Glass, glass plate, optical filter, imaging element, mobile communication device, and imaging device

Abstract

Provided are a glass, a glass plate, and an optical filter that can suppress a decrease in the transmittance of obliquely incident visible light. Also provided are an imaging element, a mobile communication apparatus, and an imaging apparatus that each comprise the optical filter. The glass according to the present invention contains, in terms of cation percentages, 10-40% of Cu and 10-80% of P, and has a refractive index of 1.550 or greater at a wavelength of 546 nm.

Description

Glass, glass plates, optical filters, image sensors, mobile communication devices, and imaging devices.

[0001] This disclosure relates to glass, glass plates, optical filters, image sensors, mobile communication devices, and imaging devices.

[0002] Solid-state image sensors such as CCDs and CMOS sensors used in digital cameras and smartphones have spectral sensitivity ranging from the visible region to the near-infrared region around 1200 nm. To obtain good color reproduction, the luminous sensitivity of the solid-state image sensor is corrected using an infrared cut filter to which a specific substance that absorbs infrared light is added. Fluorophosphate glass and optical glass with copper (Cu) added to phosphate glass have been developed and are used as such infrared cut filters or as substrates for such infrared cut filters. The composition of such glass is disclosed, for example, in Patent Document 1.

[0003] International Publication No. 2024 / 048512

[0004] Generally, in optical glass with light absorption properties, light incident at an oblique angle tends to have lower transmittance compared to light incident perpendicularly, because the optical path is longer. In particular, in optical filters for image sensors, this change in transmittance can lead to a decrease in color reproduction and other performance characteristics.

[0005] In view of the above issues, this disclosure aims to provide glass, glass plates, and optical filters that can suppress the reduction in transmittance of obliquely incident visible light, as well as an image sensor, mobile communication device, and imaging device equipped with the optical filter.

[0006] This disclosure includes the following embodiments: [1] A glass containing 10 to 40% Cu and 10 to 80% P in terms of cation percentage, and having a refractive index of 1.550 or more at a wavelength of 546 nm. [2] The glass according to [1], wherein when formed into a plate and two opposing main surfaces are processed to a mirror finish, α represented by the following formula (1) is 12 or more, and β represented by the following formula (2) is 1.76 or less. α = {-log(T ９００－１０００ / 100)-0.018} / t...(1) β={-log(T ４００( / 100) - 0.036} / t ... (2) where T ９００－１０００ This shows the average light transmittance including external reflection at an incident angle of 0 degrees and a wavelength of 900 nm to 1000 nm. ４００ t represents the light transmittance including external reflection at an incident angle of 0 degrees and a wavelength of 400 nm, and t represents the plate thickness (mm). [3] The glass according to [1] or [2], wherein the following components are contained in cation percentages, and the atomic ratio of O to P (O / P) is 2.7 to 3.4. P: 45-75%, Al: 0-20%, Cu: 10-40%, Li: 0-15%, Na: 0-15%, K: 0-15%, Cs: 0-15%, Mg: 0-30%, Ca: 0-30%, Sr: 0-30%, Ba: 0-30%, Zn: 0-30%, ΣR': 0-30%, ΣR": 0-30%, ΣM: 0-30%, ΣM': 0-30%. However, ΣR' represents the total amount of Li, Na, K, and Cs, and ΣR" represents the total amount of Mg, Ca, Sr, Ba, and Zn. ΣM represents the total amount of Y, Yb, In, La, Ce, Gd, Ti, Zr, Ge, Nb, Ta, W, and Mo, and ΣM' represents the total amount of B and Si. [4] The glass according to [3], wherein ΣR' is 10% or less. [5] The glass according to [3] or [4], wherein ΣM is 1 to 30%. [6] The glass according to any one of [3] to [5], wherein the cation percentage ratio of Nb to ΣM (Nb / ΣM) is 0.5 to 1.0. [7] A glass plate made of the glass according to any one of [1] to [4], with a plate thickness of 10 μm to 500 μm. [8] Light transmittance T including external reflection at an incident angle of 0 degrees and a wavelength of 400 nm. ４００ A glass plate as described in [7], wherein the ratio is 70% or more. [9] Average transmittance T including external reflection at an incident angle of 0 degrees and a wavelength of 900 to 1000 nm. ９００－１０００

[10] A glass plate according to [7] or [8], wherein the amount is 0.1% or less.

[11] A glass plate according to any one of [7] to [9], wherein the wavelength of the longest wavelength light that satisfies a transmittance of 50% or more at an incident angle of 0 degrees in the wavelength range of 550 to 850 nm is 590 nm or more.

[12] A glass plate according to any one of [7] to

[10] , wherein the reflectance at an incident angle of 0 degrees in the wavelength range of 400 to 700 nm is 1% or less.

[13] An optical filter for cutting near-infrared rays, comprising the glass plate according to any one of [7] to

[11] .

[14] An image sensor comprising the optical filter for cutting near-infrared rays according to

[12] .

[15] A mobile communication device or imaging device comprising the image sensor according to

[13] .

[0007] This disclosure provides glass, a glass plate, and an optical filter that can suppress the reduction in transmittance of obliquely incident visible light, as well as an image sensor, a mobile communication device, and an imaging device equipped with the optical filter.

[0008] This is a schematic diagram illustrating the refractive index of glass and the path of light within glass. The graph shows the relationship between the transmittance and refractive index of light at an incident angle of 60 degrees, when the transmittance of normally incident light is 10%, 5%, and 1%.

[0009] The embodiments of the invention will be described below. For clarity, the following description may be simplified as appropriate, and the scale of each component may differ significantly. "Film," "layer," and "substrate" differ only in name and do not distinguish in thickness or physical properties. Unless otherwise specified, the numerical range indicated by "~" includes the values ​​written before and after it as the lower and upper limits. Unless otherwise specified, "log" indicates the common logarithm. Unless otherwise specified, "transmittance" is expressed as a percentage.

[0010] In the present disclosure, for a specific wavelength range, a transmittance of, for example, 90% or more means that the transmittance does not fall below 90% in the entire wavelength range, that is, the minimum transmittance in that wavelength range is 90% or more. Similarly, for a specific wavelength range, a transmittance of, for example, 1% or less means that the transmittance does not exceed 1% in the entire wavelength range, that is, the maximum transmittance in that wavelength range is 1% or less. The same applies to the reflectance. The average transmittance and average reflectance in a specific wavelength range are the arithmetic mean of the transmittance or reflectance for each 1 nm in that wavelength range. Note that the spectral characteristics can be measured using an ultraviolet-visible spectrophotometer.

[0011] [Glass] The glass according to the present disclosure contains 10 to 40% of Cu and 10 to 80% of P in terms of cation percentage and has a refractive index of 1.550 or more at a wavelength of 546 nm. In the glass having such a composition, the reduction in the transmittance of obliquely incident visible light can be suppressed for the following reasons.

[0012] As a cause of the decrease in the transmittance of obliquely incident light, it can be mentioned that the optical path in the glass is longer for obliquely incident light than for perpendicularly incident light. FIG. 1 is a schematic diagram showing the optical path in the glass. The light incident perpendicularly to the glass surface travels straight without refraction, so the optical path length D Ｎ in the glass coincides with the thickness of the glass (right in FIG. 1). On the other hand, the light incident at an incident angle θ １ (θ １ > 0) travels through the glass with a refractive index n at a refraction angle θ / / 这里的斜杠是原文中的格式,不是错误,保留即可 ２ and the length D Ｏ of the path through which the light passes in the glass is (1 / cosθ ２ ) times that of D Ｎ (left in FIG. 1). Since the transmittance of light decreases exponentially with respect to the optical path length in the glass, the obliquely incident light has a lower transmittance.

[0013] Here, when the refractive index n increases, the refraction angle θ ２ becomes smaller and the path length D Ｏ also decreases. Specifically, assuming the refractive index of air is 1, the refraction angle θ ２ is θ １ and the refractive index n are used to obtain θ ２ = sin －１ (sinθ１ It is expressed as ( / n). Table 1 shows the values ​​of each refractive index n and the transmittance T of normally incident light. Ｎ This table summarizes the transmittance of light at an incident angle of 60 degrees, calculated from the following: The calculation assumes a thickness of 200 μm and a refractive index n and transmittance T at a certain wavelength λ (nm). Ｎ The experiment was conducted assuming a glass plate with a transmittance of 200 μm thickness (excluding reflection). Any glass with light absorption properties can be used as such a glass plate; for example, it can be applied to phosphate glass containing Cu. Figure 2 shows the transmittance T of normally incident light. Ｎ This graph shows the relationship between the transmittance and refractive index of light at an incident angle of 60 degrees for refractive indices of 10%, 5%, and 1%. The vertical axis of Figure 2 represents how many times greater the transmittance at each refractive index is compared to the transmittance at a refractive index of n = 1.52.

[0014]

[0015] As shown in Table 1 and Figure 2, increasing the refractive index n of the glass can suppress the decrease in transmittance of obliquely incident light. In particular, the effect of suppressing the decrease in transmittance is greater when the transmittance of normally incident light is low. As described above, if the refractive index at a wavelength of 546 nm is 1.550 or higher, the decrease in transmittance of obliquely incident visible light can be suppressed. The refractive index is preferably 1.560 or higher, more preferably 1.570 or higher, even more preferably 1.580 or higher, particularly preferably 1.590 or higher, and most preferably 1.600 or higher.

[0016] The refractive index of glass can be measured, for example, according to the V-block method specified in JIS B 7071-2:2018. In this case, the e-line (wavelength 546.07 nm) of a mercury lamp is used as the light source. In addition, in the wavelength range where absorption is almost nonexistent, the transmittance T (%) under normal incidence is measured for glass that has been mirror-polished on both sides, and T / 100 = 2n / (n ２It is also possible to convert to refractive index using the relationship (+1). Note that in regions with absorption, it is necessary to correct for transmittance. Alternatively, it can be determined by measuring the reflectance of one side. In that case, it is desirable to eliminate the effect of back surface reflection. For example, for a plate of glass, one main surface (called the first surface) is mirror-polished, and the opposite surface (called the second surface) is roughened by grinding with a grinding wheel, for example, #230 grit. The second surface and the end surface are painted with a black marker or paint to prevent light transmission and suppress reflection. For this sample, the specular reflectance of the first surface is measured with a spectrophotometer. The angle of incidence of the incident light is preferably within 10 degrees, for example, from the viewpoint of suppressing the effect of polarization characteristics. From the reflectance R, n = (1 - R ０．５ ) / (1+R) ０．５ The conversion can be done using the following relationship: 546 nm is preferable for measuring reflectance.

[0017] Furthermore, when the glass according to this disclosure is formed into a plate and the two opposing main surfaces are processed to a mirror finish, it is preferable that α, represented by the following formula (1), is 12 or more, and β, represented by the following formula (2), is 1.76 or less. α = {-log(T ９００－１０００ / 100)-0.018} / t...(1) β={-log(T ４００ ( / 100) - 0.036} / t ... (2) where T ９００－１０００ This shows the average light transmittance including external reflection at an incident angle of 0 degrees and a wavelength of 900 nm to 1000 nm. ４００ t represents the light transmittance including external reflection at an incident angle of 0 degrees and a wavelength of 400 nm, and t represents the plate thickness (mm).

[0018] A value of α of 12 or greater indicates that the glass has excellent infrared-cutting performance. Furthermore, a value of β of 1.76 or less indicates that the glass has excellent visible light transmittance. The glass of the first embodiment, which satisfies both of these conditions simultaneously, exhibits excellent infrared-cutting performance relative to its thickness and also has excellent visible light transmittance.

[0019] The values ​​"0.018" in equation (1) and "0.036" in equation (2) are constants that correct for reflection loss due to external reflection. These values ​​were determined experimentally, and it has been confirmed that the effect of film thickness is extremely small. α and β are values ​​that do not depend on the plate thickness and are mainly determined by the composition of the glass.

[0020] When the optical density (OD) of the glass is 2.4 or more as an average value for a plate thickness of 0.20 mm at wavelengths of 900 nm to 1000 nm, the above α may be 12 or more, preferably 16 or more, and more preferably 20 or more. When the OD of the glass is less than 2.4 as a plate thickness of 0.20 mm, the above α may be 12 to 16. The above β may be 1.76 or less, preferably 1.33 or less, more preferably 0.98 or less, and even more preferably 0.68 or less.

[0021] The method for calculating OD is as follows: First, the wavelength λ is of interest. ０ or wavelength range λ １ from λ ２ The transmittance spectrum, T(λ), is measured. Here, the measurement is performed using a spectrophotometer that maintains sufficient detection sensitivity (linearity of absorbance with respect to concentration) in the relevant wavelength range. The obtained transmittance spectrum is converted to optical concentration OD(λ) using the following formula: OD(λ) = -log(T(λ) / 100) Here, T(λ) represents the external transmittance at wavelength λ (nm). If there is only one wavelength of interest, λ ０ OD(λ) ０ Let ) be OD. On the other hand, when calculating the average over a wavelength range, the average OD over the wavelength range of interest can be calculated by integrating OD(λ) over the wavelength range of interest and dividing by the wavelength width, that is, by using the following formula.

[0022]

[0023] (Transmittance T ９００－１０００ and T ４００(Measurement Method) The glass to be measured is formed into a plate shape as needed. Known methods such as the float method, fusion method, and roll-out method can be used for forming. Specifically, the glass to be measured is placed in a crucible, heated and melted in an electric furnace under atmospheric conditions at a temperature of 950°C to 1300°C, thoroughly stirred and clarified, and then formed into a flat plate shape using various forming methods. Next, the two opposing main surfaces are polished to a mirror finish. This results in a glass plate for measurement. Transmittance T ９００－１０００ and T ４００ The external reflection can be measured using a spectrophotometer. The glass plate used for measurement should be mirror-finished by grinding and polishing with fixed abrasive grains and loose abrasive grains, for example, to reduce the haze to 0.1% or less. The haze can be measured using an existing haze meter. In this transmittance measurement, the thickness of the glass plate used for measurement is not particularly limited, but from the standpoint of processing and handling, 1 μm to 10,000 μm is preferred, and 5 μm to 8,000 μm is more preferred. If the glass to be measured is available in plate form, it may be prepared as a glass plate for measurement by simply mirror-finishing it as needed. In this case, the plate thickness may be outside the above range.

[0024] In this embodiment, when the glass is formed into a plate and the two opposing main surfaces are processed to a mirror finish, it is preferable that γ, represented by the following formula (3), is 6 or more. γ = {-log(T １２００ ( / 100) - 0.018} / t ≥ 6.0 …(3) where T １２００ This value represents the light transmittance, including external reflection, at an incident angle of 0 degrees and a wavelength of 1200 nm.

[0025] A γ value of 6 or higher indicates that the glass has superior infrared-cutting performance. A γ value of 6.5 or higher is preferable, 7 or higher is more preferable, 7.5 or higher is even more preferable, 8 or higher is even more preferable, 9 or higher is even preferable, and 10 or higher is particularly preferable.

[0026] The glass according to this disclosure is a phosphate glass containing 10-40% Cu and 10-80% P in terms of cation percentage. Phosphate glass containing 10% or more Cu is excellent in terms of infrared cut performance, and glass with large α and γ values ​​can be obtained. By reducing the Cu content to 40% or less, glass with excellent visible light transmittance and a small β value can be obtained.

[0027] The glass according to this disclosure preferably contains the following components in cation percentages, with an atomic ratio of O to P (O / P) of 2.7 to 3.4. P: 45-75%, Al: 0-20%, Cu: 10-40%, Li: 0-15%, Na: 0-15%, K: 0-15%, Cs: 0-15%, Mg: 0-30%, Ca: 0-30%, Sr: 0-30%, Ba: 0-30%, Zn: 0-30%, ΣR': 0-30%, ΣR": 0-30%, ΣM: 0-30%, ΣM': 0-30%. However, ΣR' represents the total amount of Li, Na, K, and Cs, and ΣR" represents the total amount of Mg, Ca, Sr, Ba, and Zn. ΣM represents the total amount of Y, Yb, In, La, Ce, Gd, Ti, Zr, Ge, Nb, Ta, W, and Mo, and ΣM' represents the total amount of B and Si.

[0028] Glass having the above composition achieves both excellent infrared-cutting performance and visible light transmission, and also exhibits excellent weather resistance.

[0029] As stated above, the glass relating to this disclosure contains 10-80% P. P is mainly P ５＋ It is contained as P. ５＋ P is the main component of phosphate glass and an essential component for enhancing near-infrared ray blocking properties. ５＋If the content of P is 10% or more, the effect can be sufficiently obtained, and if it is 80% or less, problems such as glass instability, decreased refractive index, and reduced weather resistance are less likely to occur. The content of P is preferably 30% or more, more preferably 40% or more, even more preferably 45% or more, particularly preferably 50% or more, and most preferably 55% or more. Furthermore, the content of P is preferably 75% or less, more preferably 74% or less, even more preferably 73% or less, particularly preferably 72% or less, and most preferably 71% or less. ５＋ From the viewpoint of suppressing crucible erosion and inhibiting the volatilization of components, phosphoric acid, liquid phosphoric acid, or a salt thereof are preferred as raw materials.

[0030] The glass relating to this disclosure may contain 0 to 20% Al. Al is mainly Al ３＋ It is contained as Al ３＋ Al is a component that forms glass and improves the strength and weather resistance of the glass. From the viewpoint of vitrification stability and infrared cut properties, the Al content is 20% or less. The Al content may be 0% or more, and from the viewpoint of glass strength and weather resistance, it is more preferably 0.50% or more, 1.00% or more, 1.50% or more, 2.00% or more, 2.50% or more, 3.00% or more, 3.50% or more, 4.00% or more, 4.50% or more, and particularly preferably 5% or more. Furthermore, from the viewpoint of vitrification stability and infrared cut properties, the Al content is preferably 18% or less, more preferably 17.00% or less, 16.00% or less, 15.00% or less, 14.00% or less, 13.00% or less, 12.00% or less, 11.00% or less, and particularly preferably 10% or less. ３＋ As a raw material, AlF ３ Al ２ O ３ Al(OH) ３ Al(PO ３ ) ３ The following can be used.

[0031] The glass relating to this disclosure contains 10-40% Cu. Cu is mainly Cu ＋ or Cu ２＋It is contained in an amount of 10-40%. The Cu content is preferably 11% or more, more preferably 12% or more, even more preferably 13% or more, particularly preferably 15% or more, and most preferably 17% or more. On the other hand, the Cu content is preferably 39% or less, more preferably 38% or less, even more preferably 37% or less, particularly preferably 36% or less, and most preferably 35% or less. Also, from the viewpoint of visible light transmittance and infrared cut properties, monovalent copper ions Cu relative to total Cu ＋ Percentage (Cu ＋ (Total Cu amount) × 100 [%] is preferably 0.01 to 4.0%. ２＋ or Cu ＋ As raw materials, CuO, Cu ２ SO ４ CuNO ３ Cu(PO ３ ) ２ The following can be used.

[0032] The glass relating to this disclosure may contain 0 to 15% Li. Li is mainly Li ＋ It is contained as Li ＋ These are components that lower the melting temperature of the glass, lower the liquidus temperature of the glass, and stabilize the vitrification process. From the viewpoint of vitrification stability and infrared cut performance, the Li content is preferably 14% or less, more preferably 13.00% or less, 12.00% or less, 11.00% or less, 10.00% or less, 9.00% or less, 8.00% or less, 7.00% or less, 6.00% or less, 5.00% or less, 4.00% or less, 3.00% or less, 2.00% or less, 1.00% or less, 0.1% or less, and particularly preferably no Li content.

[0033] The glass relating to this disclosure may contain 0 to 15% Na. Na is mainly Na ＋ It is contained as Na. ＋This component is used to lower the melting temperature of the glass, lower the liquidus temperature of the glass, and stabilize the vitrification process. From the viewpoint of vitrification stability and infrared-cutting performance, the Na content is preferably 12% or less, more preferably 10% or less, even more preferably 8% or less, and particularly preferably 6% or less.

[0034] The glass relating to this disclosure may contain 0 to 15% K. K is mainly K ＋ It is contained as K. ＋ This component has effects such as lowering the melting temperature of the glass and lowering the liquidus temperature of the glass. The content of K is preferably 14% or less, more preferably 12% or less, even more preferably 10% or less, and particularly preferably 9% or less.

[0035] The glass relating to this disclosure may contain 0 to 15% Cs. Cs is mainly Cs ＋ It is contained as Cs. ＋ This component has effects such as lowering the melting temperature of the glass and lowering the liquidus temperature of the glass. The Cs content is preferably 14% or less, more preferably 13% or less, even more preferably 12% or less, and particularly preferably 10% or less.

[0036] In the glass according to this disclosure, the total amount of Li, Na, K, and Cs (ΣR') may be 0 to 30%. From the viewpoint of lowering the melting temperature of the glass, lowering the liquidus temperature of the glass, and stabilizing vitrification, ΣR' is preferably 0.1% or more, more preferably 1% or more, even more preferably 3% or more, particularly preferably 5% or more, and most preferably 8% or more. On the other hand, from the viewpoint of vitrification stability, ΣR' is 30% or less, preferably 20% or less, more preferably 15% or less, and even more preferably 10% or less. As raw materials for R', carbonates, nitrates, hydroxides, metaphosphates, orthophosphates, etc., can be used.

[0037] The glass relating to this disclosure may contain 0 to 30% Mg. Mg is mainly Mg ２＋ It is contained as Mg ２＋This component is used to lower the melting temperature of the glass, lower the liquidus temperature of the glass, stabilize vitrification, and increase the strength of the glass. From the viewpoint of vitrification stability and infrared cut performance, the Mg content is preferably 20% or less, more preferably 15% or less, even more preferably 10% or less, particularly preferably 5% or less, and most preferably 3% or less.

[0038] The glass relating to this disclosure may contain 0 to 30% Ca. Ca is mainly Ca ２＋ It is contained as Ca ２＋ These are components used to lower the melting temperature of the glass, lower the liquidus temperature of the glass, stabilize vitrification, and increase the strength of the glass. From the viewpoint of vitrification stability and infrared cut performance, the Ca content is preferably 20% or less, more preferably 15% or less, even more preferably 10% or less, particularly preferably 8% or less, and most preferably 6% or less.

[0039] The glass relating to this disclosure may contain 0 to 30% Sr. Sr is mainly Sr ２＋ It is contained as Sr. ２＋ This component is used to lower the melting temperature of the glass, lower the liquidus temperature of the glass, and stabilize the vitrification process. From the viewpoint of vitrification stability and infrared cut performance, the Sr content is preferably 20% or less, more preferably 15% or less, even more preferably 10% or less, particularly preferably 8% or less, and most preferably 6% or less.

[0040] The glass relating to this disclosure may contain 0 to 30% Ba. Ba is mainly Ba ２＋ It is contained as Ba ２＋ This component is used to lower the melting temperature of the glass, lower the liquidus temperature of the glass, and stabilize the vitrification process. From the viewpoint of vitrification stability and infrared cut performance, the Ba content is preferably 20% or less, more preferably 15% or less, even more preferably 10% or less, particularly preferably 8% or less, and most preferably 6% or less.

[0041] Furthermore, the glass relating to this disclosure may contain 0 to 30% Zn. Zn is mainly Zn ２＋ It is contained as Zn. ２＋ This has effects such as lowering the melting temperature of the glass and lowering the liquidus temperature of the glass. From the viewpoint of vitrification stability and infrared cut performance, the Zn content is preferably 20% or less, more preferably 15% or less, even more preferably 10% or less, particularly preferably 8% or less, and most preferably 6% or less.

[0042] In the glass according to this disclosure, the total amount of Mg, Ca, Sr, Ba, and Zn (ΣR'') may be 0 to 30%. From the viewpoint of lowering the melting temperature of the glass, lowering the liquidus temperature of the glass, and stabilizing vitrification, ΣR'' is preferably 0.1% or more, more preferably 0.5% or more, and even more preferably 1% or more. On the other hand, from the viewpoint of vitrification stability, ΣR'' is preferably 20% or less, more preferably 15% or less, even more preferably 10% or less, particularly preferably 8% or less, and most preferably 6% or less. As raw materials for R'', carbonates, nitrates, hydroxides, metaphosphates, orthophosphates, fluorides, etc., can be used.

[0043] The glass according to this disclosure may contain one or more elements selected from Y, Yb, In, La, Ce, Ti, Zr, Ge, Nb, Ta, W, and Mo in a total amount (ΣM) of 0 to 30%. The inclusion of these elements improves the refractive index and weather resistance of the glass. To achieve both improved refractive index and weather resistance, ΣM is preferably 0.2% or more, more preferably 0.5% or more, and even more preferably 1% or more. Furthermore, the glass according to this disclosure preferably contains Nb. The cation percentage ratio of Nb to ΣM (Nb / ΣM) is preferably 0.5 to 1.0, and more preferably 0.6 to 1.0. As raw materials for M, oxides, carbonates, nitrates, fluorides, phosphates, etc., can be used.

[0044] The glass according to this disclosure may contain one or more elements selected from B and Si in a total amount (ΣM') of 0 to 30%. The inclusion of these elements can improve melting properties. Preferably, the amount is 0.2% or more, more preferably 0.5% or more, and even more preferably 1% or more. As raw materials for B or Si, oxides, hydroxides, etc., can be used.

[0045] In the glass according to this disclosure, the atomic ratio of O to P (O / P) is preferably 2.7 to 3.4, more preferably 2.7 to 3.3, and even more preferably 2.7 to 3.2, in order to improve infrared cut performance.

[0046] The glass relating to this disclosure may contain F. F is mainly F － It is contained as follows. From the viewpoint of infrared cut performance and the mechanical strength of the glass, the content of F is preferably 1% by mass or less, more preferably 0.8% by mass or less, and even more preferably 0.5% by mass or less, based on 100% by mass of the total amount of glass.

[0047] The glass according to this disclosure preferably contains a large amount of cations of elements with large atomic weights (one or more selected from Cu, Zn, Cs, Ba, Y, Yb, In, La, Ce, Ti, Zr, Ge, Nb, Ta, W, and Mo) from the viewpoint of improving the refractive index. The total content of the above elements is preferably 12% or more, more preferably 15% or more, even more preferably 17.5% or more, particularly preferably 20% or more, and most preferably 25% or more, in terms of cation percentage.

[0048] The glass according to this disclosure may contain other elements not mentioned above, as necessary or unavoidable, to the extent that it achieves the effects of the present invention. The total content of other elements is preferably 8% by mass or less, more preferably 5% by mass or less, even more preferably 1% by mass or less, and particularly preferably 0.1% by mass or less, based on 100% by mass of the total amount of glass.

[0049] The glass according to the present disclosure is in the form of powder with a particle size of 53 μm to 106 μm from the viewpoint of reliability in a high-temperature and high-humidity environment. It is preferable that the weight increase rate with respect to the initial weight after holding about 33 mg of the powder in an environment of 85° C. and a relative humidity of 85% for 24 hours is 45% or less, more preferably 35% or less, and still more preferably 25% or less.

[0050] (Method for measuring the weight increase rate) The glass to be measured is pulverized into powder as necessary. The pulverization method may be any method such as wet pulverization, dry pulverization, or jet mill. By classifying the obtained powder using test sieves with mesh openings of 53 μm and 106 μm, a test powder with a particle size of 53 μm to 106 μm can be obtained. Put about 33 mg of the test powder (let the actual measured weight be W ０ ) into a container, place it still in a thermo-hygrostat, and after leaving it still for 24 hours under the conditions of a temperature of 85° C. and a relative humidity of 85%, measure the weight, and subtract the container weight and the initial weight W ０ to measure the weight increase amount ΔW. The weight increase rate can be calculated by expressing the value obtained by dividing ΔW by the initial weight W ０ as a percentage. Note that “about 33 mg” refers to a weight within the range of “33 mg ± 1.0 mg”.

[0051] The glass according to the present disclosure suppresses the generation of bubbles. When formed into a plate shape, βOH represented by the following formula (4) is preferably 0.05 to 4.0 mm －１ and more preferably 0.1 to 3.5 mm －１ . βOH = (1 / t) log(τ １ / τ ２ )... (4) However, t indicates the plate thickness (mm), τ １ indicates the light transmittance at a wave number of 4000 cm －１ , and τ ２ indicates the minimum value of the light transmittance at a wave number of 2700 to 3450 cm －１ .

[0052] (Method for measuring the light transmittances τ １ , τ ２ ) The method for measuring the light transmittance is the same as that for the above T ９００－１０００ and T ４００ . However, the transmittances τ １ , τ２ A Fourier transform infrared spectrophotometer (FT-IR) is used for the measurement.

[0053] The glass according to this disclosure preferably has a glass transition temperature Tg of 385°C or higher, more preferably 390°C or higher, more preferably 400°C or higher, more preferably 410°C or higher, more preferably 420°C or higher, even more preferably 430°C or higher, even more preferably 440°C or higher, and particularly preferably 450°C or higher. If Tg is 385°C, the strength of the glass network is sufficient and the chemical durability is excellent. The glass transition temperature can be measured by differential scanning calorimetry (DSC), thermomechanical analysis (TMA), or dilatometer.

[0054] The glass relating to this disclosure suppresses cation migration by improving the packing of constituent atoms, and therefore has a density of 2.60 g / cm³. ３ Preferably, it should be 2.80 g / cm³ or more. ３ The above is preferable. On the other hand, from the viewpoint of weight reduction, the density should be 3.50 g / cm³. ３ Preferably, it is 3.30 g / cm³. ３ The following is more preferable. The density can be measured by the Archimedes method.

[0055] The glass relating to this disclosure has an average coefficient of thermal expansion (CTE) of 50 × 10 in the range of 100°C to 300°C. －７ / ℃ or higher, 95 x 10 －７ A temperature of / °C or lower is preferable.

[0056] When the glass according to this disclosure is used as a color correction filter for a solid-state image sensor, it may also function as a cover glass for hermetically sealing the solid-state image sensor. In this case, by reducing the difference in CTE between the glass and the package material, delamination and damage at the joint can be suppressed, and an excellent hermetically sealed state can be maintained.

[0057] Generally, materials such as glass, crystallized glass, ceramics, and alumina are used as packaging materials, taking heat resistance into consideration. From the viewpoint of minimizing the difference in CTE between these packaging materials and glass, it is preferable that the glass according to this disclosure has a CTE in the temperature range of 100°C to 300°C. Furthermore, the CTE of this glass is 50 × 10 －７ Preferably above / ℃, more preferably 60 × 10 －７ / ℃ or higher, more preferably 65 × 10 －７ / ℃ or higher, more preferably 70 × 10 －７ / ℃ or higher, particularly preferably 75 × 10 －７ It is above / ℃. Also, 95 × 10 －７ Preferably below / ℃, more preferably 90 × 10 －７ / ℃ or lower, more preferably 85 × 10 －７ It is below / ℃.

[0058] The glass according to this disclosure can suppress the decrease in transmittance of obliquely incident visible light, and therefore can be suitably used as an optical filter or a substrate for an optical filter.

[0059] [Glass Plate] The glass plate according to this disclosure is made of the glass according to this disclosure and is characterized by having a plate thickness of 10 μm to 500 μm. The plate thickness is preferably 400 μm or less, more preferably 300 μm or less, and particularly preferably 250 μm or less. Furthermore, it is desirable that the two opposing main surfaces be mirror polished so that the haze is 0.1% or less. Since the glass plate is made of the glass, it can suppress the decrease in transmittance of obliquely incident visible light.

[0060] The glass plate according to this disclosure preferably has a refractive index of 1.550 or higher at a wavelength of 546 nm, more preferably 1.560 or higher, even more preferably 1.570 or higher, even more preferably 1.580 or higher, particularly preferably 1.590 or higher, and most preferably 1.600 or higher.

[0061] The glass plate relating to this disclosure has a light transmittance T including external reflection at an incident angle of 0 degrees and a wavelength of 400 nm. ４００It is preferable that the β is 70% or more, more preferably 72% or more, even more preferably 74% or more, and particularly preferable 75% or more. Furthermore, in the glass plate according to this disclosure, the β is preferably 1.76 or less, more preferably 1.33 or less, even more preferably 0.98 or less, and particularly preferable 0.68 or less.

[0062] The glass plate relating to this disclosure has an average transmittance T including external reflection at an incident angle of 0 degrees and a wavelength of 900 to 1000 nm. ９００－１０００ It is preferable that α is 0.1% or less, more preferably 0.09% or less, even more preferably 0.08% or less, and particularly preferably 0.07% or less. Furthermore, in the glass plate according to this disclosure, α is preferably 12 or more, more preferably 16 or more, and particularly preferably 20 or more.

[0063] Furthermore, in order to be superior in terms of visible light transmittance, the glass plate according to this disclosure preferably has a wavelength of 590 nm or more, more preferably 600 nm or more, even more preferably 610 nm or more, and particularly preferably 620 nm or more, in the range of wavelengths from 550 to 850 nm at an incident angle of 0 degrees. Furthermore, in the range of wavelengths from 550 to 850 nm, the glass plate according to this disclosure has a wavelength of λ that satisfies the first light satisfying the following formula (5) when viewed from the long wavelength side. １．３３ When that happens, the λ １．３３ It is preferable that the wavelength is 570 nm or greater. {-log(T Ｘ ( / 100) - 0.018} / t = 1.33 ... (5) However, T Ｘ This value represents the light transmittance including external reflection at an incident angle of 0 degrees and wavelength X nm, where X is between 550 nm and 850 nm, and t represents the plate thickness (mm).

[0064] Furthermore, the glass plate according to this disclosure preferably has a reflectance of 1% or less in the wavelength range of 400 to 700 nm, more preferably 0.9% or less, even more preferably 0.8% or less, and particularly preferably 0.7% or less. Such reflectance can be achieved, for example, by forming a dielectric multilayer film or a moth-eye structure film in which the refractive index changes in a gradual manner from the air interface toward the glass surface.

[0065] [Optical filter for cutting near-infrared rays] The optical filter for cutting near-infrared rays according to the present disclosure is characterized by comprising the glass plate described above. The optical filter for cutting near-infrared rays according to the present disclosure may be used with the glass plate alone, or it may have other layers.

[0066] Other layers used in near-infrared cut optical filters are not particularly limited and can be appropriately selected and applied from known configurations used in optical filters. Specific examples of other layers include dielectric multilayer films, resin films containing near-infrared or ultraviolet absorbing dyes, and anti-reflective films. Specific layer configurations include "first dielectric multilayer film / resin film / glass substrate / second dielectric multilayer film" and "first dielectric multilayer film / resin film / third dielectric multilayer film / glass substrate / second dielectric multilayer film". Furthermore, as an anti-reflective film, a so-called moth-eye type anti-reflective film, in which the refractive index changes stepwise from the surface towards the substrate, can also be used.

[0067] According to the above embodiment, an optical filter with excellent transmittance in the visible light region and shielding in the near-infrared light region can be realized. When the optical filter of this embodiment is used in an imaging device such as a digital still camera, for example, it can provide an imaging device with excellent color reproduction.

[0068] [Image sensor, mobile communication device, and imaging device] The image sensor according to this embodiment is characterized by comprising the near-infrared cut optical filter. The mobile communication device and imaging device according to this embodiment are characterized by comprising the image sensor. The image sensor comprises at least a solid-state image sensor and the optical filter of this embodiment, and may further comprise an imaging lens or the like. The near-infrared cut optical filter may be arranged, for example, on the optical path between the imaging lens and the solid-state image sensor, or it may be directly attached to the solid-state image sensor, imaging lens, etc. of the imaging device via an adhesive layer.

[0069] The present invention will be described in more detail below using examples, but the present invention is not limited to these examples. Note that Example 1 is a comparative example, and Examples 2 to 15 are examples.

[0070] [Glass Manufacturing] The raw materials were weighed and mixed to achieve the compositions shown in Tables 2 and 3, placed in a crucible, and heated to 950°C to 1300°C under an atmospheric environment for 2 hours until melted. After clarification and stirring, the mixture was poured into a rectangular mold measuring 100 mm (length) x 80 mm (width) x 20 mm (height) preheated to approximately 300°C to 500°C, and then slowly cooled at approximately 1°C / min to obtain a glass block. From this block, a plate-like glass sample measuring 40 mm (length) x 30 mm (width) x approximately 0.1 mm to 0.3 mm (thickness) was obtained by optically polishing both sides. In the tables, the numerical values ​​for the elements that become cationized represent the percentage of cations. O and F are values ​​representing the content in the glass as an external proportion when the total amount of cations is set to 100%. Also, "-" in the "Nb / ΣM" column indicates that the element corresponding to M is not present.

[0071] The transmittance of the obtained glass was measured using a spectrophotometer (Hitachi High-Tech Corporation, U4100) to obtain the transmittance of light with wavelengths from 350 nm to 1200 nm, and the α, β, and λ values ​​were determined. １．３３ The result was calculated.

[0072] Furthermore, the refractive index of the glass was measured using a precision refractometer (Shimadzu Devices Corporation, product name: KPR-3000) in accordance with JIS B 7071-2:2018, after processing the glass into a rectangular parallelepiped shape with sides of 30 mm and a thickness of 10 mm. The measurement temperature was 23°C, and the e-line (wavelength 546.07 nm) of a mercury lamp was used as the light source.

[0073] The refractive index of glass can also be determined in a simple manner by measuring its reflectance. For a plate of glass, one main surface (called the first surface) is mirror-polished, and the opposite surface (called the second surface) is roughened by grinding with, for example, #230 grit abrasive. The second surface and the end surfaces are then painted with a black marker or paint to prevent light transmission and suppress reflection. The specular reflectance of the first surface of this sample is measured using a spectrophotometer. The angle of incidence of the incident light should preferably be within 10 degrees, for example, to minimize the influence of polarization characteristics. From the reflectance R, n = (1 - R) ０．５ ) / (1+R) ０．５ The conversion can be done using the following relationship: 546 nm is preferable for measuring reflectance.

[0074] Furthermore, the glass transition temperature was measured by weighing 60 mg of powdered glass, placing it in a platinum pan, and using a DSC (Bruker AXS, DSC3300SA) at a heating rate of 10°C / min. The temperature at the inflection point corresponding to the glass transition was determined from the resulting DSC chart.

[0075] Furthermore, the CTE (coefficient of thermal expansion) of the glass was measured by processing a cylindrical piece of glass with a diameter of 5 mm and a height of 20 mm, which had been thoroughly cooled, and then measuring the elongation of the sample by dividing it by the temperature difference within the measurement temperature range using a thermomechanical analyzer (Brker, product name: TD5000SA). Quartz glass was used as the standard sample during measurement. The heating rate was 5°C / min, and the measurement temperature range was 100 to 300°C.

[0076] The results are shown in the table. A "-" in the physical properties column indicates that the measurement was not performed.

[0077]

[0078]

[0079] As shown in Tables 2-3, the glasses of Examples 2-15 have a refractive index of 1.550 or higher at a wavelength of 546 nm, and it was found that they can suppress the decrease in transmittance of obliquely incident visible light.

[0080] This application claims priority based on Japanese Patent Application No. 2025-018395 filed on 6 February 2025, Japanese Patent Application No. 2025-153913 filed on 17 September 2025, and Japanese Patent Application No. 2025-281174 filed on 24 December 2025, and incorporates all of their disclosures herein.

Claims

1. A glass containing 10-40% Cu and 10-80% P cations, with a refractive index of 1.550 or higher at a wavelength of 546 nm.

2. The glass according to claim 1, wherein when formed into a plate and two opposing main surfaces are processed to a mirror finish, α represented by the following formula (1) is 12 or more, and β represented by the following formula (2) is 1.76 or less. α = {-log(T ９００－１０００ / 100)-0.018} / t...(1) β={-log(T ４００ ( / 100) - 0.036} / t ... (2) where T ９００－１０００ This shows the average light transmittance including external reflection at an incident angle of 0 degrees and a wavelength of 900 nm to 1000 nm. ４００ t represents the light transmittance including external reflection at an incident angle of 0 degrees and a wavelength of 400 nm, and t represents the plate thickness (mm).

3. The glass according to claim 1, comprising the following components in terms of cation percentage, with an atomic ratio of O to P (O / P) of 2.7 to 3.

4. P: 45-75%, Al: 0-20%, Cu: 10-40%, Li: 0-15%, Na: 0-15%, K: 0-15%, Cs: 0-15%, Mg: 0-30%, Ca: 0-30%, Sr: 0-30%, Ba: 0-30%, Zn: 0-30%, ΣR': 0-30%, ΣR": 0-30%, ΣM: 0-30%, ΣM': 0-30%. However, ΣR' represents the total amount of Li, Na, K, and Cs, and ΣR" represents the total amount of Mg, Ca, Sr, Ba, and Zn. ΣM represents the total amount of Y, Yb, In, La, Ce, Gd, Ti, Zr, Ge, Nb, Ta, W, and Mo, and ΣM' represents the total amount of B and Si.

4. The glass according to claim 3, wherein the ΣR' is 10% or less.

5. The glass according to claim 3 or 4, wherein the ΣM is 1 to 30%.

6. The glass according to claim 3 or 4, wherein the cation percentage ratio of Nb to ΣM (Nb / ΣM) is 0.5 to 1.

0.

7. A glass plate made of the glass described in any one of claims 1 to 4, having a thickness of 10 to 500 μm.

8. Light transmittance T including external reflection at an incident angle of 0 degrees and a wavelength of 400 nm. ４００ The glass plate according to claim 7, wherein the percentage is 70% or more.

9. Average transmittance T including external reflection at an incident angle of 0 degrees and a wavelength of 900–1000 nm. ９００－１０００ The glass plate according to claim 7, wherein the content is 0.1% or less.

10. The glass plate according to claim 7, wherein, in the wavelength range of 550 to 850 nm, the wavelength of light on the longest wavelength side that satisfies a transmittance of 50% or more at an incident angle of 0 degrees is 590 nm or more.

11. The glass plate according to claim 7, wherein the reflectance at an incident angle of 0 degrees in the wavelength range of 400 to 700 nm is 1% or less.

12. An optical filter for cutting near-infrared rays, comprising the glass plate described in claim 7.

13. An image sensor comprising the near-infrared cut optical filter described in claim 12.

14. A mobile communication device or imaging device comprising the image sensor described in claim 13.

Images