Optical filter

Abstract

The present invention relates to an optical filter which is provided with a light-absorbing material X700L having a maximum absorption wavelength in a wavelength region greater than 700 nm, a light-absorbing material Y970S having a maximum absorption wavelength in a wavelength region less than 970 nm, and a dielectric multilayer film, and which satisfies all specific spectral characteristics (i-1)-(i-4).

Description

TECHNICAL FIELD

[0001] The present application relates to an optical filter which selectively transmits a visible light region and a specific near-infrared light region and blocks light other than these regions. BACKGROUND

[0002] A camera using a solid-state image pickup element has expanded its use to a device such as a monitoring camera or a vehicle-mounted camera which takes a picture day and night. In such a device, it is necessary to separately acquire a (color) image based on visible light and a (monochrome) image based on infrared light.

[0003] Therefore, the use of an optical filter, so-called double bandpass filter, which has a function of selectively transmitting a specific near-infrared light in addition to a near-infrared cut filter function for transmitting visible light and faithfully reproducing an image based on the visible light, has been studied (see Patent Document 1).

[0004] PRIOR ART DOCUMENT

[0005] PATENT DOCUMENT

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2006-10764 SUMMARY

[0007] In recent years, since a laser including a region of 950 nm to 1200 nm is used in a sensor in the imaging field, there is a demand for an optical filter which can transmit near-infrared light of the above-mentioned sensing region and can block near-infrared light other than this which becomes noise.

[0008] In addition, an optical filter having a dielectric multilayer film has a problem that a spectral transmittance curve changes due to an incident angle because the optical film thickness of the dielectric multilayer film changes with the incident angle of light. For example, when the incident angle of light becomes large, the reflection characteristic shifts to the short wavelength side, and as a result, the reflection characteristic can be reduced in a region which is originally desired to be blocked. The larger the incident angle, the more likely the above-mentioned phenomenon occurs. When such a filter is used, the spectral sensitivity of a solid-state image pickup element can be affected by the incident angle. With the thinning of a camera module in recent years, it is assumed that the filter is used under a high incident angle condition, and therefore, there is a demand for an optical filter which is less affected by the incident angle.

[0009] For the shift in regions transitioning from the visible light transmission region and the short-wavelength near-infrared shading region to the near-infrared transmission region, this shift can be reduced by using absorbing materials such as pigments. However, for regions transitioning from the near-infrared transmission region to the near-infrared shading region, it is difficult to reduce the shift using absorbing materials. When the shift in this region is significant, the amount of near-infrared light transmitted varies with the angle of incidence, and the ratio of visible light to infrared light acquired by the solid-state imaging element also changes with the angle of incidence. As a result, there are concerns that this may affect the color reproduction of visible light-based (color) images and the reproduction of infrared light-based (black and white) images.

[0010] The purpose of this invention is to provide an optical filter that has excellent transmittance of visible light and certain near-infrared light, excellent shielding of other near-infrared light, and small shift in the spectral curve at high incident angles.

[0011] The present invention provides an optical filter having the following configuration.

[0012] [1] An optical filter comprising:

[0013] X, a light-absorbing material with the maximum absorption wavelength in the region greater than 700 nm. 700L ,

[0014] Y, a light-absorbing material with the maximum absorption wavelength in the region below 970 nm. 970S ,as well as

[0015] Dielectric multilayer film,

[0016] The optical filter described above satisfies all of the following spectral characteristics (i-1) to (i-4).

[0017] (i-1) In the spectral transmittance curves with wavelengths from 420 nm to 650 nm and an incident angle of 0 degrees, the average transmittance T 420－650（0deg）AVE The average transmittance T is above 75% in the spectral transmittance curve at an incident angle of 35 degrees. 420－650（35deg）AVE More than 75%

[0018] (i-2) In the spectral transmittance curves with wavelengths from 710 nm to 950 nm and an incident angle of 0 degrees, the average transmittance T 710－950（0deg）AVE For values ​​below 1%, in the spectral transmittance curve at an incident angle of 35 degrees, the average transmittance T 710－950（35deg）AVE Less than 1%

[0019] (i-3) In the spectral transmittance curves with wavelengths from 950 nm to 1200 nm and an incident angle of 0 degrees, the maximum transmittance T 950－1200（0deg）MAX With a transmittance of over 60%, the maximum transmittance T in the spectral transmittance curve at an incident angle of 35 degrees is [value missing]. 950－1200（35deg）MAXMore than 50%

[0020] (i-4) In the spectral transmittance curves with wavelengths from 950 nm to 1200 nm and an incident angle of 0 degrees, let the wavelength that will result in the maximum transmittance be λ. 950－1200（0deg）MAX When, less than λ 950－1200（0deg）MAX The wavelength region in which the transmittance is 50% at an incident angle of 0 degrees is λ. IRS（0deg）（50％） and in less than λ 950－1200（0deg）MAX The wavelength region in which the transmittance is 50% at an incident angle of 35 degrees. IRS（35deg）（50％） The following relationship must be satisfied.

[0021] |λ IRS（0deg）（50％） -λ IRS（35deg）（50％） | ≤15nm.

[0022] According to the present invention, an optical filter can be provided that exhibits excellent transmittance of visible light and certain near-infrared light at high incident angles, and also excellent shielding performance against other near-infrared light. In particular, the optical filter of the present invention provides an optical filter that exhibits excellent transmittance in the near-infrared light region of the sensing wavelength range of 950 nm to 1200 nm at high incident angles, and whose spectral transmittance curve at the boundary between the aforementioned transmittance region and the wavelength region on the desired longer wavelength side of the spectrum is not easily shifted by the incident angle and is not easily affected by the incident angle. Attached Figure Description

[0023] Figure 1 This is a cross-sectional view schematically illustrating an example of an optical filter implementation.

[0024] Figure 2 This is a cross-sectional view schematically illustrating another example of an optical filter implementation.

[0025] Figure 3 This is a graph showing the spectral transmittance curve of light-absorbing glass A.

[0026] Figure 4 This is a graph showing the spectral transmittance curve of the light-absorbing layer in Example 1-1.

[0027] Figure 5 This is a graph showing the spectral transmittance and spectral reflectance curves (A side of the dielectric multilayer film) of the optical filter in Example 2-1.

[0028] Figure 6 This is a graph showing the spectral reflectance curve (B side of the dielectric multilayer film) and absorption loss of the optical filter in Example 2-1.

[0029] Figure 7 This is a graph showing the spectral transmittance and spectral reflectance curves (A side of the dielectric multilayer film) of the optical filter in Example 2-2.

[0030] Figure 8 This is a graph showing the spectral reflectance curve (B side of the dielectric multilayer film) and absorption loss of the optical filter in Example 2-2.

[0031] Figure 9 This is a graph showing the spectral transmittance and spectral reflectance curves (A side of the dielectric multilayer film) of the optical filter in Example 2-3.

[0032] Figure 10 This is a graph showing the spectral reflectance curve (B side of the dielectric multilayer film) and absorption loss of the optical filter in Example 2-3.

[0033] Figure 11 This is a graph showing the spectral transmittance and spectral reflectance curves (A side of the dielectric multilayer film) of the optical filter in Example 2-4.

[0034] Figure 12 This is a graph showing the spectral reflectance curve (B side of the dielectric multilayer film) and absorption loss of the optical filter in Example 2-4.

[0035] Figure 13 This is a graph showing the spectral transmittance and spectral reflectance curves (A side of the dielectric multilayer film) of the optical filter in Example 2-5.

[0036] Figure 14 This is a graph showing the spectral reflectance curve (B side of the dielectric multilayer film) and absorption loss of the optical filter in Example 2-5. Detailed Implementation

[0037] The embodiments of the present invention will be described below.

[0038] In this instruction manual, near-infrared absorbing pigments are abbreviated as "NIR pigments" and ultraviolet absorbing pigments are abbreviated as "UV pigments".

[0039] In this specification, the compound represented by formula (I) is referred to as compound (I). The same applies to compounds represented by other formulas. The pigment composed of compound (I) is also referred to as pigment (I), and the same applies to other pigments. In addition, the group represented by formula (I) is also denoted as group (I), and the same applies to groups represented by other formulas.

[0040] In this specification, internal transmittance refers to the transmittance obtained by subtracting the effect of interface reflection from the measured transmittance, expressed by the formula {measured transmittance (incident angle 0 degrees) / (100 - reflectance (incident angle 5 degrees))} × 100.

[0041] In this specification, optical density is expressed as a value derived from internal transmittance according to the following formula.

[0042] Optical concentration at wavelength λnm = -log10(iT) λ / 100)

[0043] iT λ Internal transmittance at an incident angle of 0 degrees at a wavelength of λnm

[0044] In this specification, the spectral characteristics of the transmittance of glass, including the transmittance of the absorption layer when the resin contains pigments, are all referred to as "internal transmittance" when described as "transmittance". On the other hand, the transmittance measured by dissolving pigments in solvents such as dichloromethane, the transmittance of dielectric multilayer films, and the transmittance of optical filters having dielectric multilayer films are measured transmittance.

[0045] In this specification, for a specific wavelength region, a transmittance of, for example, 90% or more means that the transmittance is not less than 90% over its entire wavelength region, i.e., the minimum transmittance in that wavelength region is 90% or more. Similarly, for a specific wavelength region, a transmittance of, for example, 1% or less means that the transmittance is not more than 1% over its entire wavelength region, i.e., the maximum transmittance in that wavelength region is 1% or less. The same applies to internal transmittance. The average transmittance and average internal transmittance of a specific wavelength region are the arithmetic mean of the transmittance and internal transmittance per 1 nm of that wavelength region.

[0046] Spectral characteristics can be measured using a UV-Vis spectrophotometer.

[0047] In this specification, the “~” indicating the range of values ​​includes the upper and lower limits.

[0048] <Optical Filters>

[0049] An optical filter according to one embodiment of the present invention (hereinafter also referred to as "the filter") comprises: a light-absorbing material X having a maximum absorption wavelength in a wavelength region greater than 700 nm. 700L Y, a light-absorbing material with the maximum absorption wavelength in the region below 970 nm. 970S And dielectric multilayer films.

[0050] Through the reflective properties of dielectric multilayer films and light-absorbing materials X 700L And light-absorbing material Y 970S Its absorption characteristics enable it to function as an optical filter as a whole, achieving excellent transmittance in the visible light region and specific near-infrared light regions, as well as excellent shielding in other near-infrared light regions.

[0051] The configuration example of this filter is illustrated with reference to the accompanying drawings. Figures 1-2 This is a cross-sectional view schematically illustrating an example of an optical filter implementation.

[0052] Figure 1 The optical filter 1A shown is equipped with a light-absorbing material Y 970S The structure comprises a support 10, a dielectric multilayer film 20A stacked on one main surface of the support 10, and a light-absorbing material X disposed on the surface of the dielectric multilayer film 20A. 700L An example of light-absorbing layer 30.

[0053] Figure 2 The optical filter 1B shown is an example of having a dielectric multilayer film 20B stacked on another main surface of the support 10.

[0054] The optical filter of the embodiments of the present invention satisfies all of the following spectral characteristics (i-1) to (i-4).

[0055] (i-1) In the spectral transmittance curves with wavelengths from 420 nm to 650 nm and an incident angle of 0 degrees, the average transmittance T 420－650（0deg）AVE The average transmittance T is above 75% in the spectral transmittance curve at an incident angle of 35 degrees. 420－650（35deg）AVE It is over 75%.

[0056] (i-2) In the spectral transmittance curves with wavelengths from 710 nm to 950 nm and an incident angle of 0 degrees, the average transmittance T 710－950（0deg）AVE For values ​​below 1%, in the spectral transmittance curve at an incident angle of 35 degrees, the average transmittance T 710－950（35deg）AVE It is less than 1%.

[0057] (i-3) In the spectral transmittance curves with wavelengths from 950 nm to 1200 nm and an incident angle of 0 degrees, the maximum transmittance T 950－1200（0deg）MAX With a transmittance of over 60%, the maximum transmittance T in the spectral transmittance curve at an incident angle of 35 degrees is [value missing]. 950－1200（35deg）MAX It is over 50%.

[0058] (i-4) In the spectral transmittance curves with wavelengths from 950 nm to 1200 nm and an incident angle of 0 degrees, let the wavelength that will result in the maximum transmittance be λ. 950－1200（0deg）MAX When, less than λ 950－1200（0deg）MAX The wavelength region in which the transmittance is 50% at an incident angle of 0 degrees is λ. IRS（0deg）（50％） and less than λ 950－1200（0deg）MAX The wavelength region in which the transmittance is 50% at an incident angle of 35 degrees. IRS（35deg）（50％） The following relationship must be satisfied.

[0059] |λ IRS（0deg）（50％） -λ IRS（35deg）（50％） | ≤15nm.

[0060] The filter that satisfies all spectral characteristics (i-1) to (i-4) is a dual bandpass filter with excellent visible light transmittance as shown in characteristic (i-1), excellent transmittance of specific near-infrared light as shown in characteristic (i-3), excellent shielding of other near-infrared light as shown in characteristic (i-2), and excellent near-infrared light transmittance frequency band stability as shown in characteristic (i-4).

[0061] Satisfying the spectral characteristics (i-1) means that the transmittance in the visible light region of 420nm to 650nm is excellent even at high incident angles.

[0062] Average transmittance T 420－650（0deg）AVE Preferably, it is 77% or more, and more preferably 79% or more.

[0063] Average transmittance T 420－650（35deg）AVE Preferably, it is 77% or more, and more preferably 79% or more.

[0064] In addition, to meet the spectral characteristics (i-1), for example, dielectric multilayer films with excellent transmittance in the visible light region and light-absorbing materials X can be used. 700L Y, light-absorbing material 970S .

[0065] Satisfying the spectral characteristics (i-2) means that the shielding performance in the near-infrared region of 710nm to 950nm is excellent even at high incident angles.

[0066] Average transmittance T 710－950（0deg）AVE Preferably, it is 0.8% or less, more preferably 0.6% or less.

[0067] Average transmittance T 710－950（35deg）AVE Preferably, it is 0.8% or less, more preferably 0.6% or less.

[0068] In addition, to satisfy the spectral characteristics (i-2), for example, light-absorbing materials X can be used. 700L Y, light-absorbing material 970S It absorbs energy to block light.

[0069] Satisfying the spectral characteristics (i-3) means that even at high incident angles, the transmittance in the near-infrared region of 950nm to 1200nm is excellent.

[0070] Maximum transmittance T 950－1200（0deg）MAX Preferably, it is 65% or more, and more preferably 70% or more.

[0071] Maximum transmittance T 950－1200（35deg）MAX Preferably, it is 55% or more, and more preferably 60% or more.

[0072] In addition, to meet the spectral characteristics (i-3), for example, a dielectric multilayer film with excellent transmittance in the near-infrared region of 950 nm to 1200 nm can be used.

[0073] Satisfying the spectral characteristics (i-4) means that even at high incident angles, the spectral curve in the wavelength region of 950 nm to 1200 nm is not likely to shift in the wavelength region smaller than the maximum absorption wavelength.

[0074] |λ IRS（0deg）（50％） -λ IRS（35deg）（50％） | Preferably, it is 12nm or less, more preferably 10nm or less, and even more preferably 8nm or less.

[0075] To satisfy the spectral characteristics (i-4), for example, ytterbium-containing glass, described later, can be used as the light-absorbing material Y. 970S Through light-absorbing material Y 970S It absorbs energy to block light.

[0076] The optical filter of the embodiments of the present invention preferably further satisfies the following spectral characteristics (i-5).

[0077] (i-5) In the spectral transmittance curves with wavelengths from 950 nm to 1200 nm and an incident angle of 0 degrees, let the wavelength that will result in the maximum transmittance be λ. 950－1200（0deg）MAX When, less than λ 950－1200（0deg）MAX The wavelength region with a transmittance of 55% is λ. IRS（0deg）（55％） and in less than λ 950－1200（0deg）MAX The wavelength region with a transmittance of 45% is λ. IRS（0deg）（45％） The following relationship must be satisfied.

[0078] |10 / [λ IRS（0deg）（45％） -λ IRS（0deg）（55％） ] | ≥1.0.

[0079] The aforementioned relationship in spectral characteristics (i-5) signifies the degree of decrease in the spectral transmittance curve (cutoff slope of the near-infrared band) when switching from the desired near-infrared light transmission region to the shorter wavelength side (950 nm–1200 nm) of the desired near-infrared light shielding region. From the viewpoint of effectively acquiring light, a steeper spectral curve at the boundary between the transmission and shielding regions is ideal. A slope of 1.0 or higher in the aforementioned relationship (i-5) indicates excellent transmittance of the near-infrared light to be transmitted.

[0080] The above-mentioned relationship (slope) in the spectral characteristics (i-5) is more preferably 1.1 or more, and even more preferably 1.2 or more.

[0081] To meet the spectral characteristics (i-5), for example, ytterbium-containing glass, described later, can be used as the light-absorbing material Y. 970S Through light-absorbing material Y 970S It absorbs energy to block light.

[0082] The optical filter of the embodiments of the present invention preferably further satisfies the following spectral characteristics (i-6) to (i-8).

[0083] (i-6) In the spectral transmittance curves with wavelengths from 950 nm to 1200 nm and an incident angle of 0 degrees, let the wavelength that will result in the maximum transmittance be λ. 950－1200（0deg）MAX When, greater than λ 950－1200（0deg）MAX The wavelength region in which the transmittance is 50% at an incident angle of 0 degrees is λ. IRL（0deg）（50％） and in less than λ 950－1200（0deg）MAX The wavelength region in which the transmittance is 50% at an incident angle of 0 degrees is λ. IRS（0deg）（50％） The following relationship must be satisfied.

[0084] 10nm≤|λ IRL（0deg）（50％） -λ IRS（0deg）（50％） | ≤100nm

[0085] (i-7) In the spectral transmittance curves with wavelengths from 950 nm to 1200 nm and an incident angle of 0 degrees, let the wavelength that will achieve the maximum transmittance be λ. 950－1200（0deg）MAX When, greater than λ 950－1200（0deg）MAX The wavelength region in which the transmittance is 50% at an incident angle of 35 degrees. IRL（35deg）（50％） and in less than λ 950－1200（0deg）MAX The wavelength region in which the transmittance is 50% at an incident angle of 35 degrees. IRS（35deg）（50％） The following relationship must be satisfied.

[0086] 20nm≤|λ IRL（35deg）（50％） -λ IRS（35deg）（50％） | ≤100nm

[0087] (i-8) The wavelength λ mentioned above IRL（0deg）（50％） The wavelength λ mentioned above IRS（0deg）（50％） The wavelength λ mentioned above IRL（35deg）（50％） The wavelength λ mentioned above IRS（35deg）（50％） The following relationship must be satisfied.

[0088] | [λ] IRL（35deg）（50％） -λ IRS（35deg）（50％） ]-[λ IRL（0deg）（50％） - λIRS（0deg）（50％） ] | ≤70nm

[0089] The spectral characteristics (i-6) to (i-8) are specifications for the bandwidth of the near-infrared light transmission band.

[0090] Spectral characteristic (i-6) is an indicator of the bandwidth at an incident angle of 0 degrees, spectral characteristic (i-7) is an indicator of the bandwidth at an incident angle of 35 degrees, and spectral characteristic (i-8) is an indicator of the difference between the bandwidths at an incident angle of 0 degrees and an incident angle of 35 degrees.

[0091] From the perspective of both transmitting the desired near-infrared light and shielding the unwanted near-infrared light, the bandwidth is preferably within a specific range.

[0092] Therefore, in the spectral characteristics (i-6), |λ IRL（0deg）（50％） -λ IRS（0deg）（50％） | More preferably, 20nm~90nm.

[0093] In the spectral characteristics (i-7), |λ IRL（35deg）（50％） -λ IRS（35deg）（50％） | More preferably, 30nm to 90nm or below.

[0094] In the spectral properties (i-8), |[λ] IRL（35deg）（50％） -λ IRS（35deg）（50％） ]-[λ IRL（0deg）（50％） - λIRS（0deg）（50％） | More preferably, below 60nm.

[0095] To satisfy the spectral characteristics (i-6) to (i-8), for example, the combination of ytterbium-containing glass (described later) as the light-absorbing material Y can be used. 970S Using light-absorbing material Y 970S Energy absorption to block light and the use of light-absorbing materials X 700L It absorbs energy to block light.

[0096] The optical filter of the embodiments of the present invention preferably further satisfies the following spectral characteristics (i-9) to (i-10).

[0097] (i-9) In the spectral transmittance curves with wavelengths of 950 nm to 1200 nm and incident angles of 0 degrees, the integral value of the transmittance in the band with a transmittance of 20% or higher is set as IRP-A. （0deg） When the following relationship is satisfied,

[0098] 10 (%·nm) ≤ IRP-A （0deg） ≤100 (%) nm

[0099] (i-10) In the spectral transmittance curves with wavelengths of 950 nm to 1200 nm and an incident angle of 35 degrees, the integral value of the transmittance in the band with a transmittance of 20% or higher is set as IPR-A. （35deg） When the following relationship is satisfied,

[0100] 10 (%·nm) ≤ IRP-A （35deg） ≤100 (%) nm.

[0101] Spectral characteristics (i-9) to (i-10) define the areas of frequency bands with transmittance of 20% or more at incident angles of 0 degrees and 35 degrees in the near-infrared light transmission region. These areas represent an indicator of the amount of near-infrared light transmitted. IRP-A （0deg） Specifically, it is calculated by integrating the transmittance of the band with a transmittance of 20% or more at an incident angle of 0 degrees. IRP-A （35deg） It is also calculated based on the transmittance and wavelength at an incident angle of 35 degrees.

[0102] IRP-A （0deg） More preferably, it is 20% or more, and even more preferably, it is 90% or less.

[0103] IRP-A （35deg） More preferably, it is 20% or more, and even more preferably, it is 90% or less.

[0104] Furthermore, IRP-A is preferred. （0deg） and IRP-A （35deg） The following relationship is satisfied.

[0105] 0.5≤IRP-A （35deg） / IRP-A （0deg） ≤1.1

[0106] IRP-A （35deg） / IRP-A （0deg） This refers to the ratio of the amount of near-infrared light at an incident angle of 0 degrees to the amount of near-infrared light at an incident angle of 35 degrees. By falling within the above range, the near-infrared light acquisition efficiency of this optical filter is less affected by the incident angle, and is therefore preferred.

[0107] IRP-A （35deg） / IRP-A （0deg） More preferably, it is 0.6 or more, and even more preferably, it is 1.0 or less.

[0108] The optical filter of the embodiments of the present invention preferably further satisfies the following spectral characteristics (i-11).

[0109] (i-11) In the spectral transmittance curves with wavelengths from 420 nm to 650 nm and an incident angle of 0 degrees, the integral value of the transmittance in the band with a transmittance of 20% or higher is set as VIS-A. （0deg） In the spectral transmittance curves with wavelengths from 420 nm to 650 nm and an incident angle of 35 degrees, the integral value of the transmittance in the band with a transmittance of 20% or higher is set as VIS-A. （35deg）In the spectral transmittance curves with wavelengths from 950 nm to 1200 nm and an incident angle of 0 degrees, the integral value of the transmittance in the band with a transmittance of 20% or higher is set as IRP-A. （0deg） In the spectral transmittance curves with wavelengths of 950 nm to 1200 nm and an incident angle of 35 degrees, the integral value of the transmittance in the band with a transmittance of 20% or higher is set as IRP-A. （35deg） When the following relationship is satisfied,

[0110] 0.5≤[IRP-A （35deg） / VIS-A （35deg） ] / [IRP-A （0deg） / VIS-A （0deg） ≤1.1

[0111] In (i-11), VIS-A （0deg） and VIS-A （35deg） This specifies the area of ​​the frequency bands with a transmittance of 20% or more at incident angles of 0 degrees and 35 degrees in the visible light spectrum. This area is an indicator of the amount of visible light transmitted. (IRP-A) （0deg） and IRP-A （35deg） As illustrated in the spectral characteristics (i-9) to (i-10), these are indicators of the amount of near-infrared light transmitted.

[0112] [IRP-A] in spectral characteristics (i-11) （35deg） / VIS-A （35deg） ] / [IRP-A （0deg） / VIS-A （0deg） This refers to the ratio of the area ratio of the visible light transmission radio frequency band and the near-infrared light transmission radio frequency band at an incident angle of 0 degrees to the area ratio at an incident angle of 35 degrees. By setting this ratio within a specific range, the influence of the incident angle on the acquisition efficiency ratio of visible light and near-infrared light of this optical filter is minimized. This improves color reproduction when generating visible light (color) images in solid-state imaging elements and also suppresses color gradation, which is therefore preferable. This ratio is more preferably 0.6 or higher, and more preferably 1.0 or lower.

[0113] The optical filter of the embodiments of the present invention preferably further satisfies the following spectral characteristics (i-12).

[0114] (i-12) In the spectral transmittance curves with wavelengths from 950 nm to 1200 nm and an incident angle of 0 degrees, let the wavelength that will achieve the maximum transmittance be λ. 950－1200（0deg）MAX When, it will be less than λ 950－1200（0deg）MAX The wavelength region with a transmittance of 50% is set as λ. IRS（0deg）（50％）In the spectral reflectance curves of wavelengths from 950 nm to 1200 nm and an incident angle of 5 degrees, the wavelength with a reflectance of 50% in the wavelength region greater than 950 nm is set as λ. IRR（5deg）（50％） When the following relationship is satisfied,

[0115] |λ IRR（5deg）（50％） -λ IRS（0deg）（50％） | ≥20nm.

[0116] The spectral characteristics (i-12) indicate a complete separation between the near-infrared light transmission frequency band and the near-infrared light reflection frequency band. This frequency band is preferably compared to the reflection characteristics of a dielectric multilayer film using a light-absorbing material Y. 970S It absorbs energy to block light.

[0117] |λ IRR（5deg）（50％） -λ IRS（0deg）（50％） | More preferably, 30nm or above, and even more preferably 40nm or above.

[0118] <Light Absorbing Material Y> 970S >

[0119] This filter features a light-absorbing material, Y, which has the maximum absorption wavelength in the wavelength region below 970nm. 970S This can compensate for areas that are not shaded by the reflective properties of the dielectric multilayer film.

[0120] Light-absorbing material Y 970S Preferably, the following spectral characteristics (iii-1) and (iii-2) are satisfied.

[0121] (iii-1) Maximum optical density at wavelengths of 900–1000 nm > 0.6

[0122] (iii-2) The wavelength range of 950–1050 nm, which is the long-wavelength side of the maximum optical density at wavelengths of 900–1000 nm and has a transmittance of 50%.

[0123] Spectral characteristics (iii-1) mean that there are fewer fluctuations in spectral characteristics regardless of the incident angle. The maximum optical density at wavelengths of 900–1000 nm is more preferably 0.65 or higher.

[0124] Spectral characteristics (iii-2) mean that fluctuations in spectral characteristics can be reduced by combining dielectric multilayer films. More preferably, the wavelength is 945-1000 nm, which is longer than the maximum optical density of 900-1000 nm and has a transmittance of 50%.

[0125] Y, as a light-absorbing material 970SThere are no restrictions as long as the material can achieve the aforementioned spectral characteristics. For example, inorganic materials containing ytterbium are preferred, such as single-crystal and polycrystalline sintered bodies of Yb₂O₃, Yb:YAG (yttrium aluminum garnet), and Yb:YVO₄, as well as ytterbium-containing glasses. Among these, ytterbium-containing glasses are more preferred from the perspectives of processability, material quality stability, and ease of property adjustment. As long as the light-absorbing material Y… 970S If the material is as described above, it is easy to satisfy the above spectral characteristics (iii-1) and (iii-2).

[0126] Ytterbium-containing glass preferably has a maximum absorption wavelength of 940 nm to 970 nm.

[0127] The average internal transmittance of the ytterbium-containing glass with a preferred wavelength of 450 nm to 600 nm and an incident angle of 0 degrees is preferably 60% or more, more preferably 80% or more, and even more preferably 90% or more.

[0128] The average internal transmittance of the ytterbium-containing glass with a wavelength of 700 nm to 800 nm and an incident angle of 0 degrees is preferably 60% or more, more preferably 80% or more, and even more preferably 90% or more.

[0129] Ytterbium-containing glass exhibits excellent transmittance in the visible light region and near-infrared light from the visible light region to around 800 nm, while absorbing light in the near-infrared region below 850 nm, particularly light from 900 to 950 nm. Furthermore, because it utilizes absorption properties for light blocking, unlike dielectric multilayer films, its light-blocking performance is less affected by the angle of incidence. Therefore, by using ytterbium-containing glass, especially in the sensing wavelength region of 950 nm to 1200 nm, excellent transmittance in the near-infrared region is achieved even at high angles of incidence. The spectral transmittance curve of the boundary between this transmittance region and the desired shielding wavelength region below 950 nm is less likely to shift due to the angle of incidence, resulting in an optical filter that is less affected by the angle of incidence.

[0130] Examples of ytterbium-containing glasses include, for instance, glasses having any of the following compositions.

[0131] (1) Glass containing Yb2O3 and B2O3 as essential components, with Yb2O3 content ranging from 10 mol% to 60 mol% and B2O3 content ranging from 10 mol% to 70 mol%, based on oxides.

[0132] (2) Glass that, in addition to (1), further contains SiO2 as an essential component and has a SiO2 content of 5 mol% to 35 mol%.

[0133] (3) Glass that, in addition to (1) and (2), further contains La2O3 as an essential component and the content of La2O3 is 1 mol% to 20 mol%.

[0134] As ytterbium-containing glass, commercially available products can be used, and it can be manufactured according to known methods as described in Japanese Patent Application Publication No. 61-163138 and Japanese Patent Application Publication No. 56-78447.

[0135] In addition, as a ytterbium-containing glass, a chemically strengthened glass can be obtained by exchanging alkali metal ions (e.g., Li ions, Na ions) with smaller ionic radii present on the main surface of the glass plate with alkali metal ions at a temperature below the glass transition temperature through ion exchange. These ions are replaced with alkali ions with larger ionic radii (e.g., Na ions or K ions relative to Li ions, and K ions relative to Na ions).

[0136] From the viewpoint of facilitating optical design when installed in a camera module, the thickness of the ytterbium-containing glass is preferably 3 mm or less, more preferably 2 mm or less, and even more preferably 1 mm or less. From the viewpoint of component strength and the necessity of obtaining the desired optical properties, it is preferably 0.1 mm or more.

[0137] <Light Absorbing Material X> 700L Light absorption layer >

[0138] This filter features a light-absorbing material X that has the maximum absorption wavelength in the wavelength region greater than 700nm. 700L Therefore, it is possible to compensate for the areas that are not shaded due to the reflective properties of the dielectric multilayer film.

[0139] Optical filters preferably contain light-absorbing material X. 700L The light-absorbing layer. Furthermore, the optical filter having the aforementioned light-absorbing layer preferably satisfies all of the following spectral characteristics (ii-1) to (ii-2).

[0140] When the above-mentioned dielectric multilayer film side is the incident direction, the absorption loss at wavelength X nm will be... X The definition is as follows.

[0141] (Absorption loss) X [%] = 100 - (transmittance at 0 degrees incident angle) - (reflectance at 5 degrees incident angle)

[0142] (ii-1) Absorption loss at wavelengths of 600–830 nm 600－830 The maximum value is above 85

[0143] (ii-2) Absorption loss at wavelengths of 600–830 nm 600－830 The score is 5000 or above.

[0144] Absorption loss XIt is an indicator of the degree of light blocking due to absorption characteristics at a wavelength of X nm. The larger the value, the greater the degree to which the light of the above wavelength X is blocked due to absorption.

[0145] Absorption loss X－Y The integral value is calculated by summing the absorption losses of X to Y nm for each 1 nm wavelength. The larger the value, the higher the degree to which the wavelength region of X to Y nm is blocked due to absorption.

[0146] Satisfying the spectral characteristics (ii-1) means being able to suppress S / N wavelengths other than the desired wavelength.

[0147] Satisfying the spectral characteristics (ii-2) means that spectral characteristics can be formed through absorption.

[0148] Absorption loss 600－830 The maximum value is more preferably 87 or above, and even more preferably 90 or above.

[0149] Absorption loss 600－830 The integral value is more preferably 5500 or more, and even more preferably 6000 or more.

[0150] To satisfy the spectral characteristics (ii-1) to (ii-2), one example is the use of a light-absorbing material X, for instance, that has a maximum absorption wavelength in the range of 700 nm to 800 nm. 700L (Details will be discussed later).

[0151] Light-absorbing material X 700L Preferably, the pigment is a pigment that has the maximum absorption wavelength in the 700-800 nm wavelength region in dichloromethane (hereinafter also referred to as "NIR pigment"). By containing the above-mentioned pigment, the light absorption layer can absorb a wide range of near-infrared light absorption band centered at 720 nm, and can easily achieve both 450 nm visible light transmittance and 720 nm near-infrared light shielding.

[0152] From the viewpoint of being able to achieve wide-range absorption in the near-infrared region, it is preferable to combine two pigments with different maximum absorption wavelengths in the 700-800 nm region, and preferably to combine a pigment with a maximum absorption wavelength in the 700-740 nm region and a pigment in the 740-800 nm region.

[0153] The absorbent layer is preferably a resin film containing the pigment and the resin.

[0154] As a NIR pigment, squaric acid is preferred. Pigments, anthocyanins, phthalocyanine pigments, naphthiophthalocyanine pigments, dithiol metal complex pigments, azo pigments, polymethystyl pigments, phthalophthalocyanine pigments, naphthoquinone pigments, anthraquinone pigments, indophenol pigments, pyran Pigments, thiopyrans Pigment, ketone At least one of the following: pigment, tetradehydrocholine pigment, triphenylmethane pigment, ammonium pigment, and diammonium pigment.

[0155] As a NIR pigment, it is preferable to include at least one pigment selected from squaric acid pigments, phthalocyanine pigments, and anthocyanins. Among these NIR pigments, squaric acid is preferred from a spectral point of view. From a durability point of view, phthalocyanine pigments are preferred among pigments, particularly anthocyanin pigments.

[0156] The content of NIR pigment in the absorber layer is preferably 0.1 to 25 parts by weight, more preferably 0.3 to 15 parts by weight, relative to 100 parts by weight of resin. It should be noted that when two or more compounds are combined, the above content refers to the sum of all compounds.

[0157] In addition to the aforementioned NIR pigments, the absorption layer may also contain other pigments. Preferably, the pigments in the resin that have the maximum absorption wavelength in the 370–440 nm range (UV pigments) are preferred. This allows for effective shielding in the near-ultraviolet region.

[0158] Examples of UV pigments include Azole pigments, anthocyanins, naphthaleneimide pigments, diazole pigments, Azine pigment, Pigments include azole dyes, naphthalene-dicarboxylic acid dyes, styryl dyes, anthracene dyes, cyclic carbonyl dyes, and triazole dyes. Among these, anthocyanin dyes are particularly preferred. Furthermore, one type can be used alone, or two or more types can be used in combination.

[0159] The light-absorbing layer is preferably laminated on at least one main surface of the support. The support can be an organic material or an inorganic material. Here, as long as the light-absorbing material Y... 970S If it is an inorganic material, it can have both near-infrared light absorption energy and the function of a support, and is therefore preferred.

[0160] As for the resin in the light-absorbing layer, there are no restrictions on the type of transparent resin. One or more transparent resins selected from polyester resin, acrylic resin, epoxy resin, ethoxylate resin, polycarbonate resin, polyether resin, polyaryl ester resin, polysulfone resin, polyethersulfone resin, poly(p-phenylene) resin, polyaryl ether phosphine oxide resin, polyamide resin, polyimide resin, polyamide-imide resin, polyolefin resin, cyclic olefin resin, polyurethane resin, and polystyrene resin can be used. These resins can be used alone or in mixtures of two or more.

[0161] From the viewpoints of the spectral characteristics of the light absorption layer, glass transition temperature (Tg), and adhesion, one or more resins selected from polyimide resin, polycarbonate resin, polyester resin, and acrylic resin are preferred.

[0162] When using multiple compounds as NIR pigments or other pigments, they can be contained in the same light-absorbing layer, or they can be contained in different absorption layers.

[0163] The light-absorbing layer can be formed by dissolving or dispersing pigments, resins, or resin raw material components, and other required components, in a solvent to prepare a coating liquid, coating it onto a support, drying it, and further curing it as needed. For the support, as long as the aforementioned light-absorbing material Y... 970S If it is an inorganic material, then it can be a light-absorbing material Y. 970S Alternatively, it can be a release support used only when forming the light-absorbing layer. Furthermore, the solvent can be any stable dispersion medium or a soluble solvent.

[0164] In addition, the coating solution may contain surfactants to improve voids caused by microbubbles, depressions caused by the adhesion of foreign matter, and rejection during the drying process. Furthermore, the coating solution can be applied using methods such as dip coating, cast coating, or spin coating. When the coating solution contains transparent resin components, it can be further cured by thermosetting, photocuring, or other curing processes.

[0165] Alternatively, the absorber layer can also be formed into a film through extrusion molding. This is achieved by laminating the resulting film-like absorber layer onto a support (e.g., a light-absorbing material Y). 970S This filter can be manufactured by integrating it into one unit using methods such as hot pressing.

[0166] An absorption layer in an optical filter can have one layer or two or more layers. When there are two or more layers, each layer can have the same or different composition. In addition, it can be formed on the surface of each dielectric multilayer film, or two or more layers can be superimposed on the surface of a single dielectric multilayer film.

[0167] From the viewpoint of in-plane film thickness distribution and appearance quality within the coated substrate, the thickness of the absorption layer is 10 μm or less, preferably 5 μm or less. Furthermore, from the viewpoint of exhibiting the desired spectral characteristics with an appropriate pigment concentration, it is preferably 0.5 μm or more. It should be noted that when the optical filter has two or more absorption layers, the total thickness of each absorption layer is preferably within the above-mentioned range.

[0168] <Dielectric Multilayer Film>

[0169] This filter incorporates a dielectric multilayer film. The filter may have one or more dielectric multilayer films, preferably at least one reflective film designed to reflect a portion of near-infrared light (hereinafter also referred to as "NIR reflective film"). Other dielectric multilayer films may be designed as reflective films or anti-reflective films with reflective regions in other near-infrared areas.

[0170] This filter preferably has at least two NIR reflective films with different reflective regions.

[0171] This filter preferably comprises: a light-absorbing material Y 970S The substrate comprises a dielectric multilayer film A disposed on one main surface of the substrate, a dielectric multilayer film B disposed on the other main surface of the substrate, and a light-absorbing material X disposed on one main surface of the substrate. 700L The light-absorbing layer.

[0172] NIR reflective films preferably have, for example, materials that transmit visible light or absorb transmitted light. 700L Or light-absorbing material Y 970S The NIR reflector has wavelength selectivity, primarily reflecting near-infrared light in the transmission region and primarily reflecting other near-infrared light. The NIR reflector can be further suitably designed to reflect light in wavelength regions other than near-infrared, such as near-ultraviolet light.

[0173] A dielectric multilayer film is a stack of dielectric films with different refractive indices. More specifically, examples include low-refractive-index dielectric films, medium-refractive-index dielectric films, and high-refractive-index dielectric films, which are composed of two or more of these layers stacked together. By combining multiple dielectric films with different spectral characteristics and selecting a desired wavelength range through transmission, the reflection characteristics can be adjusted. It should be noted that the equivalent film mentioned later refers to an optically equivalent film, for example, that combines two or more films with high and low refractive indices, replacing a single film.

[0174] The dielectric multilayer film A preferably satisfies all of the following characteristics (iv-1), (iv-2) and (iv-3).

[0175] (iv-1) Having three or more stacked structures, the stacked structure comprising a high refractive index layer H composed of a high refractive index material with a refractive index of 1.9 to 3.0 at a wavelength of 500 nm. A And the refractive index of the layer with a wavelength of 500 nm being greater than 1.5 and less than 2.0, and the refractive index being lower than that of the high refractive index layer H. A M, a medium refractive index layer composed of medium refractive index material A And by (H) A / M A ) represents (where M is the intermediate refractive index layer) A From the high refractive index layer HA and low refractive index layer L A During construction, it is treated as an equivalent film, the low refractive index layer L A It is composed of a low refractive index material with a refractive index of 1.3 to 1.7 at a wavelength of 500 nm.

[0176] (iv-2) Add high refractive index layer H A The wavelength of 500nm is set as QH. A The middle refractive index layer M A The wavelength of 500nm is set to QM. A At that time, it has the property of (a) n QH A / b n QM A The layered structure represented by ) where, above a n The average value is 1.2 to 2.7, and the above b n The average value is 1.1 to 2.2.

[0177] (iv-3) The number of layers is in the range of 1 to 60.

[0178] By making the dielectric multilayer film A satisfy properties (iv-1), (iv-2) and (iv-3), a reflective layer with a cutoff length longer than the visible light band and the sensing band is obtained.

[0179] It should be noted that the stacked structure (H) A / M A They can be continuous or separate.

[0180] (H) A / M A The stacked structure represented by () is more preferably five or more.

[0181] a n b n Let be the coefficient of each basic unit, indicating how many times the physical film thickness of each basic unit is greater than QWOT (1 / 4 wavelength optical film thickness). Therefore, a n Q HA b n Q MA Indicates the optical film thickness of each film.

[0182] a n The average value is more preferably 1.2 to 2.5, and even more preferably 1.2 to 2.4. n The average value is more preferably 1.1 to 2.4, and even more preferably 1.1 to 2.3.

[0183] The number of layers in the dielectric multilayer film A is more preferably 20 to 60, and even more preferably in the range of 40 to 60.

[0184] The dielectric multilayer film B preferably satisfies all of the following properties (v-1), (v-2), and (v-3).

[0185] (v-1) has three or more stacked structures, wherein the stacked structure comprises a high refractive index layer H made of a high refractive index material with a refractive index of 1.9 to 2.0 at a wavelength of 500 nm. B And layers with a refractive index greater than 1.5 and less than 2.0 at a wavelength of 500 nm and a refractive index lower than that of the high refractive index layer H. B M, a medium refractive index layer composed of medium refractive index material B And by (H) B / M B ) represents (where M is the intermediate refractive index layer) B From the high refractive index layer H B and low refractive index layer L B During construction, it is treated as an equivalent film, the low refractive index layer L B It is composed of a low refractive index material with a refractive index of 1.3 to 1.5 at a wavelength of 500 nm.

[0186] (v-2) The high refractive index layer H B The wavelength of 500nm is set as QH. B The middle refractive index layer M B The wavelength of 500nm is set to QM. B At that time, it has (c n QH B / d n QM B The layered structure represented by ) is where c above n The average value is 1.9 to 4.9, and the above d n The average value is 1.2 to 2.9.

[0187] (v-3) The number of stacks is in the range of 1 to 60.

[0188] By making the dielectric multilayer film B satisfy characteristics (v-1), (v-2), and (v-3), a reflective layer with a cutoff shorter than the short-wavelength side of the visible light band and the sensing band can be obtained.

[0189] It should be noted that the stacked structure (H) B / M B They can be continuous or separate.

[0190] (H) B / M B The stacked structure represented by () is more preferably five or more.

[0191] c n d n Let c be the coefficient of each basic unit, indicating how many times the physical film thickness of each basic unit is greater than QWOT (1 / 4 wavelength optical film thickness). Therefore, c n QH B d n QM B Indicates the optical film thickness of each film.

[0192] c n The average value is more preferably 2.0 to 5.0, and even more preferably 2.1 to 5.0, d n The average value is more preferably 1.21 to 2.9, and even more preferably 1.22 to 2.9.

[0193] The number of layers in the dielectric multilayer film B is more preferably 10 to 60, and even more preferably in the range of 20 to 60.

[0194] The dielectric multilayer film A that meets the above characteristics is designed to primarily reflect wavelengths in the 1050–1200 nm range.

[0195] The dielectric multilayer film B that meets the above characteristics is designed to primarily reflect wavelengths in the 800–900 nm range.

[0196] The refractive index of the high refractive index material at a wavelength of 500 nm is preferably 1.9 to 3.0 or less, more preferably 1.9 to 2.8 or less, and even more preferably 1.9 to 2.6 or less. Examples of high refractive index materials include Ta2O5, TiO2, TiO, and Nb2O5. Other commercially available products include those manufactured by Canon Optron, such as OS50 (Ti3O5), OS10 (Ti4O7), OA500 (a mixture of Ta2O5 and ZrO2), and OA600 (a mixture of Ta2O5 and TiO2). Among these, TiO2 is preferred based on its film-forming properties, reproducibility of refractive index, and stability.

[0197] Medium refractive index materials are materials with a relatively lower refractive index compared to high refractive index layer materials. The refractive index at a wavelength of 500 nm is preferably below 1.5 to 2.0, more preferably below 1.5 to 1.95, and even more preferably below 1.5 to 1.9. Examples of medium refractive index materials include ZrO2, Nb2O5, Al2O3, HfO2, OM-4 and OM-6 (mixtures of Al2O3 and ZrO2) sold by Canon Optron, OA-100, and H4 and M2 (lanthanum alumina) sold by Merck. Among these, Al2O3-based compounds and mixtures of Al2O3 and ZrO2 are preferred based on factors such as film formation properties, reproducibility of refractive index, and stability.

[0198] The low-refractive-index material is a material with a relatively lower refractive index compared to the medium-refractive-index layer material. The refractive index at a wavelength of 500 nm is preferably below 1.3 to 1.7, more preferably below 1.3 to 1.65, and even more preferably below 1.3 to 1.6. Examples of low-refractive-index materials include SiO2 and SiO2. x N y Other commercially available products include MgF2, S4F, and S5F (a mixture of SiO2 and AlO2), manufactured by Canonoptron. Among these, SiO2 is preferred due to its reproducibility, stability, and cost-effectiveness in film formation.

[0199] From the viewpoint of suppressing material degradation, the film thickness (physical film thickness) of dielectric multilayer film A and dielectric multilayer film B is preferably 100 nm or more, more preferably 300 nm or more. In addition, from the viewpoint of productivity and suppressing reflection ripples in the visible light region, it is preferably 5 μm or less.

[0200] This filter may have a dielectric multilayer film C on at least one outermost surface. From the viewpoint of suppressing ripple generation in the visible light region, the dielectric multilayer film C is preferably designed as, for example, a near-infrared anti-reflection layer (NIR anti-reflection layer).

[0201] The total number of layers in the dielectric multilayer film C is preferably 25 or less, more preferably 20 or less, even more preferably 17 or less, and also preferably 10 or more. In order to suppress reflection in the visible band even if the incident angle changes, a film with low reflectivity across the entire wavelength range is preferred, rather than a film that reflects a specific wavelength.

[0202] In addition, the overall thickness (physical thickness) of the dielectric multilayer film C is preferably 200 to 600 μm.

[0203] The formation of dielectric multilayer films can utilize vacuum film formation processes such as CVD, sputtering, and vacuum evaporation, as well as wet film formation processes such as spraying and immersion.

[0204] This filter can incorporate other components such as inorganic microparticles that provide absorption by controlling the transmission and absorption of light in specific wavelength regions. Specific examples of inorganic microparticles include ITO (Indium Tin Oxides), ATO (Antimony-doped Tin Oxides), cesium tungstate, and lanthanum boride. ITO microparticles and cesium tungstate microparticles have high transmittance of visible light and exhibit light absorption over a wide range of infrared wavelengths greater than 1200 nm, making them suitable for applications requiring infrared light shielding.

[0205] <Camera Device>

[0206] The imaging device according to embodiments of the present invention preferably includes the optical filter described in the embodiments of the present invention. The imaging device preferably further includes a solid-state imaging element and a capturing lens. The optical filter of this embodiment can be disposed between the capturing lens and the solid-state imaging element, or directly attached to the solid-state imaging element and capturing lens of the imaging device via an adhesive layer. By using this filter, which possesses excellent transmittance of visible light and specific near-infrared light, has specific near-infrared light shielding properties, and whose spectral curve is not easily shifted even at high incident angles, an imaging device with excellent color reproduction for light at high incident angles can be obtained.

[0207] When an optical filter is installed in a camera device, and the device has a dielectric multilayer film A and a dielectric multilayer film B, it is generally preferable to make the dielectric multilayer film A the sensor side and the dielectric multilayer film B the lens side.

[0208] As described above, the following optical filters, etc., are disclosed in this specification.

[0209] [1] An optical filter comprising:

[0210] X, a light-absorbing material with the maximum absorption wavelength in the region greater than 700 nm. 700L ,

[0211] Y, a light-absorbing material with the maximum absorption wavelength in the region below 970 nm. 970S ,as well as

[0212] Dielectric multilayer film,

[0213] The optical filter described above satisfies all of the following spectral characteristics (i-1) to (i-4).

[0214] (i-1) In the spectral transmittance curves with wavelengths from 420 nm to 650 nm and an incident angle of 0 degrees, the average transmittance T 420－650（0deg）AVEThe average transmittance T is above 75% in the spectral transmittance curve at an incident angle of 35 degrees. 420－650（35deg）AVE It is over 75%.

[0215] (i-2) In the spectral transmittance curves with wavelengths from 710 nm to 950 nm and an incident angle of 0 degrees, the average transmittance T 710－950（0deg）AVE For values ​​below 1%, in the spectral transmittance curve at an incident angle of 35 degrees, the average transmittance T 710－950（35deg）AVE Less than 1%,

[0216] (i-3) In the spectral transmittance curves with wavelengths from 950 nm to 1200 nm and an incident angle of 0 degrees, the maximum transmittance T 950－1200（0deg）MAX With a transmittance of over 60%, the maximum transmittance T in the spectral transmittance curve at an incident angle of 35 degrees is [value missing]. 950－1200（35deg）MAX More than 50%,

[0217] (i-4) In the spectral transmittance curves with wavelengths from 950 nm to 1200 nm and an incident angle of 0 degrees, let the wavelength that will result in the maximum transmittance be λ. 950－1200（0deg）MAX When, less than λ 950－1200（0deg）MAX The wavelength region in which the transmittance is 50% at an incident angle of 0 degrees is λ. IRS（0deg）（50％） and in less than λ 950－1200（0deg）MAX The wavelength region in which the transmittance is 50% at an incident angle of 35 degrees. IRS（35deg）（50％） The following relationship must be satisfied.

[0218] |λ IRS（0deg）（50％） -λ IRS（35deg）（50％） | ≤15nm.

[0219] [2] The optical filter according to [1] further satisfies the following spectral characteristics (i-5).

[0220] (i-5) In the spectral transmittance curves with wavelengths from 950 nm to 1200 nm and an incident angle of 0 degrees, let the wavelength that will result in the maximum transmittance be λ. 950－1200（0deg）MAX When, less than λ 950－1200（0deg）MAX The wavelength region with a transmittance of 55% at wavelength λ IRS（0deg）（55％） and in less than λ 950－1200（0deg）MAX The wavelength region with a transmittance of 45% at wavelength λ IRS（0deg）（45％） The following relationship must be satisfied.

[0221] |10 / [λ IRS（0deg）（45％） -λ IRS（0deg）（55％） ] | ≥1.0.

[0222] [3] The optical filter according to [1] or [2], wherein the optical filter further satisfies the following spectral characteristics (i-6) to (i-8).

[0223] (i-6) In the spectral transmittance curves with wavelengths from 950 nm to 1200 nm and an incident angle of 0 degrees, let the wavelength that will result in the maximum transmittance be λ. 950－1200（0deg）MAX When, greater than λ 950－1200（0deg）MAX The wavelength region in which the transmittance is 50% at an incident angle of 0 degrees is λ. IRL（0deg）（50％） and in less than λ 950－1200（0deg）MAX The wavelength region in which the transmittance is 50% at an incident angle of 0 degrees is λ. IRS（0deg）（50％） The following relationship must be satisfied.

[0224] 10nm≤|λ IRL（0deg）（50％） -λ IRS（0deg）（50％） | ≤100nm,

[0225] (i-7) In the spectral transmittance curves with wavelengths from 950 nm to 1200 nm and an incident angle of 0 degrees, let the wavelength that will achieve the maximum transmittance be λ. 950－1200（0deg）MAX When, greater than λ 950－1200（0deg）MAX The wavelength region in which the transmittance is 50% at an incident angle of 35 degrees. IRL（35deg）（50％） and in less than λ 950－1200（0deg）MAX The wavelength region in which the transmittance is 50% at an incident angle of 35 degrees. IRS（35deg）（50％） The following relationship must be satisfied.

[0226] 20nm≤|λ IRL（35deg）（50％） -λ IRS（35deg）（50％） | ≤100nm,

[0227] (i-8) The wavelength λ mentioned above IRL（0deg）（50％） The wavelength λ mentioned above IRS（0deg）（50％） The wavelength λ mentioned above IRL（35deg）（50％） The wavelength λ mentioned above IRS（35deg）（50％） The following relationship must be satisfied.

[0228] | [λ] IRL（35deg）（50％） -λ IRS（35deg）（50％） ]-[λ IRL（0deg）（50％） - λIRS（0deg）（50％） ] | ≤70nm.

[0229] [4] An optical filter according to any one of [1] to [3], wherein the optical filter further satisfies the following spectral characteristics (i-9) and (i-10).

[0230] (i-9) In the spectral transmittance curves with wavelengths of 950 nm to 1200 nm and incident angles of 0 degrees, the integral value of the transmittance in the band with a transmittance of 20% or higher is set as IRP-A. （0deg） When the following relationship is satisfied,

[0231] 10 (%·nm) ≤ IRP-A （0deg）≤100 (%) nm

[0232] (i-10) In the spectral transmittance curves with wavelengths of 950 nm to 1200 nm and an incident angle of 35 degrees, the integral value of the transmittance in the band with a transmittance of 20% or higher is set as IPR-A. （35deg） When the following relationship is satisfied,

[0233] 10 (%·nm) ≤ IRP-A （35deg） ≤100 (%) nm.

[0234] [5] According to the optical filter described in [4], wherein the above-mentioned IRP-A （0deg） And the above IRP-A （35deg） The following relationship must be satisfied.

[0235] 0.5≤IRP-A （35deg） / IRP-A （0deg） ≤1.1.

[0236] [6] An optical filter according to any one of [1] to [5], wherein the optical filter further satisfies the following spectral characteristics (i-11).

[0237] (i-11) In the spectral transmittance curves with wavelengths from 420 nm to 650 nm and an incident angle of 0 degrees, the integral value of the transmittance in the band with a transmittance of 20% or higher is set as VIS-A. （0deg） In the spectral transmittance curves with wavelengths from 420 nm to 650 nm and an incident angle of 35 degrees, the integral value of the transmittance in the band with a transmittance of 20% or higher is set as VIS-A. （35deg） In the spectral transmittance curves with wavelengths from 950 nm to 1200 nm and an incident angle of 0 degrees, the integral value of the transmittance in the band with a transmittance of 20% or higher is set as IRP-A. （0deg） In the spectral transmittance curves with wavelengths of 950 nm to 1200 nm and an incident angle of 35 degrees, the integral value of the transmittance in the band with a transmittance of 20% or higher is set as IRP-A. （35deg） When the following relationship is satisfied,

[0238] 0.5≤[IRP-A （35deg） / VIS-A （35deg） ] / [IRP-A （0deg） / VIS-A （0deg） ] ≤1.1.

[0239] [7] An optical filter according to any one of [1] to [6], wherein the optical filter further satisfies the following spectral characteristics (i-12).

[0240] (i-12) In the spectral transmittance curves with wavelengths from 950 nm to 1200 nm and an incident angle of 0 degrees, let the wavelength that will achieve the maximum transmittance be λ. 950－1200（0deg）MAX When, it will be less than λ 950－1200（0deg）MAX The wavelength region with a transmittance of 50% is defined as λ. IRS（0deg）（50％） In the spectral reflectance curves of wavelengths from 950 nm to 1200 nm and incident angles of 5 degrees, the wavelengths with a reflectance of 50% in the wavelength region greater than 950 nm are designated as λ. IRR（5deg）（50％） When the following relationship is satisfied,

[0241] |λ IRR（5deg）（50％） -λ IRS（0deg）（50％） | ≥20nm.

[0242] [8] An optical filter according to any one of [1] to [7], wherein the light-absorbing material Y 970S It satisfies the following spectral characteristics (iii-1) and (iii-2).

[0243] (iii-1) Maximum optical density at wavelengths of 900–1000 nm > 0.6

[0244] (iii-2) The wavelength range of 950-1050 nm is the long-wavelength side with the maximum optical density at wavelengths of 900-1000 nm and a transmittance of 50%.

[0245] [9] An optical filter according to any one of [1] to [8], wherein the light-absorbing material Y 970S It is an inorganic material containing ytterbium.

[0246]

[10] An optical filter according to any one of [1] to [9], wherein the light-absorbing material Y 970S It is glass containing ytterbium.

[0247]

[11] An optical filter according to any one of [1] to

[10] , wherein the optical filter comprises the light-absorbing material X described above. 700L Light absorption layer,

[0248] The optical filter described above satisfies all of the following spectral characteristics (ii-1) and (ii-2).

[0249] When the above-mentioned dielectric multilayer film side is the incident direction, the absorption loss at wavelength X nm will be... X The definition is as follows:

[0250] (Absorption loss) X ) [%] = 100 - (transmittance at 0 degrees incident angle) - (reflectance at 5 degrees incident angle).

[0251] (ii-1) Absorption loss at wavelengths of 600–830 nm 600－830 The maximum value is above 85.

[0252] (ii-2) Absorption loss at wavelengths of 600–830 nm 600－830 The score is 5000 or higher.

[0253]

[12] The optical filter according to any one of [1] to

[11] , wherein the optical filter comprises:

[0254] The light-absorbing material Y mentioned above 970S The substrate formed

[0255] A dielectric multilayer film A disposed on one main surface of the aforementioned substrate, and

[0256] The light-absorbing material X is disposed on one main surface side of the substrate described above. 700L Light absorption layer,

[0257] The above-mentioned dielectric multilayer film A satisfies the following characteristics (iv-1), (iv-2) and (iv-3).

[0258] (iv-1) Having three or more stacked structures, the stacked structures comprising a high refractive index layer H made of a high refractive index material with a refractive index of 1.9 to 3.0 at a wavelength of 500 nm. A And a medium refractive index layer M composed of a medium refractive index material with a wavelength of 500 nm and a refractive index of 1.5–2.0, which is lower than that of high refractive index materials. A And by (H) A / M A ) represents (where M is the intermediate refractive index layer) A From the high refractive index layer H A and low refractive index layer L A When constructed, it is used as an equivalent film, the low refractive index layer L A It is composed of a low refractive index material with a refractive index of 1.3 to 1.7 at a wavelength of 500 nm.

[0259] (iv-2) Add high refractive index layer H A The wavelength of 500nm is set as QH. A The middle refractive index layer M A The wavelength of 500nm is set to QM. A At that time, it has the property of (a) n QH A / b n QM A The layered structure represented by ) where, above a n The average value is 1.2 to 2.7, and the above b nThe average value is 1.1 to 2.2.

[0260] (iv-3) The number of layers is in the range of 1 to 60.

[0261]

[13] The optical filter according to any one of [1] to

[12] , wherein the optical filter comprises:

[0262] The light-absorbing material Y mentioned above 970S The substrate formed

[0263] A dielectric multilayer film A disposed on one main surface side of the above substrate,

[0264] The dielectric multilayer film B disposed on the other main surface of the aforementioned substrate, and

[0265] The light-absorbing material X is disposed on one main surface side of the substrate described above. 700L Light absorption layer,

[0266] The above-mentioned dielectric multilayer film B satisfies the following characteristics (v-1), (v-2) and (v-3).

[0267] (v-1) has three or more stacked structures, wherein the stacked structures include a high refractive index layer H composed of a high refractive index material with a refractive index of 1.9 to 3.0 at a wavelength of 500 nm. B And a medium refractive index layer M composed of a medium refractive index material with a wavelength of 500 nm and a refractive index of 1.5–2.0, which is lower than that of high refractive index materials. B And by (H) B / M B ) represents (where M is the intermediate refractive index layer) B From the high refractive index layer H B and low refractive index layer L B During construction, it is treated as an equivalent film, the low refractive index layer L B It is composed of a low refractive index material with a refractive index of 1.3 to 1.7 at a wavelength of 500 nm.

[0268] (v-2) The high refractive index layer H B The wavelength of 500nm is set as QH. B The middle refractive index layer M B The wavelength of 500nm is set to QM. B At that time, it has the property of (c) n QH B / d n QM B The layered structure represented by ) is where c above n The average value is 1.9 to 5.0, and the above d n The average value is 1.2 to 2.9.

[0269] (v-3) The number of stacks is in the range of 1 to 60.

[0270]

[14] A camera device comprising the optical filter described in any one of [1] to

[13] .

[0271] Example

[0272] The present invention will now be described in more detail with reference to embodiments.

[0273] The spectral characteristics were measured using a UV-Vis spectrophotometer (Hitachi High Technology Co., Ltd., UH-4150 model).

[0274] It should be noted that the spectral characteristics when the incident angle is not specifically specified are the values ​​measured at an incident angle of 0 degrees (the direction perpendicular to the principal surface of the optical filter).

[0275] The pigments used in each example are described below.

[0276] Compound 1 (squamous acid) Compound: synthesized based on U.S. Patent No. 5,543,086.

[0277] Compound 2 (partial cyanide compound): synthesized based on German Patent Publication No. 10109243.

[0278] Compound 3 (cyanin compound): synthesized based on Dyes and pigments 73 (2007) 344-352.

[0279] It should be noted that compounds 1 and 3 are near-infrared absorbing pigments (NIR pigments), and compound 2 is a near-ultraviolet absorbing pigment (UV pigment).

[0280]

[0281] <Spectral properties of pigments>

[0282] The maximum absorption wavelengths in the absorption spectra measured by dissolving the above pigments (compounds 1-3) in dichloromethane are shown in Table 2 below.

[0283] <Light-absorbing glass (light-absorbing material Y) 970S Spectral characteristics of ) >

[0284] Glass A, manufactured by the following method, is used as the light-absorbing material Y. 970S .

[0285] Expressed as mol% by oxide conversion, the raw materials were weighed and mixed in the following proportions: SiO2: 7.5%, B2O3: 23.6%, P2O5: 7.5%, Yb2O3: 47.2%, Ga2O3: 11.8%, and La2O3: 2.4%. The mixture was placed in a crucible with an internal volume of approximately 400 cc and melted at 1400–1650 °C for 2 hours under atmospheric conditions. Then, the mixture was clarified and stirred, and poured into a rectangular mold with dimensions of 100 mm (length) × 50 mm (width) × 20 mm (height) preheated to approximately 300–500 °C. The mold was slowly cooled to room temperature at a rate of approximately -1 °C / min, and cut into specified thicknesses within a range of 40 mm (length) × 30 mm (width) × 0.3–1.5 mm. Both sides were optically polished to obtain a plate-like glass A.

[0286] It should be noted that the raw materials used for the glass are the substances described below.

[0287] SiO2: oxide

[0288] B2O3: Selected from one or more of oxides, PBO4, and H3BO3

[0289] P2O5: any one or more of H3PO4 and PBO4

[0290] GeO2: Oxide

[0291] ZrO2: Oxide

[0292] Ga2O3: Oxide

[0293] Yb₂O₃: Oxide

[0294] La2O3: oxide

[0295] Al2O3: any one or more of oxides and Al(OH)3

[0296] It should be noted that the raw materials for glass are not limited to the substances mentioned above, and well-known raw materials may also be used.

[0297] [evaluate]

[0298] For the glass plate prepared by the above operation, a spectrophotometer (manufactured by Japan Spectrophotometer Co., Ltd., V-570) was used to measure the spectral transmittance curve and spectral reflectance curve in the wavelength range of 350 to 1200 nm, and the optical concentration was calculated based on the obtained transmittance.

[0299] The results are shown in Table 1 below. It should be noted that the spectral characteristics shown in the table below were evaluated using internal transmittance to avoid the influence of reflections from the air and glass interfaces.

[0300] Internal transmittance (%) = {Measured transmittance} （0deg） / (100 - reflectivity) （5deg） )}×100

[0301] In addition, the spectral transmittance curve of glass A is shown in... Figure 3 .

[0302]

[0303] <Example 1-1: Spectral characteristics of the light absorption layer>

[0304] The pigments of compounds 1-4 were dissolved in polyimide resin C-3G30G manufactured by Mitsubishi Gas Chemical Co., Ltd., and mixed separately at the concentrations listed in the table below. The mixtures were stirred at 50°C for 2 hours to obtain a coating solution. The coating solution was then applied to alkali glass (SCHOTT, D263 glass, 0.2 mm thick) using a spin coating method to form a light-absorbing layer with the film thickness shown in the table below.

[0305] The spectral transmittance and spectral reflectance curves of the obtained light-absorbing layer were measured using a UV-Vis spectrophotometer in the wavelength range of 350–1200 nm.

[0306] The results are shown in Table 2 below.

[0307] It should be noted that the spectral characteristics shown in the table below are evaluated using internal transmittance to avoid the influence of reflections from the air and glass interfaces.

[0308] Internal transmittance (%) = {Measured transmittance} （0deg） / (100 - reflectivity) （5deg） )}×100

[0309] Furthermore, the spectral transmittance curve of the light-absorbing layer in Example 1-1 is shown in... Figure 4 .

[0310] It should be noted that Example 1-1 is a reference example.

[0311]

[0312] <Example 2-1: Spectral Characteristics of Optical Filters>

[0313] A dielectric multilayer film A1 (reflective film) is formed by alternately stacking SiO2 and TiO2 on one main surface of a glass substrate (light-absorbing glass A) through vapor deposition.

[0314] A dielectric multilayer film B1 (reflective film) is formed by alternately stacking SiO2 and TiO2 on another main surface of a glass substrate (light-absorbing glass A) through vapor deposition.

[0315] With the same composition as the light-absorbing layer in Example 1-1, a resin solution was coated on the surface of the dielectric multilayer film A1, and the organic solvent was removed by heating, thereby forming a light-absorbing layer with a thickness of 1.4 μm.

[0316] A dielectric multilayer film C1 (anti-reflective film) is formed by alternating layers of SiO2 and TiO2 on the surface of the light-absorbing layer through vapor deposition.

[0317] Based on the above, manufacture optical filter 2-1.

[0318] <Example 2-2>

[0319] An optical filter 2-2 is manufactured by forming a dielectric multilayer film A2 (reflective film) to replace the dielectric multilayer film A1 (reflective film) and a dielectric multilayer film B2 (reflective film) to replace the dielectric multilayer film B1 (reflective film). Otherwise, the optical filter 2-2 is manufactured by operating in the same manner as in Example 2-1.

[0320] <Example 2-3>

[0321] An anti-reflective dielectric multilayer film B3 is formed to replace the reflective dielectric multilayer film B1. Otherwise, the optical filter 2-3 is manufactured in the same manner as in Example 2-1.

[0322] <Example 2-4>

[0323] Optical filter 2-4 is manufactured in the same manner as in Example 2-1, except that it is made by replacing light-absorbing glass A with glass B (D263 glass, borosilicate glass, manufactured by Schott, with a thickness of 0.30 mm) which does not absorb light.

[0324] <Example 2-5>

[0325] Optical filter 2-5 is manufactured in the same manner as in Example 2-1, except that it is made by replacing light-absorbing glass A with glass B (D263 glass, borosilicate glass, manufactured by Schott, with a thickness of 0.56 mm) which does not absorb light.

[0326] The structures of dielectric multilayer films A1-A2, dielectric multilayer films B1-B3, and dielectric multilayer film C1 are shown in Tables 3-8 below. It should be noted that the order of the numbers (No.) corresponds to the stacking order.

[0327] a of dielectric multilayer film A1 n The average value is 1.74, b n The average value is 1.72.

[0328] a of dielectric multilayer film A2 n The average value is 1.73, b n The average value is 1.73.

[0329] c of dielectric multilayer film B1 n The average value is 3.46, d n The average value is 1.65.

[0330] c of dielectric multilayer film B2 n The average value is 3.29, d n The average value is 1.95.

[0331]

[0332]

[0333]

[0334]

[0335]

[0336]

[0337] For each optical filter obtained above, the spectral transmittance curves at incident angles of 0 degrees and 35 degrees and the spectral reflectance curves at incident angles of 5 degrees and 35 degrees in the wavelength range of 350–1200 nm were measured using a UV-Vis spectrophotometer.

[0338] Based on the obtained spectral characteristics data, the characteristics shown in Table 9 below are calculated.

[0339] In addition, the spectral transmittance curves, spectral reflectance curves, and absorption loss of the optical filters in Examples 2-1 to 2-5 are shown in the figure. Figures 5-14 .

[0340] It should be noted that Examples 2-1 to 2-3 are examples, and Examples 2-4 to 2-5 are comparative examples.

[0341]

[0342] Based on the above results, it can be seen that the optical filters of Examples 2-1, 2-2, and 2-3 have excellent transmittance of visible light and near-infrared light in the range of 950–1200 nm, excellent light-blocking properties of other near-infrared light, especially in the wavelength range of 710–950 nm, and small shift of the spectral curve even at high incident angles.

[0343] Without using light-absorbing material Y 970s In the optical filters of Examples 2-4 and 2-5 (light-absorbing glass A), the average transmittance of 710-950 nm at an incident angle of 35 degrees is greater than 1%, and the light-shielding properties in this wavelength region are particularly insufficient at high incident angles.

[0344] The present invention has been described in detail with reference to specific embodiments, and it is obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. This application is based on Japanese Patent Application No. 2023-083282, filed on May 19, 2023, the contents of which are incorporated herein by reference.

[0345] Industrial availability

[0346] The optical filter of this invention exhibits excellent transmittance of visible light and certain near-infrared light, while also providing near-infrared light shielding. In recent years, it has proven useful in the development of high-performance information acquisition devices, such as cameras and sensors for transport aircraft.

[0347] Symbol Explanation

[0348] 1A, 1B… Optical filters

[0349] 10…Support

[0350] 20A, 20B... Dielectric multilayer films

[0351] 30…light absorption layer

Claims

1. An optical filter, comprising: X, a light-absorbing material with the maximum absorption wavelength in the region greater than 700 nm. 700L , Y, a light-absorbing material with the maximum absorption wavelength in the region below 970 nm. 970S ,as well as Dielectric multilayer film, The optical filter satisfies all of the following spectral characteristics (i-1) to (i-4). (i-1) In the spectral transmittance curves with wavelengths from 420 nm to 650 nm and an incident angle of 0 degrees, the average transmittance T 420－650（0deg）AVE The average transmittance T is above 75% in the spectral transmittance curve at an incident angle of 35 degrees. 420－650（35deg）AVE It is over 75%. (i-2) In the spectral transmittance curves with wavelengths from 710 nm to 950 nm and an incident angle of 0 degrees, the average transmittance T 710－950（0deg）AVE For values ​​below 1%, in the spectral transmittance curve at an incident angle of 35 degrees, the average transmittance T 710－950（35deg）AVE Less than 1%, (i-3) In the spectral transmittance curves with wavelengths from 950 nm to 1200 nm and an incident angle of 0 degrees, the maximum transmittance T 950－1200（0deg）MAX With a transmittance of over 60%, the maximum transmittance T in the spectral transmittance curve at an incident angle of 35 degrees is [value missing]. 950－1200（35deg）MAX More than 50%, (i-4) In the spectral transmittance curves with wavelengths from 950 nm to 1200 nm and an incident angle of 0 degrees, let the wavelength that will result in the maximum transmittance be λ. 950－1200（0deg）MAX When, less than λ 950－1200（0deg）MAX The wavelength region in which the transmittance is 50% at an incident angle of 0 degrees is λ. IRS（0deg）（50％） and in less than λ 950－1200（0deg）MAX The wavelength region in which the transmittance is 50% at an incident angle of 35 degrees. IRS（35deg）（50％） The following relationship must be satisfied. |l IRS（0deg）（50％） -l IRS（35deg）（50％） |≤15nm.

2. The optical filter according to claim 1, wherein, The optical filter further satisfies the following spectral characteristics (i-5). (i-5) In the spectral transmittance curves with wavelengths from 950 nm to 1200 nm and an incident angle of 0 degrees, let the wavelength that will result in the maximum transmittance be λ. 950－1200（0deg）MAX When, less than λ 950－1200（0deg）MAX The wavelength region with a transmittance of 55% is λ. IRS（0deg）（55％） and in less than λ 950－1200（0deg）MAX The wavelength region with a transmittance of 45% is λ. IRS（0deg）（45％） The following relationship must be satisfied. |10 / [min IRS（0deg）（45％） -l IRS（0deg）（55％） ]|≥1.0。 3. The optical filter according to claim 1, wherein, The optical filter further satisfies the following spectral characteristics (i-6) to (i-8). (i-6) In the spectral transmittance curves with wavelengths from 950 nm to 1200 nm and an incident angle of 0 degrees, let the wavelength that will result in the maximum transmittance be λ. 950－1200（0deg）MAX When, greater than λ 950－1200（0deg）MAX The wavelength region in which the transmittance is 50% at an incident angle of 0 degrees is λ. IRL（0deg）（50％） and in less than λ 950－1200（0deg）MAX The wavelength region in which the transmittance is 50% at an incident angle of 0 degrees is λ. IRS（0deg）（50％） The following relationship must be satisfied. 10nm≤|λ IRL（0deg）（50％） -l IRS（0deg）（50％） |≤100nm, (i-7) In the spectral transmittance curves with wavelengths from 950 nm to 1200 nm and an incident angle of 0 degrees, let the wavelength that will achieve the maximum transmittance be λ. 950－1200（0deg）MAX When, greater than λ 950－1200（0deg）MAX The wavelength region in which the transmittance is 50% at an incident angle of 35 degrees. IRL（35deg）（50％） and in less than λ 950－1200（0deg）MAX The wavelength region in which the transmittance is 50% at an incident angle of 35 degrees. IRS（35deg）（50％） The following relationship must be satisfied. 20nm≤|λ IRL（35deg）（50％） -l IRS（35deg）（50％） |≤100nm, The wavelength λ mentioned in (i-8) IRL（0deg）（50％） The wavelength λ IRS（0deg）（50％） The wavelength λ IRL（35deg）（50％） The wavelength λ IRS（35deg）（50％） The following relationship must be satisfied. |[l IRL（35deg）（50％） -l IRS（35deg）（50％） ]-[l IRL（0deg）（50％） - λIRS（0deg）（50％） ｽ|≤70nm.

4. The optical filter according to claim 1, wherein, The optical filter further satisfies the following spectral characteristics (i-9) and (i-10). (i-9) In the spectral transmittance curves with wavelengths of 950 nm to 1200 nm and incident angles of 0 degrees, the integral value of the transmittance in the band with a transmittance of 20% or higher is set as IRP-A. （0deg） When the following relationship is satisfied, 10(%·nm)≤IRP-A （0deg） ≤100(%·nm), (i-10) In the spectral transmittance curves with wavelengths of 950 nm to 1200 nm and an incident angle of 35 degrees, the integral value of the transmittance in the band with a transmittance of 20% or higher is set as IPR-A. （35deg） When the following relationship is satisfied, 10(%·nm)≤IRP-A （35deg） ≤100 (% nm).

5. The optical filter according to claim 4, wherein, The IRP-A （0deg） and the IRP-A （35deg） The following relationship must be satisfied. 0.5≤IRP-A （35deg） / IRP-A （0deg） ≤1.1。 6. The optical filter according to claim 1, wherein, The optical filter further satisfies the following spectral characteristics (i-11). (i-11) In the spectral transmittance curves with wavelengths from 420 nm to 650 nm and an incident angle of 0 degrees, the integral value of the transmittance in the band with a transmittance of 20% or higher is set as VIS-A. （0deg） In the spectral transmittance curves with wavelengths from 420 nm to 650 nm and an incident angle of 35 degrees, the integral value of the transmittance in the band with a transmittance of 20% or higher is set as VIS-A. （35deg） In the spectral transmittance curves with wavelengths from 950 nm to 1200 nm and an incident angle of 0 degrees, the integral value of the transmittance in the band with a transmittance of 20% or higher is set as IRP-A. （0deg） In the spectral transmittance curves with wavelengths of 950 nm to 1200 nm and an incident angle of 35 degrees, the integral value of the transmittance in the band with a transmittance of 20% or higher is set as IRP-A. （35deg） When the following relationship is satisfied, 0.5≤[IRP-A （35deg） / VIS-A （35deg） ] / [IRP-A （0deg） / VIS-A （0deg） ]≤1.1。 7. The optical filter according to claim 1, wherein, The optical filter further satisfies the following spectral characteristics (i-12). (i-12) In the spectral transmittance curves with wavelengths from 950 nm to 1200 nm and an incident angle of 0 degrees, let the wavelength that will achieve the maximum transmittance be λ. 950－1200（0deg）MAX When, it will be less than λ 950－1200（0deg）MAX The wavelength region with a transmittance of 50% is set as λ. IRS（0deg）（50％） In the spectral reflectance curves of wavelengths from 950 nm to 1200 nm and an incident angle of 5 degrees, the wavelength with a reflectance of 50% in the wavelength region greater than 950 nm is set as λ. IRR（5deg）（50％） When the following relationship is satisfied, |l IRR（5deg）（50％） -l IRS（0deg）（50％） |≥20nm.

8. The optical filter according to claim 1, wherein, The light-absorbing material Y 970S It satisfies the following spectral characteristics (iii-1) and (iii-2). (iii-1) Maximum optical density at wavelengths of 900–1000 nm > 0.6 (iii-2) The wavelength range of 950-1050 nm is the long-wavelength side with the maximum optical density at wavelengths of 900-1000 nm and a transmittance of 50%.

9. The optical filter according to claim 1, wherein, The light-absorbing material Y 970S It is an inorganic material containing ytterbium.

10. The optical filter according to claim 1, wherein, The light-absorbing material Y 970S It is glass containing ytterbium.

11. The optical filter according to claim 1, wherein, The optical filter includes the light-absorbing material X. 700L Light absorption layer, The optical filter satisfies all of the following spectral characteristics (ii-1) and (ii-2). When the dielectric multilayer film side is the incident direction, the absorption loss at wavelength X nm will be... X The definition is as follows: (Absorption loss) X ) [%] = 100 - (transmittance at 0 degrees incident angle) - (reflectance at 5 degrees incident angle). (ii-1) Absorption loss at wavelengths of 600–830 nm 600－830 The maximum value is above 85. (ii-2) Absorption loss at wavelengths of 600–830 nm 600－830 The score is 5000 or higher.

12. The optical filter according to claim 1, wherein, The optical filter has the following features: The light-absorbing material Y 970S The substrate formed A dielectric multilayer film A disposed on one main surface side of the substrate, and The light-absorbing material X is disposed on one main surface side of the substrate. 700L Light absorption layer, The dielectric multilayer film A satisfies the following characteristics (iv-1), (iv-2), and (iv-3). (iv-1) Having three or more stacked structures, the stacked structure comprising a high refractive index layer H composed of a high refractive index material with a refractive index of 1.9 to 3.0 at a wavelength of 500 nm. A And a medium refractive index layer M composed of a medium refractive index material with a wavelength of 500 nm and a refractive index of 1.5–2.0, which is lower than that of high refractive index materials. A And by (H) A / M A ) indicates that, among which, the intermediate refractive index layer M A From the high refractive index layer H A and low refractive index layer L A During construction, it is treated as an equivalent film, the low refractive index layer L A It is composed of a low refractive index material with a refractive index of 1.3 to 1.7 at a wavelength of 500 nm. (iv-2) Add high refractive index layer H A The wavelength of 500nm is set as QH. A The middle refractive index layer M A The wavelength of 500nm is set to QM. A At that time, it has the property of (a) n QH A / b n QM A The layered structure represented by ) wherein, the a n The average value is 1.2 to 2.7, and the b n The average value is 1.1 to 2.

2. (iv-3) The number of layers is in the range of 1 to 60.

13. The optical filter according to claim 1, wherein, The optical filter has the following features: The light-absorbing material Y 970S The substrate formed A dielectric multilayer film A disposed on one main surface side of the substrate A dielectric multilayer film B disposed on the other main surface of the substrate, and The light-absorbing material X is disposed on one main surface side of the substrate. 700L Light absorption layer, The dielectric multilayer film B satisfies the following characteristics (v-1), (v-2), and (v-3). (v-1) has three or more stacked structures, the stacked structure including a high refractive index layer H composed of a high refractive index material with a refractive index of 1.9 to 3.0 at a wavelength of 500 nm. B And a medium refractive index layer M composed of a medium refractive index material with a wavelength of 500 nm and a refractive index of 1.5–2.0, which is lower than that of high refractive index materials. B And by (H) B / M B ) indicates that, among which, the intermediate refractive index layer M B From the high refractive index layer H B and low refractive index layer L B During construction, it is treated as an equivalent film, the low refractive index layer L B It is composed of a low refractive index material with a refractive index of 1.3 to 1.7 at a wavelength of 500 nm. (v-2) The high refractive index layer H B The wavelength of 500nm is set as QH. B The middle refractive index layer M B The wavelength of 500nm is set to QM. B At that time, it has the property of (c) n QH B / d n QM B The layered structure represented by ) wherein, the c n The average value is 1.9 to 5.0, and the d n The average value is 1.2 to 2.

9. (v-3) The number of stacks is in the range of 1 to 60.

14. A camera device comprising an optical filter according to any one of claims 1 to 13.

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