JP2004013081A - Composite optical element, method for manufacturing the same, and optical apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite optical element having high adhesion strength though the composite optical element has an optical face consisting of joining faces made of resins. <P>SOLUTION: The composite optical element is formed by sticking together at least two optical layers 11, 12 made of the resins and having different refractive indexes at the optical face of each of the optical layers. Where, a thin film 13 having good adhesion to the two resins is provided between the two optical layers 11, 12. Optimizing the material of the thin film 13 suppresses a decrease in optical performance caused by thin film formation. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a composite optical element having a joint surface between resins in an optical path, a method of manufacturing the composite optical element, and an optical device.
[0002]
[Prior art]
BACKGROUND ART Optical elements made of resin (so-called plastic optical elements) have been widely used in various optical systems and optical devices, replacing a part of glass optical elements.
For example, at present, most of eyeglass lenses are formed by molding a heat-curable resin or an ultraviolet-curable resin. Most of the pickup lenses of the optical disk drive are formed by molding (injection molding) a thermoplastic resin.
[0003]
The background behind the practical use of resin-made optical elements in this way is the advancement of molding technology in addition to the practical use of optical resins having various refractive indexes and dispersions due to the progress of material technology. .
Actually, the initial optical element made of resin was only a single lens, but with the advance of molding technology, a composite optical element formed by bonding resin to glass has been put to practical use.
[0004]
For example, a resin is formed by bonding (adhering) a resin onto a glass lens processed into a spherical surface and forming the surface of the resin into an aspherical surface. This is called a compound aspheric lens, and is applied to a camera lens or the like.
In recent years, it has been proposed that the diffractive optical element is also a composite type. The composite diffractive optical element forms a concavo-convex pattern at an interface between two layers, and the interface functions as a diffraction surface. For example, JP-A-9-127321 discloses a diffractive optical element having a two-layer structure, and JP-A-9-127322 discloses a diffractive optical element having a three-layer structure. These composite type diffractive optical elements have a characteristic that the diffraction efficiency is almost constant over a wide wavelength range, and are particularly effective for correcting chromatic aberration of a camera lens or the like.
[0005]
Further, as for the material to be composited, not only the combination of glass and resin, but also the combination of resins (different resins) has become possible due to the advance of the material technology of the optical resin. JP-A-9-127321 and JP-A-9-127322 also propose the compounding of resins.
[0006]
[Problems to be solved by the invention]
However, a composite optical element formed by laminating a resin has not yet reached the level of practical use despite being proposed. The reason is that, since the adhesive strength at the interface between the laminated resins is low, the environmental resistance of the composite optical element and the optical device equipped with the composite optical element are low, and the reliability is low.
[0007]
In particular, the complex type diffractive optical element needs to have an interface that is a "discontinuous optical surface" (an optical surface that is not as smooth as a simple refraction surface and has a discontinuous surface inclination). Even if resin is laminated, the adhesion strength tends to be low.
Therefore, the present invention provides a composite optical element having a high adhesion strength while having an optical surface formed of a bonding surface between resins, a method of manufacturing the composite optical element, and an optical element having high performance and high environmental resistance. It is intended to provide a device.
[0008]
[Means for Solving the Problems]
The composite optical element according to claim 1, wherein at least two resin optical layers having different refractive indices are laminated on an optical surface of the optical layer, wherein the composite optical element is disposed between the two optical layers. And a transparent thin film having good adhesion to the two resins.
[0009]
The composite optical element according to claim 2 is the composite optical element according to claim 1, wherein a difference in refractive index between the thin film and one of the two optical layers is suppressed to 0.01 or less. It is characterized by having.
A composite optical element according to a third aspect is the composite optical element according to the first or second aspect, wherein the thin film is made of an inorganic oxide.
[0010]
The composite optical element according to claim 4 is the composite optical element according to any one of claims 1 to 3, wherein the optical surface of the optical layer is a discontinuous optical surface. Features.
The composite optical element according to claim 5 is the composite optical element according to claim 4, wherein the thickness of the thin film is within 1/10 of the height of irregularities provided on the optical surface of the optical layer. It is characterized by being.
[0011]
The method of manufacturing a composite optical element according to claim 6 is a method of manufacturing a composite optical element in which a first optical layer and a second optical layer made of resins having different refractive indexes are laminated. A first forming procedure for forming the first optical layer, and forming the first optical layer and the second optical layer on an optical surface of the formed first optical layer. And a second forming step of forming the second optical layer on the thin film.
[0012]
A method of manufacturing a composite optical element according to claim 7, wherein in the method of manufacturing a composite optical element according to claim 6, in the film forming procedure, the material of the thin film is the thin film and the second optical element. It is characterized in that the refractive index is selected so as to be 0.01 or less with respect to the layer.
The method of manufacturing a composite optical element according to claim 8 is the method of manufacturing a composite optical element according to claim 6 or 7, wherein an inorganic oxide is formed in the film forming procedure. And
[0013]
According to a ninth aspect of the present invention, in the method of manufacturing a composite optical element according to the eighth aspect, in the film forming procedure, the inorganic oxide is formed by a vacuum film forming method. It is characterized.
The method of manufacturing a composite optical element according to claim 10 is the method of manufacturing a composite optical element according to claim 8 or 9, wherein the film forming procedure includes the step of silane coupling to the thin film after film formation. Processing is performed.
[0014]
The method of manufacturing a composite optical element according to claim 11 is the method of manufacturing a composite optical element according to any one of claims 6 to 10. The optical surface of the optical layer is processed into a discontinuous optical surface. The method of manufacturing a composite optical element according to claim 12 is the method of manufacturing a composite optical element according to claim 11, wherein, in the film forming procedure, the thickness of the thin film is set to the thickness of the first optical layer. The height is set within 1/10 of the height of the unevenness on the optical surface.
[0015]
An optical device according to a thirteenth aspect is an optical device that imparts predetermined optical characteristics to incident light, and includes at least one composite optical element according to any one of the first to fifth aspects. It is characterized by the following.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to FIGS. 1, 2, 3, 4, 5, 6, and 7. FIG.
[0017]
In the present embodiment, a composite optical element having an optical surface composed of a bonding surface between resins is manufactured.
FIG. 1 is a diagram illustrating the configuration of the composite optical element according to the present embodiment.
The composite optical element of the present embodiment is formed by joining a first optical layer 11 (refractive index n ₁ ) and a second optical layer 12 (refractive index n ₂ ) made of resin having different refractive indexes. This is a composite diffractive optical element having a layer structure.
[0018]
This composite type diffractive optical element is characterized in that the first optical layer 11 and the second optical layer 12 are joined via a thin film 13 on each optical surface.
Incidentally, in the composite optical element shown in FIG. 1, the cross section of the bonding surface S1 between the first optical layer 11 and the second optical layer 12 is a rectangular diffraction surface. The front surface (interface with the outside) 12a of the second optical layer 12 and the back surface (interface with the outside) 11b of the first optical layer 11 are flat.
[0019]
The present invention can be applied to another composite optical element in which the number of layers and the type of each optical surface are different from those described above. Incidentally, the number of layers is determined according to the number of optical surfaces to be provided to the composite optical element (that is, the number of functions), and the shape of each optical surface is determined according to the type of function to be provided to each optical surface. Is determined.
For example, depending on the shape of the optical surface, a blazed diffraction grating (consisting of a saw-toothed uneven pattern) as shown in FIG. 2A, and a phase-type Fresnel zone plate as shown in FIG. (Consisting of an annular concavo-convex pattern in which the forming pitch varies depending on the radial position), a binary optical element (consisting of a step-like concavo-convex pattern) as shown in FIG. 2C, and as shown in FIG. 2D. Each function such as a microlens array (comprising a plurality of minute convex or concave patterns) can be provided. Although not shown, the function of a concave or convex refraction lens or prism can be imparted to the optical surface.
[0020]
Hereinafter, a case where the bonding surface S1 is a rectangular diffraction surface and the surface 12a of the second optical layer 12 is a flat refraction surface (see FIG. 1) will be described.
Light incident on the composite optical element from the side of the first optical layer 11 depends on the difference in the refractive index between the first optical layer 11 and the second optical layer 12 at the joint surface s1. The traveling direction is changed, and further, on the surface 12a of the second optical layer 12, the traveling direction is changed according to the difference in the refractive index between the second optical layer 12 and the outside world (for example, air). Further, since the bonding surface S1 is a diffraction surface, diffracted light is generated at the bonding surface S1 according to the difference in the refractive index and the period of the unevenness of the diffraction surface.
[0021]
FIG. 3 is a diagram illustrating a procedure for manufacturing the composite optical element of the present embodiment.
The manufacturing procedure of the composite optical element of the present embodiment is roughly divided into the following steps 1 to 3.
Step 1: Step of forming the first optical layer 11 made of resin (including processing of the surface 11a of the first optical layer 11) (FIG. 3A)
Step 2: Step of forming a thin film 13 on the surface 11a of the first optical layer 11 (FIG. 3B)
Step 3: a step of forming the second optical layer 12 on the thin film 13 (including processing of the surface 12a of the second optical layer 12) (FIG. 3C)
Hereinafter, each step will be described in more detail.
[0022]
(Step 1)
As a method for forming the first optical layer 11 made of resin, any of the well-known forming methods can be applied.
For example, a prototype of the first optical layer 11 (optical resin having a refractive index n ₁₎ is prepared, the surface of the original, for example, to form the cutting, grinding, the surface 11a is subjected to mechanical processing such as grinding .
[0023]
Incidentally, the optical resin used for the first optical layer 11 includes, for example, polycarbonate, polystyrene, polymethyl methacrylate, diethylene glycol bisallyl carbonate, polymethyl methacrylate, polytrifluoromethyl methacrylate, and polybutyl isobutyl methacrylate. , Polymethyl acrylate, poly α-bromomethyl acrylate, poly-2,3-dibromopropyl methacrylate, diallyl phthalate, polyphenyl methacrylate, poly (vinyl benzoate), poly (pentachlorophenyl methacrylate), polychlorostyrene , Polyvinyl naphthalene, polyvinyl carbazole, silicone polymer, acrylic resin, urethane resin, epoxy resin, ene-thiol resin, thiourethane resin, epoxy resin, etc. And a resin material, it is possible to use a photopolymer.
[0024]
In addition to the mechanical processing, processing such as dry etching and hologram (irradiating the photopolymer with interference light) can be applied to the processing of the surface 11a.
Alternatively, the first optical layer 11 (along with its surface 11a) may be formed. As a molding method, in addition to injection molding, molding with a photo-curable resin and molding with a heat-curable resin can be applied.
[0025]
Of these, molding with a photocurable resin is preferable from the viewpoints of abundant types of materials, high shape transferability, high productivity, and the like.
(Step 2)
The thin film 13 has a property of being in intimate contact with both the first optical layer 11 and a second optical layer 12 to be described later, and a property of sufficiently transmitting light having a wavelength used by the composite optical element (transmittance). .
[0026]
To form such a thin film 13, any one of the following (thin film forming method 1) and (thin film forming method 2) methods can be applied.
(Thin film forming method 1) An epoxy-based, acrylic-based, cyanoacrylate-based, or urethane-based adhesive is thinly applied.
(Thin Film Forming Method 2) A thin inorganic oxide film is formed, and preferably, a silane coupling treatment is performed after the film formation.
[0027]
Here, it is preferable that the thin film 13 is formed as thin as possible (details will be described later). In this regard, (thin film forming method 2) is preferable because (thin film forming method 1) can be made thinner. In addition, according to the (thin film forming method 2), the uniformity of the thin film 13 can be increased, which is preferable. (Thin film forming method 2) is also preferable in that it is easy to set the refractive index of the thin film 13 to a desired value (described later).
[0028]
Hereinafter, (Thin film forming method 2) will be described in detail.
There is no particular limitation on the type of inorganic oxide to be used as the material of the thin film 13. For example, silicon oxide SiO ₂ , titanium oxide TiO ₂ , aluminum oxide Al ₂ O ₃ , tin (II) oxide SnO ₂ , zirconium oxide ZrO One or a mixture of _two .
[0029]
If mixed, the control of the refractive index of the thin film 13 is further facilitated. For example, the refractive index of the thin film 13 can be variously set by mixing low refractive index silicon oxide SiO ₂ and high refractive index titanium oxide TiO ₂ and adjusting the mixing ratio.
As a method for forming the inorganic oxide film, a vacuum film forming method such as vacuum evaporation or sputtering, or a so-called sol-gel method in which an alcohol solution of an inorganic oxide alkoxide is heated after application is applicable.
[0030]
Note that the former vacuum film forming method is preferable because the uniformity of the thin film 13 can be improved and the thin film 13 can be made thinner. It is also preferable in that the adhesion between the first optical layer 11 and the second optical layer 12 is surely increased without complicated post-processing or pre-processing.
In order to surely increase the adhesion in the sol-gel method, it is necessary to activate the first interface 11a in advance. Activation methods include ultraviolet irradiation, immersion in an alkaline solution, and plasma irradiation.
[0031]
Further, in this (thin film forming method 2), in order to further strengthen the adhesion between the surface 13a of the thin film 13 and the second optical layer 12 formed thereafter, the surface 13a after film formation is It is preferable to perform a silane coupling treatment.
In the silane coupling treatment, for example, a water / alcohol solution of a silane coupling agent (acetic acid is added if necessary) is applied to the surface 13a of the thin film 13 by dipping or spin coating, and then heated to about 80 degrees. .
[0032]
(Step 3)
As a method for forming the second optical layers 12 (an optical resin having a refractive index n _2), any of various methods can be applied (described above) to form the first optical layers 11 are formed can be applied. As the molding, in addition to injection molding, molding with a photocurable resin and molding with a heat curable resin can be applied.
[0033]
Of these, molding with a photocurable resin is preferable from the viewpoints of abundant types of materials, high shape transferability, high productivity, and the like.
Hereinafter, a case where molding using a photocurable resin is applied will be described.
FIG. 4 is a diagram for explaining in detail a method of forming the second optical layer 12 (molding with a photocurable resin).
[0034]
On the surface 13a of the thin film 13, dropping the uncured material 12 'of the proper amount of the photocurable resin (refractive index _{n 2)} (Figure 4 (a)).
Next, a mold 15 (FIG. 4 (b)) having a molding surface 15a having an inverted shape (in this case, a plane) of the surface 12a of the second optical layer 12 is prepared, and the molding surface 15a is placed on the surface 13a. The second optical layer 12 is brought closer by the designed value of the thickness, and light for curing is irradiated from the side of the first optical layer 11 (FIG. 4C) to cure the uncured material 12 '. Let it. When the curing is completed, the light irradiation is stopped and the mold is released (FIG. 4D).
[0035]
If a mold made of a transparent member such as glass (a member transparent to curing light) is used instead of the mold 15, curing light can be irradiated from the opposite direction to the above-described irradiation direction.
FIG. 5 is a partially enlarged view of a cross section of the composite optical element of the present embodiment.
In the composite optical element of the present embodiment manufactured as described above, a thin film 13 is provided on the bonding surface S1 between the first optical layer 11 and the second optical layer 12, as shown in FIG. Intervene. It is desirable that the thin film 13 does not affect the optical performance of the composite optical element, in particular, the optical function (here, the diffraction function) of the bonding surface S1.
[0036]
Therefore, in the present embodiment, the thickness t of the thin film 13 is as thin as possible, and at least the height of the unevenness provided on the bonding surface S1 (here, the height of the unevenness provided on the surface 11a of the first optical layer 11). It is preferable that the height can be suppressed within 1/10 of L. When the vacuum film forming method is applied to the above step 2, the thickness t of the thin film 13 can be easily controlled by the film forming time or the like.
[0037]
By the way, since the thin film 13 is formed in close contact with the surface 11a of the first optical layer 11, the interface (the surface 11a) between the first optical layer 11 and the thin film 13 has the optical function of the bonding surface S1. There is no possibility to make it worse.
However, the interface (surface 13a) between the thin film 13 and the second optical layer 12 may have poor surface accuracy depending on the film formation accuracy of the thin film 13 in step 2, so that the optical function of the bonding surface S1 May worsen.
[0038]
Therefore, in the present embodiment, the refractive index difference between the thin film 13 and the second optical layer 12 is set to be sufficiently smaller than the refractive index difference between the first optical layer 11 and the second optical layer 12. That is, the refractive index of the thin film 13 is preferably set to a value as close as possible to that of the second optical layer 12. Substantially, the refractive index difference may be 0.01 or less.
As described above, if the difference in the refractive index between the thin film 13 and the second optical layer 12 is small, even if the surface accuracy of the surface 13a of the thin film 13 is somewhat poor, the deviation in the traveling direction of the incident light on the surface 13a becomes small. Therefore, the thin film 13 can be optically regarded as the same layer as the second optical layer 12. Therefore, the influence of the surface 13a is almost eliminated.
[0039]
When (the thin film forming method 1) is applied to the above step 2, the refractive index of the thin film 13 can be set by optimizing the type of the adhesive to be used.
When (thin film forming method 2) is applied to the above step 2, the refractive index of the thin film 13 is optimized by optimizing the type of the inorganic oxide to be used, or the combination of the inorganic oxide to be used and the mixing ratio thereof. Can be set by optimization.
[0040]
FIG. 6 is a diagram illustrating a variation of the layer structure of the composite optical element of the present embodiment.
In the above embodiment, the composite optical element having a two-layer structure has been described. However, since the optical element may have a multilayer structure of three or more, a supplementary description will be given below.
First, in order to form a multilayer structure having three or more layers, the above steps 2 and 3 may be repeated.
[0041]
At this time, the refractive index difference between the n-th thin film 13 _n (thin film formed on the surface of the _n- th optical layer 11 _n ) and the (n + 1) -th optical layer 11 _{(n + 1)} is equal to the n-th optical layer 11 _n and preferably set sufficiently small relative to the refractive index difference between the optical layer 11 _{(n + 1)} of the (n + 1).
That is, it is preferable that the refractive index nn of the _{n- th} thin film 13 _n be as close as possible to the refractive index of the _{(n + 1) -th} optical layer 11 _{(n + 1)} to be formed thereafter. It is desirable to set it to 0.01 or less.
[0042]
Although the final surface a (surface) of the composite optical element is a flat refraction surface in FIG. 6, other optical surfaces (for example, a convex spherical surface or aspherical surface, a concave spherical surface or an aspherical surface, or a diffraction surface). Needless to say, the surface may be a discontinuous optical surface such as a surface.
Further, in the present embodiment, each optical surface of the composite optical element is a flat surface, or an uneven pattern is formed on the flat surface, but a concave spherical surface or an aspheric surface, a convex spherical surface or an aspheric surface, or An uneven pattern may be formed on those curved surfaces.
[0043]
In the present embodiment, the composite optical element including only the resin optical layer is described. However, the present invention is also applicable to a resin optical layer laminated on a glass substrate (described later). Example).
Incidentally, a composite optical element comprising only a resin optical layer can be manufactured by laminating a resin optical layer on a glass substrate and then peeling off the glass substrate.
[0044]
Further, in the present embodiment, if the respective materials of the two adjacent resinous optical layers are selected so that not only the refractive index but also the dispersion characteristics are different from each other, and if the joint surface thereof is a diffractive surface, a wide range can be obtained. A composite diffractive optical element having high diffraction efficiency over a wavelength range can be realized.
Such composite type diffractive optical elements include cameras, microscopes, binoculars, telescopes, head mounted displays, etc., as well as industrial equipment such as semiconductor manufacturing equipment (particularly its alignment optical system and illumination optical system) and machine tools, The present invention is widely applicable to measuring devices such as spectrophotometers, electric devices used for optical communication, amplifiers, duplexers, and optical devices such as optical transceivers and optical circuit elements.
[0045]
FIG. 7 is a diagram showing an example in which the composite optical element of the present invention is applied to an imaging optical system (a so-called interchangeable lens) of a camera system. This imaging optical system is detachable from a camera body (not shown).
In FIG. 7, an arrow indicates the composite optical element 10 (the thin film 3 is formed on the joint surface S between the resin layers 1 and 2) to which the present invention is applied. The shape of each optical surface including the bonding surface S of the composite optical element 10 and the material of each optical layer and thin film are selected so as to correct the chromatic aberration of the imaging optical system. This enhances the performance of the imaging optical system.
[0046]
Since the composite optical element 10 has a high adhesion strength between the bonding surfaces S of the resin layers 1 and 2, not only improves the overall performance of the imaging optical system, but also the environment resistance of the imaging optical system and, consequently, the camera system. Can also maintain high environmental resistance.
Needless to say, the composite optical element of the present invention can be applied to a lens-integrated camera.
[0047]
【Example】
An embodiment of the present invention will be described with reference to FIGS.
In the present embodiment, a composite Fresnel zone plate in which a first optical layer 21 and a second optical layer 22 are laminated on a glass substrate 20 is manufactured (see FIG. 10C).
[0048]
FIG. 8 is a diagram illustrating a procedure for forming the first optical layer 21, FIG. 9 is a diagram illustrating a procedure for forming the thin film 23, and FIG. 10 is a diagram illustrating a procedure for forming the second optical layer 22.
First, as a material of the first optical layer 21, a mixture of hexafunctional cyclic urethane acrylate and isobornyl methacrylate (refractive index nd ₁ = 1.490 for d-line), which is a kind of ultraviolet curable resin, is prepared. An uncured product 21 ′ of this mixture was dropped on a glass substrate (optical glass) 20 (FIG. 8A).
[0049]
A mold 25 having a molding surface 25a having an inverted shape of the Fresnel zone plate (grating height T = 12.4 μm, pitch 3 mm (central part) to 160 μm (peripheral part)) as shown in FIG. 8B is prepared. Then, the molding surface 25a was applied to the surface of the uncured material 21 'to spread it over the entire glass substrate 20, and irradiated with ultraviolet light (UV) from the glass substrate 20 side (FIG. 8C).
[0050]
Thereafter, when the uncured material 21 ′ was cured, the irradiation of the ultraviolet rays was stopped, and the mold was released to complete the first optical layer 21 (FIG. 8D).
Further, a mixed film of silicon oxide SiO ₂ and titanium oxide TiO ₂ (refractive index n ₃ = 1.54) is formed on the first optical layer 21 as the thin film 23, and the thickness t becomes about 0.1 μm. A film was formed by a vacuum deposition method as shown in FIGS. 9A and 9B.
[0051]
Thereafter, an acetic acid / ethanol solution of γ-methacryloxypropyltrimethoxysilane as a silane coupling agent was spin-coated on the surface 23a of the thin film 23, and then subjected to a heat treatment at 80 ° C. for 5 minutes (FIG. 9C). .
Next, as a material of the second optical layer 22, ethoxylated bisphenol A dimethacrylate (refractive index nd ₂ = 1.541 for d-line), which is a kind of ultraviolet curable resin, is prepared, and the uncured product 22 ′ is obtained. Was dropped on the surface 23a of the thin film 23 (FIG. 10A).
[0052]
A mold 15 having a flat molding surface 15a as shown in FIG. 10B is prepared, and the molding surface 15a is applied to the surface of the uncured material 22 'and is spread over the entire first optical layer 21. At the same time, ultraviolet rays (UV) were irradiated from the glass substrate 20 side.
Thereafter, when the uncured material 22 'was cured, the irradiation of the ultraviolet rays was stopped, and the mold was released to complete the second optical layer 22 (FIG. 10C).
[0053]
The composite Fresnel zone plate completed as described above has the thin film 23 (mixed film of silicon oxide SiO ₂ and titanium oxide TiO ₂ ) formed on the bonding surface S2, and thus the first optical layer 21 The second optical layer 22 adhered firmly.
[0054]
Moreover, the thickness t (= 0.1 μm) of the thin film 23 is sufficiently smaller than the height T (= 12.4 μm) of the unevenness of the zone plate, and the refractive index n ₃ (= 1.54). ) Is sufficiently close to the refractive index n ₂ (= 1.541) of the second optical layer 22, so that a sufficiently high function as a zone plate was obtained.
[0055]
【The invention's effect】
INDUSTRIAL APPLICABILITY As described above, according to the present invention, a composite optical element having a high adhesion strength while having an optical surface composed of a bonding surface between resins, a method of manufacturing the composite optical element, and high performance and environmental resistance Optical device with a high level is realized.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a configuration of a composite optical element according to an embodiment.
FIG. 2 is a view showing a variation of a bonding surface S1 of the composite optical element.
FIG. 3 is a diagram illustrating a manufacturing procedure of the composite optical element according to the embodiment.
FIG. 4 is a diagram illustrating in detail a method of forming the second optical layer 12 (molding with a photocurable resin).
FIG. 5 is a partially enlarged view of a cross section of the composite optical element of the embodiment.
FIG. 6 is a diagram illustrating a variation of the layer structure of the composite optical element according to the embodiment.
FIG. 7 is a diagram showing an example in which the composite optical element of the present invention is applied to an imaging optical system (interchangeable lens) of a camera system.
FIG. 8 is a diagram illustrating a procedure for forming a first optical layer 21 according to the embodiment.
FIG. 9 is a diagram illustrating a procedure for forming a thin film 23 according to an example.
FIG. 10 is a diagram illustrating a procedure for forming a second optical layer 22 according to the embodiment.
[Explanation of symbols]
1,11,21 1st optical layers 2,12,22 2nd optical layers 3,13,23, thin film 11n nth optical layer 13n nth thin film 12 ', 22' Material of second optical layer Uncured material 21 'of uncured material 15, 25 of first optical layer material Molds S1, S2, S

Claims (13)

In a composite optical element in which at least two resin optical layers having different refractive indexes are laminated on the optical surface of the optical layer,
A composite optical element comprising a transparent thin film having good adhesion to the two resins between the two optical layers. The composite optical element according to claim 1,
A composite optical element, wherein a difference in refractive index between the thin film and one of the two optical layers is suppressed to 0.01 or less. The composite optical element according to claim 1 or 2,
The composite optical element, wherein the thin film is made of an inorganic oxide. The composite optical element according to any one of claims 1 to 3,
The composite optical element, wherein the optical surface of the optical layer is a discontinuous optical surface. The composite optical element according to claim 4,
The composite optical element according to claim 1, wherein a thickness of the thin film is within 1/10 of a height of irregularities provided on an optical surface of the optical layer. A method of manufacturing a composite optical element for manufacturing a composite optical element in which a first optical layer and a second optical layer made of resins having different refractive indexes are laminated,
A first forming procedure for forming the first optical layer;
A film forming procedure of forming a transparent thin film in close contact with both the first optical layer and the second optical layer on the optical surface of the formed first optical layer;
A second forming step of forming the second optical layer on the thin film. The method for manufacturing a composite optical element according to claim 6,
In the film forming procedure,
A method for manufacturing a composite optical element, wherein a material of the thin film is selected such that a difference in refractive index between the thin film and the second optical layer is 0.01 or less. The method for manufacturing a composite optical element according to claim 6 or 7,
In the film forming procedure,
A method for producing a composite optical element, comprising forming an inorganic oxide film. The method for manufacturing a composite optical element according to claim 8,
In the film forming procedure,
A method of manufacturing a composite optical element, comprising forming the inorganic oxide by a vacuum film forming method. The method for manufacturing a composite optical element according to claim 8 or 9,
In the film forming procedure,
A method for producing a composite optical element, comprising subjecting the thin film after film formation to a silane coupling treatment. The method for manufacturing a composite optical element according to any one of claims 6 to 10,
In the first forming procedure,
A method of manufacturing a composite optical element, comprising processing an optical surface of the first optical layer into a discontinuous optical surface. The method for manufacturing a composite optical element according to claim 11,
In the film forming procedure,
A method of manufacturing a composite optical element, wherein a thickness of the thin film is set to be within 1/10 of a height of irregularities on an optical surface of the first optical layer. In an optical device that imparts predetermined optical characteristics to incident light,
An optical device comprising at least one composite optical element according to claim 1.

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