optical filter

Abstract

The present application relates to a kind of optical filters, the optical filter has: near-infrared absorbing glass, medium multilayer film being stacked on the two main surfaces of the near-infrared absorbing glass, and absorption layer being stacked on at least one surface of the medium multilayer film and having maximum absorption wavelength in near-infrared light region, wherein the optical filter satisfies all specified spectral characteristics (i-1) ~ (i-5).

Description

Technical Field

[0001] The present invention relates to filters that selectively transmit light in the visible light region and a specific near-infrared light region, and block light outside of these regions. Background Technology

[0002] Imaging devices using solid-state imaging elements are being expanded to include surveillance cameras, vehicle cameras, and other devices that capture images day and night. For such devices, it is necessary to acquire both visible light-based (color) images and infrared-based (black and white) images.

[0003] Therefore, research is underway on filters that, in addition to having the function of a near-infrared cutoff filter for transmitting visible light and faithfully reproducing an image based on that visible light, also have the function of selectively transmitting specific near-infrared light, namely, a dual-band filter.

[0004] Patent Document 1 describes a filter obtained by combining a dielectric multilayer film with a resin substrate containing near-infrared absorbing pigments, which transmits visible light and near-infrared light around 800 nm, while blocking other light.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent No. 5884953 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] However, the filter described in Patent Document 1 has insufficient shielding properties for near-infrared light in the 1000nm to 1200nm range.

[0010] In recent years, to reduce the size of imaging devices in AR / VR devices and save space, research has been conducted on imaging devices capable of simultaneously acquiring images based on visible light and infrared light. AR / VR devices require higher image quality compared to vehicle cameras and surveillance cameras. Because imaging elements are sensitive in the 1000nm–1200nm wavelength range, insufficient shielding in the near-infrared region (1000nm–1200nm) can lead to image quality degradation in both visible and infrared light images due to unwanted light, known as glare and ghosting, resulting in insufficient image quality for use in AR / VR devices. Therefore, filters capable of adequately blocking the 1000nm–1200nm region are needed.

[0011] Furthermore, from a performance perspective, it is desirable for filters to be calibrated in a way that makes the light receiving sensitivity curve of the imaging element approximate the human visual sensitivity curve, and to be weather resistant even under high temperature and high humidity conditions.

[0012] The purpose of this invention is to provide a filter that has excellent transmittance of visible light and certain near-infrared light, can effectively block other near-infrared light, especially light in the wavelength range of 1000nm to 1200nm, and has excellent visual sensitivity correction in the visible light region and high reliability related to weather resistance.

[0013] means for solving problems

[0014] The present invention provides a filter having the following configuration.

[0015] [1] A filter, the filter comprising:

[0016] Near-infrared absorbing glass,

[0017] The dielectric multilayer film and the dielectric film stacked on the two main surfaces of the near-infrared absorbing glass

[0018] An absorption layer, stacked on the surface of at least one of the aforementioned dielectric multilayer films and having a maximum absorption wavelength in the near-infrared region, wherein...

[0019] The filter satisfies all of the following spectral characteristics (i-1) to (i-5):

[0020] (i-1) In the spectral transmittance curves at wavelengths of 450 nm to 600 nm and incident angles of 0 degrees, the average transmittance T 450-600(0deg)AVE It is over 60%;

[0021] (i-2) In the spectral transmittance curves at wavelengths of 700 nm to 750 nm and incident angles of 0 degrees, the average transmittance T 700-750(0deg)AVE Less than 5%;

[0022] (i-3) In the spectral transmittance curves at wavelengths of 1050 nm to 1200 nm and incident angles of 0 degrees, the maximum transmittance T 1050-1200(0deg)MAX Below 7%;

[0023] (i-4) In the spectral transmittance curves at wavelengths of 800 nm to 1000 nm and incident angles of 0 degrees, the maximum transmittance T 800-1000(0deg)MAX It is over 20%;

[0024] (i-5) Let the maximum transmittance in the spectral transmittance curve with wavelengths from 450 nm to 600 nm and an incident angle of 0 degrees be T. 450-600(0deg)MAX hour,

[0025] In the spectral transmittance curve at an incident angle of 0 degrees, the transmittance is the value of T. 450-600(0deg)MAX 70% of the wavelength λ (70％) and transmittance is the T 450-600(0deg)MAX λ at 30% (30％) Included in the 600nm to 700nm range,

[0026] In the wavelength λ (70％) Let the transmittance be T. (70％) The wavelength λ (30％) Let the transmittance be T. (30％) When the following relationship is satisfied:

[0027] -2≤[T (30％) -T (70％) ] / [λ (30％) -λ (70％) ]≤-0.75.

[0028] Invention Effects

[0029] According to the present invention, a filter can be provided that exhibits excellent transmittance of visible light and specific near-infrared light, particularly in the wavelength range of 800 nm to 900 nm, excellent shielding of other near-infrared light, particularly in the wavelength range of 1000 nm to 1200 nm, excellent visual sensitivity correction in the visible light region, and high reliability related to weather resistance. Attached Figure Description

[0030] Figure 1 This is a cross-sectional view schematically illustrating an example of a filter according to one embodiment.

[0031] Figure 2 This is a cross-sectional view schematically illustrating another example of a filter according to one embodiment.

[0032] Figure 3 This is a graph showing the spectral transmittance curve of near-infrared absorbing glass.

[0033] Figure 4 This is a graph showing the spectral transmittance curves of the absorption layers in Examples 1-1 and 1-2.

[0034] Figure 5 This is a graph showing the spectral transmittance curve of the filter in Example 2-1.

[0035] Figure 6 This is a graph showing the spectral transmittance curve of the filter in Example 2-2.

[0036] Figure 7 This is a graph showing the spectral transmittance curve of the filter in Example 2-3.

[0037] Figure 8 This is a graph showing the spectral transmittance curve of the filter in Example 2-5.

[0038] Figure 9 This is a graph showing the spectral transmittance curve of the filter in Example 2-6. Detailed Implementation

[0039] The embodiments of the present invention will be described below.

[0040] In this specification, near-infrared absorbing pigments are sometimes referred to as "NIR pigments" and ultraviolet absorbing pigments are sometimes referred to as "UV pigments".

[0041] In this specification, compounds represented by formula (I) are referred to as compound (I). The same applies to compounds represented by other formulas. Pigments containing compound (I) are also referred to as pigment (I), and the same applies to other pigments. Furthermore, groups represented by formula (I) are also denoted as group (I), and the same applies to groups represented by other formulas.

[0042] 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 / (100-reflectance)}×100.

[0043] In this specification, absorbance is expressed as -log 10 The formula for ((internal) transmittance / 100) is derived from (internal) transmittance.

[0044] In this specification, the transmittance of the substrate and the transmittance of the absorption layer, including those containing pigments in the resin, are all referred to as "internal transmittance" when denoted as "transmittance". On the other hand, the transmittance measured by dissolving the pigment in a solvent such as dichloromethane, the transmittance of the dielectric multilayer film, and the transmittance of the filter having the dielectric multilayer film are measured transmittance.

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

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

[0047] In this specification, the "~" sign indicating a numerical range includes both the upper and lower limits.

[0048] <Filter>

[0049] A filter according to one embodiment of the present invention (hereinafter also referred to as "the filter") comprises a near-infrared absorbing glass, a dielectric multilayer film stacked on two main surfaces of the near-infrared absorbing glass, and an absorbing layer stacked on the surface of at least one dielectric multilayer film and having a maximum absorption wavelength in the near-infrared light region.

[0050] By utilizing the reflective properties of the dielectric multilayer film and the absorption properties of the near-infrared absorbing glass and absorption layer, the filter as a whole can achieve excellent transmittance in the visible light region and a specific near-infrared light region, as well as excellent shielding in other near-infrared light regions.

[0051] The configuration example of this filter will be described using the accompanying drawings. Figures 1-2 This is a cross-sectional view schematically illustrating an example of a filter according to one embodiment.

[0052] Figure 1 The filter 1A shown is an example having a near-infrared absorbing glass 10, a dielectric multilayer film 21 stacked on one main surface of the near-infrared absorbing glass 10, and a dielectric multilayer film 22 stacked on the other main surface of the near-infrared absorbing glass 10, and having an absorption layer 30 on the surface of the dielectric multilayer film 22.

[0053] Here, the dielectric multilayer films 21 and 22 are preferably laminated in contact with the main surfaces of the near-infrared absorbing glass 10. Near-infrared absorbing glass often uses phosphate glass or fluorophosphate glass containing copper or iron to absorb near-infrared radiation; however, components such as P2O5 contained in the glass tend to leach into water in the environment. Dielectric multilayer films are typically made of inorganic materials; therefore, by directly laminating the dielectric multilayer film onto the two main surfaces of the near-infrared absorbing glass, the dielectric multilayer film also functions as a barrier layer to prevent the glass from contacting water. This suppresses the deterioration of the near-infrared absorbing glass, resulting in a highly reliable filter.

[0054] Figure 2 The filter 1B shown is an example in which a dielectric multilayer film 23 is also provided on the surface of the absorption layer 30.

[0055] The filter of the present invention satisfies all of the following spectral characteristics (i-1) to (i-5):

[0056] (i-1) In the spectral transmittance curves at wavelengths of 450 nm to 600 nm and incident angles of 0 degrees, the average transmittance T 450-600(0deg)AVE It is over 60%;

[0057] (i-2) In the spectral transmittance curves at wavelengths of 700 nm to 750 nm and incident angles of 0 degrees, the average transmittance T 700-750(0deg)AVE Less than 5%;

[0058] (i-3) In the spectral transmittance curves at wavelengths of 1050 nm to 1200 nm and incident angles of 0 degrees, the maximum transmittance T 1050-1200(0deg)MAX Below 7%;

[0059] (i-4) In the spectral transmittance curves at wavelengths of 800 nm to 1000 nm and incident angles of 0 degrees, the maximum transmittance T 800-1000(0deg)MAX It is over 20%;

[0060] (i-5) Let the maximum transmittance in the spectral transmittance curve with wavelengths from 450 nm to 600 nm and an incident angle of 0 degrees be T. 450-600(0deg)MAX hour,

[0061] In the spectral transmittance curve at an incident angle of 0 degrees, the transmittance is the value of T. 450-600(0deg)MAX 70% of the wavelength λ (70％) and transmittance is the T 450-600(0deg)MAX λ at 30% (30％) Included in the 600nm to 700nm range,

[0062] In the wavelength λ (70％) Let the transmittance be T. (70％) The wavelength λ (30％) Let the transmittance be T. (30％) When the following relationship is satisfied:

[0063] -2≤[T (30％) -T (70％) ] / [λ (30％) -λ (70％) ]≤-0.75.

[0064] The filter that satisfies all spectral characteristics (i-1) to (i-5) is a dual-band filter that has excellent transmittance of visible light as shown in characteristic (i-1), excellent transmittance of specific near-infrared light as shown in characteristic (i-4), excellent shielding of other near-infrared light as shown in characteristics (i-2) and (i-3), and excellent visual sensitivity correction in the visible light region as shown in characteristic (i-5).

[0065] By satisfying the spectral characteristics (i-1), it means that the transmittance in the visible light region of 450nm to 600nm is excellent.

[0066] T 450-600(0deg)AVE Preferably, it is 80% or more, and more preferably 88% or more.

[0067] In addition, to meet the spectral characteristics (i-1), examples include using a multilayer film, an absorption layer, or a glass with excellent transmittance in the visible light region.

[0068] By satisfying the spectral characteristics (i-2), it means that the shielding performance in the near-infrared region of 700nm to 750nm is excellent.

[0069] T 700-750(0deg)AVE Preferably, it is 2% or less, more preferably 1% or less.

[0070] In addition, to meet the spectral characteristics (i-2), for example, an absorption layer containing near-infrared absorbing pigments can be used to shield light by utilizing the absorption capacity of the pigments.

[0071] By satisfying the spectral characteristics (i-3), it means that the shielding performance in the near-infrared region of 1000nm to 1200nm is excellent.

[0072] T 1050-1200(0deg)MAX Preferably, it is 3% or less, more preferably 1% or less.

[0073] In addition, to meet the spectral characteristics (i-3), for example, one could use glass that absorbs near-infrared light beyond 1000 nm.

[0074] By satisfying the spectral characteristics (i-4), it means that the transmittance in the near-infrared region of 800nm ​​to 1000nm is excellent.

[0075] T 800-1000(0deg)MAX Preferably, it is 40% or more, and more preferably 60% or more.

[0076] In addition, to meet the spectral characteristics (i-4), for example, a dielectric multilayer film with excellent transmittance in the near-infrared region of 800 nm to 1000 nm can be used.

[0077] The relationship in spectral characteristics (i-5) [T] (30％) -T (70％) ] / [λ (30％) -λ (70％) [i] refers to the degree of decrease in the spectral transmittance curve (the slope of the visible light band cutoff) in the wavelength range of 600nm to 700nm when switching from the visible light to the near-infrared light to be shielded. From the viewpoint of effectively acquiring light, a steeper spectral curve in the boundary region between the transmission and shielding areas is more ideal. On the other hand, from a performance perspective, correcting the spectral curve in a way that makes the light receiving sensitivity approximate the visual sensitivity curve can closely approximate the perception of human vision. A relationship (slope) in the above formula (i-5) of spectral characteristics with a value of -2 or higher and -0.75 or lower indicates excellent visual sensitivity correction in the visible light region.

[0078] The above-mentioned relationship (slope) in the spectral characteristics (i-5) is preferably -1.5 or higher, and more preferably -0.8 or lower.

[0079] To meet the spectral characteristics (i-5), for example, an absorption layer containing near-infrared absorbing pigments can be used to shield light by utilizing the absorption capacity of the pigments.

[0080] The filter of the present invention preferably also satisfies the following spectral characteristics (i-6):

[0081] (i-6) Let the transmittance at wavelength λ in the spectral transmittance curve at an incident angle of 0 degrees be T. (0deg) (λ), let the transmittance at wavelength λ in the spectral transmittance curve at an incident angle of 35° be T. (35deg) When (λ), the following relationship is satisfied in the wavelength range of 450nm≤λ≤600nm:

[0082] |T (0deg) (λ)-T (35deg) (λ)|≤10%.

[0083] The relationship of characteristic (i-6) means that even at high incident angles, the transmittance of visible light in the range of 450nm to 600nm is not easily changed, i.e., ripples are suppressed.

[0084] |T (0deg) (λ)-T (35deg) (λ)| is preferably 7% or less, more preferably 4% or less.

[0085] Depending on the number of layers in the multilayer film used to reflect the near-infrared region, the transmittance in the visible light region changes due to interference caused by reflected light at the interfaces of each layer, thus producing ripples. The higher the angle of incidence, the larger the ripples. To meet the characteristics (i-6), examples include using a dielectric multilayer film that suppresses ripples by controlling the number of layers, and using near-infrared absorbing glass to compensate for the light shielding in the near-infrared region.

[0086] The filter of the present invention preferably also satisfies the following spectral characteristics (i-7):

[0087] (i-7) Let the maximum transmittance in the spectral transmittance curve with wavelengths from 450 nm to 600 nm and an incident angle of 0 degrees be T. 450-600(0deg)MAX hour,

[0088] The T under the condition of incident angle 0 degrees 450-600(0deg)MAX wavelength λ when it is 50% VIS(0deg)(50％) And T under the condition of an incident angle of 35 degrees 450-600(0deg)MAX wavelength λ when it is 50% VIS(35deg)(50％)Included in the 600nm to 700nm range, and

[0089] The following relationship must be satisfied:

[0090] |λ VIS(0deg)(50％) -λ VIS(35deg)(50％) |≤10nm.

[0091] By satisfying the spectral characteristics (i-7), it means that even at high incident angles, the spectral curve in the range of 600nm to 700nm is not easily shifted.

[0092] |λ VIS(0deg)(50％) -λ VIS(35deg)(50％) | Preferably below 7nm, more preferably below 5nm.

[0093] To meet the spectral characteristics (i-7), for example, an absorption layer containing near-infrared absorbing pigments can be used to shield light by utilizing the absorption capacity of the pigments.

[0094] The filter of the present invention preferably also satisfies the following spectral characteristics (i-8):

[0095] (i-8) Let the maximum transmittance in the spectral transmittance curve at wavelengths of 800 nm to 1000 nm and an incident angle of 0 degrees be T. 800-1000(0deg)MAX Let the wavelength at which the maximum transmittance is achieved be λ. 800-1000(0deg)MAX hour,

[0096] In 750nm~λ 800-1000(0deg)MAX In the spectral transmittance curve with a transmittance in the range of nm and an incident angle of 0 degrees, the transmittance is T. 800-1000(0deg)MAX λ at 50% of the wavelength IRS(0deg)(50％) and in 750nm~λ 800-1000(0deg)MAX In the spectral transmittance curve with a transmittance in the range of nm and an incident angle of 35 degrees, the transmittance is T. 800-1000(0deg)MAX λ at 50% of the wavelength IRS(35deg)(50％) The following relationship must be satisfied:

[0097] |λ IRS(0deg)(50％) -λ IRS(35deg)(50％) |≤30nm.

[0098] By satisfying the spectral characteristics (i-8), it means that even at high incident angles, 750 nm~λ 800-1000(0deg)MAX The spectral curves in the nm range are also not easily shifted.

[0099] |λ IRS(0deg)(50％) -λ IRS(35deg)(50％) | Preferably below 20nm, more preferably below 10nm.

[0100] To meet the spectral characteristics (i-8), for example, an absorption layer containing near-infrared absorbing pigments can be used to shield light by utilizing the absorption capacity of the pigments.

[0101] The filter of the present invention preferably also satisfies the following spectral characteristics (i-9):

[0102] (i-9) Let the maximum transmittance in the spectral transmittance curve at wavelengths of 800 nm to 1000 nm and an incident angle of 0 degrees be T. 800-1000(0deg)MAX Let the wavelength at which the maximum transmittance is achieved be λ. 800-1000(0deg)MAX hour,

[0103] In λ 800-1000(0deg)MAX In the spectral transmittance curve for the range of nm to 1050 nm and with an incident angle of 0 degrees, the transmittance is T. 800-1000(0deg)MAX λ at 50% of the wavelength IRL(0deg)(50％) and in λ 800-1000(0deg)MAX In the spectral transmittance curve for the range of nm to 1050 nm and an incident angle of 35 degrees, the transmittance is T. 800-1000(0deg)MAX λ at 50% of the wavelength IRL(35deg)(50％) The following relationship must be satisfied:

[0104] |λ IRL(0deg)(50％) -λ IRL(35deg)(50％) |≤60nm.

[0105] By satisfying the spectral property (i-9), it means that even at high incident angles, λ 800-1000(0deg)MAX The spectral curves in the range of nm to 1050 nm are also not easily shifted.

[0106] |λ IRL(0deg)(50％) -λ IRL(35deg)(50％) | Preferably, it is below 55nm, more preferably below 50nm.

[0107] To meet the spectral characteristics (i-9), for example, an absorption layer containing near-infrared absorbing pigments can be used to shield light by utilizing the absorption capacity of the pigments.

[0108] The filter of the present invention preferably also satisfies the following spectral characteristics (i-10) to (i-11):

[0109] (i-10) In the spectral reflectance curve at an incident angle of 5 degrees on at least one surface, the average reflectance R in the wavelength range of 450 nm to 600 nm. 450-600(5deg)AVE Less than 15%;

[0110] (i-11) In the spectral reflectance curves at an incident angle of 5 degrees on at least one surface, the average reflectance R in the wavelength range of 1050 nm to 1200 nm is... 1050-1200(5deg)AVE It is over 40%.

[0111] The spectral characteristics (i-10) and (i-11) imply that at least one of the dielectric multilayer films is a multilayer film with reflective properties in the near-infrared region.

[0112] R 450-600(5deg)AVE Preferably, it is 5% or less, more preferably 3% or less.

[0113] R 1050-1200(5deg)AVE Preferably, it is 80% or more, and more preferably 90% or more.

[0114] Near-infrared absorbing glass

[0115] This filter features near-infrared absorbing glass. By utilizing the absorption capacity of the glass to block light in the near-infrared region, it can compensate for the light-shielding properties of the dielectric multilayer film.

[0116] Near-infrared absorbing glass preferably satisfies all of the following spectral characteristics (iii-1) to (iii-3):

[0117] (iii-1) Average internal transmittance T in the spectral transmittance curves of wavelengths from 450 nm to 600 nm G_450-600AVE It is over 80%;

[0118] (iii-2) Average internal transmittance T in the spectral transmittance curves with wavelengths from 1050 nm to 1200 nm G_1050-1200AVE Less than the average internal transmittance T G_450-600AVE ;

[0119] (iii-3) Internal transmittance T in the wavelength range of 800 nm to 1000 nm G_800-1000 Monotonous decrease.

[0120] Characteristic (iii-1) means excellent transmittance in the visible light region of wavelengths from 450 nm to 600 nm.

[0121] T G_450-600AVE Preferably, it is 90% or more, and more preferably 95% or more.

[0122] Characteristic (iii-2) means that it has excellent light shielding properties in the near-infrared region with wavelengths of 1050 nm to 1200 nm.

[0123] T G_1050-1200AVE Preferably, it is 30% or less, more preferably 20% or less.

[0124] By satisfying characteristic (iii-3), it means that the absorption band extends to the wavelength range beyond 1000 nm, and light within that wavelength range can be sufficiently absorbed. Here, monotonic reduction refers to the internal transmittance T at the preferred wavelength of 800 nm. G_800Internal transmittance T at a wavelength of 900nm G_900 Internal transmittance T at a wavelength of 1000nm G_1000 The following relationship must be satisfied:

[0125] T G_800 >T G_900 >T G_1000 .

[0126] In addition, T G_800 Preferably 55% or more, T G_1000 Preferably below 40%.

[0127] In particular, by utilizing the absorption capacity of glass as shown in characteristic (iii-2) to shield light with wavelengths from 1050 nm to 1200 nm, it is possible to adequately shield light in this wavelength range, which has room for improvement in conventional filters.

[0128] As for near-infrared absorbing glass, there are no restrictions as long as the glass can obtain the above-mentioned spectral characteristics. For example, fluorophosphate glass or phosphate glass containing iron or copper is preferred. From the viewpoint of easily obtaining the above-mentioned spectral characteristics, fluorophosphate glass or phosphate glass containing iron is more preferred, and phosphate glass containing iron is particularly preferred.

[0129] Examples of iron-containing phosphate glasses (ferrophosphate glasses) include glasses having any of the following compositions.

[0130] (1) Glass containing P2O5, Al2O3, R'O (wherein R'O represents any one or more selected from MgO, CaO, SrO, BaO and ZnO) as essential components and substantially free of F (fluorine content) based on oxide mole % and containing Fe2O3: 0.1% to 35%.

[0131] (2) Glass containing, in molar percentage based on oxides: P2O5: 40%–75%, Al2O3: 5%–22%, R2O: 0%–20% (where R2O represents the total amount of Li2O, Na2O and K2O), R”O: 0.1%–35% (where R”O represents the total amount of MgO, CaO, SrO, BaO and ZnO), and Fe2O3: 5%–35%.

[0132] (3) Glass containing, based on the mole percent of oxides: P2O5: 25%–75%, Al2O3: 2.5%–22%, R2O: 0%–35% (wherein R2O represents the total amount of Li2O, Na2O and K2O), R”O: 0.1%–35% (wherein R”O represents the total amount of MgO, CaO, SrO, BaO and ZnO), and Fe2O3: 0.1%–5% (wherein excluding 5%).

[0133] (4) Glass containing, in molar percentage based on oxides: 40%–75% P2O5, 5%–22% Al2O3, 0.1%–20% R2O (wherein R2O represents the total amount of Li2O, Na2O and K2O), 0.1%–25% R”O (wherein R”O represents the total amount of MgO, CaO, SrO, BaO and ZnO), and 0.1%–5% Fe2O3 (wherein excluding 5%).

[0134] In addition, in the glass with the above-mentioned composition (1) to (4), it is preferable to contain 0.1% to 20% ZnO based on the mole % of oxides.

[0135] In the glass with the compositions described in (1) to (4) above, the divalent iron (Fe2O3) in the total iron (total Fe content) converted to Fe2O3 2+ The mass ratio of Fe 2+ The percentage of total Fe (%) × 100% is preferably 25% to 99%.

[0136] As a near-infrared absorbing glass, commercially available products can be used, or it can be manufactured using known methods. For example, ferrophosphate glass as described in International Publication No. 2020 / 262296 can be used.

[0137] Alternatively, as a near-infrared absorbing glass, the following chemically strengthened glass can also be used: a chemically strengthened glass obtained by exchanging alkali metal ions with small ionic radii (e.g., Li ions, Na ions) present in the main surface of the glass plate with alkali metal ions with larger ionic radii (e.g., Na ions or K ions for Li ions, and K ions for Na ions) through ion exchange at a temperature below the glass transition temperature.

[0138] From the viewpoint of minimizing the height of the camera module, the thickness of the near-infrared absorbing glass is preferably 0.5 mm or less, more preferably 0.3 mm or less. From the viewpoint of component strength, the thickness of the near-infrared absorbing glass is preferably 0.15 mm or more.

[0139] <Dielectric Multilayer Film>

[0140] In this filter, a multilayer dielectric film is stacked on both sides of the near-infrared absorbing glass. This effectively suppresses the ingress of water, a cause of deterioration in the near-infrared absorbing glass, resulting in a filter with excellent weather resistance.

[0141] In this filter, at least one of the dielectric multilayer films is preferably designed as a near-infrared reflective layer (hereinafter also referred to as NIR reflective layer). The other dielectric multilayer film is preferably designed as an NIR reflective layer, a reflective layer having a reflective region other than the near-infrared region, or an anti-reflective layer.

[0142] The NIR reflective layer in this filter, for example, transmits visible light and a specific near-infrared light, and primarily reflects the transmission region of the absorption layer and the wavelength selectivity of light other than the specific near-infrared light. It should be noted that the reflective region of the NIR reflective layer may also include the light-shielding region in the near-infrared region of the absorption layer. The NIR reflective layer can be appropriately designed to block light of wavelengths other than the near-infrared region, such as near-ultraviolet light, in addition to its NIR reflective properties.

[0143] As a dielectric multilayer film designed as an NIR reflective layer, it preferably satisfies the following spectral characteristics:

[0144] (iv-1) Average reflectance R in the spectral reflectance curves of wavelengths from 450 nm to 600 nm D 450-600AVE Less than 2%;

[0145] (iv-2) Average reflectance R in the spectral reflectance curves of wavelengths from 1000 nm to 1200 nm D_1000-1200AVE It is over 40%.

[0146] A portion of the near-infrared region (700nm–1000nm) requires a certain degree of transmittance. The reflective properties of the dielectric multilayer film and the absorption characteristics of the near-infrared absorbing pigments must be considered, and the reflective properties of the dielectric multilayer film should be appropriately designed to ensure that the overall filter achieves the target transmittance.

[0147] Regarding NIR reflective layers, examples include: low-refractive-index dielectric films, medium-refractive-index dielectric films, and high-refractive-index dielectric films, which are composed of dielectric multilayer films obtained by stacking two or more of these dielectric films. The high-refractive-index film preferably has a refractive index of 1.6 or higher, more preferably 2.2 to 2.5. Examples of materials for high-refractive-index films include: Ta2O5, TiO2, TiO, and Nb2O5. Other commercially available examples include OS50 (Ti3O5), OS10 (Ti4O7), OA500 (a mixture of Ta2O5 and ZrO2), and OA600 (a mixture of Ta2O5 and TiO2) manufactured by Canon Optronics Corporation. Among these, TiO2 is preferred from the perspectives of film formation properties, reproducibility of refractive index, and stability.

[0148] Medium refractive index films are preferably those with a refractive index greater than or equal to 1.6 and less than 2.2. Examples of materials suitable for medium refractive index films include: ZrO2, Nb2O5, Al2O3, HfO2, OM-4 and OM-6 (mixtures of Al2O3 and ZrO2) sold by Canon Optronics Corporation, OA-100, and H4 and M2 (alumina-lanthanum oxide) sold by Merck. Among these, Al2O3 compounds and mixtures of Al2O3 and ZrO2 are preferred based on factors such as film-forming properties, reproducibility of refractive index, and stability.

[0149] The low refractive index film preferably has a refractive index of less than 1.6, more preferably greater than or equal to 1.45 and less than 1.55. Examples of materials that can be used for low refractive index films include SiO2 and SiO2. x N y、 MgF2, etc. Other commercially available products include S4F and S5F (a mixture of SiO2 and Al2O3) manufactured by Canon Optron Corporation. Among these, SiO2 is preferred based on factors such as film-forming reproducibility, stability, and cost-effectiveness.

[0150] Regarding NIR reflective layers, in order to transmit visible light and specific near-infrared light, one example is combining multiple layers of media with different spectral characteristics when transmitting and selecting the desired wavelength.

[0151] For example, the thickness and number of layers can be adjusted by the materials that make up the membrane.

[0152] For NIR reflective layers, from the viewpoint of controlling the transmission and shielding bands, the total number of layers of the dielectric multilayer film constituting the reflective layer is preferably 20 or more, more preferably 25 or more, and from the viewpoint of suppressing ripples, it is preferably 50 or less.

[0153] Furthermore, from the viewpoint of suppressing the deterioration of near-infrared absorbing glass, the thickness of each dielectric multilayer film is preferably 600 nm or more, more preferably 1 μm 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.

[0154] In addition, in the formation of dielectric multilayer films, vacuum film formation processes such as CVD, sputtering, and vacuum evaporation can be used; wet film formation processes such as spraying and immersion can also be used.

[0155] The specified spectral characteristics can be obtained using a single NIR reflective layer (a set of dielectric multilayer films), or using two or more NIR reflective layers. When there are two or more NIR reflective layers, each reflective layer can have the same or different configurations. Typically, the two reflective layers consist of multiple reflective layers with different reflection bands. When using two reflective layers, one can be configured as a near-infrared reflective layer that shields short-wavelength light in the near-infrared region, and the other as a near-infrared / near-ultraviolet reflective layer that shields both long-wavelength light and near-ultraviolet light in the same near-infrared region.

[0156] Examples of antireflective layers include: multilayer dielectric films, intermediate refractive index media, and moth-eye structures with gradually changing refractive index. Among these, multilayer dielectric films are preferred from the viewpoint of optical efficiency and productivity. Antireflective layers are obtained by alternately stacking high-refractive-index and low-refractive-index dielectric films, similar to reflective layers.

[0157] <Absorbing Layer>

[0158] In this filter, an absorption layer having a maximum absorption wavelength in the near-infrared region is provided on the surface of at least one of the aforementioned dielectric multilayer films. This effectively shields light in the near-infrared region. Furthermore, by stacking the absorption layer between the dielectric multilayer films without it contacting the near-infrared absorbing glass, water ingress into the glass can be prevented.

[0159] The absorption layer preferably satisfies all of the following spectral characteristics (ii-1) to (ii-2):

[0160] (ii-1) Let λ be the shortest wavelength at which the internal transmittance is 30% in the spectral transmittance curve of wavelengths from 650 nm to 720 nm. A_VIS(30％) The shortest wavelength with an internal transmittance of 30% in the spectral transmittance curve of 720nm to 1000nm is set as λ. A_IR(30％) When the following relationship is satisfied:

[0161] |λ A_IR(30％) -λ A_VIS(30％) |≥100nm.

[0162] (ii-2) Set the absorbance at a wavelength of 450 nm as A A_450 Let the absorbance at a wavelength of 720nm be A. A_720 When the following relationship is satisfied:

[0163] A A_720 -A A_450 ≥1.

[0164] In property (ii-1) |λ A_IR(30％) -λ A_VIS(30％) | is an indicator of the near-infrared light absorption band centered at 720nm, measured by |λ A_IR(30％) -λ A_VIS(30％) |Above 100nm means it is an absorption layer that absorbs light over a wide range in that region.

[0165] |λ A_IR(30％) -λ A_VIS(30％) |More preferably, it is 120 nm or higher. Furthermore, the longer the wavelength of maximum absorption of the pigment, the more difficult it is to maintain high transmittance in the visible light region. From this perspective, |λ A_IR(30％) -λ A_VIS(30％) | Preferably below 150nm.

[0166] To satisfy characteristic (ii-1), for example, as a near-infrared absorbing pigment, one could combine two pigments with different maximum absorption wavelengths within the range of 680 nm to 800 nm; preferably, a combination of a pigment with a maximum absorption wavelength within the range of 680 nm to 740 nm and a pigment with a maximum absorption wavelength within the range of 740 nm to 800 nm. Furthermore, from the viewpoint of achieving a wide range of absorption with a small amount added, the use of squaric acid can be cited. Salt pigment.

[0167] Characteristic (ii-2) means that it is an absorption layer that combines high visible light transmittance at 450nm and high near-infrared light shielding at 720nm.

[0168] A A_720 -A A_450 Preferably, it is 1.5 or more, and more preferably 2 or more.

[0169] To satisfy characteristic (ii-2), for example, as a near-infrared absorbing pigment, from the viewpoint of strongly absorbing light near 720 nm while maintaining high transmittance in the visible light region, the use of symmetrical squaric acid pigments can be cited. Salt pigment.

[0170] The absorbing layer preferably contains a pigment (NIR pigment) in dichloromethane that has a maximum absorption wavelength in the range of 680 nm to 800 nm. By including this pigment, the absorbing layer, as shown in the above characteristics (ii-1) and (ii-2), can absorb the near-infrared light absorption band centered at 720 nm over a wide range, and easily achieves both visible light transmittance of 450 nm and near-infrared light shielding of 720 nm. Thus, the absorption characteristics of the pigment can be used to shield light in the near-infrared region around 720 nm, where the shielding effect is slightly weaker than that of infrared absorbing glass.

[0171] From the viewpoint that it can absorb light in the near-infrared region over a wide range, it is preferable to combine two pigments with different maximum absorption wavelengths that are in the range of 680 nm to 800 nm. It is even more preferable to combine a pigment with a maximum absorption wavelength in the range of 680 nm to 740 nm and a pigment with a maximum absorption wavelength in the range of 740 nm to 800 nm.

[0172] In addition, the absorbent layer is preferably a resin film containing the pigment and the resin.

[0173] Examples of NIR pigments include: squaric acid. Salt compounds, anthocyanin compounds, etc. Among these, from the viewpoints of easily satisfying the above characteristics (ii-1) and (ii-2) of the absorption layer, the range of maximum absorption wavelength, the transmittance in the visible light region, solubility in the resin, and durability, squaric acid is preferred. Salt compounds.

[0174] Squamous acid as a NIR pigment The salt compounds are preferably those represented by formula (I) and those represented by formula (II).

[0175] It should be noted that within the squaric acid... When a salt compound contains two or more identical symbols, these symbols can be the same or different. The same applies to anthocyanin compounds.

[0176] <Square acid inner> Salt compound (I)>

[0177]

[0178] The symbols in the above formula are as follows.

[0179] R 24 and R 26Each of the following can independently represent a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group with 1 to 20 carbon atoms or an alkoxy group with 1 to 20 carbon atoms, an acyl group with 1 to 10 carbon atoms, an aryl group with 6 to 11 carbon atoms, an aralkyl group with 7 to 18 carbon atoms that may have substituents and may have oxygen atoms between carbon atoms, and -NR. 27 R 28 (R 27 and R 28 Each independently represents a hydrogen atom, an alkyl group with 1 to 20 carbon atoms, or a -C(=O)-R group. 29 (R 29 -NHR represents a hydrogen atom, a halogen atom, a hydroxyl group, a hydrocarbon group that may have substituents and may contain unsaturated bonds between carbon atoms, an oxygen atom, or a saturated or unsaturated ring structure with 1 to 25 carbon atoms. 30 or -SO2-R 30 (R 30 Each group represents one or more hydrogen atoms that can be substituted with halogen atoms, hydroxyl groups, carboxyl groups, sulfonyl groups, or cyano groups, and may contain unsaturated bonds, oxygen atoms, saturated or unsaturated ring structures of 1 to 25 carbon atoms (hydrocarbon groups), or groups represented by the following formula (S) (R). 41 and R 42 Independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms; k is 2 or 3).

[0180]

[0181] R 21 and R 22 They can connect with each other and together with nitrogen atoms to form five- or six-membered heterocycles A, R 22 and R 25 They can connect with each other and form five- or six-membered heterocycles B and R together with nitrogen atoms. 21 and R 23 They can connect with each other and form five- or six-membered heterocyclic C atoms together with nitrogen atoms.

[0182] As R in the case of forming heterocyclic A 21 and R 22 The bonded divalent group -Q- indicates that the hydrogen atom can be replaced by an alkylene group with 1 to 6 carbon atoms, an aryl group with 6 to 10 carbon atoms, or an alkylene group or alkylene group with 1 to 10 carbon atoms that has a substituent.

[0183] As R in the case of forming heterocyclic B 22 and R 25 The bonded divalent group -X 1 -Y 1- and R in the case of forming heterocyclic C 21 and R 23 The bonded divalent group -X 2 -Y 2 -(The side bonded to nitrogen is X) 1 and X 2 ), X 1 and X 2 Each is a group represented by the following formula (1x) or (2x), Y 1 and Y 2 Each is a group selected from any of the following formulas (1y) to (5y). In X 1 and X 2 When each of the groups is represented by the following formula (2x), Y 1 and Y 2 Each can be a single bond, in which case there can be oxygen atoms between carbon atoms.

[0184]

[0185] In formula (1x), each of the four Zs independently represents a hydrogen atom, a hydroxyl group, an alkyl group with 1 to 6 carbon atoms or an alkoxy group with 1 to 6 carbon atoms, or -NR. 38 R 39 (R 38 and R 39 Each can independently represent an alkyl group having 1 to 20 hydrogen atoms. 31 ~R 36 Each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 10 carbon atoms, R 37 It represents an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 10 carbon atoms.

[0186] R 27 R 28 R 29 R 31 ~R 37 R without the formation of heterocycles 21 ~R 23 and R 25 Each can bond with any of these groups to form a five-membered or six-membered ring. R 31 With R 36 Direct bonding is possible, R 31 With R 37 They can be bonded directly.

[0187] R without heterocyclic formation 21 R 22 R 23 and R 25Each of the following can be independently represented as a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group having 1 to 20 carbon atoms or an alkoxy group having 1 to 20 carbon atoms, an acyl group having 1 to 10 carbon atoms, an aryl group having 6 to 11 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms that may have substituents and may have oxygen atoms between carbon atoms.

[0188] As compound (I), for example, compounds represented by any one of formulas (I-1) to (I-3) can be cited. From the viewpoints of solubility in resin, heat resistance and light resistance in resin, and visible light transmittance of the resin layer containing the compound, compounds represented by formula (I-1) are particularly preferred.

[0189]

[0190] The symbols in equations (I-1) to (I-3) are defined in the same way as the same symbols in equation (I), and the preferred methods are also the same.

[0191] In compound (I-1), as X 1 Preferred group (2x) is used as Y. 1 Preferably, a single bond or a group (1y). In this case, as R 31 ~R 36 Preferably, it is an alkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom or a methyl group. It should be noted that, as -Y 1 -X 1 Specifically, examples can be given of divalent organic groups represented by formulas (11-1) to (12-3).

[0192] -C(CH3)2-CH(CH3)-……(11-1)

[0193] -C(CH3)2-CH2-……(11-2)

[0194] -C(CH3)2-CH(C2H5)-……(11-3)

[0195] -C(CH3)2-C(CH3)(nC3H7)-……(11-4)

[0196] -C(CH3)2-CH2-CH2-……(12-1)

[0197] -C(CH3)2-CH2-CH(CH3)-……(12-2)

[0198] -C(CH3)2-CH(CH3)-CH2-……(12-3)

[0199] Furthermore, in compound (I-1), from the viewpoints of solubility, heat resistance, and the steepness of the change near the boundary between the visible and near-infrared regions in the spectral transmittance curve, R 21 More preferably, the group represented by formula (4-1) or (4-2) is preferred.

[0200]

[0201] In equations (4-1) and (4-2), R 71 ~R 75 Independently representing an alkyl group having 1 to 4 carbon atoms, a hydrogen atom, a halogen atom, or a carbon atom.

[0202] In compound (I-1), R 24 Preferred is -NR 27 R 28 As -NR 27 R 28 From the viewpoint of solubility in resins and coating solvents, -NH-C(=O)-R is preferred. 29 or -NH-SO2-R 30 .

[0203] In compound (I-1) R 24 -NH-SO2-R 30 The compounds are shown in formula (I-12).

[0204]

[0205] R 23 and R 26 The preferred atoms are hydrogen atoms, halogen atoms, or alkyl groups having 1 to 6 carbon atoms or alkoxy groups having 1 to 6 carbon atoms, and more preferably all of them are hydrogen atoms.

[0206] From the perspective of lightfastness, R 30 Independently preferred are alkyl groups having 1 to 12 branched carbon atoms, alkoxy groups having 1 to 12 branched carbon atoms, or hydrocarbon groups having 6 to 16 carbon atoms with an unsaturated ring structure. Examples of unsaturated ring structures include benzene, toluene, xylene, furan, and benzofuran. 30 More preferably, it is an alkyl group that may have a branched chain and a carbon number of 1 to 12, or an alkoxy group that may have a branched chain and a carbon number of 1 to 12. It should be noted that, in the representation of R... 30 In each of the groups, some or all of the hydrogen atoms can be replaced by halogen atoms, especially fluorine atoms.

[0207] More specifically, examples of compounds (I-12) can be found in the table below. Furthermore, the compounds shown in the table below are in squaric acid. The symbols on the left and right sides of the salt skeleton have the same meaning.

[0208] [Table 1]

[0209]

[0210] Among these compounds (I-12), from the viewpoints of visible light transmittance, solubility in resin, heat resistance, and light resistance, (I-12-1), (I-12-6), (I-12-11), (I-12-16), (I-12-21), and (I-12-26) are preferred, and from the viewpoints of heat resistance and light resistance, (I-12-11) and (I-12-26) are more preferred.

[0211] <Square acid inner> Salt compound (II) >

[0212]

[0213] The symbols in the above formula are as follows.

[0214] Each ring Z is an independent five-membered or six-membered ring with 0 to 3 heteroatoms in the ring, and the hydrogen atoms in ring Z can be substituted.

[0215] R 1 and R 2 They can connect with each other and form heterocycles A1,R together with nitrogen atoms. 2 and R 3 They can connect with each other and form heterocycles B1 and R together with nitrogen atoms. 1 The carbon atoms or heteroatoms constituting ring Z can connect with each other and form heterocycle C1 together with nitrogen atoms. In this case, hydrogen atoms in heterocycles A1, B1, and C1 can be substituted. R in the absence of heterocycle formation... 1 and R 2 Each can independently represent a hydrogen atom, a halogen atom, or a hydrocarbon group that may contain unsaturated bonds, heteroatoms, saturated or unsaturated ring structures between carbon atoms and may have substituents. R 4 And R in the case of no heterocycle formation 3 Each can independently represent a hydrogen atom, a halogen atom, or an alkyl or alkoxy group that may contain heteroatoms between carbon atoms and may have substituents.

[0216] As for compound (II), examples include compounds represented by any of formulas (II-1) to (II-3), and from the viewpoint of solubility in resin and visible light transmittance in resin, compounds represented by formula (II-3) are particularly preferred.

[0217]

[0218] In equations (II-1) and (II-2), R 1 and R 2 Each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 15 carbon atoms that may have substituents; R 3 ~R 6 Each can independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 10 carbon atoms that may have substituents.

[0219] In equation (II-3), R 1 R 4 and R 9 ~R 12 Each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 15 carbon atoms that may have substituents; R 7 and R 8 Each can independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 5 carbon atoms that may have substituents.

[0220] From the perspectives of solubility in resins and visible light transmittance, R in compounds (II-1) and (II-2) 1 and R 2 Alkyl groups having 1 to 15 carbon atoms are preferred, alkyl groups having 7 to 15 carbon atoms are more preferred, and R is even more preferred. 1 and R 2 At least one of them is a branched alkyl group having 7 to 15 carbon atoms, with R being particularly preferred. 1 and R 2 Both are branched alkyl groups with 8 to 15 carbon atoms.

[0221] From the perspectives of solubility in transparent resins and visible light transmittance, R in compound (II-3) 1 Alkyl groups having 1 to 15 carbon atoms are preferred, more preferably alkyl groups having 1 to 10 carbon atoms, and particularly preferably ethyl or isopropyl.

[0222] From the perspectives of visible light transmittance and ease of synthesis, R 4 The preferred atoms are hydrogen atoms or halogen atoms, with hydrogen atoms being particularly preferred.

[0223] R 7 and R 8 The preferred components are hydrogen atoms, halogen atoms, and alkyl groups having 1 to 5 carbon atoms that can be replaced by halogen atoms; more preferably, hydrogen atoms, halogen atoms, and methyl groups.

[0224] R 9 ~R 12The preferred components are hydrogen atoms, halogen atoms, and alkyl groups with 1 to 5 carbon atoms that can be replaced by halogen atoms.

[0225] As -CR 9 R 10 -CR 11 R 12 - Examples of divalent organic groups can be found in the following groups (13-1) to (13-5).

[0226] -CH(CH3)-C(CH3)2-……(13-1)

[0227] -C(CH3)2-CH(CH3)-……(13-2)

[0228] -C(CH3)2-CH2-……(13-3)

[0229] -C(CH3)2-CH(C2H5)-……(13-4)

[0230] -CH(CH3)-C(CH3)(CH2-CH(CH3)2)-……(13-5)

[0231] More specifically, examples of compounds (II-3) can be found in the table below. Furthermore, the compounds shown in the table below are in squaric acid. The symbols on the left and right sides of the salt skeleton have the same meaning.

[0232] [Table 2]

[0233]

[0234] Compounds (I) through (II) can each be manufactured by known methods. Compound (I) can be manufactured by the methods described in U.S. Patent No. 5,543,086, U.S. Patent Application Publication No. 2014 / 0061505, and International Publication No. 2014 / 088063. Compound (II) can be manufactured by the methods described in International Publication No. 2017 / 135359.

[0235] The content of NIR pigment in the absorbent layer is preferably 0.1 to 25 parts by mass relative to 100 parts by mass of resin, more preferably 0.3 to 15 parts by mass. It should be noted that when two or more compounds are combined, the above content refers to the sum of all compounds.

[0236] The absorption layer may contain other pigments besides the aforementioned NIR pigments. Preferably, these other pigments are those with the maximum absorption wavelength in the resin within the range of 370 nm to 440 nm (UV pigments). This effectively shields light in the near-ultraviolet region.

[0237] Examples of UV pigments include: Azole pigments, anthocyanins, naphthalene dicarboximide pigments, diazole pigments, Azine pigment, UV pigments include azole dyes, naphthalene-dicarboxylic acid dyes, styrene dyes, anthracene dyes, cyclic carbonyl dyes, and triazole dyes. Among these, anthocyanin dyes are particularly preferred. Furthermore, UV pigments can be used alone or in combination with two or more.

[0238] <Resin>

[0239] There are no restrictions on the type of resin used in the absorbent layer, as long as it is transparent. One or more transparent resins selected from polyester resins, acrylic resins, epoxy resins, olefin-thiol resins, polycarbonate resins, polyether resins, polyaryl ester resins, polysulfone resins, polyethersulfone resins, poly(p-phenylene) resins, polyaryl ether phosphine oxide resins, polyamide resins, polyimide resins, polyamide-imide resins, polyolefin resins, cyclic olefin resins, polyurethane resins, and polystyrene resins can be used. These resins can be used alone or in combination of two or more.

[0240] From the viewpoints of the spectral characteristics of the absorption layer, glass transition temperature (Tg), and adhesion, it is preferable to select one or more resins selected from polyimide resin, polycarbonate resin, polyester resin, and acrylic resin.

[0241] When using multiple compounds as NIR pigments or other pigments, these compounds can be contained in the same absorber layer, or they can be contained in different absorber layers.

[0242] The absorbent layer can be formed by dissolving or dispersing pigments, resins, or resin raw materials and other components as needed in a solvent to prepare a coating liquid, coating it onto a multilayer dielectric film and drying it, and further curing it as needed. Alternatively, the coating liquid can be coated onto a peelable support to form the absorbent layer separately. Furthermore, the solvent can be any dispersion medium that can stably disperse the material or a solvent that can dissolve it.

[0243] Furthermore, the coating liquid may contain surfactants to improve voids caused by microbubbles, depressions caused by foreign matter adhesion, and pinholes during the drying process. In addition, the coating liquid can be applied using methods such as dip coating, cast coating, or spin coating. Furthermore, when the coating liquid contains transparent resin components, it can be further cured by heat curing, light curing, or other curing processes.

[0244] Alternatively, the absorber layer can also be manufactured into a film shape by extrusion molding. This filter can be manufactured by laminating the obtained film-shaped absorber layer onto a dielectric multilayer film and integrating it by means of hot pressing or the like.

[0245] A filter can have one absorption layer or two or more absorption layers. When there are two or more absorption layers, the composition of each layer can be the same or different. In addition, absorption layers can be formed on the surface of each dielectric multilayer film, or two or more absorption layers can be superimposed on the surface of a single dielectric multilayer film.

[0246] 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, the thickness of the absorption layer is preferably 0.5 μm or more. It should be noted that when the filter has two or more absorption layers, the total thickness of each absorption layer is preferably within the above-mentioned range.

[0247] This filter can incorporate other constituent elements such as inorganic microparticles that generate absorption by controlling the transmission and absorption of light within a specific wavelength range. Specific examples of inorganic microparticles include: ITO (indium tin oxide), ATO (antimony-doped tin oxide), cesium tungstate, and lanthanum boride. ITO microparticles and cesium tungstate microparticles have high visible light transmittance and exhibit light absorption over a wide range of infrared wavelengths greater than 1200 nm, thus enabling their use in applications requiring infrared light shielding.

[0248] In summary, this specification discloses the following filters, etc.

[0249] [1] A filter, comprising:

[0250] Near-infrared absorbing glass,

[0251] The dielectric multilayer film and the dielectric multilayer film stacked on the two main surfaces of the near-infrared absorbing glass

[0252] An absorption layer, stacked on the surface of at least one of the aforementioned dielectric multilayer films, and having a maximum absorption wavelength in the near-infrared region, wherein...

[0253] The filter satisfies all of the following spectral characteristics (i-1) to (i-5):

[0254] (i-1) In the spectral transmittance curves at wavelengths of 450 nm to 600 nm and incident angles of 0 degrees, the average transmittance T 450-600(0deg)AVE It is over 60%;

[0255] (i-2) In the spectral transmittance curves at wavelengths of 700 nm to 750 nm and incident angles of 0 degrees, the average transmittance T 700-750(0deg)AVE Less than 5%;

[0256] (i-3) In the spectral transmittance curves at wavelengths of 1050 nm to 1200 nm and incident angles of 0 degrees, the maximum transmittance T 1050-1200(0deg)MAX Below 7%;

[0257] (i-4) In the spectral transmittance curves at wavelengths of 800 nm to 1000 nm and incident angles of 0 degrees, the maximum transmittance T 800-1000(0deg)MAX It is over 20%;

[0258] (i-5) Let the maximum transmittance in the spectral transmittance curve with wavelengths from 450 nm to 600 nm and an incident angle of 0 degrees be T. 450-600(0deg)MAX hour,

[0259] In the spectral transmittance curve at an incident angle of 0 degrees, the transmittance is the value of T. 450-600(0deg)MAX 70% of the wavelength λ (70％) and transmittance is the T 450-600(0deg)MAX λ at 30% (30％) Included in the 600nm to 700nm range,

[0260] In the wavelength λ (70％) Let the transmittance be T. (70％) The wavelength λ (30％) Let the transmittance be T. (30％) When the following relationship is satisfied:

[0261] -2≤[T (30％) -T (70％) ] / [λ (30％) -λ (70％) ]≤-0.75.

[0262] [2] According to the filter described in [1], the filter also satisfies the following spectral characteristics (i-6):

[0263] (i-6) Let the transmittance at wavelength λ in the spectral transmittance curve at an incident angle of 0 degrees be T. (0deg) (λ), let the transmittance at wavelength λ in the spectral transmittance curve at an incident angle of 35° be T.(35deg) When (λ), the following relationship is satisfied in the wavelength range of 450nm≤λ≤600nm:

[0264] |T (0deg) (λ)-T (35deg) (λ)|≤10%.

[0265] [3] The filter according to [1] or [2], wherein the filter also satisfies the following spectral characteristics (i-7):

[0266] (i-7) Let the maximum transmittance in the spectral transmittance curve with wavelengths from 450 nm to 600 nm and an incident angle of 0 degrees be T. 450-600(0deg)MAX hour,

[0267] The T under the condition of incident angle 0 degrees 450-600(0deg)MAX wavelength λ when it is 50% VIS(0deg)(50％) And T under the condition of an incident angle of 35 degrees 450-600(0deg)MAX wavelength λ when it is 50% VIS(35deg)(50％) Included in the 600nm to 700nm range, and

[0268] The following relationship must be satisfied:

[0269] |λ VIS(0deg)(50％) -λ VIS(35deg)(50％) |≤10nm.

[0270] [4] The filter according to any one of [1] to [3], wherein the filter further satisfies the following spectral characteristics (i-8):

[0271] (i-8) Let the maximum transmittance in the spectral transmittance curve at wavelengths of 800 nm to 1000 nm and an incident angle of 0 degrees be T. 800-1000(0deg)MAX Let the wavelength at which the maximum transmittance is achieved be λ. 800-1000(0deg)MAX hour,

[0272] In 750nm~λ 800-1000(0deg)MAX In the spectral transmittance curve with a transmittance in the range of nm and an incident angle of 0 degrees, the transmittance is T. 800-1000(0deg)MAX λ at 50% of the wavelength IRS(0deg)(50％) and in 750nm~λ 800-1000(0deg)MAX In the spectral transmittance curve with a transmittance in the range of nm and an incident angle of 35 degrees, the transmittance is T. 800-1000(0deg)MAX λ at 50% of the wavelength IRS(35deg)(50％) The following relationship must be satisfied:

[0273] |λ IRS(0deg)(50％) -λ IRS(35deg)(50％) |≤30nm.

[0274] [5] The filter according to any one of [1] to [4], wherein the filter further satisfies the following spectral characteristics (i-9):

[0275] (i-9) Let the maximum transmittance in the spectral transmittance curve at wavelengths of 800 nm to 1000 nm and an incident angle of 0 degrees be T. 800-1000(0deg)MAX Let the wavelength at which the maximum transmittance is achieved be λ. 800-1000(0deg)MAX hour,

[0276] In λ 800-1000(0deg)MAX In the spectral transmittance curve for the range of nm to 1050 nm and with an incident angle of 0 degrees, the transmittance is T. 800-1000(0deg)MAX λ at 50% of the wavelength IRL(0deg)(50％) and in λ 800-1000(0deg)MAX In the spectral transmittance curve for the range of nm to 1050 nm and an incident angle of 35 degrees, the transmittance is T. 800-1000(0deg)MAX λ at 50% of the wavelength IRL(35deg)(50％) The following relationship must be satisfied:

[0277] |λ IRL(0deg)(50％) -λ IRL(35deg)(50％) |≤60nm.

[0278] [6] The filter according to any one of [1] to [5], wherein the thickness of the dielectric multilayer film stacked on the two main surfaces of the near-infrared absorbing glass is 600 nm or more.

[0279] [7] The filter according to any one of [1] to [6], wherein the near-infrared absorbing glass is a fluorophosphate glass or phosphate glass containing iron or copper.

[0280] [8] The filter according to any one of [1] to [7], wherein the near-infrared absorbing glass satisfies all of the following spectral characteristics (iii-1) to (iii-3):

[0281] (iii-1) Average internal transmittance T in the spectral transmittance curves of wavelengths from 450 nm to 600 nm G_450-600AVE It is over 80%;

[0282] (iii-2) Average internal transmittance T in the spectral transmittance curves of wavelengths from 1050 nm to 1200 nm G_1050-1200AVE Less than the average internal transmittance T G_450-600AVE ;

[0283] (iii-3) Internal transmittance T in the wavelength range of 800 nm to 1000 nm G_800-1000 Monotonous decrease.

[0284] [9] The filter according to any one of [1] to [8], wherein the absorption layer contains a pigment in dichloromethane having a maximum absorption wavelength in the range of 680 nm to 800 nm.

[0285]

[10] The filter according to any one of [1] to [9], wherein the filter further satisfies the following spectral characteristics (i-10) to (i-11):

[0286] (i-10) In the spectral reflectance curve at an incident angle of 5 degrees on at least one surface, the average reflectance R in the wavelength range of 450 nm to 600 nm. 450-600(5deg)AVE Less than 15%;

[0287] (i-11) In the spectral reflectance curves at an incident angle of 5 degrees on at least one surface, the average reflectance R in the wavelength range of 1050 nm to 1200 nm is... 1050-1200(5deg)AVE It is over 40%.

[0288]

[11] The filter according to any one of [1] to

[10] , wherein the absorption layer satisfies all of the following spectral characteristics (ii-1) to (ii-2):

[0289] (ii-1) Let λ be the shortest wavelength at which the internal transmittance is 30% in the spectral transmittance curve of wavelengths from 650 nm to 720 nm. A_VIS(30％) The shortest wavelength with an internal transmittance of 30% in the spectral transmittance curve of 720nm to 1000nm is set as λ. A_IR(30％) When the following relationship is satisfied:

[0290] |λ A_IR(30％) -λ A_VIS(30％) |≥100nm.

[0291] (ii-2) Set the absorbance at a wavelength of 450 nm as A A_450 Let the absorbance at a wavelength of 720nm be A. A_720 When the following relationship is satisfied:

[0292] A A_720 -A A_450 ≥1.

[0293]

[12] An imaging device, wherein the imaging device comprises any one of [1] to

[11] filters.

[0294] Example

[0295] Next, the invention will be described in more detail through examples.

[0296] The various spectral characteristics were measured using a UV-Vis spectrophotometer (Hitachi High Technology Co., Ltd. UH-4150 model).

[0297] It should be noted that the spectral characteristics without a specified incident angle are values ​​measured at an incident angle of 0 degrees (the direction perpendicular to the main surface of the filter).

[0298] The pigments used in each example are described below.

[0299] Compound 1 (squamous acid) Salt compounds: synthesized based on the specifications in U.S. Patent No. 5,543,086, U.S. Patent Application Publication No. 2014 / 0061505, and International Publication No. 2014 / 088063.

[0300] Compound 2 (squamous acid) Salt compounds: based on international publication No. 2017 / 135359.

[0301] Compound 3 (particulate cyanide compound): synthesized based on German Patent Publication No. 10109243.

[0302] Compound 4 (particulate cyanide compound): synthesized based on German Patent Publication No. 10109243.

[0303] It should be noted that compounds 1 and 2 are near-infrared absorbing pigments (NIR pigments), while compounds 3 and 4 are ultraviolet absorbing pigments (UV pigments).

[0304] Compound 1

[0305] Compound 2

[0306] Compound 3

[0307] Compound 4

[0308] <Spectral properties of pigments>

[0309] The maximum absorption wavelengths in the absorption spectra measured by dissolving the above pigments (compounds 1-4) in dichloromethane are shown.

[0310] [Table 3]

[0311] Compound 1 698nm Compound 2 742nm Compound 3 397nm Compound 4 399nm

[0312] <Spectral Characteristics of Near-Infrared Absorbing Glass>

[0313] As a near-infrared absorbing glass, an iron phosphate glass with the composition shown in the table below was manufactured in accordance with International Publication No. 2020 / 262296.

[0314] For near-infrared absorbing glass, the spectral transmittance curves in the wavelength range of 350 nm to 1200 nm were measured using a UV-Vis spectrophotometer.

[0315] The results are shown in the table below. It should be noted that, for the spectral characteristics shown in the table, internal transmittance was used for evaluation to avoid the influence of reflections at the air and glass interfaces.

[0316] Internal transmittance (%) = {Measured transmittance} (0deg) / (100-reflectivity) (5deg) )}×100

[0317] In addition, the spectral transmittance curve of the near-infrared absorbing glass (0.21 mm thick iron phosphate glass) is as follows: Figure 3 As shown.

[0318] [Table 4]

[0319]

[0320] <Examples 1-1 to 1-2: Spectral characteristics of the absorption layer>

[0321] In a polyimide resin solution prepared in the same manner as when calculating the spectral properties of the aforementioned compounds, one of the pigments from compounds 1 to 4 was mixed at the concentrations listed in the table below and stirred at 50°C for 2 hours to dissolve it, thereby obtaining a coating solution. The obtained coating solution was then applied onto alkaline glass (D263 glass manufactured by Schott AG, 0.2 mm thick) by spin coating, thereby forming an absorption layer with the film thickness shown in the table below.

[0322] The spectral transmittance curves of the obtained absorption layer in the wavelength range of 350 nm to 1200 nm were measured using a UV-Vis spectrophotometer.

[0323] The results obtained by setting the transmittance at the maximum absorption wavelength to 10% are shown in the table below.

[0324] It should be noted that, for the spectral characteristics shown in the table below, the internal transmittance is used for evaluation to avoid the influence of reflection at the air interface and glass interface.

[0325] Internal transmittance (%) = {Measured transmittance} (0deg) / (100-reflectivity) (5deg) )}×100

[0326] Absorbance is a value obtained by converting internal transmittance using the following formula.

[0327] Absorbance = -log 10 (Internal transmittance / 100)

[0328] In addition, the spectral transmittance curves of the absorption layers in Examples 1-1 and 1-2 are as follows: Figure 4 As shown.

[0329] It should be noted that Examples 1-1 to 1-2 are for reference only.

[0330] [Table 5]

[0331]

[0332] <Example 2-1: Spectral Characteristics of Filters>

[0333] On one side of near-infrared absorbing glass (ferrophosphate glass), 28 layers of SiO2 and TiO2 are alternately deposited by vapor deposition, thereby forming a first dielectric multilayer film (reflective film). On the other side of near-infrared absorbing glass (ferrophosphate glass), 41 layers of SiO2 and TiO2 are alternately deposited by vapor deposition, thereby forming a second dielectric multilayer film (reflective film).

[0334] A resin solution with the same composition as the absorber layer in Example 1-1 was coated on the surface of a second dielectric multilayer film, and the organic solvent was removed by heating, thereby forming an absorber layer with a thickness of 1 μm.

[0335] Nine layers of SiO2 and TiO2 are alternately stacked on the surface of the absorption layer by vapor deposition, thereby forming a third dielectric multilayer film (antireflective film).

[0336] The above operations were used to manufacture filter 2-1.

[0337] <Example 2-2>

[0338] The near-infrared absorbing glass (ferrophosphate glass) was changed to a non-absorbing glass (alkaline glass, D263 manufactured by Schott), and otherwise the filter was manufactured in the same manner as in Example 2-1.

[0339] <Example 2-3>

[0340] On one side of a near-infrared absorbing glass (ferrophosphate glass), 40 layers of SiO2 and TiO2 are alternately deposited by vapor deposition to form a first dielectric multilayer film (reflective film). On the other side of the near-infrared absorbing glass (ferrophosphate glass), 19 layers of SiO2 and TiO2 are alternately deposited by vapor deposition to form a second dielectric multilayer film (anti-reflective film). Otherwise, a filter is manufactured in the same manner as in Example 2-1.

[0341] <Example 2-4>

[0342] On one side of a near-infrared absorbing glass (ferrophosphate glass), 66 layers of SiO2 and TiO2 were alternately stacked by vapor deposition to form a first dielectric multilayer film (reflective film). No second dielectric multilayer film was formed. Otherwise, a filter was manufactured in the same manner as in Example 2-1.

[0343] <Example 2-5>

[0344] The number of layers in the first dielectric multilayer film (reflective film) was changed to 50 layers, and the number of layers in the second dielectric multilayer film (reflective film) was changed to 39 layers. The composition of the absorption layer was the same as in Example 1-2. Otherwise, the filter was manufactured in the same way as in Example 2-1.

[0345] <Example 2-6>

[0346] The number of layers in the first dielectric multilayer film (reflective film) was changed to 82 layers, and the number of layers in the second dielectric multilayer film (reflective film) was changed to 76 layers. No absorption layer and third dielectric multilayer film were formed. Otherwise, the filter was manufactured in the same manner as in Example 2-1.

[0347] <Example 2-7>

[0348] The near-infrared absorbing glass (ferrophosphate glass) was changed to a non-absorbent glass (alkaline glass, D263 manufactured by Schott), the number of layers of the first dielectric multilayer film (reflective film) was changed to 50 layers, and the second dielectric multilayer film was not formed. Otherwise, the filter was manufactured in the same manner as in Example 2-1.

[0349] The reflectances of the first and second dielectric multilayer films in the above filters are shown in the table below. When the dielectric multilayer film is the outermost layer, the reflectance is estimated based on the reflectance on alkaline glass. When the dielectric multilayer film is not the outermost layer, the reflectance is estimated based on the reflectance when the dielectrics on both sides are alkaline glass and polyimide resin (the resin used in the absorption layer).

[0350] For each filter obtained through the above operations, the spectral transmittance curves at incident angles of 0 degrees and 35 degrees, and the spectral reflectance curves at an incident angle of 5 degrees, were measured using a UV-Vis spectrophotometer within the wavelength range of 350 nm to 1200 nm. It should be noted that the reflectance characteristics were measured from the first dielectric multilayer film side or the third (or second) dielectric multilayer film side.

[0351] The properties shown in the table below are calculated based on the obtained spectral data.

[0352] In addition, the spectral transmittance curves of the filters in Examples 2-1, 2-2, 2-3, 2-5, and 2-6 are as follows: Figures 5-9 As shown. It should be noted that the solid line represents the result at an incident angle of 0°, and the dashed line represents the result at an incident angle of 35°.

[0353] It should be noted that Examples 2-1, 2-3, and 2-5 are examples, while Examples 2-2, 2-4, 2-6, and 2-7 are comparative examples.

[0354] [Table 6]

[0355]

[0356] From the above results, it can be seen that the filters of Examples 2-1, 2-3, and 2-5 are filters with excellent transmittance in visible light and near-infrared light (800nm–900nm), excellent shielding in the near-infrared light range, especially in the wavelength range of 1000nm–1200nm, excellent visual sensitivity correction in the visible light region, and high reliability related to weather resistance. Furthermore, the filters of Examples 2-1 and 2-3, which used two NIR pigments, are filters with the following characteristics: |λ IRS(0deg)(50％) -λ IRS(35deg)(50％) | is below 30nm, therefore even at high incident angles, 750nm~λ 800-1000(0deg)MAX Spectral curves in the nm range are also less prone to shift.

[0357] The filters in Examples 2-2 and 2-7, which did not use near-infrared absorbing glass, achieved the maximum transmittance T. 1050-1200(0deg)MAX The result is that the light shielding is greater than 7% and the light shielding is low in the 1050nm to 1200nm range.

[0358] Based on the results of reliability tests in Examples 3-1 to 3-3 described later, it is inferred that the filter in Example 2-4, which has an absorption layer stacked on one main surface of the near-infrared absorbing glass and no dielectric multilayer film stacked on the two surfaces of the glass, is a filter with glass that is prone to deterioration and has low reliability.

[0359] The filters in Examples 2-6 without an absorption layer yielded the following results: [T (30％) -T (70％) ] / [λ (30％) -λ (70％) If the value is less than -2, the visual sensitivity correction in the visible light region is low.

[0360] <Examples 3-1 to 3-3: Reliability Testing>

[0361] The relationship between film thickness and reliability of dielectric multilayer films formed on near-infrared absorbing glass was evaluated.

[0362] SiO2 and TiO2 are alternately deposited on one side of a near-infrared absorbing glass (ferrophosphate glass) by vapor deposition, thereby forming a dielectric multilayer film. The number of layers in each dielectric multilayer film is shown in the table below.

[0363] A glass substrate with a dielectric multilayer film was left to stand at 85°C and 85% relative humidity for 250 hours, and then its appearance was observed. Additionally, an adhesive tape (adhesive strength 3.9 N / 10 mm, Cellotape manufactured by Nichiban Co., Ltd. (registered trademark), equivalent to No. 405) was adhered to the surface of the dielectric multilayer film, and then the tape was peeled off vertically to conduct a peel test.

[0364] The results are shown in the table below.

[0365] It should be noted that Examples 3-1 to 3-3 are for reference only.

[0366] [Table 7]

[0367]

[0368] The results above show that, from the perspective of preventing glass degradation due to near-infrared absorption, a thicker dielectric multilayer film is preferred.

[0369] The present invention has been described in detail with reference to specific embodiments, but various changes or modifications can be made without departing from the spirit and scope of the invention, which will be apparent to those skilled in the art. This application is based on Japanese Patent Application No. 2021-126030, filed on July 30, 2021, the contents of which are incorporated herein by reference.

[0370] Industrial practicality

[0371] The filter of this invention exhibits excellent transmittance of visible light and a specific type of near-infrared light, and also possesses near-infrared light shielding properties. It is useful in applications where high-performance technologies are increasingly being developed, such as in information acquisition devices like cameras or sensors for conveyors.

[0372] Label Explanation

[0373] 1A, 1B... filters

[0374] 10...Near-infrared absorbing glass

[0375] 21, 22, 23... Dielectric multilayer films

[0376] 30… Absorption Layer

Claims

1. A filter, the filter comprising: Near-infrared absorbing glass, The dielectric multilayer film and the dielectric multilayer film stacked on the two main surfaces of the near-infrared absorbing glass An absorption layer, stacked on the surface of at least one of the aforementioned dielectric multilayer films, and having a maximum absorption wavelength in the near-infrared region, wherein... The filter satisfies all of the following spectral characteristics (i-1) to (i-5) and (i-8): (i-1) In the spectral transmittance curves at wavelengths of 450 nm to 600 nm and incident angles of 0 degrees, the average transmittance T 450-600（0deg）AVE It is over 60%; (i-2) In the spectral transmittance curves at wavelengths of 700 nm to 750 nm and incident angles of 0 degrees, the average transmittance T 700-750（0deg）AVE Less than 5%; (i-3) In the spectral transmittance curves at wavelengths of 1050 nm to 1200 nm and incident angles of 0 degrees, the maximum transmittance T 1050-1200（0deg）MAX Below 7%; (i-4) In the spectral transmittance curves at wavelengths of 800 nm to 1000 nm and incident angles of 0 degrees, the maximum transmittance T 800-1000（0deg）MAX It is over 20%; (i-5) Let the maximum transmittance in the spectral transmittance curve with wavelengths from 450 nm to 600 nm and an incident angle of 0 degrees be T. 450-600（0deg）MAX hour, In the spectral transmittance curve at an incident angle of 0 degrees, the transmittance is the value of T. 450-600（0deg）MAX λ at 70% （70%） and transmittance is the T 450-600（0deg）MAX λ at 30% （30%） Included in the 600nm to 700nm range, In the wavelength λ （70%） Let the transmittance be T. （70%） The wavelength λ （30%） Let the transmittance be T. （30%） When the following relationship is satisfied: -2≤[T （30%） -T （70%） ] / [l （30%） -l （70%） ]≤-0.75, (i-8) Let the maximum transmittance in the spectral transmittance curve at wavelengths of 800 nm to 1000 nm and an incident angle of 0 degrees be T. 800-1000（0deg）MAX Let the wavelength at which the maximum transmittance is achieved be λ. 800-1000（0deg）MAX hour, In 750nm~λ 800-1000（0deg）MAX In the spectral transmittance curve with a transmittance in the range of nm and an incident angle of 0 degrees, the transmittance is T. 800-1000（0deg）MAX λ at 50% IRS（0deg）（50%） and in 750nm~λ 800-1000（0deg）MAX In the spectral transmittance curve with a transmittance in the range of nm and an incident angle of 35 degrees, the transmittance is T. 800-1000（0deg）MAX λ at 50% IRS（35deg）（50%） The following relationship must be satisfied: |l IRS（0deg）（50%） -l IRS（35deg）（50%） |≤30nm.

2. The filter according to claim 1, wherein, The filter also satisfies the following spectral characteristics (i-6): (i-6) Let the transmittance at wavelength λ in the spectral transmittance curve at an incident angle of 0 degrees be T. （0deg） (λ), Let the transmittance at wavelength λ in the spectral transmittance curve at an incident angle of 35° be T. （35deg） When (λ), the following relationship is satisfied in the wavelength range of 450nm≤λ≤600nm: |T （0deg） (λ)-T （35deg） (λ)|≤10%.

3. The filter according to claim 1, wherein, The filter also satisfies the following spectral characteristics (i-7): (i-7) Let the maximum transmittance in the spectral transmittance curve with wavelengths from 450 nm to 600 nm and an incident angle of 0 degrees be T. 450-600（0deg）MAX hour, The T under the condition of incident angle 0 degrees 450-600（0deg）MAX wavelength λ when it is 50% VIS（0deg）（50%） And T under the condition of an incident angle of 35 degrees 450-600（0deg）MAX wavelength λ when it is 50% VIS（35deg）（50%） Included in the 600nm to 700nm range, and The following relationship must be satisfied: |l VIS（0deg）（50%） -l VIS（35deg）（50%） |≤10nm.

4. The filter according to claim 1, wherein, The filter also satisfies the following spectral characteristics (i-9): (i-9) Let the maximum transmittance in the spectral transmittance curve at wavelengths of 800 nm to 1000 nm and an incident angle of 0 degrees be T. 800-1000（0deg）MAX Let the wavelength at which the maximum transmittance is achieved be λ. 800-1000（0deg）MAX hour, In λ 800-1000（0deg）MAX In the spectral transmittance curve for the range of nm to 1050 nm and with an incident angle of 0 degrees, the transmittance is T. 800-1000（0deg）MAX λ at 50% IRL（0deg）（50%） and in λ 800-1000（0deg）MAX In the spectral transmittance curve for the range of nm to 1050 nm and an incident angle of 35 degrees, the transmittance is T. 800-1000（0deg）MAX λ at 50% IRL（35deg）（50%） The following relationship must be satisfied: |l IRL（0deg）（50%） -l IRL（35deg）（50%） |≤60nm.

5. The filter according to claim 1, wherein, The thickness of the dielectric multilayer film stacked on the two main surfaces of the near-infrared absorbing glass is 600 nm or more.

6. The filter according to claim 1, wherein, The near-infrared absorbing glass is a fluorophosphate glass or phosphate glass containing iron or copper.

7. The filter according to claim 1, wherein, The near-infrared absorbing glass satisfies all of the following spectral characteristics (iii-1) to (iii-3): (iii-1) Average internal transmittance T in the spectral transmittance curves of wavelengths from 450 nm to 600 nm G_450-600AVE It is over 80%; (iii-2) Average internal transmittance T in the spectral transmittance curves of wavelengths from 1050 nm to 1200 nm G_1050-1200AVE Less than the average internal transmittance T G_450-600AVE ; (iii-3) Internal transmittance T in the wavelength range of 800 nm to 1000 nm G_800-1000 Monotonous decrease.

8. The filter according to claim 1, wherein, The absorber layer contains a pigment in dichloromethane that has a maximum absorption wavelength in the range of 680 nm to 800 nm.

9. The filter according to claim 1, wherein, The filter also satisfies the following spectral characteristics (i-10) to (i-11): (i-10) The average reflectance R in the wavelength range of 450 nm to 600 nm in the spectral reflectance curve at an incident angle of 5 degrees on at least one surface. 450-600（5deg）AVE Below 15%; (i-11) In the spectral reflectance curve at an incident angle of 5 degrees on at least one surface, the average reflectance R in the wavelength range of 1050 nm to 1200 nm. 1050-1200（5deg）AVE It is over 40%.

10. The filter according to claim 1, wherein, The absorption layer satisfies all of the following spectral characteristics (ii-1) to (ii-2): (ii-1) Let λ be the shortest wavelength at which the internal transmittance is 30% in the spectral transmittance curve of wavelengths from 650 nm to 720 nm. A_VIS（30%） The shortest wavelength with an internal transmittance of 30% in the spectral transmittance curve of 720nm to 1000nm is set as λ. A_IR（30%） When the following relationship is satisfied: |l A_IR（30%） -l A_VIS（30%） |≥100nm; (ii-2) Let the absorbance at a wavelength of 450 nm be A. A_450 Let the absorbance at a wavelength of 720nm be A. A_720 When the following relationship is satisfied: A A_720 -A A_450 ≥1。 11. An imaging device, wherein, The imaging device comprises the filter according to any one of claims 1 to 10.

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