WO2018180269A1 - 光学素子および光学素子の製造方法 - Google Patents

光学素子および光学素子の製造方法 Download PDF

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Publication number
WO2018180269A1
WO2018180269A1 PCT/JP2018/008493 JP2018008493W WO2018180269A1 WO 2018180269 A1 WO2018180269 A1 WO 2018180269A1 JP 2018008493 W JP2018008493 W JP 2018008493W WO 2018180269 A1 WO2018180269 A1 WO 2018180269A1
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WIPO (PCT)
Prior art keywords
optical element
light
optical
optical filter
adhesive layer
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PCT/JP2018/008493
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English (en)
French (fr)
Japanese (ja)
Inventor
剛守 若林
大井　好晴
本間　雅彦
正宙 南舘
Original Assignee
Ａｇｃ株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Application filed by Ａｇｃ株式会社 filed Critical Ａｇｃ株式会社
Priority to JP2019509098A priority Critical patent/JPWO2018180269A1/ja
Priority to CN201880020783.6A priority patent/CN110462458A/zh
Publication of WO2018180269A1 publication Critical patent/WO2018180269A1/ja

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/04—Prisms
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/20—Filters
    • G02B5/22—Absorbing filters
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/20—Filters
    • G02B5/26—Reflecting filters
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/20—Filters
    • G02B5/28—Interference filters
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B7/00—Mountings, adjusting means, or light-tight connections, for optical elements
    • G02B7/18—Mountings, adjusting means, or light-tight connections, for optical elements for prisms; for mirrors

Definitions

  • the present invention relates to an optical element and a method for manufacturing the optical element.
  • an image pickup apparatus equipped with a solid-state image pickup device such as a CCD or a CMOS image sensor has been further reduced in size and functionality.
  • a solid-state image pickup device such as a CCD or a CMOS image sensor
  • the size can be reduced by using a deflection element such as a prism that bends light.
  • Patent Document 1 includes a prism that bends light transmitted through an imaging lens group, and a cover glass that transmits light bent by the prism, and includes an exit surface of the prism that emits light, and an incident surface of the cover glass. Describes an imaging apparatus using an optical component bonded with an optically transparent adhesive.
  • the present invention provides an optical element that integrates a deflecting element that bends light and an optical filter and that is easy to manufacture with little light loss, and an optical element in which the deflecting element and the optical filter are integrated by an adhesive layer.
  • the object is to provide a manufacturing method.
  • the optical element of the present invention selectively deflects light that deflects incident light and emits light in at least a part of the region from the ultraviolet region to the near infrared region that is located on the incident side or the emission side of the deflection element.
  • the refractive index of the member having the maximum layer thickness among the members included in the optical filter is n F , the relationship of the following expressions (1) and (2) is satisfied.
  • ⁇ n GF
  • ⁇ n PG
  • the optical element manufacturing method of the present invention includes a deflection element that deflects and emits incident light, and light in at least a part of the region from the ultraviolet region to the near infrared region that is located on the incident side or the emission side of the deflection element.
  • ⁇ 0.5 and ⁇ n PG
  • a step of producing a precursor, and said optics In the case where the optical element is used as a child precursor, the composition layer for forming the adhesive layer is cured by irradiating light in the ultraviolet region from the side which becomes the incident side when the optical element is used or the side which becomes the outgoing side when the optical element is used. Including a step of forming an adhesive layer.
  • an optical element that integrates a deflecting element that bends light and an optical filter and that is easy to manufacture with little optical loss. Further, according to the present invention, it is possible to provide a method for easily manufacturing an optical element in which a deflection element and an optical filter are integrated by an adhesive layer.
  • the optical element of the present invention is disposed and used immediately before the light receiving surface of a solid-state image pickup element, it is advantageous for downsizing of the image pickup apparatus.
  • FIG. 9B is a plan view of the optical element shown in FIG. 9A. It is sectional drawing which shows the modification of the optical element of embodiment which has a light shielding film. It is sectional drawing which shows the modification of the optical element of embodiment which has a light shielding film. It is a perspective view which shows the modification of the optical element of embodiment which has a light shielding film. It is sectional drawing which shows the modification of the optical element of embodiment which has a light shielding film.
  • FIG. 13B is a plan view of the optical element shown in FIG. 13A. It is sectional drawing which shows the modification of the optical element of embodiment which has a light shielding film.
  • FIG. 14B is a plan view of the optical element shown in FIG. 14A. It is sectional drawing which shows the optical element of a manufacture example.
  • UV ultraviolet light or ultraviolet light
  • NIR near infrared light or near infrared light
  • refractive index means a refractive index with respect to light having a wavelength of 589 nm.
  • “Curable material” refers to an uncured material that is cured by heating or light irradiation to become a cured material, and “cured material” is obtained by curing the curable material by heating or light irradiation. This refers to the cured product.
  • “to” representing a numerical range includes upper and lower limits.
  • the “incident side” of an optical element refers to a side where light enters the optical element from the light entering direction along the optical axis of the imaging device or the like when used.
  • the “emission side” of the optical element refers to a side on which light incident from the incident side of the optical element is deflected and emitted in a predetermined direction, for example, the direction of the element that receives the emitted light.
  • FIG. 1 is a cross-sectional view showing an example of the optical element of the present embodiment.
  • FIG. 2 is a cross-sectional view schematically showing an example of an imaging apparatus including the optical element of the present embodiment shown in FIG.
  • An optical element 10 shown in FIG. 1 selectively deflects incident light and deflects and emits light in at least a part of the region from the ultraviolet region to the near infrared region located on the exit side of the deflecting element 1.
  • An optical filter 2 to be blocked, and an adhesive layer 3 that is located between the deflection element 1 and the optical filter 2 and that integrates the deflection element 1 and the optical filter 2 are provided.
  • the optical filter 2 is located on the exit side of the deflecting element 1, but in the optical element of the present invention, the optical filter 2 may be located on the incident side of the deflecting element 1.
  • the optical element 10 is arranged in the order of the optical filter 2, the adhesive layer 3, and the deflection element 1 from the light incident side.
  • a direction in which light is emitted from the deflection element 1 is defined as a Z-axis direction, and two directions perpendicular to the Z-axis direction and perpendicular to each other are defined as an X-axis direction (a direction perpendicular to the paper surface).
  • the Y-axis direction (direction parallel to the paper surface) is defined.
  • the Z-axis direction is referred to as the “Z direction”.
  • the X direction, the Y direction, and the Z direction are the same as those shown in FIG. 1 and 2 are YZ sectional views.
  • the refractive index of the deflecting element 1 is n P
  • the refractive index of the adhesive layer 3 is n G
  • the member having the largest layer thickness among the members included in the optical filter 2 (hereinafter referred to as “thickest member”).
  • n GF
  • ⁇ n PG
  • the refractive index of the deflecting element is also referred to as “refractive index n P ”
  • the refractive index of the adhesive layer is also referred to as “refractive index n G ”
  • the refractive index of the thickest member included in the optical filter is also referred to as “refractive index n F ”.
  • the deflection element 1 is a right-angle prism, and has an incident surface 1a on which light is incident, a reflecting surface 1b that reflects incident light, and an emitting surface 1c that emits reflected light.
  • the adhesive layer 3 and the optical filter 2 each have two main surfaces parallel to the emission surface 1 c of the deflection element 1.
  • One of the two main surfaces of the adhesive layer 3 is a main surface in contact with the output surface 1c of the deflecting element 1, and is an incident surface 3a on which light emitted from the deflecting element 1 is incident, and the other emits the light. This is the exit surface 3b.
  • One of the two main surfaces of the optical filter 2 is a main surface in contact with the output surface 3b of the adhesive layer 3, and is an incident surface 2a on which light emitted from the adhesive layer 3 enters, and the other emits the light. This is the emission surface 2b.
  • the light is incident on the incident surface 1 a of the deflecting element 1 from the Y direction, deflected by reflection on the reflecting surface 1 b of the deflecting element 1, and then emitted from the emitting surface 1 c of the deflecting element 1 in the Z direction.
  • the light passes through the adhesive layer 3 and the optical filter 2 and is emitted from the emission surface 2 b of the optical filter 2 in the Z direction.
  • the optical element of the present embodiment combines the functions of the deflection element and the optical filter by integrating the deflection element and the optical filter using the adhesive layer as described above. That is, in the optical element of the present embodiment, the light incident from the incident surface is deflected, and at least a part of the light from the ultraviolet region to the near infrared region is selectively blocked and emitted. Thus, according to the optical element of the present embodiment, it is possible to reduce the size of the imaging apparatus. Furthermore, since the relationship between the refractive indexes of the deflecting element, the adhesive layer, and the optical filter satisfies the expressions (1) and (2), the optical loss of the optical element of the present embodiment is small.
  • FIG. 2 shows a configuration example of an imaging apparatus 100 having an objective lens 5, an object-side prism 6, an imaging lens group 8 (comprising lenses 81, 82, and 83), a lens moving mechanism 7, an optical element 10, and a solid-state imaging element 4. It is.
  • Incident light from the Z direction taken into the objective lens 5 is deflected in the Y direction by the reflecting surface of the object side prism 6, passes through the imaging lens group 8, and enters the optical element 10.
  • the light emitted from the optical element 10 enters the light receiving surface 41 of the solid-state image sensor 4 and is converted into an electrical signal.
  • the thickness of the imaging device 100 in the Z direction is reduced.
  • the imaging lens group 8 can be thinned by moving a part of the imaging lens group 8 in the Y direction by using a lens moving mechanism 7 such as a stepping motor, thereby providing a zoom lens function and a focus adjustment function.
  • a lens moving mechanism 7 such as a stepping motor
  • the optical element 10 is arranged so that incident light from the Y direction is deflected in the Z direction by the deflecting element 1 and emitted.
  • the optical element 10 may be arranged so as to be rotated by 90 ° about the Y direction as a rotation axis, and thereby the incident light from the Y direction is deflected in the X direction and emitted. it can.
  • the F number changes according to the aperture stop diameter.
  • the brightness changes.
  • ⁇ Deflection element> a right-angle prism is illustrated as the deflecting element 1.
  • incident light is deflected and emitted, and the expression (2) is expressed in relation to the refractive index with the adhesive layer.
  • n P refractive index
  • the deflection element include a diffraction element and a prism.
  • the diffractive element include a blazed reflection diffraction grating and a volume hologram diffractive element having a saw-shaped cross section.
  • the prism include a triangular prism and a free-form surface prism having a non-planar reflecting surface.
  • the blazed reflective diffraction grating exhibits a function as a deflecting element having high + 1st order diffraction efficiency at a predetermined diffraction angle, for example, by adjusting the grating material and the blazed shape.
  • a prism is preferable from the viewpoint of stably processing a high-precision optical reflecting surface, and a triangular prism is more preferable.
  • the angle formed by the incident surface and the output surface is 90 ° in the cross section of the YZ plane, and the angle formed by the incident surface and the reflective surface (for example, indicated by ⁇ in FIG. 3).
  • the angle between the reflecting surface and the exit surface is in the range of 40 to 50 °
  • the cross section of the YZ plane is an isosceles right triangle.
  • FIG. 3 is a schematic diagram showing the relationship between the incident angle ⁇ 0 and the outgoing angle ⁇ of light in the optical element 10 shown in FIG.
  • the deflection element 1 is a triangular prism having a YZ plane cross section with a right isosceles triangle and extending in the X direction, that is, a right angle prism (hereinafter, the deflection element 1 is also referred to as a right angle prism 1).
  • the angle between the incident surface 1a and the reflecting surface 1b of the right-angle prism 1 and the angle between the emitting surface 1c and the reflecting surface 1b are both 45 °.
  • the angle formed by the incident surface 1a and the reflecting surface 1b is denoted by ⁇
  • the angle formed by the emitting surface 1c and the reflecting surface 1b is denoted by ⁇ .
  • the description of the right-angle prism 1 when these angles are described as ⁇ and ⁇ , the description can be generalized to a triangular prism as it is.
  • the light incident at an incident angle theta 0 to the incident surface 1a of the light of the rectangular prism 1 having a refractive index n P is refracted by the internal prism propagates in refraction angle theta 'incident surface 1a, the reflection surface 1b is reached.
  • the angle formed by the incident surface 1a and the reflecting surface 1b is ⁇ , and the incident angle to the reflecting surface 1b is ( ⁇ ′).
  • n P ⁇ sin ( ⁇ ′) ⁇ 1 it is necessary to satisfy n P ⁇ sin ( ⁇ ′) ⁇ 1 in order for the incident light on the reflecting surface 1b to be deflected to the emitting surface 1c by total reflection. That is, the refractive index n P of the right-angle prism 1, it is necessary to satisfy the following relation.
  • FIG. 4 shows that total reflection is possible if the region is above the straight line indicating the relationship between the incident angle ⁇ m and the refractive index n P.
  • the light totally reflected by the reflection surface 1b of the right-angle prism 1 reaches the emission surface 1c.
  • the angle formed by the exit surface 1c and the reflection surface 1b is ⁇ , and the incident angle to the exit surface 1c is ( ⁇ + ⁇ ′).
  • n P 1.50 to 1.98
  • the light totally reflected by the reflecting surface 1b has a refractive index n G of the adhesive layer 3 described below in the range of 1.35 to 1.80 and a refractive index n F of the optical filter 2 of 1.35 to 2.50.
  • n G refractive index of the adhesive layer 3
  • the reflective layer examples include a metal film such as Ag or Al, a high refractive index dielectric film (hereinafter referred to as “high refractive index film”) and a low refractive index dielectric film (hereinafter referred to as “low refractive index”).
  • a dielectric multilayer film or the like in which films are referred to may be used.
  • the prism having a reflective layer formed on the reflective surface there is an advantage that an inexpensive prism material can be used as compared with the case of using a prism capable of total reflection on the reflective surface.
  • the process of forming the reflective layer becomes a load, and the reflectance is less than 100%, which is disadvantageous in terms of productivity and performance.
  • the deflecting element 1 includes a configuration including a prism and a reflective layer.
  • Deflecting element is made of a material having a refractive index n P satisfying formula (2) in relation to the refractive index of the adhesive layer.
  • Refractive index n P of the material used for the deflection element preferably 1.4 to 2.5.
  • the refractive index n P is preferably 1.70 or more, more preferably 1.75 or more, and 1.80 or more from the viewpoint that the larger the maximum capture angle, the smaller the F-number bright imaging lens. Is more preferable.
  • a reflective layer may be provided on the reflective surface when n P is 1.55 or less and the maximum incident angle ⁇ m is 8 ° or more. Even when a reflective layer is provided, the refractive index n P is the refractive index of the prism material.
  • the upper limit of n P is composition, from the viewpoint of the difference between the refractive index n G of the adhesive layer can be 0.5 or less, 2.1 is preferred, 2.0 is more preferable.
  • glass having the n P, resin and the like, glass being preferred.
  • the deflection element in addition to the refractive index n P, depending on the type of adhesive layer and the optical filter, there are cases where UV permeability is required.
  • the adhesive layer described below includes an ultraviolet curable material obtained by using an ultraviolet curable material, and the optical filter has a function of blocking UV, the deflecting element has UV transparency. It is good to have.
  • the light transmission of the deflection element refers to the light transmission in the relationship between the incident light and the light that is deflected and emitted after the incidence.
  • the wavelength of UV for which the deflection element is required to transmit is generally in the range of 250 to 400 nm depending on the ultraviolet curable material used for the adhesive layer.
  • a wavelength in the vicinity of i-line (365 nm) where the emission intensity of the HgXe discharge lamp is high is preferably used.
  • the maximum transmittance at a wavelength of 340 to 390 nm is preferably 10% or more, and more preferably 50% or more.
  • the transmittance of the deflecting element with respect to 365 nm light is preferably 5% or more, more preferably 20% or more, and further preferably 50% or more. Higher transmittance is more advantageous for shortening the UV irradiation time, preferably 70% or more, and more preferably 80% or more.
  • the deflection element may transmit visible light.
  • Any of the glass of 1.70 ⁇ n P described above has an internal transmittance of UV wavelength 365 nm of 10% or more and an internal transmittance in the visible region of 420 nm to 700 nm of 92% or more. Can be used as material.
  • the three corners in the YZ cross section are right angles or acute angles, so that chipping is performed. And easily cause cracks. Therefore, it is preferable to chamfer these corners.
  • the triangular prism 11 used in the optical element of the present embodiment illustrated in FIG. 5 is obtained by chamfering the three corners in the YZ section of the right-angle prism 1 shown in FIG.
  • the triangular prism 11 includes a W1 surface having a width w1 at a corner where the incident surface 1a and the reflecting surface 1b intersect, a W2 surface having a width w2 at a corner where the reflecting surface 1b and the emitting surface 1c intersect, and the incident surface 1a.
  • the W1 surface, the W2 surface, and the C surface are chamfered portions.
  • the occurrence of chipping and cracks can be reduced by having a chamfered portion obtained by chamfering the corner portion.
  • the chamfering process is performed within a range where the signal light effective width ⁇ in of the incident surface 1a of the triangular prism 11 and the signal light effective width ⁇ out of the output surface 1c can be secured.
  • the reflected light path deviation angle on the reflecting surface is larger than the refracted optical path deviation angle on the transmission refracting surface having the same inclination angle deviation, and thus is required for the reflecting surface.
  • the surface accuracy is about 2 to 4 times that of the transmission refractive surface. Therefore, the flatness of the reflecting surface 1b of the triangular prism 11 is related to the wavefront aberration that affects the resolution of the imaging device, and the rigidity of the prism material used, the film formation stress on the light incident surface 1a, and the light exit surface 1c, and bonding. Depends on the adhesive layer.
  • an antireflection layer or a reflection layer may be formed on the incident surface 1a and the exit surface 1c of the triangular prism 11 as described later, and film stress is generated at that time.
  • the difference in thermal expansion coefficient (when a thermosetting material is used for forming the adhesive layer) or polymerization shrinkage Residual stress is generated due to (when a thermosetting material or a photocurable material is used for forming the adhesive layer). Due to the influence of these stresses, if the chamfer widths w1 and w2 are narrow, the flatness of the end portion of the reflecting surface 1b of the triangular prism 11 may not be ensured.
  • an optical element using the triangular prism 11 is used in, for example, an imaging apparatus as shown in FIG. 2, there is a possibility that the aberration of the imaging lens system is deteriorated and the resolution of the imaging apparatus is lowered. .
  • the chamfering widths w1 and w2 at the chamfered portion are preferably independently 0.1 mm or more, and more preferably 0.2 mm or more.
  • the chamfer widths w1 and w2 are preferably independently 0.4 mm or less.
  • the chamfer width c is preferably about 0.05 to 0.2 mm.
  • the W1 surface, W2 surface, and C surface, which are the chamfered portions shown in FIG. 5, are preferably diffusing surfaces that prevent light incident on this surface from becoming stray light, similarly to the side surfaces of the deflecting element described later. Further, it is more preferable that a light absorption / shielding film is provided on these surfaces.
  • the adhesive layer 3 is provided between the deflection element 1 and the optical filter 2 and has a function of bonding and integrating the two.
  • the adhesive layer 3 is transparent to light having a predetermined wavelength to be transmitted by the optical element 10, for example, light in a wavelength range that the solid-state imaging device receives as signal light, and has an expression in relation to the refractive index with the optical filter 2.
  • Any adhesive layer having a refractive index n G that satisfies (1) and satisfies the formula (2) in relation to the refractive index with the deflecting element 1 can be used without particular limitation.
  • the constituent material of the adhesive layer preferably includes a thermosetting material or a photo-curing material.
  • a thermosetting material or a photo-curing material As the photocurable material, an ultraviolet curable material is preferable.
  • a thermosetting material or a photo-curing material that fixes and solidifies by polymerization by heating or irradiation with light such as ultraviolet rays, in other words, is used. Can be used.
  • the photocurable material completes the polymerization and solidification in a short time and has high productivity.
  • the photo-curable material is advantageous when a member having low heat resistance is included because other members constituting the optical element are not easily affected by heat during curing.
  • an ultraviolet curable material is preferable, and when an ultraviolet curable material is used, it is preferable to add a photopolymerization initiator.
  • the light irradiation wavelength and the polymerization sensitivity for the ultraviolet curable material depend on the type of the ultraviolet curable material or the type of the photopolymerization initiator.
  • an ultraviolet curable material when an ultraviolet curable material is used, light in the wavelength range of 250 to 400 nm is used as irradiation light, and light in the vicinity of i-line (365 nm) where the emission intensity of the HgXe discharge lamp is high is often used.
  • thermosetting material for example, EPO-TEK epoxy resin, # 301, # 301-2, # 310M-1, etc.
  • the photocurable material include, for example, an ultraviolet curable material, a mercaptoester resin from Norland-Products, an epoxy resin from NOA60 series and NTT-AT, AT3925M, 3727E, an acrylate resin, # 18165, # 6205. Etc. can be used.
  • the adhesive layer 3 is a layer containing a cured material obtained by curing a curable material that is cured by light and / or heat. If necessary, the adhesive layer 3 is within a range that does not impair the effects of the present invention, and various additives made of non-cured materials in addition to the cured material, for example, UV absorbers, NIR absorbers and other absorbents, polymerization initiators, A polymerization inhibitor may be included.
  • Refractive index n G of the adhesive layer 3 satisfies the formula (1) in relation to the refractive index of the optical filter 2, and the refractive index of the relationship between the deflection element 1 satisfying the formula (2) refractive index n G It is.
  • the refractive index n G of the adhesive layer 3 depends on the deflecting element 1 and the optical filter 2 to be combined, but specifically, it is preferably 1.35 to 1.80, more preferably 1.45 to 1.65. If n G is 1.35 or more, it is preferable in that the thickest member included in the optical filter 2 can use inexpensive and abundant kinds of materials with a refractive index n F , and if it is 1.80 or less, the refractive index n. Since the difference in refractive index between P and refractive index n F can be suppressed, it is preferable in that Fresnel reflection at each interface is small.
  • the adhesive layer 3 is transparent to light of a predetermined wavelength that the optical element 10 should transmit. Although it depends on the optical device in which the optical element is used, it is generally preferable that it exhibits high transparency to at least visible light.
  • the thickness of the adhesive layer 3 is preferably 1 to 20 ⁇ m and more preferably 2 to 10 ⁇ m from the viewpoint of transparency, adhesive strength, productivity, and the like.
  • the deflecting element 1 or the optical filter 2 needs to be a material that transmits UV for the following manufacturing reasons.
  • the optical element 10 of FIG. 1 first, the optical element in which the adhesive layer 3 in the optical element 10 is a layer made of an adhesive layer forming composition containing an ultraviolet curable material for obtaining the adhesive layer 3. A precursor is prepared. Next, the UV curable material in the layer made of the composition for forming the adhesive layer is cured by irradiating UV from the deflecting element 1 side or the optical filter 2 side of the optical element precursor to form the adhesive layer 3.
  • a UV reflecting layer is formed on the deflecting element 1
  • a UV absorber containing layer or a UV reflecting layer is formed on the optical filter 2, and the like.
  • the adhesive layer can receive UV incident from the deflecting element side of the optical element or incident from the optical filter side of the optical element.
  • the optical element is configured so as to be able to receive UV.
  • the adhesive layer there may be a member having UV blocking properties on both the deflection element side and the optical filter side of the adhesive layer. It is preferable that no member having UV blocking properties be present on one side, and a configuration in which a sufficient amount of UV can reach the adhesive layer from the deflecting element side is preferable.
  • the value described for the deflection element can be applied to the UV transmittance of the deflection element or the optical filter.
  • the optical filter in the optical element of the present invention is an optical filter that selectively blocks light in at least a part of the region from the ultraviolet region to the near infrared region, and the refractive index n F of the thickest member included in the optical filter.
  • the optical filter examples include an optical filter that selectively blocks both (i) UV and (ii) light in at least a part of the region from the visible region to the near infrared region.
  • the deflecting element preferably has UV transparency.
  • the maximum transmittance at a wavelength of 340 to 390 nm is 10% or more. Preferably there is.
  • optical filters include (i) UV and (ii-1) blocking NIR and transmitting visible light, and (i) UV and (ii-2) blocking visible light. And an NIR transmission filter that transmits NIR. Further, (i) UV and (ii-3) block light in the first region in the near infrared region, and visible light and light in the second region on the longer wavelength side than the first region in the near infrared region. A band-pass filter that transmits light is also included.
  • These optical filters have (i) UV blocking properties such as, for example, blocking properties with an average UV transmittance of 300 to 400 nm being preferably 10% or less, and more preferably 2% or less.
  • the NIR blocking property of the NIR cut filter is preferably a blocking property such that the average transmittance of NIR having a wavelength of 700 to 1100 nm is 5% or less, and more preferably 2% or less.
  • the visible light transmittance in the NIR cut filter for example, the average transmittance of visible light having a wavelength of 440 to 620 nm is preferably 80% or more, and more preferably 90% or more.
  • the visible light blocking property of the NIR transmission filter is preferably, for example, a blocking property in which the average transmittance of visible light having a wavelength of 400 to 730 nm is 5% or less, and more preferably 2% or less.
  • the NIR transmittance in the NIR transmission filter for example, it is preferable that the NIR wavelength has a continuous wavelength region of 40 nm or more with a transmittance of 80% or more between NIR wavelengths of 800 to 1000 nm, and preferably has a wavelength region of 80 nm or more.
  • the blocking property of blocking the light in the first region in the near-infrared region of the band-pass filter has a second wavelength which is longer than the first region at the NIR wavelength of 700 to 1100 nm.
  • the average transmittance of NIR in the first region excluding the continuous transmission wavelength band in the region is preferably 5% or less, and more preferably 2% or less.
  • the NIR transmittance of the second region on the longer wavelength side of the first region in the band pass filter for example, continuous 40 nm or more and 80 nm with a transmittance of 80% or more between NIR wavelengths 800 to 1000 nm. It may have the following wavelength range, and preferably has a wavelength range of 40 nm or more and 60 nm or less.
  • the visible light transmittance in the band-pass filter is preferably the same visible light transmittance as (ii-1).
  • 6A to 6C which are specific structures of the optical filter having selective light blocking properties, are YZ cross-sectional views respectively showing the optical filters 2A, 2B, and 2C used in the optical element of the present embodiment.
  • the optical filters 2A, 2B and 2C can be used in place of the optical filter 2 of the optical element 10 shown in FIG. 1, for example.
  • the left side shows the incident surface 2a in contact with the adhesive layer 3, and the right side shows the outgoing surface 2b in contact with the atmosphere.
  • the shape of the absorption-type substrate 21 is a parallel plate shape having a pair of main surfaces facing each other, and light is blocked by absorption.
  • the thickest member included in the optical filter is the absorption substrate 21, and the refractive index n F of the optical filter 2 ⁇ / b> A is the refractive index of the absorption substrate 21.
  • the absorbing substrate 21 examples include an absorbing glass substrate or a resin substrate containing a resin and an absorbing dye (hereinafter referred to as “absorbing resin substrate”).
  • the thickness of the absorption substrate 21 is preferably 20 ⁇ m or more, although it depends on the configuration. In the case of an absorption type glass substrate, the thickness is preferably 50 to 500 ⁇ m, and in the case of an absorption type resin substrate, the thickness is preferably 20 to 200 ⁇ m.
  • the absorption glass substrate is obtained by forming absorption glass into a parallel plate shape.
  • the absorption type glass include fluorophosphate glass containing CuO, phosphate glass containing CuO, and the like.
  • the fluorophosphate glass containing CuO and the phosphate glass containing CuO are collectively referred to as “CuO-containing glass”.
  • CuO-containing glass typically has an ability to absorb NIR having a wavelength of 700 to 1100 nm.
  • the absorption ability in the near infrared region can be adjusted by adjusting the CuO content and thickness.
  • CuO-containing glass containing one or more of Fe 2 O 3 , MoO 3 , WO 3 , CeO 2 , Sb 2 O 3 , V 2 O 5, etc. is a short wavelength side in the ultraviolet region, For example, it has an absorption characteristic at a wavelength of 300 nm or less.
  • the refractive index of the absorption type glass substrate is preferably 1.40 to 1.75, more preferably 1.45 to 1.60, as the refractive index of the CuO-containing glass.
  • the absorbing resin substrate is a substrate in which the absorbing dye is uniformly dissolved or dispersed in the resin.
  • the resin is a matrix component for forming a parallel plate shape, and a transparent resin is preferable.
  • the absorbing dye a dye that selectively absorbs light having a cutoff wavelength required for the optical filter 2 is used. Specific examples include a dye that selectively absorbs light in at least a part of the region from the ultraviolet region to the near infrared region, and a UV absorbing dye that selectively absorbs light in the wavelength region corresponding to the above (i). And any one of the absorbing dyes that selectively absorb light in the wavelength regions corresponding to the above (ii-1), (ii-2), and (ii-3), respectively.
  • the absorption wavelength band and the light absorption characteristics can be adjusted by selecting the absorption dye and adjusting the concentration and thickness.
  • the refractive index of the absorptive resin substrate depends on the refractive index of the resin that is the matrix component.
  • the refractive index of the absorptive resin substrate is preferably 1.35 to 1.75, more preferably 1.45 to 1.60.
  • the optical filter 2B shown in FIG. 6B includes a parallel plate-shaped substrate 21B having a pair of opposing main surfaces, and an absorption layer 22 formed on one main surface of the substrate 21B.
  • the main surface that is not in contact with the absorption layer 22 of the substrate 21B is the incident surface 2a that is in contact with the adhesive layer 3
  • the main surface that is not in contact with the substrate 21B of the absorption layer 22 is the emission surface 2b that is in contact with the atmosphere.
  • the absorption layer 22 is formed on the main surface opposite to the adhesive layer 3 side of the substrate 21B.
  • the optical filter 2 used in the optical element 10 may have a configuration having the absorption layer 22 on the adhesive layer 3 side of the substrate 21B.
  • the absorbing layer 22 is formed on the main surface opposite to the adhesive layer 3 side of the substrate 21B from the viewpoint that the closer to the light receiving surface of the solid-state imaging device, the reflected light tends to be stray light that affects image quality degradation.
  • the optical filter 2B is preferable.
  • the substrate 21B may be the same absorption substrate as the absorption substrate 21 in the optical filter 2A, or may be a transparent substrate having no absorption from the ultraviolet region to the near infrared region.
  • the transparent substrate include transparent glass, crystal such as crystal, lithium niobate, and sapphire, chemically tempered glass obtained by chemically strengthening soda lime glass, crystallized glass, or a substrate made of a transparent resin. These thicknesses can be the same as those of the absorption glass substrate and the absorption resin substrate, respectively.
  • the absorption layer 22 has a thickness of about 1 to 50 ⁇ m as described below, and is thinner than the substrate 21B. Therefore, in the optical filter 2B, the thickest member included in the optical filter is the substrate 21B.
  • the refractive index n F of the optical filter 2B is the refractive index of the substrate 21B.
  • the refractive index of the substrate 21B is preferably 1.40 to 1.75, and preferably 1.45 to 1.60, as in the case where the absorption substrate 21 is an absorption glass substrate.
  • the substrate 21B is a transparent resin substrate or an absorption resin substrate, it is preferably 1.35 to 1.75, and preferably 1.45 to 1.60, as in the case where the absorption substrate 21 is an absorption resin substrate.
  • the absorbing layer 22 is a layer in which the absorbing dye is uniformly dissolved or dispersed in the resin.
  • the resin and the absorbing dye can be the same as those of the absorbing resin substrate. Since the absorption layer 22 can be formed on the substrate 21B by a method such as wet coating, for example, the absorption layer 22 can be thinned, whereas the absorption resin substrate maintains its shape by itself and has a corresponding thickness. Is different.
  • the absorption layer 22 is thinner than the substrate 21B, preferably 1 to 50 ⁇ m, more preferably 2 to 20 ⁇ m.
  • the resin used for the absorption layer 22 is preferably a transparent resin.
  • the absorbing dye include a dye that can selectively absorb at least a part of light ranging from the ultraviolet region to the near infrared region when the absorption layer 22 containing the substrate and the substrate 21B are combined to form the optical filter 2B. .
  • a UV-absorbing dye that selectively absorbs light in a wavelength region corresponding to (i) above, and a wavelength region corresponding to each of (ii-1), (ii-2), and (ii-3) above Absorption dyes that selectively absorb the light.
  • the absorption dye when the absorption layer 22 and the substrate 21B are combined into the optical filter 2B, the absorption dye that can exhibit the absorption and transmission characteristics of the NIR cut filter, the NIR transmission filter, or the band transmission filter is used alone. Or a combination of two or more.
  • a plurality of absorbing layers containing different absorbing dyes may be sequentially formed on the substrate 21B to form the laminated absorbing layer 22.
  • An optical filter 2C shown in FIG. 6C is formed on a parallel plate-shaped substrate 21C having a pair of main surfaces facing each other, an absorption layer 22 formed on one main surface of the substrate 21C, and the other main surface.
  • the reflective layer 23 is made of.
  • the main surface that is not in contact with the substrate 21C of the reflective layer 23 is the incident surface 2a that is in contact with the adhesive layer 3
  • the main surface that is not in contact with the substrate 21C of the absorption layer 22 is the emission surface 2b that is in contact with the atmosphere. .
  • the reflective layer 23 is formed on the main surface of the substrate 21C on the adhesive layer 3 side, and the absorption layer 22 is formed on the main surface on the opposite side.
  • the optical filter 2 used in the optical element 10 may have a configuration in which the absorption layer 22 is provided on the adhesive layer 3 side of the substrate 21C and the reflection layer 23 is provided on the opposite side. Further, the optical filter 2 may have a configuration in which the absorption layer 22 and the reflective layer 23 are laminated in that order on the main surface of the substrate 21C on the adhesive layer 3 side or on the main surface on the opposite side.
  • the substrate 21C has the reflective layer 23 on the adhesive layer 3 side, and the opposite side is the absorbing layer 22.
  • the optical filter 2C having
  • the substrate 21C can be the same as the substrate 21B in the optical filter 2B.
  • the absorption layer 22 is the optical filter 2C, except that the absorption dye to be used is appropriately selected so that the blocking characteristics required for the optical filter 2 can be obtained together with the absorption characteristics of the substrate 21C and the reflection characteristics of the reflection layer 23.
  • the refractive index n F of the optical filter 2C is the refractive index of the substrate 21C.
  • the reflection layer 23 is a layer having a reflection wavelength band that selectively reflects light in at least a part of the region from the ultraviolet region to the near infrared region.
  • the reflective layer 23 preferably has a reflection characteristic that exhibits the absorption transmission characteristic of the NIR cut filter, the NIR transmission filter, or the band transmission filter by functioning in a complementary manner with the substrate 21 ⁇ / b> C and the absorption layer 22.
  • the reflective layer 23 preferably has a reflection characteristic that blocks a part of light in the ultraviolet region. In that case, it is preferable to have UV blocking properties such that the average transmittance at a wavelength of 350 to 400 nm is 10% or less, and preferably 2% or less.
  • the reflective layer 23 is preferably composed of a dielectric multilayer film in which low refractive index films and high refractive index films are alternately laminated.
  • the dielectric multilayer film may be configured to include a metal film as necessary.
  • the dielectric multilayer film is designed by using a conventionally known method for the specific number of layers and film thickness, and the refractive index of the high refractive index material and low refractive index material to be used according to the required optical characteristics. Can be manufactured.
  • the reflective layer 23 is a dielectric multilayer film
  • the total film thickness is preferably 1 to 10 ⁇ m, and more preferably 2 to 6 ⁇ m.
  • Various members such as an absorption type glass substrate, an absorption type resin substrate, a transparent substrate, an absorption layer, a reflection layer, and constituent materials included in the configuration of the optical filters 2A, 2B, and 2C and the constituent materials thereof are, for example, Is exemplified.
  • the optical filter 2 is not limited to the configuration of the optical filters 2A, 2B, and 2C, and may be configured according to the gist of the present invention. It can be changed as appropriate.
  • the optical filter 2 may be composed of the substrate 21B and the reflective layer 23 formed on one or both of the main surfaces thereof.
  • the absorption layer 22 may be formed on both main surfaces of the substrate 21B.
  • R
  • 2 / (n1 + n2) 2 That is, if ⁇ n
  • , R ⁇ n 2 / (n1 + n2) 2 , R> 0.09 / (n1 + n2) 2 when ⁇ n> 0.3, and R> 0 when ⁇ n> 0.2. 0.04 / (n1 + n2) 2 and ⁇ n> 0.1, R> 0.01 / (n1 + n2) 2 .
  • Expression is defined in the optical element of the present invention (1) is a graph showing the relation between the refractive index n F the refractive index n G, Equation (2) shows the relationship between refractive index n G and the refractive index n P.
  • the refractive index n F the refractive index n G can be replaced by n1 and n2
  • the refractive index n P and the refractive index n G can be replaced by n1 and n2.
  • n G + n F and n P + n G are required to be 2.6 or more from the viewpoint of an actual optical material having a transmission wavelength region within a wavelength range of 350 to 1100 nm.
  • FIG. 7 shows the result of calculating the reflectance R [%] by adapting this to n1 + n2.
  • FIG. 7 is a graph showing the relationship between the refractive index sum (n1 + n2) and the reflectance R [%] at optical interfaces having different refractive indexes (n1, n2).
  • ⁇ n GF and ⁇ n PG are preferably 0.3 or less, more preferably 0.2 or less, and particularly preferably 0.1 or less.
  • an antireflection layer may be formed at the interface between the adhesive layer and the optical filter in order to reduce Fresnel reflection.
  • [Delta] n PG may form an anti-reflection layer at the interface of the adhesive layer and likewise deflecting element in the case of 0.2-0.5. Since it is difficult to form the antireflection layer on the adhesive layer, the antireflection layer is preferably formed on the surface in contact with the adhesive layer of the optical filter or the surface in contact with the adhesive layer of the deflection element.
  • the relational expression of the reflectance R is for the case of normal incidence, but if the incident angle is 30 ° or less, the difference from the reflectance for normal incidence is slight.
  • the optical element of the present invention has an antireflection layer at the interface between the deflecting element and the adhesive layer and at the interface between the adhesive layer and the optical filter under the refractive index relationship of the expressions (1) and (2). May be.
  • the optical element may have an antireflection layer on a surface in contact with the atmosphere.
  • An antireflection layer may be provided in one place among these, may be provided in two places, and may be provided in all the places. In particular, when the reflectance of the reflected light generated at these interfaces is 1% or more, it is preferable to form an antireflection layer to reduce the reflectance to 0.5% or less.
  • FIG. 8 is an example of an optical element further including an antireflection layer in the optical element of the present embodiment.
  • An optical element 10A shown in FIG. 8 includes an antireflection layer on the incident surface 1a that is an interface with the air of the deflection element 1, in addition to the deflection element 1, the adhesive layer 3, and the optical filter 2 in the optical element 10 shown in FIG. 12a, the antireflection layer 12b on the exit surface 1c which is the interface in contact with the adhesive layer 3 of the deflecting element 1, the antireflection layer 13a on the entrance surface 2a which is the interface in contact with the adhesive layer 3 of the optical filter 2, and the air of the optical filter 2
  • the antireflection layer 13b is provided on the emission surface 2b which is the interface with the.
  • the antireflection layer 12a taking into account the range of the incident angle of light, is designed in accordance with the refractive index n P of the deflecting elements 1, a dielectric multilayer film formed by alternately laminating a low refractive index film and the high refractive index film An antireflective layer consisting of can be used.
  • the antireflection layer 12b an anti-reflection layer comprising a single layer dielectric film having a thickness d c the refractive index n c, specifically, by using the antireflection layer satisfies the following two formulas, deflection
  • the reflectance R at the interface between the element 1 and the adhesive layer 3 can be reduced.
  • ⁇ c corresponds to the center wavelength of the light required for the light emitted from the optical element 10A, for example, the center wavelength of the incident signal light detected by the solid-state image sensor 4 in the imaging apparatus 100 shown in FIG.
  • ⁇ S the wavelength of the light required for the light emitted from the optical element 10A
  • ⁇ L the longest wavelength of the incident signal light detected by the solid-state image sensor 4 in the imaging apparatus 100 shown in FIG.
  • the antireflection layer 12b may be a dielectric multilayer film in the same manner as the antireflection layer 12a.
  • the antireflection layer 13a is provided according to the value of ⁇ n GF in the same manner as the antireflection layer 12b is provided according to the value of ⁇ n PG .
  • ⁇ n GF is 0.1 or less, the antireflection layer 13a may not be provided.
  • ⁇ n PG 0.2 to 0.5, R ⁇ 1.0% depending on the refractive index value.
  • An antireflection layer 13a may be provided.
  • the antireflective layer 13a like the anti-reflection layer 12b, the film thickness d antireflection layer or reflectance made of a single layer dielectric film c R was designed to reduce the refractive index n c An antireflection layer made of a dielectric multilayer film is used.
  • the antireflection layer 13b is formed to reduce reflection at the interface between the optical filter 2 and air.
  • a dielectric multilayer film in which low refractive index films and high refractive index films are alternately laminated may be used.
  • the optical filter 2 may be, for example, the optical filter 2A, 2B, or 2C shown in FIGS. 6A to 6C.
  • an anti-reflection layer including a dielectric multilayer film which is designed in accordance with the refractive index n F of the absorption-type substrate 21 can be used.
  • an antireflection layer made of a dielectric multilayer film designed according to the refractive index of the absorption layer 22 can be used as the antireflection layer 13b.
  • the optical filter has a function of selectively blocking light in at least a part of the region from the ultraviolet region to the near infrared region.
  • the optical filter selectively selects, for example, (i) UV and (ii-1) NIR, (ii-2) visible light, or (ii-3) light in the first region in the near infrared region. It has a function to shut off.
  • the optical element of the present invention may have a configuration in which a part of the blocking performance is shared by other than the optical filter.
  • a reflective layer that reflects light in a wavelength range selected from the above (i), (ii-1), (ii-2), and (ii-3) is, for example, an optical element 10A shown in FIG.
  • the deflection element 1 may be provided on the incident surface 1a or the emission surface 1c.
  • the optical filter 2 may have a configuration that does not have the light blocking property of the reflective layer provided on the deflection element 1. In this way, the optical element as a whole is designed to have a light transmission and blocking performance in a predetermined region.
  • the first light shielding film that partially blocks light incident on the optical element from the incident side and / or the second light shielding film that blocks light incident on the optical element from the side surface May be further provided.
  • the “light-shielding film” refers to a film that blocks at least visible light of incident light.
  • the light shielding film preferably blocks light of all wavelengths from the ultraviolet region to the near infrared region.
  • the light shielding film may have a light transmittance of 10% or less at a wavelength of 350 to 1000 nm, and preferably 2% or less.
  • reflected light generated on the surface of each optical member of the imaging lens system or light scattered on the wall surface of a housing (not shown) such as a lens holder becomes stray light and enters the optical element 10, the cause of image quality deterioration It becomes.
  • the imaging apparatus 100 In order to block such stray light other than the signal light used in the solid-state imaging device 4 before entering the light-receiving surface 41 of the solid-state imaging device 4, the imaging apparatus 100 has a configuration other than the opening corresponding to the light-receiving surface 41. It is preferable to have a light shielding film in the region. When the light shielding film is formed on the optical element 10 on the side close to the light receiving surface 41 of the solid-state imaging element 4 in the imaging apparatus 100, it is effective in removing stray light.
  • the optical element 10 may have a first light shielding film that partially blocks light from the incident side of the optical element 10.
  • the optical element 10 preferably has a second light shielding film that blocks light incident on the optical element 10 from the side surface.
  • the optical element 10 may have both the first light shielding film and the second light shielding film.
  • FIGS. 9A, 9B, FIG. 10, FIG. 11, and FIG. 12 show a cross-sectional view, a plan view, and a perspective view, respectively, of optical elements 10B, 10C, 10D, and 10E having a light shielding film in the optical element of the present invention.
  • Optical elements 10B, 10C, and 10D shown in FIGS. 9A, 9B, 10, and 11 include an optical element having a light shielding film 15 as a first light shielding film that partially blocks light incident from the incident side of the optical element. It is an example.
  • An optical element 10E shown in FIG. 12 is an example of an optical element having a light shielding film 15B as a second light shielding film that blocks light incident from the side surface of the optical element.
  • FIG. 9A shows an optical element 10B in which the light shielding film 15 is formed at the interface with the air of the optical filter 2 in the optical element 10 shown in FIG. 1, and FIG. 9B shows the optical element 10B viewed from the light shielding film 15 side.
  • the deflection element 1, the adhesive layer 3, and the optical filter 2 can be the same as those of the optical element 10.
  • the shape of the light shielding film 15 has a frame-like shape in which the outer periphery coincides with the outer periphery of the emission surface 2b of the optical filter 2 in the shape of the main surface.
  • the light shielding film 15 for example, a structure in which a metal film such as Cr and an antireflection layer such as CrOx that prevents surface reflection of the metal film are laminated, or a resin light shielding film containing a light absorber and a resin that exhibits light shielding properties. Etc. can be exemplified.
  • the light absorber include inorganic or organic colorants such as carbon black and titanium black.
  • Resin is a matrix component for forming a light shielding film.
  • the resin light-shielding film is formed on the emission surface 2b of the optical filter 2 by a printing method or a photolithography method using a light absorber and a photocurable material (resin).
  • the formation method of the light absorber, the photocurable material (resin), and also the light shielding film containing these in a resin light shielding film is illustrated by WO2014 / 021245A, for example.
  • the thickness of the light shielding film 15 is preferably about 50 to 500 nm in the case of a structure in which an antireflection layer is laminated, and is preferably about 0.1 to 400 ⁇ m in the case of a resin light shielding film.
  • the thickness is more preferably 0.2 to 100 ⁇ m, and even more preferably 0.5 to 10 ⁇ m.
  • An optical element 10C shown in FIG. 10 is an example in which, in the optical element 10B shown in FIGS. 9A and 9B, the light shielding film 15 is provided on the incident surface 2a of the optical filter 2 instead of on the outgoing surface 2b of the optical filter 2.
  • the optical element 10D shown in FIG. 11 is an example in which the light shielding film 15 is provided on the incident surface 1a of the deflecting element 1 instead of on the outgoing surface 2b of the optical filter 2 in the optical element 10B shown in FIGS. 9A and 9B. is there.
  • the light shielding film 15 included in the optical element 10C and the optical element 10D can be the same as the light shielding film 15 included in the optical element 10B, except that the arrangement position is different.
  • Each of the optical elements 10B, 10C, and 10D is an example in which the light shielding film 15 is provided on each surface on the emission surface 2b of the optical filter 2, the incident surface 2a of the optical filter 2, and the incident surface 1a of the deflection element 1.
  • these two surfaces (1a + 2a, 1a + 2b, 2a + 2b) or three surfaces (1a + 2a + 2b) may be formed.
  • An optical element 10E shown in FIG. 12 is an example having the light shielding film 15B over the entire area of both side surfaces of the deflection element 1 in the side surface of the optical element in the optical element 10 shown in FIG.
  • the deflection element 1 in the optical element 10 shown in FIG. 1 is a triangular prism, and has large areas on the side surfaces 1d and 1e perpendicular to the light incident / exit surfaces 1a and 1c. Therefore, when stray light entering the prism reaches the side surface, it may be reflected and transmitted through the light exit surface 1c and emitted from the optical element 10. In that case, for example, in the imaging apparatus 100 illustrated in FIG. 2, the ratio of stray light emitted from the optical element 10 to the light receiving surface 41 of the solid-state imaging element 4 is high. In particular, in the case of a triangular prism having a high refractive index, the light incident on the side surface 1d or 1e is totally reflected, and stray light reaching the light receiving surface 41 increases.
  • the light shielding film 15B can have a configuration other than the shape, for example, a layer configuration, a constituent material, and a formation method, in the same manner as the light shielding film 15 included in the optical element 10B. In forming the light shielding film 15B, it is preferable to form the light shielding film 15B after making the side surfaces 1d and 1e have a non-flat diffusion surface, since substantial stray light is further reduced.
  • the side surfaces 1d and 1e As a method of setting the side surfaces 1d and 1e as the diffusing surface, when the deflecting element 1 is processed into a triangular prism shape, cutting is performed using a cutting blade such that the side surfaces 1d and 1e become rough surfaces, or the side surface 1d after cutting. And 1e are lapped and polished to form a diffusion surface corresponding to a rating of # 1000 or less.
  • stray light emitted from the emission surface of the optical element can be reduced to some extent only by using the side surfaces 1 d and 1 e of the deflection element 1 as diffusion surfaces. That is, by making the side surfaces 1d and 1e of the deflecting element 1 diffusing surfaces, generation of total reflected light generated on the optical flat surface is suppressed (increased transmitted light to the air side), and incident light is diffused at a wide angle. Thus, for example, the amount of stray light that enters the light receiving surface 41 of the solid-state imaging device 4 as a bright spot can be reduced.
  • the side surfaces 1d and 1e of the deflecting element 1 are preferably formed with the light shielding film 15B after forming the diffusion surface.
  • the size (outer edge) of the exit surface 1c of the deflection element 1 and the entrance / exit surfaces 2a and 2b of the optical filter 2 are substantially the same.
  • the deflecting element may be a prism, and (I) on each surface where the prism and the optical filter face each other, the outer edge of the prism may be inside the outer edge of the optical filter. (II) In each surface where the prism and the optical filter face each other, the configuration may be such that the outer edge of the prism is outside the outer edge of the optical filter.
  • FIG. 13A shows an optical element 10F similar to the optical element 10B except for the configuration of (I) above in the optical element 10B shown in FIGS. 9A and 9B.
  • FIG. 13B is a diagram of the optical element 10F viewed from the light shielding film 15 side.
  • the outer edge of the exit surface 1 c of the deflecting element 1 is inside the outer edges of the entrance / exit surfaces 2 a and 2 b of the optical filter 2.
  • the length in the Y direction of the exit surface 1c of the deflection element 1 is L p
  • the length in the X direction is W p
  • the length in the Y direction of the entrance and exit surfaces 2a and 2b of the optical filter 2 is L.
  • the length of X direction is indicated by W F
  • L F> L P has been shown to be a W F> W P.
  • the configuration (I) is advantageous in that the light shielding film 15 can be formed so as to surely include the outer periphery of the deflection element 1, and stray light can be reliably reduced.
  • FIG. 14A shows an optical element 10G similar to the optical element 10B except for the configuration of (II) above in the optical element 10B shown in FIGS. 9A and 9B.
  • FIG. 14B is a diagram of the optical element 10G viewed from the light shielding film 15 side.
  • the outer edge of the exit surface 1c of the deflecting element 1 is outside the outer edges of the entrance / exit surfaces 2a and 2b of the optical filter 2.
  • the length in the Y direction of the exit surface 1c of the deflecting element 1 is L p
  • the length in the X direction is W p
  • the length in the Y direction of the entrance and exit surfaces 2a and 2b of the optical filter 2 is L.
  • F the length of X direction is indicated by W F
  • L F ⁇ L P has been shown to be a W F ⁇ W P.
  • optical element of the present invention has been described above using the optical elements 10, 10A to 10G, but the optical element of the present invention is not limited to the above-described embodiment. These embodiments can be changed or modified without departing from the spirit and scope of the present invention.
  • the production method of the present invention includes the following steps (A) and (B).
  • a step of producing an optical element precursor having a composition layer for forming an adhesive layer containing an ultraviolet curable material between the deflecting element and the optical filter here, the optical element precursor is an optical element to be manufactured.
  • the composition layer for adhesive layer formation containing an ultraviolet curable material instead of an adhesive layer in the arrangement
  • Process (A) The process (A) is located between the deflection element 1 and the optical filter 2 located on the exit side of the deflection element 1 and between the deflection element 1 and the optical filter 2 and is cured by the following process (B). In this step, a precursor of the optical element 10 having the adhesive layer forming composition layer, which becomes the adhesive layer 3 for integrating the deflecting element 1 and the optical filter 2, is prepared.
  • the composition for forming an adhesive layer constituting the composition layer for forming an adhesive layer contains an ultraviolet curable material.
  • the ultraviolet curable material is as described above.
  • the composition for forming an adhesive layer preferably contains the above-described photopolymerization initiator and, if necessary, contains various additives. Further, in order to prevent the curable material from being polymerized and solidified by light, heat, air or the like during storage, a polymerization inhibitor may be mixed and used.
  • the composition for forming an adhesive layer may further contain a solvent in order to ensure good coatability.
  • the solvent is a component that is removed from the composition layer for forming an adhesive layer by drying or the like during the manufacturing process of the optical element.
  • an adhesive layer forming composition containing each of the above components is prepared so that the cured film thickness on the exit surface 1 c of the deflection element 1 becomes a desired thickness.
  • the composition for forming an adhesive layer is uniformly applied to obtain the deflection element 1 with the composition layer for forming an adhesive layer.
  • the optical filter 2 is laminated on the composition layer for forming an adhesive layer so that the incident surface 2a of the optical filter 2 is in contact therewith.
  • the composition for forming the adhesive layer to be used contains a solvent, the solvent is dried and removed before the optical filter 2 is laminated.
  • the surface on which the composition for forming an adhesive layer is applied may be the incident surface 2a of the optical filter 2.
  • the deflecting element 1 is laminated so that the exit surface 1c of the deflecting element 1 is in contact with the adhesive layer forming composition layer formed on the incident surface 2a of the optical filter 2.
  • the composition for forming an adhesive layer to be used contains a solvent, the solvent is dried and removed before the deflection element 1 is laminated.
  • the precursor of the optical element 10 which has the composition layer for contact bonding layer formation instead of the contact bonding layer 3 in the optical element 10 is produced.
  • Step (B) Step About the precursor of the optical element 10 obtained in the step (A), UV is applied to the composition layer for forming the adhesive layer according to the curing conditions of the ultraviolet curable material contained in the composition for forming the adhesive layer. Irradiate. Thereby, an ultraviolet curable material hardens
  • the precursor of the optical element 10 is irradiated with UV from the incident surface 1a side of the deflecting element 1, or from the output surface 2b side of the optical filter 2.
  • the method of irradiating UV is mentioned.
  • UV may be irradiated from the reflecting surface 1b side.
  • permeability of UV used for photopolymerization hardening is high. It is preferable to perform UV irradiation from the side because productivity is improved.
  • the deflecting element 1 is configured to have UV transparency, and the composition for forming an adhesive layer is irradiated with UV from the incident surface 1a side or the reflecting surface 1b side of the deflecting element 1.
  • the physical layer is an adhesive layer.
  • the optical filter 2 is designed so as not to have UV blocking properties, and UV is irradiated from the emission surface 2b side of the optical filter 2 for forming an adhesive layer.
  • the composition layer is an adhesive layer. In the production method of the present invention, the former is preferred.
  • an optical element in which a deflection element and an optical filter are integrated by an adhesive layer can be easily manufactured by using UV irradiation.
  • the optical element 10H shown in a sectional view in FIG. 15 is similar to the deflection element 11 shown in FIG. 5, the optical filter 2C shown in FIG. 6C on the emission side of the deflection element 11, and the deflection element 11 and the optical filter 2C. There is an adhesive layer 3 between them.
  • the optical element 10H has an antireflection layer 12a on the incident surface 1a of the deflection element 11, an antireflection layer 12b on the emission surface 1c of the deflection element 11, and an antireflection film 13b on the emission surface 2b of the optical filter 2C.
  • the optical element 10H further includes, on the antireflection film 13b, a light shielding film 15 having a frame shape in which the outer periphery coincides with the outer periphery of the antireflection film 13b in the shape of the main surface.
  • a light shielding film 15B similar to that shown in FIG. 12 is provided over the entire area on the two side surfaces 1d and 1e.
  • the refractive index n P at a wavelength of 589nm is 1.75 or more
  • the internal transmittance of a transparent and ultraviolet wavelengths 365nm in wavelength range 400 ⁇ 1100 nm is cutting a 10 percent or more optical glass triangular prism shape.
  • the triangular prism prism cross section is an isosceles right triangle with an apex angle of 90 °.
  • the light incident surface incident from the Y direction, the light output surface emitted in the Z direction, and the total reflection surface deflected from the Y direction to the Z direction are all polished into an optical mirror surface. Furthermore, C surface processing and Chamfering of W1 surface and W2 surface are performed, and each chamfering part is obtained.
  • the width of the isosceles surface that is the light incident / exit surface of the triangular prism is processed to a dimension that covers the signal light effective width ⁇ in of the light incident surface and the signal light effective width ⁇ out of the light output surface.
  • antireflection layers 12a and 12b are formed so as to cover the effective widths ⁇ in and ⁇ out of the air interface which is the light incident surface 1a of the triangular prism and the adhesive layer interface which is the light emitting surface 1c.
  • the residual reflection in the signal light wavelength region is 0.5% or less.
  • the triangular prism is cut into the element shape shown in FIG. 12 using a dicing device in parallel with the ZY plane so that the dimension in the X direction covers the light receiving surface of the solid-state imaging device, and the cut surfaces 1d and 1e are optically cut.
  • the diffusion surface In order to prevent the light incident from the cut surfaces 1d and 1e from becoming stray light, a light shielding film-forming composition containing a light absorber and an ultraviolet curable resin is further applied thereon, and a light shielding film 15B is formed by UV irradiation. Thus, the deflecting element 11 with a light shielding film is obtained.
  • the optical filter 2C is a NIR cut filter that transmits visible light and blocks UV and NIR.
  • a filter function that blocks UV of 300 to 400 nm and NIR of 700 to 1100 nm and transmits visible light of 420 to 660 nm.
  • an NIR absorption type glass substrate 21C obtained by adding CuO or the like to a fluorophosphate glass is used as the substrate 21C of the optical filter 2C.
  • the thickest member in the optical filter 2C is the glass substrate 21C, and n F ⁇ 1.52.
  • a reflective layer 23 made of a dielectric multilayer film having reflection wavelength bands of 350 to 400 nm and 700 to 1100 nm is formed on the interface of the optically polished NIR absorption glass substrate 21C on the adhesive layer 3 side.
  • an absorption layer 22 containing an NIR absorbing dye having an absorption maximum wavelength at 650 to 750 nm is formed at the air interface on the light emitting surface (solid-state imaging device) side of the NIR absorption type glass substrate 21C.
  • the absorbing layer 22 optionally contains a UV absorbing dye.
  • the NIR absorption type glass substrate 21C has an absorption maximum wavelength in the vicinity of 900 nm. However, when it is attempted to increase the absorption of NIR, the NIR absorption type glass substrate absorbs visible light and causes a decrease in visible light transmittance. Therefore, the glass substrate thickness is adjusted so as to suppress a decrease in visible light transmittance. Similarly, the content of the NIR absorbing dye in the absorption layer 22 is adjusted so as to suppress a decrease in visible light transmittance. When the NIR absorption type glass substrate 21C and the absorption layer 22 are adjusted so as to suppress the decrease in the transmittance of visible light, the wavelength regions where transmitted light is generated are generated at 350 to 400 nm and 700 to 1100 nm. The reflective layer 23 having a wavelength band is designed.
  • the refractive index n F of the glass substrate 21C can be realized so that the reflective layer 23 having a small number of layers and a total film thickness can exhibit high transmittance in the visible range of 420 to 660 nm and low transmittance in the reflected wavelength range.
  • a dielectric multilayer film is designed on the premise that the adhesive layer 3 having a refractive index n G of 0.1 or less is used.
  • the reflection wavelength band shifts to a short wavelength region as the incident angle of incident light increases, and the spectral transmittance of the entire optical filter 2C changes.
  • the absorption layer 22 complements the NIR absorptivity of the NIR absorption type glass substrate 21C, and also has a role of reducing the incident angle dependency of such spectral characteristics.
  • the antireflection layer 13b is formed on the air interface of the absorption layer 22 of the optical filter 2C, and the residual reflection with respect to the signal light wavelength region at the interface is 0.5% or less. Further, a frame-shaped light shielding film 15 is formed in a peripheral region other than the signal light transmission effective region at the air interface of the antireflection layer 13b to obtain an optical filter 2C with a light shielding film.
  • UV is irradiated from the incident surface or / and the total reflection surface of the deflecting element (triangular prism) 11 to polymerize and solidify the ultraviolet curable material in the composition layer for forming the adhesive layer, whereby the adhesive layer 3 is obtained.
  • the optical element 10H when the difference in refractive index n P and the refractive index n G is small, it provided the optical filter 2B shown in Figure 6B in place of the optical filter 2C the exit side of the deflecting element 11, deflection elements 11
  • the adhesive layer 3 may be provided between the optical filter 2B, the reflective layer 23 on the emission surface 1c of the deflection element 11, and the antireflection layer 12b.
  • the antireflection layer 12a, the antireflection layer 13b, and the light shielding films 15 and 15B can be configured similarly to the optical element 10H.
  • the optical element of the present invention is an optical element having both a light deflection function and a selective blocking function.
  • the optical element is disposed immediately before the light-receiving surface of the solid-state image sensor. If used, it is advantageous for downsizing of the imaging device.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Optical Elements Other Than Lenses (AREA)
  • Optical Filters (AREA)
  • Mounting And Adjusting Of Optical Elements (AREA)
PCT/JP2018/008493 2017-03-31 2018-03-06 光学素子および光学素子の製造方法 WO2018180269A1 (ja)

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US20210063617A1 (en) * 2019-08-30 2021-03-04 Samsung Electro-Mechanics Co., Ltd. Prism for optical imaging system
CN113880461A (zh) * 2020-07-01 2022-01-04 佳能株式会社 光学元件制造方法、光学元件、光学设备和图像捕获设备
WO2022243228A1 (de) * 2021-05-17 2022-11-24 Schott Ag Optisches system für periskopkameramodul
JP7526815B2 (ja) 2020-05-12 2024-08-01 エイエムエス－オスラム エイジア パシフィック プライヴェット リミテッド 光学プリズムの製造方法

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US20210063616A1 (en) * 2019-08-30 2021-03-04 Samsung Electro-Mechanics Co., Ltd. Prism for optical imaging system
TWI770808B (zh) 2021-02-05 2022-07-11 大陸商信泰光學（深圳）有限公司 鏡頭模組（四）
CN113050208B (zh) * 2021-03-10 2023-07-14 浙江舜宇光学有限公司 树脂棱镜镜片及其的镀膜方法和长焦摄像头

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JP2007225636A (ja) * 2006-02-21 2007-09-06 Sony Corp ダイクロイックフィルタおよび色分解プリズム
JP2012068509A (ja) * 2010-09-24 2012-04-05 Hoya Corp 撮影光学系、及び撮影装置
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US20210063617A1 (en) * 2019-08-30 2021-03-04 Samsung Electro-Mechanics Co., Ltd. Prism for optical imaging system
JP7526815B2 (ja) 2020-05-12 2024-08-01 エイエムエス－オスラム エイジア パシフィック プライヴェット リミテッド 光学プリズムの製造方法
CN113880461A (zh) * 2020-07-01 2022-01-04 佳能株式会社 光学元件制造方法、光学元件、光学设备和图像捕获设备
CN113880461B (zh) * 2020-07-01 2024-01-12 佳能株式会社 光学元件制造方法、光学元件、光学设备和图像捕获设备
WO2022243228A1 (de) * 2021-05-17 2022-11-24 Schott Ag Optisches system für periskopkameramodul

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