group.

In the case of the combination of the compound having the skeleton structure shown in Chemical formula 1 such as (3), the transition metal compound and the phosphorus compound by the above-mentioned means, the mechanism has not been sufficiently clarified,
Recently, it has been drawing attention as a composition that repairs oxygen more efficiently than in the cases described in (1) and (2) above.

According to a fourth aspect of the present invention, an adhesive for fixing the holding member and the diffraction grating forming the internal space and / or the holding member contains the oxygen scavenger. This efficiently absorbs and removes oxygen and water in the internal space formed by the diffraction grating, the holding member, and an adhesive that bonds the diffraction grating to the holding member, and It is possible to prevent moisture absorption and oxidative deterioration of the light receiving element housed in.

The effect of the invention according to claim 5 is that the adhesive and the holding member according to claim 4 contain a low hygroscopic material, so that the constituent material itself is made more hydrophobic to prevent moisture permeation and to further absorb moisture. And oxidative deterioration can be prevented.

According to a sixth aspect of the present invention, the oxygen scavenger is formed in the internal space formed by the holding member, the diffraction grating, and an adhesive for fixing the diffraction grating and the holding member. By installing an oxygen scavenger package containing an agent, when the internal space is a highly sealed space, various work such as coating the internal space constituent material with a resin or mixing an oxygen scavenger Without, simply by placing an oxygen scavenger in the internal space, to sufficiently remove oxygen and moisture in the internal space, of the light-receiving element housed in the internal space Moisture absorption and oxidative deterioration can be prevented.

[0038]

【Example】

[First Embodiment] FIG. 1 is a longitudinal sectional view of a main portion of an optical pickup device according to the present embodiment. In the optical pickup device shown in FIG. 1, components having the same functions as those of the conventional device shown in FIG. 4 are designated by the same reference numerals.

(Structure) The optical pickup device of this embodiment has an objective lens (not shown in FIG. 1) for focusing the light beam from the light source 1 on a disc (not shown), and the reflected light from the disc 2. Pair of light receiving elements 4 for detecting light
1, diffraction gratings 5 and 6 provided in the light flux from the light source 1 to the disk, a holding body (not shown in FIG. 1) for holding the objective lens, and a silicon-made support for the light source 1 and the light receiving element 4. Substrate 11, light receiving element 4 and substrate 1
In order to hold 1 and the diffraction gratings 5 and 6 at a predetermined distance from each other, a step portion for fitting and holding the diffraction gratings 5 and 6 is provided on the upper inner surface, and the substrate 11 and the diffraction grating 5 are provided. And a holding member 8 for holding 6.

The objective lens 3 and the holder 7 shown in FIG. 4 described as a conventional example are used as the objective lens and the holder for holding the objective lens. Amorphous polyolefin resin, which is a low hygroscopic plastic material having a moisture absorption rate of 0.1% by weight or less, for example, Zeon Co., Ltd., trade name Z
The diffraction grating 6 formed on the front and back surfaces of a flat-plate molded article molded by EONEX, Mitsui Petrochemical Co., Ltd., trade name APO, Japan Synthetic Rubber Co., Ltd., trade name Arton, etc., has a bottomed cylindrical shape. The upper surface of the member 8 is fixed with an adhesive 9 so as to be flush with the upper end surface of the holding member 8.

Further, the light source 1, the light receiving element 4 and these light sources 1
And the silicon substrate 11 that supports the light receiving element 4,
It is housed in an internal space formed by the diffraction grating 5 and the holding member 8.

The holding member 8 is an amorphous polyolefin resin which is a low hygroscopic plastic material, for example, ZEON Corporation, trade name ZEONEX, Mitsui Petrochemical Co., Ltd., trade name APO, Japan Synthetic Rubber Co., Ltd., trade name. It is formed by Arton. The adhesive 9 is interposed in the space between the outer peripheral surfaces of the diffraction gratings 5 and 6 and the inner peripheral surface of the holding member 8 as described above, and the diffraction gratings 5 and 6 facing the interior space are described. The resin film 10 is coated on the outside of the effective optical performance range, and on a part of the holding member 8.

The resin film 10 contains a gas barrier low hygroscopic plastic material containing 10% by weight of "Ageless" (trade name) manufactured by Mitsubishi Gas Chemical Co., Ltd., which contains iron fine powder and sodium chloride as main components as oxygen scavengers. Amorphous polyolefin resin, such as ZEON CORPORATION, trade name ZEONEX, Mitsui Petrochemical Co., Ltd., trade name APO,
Nippon Synthetic Rubber Co., Ltd., trade name ARTON, etc., dissolved in a specific organic solvent such as toluene, xylene, etc. to fix a 70% by weight solid content solution to the diffraction gratings 5, 6 and the holding member 8 with an adhesive 9. Previously, it was applied to a predetermined position in the internal space to a thickness of about 30 μm, and the solvent was volatilized at room temperature to form it.

(Operation) According to the optical pickup device of this embodiment, the diffraction grating 5 itself is made of the gas barrier property and low hygroscopic plastic material, and the holding member 8 and the diffraction grating 5 facing the inside space are formed. Since a part of the surface is covered with a gas barrier low hygroscopic resin mixed with an oxygen scavenger to form the resin film 10, oxygen and water in the internal space can be absorbed and removed, and also from the outside. It was possible to shut out the permeation of oxygen and water into the internal space.

(Effect) Oxidative deterioration of the light receiving element 4 in the internal space, dimensional change due to moisture absorption, generation of minute current, etc. can be prevented, and occurrence of error and deterioration of detection function of focusing error signal and tracking error signal are prevented. It is possible to provide a highly reliable optical pickup device.

[Second Embodiment] FIG. 2 is a vertical sectional view showing the main part of an optical pickup device according to a second embodiment. The optical pickup device of this embodiment is different from the device of the first embodiment in that the diffraction gratings 5 and 6 are fixed to the inner surface of the upper part of the holding member 8 by the adhesive 9 in the first embodiment. While the resin film 10 containing the oxygen scavenger was formed on a part of the surfaces of the holding member 8 and the diffraction grating 5 facing the internal space,
The diffraction gratings 5 and 6 are placed on the upper end surface of the holding member 18 via an adhesive 19, and an oxygen scavenger is mixed in the holding member 18 and the adhesive 19. As the base resin of the holding member 18 and the adhesive 19 in this embodiment, the amorphous polyolefin resin, which is the low hygroscopic plastic material adopted in Embodiment 1, is used.

The holding member 18 was formed from a molding material in which 20 parts by weight of the same oxygen scavenger as in Example 1 was mixed with 100 parts by weight of the base resin. As the adhesive 19, a solution prepared by dissolving 10 parts by weight of the same oxygen scavenger as in Example 1 in 100 parts by weight of the base resin and dissolving 45% by weight in toluene was applied to the adhesive part. After that, the holding member 18 and the diffraction grating 5 were attached to each other, and toluene was volatilized and adhered while being pressed. The other configurations are similar to those of the first embodiment, and thus the description thereof is omitted.

According to the optical pickup device of the second embodiment, in addition to the same actions and effects as those of the first embodiment, there is no step of forming the resin film 10, so that the cost can be further reduced. Play.

[Third Embodiment] FIG. 3 is a vertical sectional view of the essential parts of an optical pickup device according to a third embodiment.

(Structure) The structure of the optical pickup device according to the third embodiment is the same as that of the first embodiment, but in the first embodiment, one of the surfaces of the holding member 8 and the diffraction grating 5 facing the internal space. While the resin film 10 containing the oxygen scavenger was formed on the part, in Example 3, two oxygen scavenger packages 12 containing the oxygen scavenger were installed in the internal space. It is a feature. As the oxygen repairing agent used in this example, an RP agent of “RP system” (trade name, manufactured by Mitsubishi Gas Chemical Co., Inc.) using metaxylylenediamine, a transition metal compound and a phosphorus compound was used. What was wrapped with the wrapping paper which laminated | stacked and was fixed and set to the holding member 8 as the oxygen scavenger package 12 through the double-sided tape which is not shown in figure. The other configurations are similar to those of the first embodiment, and thus the description thereof is omitted.

In addition to the actions and effects similar to those of the first embodiment,
In this example, there is no step of forming the resin film 10 as in Example 1, there is no need to custom-make a resin mixed with an oxygen scavenger as in Example 2, and a commercially available material can be used. , Lower cost is possible.

[0052]

According to the present invention described above, the following effects can be obtained.

According to the first aspect of the present invention, oxygen and water which enter the material of the diffraction grating or the holding member from the outside can be shut out by the covered resin layer,
It is possible to provide an optical pickup device capable of preventing moisture absorption and oxidative deterioration of the light receiving element in the internal space.

According to the second aspect of the invention, it is possible to provide an optical pickup device in which the diffraction grating itself is entirely hydrophobic, and water from the outside can be more easily shut out.

According to the third aspect of the present invention, since the gas barrier resin contains the oxygen scavenger, oxygen and moisture which are to permeate through the resin, and further oxygen and moisture in the internal space are also included. Since it is absorbed and removed, it is possible to provide an optical pickup device capable of reliably protecting the light receiving element from moisture absorption and oxidative deterioration.

According to the invention described in claim 4, oxygen and water in the internal space are efficiently absorbed and removed by the action of the oxygen repairing agent, and the moisture absorption of the light receiving element housed in the internal space is performed. It is possible to provide an optical pickup device capable of preventing deterioration due to oxidation.

According to the invention described in claim 5, since the low hygroscopic material is contained in the adhesive or the holding member in claim 4, the constituent material itself is increased in hydrophobicity to prevent water permeation,
It is possible to provide an optical pickup device that can further prevent moisture absorption and oxidative deterioration.

According to the sixth aspect of the present invention, oxygen and water in the internal space can be sufficiently removed and stored in the internal space only by inserting the oxygen scavenger into the internal space. It is possible to provide an optical pickup device capable of preventing moisture absorption and oxidative deterioration of the existing light receiving element.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing a main part of an optical pickup device according to a first embodiment of the present invention.

FIG. 2 is a vertical sectional view showing a main part of the optical pickup device according to the first embodiment of the present invention.

FIG. 3 is a vertical sectional view showing a main part of the optical pickup device according to the first embodiment of the present invention.

FIG. 4 is a schematic perspective view of a conventional device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 light source 2 disk 3 objective lens 4 light receiving element 5 diffraction grating 6 diffraction grating 8 holding member 9 adhesive 10 resin film 11 substrate 12 oxygen repair agent package

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Issei Tokuda 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Co., Ltd. (72) Inventor Ken Yamazaki 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Industry Co., Ltd.

Claims (6)

[Claims] 1. An objective lens for focusing a light beam from a light source on a disc, a light receiving element for detecting reflected light from the disc, a diffraction grating provided in the light beam from the light source to the disc, An optical pickup device comprising: a holder that holds an objective lens; a substrate that supports the light source and the light receiving element; and a holding member that holds the substrate and the diffraction grating, the light source and the light receiving element, the light source and the light receiving element. A substrate supporting the element is housed in an internal space formed by the diffraction grating, the holding member, and an adhesive that bonds the diffraction grating to the holding member, and the diffraction grating facing the inside of the internal space is formed. An optical pickup device characterized in that a part and / or a part of the holding member is coated with a resin having a gas barrier property. 2. The optical pickup device according to claim 1, wherein the resin having the diffraction grating and the gas barrier property contains a low hygroscopic material. 3. The optical pickup device according to claim 1, wherein the resin having gas barrier properties contains an oxygen scavenger. 4. An objective lens for focusing a light beam from a light source on a disc, a light receiving element for detecting a reflected light from the disc, a diffraction grating provided in the light beam from the light source to the disc, An optical pickup device comprising: a holder that holds an objective lens; a substrate that supports the light source and the light receiving element; and a holding member that holds the substrate and the diffraction grating, the light source and the light receiving element, the light source and the light receiving element. A substrate for holding, is housed in an internal space formed by the diffraction grating and the holding member and an adhesive for joining the diffraction grating and the holding member, in the adhesive and / or the holding member, An optical pickup device comprising an oxygen scavenger. 5. The optical pickup device according to claim 4, wherein the diffraction grating and the adhesive and / or the holding member contain a low hygroscopic material. 6. An objective lens for focusing a light beam from a light source on a disc, a light receiving element for detecting reflected light from the disc, a diffraction grating provided in the light beam from the light source to the disc, An optical pickup device comprising: a holder that holds an objective lens; a substrate that supports the light source and the light receiving element; and a holding member that holds the substrate and the diffraction grating, the light source and the light receiving element, the light source and the light receiving element. A substrate supporting the same is housed in an internal space formed by the diffraction grating, the holding member, and an adhesive that bonds the diffraction grating to the holding member, and an oxygen scavenger is included in the internal space. An optical pickup device characterized in that an oxygen scavenger package is installed.