CN112612071A

CN112612071A - Optical member and camera module

Info

Publication number: CN112612071A
Application number: CN202010982984.3A
Authority: CN
Inventors: 岸田宽之
Original assignee: JSR Corp
Current assignee: JSR Corp
Priority date: 2019-09-19
Filing date: 2020-09-17
Publication date: 2021-04-06
Also published as: KR20210033914A; JP2021047325A; JP7251423B2; TW202113424A

Abstract

The present invention addresses the problem of providing an optical member and a camera module that selectively reflect visible light in a specific wavelength range, but suppress reflection of light in the specific wavelength range, in order to improve the problems of image defects and thinning of conventional optical filters. The optical member of the present invention includes a reflection surface, and the average reflectance of unpolarized light incident at 45 DEG from the vertical to the reflection surface is 80% or more in a wavelength region of 400nm to 640nm, and 8% or less in a wavelength region of 700nm to 1150 nm. The optical member reflects light in a wavelength region of 400nm to 640nm, but suppresses reflection of light in a wavelength region of 700nm to 1150 nm.

Description

Optical member and camera module

Technical Field

The present invention relates to an optical member and a camera module using the same.

Background

In solid-state imaging devices such as video cameras (cameras), digital still cameras (digital still cameras), and mobile phones with camera functions, image sensors (image sensors) such as Charge Coupled Devices (CCDs) and Complementary Metal Oxide Semiconductors (CMOSs) are used. For these image sensors, a silicon photodiode having sensitivity to near-infrared light that cannot be perceived by human eyes is used in its light receiving section. In these image sensors, it is necessary to perform a sensitivity correction that makes a natural color tone appear to human eyes, and an optical filter that selectively transmits or blocks light in a specific wavelength region, for example, a near infrared cut filter, is often used.

As such an optical filter, filters manufactured by various methods have been used since now. For example, the following filters are known: an absorptive glass type infrared cut filter in which copper oxide is dispersed in phosphoric acid glass (patent document 1); or a resin-type infrared cut filter having a layer in which a dye having absorption in the near-infrared band is dispersed (patent document 2); a glass substrate-coated infrared cut filter having a transparent dielectric substrate (glass substrate), an infrared reflecting layer, and an infrared absorbing layer (patent document 3); a resin-type near-infrared cut filter using a transparent resin as a base material, the transparent resin containing a dye having a maximum absorption in a region having a wavelength of 600nm to 800nm, and using dielectric multilayer films having near-infrared reflection performance on both surfaces of the base material (patent document 4); a glass substrate-coated infrared cut filter in which a resin layer containing a coloring matter having absorption in the vicinity of a region having a wavelength of 695nm or more and 720nm or less is provided on a glass substrate (patent document 5).

In recent years, camera modules have been increasingly thinned, and further thinning and optical telescopic functions have been required. A reflection type imaging camera module is known which can secure an optical path length of an optical telescopic type even if it is thin (patent document 6).

[ Prior art documents ]

[ patent document ]

[ patent document 1] International publication No. 2011/071157

[ patent document 2] Japanese patent laid-open No. 2008-303130

[ patent document 3] Japanese patent laid-open No. 2014-52482

[ patent document 4] Japanese patent application laid-open No. 2011-100084

[ patent document 5] Japanese patent laid-open No. 2014-63144

[ patent document 6] Japanese patent laid-open No. 2007-19860

Disclosure of Invention

[ problems to be solved by the invention ]

In the optical filter having the near-infrared light reflecting property on the surface of the base material as described in the above publication, a phenomenon in which light reflected on the surface of the optical filter enters the image sensor again, so-called ghost, occurs. That is, image defects may occur in image capturing using a camera module including the optical filter. In particular, near infrared rays having a low human visibility form an image different from an image visible to the human eye, and thus cause a significant image failure.

In order to prevent such image defects, an antireflection layer may be provided in the optical filter, but in such a case, the thickness of the optical filter is greatly affected. In recent years, camera modules are required to have both a thin shape and high performance of an optical telescopic function, but in order to achieve high performance, it is difficult to make the thin shape when the optical filter, the zoom lens, or the like is provided in the optical path.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an optical member that selectively reflects visible light in a specific wavelength range and suppresses reflection of light in the specific wavelength range, and a camera module using the optical member, in order to improve the problems of image defects and thinning of an existing optical filter.

[ means for solving problems ]

The invention for solving the above problem is an optical member including a reflection surface, and a wavelength region in which an average reflectance of unpolarized light incident at 45 ° from a vertical angle to the reflection surface is 400nm to 640nm is 80% or more, and a wavelength region in which 700nm to 1150nm is 8% or less.

Another invention to solve the above problem is a camera module including an optical member, wherein the optical member includes a reflection surface, and a wavelength region in which an average reflectance of unpolarized light incident at 45 ° from a vertical angle to the reflection surface is 400nm to 640nm is 80% or more, and a wavelength region in which the average reflectance is 700nm to 1150nm is 8% or less.

Here, the "average reflectance" refers to a ratio of the amount of light of unpolarized light rays reflected by specular reflection, that is, at the same angle as the incident angle of the unpolarized light rays, to the amount of light of the incident unpolarized light rays.

[ Effect of the invention ]

In the optical member of the present invention, light incident in a wavelength region of 400nm or more and 640nm or less is reflected and the optical path length is converted, but reflection of light incident in a wavelength region of 700nm or more and 1150nm or less to the optical member can be suppressed. The optical member selectively reflects visible light of a specific wavelength region, but can suppress reflection of light of a specific wavelength region. In addition, the camera module of the present invention can realize thinning while suppressing an image failure.

Drawings

Fig. 1 is a schematic front view showing an optical member of an embodiment of the present invention.

Fig. 2 is a schematic front view showing an optical member according to another embodiment of the present invention.

Fig. 3 is a schematic front view showing an optical member according to still another embodiment of the present invention.

Fig. 4 is a schematic perspective view illustrating the optical member of fig. 1.

Fig. 5A is a schematic front view showing an optical member having a dielectric multilayer film according to still another embodiment of the present invention.

Fig. 5B is a schematic front view showing an optical member having a dielectric multilayer film according to still another embodiment of the present invention.

Fig. 5C is a schematic front view showing an optical member having a dielectric multilayer film according to still another embodiment of the present invention.

Fig. 5D is a schematic front view showing an optical member having a dielectric multilayer film according to still another embodiment of the present invention.

Fig. 5E is a schematic front view showing an optical member having a dielectric multilayer film according to still another embodiment of the present invention.

Fig. 5F is a schematic front view showing an optical member having a dielectric multilayer film according to still another embodiment of the present invention.

Fig. 6A is a schematic front view showing an optical path in the optical member of fig. 5B.

Fig. 6B is a schematic perspective view showing an optical path length in the optical member of fig. 5B.

Fig. 7A is a schematic front view showing an optical member having a light-shielding film according to still another embodiment of the present invention.

Fig. 7B is a schematic perspective view showing an optical member having a light-shielding film according to still another embodiment of the present invention.

Fig. 8A is a schematic perspective view showing an optical member having a concave-convex portion according to still another embodiment of the present invention.

Fig. 8B is a schematic plan view showing an optical member having a concave-convex portion according to still another embodiment of the present invention.

Fig. 8C is a schematic bottom view showing an optical member having a concave-convex portion according to still another embodiment of the present invention, as viewed from a direction perpendicular to the inclined surface.

Fig. 9A is a schematic plan view showing one embodiment of a camera module of the embodiment of the present invention.

Fig. 9B is a schematic plan view showing one embodiment of a camera module of the embodiment of the present invention.

Fig. 9C is a schematic plan view showing an embodiment of a camera module according to an embodiment of the present invention.

Fig. 9D is a schematic plan view showing an embodiment of a camera module according to an embodiment of the present invention.

Fig. 9E is a schematic plan view showing an embodiment of a camera module according to an embodiment of the present invention.

Fig. 9F is a schematic plan view showing an embodiment of a camera module according to an embodiment of the present invention.

Fig. 9G is a schematic plan view showing an embodiment of a camera module according to an embodiment of the present invention.

Fig. 9H is a schematic plan view showing an embodiment of a camera module according to an embodiment of the present invention.

Fig. 9I is a schematic plan view showing one embodiment of a camera module of the embodiment of the present invention.

Fig. 9J is a schematic plan view showing an embodiment of a camera module according to an embodiment of the present invention.

Fig. 9K is a schematic plan view showing an embodiment of a camera module according to an embodiment of the present invention.

Fig. 9L is a schematic plan view showing an embodiment of a camera module according to an embodiment of the present invention.

Fig. 10A is a conceptual diagram illustrating a method of measuring the transmittance of unpolarized light incident at 45 ° of an optical member.

Fig. 10B is a conceptual diagram illustrating a method of measuring the reflectance of unpolarized light rays incident at 45 ° on the optical member.

Fig. 10C is a conceptual diagram illustrating a method of measuring the reflectance of unpolarized light incident at 5 ° on the optical member.

Fig. 10D is a conceptual diagram illustrating a method for measuring the reflectance of an unpolarized light beam incident at 45 ° of an optical member including a prismatic substrate.

Fig. 10E is a conceptual diagram illustrating a method of measuring the spectral transmission efficiency of the optical member.

Fig. 10F is a conceptual diagram illustrating a method of measuring 100% of the light amount to be used as a reference in the spectral transmittance efficiency measurement.

FIG. 10G is a conceptual diagram showing a method of measuring spectral transmission efficiency through a cover glass.

Fig. 11 is a graph showing the different wavelengths of the blue, green, and red sensor pixels.

[ description of symbols ]

1. 11, 21, 31, 41a to 41e, 51, 61, 71: optical member

2. 12, 22, 32, 42: reflecting surface

3. 43: light incident surface

4. 44: light exit surface

5: prism

23: reflective layer

24. 35, 45, 53, 63, 73: base material

36a, 36b, 46a, 46b, 46 c: dielectric multilayer film

52. 62a, 62 b: light shielding film

72a, 72 b: convex part

101a to 1011: camera module

102: lens and lens assembly

103a, 103 b: optical filter

104a, 104 b: optical sensor

105: absorbent body

106: lens replacing planar optical element

107. 203: cover glass

108: optical system housing unit

201: integrating sphere

202: mirror with mirror head

H: height

L: light (es)

L: length of

L1: reflected light

L2: transmitted light

W: width of

Detailed Description

[ optical Member ]

The optical member includes a reflection surface, and a wavelength region in which an average reflectance of unpolarized light incident at 45 DEG from a vertical angle to the reflection surface is 400nm to 640nm is 80% or more, and a wavelength region in which the average reflectance is 700nm to 1150nm is 8% or less.

The optical member reflects light in a wavelength region of 400nm to 640nm, but suppresses reflection of light in a wavelength region of 700nm to 1150 nm. Here, "reflection" means a reflectance of 65% or more in specular reflection, and "reflection suppression" means a reflectance of 20% or less in specular reflection. Light in a wavelength range of 400nm to 640nm incident on the optical member is reflected by the reflection surface, and the optical path length is converted. In addition, reflection of light incident on the optical member in a wavelength region of 700nm or more and 1150nm or less is suppressed, and light that is not reflected is transmitted through or absorbed by the optical member. For example, when light enters the reflective surface at 45 ° from the vertical direction, light in a wavelength region of 400nm or more and 640nm or less is reflected at a reflection angle of 45 ° by specular reflection, and 90 ° conversion is performed with respect to the direction of optical path entrance, while the optical path conversion is suppressed in light in a wavelength region of 700nm or more and 1150nm or less. With the optical member, for example, one member can be used which has both the function of a mirror that reflects visible light and the function of an optical filter that shields near-infrared light.

The optical member can perform specular reflection of light in a wavelength region of 400nm to 640nm, and can perform optical path conversion of the visible light by the specular reflection. For example, in the case where the optical member is used in a camera module, since a sufficient optical path length can be ensured by performing the optical path conversion, a zoom lens or the like can be incorporated in the optical path.

The optical member can suppress reflection of light in a wavelength region of 700nm to 1150nm, which has high sensitivity to a silicon photodiode used in an optical sensor and low human visibility. In the case where the optical member is used for a camera module, reflection of light in a wavelength region of 700nm or more and 1150nm or less can be suppressed, thereby hindering perception in a silicon photodiode. As a result, the visibility correction in the camera module for rendering red to have a natural hue for the human eye is improved. Further, it is possible to suppress the occurrence of image defects such as ghosts of reflected light from the optical filter, which are generated when the optical filter is used.

The maximum reflectance of unpolarized light incident on the reflection surface at 45 DEG from the vertical in the optical member may be 20% or less in a wavelength region of 700nm to 1150 nm. This can suppress reflection of light in a wavelength region of 700nm to 1150 nm.

The optical member may have a reflectance of 65% or more at a wavelength of 650nm for unpolarized light incident on the reflection surface at 45 ° from the vertical. This makes it possible to perform specular reflection of light having a wavelength of 650nm, and to perform optical path conversion of light having a wavelength of 650nm, which has a high human visibility, by the specular reflection.

[ reflecting surface ]

The embodiment of the reflecting surface is not limited. For example, the reflecting surface may be formed on a base material, or may be formed on an inclined surface of a prism. When the inclined surface of the prism constitutes the reflection surface, the shape of the prism is not limited. The reflecting surface may be formed on the surface of a single layer of resin or a laminated film, or may be formed by coating a substrate.

[ base Material ]

The optical member may include a base material containing a compound having an absorption maximum in a wavelength region of 680nm or more and 1200nm or less, and a reflective layer constituting the reflective surface. The optical member can suppress reflection of light in a wavelength region of 700nm or more and 1150nm or less, in which sensitivity to a silicon photodiode is high and visibility to a human is low, by the compound contained in the base material absorbing light in a region of 680nm or more and 1200nm or less. The material, shape, and the like of the base are not particularly limited as long as the effects of the present invention are not impaired, and a transparent inorganic material, a transparent resin, and the like can be used. The optical member may be formed of one substrate as shown in fig. 5A or 5B, may be formed of a plurality of substrates as shown in fig. 5C, 5D, or 5E, or may be formed of a substrate having a curved surface as shown in fig. 5F.

[ reflection layer ]

The embodiment of the reflective layer is not limited. For example, the dielectric multilayer film, the high refractive index material layer containing the high refractive index material, the medium refractive index material layer containing the medium refractive index material, the low refractive index material layer containing the low refractive index material, the metal layer, the semiconductor layer, the resin layer in which the high refractive index material, the medium refractive index material, and the low refractive index material are dispersed, and the like can be used. In addition, an embodiment in which a plurality of reflective layers are combined is also possible. Further, the reflective layer may be laminated on one surface of the substrate, or the reflective layer may be laminated on a plurality of surfaces. When the reflective layer is laminated on the substrate, the reflective surface may be formed on the surface of the reflective layer, or may be formed on the surface of the reflective layer in contact with the substrate.

[ Compound ]

The compound is not particularly limited as long as it has maximum absorption in a wavelength region of 680nm to 1200 nm. Examples thereof include: squarylium compounds, phthalocyanine compounds, naphthalocyanine compounds, croconium (crosonium) compounds, hexaporphyrin (hexaphyrin) compounds, azo compounds, naphthoquinone compounds, polymethine compounds, oxonol compounds, pyrrolopyrrole compounds, triarylmethane pigments, diimmonium compounds, dithiol complex compounds, dithiolene complex compounds, dipyrromethene compounds, mercaptophenol complex compounds, mercaptonaphthol complex compounds, and the like. Further, the compounds may be used singly or in combination of two or more.

The compound is preferably contained in a range of 0.01 mass% or more and 80.0 mass% or less with respect to the base material. When the content of the base material is within the above range, appropriate optical characteristics can be easily obtained.

[ prism ]

The optical member may include a prism having a triangular cross section with an apex angle of 70 ° or more and 120 ° or less. In this case, the reflecting surface is formed by an inclined surface facing the apex angle of the prism. This makes it possible to perform specular reflection at a constant reflection angle without changing the inclination angle of the reflection surface. The vertex angle is more preferably 80 ° or more and 110 ° or less, and is further preferably substantially a right angle.

[ light incidence plane ]

The prism may further include a light incident surface through which light incident toward the reflecting surface passes. As the optical characteristics of the light incident surface, the average reflectance of unpolarized light incident on the light incident surface at 5 ° from the vertical is more preferably 20% or less in a wavelength region of 400nm to 640 nm. When the optical characteristics of the light incident surface are within the above range, the light incident on the light incident surface in a direction substantially perpendicular to the light incident surface can be prevented from reflecting visible light in a wavelength range of 400nm to 640 nm.

The average reflectance of the light incident on the light incident surface at 5 ° from the vertical in the unpolarized light wavelength range is preferably 20% or less, more preferably 10% or less, and still more preferably 5% or less. If the optical characteristics of the light incident surface are within the above range, when light enters the light incident surface in a direction substantially perpendicular to the light incident surface, reflection of light in a wavelength region of 700nm or more and 1150nm or less by the light incident surface can be prevented.

[ light exit surface ]

The prism may further include a light exit surface through which the light reflected at the reflection surface passes. As the optical characteristics of the light emitting surface, the average reflectance of unpolarized light incident on the light emitting surface at 5 ° from the vertical is preferably 20% or less, more preferably 10% or less, and even more preferably 5% or less in a wavelength region of 750nm to 1150 nm. If the optical characteristics of the light exit surface are within the above range, when the light reflected by the reflection surface enters the light exit surface in a direction substantially perpendicular to the light exit surface, reflection of light in a wavelength region of 750nm to 1150nm by the light exit surface can be prevented.

[ spectral transmittance efficiency ]

The prism is configured such that, in an unpolarized light beam which is incident on the light incident surface, reflected at an angle of 45 DEG from the vertical to the reflection surface, and transmitted through the light exit surface, the average transmission efficiency is 80% or more in a wavelength region of 400nm or more and 640nm or less, 8% or less in a wavelength region of 700nm or more and 1150nm or less, and the transmittance is 80% or more in a wavelength region of 600nm and the maximum transmission efficiency is 20% or less in a wavelength region of 700nm or more and 1150nm or less. Here, the "average transmission efficiency" refers to a ratio of the amount of unpolarized light emitted from the light emitting surface to the amount of unpolarized light incident on the light incident surface, the ratio being obtained by reflection of the unpolarized light by the reflecting surface. When the optical characteristics of the prism are within the above range, the light incident on the prism can be reflected by the reflection surface and transmitted from the light emission surface, thereby suppressing the transmission of light in a wavelength region of 700nm or more and 1150nm or less where the human visibility is low, and transmitting light in a wavelength region of 400nm or more and 640nm or less where the human visibility is high.

[ Camera Module ]

The camera module is a camera module including an optical member having a reflection surface, and a wavelength region in which an average reflectance of unpolarized light incident at 45 DEG from a vertical angle to the reflection surface is 400nm to 640nm is 80% or more, and a wavelength region in which the average reflectance is 700nm to 1150nm is 8% or less.

According to the camera module, the reflection of the reflection surface is suppressed for light in a wavelength region of 700nm or more and 1150nm or less where the human visibility is low, and the visibility correction in which red color has a natural color tone for the human eye is improved. Further, since the camera module can ensure a sufficient optical path length by converting the optical path length of light in a wavelength region of 400nm to 640nm, a zoom lens or the like can be incorporated into the optical path, and high performance of the optical telescopic function can be achieved. Further, the camera module can reduce an optical filter for blocking near infrared light, and can suppress the occurrence of image defects such as ghosts due to reflected light when the optical filter is used. The camera module is easy to realize thinning by reducing the optical filter.

The camera module may further include an optical sensor. The optical sensor may include, for example, a light receiving surface in which a plurality of photodiodes are arranged in a matrix. The optical sensor may receive light reflected by the optical member, perform photoelectric conversion, and output an image pickup signal.

The camera module may thereby include a lens, which may have no optical filter between the lens and the optical sensor. By reducing the optical filter, the camera module can be easily thinned.

The camera module may thereby comprise a periscope-shaped optical system housing unit. The optical system housing unit is configured to dispose a plurality of the optical members such that optical paths thereof are substantially perpendicular to each other. Thus, a longer optical path length can be ensured, and therefore, high performance and thinning of the optical telescopic function can be realized. In addition, the optical system housing unit may dispose the lens, the planar optical member, and the like between one of the optical members and the other of the optical members.

The camera module is useful for solid-state imaging devices such as digital still cameras, cameras for mobile phones, digital video cameras, surveillance cameras, cameras for vehicles, and web cameras. Since both the optical path conversion of visible light and the shielding of near-infrared light can be achieved by the optical member included in the camera module, the camera module can be easily designed to be small and thin, and can achieve high performance of the optical telescopic function.

The camera module may include an absorber that absorbs light of a particular wavelength region. The absorber is provided on an optical path of light that enters the optical member and passes through the reflection surface without being reflected. As the optical characteristics of the absorber, the average reflectance with respect to an unpolarized light ray incident on the absorber at 5 ° from the vertical direction is preferably 10% or less, more preferably 5% or less, in a wavelength region of 700nm or more and 1150nm or less. If the optical characteristics of the absorber are within the above range, light that has not been reflected and has passed through the reflection surface can be absorbed, and diffuse reflection within the camera module can be prevented.

The camera module may include a near infrared sensor that receives light of a particular wavelength region. The near-infrared sensor is provided on an optical path of light that enters the optical member and passes through the reflection surface without being reflected. The light which is not reflected and passes through the reflecting surface can be received, and the brightness around the camera module can be sensed. Thus, the light receiving section for solid-state imaging and the light receiving section for ambient light can be provided in one piece, and a camera module with high design can be provided.

[ details of embodiments of the present invention ]

Hereinafter, an optical member and a camera module according to an embodiment of the present invention will be described in detail with reference to the drawings.

[ details of embodiments of optical Member ]

The optical member 1 shown in fig. 1 includes a prism 5 having a right-angled isosceles triangle cross section. The prism 5 has a right triangular prism shape and includes a reflection surface 2, a light incident surface 3, and a light emitting surface 4. Two planes orthogonal to each other constitute a light incident surface 3 and a light emitting surface 4, and an inclined surface intersecting the light incident surface 3 and the light emitting surface 4 at an acute angle (45 ° in the embodiment of fig. 1) constitutes a reflecting surface 2.

Light incident from the light incident surface 3 of the optical member 1 passes through the light incident surface 3 and is reflected by the reflecting surface 2. The light reflected by the reflection surface 2 is transmitted through the light exit surface 4 and emitted from the optical member 1. As the optical characteristics of the reflecting surface 2, the wavelength region in which the average reflectance of unpolarized light incident on the reflecting surface 2 at 45 ° from the vertical is 400nm to 640nm is 80% or more, and the wavelength region in which the average reflectance is 700nm to 1150nm is 8% or less.

The optical member 1 can perform specular reflection of visible light of 400nm to 640nm by the reflecting surface 2, and can perform optical path length conversion by the specular reflection. The optical member 1 can suppress reflection of light in a wavelength region of 700nm to 1150nm, which has high sensitivity to a silicon photodiode and low human visibility. Further, the optical member 1 can suppress the loss of the amount of light involved in the optical path length conversion in the visible light of 400nm or more and 640nm or less.

In addition, regarding the optical characteristics of the reflecting surface 2 in the optical member 1, the maximum reflectance of unpolarized light incident on the reflecting surface 2 at 45 ° from the vertical may be 20% or less in a wavelength region of 700nm or more and 1150nm or less. When light incident on the optical member 1 is incident on the reflection surface 2 at 45 ° from the vertical, the optical member 1 can prevent reflection of light in a wavelength region of 700nm or more and 1150nm or less by the reflection surface 2. Thus, the optical member 1 can suppress specular reflection and optical path conversion of light in a wavelength region of 700nm to 1150nm, which have high sensitivity for a silicon photodiode used in an optical sensor.

Further, regarding the optical characteristics of the reflecting surface 2 of the optical member 1, the reflectance of unpolarized light incident on the reflecting surface 2 at 45 ° from the vertical may be 65% or more at a wavelength of 650 nm. When light incident on the optical member 1 is incident on the reflection surface 2 at 45 ° from the vertical, the optical member 1 can perform optical path length conversion by specular reflection of light having a wavelength of 650nm with high human visibility.

According to the optical member 1, both the optical path conversion of visible light and the near-infrared light shielding performance are achieved by one member. Further, according to the optical member 1, for example, one member can be used which has both a function of a mirror which reflects visible light and a function of an optical filter which shields near infrared light.

In the above embodiment, the case where the prism 5 has a right isosceles triangle cross section was described, but the shape of the prism 5 is not limited thereto as long as it has a triangle cross section. One of the apex angles in the triangular cross section may be 70 ° or more and 120 ° or less, more preferably 80 ° or more and 110 ° or less, and further preferably substantially a right angle. In the case where the prism 5 has a right-angled triangular cross section, the two sides constituting the right angle may be the same length or different lengths. The prism 5 may be made of a material used for a base material described later.

In the embodiment of the optical member 1 shown in fig. 1, the form of the prism having a shape with a right-angled triangular cross section is described, but the shape of the prism is not limited to the triangular prism shape, and may be a quadrangle or other polygonal shape. The resin composition may be in the form of a film, a flat plate, etc., a single layer resin, a laminated structure, etc. For example, as shown in fig. 2, the optical member 11 may have a flat plate shape including a reflecting surface 12.

When the optical member 11 is in a plate shape, the thickness is not particularly limited as long as it is appropriately selected according to the intended use, and is preferably 0.01mm or more and 0.2mm or less, more preferably 0.015mm or more and 0.15mm or less, and particularly preferably 0.02mm or more and 0.1mm or less. When the thickness of the optical member is in the above range, the handling ease is excellent, and a camera module or the like using the obtained optical member can be further reduced.

As in the optical member 21 shown in fig. 3, the reflective layer 23 constituting the reflective surface 22 may be provided. For example, the reflective layer 23 may be laminated on the substrate 24. The substrate 24 may contain a compound having an absorption maximum in a wavelength region of 680nm or more and 1200nm or less. The optical member 21 can suppress reflection of light in a wavelength region of 700nm to 1150nm, which has high sensitivity to a silicon photodiode and low human visibility, by absorbing light in a region of 680nm to 1200 nm.

The compound is not particularly limited as long as it has maximum absorption in a wavelength region of 680nm to 1200 nm. Examples thereof include: squarylium compounds, phthalocyanine compounds, naphthalocyanine compounds, ketanium compounds, hexatomic porphyrin compounds, azo compounds, naphthoquinone compounds, polymethine compounds, oxonol compounds, pyrrolopyrrole compounds, diimmonium compounds, dithiol complex compounds, dithiolene complex compounds, dipyrromethene compounds, mercaptophenol complex compounds, mercaptonaphthol complex compounds, copper oxide compounds, copper phosphate compounds, copper phosphonate compounds, and the like. The compound is preferably contained in a range of 0.01 mass% or more and 80.0 mass% or less with respect to the substrate 24.

The squarylium compound is not particularly limited as long as the effect of the present invention is not impaired, and examples thereof include a squarylium dye having a squaric acid structure. Some of the squarylium compounds also include those having no maximum absorption in the wavelength region of 680nm to 1200nm, and the squarylium compounds having maximum absorption in the wavelength region of 680nm to 1200nm are selected or those having maximum absorption in the wavelength region of 680nm to 1200nm are used in combination, and the compounds contained in the substrate 24 can be used.

The phthalocyanine-based compound or the naphthalocyanine-based compound is not particularly limited as long as the effects of the present invention are not impaired, and examples thereof include metal phthalocyanines and metal naphthalocyanines. As the central metal, copper, zinc, cobalt, vanadium, iron, nickel, tin, silver, magnesium, sodium, lithium, lead, or the like can be used. The phthalocyanine-based compound or the naphthalocyanine-based compound also includes a compound having no maximum absorption in a wavelength region of 680nm to 1200nm, and the phthalocyanine-based compound or the naphthalocyanine-based compound having a maximum absorption in a wavelength region of 680nm to 1200nm is selected or used in combination with the phthalocyanine-based compound or the naphthalocyanine-based compound having a maximum absorption in a wavelength region of 680nm to 1200nm, and can be used as the compound contained in the substrate 24.

The ketanium compound is not particularly limited as long as the effect of the present invention is not impaired, and examples thereof include a ketanium dye having a ketanium structure. Some of the kreonium-based compounds also include those having no maximum absorption in the wavelength region of 680nm to 1200nm, and the kreonium-based compounds having maximum absorption in the wavelength region of 680nm to 1200nm may be selected or used in combination with the kreonium-based compounds having maximum absorption in the wavelength region of 680nm to 1200nm, and may be used as the above-mentioned compounds contained in the substrate 24.

The six-membered porphyrin-based compound is not particularly limited as long as the effect of the present invention is not impaired, and examples thereof include six-membered porphyrins and florin (florin) -type six-membered porphyrins. Some of the six-membered porphyrin-based compounds also include those having no maximum absorption in the wavelength region of 680nm or more and 1200nm or less, and by selecting the six-membered porphyrin-based compounds having maximum absorption in the wavelength region of 680nm or more and 1200nm or using the six-membered porphyrin-based compounds having maximum absorption in the wavelength region of 680nm or more and 1200nm or less in combination, the compounds contained in the substrate 24 can be used.

The azo-based compound is not particularly limited as long as the effects of the present invention are not impaired, and examples thereof include diazo-based pigments and trisazo-based pigments. Some of the azo-based compounds also include those having no maximum absorption in the wavelength region of 680nm to 1200nm, and azo-based compounds having maximum absorption in the wavelength region of 680nm to 1200nm, or azo-based compounds having maximum absorption in the wavelength region of 680nm to 1200nm, may be used in combination as the compounds contained in the substrate 24.

The naphthoquinone-based compound is not particularly limited as long as the effects of the present invention are not impaired, and examples thereof include 1, 4-disubstituted 5, 8-naphthoquinone derivatives. Some of the naphthoquinone-based compounds also include those having no maximum absorption in the wavelength region of 680nm or more and 1200nm or less, and the naphthoquinone-based compounds having maximum absorption in the wavelength region of 680nm or more and 1200nm or less are selected and used in combination, and can be used as the compounds contained in the substrate 24.

The polymethine compound is not particularly limited as long as the effect of the present invention is not impaired, and examples thereof include: cyanines, merocyanines, carbocyanines, azacyanines, thiacyanines, bruke's merocyanines, and the like. The oxonol-based compound is not particularly limited as long as the effects of the present invention are not impaired, and examples thereof include oxonols such as oxonol VI. The polymethine-based compound or oxonol-based compound may partially include those having no maximum absorption in a wavelength region of 680nm or more and 1200nm or less, and the polymethine-based compound or oxonol-based compound having maximum absorption in a wavelength region of 680nm or more and 1200nm or less may be used in combination as the above-mentioned compounds contained in the substrate 24.

The pyrrolopyrrole-based compound is not particularly limited as long as the effect of the present invention is not impaired, and examples thereof include compounds having a diketopyrrolopyrrole structure. Some of the pyrrolopyrrole-based compounds also include those having no maximum absorption in the wavelength region of 680nm or more and 1200nm or less, and the pyrrolopyrrole-based compounds having maximum absorption in the wavelength region of 680nm or more and 1200nm or less are selected or used in combination as the compounds contained in the substrate 24.

The diimmonium compound is not particularly limited as long as the effect of the present invention is not impaired, and examples thereof include diimmonium salts such as bis (trifluoromethanesulfonyl) imide ion, periodate ion, and tetrafluoroborate ion, and diimmonium compounds described in paragraphs [0049] to [0061] of international publication No. 2018/043564. Some of the diimmonium compounds also include those having no maximum absorption in the wavelength region of 680nm to 1200nm, and the diimmonium compounds having maximum absorption in the wavelength region of 680nm to 1200nm may be selected or used in combination with the diimmonium compounds having maximum absorption in the wavelength region of 680nm to 1200nm, and may be used as the compounds contained in the substrate 24.

The dithiol complex compound is not particularly limited as long as the effect of the present invention is not impaired, and examples thereof include dithiol metal complexes. Examples of the dithiolene complex-based compound include a dithiolene metal complex and the like. As the central metal, a transition metal or the like may be used together. A part of the dithiol complex-based compound or dithiolene complex-based compound also includes a compound having no maximum absorption in a wavelength region of 680nm or more and 1200nm or less, and the dithiol complex-based compound or dithiolene complex-based compound having a maximum absorption in a wavelength region of 680nm or more and 1200nm or less is used in combination, and can be used as the compound contained in the substrate 24.

The dipyrromethene-based compound is not particularly limited as long as the effects of the present invention are not impaired, and examples thereof include a dipyrromethene-based boron complex compound and the like. Some of the dipyrromethene-based compounds also include those having no maximum absorption in the wavelength region of 680nm or more and 1200nm or less, and a dipyrromethene-based compound having a maximum absorption in the wavelength region of 680nm or more and 1200nm or less is used in combination, and can be used as the compound contained in the substrate 24.

The thiol phenol complex compound is not particularly limited as long as the effects of the present invention are not impaired, and examples thereof include metal complexes of thiol phenol derivatives. Examples of the mercaptonaphthol complex compound include a metal complex of a mercaptonaphthol derivative. As the central metal, a transition metal or the like may be used together. A part of the thiol-phenol complex compound or thiol-naphthol complex compound also includes a compound having no maximum absorption in a wavelength region of 680nm or more and 1200nm or less, and the compound contained in the substrate 24 can be used by selecting a thiol-phenol complex compound or thiol-naphthol complex compound having a maximum absorption in a wavelength region of 680nm or more and 1200nm or using a thiol-phenol complex compound or thiol-naphthol complex compound having a maximum absorption in a wavelength region of 680nm or more and 1200nm or less in combination.

The compounds can be synthesized using generally known methods. Examples of the synthesis method include methods described in Japanese patent laid-open publication No. 60-228448, Japanese patent laid-open publication No. 1-146846, Japanese patent laid-open publication No. 1-228960, Japanese patent laid-open publication No. 4081149, Japanese patent laid-open publication No. 63-124054, "phthalocyanine-chemical and function-" (IPC, 1997), Japanese patent laid-open publication No. 2007-1699315, Japanese patent laid-open publication No. 2009-108267, Japanese patent laid-open publication No. 2010-241873, Japanese patent laid-open publication No. 3699464, and Japanese patent laid-open publication No. 4740631.

[ base Material ]

The substrate 24 may be a transparent inorganic material. The transparent inorganic material is not particularly limited, and includes: quartz, borosilicate glass, silicate glass, chemically strengthened glass, physically strengthened glass, soda glass, phosphate glass, alumina glass, sapphire glass, colored glass, and the like. Examples of commercially available products of these include: d263, BK7, B270, KG1 manufactured by Schottky (SCHOTT) corporation or a product obtained by cutting KGl into the shape of the base material, KG3 or a product obtained by cutting KG3 into the shape of the base material, KG5 or a product obtained by cutting KG5 into the shape of the base material; a C5000 cut from stock grocery (HOYA) (strand) into the shape of the base material, a CD5000 cut from stock grocery (HOYA) into the shape of the base material, and E-CM500S cut from stock grocery (HOYA) into the shape of the base material; gorilla glass (gorilla glass) and willow glass (WillowGlass) manufactured by Corning (Corning); BS 1-BS 11 manufactured by Songlanzi industry (Strand) and BS 1-BS 11 cut into the shape of the base material; seaselames (Hicerams) manufactured by Nippon insulator (NGkinsulators) (thigh), and the like. Among these, borosilicate glass or phosphate glass is preferable in terms of high visible light transmittance and excellent near-infrared shielding performance, and the borosilicate glass is not particularly limited, and examples thereof include D263, BK7, B270, KG1, KG3, KG5, and the phosphate glass is not particularly limited, and examples thereof include copper phosphate glass containing copper atoms. Copper phosphate glasses containing copper atoms can be obtained by the methods described in, for example, Japanese patent laid-open publication No. 2015-522500, International publication No. 2011/071157, and International publication No. 2017/208679. The phosphate glass is preferably a fluorophosphate glass which tends to have little change in optical characteristics under a high-temperature and high-humidity environment and contains fluorine atoms.

The material of the substrate 24 may be transparent resin. The transparent resin is not particularly limited as long as the effects of the present invention are not impaired, and for example, in order to produce a substrate which can form a dielectric multilayer film by high-temperature vapor deposition at a vapor deposition temperature of 100 ℃ or higher while ensuring thermal stability and moldability into a plate-like body, a resin having a glass transition temperature (Tg) of preferably 110 ℃ or higher and 380 ℃ or lower, more preferably 110 ℃ or higher and 370 ℃ or lower, and still more preferably 120 ℃ or higher and 360 ℃ or lower may be cited. Further, when the Tg of the resin is 150 ℃ or higher, even when an additive is added to the resin at a high concentration to lower the Tg, the resin is particularly preferable because the resin can be a substrate on which a dielectric multilayer film can be formed by vapor deposition at a high temperature.

When a resin plate having a thickness of 0.05mm and containing only the resin is formed as the transparent resin, it is preferable to use a resin having a total light transmittance (Japanese Industrial Standards (JIS) K7375) of 50% or more and 96% or less, more preferably 60% or more and 96% or less, and particularly preferably 70% or more and 96% or less. When a resin having a total light transmittance in such a range is used, the obtained substrate exhibits good transparency as an optical film.

The transparent resin has a weight average molecular weight (Mw) of usually 15,000 or more and 350,000 or less, preferably 30,000 or more and 250,000 or less in terms of polystyrene as measured by a Gel Permeation Chromatography (GPC) method, and a number average molecular weight (Mn) of usually 10,000 or more and 150,000 or less, preferably 20,000 or more and 100,000 or less.

Examples of the transparent resin include: a cyclic polyolefin resin, an aromatic polyether resin, a polyimide resin, a fluorene polyester resin, a polycarbonate resin, a polyamide resin, an aromatic polyamide resin, a polysulfone resin, a polyether sulfone resin, a polyphenylene resin, a polyamideimide resin, a polyethylene naphthalate resin, a fluorinated aromatic polymer resin, a (modified) acrylic resin, an epoxy resin, a silsesquioxane ultraviolet curable resin, a maleimide resin, an alicyclic epoxy thermosetting resin, a polyether ether ketone resin, a polyarylate resin, an allyl ester curable resin, an acrylic ultraviolet curable resin, a vinyl ultraviolet curable resin, a resin containing silica as a main component formed by a sol-gel method, and the like. Among these, in order to obtain an optical member having a better balance among transparency (optical characteristics), heat resistance, reflow resistance, and the like, it is preferable to use a cyclic polyolefin resin, an aromatic polyether resin, a fluorene polyester resin, a polycarbonate resin, a polyimide resin, a fluorinated aromatic polymer resin, or an acrylic ultraviolet-curable resin. One kind of the transparent resin may be used alone, or two or more kinds thereof may be used.

The substrate can be used to form a prism as in the optical member 1 shown in fig. 4. In the optical member 1, the length L in fig. 4 may be 0.5mm to 100mm, the width W may be 0.5mm to 100mm, the height H may be 0.5mm to 100mm, more preferably the length L may be 0.5mm to 50mm, the width W may be 0.5mm to 50mm, the height H may be 0.5mm to 50mm, still more preferably the length L may be 0.5mm to 20mm, the width W may be 0.5mm to 20mm, and the height H may be 0.5mm to 20 mm.

[ method for producing base Material ]

When the substrate 24 is a plate-like substrate including the transparent resin, the substrate 24 can be formed by, for example, melt molding or tape casting, and if necessary, a coating agent such as an antireflective agent, a hard coat agent, or an antistatic agent is applied after molding, whereby a substrate on which an overcoat layer is laminated can be produced.

When the substrate 24 is a substrate in which a transparent resin layer containing an additive or the transparent resin is laminated on a transparent inorganic material support or a resin support, for example, a resin solution containing an additive is melt-molded or cast on a transparent inorganic material support or a resin support, and is preferably applied by a method such as spin coating, slit coating, or ink jet, and then the solvent is dried and removed, and further, light irradiation or heating is performed as necessary, whereby a substrate in which the transparent resin layer is formed on a transparent inorganic material support or a resin support can be manufactured.

[ melt Molding ]

Specific examples of the melt molding include the following methods: a method of melt-molding pellets obtained by melt-kneading a resin and an additive in a case where the base material 24 contains the resin and the additive; a method of melt-molding a resin composition containing a resin and an additive; a method of melt-molding pellets obtained by removing a solvent from a resin composition containing an additive, a resin, a solvent, and the like. Examples of the melt molding method include: injection molding, melt extrusion molding, blow molding, and the like. In the case where the substrate 24 contains a transparent inorganic material, the following methods can be cited: a method of melting a transparent inorganic material in a crucible using a platinum crucible, a platinum-rhodium crucible, a gold crucible, an iridium crucible, a crucible made of alumina porcelain, or the like, and then molding by an overflow method, a float method, or the like, depending on the melting point or releasability of the inorganic material.

[ tape casting ]

The casting may be performed by casting a resin composition containing an additive, a resin, a solvent, and the like on a suitable support to remove the solvent. Further, the following method is also possible: a curable composition containing an additive, a photocurable resin, a thermosetting resin, or the like is cast on an appropriate support to remove a solvent, and then cured by an appropriate method such as ultraviolet irradiation or heating.

In the case where the substrate 24 is a plate-like substrate including the transparent resin layer containing an additive, the substrate 24 can be obtained by peeling off the coating film from the support after the casting molding. When the substrate 24 is a plate-like substrate in which a transparent resin layer such as a top coat layer containing an additive, a curable resin, or the like is laminated on a support such as a transparent inorganic material support or a resin support, the substrate 24 can be obtained, for example, by not peeling off a coating film after casting.

Examples of the support include: glass plates, steel belts, steel cylinders, and supports made of transparent resin (e.g., polyester film and cycloolefin resin film).

Further, the transparent resin layer may be formed on the optical member by a method of applying the resin composition to the optical member made of a transparent inorganic material, a transparent resin, or the like and drying the resin composition by a solvent, a method of applying the curable composition and curing and drying the curable composition, or the like.

In the case where the substrate is a prismatic substrate including a transparent resin layer containing an additive, it can be obtained by melt molding.

The amount of residual solvent in the substrate obtained by the process is preferably as small as possible. Specifically, the residual solvent amount is preferably 3% by mass or less, more preferably 1% by mass or less, and still more preferably 0.5% by mass or less, based on 100% by mass of the transparent resin layer or the transparent resin substrate. When the amount of the residual solvent is within the above range, a transparent resin layer or a transparent resin substrate which is hardly deformed or changed in properties and can easily exhibit desired functions can be easily obtained.

[ additives ]

The base material 24 may contain additives such as an antioxidant, a light stabilizer, a fluorescence quencher, and an ultraviolet absorber within a range not impairing the effects of the present invention. These additives may be used singly or in combination of two or more.

Examples of the antioxidant include: 2, 6-di-tert-butyl-4-methylphenol, 2 ' -dioxy-3, 3 ' -di-tert-butyl-5, 5 ' -dimethyldiphenylmethane, tetrakis [ methylene-3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] methane, tris (2, 4-di-tert-butylphenyl) phosphite.

Examples of the ultraviolet absorber include: azomethine compounds, indole compounds, triazole compounds, triazine compounds, oxazole compounds, merocyanine compounds, cyanine compounds, naphthalimide compounds, oxadiazole compounds, oxazine compounds, oxazolidine compounds, naphthalenedicarboxylic acid compounds, styrene compounds, anthracene compounds, cyclic carbonyl compounds, and the like.

The ultraviolet absorber preferably has an absorption maximum wavelength in a range of preferably 350nm to 410nm, more preferably 350nm to 405nm, and further preferably 360nm to 400 nm. By having the absorption maximum wavelength in the above range, an optical member more excellent in the correction of the visual sensitivity can be easily obtained. In addition, the absorption maximum wavelength can be measured using a solution in which an ultraviolet absorber is dissolved in methylene chloride.

[ dielectric multilayer film ]

The reflective layer constituting the reflective surface in the optical member of the present invention may be a dielectric multilayer film. The dielectric multilayer film may be plural. For example, in the optical member 31 shown in fig. 5A, the reflective layer constituting the reflective surface 32 is a dielectric multilayer film 36a, and the other surface of the substrate 35 has a dielectric multilayer film 36 b. The optical member 31 may have the dielectric multilayer film 36a only on the surface constituting the reflection surface of the base material 35. In order to suppress the warpage thereof, the optical member 31 preferably has the dielectric multilayer film 36a and the dielectric multilayer film 36b on both surfaces of the base material, and the absolute value of the difference in the total physical film thickness between the dielectric multilayer film 36a and the dielectric multilayer film 36b is more preferably less than 5.0 μm. More preferably less than 4.0. mu.m, still more preferably less than 3.0. mu.m, yet more preferably less than 2.0. mu.m, particularly preferably less than 1.5. mu.m, most preferably less than 1.0. mu.m. In the case where the absolute value of the difference in the total physical film thickness between the

dielectric multilayer films

36a and 36b is 0.1 μm or more and less than 5.0 μm, it is preferable that the temperature at the time of forming one of the dielectric multilayer films is different from the temperature at the time of forming the other dielectric multilayer film in the range of about 10 ℃ to about 80 ℃ in terms of suppressing warpage.

As in the optical member 41a shown in fig. 5B, the dielectric multilayer film 46a may constitute the reflection surface 42 included in the prism-shaped base 45. The dielectric multilayer film 46b may form the light incident surface 43, and the dielectric multilayer film 46c may form the light emitting surface 44. As shown in fig. 6A and 6B, light L incident from the light incident surface 43 of the optical member 41a passes through the light incident surface 43 and is reflected by the reflecting surface 42. The reflected light L1 reflected by the reflection surface 42 is transmitted through the light exit surface 44 and is emitted from the optical member 41 a. The transmitted light L2 that is not reflected by the reflection surface 42 passes through the reflection surface 42 and is emitted from the optical member 41 a. The optical member of the present invention may be formed of a plurality of substrates 45 as shown in fig. 5C, 5D, or 5E, or the substrate 45 may have a curved surface as shown in fig. 5F.

The dielectric multilayer film may include, for example, a high refractive index material layer, a low refractive index material layer, a medium refractive index material layer, and the like.

The material constituting the high refractive index material layer may have a refractive index of 2.0 or more, and a material having a refractive index of 2.0 or more and 3.6 or less is usually selected. The refractive index is a value indicating light having a wavelength of 550 nm.

Examples of the material constituting the high refractive index material layer include: materials containing titanium oxide, zirconium oxide, tantalum oxide, niobium oxide, lanthanum oxide, zinc sulfide, barium titanate, silicon, and the like as a main component, and containing hydrogen, titanium oxide, niobium oxide, hafnium oxide, tin oxide, cerium oxide, and the like in an amount exceeding 0 mass% and 10 mass% or less, for example, with respect to the main component; and a material in which titanium oxide, zirconium oxide, tantalum oxide, niobium oxide, lanthanum oxide, zinc sulfide, barium titanate, silicon, or the like is dispersed in a resin such as the above-mentioned transparent resin.

The material constituting the low refractive index material layer may have a refractive index of less than 1.6, and a material having a refractive index of 1.2 or more and less than 1.6 is usually selected. Examples of such materials include: silicon dioxide, lanthanum fluoride, magnesium fluoride, sodium aluminum hexafluoride, and the like. Examples of the transparent resin include those having silica, lanthanum fluoride, magnesium fluoride, and sodium aluminum hexafluoride dispersed therein.

As a material constituting the medium refractive index material layer, a material having a refractive index of 1.6 or more and less than 2.0 is cited. Examples of such materials include: aluminum oxide, bismuth oxide, europium oxide, yttrium oxide, ytterbium oxide, samarium oxide, indium oxide, magnesium oxide and molybdenum oxide. A material obtained by mixing these materials with a material constituting the high refractive index material layer and a material constituting the low refractive index material layer; and a material obtained by mixing a material constituting the high refractive index material layer and a material constituting the low refractive index material layer, and a material obtained by dispersing these materials in a resin such as the transparent resin.

The dielectric multilayer film may have a metal layer or a semiconductor layer of about 1nm to 100 nm. Examples of the material constituting these layers include materials having a refractive index of about 0.1 to 5.0. As such materials, there can be mentioned: gold, silver, copper, zinc, aluminum, tungsten, titanium, magnesium, nickel, silicon hydride, germanium, and the like.

The method for forming the dielectric multilayer film is not particularly limited as long as a dielectric multilayer film in which these material layers are stacked can be formed. For example, a dielectric multilayer film in which high refractive index material layers and low refractive index material layers are alternately stacked or a dielectric multilayer film in which high refractive index material layers, medium refractive index material layers, and low refractive index material layers are alternately stacked can be directly formed on the substrate by a Chemical Vapor Deposition (CVD) method, a sputtering method, a vacuum evaporation method, an ion-assisted evaporation method, an ion plating method, or the like. In the case of laminating the layer including the transparent resin, the layer may be formed by melt molding, cast molding, or the like, and is preferably formed by spin coating, dip coating, slit coating, gravure coating, or the like, as in the method of forming the base material.

Among these, the sputtering method, the ion-assisted deposition method, or the ion plating method is preferable from the viewpoint of little change in the optical characteristics of the dielectric multilayer film due to adhesion to the substrate and humidity.

Examples of the apparatus capable of performing the ion-assisted deposition include: syrushro series manufactured by buhlenberger Optics (Buhler Leybold Optics), OTFC series manufactured by mitsung, MIC series manufactured by shintron, EPD series manufactured by shintron, VCD series manufactured by shintron, Sapio series manufactured by showa and vacuum, and the like.

In the ion-assisted deposition, it is preferable that a film formation rate of the deposition is controlled by a crystal oscillator, and an optical film thickness of each layer of the dielectric multilayer film is controlled by an optical monitor estimated from a reflection intensity. When a layer having a physical thickness of 60nm or less is formed, it is preferable to control the film thickness by using an integrated value of the film formation rate of a crystal oscillator. By controlling the film thickness using the integrated value of the film formation rate of the crystal oscillator, variation in optical film thickness control using an optical monitor can be reduced.

The dielectric multilayer film is preferably formed at 90 ℃ or higher. By setting the temperature to 90 ℃ or higher, film peeling, cracking, or the like of the obtained dielectric multilayer film when the obtained optical member is heated to 90 ℃ is reduced. The formation temperature of the dielectric multilayer film is more preferably 120 ℃ or higher from the viewpoint of increasing the heat resistance temperature of the optical member.

In the case where the dielectric multilayer film is formed by vapor deposition, the vapor deposition start degree of vacuum is preferably 0.01Pa or less, more preferably 0.005Pa or less, and still more preferably 0.001Pa or less. By further setting the vacuum degree at the start of vapor deposition to a high vacuum, the water content in the obtained dielectric multilayer film can be reduced, and the phenomenon that the optical characteristics of the obtained optical member change depending on humidity can be reduced. In the case where the dielectric multilayer film is formed by the ion-assisted evaporation, the degree of vacuum in the formation of the dielectric multilayer film is preferably 0.05Pa or less. By setting 0.05Pa or less, the obtained dielectric multilayer film has good smoothness and an optical member having low haze can be obtained.

The gas introduced into the ion gun serving as the ion supply device in the ion-assisted deposition is preferably oxygen gas or a mixed gas of oxygen gas and a rare gas. By using oxygen gas or a mixed gas of oxygen gas and a rare gas, a dielectric multilayer film having a film with less absorption, good smoothness, and less crystallinity can be obtained.

The optical member of the present invention can be obtained by appropriately setting the structure of the dielectric multilayer film, specifically, by appropriately selecting the types of materials constituting the high refractive index material layer, the intermediate refractive index material layer, the low refractive index material layer, and the like, the thicknesses, the stacking order, the number of stacked layers, and the like of the respective layers such as the high refractive index material layer, the intermediate refractive index material layer, the low refractive index material layer, and the like.

[ reflection band ]

The dielectric multilayer film forms a reflection band by optical interference by appropriately setting the film thickness of each layer to be laminated. Here, the reflection band is a wavelength band in which the reflectance is 80% or more when the light is incident at an angle of 45 ° from the dielectric multilayer film formation surface. In order to allow a visible light wavelength region of 400nm or more and 640nm or less to efficiently reach a sensor, an optical member of the present invention includes a reflection surface having the reflection band with a reflectance of 80% or more in the wavelength region. In order to allow the visible light to reach the sensor more efficiently, the reflectance is 85% or more, and more preferably 90% or more. In order to prevent the near infrared wavelength region of 700nm or more and 1150nm or less, which is a low visibility level of human eyes and causes noise or ghost, from entering the sensor, the sensor does not have a reflection band in the wavelength region. The reflectance in the wavelength region of 700nm to 1150nm is 8% or less, and from the viewpoint of further reducing noise, 6% or less, and more preferably 4% or less.

[ other functional films ]

The optical member of the present invention may suitably have a functional film such as an antireflection layer, a hard coat film, an antistatic film, or the like between the substrate and the dielectric multilayer film, on the surface of the substrate opposite to the surface on which the dielectric multilayer film is provided, or on the surface of the dielectric multilayer film opposite to the surface on which the substrate is provided, for the purpose of improving the surface hardness of the substrate or the dielectric multilayer film, improving chemical resistance, antistatic properties, removing damage, or the like, within a range not to impair the effects of the present invention. The optical member of the present invention may comprise one layer of the functional film, or may comprise two or more layers. When the optical member of the present invention includes two or more functional films, the optical member may include two or more identical layers or may include two or more different layers.

The method for laminating the functional film is not particularly limited, and examples thereof include: and a method of melt-molding or tape-casting a coating agent such as an antireflective agent, a hard coat agent, and an antistatic agent on the substrate or the dielectric multilayer film in the same manner as described above. In addition, the method can also be manufactured as follows: a curable composition containing the coating agent or the like is applied to the substrate or the dielectric multilayer film by a bar coater or the like, and then cured by ultraviolet irradiation or the like.

Examples of the coating agent include Ultraviolet (UV)/Electron Beam (EB) curable resins and thermosetting resins, and specifically include: vinyl compounds, urethane resins, acrylic urethane resins, acrylate resins, epoxy resins, and epoxy acrylate resins. The curable composition containing these coating agents includes: and curable compositions of vinyl, urethane, acrylic urethane, acrylate, epoxy, and epoxy acrylate.

The curable composition may also contain a polymerization initiator. As the polymerization initiator, a known photopolymerization initiator, a thermal polymerization initiator, or the like can be used, and a photopolymerization initiator and a thermal polymerization initiator can be used in combination. The polymerization initiator may be used singly or in combination of two or more.

In the curable composition, the proportion of the polymerization initiator is preferably 0.1 to 10% by mass, more preferably 0.5 to 10% by mass, and particularly preferably 1 to 5% by mass, when the total amount of the curable composition is 100% by mass. When the blending ratio of the polymerization initiator is in the above range, the obtained curable composition is excellent in curing properties and handling properties, and the functional film such as an anti-reflection layer, a hard coat film, an antistatic film, etc. having a desired hardness can be easily obtained.

An organic solvent may be added to the curable composition, and a known solvent may be used as the organic solvent. Specific examples of the organic solvent include: alcohols such as methanol, ethanol, isopropanol, butanol and octanol, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, esters such as ethyl acetate, butyl acetate, ethyl lactate, γ -butyrolactone, propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate, ethers such as ethylene glycol monomethyl ether and diethylene glycol monobutyl ether, aromatic hydrocarbons such as benzene, toluene and xylene, and amides such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone. These solvents may be used alone or in combination of two or more.

The thickness of the functional film is preferably 0.9 to 30 μm, more preferably 0.9 to 20 μm, and particularly preferably 0.9 to 5 μm.

For the purpose of improving the adhesion between the substrate and the functional film or the dielectric multilayer film or the adhesion between the functional film and the dielectric multilayer film, the surface of the substrate, the functional film, or the dielectric multilayer film may be subjected to a surface treatment such as corona treatment, plasma treatment, or vacuum ultraviolet treatment.

[ light-shielding film ]

In addition, the optical member of the present invention may have a light-shielding film at a part of the outermost layer or layers thereof. For example, the optical member 51 of fig. 7A has a light-shielding film 52 on the surface of a base material 53. The optical member 61 in fig. 7B has a light shielding film 62a and a light shielding film 62B on the light incident surface and the light emitting surface of the substrate 63. By having the light shielding film in this manner, in the solid-state imaging device or the camera module including the optical member 51 or the optical member 61, light reflected by the frame or the lens can be suppressed from being incident on the sensor, an image in which ghosting is suppressed can be easily obtained, and thus it is preferable.

As materials for forming the light-shielding film, there can be mentioned: a resin material such as a thermosetting resin, an ultraviolet curable resin, or a thermoplastic resin, a metal material such as chromium, molybdenum, tungsten, iron, nickel, titanium, or chromium, an oxide of the metal material, a carbon material such as graphite or a carbon nanotube, or fullerene (fullerene), an absorbing material containing one or more pigments, one or more dyes, or the like. Among these, in terms of ease of shape control and the like, it is preferable to include an ultraviolet curable resin.

The thickness of the light-shielding film is preferably 0.1 μm or more and 10 μm or less. When the thickness of the light-shielding film is less than 0.1 μm, it tends to be difficult to obtain a sufficient Optical Density (OD value), and when it exceeds 10 μm, the influence of diffraction or reflection on the end face of the light-shielding film tends to be large. Preferably, the thickness is 0.5 μm or more and 4.0 μm or less.

The light shielding film provided in the optical member of the present invention may be one portion or a plurality of portions. Here, regarding the number of light-shielding films, a continuous band is regarded as having one light-shielding film, and a plurality of light-shielding films means a plurality of discontinuous light-shielding films.

The light-shielding film preferably has an OD value of 3.0 or more, more preferably 4.0 or more, in total light transmittance under a D65 light source (a standard light source defined by the international commission on illumination (CIE)). If the OD value is in the above range, stray light can be sufficiently blocked.

The method for forming the light-shielding film is not particularly limited, and examples thereof include: coating method, sputtering method, vacuum evaporation method, screen printing method, and the like. As the coating method, there may be mentioned: spin coating, bar coating, dip coating, casting, spray coating, bead coating, wire bar coating, blade coating, roll coating, curtain coating, slit die coating, gravure coating, slit reverse coating, microgravure coating, and comma coating. The coating in these methods can be carried out several times.

The light-shielding film may cooperate with a plurality of light-shielding films to form a Fresnel zone plate (Fresnel zone plate) or a mosaic mask (mosaic mask). The optical member constituting the fresnel zone plate may be replaced with a lens, and the obtained solid-state imaging device, camera module, sensor module, and the like may be preferably further thinned. A light-shielding film constituting the mosaic mask is preferable because a lens is not required and image data with a variable focal length is obtained by performing calculation processing on an obtained image.

The optical member of the present invention may have a concave-convex portion at a position not related to the optical path. Fig. 8A shows an example in which rectangular parallelepiped

convex portions

72a and 72b are provided on both side surfaces of the optical member 71. Fig. 8B is a plan view of the optical member 71 as viewed from a direction perpendicular to the light incident surface. Fig. 8C is a bottom view of the optical member 71 as viewed from a direction perpendicular to the reflection surface. In a camera module including the optical member of the present invention, when the incident angle of light is shifted due to the shift of the optical member, the optical path of light reaching the sensor may be distorted. The optical member of the present invention preferably has a concave-convex portion, and more preferably includes a convex portion having a ridge, from the viewpoint of fixing the angle of the optical member with the concave-convex portion as a reference, which does not relate to the position of the optical path. In addition, the concave-convex portion may be a recess.

The optical member of the present invention has a thin structure and excellent visibility correction characteristics, and has excellent cut-off characteristics in the near infrared band even when the incident light is at a high angle. Therefore, the present invention is useful for correcting the visibility of a solid-state imaging device such as a solid-state imaging device, a camera module, or a sensor which is capable of coping with high-angle incidence.

[ details of embodiment of Camera Module ]

The camera module 101a shown in fig. 9A includes the optical member 1, and the optical member 1 includes the reflective surface 2. The camera module 101a further includes a lens 102, an optical filter 103a and an optical sensor 104 a. The camera module 101B shown in fig. 9B includes the optical member 11, and the optical member 11 includes the reflective surface 12. In addition, the camera module of the present invention may not include an optical filter between the lens and the optical sensor. For example, in the camera module 101C of fig. 9C, the optical filter 103a is not provided between the lens 102 and the optical sensor 104a, and the cover glass 107 is provided on the optical path of the optical member 1 before light is incident.

Light incident on the camera module 101a shown in fig. 9A is reflected by the reflection surface 2, passes through the lens 102, and is received by the optical sensor 104 a. The lens 102 may be one or more pieces. The lens 102 is appropriately set to a convex lens, a concave lens, or the like according to the zoom performance of the camera module 101a or the like.

The camera module 101a can ensure a sufficient optical path length by performing optical path conversion of light incident on the optical member 1 by using the reflection surface 2. Thus, multiple lenses 102 may be incorporated in the optical path. The camera module 101a may have a zoom function or the like through the lens 102. Further, the camera module 101a can suppress reflection of light in a wavelength region of 700nm to 1150nm, which has high sensitivity to a silicon photodiode, according to the optical characteristics of the reflection surface 2, and thus can prevent the optical sensor 104a from sensing light in a wavelength region of 700nm to 1150 nm. As a result, the visibility correction for rendering red to have a natural hue for the human eye in the camera module 101a becomes good. Further, the camera module 101a can reduce an optical filter for shielding near infrared light from its structure, and can suppress the occurrence of image defects such as ghost due to reflected light, which occurs when the optical filter is used.

The camera module 101D shown in fig. 9D includes a lens 102, an optical member 1 disposed in front of the lens 102 in the optical path, and an optical member 1 disposed behind the lens 102 in the optical path. The camera module 101d further includes a periscope-shaped optical system housing unit 108, and the optical system housing unit 108 includes two optical members 1, and the two optical members 1 are arranged so that optical paths thereof are substantially perpendicular to each other. Since the optical system housing unit 108 having a periscope shape has a light incident surface parallel to the sensor surface, the sensor width is not limited by the thickness of the camera module, and a sensor having a larger area can be preferably used. The camera module 101d having the above-described configuration can ensure a long optical path length by bending the optical path twice, and thus can realize high performance and thin optical telescopic function. There may be a lens 102 or a lens instead of the planar optical element 106 between one optical component 1 and another optical component 1. Although not shown in fig. 9D, the camera module 101D may include an optical filter or a plurality of optical system accommodation units.

The camera module 101E shown in fig. 9E includes an absorber 105 that absorbs light of a specific wavelength region. The absorber 105 may be provided on the optical path of the light that enters the optical member 1 and passes through the reflection surface 2 without being reflected. As the optical characteristics of the absorber 105, the average reflectance with respect to an unpolarized light ray incident on the absorber 105 at 5 ° from the vertical direction is preferably 10% or less, more preferably 5% or less, in a wavelength region of 700nm to 1150 nm.

As the absorber 105, for example, a near-infrared light absorbing dye having a steep absorption characteristic is contained in a transparent resin. Examples of the near-infrared light absorbing dye include a metal complex compound, a dye, and a pigment that function as a dye that absorbs near-infrared light, and examples thereof include: phthalocyanine-based compounds, naphthalocyanine-based compounds, polymethine-based colorants, cyanine-based colorants, squarylium-based colorants, ketanium-based colorants, dithiol metal complex-based compounds, and the like.

The camera module 101F shown in fig. 9F does not include an optical filter, and the optical sensor 104b is provided on the optical path of the light that has not been reflected but has passed through the reflection surface 2. The optical sensor 104b may be an ambient light sensor. The camera module of the structure can receive light that is not reflected but transmitted through the reflection surface 2, thereby sensing the brightness of the surroundings of the camera module 101 f. Thus, the light-receiving section for solid-state imaging and the light-receiving section for ambient light can be provided in one module, and a camera module with high design can be provided. The optical sensor 104b included in the camera module 101f may be a near infrared ray sensor. The near infrared sensor can perform night vision imaging or measure the distance to an object.

As the camera module 101G of fig. 9G, the camera module of the present invention may be provided with an optical filter 103b in front of the optical sensor 104 b. In addition, the optical filter 103a may be provided in front of the optical sensor 104 a. The camera module 101g includes at least one of an optical filter 103a and an optical filter 103 b.

As the camera module 101H of fig. 9H, the camera module of the present invention may provide a lens having a function as a lens such as a fresnel zone plate, a fresnel lens, a super lens (metalens), a mosaic mask, or the like between the optical sensor 104a and the optical filter 103a instead of the planar optical element 106. In addition, as the camera module 101I including the optical member 1 of fig. 9I, light may not be incident from the light incident surface of the optical member 1, but may be reflected by the reflection surface 2.

As the camera module 101J of fig. 9J, the camera module of the present invention may include the optical member 11 in a rotatable state. When the optical member 11 is fixed at an appropriate angle, light is guided to the optical sensor 104a, and light is not guided in the case of other angles, so a shutter function using the optical member 11 can be provided.

As shown in fig. 9K, the camera module 101K of the present invention may have two optical members 1, and a lens 102 is disposed between the second optical member 1, where light is reflected, and the optical sensor 104 a.

As the camera module 1011 of fig. 9L, the camera module of the present invention preferably does not have an optical filter in front of the optical sensor 104a from the viewpoint of reducing noise and/or ghost caused by near infrared rays. More preferably, a cover glass 107 having a near infrared ray cut-off performance is further provided on the front surface of the optical member 11. The cover glass 107 is not limited as long as the effect of the present invention of transmitting light of a specific wavelength is not impaired, and the same material as the optical member, for example, a transparent inorganic material or a transparent resin may be used as the base material. From the viewpoint of being less vulnerable to injury, a transparent inorganic material is preferable. The cover glass 107 may have an antireflection layer or a dielectric multilayer film in order to improve the sensitivity of the optical sensor and reduce image defects. In order to reduce image defects caused by near infrared rays even when a light source that strongly emits near infrared rays is incident on the optical sensor, the cover glass 107 is preferably a dielectric multilayer film having a near infrared ray cut function, and the average transmittance of light incident from the direction perpendicular to the cover glass 107 is preferably 10% or less at a wavelength of 800nm or more and 1150nm or less. Examples of such a dielectric multilayer film include design (VII) shown in table 7, which will be described later.

The camera module of the present invention may further include a focus adjustment mechanism, a phase detection mechanism, a distance measurement mechanism, an iris authentication mechanism, a vein authentication mechanism, a face authentication mechanism, a blood flow meter, an oxidized or reduced hemoglobin meter, a vegetation index meter, and the like. Such a camera module may be preferably used for a device that outputs an image or information as an electric signal. In addition, the camera module may be a structure having a lens or a structure without a lens. In addition, a reflective lens is preferably used as the lens from the viewpoint of obtaining an image with a reduced optical path length and less aberration.

As a member constituting the solid-state imaging device, a photoelectric conversion device that converts light of a specific wavelength into electric charges, such as silicon, an avalanche diode (avalanche diode), black silicon, InGaAs, selenium, or an organic photoelectric conversion film, is used.

[ Black silicon ]

Black silicon can be used in the light-receiving portion of the solid-state imaging device using the present filter. Black silicon can be obtained, for example, by: laser irradiation is performed on a silicon wafer under a specific environment, thereby forming a minute burr (spike) on the silicon surface. In the case of using black silicon, black silicon is more preferably used for an image pickup element using near infrared rays because of its high sensitivity of light reception in the near infrared ray band as compared with the case of using a silicon photodiode. As a commercial product of CMOS using black silicon, XQE series by the american night vision technology (sion yx) company and the like can be cited.

[ other embodiments ]

The embodiments disclosed herein are not intended to limit the configuration of the present invention. Therefore, the embodiments may omit, replace, or add components of each part of the embodiments based on the description of the present specification and the common technical knowledge, and it should be understood that these are included in the scope of the present invention.

[ examples ]

The present invention will be described more specifically with reference to the following examples, but the present invention is not limited to these examples at all. Unless otherwise specified, "part" means "part by mass". The methods for measuring the respective physical property values and the methods for evaluating the physical properties are as follows.

[ molecular weight ]

The molecular weight of the resin was measured by using a GPC apparatus (HLC-8220 type, column: TSKgel. alpha. -M, developing solvent: Tetrahydrofuran (THF)) manufactured by Tosoh (Tosoh), and the weight average molecular weight (Mw) and the number average molecular weight (Mn) in terms of standard polystyrene.

[ glass transition temperature (Tg) ]

Using a differential scanning calorimeter (DSC6200) manufactured by precision electronics Nanotechnologies (SII Nanotechnologies) (inc.), at a temperature rising rate: the measurement was carried out at 20 ℃ per minute under a nitrogen stream.

[ resin Synthesis example 1]

The following 8-methyl-8-methoxycarbonyltetracyclo [4.4.0.1 ] is introduced^2，5.1^7，10]Dodeca-3-ene (hereinafter also referred to as "DNM (8-methyl-8-methoxy carbonyl tetracyclo [4.4.0.1 ]^2，5.1^7，10]dodeca-3-ene) ") 100 parts, 1-hexene (molecular weight modifier) 18 parts, and toluene (solvent for ring-opening polymerization) 300 parts were charged into the reaction vessel purged with nitrogen, and the solution was heated to 80 ℃. Then, triethylaluminum was added as a polymerization catalyst to the solution in the reaction vessel0.2 parts of a toluene solution of methanol-modified tungsten hexachloride (0.6 mol/liter) and 0.9 parts of a toluene solution of methanol-modified tungsten hexachloride (concentration 0.025 mol/liter), and the solutions were heated and stirred at 80 ℃ for 3 hours, thereby performing a ring-opening polymerization reaction, thereby obtaining a ring-opening polymer solution. The polymerization conversion in the polymerization reaction was 97%.

[ solution 1]

1,000 parts of the ring-opening polymerization solution obtained in the manner described above was charged into an autoclave, and 0.12 part of RuHCl (CO) [ P (C) was added to the ring-opening polymerization solution₆H₅)₃]₃At a hydrogen pressure of 100kg/cm²And the reaction temperature was 165 ℃ and the mixture was stirred with heating for 3 hours to effect hydrogenation. After the obtained reaction solution (hydrogenated polymer solution) was cooled, hydrogen gas was released under pressure. The reaction solution was poured into a large amount of methanol, and a solidified product was separated and recovered, and dried to obtain a hydrogenated polymer (hereinafter also referred to as "resin a"). The obtained resin A had a number average molecular weight (Mn) of 32,000, a weight average molecular weight (Mw) of 137,000, and a glass transition temperature (Tg) of 165 ℃.

[ base Material A ]

100 parts of the resin A obtained in resin Synthesis example 1 and methylene chloride were charged into a vessel to prepare a solution having a resin concentration of 20% by weight. The obtained solution was cast onto a smooth glass plate, dried at 20 ℃ for 8 hours, and then peeled from the glass plate. The peeled coating film was further dried under reduced pressure at 140 ℃ for 2 hours to obtain a substrate A comprising a transparent resin substrate having a thickness of 0.1mm, a length of 60mm and a width of 60 mm.

[ base material B ]

To a vessel, 100 parts of cycloolefin resin (japanese pulsatilla (Zeon) (strand), pulsatillae (ZEONEX)) and cyclohexane were added to prepare a solution having a resin concentration of 20 wt%. The obtained solution was cast onto a smooth glass plate, dried at 20 ℃ for 8 hours, and then peeled from the glass plate. The peeled coating film was further dried under reduced pressure at 150 ℃ for 2 hours to obtain a substrate B comprising a transparent resin substrate having a thickness of 0.1mm, a length of 60mm and a width of 60 mm.

[ base material C ]

A glass substrate (D263T eco, manufactured by Schottky (SCHOTT) Co., Ltd.) having a thickness of 0.1mm was used as the substrate C.

[ base Material D ]

Into a vessel, 100 parts of the resin a obtained in resin synthesis example 1, 0.04 parts of the compound a, 0.08 parts of the compound D described later, and methylene chloride were charged to prepare a solution having a resin concentration of 20% by weight. The obtained solution was cast onto a smooth glass plate, dried at 20 ℃ for 8 hours, and then peeled from the glass plate. The peeled coating film was further dried under reduced pressure at 140 ℃ for 2 hours to obtain a substrate D comprising a transparent resin substrate having a thickness of 0.1mm, a length of 60mm and a width of 60 mm.

[ base material E ]

A triangular prism (TECHSEC) (registered trademark) of synthetic quartz, which has a length L of 5.0mm, a width W of 5.0mm and a height H of 5.0mm as shown in FIG. 4, was used as a substrate E.

[ injection Molding base Material ]

[ base material F ]

Regarding a cycloolefin resin (Raonix (ZEONEX) T62R manufactured by Raynaud (Zeon) Co., Ltd., Japan), Laobao Schottky (ROBOSHOT) S-2000i30B manufactured by FANUC was used as an injection molding machine, and a length L5.0 mm, a width W5.0 mm, and a height H5.0 mm shown in FIG. 4 were formed at a cylinder temperature of 320 ℃, a mold temperature of 160 ℃, an injection speed of 20mm/S, a dwell time of 6 minutes, and a cycle time of 20 minutes, thereby obtaining a rectangular prism made of a cycloolefin resin. The obtained rectangular prism was used as a base material F.

[ base material G ]

The resin a obtained in resin synthesis example 1 was subjected to the same injection molding conditions as those for the base material F to form a rectangular prism made of a cycloolefin resin, having a length L of 5.0mm, a width W of 5.0mm and a height H of 5.0mm as shown in fig. 4. The obtained rectangular prism was used as a substrate G.

[ base material H ]

With respect to the resin A obtained in resin Synthesis example 1, the resin A was preheated at 100 ℃ for 1 hour by using a microwave molding apparatus, and then the irradiation intensity of the microwave was set to 3kW, the temperature rise rate was set to 5 ℃/min, the target temperature was set to 180 ℃ and the temperature holding time was set to 10 minutes, thereby obtaining a rectangular prism made of a cycloolefin resin having a length L of 5.0mm, a width W of 5.0mm and a height H of 5.0mm as shown in FIG. 4. A cube A comprising resin A having a length of 1.0mm, a width of 1.0mm and a depth of 1.0mm was also formed. After methylene chloride was applied to one surface of the obtained cube a, as shown in fig. 8A, two rectangular prisms were pressure-bonded to the cycloolefin resin, and then dried at 150 ℃ for 30 minutes, thereby using a rectangular prism having a concave and convex portion at a position not related to the optical path as a base material H.

[ base material I ]

41 parts of P are weighed₂

O

₅5 parts of Al₂O₃24 parts of Na₂O, 6 parts of MgF₂6 parts of CaO, 12 parts of BaO and 0.035 part of CuO. Placing into a platinum crucible, and heating and melting at 1000 deg.C. After sufficiently stirring and clarifying, the mixture was cast into a mold to obtain a copper phosphate glass rectangular prism having a length L of 5.0mm, a width W of 5.0mm and a height H of 5.0mm as shown in FIG. 4. The obtained rectangular prism was used as a substrate I.

[ base material J ]

The resin a obtained in resin synthesis example 1 and the compound a described later were subjected to injection molding conditions of length L5.0 mm, width W5.0 mm, and height H5.0 mm shown in fig. 4, to obtain a rectangular prism made of a cycloolefin resin. The obtained rectangular prism was used as a base material J.

[ coating film A ]

The following resin composition (1) was applied to the surface of the substrate shown in table 8 below by spin coating, and then heated on a hot plate at 80 ℃ for 2 minutes to evaporate and remove the solvent, thereby forming a cured layer. At this time, the coating conditions of the spin coater were adjusted so that the thickness of the hardened layer became about 0.8 μm.

Resin composition (1): an ethylene oxide isocyanurate-modified triacrylate (trade name: Aronix M-315, manufactured by Toyo Seisaku K.K.), 30 parts of 1, 9-nonanediol diacrylate, 20 parts of methacrylic acid, 30 parts of glycidyl methacrylate, 5 parts of 3-glycidoxypropyltrimethoxysilane, 1-hydroxycyclohexyl benzophenone (trade name: IrGACURE)184, 5 parts of Ciba specialty chemical (manufactured by Ciba specialty chemical) and 1 part of Sanger (san-aid) SI-110 as a main agent (manufactured by Sanxin chemical industries, K.) were mixed and dissolved in propylene glycol monomethyl ether acetate so that the solid content concentration became 50% by weight, and then the mixture was filtered through a millipore filter (Millipore filter) having a pore size of 0.2 μ M.

Next, 100 parts of the resin a obtained in resin synthesis example 1, 0.48 parts of the compound a described later, 0.8 parts of the compound D described later, and methylene chloride were charged into a vessel to obtain a solution (a) having a resin concentration of 15 mass%. The solution (a) was applied onto the cured layer by a spin coater so that the dried film thickness became 10 μm, and the cured layer was heated on a hot plate at 80 ℃ for 30 minutes to evaporate and remove the solvent, thereby forming a transparent resin layer. Then, exposure was performed from the glass plate side using a UV conveyor belt type exposure machine (exposure amount: 500 mJ/cm)²Illuminance: 200mW) was added, followed by calcination at 210 ℃ for 5 minutes in an oven, thereby obtaining a coating film a.

[ coating film B ]

A coating film B was obtained in the same manner except that 0.8 part of the compound B described later was used instead of 0.4 part of the compound a and 0.8 part of the compound D in the coating film a.

[ coating film C ]

A coating film C was obtained in the same manner except that 0.2 parts of compound a, 0.68 parts of compound C described later, and 0.8 parts of compound D were used instead of 0.4 parts of compound a and 0.8 parts of compound D in coating film a.

[ coating film D ]

A coating film D was obtained in the same order except that 0.2 parts of the compound a was used instead of 0.4 parts of the compound a and 0.8 parts of the compound D in the coating film a.

[ coating film E ]

After coating the resin composition (1) with a spin coater so that the dried film thicknesses became 0.002mm, respectively, the resultant was dried at 80 ℃ for 3 minutes using an inert oven (an inert oven DN410I manufactured by Yamato science). At 300g/cm²The resin near infrared ray cut filter Lumikuru (Lumicle) UCF (Lumicle)100-132) was pressed against the coated film, and then the film was exposed to ultraviolet radiation by a UV conveyor exposure machine (Eyeuv curing apparatus, model US2-X0405, 60Hz) under a metal halide lamp illuminance of 270mW/cm²And an exposure amount of 500mJ/cm²UV hardening was performed, thereby obtaining a coating film E.

[ coating film F ]

To a vessel, 100 parts of resin a obtained in resin synthesis example 1, 0.16 part of compound B described later, and methylene chloride were added to prepare a solution having a resin concentration of 20% by weight. The obtained solution was cast onto a smooth glass plate, dried at 20 ℃ for 8 hours, and then peeled from the glass plate. The peeled coating film was further dried under reduced pressure at 140 ℃ for 2 hours to obtain a transparent resin film having a thickness of 0.05mm, a length of 60mm and a width of 60 mm. After the following resin composition (2) was applied to a substrate by spin coating, the substrate was heated on a hot plate at 80 ℃ for 2 minutes to evaporate and remove the solvent, thereby forming a cured layer. At this time, the coating conditions of the spin coater were adjusted so that the thickness of the hardened layer became about 2 μm.

Resin composition (2): the composition comprises 60 parts of tricyclodecane dimethanol acrylate, 40 parts of dipentaerythritol hexaacrylate, 5 parts of 1-hydroxycyclohexyl phenyl ketone and methyl ethyl ketone (used so that the solid content concentration is 30 mass%).

At 300g/cm²The transparent resin film was pressed onto the coated cured layer, and then the cured layer was exposed to light using a UV conveyor belt type exposure machine (Eguno (Eyegraphics) (Strand) manufacturing, an apparatus for eye ultraviolet curing, model US2-X0405, 60Hz) at a metal halide lamp illuminance of 270mW/cm²And an exposure amount of 500mJ/cm²UV hardening was performed, thereby obtaining a coating film F.

[ coating film G ]

A coating film G was obtained in the same manner except that 0.04 parts of compound a, 0.14 parts of compound C, and 0.16 parts of compound D were used instead of 0.16 parts of compound B in the coating film F.

[ Evaporation coating A ]

Using an ion-assisted vacuum deposition apparatus, an ion current density per unit area (μ A/cm) was performed using a layer whose physical film thickness was controlled to 60nm or less by the cumulative film thickness of a crystal oscillator using a mixed gas of oxygen and argon as a supply gas to an ion gun at a deposition temperature of 120 ℃ and a starting pressure of 0.0001Pa²) Divided by the film formation rate

The obtained ion current density per unit film formation rate-area is

While forming a silicon dioxide layer (SiO)₂: a refractive index of light of 550nm of 1.47), and an ion current density per unit film formation rate-area of

Above and

the following ion assisted, simultaneous formation of a titanium oxide layer (TiO)₂: a refractive index of light of 550nm of 2.48) was used, and a dielectric multilayer film of the following design (I) in which a silicon oxide layer and a titanium oxide layer were alternately laminated was provided.

[ Table 1]

[ Evaporation B ]

A dielectric multilayer film was provided in the same order except that the design (I) of the vapor deposition a was changed to the design (II) shown in table 2.

[ Table 2]

[ Evaporation coating C ]

A dielectric multilayer film was provided in the same order except that the design (I) of the vapor deposition a was changed to the design (III) shown in table 3. [ Table 3]

[ Evaporation deposition D ]

A silicon dioxide layer (SiO) was obtained by using an RF magnetron sputtering apparatus, and forming a film while supplying a gas having a mixing ratio of 20% of oxygen/(argon + hydrogen + oxygen) of 20SCCM at an RF power of 300W, using silicon as a deposition source₂: a refractive index of light of 550nm was 1.46), and film formation was performed while supplying a gas having a mixing ratio of hydrogen/(argon + hydrogen) of 5% at 20SCCM, thereby obtaining an amorphous silicon layer (α -Si: h: a refractive index of light of 550nm was 4.1), and the dielectric multilayer films of the design (IV) shown in table 4 were provided in which the silicon dioxide layer and the amorphous silicon layer were alternately laminated.

[ Table 4]

[ Evaporation E ]

A dielectric multilayer film was provided in the same order except that the design (I) of the vapor deposition a was changed to the design (V) shown in table 5.

[ Table 5]

[ vapor deposition F ]

The film was formed using an RF magnetron sputtering apparatus with an RF power of 300W using Al as a deposition source, and the obtained Al was set to a 50nm deposited film.

[ vapor deposition G ]

The film was formed using an RF magnetron sputtering apparatus with an RF power of 300W using Ag as a deposition source, and the Ag thus obtained was set to a 100nm deposited film.

[ vapor deposition H ]

A dielectric multilayer film was provided in the same order except that the design (I) of the vapor deposition a was changed to the design (VI) shown in table 6.

[ Table 6]

[ Evaporation I ]

A dielectric multilayer film was provided in the same order except that the design (I) of vapor deposition a was changed to the design (VII) shown in table 7.

[ Table 7]

[ light-shielding film A ]

An ultraviolet ray hardening light-shielding ink (UltraPackUVK +180 manufactured by maragbo (Marabu)) was applied to the outer periphery of the optical member by screen printing with a width of 1mm and a thickness of 10 μm. Manufactured using a UV conveyor belt exposure machine (Eygraphics) (Strand), eDevice for ye ultraviolet hardening, model US2-X0405, 60Hz), and illuminance of 100mW/cm for metal halide lamp²Exposure dose of 200mJ/cm²UV curing was performed, thereby obtaining a light-shielding film a.

[ Compound A ]

As the compound, a compound a represented by the following chemical formula (a) was used. The maximum absorption wavelength of compound A when dissolved in methylene chloride was 698 nm.

[ solution 2]

[ Compound B ]

As the compound, a compound B represented by the following chemical formula (B) was used. The maximum absorption wavelength of the compound B in the resin A is 1095 nm.

[ solution 3]

[ Compound C ]

As the compound, a compound C represented by the following chemical formula (C) was used. The maximum absorption wavelength of compound C when dissolved in methylene chloride was 738 nm.

[ solution 4]

< ultraviolet absorber >

As the ultraviolet absorber, "Bonasorb (BONASORB) UA-3911" manufactured by Orient (Orient) chemical industry (Strand) was used as compound D. The maximum absorption wavelength of compound D when dissolved in methylene chloride was 391 nm.

[ example 1]

The substrate a was prepared, and the optical member was obtained by performing the vapor deposition B on the dielectric multilayer film 36a (hereinafter, referred to as "a-plane" in examples 1 to 5, comparative example 1, and comparative example 2) and performing the vapor deposition a on the dielectric multilayer film 36B (hereinafter, referred to as "B-plane" in examples 1 to 5, comparative example 1, and comparative example 2) included in the optical member 31 shown in fig. 5A.

[ examples 2 to 5]

Optical members were obtained in the same manner as in example 1, except that the optical members were produced using the substrates, the vapor deposition methods, and the light-shielding films shown in examples 2 to 5 of table 8 below.

Comparative examples 1 to 2

Optical members were obtained in the same manner as in example 1, except that the optical members were produced using the substrates, vapor deposition methods, and light-shielding films shown in comparative examples 1 to 2 of table 8 below.

[ example 6]

The substrate E was prepared, and the dielectric multilayer film 46a (hereinafter, referred to as "a-plane" in examples 6 to 18 and comparative example 3) included in the optical member 41a shown in fig. 5B was vapor-deposited in the vapor deposition C, the dielectric multilayer film 46B (hereinafter, referred to as "B-plane" in examples 6 to 18 and comparative example 3) was vapor-deposited in the vapor deposition a, and the dielectric multilayer film 46C (hereinafter, referred to as "C-plane" in examples 6 to 18 and comparative example 3) was vapor-deposited in the vapor deposition a. Further, a light-shielding film a is formed on the B-plane and the C-plane to obtain an optical member.

[ example 7]

The optical member is obtained by forming the substrate G, forming a coating film a on the B surface, vapor-depositing the a surface in the vapor deposition C, vapor-depositing the B surface in the vapor deposition a, and vapor-depositing the C surface in the vapor deposition a.

Examples 8 to 17 and comparative example 3

Optical members were obtained in the same manner as in example 6 or example 7, except that the optical members were produced using the base materials, light absorbers, vapor deposition methods, and light-shielding films shown in examples 8 to 17 and comparative example 3 in table 8 below. In example 11 and example 12, as shown in fig. 9I, an optical member was used.

[ example 18]

An optical member was obtained in the same manner as in example 17. Further, a cover glass was obtained by providing a substrate C on one surface thereof with a vapor deposition I.

[ Table 8]

[ evaluation of optical Properties ]

The optical members produced in examples 1 to 18 and comparative examples 1 to 3 were evaluated for their optical characteristics by the methods shown in fig. 10A to 10G. Fig. 10A is a method for measuring the transmittance of unpolarized light incident at 45 ° of an optical member. Fig. 10B shows a method for measuring the reflectance of unpolarized light incident at 45 ° to the optical member. Fig. 10C shows a method for measuring the reflectance of unpolarized light incident at 5 ° on the optical member. Fig. 10D shows a method for measuring the reflectance of an unpolarized light beam incident at 45 ° of an optical member including a prismatic substrate. In example 11 and example 12, assuming that an optical member is used as in the camera module shown in fig. 9I, the reflectance in fig. 10D is regarded as spectral transmission efficiency. Fig. 10E is a method for measuring the spectral transmission efficiency of the optical members in examples 6 to 10, 13 to 17, and comparative example 3. Fig. 10F shows a method for measuring 100% of the light amount to be used as a reference in the spectral transmission efficiency measurement. FIG. 10G is a method for measuring spectral transmission efficiency by interposing the cover glass of example 18.

[ transmittance ]

The transmittance in each wavelength region of the optical member was measured using a spectrophotometer (V-7200) and an automatic absolute reflectance measuring unit (V-7030) manufactured by Japan Spectroscopy, Inc. Here, the transmittance of light incident at an angle of 45 ° from the perpendicular direction with respect to the surface direction of the optical member is measured as follows: as shown in fig. 10A, light L (P-polarized light and S-polarized light) is incident at an angle of 45 ° from the vertical direction with respect to the surface direction of the optical member 11, and the light transmitted in the vertical direction is reflected by a mirror 202 and then converged by an integrating sphere 201. The average transmittance at the wavelengths Anm to Bnm is calculated by measuring the transmittance at each wavelength in units of 1nm of Anm to Bnm and dividing the total value of the transmittances by the number of measured transmittances (wavelength range, B-a + 1). The transmission of unpolarized light is calculated from the average of the S-polarized light transmission and the P-polarized light transmission. The maximum transmittance at the wavelengths from Anm to Bnm is measured for the transmittance at each wavelength in units of 1nm from Anm to Bnm, and the maximum value of the transmittance is used.

[ reflectance ]

The reflectance of the optical member in each wavelength region was measured using a spectrophotometer (V-7200) and an automatic absolute reflectance measuring unit (V-7030) manufactured by Japan Spectroscopy, Inc. Here, the reflectance of an unpolarized light ray incident at an angle of 45 ° with respect to the perpendicular direction to the surface of the optical member is measured as follows: as shown in fig. 10B, light L incident at an angle of 45 ° with respect to the vertical direction of a specific surface of the optical member 11 is collected by the integrating sphere 201 via the mirror 202. Similarly, the reflectance of an unpolarized light ray incident at an angle of 5 ° with respect to the perpendicular direction to the surface of the optical member was measured as follows: as shown in fig. 10C, light reflected by an unpolarized light beam incident at an angle of 5 ° with respect to the vertical direction of a specific surface of the optical member is converged by integrating sphere 201 via mirror 202.

Similarly, when the optical member is not a flat plate, the reflectance of an unpolarized light ray incident at an angle of 45 ° with respect to the perpendicular direction to the surface of the optical member is measured as follows: as shown in fig. 10D, light reflected by optical member 1 is converged by integrating sphere 201 via mirror 202 with respect to light beam L incident at an angle of 45 ° with respect to the vertical direction of the specific surface.

The average reflectance at the wavelengths Anm to Bnm is calculated by measuring the reflectance at each wavelength of 1nm in units of Anm to Bnm and dividing the total value of the reflectances by the number of measured reflectances (reflectance, B-a + 1). The maximum reflectance at the wavelengths Anm to Bnm is measured for the reflectance at each wavelength in units of 1nm from Anm to Bnm, and the maximum value of the reflectance is used.

[ spectral transmittance efficiency ]

In examples 6 to 10, 13 to 17, and comparative example 3, the spectral transmission efficiency T (λ) using the optical member was measured as follows: when the light amount in fig. 10F is 100%, the light L reflected by the reflection surface after passing through the substrate is converged by the integrating sphere 201 via the mirror 202 as in the position of fig. 10E. In example 11 and example 12, assuming that an optical member is used as in the camera module shown in fig. 9I, the reflectance obtained by the arrangement of the optical member 1 shown in fig. 10D is set as the spectral transmission efficiency T (λ). In example 18, assuming that an optical member is used through a cover glass as in the camera module shown in fig. 9C or 9L, the reflectance obtained by the arrangement of the optical member 1 and the cover glass 203 shown in fig. 10G is set as the spectral transmission efficiency T (λ). With respect to the optical member having the light-shielding film, a portion of the inner portion of the light-shielding film where no light-shielding film is provided was evaluated.

The average transmission efficiency at the wavelengths Anm to Bnm is calculated by measuring the spectral transmission efficiency at each wavelength of 1nm in units of Anm to Bnm and dividing the total value of the spectral transmission efficiencies by the number of measured spectral transmission efficiencies (reflectance, B-a + 1). The maximum transmission efficiency at the wavelengths Anm to Bnm is measured as the spectral transmission efficiency at each wavelength in units of 1nm from Anm to Bnm, and the maximum value of the spectral transmission efficiency is used.

[ noise amount evaluation ]

[ evaluation of N/S sensitivity ]

As an index for evaluating the noise amount of an optical sensor including an optical member, evaluation of the ratio of noise N generated by near infrared rays to signal S generated by visible rays, and N/S sensitivity was performed. The N/S sensitivity evaluation is calculated from the spectral transmission efficiency T (λ) of the optical member, the sensitivity B (λ) for the blue pixel in the sensor pixel having a different wavelength, the sensitivity G (λ) for the green pixel having a different wavelength, and the sensitivity R (λ) for the red pixel having a different wavelength, by the following equation.

The signal intensity S is the sum of calculated values in which the wavelength ranges of 380nm to 780nm for blue, green, and red pixels are multiplied by the transmittance and the sensor pixel sensitivity for each 1nm wavelength of the optical filter. The noise intensity N is the sum of calculated values in which the wavelength ranges 781nm to 1050nm of the blue, green, and red pixels are multiplied by the transmittance and the sensor pixel sensitivity, which differ for each 1nm wavelength of the optical filter. The N/S sensitivity evaluation uses the calculated values of N and S, and the noise intensity N divided by the signal intensity S as an index. The wavelength-dependent sensitivities of the blue, green, and red sensor pixels are based on the description of japanese patent application laid-open No. 2017-216678, and the values shown in fig. 11 are used.

[ number 1]

N/S＝(N_{Blue 0}+N_Green+N_{Red wine})/(S_{Blue (B)}+S_Green+S_{Red wine})

[ evaluation results of optical characteristics ]

The optical characteristics of the optical members of examples 1 to 18 and comparative examples 1 to 3, which were prepared as shown in table 8, were evaluated. The evaluation results are shown in table 9.

[ Table 9]

From the results of the above table 9, the optical members of the examples were able to reflect light of a specific wavelength, and were low in N/S sensitivity, and thus suitable as the optical members of the present invention. The optical members of comparative examples 1 to 3 have high N/S sensitivity because reflection of light in a wavelength region of 700nm to 1150nm is not suppressed, and are not suitable as the optical member of the present invention.

[ industrial applicability ]

The optical member of the present invention is particularly useful as an optical member constituting a camera module. The camera module of the present invention is particularly useful in a digital still camera, a camera for a mobile phone, a camera for a smartphone, a digital video camera, a Personal Computer (PC) camera, a monitoring camera, a camera for an automobile, a television, a car navigation system, a portable information terminal, a personal computer, a video game machine, a portable game machine, a fingerprint authentication system, an ambient light sensor, a distance measurement sensor, an iris authentication system, a face authentication system, a distance measurement camera, a digital music player, and the like.

Claims

1. An optical member comprising a reflective surface,

the average reflectance of unpolarized light incident on the reflection surface at 45 DEG from the vertical is 80% or more in a wavelength region of 400nm to 640nm, and 8% or less in a wavelength region of 700nm to 1150 nm.

2. The optical member according to claim 1, wherein a wavelength region in which a maximum reflectance of unpolarized light incident on the reflection surface at 45 ° from the vertical is 700nm or more and 1150nm or less is 20% or less.

3. The optical member according to claim 1 or 2, wherein the reflectance of unpolarized light rays incident at 45 ° from the perpendicular to the reflection surface is 65% or more at a wavelength of 650 nm.

4. The optical member according to claim 1 or 2, comprising a substrate, and a reflective layer constituting the reflective surface,

the substrate contains a compound having an absorption maximum in a wavelength region of 680nm to 1200 nm.

5. Optical member according to claim 1 or 2, comprising a prism having a triangular cross section with an apex angle of 70 ° or more and 120 ° or less,

the reflecting surface is formed on an inclined surface facing the apex angle of the prism.

6. A camera module comprising optical means, in which camera module,

the optical member includes a reflective surface and a reflective surface,

7. The camera module of claim 6, further comprising an optical sensor.

8. The camera module of claim 7, further comprising a lens,

no optical filter is included between the lens and the optical sensor.

9. The camera module of claim 6, 7 or 8, further comprising a periscope-shaped optical system housing unit.