Glass, glass plate, optical filter, imaging element, mobile communication device, and imaging device
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2026-02-03
- Publication Date
- 2026-08-13
Smart Images
Figure JP2026003878_13082026_PF_FP_ABST
Abstract
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] Japanese Patent Publication No. 2010-008908
[0004] With the demand for thinner devices such as smartphones, not only the imaging device itself but also the components within it need to be made thinner. Furthermore, as optical systems become smaller, the deterioration of image quality due to ghosting and flare caused by various types of stray light is becoming more pronounced.
[0005] In view of the above issues, this disclosure aims to provide glass, glass plates, and optical filters that achieve both sufficient infrared cut performance and high visible light transmittance in a thin plate, as well as image sensors, mobile communication devices, and imaging devices equipped with such optical filters.
[0006] This disclosure includes the following embodiments: [1] Glass formed into a plate and with two opposing main surfaces processed to a mirror finish, wherein α represented by the following formula (1) is 12 or greater, 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 value of light transmittance including external reflection at wavelengths of 900-1000 nm, and T ４００shows the light transmittance including external reflection at a wavelength of 400 nm, and t represents the plate thickness (mm). [2] The glass according to [1], when formed into a plate shape, further has γ represented by the following formula (3) of 6 or more. γ = {−log(T １２００ / 100) − 0.018} / t ≥ 6.0...(3) However, T １２００ shows the light transmittance including external reflection at a wavelength of 1200 nm. [3] The glass according to [1] or [2], which is a phosphate glass containing 10 to 30% of Cu in terms of cation percentage. [4] The glass contains the following components in terms of cation percentage and has an atomic number ratio (O / P) of O to P of 2.7 to 3.4. P: 55 to 75%, Al: 0 to 20%, Cu: 10 to 30%, Li: 0 to 15%, Na: 0 to 15%, K: 0 to 15%, Cs: 0 to 15%, Mg: 0 to 10%, Ca: 0 to 10%, Sr: 0 to 10%, Ba: 0 to 10%, Zn: 0 to 10%, ΣR': 0 to 30%, ΣR'': 0 to 10%, ΣM: 0 to 10%. However, ΣR' represents the total amount of Li, Na, K, and Cs, ΣR'' represents the total amount of Mg, Ca, Sr, Ba, and Zn, and ΣM represents the total amount of Y, Yb, In, La, Ce, B, Si, Ti, Zr, Ge, Nb, Ta, W, and Mo. [5] The glass according to [4], wherein the ΣR' is 10% or less. [6] The glass according to [4] or [5], wherein the ΣM is 1 to 10%. [7] The glass according to any one of [4] to [6], wherein the cation percentage ratio (Nb / ΣM) of Nb to ΣM is 0.5 to 1.0. [8] The glass according to any one of [1] to [7], which is in the form of powder with a particle size of 53 μm to 106 μm, and 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. [9] The glass according to any one of [1] to [8], wherein the fluorine content is 1% by mass or less.
[10] The glass according to any one of [1] to [9], when formed into a plate shape, has βOH represented by the following formula (4) of 0.05 to 4.0 mm －１ is. βOH = (1 / t)log(τ １ / τ ２) ... (4) However, t indicates the plate thickness (mm), τ １ The wave number is 4000 cm. －１ The light transmittance of τ is shown, ２ The wave number is 2700-3450 cm. －１ The minimum value of light transmittance is shown.
[11] A glass according to any one of [1] to
[10] , wherein the glass transition temperature Tg is 385°C or higher.
[12] The average coefficient of thermal expansion (CTE) from 100°C to 300°C is 50 × 10 －７ / ℃~95×10 －７ Glass according to any of [1] to
[11] , which is / ℃.
[13] A glass plate made of glass according to any of [1] to
[12] , with a plate thickness of 10 μm to 300 μm.
[14] A glass plate according to
[13] , wherein β, represented by the following formula (2), is 1.33 or less. β = {-log(T ４００ ( / 100) - 0.036} / t ... (2) where T ４００ β represents the light transmittance including external reflection at a wavelength of 400 nm, and t represents the plate thickness (mm).
[15] The glass plate according to
[14] , wherein β is 0.98 or less.
[16] The glass plate according to
[14] , wherein β is 0.68 or less.
[17] The glass plate according to any one of
[13] to
[16] , wherein α represented by the following formula (1) is 16 or more. α = {-log(T) ９００－１０００ ( / 100) - 0.018} / t ≥ 16 … (1) where T ９００－１０００ λ represents the average value of light transmittance including external reflection at wavelengths of 900 to 1000 nm, and t represents the plate thickness (mm).
[18] In the range of wavelengths of 550 to 850 nm, the wavelength of the first light that satisfies the following equation (5) when viewed from the long wavelength side is λ １．３３ When that happens, the λ １．３３ A glass plate according to any one of
[13] to
[17] , wherein the wavelength is 570 nm or greater. {-log(T Ｘ ( / 100) - 0.018} / t = 1.33 ... (5) However, T Ｘ
[19] An optical filter for cutting near-infrared rays, comprising a glass plate as described in any of
[13] to
[18] .
[20] An image sensor comprising the optical filter for cutting near-infrared rays as described in
[19] .
[21] A mobile communication device or imaging device comprising the image sensor as described in
[20] .
[0007] This disclosure provides glass, glass plates, and optical filters that achieve both sufficient infrared cut performance in a thin plate and high visible light transmittance, as well as an image sensor, mobile communication device, and imaging device equipped with the optical filter.
[0008] These are the transmittance spectra of the glass plates in Example 1, Example 2, and Example 31.
[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 this disclosure, a transmittance of, for example, 90% or more in a specific wavelength range means that the transmittance does not fall below 90% across the entire wavelength range, i.e., the minimum transmittance in that wavelength range is 90% or more. Similarly, a transmittance of, for example, 1% or less in a specific wavelength range means that the transmittance does not exceed 1% across the entire wavelength range, i.e., the maximum transmittance in that wavelength range is 1% or less. The same applies to reflectance. The average transmittance and average reflectance in a specific wavelength range are the arithmetic mean of the transmittance or reflectance for every 1 nm in that wavelength range. Spectral characteristics can be measured using an ultraviolet-visible spectrophotometer.
[0011] [Glass] The glass according to the first embodiment of the present disclosure is characterized in that, 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 wavelengths of 900 nm to 1000 nm. ４００ t represents the light transmittance including external reflection at a wavelength of 400 nm, and t represents the plate thickness (mm).
[0012] 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.
[0013] 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.
[0014] 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.
[0015] The method for calculating OD is as follows: First, the wavelength λ is of interest. ０ or wavelength range λ １ from λ ２The 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 light transmittance including external reflection at wavelength λ (nm). If the wavelength of interest is a single point, 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.
[0016]
[0017] (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.
[0018] In the first 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 indicates the light transmittance, including external reflection, at a wavelength of 1200 nm.
[0019] 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.
[0020] The glass of the first embodiment is preferably phosphate glass containing 10 to 30% Cu by cation percentage. Phosphate glass containing 10% or more Cu is excellent in terms of infrared cut performance and yields glass with large α and γ values. Since the Cu content of the glass of the first embodiment is 30% or less, it has excellent visible light transmittance and yields glass with a small β value. In the glass of the first embodiment, the Cu content is preferably 12 to 28% by cation percentage, and more preferably 15 to 25%.
[0021] The glass according to the second embodiment of this disclosure contains the following components in terms of cation percentage, and the atomic ratio of O to P (O / P) is 2.7 to 3.4. P: 55-75%, Al: 0-20%, Cu: 10-30%, Li: 0-15%, Na: 0-15%, K: 0-15%, Cs: 0-15%, Mg: 0-10%, Ca: 0-10%, Sr: 0-10%, Ba: 0-10%, Zn: 0-10%, ΣR': 0-30%, ΣR'': 0-10%, ΣM: 0-10%. However, ΣR' represents the total amount of Li, Na, K, and Cs, ΣR'' represents the total amount of Mg, Ca, Sr, Ba, and Zn, and ΣM represents the total amount of Y, Yb, In, La, Ce, B, Si, Ti, Zr, Ge, Nb, Ta, W, and Mo.
[0022] Because the glass of the second embodiment has the above composition, it achieves both excellent infrared cut performance and visible light transmittance, and also has excellent weather resistance.
[0023] This glass contains 55-75% phosphorus (P). P is primarily 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 55% or more, the effect can be obtained sufficiently, and if it is 75% or less, problems such as glass instability or reduced weather resistance are less likely to occur. The content of P is preferably 56% or more, more preferably 57% or more, and even more preferably 58% or more. Furthermore, the content of P is preferably 74% or less, more preferably 73% or less, even more preferably 72% or less, and particularly 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.
[0024] This glass may contain 0-20% 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(PO３ ) ３ The following can be used.
[0025] This glass contains 10-30% Cu. Cu is mainly Cu ＋ or Cu ２＋ It is contained in a concentration of 10-30%. A Cu content of 10% or more provides excellent infrared blocking performance. Furthermore, a Cu content of 30% or less provides excellent visible light transmittance. The Cu content is preferably 11% or more, more preferably 12% or more, even more preferably 13% or more, and particularly preferably 14% or more. On the other hand, the Cu content is preferably 29% or less, more preferably 28% or less, even more preferably 27% or less, and particularly preferably 26% or less. Also, from the viewpoint of visible light transmittance and infrared blocking performance, 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 ,Cd ２ P ２ O ７ The following can be used.
[0026] This glass may contain 0-15% 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.
[0027] This glass may contain 0-15% 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 14% or less, more preferably 13% or less, even more preferably 12% or less, and particularly preferably 10% or less.
[0028] This glass may contain 0-15% 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 13% or less, even more preferably 12% or less, and particularly preferably 10% or less.
[0029] This glass may contain 0-15% 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.
[0030] In this glass, the total amount of Li, Na, K, and Cs (ΣR') is 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 25% or less, and even more preferably 10% or less. As raw materials for R', carbonates, nitrates, hydroxides, metaphosphates, orthophosphates, etc., can be used.
[0031] This glass may contain 0-10% 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 the vitrification process, and increase the strength of the glass. From the viewpoint of vitrification stability and infrared-cutting performance, the Mg content is preferably 8% or less, more preferably 6% or less, even more preferably 5% or less, and particularly preferably 3% or less.
[0032] This glass may contain 0-10% Ca. Ca is mainly Ca ２＋ It is contained as Ca 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 Ca content is preferably 9% or less, more preferably 8% or less, even more preferably 7% or less, and particularly preferably 6% or less.
[0033] This glass may contain 0-10% 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 9% or less, more preferably 8% or less, even more preferably 7% or less, and particularly preferably 6% or less.
[0034] This glass may contain 0-10% 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-cutting performance, the Ba content is preferably 9% or less, more preferably 8% or less, even more preferably 7% or less, and particularly preferably 6% or less.
[0035] Furthermore, this glass may contain Zn. The Zn is mainly Zn２＋ 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 0 to 10%, more preferably 8% or less, even more preferably 7% or less, and particularly preferably 6% or less.
[0036] In this glass, the total amount of Mg, Ca, Sr, Ba, and Zn (ΣR'') is 0 to 10%. 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 10% or less, preferably 9% or less, and more preferably 8% or less. As raw materials for R'', carbonates, nitrates, hydroxides, metaphosphates, orthophosphates, fluorides, etc., can be used.
[0037] This glass may contain one or more elements selected from Y, Yb, In, La, Ce, B, Si, Ti, Zr, Ge, Nb, Ta, W, and Mo in a total amount (ΣM) of 0 to 10%. The inclusion of these elements improves the weather resistance of the glass. From the viewpoint of weather resistance, ΣM is preferably 0.2% or more, more preferably 0.5% or more, and even more preferably 1% or more. Furthermore, this glass preferably contains Nb among these elements. 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.
[0038] In order to improve infrared-cutting performance, the atomic ratio of O to P (O / P) of this glass is preferably 2.7 to 3.4, more preferably 2.7 to 3.3, and even more preferably 2.7 to 3.2.
[0039] This glass 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.
[0040] This glass 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.
[0041] The glass of the second embodiment may further satisfy the characteristics of the first embodiment. Furthermore, the glass of the first embodiment may satisfy the composition of the glass of the second embodiment. The following describes preferred configurations and characteristics common to the glass of the first and second embodiments.
[0042] In this embodiment, the glass is a powder with a particle size of 53 μm to 106 μm, and the weight increase rate from the initial weight after holding approximately 33 mg of the powder in an environment of 85°C and 85% relative humidity for 24 hours is preferably 45% or less, more preferably 35% or less, and even more preferably 25% or less.
[0043] (Method for measuring weight increase rate) The glass to be measured is crushed into powder as necessary. Any crushing method is acceptable, such as wet crushing, dry crushing, or jet milling. The obtained powder is separated using test sieves with mesh sizes of 53 μm and 106 μm to obtain test powder with particle sizes of 53 μm to 106 μm. Approximately 33 mg of this test powder (actual measured weight is W ０ The substance (as defined below) is placed in a container and left to stand in a constant temperature and humidity chamber. After standing for 24 hours under conditions of 85°C and 85% relative humidity, the weight is measured, and the weight increase ΔW can be measured by subtracting the initial weight W0 from the container weight. ΔW is then calculated from the initial weight W0. ０ The weight increase rate can be calculated by dividing by the given value and expressing it as a percentage. Note that "approximately 33 mg" refers to a weight within the range of "33 mg ± 1.0 mg".
[0044] From the viewpoint of suppressing the generation of bubbles, when the glass of this embodiment is formed into a plate shape, βOH represented by the following formula (4) is 0.05 to 4.0 mm －１ is preferably, 0.1 to 3.5 mm －１ is more preferable. βOH = (1 / t)log(τ １ / τ ２ ) …(4) However, t represents the plate thickness (mm), and τ １ represents the light transmittance at a wave number of 4000 cm －１ , and τ ２ represents the minimum value of the light transmittance at a wave number of 2700 to 3450 cm －１ .
[0045] (Measurement method of light transmittance τ １ , τ ２ ) The measurement method of the light transmittance is the same as that of the above T ９００－１０００ and T ４００ . However, for the measurement of the transmittance τ １ , τ ２ , a Fourier transform infrared spectrophotometer (FT-IR) is used.
[0046] For the glass of this embodiment, from the viewpoint of suppressing the movement of cations by improving the packing of constituent atoms, the density is preferably 2.60 g / cm
[0047] ３ or more, and more preferably 2.80 or more. On the other hand, from the viewpoint of weight reduction, the density is preferably 3.50 g / cm ３ or less, and more preferably 3.30 g / cm ３ or less. The density can be measured by the Archimedes method.
[0048] The glass of this embodiment 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.
[0049] When the glass of this embodiment 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.
[0050] 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 of this embodiment has a CTE within the temperature range of 100°C to 300°C. Furthermore, the CTE of the glass of this embodiment 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 / ℃.
[0051] The glass of this embodiment can be suitably used as an optical filter or a substrate for an optical filter because it achieves both sufficient infrared blocking performance in a thin sheet and high visible light transmittance.
[0052] [Glass Plate] The glass plate of the present disclosure is made of the glass of the present disclosure and is characterized by having a plate thickness of 10 μm to 300 μm. The plate thickness is preferably 280 μm or less, more preferably 250 μm or less, and particularly preferably 200 μm or less. Since the glass plate is made of the first or second glass, it achieves both infrared cut performance and high visible light transmittance.
[0053] In this embodiment, the glass plate preferably has a β of 1.76 or less, more preferably 1.33 or less, even more preferably 0.98 or less, and particularly preferably 0.68 or less. In addition, the glass plate in this embodiment preferably has an α of 12 or more, even more preferably 16 or more, and particularly preferably 20 or more.
[0054] Furthermore, the glass plate of this embodiment is superior in terms of visible light transmittance, and in the wavelength range of 550 to 850 nm, the wavelength of the first light that satisfies the following equation (5) when viewed from the long wavelength side is λ 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 indicates the light transmittance including external reflection at wavelength X nm, where X is between 550 nm and 850 nm, and t is the plate thickness (mm).
[0055] [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.
[0056] 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.
[0057] According to the above embodiment, an optical filter can be realized that exhibits excellent transmittance in the visible light region and shielding in the near-infrared light region. 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.
[0058] [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.
[0059] The present invention will be described in more detail below using examples, but the present invention is not limited to these examples. Examples 1 and 2 are comparative examples, and Examples 3 to 101 are examples.
[0060] [Glass Manufacturing] The raw materials were weighed and mixed to achieve the compositions shown in Tables 1 to 10, 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 glass sample in the form of a plate measuring 40 mm (length) x 30 mm (width) x approximately 0.1 mm to 0.3 mm (thickness) with both sides optically polished was obtained. In the tables, the numerical values for the elements that cationize 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 / M" column indicates that the element corresponding to M is not present.
[0061] 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.
[0062] <Measurement Method> Weight Increase: Glass was crushed using a stamp mill and an agate mortar, and the resulting glass particles were classified using a stainless steel sieve. Glass particles that passed through the 106 μm sieve but not the 53 μm sieve were weighed using an electronic balance to a weight of approximately 33 mg. ０ The following was recorded. The weighed glass granules were lightly spread evenly in an aluminum pan with a diameter of 6 mm and a height of 5 mm. The aluminum pan containing the glass was moved to a high-temperature, high-humidity chamber and left to stand for 24 hours in an environment of 85°C and 85% relative humidity. After the predetermined time had elapsed, the aluminum pan was removed, cooled to room temperature, and then weighed again using an electronic balance. The weight W was obtained by subtracting the weight of the aluminum pan. ２４ The weight increase ΔW was measured. The weight increase ΔW is given by ΔW = (W ２４ ―W ０ ) is calculated, and the weight increase rate is ΔW / W ０The values were calculated using a multiplication factor of 100. Tg: 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 of the inflection point corresponding to the glass transition was determined from the obtained DSC chart. Density: Measured at 25°C using the Archimedes method with pure water. CTE: A cylindrical sample with a diameter of 5 mm and a height of 20 mm was measured using a thermomechanical analyzer (Bruker, 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. The results are shown in the table. A "-" in the physical properties column indicates that the measurement was not performed.
[0063]
[0064]
[0065]
[0066]
[0067]
[0068]
[0069]
[0070]
[0071]
[0072]
[0073] As shown in Tables 1 to 10, the glass in Examples 3 to 101 demonstrated excellent weather resistance while simultaneously achieving both infrared-cutting performance and high visible light transmittance.
[0074] 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. Glass in which, when formed into a plate and the two opposing main surfaces are polished to a mirror finish, α, represented by the following formula (1), is 12 or greater, 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 wavelengths of 900 nm to 1000 nm. ４００ t represents the light transmittance including external reflection at a wavelength of 400 nm, and t represents the plate thickness (mm).
2. The glass according to claim 1, wherein, when formed into a plate, 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 indicates the light transmittance, including external reflection, at a wavelength of 1200 nm.
3. The glass according to claim 1 or 2, which is a phosphate glass containing 10 to 30% Cu by cation percentage.
4. A glass containing 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: 55-75%, Al: 0-20%, Cu: 10-30%, Li: 0-15%, Na: 0-15%, K: 0-15%, Cs: 0-15%, Mg: 0-10%, Ca: 0-10%, Sr: 0-10%, Ba: 0-10%, Zn: 0-10%, ΣR': 0-30%, ΣR'': 0-10%, ΣM: 0-10%. However, ΣR' represents the total amount of Li, Na, K, and Cs, ΣR'' represents the total amount of Mg, Ca, Sr, Ba, and Zn, and ΣM represents the total amount of Y, Yb, In, La, Ce, B, Si, Ti, Zr, Ge, Nb, Ta, W, and Mo.
5. The glass according to claim 4, wherein the ΣR' is 10% or less.
6. The glass according to claim 4 or 5, wherein the ΣM is 1 to 10%.
7. The glass according to claim 4 or 5, wherein the cation percentage ratio of Nb to ΣM (Nb / ΣM) is 0.5 to 1.
0.
8. The glass according to claim 1 or 4, wherein the powder has a particle size of 53 μm to 106 μm, and the weight increase rate after holding approximately 33 mg of the powder in an environment with a temperature of 85°C and a relative humidity of 85% for 24 hours is 45% or less.
9. The glass according to claim 1 or 4, wherein the fluorine content is 1% by mass or less.
10. When formed into a plate shape, βOH represented by the following formula (4) is 0.05 to 4.0 mm －１ The glass according to claim 1 or 4, wherein βOH=(1 / t)log(τ １ / τ ２ )...(4) However, t represents the plate thickness (mm), and τ １ represents the light transmittance at a wave number of 4000 cm －１ , and τ ２ represents the minimum value of the light transmittance at a wave number of 2700 cm －１ to 3450 cm －１ .
11. The glass according to claim 1 or 4, wherein the glass transition temperature Tg is 385°C or higher.
12. The average coefficient of thermal expansion (CTE) from 100°C to 300°C is 50 × 10⁻⁶. －７ / ℃~95×10 －７ The glass according to claim 1 or 4, wherein the temperature is / ℃.
13. A glass plate made of the glass described in claim 1 or 4, having a thickness of 10 μm to 300 μm.
14. The glass plate according to claim 13, wherein β, represented by the following formula (2), is 1.33 or less. β = {-log(T ４００ ( / 100) - 0.036} / t ... (2) where T ４００ t represents the light transmittance including external reflection at a wavelength of 400 nm, and t represents the plate thickness (mm).
15. The glass plate according to claim 13, wherein β is 0.98 or less.
16. The glass plate according to claim 13, wherein β is 0.68 or less.
17. The glass plate according to claim 13, wherein α, represented by the following formula (1), is 16 or greater. α = {-log(T ９００－１０００ ( / 100) - 0.018} / t ... (1) where T ９００－１０００ t represents the average light transmittance including external reflection at wavelengths of 900 nm to 1000 nm, and t represents the plate thickness (mm).
18. In the wavelength range of 550 to 850 nm, the wavelength of light on the longest wavelength side that satisfies the following equation (5) is λ. １．３３ When that happens, the λ １．３３ A glass plate according to claim 13, wherein the wavelength is 570 nm or greater. {-log(T Ｘ ( / 100) - 0.018} / t = 1.33 ... (5) However, T Ｘ This indicates the light transmittance including external reflection at wavelength X nm, where X is between 550 nm and 850 nm, and t is the plate thickness (mm).
19. An optical filter for cutting near-infrared rays, comprising the glass plate described in claim 13.
20. An image sensor comprising the near-infrared cut optical filter described in claim 19.
21. A mobile communication device or imaging device comprising the image sensor described in claim 20.