KR20180101761A - Near-infrared cut filter and Device including the same - Google Patents

Abstract

The present invention relates to a near-infrared ray cut filter comprising a near infrared ray absorbing layer and a near infrared ray reflecting layer on a transparent substrate. The near-infrared ray cut filter has a first absorption maximum in a 650 to 800 nm wavelength region. The wavelength range of an absorption band having transmittance of 1% or less in the wavelength region is wide. So, the dependence of incident light on an incident angle is small and a wide viewing angle is wide.

Description

[0001] The present invention relates to a near-infrared cut filter and a device including the near-infrared cut filter,

More particularly, the present invention relates to a near-infrared light blocking filter comprising a near-infrared absorbing layer and a near-infrared reflecting layer on a transparent substrate, having a first absorption maximum in a wavelength range of 650 to 800 nm, A near infrared ray having a second absorption maximum in a wavelength range of 800 to 1200 nm and a wavelength range of 650 nm to 800 nm and a wavelength range of absorption band of 1% or less in transmittance of 1% To a cut-off filter.

The NIR filter is a type of optical filter, and is a filter used in a camera module or the like. For example, a camera sensor can sense near infrared rays (700 to 1100 nm) as well as visible light (400 to 700 nm) required for image realization and recognize it as noise. When a near-infrared ray cut filter is used, It is possible to realize natural colors such as those seen by human eyes on the device. Accordingly, near infrared rays filters are used for digital cameras, smart phones, CCTV, vehicle front / rear sensing devices, and black box cameras. Normally, the NIR filter is bonded to the lens housing or VCA for autofocusing using a UV curing adhesive in the camera module, and is positioned directly above the CMOS image sensor.

On the other hand, the near-IR blocking filter can be classified into a reflective IR filter (RED IR filter) and an absorption type IR filter (Blue Filter).

The red IR filter is a type of reflective IR filter, which is referred to as a red IR filter because it looks reddish when viewed by eyes. Using a transparent glass substrate, a multilayer of SiO ₂ and TiO ₂ is coated thereon, and the difference in the refractive index of the coated material is utilized to maximally transmit visible light and shut off light in the near infrared region. Have been used in low-pixel-camera modules. The red IR filter has a structure in which a dielectric thin film (H layer) having a high refractive index and a dielectric thin film (L layer) having a low refractive index are alternately laminated on a glass substrate. Reflection / refraction of light due to a refractive index difference occurs at the interface between the H layer and the L layer, and the reflected / refracted light is superimposed on each other to cause an interference phenomenon to be reinforced / canceled, thereby blocking near infrared rays.

On the other hand, a blue filter (hybrid IR filter) is used as the absorption type IR filter, and a reflective coating is applied to a blue glass substrate which absorbs near-infrared light and transmits visible light, thereby removing near- When viewed from the naked eye, the substrate is referred to as a blue filter because it looks blue, and it is also called a hybrid type in view of the application of special glass and reflective coatings.

On the other hand, in the case of a cellular phone camera, when a reflection type filter is used in a high pixel (more than 5 mega pixels), slimness, and miniaturization tendency, there occurs a difference in the interference result depending on the incident light angle, There is a problem. Particularly, in the case of a mobile phone camera having a resolution of 8 megapixel pixels or more, when the reflection type filter is used, the color of the center portion and the peripheral portion of the image are different, and color blurring occurs. Therefore, recently, a high-resolution (8-megapixel or higher) mobile phone camera module adopts a blue filter which absorbs near infrared rays and can minimize changes in characteristics due to incident angle.

In the case of the blue filter, which is an absorption type IR filter, since the light of the infrared wavelength band is absorbed by the material itself, there is an advantage that the image difference problem of the peripheral part can be solved. However, in the case of the blue filter, there is a problem that the substrate material, blue glass, is weak in moisture and has a weaker blueglass strength than general transparent glass, so that there is a limit in making the filter thickness thinner.

Accordingly, there has been a demand for a filter product capable of solving the problem of strength and thickness, which is a drawback of conventional blue filters, due to the slimming of cellular phones and the like. Accordingly, visible light is transmitted with a thickness of 100 탆 or less, It is required to develop a new material capable of replacing a blue filter having a function of blocking near-infrared rays.

On the other hand, Japanese Unexamined Patent Application Publication Nos. 2005-338395, 2011-100084 and 2012-8532 disclose a near-infrared cut filter, a solid-state imaging device and a camera module having the same, There is a problem that the near infrared absorption effect or the viewing angle is not sufficient for use.

Japanese Laid-Open Patent Application No. 2005-338395 Japanese Laid-Open Patent No. 2011-100084 Japanese Laid-Open Patent Application No. 2012-8532

A problem to be solved by the present invention is to provide a near-infrared ray cut filter for a solid-state image pickup element having a small dependency on the incident angle of transmitted light and a wide viewing angle, and a solid-state image pickup device employing the same.

In order to solve the above technical problem, the present invention relates to a transparent substrate, which comprises a near infrared absorbing layer and a near infrared reflecting layer on a transparent substrate, and has i) a first absorption maximum in a wavelength range of 650 to 800 nm, ii) Wherein an absolute value of a difference between a longest wavelength (A1) having a transmittance of 1% and a shortest wavelength (A2) of 35 nm or more is provided.

The present invention further provides a near infrared ray blocking filter satisfying the following conditions: iii) a wavelength of 650 to 800 nm, wherein the near infrared ray reflecting layer has a transmittance of 50% and a near infrared ray absorbing layer has a transmittance of 50% And further has a second absorption maximum in the wavelength range of 1200 nm.

The present invention also provides a solid-state imaging device including a near-infrared ray blocking filter having near-infrared ray blocking characteristics as described above.

The near infrared ray blocking filter according to the present invention has an absorption maximum in a wavelength range of 650 to 800 nm and has a wavelength range of 35 nm or more in an absorption band with a transmittance of 1% or less in a wavelength region of 650 to 800 nm, a transmittance of 50% The transmittance of the near infrared ray absorbing layer is 50% and the deviation of the wavelength is 70 nm or more. As a result, it is possible to provide a near-infrared ray cut filter which has a small dependency on the incident angle, a wide viewing angle, less image distortion, and is thinner.

In addition, another near IR blocking filter according to the present invention may further have a second absorption maximum in a wavelength range of 800 to 1200 nm, thereby reducing manufacturing cost by reducing the number of reflection films.

FIG. 1 is a schematic diagram showing a structure of a near-infrared ray blocking filter according to an embodiment of the present invention.
FIGS. 2 to 6 are graphs showing light transmittance of a near-infrared cut filter according to an embodiment of the present invention and a comparative example.

Hereinafter, the present invention will be described in more detail with reference to examples.

The near infrared ray blocking filter according to one embodiment of the present invention is a near infrared ray blocking filter comprising a near infrared ray absorbing layer and a near infrared ray reflecting layer on a transparent substrate and having i) a first absorption maximum in a wavelength range of 650 to 800 nm, the absolute value of the difference between the longest wavelength (A1) with which the transmittance is 1% and the shortest wavelength (A2) is 35 nm or more.

The near infrared ray blocking filter according to another embodiment of the present invention is characterized in that iii) the deviation of the wavelength of the near infrared ray absorbing layer from the transmittance of 50% and the transmittance of the near infrared ray absorbing layer by 50% is 70 nm or more in the wavelength region of 650 to 800 nm .

In addition, the near-infrared cut-off filter according to another embodiment of the present invention is characterized in that the near-infrared absorption layer has a second absorption maximum in the range of 800 to 1200 nm.

The near infrared ray blocking filter according to the present invention is characterized in that a near infrared ray absorbing layer and a near infrared ray reflecting layer are formed on one surface or both surfaces of a transparent substrate. Specifically, the near-infrared absorbing layer can be prepared by coating an absorbing layer resin composition comprising a near-infrared absorbing dye, a binder resin and an organic solvent on one or both surfaces of a transparent substrate, drying the organic solvent, or curing the resin composition and drying have.

Examples of the transparent substrate usable in the present invention include a transparent glass substrate and a transparent resin substrate. Specific examples of the transparent resin substrate include an olefin resin, a polycarbonate resin, a polysulfone resin, a polyether sulfone resin, a polyarylate resin, a polyparaphenylene resin, a polyarylene ether phosphine oxide resin, a polyimide resin , A polyetherimide resin, a polyamideimide resin, an acrylic resin, a modified acrylic resin, and a polyethylene naphthalate resin, but the present invention is not particularly limited thereto. It is also possible to use a transparent substrate having an organic solvent blocking layer formed thereon. When such a substrate is used, there is an effect of preventing the organic solvent contained in the resin composition from being absorbed by the transparent resin substrate during the near infrared absorbing layer coating.

An absorption layer resin composition containing a near infrared absorbing dye, a binder resin and an organic solvent is coated on the transparent substrate to form a near infrared absorbing layer.

The absorption dye usable in the present invention is not particularly limited as long as it is a compound having an absorption maximum in a wavelength range of 650 to 800 nm or a wavelength range of 800 to 1200 nm. Based metal complex systems, metal complexes, metal complexes, metal complexes, metal complexes, metal complexes, metal complexes, metal complexes, Anthraquinone type, coumarin type, naphthoquinone type, and indophenol type compounds. Of these, at least one of them can be selected and used.

Among them, the squarylium compound has a small absorption of visible light in the absorption spectrum, an absorption peak at the maximum absorption wavelength (? _Max ), a steep slope at the visible light side, and a high storage stability and high light stability Therefore, it is preferable for use as an absorbent. Further, the dye containing a cyanine compound has a low absorption of visible light in the absorption spectrum, a high absorption rate of light on the long wavelength side in the wavelength region near the maximum absorption wavelength (? _Max ), low cost, It is known that it can secure stability. Further, the dye containing the phthalocyanine compound is excellent in heat resistance and weather resistance, and thus is suitable for use as an absorbent.

As a specific example of the present invention, compounds having an absorption maximum in the wavelength range of 650 to 800 nm include S0149, S2027, S0315, S0982, S0366, S2086, S2364, S2137, S0773, S0268, S2138, S0450, S2084 (Manufactured by Exciton), NIR700A, NIR700B, NIR714A, NIR720B, NIR721A, NIR733B, NIR739B, NIR756B, NIR757A, NIR762A, NIR762A, NIR762A, (Manufactured by Epolin), SDA5266, SDA6531, SDA3357, SDA5177, SDA2826, SDA3598, SDA5133, SDB3321, SDB4322, SDA3903, SDA3388, Epolight6681, Epolight6684, Epolight6684, Epolight6084, Epolight6698, Epolight6818, Epolight4101, SDA1155, SDA3517, SDA7633 (manufactured by HWSands), and the like.

Examples of the compound having an absorption maximum in the wavelength range of 800 to 1200 nm include IR165 (manufactured by Exciton), NIR1072A (manufactured by QCR), Epolight 3072, Epolight1117, Epolight1178 (manufactured by Epolin), SDA1906, SDA3734, SDA3755, SDA5400, SDA7630, SDA88323 (Manufactured by HWSands).

The resin composition for forming the near infrared absorbing layer according to the present invention includes a binder resin and an organic solvent in addition to the absorbing dye. The binder resin that can be used in the present invention is not particularly limited, but is preferably a transparent resin having excellent thermal stability and solubility in an organic solvent, and capable of forming a near infrared absorbing layer capable of forming a dielectric multi- (Tg) of 100 to 350 占 폚, preferably 110 to 300 占 폚, and more preferably 120 to 250 占 폚.

Examples of usable binder resins include polycarbonate resins, olefin resins, acrylic resins, modified acrylic resins, aromatic polyether resins, polyimide resins, fluorene polycarbonate resins, fluorene polyester resins , A polyamide resin, a polyarylate resin, a polysulfone resin, a polyether sulfone resin, a polyparaphenylene resin, a polyamideimide resin, a polyethylene naphthalate resin, a fluorinated aromatic polymer resin, Epoxy resins, and the like. One or more of these resins can be selected and used, but the present invention is not limited thereto.

Examples of the organic solvent for use in the resin composition for forming the near infrared absorbing layer of the present invention include aromatic hydrocarbons such as benzene, toluene and xylene; Esters such as ethyl acetate, butyl acetate, ethyl lactate, propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate; Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; Halogenated hydrocarbons such as methylene chloride, chloroform and carbon tetrachloride; ethylene glycol nomethyl methyl ether; Ethers such as diethylene glycol monobutyl ether; And amides such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone. These solvents may be used alone or in admixture of two or more.

Depending on the purpose of use, the resin composition for forming a near-infrared absorbing layer may contain additives such as an ultraviolet absorber, an antioxidant, a leveling agent, and an antifoaming agent.

The content of the near infrared absorbing dye in the resin composition for forming the near infrared absorbing layer according to the present invention is preferably 0.1 to 5 parts by weight based on 100 parts by weight of the resin composition. When the content of the near infrared absorbing dye is less than the above range, the absorption band region having a transmittance of 1% or less in the wavelength region of 650 to 800 nm is shortened. When the content exceeds the above range, the content of the absorbent in the resin composition is high, .

The content of the binder resin in the resin composition for forming the near infrared absorbing layer according to the present invention is preferably 5 to 20 parts by weight based on 100 parts by weight of the resin composition.

The content of the organic solvent in the resin composition for forming the near infrared absorbing layer according to the present invention is preferably 75 to 95 parts by weight based on 100 parts by weight of the resin composition.

Meanwhile, the near-infrared absorbing layer of the near-infrared blocking filter according to the present invention may be formed by coating the resin composition for forming an absorbing layer containing an absorbing dye, a binder resin and an organic solvent on one side or both sides of a transparent glass substrate or a transparent resin substrate to dry the solvent Or hardening and drying. The method of forming the near infrared ray absorbing layer is not particularly limited, and for example, bar coating, spin coating, slot die coating, micro gravure coating, slit coating, and comma coating can be applied.

At this time, the thickness of the near infrared absorbing layer formed is in the range of 0.1 to 30 占 퐉, preferably 0.3 占 퐉 to 20 占 퐉, and more preferably 0.5 占 퐉 to 10 占 퐉. The thickness of the near infrared absorbing layer is suitable because the molar extinction coefficient and the solubility of the absorbing agent to be used, that is, the absorbing dye, can be minimized as the thickness of the absorbing layer is increased.

The near infrared ray blocking filter of the present invention is manufactured by forming a near infrared ray reflecting layer on one surface or both surfaces of the near infrared ray absorbing layer. The near-infrared reflecting layer is not particularly limited, but it is preferable to use a dielectric multi-layered film in which a high refractive index material having a refractive index of 1.7 or more and a low refractive index material having a refractive index of 1.6 or less are alternately laminated. Examples of the dielectric film include SiO ₂ , MgF ₂ , Al ₂ O ₃ , and Y ₂ O ₃ , which are low refractive index materials, and TiO ₂ , Ta ₂ O ₅ , and Nb ₂ O ₅ can be used as the high refractive index material . In the present invention, SiO ₂ as a low refractive index material and TiO ₂ as a high refractive index material are alternately laminated to form a near infrared ray reflective film.

The method for forming the near-infrared reflecting layer is not particularly limited, and for example, a CVD method, a sputtering method, a PVD method, or the like can be applied. In the present invention, the PVD method is applied. In this method, SiO ₂ (n = 1.45) and TiO ₂ (n = 2.35), which are low refractive index materials and niobium high refractive index materials, are alternately evaporated by vacuum evaporation to form a near- . In addition, the ion beam assisted deposition method was used to enhance the physical properties of the near-ultraviolet reflective film by increasing the evaporation energy of the oxide substance by emitting an ion beam during evaporation of the oxide film.

Hereinafter, the performance of the near-IR blocking filter according to the present invention will be described based on the result of measurement of the light transmittance of the near IR blocking filter. The near IR blocking filter according to the present invention is characterized by having a wide wavelength range where the transmittance is 1% in the absorption band existing in the wavelength range of 650 to 800 nm. Specifically, referring to the graph of FIG. 2, the near-infrared cut filter according to the present invention is characterized in that the absorption band existing in the wavelength range of 650 to 800 nm has the longest wavelength A1 with a transmittance of 1% ) Is 35 nm or more in absolute value.

As shown in FIG. 3, in general, the near-infrared reflection layer has a high dependency on the incident angle with respect to the transmitted light, and the spectrum for the 30-degree transmitted light is shifted by 20 nm in short wavelength in the spectrum for the zero-degree transmitted light. As a result, as shown in the graph of FIG. 4, the near-infrared absorbing layer using the near infrared absorbing layer causes a spectrum deviation according to the angle of the transmitted light. The near infrared absorbing layer according to the present invention absorbs a broader spectrum than the spectrum deviation due to the incident angle of the transmitted light of the near- Band, it is possible to remarkably reduce the dependence of the incident angle.

Further, another optical characteristic of the near-infrared ray blocking filter according to the present invention is that the near infrared ray reflecting layer has a transmittance of 50% wavelength and the near infrared ray absorbing layer has a transmittance of 50% wavelength deviation of 70 nm or more in a 650 to 800 nm wavelength region. 5, the near infrared ray blocking filter according to an embodiment of the present invention has a near infrared ray absorbing layer with a transmittance of 50% wavelength of 642.75 nm and a near infrared absorbing layer with a transmittance of 50% wavelength of 720.24 nm and the difference is 77.49 nm. When the absolute value of the difference between the 50% wavelength of the transmittance of the near infrared ray absorbing layer and the 50% wavelength of the transmittance of the near infrared ray reflecting layer is 70 nm or more, the transmittance of the near infrared ray cut filter is 50% And the absolute value of the difference between them is 1.6 nm, and the off-slope change due to the incident angle is small.

6 is a schematic diagram of a near infrared ray blocking filter according to another embodiment of the present invention. The near infrared ray blocking filter has a first absorption peak in a wavelength region of 650 to 800 nm and a second absorption peak in a wavelength region of 800 to 1200 nm Is a graph showing the light transmittance in the case where the light-emitting layer is formed. Thus, the addition of a near infrared absorbent in the 800 to 1200 nm wavelength range can more effectively block the near infrared rays in various wavelength ranges.

As described above, the present invention can provide a near-IR blocking filter that has a small dependence on incident angle, a wide viewing angle, less image distortion, and a reduced thickness. Using such a near-IR blocking filter, A solid-state imaging device can be provided. Examples of specific devices to which the NIR filter according to the present invention can be applied include digital cameras, cameras for mobile phones or smart phones, digital video cameras, cameras for wearable devices, PC cameras, surveillance cameras, automobile cameras, , A laser rangefinder, a virtual touch panel, a license plate recognition device, a television, a car navigation system, a portable information terminal, a personal computer, a video game machine, a portable game machine, a fingerprint authentication system and a digital music player.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the following examples are provided to illustrate the present invention and should not be construed as limiting the scope of the present invention.

≪ Example 1 >

1-1: Preparation of Resin Composition Containing an Absorbent

As a binder for a resin composition, 400 parts by weight of an organic solvent (cyclohexanone) is dissolved in 100 parts by weight of a polycarbonate resin to prepare a polycarbonate resin solution. ABS 694 (manufactured by Exciton Company) was dissolved in an organic solvent (toluene) at a concentration of 2% as an absorbent for the first absorption maximum.

To prepare a resin composition for a near infrared ray absorbing layer, 48.4 parts by weight of the absorbent solution for the first absorption maximum and 51.6 parts by weight of an organic solvent (cyclohexanone) were mixed with 100 parts by weight of the polycarbonate resin solution to prepare a resin for a near infrared absorbing layer having a solid content of 10% A composition was prepared.

1-2: Fabrication of an absorbing substrate having a near infrared absorbing layer

As the transparent resin substrate, a polycarbonate film having excellent heat resistance and containing an organic solvent blocking layer on both sides is used. The resin composition for a near infrared ray absorbing layer is coated on one surface of a polycarbonate film by a bar coating method, and then the organic solvent is dried at 160 DEG C for 10 minutes to form a near infrared absorbing layer having a thickness of 3.5 mu m on the polycarbonate film. A near infrared ray absorbing substrate having a near infrared ray absorbing layer formed on both surfaces thereof is also produced in the same manner on the opposite surface of the polycarbonate film.

1-3: Manufacture of near-IR blocking filter with near-infrared reflection layer

A near infrared ray reflection layer was formed on both sides of the near infrared ray absorbing substrate coated with the near infrared ray absorbing layer to prepare a near infrared ray blocking filter. The near-infrared reflecting layer is a dielectric multi-layered film in which a high refractive index material (TiO ₂ ) having a refractive index of 1.7 or more and a low refractive index material (SiO ₂ ) having a refractive index of 1.6 or less are alternately laminated.

A first near infrared ray reflective layer (AR vapor deposition film) was formed as a dielectric multilayer film having 22 layers on one surface of the near infrared ray absorbing substrate manufactured in Example 1-2, and a second near infrared ray reflecting layer was formed on the opposite surface as a dielectric multilayer film (IR vapor deposition film) To prepare a near infrared ray blocking filter.

≪ Example 2 >

Except that an olefin film was used instead of the polycarbonate film as the transparent resin substrate on which the near infrared absorbing layer was formed and an olefin resin was used instead of the polycarbonate resin as the binder for the resin composition.

≪ Example 3 >

Except that a transparent resin substrate on which the near infrared absorbing layer was formed was used as an olefin film instead of a polycarbonate film and an acrylic resin was used in place of a polycarbonate resin as a binder for a resin composition.

<Example 4>

As a binder for a resin composition, 400 parts by weight of an organic solvent (cyclohexanone) is dissolved in 100 parts by weight of a polycarbonate resin to prepare a polycarbonate resin solution. ABS 694 (manufactured by Exciton Company) was dissolved in an organic solvent (toluene) at a concentration of 2% as a first absorbent maximum absorbent and NIR 1072A (manufactured by QCR) was added to an organic solvent (cyclohexanone) % &Lt; / RTI &gt;

48.4 parts by weight of the absorbent solution for the first absorption maximum, 29.0 parts by weight of the absorbent solution for the second absorption maximum layer, and 22.6 parts by weight of the organic solvent (cyclohexanone) were added to 100 parts by weight of the polycarbonate resin solution, To prepare a resin composition for a near-infrared absorbing layer having a solid content of 10%.

Thereafter, a near-infrared absorbing layer was formed, and a near-infrared cut filter having a near-infrared reflecting layer was formed in the same manner as in Example 1. [

&Lt; Comparative Example 1 &

In Comparative Example 1, a near-infrared absorbing resin composition was applied to a transparent glass substrate by spin coating, and the solvent was removed to prepare a near infrared absorbing layer Respectively.

The near infrared ray shielding filter having the near infrared ray reflecting layer formed thereon was prepared in the same manner as in Example 1.

&Lt; Experimental Example > NIR blocking effect test

The maximum absorption wavelength of the near infrared absorbing layer prepared in Comparative Example 1 and Examples 1 to 3 and the wavelength range of the absorption band having a transmittance of 1% or less in the wavelength region of 650 to 800 nm are shown in Table 1 below.

Abs Max A1 A2 Abs. Band Comparative Example 1 669 nm - - - Example 1 722 nm 741 nm 700 nm 42 nm Example 2 709 nm 727 nm 688 nm 39 nm Example 3 714 nm 732 nm 691 nm 42 nm

Abs. Max: Maximum absorption wavelength at 650 to 800 nm.

- A1: Wavelength 650 to 800 nm The longest wavelength at which the transmittance is 1% in the absorption band region.

- A2: Wavelength 650 to 800 nm The shortest wavelength at which the transmittance is 1% in the absorption band region.

Abs. Band: The absolute value of the difference between the longest wavelength and the shortest wavelength at which the transmittance becomes 1% in the absorption band at a wavelength of 650 to 800 nm.

As can be seen from this result, the near-IR cut filter fabricated according to an embodiment of the present invention has i) a first absorption maximum in the 650 to 800 nm wavelength range, ii) an absorption in the 50 to 800 nm wavelength range It can be confirmed that the absolute value of the difference between the longest wavelength A1 and the shortest wavelength A2 at which the transmittance is 1% is 35 nm or more in the band. Further, as shown in the transmission spectra of the near infrared absorbing layers of Comparative Example 1 and Examples 1 to 3 in Fig. 2, the absorption band of the embodiment according to the present invention has a width of the absorption band having a transmittance of 1% or less in the 650 to 800 nm wavelength range wide. Therefore, it can be seen that the near-infrared ray absorbing layer according to the embodiment of the present invention can provide a near-infrared ray blocking filter having a smaller incident angle dependency by using an absorption band broader than the spectral deviation due to the incident angle of transmitted light of the near-infrared ray reflecting layer.

In FIG. 3, a near infrared ray shielding filter is fabricated by forming a first near infrared ray reflecting film (AR vapor deposition film) on the near infrared absorbing layer of 1 and forming a second near infrared ray reflecting film (IR vapor deposition film) on the opposite side to evaluate the light transmittance according to incident light A graph showing the results is shown. The near infrared absorbing layer of Comparative Example 1 in which there is no absorption band with a transmittance of 1% or less above 600 to 800 nm has a deviation of 50% wavelength with respect to the second near infrared ray reflecting film (IR vapor deposition film) And the deviation at the 10% transmittance wavelength is 24.6 nm, which indicates that a large off slope change occurs.

On the other hand, in FIG. 4, a first near-infrared ray reflection film (AR vapor deposition film) is formed on one surface of the light absorption layer of Example 1 and a second near infrared ray reflection film (IR vapor deposition film) having a light transmittance of 50% And the results of the evaluation of the light transmittance according to the incident light are shown. 5, the near infrared ray absorbing layer has a transmittance of 50% wavelength of 638.5 nm and the second near infrared ray reflective layer has a transmittance of 50% of wavelength of 715.0 nm, which is a difference of 76.5 nm. Thus, when the absolute value of the difference between the 50% wavelength of the transmittance of the near infrared ray absorbing layer and the 50% wavelength of the transmittance of the near infrared ray reflecting layer is 70 nm or more, the deviation is 1.7 nm at a transmittance of 50% It is possible to provide a near-infrared ray cut filter having a small off-slope change.

6 also shows the results of the evaluation of the light transmittance of the near infrared absorbing layer further including the second absorption maximum at 800 to 1200 nm. When the near infrared ray absorption function is further included in the wavelength range of 800 to 1200 nm, the number of layers of the near infrared ray reflection film can be reduced, and a near-infrared ray filter capable of manufacturing cost and thinning can be provided.

10: transparent substrate
20a, 20b: near infrared absorbing layer
30a, 30b: Near infrared ray reflective layer

Claims (18)

1. A near infrared ray shielding filter comprising a near infrared absorbing layer and a near infrared ray reflecting layer on a transparent substrate, the filter having i) a first absorption maximum in a wavelength range of 650 to 800 nm, ii) an absorption band in a wavelength range of 650 to 800 nm, Wherein the absolute value of the difference between the longest wavelength (A1) of 1% and the shortest wavelength (A2) is 35 nm or more. The method according to claim 1,
Iii) a near infrared ray blocking filter having a transmittance of 50% of the near infrared ray reflecting layer and a transmittance of 50% of the near infrared ray absorbing layer of 70 nm or more in a wavelength range of 650 to 800 nm. The method according to claim 1,
Wherein the near-infrared absorbing layer further comprises a second absorption maximum in a wavelength range of 800 to 1200 nm. The method according to claim 1,
Wherein the transparent substrate is selected from a transparent glass substrate or a transparent resin substrate. 5. The method of claim 4,
The transparent resin substrate may be formed of a resin such as an olefin resin, a polycarbonate resin, a polysulfone resin, a polyether sulfone resin, a polyarylate resin, a polyparaphenylene resin, a polyarylene ether phosphine oxide resin, a polyimide resin, A polyamideimide resin, an acrylic resin, a modified acrylic resin, and a polyethylene naphthalate resin. The method according to claim 1,
Wherein the near-infrared absorbing layer is formed on one or both surfaces of the transparent substrate. The method according to claim 1,
Characterized in that the near-infrared absorbing layer comprises a near infrared absorbing dye and a binder resin. 8. The method of claim 7,
The near-infrared absorbing dye may be at least one selected from the group consisting of squarylium, cyanine, azo, azo-metal complex, indole, porphyrin, phthalocyanine, naphthalocyanine, squarylium, diimonium, imidazole, A neodymium compound, a cyanine compound, a cyanine compound, a cyanine compound, a nickel metal complex compound, a dicyanobiphenyl compound, an anthraquinone compound, a coumarin compound, a naphthoquinone compound and an indophenol compound. 8. The method of claim 7,
The binder resin may be an olefin resin, an acrylic resin, a modified acrylic resin, an aromatic polyether resin, a polyimide resin, a fluorene polycarbonate resin, a fluorene polyester resin, a polycarbonate resin, A group consisting of a polyarylate resin, a polysulfone resin, a polyether sulfone resin, a polyparaphenylene resin, a polyamideimide resin, a polyethylene naphthalate resin, a fluorinated aromatic polymer resin, a urethane resin and an epoxy resin Wherein the near infrared ray blocking filter is made of at least one resin selected from the group consisting of a fluorine-containing resin and a fluorine-containing resin. The method according to claim 1,
Wherein the thickness of the near infrared absorbing layer is in the range of 1 to 30 占 퐉. The method according to claim 1,
Wherein the near-infrared absorbing layer is formed by coating an absorption layer resin composition comprising a near-infrared absorbing dye, a binder resin, and an organic solvent on one or both surfaces of a transparent substrate, followed by drying the organic solvent. 12. The method of claim 11,
Wherein the content of the near infrared absorbing dye is 0.1 to 5 parts by weight based on the resin composition, the content of the binder resin is 5 to 20 parts by weight, and the content of the organic solvent is 75 to 95 parts by weight. The method according to claim 1,
Wherein the near-infrared reflecting layer is formed on one or both surfaces of the near infrared absorbing layer. The method according to claim 1,
Wherein the near-infrared reflecting layer is a dielectric multilayer film. 15. The method of claim 14,
Wherein the dielectric multi-layer film has a high refractive index material having a refractive index of 1.7 or more and a low refractive index material having a refractive index of 1.6 or less. The method according to claim 1,
Wherein the thickness of the near-infrared reflecting layer is in the range of 1.0 to 5.0 mu m. The method according to claim 1,
Wherein the reflective layer is fabricated by a CVD method, a sputtering method, or a PVD method. 17. A solid-state image pickup device comprising a near-infrared cut filter according to any one of claims 1 to 17.

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