JP5609754B2 - Near-infrared cut filter glass - Google Patents

Description

  The present invention relates to a near-infrared cut filter glass used for a visibility correction filter of a solid-state imaging device.

  Digital still cameras and video cameras use solid-state image sensors such as CCDs and CMOSs as image sensors. In recent years, these cameras have improved the image resolution accompanying the increase in the number of pixels. On the other hand, if the number of pixels is increased without increasing the light receiving area of the solid-state imaging device, the area of the unit pixel size is reduced. Due to the decrease in the absolute amount of incident light, the number of electrons for each pixel that is the source of the output signal decreases, causing a problem that the sensor sensitivity decreases.

On the other hand, several methods for improving the sensitivity of the solid-state imaging device have been proposed, and one of them is a method of increasing the thickness of the semiconductor layer of the device (Patent Document 1: Paragraph). 0006). According to this, the thicker the semiconductor layer is, the more light is absorbed, and the current output corresponding to the amount of light is increased.
However, when the film thickness of the semiconductor layer is increased, another problem arises that the sensitivity of the long wavelength component (light in the infrared region) increases. This is described in detail in Patent Document 2 (paragraphs 0018 and 0094), but in summary, the absorption coefficient of electromagnetic waves by the semiconductor layer is longer in the longer wavelength component than in the shorter wavelength component. There is a characteristic that it is small. This means that the component on the short wavelength side of the electromagnetic wave incident on the semiconductor layer has a large proportion of absorption in the semiconductor layer and is largely absorbed on the surface of the semiconductor layer, whereas on the long wavelength side This component means that since the absorption ratio in the semiconductor layer is small, the degree of absorption at the surface of the semiconductor layer is small and it reaches a deeper place. For this reason, when the sensitivity of the solid-state imaging device is improved by increasing the film thickness of the semiconductor layer, it is necessary to cut the long wavelength component in the incident light to the solid-state imaging device more reliably than before.

  On the other hand, since the solid-state imaging device has spectral sensitivity ranging from the visible region to the near infrared region in the vicinity of 1100 nm, good color reproducibility cannot be obtained as it is. Therefore, the visibility is corrected using a near-infrared cut filter glass to which a specific substance that absorbs infrared rays is added. This near-infrared cut filter glass has been proposed as an optical glass in which CuO is added to an aluminophosphate-based glass or fluorophosphate-based glass so as to selectively absorb light in the near-infrared region and to have high weather resistance. (Patent Documents 3 and 4).

JP 2004-119494 A JP 2009-135550 A JP-A-6-234546 Japanese Patent Laid-Open No. 6-16451

However, the spectral characteristics of the conventional near-infrared cut filter glass have a problem that a steep cut-off characteristic cannot be realized particularly in a wavelength region near 600 to 700 nm. Therefore, there is a demand for a glass having spectral characteristics that can selectively cut light in the near infrared region while maintaining high visible region transmittance.
As a method for improving the near-infrared light cutting performance of the near-infrared cut filter glass, the following methods are known.
One method is to increase the amount of CuO added to the glass containing a Cu ²⁺ component that absorbs light in the near infrared region. However, simply increasing the amount of CuO added can reduce the near-infrared transmittance, but also has a negative effect of reducing the visible transmittance.

As another method, a dielectric multilayer film (near infrared cut film) in which several tens of dielectric thin films having different refractive indexes are alternately laminated is formed on the optical action surface of the near infrared cut filter glass. In order to compensate for the near-infrared cutting property of glass. Unlike the light absorption effect by the Cu ²⁺ component in the glass, the mechanism for cutting light in the near-infrared region by the dielectric multilayer film is based on the light reflection effect due to the interference of substances having a refractive index difference. Cut-off characteristics can be realized. However, near-infrared light incident on the dielectric multilayer film is reflected by the dielectric multilayer film but becomes stray light in the solid-state imaging device without being attenuated, and this stray light is incident on the dielectric multilayer film again obliquely. Therefore, there is a possibility that the dielectric multilayer film cannot be sufficiently cut and reaches the solid-state imaging device and is recognized as noise. In addition, this method has a problem that the manufacturing cost of the near infrared cut filter glass is increased.
The present invention has been made on the basis of such a background, and it is possible to achieve both high transmittance in the visible region and low transmittance in the near infrared region, and a near infrared ray having high weather resistance. It aims at providing cut filter glass at low cost.

As a result of intensive studies to achieve the above object, the present inventor made a conventional near-infrared cut made of phosphate glass or fluorophosphate glass by making the phosphate glass composition into a specific range. It has been found that a near-infrared cut filter glass capable of coexistence of increasing the visible region transmittance and decreasing the near-infrared region transmittance is obtained compared to the filter glass.
Specifically, for the copper ions in the glass component, the ratio of the Cu ²⁺ component having absorption in the near infrared region as much as possible is higher than the Cu ⁺ component that causes absorption in the ultraviolet region and lowers the transmittance in the visible region. To exist.
In addition, when the distortion of the structure of Cu ^{2+ in} the glass is small, attention is paid to the fact that the absorption of light in the near infrared region of Cu ²⁺ increases. It was thought that it was easy to coordinate and the distortion around Cu ²⁺ was reduced. This is because when the strain around Cu ²⁺ decreases, the energy difference between the bands of ² E _g → ² T _2g decreases, and the absorption peak of Cu ²⁺ moves to the longer wavelength side.
As a result, the present inventors have found a phosphate glass composition suitable as a near-infrared cut filter glass that has a high abundance ratio of Cu ^{2+ in} the glass and can make the absorption of light in the near-infrared region by Cu ²⁺ higher. .

The near infrared cut filter glass of the present invention is
In mass% display of the following oxide conversion,
P ₂ O ₅ 65-74%,
Al ₂ O ₃ 5-10%,
B ₂ O ₃ 0.5~3%,
Li ₂ O 0-10%,
Na ₂ O 3-10%,
Li ₂ O + Na ₂ O 3-15%,
MgO 0-2%,
CaO 0-2%,
SrO 0-5%,
BaO 3-9%,
MgO + CaO + SrO + BaO 3-15%,
CuO 0.5-20%,
And substantially free of K ₂ O,
Na ₂ O / (Li ₂ O + MgO + CaO + SrO + BaO) 0.5-3,
It is characterized by being.

The near infrared cut filter glass of the present invention is
_{P 2 O 5 / Al 2 O} 3 6.5~10,
(BaO + B ₂ O ₃ ) / Al ₂ O ₃ 0.3-2.4,
It is characterized by being.
Further, the near-infrared cut filter glass of the present invention is characterized by substantially not containing F, PbO, As ₂ O ₃ , Sb ₂ O ₃ , CeO ₂ , V ₂ O ₅ , SiO ₂ , or a rare earth element. .

  According to the present invention, by setting the phosphate glass composition to a specific range, the visible light transmittance can be increased without increasing the CuO content in the glass or providing a dielectric multilayer film (near infrared cut film). It is possible to provide a near-infrared cut filter glass that can keep the transmittance of light in the near-infrared region low while maintaining a high value at low cost.

It is a figure which shows the spectral transmittance of the near-infrared cut filter glass of an Example and a comparative example. It is a figure which shows the relationship between the wave number of the absorption peak of Cu2 ⁺ , and the field strength of each element.

  The object of the present invention is achieved by the above configuration, and the reason why the contents (mass% display) of the respective components constituting the near infrared cut filter glass of the present invention are limited as described above will be described below.

P ₂ O ₅ is a main component (glass-forming oxide) that forms glass, and is an essential component for enhancing near-infrared cutting properties. However, if it is less than 65%, the effect cannot be obtained sufficiently, and 74% If it exceeds, the melting temperature rises and the transmittance in the visible region is lowered, which is not preferable. Preferably it is 67 to 73%, more preferably 68 to 72%.

Al ₂ O ₃ is an essential component for enhancing the weather resistance, but if it is less than 5%, the effect cannot be sufficiently obtained, and if it exceeds 10%, the melting temperature of the glass becomes high, the near-infrared cutting property and the visible range. This is not preferable because the permeability is lowered. Preferably it is 6-10%, More preferably, it is 7-9%.

B ₂ O ₃ is an essential component for lowering the melting temperature of the glass, but if it is less than 0.5%, the effect cannot be sufficiently obtained, and if it exceeds 3%, the near-infrared cutting property is lowered, which is not preferable. . Preferably it is 0.7 to 2.5% or less, More preferably, it is 0.8 to 2.0%.

Although Li ₂ O is not an essential component, it has an effect of lowering the melting temperature of the glass. However, if it exceeds 10%, the glass becomes unstable, which is not preferable. Preferably it is 0 to 5%, more preferably 0 to 3%.

Na ₂ O is an essential component for lowering the melting temperature of the glass, but if it is less than 3%, the effect cannot be sufficiently obtained, and if it exceeds 10%, the glass becomes unstable. Preferably it is 4-9%, More preferably, it is 5-9%.

Li ₂ O + Na ₂ O is an essential component for lowering the melting temperature of the glass, but if it is less than 3%, the effect is not sufficient, and if it exceeds 15%, the glass becomes unstable, which is not preferable. Preferably it is 4-13%, More preferably, it is 5-10%.

K ₂ O is not substantially contained in the glass of the present invention. K ₂ O is known to have an effect of lowering the melting temperature of glass. However, the present inventors have confirmed that when the phosphoric acid glass contains both K ₂ O and Na ₂ O, the melting temperature of the glass is lower than when K ₂ O is not contained but only Na ₂ O is contained. The result became higher. The reason can be considered as follows. The liquidus temperature in the case of equimolar mixing of P ₂ O ₅ and Na ₂ O is about 628 ° C. from the two-component phase diagram. On the other hand, the liquidus temperature in the case of equimolar mixing of P ₂ O ₅ and K ₂ O exceeds 800 ° C. from the phase diagram of the two-component system. This suggests that in the phosphate glass, when a part of Na ₂ O is replaced with K ₂ O, the liquidus temperature increases and the melting temperature also increases. In addition, in the present invention, “not containing substantially” means not intentionally using as a raw material, and it is regarded as substantially free of raw material components and inevitable impurities mixed in from the manufacturing process. Further, considering the inevitable impurities, the fact that it does not contain substantially means that the content is 0.05% or less.

  Although MgO is not an essential component, it has the effect of increasing the stability of the glass. However, if it exceeds 2%, the near-infrared cutting property is deteriorated, which is not preferable. Preferably it is 1% or less, and it is more preferable not to contain.

  Although CaO is not an essential component, it has the effect of increasing the stability of the glass. However, if it exceeds 2%, the near-infrared cutting property is deteriorated, which is not preferable. Preferably it is 1.5% or less, and it is more preferable not to contain.

  Although SrO is not an essential component, it has an effect of increasing the stability of the glass. However, if it exceeds 5%, the near-infrared cutting property is lowered, which is not preferable. Preferably it is 0 to 4%, more preferably 0 to 3%.

  BaO is an essential component for lowering the melting temperature of glass, but if it is less than 3%, the effect cannot be sufficiently obtained, and if it exceeds 9%, the glass becomes unstable, which is not preferable. Preferably it is 3-8%, More preferably, it is 4-8%.

  MgO + CaO + SrO + BaO is an essential component for increasing the stability of the glass and lowering the melting temperature of the glass. However, if it is less than 3%, the effect is not sufficient, and if it exceeds 15%, the glass becomes unstable. It is not preferable. Preferably it is 3-12%, More preferably, it is 4-10%.

  CuO is an essential component for improving the near-infrared cutting property, but if it is less than 0.5%, the effect cannot be sufficiently obtained, and if it exceeds 20%, the visible region transmittance is lowered, which is not preferable. Preferably it is 1 to 15%, more preferably 2 to 10%. Most preferably, it is 3 to 9%.

In the near-infrared cut filter glass of the present invention, in order to obtain a spectral characteristic having a high visible region transmittance and a low near-infrared region light transmittance, the copper ion in the glass component has absorption in the ultraviolet region and is visible region. It is important that Cu ²⁺ having absorption in the near-infrared region is present as much as possible as compared to Cu ⁺ that causes a decrease in transmittance.
Copper in the glass component tends to be reduced as the melting temperature of the glass increases, that is, Cu ²⁺ is reduced to Cu ⁺ . Therefore, in order to make much Cu ²⁺ exist, it is effective to make the melting temperature of the glass as low as possible. In addition, the melting temperature of the near-infrared cut filter glass of the present invention is preferably 1150 ° C. or lower, more preferably 1100 ° C. or lower, and further preferably 1080 ° C. or lower.
Therefore, the ratio of BaO and B ₂ O _{3 having} the effect of lowering the glass melting temperature is increased with respect to Al ₂ O ₃ having the effect of increasing the glass melting temperature. The balance in these glass components may be (BaO + B ₂ O ₃ ) / Al ₂ O ₃ , but if it is too large, the weather resistance will be lowered, so these ratios are 0.3 to 2.4. Range. Furthermore, these ratios are preferably 0.3 to 2.0, and more preferably 0.5 to 1.5.

In the near-infrared cut filter glass of the present invention, in order to obtain a spectral characteristic having a high visible region transmittance and a low near-infrared region light transmittance, specifically, a steep cut-off property of light in the vicinity of 600 to 700 nm. Reduces the distortion of the Cu ²⁺ 6-coordinate structure in the glass and shifts the absorption peak of Cu ²⁺ to the longer wavelength side, that is, makes the absorption of light in the near infrared region by Cu ²⁺ in the glass more functional. This is very important.
Therefore, in order to reduce the distortion of the Cu ²⁺ hexacoordinate structure in the glass, the number of non-bridging oxygens in the glass is large, and the field strength of the modified oxide (the field strength is the valence Z The value divided by the square of r: Z / r ² , which represents the degree of strength with which the cation attracts oxygen, was thought to be small.

In order to increase the number of non-bridging oxygen in the glass, it is necessary to increase the amount of P ₂ O ₅ in the network oxide forming the glass network compared to other network oxides. Since P ₂ O ₅ contains more oxygen in the molecule than Al ₂ O ₃ or B ₂ O ₃ , Cu ²⁺ easily coordinates non-bridging oxygen, and strain around Cu ²⁺ is reduced. On the other hand, in order to increase the weather resistance of the glass, it is effective to increase the ratio of Al ₂ O ₃ having an influence on the weather resistance in the ratio with P ₂ O ₅ .
Therefore, the balance of the network oxide contained in the glass is such that P ₂ O ₅ / Al ₂ O ₃ is in the range of 6.5 to 10. Furthermore, these ratios are preferably 7 to 10, and more preferably 7 to 9.5.

Regarding the field strength of the modified oxide in the glass, P ₂ O ₅ : 70%, Al ₂ O ₃ : 10%, CuO: 4%, X _n O (X is Li, Na, K, Ba, Sr, Ca, Zn represents Mg or Mg. When X is Li, Na, or K, n represents 2, and when X is Ba, Sr, Ca, Zn, or Mg, n represents 1.): 20 % (All moles are shown. 4% of CuO is added as an outer layer to 100% of P ₂ O ₅ , Al ₂ O ₃ and X _n O in total). FIG. 2 shows the relationship between the wave number of the absorption peak of Cu ²⁺ and the field strength of each element when the kind of certain X _n O is changed. It can be seen that the smaller the field strength of the modified oxide, the smaller the wave number of the absorption peak and the higher the light absorption of Cu ^{2+ in} the near infrared region.
Accordingly, in order to reduce the average value of the field strength of the modified oxide in the glass, it is effective to contain more Na ₂ O having a relatively small field strength than other modified oxides. I understand that.
Therefore, the balance of the modified oxide contained in the glass may be Na ₂ O / (Li ₂ O + MgO + CaO + SrO + BaO), but if it is too large, the weather resistance will be lowered, so these ratios are 0.5-3. Range. Furthermore, these ratios are preferably 0.5 to 2.5, and more preferably 0.7 to 2.

The glass of the present invention preferably contains substantially no F, PbO, As ₂ O ₃ , Sb ₂ O ₃ , CeO ₂ , V ₂ O ₅ , SiO ₂ or rare earth elements. F, As ₂ O ₃ , Sb ₂ O ₃ , and CeO ₂ are used in conventional glasses as excellent fining agents capable of generating a fining gas in a wide temperature range. PbO is used as a component that lowers the viscosity of the glass and improves manufacturing workability. However, since F, PbO, As ₂ O ₃ and Sb ₂ O ₃ are environmentally hazardous substances, it is desirable that they are not contained as much as possible. Further, CeO ₂ , V ₂ O ₅ , when contained in the glass, the transmittance in the visible region of the glass is lowered, so in the near infrared cut filter glass of the present invention that is required to have a high visible region transmittance, It is desirable not to contain as much as possible. Further, when SiO ₂ and rare earth elements are contained in the glass, the near-infrared cut property of the glass is lowered, so that it is preferably not contained in the near-infrared cut filter glass of the present invention.

  The spectral characteristics of the near-infrared cut filter glass of the present invention are as follows. When the spectral transmittance at a wavelength of 600 to 700 nm is converted so that the wavelength at which the transmittance is 50% is 631 nm, the average transmittance at a wavelength of 430 to 565 nm is It is preferably 87.2% or more, more preferably 87.5% or more, and further preferably 88.0% or more. Similarly, the average transmittance at a wavelength of 700 to 725 nm is preferably 10% or less, more preferably 9.5% or less, and further preferably 9% or less. Similarly, the average transmittance at a wavelength of 1000 to 1200 nm is preferably 3% or less, more preferably 2.5% or less, and further preferably 2% or less.

  The near-infrared cut filter glass of the present invention can be produced as follows. First, the raw materials are weighed and mixed so that the obtained glass has the above composition range. This raw material mixture is accommodated in a platinum crucible and heated and melted at a temperature of 900 to 1200 ° C. in an electric furnace. After sufficiently stirring and clarifying, it is cast into a mold, slowly cooled, then cut and polished to form a flat plate having a predetermined inner thickness.

  The near-infrared cut filter glass of the present invention is also characterized in that the glass is stable by having the above glass configuration. “Stable glass” includes two things: stability in the temperature range near the liquidus temperature and stability in the temperature range near the glass transition point Tg. Specifically, the stability in the temperature range near the liquidus temperature is that the liquidus temperature is low and the growth of devitrification is slow near the liquidus temperature, and the temperature range near the glass transition point Tg. The stability in is that the crystallization temperature Tc and the crystallization start temperature Tx are high, and the growth of devitrification is slow in the vicinity of Tc · Tx. Thereby, it is possible to obtain a glass that is less likely to be devitrified in the glass melt molding process and that is easy to manufacture with a high yield.

The near-infrared cut filter glass of the present invention is excellent in near-infrared cutability as described above, and is excellent in devitrification resistance because it is a stable glass. For this reason, it can be suitably used as a visibility correction filter for a solid-state imaging device.
And without increasing the content of CuO in the glass or providing a dielectric multilayer film (near infrared cut film), the near infrared cut filter glass cuts light in the near infrared range while maintaining a high visible range transmittance. It is possible to improve the property. In order to obtain desired spectral characteristics, it is naturally possible to provide a dielectric multilayer film (near infrared cut film) in the near infrared cut filter glass of the present invention, but it is provided because the near infrared cut property of the glass is high. It is possible to reduce the number of layers of the dielectric multilayer film, and even when the dielectric multilayer film is provided on the glass, the manufacturing cost of the near-infrared cut filter glass can be reduced as compared with the conventional case.

Examples and Comparative Examples of the present invention are shown in Tables 1 and 2. In this specification, Examples 1 to 8 are examples, and Examples 9 to 11 are comparative examples. In the table, the blank of each component means that the content is 0% by mass.
These glasses weigh and mix the raw materials so as to have the composition (mass%) shown in the table, put them in a platinum crucible with an internal volume of about 1000 cc, melt at 900-1200 ° C for 1-3 hours, clarify, and stir, The sample was cast into a rectangular mold having a length of 100 mm × width 100 mm × height 20 mm preheated to about 100 to 400 ° C., and then slowly cooled at about 1 ° C./minute to obtain a sample. Moreover, it observed visually at the time of the said sample preparation, and confirmed that there was no bubble and striae in the obtained glass sample. In addition, the raw material of each glass is H ₃ PO ₄ or a metaphosphate raw material in the case of P ₂ O ₅ , Al (PO ₃ ) ₃ or Al (OH) ₃ in the case of Al ₂ O ₃ , B ₂ O _{3 H} 3 BO ₃ in the case of the LiCO ₃ for Li ₂ O, the NaCO ₃ in the case of Na ₂ O, the KCO ₃ for _{K 2} O, in the case of MgO and MgO, if the CaO Used CaCO ₃ , SrCO ₃ for SrO, BaPO ₃ for BaO, and CuO for CuO.

  About the glass produced as mentioned above, spectral characteristics and glass melting temperature were evaluated by the following methods.

Spectral characteristics were evaluated using an ultraviolet-visible near-infrared spectrophotometer (trade name: V-570, manufactured by JASCO Corporation). Specifically, a glass sample in which both sides of 30 mm long × 30 mm wide × 0.3 mm thick were optically polished was prepared, and the transmittance was measured. About the measured transmittance, the transmittance characteristic converted so that the wavelength at which the transmittance is 50% is 631 nm, the average transmittance of the wavelength 430 nm to 565 nm, the average transmittance of the wavelength 700 nm to 725 nm, the wavelength 1000 nm to 1200 nm The average transmittance is calculated in the table.
In the above, the spectral characteristic of the glass is a transmittance characteristic that is converted (half-value correction) so that the wavelength at which the transmittance is 50% is 631 nm. This is because the transmittance of the glass varies depending on the thickness, but if it is a homogeneous glass, the transmittance of a predetermined thickness can be obtained by calculation if the thickness and transmittance of the glass in the direction of light transmission are known. This is because it can. As a specific method of half-value correction, the absorption coefficient of glass is obtained from the transmittance measured with an ultraviolet-visible near-infrared spectrophotometer and the reflectance calculated from the refractive index of the glass, and the transmittance at a wavelength of 631 nm is obtained. The wall thickness that is 50% is calculated and converted to the transmittance at this wall thickness.
As for the melting temperature of the glass, the glass block melted at different temperatures is visually observed, and the lowest temperature at which no contamination is observed is shown in the table.

From the spectral characteristics of the glass of Example and Comparative Example shown in FIG. 1 and Table, each glass of the Example has a higher average transmittance at wavelengths of 430 to 565 nm than those of Comparative Example, and wavelengths of 700 to 800 nm and The average transmittance at a wavelength of 1000 to 1200 nm is suppressed to a low level, and both the near-infrared light cutting property and the high visible light transmittance are compatible. Example 9 of the comparative example has a high transmittance in the visible region, but the near-infrared region has a poor light-cutting property. Examples 10 and 11 have good near-infrared region light-cutting properties, but the visible-region transmittance is low. Low. As one of the factors that cause such spectral characteristics, it is considered that each glass of the example has a lower melting temperature of the glass than each glass of the comparative example.
For this reason, the near-infrared cut filter glass of the present invention eliminates the need to provide a near-infrared cut film (dielectric multilayer film) on the glass surface to supplement the near-infrared cut ability. It can be manufactured. Moreover, since the visible region transmittance of the glass is high and the near-infrared cut property is high, it can be suitably used as a near-infrared cut filter glass for a solid-state imaging device.

  As the weather resistance evaluation of the glass, the average transmittance deterioration degree of the visible region transmittance was investigated for the glasses of Example 1 (Example) and Example 9 (Comparative Example). As an investigation method, the transmittance of the glass before and after being held at a high temperature and high humidity for a predetermined time was measured, and the ratio of the decrease in the average transmittance at wavelengths of 430 nm to 565 nm was defined as the degree of deterioration. In addition, as conditions for high temperature and high humidity, the optically polished glass sample was held in a high temperature and high humidity tank having a temperature of 85 ° C. and a relative humidity of 85% for 168 hours. As a result, the glass of Example 1 had a degree of deterioration of 8.7%, and the glass of Example 10 had a degree of deterioration of 61.1%. Therefore, it turns out that the glass of this invention is equipped with the high weather resistance compared with the conventional phosphate glass.

According to the present invention, when the glass composition of the phosphate glass is set within a specific range, the abundance ratio of Cu ²⁺ in the copper ions in the glass is increased by lowering the melting temperature of the glass. Further, by reducing the field strength of the modified oxide, the absorption of light in the near infrared region by Cu ²⁺ in the glass can be made to function more highly. As a result, it is possible to provide a near-infrared cut filter glass capable of keeping the transmittance of light in the near infrared region low while maintaining the visible region transmittance high, at a low cost.

Claims (3)

In mass% display of the following oxide conversion,
P ₂ O ₅ 65-74%,
Al ₂ O ₃ 5-10%,
B ₂ O ₃ 0.5~3%,
Li ₂ O 0-10%,
Na ₂ O 3-10%,
Li ₂ O + Na ₂ O 3-15%,
MgO 0-2%,
CaO 0-2%,
SrO 0-5%,
BaO 3-9%,
MgO + CaO + SrO + BaO 3-15%,
CuO 0.5-20%,
And substantially free of K ₂ O,
Na ₂ O / (Li ₂ O + MgO + CaO + SrO + BaO) 0.5-3,
Near-infrared cut filter glass characterized by being. _{P 2 O 5 / Al 2 O} 3 6.5~10,
(BaO + B ₂ O ₃ ) / Al ₂ O ₃ 0.3-2.4,
The near-infrared cut filter glass according to claim 1, wherein Substantially _{F, PbO, As 2 O 3} , Sb 2 O 3, CeO 2, V 2 O 5, SiO 2, near infrared of claim 1 or claim 2, characterized in that does not include a rare earth element Cut filter glass.

Images