JP7326993B2 - OPTICAL FILTER, MANUFACTURING METHOD THEREOF AND USE THEREOF - Google Patents

Description

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

CCD and CMOS image sensors, which are solid-state image sensors, are used in conventional solid-state image sensors such as video cameras, digital still cameras, and mobile phones with camera functions. Silicon photodiodes are used that are sensitive to near-infrared rays, which are invisible to the human eye. For these solid-state image sensors, it is necessary to perform luminosity correction so that colors look natural when viewed by the human eye. filter) is often used.

As such optical filters, filters manufactured by various methods have been conventionally used. For example, an absorptive glass type infrared cut filter in which copper oxide is dispersed in phosphate glass (for example, Patent Document 1), or a resin type infrared cut filter having a layer in which a dye having absorption in the near-infrared band is dispersed (for example, Patent Document 2), a glass substrate-coated infrared cut filter having a dielectric substrate (glass substrate), an infrared reflective layer, and an infrared absorbing layer (for example, Patent Document 3); A resin-type near-infrared cut filter (Patent Document 4) that contains a dye that has an absorption maximum in the band and uses a dielectric multilayer film that has near-infrared reflection performance on both sides of the substrate (Patent Document 4). Various types are known, such as a glass substrate-coated infrared cut filter (Patent Document 5) provided with a resin layer containing a dye having

Also, a bandpass filter is used for an imaging device having a distance measuring sensor that uses near-infrared rays. As the band-pass filter, a band-pass filter having a transmission band in a part of the visible range and the near-infrared band (Patent Document 6) is known.

Furthermore, a near-infrared cut filter that reduces the average transmittance of wavelengths 770 to 1800 nm to 15% or less (for example, Patent Document 7) is known in order to suppress the effects on living tissue.

WO2011/071157 Japanese Patent Application Laid-Open No. 2008-303130 JP 2014-052482 A JP 2011-100084 A JP 2014-063144 A WO2011/033984 JP 2015-161731 A WO2016/171219

H. Written by Angus Macleod, translated by Tokai Kogaku Co., Ltd., etc., "MACLEOD: Principles of Optical Thin Films" 4th edition, published by Adcom Media Co., Ltd.

In recent years, solid-state imaging devices have become more sensitive and thinner, and the optical filter used for visibility correction requires high visible light even if the incident angle of light entering there is large (e.g., 45°). Transmittance and low near-infrared transmittance have come to be demanded.

In the above-mentioned conventional absorptive glass type infrared cut filter in which copper oxide is dispersed in phosphate glass for image pickup devices, and resin type infrared cut filter having a layer in which a dye that absorbs in the near infrared band is dispersed, low near-field In order to achieve infrared transmittance, it is necessary to add a large amount of copper oxide or a dye that absorbs in the near-infrared band. It was difficult to achieve both high transmittance. As another means of achieving a low near-infrared transmittance in the conventional filter, a method of increasing the film thickness of the optical filter in order to increase the absorption intensity in the near-infrared band can be considered. It was difficult to achieve compatibility with
Further, when the filter described in Patent Document 7 is used in a solid-state imaging device, the transmittance at wavelengths of 1000 to 1200 nm is high, and the shielding performance for visibility correction is insufficient.

In the above-mentioned conventional optical filter having a dielectric multilayer film for an image pickup device, a laminate of dielectric layers with an optical film thickness that is about a quarter of the wavelength of the near-infrared reflection band is used. Although it is easy to achieve light transmittance and low near-infrared transmittance, it was found that when the incident angle becomes high (when the incident angle is high), the reflection band tends to shift to the short wavelength side. Therefore, it has been difficult to keep the transmittance of light with a wavelength of 1100 nm, to which the imaging element is sensitive, low.

By the way, in such a laminated body of dielectric layers having an optical film thickness of about a quarter of the wavelength of the reflection band, the reflection band can be shifted to the long wavelength side by increasing the film thickness of each laminated layer. is conventionally known to be possible. Therefore, by increasing the film thickness of each laminated layer, it is possible to keep the transmittance of light with a wavelength of 1100 nm low even if the reflection band shifts to the short wavelength side when the incident angle is high. However, it is known that when the film thickness of each laminated layer is increased in this way, the obtained optical filter has the characteristic of reflecting light having a wavelength in the vicinity of one-third of the reflection band. (Fig. 3A of International Publication No. 2016/171219, H. Angus Macleod, translated by Tokai Kogaku Co., Ltd., "MACLEOD: Principles of Optical Thin Films", 4th edition, published by Adcom Media Co., Ltd., etc.).
For example, a filter having a dielectric multilayer film that cuts light with a wavelength of about 1100 nm at high-angle incidence cuts light with a wavelength of about 1260 nm for light that is incident from the vertical direction of the filter surface (when incident at 0°). tend to cut. In this case, light in the blue visible light band with a wavelength of around 420 to 450 nm, which corresponds to a wavelength around one-third of the reflection band around the wavelength of 1260 nm, is also reflected, and the transmittance of the blue visible light band is reduced. , there is a problem that visibility correction capability is lowered.

Conventionally thin, at 0° incidence, visible light transmittance is high, visible light reflectance is low, and visibility correction characteristics are excellent. However, an optical filter having a low transmittance for light with a wavelength of 1100 nm has not been obtained.

The present invention improves the drawbacks of conventional optical filters such as near-infrared cut filters. Provided is an optical filter which is excellent in shielding properties for light with a wavelength of 1100 nm even when incident at a high angle.

As a result of intensive studies aimed at solving the above problems, the inventors of the present invention have found that the above problems can be solved by the following configuration example, and have completed the present invention.
A configuration example of the present invention is as follows.
In the present invention, descriptions such as "A to B" representing a numerical range are synonymous with "A or more and B or less", and A and B are included in the numerical range. Further, in the present invention, the wavelengths A to B nm represent the characteristics at a wavelength resolution of 1 nm in the wavelength region from the wavelength A nm to the wavelength B nm.

[1] A method for manufacturing an optical filter, which includes the step of forming a dielectric multilayer film on a substrate and satisfies the following requirements (C), (E), (F) and (G) in the wavelength range of 300 to 1600 nm.
(C) has the longest wavelength value λ _traUV5 at a wavelength of 380 nm or more and less than 430 nm, at which the transmittance of light incident from the direction perpendicular to the surface direction of the optical filter is 5%; The average transmittance of light incident from the direction perpendicular to the surface direction of the optical filter is 5% or less. % (G) _{λ traIR5 /} λ _traUV5 ≧3.10

[2] The manufacturing method according to [1], wherein the optical filter further satisfies the following requirements (a) to (c).
(a) In addition to the three layers adjacent to the substrate and the outermost layer, at least two continuous layers a having a physical thickness of 60 nm or less have a continuous layer a (b) Adjacent to the continuous layer a, a physical film (c) A continuous layer c in which at least two layers having a physical thickness of 60 nm or less are adjacent to the layer b on the opposite side of the continuous layer a.

[3] The manufacturing method according to [1] or [2], wherein the optical filter further satisfies the following requirement (d).
(d) a high refractive index layer having a refractive index of 2.0 or more for light at a wavelength of 550 nm and an optical thickness of 160 to 320 nm at a wavelength of 550 nm; It has 4 or more layers alternately with layers having a lower refractive index than the refractive index layers

[4] An optical filter having a substrate and a dielectric multilayer film and satisfying the following requirements (C), (E), (F) and (G) in the wavelength range of 300 to 1600 nm.
(C) has the longest wavelength value λ _traUV5 at a wavelength of 380 nm or more and less than 430 nm, at which the transmittance of light incident from the direction perpendicular to the surface direction of the optical filter is 5%; The average transmittance of light incident from the direction perpendicular to the surface direction of the optical filter is 5% or less. % (G) _{λ traIR5 /} λ _traUV5 ≧3.10

[5] The optical filter of [4], which further satisfies the following requirements (A), (B), (D) and (H) in the wavelength range of 300 to 1600 nm.
(A) At a wavelength of 300 to 380 nm, the average transmittance of light incident from the direction perpendicular to the surface direction of the optical filter is 5% or less. (B) At a wavelength of 380 to 430 nm, the direction perpendicular to the surface direction of the optical filter. (D) The average transmittance of light incident from the direction perpendicular to the surface direction of the optical filter at a wavelength of 440 to 580 _nm is 60% or more (H ) At a wavelength of 720 to 1000 nm, the average transmittance of light incident from the direction perpendicular to the surface direction of the optical filter is 1% or less.

[6] The optical filter according to [4], which further satisfies the following requirements (A), (B), (D), (J) and (K) in the wavelength range of 300 to 1600 nm.
(A) At a wavelength of 300 to 380 nm, the average transmittance of light incident from the direction perpendicular to the surface direction of the optical filter is 5% or less. (B) At a wavelength of 380 to 430 nm, the direction perpendicular to the surface direction of the optical filter. (D) The average transmittance of light incident from the direction perpendicular to the surface direction of the optical filter at a wavelength of 440 to 580 _nm is 60% or more (J ) At a wavelength of 720 to 1000 nm, the average transmittance of light incident perpendicular to the surface direction of the optical filter is 30% or less. have a continuous wavelength of 5 nm or more at which the transmittance of the light is 50% or more

[7] The optical filter according to any one of [4] to [6], which further satisfies the following requirements (O) to (Q) in the wavelength range of 300 to 1600 nm.
(O) At wavelengths of 370 nm or more and less than 430 nm, it has the longest wavelength value λ _traUV1 at which the transmittance of light incident in the direction perpendicular to the surface direction of the optical filter is 1%. (Q) λ traIR1 /λ _traUV1 ≥ 3.10 (Q) λ _traIR1 /λ _traUV1 ≥ 3.10

[8] The optical filter according to any one of [4] to [7], which further satisfies the following requirements (R) to (U) in the wavelength range of 300 to 1600 nm.
(R) having a wavelength of 370 to 430 nm and a wavelength λ _refUV50 at which the reflectance of unpolarized light incident at an angle of 5° from the vertical direction of at least one surface of the optical filter is 50% (S) wavelength of 1150 to 1600 nm (T) λ _refIR90 /λ _traUV5 ≥ 3, the shortest wavelength value λ _refIR90 at which the reflectance of unpolarized light incident at an angle of 5° from the vertical direction of at least one surface of the optical filter is 90%. .10
(U) At a wavelength of 1000 to 1200 nm, the average reflectance of an unpolarized light beam incident at an angle of 5° from the vertical direction of at least one surface of the optical filter is 90% or more.

[9] The optical filter according to any one of [4] to [8], which further satisfies the following requirements (V) and (W) in the wavelength range of 300 to 1600 nm.
(V) It has the shortest wavelength value λ _refIR95 at which the reflectance of unpolarized light incident at an angle of 5° from the vertical direction of at least one surface of the optical filter is 95% in the wavelength range of 1150 to 1600 nm. _λrefIR95 / _λtraUV5 ≧3.10

[10] The optical filter according to any one of [4] to [9], further satisfying the following requirements (a) to (c).
(a) In addition to the three layers adjacent to the substrate and the outermost layer, at least two continuous layers a having a physical thickness of 60 nm or less have a continuous layer a (b) Adjacent to the continuous layer a, a physical film (c) A continuous layer c in which at least two layers having a physical thickness of 60 nm or less are adjacent to the layer b on the opposite side of the continuous layer a.

[11] The optical filter according to any one of [4] to [10], further satisfying the following requirement (d).
(d) a high refractive index layer having a refractive index of 2.0 or more for light at a wavelength of 550 nm and an optical thickness of 160 to 320 nm at a wavelength of 550 nm; It has 4 or more layers alternately with layers having a lower refractive index than the refractive index layers

[12] The optical filter according to any one of [4] to [11], wherein the substrate satisfies the following requirement (Y) in the wavelength range of 300 to 1600 nm.
(Y) has an absorption maximum wavelength λ (DA_Tmin) at a wavelength of 685 to 780 nm

[13] The optical filter according to any one of [4] to [12], wherein the substrate satisfies the following requirement (Z) in the wavelength range of 300 to 1600 nm.
(Z) having a stopband of 30 nm or more, with a wavelength of 680 to 800 nm and a transmittance of 5% or less for light incident perpendicularly to the surface direction of the substrate;

[14] A solid-state imaging device comprising the optical filter according to any one of [4] to [13].
[15] A camera module comprising the optical filter according to any one of [4] to [13].

According to the present invention, it is thin (eg, 0.21 mm or less), has high visible light transmittance and low visible light reflectance at 0° incidence, is excellent in visibility correction, and has a wavelength of 1100 nm even at high angle incidence. It is possible to provide an optical filter having excellent light shielding properties, and an apparatus, a camera module, a sensor module, etc. using the optical filter.

FIG. 1 is a schematic diagram showing a configuration example of the optical filter of the present invention. FIG. 2 is a schematic diagram showing a method for measuring the transmittance of the optical filter of the present invention. FIG. 3 is a schematic diagram showing a method for measuring the reflectance of the optical filter of the present invention. FIG. 4 is a schematic diagram showing an example of a solid-state imaging device and a module equipped with the optical filter of the present invention. FIG. 5 is a schematic diagram showing an example of a lensless solid-state imaging device and a module equipped with the optical filter of the present invention. FIG. 6 shows the transmittance (0°T) of the optical filter obtained in Example 1 for light incident from the direction perpendicular to the surface direction (the same shall apply hereinafter. ], the transmittance (45°T) of light incident at an angle of 45° from the direction perpendicular to the plane direction [the same shall apply hereinafter. ] and the reflectance (5°R) of a non-polarized light incident on the plane Y at an angle of 5° from the direction perpendicular to the surface Y [the same shall apply hereinafter. ] and FIG. (B) is an enlarged view of the wavelength 1000 to 1600 nm portion of (A). 7 is a diagram showing the transmittance (0°T and 45°T) and 5°R in plane Y of the optical filter obtained in Example 2. FIG. (B) is an enlarged view of the wavelength 1000 to 1600 nm portion of (A). 8 is a diagram showing the transmittance (0°T and 45°T) and 5°R in plane Y of the optical filter obtained in Example 3. FIG. (B) is an enlarged view of the wavelength 1000 to 1600 nm portion of (A). 9 is a diagram showing the transmittance (0°T and 45°T) and 5°R in plane Y of the optical filter obtained in Example 4. FIG. (B) is an enlarged view of the wavelength 1000 to 1600 nm portion of (A). 10 is a diagram showing the transmittance (0°T and 45°T) and 5°R in plane Y of the optical filter obtained in Example 5. FIG. (B) is an enlarged view of the wavelength 1000 to 1600 nm portion of (A). 11 is a diagram showing the transmittance (0°T and 45°T) and 5°R in plane Y of the optical filter obtained in Example 6. FIG. (B) is an enlarged view of the wavelength 1000 to 1600 nm portion of (A). 12 is a diagram showing the transmittance (0°T and 45°T) and 5°R in plane Y of the optical filter obtained in Example 7. FIG. (B) is an enlarged view of the wavelength 1000 to 1600 nm portion of (A). 13 is a diagram showing the transmittance (0°T and 45°T) and 5°R in plane Y of the optical filter obtained in Example 8. FIG. (B) is an enlarged view of the wavelength 1000 to 1600 nm portion of (A). 14 is a diagram showing the transmittance (0°T and 45°T) and 5°R in plane Y of the optical filter obtained in Example 9. FIG. (B) is an enlarged view of the wavelength 1000 to 1600 nm portion of (A). 15 is a diagram showing the transmittance (0°T and 45°T) and 5°R in plane Y of the optical filter obtained in Example 10. FIG. (B) is an enlarged view of the wavelength 1000 to 1600 nm portion of (A). 16 is a diagram showing the transmittance (0°T and 45°T) and 5°R in plane Y of the optical filter obtained in Example 11. FIG. (B) is an enlarged view of the wavelength 1000 to 1600 nm portion of (A). 17 is a diagram showing the transmittance (0°T and 45°T) and 5°R in plane Y of the optical filter obtained in Example 12. FIG. (B) is an enlarged view of the wavelength 1000 to 1600 nm portion of (A). 18 is a diagram showing the transmittance (0°T and 45°T) and 5°R on the plane Y of the optical filter obtained in Comparative Example 1. FIG. (B) is an enlarged view of the wavelength 1000 to 1600 nm portion of (A). 19 is a diagram showing the transmittance (0°T and 45°T) and 5°R on the plane Y of the optical filter obtained in Comparative Example 2. FIG. (B) is an enlarged view of the wavelength 1000 to 1600 nm portion of (A). 20 is a diagram showing the transmittance (0°T and 45°T) and 5°R in plane Y of the optical filter obtained in Comparative Example 3. FIG. (B) is an enlarged view of the wavelength 1000 to 1600 nm portion of (A). 21 is a diagram showing the transmittance (0°T and 45°T) and 5°R in plane Y of the optical filter obtained in Comparative Example 4. FIG. (B) is an enlarged view of the wavelength 1000 to 1600 nm portion of (A).

<<Method for Manufacturing Optical Filter and Optical Filter>>
A method for manufacturing an optical filter according to the present invention (hereinafter also referred to as "this method") includes a step of forming a dielectric multilayer film on a substrate, and in a wavelength range of 300 to 1600 nm, the following requirements (C), ( A method for manufacturing an optical filter satisfying E), (F) and (G), wherein the optical filter according to the present invention (hereinafter also referred to as "this filter") has a substrate and a dielectric multilayer film, and , an optical filter that satisfies the following requirements (C), (E), (F) and (G) in the wavelength range of 300 to 1600 nm.
(C) has the longest wavelength value λ _traUV5 at a wavelength of 380 nm or more and less than 430 nm, at which the transmittance of light incident from the direction perpendicular to the surface direction of the optical filter is 5%; The average transmittance of light incident from the direction perpendicular to the surface direction of the optical filter is 5% or less. % (G) _{λ traIR5 /} λ _traUV5 ≧3.10

This filter has a substrate and a dielectric multilayer film, and is a filter (I) that satisfies the following requirements (A) to (H) in the wavelength range of 300 to 1600 nm, or the following requirements (A) to ( Filter (II) satisfying G), (J) and (K) is preferred.
When using this filter as a near-infrared cut filter, filter (I) is preferable, and when using it for a near-infrared sensor, filter (II) is preferable.

(A) At a wavelength of 300 to 380 nm, the average transmittance of light incident from the direction perpendicular to the surface direction of the optical filter is 5% or less Reflection of about one-third of the wavelength of the near-infrared reflection band by the dielectric multilayer film , a narrow transmission band of about 1 to 20 nm tends to be formed at a wavelength of 300 to 380 nm. Here, by appropriately designing the dielectric multilayer film, suppressing the formation of a narrow transmission band at a wavelength of 300 to 380 nm, and satisfying the requirement (A), near-ultraviolet rays that are difficult or invisible to the human eye can be emitted. When this filter is used for a solid-state imaging device, a sensor application, a camera module, etc., it is superior in luminosity correction of the imaging device, and a good image close to the image seen by the human eye can be easily obtained. can.
The average transmittance is more preferably 2% or less, still more preferably 1% or less, and particularly preferably 0.5% or less. The lower the average transmittance, the better. For example, the lower limit is 0%.

(B) Having a wavelength λ _UV50 at which the transmittance of light incident from the direction perpendicular to the surface direction of the optical filter is 50% at a wavelength of 380 to 430 nm By satisfying the requirement (B), it is visible to the human eye It is possible to achieve both the shielding of near-ultraviolet rays that are difficult to see or invisible, and the high transmittance of the blue band and the visible light band in the vicinity thereof. The luminosity correction of the element is excellent, and a good image close to the image seen by the human eye can be easily obtained.
The λ _UV50 is more preferably between 390 and 430 nm, particularly preferably between 395 and 425 nm.

(C) Having the longest wavelength value λ _traUV5 at which the transmittance of light incident from the direction perpendicular to the surface direction of the optical filter is 5% at a wavelength of 380 nm or more and less than 430 nm By satisfying the requirement (C), It can sufficiently shield near-ultraviolet rays that are invisible or invisible to the human eye, and when this filter is used for solid-state imaging devices, sensor applications, camera modules, etc., images from ultraviolet rays that are invisible or invisible to the human eye can be obtained. color change can be suppressed.
The λ _traUV5 is more preferably 380 to 428 nm, still more preferably 385 to 428 nm, particularly preferably 390 to 426 nm.

(D) At a wavelength of 440 to 580 nm, the average transmittance of light incident from the direction perpendicular to the surface direction of the optical filter is 60% or more. By satisfying the requirement (D), it is possible to maintain a high visible light transmittance. When a filter that satisfies the requirement (D) is used in a solid-state imaging device, a sensor application, a camera module, or the like, it is superior in luminosity correction of the imaging element, and a good image close to the image seen by the human eye can be easily obtained. be able to.
The average transmittance is more preferably 65% or higher, still more preferably 70% or higher, even more preferably 75% or higher, particularly preferably 80% or higher, and most preferably 84% or higher. The higher the average transmittance, the better. For example, the upper limit is 100%.

(E) At a wavelength of 1000 to 1200 nm, the average transmittance of light incident from the direction perpendicular to the surface direction of the optical filter is 5% or less. , It can be suitably used as a bandpass filter that cuts near-infrared rays in this wavelength range, can block near-infrared rays invisible to the human eye, and has low transmission of near-infrared rays with a wavelength of 1100 nm at high angle incidence rate can be maintained. When a filter that satisfies requirement (E) is used in a solid-state imaging device, sensor application, camera module, etc., it is superior in luminosity correction of imaging devices such as silicon photodiodes and black silicon photodiodes, Even when capturing an image of a light source such as a heater, an incandescent light bulb, or a near-infrared sensor that emits a large amount of near-infrared rays that are invisible to the human eye, it is possible to obtain a good image that is close to what the human eye can see.
The average transmittance is more preferably 3% or less, still more preferably 2% or less, and particularly preferably 1.5% or less. The lower the average transmittance, the better. For example, the lower limit is 0%.

(F) having a shortest wavelength value λ _traIR5 at which the transmittance of light incident in the direction perpendicular to the surface direction of the optical filter is 5% at a wavelength _of 1150 to 1600 nm. It is preferably between 1600 nm, more preferably between 1280 and 1500 nm, even more preferably between 1300 and 1500 nm, particularly preferably between 1330 and 1500 nm and most preferably between 1360 and 1500 nm.
When λ _traIR5 is within the above range, even when the near-infrared reflection band due to the dielectric multilayer film shifts to the short wavelength side when the incident angle of the light incident on the optical filter becomes high, the wavelength is 1100 nm. can keep the transmittance of light low.

(G) _λtraIR5 / _λtraUV5 ≥ 3.10
By satisfying the requirements (F) and (G), a conventional optical filter using a laminate (dielectric multilayer film) of layers with an optical thickness of about 1/4 of the near-infrared reflection band could not be obtained. It is possible to achieve both high transmittance in the blue band of light incident from the direction perpendicular to the surface direction of the optical filter and the visible light band in the vicinity thereof, and low transmittance in near infrared rays with a wavelength of 1100 nm at high angle incidence. can. For this reason, when a filter that satisfies the requirement (G) is used in a thin solid-state imaging device with a wide angle of view, a sensor, a camera module, etc., it is excellent in luminosity correction of the imaging element such as blue, and is invisible to the human eye. Even when capturing an image of a light source that emits a large amount of near-infrared rays that are not visible to the human eye, it is possible to obtain a good image that is close to what the human eye can see.

A laminate (dielectric multilayer film) of layers having an optical thickness of about 1/4 of the near-infrared reflection band tends to reflect a wavelength of about 1/3 of the reflection band. For this reason, a stack of layers having an optical thickness about 1/4 of the near-infrared reflection band tends to satisfy λ _traIR5 /λ _traUV5 ≤3.0. In addition, about 3.0<λ _traIR5 /λ _traUV5 <3.1, due to the property that the refractive index differs for each wavelength (wavelength dispersion), a laminate of layers with an optical thickness of about 1/4 of the near-infrared reflection band But it can be achieved.

The λ _traIR5 /λ _traUV5 is more preferably 3.15 or more, still more preferably 3.19 or more, still more preferably 3.24 or more, particularly preferably 3.29 or more, most preferably 3.34 or more, It is preferably 4.10 or less, more preferably 3.8 or less.

In a conventional optical filter having a laminate (dielectric multilayer film) of layers with an optical thickness of about 1/4 of the near-infrared reflection band, light in a wavelength range of about 1/3 of the reflection band is reflected. There is a tendency. For this reason, an optical filter having such a conventional dielectric multilayer film and having a high transmittance in the blue band that satisfies the requirement (C) is about three times the wavelength of the requirement (C). Transmittance after 1100 nm tends to be high. Alternatively, an optical filter having a conventional dielectric multilayer film and having a low transmittance at a wavelength of 1100 nm or later at high-angle incidence that satisfies the requirement (F) has λ _traUV5 at a wavelength longer than 430 nm. , it becomes difficult to satisfy the requirement (C), and the transmittance of the blue band and the visible light band in the vicinity thereof tends to be low.
Since this filter satisfies requirements (C), (F) and (G), it has high transmittance in the blue band and its neighboring visible light band and low transmittance for light with a wavelength of 1100 nm, especially at high angles of incidence. has a low transmittance for light with a wavelength of 1100 nm.
The optical film thickness is represented by physical film thickness×refractive index. Therefore, the physical film thickness can be calculated by optical film thickness/refractive index.

(H) At a wavelength of 720 to 1000 nm, the average transmittance of light incident from the direction perpendicular to the surface direction of the optical filter is 1% or less By satisfying the requirement (H), the filter (I) can be used as a near-infrared cut filter. This filter (I) can be preferably used, and can further shield near-infrared rays that are difficult or invisible to the human eye, and when this filter (I) is used for solid-state imaging devices, sensor applications, camera modules, etc., , a black silicon photodiode or other imaging device is excellent in luminosity correction, and a good image close to that seen by the human eye can be obtained.
The average transmittance is more preferably 0.5% or less, still more preferably 0.2% or less, and particularly preferably 0.1% or less. The lower the average transmittance, the better. For example, the lower limit is 0%.

(J) The average transmittance of light incident in the direction perpendicular to the surface direction of the optical filter at a wavelength of 720 to 1000 nm is 30% or less, and the average transmittance is more preferably 18% or less, and still more preferably 10% or less. , particularly preferably 8% or less. The lower limit of the average transmittance is, for example, 1% from the viewpoint of securing the sensitivity of the near-infrared sensor.

(K) A band with a wavelength of 720 to 1000 nm, in which the transmittance of light incident in the direction perpendicular to the surface direction of the optical filter is 50% or more in a continuous wavelength of 5 nm or more is more preferably 5 to 120 nm, still more preferably 5 to 70 nm, and particularly preferably 10 to 45 nm.
If the width of the band where the transmittance is 50% or more is below the above range, noise tends to increase when performing sensing using the near-infrared sensor due to insufficient sensitivity of the near-infrared sensor. , It becomes difficult to achieve the requirement (J), the performance of cutting near-infrared rays that are difficult to see or invisible to the human eye is insufficient, and the visibility correction tends to be insufficient, or wavelengths other than those used for sensing Noise tends to increase.

An optical filter that blocks near-infrared rays that are invisible or difficult to see with the human eye while forming a transmission band at specific wavelengths, such as a dual bandpass filter, by satisfying requirements (J) and (K). can be obtained. When this filter (II) is used in a near-infrared sensor, a solid-state imaging device, or a module, high sensitivity in the sensing wavelength and luminosity correction by cutting near-infrared rays result in good images close to those seen by the human eye. Images, distance information, etc. can be obtained easily.

This filter preferably satisfies the following requirements (O) to (Q) in the wavelength region of 300 to 1600 nm.

(O) having the longest wavelength value λ _traUV1 at which the transmittance of light incident from the direction perpendicular to the surface direction of the optical filter is 1% at a wavelength of 370 nm or more and less than 430 nm. By satisfying the requirement (O), It is possible to shield near ultraviolet rays that are difficult or invisible to the human eye. It is possible to further suppress the color change of an image caused by invisible or hard-to-see ultraviolet rays.
The λ _traUV1 is more preferably 375 to 428 nm, still more preferably 380 to 428 nm, even more preferably 385 to 428 nm, particularly preferably 390 to 426 nm.

(P) Having the shortest wavelength value λ _traIR1 at which the transmittance of light incident from the direction perpendicular to the surface direction of the optical filter is 1% at a wavelength of 1150 to 1600 nm By satisfying the requirement (P), the optical Even when the incident angle of light incident on the filter is high, the transmittance of near-infrared rays with a wavelength of 1100 nm can be suppressed to a lower level. For this reason, when a filter that satisfies the requirement (P) is used for a thin solid-state imaging device with a wide angle of view, a sensor, a camera module, etc., it has a higher sensitivity, and a near-infrared sensor that is invisible to the human eye, such as a near-infrared sensor. Even when capturing an image of a light source that emits a large amount of near-infrared rays, it is possible to easily obtain a good image that is close to what the human eye can see.
The λ _traIR1 is more preferably between 1250 and 1600 nm, more preferably between 1280 and 1500 nm, still more preferably between 1300 and 1500 nm, particularly preferably between 1330 and 1500 nm, and most preferably between 1360 and 1500 nm.
When λ _traIR1 is within the above range, the transmittance of light with a wavelength of 1100 nm can be kept lower even when the reflection band of the dielectric multilayer film is shifted to the short wavelength side at high-angle incidence, preferred.

When this filter satisfies both requirements (O) and (P), it has high transmittance in the blue band and the visible light band in the vicinity thereof and low transmittance of light with a wavelength of 1100 nm, especially at a wavelength of 1100 nm at high angles of incidence. The low transmittance of light and the better balance.

(Q) _λtraIR1 / _λtraUV1 ≥ 3.10
By satisfying the requirement (Q), an optical filter that cannot be obtained with a conventional optical filter using a laminate (dielectric multilayer film) of layers with an optical thickness of about 1/4 of the near-infrared reflection band. It is possible to easily achieve both high transmittance in the blue band of light incident from the direction perpendicular to the surface direction and the visible light band in the vicinity thereof and low transmittance in near infrared rays with a wavelength of 1100 nm when incident at a high angle. can. For this reason, when a filter that satisfies the requirement (Q) is used in a thin solid-state imaging device with a wide angle of view, a sensor, a camera module, etc., it is excellent in luminosity correction of the imaging element such as blue, and is visible to the human eye. Even when an image is taken of a light source that emits a large amount of near-infrared rays, a good image that is close to that seen by the human eye can be obtained.
The λ _traIR1 /λ _traUV1 is more preferably 3.11 or more, still more preferably 3.15 or more, still more preferably 3.21 or more, particularly preferably 3.26 or more, most preferably 3.34 or more, It is preferably 4.10 or less, more preferably 3.8 or less.

In a conventional optical filter having a laminate (dielectric multilayer film) of layers with an optical thickness of about 1/4 of the near-infrared reflection band, light in a wavelength range of about 1/3 of the reflection band is reflected. There is a tendency. Therefore, an optical filter having such a conventional dielectric multilayer film and having a high transmittance in the blue band that satisfies the requirement (O) has a wavelength that is about three times as large as the requirement (O). Transmittance after 1100 nm tends to be high. Alternatively, an optical filter having a conventional dielectric multilayer film and having a low transmittance at a wavelength of 1100 nm or later at high-angle incidence that satisfies the requirement (P) has λ _traUV1 at a wavelength longer than 430 nm. , it becomes difficult to satisfy the requirement (O), and the transmittance of the blue band and the visible light band in the vicinity thereof tends to be low.
When this filter satisfies both requirements (O) and (P), it has high transmittance in the blue band and the visible light band in the vicinity thereof and low transmittance of light with a wavelength of 1100 nm, especially at a wavelength of 1100 nm at high angles of incidence. The low transmittance of light and the excellent balance.

This filter preferably satisfies the following requirements (R) to (U) in the wavelength region of 300 to 1600 nm.
In addition, in the following requirements (R), (S), (U), (V) and (α), one surface of the present filter (hereinafter also referred to as "surface X", the other surface is also referred to as "surface Y" ) should be within the following range for non-polarized light incident at an angle of 5° from the vertical direction.
The surface X usually refers to the main surface of the optical filter, and refers to one of the surfaces having the largest area. In this case, the plane Y is the other of the planes with the largest area.

The term "unpolarized light" refers to light having no bias in the direction of polarization, and refers to a collection of waves in which the electric field is substantially uniformly distributed in all directions. For the "average transmittance of non-polarized light", the average value of "average transmittance of S-polarized light" and "average transmittance of P-polarized light" may be used. For the "average reflectance of non-polarized light", the average value of "average reflectance of S-polarized light" and "average reflectance of P-polarized light" may be used.
Since it is extremely difficult to measure the reflectance of non-polarized light incident from the vertical direction, the present invention measured the reflection characteristics of the non-polarized light incident from the vertical direction at an angle of 5°.

(R) Having a wavelength λ _refUV50 at which the reflectance of unpolarized light incident at an angle of 5° from the vertical direction of at least one surface of the optical filter is 50% at a wavelength of 370 to 430 nm Satisfying requirement (R) Thus, it is possible to easily achieve both the function of reflecting ultraviolet rays that promote deterioration and the function of reducing ghosts in reflected blue light. If λ _refUV50 is below the above range, optical filters and imaging elements used in solid-state imaging devices tend to be easily deteriorated by ultraviolet rays. In addition, when λ _refUV50 exceeds the above range, when the filter is used for solid-state imaging devices, sensors, camera modules, etc., the blue light reflected on the surface of the optical filter becomes a ghost, and image defects are likely to occur.
The λ _refUV50 is more preferably 380 to 430 nm, still more preferably 390 to 430 nm, particularly preferably 395 to 425 nm.

(S) Having the shortest wavelength value λ _refIR90 at which the reflectance of unpolarized light incident at an angle of 5° from the vertical direction of at least one surface of the optical filter at a wavelength of 1150 to 1600 nm is 90% Requirement (S ), the transmittance of near-infrared rays with a wavelength of 1100 nm can be kept lower even when the incident angle of light incident on the optical filter is high. Therefore, when a filter that satisfies the requirement (S) is used in a thin solid-state imaging device with a wide angle of view, a sensor, a camera module, etc., it prevents the temperature rise of the filter, the imaging element, the sensor, the camera module, etc. due to near-infrared rays. It is possible to suppress the generation of thermal noise. In addition, even when capturing images of light sources such as halogen lamps, halogen heaters, incandescent light bulbs, flames, and near-infrared sensors that emit a large amount of near-infrared rays that are invisible to the human eye, it is easy to obtain good images that are close to what the human eye can see. can get to
The λ _refIR90 is more preferably between 1250 and 1600 nm, more preferably between 1280 and 1500 nm, still more preferably between 1300 and 1500 nm, particularly preferably between 1330 and 1500 nm, and most preferably between 1360 and 1500 nm.
When λ _refIR90 is within the above range, even when the reflection band of the dielectric multilayer film shifts to the short wavelength side at high angle incidence, the transmittance of light with a wavelength of 1100 nm can be kept low, which is preferable. is.

(T) _λrefIR90 / _λtraUV5 ≥ 3.10
By satisfying the requirement (T), an optical filter that cannot be obtained with a conventional optical filter using a laminate (dielectric multilayer film) of layers with an optical thickness of about 1/4 of the near-infrared reflection band. It is possible to more easily achieve both a high transmittance in the blue band of light incident from the direction perpendicular to the surface direction and a visible light band in the vicinity thereof, and a low transmittance in the near-infrared rays with a wavelength of 1100 nm at high-angle incidence. can. For this reason, when a filter that satisfies the requirement (T) is used in a thin solid-state imaging device with a wide angle of view, a sensor, a camera module, etc., it is excellent in luminosity correction of the image sensor such as blue, and is visible to the human eye. Even when capturing an image of a light source that emits a large amount of near-infrared rays that are not visible to the human eye, it is possible to easily obtain a good image that is close to that seen by the human eye.
The λ _refIR90 /λ _traUV5 is more preferably 3.13 or higher, still more preferably 3.15 or higher, still more preferably 3.20 or higher, particularly preferably 3.26 or higher, and most preferably 3.34 or higher, It is preferably 4.10 or less, more preferably 3.8 or less from the viewpoint of easily maintaining a high transmittance in the visible light band at high-angle incidence. If λ _refIR90 /λ _traUV5 exceeds the above upper limit, the number of layers of the dielectric multilayer film to be provided tends to increase, and it may be difficult to suppress the warping of the obtained optical filter, or the visible It can be difficult to meet the high transmittance of the light band.

(U) At a wavelength of 1000 to 1200 nm, the average reflectance of unpolarized light incident at an angle of 5° from the vertical direction of at least one surface of the optical filter is 90% or more. Even when the incident angle of light incident on the filter is high, the transmittance of near-infrared rays with a wavelength of 1100 nm can be suppressed to a lower level. When a filter that satisfies requirement (U) is used in a thin solid-state imaging device with a wide angle of view, a sensor, a camera module, etc., it is possible to prevent temperature rise in the filter, imaging element, sensor, camera module, etc. due to near-infrared rays. , the generation of thermal noise can be suppressed. In addition, even when capturing images of light sources such as halogen lamps, halogen heaters, incandescent light bulbs, flames, and near-infrared sensors that emit a large amount of near-infrared rays that are invisible to the human eye, it is easy to obtain good images that are close to what the human eye can see. can get to
The average reflectance is preferably 92% or higher, more preferably 95% or higher, particularly preferably 98% or higher. The higher the average reflectance, the better. For example, the upper limit is 100%.

This filter preferably satisfies the following requirements (V) to (W) in the wavelength range of 300 to 1600 nm.

(V) Having the shortest wavelength value λ _refIR95 at which the reflectance of unpolarized light incident at a wavelength of 1150 to 1600 nm at an angle of 5° from the vertical direction of at least one surface of the optical filter is 95% Requirement (V ), the transmittance of near-infrared rays with a wavelength of 1100 nm can be kept lower even when the incident angle of light incident on the optical filter is high. For this reason, when a filter that satisfies requirement (V) is used in a thin, high-sensitivity solid-state imaging device with a wide angle of view, a sensor, a camera module, etc., the near-infrared filter, imaging element, sensor, camera module, etc. It is possible to further prevent overheating and suppress the generation of thermal noise. In addition, even when capturing images of light sources such as halogen lamps, halogen heaters, incandescent light bulbs, flames, and near-infrared sensors that emit a large amount of near-infrared rays that are invisible to the human eye, it is easy to obtain good images that are close to what the human eye can see. can get to
The λ _refIR95 is more preferably between 1250 and 1600 nm, more preferably between 1280 and 1500 nm, even more preferably between 1300 and 1500 nm, particularly preferably between 1330 and 1500 nm, and most preferably between 1360 and 1500 nm.
When λ _refIR95 is within the above range, the transmittance of light with a wavelength of 1100 nm can be kept low even when the near-infrared reflection band of the dielectric multilayer film shifts to the short wavelength side at high-angle incidence. , is preferred.

(W) _λrefIR95 / _λtraUV5 ≥ 3.10
By satisfying the requirement (W), an optical filter that cannot be obtained with a conventional optical filter using a laminate (dielectric multilayer film) of layers with an optical thickness of about 1/4 of the near-infrared reflection band. It is possible to easily achieve both a high transmittance in the blue band of light incident from the direction perpendicular to the surface direction and a visible light band in the vicinity thereof, and a low transmittance in the near-infrared rays with a wavelength of 1100 nm at high-angle incidence. . For this reason, when a filter that satisfies the requirement (W) is used in a thin solid-state imaging device with a wide angle of view, a sensor, a camera module, etc., it is excellent in luminosity correction of the image sensor such as blue, and is visible to the human eye. Even when capturing an image of a light source that emits a large amount of near-infrared rays that are not visible to the human eye, it is possible to easily obtain a good image that is close to that seen by the human eye. On the other hand, when an optical filter that does not satisfy the requirement (W) is designed to have high transmittance in the blue band and the visible light band near it, the transmittance of near-infrared rays with a wavelength of 1100 nm at high-angle incidence is reduced. If the transmittance of near-infrared rays with a wavelength of 1100 nm at high-angle incidence is designed to be low, it is difficult to increase the transmittance of the blue band and the visible light band in the vicinity thereof. tend to become
Even if it is designed so that the transmittance of the blue band and the visible light band in the vicinity thereof is high, the transmittance of near _infrared rays with a wavelength of 1100 nm at high angle incidence can be reduced. λ _traUV5 is more preferably 3.15 or more, still more preferably 3.21 or more, still more preferably 3.27 or more, particularly preferably 3.34 or more, and most preferably 3.40 or more. It is preferably 4.10 or less, more preferably 3.8 or less, from the viewpoint of easily maintaining a high transmittance in the visible light band. If λ _refIR95 /λ _traUV5 exceeds the upper limit, it may be difficult to achieve high transmittance in the visible light band at high-angle incidence.

This filter preferably satisfies the following requirement (X) in the wavelength range of 300 to 1600 nm.
(X) A filter that satisfies the requirement (X) having a wavelength λ _IR50 at which the transmittance of light incident from the direction perpendicular to the surface direction of the optical filter is 50% in the wavelength range of 620 to 715 nm is used for solid-state imaging devices and sensors. Alternatively, when used in a camera module, etc., it becomes easy to make the sensitivity of the solid-state imaging device, sensor, camera module, etc. close to the relative luminosity curve of the human eye. Excellent.
λ _IR50 is preferably between 620 and 680 nm, more preferably between 620 and 670 nm, still more preferably between 620 and 660 nm, particularly preferably between 625 and 650 nm. If the λ _IR50 is below the above range, the resulting image tends to be less reddish than the image seen by the human eye, and luminosity correction tends to be insufficient. There is a tendency that the redness of the obtained image increases and the luminosity correction tends to be insufficient.

In terms of superior in-plane distribution of colors near blue in images obtained by solid-state imaging devices, camera modules, etc., this filter has a wavelength of 420 to 450 nm. The average light transmittance is preferably 65% or higher, more preferably 70% or higher, and particularly preferably 80% or higher. The higher the average transmittance, the better. For example, the upper limit is 100%.

In terms of superior in-plane distribution of colors near red in images obtained by solid-state imaging devices, camera modules, etc., this filter has a wavelength of 600 to 650 nm. The average light transmittance is preferably 30 to 96%.
When the average transmittance is less than the above range and the filter is used in a solid-state imaging device, red color reproducibility of an image obtained tends to be difficult due to insufficient red sensitivity. When the filter is used in a solid-state imaging device, the visibility correction tends to be insufficient due to the difference between the sensitivity of the solid-state imaging device and human visibility, and the obtained image becomes reddish. tend to be dull in color.
The average transmittance is preferably 35-85%, more preferably 40-80%, still more preferably 45-80%, particularly preferably 50-75%, and most preferably 50-70%.

In this filter, the transmittance of light with a wavelength of 1100 nm incident at an angle of 45° from the direction perpendicular to the surface direction of the optical filter is preferably 2.0% or less, more preferably 1.5% or less, and particularly preferably 1.5% or less. is 1.1% or less.
When the present filter has the above-described transmittance, even when the incident angle of the light incident on the optical filter becomes high, it becomes easy to keep the transmittance of the light having a wavelength of 1100 nm, to which the imaging element is sensitive, low, This filter can be suitably used as a filter when using an imaging device or the like having sensitivity to this wavelength.

This filter has an average transmittance of preferably 10.0% or less, more preferably 8.0%, for light with a wavelength of 1100 to 1150 nm and incident at an angle of 45° from the direction perpendicular to the surface direction of the optical filter. 4.0% or less is particularly preferable.
When the present filter has the above average transmittance, even when the incident angle of the light incident on the optical filter becomes high, it becomes easy to keep the transmittance of the light having a wavelength of 1100 nm, to which the imaging element is sensitive, low. , the present filter can be suitably used as a filter in the case of using an imaging element having sensitivity to this wavelength.

This filter has a wavelength Xa at which the transmittance of light incident from the direction perpendicular to the surface direction of the optical filter is 5% at a wavelength of 600 to 750 nm, and It has a wavelength Xb at which the transmittance of light incident at an angle is 5%, and the absolute value of the difference between Xa and Xb is preferably 50 nm or less, more preferably 35 nm or less, and particularly preferably 30 nm or less.
When the absolute value of the difference between Xa and Xb is within the above range, it is possible to easily obtain a near-infrared cut filter with a wide viewing angle and a small incidence angle dependence of the absorption wavelength.

In the wavelength range of 300 to 1600 nm, the filter preferably satisfies the following requirement (α).
(α) An optical filter having an average reflectance of 4% or less at a wavelength of 440 to 580 nm for unpolarized light incident at an angle of 5° from the direction perpendicular to at least one surface direction of the optical filter, which satisfies the requirement (α), When used for solid-state imaging devices, sensor applications, or camera modules, the light reflected on the lens or sensor surface is reflected by the optical filter surface and enters the sensor again, or the light reflected by the optical filter surface is reflected by the lens or frame. It is possible to easily reduce the ghost, which is an image quality defect caused by the light being reflected by, etc., and incident on the sensor again.
The average reflectance is preferably 3% or less, more preferably 2.5% or less.

The thickness of this filter is 0.01 to 0.21 mm, more preferably 0.015 to 0.14 mm, particularly preferably 0.02 to 0.12 mm.
If the thickness is less than the above range, the dielectric multilayer film of the present filter is likely to warp due to stress, and it may be difficult to use the filter for solid-state imaging devices, sensors, camera modules, and the like. In addition, when the thickness exceeds the above range, it tends to be difficult to use in thin solid-state imaging devices, sensors, camera modules, and the like.

<Substrate>
The substrate is not particularly limited in material, shape, etc., as long as it does not impair the effects of the present invention. The substrate may be a single layer as in FIG. 1(A) or (B) or a multi-layer as in FIGS. 1(C)-(G), but has a layer containing an additive. is preferred.

Specific examples of the substrate include the following (a) to (c). Among these, the following (b) and (c) are preferable because an optical filter having desired optical properties can be easily obtained.
(a) A substrate made of an inorganic material (which may or may not have absorption in the near-infrared region, the near-ultraviolet region, etc.)
(b) Substrate made of resin (substrate made of resin, the substrate does not have to contain the additive described below, but the substrate preferably contains the additive described below)
(c) An inorganic support or a substrate in which a resin layer is laminated on a resin support (the inorganic support may or may not have absorption in the near-infrared region, the near-ultraviolet region, etc.). The resin support and resin layer may not contain the following additives, but at least one of them preferably contains the following additives.)

The thickness of the substrate is not particularly limited, and may be appropriately selected according to the desired application. ~0.1 mm.
When the thickness of the substrate is within the above range, an optical filter that is easy to handle can be obtained, and a solid-state imaging device, a camera module, or the like using the obtained filter can be made thinner and more compact.

〈Inorganic material〉
Although the inorganic material is not particularly limited, quartz, borosilicate glass, silicate glass, chemically strengthened glass, physically strengthened glass, soda glass, phosphate glass, alumina glass, sapphire glass, colored glass, etc. are mentioned. These commercially available products include SCHOTT D263, BK7, B270, KG1 or KG1 having the thickness of the substrate, KG3 or KG3 having the thickness of the substrate, KG5 or KG5 having the thickness of the substrate. C5000 or C5000 manufactured by HOYA CORPORATION as the thickness of the substrate, CD5000 or CD5000 as the thickness of the substrate, E-CM500S or E-CM500S as the thickness of the substrate , Gorilla Glass and Willow Glass manufactured by Corning, BS1 to 11 and BS1 to 11 manufactured by Matsunami Glass Industry Co., Ltd., and Hiceram manufactured by NGK INSULATORS, LTD. Among these, borosilicate-based glass or phosphate-based glass is preferable from the viewpoint of high visible light transmittance and excellent near-infrared shielding performance, and borosilicate-based glass is not particularly limited. , BK7, B270, KG1, KG3, KG5, etc., and examples of the phosphate glass include, but are not limited to, copper phosphate glass containing copper atoms. Phosphate copper salt glass containing copper atoms can be obtained, for example, by the methods described in JP-A-2015-522500, WO 2011/071157, and WO 2017/208679. As the phosphate-based glass, fluorophosphate-based glass containing fluorine atoms, which tends to have little change in optical properties in a high-temperature and high-humidity environment, is preferable.

<resin>
The resin is not particularly limited as long as it does not impair the effects of the present invention. Resins having a glass transition temperature (Tg) of preferably 110 to 380.degree. C., more preferably 110 to 370.degree. C., and even more preferably 120 to 360.degree. Further, when the Tg of the resin is 140° C. or higher, even if the Tg is lowered by adding an additive to the resin at a high concentration, the substrate can be formed by vapor deposition of a dielectric multilayer film at a high temperature. Especially preferred.

As for the resin, when a resin plate having a thickness of 0.05 mm is formed from only the resin, the total light transmittance (JIS K7375) of the resin plate is preferably 50 to 96%, more preferably 60 to 96%. It is desirable to use a resin having a content of 70 to 96%, particularly preferably 70 to 96%. When a resin having a total light transmittance within this range is used, the obtained substrate exhibits good transparency as an optical film.

The polystyrene-equivalent weight average molecular weight (Mw) measured by the gel permeation chromatography (GPC) method of the resin is usually 15,000 to 350,000, preferably 30,000 to 250,000, and the number average The molecular weight (Mn) is usually 10,000-150,000, preferably 20,000-100,000.

Examples of resins include cyclic (poly)olefin-based resins, aromatic polyether-based resins, polyimide-based resins, polycarbonate-based resins, polyester-based resins, polyamide (aramid)-based resins, polysulfone-based resins, and polyethersulfone-based resins. , polyparaphenylene resins, polyamideimide resins, polyethylene naphthalate resins, fluorinated aromatic polymer resins, (modified) acrylic resins, epoxy resins, silsesquioxane ultraviolet curable resins, maleimide resins , alicyclic epoxy thermosetting resins, polyether ether ketone resins, polyarylate resins, allyl ester curing resins, acrylic ultraviolet curing resins, vinyl ultraviolet curing resins, and silica formed by the sol-gel method. A resin as a main component can be mentioned. Among these, cyclic (poly)olefin-based resins, aromatic polyether-based resins, polycarbonate-based resins, polyester-based resins, polyimide-based resins, fluorinated aromatic polymer-based resins, and acrylic UV-curable resins can be used. , transparency (optical properties), heat resistance, reflow resistance, and the like, so that an optical filter having an excellent balance can be obtained.
One type of resin may be used alone, or two or more types may be used.

[Cyclic (poly)olefin resin]
As the cyclic (poly)olefin resin, at least one monomer selected from the group consisting of a monomer represented by the following formula (X ₀ ) and a monomer represented by the following formula (Y ₀ ) and resins obtained by hydrogenating said resins are preferred.

In formula (X ₀ ), R ^x1 to R ^x4 each independently represent an atom or group selected from (i′) to (ix′) below, k ^x , m ^x and p ^x each independently represent 0 Represents an integer from ~4.
(i') a hydrogen atom (ii') a halogen atom (iii') a trialkylsilyl group (iv') a substituted or unsubstituted carbon number 1 having a linking group containing an oxygen atom, a sulfur atom, a nitrogen atom or a silicon atom ~30 hydrocarbon group (v') substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms (vi') polar group (excluding (ii') and (iv'))
(vii') an alkylidene group formed by bonding R ^x1 and R ^x2 or R ^x3 and R ^x4 together (provided that R ^x1 to R ^x4 not involved in the bonding are each independently ) to represent an atom or group selected from (vi′).)
(viii') R ^x1 and R ^x2 or R ^x3 and R ^x4 are bonded to each other to form a monocyclic or polycyclic hydrocarbon ring or heterocyclic ring (provided that R ^x1 to R ^x4 each independently represents an atom or group selected from (i') to (vi').)
(ix') a monocyclic hydrocarbon ring or heterocyclic ring formed by bonding R ^x2 and R ^x3 together (provided that R ^x1 and R ^x4 not involved in the bond are each independently the above (i ') to represent an atom or group selected from (vi').)

In formula (Y ₀ ), R ^y1 and R ^y2 each independently represent an atom or group selected from the above (i′) to (vi′), or R ^y1 and R ^y2 are mutually bonded to Each of k ^y and p ^y independently represents an integer from 0 to 4, representing a formed monocyclic or polycyclic alicyclic hydrocarbon, aromatic hydrocarbon or heterocyclic ring.

[Aromatic polyether resin]
The aromatic polyether-based resin preferably has at least one structural unit selected from the group consisting of structural units represented by the following formula (1) and structural units represented by the following formula (2).

（式（１）中、Ｒ¹～Ｒ⁴はそれぞれ独立に、炭素数１～１２の１価の有機基を示し、ａ～ｄはそれぞれ独立に、０～４の整数を示す。）

(In Formula (1), R ¹ to R ⁴ each independently represent a monovalent organic group having 1 to 12 carbon atoms, and a to d each independently represent an integer of 0 to 4.)

（式（２）中、Ｒ¹～Ｒ⁴およびａ～ｄはそれぞれ独立に、前記式（１）中のＲ¹～Ｒ⁴およびａ～ｄと同義であり、Ｙは、単結合、－ＳＯ₂－または－ＣＯ－を示し、Ｒ⁷およびＲ⁸はそれぞれ独立に、ハロゲン原子、炭素数１～１２の１価の有機基またはニトロ基を示し、ｇおよびｈはそれぞれ独立に、０～４の整数を示し、ｍは０または１を示す。但し、ｍが０のとき、Ｒ⁷はシアノ基ではない。）

(In 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 Formula (1) above; Y is a single bond; 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, g and h each independently represent 0 to 4 and m is 0 or 1. However, when m is 0, R ⁷ is not a cyano group.)

In addition, the aromatic polyether-based resin further has 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). may be

（式（３）中、Ｒ⁵およびＲ⁶はそれぞれ独立に、炭素数１～１２の１価の有機基を示し、Ｚは、単結合、－Ｏ－、－Ｓ－、－ＳＯ₂－、－ＣＯ－、－ＣＯＮＨ－、－ＣＯＯ－または炭素数１～１２の２価の有機基を示し、ｅおよびｆはそれぞれ独立に、０～４の整数を示し、ｎは０または１を示す。

(In 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; e and f each independently represent an integer of 0 to 4; n represents 0 or 1;

（式（４）中、Ｒ⁷、Ｒ⁸、Ｙ、ｍ、ｇおよびｈはそれぞれ独立に、前記式（２）中のＲ⁷、Ｒ⁸、Ｙ、ｍ、ｇおよびｈと同義であり、Ｒ⁵、Ｒ⁶、Ｚ、ｎ、ｅおよびｆはそれぞれ独立に、前記式（３）中のＲ⁵、Ｒ⁶、Ｚ、ｎ、ｅおよびｆと同義である。）

(in formula (4), R ⁷ , R ⁸ , Y, m, g and h are each independently synonymous with R ⁷ , R ⁸ , Y, m, g and h in formula (2); R ⁵ , R ⁶ , Z, n, e and f are each independently synonymous with R ⁵ , R ⁶ , Z, n, e and f in the formula (3).)

[Polyester resin]
The polyester-based resin is not particularly limited, and can be synthesized, for example, by the methods described in JP-A-2010-285505 and JP-A-2011-197450.

[Polyimide resin]
The polyimide resin is not particularly limited as long as it is a polymer compound containing an imide bond in the repeating unit. can do.

[Polycarbonate resin]
The polycarbonate-based resin is not particularly limited, but can be synthesized, for example, by the method described in JP-A-2008-163194.

[Fluorinated aromatic polymer resin]
The fluorinated aromatic polymer resin is not particularly limited, but at least one selected from the group consisting of an aromatic ring having at least one fluorine atom, an ether bond, a ketone bond, a sulfone bond, an amide bond, an imide bond and an ester bond It is preferably a polymer containing a repeating unit containing one bond, and can be synthesized, for example, by the method described in JP-A-2008-181121.

[Acrylic UV curable resin]
The acrylic UV-curable resin is not particularly limited, but is synthesized from a resin composition containing a compound having one or more acrylic or methacrylic groups in the molecule and a compound that is decomposed by ultraviolet rays to generate active radicals. things can be mentioned. The acrylic UV-curable resin is a substrate in which a resin layer (absorbing layer) containing an additive and a curable resin is laminated on an inorganic support or a resin support, or a substrate containing an additive. When using a substrate in which a resin layer such as an overcoat layer made of a curable resin or the like is laminated on a resin support, the curable resin can be particularly suitably used.

[Resin mainly composed of silica formed by sol-gel method]
Examples of the sol-gel method silica-based resin include tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, dimethoxydiethoxysilane, methoxytriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, diphenyldimethoxysilane, A compound obtained by a sol-gel reaction caused by hydrolysis of one or more silanes selected from phenylalkoxysilanes such as diphenyldiethoxysilane can be used as the resin.

[Commercial goods]
As the resin, the following commercially available products can be used.
Examples of commercially available cyclic (poly)olefin resins include ARTON manufactured by JSR Corporation, ZEONOR manufactured by Nippon Zeon Co., Ltd., APEL manufactured by Mitsui Chemicals, Inc., and TOPAS manufactured by Polyplastics Co., Ltd. . Sumika Excel PES manufactured by Sumitomo Chemical Co., Ltd. and the like can be mentioned as commercial products of polyether sulfone-based resins. Commercially available polyimide resins include Neoprim L manufactured by Mitsubishi Gas Chemical Co., Ltd., and the like. Examples of commercially available polycarbonate-based resins include Pure Ace manufactured by Teijin Limited and Iupizeta EP-5000 manufactured by Mitsubishi Gas Chemical Company, Inc. OKP4HT manufactured by Osaka Gas Chemicals Co., Ltd. and the like can be mentioned as commercial products of the polyester-based resin. Examples of commercially available acrylic resins include Acryvure manufactured by Nippon Shokubai Co., Ltd., and the like. Commercially available silsesquioxane-based UV-curable resins include Silplus manufactured by Nippon Steel Chemical Co., Ltd., and the like.

<Substrate manufacturing method>
The resin substrate, resin support, and resin layer can be formed, for example, by melt molding or cast molding, and if necessary, antireflection agents, hard coating agents and/or antistatic agents, etc., can be added after molding. A substrate having an overcoat layer laminated thereon can be produced by coating with the coating agent.

When the substrate is a substrate in which a resin layer containing an additive and a resin is laminated on an inorganic support or a resin support, for example, the additive is added to the inorganic support or the resin support. By melt-molding or cast-molding the containing resin solution, the solvent is removed by drying preferably after coating by a method such as spin coating, slit coating, or inkjet, and if necessary, light irradiation or heating is performed. Alternatively, a substrate having a resin layer formed on an inorganic support or a resin support can be produced.

[Melt molding]
As the melt molding, specifically, when the substrate contains a resin and an additive, a method of melt molding a pellet obtained by melt-kneading the resin and the additive; A method of melt-molding a resin composition containing the resin composition; or a method of melt-molding pellets obtained by removing the solvent from a resin composition containing an additive, a resin and a solvent. Examples of melt molding methods include injection molding, melt extrusion molding, and blow molding. When the substrate contains an inorganic material, a platinum crucible, a platinum-rhodium crucible, a gold crucible, an iridium crucible, an alumina porcelain crucible, or the like is used depending on the melting point and releasability of the inorganic material. Examples include a method of molding by an overflow method, a float method, or the like after melting the material.

[Cast molding]
As the cast molding, a method of casting a resin composition containing an additive, a resin and a solvent onto a suitable support and removing the solvent; or an additive and a photocurable resin and/or a thermosetting resin. A method of casting a curable composition containing on a suitable support, removing the solvent, and then curing by an appropriate technique such as ultraviolet irradiation or heating.

When the substrate is a substrate (resin substrate) composed of a resin layer containing an additive, the substrate can be obtained by peeling off the coating film from the support after cast molding, and When the substrate is a substrate in which a resin layer such as an overcoat layer containing an additive and a resin is laminated on a support such as an inorganic support or a resin support, the substrate can be obtained, for example, by not peeling off the coating film after cast molding.

Examples of the support include a glass plate, a steel belt, a steel drum, and a support made of resin (eg, polyester, cyclic olefin resin).

Furthermore, by a method of coating the resin composition on an optical component made of an inorganic material or a resin and drying the solvent, or a method of coating the curable composition and drying and curing, etc., A resin layer can also be formed.

The amount of residual solvent in the resin layer and resin substrate obtained by the above method should be as small as possible. Specifically, the amount of residual solvent is preferably 3% by mass or less, more preferably 1% by mass or less, and still more preferably 0.5% by mass or less with respect to 100% by mass of the resin layer or resin substrate. . When the amount of residual solvent is within the above range, it is possible to easily obtain a resin layer or a resin substrate which is resistant to deformation and changes in properties and which can easily exhibit desired functions.

[Additive]
The substrate may contain additives such as antioxidants, fluorescence quenchers, and absorbers (eg, infrared absorbers, ultraviolet absorbers) within a range that does not impair the effects of the present invention. These additives may be used individually by 1 type, and may be used 2 or more types.

Examples of the antioxidant include 2,6-di-t-butyl-4-methylphenol, 2,2'-dioxy-3,3'-di-t-butyl-5,5'-dimethyldiphenylmethane, tetrakis[methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate]methane, tris(2,4-di-t-butylphenyl)phosphite.

Examples of the infrared absorber include, but are not limited to, squarylium-based compounds, phthalocyanine-based compounds, naphthalocyanine-based compounds, croconium-based compounds, hexaphylline-based compounds, azo-based compounds, naphthoquinone-based compounds, oxonol-based compounds, and pyrrolopyrrole. type compounds, triarylmethane-based dyes, diimonium-based compounds, dithiol complex-based compounds, dithiolene complex-based compounds, dipyrromethene-based compounds, mercaptophenol complex-based compounds, mercaptonaphthol complex-based compounds, and polymethine-based compounds.

Although not particularly limited as an infrared absorbing agent, Japanese Patent No. 3366697, Japanese Patent No. 2846091, Japanese Patent No. 2864475, Japanese Patent No. 3703869, JP-A-60-228448, JP-A-1-146846 , JP-A-1-228960, Patent No. 4081149, JP-A-63-124054, "Phthalocyanine-Chemistry and Function-" (IPC, 1997), JP-A-2007-169315, JP-A 2009-108267, JP 2010-241873, Japanese Patent No. 3699464, Japanese Patent No. 4740631, International Publication No. 2013/054864, International Publication No. 2015/025779, International Publication No. 2017/051867, etc. and dyes described in .

The infrared absorbing agent preferably has a maximum absorption wavelength in the range of 670 to 950 nm, more preferably 680 to 900 nm, still more preferably 685 to 800 nm, particularly preferably 685 to 780 nm.
By using a resin layer or a resin substrate containing an infrared absorbent having a maximum absorption wavelength in the above range, the incident angle dependence of colors near red is improved, and an optical filter excellent in luminosity correction can be easily obtained. can be done.
The maximum absorption wavelength of the infrared absorbing agent can be measured using a solution of the infrared absorbing agent dissolved in dichloromethane.

Examples of the ultraviolet absorber include azomethine-based compounds, indole-based compounds, triazole-based compounds, triazine-based compounds, oxazole-based compounds, merocyanine-based compounds, cyanine-based compounds, naphthalimide-based compounds, oxadiazole-based compounds, and oxazine-based compounds. compounds, oxazolidine-based compounds, naphthalic acid-based compounds, styryl-based compounds, anthracene-based compounds, and cyclic carbonyl-based compounds.

The ultraviolet absorber preferably has a maximum absorption wavelength in the range of 350 to 410 nm, more preferably 350 to 405 nm, still more preferably 360 to 400 nm. By having a maximum absorption wavelength within the above range, an optical filter that satisfies the requirements (C) and (O) can be easily obtained.
The absorption maximum wavelength can be measured using a solution of an ultraviolet absorber dissolved in dichloromethane.

The additive may be mixed with a resin or the like when manufacturing the resin layer (resin substrate), or may be added when synthesizing the resin.
The amount of the additive to be added may be appropriately selected according to the desired properties. 0.01 to 5.0 parts by mass, preferably 0.05 to 3.5 parts by mass.

<Absorbing layer>
The substrate preferably has a layer (absorbing layer) that absorbs light, and more preferably has an absorbing layer containing the absorbing agent. One absorption layer may be included in the substrate, or two or more layers may be included. When two or more layers are included, the absorbent layer may be continuous, may have another layer interposed therebetween, may be present only on one side of the support, or may be present on both sides of the support. may exist in The resin substrate may be the absorption layer.

When the substrate contains the infrared absorbing agent, it is preferable to use two or more kinds of infrared absorbing agents having different maximum absorption wavelengths. As a result, the incident angle dependence of colors near red is further improved, and an optical filter with excellent luminosity correction can be easily obtained. The maximum absorption wavelength λ (DA_Tmin ), a first infrared absorbent (DA) having a maximum absorption wavelength λ at 685 to 710 nm, and a second having a maximum absorption wavelength λ at a wavelength of 710 to 780 nm and an infrared absorber (DB). As a result, it is possible to easily obtain an optical filter excellent in visibility correction while maintaining high transmittance in visible light.

Therefore, for the same reason as above, the substrate preferably satisfies the following requirement (Y) in the wavelength range of 300 to 1600 nm.
(Y) Has a maximum absorption wavelength λ (DA_Tmin) at a wavelength of 685 to 780 nm The maximum absorption wavelength λ (DA_Tmin) is more preferably 685 to 710 nm and 710 to 780 nm.
The maximum absorption wavelength λ of the substrate refers to the wavelength of the absorption peak in the transmittance curve of the light incident from the direction perpendicular to the surface direction of the substrate.
By using a substrate having a maximum absorption wavelength λ (DA_Tmin) within the above range, it becomes easy to satisfy the following requirement (Z).

The substrate preferably satisfies the following requirement (Z) in the wavelength range of 300 to 1600 nm.
(Z) At a wavelength of 680 to 800 nm, the width of the stop band at which the transmittance of light incident perpendicular to the surface direction of the substrate is 5% or less is 30 nm or more. By satisfying the requirement (Z), a high angle Even when the near-infrared reflection band of the dielectric multilayer film shifts to the short wavelength side at the time of incidence, it is possible to further suppress the decrease in the transmittance of light such as red light. Therefore, when such a filter is used in a solid-state imaging device, it is possible to suppress color shading in which the color is different between the center and the edges of the image, and a good image can be obtained.
The width of the stop band is more preferably 35 nm or more, still more preferably 45 nm or more, particularly preferably 50 nm or more, and more preferably 121 nm or less.

<Dielectric multilayer film>
The present filter may have a dielectric multilayer film on one surface of the substrate as shown in FIG. 1(A), and a plurality of dielectric multilayer films as shown in FIGS. may have From the viewpoint of suppressing warping of the optical filter, it is preferable to have dielectric multilayer films on both sides of the substrate. When the substrate has dielectric multilayer films on both sides, the absolute value of the difference in the total physical film thickness of the dielectric multilayer films on each side is preferably less than 5.0 μm. It is more preferably less than 4.0 μm, even more preferably less than 3.0 μm, even more preferably less than 2.0 μm, particularly preferably less than 1.5 μm, and most preferably less than 1.0 μm.
When the absolute value of the difference in the total physical film thickness of the dielectric multilayer film on each surface is 0.1 μm or more and less than 5.0 μm, the temperature when forming the dielectric multilayer film on one surface is It is preferable that the temperature at which the dielectric multilayer film is formed on the other surface is different by about 10 to 80.degree.

The dielectric multilayer film is not particularly limited, but specifically, it may be a multilayer film containing (a combination of) any two or more layers of a high refractive index material layer, a low refractive index material layer, and a medium refractive index material layer. preferable.

Examples of the material forming the high refractive index material layer include materials having a refractive index of 2.0 or more, and materials having a refractive index of 2.0 to 3.6 are usually selected. In the present invention, the refractive index represents a value for light with a wavelength of 550 nm.

Materials constituting the high refractive index material layer include, for example, titanium oxide, zirconium oxide, tantalum oxide, niobium oxide, lanthanum oxide, zinc oxide, zinc sulfide, barium titanate, silicon, and the like. Titanium oxide, hafnium oxide, tin oxide and/or cerium oxide containing a small amount (for example, 0 to 10% by mass based on the main component); Examples thereof include those in which tantalum oxide, niobium oxide, lanthanum oxide, zinc oxide, zinc sulfide, barium titanate and/or silicon are dispersed.

As a material constituting the low refractive index material layer, a material having a refractive index of less than 1.6 can be mentioned, and a material having a refractive index of 1.2 to less than 1.6 is usually selected. Examples of such materials include silica, lanthanum fluoride, magnesium fluoride, sodium aluminum hexafluoride; resins such as the resins described above; Examples include those dispersed in a resin.

A material having a refractive index of 1.6 or more and less than 2.0 can be used as a material for forming the medium refractive index material layer. Examples of such materials include aluminum oxide, bismuth oxide, europium oxide, yttrium oxide, ytterbium oxide, samarium oxide, indium oxide, magnesium oxide, and molybdenum oxide; these materials and materials constituting the high refractive index material layer. and/or a mixture of a material constituting the low refractive index material layer; a mixture of a material constituting the high refractive index material layer and a material constituting the low refractive index material layer; Examples thereof include those obtained by mixing those dispersed in resins such as the resins described above.

The dielectric multilayer film may have a metal layer and/or a semiconductor layer with a thickness of about 1 to 100 nm. Materials constituting these layers include materials having a refractive index of 0.1 to 5.0. Such materials include gold, silver, copper, zinc, aluminum, tungsten, titanium, magnesium, nickel, silicon, silicon hydride, germanium, and the like. Since these metal layers and semiconductor layers tend to have high extinction coefficients at wavelengths in the visible light band, when these layers are provided, they are preferably thin layers with a thickness of about 1 to 20 nm.

The method for forming the dielectric multilayer film is not particularly limited as long as the dielectric multilayer film is formed by stacking these material layers. For example, a dielectric multilayer in which a high refractive index material layer and a low refractive index material layer are alternately laminated directly on a substrate by a CVD method, a sputtering method, a vacuum deposition method, an ion-assisted deposition method, an ion plating method, or the like. A film or a dielectric multilayer film in which high refractive index material layers, medium refractive index material layers, and low refractive index material layers are alternately laminated can be formed. When laminating a layer containing a resin, it can be formed by melt molding or cast molding, preferably by spin coating, dip coating, slit coating, gravure coating, or the like, in the same manner as the substrate molding method described above.

Among these, the sputtering method, the ion-assisted vapor deposition method, and the ion plating method are preferable from the viewpoints of adhesiveness to the substrate and little change in the optical properties of the dielectric multilayer film due to humidity. The ion-assisted vapor deposition method is more preferable because it contains less foreign matter.

For example, devices capable of performing ion-assisted deposition include the SYRUSpro series manufactured by Buehler Leybold Optics, the OTFC series manufactured by Optorun Co., Ltd., the MIC series and EPD series manufactured by Shincron Co., Ltd., and the VCD series manufactured by ShinMaywa Industries, Ltd. , Sapio series manufactured by Showa Shinku Co., Ltd., and the like.

In ion-assisted vapor deposition, it is preferable to control the film formation rate of vapor deposition with a crystal oscillator and control the optical film thickness of each layer of the dielectric multilayer film with an optical monitor that estimates from the reflection intensity. When forming a layer with a physical thickness of 60 nm or less, it is preferable to control the film thickness based on the integrated value of the film formation rate of the crystal resonator. By controlling the film thickness based on the integrated value of the film formation rate of the crystal oscillator, it is possible to reduce the deviation of the optical film thickness control by the optical monitor.

This filter preferably has at least one dielectric multilayer film formed at a temperature of 90° C. or higher. By having the dielectric multilayer film formed at a temperature of 90° C. or higher, when the obtained optical filter is heated to 90° C., the occurrence of film peeling, breakage, and cracking of the dielectric multilayer film is reduced. From the viewpoint of improving the heat resistance temperature of the optical filter, the formation temperature of the dielectric multilayer film is more preferably 120° C. or higher.

When the dielectric multilayer film is formed by vapor deposition, the vapor deposition is preferably started under vacuum. It is more preferably 0.005 Pa or less, still more preferably 0.001 Pa or less. By increasing the starting pressure to a higher vacuum, it is possible to reduce the moisture content in the resulting dielectric multilayer film, thereby reducing the phenomenon in which the optical properties of the resulting optical filter change according to humidity.
When the dielectric multilayer film is formed by ion-assisted vapor deposition, the degree of vacuum during the formation of the multilayer film is preferably 0.05 Pa or less. By setting the viscosity to 0.05 Pa or less, the obtained dielectric multilayer film has good smoothness, and an optical filter with low haze can be obtained.

Further, the gas introduced into the ion gun, which is an ion supply device in ion-assisted deposition, is preferably oxygen gas or a mixed gas of oxygen gas and rare gas. By using an oxygen gas or a mixed gas of an oxygen gas and a rare gas, it is possible to obtain a dielectric multilayer film that absorbs little light with a wavelength of 440 to 580 nm in the visible light region, has excellent smoothness, and has few crystals. .

By appropriately setting the structure of the dielectric multilayer film, specifically, the types of materials constituting the high refractive index material layer, the medium refractive index material layer, the low refractive index material layer, etc., the high refractive index material layer and the By appropriately selecting the thickness of each layer such as the medium refractive index material layer and the low refractive index material layer, the order of lamination, and the number of layers, it is possible to obtain an optical filter that satisfies the above requirements.

[Reflection band]
The dielectric multilayer film preferably has a reflection band in its transmittance curve due to optical interference. By appropriately setting the film thickness of each layer to be laminated, a dielectric multilayer film having the reflection band can be obtained. Here, the reflection band means a wavelength band in which the reflectance of light incident at an angle of 5° from the surface of the dielectric multilayer film is 90% or more. In order to sufficiently reduce the transmittance of light with a wavelength of 1100 nm when incident at a high angle, at least one of the dielectric multilayer films used in this filter preferably includes a reflection band of 1200 to 1250 nm. It more preferably includes the band from ˜1270 nm, even more preferably from 1200 to 1290 nm, and most preferably from 1200 to 1310 nm.

The dielectric multilayer film preferably has a continuous reflection band of 100 nm or more in the wavelength range of 700 to 1600 nm. The width (wavelength range) of this reflection band is called the reflection bandwidth.
At least one of the dielectric multilayer films used in the present filter preferably has a reflection bandwidth of 385 nm or more, more preferably 420 nm or more, particularly preferably 450 nm or more, and preferably 500 nm or more. Most preferred. If the reflection bandwidth is within the above range, an optical filter that satisfies the requirement (E) can be easily obtained.
Further, the present filter has two dielectric multilayer films, one of which has a reflection bandwidth of 385 nm or more, and the other dielectric multilayer has a reflection bandwidth of preferably 215 nm or more, It is more preferably 250 nm or more, particularly preferably 280 nm or more, and most preferably 320 nm or more.
An optical filter containing a dielectric multilayer film having the above reflection bandwidth can block a wide range of wavelengths in the range of 700 to 1600 nm, and even when the transmission characteristics shift to the short wavelength side at high angle incidence, The shielding performance of light with a wavelength of 1100 nm can be maintained.

At least one of the dielectric multilayer films used in this filter preferably satisfies the following requirements (a) to (c).
(a) In addition to the three layers adjacent to the substrate and the outermost layer, at least two continuous layers a having a physical thickness of 60 nm or less have a continuous layer a (b) Adjacent to the continuous layer a, a physical film (c) A continuous layer c of at least two layers having a physical thickness of 60 nm or less adjacent to the layer b on the opposite side of the continuous layer a.

In addition, it is preferable that at least one of the dielectric multilayer films used in this filter satisfies the following requirement (d).
(d) a high refractive index layer having a refractive index of 2.0 or more for light at a wavelength of 550 nm and an optical thickness of 160 to 320 nm at a wavelength of 550 nm; It has 4 or more layers alternately with layers having a lower refractive index than the refractive index layers

By using a dielectric multilayer film that satisfies the requirements (a) to (c) and a dielectric multilayer film that satisfies the requirement (d), it has a reflection band in the near-infrared band, and the wavelength of the near-infrared reflection band is about 1/ It is possible to suppress the decrease in the transmittance of the wavelength of No. 3, and easily obtain an optical filter that satisfies a high blue transmittance and a low near-infrared transmittance at high-angle incidence. Further, by using a dielectric multilayer film satisfying requirements (a) to (c) and a dielectric multilayer film satisfying requirement (d), an optical filter satisfying requirements (c) and (g) can be easily obtained. can.
The dielectric multilayer film satisfying requirements (a) to (c) and the dielectric multilayer film satisfying requirement (iv) may be one dielectric multilayer film satisfying requirements (a) to (iv). , the dielectric multilayer film satisfying the requirements (a) to (c) and the dielectric multilayer film satisfying the requirement (iv) may be different.

At least one of the dielectric multilayer films used in the present filter preferably has two or more layer groups when a layer group consists of a combination of five layers that satisfy the requirements (a) to (c), Having three or more is more preferable, and having four or more is particularly preferable. Here, only one layer group to which a specific layer belongs is provided. When a plurality of layer groups are adjacent to each other, each layer belongs to one of the layer groups. The upper limit of the number of layers is not particularly limited. tends to increase, the number is preferably 6 or less, more preferably 5 or less.

In the requirements (a) and (c), at least two continuous layers (continuous layers a and c) having a physical thickness of 60 nm or less are preferably three or more in total in the dielectric multilayer film, more preferably is preferably 5 or more, particularly preferably 7 or more. Note that here, the continuous layer itself is counted as one instead of counting the layers constituting the continuous layer as one. The greater the number of at least two continuous layers (continuous layers a and c) having a physical thickness of 60 nm or less, the easier it is to achieve both a high blue transmittance and a low near-infrared transmittance at high-angle incidence.
Each of the continuous layers a and c is preferably a continuous layer in which two layers each having a physical thickness of 60 nm or less are continuous.

Layers with a physical thickness of 60 nm or less in the three layers adjacent to the substrate match the complex refractive index of the substrate and the complex refractive index of the dielectric multilayer film, and reduce the local transmittance in the visible light range (hereinafter (also called "ripple").
A layer having a physical thickness of 60 nm or less provided as the outermost layer of the dielectric multilayer film matches the refractive index of an incident medium such as air or an output medium with the complex refractive index of the dielectric multilayer film, thereby reducing ripples in the visible light range. It tends to be provided for the purpose of suppressing the occurrence.

It is preferable that the layer b existing between the continuous layer a and the continuous layer c is one layer.

The number of alternately continuous layers (the total number of layers of the high refractive index layer and the lower refractive index layer) in the requirement (d) is more preferably 8 layers or more, more preferably 10 layers or more, and particularly preferably 14 layers. 18 layers or more, most preferably 18 layers or more.
As the number of alternate layers of high refractive index layers having a refractive index of 2.0 or more and layers having a lower refractive index than the high refractive index layers in the dielectric multilayer film increases, the reflection characteristics in the near-infrared band tend to increase. For this reason, when an optical filter having such a dielectric multilayer film is used in a solid-state imaging device, sensor, or module, when an image is taken of a light source that emits a large amount of near-infrared rays invisible to the human eye, such as a near-infrared sensor, Also in , it is possible to obtain a good image that is close to the image seen by the human eye.

When producing the filter (II) having a reflection band in the range of 720 to 1250 nm, at least one of the dielectric multilayer films used in the filter (II) has a wavelength of 720 to 1250 nm, which is the reflection band. The layer may have a thickness, ie, an optical thickness in the range of 360 to 625 nm. A layer having such an optical thickness is called a cavity, and a dielectric multilayer film having the cavity can form a transmission band within its reflection band. An optical filter having a transmission band in the near-infrared reflection band in the wavelength range of 720 to 1250 nm has an optical thickness of 1/2 of the reflection band, that is, a layer having an optical thickness in the range of 360 to 625 nm. is preferred. Having a layer with an optical thickness in the range of 360 to 625 nm makes it possible to easily obtain an optical filter that satisfies the requirement (F). Therefore, it is possible to achieve both a high transmittance in the reflection band and a low transmittance around the transmission band. A plurality of cavities may be provided. A dielectric multilayer film with two cavities is called a double-cavity type, and a dielectric multilayer film with three cavities is called a triple-cavity type. can be widely secured.

<Other functional films>
In the present filter, a dielectric multilayer film is provided between the substrate and the dielectric multilayer film, the surface opposite to the dielectric multilayer film-provided surface of the substrate, or the substrate of the dielectric multilayer film is provided within the range that does not impair the effects of the present invention. For the purpose of improving the adhesion between the substrate and the dielectric multilayer film, improving the surface hardness of the substrate and the dielectric multilayer film, improving chemical resistance, antistatic, and removing scratches, etc. , an adhesion layer (adhesive layer), an antireflection layer, a hard coat film, an antistatic film, and other functional films as appropriate.
The present filter may include one layer of the functional membrane, or may include two or more layers. When the present filter contains two or more layers of the functional membrane, 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 coating agent such as an antireflection agent, a hard coating agent and/or an antistatic agent is melt-molded or cast-molded onto a substrate or dielectric multilayer film in the same manner as described above. methods and the like.
It can also be produced by applying a curable composition containing the coating agent and the like on a substrate or a dielectric multilayer film by a known method such as a bar coater, and then curing the composition by ultraviolet irradiation or the like.

Examples of the coating agent include ultraviolet (UV)/electron beam (EB) curable resins and thermosetting resins. Specifically, vinyl compounds, urethane, urethane acrylate, acrylate, epoxy and epoxy acrylate resins. These may be used individually by 1 type, and may use 2 or more types. 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.

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.

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. Particularly preferably, it is 1 to 5% by mass. When the blending ratio of the polymerization initiator is within the above range, the curable composition has excellent curing characteristics and handleability, and functional films such as antireflection layers, hard coat films, and antistatic films having desired hardness can be easily obtained. be able to.

The curable composition may contain an organic solvent, and known solvents can be used as the organic solvent. 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- and amides such as methylpyrrolidone.
These solvents may be used individually by 1 type, and may be used 2 or more types.

The thickness of the functional film is preferably 0.1-30 μm, more preferably 0.1-20 μm, particularly preferably 0.1-5 μm.

Corona treatment or plasma treatment on the surface of the substrate, functional film or dielectric multilayer film for the purpose of improving the adhesion between the substrate and the functional film and/or the dielectric multilayer film or the adhesion between the functional film and the dielectric multilayer film. Other surface treatments may be applied.

[Light shielding layer]
In addition, the present filter may have a light shielding layer in the outermost layer of the optical filter or part of the layers, as shown in FIGS. 1(F) and (G). The light-shielding layer is a layer that blocks (cuts) light, and by having the light-shielding layer, in a solid-state imaging device or camera module equipped with an optical filter, light reflected by the frame or lens is suppressed from entering the sensor. This is preferable because an image in which ghosts are suppressed can be easily obtained.

Materials for forming the light shielding layer include resin materials such as thermosetting resins, ultraviolet curable resins, and thermoplastic resins; metal materials such as chromium, molybdenum, tungsten, iron, nickel, titanium, and lower chromium oxide; graphite and carbon nanotubes; Carbon materials such as fullerene, absorption materials made of pigments, and the like can be used. These materials may be used alone or in combination of two or more, and two or more of these materials may be used. Among these, it is preferable to contain an ultraviolet curable resin from the viewpoint of easiness of shape control.

The thickness of the light shielding layer is preferably 0.1 to 10 μm.
When the thickness of the light shielding layer is less than 0.1 μm, it tends to be difficult to obtain a sufficient optical density (hereinafter also referred to as “OD value”). influence tends to be greater. The thickness is preferably 0.5 to 4.0 μm.

The light shielding layer provided on the optical filter may be provided at one location or at a plurality of locations. Here, regarding the number of light shielding layers, a continuous layer is regarded as one light shielding layer, and having a plurality of light shielding layers means having a plurality of discontinuous light shielding layers.

The light-shielding layer has an OD value of preferably 3.0 or more, more preferably 4.0 or more in terms of total light transmittance in a D65 light source (a standard light source defined by the International Commission on Illumination (CIE)). It is desirable to have
When the OD value is within the above range, stray light can be sufficiently shielded.

A method for forming the light shielding layer is not particularly limited, and examples thereof include a coating method, a sputtering method, a vacuum deposition method, and the like.
The coating methods include spin coating, bar coating, dip coating, casting, spray coating, bead coating, wire bar coating, blade coating, roller coating, curtain coating, slit die coating, A gravure coating method, a slit reverse coating method, a micro gravure method, a comma coating method, and the like can be mentioned. Application in these methods may be performed in multiple steps.

The light shielding layer may cooperate with a plurality of light shielding layers to form a Fresnel zone plate or mosaic mask. An optical filter having a Fresnel zone plate formed thereon can be used as a substitute for a lens, and the obtained solid-state imaging device, camera module, sensor module, etc. can be made thinner, which is preferable. An optical filter that forms a mosaic mask is preferable because it can eliminate the need for a lens, and image data that can change the focal length can be obtained by computationally processing the obtained image.

<Uses of optical filters>
This filter is thin, has excellent luminosity correction characteristics, and has excellent cut characteristics in the near-infrared band even when incident light is at a high angle. Therefore, it is useful for visibility correction of solid-state imaging devices such as solid-state imaging devices, camera modules, and sensors that are compatible with high-angle incidence. 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 , ambient light sensors, distance measurement sensors, iris recognition systems, face recognition systems, distance measurement cameras, digital music players, etc.

FIG. 4 shows an example of arrangement of members when this filter is used in a solid-state imaging device or module. In FIG. 4, the main filter 1 is configured with a lens 32 and an image sensor (image sensor) 24 . The optical filter 1 may be positioned in front of the lens as shown in FIG. 4A or behind the lens as shown in FIG. 4B. The present filter may also be used in a lensless solid-state imaging device using an optical element 33 such as a Fresnel zone plate, a Fresnel lens, or a metalens, which functions as a lens, as shown in FIG. 5(A).

The camera module includes, for example, the present filter, an image sensor, a focus adjustment mechanism, a phase detection mechanism, a distance measurement mechanism, an iris authentication mechanism, a vein authentication mechanism, a face authentication mechanism, a blood flow meter, an oxidized type or a reduced type A device that includes a hemoglobin amount meter, a vegetation index meter, and the like, and that outputs images and information as electric signals can be mentioned. Such a camera module may be configured with a lens as shown in FIG. 4, or may be configured without a lens as shown in FIG.

Photoelectric conversion elements such as silicon, black silicon, and organic photoelectric conversion films, which convert light of a specific wavelength into electric charges, are used as members constituting the solid-state imaging device. This filter is suitably used for applications using solid-state imaging devices such as black silicon and organic photoelectric conversion films in which it is difficult to suppress dark current.

[Black Silicon]
Black silicon may be used for the light receiving portion of the solid-state imaging device using this filter. Black silicon can be obtained, for example, by irradiating a silicon wafer with a laser under a specific atmosphere to form minute spikes on the silicon surface. When black silicon is used, the light receiving sensitivity in the near-infrared band is higher than in the case of using a silicon photodiode. Therefore, black silicon is preferably used for imaging devices using near-infrared rays. Commercially available CMOS products using black silicon include XQE series from SiOnyx.

EXAMPLES The present invention will be described in more detail below based on examples, but the present invention is by no means limited to these examples. In addition, "parts" means "parts by mass" unless otherwise specified. In addition, the method for measuring each physical property value and the method for evaluating physical properties are as follows.

<Molecular weight>
Using a GPC apparatus manufactured by Tosoh Corporation (HLC-8220, column: TSKgelα-M, developing solvent: THF), the weight average molecular weight (Mw) and number average molecular weight (Mn) in terms of standard polystyrene were measured.

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

<Spectral transmittance>
The transmittance of the optical filter in each wavelength region was measured using a spectrophotometer (U-4100) manufactured by Hitachi High-Technologies Corporation.
Here, as shown in FIG. Hitachi High-Tech Fielding Co., Ltd., 12 V 50 W, Part No. 885-1200) is incident, and the light 6 transmitted in the vertical direction is measured with a spectrophotometer 7. 45 in the vertical direction of the surface of the optical filter As shown in Fig. 2(B), the transmittance of the non-polarized light beam incident at an angle of 10° is measured by using a halogen lamp (manufactured by Hitachi High-Tech Fielding Co., Ltd.) at an angle of 45° with respect to the direction perpendicular to the surface of the optical filter 1. , 12V50W, Part No. 885-1200) as a light source (S-polarized light and P-polarized light) 6′ is incident, and the light 6′ transmitted at an angle of 45° with respect to the vertical direction is detected by a spectrophotometer 7 Measured in
In addition, the average transmittance of wavelengths A to B nm is obtained by measuring the transmittance at each wavelength of 1 nm or more and B nm or less, and calculating the total of the transmittances. ).
A value calculated from the average of the S-polarized light transmittance and the P-polarized light transmittance was used as the transmittance of non-polarized light.
0°T represents the transmittance at 0° incidence, and 45°T represents the transmittance at 45° incidence.

<Spectral reflectance>
The reflectance of the optical filter in each wavelength region was measured using a spectrophotometer (U-4100) manufactured by Hitachi High-Technologies Corporation.
Here, the reflectance of a non-polarized light beam incident at an angle of 5° with respect to the direction perpendicular to the surface of the optical filter is, as shown in FIG. A halogen lamp (manufactured by Hitachi High-Tech Fielding Co., Ltd., 12V50W, Part No. 885-1200) was used as the light source, and the reflected light 11 of unpolarized light was measured with the spectrophotometer 7 .
In addition, the average reflectance of wavelengths A to B nm is obtained by measuring the reflectance at each wavelength of 1 nm or less from A nm to B nm, and the total reflectance is the number of measured reflectances (wavelength range, BA + 1 ).
A value calculated from the average of the S-polarized reflectance and the P-polarized reflectance was used as the reflectance of non-polarized light.
5°R represents the reflectance at 5° incidence.

The infrared absorbing agents used in the following examples were synthesized by a generally known method. As the synthesis method, for example, JP-A-60-228448, JP-A-1-146846, JP-A-1-228960, JP-A-4081149, JP-A-63-124054, "phthalocyanine -Chemistry and Function-" (IPC, 1997), JP 2007-169315, JP 2009-108267, JP 2010-241873, JP 3699464, JP 4740631 The methods described can be mentioned.

<Resin Synthesis Example 1>
8-methyl-8-methoxycarbonyltetracyclo[4.4.0.1 ^2,5 . 1 ^7,10 ]dodeca-3-ene 100 parts, 1-hexene (molecular weight modifier) 18 parts and toluene (solvent for ring-opening polymerization reaction) 300 parts were charged into a reaction vessel purged with nitrogen, and the solution was heated to 80°C. heated to Next, 0.2 parts of a toluene solution of triethylaluminum (concentration: 0.6 mol/liter) and a toluene solution of methanol-modified tungsten hexachloride (concentration: 0.025 mol/liter) were added to the solution in the reaction vessel as polymerization catalysts. 9 parts were added, and the solution was heated and stirred at 80° C. for 3 hours to carry out ring-opening polymerization reaction to obtain a ring-opening polymer solution. The polymerization conversion rate in this polymerization reaction was 97%.

An autoclave was charged with 1,000 parts of the ring-opened polymer solution thus obtained, and 0.12 part of RuHCl(CO)[P(C ₆ H ₅ ) ₃ ] ₃ was added to the ring-opened polymer solution. Then, under the conditions of a hydrogen gas pressure of 100 kg/cm ² and a reaction temperature of 165° C., a hydrogenation reaction was carried out by heating and stirring for 3 hours. After cooling the resulting reaction solution (hydrogenated polymer solution), hydrogen gas was released. This reaction solution was poured into a large amount of methanol to separate and recover a solidified product, which was dried to obtain a hydrogenated polymer (hereinafter also referred to as "resin A"). The resulting resin A had an Mn of 32,000, an Mw of 137,000, and a Tg of 165°C.

[Example 1]
On both sides of a borosilicate glass substrate (manufactured by SCHOTT, D263, thickness 0.1 mm), using an ion-assisted vacuum deposition apparatus, starting pressure 0.0001 Pa, deposition temperature 120 ° C., oxygen and argon as supply gases to the ion gun A layer with a physical thickness of 60 nm or less is controlled by the integrated film thickness of the crystal oscillator, and a dielectric multilayer film [silica (SiO ₂ : 550 nm light Layers with a refractive index of 1.46) and layers of titanium oxide (TiO ₂ : a layer with a refractive index of 2.49 for light at 550 nm) are alternately laminated] to obtain an optical filter 1 having a thickness of 0.11 mm. .
The optical properties of the obtained optical filter 1 are shown in FIG. 6 and Table 8.

[Example 2]
The following curable composition solution (1) was applied to a borosilicate glass support (manufactured by SCHOTT, D263, thickness 0.1 mm) with a spin coater and heated on a hot plate at 80 ° C. for 2 minutes to remove the solvent. It was volatilized and removed to form a cured 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. Next, on the cured layer, using a bar coater (manufactured by Yasuda Seiki Seisakusho Co., Ltd., automatic film applicator, model number 542-AB), the following resin composition (1) is applied and coated on a hot plate at 80 ° C. It was heated for 5 minutes to volatilize and remove the solvent to form a resin layer. At this time, the coating conditions of the bar coater were adjusted so that the film thickness of the resin layer was about 10 μm. Next, from the glass side, exposure is performed using a UV conveyor type exposure machine (eye UV curing device, model US2-X0405, 60 Hz, manufactured by Eye Graphics Co., Ltd.) (exposure amount: 500 mJ/cm ² , illuminance: 200 mW). After that, it was baked in an oven at 210° C. for 5 minutes to form a substrate having a thickness of 0.111 mm and having a resin absorption layer containing an infrared absorber.

Curable composition solution (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 parts, glycidyl methacrylate 30 parts, 3-glycidoxypropyltrimethoxysilane 5 parts, 1-hydroxycyclohexylbenzophenone (trade name: IRGACURE 184, manufactured by Chiba Specialty Chemical Co., Ltd.) 5 parts and San-Aid SI-110 main agent ( Sanshin Chemical Industry Co., Ltd.) 1 part was mixed, dissolved in propylene glycol monomethyl ether acetate so that the solid content concentration was 50 wt%, and then filtered through a Millipore filter with a pore size of 0.2 μm Solution resin composition ( 1): 100 parts of resin A obtained in Resin Synthesis Example 1, 0.338 parts of compound (B) described later, 0.945 parts of compound (C), dichloromethane (solvent, concentration of resin A becomes 10% by mass composition containing

A dielectric multilayer film was formed on the obtained substrate in the same manner as in Example 1 as in Design 2 in Table 3 to obtain an optical filter 2 with a thickness of 0.12 mm.
The optical properties of the obtained optical filter 2 are shown in FIG. 7 and Table 8.

[Example 3]
100 parts of Resin A obtained in Resin Synthesis Example 1, 0.048 parts of compound (A) described later, and dichloromethane were added to a container to prepare a solution having a resin concentration of 8% by mass. The resulting solution was cast on a borosilicate glass substrate (manufactured by SCHOTT, D263, thickness 0.1 mm), dried at 60°C for 8 hours, and further dried at 140°C under reduced pressure for 4 hours. By peeling from the material, a resin substrate (absorbing layer) having a thickness of 0.1 mm and containing an infrared absorbing agent was obtained.

A dielectric multilayer film was formed on the resulting substrate in the same manner as in Example 1, as in Design 3 in Table 3, to obtain an optical filter 3 with a thickness of 0.11 mm.
The optical properties of the obtained optical filter 3 are shown in FIG. 8 and Table 8.

[Example 4]
100 parts of the resin A obtained in Resin Synthesis Example 1, 0.0338 parts of the compound (B) described later, 0.0945 parts of the compound (C) described later, and dichloromethane were added to a container to give a resin concentration of 20% by mass. was prepared. The resulting solution was cast on a borosilicate glass substrate (manufactured by SCHOTT, D263, thickness 0.1 mm), dried at 60°C for 8 hours, and further dried at 140°C under reduced pressure for 4 hours. By peeling from the material, a resin substrate (absorbing layer) having a thickness of 0.1 mm and containing an infrared absorbing agent was obtained.

A dielectric multilayer film was formed on the resulting substrate in the same manner as in Example 1, as in Design 4 in Table 4, to obtain an optical filter 4 with a thickness of 0.11 mm.
The optical properties of the obtained optical filter 4 are shown in FIG. 9 and Table 8.

[Example 5]
100 parts of Resin A obtained in Resin Synthesis Example 1 and dichloromethane were added to a container to obtain a solution (A) having a resin concentration of 8% by mass. The resulting solution (A) was cast on a borosilicate glass substrate (manufactured by SCHOTT, D263, thickness 0.1 mm), dried at 60°C for 8 hours, and further dried at 140°C under reduced pressure for 4 hours. After that, it was peeled off from the substrate to obtain a resin film with a thickness of 0.09 mm. Using a bar coater (manufactured by Yasuda Seiki Seisakusho Co., Ltd., automatic film applicator, model number 542-AB) on the resin film, the following resin composition (3) is applied, and the four sides of the film periphery are coated with a stainless steel jig. After being fixed at room temperature for 30 minutes, it was dried at 60 ° C. for 8 hours, and further dried at 140 ° C. under reduced pressure for 4 hours. of the substrate (absorbing layer) was obtained. At this time, the coating conditions of the bar coater were adjusted so that the thickness increase after drying was 0.01 mm.
Resin composition (3): 100 parts of Resin A obtained in Resin Synthesis Example 1, 0.034 part of compound (B) described later, 0.095 part of compound (C) described later, 0.095 part of compound (E) described later. 045 parts and a solution with a resin concentration of 20% by weight containing dichloromethane

A dielectric multilayer film was formed on the resulting substrate in the same manner as in Example 1, as Design 5 in Table 4, to obtain an optical filter 5 with a thickness of 0.11 mm.
The optical properties of the obtained optical filter 5 are shown in FIG. 10 and Table 8.

[Example 6]
100 parts of the resin A obtained in Resin Synthesis Example 1, 0.068 parts of the compound (B) described later, 0.189 parts of the compound (C) described later, and dichloromethane were added to a container to obtain a solution having a resin concentration of 20% by mass. was prepared. The resulting solution was cast on a borosilicate glass substrate (manufactured by SCHOTT, D263, thickness 0.1 mm), dried at 60°C for 8 hours, and further dried at 140°C under reduced pressure for 4 hours. By peeling from the material, a resin support (absorbing layer) having a thickness of 0.05 mm and containing an infrared absorbing agent was obtained.

Hard coating agent "Beamset" manufactured by Arakawa Chemical Industries, Ltd. is used with a bar coater (manufactured by Yasuda Seiki Seisakusho Co., Ltd., automatic film applicator, model number 542-AB), and the film thickness after drying with a coater bar is 0. Both sides of the resin support were coated so as to have a thickness of 0.001 mm. After drying at 80 ° C. for 3 minutes using an inert oven (inert oven DN410I manufactured by Yamato Scientific Co., Ltd.), a UV conveyer (manufactured by Eye Graphics Co., Ltd., eye ultraviolet curing device, model US2-X0405, 60 Hz). was cured with a metal halide lamp (illuminance of 270 mW/cm ² , exposure amount of 500 mJ/cm ² ) to obtain a substrate on which a transparent cured layer was formed.

Using an ion-assisted vacuum vapor deposition apparatus, the obtained substrate is subjected to a starting pressure of 0.0001 Pa and a vapor deposition starting temperature of 120° C. for the surface X, and a starting pressure of 0.0001 Pa and a vapor deposition starting temperature of 90° C. for the surface Y. Using a mixed gas of oxygen and argon as a supply gas to the ion gun, the layer with a physical thickness of 60 nm or less is controlled by the integrated thickness of the crystal oscillator, and a dielectric multilayer film [ Silica (SiO ₂ : refractive index for light at 550 nm: 1.46) layers and titanium oxide (TiO ₂ : refractive index for light at 550 nm: 2.49) layers are alternately laminated], and a thickness of 0 is formed. An optical filter 6 of 0.06 mm was obtained.
The optical characteristics of the obtained optical filter 6 are shown in FIG. 11 and Table 8.

[Example 7]
In a container, 100 parts of resin A obtained in Resin Synthesis Example 1, 0.034 parts of compound (B) described later, 0.095 parts of compound (C) described later, 0.045 parts of compound (E) described later and dichloromethane was added to prepare a solution having a resin concentration of 20% by mass. The resulting solution was cast on a borosilicate glass substrate (manufactured by SCHOTT, D263, thickness 0.1 mm), dried at 60°C for 8 hours, and further dried at 140°C under reduced pressure for 4 hours. By peeling from the material, a resin support (absorbing layer) having a thickness of 0.1 mm and containing the infrared absorbent and the ultraviolet absorbent was obtained.

Arakawa Chemical Industries Co., Ltd. hard coating agent "Beam Set" is used with a bar coater (manufactured by Yasuda Seiki Seisakusho Co., Ltd., automatic film applicator, model number 542-AB), and the film thickness after drying with a coater bar is 0. Both sides of the resin support were coated so as to have a thickness of 0.002 mm. After drying at 80 ° C. for 3 minutes using an inert oven (inert oven DN410I manufactured by Yamato Scientific Co., Ltd.), a UV conveyer (manufactured by Eye Graphics Co., Ltd., eye ultraviolet curing device, model US2-X0405, 60 Hz). was cured with a metal halide lamp (illuminance of 270 mW/cm ² , exposure amount of 500 mJ/cm ² ) to obtain a substrate on which a transparent cured layer was formed.

A dielectric multilayer film was formed on the resulting substrate in the same manner as in Example 6 as in Design 7 in Table 5 to obtain an optical filter 7 with a thickness of 0.11 mm.
The optical characteristics of the obtained optical filter 7 are shown in FIG. 12 and Table 8.

[Example 8]
In the same procedure as in Example 2, except that the resin composition (1) in Example 2 was changed to the resin composition (4) described later, a resin layer having a thickness of 0.05 mm containing an infrared absorber and an ultraviolet absorber was formed. A 111 mm substrate was formed.
Resin composition (4): 100 parts of Resin A obtained in Resin Synthesis Example 1, 0.04 part of compound (A) described later, 0.184 part of compound (B) described later, 0.184 part of compound (C) described later. 945 parts, 0.21 parts of compound (D) described later, 0.75 parts of compound (E) described later, dichloromethane (solvent, used so that the concentration of resin A is 10% by mass).

A dielectric multilayer film was formed on the resulting substrate in the same manner as in Example 6, as in Design 8 in Table 5, to obtain an optical filter 8 with a thickness of 0.12 mm.
The optical properties of the obtained optical filter 8 are shown in FIG. 13 and Table 8.

[Example 9]
On a near-infrared absorbing glass support (manufactured by Matsunami Glass Industry Co., Ltd., BS11 polished to a thickness of 0.05 mm), the curable composition solution (1) was applied by spin coating, and then 80 on a hot plate. C. for 2 minutes to volatilize and remove the solvent to form a cured 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. Next, on the cured layer, a bar coater (manufactured by Yasuda Seiki Seisakusho Co., Ltd., automatic film applicator, model number 542-AB) is used, and the following is applied so that the film thickness after drying with the coater bar is 0.01 mm each. Resin composition (5) was applied. Then, it was heated on a hot plate at 80° C. for 5 minutes to volatilize and remove the solvent to form a resin layer. After that, it is exposed from the glass 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 contain an infrared absorber and an ultraviolet absorber. A substrate having a thickness of 0.06 mm was formed from a near-infrared absorbing glass support having a resin-made absorbing layer.
Resin composition (5): 100 parts of resin A obtained in Resin Synthesis Example 1, 0.25 parts of compound (B) described later, 0.75 parts of compound (E) described later, dichloromethane (solvent, concentration of resin A A composition containing 20% by mass)

A dielectric multilayer film was formed on the resulting substrate in the same manner as in Example 6, as in Design 9 in Table 5, to obtain an optical filter 9 with a thickness of 0.07 mm.
The optical properties of the obtained optical filter 9 are shown in FIG. 14 and Table 8.

[Example 10]
In a container, 100 parts of resin A obtained in Resin Synthesis Example 1, 0.068 parts of compound (B) described later, 0.189 parts of compound (C) described later, 0.09 part of compound (E) described later and dichloromethane was added to prepare a solution having a resin concentration of 20% by mass. The resulting solution was cast on a borosilicate glass substrate (manufactured by SCHOTT, D263, thickness 0.1 mm), dried at 60°C for 8 hours, and further dried at 140°C under reduced pressure for 4 hours. A 0.05 mm-thick resin substrate (absorbing layer) containing an infrared absorbent and an ultraviolet absorbent was obtained by peeling from the substrate.

A dielectric multilayer film was formed on the resulting substrate in the same manner as in Example 6, as in Design 10 in Table 6, to obtain an optical filter 10 with a thickness of 0.06 mm.
The optical properties of the obtained optical filter 10 are shown in FIG. 15 and Table 8.

[Example 11]
In the same procedure as in Example 2, except that the resin composition (1) in Example 2 was changed to the resin composition (6) described later, a resin layer having a thickness of 0.05 mm and containing an infrared absorber and an ultraviolet absorber was formed. A 111 mm substrate was formed.
Resin composition (6): 100 parts of Resin A obtained in Resin Synthesis Example 1, 0.338 parts of compound (B) described later, 0.945 parts of compound (C) described later, 0.945 parts of compound (E) described later. 45 parts of a composition containing dichloromethane (solvent, used so that the concentration of resin A is 10% by weight)

On the obtained substrate, using an ion-assisted vacuum vapor deposition apparatus, on the surface X, at a start pressure of 0.0001 Pa, a vapor deposition start temperature of 120° C., and a mixed gas of oxygen and argon as a supply gas to the ion gun, a thickness of 60 nm was obtained. The layers with the following physical thicknesses are controlled by the cumulative thickness of the crystal oscillator, and as in Design 11 in Table 6, a dielectric multilayer film [silica (SiO ₂ : refractive index of 550 nm light: 1.46) layer and oxide Titanium (TiO ₂ : refractive index of 550 nm light: 2.49) layers] are alternately laminated], and the surface Y is subjected to an ion gun at a starting pressure of 0.0001 Pa and a vapor deposition starting temperature of 70 ° C. Using a mixed gas of oxygen and argon as a supply gas, the layer with a physical thickness of 60 nm or less is controlled by the integrated thickness of the crystal oscillator, and a dielectric multilayer film [silica ( SiO ₂ : refractive index of 550 nm light: 1.46) layer, titanium oxide (TiO ₂ : refractive index of 550 nm light: 2.49) layer and tantalum oxide (Ta ₂ O ₅ : refractive index of 550 nm light: 2.14) ) layers are laminated alternately] to obtain an optical filter having a thickness of 0.12 mm.

On one surface of the obtained optical filter, a light-shielding UV-curable resin (CFPR-BK-416 manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied by a spin coating method to a thickness of 3 μm. After heating at ℃ for 5 minutes, the surface was cured by irradiating ultraviolet light with an exposure amount of 200 mJ/cm ² from a high-pressure mercury lamp through a photomask. After that, by removing the unexposed portions with an alkaline developer ("N-A3K" manufactured by Tokyo Ohka Kogyo Co., Ltd.), the optical filter has two types of light shielding layers with a width of 500 μm or 2 mm on the outer circumference of one surface. An optical filter 11 was obtained.
FIG. 16 and Table 8 show the optical characteristics of the portion of the obtained optical filter 11 where the light shielding layer is not formed.

[Example 12]
In a container, 100 parts of resin A obtained in Resin Synthesis Example 1, 0.004 parts of compound (A) described later, 0.018 parts of compound (B) described later, 0.095 parts of compound (C) described later, 0.021 part of the compound (D), 0.075 part of the later-described compound (E) and dichloromethane were added to prepare a solution having a resin concentration of 20% by mass. The resulting solution was cast on a borosilicate glass substrate (manufactured by SCHOTT, D263, thickness 0.1 mm), dried at 60°C for 8 hours, and further dried at 140°C under reduced pressure for 4 hours. By peeling from the material, a resin substrate (absorbing layer) having a thickness of 0.11 mm and containing an infrared absorbent and an ultraviolet absorbent was obtained.

On the obtained substrate, using an ion-assisted vacuum vapor deposition apparatus, on the surface X, at a start pressure of 0.0001 Pa, a vapor deposition start temperature of 120° C., and a mixed gas of oxygen and argon as a supply gas to the ion gun, a thickness of 60 nm was obtained. The layers with the following physical thicknesses are controlled by the cumulative thickness of the crystal oscillator, and as in design 12 in Table 6, dielectric multilayer films [silica (SiO ₂ : refractive index of 550 nm light: 1.46) layer and oxide Titanium (TiO ₂ : refractive index of 550 nm light: 2.49) layers] are alternately laminated], and the surface Y is subjected to an ion gun at a starting pressure of 0.0001 Pa and a vapor deposition starting temperature of 70 ° C. Using a mixed gas of oxygen and argon as a supply gas, the layer with a physical thickness of 60 nm or less is controlled by the integrated thickness of the crystal oscillator, and a dielectric multilayer film [silica ( SiO ₂ : refractive index of 550 nm light: 1.46) layer, titanium oxide (TiO ₂ : refractive index of 550 nm light: 2.49) layer and tantalum oxide (Ta ₂ O ₅ : refractive index of 550 nm light: 2.14) ) layers are laminated alternately] to obtain an optical filter 12 having a thickness of 0.12 mm.
The optical properties of the obtained optical filter 12 are shown in FIG. 17 and Table 8.

[Comparative Example 1]
On one side of a borosilicate glass substrate (manufactured by SCHOTT, D263, thickness 0.1 mm), using an ion-assisted vacuum deposition apparatus, a mixture of oxygen and argon is supplied to an ion gun at a deposition temperature of 120 ° C. Using a gas, the layer with a physical thickness of 60 nm or less was controlled by the integrated thickness of the crystal oscillator, and the dielectric multilayer film of design 13 listed in Table 7 [silica (SiO ₂ : refractive index of 550 nm light of 1 .46) layers and titanium oxide (TiO ₂ : refractive index of 550 nm light: 2.49) layers] were formed to obtain an optical filter 13 having a thickness of 0.1 mm.
The optical properties of the obtained optical filter 13 are shown in FIG. 18 and Table 9.

[Comparative Example 2]
In Example 5, the same procedure as in Example 5 was performed except that the following resin composition (7) was used instead of resin composition (3), and the dielectric multilayer film was changed to design 14 shown in Table 7. An optical filter 14 was obtained in the procedure. The optical properties of the obtained optical filter 14 are shown in FIG. 19 and Table 9.
Resin composition (7): 100 parts of Resin A obtained in Resin Synthesis Example 1, 0.034 part of compound (B) described later, 0.095 part of compound (C) described later, 0.095 part of compound (E) described later. 09 parts and a solution with a resin concentration of 20% by weight containing dichloromethane

[Comparative Example 3]
An optical filter 15 was obtained in the same manner as in Comparative Example 2, except that the dielectric multilayer film was changed to Design 15 shown in Table 7. The optical properties of the obtained optical filter 15 are shown in FIG. 20 and Table 9.

[Comparative Example 4]
In Example 9, the following resin composition (8) was used instead of resin composition (5), and the dielectric multilayer film was changed to design 16 shown in Table 7. An optical filter 16 was obtained in the procedure. The optical properties of the obtained optical filter 16 are shown in FIG. 21 and Table 9.
Resin composition (8): 100 parts of resin A obtained in Resin Synthesis Example 1, 0.025 parts of compound (B) described later, 0.09 part of compound (E) described later, dichloromethane (solvent, concentration of resin A A composition containing 20% by mass)

With 1050 nm as the central wavelength of the infrared reflection band, TiO ₂ (refractive index at 550 nm: 2.49) and SiO ₂ (refractive index at 550 nm: 1.46) having an optical film thickness about 1/4 of the reflection band We designed a dielectric multilayer film containing a stack of An optical filter having a dielectric multilayer film of this design also reflected light in the wavelength range of 350 to 400 nm, which is about one-third the wavelength of the infrared reflection band. When this dielectric multilayer film was used, the reflection band shifted to the short wavelength side at high angle incidence, and the transmittance of light with a wavelength of 1100 nm increased.

In order to suppress the increase in the transmittance, the center wavelength of the infrared reflection band is made longer. It is thought that the outer reflection band can be shifted to the longer wavelength side. By shifting the infrared reflection band of the dielectric multilayer film to the longer wavelength side in this way, an optical filter having the dielectric multilayer film can suppress an increase in transmittance at a wavelength of 1100 nm even at 45° incidence. However, instead, the transmittance of 420 to 450 nm, which is about one-third of the wavelength of the reflection band, is lowered, and when this optical filter is used in a solid-state imaging device, blue visibility correction is insufficient. became.

In general, a dielectric multilayer film forming a reflection band locally causes a drop in transmittance (ripple) at a wavelength about half of the desired reflection band. In order to reduce this, in dielectric multilayer films, a method of varying the optical film thickness for each layer to be laminated is often used.
However, such a dielectric multilayer film in which the optical film thickness varies for each laminated layer tends to reduce the bandwidth of the reflection band. It was confirmed that it tends to be difficult to simultaneously achieve a low transmittance for light with a wavelength of 1100 nm at high-angle incidence. Specifically, when the ripple in the visible light band, which is about half the infrared reflection band, was reduced, the transmittance of light with a wavelength of 1100 nm at 45° incidence increased.

<Infrared absorber>
Compound (A): Maximum absorption wavelength 698 nm when dissolved in dichloromethane

Compound (B): Maximum absorption wavelength 704 nm when dissolved in dichloromethane

Compound (C): Maximum absorption wavelength 733 nm when dissolved in dichloromethane

Compound (D): Maximum absorption wavelength 738 nm when dissolved in dichloromethane

<Ultraviolet absorber>
Compound (E): "BONASORB UA-3911" manufactured by Orient Chemical Industry Co., Ltd.

REFERENCE SIGNS LIST 1 Optical filter 2 Substrate 3, 3' Dielectric multilayer film 4, 4' Functional film or absorption layer 5 Light blocking layer 6, 6' Light 7 Spectrophotometer 11 Reflected light 24 Image sensor 25 Image sensor frame 26 Frame 31 Housing 32 Lens 33 Fresnel zone plate and Fresnel lens Substitute optical elements for lenses such as

Claims (10)

An optical filter having a substrate and a dielectric multilayer film satisfying the following requirements (a) to (d) and satisfying the following requirements (C), (E), (F) and (G).
(C) has the longest wavelength value λ _traUV5 at a wavelength of 380 nm or more and less than 430 nm, at which the transmittance of light incident from the direction perpendicular to the surface direction of the optical filter is 5%; The average transmittance of light incident from the direction perpendicular to the surface direction of the optical filter is 5% or less. % (G) _{λ traIR5 /} λ _traUV5 ≧3.15
(b) In addition to the three layers adjacent to the substrate and the outermost layer, it has a continuous layer a in which at least two layers having a physical thickness of 60 nm or less are continuous.
(b) Adjacent to the continuous layer a, there is a layer b having a physical thickness of more than 60 nm.
(c) A continuous layer c in which at least two layers having a physical film thickness of 60 nm or less are continuous adjacent to the layer b on the side opposite to the continuous layer a.
(d) a high refractive index layer having a refractive index of 2.0 or more for light at a wavelength of 550 nm and an optical thickness of 160 to 320 nm at a wavelength of 550 nm; It has 4 or more layers alternately with layers having a lower refractive index than the refractive index layers 2. The optical filter of claim 1, further satisfying the following requirements (A), (B), (D) and (H).
(A) At a wavelength of 300 to 380 nm, the average transmittance of light incident from the direction perpendicular to the surface direction of the optical filter is 5% or less. (B) At a wavelength of 380 to 430 nm, the direction perpendicular to the surface direction of the optical filter. (D) At a wavelength of 440 to 580 _nm , the average transmittance of light incident from the direction perpendicular to the surface direction of the optical filter is 60% or more (H ) At a wavelength of 720 to 1000 nm, the average transmittance of light incident from the direction perpendicular to the surface direction of the optical filter is 1% or less. 2. The optical filter of claim 1, further satisfying the following requirements (A), (B), (D), (J) and (K).
(A) At a wavelength of 300 to 380 nm, the average transmittance of light incident from the direction perpendicular to the surface direction of the optical filter is 5% or less. (B) At a wavelength of 380 to 430 nm, the direction perpendicular to the surface direction of the optical filter. (D) At a wavelength of 440 to 580 _nm , the average transmittance of light incident from the direction perpendicular to the surface direction of the optical filter is 60% or more (J ) At a wavelength of 720 to 1000 nm, the average transmittance of light incident perpendicular to the surface direction of the optical filter is 30% or less. have a continuous wavelength of 5 nm or more at which the transmittance of the light is 50% or more The optical filter according to any one of claims 1 to 3, further satisfying the following requirements (O) to (Q).
(O) At wavelengths of 370 nm or more and less than 430 nm, it has the longest wavelength value λ _traUV1 at which the transmittance of light incident from the direction perpendicular to the surface direction of the optical filter is 1%. (Q) λ traIR1 /λ _traUV1 ≧3.10 (Q) λ _traIR1 /λ _traUV1 ≧3.10 The optical filter according to any one of claims 1 to 4, further satisfying the following requirements (R) to (U).
(R) having a wavelength of 370 to 430 nm and a wavelength λ _refUV50 at which the reflectance of unpolarized light incident at an angle of 5° from the vertical direction of at least one surface of the optical filter is 50% (S) wavelength of 1150 to 1600 nm (T) λ _refIR90 /λ _traUV5 ≥ 3, the shortest wavelength value λ _refIR90 at which the reflectance of unpolarized light incident at an angle of 5° from the vertical direction of at least one surface of the optical filter is 90%. .10
(U) At a wavelength of 1000 to 1200 nm, the average reflectance of an unpolarized light beam incident at an angle of 5° from the vertical direction of at least one surface of the optical filter is 90% or more. 6. The optical filter according to any one of claims 1 to 5, further satisfying the following requirements (V) and (W).
(V) It has the shortest wavelength value λ _refIR95 at which the reflectance of unpolarized light incident at an angle of 5° from the vertical direction of at least one surface of the optical filter is 95% at a wavelength of 1150 to 1600 nm. λ _refIR95 /λ _traUV5 ≧3.10 The optical filter according to any one of claims 1 to 6 , wherein the substrate satisfies the following requirement (Y).
(Y) has a maximum absorption wavelength λ (DA_Tmin) at a wavelength of 685 to 780 nm The optical filter according to any one of claims 1 to 7 , wherein said substrate satisfies the following requirement (Z).
(Z) having a stopband of 30 nm or more, with a wavelength of 680 to 800 nm and a transmittance of 5% or less for light incident perpendicularly to the surface direction of the substrate; A solid-state imaging device comprising the optical filter according to any one of claims 1 to 8 . A camera module comprising the optical filter according to any one of claims 1 to 8 .