JP7255600B2 - Optical filter and its use - Google Patents

Description

The present invention relates to optical filters and uses thereof. More specifically, it relates to an optical filter having specific optical properties (for example, a near-infrared cut filter), and a solid-state imaging device and camera module using the optical filter.

2. Description of the Related Art Solid-state imaging devices such as video cameras, digital still cameras, and mobile phones with camera functions use CCD and CMOS image sensors, which are solid-state imaging devices for color images. Since these solid-state imaging devices use a sensor sensitive to near-infrared rays in the light receiving part, it is necessary to perform visibility correction, and an optical filter (for example, a near-infrared cut filter) is often used. .

As such optical filters, those manufactured by various methods have been conventionally used. For example, a near-infrared cut filter having a near-infrared reflective film obtained by laminating a dielectric multilayer film on a norbornene-based resin is known. (See Patent Document 1, for example). However, with a near-infrared cut filter having such a near-infrared reflective film, the light transmission characteristics are highly dependent on the incident angle, and solid-state imaging devices with a wide viewing angle have the problem that the color tone differs between the center and the periphery of the image. Was.

Optical filters such as near-infrared cut filters containing near-infrared absorbers are widely known as examples of improved incident angle dependence. Specifically, a near-infrared cut filter is known in which a resin is used as a base material, and a near-infrared absorber having steep absorption characteristics is contained in the resin to improve the incident angle dependence of the near-infrared region. (See, for example, Patent Document 2).

In recent years, image sensing systems that detect not only wavelengths of 400 nm to 700 nm, to which humans have high visibility, but also near-infrared rays, and measure the degree of growth of plants and the amount of oxygenated hemoglobin in humans have been studied (for example, Patent Document 3 and 4). For example, in Patent Document 3, it is known that the reflectance of rice leaves at a wavelength of 500 nm to 800 nm varies depending on the nitrogen content. A method for obtaining the index has been proposed.

Further, for example, using an ultraviolet laser with a wavelength of 355 nm as a light source, the ratio (F690/F740) of the fluorescence intensity (F690) at a wavelength of 690 nm and the fluorescence intensity (F740) at a wavelength of 740 nm (F690/F740) is an indicator of the chlorophyll concentration in the plant body. It is known that it can be diagnosed (see, for example, Non-Patent Document 1).

However, in such an image sensing system that combines visible light with a wavelength of 400 to 700 nm and near-infrared light, an optical filter such as a near-infrared cut filter containing a conventional near-infrared absorbent has a wavelength of 700 to 700 nm used for detection. Light transmittance at 750 nm was low, and it was difficult to maintain sufficient sensitivity.

It is known that a near-infrared cut filter having a near-infrared reflective film formed by laminating a dielectric multilayer film shifts the reflection band to a longer wavelength by increasing the thickness of the laminated dielectric multilayer film. Therefore, it is easy to provide a dielectric multilayer film with a high transmittance at a wavelength of 700 nm to 750 nm. Another problem is that the intensity of light obtained by sensing differs depending on the incident angle between the center and the periphery of the image.

In addition, as the performance of solid-state imaging devices has advanced, conventional optical filters sometimes degrade image quality due to ghosts caused by reflection of the optical filters. In particular, there has been a problem of ghost generation due to re-injection of part of the stray light into another position of the sensor due to reflection of light rays of wavelength 680 to 720 nm on the optical filter. Therefore, it is required to lower the reflectance at wavelengths of 680 to 720 nm.
However, conventional optical filters have not satisfactorily met the demand for both suppression of ghosts and improvement in red sensor sensitivity.

Japanese Patent No. 4513420 JP-A-2012-8532 JP 2016-146784 A International Publication No. 2018/123676 pamphlet

H. K. Lichtenthaler et al. : Detection of Vegetation Stress Via a New High Resolution Fluorescence Imaging System,". Plant Physiol. , 148, 599-612 (1996)

An object of the present invention is to provide an optical filter having low incidence angle dependence in the near-infrared region and excellent transmittance characteristics of light with a wavelength of 700 to 750 nm required for sensing, and improved ghost, and the optical filter. An object of the present invention is to provide a device using a filter.

An optical filter according to one aspect of the present invention is characterized by satisfying the following requirements (A) to (D).
(A) In the wavelength range of 430 to 580 nm, the average value of transmittance measured in the direction perpendicular to the surface of the optical filter is 75% or more.
(B) In the wavelength range of 800 to 1000 nm, the average transmittance measured in the direction perpendicular to the surface of the optical filter is 10% or less.
(C) In the wavelength range of 700 to 750 nm, the average transmittance measured in the direction perpendicular to the surface of the optical filter is more than 46%.
(D) In the wavelength range of 560 to 800 nm, the shortest wavelength value (Ya) at which the transmittance is 50% when measured from the direction perpendicular to the surface of the optical filter, and the value perpendicular to the surface of the optical filter The absolute value of the difference from the value of the shortest wavelength (Yb) at which the transmittance is 50% when measured from an angle of 30° from the direction is less than 15 nm.

According to the present invention, an optical filter having low incidence angle dependence in the near-infrared region and excellent transmittance characteristics of light with a wavelength of 700 to 750 nm necessary for sensing, and improved ghost, and the optical filter. A device using a filter can be provided. The optical filter of the present invention is suitable as a near-infrared cut filter.

It is a schematic diagram which shows an example of the optical filter of this invention. It is a schematic diagram which shows an example of the optical filter of this invention. This is intensity data for each wavelength, which is made public by the New Energy and Industrial Technology Development Organization, and is obtained by normalizing the irradiation amount data in Gifu on a certain date and time with a maximum value of 1.0. It is an example of the wavelength-dependent sensitivity of each sensor pixel for green and near-infrared rays. FIG. 3 is a diagram showing optical characteristics of a dual-wavelength region transmission filter that transmits green and near-infrared rays and is prepared for green sensitivity and near-infrared sensitivity evaluation. FIG. 4 is a schematic diagram showing an example of a method of measuring transmittance when measured in a direction perpendicular to the surface of an optical filter; FIG. 4 is a schematic diagram showing an example of a method of measuring transmittance when measured at an angle of 30° from the direction perpendicular to the plane of the optical filter; FIG. 4 is a schematic diagram showing an example of a method for measuring the reflectance of light incident at an angle of 5° from the perpendicular direction to the surface of an optical filter; 1 is a schematic diagram showing an example of a camera module; FIG. FIG. 4 is a schematic diagram illustrating an example of a ghosting mechanism in a camera module; FIG. 4 is a schematic diagram showing an example of a ghost; 2 is a diagram showing optical properties of the optical filter obtained in Example 1. FIG. FIG. 10 is a diagram showing optical properties of an optical filter obtained in Example 5; 3 is a diagram showing optical properties of an optical filter obtained in Comparative Example 1. FIG. FIG. 10 is a diagram showing optical characteristics of an optical filter obtained in Comparative Example 4; FIG. 10 is a diagram showing optical characteristics of an optical filter obtained in Comparative Example 7;

Embodiments of the present invention will be described with reference to the drawings as necessary, but these drawings are provided for illustration purposes only and the present invention is not limited to these drawings. Also, it should be noted that the drawings are schematic, and the relationship between thickness and planar dimensions, the ratio of thicknesses, etc. are different from the actual ones. Furthermore, in the following description, constituents having the same or substantially the same functions and configurations are denoted by the same reference numerals, and overlapping descriptions are omitted. As one embodiment of the optical filter of the present invention, as shown in FIG. Also, the optical filter of the present invention may have other functional films 13 as shown in FIG.

[Optical filter]
The optical filter of the present invention satisfies the following requirements (A) to (D).
(A) In the wavelength range of 430 to 580 nm, the average value of transmittance measured in the direction perpendicular to the surface of the optical filter is 75% or more.
(B) In the wavelength range of 800 to 1000 nm, the average transmittance measured in the direction perpendicular to the surface of the optical filter is 10% or less.
(C) In the wavelength range of 700 to 750 nm, the average transmittance measured in the direction perpendicular to the surface of the optical filter is more than 46%.
(D) In the wavelength range of 560 to 800 nm, the shortest wavelength value (Ya) at which the transmittance is 50% when measured from the direction perpendicular to the surface of the optical filter, and the value perpendicular to the surface of the optical filter The absolute value of the difference from the value of the shortest wavelength (Yb) at which the transmittance is 50% when measured from an angle of 30° from the direction is less than 15 nm.

By using an optical filter that satisfies the requirement (A), the amount of light captured by the solid-state imaging device can be increased in the wavelength range of 430 nm to 580 nm. The average transmittance in requirement (A) is preferably 80% or more. If it is 80% or more, imaging becomes possible even in a darker environment.

By using an optical filter that satisfies the requirement (B), the amount of light captured by the solid-state imaging device can be reduced in the wavelength range of 800 nm to 1000 nm. This makes it possible to shield light that is invisible to the human eye and unnecessary for sensing. The average transmittance in requirement (B) is preferably 7% or less, more preferably 6% or less, and even more preferably 5% or less.

By using an optical filter that satisfies the requirement (C), the amount of light captured by the solid-state imaging device is ensured in the wavelength range of 700 nm to 750 nm, and the sensing sensitivity is improved. The average transmittance in requirement (C) is preferably 55% or higher, more preferably 65% or higher, and even more preferably 75% or higher. The higher the transmittance, the better. For example, the upper limit is preferably 100%, more preferably 90%, and even more preferably 80%. Within this range, the amount of light taken in by the solid-state imaging device is adjusted, and the light necessary for sensing can be efficiently transmitted.

By using an optical filter that satisfies the requirement (D), the incident angle dependence of the amount of light incident on the solid-state imaging device can be reduced in the wavelength range of 560 nm to 800 nm. As a result, the incident angle dependency of the spectral sensitivity of the solid-state imaging device in this wavelength range can be reduced. By reducing the incident angle dependence, the difference in color tone between the center and the periphery of the image obtained by the solid-state imaging device and sensor sensitivity is small, resulting in higher sensitivity.

Preferably, the optical filter of the present invention further satisfies the following requirement (E).
(E) The wavelength value (Ya) in the requirement (D) is 730 nm or more and 800 nm or less.

By using an optical filter that satisfies the requirement (E), the visible light transmittance with a wavelength of 400 to 700 nm and the transmittance of near infrared rays with a wavelength of 700 to 750 nm used for sensing are kept high, and a wavelength of 800 nm, which is unnecessary for sensing, is kept high. It becomes easy to achieve both a low transmittance (high shielding property) of up to 1200 nm. The wavelength (Ya) is preferably 740 nm or more and 800 nm or less, more preferably 745 nm or more and 800 nm or less.

The optical filter of the present invention preferably further satisfies the following requirements (Z1) and (Z2).
(Z1) At a wavelength of 700 nm, the reflectance when measured at an angle of 5° from the direction perpendicular to the surface of the optical filter is 10% or less regardless of the surface of the optical filter.
(Z2) In the wavelength range of 600 nm or more, which of the optical filters has the shortest wavelength value (Za) at which the reflectance is 50% when measured at an angle of 5° from the direction perpendicular to the surface of the optical filter. It is 730 nm or more even when incident from the surface of .
By using an optical filter that satisfies the requirements (Z1) and (Z2), it is possible to suppress the occurrence of ghost caused by the light reflected by the optical filter.

A near-infrared reflective film made of a dielectric multilayer film tends to shift the reflection band to a shorter wavelength as the oblique incidence increases at a higher angle from the surface of the optical filter. Therefore, the wavelength (Za) in the requirement (Z2) is more preferably 740 nm or longer, still more preferably 750 nm or longer, and particularly preferably 780 nm or longer. As a result, it is possible to sufficiently suppress the occurrence of a ghost even in light that is visible to the human eye and that has entered the surface of the optical filter at a high angle.
The optical filter of the present invention preferably has a substrate containing a near-infrared absorbing agent and a near-infrared reflecting film.

An optical filter having a substrate containing a near-infrared absorber can suppress near-infrared reflection of the optical filter and reduce ghosts. An optical filter having a near-infrared reflective film has excellent near-infrared shielding performance and excellent transmission performance for visible light in the wavelength range of 430 to 580 nm, and can make the obtained solid-state imaging device highly sensitive.

When the near-infrared absorbing agent has an absorption maximum wavelength in the wavelength range of 751 to 950 nm, and the near-infrared absorbing agent is contained in an amount such that the transmittance of the base material at the absorption maximum wavelength is 10%. , the longest wavelength (Aa) at which the transmittance of the base material is 70% in the range of 430 nm or more and the maximum absorption wavelength or less, and the longest wavelength (Aa) at which the transmittance of the base material is 30% in the range of 580 nm or more. It is preferred that the absolute value of the difference from the short wavelength (Ab) is less than 150 nm.

By using an optical filter having a substrate containing a near-infrared absorbing agent in which the absolute value of the difference between (Aa) and (Ab) is less than 150 nm, the transmittance of near-infrared rays having a wavelength of 700 to 750 nm is increased. It becomes easy to achieve both a low transmittance (high shielding property) at a wavelength of 800 to 1200 nm, which is not necessary for sensing. The smaller the absolute value of the difference, the better, more preferably less than 100 nm, and even more preferably less than 70 nm. The lower limit is 1 nm.

Having an absorption maximum wavelength at a wavelength of 751 to 950 nm, which is a characteristic of the preferred range of the near-infrared absorbent, and that the absolute value of the difference between the (Aa) and the (Ab) is less than 150 nm, The characteristics of one type of absorbent may be satisfied, or the characteristics of a mixture of multiple types may be satisfied. In addition, the near-infrared absorbing agent in which multiple types are mixed may include one that does not satisfy the properties by itself.

[Base material]
The substrate preferably has transparency. The term "transparency" as used in the present invention means that the average value of transmittance in the wavelength range of 420 to 600 nm is 50% or more. Examples of materials for such a substrate include glass, tempered glass, special glass such as phosphate glass, fluorophosphate glass, alumina glass, yttrium aluminate, and yttrium oxide, and resin.

The base material may be composed of one layer or multiple layers, may be composed of one material selected from the above materials, may be composed of a plurality of materials, or may be an appropriately mixed material. At least one of the layers constituting the substrate preferably contains a near-infrared absorbent, and may also contain a near-ultraviolet absorbent. The layer containing the near-infrared absorbent and the layer containing the near-ultraviolet absorbent may be the same layer or different layers.

<Glass>
Examples of the glass include silicate glass, soda lime glass, borosilicate glass, and quartz glass.

<Tempered glass>
Examples of the tempered glass include physically tempered glass, tempered laminated glass, and chemically tempered glass. Among these, chemically strengthened glass is preferable because it has a thin compressed layer and can be processed to have a thin base material. Specific examples of the chemically strengthened glass include "Dragontrail" manufactured by Asahi Glass Co., Ltd. and "Gorilla Glass" manufactured by Corning.

<Special glass>
Examples of the phosphate glass and the fluorophosphate glass include BS3, BS4, BS6, BS7, BS8, BS10, BS11, BS12, BS13, BS16, BS17 manufactured by Matsunami Glass Industry Co., Ltd., International Publication No. 2012/018026. and the fluorophosphate-based glass described in . Examples of the alumina glass include "Hiceram" manufactured by NGK Insulators, Ltd., and the like. Examples of the yttrium aluminate and the yttrium oxide include "EXYRIA (registered trademark)" manufactured by CoorsTek.

<Resin>
Examples of the resin include polyester-based resins, polyether-based resins, acrylic-based resins, polyolefin-based resins, polycycloolefin-based resins, norbornene-based resins, polycarbonate-based resins, ene-thiol-based resins, epoxy-based resins, and polyamide-based resins. Resins, polyimide-based resins, polyurethane-based resins, polystyrene-based resins, and the like can be used. Among these, norbornene-based resins, polyimide-based resins, and polyether-based resins are preferred.

The refractive index of the resin can be adjusted by a method of adjusting the molecular structure of the raw material component. Specifically, there is a method of imparting a specific structure to the main chain or side chain of the polymer of the raw material component. Although the structure to be imparted in the polymer is not particularly limited, examples thereof include a norbornene skeleton and a fluorene skeleton.

A commercially available product may be used as the resin. Commercially available products include “Ogsol (registered trademark) EA-F5003” (acrylic resin, refractive index: 1.60) manufactured by Osaka Gas Chemicals Co., Ltd., “Polymethyl methacrylate” manufactured by Tokyo Chemical Industry Co., Ltd. (refractive index : 1.49), "Polyisobutyl methacrylate" (refractive index: 1.48) manufactured by Tokyo Chemical Industry Co., Ltd., "BR50" (refractive index: 1.56) manufactured by Mitsubishi Rayon Co., Ltd., and the like.

Commercially available polyester resins include, for example, "OKP4HT" (refractive index: 1.64), "OKP4" (refractive index: 1.61), "B-OKP2" (manufactured by Osaka Gas Chemicals Co., Ltd.). refractive index: 1.64), "OKP-850" (refractive index: 1.65), Toyobo Co., Ltd. "Vylon (registered trademark) 103" (refractive index: 1.55), etc., polycarbonate-based Commercially available resins include, for example, “LeXan (registered trademark) ML9103” (refractive index: 1.59) manufactured by Sabic, “xylex (registered trademark) 7507” manufactured by Mitsubishi Gas Chemical Co., Ltd. “EP5000” (refractive index: index: 1.63), Teijin Kasei Co., Ltd. "SP3810" (refractive index: 1.63), "SP1516" (refractive index: 1.60), "TS2020" (refractive index: 1.59), etc. Examples of commercially available norbornene resins include "ARTON (registered trademark) (refractive index: 1.51)" manufactured by JSR Corporation, "ZEONEX (registered trademark) (refractive index: 1.51) manufactured by Nippon Zeon Co., Ltd." 1.53) and the like.

A polyether resin is a polymer obtained by a reaction to form an ether bond in the main chain, and contains at least one structural unit selected from the group consisting of structural units represented by the following formulas (1) and (2). It is preferably a polymer having In addition, it may have a structural unit represented by the following formula (3).

前記式（１）中、Ｒ¹～Ｒ⁴は、それぞれ独立に炭素数１～１２の１価の有機基を示す。ａ～ｄは、それぞれ独立に０～４の整数を示し、好ましくは０または１であり、より好ましくは０である。

In formula (1), R ¹ to R ⁴ each independently represent a monovalent organic group having 1 to 12 carbon atoms. a to d each independently represents an integer of 0 to 4, preferably 0 or 1, more preferably 0;

The monovalent organic group having 1 to 12 carbon atoms includes a monovalent hydrocarbon group having 1 to 12 carbon atoms, and a 1 carbon atom containing at least one atom selected from the group consisting of an oxygen atom and a nitrogen atom. to 12 monovalent organic groups.

Examples of monovalent hydrocarbon groups having 1 to 12 carbon atoms include linear or branched hydrocarbon groups having 1 to 12 carbon atoms, alicyclic hydrocarbon groups having 3 to 12 carbon atoms and 6 to 12 carbon atoms. An aromatic hydrocarbon group etc. are mentioned.

The straight or branched hydrocarbon group having 1 to 12 carbon atoms is preferably a straight or branched hydrocarbon group having 1 to 8 carbon atoms, and a straight or branched hydrocarbon group having 1 to 5 carbon atoms. A hydrogen group is more preferred.

Preferred specific examples of the linear or branched hydrocarbon group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group and n-pentyl. groups, n-hexyl groups and n-heptyl groups.

As the alicyclic hydrocarbon group having 3 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 8 carbon atoms is preferable, and an alicyclic hydrocarbon group having 3 or 4 carbon atoms is more preferable.
Preferred specific examples of alicyclic hydrocarbon groups having 3 to 12 carbon atoms include cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group and cyclohexyl group; cyclobutenyl group, cyclopentenyl group and cyclohexenyl group; cycloalkenyl groups such as The binding site of the alicyclic hydrocarbon group may be any carbon on the alicyclic ring.

Examples of the aromatic hydrocarbon group having 6 to 12 carbon atoms include a phenyl group, a biphenyl group and a naphthyl group. The attachment site of the aromatic hydrocarbon group may be any carbon on the aromatic ring.

The organic group having 1 to 12 carbon atoms containing an oxygen atom includes an organic group consisting of a hydrogen atom, a carbon atom and an oxygen atom. Organic groups of numbers 1 to 12 and the like can be mentioned preferably.

Examples of organic groups having a total of 1 to 12 carbon atoms and having an ether bond include alkoxy groups having 1 to 12 carbon atoms, alkenyloxy groups having 2 to 12 carbon atoms, alkynyloxy groups having 2 to 12 carbon atoms, and 6 to 12 carbon atoms. aryloxy groups and alkoxyalkyl groups having 1 to 12 carbon atoms, and specifically, methoxy group, ethoxy group, propoxy group, isopropyloxy group, butoxy group, phenoxy group, propenyloxy group, cyclohexyloxy group and methoxymethyl groups.

The organic group having a total carbon number of 1 to 12 and having a carbonyl group includes an acyl group having a carbon number of 2 to 12, and specific examples thereof include an acetyl group, a propionyl group, an isopropionyl group and a benzoyl group. .

Organic groups having a total of 1 to 12 carbon atoms and having an ester bond include acyloxy groups having 2 to 12 carbon atoms, and specifically, acetyloxy, propionyloxy, isopropionyloxy and benzoyloxy groups. etc.

The organic group having 1 to 12 carbon atoms containing a nitrogen atom includes an organic group consisting of a hydrogen atom, a carbon atom and a nitrogen atom, and specifically includes a cyano group, an imidazole group, a triazole group, a benzimidazole group and a benz A triazole group and the like can be mentioned.

The organic group having 1 to 12 carbon atoms containing an oxygen atom and a nitrogen atom includes an organic group consisting of a hydrogen atom, a carbon atom, an oxygen atom and a nitrogen atom, and specifically includes an oxazole group and an oxadiazole group. groups, benzoxazole groups and benzoxadiazole groups.

R ¹ to R ⁴ in the formula (1) are preferably monovalent hydrocarbon groups having 1 to 12 carbon atoms, and aromatic groups having 6 to 12 carbon atoms, from the viewpoint of water absorption (wetness) of the resin (1). A hydrocarbon group is more preferred, and a phenyl group is even more preferred.

In the above formula (2), R ¹ to R ⁴ and a to d are each independently the same as R ¹ to R ⁴ and a to d in the above formula (1), Y is a single bond, —SO _2- or -CO-, R ⁷ and R ⁸ each independently represent a halogen atom, a monovalent organic group having 1 to 12 carbon atoms or a nitro group, and m represents 0 or 1; However, when m is 0, ^R7 is not a cyano group. g and h each independently represents an integer of 0 to 4, preferably 0;

Examples of the monovalent organic group having 1 to 12 carbon atoms include those similar to the monovalent organic group having 1 to 12 carbon atoms in the formula (1).
In the resin (1), the molar ratio of the structural unit (1) and the structural unit (2) (where the total of both (structural unit (1) + structural unit (2)) is 100) is , From the viewpoint of optical properties, heat resistance and mechanical properties, it is preferable that structural unit (1): structural unit (2) = 50: 50 to 100: 0, structural unit (1): structural unit (2) = 70:30 to 100:0, more preferably Structural Unit (1): Structural Unit (2) = 80:20 to 100:0. In this specification, mechanical properties refer to properties such as tensile strength, elongation at break, and tensile elastic modulus of resin.

Further, the resin (1) further contains at least one structural unit selected from the group consisting of structural units represented by the following formula (3) and structural units represented by the following formula (4) (hereinafter referred to as "structural unit (3 -4)”.). When the resin (1) has such a structural unit (3-4), the mechanical properties of the substrate containing the resin (1) are improved, which is preferable.

In the above formula (3), R ⁵ and R ⁶ each independently represent a monovalent organic group having 1 to 12 carbon atoms, Z is a single bond, —O—, —S—, —SO ₂ —, -CO-, -CONH-, -COO- or a divalent organic group having 1 to 12 carbon atoms, where n is 0 or 1; e and f each independently represents an integer of 0 to 4, preferably 0;

Examples of the monovalent organic group having 1 to 12 carbon atoms include those similar to the monovalent organic group having 1 to 12 carbon atoms in the formula (1).
The divalent organic group having 1 to 12 carbon atoms is a group consisting of a divalent hydrocarbon group having 1 to 12 carbon atoms, a divalent halogenated hydrocarbon group having 1 to 12 carbon atoms, an oxygen atom and a nitrogen atom. A divalent organic group having 1 to 12 carbon atoms containing at least one atom selected from, and a divalent organic group having 1 to 12 carbon atoms containing at least one atom selected from the group consisting of an oxygen atom and a nitrogen atom and the like.

The divalent hydrocarbon group having 1 to 12 carbon atoms includes a linear or branched divalent hydrocarbon group having 1 to 12 carbon atoms, a divalent alicyclic hydrocarbon group having 3 to 12 carbon atoms, and Examples thereof include divalent aromatic hydrocarbon groups having 6 to 12 carbon atoms.

The linear or branched divalent hydrocarbon group having 1 to 12 carbon atoms includes methylene group, ethylene group, trimethylene group, isopropylidene group, pentamethylene group, hexamethylene group and heptamethylene group.

Examples of divalent alicyclic hydrocarbon groups having 3 to 12 carbon atoms include cycloalkylene groups such as cyclopropylene group, cyclobutylene group, cyclopentylene group and cyclohexylene group; cyclobutenylene group, cyclopentenylene group and A cycloalkenylene group such as a cyclohexenylene group and the like can be mentioned.

Examples of the divalent aromatic hydrocarbon group having 6 to 12 carbon atoms include phenylene group, naphthylene group and biphenylene group.
Examples of the divalent halogenated hydrocarbon group having 1 to 12 carbon atoms include a linear or branched divalent halogenated hydrocarbon group having 1 to 12 carbon atoms, and a divalent halogenated lipid having 3 to 12 carbon atoms. Cyclic hydrocarbon groups and divalent halogenated aromatic hydrocarbon groups having 6 to 12 carbon atoms are included.

The linear or branched divalent halogenated hydrocarbon group having 1 to 12 carbon atoms includes a difluoromethylene group, a dichloromethylene group, a tetrafluoroethylene group, a tetrachloroethylene group, a hexafluorotrimethylene group and a hexachlorotrimethylene group. , hexafluoroisopropylidene group and hexachloroisopropylidene group.

As the divalent halogenated alicyclic hydrocarbon group having 3 to 12 carbon atoms, at least some of the hydrogen atoms in the groups exemplified for the divalent alicyclic hydrocarbon group having 3 to 12 carbon atoms are fluorine atoms. , a group substituted with a chlorine atom, a bromine atom or an iodine atom.

As the divalent halogenated aromatic hydrocarbon group having 6 to 12 carbon atoms, at least some of the hydrogen atoms in the groups exemplified in the divalent aromatic hydrocarbon group having 6 to 12 carbon atoms are fluorine atoms, chlorine A group substituted with an atom, a bromine atom or an iodine atom, and the like.

The organic group having 1 to 12 carbon atoms and containing at least one atom selected from the group consisting of an oxygen atom and a nitrogen atom includes an organic group consisting of a hydrogen atom and a carbon atom and an oxygen atom and/or a nitrogen atom. and divalent organic groups having a total of 1 to 12 carbon atoms having an ether bond, a carbonyl group, an ester bond or an amide bond and a hydrocarbon group.

The divalent halogenated organic group having 1 to 12 carbon atoms containing at least one atom selected from the group consisting of an oxygen atom and a nitrogen atom is specifically selected from the group consisting of an oxygen atom and a nitrogen atom. Groups in which at least part of the hydrogen atoms of the exemplified groups in the divalent organic group having 1 to 12 carbon atoms containing at least one atom are substituted with a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, and the like. .

Z in the above formula (3) is preferably a single bond, —O—, —SO ₂ —, —CO—, or a divalent organic group having 1 to 12 carbon atoms. From the point of view, a divalent hydrocarbon group having 1 to 12 carbon atoms, a divalent halogenated hydrocarbon group having 1 to 12 carbon atoms, or a divalent alicyclic hydrocarbon group having 3 to 12 carbon atoms is more preferable.

The substrate preferably has a resin layer containing a near-infrared absorber, and the resin layer preferably contains at least one selected from the group consisting of norbornene-based resins, polyimide-based resins and polyether resins.

By having the resin layer, it is possible to obtain an optical filter having high transparency at a wavelength of 430 to 580 nm, high heat resistance, resistance to warping and fracture, and low in-plane retardation R ₀ . Therefore, a solid-state imaging device including an optical filter having the resin layer has high image quality and can be easily manufactured.

The average transmittance of the resin layer at a wavelength of 430 to 580 nm is preferably 70% or more at a thickness of 1 μm, because the solid-state imaging device has high sensitivity.
The glass transition temperature of the resin layer is preferably 140° C. or higher because the solid-state imaging device can be manufactured by a low-temperature reflow process.

The Young's modulus of the resin layer is preferably 2 GPa or more from the viewpoint of obtaining an optical filter that is less likely to warp.
The in-plane retardation R ₀ of the resin layer is preferably 50 nm or less, more preferably 20 nm or less, still more preferably 10 nm or less, and particularly preferably 5 nm or less. An optical filter with a small in-plane phase difference R ₀ enables accurate detection of polarization characteristics and reduces errors when an imaging device having different sensitivities depending on polarization is provided.

The resin layer may be one layer in the base material, or may include a plurality of layers, and the base material may be composed of only the resin layer.
The thickness of the base material can be appropriately selected according to the desired application and is not particularly limited, but the upper limit is preferably 250 μm or less, more preferably 200 μm or less, and still more preferably 150 μm or less, and the lower limit is It is preferably 30 μm or more, more preferably 40 μm or more. If the thickness is within the above range, a sufficiently thin solid-state imaging device with little warping of the optical filter can be obtained.

<Method for producing resin layer>
The resin layer can be formed, for example, by melt molding or cast molding, and if necessary, after molding, it can be manufactured by a method of coating with a coating agent such as an antireflection agent, a hard coating agent and/or an antistatic agent. can be done.

(A) Melt molding The resin layer is formed by melt-molding pellets obtained by melt-kneading a resin and a near-infrared absorber; melt-molding a resin composition containing a resin and a near-infrared absorber. method; or a method of melt-molding pellets obtained by removing the solvent from a resin composition containing a near-infrared absorber, a resin and a solvent. Examples of melt molding methods include injection molding, melt extrusion molding, and blow molding.

(B) Cast molding The resin layer is formed by casting a resin composition containing a near-infrared absorber, a resin and a solvent on a suitable support and removing the solvent; antireflection agent, hard coating agent and/or A method of casting a resin composition containing a coating agent such as an antistatic agent, a near-infrared absorbent, and a resin on a suitable support; A curable composition containing a coating agent, a dye compound, and a resin may be cast on a suitable support, cured and dried.

The support is not particularly limited, and a support made of glass, tempered glass, special glass, or a resin, which is exemplified as the material of the substrate, can be used. For example, steel belts, steel drums, etc. may be used.

When the substrate is a substrate made of resin, the substrate can be obtained by peeling off the coating film from the support after cast molding. In the case of a base material having a resin layer laminated thereon, the base material can be obtained by not peeling off the coating film after cast molding.

The amount of residual solvent in the resin layer obtained by the above method should be as small as possible. % or less. When the amount of residual solvent is within the above range, a resin layer that can easily exhibit desired functions without causing deformation of the optical filter or change in optical properties can be obtained.

[Near-infrared absorber]
The near-infrared absorber preferably has a maximum absorption wavelength in the range of 751 to 950 nm, more preferably 760 to 940 nm, even more preferably 770 to 930 nm, particularly preferably 775 to 925 nm. Since the absorption maximum wavelength is in the above range, the amount of light taken in by the solid-state imaging device is adjusted in the wavelength range of 700 nm to 750 nm, and light in the range of wavelengths 751 nm or more, to which human visibility is low, enters the solid-state imaging device. The amount of light entering can be reduced, and the solid-state imaging device can be brought closer to human visibility.

Examples of the near-infrared absorber include cyanine dyes, phthalocyanine dyes, dithiol dyes, diimmonium dyes, squarylium dyes, croconium dyes, and copper phosphate salts. The structure of these dyes is not particularly limited, and generally known dyes and commercial products can be used as long as they do not impair the effects of the present invention. Further, the near-infrared absorbing agent added to the optical filter may be of one type or plural types as long as it does not impair the effects of the present invention.

The near-infrared absorbing agent is preferably contained in a range of 0.01 to 60.0% by mass with respect to the resin layer. If the content of the near-infrared absorbing agent is within the above range, appropriate optical properties are likely to be obtained. If it is contained in an amount of more than 60.0% by mass, the aforementioned properties such as high transparency, high heat resistance, resistance to warping, and resistance to breakage are lost. Become.

Moreover, the near-infrared absorbent preferably satisfies the following conditions (a) and (b).
(a) (absorbance λ ₇₀₀ ) / (absorbance λ _max ) ≤ 0.1
(b) (absorbance λ ₇₅₁ ) / (absorbance λ _max ) ≧0.1

Here, the absorbance of the near-infrared absorbent at a wavelength of 700 nm is "absorbance λ ₇₀₀ ", the absorbance at a wavelength of 751 nm is "absorbance λ ₇₅₁ ", the absorbance at the maximum absorption wavelength is "absorbance λ _max ", and the absorbance λ at wavelength λ is , is calculated from the transmittance λ at the wavelength λ according to the generally used formula below.

Absorbance λ = -Log (internal transmittance λ)
For example, when the internal transmittance λ is 0.1 (10%), the absorbance is 1.0. The internal transmittance is a value obtained by subtracting the surface reflectance from the obtained transmittance, and is obtained by dividing the obtained transmittance by the transmittance of the medium excluding the near-infrared absorbent.

When the above conditions (a) and (b) are satisfied, it is possible to obtain an optical filter that has a high transmittance at a wavelength of 700 to 750 nm required for sensing and sufficiently shields unnecessary wavelengths for both visibility and sensing. . By the way, the absorbance λ ₇₀₀ of the optical filter is preferably 0.25 or less, more preferably 0.2 or less, and still more preferably 0.2 or less, in order to maintain high transmittance at a wavelength of 700 to 750 nm required for sensing and to maintain the requirement (C). is 0.18 or less, particularly preferably 0.16 or less. The lower limit of the absorbance λ ₇₀₀ of the optical filter is zero. By using a near-infrared absorbing agent that satisfies the condition (a), it is possible to set the absorbance λ ₇₀₀ of the optical filter within the above range.

In addition, in order to sufficiently block light with long wavelengths from 751 nm that is unnecessary for both visual sensitivity and sensing to achieve requirement (D), the absorbance λ ₇₅₁ of the optical filter is preferably 0.2 or more, more preferably is 0.21 or more, more preferably 0.23 or more, and particularly preferably 0.25 or more. Also, the absorbance λ ₇₅₁ of the optical filter is preferably 0.8 or less, more preferably 0.6 or less, still more preferably 0.5 or less. By using a near-infrared absorbing agent that satisfies the above condition (b), the absorbance λ ₇₅₁ of the optical filter can be made within the above range.

However, in near-infrared absorbents that satisfy the condition (b), (absorbance λ ₇₅₁ ) / (absorbance λ _max ) tends to decrease as the maximum absorption wavelength λ _max increases from 751 nm to 950 nm. . Therefore, as the maximum absorption wavelength (λ _max ) increases from 751 nm to 950 nm, it is necessary to increase the concentration of the near-infrared absorbent contained in the substrate. On the other hand, if the substrate contains an excessive amount of the near-infrared absorbing agent that satisfies the condition (a), it may become difficult for the optical filter to maintain the requirement (C). Therefore, the near-infrared absorbent contained in the substrate preferably satisfies the following condition (c).
(c) 1.5≧Σ _dye(n) [((950−shortest absorption maximum wavelength)×dye concentration×dye medium thickness)]>0.2

Here, " _dye(n) " in "Σ dye(n)" means each near-infrared absorbing agent contained in the substrate. In addition, "shortest absorption maximum wavelength" means the shortest wavelength (nm) among absorption maximum wavelengths at wavelengths 751 to 950 nm, and "dye concentration" means the concentration of the near-infrared absorbent contained in the base material. (% by mass), and "dye medium thickness" means the thickness (mm) of the substrate containing the near-infrared absorber.

By using the near-infrared absorbent that satisfies the conditions (a) and (b) at the concentration of the condition (c), the absorbance λ ₇₀₀ and the absorbance λ ₇₅₁ of the optical filter can be set within the preferred ranges described above. , it becomes easier to satisfy requirements (C) and (D).

<Cyanine dye>
The cyanine dye is not particularly limited as long as it does not impair the effects of the present invention. cyanine dyes.

Some of the cyanine dyes include those that do not have a maximum absorption wavelength in the wavelength range of 751 to 950 nm. Combined use of a cyanine dye that has no wavelength and a cyanine dye that has a maximum absorption wavelength of 751 to 950 nm, or a cyanine dye that has no maximum absorption wavelength of 751 to 950 nm and a maximum absorption wavelength of 751 to 950 nm. It can be used as a near-infrared absorbing agent for obtaining the effect of the present invention by using a dye other than a cyanine dye with

<Phthalocyanine dye>
The phthalocyanine dye is not particularly limited as long as it does not impair the effects of the present invention. JP-A-4-39361, JP-A-5-78364, JP-A-5-222047, JP-A-5-222301, JP-A-5-222302, JP-A-5-345861, JP-A-H9 6-25548, JP-A-6-107663, JP-A-6-192584, JP-A-6-228533, JP-A-7-118551, JP-A-7-118552, JP-A-8- 120186, JP-A-8-225751, JP-A-9-202860, JP-A-10-120927, JP-A-10-182995, JP-A-11-35838, JP-A-2000-26748 Publications, JP 2000-63691, JP 2001-106689, JP 2004-18561, JP 2005-220060, JP 2007-169343, JP 2013-195480 Paragraphs [0026] to [0027], compounds described in Table 1 of WO 2015/025779 and the like.

Some of the phthalocyanine dyes include those that do not have a maximum absorption wavelength in the wavelength range of 751 to 950 nm. A combination of a phthalocyanine dye that has no wavelength and a phthalocyanine dye that has a maximum absorption wavelength at a wavelength of 751 to 950 nm, or a phthalocyanine dye that has no maximum absorption wavelength at a wavelength of 751 to 950 nm and a maximum absorption wavelength at a wavelength of 751 to 950 nm. By using a dye other than the phthalocyanine-based dye having Phthalocyanine dyes often have steep absorption characteristics in the vicinity of the maximum absorption wavelength, and when a phthalocyanine dye is used in the optical filter of the present invention, it can be used in combination with at least one other near-infrared absorber. preferable.

<Dithiol dye>
The dithiol-based dye is not particularly limited as long as it does not impair the effects of the present invention.

Some dithiol dyes include those that do not have a maximum absorption wavelength at a wavelength of 751 to 950 nm, but select a dithiol dye that has a maximum absorption wavelength at a wavelength of 751 to 950 nm, or have a maximum absorption wavelength at a wavelength of 751 to 950 nm. A combination of a dithiol dye that has no wavelength and a dithiol dye that has a maximum absorption wavelength at a wavelength of 751 to 950 nm, or a dithiol dye that has no maximum absorption wavelength at a wavelength of 751 to 950 nm and a maximum absorption wavelength at a wavelength of 751 to 950 nm. It can be used as a near-infrared absorbing agent to obtain the effect of the present invention by using a dye other than a dithiol dye in combination.
Alternatively, a counterion conjugate of a dithiol dye may be used as described in WO1998/034988, for example.

<Squarylium dye>
The squarylium-based dye is not particularly limited as long as it does not impair the effects of the present invention. , and squarylium-based dyes described in JP-A-2014-052431, and may be synthesized by a generally known method.

In the above formulas (4) to (6), X independently represents an oxygen atom, a sulfur atom, a selenium atom or —NH—, and each of the R ¹ and R ^1′ independently represents a hydrogen atom, a chlorine atom, fluorine atom, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, cyclohexyl group, phenyl group, hydroxyl group, amino group, dimethylamino group and nitro group; Preferred are a hydrogen atom, a chlorine atom, a fluorine atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group and a hydroxyl group. R ² to R ⁸ each independently represent a hydrogen atom, a halogen atom, a sulfo group, a hydroxyl group, a cyano group, a nitro group, a carboxyl group, a phosphoric acid group, -L ¹ or -NR ^g R ^h group. R ^g and R ^h are each independently a hydrogen atom, -L ^a , -L ^b , -L ^c , -L ^d , -L ^e , -L ^f , -L ^g , -L ^h or -C(O) R ⁱ group (R ⁱ represents -L ^a , -L ^b , -L ^c , -L ^d or -L ^e ), R ₉ is independently a hydrogen atom, -L ^a , -L ^b , -L ^c , -L ^d , -L ^e , -L ^f , -L ^g or -L ^h .
L ¹ is L ^a , L ^b , L ^c , L ^d , L ^e , L ^f , L ^g or L ^h .

The above L ^a to L ^h represent the following groups.
(L ^a ) an aliphatic hydrocarbon group having 1 to 12 carbon atoms which may have a substituent L (L ^b ) a halogen-substituted alkyl group having 1 to 12 carbon atoms which may have a substituent L ( L ^c ) an alicyclic hydrocarbon group having 3 to 14 carbon atoms which may have a substituent L (L ^d ) an aromatic hydrocarbon group having 6 to 14 carbon atoms which may have a substituent L (L ^e ) the heterocyclic group having 3 to 14 carbon atoms which may have a substituent L (L ^f ) the alkoxy group having 1 to 12 carbon atoms which may have a substituent L (L ^g ) the above an acyl group having 1 to 12 carbon atoms which may have a substituent L (L ^h ) an alkoxycarbonyl group having 1 to 12 carbon atoms which may have a substituent L (L ⁱ ) having a substituent L a sulfide group or disulfide group having 1 to 12 carbon atoms which may be substituted R ⁹ independently represents a hydrogen atom, -L ^a , -L ^b , -L ^c , -L ^d or -L ^e ;

The maximum absorption wavelength of the compound (5) can be adjusted by a substituent, and X is preferably a sulfur atom because it tends to be a compound having a maximum absorption wavelength of 751 to 950 nm.

Some squarylium-based dyes include those that do not have a maximum absorption wavelength in the wavelength range of 751 to 950 nm. A combination of a squarylium dye with no wavelength and a squarylium dye with a maximum absorption wavelength of 751 to 950 nm, or a squarylium dye without a maximum absorption wavelength of 751 to 950 nm and a maximum absorption wavelength of 751 to 950 nm. It can be used as a near-infrared absorber to obtain the effect of the present invention by using a dye other than the squarylium dye.

<Diimmonium dye>
The diimonium-based dye is not particularly limited as long as it does not impair the effects of the present invention. Japanese Patent No. 4252961, Japanese Patent Application Laid-Open No. 63-165392, WO2004/048480, etc., and diimmonium-based dyes, which may be synthesized by a generally known method.

In formulas (7-1) and (7-2), Rdi1 to Rdi12 each independently represent a hydrogen atom, a halogen atom, a sulfo group, a hydroxyl group, a cyano group, a nitro group, a carboxyl group, a phosphate group, a -SR ⁱ group. , —SO ₂ R ⁱ group, —OSO ₂ R ⁱ group, or any of L ^a to L ^h below, wherein R ^g and R ^h each independently represent a hydrogen atom, —C(O)R i group, or —C(O)R ⁱ group, or Represents any one of L ^a to L ^e , R ⁱ represents any one of L ^a to L ^e below,
(L ^a ) Aliphatic hydrocarbon group having 1 to 12 carbon atoms (L ^b ) Halogen-substituted alkyl group having 1 to 12 carbon atoms (L ^c ) Alicyclic hydrocarbon group having 3 to 14 carbon atoms (L ^d ) Carbon Aromatic hydrocarbon group having 6 to 14 carbon atoms (L ^e ) Heterocyclic group having 3 to 14 carbon atoms (L ^f ) Alkoxy group having 1 to 12 carbon atoms (L ^g ) Number of carbon atoms which may have substituent L 1 to 12 acyl groups,
(L ^h ) an alkoxycarbonyl group having 1 to 12 carbon atoms which may have a substituent L

The substituent L is an aliphatic hydrocarbon group having 1 to 12 carbon atoms, a halogen-substituted alkyl group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 14 carbon atoms, or an aromatic hydrocarbon group having 6 to 14 carbon atoms. at least one selected from the group consisting of a hydrogen group and a heterocyclic group having 3 to 14 carbon atoms,
adjacent Rdi1 and Rdi2, Rdi3 and Rdi4, Rdi5 and Rdi6, and Rdi7 and Rdi8 may form a ring optionally having a substituent L;
X represents an anion necessary to neutralize the charge,

Rdi1 to Rdi8 are preferably selected from hydrogen atom, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, cyclohexyl group, phenyl group and benzyl group. more preferably a group selected from an isopropyl group, a sec-butyl group, a tert-butyl group and a benzyl group.

Rdi9 to Rdi12 are preferably hydrogen atom, chlorine atom, fluorine atom, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, cyclohexyl group, phenyl group, hydroxyl group, amino group, dimethylamino group, cyano group, nitro group, methoxy group, ethoxy group, n-propoxy group, n-butoxy group, acetylamino group, propionylamino group, N-methylacetylamino group, trifluoro a group selected from a methanoylamino group, pentafluoroethanoylamino group, tert-butanoylamino group, cyclohexynoylamino group, n-butylsulfonyl group, methylthio group, ethylthio group, n-propylthio group and n-butylthio group; and more preferably chlorine atom, fluorine atom, methyl group, ethyl group, n-propyl group, isopropyl group, tert-butyl group, hydroxyl group, dimethylamino group, methoxy group, ethoxy group, acetylamino group, propionylamino group , a trifluoromethanoylamino group, a pentafluoroethanoylamino group, a tert-butanoylamino group and a cyclohexynoylamino group, and particularly preferably a methyl group, an ethyl group, an n-propyl group and isopropyl is a group selected from groups.

The X ^- is an anion necessary to neutralize the charge, and when the anion is divalent as in formula (7-2), one ion In the case of valence, two ions are required. In the latter case, the two anions X ⁻ may be the same or different, but are preferably the same from the viewpoint of synthesis. X ⁻ or X ²⁻ is not particularly limited as long as it is such an anion.

Among the near-infrared absorbents, the compounds represented by formula (4), formula (5), formula (7-1) and formula (7-2) have high visible light transmittance and a wavelength of 700 to 750 nm. It is preferable from the absorption characteristics in the range and the shielding performance in the wavelength range of 800 to 1100 nm.

[Near-infrared reflective film]
The near-infrared reflective film that can be used in the present invention is a film that has the ability to reflect near-infrared rays. As such a near-infrared reflective film, an aluminum deposition film, a noble metal thin film, a resin film in which metal oxide fine particles containing indium oxide as a main component and containing a small amount of tin oxide are dispersed, or a high refractive index material layer and a low refractive index material layer and a low refractive index material layer A dielectric multilayer film in which dielectric layers are alternately laminated and the like. With such a near-infrared reflective film, near-infrared rays can be cut more effectively.

In the present invention, the near-infrared reflective film may be provided on one side or both sides of the substrate. When provided on one side, the manufacturing cost and ease of manufacture are excellent, and when provided on both sides, an optical filter having high strength and less warping can be obtained.

Among the near-infrared reflective films, it has little scattering, good adhesion, high transmission characteristics of visible light in the wavelength range of 430 to 580 nm, and high light shielding performance in the wavelength range of 800 to 1100 nm. Therefore, a dielectric multilayer film in which high refractive index material layers and low refractive index material layers are alternately laminated is preferable. When the near-infrared reflective film is a dielectric multilayer film, the image quality of the obtained solid-state imaging device can be improved.

<Dielectric multilayer film>
A material having a refractive index of 1.7 or more can be used as a material constituting the high refractive index material layer, and a material having a refractive index ranging from 1.7 to 2.5 is usually selected. Examples of such materials include titanium oxide, zirconium oxide, tantalum pentoxide, niobium pentoxide, lanthanum oxide, yttrium oxide, zinc oxide, zinc sulfide, or indium oxide. and/or those containing a small amount (for example, 0 to 10% relative to the main component) of cerium oxide or the like.

A material having a refractive index of less than 1.7 can be used as a material constituting the low refractive index material layer, and a material having a refractive index ranging from 1.2 to less than 1.7 is usually selected. Such materials include, for example, resin, silica, alumina, lanthanum fluoride, magnesium fluoride, sodium aluminum hexafluoride, mixtures thereof, and depleted materials having a refractive index of less than 1.7. and the like.

The method of stacking the high refractive index material layer and the low refractive index material layer is not particularly limited as long as the dielectric multilayer film is formed by stacking these material layers. For example, a high refractive index material layer and a low refractive index material layer and a low refractive index material layer are formed directly on the base material by CVD, vacuum deposition, sputtering, ion-assisted deposition, ion plating, radical-assisted sputtering, ion beam sputtering, or the like. A dielectric multilayer film can be formed by alternately laminating dielectric material layers. The ion-assisted vapor deposition method, the ion-plating method, and the radical-assisted sputtering method are preferable because the optical film thickness of the multilayer film to be obtained is less likely to change depending on the environment, and a good quality film can be obtained. The ion-assisted vapor deposition method is more preferable because the resulting optical filter is less warped.

The thickness of each of the high refractive index material layer and the low refractive index material layer is usually 0.1λ except for the two layers adjacent to the substrate and the outermost layer, where λ (nm) is the near-infrared wavelength to be shielded. An optical thickness of ~0.5λ is preferred. When the optical thickness is in this range, the product (n × d) of the refractive index (n) and the film thickness (d) is calculated as λ/4. The thickness of each layer of the material layer becomes almost the same value, and there is a tendency to easily control the shielding and transmission of a specific wavelength from the relationship between the optical characteristics of reflection and refraction. The two layers adjacent to the substrate preferably have a physical thickness of 5 nm to 45 nm or less. Further, the outermost layer preferably has an optical thickness of 0.05 to 0.2λ. If the thickness of the two layers adjacent to the substrate and the outermost layer are within the above range, the reflectance of visible light can be reduced, and together with the above requirement (Z), the ghost can be reduced.

Also, the total number of laminated layers of the high refractive index material layer and the low refractive index material layer in the dielectric multilayer film is desirably 5 to 60 layers, preferably 10 to 50 layers.
Furthermore, if the base material is warped when the dielectric multilayer film is formed, in order to solve this problem, the dielectric multilayer film is formed on both sides of the base material, or the dielectric multilayer film is formed on the base material. A method of irradiating electromagnetic waves such as ultraviolet rays to the surface on which the is formed can be adopted. When the electromagnetic wave is applied, the irradiation may be performed during the formation of the dielectric multilayer film, or may be performed separately after the formation.

However, in the conventional design method as described in Patent Document 1 and Patent Document 2, when a dielectric multilayer film that shields wavelengths of 751 to 1200 nm is formed, the transmittance at wavelengths of 700 to 750 nm required for sensing may also decrease. Therefore, in order to obtain an optical filter that satisfies the requirements (C) and (Z2), the dielectric multilayer film is preferably designed to satisfy the following condition (e).
(e) Layers other than the two layers adjacent to the substrate and the outermost layer do not include a layer having an optical thickness of 205 nm or less (hereinafter also referred to as "layer (e1)").

Here, the optical film thickness represents a physical quantity of physical film thickness×refractive index, and the refractive index is the refractive index at a wavelength of 550 nm.
A dielectric multilayer film in which layers having different refractive indices are laminated is designed to block wavelengths in the vicinity of (optical film thickness)×4. Since the layers other than the two layers adjacent to the substrate and the outermost layer adjacent to the emission medium are layers that contribute to the formation of a shielding layer that reduces transmittance, in order to satisfy requirement (C), the layer ( It is preferred not to include e1).

In order to satisfy the requirement (Z2), it is preferable that both dielectric multilayer films formed on both sides of the base material satisfy the condition (e). As a result, an optical filter that has a high transmittance of wavelengths of 700 to 750 nm required for sensing and blocks wavelengths of 751 to 1200 nm can be obtained. The optical thickness of the layer (e1) under condition (e) is preferably 210 nm or less, more preferably 215 nm or less.
Moreover, in order to satisfy the requirement (Z1), the dielectric multilayer film is preferably designed to satisfy the following condition (f).
(f) The standard deviation of the optical film thickness of the two layers adjacent to the substrate and the layers other than the outermost layer is 6 to 20 nm.

By designing a dielectric multilayer film that satisfies the condition (f), the requirement (B), "In the wavelength range of 800 to 1000 nm, the average transmittance when measured from the direction perpendicular to the surface of the optical filter is 10% or less" and the requirement (Z1). When the optical filter has dielectric multilayer films on both sides of the substrate, it is more preferable that both the dielectric multilayer films on both sides satisfy the condition (f). The standard deviation of the optical film thickness under the condition (f) is preferably 6-18 nm, more preferably 6-16 nm.

[Near UV absorber]
Near-ultraviolet absorbers that can be used in the present invention include azomethine-based compounds, indole-based compounds, benzotriazole-based compounds, triazine-based compounds, merophthalocyanine-based compounds, oxazole-based compounds, naphthylimide-based compounds, oxadiazole-based compounds, It is preferably at least one selected from the group consisting of oxazine-based compounds, oxazolidine-based compounds, and anthracene-based compounds, and preferably has at least one absorption maximum at a wavelength of 300 to 420 nm. By containing such a near-ultraviolet absorber in addition to the near-infrared absorber, it is possible to obtain an optical filter having a small incident angle dependence even in the near-ultraviolet wavelength region.

(A) Azomethine-based compound The azomethine-based compound is not particularly limited, but can be represented, for example, by the following formula (8).

式（８）中、Ｒ^a1～Ｒ^a5は、それぞれ独立に水素原子、ハロゲン原子、水酸基、カルボキシ基、炭素数１～１５のアルキル基、炭素数１～９のアルコキシ基または炭素数１～９のアルコキシカルボニル基を表す。

In formula (8), R ^a1 to R ^a5 are each independently a hydrogen atom, a halogen atom, a hydroxyl group, a carboxy group, an alkyl group having 1 to 15 carbon atoms, an alkoxy group having 1 to 9 carbon atoms or an alkoxy group having 1 to 9 carbon atoms. represents an alkoxycarbonyl group.

(B) Indole-based compound Although the indole-based compound is not particularly limited, it can be represented, for example, by the following formula (9).

式（９）中、Ｒ^b1～Ｒ^b5は、それぞれ独立に水素原子、ハロゲン原子、水酸基、カルボキシ基、シアノ基、フェニル基、アラルキル基、炭素数１～９のアルキル基、炭素数１～９のアルコキシ基または炭素数１～９のアルコキシカルボニル基を表す。

In formula (9), R ^b1 to R ^b5 each independently represent a hydrogen atom, a halogen atom, a hydroxyl group, a carboxy group, a cyano group, a phenyl group, an aralkyl group, an alkyl group having 1 to 9 carbon atoms, or an alkyl group having 1 to 9 carbon atoms. or an alkoxycarbonyl group having 1 to 9 carbon atoms.

(C) Benzotriazole-Based Compound Although the benzotriazole-based compound is not particularly limited, it can be represented, for example, by the following formula (10).

式（１０）中、Ｒ^c1～Ｒ^c3は、それぞれ独立に水素原子、ハロゲン原子、水酸基、アラルキル基、炭素数１～９のアルキル基、炭素数１～９のアルコキシ基、または置換基として炭素数１～９のアルコキシカルボニル基を有する炭素数１～９のアルキル基を表す。

In formula (10), R ^c1 to R ^c3 each independently represent a hydrogen atom, a halogen atom, a hydroxyl group, an aralkyl group, an alkyl group having 1 to 9 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, or a carbon atom as a substituent. It represents an alkyl group having 1 to 9 carbon atoms and having 1 to 9 alkoxycarbonyl groups.

(D) Triazine-based compound The triazine-based compound is not particularly limited, but can be represented by, for example, the following formulas (11), (12), or (13).

In formulas (11) to (13), R ^d1 is independently a hydrogen atom, an alkyl group having 1 to 15 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, an alkenyl group having 3 to 8 carbon atoms, It represents an aryl group having 6 to 18 carbon atoms, an alkylaryl group having 7 to 18 carbon atoms or an arylalkyl group. However, these alkyl groups, cycloalkyl groups, alkenyl groups, aryl groups, alkylaryl groups and arylalkyl groups may be substituted with a hydroxy group, a halogen atom, an alkyl group having 1 to 12 carbon atoms or an alkoxy group, It may be interrupted by an oxygen atom, sulfur atom, carbonyl group, ester group, amide group or imino group. Also, the replacement and interruption may be combined. R ^d2 to R ^d9 each independently represent a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group having 1 to 15 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, an alkenyl group having 3 to 8 carbon atoms, a carbon It represents an aryl group having 6 to 18 atoms, an alkylaryl group having 7 to 18 carbon atoms or an arylalkyl group.

(E) Commercial products “S0511” manufactured by FewChemicals, “Lumogen (registered trademark) Fviolet 570” manufactured by BASF, “Uvitex (registered trademark) OB”, “Hakkol RF-K” manufactured by Showa Chemical Industry Co., Ltd., Japan Examples include "Nikkafluor EFS" and "Nikkafluor SB-conc" manufactured by Kagaku Kogyo Co., Ltd. "ABS 407" manufactured by Exiton, QCR Solutions Corp. "UV 381A", "UV 381B", "UV 382A", "UV 386A" manufactured by BASF, "TINUVIN 326", "TINUVIN 460", "TINUVIN 479" manufactured by Orient Chemical Co., Ltd. "BONASORB UA3911" manufactured by Orient Chemical Co., Ltd. etc. may be used.

<Other ingredients>
The resin layer further contains additives such as an antioxidant, a dispersant, a flame retardant, a plasticizer, a heat stabilizer, a light stabilizer, and a metal complex compound within a range that does not impair the effects of the present invention. may Moreover, when manufacturing a resin base material by the above-mentioned cast molding, it is possible to facilitate the manufacture of the resin base material by adding a leveling agent or an antifoaming agent. These other components may be used individually by 1 type, and may use 2 or more types together.

Examples of the antioxidant include 2,6-di-t-butyl-4-methylphenol, 2,2'-dioxy-3,3'-di-t-butyl-5,5'-dimethyldiphenylmethane, and Tetrakis[methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate]methane, 1,3,5-tris(3,5-di-t-butyl-4-hydroxybenzyl)- 1,3,5-triazyl-2,4,6(1H,3H,5H)-trione and the like. These additives may be mixed together with the resin when manufacturing the resin base material, or may be added when manufacturing the resin. Further, the amount to be added is appropriately selected according to the desired properties, but it is usually 0.01 to 5.0 parts by mass, preferably 0.05 to 2.0 parts by mass, per 100 parts by mass of the resin. Department.

[Other functional films]
The optical filter of the present invention can be appropriately provided with a functional film as long as the effects of the present invention are not impaired.

The optical filter of the present invention may contain one layer of functional films, or may contain two or more layers. When the optical filter of the present invention contains two or more layers of functional films, it may contain two or more similar layers or two or more different layers.

The method of laminating the functional film is not particularly limited, but a method of melt molding or cast molding a coating agent such as an antireflection agent, a hard coating agent and/or an antistatic agent on the substrate or the near-infrared reflective film. etc. can be mentioned.

The coating agent can also be produced by coating the curable composition on the substrate or the near-infrared reflective film using a bar coater or the like, and then curing the composition by ultraviolet irradiation and/or heating. It is preferable to have a functional film of a curable composition in order to improve the breaking strength of the resulting substrate, make it less likely to be damaged, reduce warping, and the like.

Examples of the curable composition include ultraviolet (UV)/electron beam (EB) curable resins and thermosetting resins. Specifically, vinyl compounds, urethane-based, urethane-acrylate-based, and acrylate-based , epoxy and epoxy acrylate resins. Examples of the curable composition containing these coating agents include vinyl-based, urethane-based, urethane-acrylate-based, acrylate-based, epoxy-based and epoxy-acrylate-based curable compositions.

Components contained in the urethane-based or urethane acrylate-based curable composition include, for example, tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, bis(2-hydroxyethyl)isocyanurate di(meth)acrylate, Oligourethane (meth)acrylates having two or more (meth)acryloyl groups in the molecule can be mentioned. These components may be used individually by 1 type, and may use 2 or more types together. Further, an oligomer or polymer such as polyurethane (meth)acrylate or an oligomer or polymer such as polyester (meth)acrylate may be blended.

Examples of the vinyl compounds include vinyl acetate, vinyl propionate, divinylbenzene, ethylene glycol divinyl ether, diethylene glycol divinyl ether, and triethylene glycol divinyl ether, but are not limited to these examples. do not have. These components may be used individually by 1 type, and may use 2 or more types together.

Components contained in the epoxy-based or epoxy-acrylate-based curable composition are not particularly limited, but glycidyl (meth)acrylate, methylglycidyl (meth)acrylate, and oligos having two or more (meth)acryloyl groups in the molecule. Epoxy (meth)acrylates and the like can be mentioned. These components may be used individually by 1 type, and may use 2 or more types together. Furthermore, an oligomer or polymer such as polyepoxy (meth)acrylate may be blended.

Commercially available products of the curable composition include "LCH" and "LAS" manufactured by Toyo Ink Mfg. Co., Ltd.; "Beamset" manufactured by Arakawa Chemical Industries, Ltd.; UVACURE"; "Opstar" and "Desolite Z" manufactured by JSR Corporation.

Moreover, the curable composition may contain a polymerization initiator. As the polymerization initiator, a known photopolymerization initiator or thermal polymerization initiator can be used, and a photopolymerization initiator and a thermal polymerization initiator may be used in combination. A polymerization initiator may be used individually by 1 type, and may use 2 or more types together.

In the curable composition, the mixing ratio of the polymerization initiator is preferably 0.1 to 10% by mass, more preferably 0.5 to 10% by mass, when the total amount of the curable composition is 100% by mass. More preferably, it is 1 to 5% by mass. When the blending ratio of the polymerization initiator is within the above range, the curing properties and handling properties of the curable composition are excellent, and functional films such as antireflection films, hard coat films and antistatic films having desired hardness can be obtained. can.

Furthermore, an organic solvent may be added as a solvent to the curable composition, and known organic solvents can be used. Specific examples of organic solvents include alcohols such as methanol, ethanol, isopropanol, butanol and octanol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; ethyl acetate, butyl acetate, ethyl lactate, γ-butyrolactone and propylene. esters such as 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; dimethylformamide, dimethylacetamide, N- Amides such as methylpyrrolidone can be mentioned. These solvents may be used singly or in combination of two or more.

The thickness of the functional film is preferably 0.1 μm to 20 μm, more preferably 0.5 μm to 10 μm, particularly preferably 0.7 μm to 5 μm.
In addition, for the purpose of increasing the adhesion between the base material and the functional film and/or the near-infrared reflective film, and the adhesion between the functional film and the near-infrared reflective film, the surface of the base material and the functional film may be subjected to corona treatment, plasma treatment, or the like. surface treatment may be applied.

The above materials are used as materials for low-pass filters and wavelength plates to reduce moire and false colors in imaging devices such as digital still cameras, digital video cameras, surveillance cameras, vehicle-mounted cameras, web cameras, and unmanned aerial vehicles. may occur.

[Applications of optical filters]
The optical filter of the present invention has characteristics of wide viewing angle, high red sensitivity, and improved ghost. Therefore, it is useful for visibility correction of solid-state imaging devices such as CCDs and CMOSs in camera modules. In particular, digital still cameras, mobile phone cameras, digital video cameras, PC cameras, surveillance cameras, automobile cameras, televisions, car navigation systems, personal digital assistants, personal computers, video game machines, portable game machines, fingerprint authentication systems, distance measurement sensors , iris recognition systems, face recognition systems, range finding cameras, digital music players, etc.

<Solid-state imaging device>
A solid-state imaging device of the present invention comprises the optical filter of the present invention. Here, the solid-state imaging device is an image sensor having a solid-state imaging device such as CCD or CMOS. Photoelectric conversion elements such as silicon photodiodes and organic semiconductors that convert light of a specific wavelength into electric charges are used as members constituting the solid-state imaging device. Further, the pixels constituting the solid-state imaging device have pixels sensitive to at least near-infrared rays with a wavelength of 700 to 750 nm.

In the solid-state imaging device of the present invention, a polarizer such as a retardation film or wire grid may be provided over the entire surface of the solid-state imaging device. When a polarizing element is provided, phase information of an image can be obtained, and an image excluding the reflected light of the object and the shape of the object can be three-dimensionally measured, which is more preferable.

<Wire grid>
The wire grid provided in the solid-state imaging device of the present invention can be made of aluminum, nickel, silver, platinum, tungsten, or alloys containing these metals, etc. It is preferable to provide the polarizer described in the publication.

<Camera module>
A camera module of the present invention comprises the optical filter of the present invention. Here, the camera module is a device that includes an image sensor, a focus adjustment mechanism, a phase detection mechanism, a distance measurement mechanism, or the like, and outputs an image and distance information as electrical signals. Here, the case where the optical filter of the present invention is used in a camera module will be specifically described. A cross-sectional schematic diagram 9 of the camera module 400 is shown.

In the case of the optical filter 1 of the present invention, there is no significant difference in transmission wavelength between light incident from the vertical direction and light incident at 30° to the vertical direction of the filter 1 (incidence angle dependency of absorption (transmission) wavelength is small), even if the filter 1 is provided between the lens 301 and the sensor 302, the color change of the entire sensor is small. Therefore, when the optical filter 1 of the present invention is used in a camera module, it is possible to use a lens that can handle a higher angle of incidence, and the height of the camera module can be reduced.

[ghost]
A ghost that causes image quality deterioration in the present invention means that light reflected on the surface or back surface of an optical component between the subject and the image pickup device is reflected by other components, etc., and enters the image pickup device at a position different from the original image pickup position. This is an image defect caused by light.

As shown in FIG. 10, when the light reflected by the surface of the optical filter 1 is further reflected by the lens, transmitted through the optical filter 1, and incident on the sensor 302, a ghost 304 is generated. Alternatively, when the light reflected from the sensor 302 is further reflected by the rear surface of the optical filter 1 and enters the sensor 302, a ghost 305 is generated.

Conventional optical filters have a large reflection, especially in the vicinity of wavelengths of 680 to 720 nm, causing ghosts. However, the optical filter 1 of the present invention has a reflectance of 10% or less on both surfaces at a wavelength of 700 nm and a value of (Za) on both surfaces of 730 nm or more. The rate will be lower than 50%. Therefore, both surfaces of the filter have little reflection in the vicinity of wavelengths of 680 to 720 nm. Therefore, ghosts 304 and 305 that are erroneously incident on the sensor are less likely to occur, and good image quality can be obtained.
FIG. 11 is an example of a ghost.

EXAMPLES The present invention will be described below with reference to Examples, but the present invention is not limited to these Examples. "Parts" and "%" mean "mass parts" and "mass%" unless otherwise specified.
Methods for measuring and evaluating various physical properties in Examples are as follows.

<Transmittance>
The transmittance was measured using a spectrophotometer "U-4100" manufactured by Hitachi High-Technologies Corporation. The transmittance measured in the direction perpendicular to the surface of the base material or the optical filter was obtained by measuring a non-polarized light beam passing through the optical filter perpendicularly as shown in FIG. Also, the transmittance when measured at an angle of 30° with respect to the direction perpendicular to the surface of the optical filter is, as shown in FIG. S-polarized light was measured and calculated from their average.

In addition, the average value of the transmittance at wavelengths A to B nm is obtained by measuring the transmittance at each wavelength of 1 nm or less from Anm to Bnm, and summing the transmittances. −A+1).

<Reflectance>
The spectral reflectance was measured using a spectrophotometer "U-4100" manufactured by Hitachi High-Technologies Co., Ltd., as shown in FIG. and the intensity of light reflected from the back surface, and the intensity of light reflected from the front surface and the back surface incident from the other surface were measured by absolute reflectometry.

In addition, the average value of the reflectance of wavelengths A to B nm is obtained by measuring the reflectance at each wavelength in increments of 1 nm from A nm to B nm, and calculating the total reflectance as the number of measured reflectances (wavelength range, B −A+1).

<Evaluation of absorbent>
The evaluation of the absorbent is carried out by adding various absorbents to 100 parts by mass of norbornene resin "ARTON" (refractive index 1.52, glass transition temperature 160 ° C.) manufactured by JSR Corporation, and then adding methylene chloride. A solution with a solid content of 30% by mass was obtained. Next, the obtained solution was cast on a smooth glass plate, dried at 50° C. for 8 hours, and further dried at 100° C. under reduced pressure for 1 hour, and peeled off to obtain a substrate having a thickness of 0.1 mm. The amount of the various absorbents added was adjusted to a concentration at which the transmittance of the resulting base material at the maximum absorption wavelength was 10%. From the transmittance of the obtained base material, the absorption maximum wavelength, the shortest absorption maximum wavelength, the absorbance λ ₇₀₀ , the absorbance λ ₇₅₁ , and the absolute value of the difference between (Aa) and (Ab) were calculated.

<Refractive index>
Unless otherwise specified, the refractive indices of various materials in this specification are values at a wavelength of 550 nm.

<Glass transition temperature>
Using a differential scanning calorimeter "DSC6200" manufactured by SII Nanotechnologies Co., Ltd., the temperature was measured at a rate of temperature increase of 20°C per minute under a nitrogen stream.

<In-plane retardation R ₀ >
Using a phase difference meter (“KOBRA-HBR” manufactured by Oji Scientific Instruments Co., Ltd.), the 550 nm phase difference of the base material obtained in the example was measured and defined as an in-plane phase difference R ₀ .

<Evaluation of green sensitivity and near-infrared sensitivity>
As the effect of the optical filter on the visible light sensitivity and near-infrared sensitivity, as a numerical value corresponding to the evaluation of the imaging device configured as shown in FIG. Using T ₀ (λ) and transmittance T ₃₀ (λ) for each wavelength incident at an angle of 30 degrees from the vertical direction, the sensitivity of the green pixel and the sensitivity of the near-infrared pixel can be calculated from the following equations (i) to (v). Calculated.

G ₀ represents the sensitivity of the green pixel when sunlight enters the optical filter from the vertical _direction . , the intensity of sunlight by wavelength I (λ), the sensitivity by wavelength G (λ) of the green sensor pixel, and the transmittance by wavelength DT (λ) of the two-wavelength region transmission filter that transmits green and near-infrared rays. It was calculated as the sum of calculated values for each 1 nm of the product of .

IR ₀ represents the sensitivity of a pixel to near _- infrared rays when sunlight enters the optical filter from the vertical direction. ), the intensity of sunlight by wavelength I (λ), the sensitivity by wavelength IR (λ) of the near-infrared sensor pixel, and the transmittance by wavelength DT (λ ) and calculated as the sum of calculated values for each 1 nm.

G ₃₀ represents the sensitivity of the green pixel when sunlight is incident on the optical filter at an angle of 30° from the vertical direction. T ₀ (λ), intensity of sunlight by wavelength I (λ), sensitivity of green sensor pixel by wavelength G (λ), and transmittance by wavelength of dual wavelength region transmission filter that transmits green and near-infrared rays. It was calculated as the sum of calculated values for each 1 nm of the product with DT(λ).

IR ₃₀ represents the sensitivity of a pixel to near-infrared rays when sunlight is incident on the optical filter at an angle of 30° from the vertical direction. rate T ₀ (λ), intensity I (λ) of sunlight at different wavelengths, sensitivity IR (λ) of near-infrared sensor pixels at different wavelengths, and wavelengths of dual-wavelength transmission filters that transmit green and near-infrared rays. It was calculated as the sum of the calculated values for each 1 nm of the product with the transmittance DT(λ).

G _N represents the amount of noise in the green pixel at a _wavelength of 800 to 1200 nm. Calculation of the product of I (λ), the sensitivity IR (λ) by wavelength of the near-infrared sensor pixel, and the transmittance DT (λ) by wavelength of the dual wavelength region transmission filter that transmits green and near infrared rays for each 1 nm Calculated as the sum of the values.

As shown in Fig. 3, the intensity of sunlight by wavelength I(λ) is calculated based on the irradiation dose data in Gifu on a certain date and time published by the National Research and Development Agency New Energy and Industrial Technology Development Organization, with a maximum intensity of 1 A value normalized to 0.0 was used. Based on the description of Japanese Patent Application Laid-Open No. 2017-216678, the values shown in FIG. 4 were used for the sensitivity by wavelength of each sensor pixel for green and near-infrared rays.

A dual-wavelength region transmission filter that transmits green and near-infrared rays was applied to one surface of a glass substrate (SCHOTT D263, thickness 0.1 mm) using an ion-assisted vacuum deposition apparatus at a deposition temperature of 120 ° C. Design (0) shown in 2. Dielectric of [silica (SiO ₂ : refractive index 1.46 at 550 nm) layers and titania (TiO ₂ : refractive index 2.48 at 550 nm) layers are alternately laminated] It was obtained by forming a multilayer film. FIG. 5 shows the wavelength-dependent transmittance DT(λ) of the dual-wavelength transmission filter.

From the obtained pixel sensitivity, an optical filter that satisfies both the following requirements (Xa) and (Xb) has a small amount of change in sensitivity even at a high incident angle in green pixels, and a wavelength of 800 to 1200 nm, which has low human visibility. The amount of noise was small, and the green sensitivity was set to 〇. An optical filter that does not satisfy both the requirements (Xa) and (Xb) was evaluated as x for green sensitivity.
Requirement (Xa) _0.8≤G30 / _G0≤1.2
Requirement (Xb) G _N /G ₀ ≤ 0.05

An optical filter that satisfies both the following requirements (Y) and (Z) has high near-infrared sensitivity compared to green pixels, and the change in near-infrared sensitivity is small even at wide viewing angles. bottom. If the requirement (Y) is not satisfied, IR ₀ needs to increase the sensor sensitivity by about 5 times or more compared to G ₀ , and it is expected that the amount of noise will also increase by 5 times or more. Also, when the requirement (Z) is not satisfied, the sensitivity at IR ₃₀ fluctuates by 0.2 times that of IR ₀ . That is, if the requirements (Y) and (Z) are not met, it will be difficult to offset the amount of noise in the IR ₃₀ during sensing under a solar light source. For this reason, optical filters that do not satisfy both the requirements (Y) and (Z) were given the near-infrared sensitivity x.
Requirement (Y) IR ₀ /G ₀ is 0.21 or more Requirement (Z) 0.8≦IR ₃₀ /IR ₀ ≦1.2

<Ghost evaluation>
An imaging device ("KBCR-M04VG" manufactured by Shikino Hitec Co., Ltd.) was constructed by using the obtained optical filter between the lens and the sensor. Under an environment that shields the surrounding stray light, when the image is divided horizontally into 5 with 1 to 5 rows from left to right and 1 to 5 rows from top to bottom when vertically divided into 5, halogen The image was taken so that the light source ("ALA-100" manufactured by Asahi Spectrosco Co., Ltd.) was located at the position of 2 rows and 4 columns. At this time, in the ghost generated in the 1st row-5th column region, the region having a red sensitivity of 80 or more was defined as the ghost region, and the area thereof was evaluated. A ghost performance of 20% or less in the 1st row-5th column region was evaluated as ◯, and a ghost performance of more than 20% was evaluated as x.

[Example 1]
Compound (14) represented by the following formula (14) (absorption maximum wavelength: 887 nm, the above ( Absolute value of difference between Aa) and (Ab): 94 nm, absorbance _λ700 /absorbance _λmax : 0.08, absorbance _λ751 /absorbance _λmax : 0.31) 0.078 parts by mass, and a phenolic antioxidant 0.05 part by mass of ("adekastab AO-20" manufactured by ADEKA) was added, and further methylene chloride was added to dissolve, to obtain a solution with a solid content of 30% by mass. Then, the resulting solution was cast on a smooth glass plate, dried at 50° C. for 8 hours, further dried at 100° C. under reduced pressure for 1 hour, and then peeled off. By stretching this resin film at 180° C., a substrate having a thickness of 0.1 mm, a side length of 60 mm and an in-plane retardation Ro of 5 nm was obtained. The obtained base material had a value of “(950−shortest absorption maximum wavelength)×dye concentration×dye medium thickness” of 1.3, satisfying the condition (c).

Design (1) and design (2) [silica (SiO ₂ : layers with a refractive index of 1.46 at 550 nm and titania (TiO ₂ : layers with a refractive index of 2.48 at 550 nm) are alternately laminated] to obtain an optical filter with a thickness of 0.107 mm. . Design (1) and Design (2) are shown in Table 2. Both surfaces had a reflectance of 10% or less at a wavelength of 700 nm.

Table 1 and FIG. 12 show the results of the requirements (A) to (E) and (Za), which were obtained by measuring the transmittance and reflectance of the obtained optical filter.
As a result of evaluating the sensitivity of this optical filter, the green sensitivity was ◯ and the near-infrared sensitivity was ◯. Also, as a result of conducting a ghost evaluation, the ghost performance was ◯. The obtained optical filter was suitable for a solid-state imaging device sensitive to near-infrared rays.

[Example 2]
Compound (14) in Example 1 was replaced with compound (15) represented by the following formula (15) (maximum absorption wavelength: 898 nm, absolute value of difference between (Aa) and (Ab): 110 nm, absorbance λ ₇₀₀ /absorbance λ _max : 0.05, absorbance λ ₇₅₁ /absorbance λ _max : 0.1) A substrate was obtained in the same manner except that the ratio was changed to 0.05 parts by mass. The obtained base material had a value of “(950−shortest absorption maximum wavelength)×dye concentration×dye medium thickness” of 0.74, which satisfied the condition (c).

On both sides of the obtained base material, using an ion-assisted vacuum vapor deposition apparatus, a near-infrared reflective film consisting of a dielectric multilayer film was designed at a vapor deposition temperature of 120° C. (2) [Silica (SiO ₂ : refractive index 1.0 at 550 nm). 46) layer and titania (TiO ₂ : refractive index 2.48 at 550 nm) layer] to obtain an optical filter having a thickness of 0.107 mm. The design (2) is shown in Table 2.

Table 1 shows the results of the requirements (A) to (E) and (Za), which were obtained by measuring the transmittance and reflectance of the obtained optical filter. Both surfaces had a reflectance of 10% or less at a wavelength of 700 nm.

As a result of evaluating the sensitivity of this optical filter, the green sensitivity was ◯ and the near-infrared sensitivity was ◯. Also, as a result of conducting a ghost evaluation, the ghost performance was ◯. The obtained optical filter was suitable for a solid-state imaging device sensitive to near-infrared rays.

[Example 3]
Compound (14) in Example 1 was replaced with compound (16) represented by the following formula (16) (maximum absorption wavelength: 897 nm, absolute value of difference between (Aa) and (Ab): 134 nm, absorbance λ ₇₀₀ /absorbance λ _max : 0.1, absorbance λ ₇₅₁ /absorbance λ _max : 0.2) A base material was obtained in the same procedure except that it was changed to 0.064 parts by mass. The obtained base material had a value of “(950−shortest absorption maximum wavelength)×dye density×dye medium thickness” of 0.32, which satisfied the condition (c).

On both sides of the obtained base material, using an ion-assisted vacuum vapor deposition apparatus, a near-infrared reflective film consisting of a dielectric multilayer film was designed at a vapor deposition temperature of 120° C. (3) [Silica (SiO ₂ : refractive index 1.0 at 550 nm). 46) layer and titania (TiO ₂ : refractive index 2.48 at 550 nm) layer] to obtain an optical filter having a thickness of 0.104 mm. The design (3) is shown in Table 2.

Table 1 shows the results of the requirements (A) to (E) and (Za), which were obtained by measuring the transmittance and reflectance of the obtained optical filter. Both surfaces had a reflectance of 10% or less at a wavelength of 700 nm.

As a result of evaluating the sensitivity of this optical filter, the green sensitivity was ◯ and the near-infrared sensitivity was ◯. Also, as a result of conducting a ghost evaluation, the ghost performance was ◯. The obtained optical filter was suitable for a solid-state imaging device sensitive to near-infrared rays.

[Example 4]
Compound (14) in Example 1 was replaced with compound (17) represented by the following formula (17) (maximum absorption wavelength: 844 nm, absolute value of difference between (Aa) and (Ab): 84 nm, absorbance λ ₇₀₀ /absorbance λ _max : 0.08, absorbance λ ₇₅₁ /absorbance λ _max : 0.26) A substrate was obtained in the same manner except that the ratio was changed to 0.05 parts by mass. "(950−shortest absorption maximum wavelength)×dye density×dye medium thickness" of the obtained substrate was 0.54, which satisfied the condition (c).

On both sides of the obtained base material, using an ion-assisted vacuum vapor deposition apparatus, a near-infrared reflective film consisting of a dielectric multilayer film was designed at a vapor deposition temperature of 120° C. (3) [Silica (SiO ₂ : refractive index 1.0 at 550 nm). 46) layer and titania (TiO ₂ : refractive index 2.48 at 550 nm) layer] to obtain an optical filter having a thickness of 0.104 mm. The design (3) is shown in Table 2.

Table 1 shows the results of the requirements (A) to (E) and (Za), which were obtained by measuring the transmittance and reflectance of the obtained optical filter. Both surfaces had a reflectance of 10% or less at a wavelength of 700 nm.

As a result of evaluating the sensitivity of this optical filter, the green sensitivity was ◯ and the near-infrared sensitivity was ◯. Also, as a result of conducting a ghost evaluation, the ghost performance was ◯. The obtained optical filter was suitable for a solid-state imaging device sensitive to near-infrared rays.

[Example 5]
A substrate was obtained in the same manner as in Example 1, except that the amount of compound (14) in Example 1 was changed to 0.07 parts by mass. The obtained base material had a value of “(950−shortest absorption maximum wavelength)×dye concentration×dye medium thickness” of 1.1, which satisfied the condition (c).

On both sides of the obtained substrate, using an ion-assisted vacuum deposition apparatus, a near-infrared reflective film consisting of a dielectric multilayer film was formed at a deposition temperature of 120 ° C. (4) and (5) [Silica (SiO ₂ : A 550 nm refractive index 1.46) layer and a titania (TiO ₂ : 550 nm refractive index 2.48) layer are laminated alternately] to obtain an optical filter having a thickness of 0.104 mm. The designs (4) and (5) are shown in Table 2.

Table 1 and FIG. 13 show the results of the requirements (A) to (E) and (Za), which were obtained by measuring the transmittance and reflectance of the obtained optical filter. Both surfaces had a reflectance of 10% or less at a wavelength of 700 nm.

As a result of evaluating the sensitivity of this optical filter, the green sensitivity was ◯ and the near-infrared sensitivity was ◯. Also, as a result of conducting a ghost evaluation, the ghost performance was ◯. The obtained optical filter was suitable for a solid-state imaging device sensitive to near-infrared rays.

[Example 6]
After applying the following resin composition (1) to a glass plate (D263 manufactured by SCHOTT) with a thickness of 0.1 mm by spin coating, it is heated on a hot plate at 80 ° C. for 2 minutes and cured by volatilizing and removing the solvent. formed a layer. At this time, the coating conditions of the spin coater were adjusted so that the film thickness of the cured layer was about 0.8 μm.

Resin composition (1): isocyanuric acid ethylene oxide-modified triacrylate (trade name: Aronix M-315, manufactured by Toagosei Chemical Co., Ltd.) 30 parts, 1,9-nonanediol diacrylate 20 parts, methacrylic acid 20 parts, 30 parts of glycidyl methacrylate, 5 parts of 3-glycidoxypropyltrimethoxysilane, 5 parts of 1-hydroxycyclohexylbenzophenone (trade name: IRGACURE 184, manufactured by Chiba Specialty Chemical Co., Ltd.) and San-Aid SI-110 main agent (Sanshin Kagaku Kogyo Co., Ltd.) was mixed, dissolved in propylene glycol monomethyl ether acetate so that the solid content concentration was 50% by mass, and then filtered through a Millipore filter having a pore size of 0.2 μm.

To 100 parts by mass of norbornene resin "ARTON" (refractive index 1.52, glass transition temperature 160 ° C.) manufactured by JSR Corporation, 0.7 parts by mass of the compound (14) represented by the above formula (14), and a phenolic 0.1 part by mass of an antioxidant ("ADEKA STAB AO-20" manufactured by ADEKA) was added, and further methylene chloride was added to dissolve the solution to obtain a solution (A) having a solid content of 10% by mass. On the cured layer, the solution (A) is applied with a spin coater so that the film thickness after drying is 0.01 mm, heated on a hot plate at 80 ° C. for 30 minutes, and the solvent is removed by volatilization. , to form a resin layer. Next, the substrate was exposed from the glass plate side using a UV conveyor type exposure machine (exposure amount: 500 mJ/cm ² , illuminance: 200 mW) and then baked in an oven at 210°C for 5 minutes to form a base material consisting of a glass substrate and a resin layer. got The obtained base material had a value of “(950−shortest absorption maximum wavelength)×dye concentration×dye medium thickness” of 1.3, satisfying the condition (c).

Using an ion-assisted vacuum vapor deposition apparatus, a near-infrared reflective film consisting of a dielectric multilayer film was formed on both sides of the obtained substrate at a vapor deposition temperature of 120° C. (Design (4) and Design (5) [Silica (SiO ₂ : layers with a refractive index of 1.46 at 550 nm and titania (TiO ₂ : layers with a refractive index of 2.48 at 550 nm) are alternately laminated] to obtain an optical filter with a thickness of 0.104 mm. . The designs (4) and (5) are shown in Table 2.

As a result of evaluating the sensitivity of this optical filter, the green sensitivity was ◯ and the near-infrared sensitivity was ◯. Also, as a result of conducting a ghost evaluation, the ghost performance was ◯. The obtained optical filter was suitable for a solid-state imaging device sensitive to near-infrared rays.

[Comparative Example 1]
100 parts by mass of norbornene resin "ARTON" (refractive index 1.52, glass transition temperature 160 ° C.) manufactured by JSR Corporation, absorbent "NIR829A" manufactured by QCR Solutions (maximum absorption wavelength: 840 nm, above (Aa) Absolute value of difference between (Ab) and (Ab): 90 nm, absorbance λ ₇₀₀ /absorbance λ _max : 0.15, absorbance λ ₇₅₁ /absorbance λ _max : 0.38, which does not satisfy condition (a)). 113 parts by mass, and 0.05 parts by mass of a phenolic antioxidant (ADEKA Co., Ltd., "ADEKA STAB AO-20") are added, and methylene chloride is added to dissolve, and the solid content is 30% by mass. got Then, the resulting solution was cast on a smooth glass plate, dried at 50° C. for 8 hours, further dried at 100° C. under reduced pressure for 1 hour, and then peeled off. By stretching this resin film at 150° C., a substrate having a thickness of 0.1 mm, a side length of 60 mm, and an in-plane retardation Ro of 5 nm was obtained. The obtained base material had a value of “(950−shortest absorption maximum wavelength)×dye concentration×dye medium thickness” of 1.2, satisfying the condition (c).

Using an ion-assisted vacuum vapor deposition apparatus, a near-infrared reflective film consisting of a dielectric multilayer film was formed on both sides of the obtained substrate at a vapor deposition temperature of 120° C. (Design (7) and Design (6) [Silica (SiO ₂ : layers with a refractive index of 1.46 at 550 nm and titania (TiO ₂ : layers with a refractive index of 2.48 at 550 nm) are alternately laminated] to obtain an optical filter with a thickness of 0.106 mm. . Design (6) and Design (7) are shown in Table 2.

Table 1 and FIG. 14 show the measurement results of the transmittance and reflectance of the obtained optical filter and the results of the requirements (A) to (E) and (Za). Both surfaces had a reflectance of 10% or less at a wavelength of 700 nm.

As a result of evaluating the sensitivity of this optical filter, the green sensitivity was ◯, but the near-infrared sensitivity was x. Further, the obtained optical filter was evaluated for ghost, and the ghost performance was ◯. The obtained optical filter had insufficient performance for a solid-state imaging device sensitive to near-infrared rays.

[Comparative Example 2]
1,4-bis(4-amino-α,α -Dimethylbenzyl)benzene 27.66 g (0.08 mol) and 4,4'-bis(4-aminophenoxy)biphenyl 7.38 g (0.02 mol) were mixed with γ-butyrolactone 68.65 g and N,N-dimethyl. Dissolved in 17.16 g of acetamide. The resulting solution was cooled to 5°C using an ice water bath. While maintaining the same temperature, 22.62 g (0.1 mol) of 1,2,4,5-cyclohexanetetracarboxylic dianhydride and 0.50 g (0.005 mol) of triethylamine as an imidization catalyst were added all at once to the solution. bottom. After the addition was completed, the temperature was raised to 180° C., and the mixture was refluxed for 6 hours while distilling off the distillate as needed. After completion of the reaction, the internal temperature was air-cooled to 100 ° C., diluted by adding 143.6 g of N,N-dimethylacetamide, and cooled with stirring to obtain a polyimide resin solution 264 with a solid content concentration of 20% by mass. .16 g was obtained. A portion of this polyimide resin solution was poured into 1 L of methanol to precipitate the polyimide resin. The filtered polyimide resin was washed with methanol and then dried in a vacuum dryer at 100° C. for 24 hours to obtain a white powdery polyimide resin. The glass transition temperature of the resulting polyimide resin was 310°C.

In 100 parts by mass of the obtained polyimide resin, R ¹ in the formula (4) is a hydrogen group, R ^1' is a methyl group, R ² is a hydrogen group, R ³ is an iso-propyl group, R ⁴ is a hydrogen group, R A squarylium-based absorbent in which ⁵ is a hydrogen group and R ⁶ is a methyl group (maximum absorption wavelength is 770 nm, absolute value of difference between (Aa) and (Ab): 82 nm, absorbance λ ₇₀₀ /absorbance λ _max : 0.4, Absorbance λ ₇₅₁ / Absorbance λ _max : 0.9, which does not satisfy the condition (a)) 0.05 parts by mass, and Rdi1 to Rdi8 in the formula (7-1) are tert-butyl groups, Rdi9 to Rdi12 is a hydrogen group, and the anion (X ⁻ ) is a bis(trifluoromethanesulfonyl)imide anion (absorption maximum wavelength: 1094 nm, absolute value of difference between (Aa) and (Ab): 124 nm) 0.0005 Parts by mass were added, and N,N-dimethylacetamide was further added and dissolved to obtain a solution with a solid content of 30% by mass. Next, the resulting solution was cast on a smooth glass plate, dried at 50°C for 8 hours, and further dried at 140°C under reduced pressure for 1 hour, and then peeled off to obtain a substrate having a thickness of 0.05 mm and a side of 60 mm. rice field. The obtained base material had a value of “(950−shortest absorption maximum wavelength)×dye density×dye medium thickness” of 0.45, satisfying the condition (c).

An acrylate UV-curable hard coating agent ("Desolite Z-7524" manufactured by JSR Corporation) containing 2 parts by mass of a polymerization initiator was diluted with methyl ethyl ketone to a solid concentration of 45 on both sides of the obtained base material. The solution adjusted to % by mass was applied using a coater bar (Automatic film applicator manufactured by Yasuda Seiki Seisakusho, Model No. 542-AB). After drying this at 80° C. for 3 minutes, UV curing was performed using a UV conveyor ultraviolet curing device “US2-X040560Hz” manufactured by igraphics in a nitrogen atmosphere, with a metal halide lamp illuminance of 270 mW/cm ² and an integrated light intensity of 150 mJ/cm ² . As a result, a laminate having a thickness of 0.052 mm and having a hard coat layer having a thickness of 1 μm on both sides of the resin film was obtained.

On both surfaces of the obtained laminate, using an ion-assisted vacuum vapor deposition apparatus, a near-infrared reflective film consisting of a dielectric multilayer film was formed at a vapor deposition temperature of 120° C. (8) and (6) [silica (SiO _{2 )} ], respectively. : Layers with a refractive index of 1.46) at 550 nm and titania (TiO ₂ : layers with a refractive index of 2.48 at 550 nm) are laminated alternately] to obtain an optical filter with a thickness of 0.056 mm. . Design (8) and Design (6) are shown in Table 2.

Table 1 shows the measurement results of the transmittance and reflectance of the obtained optical filter and the results of the requirements (A) to (E) and (Za). Both surfaces had a reflectance of 10% or less at a wavelength of 700 nm.

As a result of evaluating the sensitivity of this optical filter, the green sensitivity was ◯ and the near-infrared sensitivity was x. Also, as a result of conducting a ghost evaluation, the ghost performance was ◯. The obtained optical filter had insufficient performance for a solid-state imaging device sensitive to near-infrared rays.

[Comparative Example 3]
35.12 g (0.253 mol) of 2,6-difluorobenzonitrile, 87.60 g (0.250 mol) of 9,9-bis(4-hydroxyphenyl)fluorene, 41.46 g of potassium carbonate ( 0.300 mol), 443 g of N,N-dimethylacetamide (hereinafter also referred to as "DMAc") and 111 g of toluene were added. Subsequently, the four-necked flask was equipped with a thermometer, a stirrer, a three-way cock with a nitrogen inlet tube, a Dean-Stark tube and a cooling tube. Then, after the inside of the flask was replaced with nitrogen, the obtained solution was reacted at 140° C. for 3 hours, and the generated water was removed from the Dean-Stark tube at any time. When the formation of water was no longer observed, the temperature was gradually raised to 160° C., and the reaction was carried out at that temperature for 6 hours. After cooling to room temperature (25° C.), the produced salt was removed with a filter paper, the filtrate was poured into methanol to reprecipitate, and the filtrate (residue) was isolated by filtration. The obtained filter cake was vacuum-dried at 60° C. overnight to obtain a polyether resin. The resulting polyether resin had a refractive index of 1.60 and a glass transition temperature of 285°C.

To 100 parts by mass of the obtained polyether resin, H.I. W. Absorbent "SDB4927" manufactured by SANDS (maximum absorption wavelength: 825 nm, absolute value of difference between (Aa) and (Ab): 98 nm, absorbance λ ₇₀₀ /absorbance λ _max : 0.1, absorbance λ ₇₅₁ /absorbance λ _max : 0.3) 0.05 parts by mass was added, and further methylene chloride was added and dissolved to obtain a solution with a solid content of 15% by mass. The resulting solution was then spin-coated onto a smooth glass plate (SCHOTT D263) with a thickness of 0.1 mm, dried at 50° C. for 8 hours, and then dried under reduced pressure at 150° C. for 1 hour to give a thickness of 0.1 mm. By forming a resin layer of 01 mm, a substrate having a side of 60 mm including the glass plate and the resin layer was obtained. The in-plane retardation Ro of the obtained substrate was 8 nm.

Subsequently, using an ion-assisted vacuum deposition apparatus, design (7) and design (6) [silica (SiO ₂ : a layer with a refractive index of 1.46 at 550 nm and a layer of titania (TiO ₂ : with a refractive index of 2.48 at 550 nm)] to obtain an optical filter with a thickness of 0.116 mm. rice field. Design (7) and Design (6) are shown in Table 2.

Table 1 shows the measurement results of the transmittance and reflectance of the obtained optical filter and the results of the requirements (A) to (E) and (Za). Both surfaces had a reflectance of 10% or less at a wavelength of 700 nm.

As a result of evaluating the sensitivity of this optical filter, the green sensitivity was ◯ and the near-infrared sensitivity was x. Also, as a result of conducting a ghost evaluation, the ghost performance was ◯. The obtained optical filter had insufficient performance for a solid-state imaging device sensitive to near-infrared rays.

[Comparative Example 4]
100 parts by mass of norbornene resin "ARTON" (refractive index 1.52, glass transition temperature 160 ° C.) manufactured by JSR Corporation, absorbent "S-2084" manufactured by FewChemicals (maximum absorption wavelength: 667 nm, above (Aa ) and (Ab): 26 nm, absorbance λ ₇₀₀ /absorbance λ _max : 0.06, absorbance λ ₇₅₁ /absorbance λ _max : 0.0, which does not satisfy the condition (b)) 0. 0087 parts by mass was added, and further methylene chloride was added to dissolve, to obtain a solution with a solid content of 30% by mass. Next, the obtained solution was cast on a smooth glass plate, dried at 50°C for 8 hours, and further dried at 140°C under reduced pressure for 3 hours, and then peeled off to obtain a substrate having a thickness of 0.1 mm and a side of 60 mm. rice field. "(950−shortest absorption maximum wavelength)×dye concentration×dye medium thickness" of the obtained substrate was 1.26, which satisfied the condition (c).

Subsequently, on both sides of the obtained substrate, using an ion-assisted vacuum deposition apparatus, a near-infrared reflective film composed of a dielectric multilayer film was formed at a deposition temperature of 120 ° C. (Design (1) and Design (9) [Silica (SiO ₂ : 550 nm refractive index 1.46) layers and titania (TiO ₂ : 550 nm refractive index 2.48) layers are alternately laminated] and has a thickness of 0.106 mm. got Design (1) and Design (9) are shown in Table 2.

Table 1 and FIG. 15 show the measurement results of the transmittance and reflectance of the obtained optical filter and the results of the requirements (A) to (E) and (Za). In addition, the reflectance at a wavelength of 700 nm exceeded 10%.

As a result of evaluating the sensitivity of this optical filter, the green sensitivity was ◯ and the near-infrared sensitivity was x. As a result of the ghost evaluation, the ghost performance was x. The obtained optical filter had insufficient performance for a solid-state imaging device sensitive to near-infrared rays.

[Comparative Example 5]
Norbornene resin "ARTON" manufactured by JSR Corporation (refractive index 1.52, glass transition temperature 160 ° C.) 100 parts by mass, absorber "SMP-54" manufactured by Hayashibara Co., Ltd. (maximum absorption wavelength: 721 nm, The absolute value of the difference between (Aa) and (Ab): 65 nm, absorbance λ ₇₀₀ /absorbance λ _max : 0.53, absorbance λ ₇₅₁ /absorbance λ _max : 0.08, and conditions (a) and (b) not satisfied) was added, and further methylene chloride was added and dissolved to obtain a solution with a solid content of 30% on a mass basis. Next, the obtained solution was cast on a smooth glass plate, dried at 50°C for 3 hours, and further dried at 100°C under reduced pressure for 3 hours, and then peeled off to obtain a substrate having a thickness of 0.1 mm and a side of 60 mm. rice field. The obtained base material had a value of “(950−shortest absorption maximum wavelength)×dye concentration×dye medium thickness” of 1.15, satisfying the condition (c).

Using an ion-assisted vacuum vapor deposition apparatus, a near-infrared reflective film consisting of a dielectric multilayer film was formed on both sides of the obtained substrate at a vapor deposition temperature of 120° C. (2) and (10) [silica (SiO ₂ : refractive index 1.45 at 550 nm, thickness 37-194 nm) and titania (TiO ₂ : refractive index 2.45 at 550 nm, thickness 11-108 nm) layer]. , an optical filter with a thickness of 0.106 mm was obtained.

Table 1 shows the measurement results of the transmittance and reflectance of the obtained optical filter and the results of the requirements (A) to (E) and (Za). In addition, the reflectance at a wavelength of 700 nm exceeded 10%.

As a result of evaluating the sensitivity of this optical filter, the green sensitivity was ◯ and the near-infrared sensitivity was x. As a result of the ghost evaluation, the ghost performance was x. The obtained optical filter had insufficient performance for a solid-state imaging device sensitive to near-infrared rays.

[Comparative Example 6]
To 100 parts by mass of norbornene resin "ARTON" (refractive index 1.52, glass transition temperature 160° C.) manufactured by JSR Corporation, 0.05 parts by mass of the compound (15) and the compound represented by the following formula (18) ( 18) (Maximum absorption wavelength: 1064 nm, absolute value of difference between (Aa) and (Ab): 139 nm, absorbance λ ₇₀₀ /absorbance λ _max : 0.05, absorbance λ ₇₅₁ /absorbance λ _max : 0.1) 0 0.04 part by mass was added, and methylene chloride was further added and dissolved to obtain a solution with a solid content of 30% by mass. Next, the obtained solution was cast on a smooth glass plate, dried at 50°C for 3 hours, and further dried at 100°C under reduced pressure for 3 hours, and peeled off to obtain an optical filter having a thickness of 0.1 mm and a side of 60 mm. rice field.

Table 1 shows the measurement results of the transmittance and reflectance of the obtained optical filter and the results of the requirements (A) to (E) and (Za). Both surfaces had a reflectance of 10% or less at a wavelength of 700 nm.

As a result of evaluating the sensitivity of this optical filter, the green sensitivity was x and the near infrared sensitivity was ◯. In addition, as a result of the ghost evaluation, the ghost performance was ◯. The obtained optical filter had insufficient performance for a solid-state imaging device sensitive to near-infrared rays.

[Comparative Example 7]
On both sides of a glass substrate (SCHOTT D263, thickness 0.1 mm), using an ion-assisted vacuum deposition apparatus, a dielectric multilayer film was deposited at a deposition temperature of 120 ° C. Design (11) and Design (11) shown in Table 2, respectively. 12) The optical filter is formed by alternately stacking silica (SiO ₂ : refractive index at 550 nm: 1.46) layers and titania (TiO ₂ : refractive index at 550 nm: 2.48) layers. Obtained. Table 1 and FIG. 16 show the measurement results of the transmittance and reflectance of the obtained optical filter and the results of the requirements (A) to (E) and (Za). Both surfaces had a reflectance of 10% or less at a wavelength of 700 nm.

As a result of evaluating the sensitivity of this optical filter, the green sensitivity was ◯ and the near-infrared sensitivity was x. As a result of the ghost evaluation, the ghost performance was x . The obtained optical filter had insufficient performance for a solid-state imaging device sensitive to near-infrared rays.

INDUSTRIAL APPLICABILITY The optical filter of the present invention is useful for correcting the sensitivity of solid-state imaging devices having sensitivity to near-infrared rays with a wavelength of 700 to 750 nm, such as CCDs and CMOSs of camera modules. In particular, digital still cameras, mobile phone cameras, smartphone cameras, digital video cameras, PC cameras, surveillance cameras, automobile cameras, televisions, car navigation systems, personal digital assistants, personal computers, video game machines, portable game machines, fingerprint authentication systems , iris authentication system, face authentication system, distance measurement sensor, distance measurement camera, digital music player, vegetation sensing system, cerebral blood flow sensing system, etc.

1: An example of the optical filter according to the present invention 10: Substrate 11: Support 12: Resin layer 13: Other functional film 21: Near-infrared reflective film 1
22: Near-infrared reflective film 2
201: Detector 301: Lens 302: Sensor 303: Bandpass filter 304: Normal detector 305: Ghost 306: Ghost 400: Camera module 401: Light source 402: Ghost

Claims (9)

An optical filter characterized by satisfying the following requirements (A) to (D) , (Z1) and (Z2) :
(A) In the wavelength range of 430 to 580 nm, the average transmittance measured in the direction perpendicular to the surface of the optical filter is 75% or more;
(B) in the wavelength range of 800 to 1000 nm, the average transmittance measured in the direction perpendicular to the surface of the optical filter is 10% or less;
(C) the average transmittance measured in the direction perpendicular to the surface of the optical filter is greater than 46% in the wavelength range of 700 to 750 nm;
(D) In the wavelength range of 560 to 800 nm, the shortest wavelength value (Ya) at which the transmittance is 50% when measured from the direction perpendicular to the surface of the optical filter, and the value perpendicular to the surface of the optical filter the absolute value of the difference from the value of the shortest wavelength (Yb) at which the transmission is 50% when measured from an angle of 30° from the direction is less than 15 nm ;
(Z1) At a wavelength of 700 nm, the reflectance when measured at an angle of 5° from the direction perpendicular to the surface of the optical filter is 10% or less when incident from either surface of the optical filter;
(Z2) In the wavelength range of 600 nm or more, the value (Za) of the wavelength of 600 nm or more at which the reflectance is 50% when measured at an angle of 5° from the direction perpendicular to the surface of the optical filter is It is 730 nm or more when incident from either surface . The optical filter according to claim 1, wherein the optical filter further satisfies the following requirement (E):
(E) The wavelength value (Ya) is 730 nm or more and 800 nm or less. 3. The optical filter according to claim 1, comprising a substrate containing a near-infrared absorbing agent and a near-infrared reflective film. The near-infrared absorbent has an absorption maximum wavelength in the wavelength range of 751 to 950 nm, and
When the near-infrared absorbing agent is contained in an amount such that the transmittance of the base material at the maximum absorption wavelength is 10%, the transmittance of the base material is 70% in the range of a wavelength of 430 nm or more and the maximum absorption wavelength or less. The absolute value of the difference between the longest wavelength (Aa) and the shortest wavelength (Ab) at which the transmittance of the substrate is 30% in the wavelength range of 580 nm or more is less than 150 nm. Item 4. The optical filter according to item 3. 5. The substrate according to claim 3 or 4, wherein the base material has a resin layer, and the resin layer contains at least one selected from the group consisting of norbornene-based resins, polyimide-based resins and polyether resins. Optical filter as described. 6. The optical filter according to claim 5, wherein the near-infrared absorbing agent is contained in a range of 0.01 to 60.0% by mass with respect to the resin layer. The optical filter according to any one of claims 3 to 6, wherein the near-infrared reflective film is a dielectric multilayer film. A solid-state imaging device comprising the optical filter according to any one of claims 1 to 7 . A camera module comprising the optical filter according to any one of claims 1 to 7 .

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