JP2014022005A - Optical pickup device and manufacturing method of optical pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain, in an optical disk device supporting an optical disk having a plurality of recording layers, an optical pickup device capable of avoiding influence due to interlayer stray light caused in the optical disk having the plurality of recording layers while suppressing an increase in cost.SOLUTION: An optical pickup device includes on an optical path of reflected light 1 incident on a photodetector 60 from an optical disk having a plurality of recording layers: a diffraction optical element 70 which transmits light of a prescribed range of wavelengths and has a diffraction grating 71 on a surface thereof on which the reflected light is incident; a second optical element 20, provided on the optical path, opposite to the surface having the diffraction grating of the diffraction optical element; and a resin filling layer 90 formed such that a space between the diffraction optical element and the second optical element is filled with a resin transmitting light of the prescribed range of wavelengths.

Description

  The present invention relates to an optical pickup device used in an optical disc apparatus corresponding to an optical disc having a plurality of recording layers.

  The optical disk apparatus receives reflected light obtained by irradiating a recording layer of an optical disk with a light beam by a photodetector and reproduces read information. In addition, a focus error signal and a track error signal are calculated from information obtained by reading the reflected light. Based on the focus error signal and the track error signal, the objective lens is perpendicular to the optical disk surface (hereinafter referred to as the focus direction) and the optical disk. The position of the radial direction (hereinafter referred to as the track direction) is controlled with respect to the rotation axis so that the focal point of the light beam follows the target track.

  At this time, the photodetector provides a light receiving area having a predetermined shape, and converts the reflected light received by the light receiving area into read information.

  The information recording layer possessed by the optical disc has one to multiple layers. The reason why the optical disk has a plurality of information recording layers is to increase the recording capacity. An optical disk having two layers for DVD and four layers for BD is commercially available. Further, development aimed at further increasing the recording capacity has been carried out, and an optical disc having 20 layers has also been developed.

  However, since the optical disk has a plurality of recording layers, when a desired recording layer is irradiated with a light beam, a part of the light beam is irradiated in another recording layer different from the desired recording layer, and interlayer stray light Will occur. Here, interlayer stray light is light in which a part of a light beam is reflected by another recording layer different from the desired recording layer irradiated. By irradiating the light receiving area of the photodetector with interlayer stray light different from the reflected light from the desired recording layer, the focus error signal and the track error signal generated from the information read by the photodetector are An error occurs in the information for irradiating the recording layer, and the position control of the objective lens cannot be performed accurately.

  Therefore, the reflected light beam path is divided into a plurality of areas where the reflected light strikes, and a diffraction grating is provided so that each area is diffracted in a different direction. There has been proposed a method for avoiding the influence of interlayer stray light even when an optical disc has a plurality of recording layers by providing a light receiving area of a photodetector so as to receive each reflected light (for example, patent document). 1).

JP 2008-135151 A (page 5-7, FIG. 1)

  A hologram element is generally a single-layer diffraction grating in which a diffraction grating is formed on one side of a transparent substrate. Such a hologram element has a cost merit because it can be mass-produced by a resin molding method using a mold.

  However, such a hologram element using a single-layer diffraction grating has a wavelength dependency of diffraction efficiency, and light that is a loss of diffraction efficiency leaks to an unnecessary area (flare) or new stray light. There is a problem that the photodetector receives light of unnecessary components.

  Further, as a hologram element, it is possible to improve the diffraction efficiency by using a laminated diffraction grating having a structure in which a pair of diffraction gratings are stacked with two single-layer diffraction gratings facing inward. There was a problem that a significant cost increase was involved.

  The present invention has been made to solve the above-described problems, and provides an optical pickup device that realizes an optical system that suppresses an increase in cost and that avoids the influence of interlayer stray light caused by an optical disk having a plurality of recording layers. To get.

  In the optical pickup device according to the present invention, the optical pickup device is provided on the optical path of the reflected light incident on the optical detector from the optical disk having a plurality of recording layers, and has a diffraction grating on the surface on which the reflected light is incident and has a predetermined range. A diffractive optical element that transmits light of a wavelength of the second, a second optical element provided on the optical path facing the surface of the diffractive optical element having the diffraction grating, the diffractive optical element, and the second And a resin-filled layer filled with a resin that transmits light having a wavelength in the predetermined range on an optical path between the optical element and the optical element.

  The present invention provides a wavelength of diffraction efficiency in a single-layer diffraction grating by providing a resin-filled layer in which a space between another optical element facing the diffraction grating is filled with a resin that transmits light in a predetermined range of wavelengths. Since the dependency can be reduced, the diffraction efficiency is improved. As a result, the generation of loss in the wideband wavelength region is greatly reduced, so that the influence of flare and stray light irradiation on the photodetector can be eliminated. For this reason, errors occurring in the focus error signal and the track error signal are suppressed, and the accuracy of objective lens position control can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS It is an external appearance perspective view of the optical pick-up apparatus which shows Embodiment 1 of this invention. 1 is an exploded perspective view of an optical system of an optical pickup device showing Embodiment 1 of the present invention. 1 is a schematic cross-sectional view of an optical system of an optical pickup device showing Embodiment 1 of the present invention. It is a perspective view which shows the diffraction grating structure of the hologram element of the optical pick-up apparatus which shows Embodiment 1 of this invention. It is a figure explaining the diffraction efficiency of a contact multilayer diffraction grating. It is a figure explaining the relationship between the diffraction efficiency of an adhesion multilayer diffraction grating, and material characteristics. It is a manufacturing flowchart figure of the optical pick-up apparatus which concerns on this Embodiment.

Embodiment 1 FIG.
FIG. 1 is an external perspective view showing an optical pickup device according to Embodiment 1 for carrying out the present invention. In FIG. 1, 10 is a light source unit, 20 is a prism, 30 is a collimator lens, 41 is a first objective lens, 42 is a second objective lens, and 50 is an actuator. Reference numeral 51 denotes a stepping motor, and reference numeral 60 denotes a photodetector (also referred to as a light detector). In FIG. 1, the x-axis direction is the track direction of the optical disk, the y-axis direction is the tangent direction with respect to the rotation axis of the optical disk, and the z-axis direction is the focus direction.

  FIG. 2 is a developed perspective view of an optical system that includes a light source unit 10, a prism 20, and a photodetector unit 60 that constitute a part of the optical pickup device shown in FIG.

  Here, in this embodiment, as an optical pickup device corresponding to a plurality of optical discs such as BD (Blu-ray: registered trademark), DVD (Digital Versatile Disc: registered trademark), and CD (Compact Disc: registered trademark), The first light source 11 and the first objective lens 41 corresponding to the BD and the second light source 12 and the second objective lens 42 corresponding to the DVD and the CD are illustrated and described as constituting two systems. Since a light source that outputs laser light having a wavelength for DVD and CD and an objective lens compatible with DVD and CD, such as the second light source 12 and the second objective lens 42, are generally known. It is.

  In the case of an optical pickup device corresponding to one optical disc standard, the optical pickup device has a one-system configuration including a light source that outputs laser light having a wavelength based on the standard and an objective lens having a numerical aperture NA (Numerical Aperture) that conforms to the standard. It goes without saying that it does not matter.

  Laser light having a wavelength based on the standard of the optical disk is output from the light source unit 10 and is incident on the objective lens via the prism 20 and the collimator lens 30. In FIG. 1, a first objective lens 41 having a numerical aperture (NA) set for BD and a second objective lens 42 compatible with DVD and CD are provided.

  The collimator lens 30 is mounted on a parallel drive device connected to the stepping motor 51 and is provided so that the position can be adjusted in the optical axis direction (x-axis direction).

  The actuator 50 adjusts the position of the first objective lens 41 and the second objective lens 42 in the focus direction (z-axis direction) of the optical disc and the track direction (x-axis direction) of the optical disc using electromagnetic driving force. Is provided. Position adjustment by the actuator 50 is controlled based on adjustment position information generated based on a focus error signal and a track error signal.

  The collimator lens 30 is a lens whose aberration has been corrected so that parallel light can be obtained from the light incident from one surface on the other surface. To the objective lens 41 or the second objective lens 42 side. On the other hand, when a parallel light beam is incident from the other surface, a light beam that provides a light beam that is condensed at one point from one surface is output. Here, the parallel light beam incident from the other surface is the reflected light of the optical disk incident through the first objective lens 41 or the second objective lens 42. Then, the reflected light beam is incident on the photodetector unit 60 while being condensed.

  The photodetector unit 60 receives the reflected light from the optical disk incident via the prism 20 and converts it into an electrical signal. Based on this electric signal, a reproduction signal, a focus error signal, and a track error signal are calculated.

  The first objective lens 41 and the second objective lens 42 receive the parallel light flux from the collimator lens 30, collect the incident parallel light flux, and irradiate the recording layer of the optical disc (not shown). Further, the reflected light from the recording layer of the optical disc is radiated by the first objective lens 41 or the second objective lens 42 to become a parallel light flux and is incident on the collimator lens 30 side. If the collimator lens 30, the first objective lens 41, and the second objective lens 42 are arranged as shown in FIG. 1, for example, a launch mirror (not shown) that bends the optical axis in the x-axis direction to the optical axis in the z-axis direction. Or the like, the collimator lens 30 enters the first objective lens 41 and the second objective lens 42, or the collimator lens 30 enters the collimator lens 30 from the first objective lens 41 and the second objective lens 42. The reflected light can be incident on the surface. At this time, when the optical disk has a plurality of recording layers, the light irradiated on the optical disk is reflected not only on the desired recording layer but also on other recording layers. Accordingly, the reflected light includes reflected light from recording layers other than the desired recording layer as interlayer stray light.

  The first objective lens 41 is an objective lens for BD, and is desirably designed with a numerical aperture NA of 0.85.

  The second objective lens 42 is an objective lens for DVD and CD. Desirable values for the numerical aperture NA of the objective lens differ between DVD and CD, which are 0.60 for DVD and 0.45 for CD, respectively, but the concentric diffractive surface centered on the optical axis is on the entrance surface of the objective lens It is possible to make DVD and CD compatible by forming a (diffraction ring zone). Here, the numerical aperture NA is different depending on the optical disk because the thickness to the recording layer of the optical disk is different with respect to the thickness of the optical disk of about 1.2 mm, and the desired spot diameter in the recording layer is different.

  Next, an optical system which is a part of the optical pickup device according to the present embodiment will be described with reference to FIG.

  In the light source unit 10, the first light source 11 and the second light source 12 are disposed on the opposite side of the prism 20, and laser light is output from the respective light sources toward the prism 20. The light source unit 10 supports the prism 20 so as to sandwich the two surfaces.

  The prism support portion 13 supporting one surface of the prism is provided with a cavity at the center. The adjustment holder 14 fixes and holds the hologram element 70 and the cylindrical lens 80 on the surface of the cylindrical lens 80 on the side of the photodetector.

  The prism support portion 13 and the adjustment holder 14 are configured to close the hologram element 70 and the cylindrical lens 80 in the cavity of the prism support portion 13. Here, the prism support portion 13 and the adjustment holder 14 are not fixed at the time of assembly, and the adjustment holder 14 is attached to be slidable in the x direction.

  A spring 62 is provided between the adjustment holder 14 and the light receiving unit 61 of the photodetector unit 60. A spring cover 63 fixed to the photo detector unit 60 is provided between the light receiving unit 61 and the spring 62, and the adjustment holder 14 is sandwiched between the prism support unit 13 and the photo detector unit 60.

  With such a configuration, the adjustment holder 14 is always sandwiched by receiving the pressure of the spring 62, and the slide position can be adjusted only in the x direction. That is, the slide position of the hologram element 70 and the cylindrical lens 80 can be adjusted in the x direction. For adjusting the slide position, for example, an optical pin is provided in the prism support portion 13 with a hole for inserting and rotating an adjustment pin having a groove at the tip, and the adjustment holder 14 is slid and adjusted according to the rotation, thereby providing an optical system. Adjustment after assembly is easily possible.

  Further, in the space between the prism 20 and the hologram element 70, a resin-filled layer 90 is provided at least in the space corresponding to the optical path of the reflected light. The resin filling layer 90 will be described later with reference to FIG.

  The first light source 11 outputs a semiconductor laser having a wavelength of 405 nm for BD. The second light source 12 is a light source that can output a semiconductor laser with a wavelength of 650 nm for DVD and a semiconductor laser with a wavelength of 780 nm for CD, and switches either of them to output.

  The prism 20 refracts or transmits the laser light from the first light source 11 or the second light source 12 and enters the collimator lens 30. Conversely, the reflected light incident from the collimator lens 30 side is refracted and incident in the + y direction where the photodetector unit 60 is arranged.

  In the configuration of the optical system in FIG. 2, the laser light from the first light source 11 is transmitted through the prism 20, proceeds straight in the + x direction, and enters the collimator lens 30. On the other hand, the laser light from the second light source 12 is once refracted by the prism 20 in the −y direction, and further refracted in the + x direction, so that the collimator lens 30 is aligned with the optical axis of the laser light from the first light source 11. Can be made incident.

  On the other hand, the case where the reflected light from the optical disk is incident on the prism 20 via the collimator lens 30 will be described. In this case, the reflected light from the optical disk is refracted in the + y direction and is incident on the photodetector 60 side through the hologram element 70 and the cylindrical lens 80.

  FIG. 3 is a schematic cross-sectional view of the optical system including the hologram element 70 provided with the resin filling layer 90 as viewed from above. In FIG. 3, the prism support portion 13 shown in FIG. 2 is not shown to show the inside of the cavity of the prism support portion 13.

  The hologram element 70 has a diffraction grating 71 on the surface facing the prism 20 side. As the material of the hologram element 70, a molded product made of an optical glass material or an optical resin material is used.

As shown in FIG. 3, in the space between the prism 20 and the hologram element 70, the resin filling layer 90 is provided at least in the space corresponding to the optical path of the reflected light 1. The resin-filled layer 90 is made of an ultraviolet curable resin that is initially in a liquid state and that undergoes a curing reaction when irradiated with light in the ultraviolet region.
Further, the resin-filled layer 90 is formed by injecting the resin-filled layer 90 so as to be in close contact with the entire surface from the bottom surface to the side surface of the diffraction grating 71 and the optical surface of the prism 20 at a liquid state, and then curing.

  The reflected light 1 passes through the resin-filled layer 90 from the prism 20, is diffracted in a desired angular direction by the diffraction grating surface 71 of the hologram element 70, and is incident on the light receiving unit 61 after adding astigmatism characteristics by the cylindrical lens 80. . Here, the light reflected from the desired recording layer of the optical disc is designed to be condensed and received by the light receiving unit 61.

  FIG. 4 is a perspective view for explaining the diffraction grating structure of the hologram element 70 used in the optical pickup device according to the present embodiment.

  The walls constituting the diffraction grating are made of independent walls, and do not intersect with other walls without intersecting with other walls. This is because if a corner part or a closed part is constituted by each wall, the resin flow becomes an obstacle when the resin material that becomes the resin filling layer 90 on the diffraction grating surface is injected, and stagnation occurs in the flow. By adopting a structure that does not intersect with other walls as in this embodiment, it does not intersect with its own wall, so that the resin flow at the time of injection of the resin material that becomes the basis of the resin filling layer 90 on the diffraction grating surface is reduced. Occurrence can be prevented.

  The structure of the diffraction grating surface of the hologram element 70 is eliminated as the resin spreads after the resin material is dropped by making the structure open as shown in FIG. The structure can secure an air escape.

  Further, the structure of the diffraction grating surface of the hologram element 70 can be provided with a wall around the diffraction grating as shown in FIG. 4B to prevent the liquid resin material from spreading to an unnecessary place in the initial stage. In this case, a groove may be provided in a part of the peripheral wall so as to secure an escape space for air that is removed as the resin spreads after the resin material is dropped.

  In this way, in the space between the prism 20 and the hologram element 70, the resin-filled layer 90 is provided at least in the space corresponding to the optical path of the reflected light, so that the adhesive multilayer is used while using the hologram element having a single-layer diffraction grating. It is possible to construct an optical system that obtains a high diffraction efficiency characteristic equivalent to that of a type diffraction grating.

  In addition, a hologram element having a single-layer diffraction grating can be manufactured at low cost because it can be mass-produced by a resin molding method using a mold, and is configured using a hologram element having a highly accurate multi-layer diffraction grating. The optical system of the optical pickup device having the cost merit can be manufactured relatively easily than the above.

  Next, the refractive index and material design of hologram element 70 and resin-filled layer 90 of the optical pickup device according to the present embodiment will be described in detail.

FIG. 5 is a cross-sectional view for explaining the concept of the contact multilayer diffraction grating. Here, λ is the wavelength, N is the refractive index, and H is the diffraction grating height. In the cross-sectional view of the diffraction grating, when the direction of the arrow is the traveling direction of light of wavelength λ, the incident side is the first grating and the emission side is the second grating. When the refractive index N ₁ (λ) with respect to the wavelength λ of the first grating material is higher than the refractive index N ₂ (λ) with respect to the wavelength λ of the second grating material, this contact multilayer diffraction The conditions for the diffraction efficiency of the grating to be 100% are as in the first equation.

Here, the conditions for selecting the lattice material using the respective refractive indexes of the spectral lines d, F, and C used for the material property index of the constituent material of the lattice will be described. Here, the wavelength λ _d of the d-line is 587.6 nm, and the refractive index for the wavelength λ _d of the first grating material is N ₁ (λ _d ). The refractive index for the wavelength λ _d of the second grating material is N ₂ (λ _d ). Similarly, the wavelength λF of the F-line lower than the d-line is 486.1 nm, and the refractive index for the wavelength λ _F of the first grating material is the refractive index for the wavelength λF of the N ₁ (λ _F ) second grating material. Is N ₂ (λ _F ). The wavelength λc of the C-line higher than the d-line is 656.3 nm, and the refractive index of the first grating material with respect to the wavelength λ _C is N ₁ (λ _C ). The refractive index of the second grating material with respect to the wavelength λF is Let N ₂ (λ _C ).

  In this case, the conditions for the first grating material and the second grating material are as follows from the first expression to the condition in the wavelength region d.

  Conditions near the wavelength band F are as shown in the third equation.

  Conditions in the vicinity of the wavelength region C are as shown in the fourth equation.

  Next, in order to make the diffraction efficiency close to 100% in a wide band from the low wavelength range F to the high wavelength range C with the wavelength range d as the center, the same condition is established in the low wavelength range F and the high wavelength range C. Select the lattice material. The following relational expression (fifth expression) is obtained from the three conditional expressions of the second expression, the third expression, and the fourth expression.

  FIG. 6 is a diagram for explaining a condition for selecting a material in which the diffraction efficiency of the multi-contact diffraction grating is close to 100%. The horizontal axis represents the average dispersion representing the difference in refractive index with respect to the wavelength of the material, and the vertical axis represents the refractive index of the material.

  Since the diffraction efficiency and the material characteristics have the relationship as shown in FIG. 6, in the contact multilayer diffraction grating, the high refractive index and low dispersion type is subsequently incident on the grating material on the first grating side where light enters. What is necessary is just to implement | achieve the combination from which the grating | lattice material of the 2nd grating | lattice side becomes a low refractive index high dispersion type | mold. That is, in the present embodiment, the grating material of the resin-filled layer 90 corresponding to the first grating side is the high refractive index and low dispersion type, and the grating material of the hologram element 70 corresponding to the second grating side is the low refractive index and high dispersion type. Will be.

In this embodiment, laser wavelengths of 405 nm, 650 nm, and 780 nm are used to support BD, DVD, and CD optical disks. Regarding the relationship indicated by d, F, and C in the conditional expression of the diffraction efficiency, the wavelength λ _d of the d line is replaced with 592.5 nm, the wavelength λ _{F of the} F line is 405 nm, and the wavelength λ _{C of the} C line is replaced with 780 nm. The same effect can be obtained by selecting the first and second lattice materials.

  In the present embodiment, since the resin filling layer in which the space between the hologram element 70 and the prism 20 is filled with resin is formed, the optical flatness is sufficiently ensured.

  Next, an assembly manufacturing procedure of the optical pickup device according to the present embodiment will be described. FIG. 7 is a manufacturing flowchart of the optical pickup device according to the present embodiment. In STEP 01, each component used in the optical pickup device according to the present embodiment is manufactured. Here, regarding the manufacture of the other components excluding the hologram element 70 and the resin-filled layer 90, it is assumed that an appropriate material is selected and manufactured in accordance with the conventional technology. The design of the hologram element 70 is as described above, and since it has a single-layer diffraction grating structure, it can be mass-produced by a resin molding method using a mold.

  In STEP02, the optical pickup device is assembled as appropriate.

  In STEP 03, after the optical pickup device is appropriately assembled in STEP 02, the liquid that is the basis of the resin filling layer 90 is dropped into the space between the prism 20 and the hologram element 70, and the grating surface of the diffraction grating 71 and the optical of the prism 20 are dropped. Adhere to the surface.

  Next, the position of the hologram element 70 is adjusted in STEP 04. In the initial stage of assembling the optical pickup device, there is a high possibility that the positions of the hologram element 70 and the light receiving unit 61 are shifted from the best positions. Therefore, a reference disc for BD is used to make a playback state. While measuring the focus error signal, the track error signal, and the RF signal, the hologram element 70 is adjusted to a position where the signal reproduction state is the best.

  As described with reference to FIG. 2, the hologram element 70 is assembled in a structure in which the slide position can be adjusted in the x direction, and the position is fixed so as to obtain the best reproduction performance while reproducing the reference optical disc. For adjusting the slide position, for example, an optical pin is provided in the prism support portion 13 with a hole for inserting and rotating an adjustment pin having a groove at the tip, and the adjustment holder 14 is slid and adjusted according to the rotation, thereby providing an optical system. Adjustment after assembly is easily possible.

  Subsequently, the reproduction state of the DVD is confirmed using the reference disk for DVD. Check the playback status of the CD using the reference disc for the CD.

  In STEP 05, when it is confirmed in STEP 04 that all reproduction states of BD, DVD, and CD satisfy the standard, the resin of the resin filling layer 90 is cured by irradiating with ultraviolet rays.

  The laser wavelength of the semiconductor laser for BD is emitted in a narrow wavelength range from 400 nm to 410 nm. Since the laser beam of the wavelength is transmitted through the resin filled layer 90 in order to reproduce the BD reference disk at the time of the assembly adjustment, a material that can be used in the resin filled layer 90 starts a curing reaction outside the wavelength range. Need to design.

  The ultraviolet curable resin used for the resin filling layer 90 uses a material that initiates a curing reaction at a wavelength of 365 nm of the LED light source.

  The ultraviolet irradiation device has a wide wavelength range characteristic of 200 nm to 450 nm with the conventional halogen lamp light source, but an LED light source can be used, and the central wavelength can be limited to 365 nm and the wavelength range can be limited to 350 nm to 380 nm. In addition, the generation of heat due to irradiation is extremely small in the LED light source, and there is no generation of distortion due to heat, and this method is suitable for resin curing in the optical path. By using such an ultraviolet curable resin material of the resin filling layer 90 and an ultraviolet curing device, the desired resin filling layer 90 can be manufactured without any problem in optical performance during the optical pickup assembly process.

  In STEP 06, an ultraviolet curable structural adhesive is applied between the photodetector 60 and the light source unit 10, and is cured and fixed by irradiation with ultraviolet rays. As a fixing method of the photodetector unit 60, a halogen lamp light source can be used as usual.

  As described above, by applying the refractive index and material selection and manufacturing method of the hologram element 70 and the resin-filled layer 90, the diffraction efficiency of the hologram element diffraction grating can be broadened to encompass BD, DVD, and CD reproduction wavelengths. Therefore, it is possible to suppress the generation of flare and unnecessary stray light that are irradiated to the photodetector due to the loss of diffraction. This eliminates errors generated in the focus error signal and track error signal generated from the received reflected light, enables accurate objective lens position control, and increases the likelihood of performance stability of the optical disc apparatus. Can do.

  Furthermore, since the diffraction grating surface of the hologram element is covered by the resin filling layer, dust and dust are not attached, and a dustproof effect is obtained.

  Since the prism and the hologram element are rigidly bonded by the resin-filled layer, they are less susceptible to environmental changes such as temperature and humidity, and the environmental resistance performance of the optical pickup is improved.

DESCRIPTION OF SYMBOLS 1 Reflected light from optical disk 10 Light source part 13 Prism support part 20 Prism 60 Photodetector part 61 Light receiving part 70 Hologram element 71 Diffraction grating 75 Groove part 80 Cylindrical lens 90 Resin filling layer

Claims (8)

A diffractive optical element that is provided on an optical path of reflected light that enters a photodetector from an optical disk having a plurality of recording layers, has a diffraction grating on a surface on which the reflected light is incident, and transmits light having a wavelength in a predetermined range When,
A second optical element provided on the optical path facing the surface of the diffractive optical element having the diffraction grating;
An optical pickup device comprising: a resin-filled layer filled with a resin that transmits light having a wavelength in the predetermined range on an optical path between the diffractive optical element and the second optical element. 2. The optical pickup device according to claim 1, wherein the grating material of the diffractive optical element is made of a material having a higher refractive index and a lower dispersion rate than a grating material made of the resin-filled layer. 3. The optical pickup according to claim 1, wherein the resin has a characteristic that a curing reaction proceeds by irradiating ultraviolet rays having a wavelength ranging from 350 nm to 380 nm with a wavelength of 365 nm as a center. apparatus. 4. The optical pickup device according to claim 1, wherein the diffraction grating includes a plurality of walls which are independent walls and do not intersect with each other. 5. A first step of providing a diffractive optical element having a diffraction grating on one surface and transmitting light of a wavelength in a predetermined range, and providing a second optical element so as to face the surface having the diffraction grating;
A second step of filling a space between the diffractive optical element and the second optical element in a liquid state with a resin material that undergoes a curing reaction with ultraviolet rays of a predetermined wavelength;
A method of manufacturing an optical pickup device comprising: a third step of forming a resin-filled layer by curing the resin material with ultraviolet rays having the predetermined wavelength after the second step. 6. The method of manufacturing an optical pickup device according to claim 5, wherein in the third step, the resin material is irradiated with ultraviolet rays from an LED light source having a wavelength of 365 nm as the ultraviolet rays having the predetermined wavelength. The fourth step of adjusting the optical axes of the diffractive optical element and the second optical element is performed between the second step and the third step. The manufacturing method of the optical pick-up apparatus of description. In the first step, the second optical element is supported by a support portion having a cavity, and the entire diffractive optical element or the diffraction grating enters the cavity, and slide adjustment is performed in a direction perpendicular to the optical axis of the reflected light. It is provided as possible,
The space for the second step is in the cavity;
8. The method of manufacturing an optical pickup device according to claim 7, wherein the fourth step is a slide adjustment in a direction orthogonal to the optical axis of the reflected light.

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