Laminate and optical filter

Abstract

To provide a laminate body and an imaging device which have a high transmission for visible light and can obtain a sharp visible light beam transmission band while accurately and efficiently blocking ultraviolet rays near a short wavelength region of a visible beam of light and infrared rays in a long wavelength region of a visible beam of light, and also can prevent a flare phenomenon.SOLUTION: The laminate body includes a near-infrared ray absorption base material and an optical absorption layer, and the average transmission of light in a 720-780nm wavelength region is equal to 1% or smaller than 1%. The transmittance of the laminate body to light with a wavelength of 750nm may be 1% or smaller than 1%.SELECTED DRAWING: Figure 14

Description

Technical Field

[0001] This application relates to a laminate, an optical filter, and an imaging device.

Background Art

[0002] An imaging device is a device manufactured in an integrated structure with an element group having a photoelectric conversion function and a storage function and a circuit having a scanning function for sequentially extracting signal charges stored in each element.

[0003] Basically, as shown in FIG. 1, the imaging device includes a lens 10 that receives external light, an optical filter 20, and an image sensor 30.

[0004] In the above structure, the optical filter 20 is used to obtain good color reproducibility and a sharp image. Usually, the optical filter 20 is formed to have a function of transmitting visible light and shielding infrared light such as ultraviolet light and / or near-infrared light. Such an optical filter 20 is required to show a transmittance curve that transmits visible light and blocks ultraviolet light and infrared light.

[0005] However, it is not easy to ensure an optical filter 20 that blocks ultraviolet light near the short-wavelength region of visible light and infrared light in the long-wavelength region of visible light and has a high transmittance for visible light.

[0006] As a known technique, an optical filter is known in which a dielectric multilayer film that reflects and / or blocks infrared light is laminated on both sides of an absorption substrate based on an absorption substrate in which a light absorption layer containing a near-infrared absorbing dye is laminated on a substrate.

[0007] Recently, with the trend of increasing pixel counts in imaging devices, image sensors have been made with higher pixel counts. As the pixel count of the image sensor increases, the sensitivity and reflectance in the near-infrared region increase, resulting in a gradually more prominent problem of petal-shaped red flares occurring in photos of subjects. Figure 2 is a diagram showing an example of the flare phenomenon. Referring to Figure 2, the petal-shaped red band indicated by the white arrow is the flare phenomenon. Specifically, in the flare phenomenon, light in the near-infrared region incident from a light source is reflected on the surface of an image sensor with improved sensitivity due to higher pixel counts, and the reflected light is further reflected by the dielectric multilayer film of the optical filter in contact with the image sensor. The further reflected light contacts the surface of the image sensor and is reflected again, and such a phenomenon continuously occurs repeatedly.

[0008] Therefore, considering the recent trend, it is necessary to secure an absorption substrate and an optical filter that have excellent optical characteristics and can prevent the flare phenomenon.

Prior Art Documents

Patent Documents

[0009]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0010] An object of the present application is to provide a laminate and an imaging device that have a high transmittance of visible light, can efficiently and accurately block ultraviolet rays in the vicinity of the short-wavelength region of visible light and infrared rays in the long-wavelength region of visible light, and can obtain a sharp visible light transmission band.

[0011] Another object of the present application is to provide a laminate and an imaging device that can prevent the flare phenomenon.

Means for Solving the Problems

[0012] Among the physical properties mentioned in this application, for those physical properties where the measurement temperature and / or measurement pressure affect the results, unless otherwise specified, they are the results measured at normal temperature and / or normal pressure.

[0013] The term "normal temperature" used in this application means the natural temperature without heating or cooling. For example, the normal temperature may be any one temperature within the range of 10°C to 30°C, and means a temperature of about 23°C or about 25°C. Also, unless otherwise specified, the unit of temperature used in this application is Celsius (°C).

[0014] The term "normal pressure" used in this application means the natural pressure without pressurization or depressurization. For example, the normal pressure usually means about 1 atmosphere at the atmospheric pressure level.

[0015] In the case of physical properties where the measured humidity affects the results in this application, the physical properties are those measured at the natural humidity without special adjustment in the state of the normal temperature and / or normal pressure.

[0016] In the case where the optical properties in this application vary depending on the wavelength of light, unless otherwise specified, the optical properties are the results obtained for light with a wavelength of 520 nm.

[0017] The term "refractive index" used in this application can be measured in the wavelength range of 400 to 1,200 nm at 25°C, and unless otherwise specified, means the refractive index obtained for light with a wavelength of 520 nm.

[0018] The term "transmittance" used in this application means the actual transmittance (measured transmittance) confirmed at a specific wavelength, unless otherwise specified. Also, the term "reflectance" used in this application means the actual reflectance (measured reflectance) confirmed at a specific wavelength, unless otherwise specified.

[0019] The term "transmittance" used in this application is a value measured using an ultraviolet-visible spectrophotometer, and unless otherwise specified, it means the transmittance of light at an incident angle of 0 degrees with respect to the normal of the surface to be measured. Also, the term "reflectance" used in this application is a value measured using an ultraviolet-visible spectrophotometer, and unless otherwise specified, it means the reflectance of light at an incident angle of 0 degrees with respect to the normal of the surface to be measured.

[0020] The term "average transmittance" used in this application, unless otherwise specified, means a value calculated by a regression equation in a cubic spline method using the MiniTab Tool, which is a statistical analysis program. Also, the term "average reflectance" used in this application, unless otherwise specified, means a value calculated by a regression equation in a cubic spline method using the MiniTab Tool, which is a statistical analysis program.

[0021] The term "maximum transmittance (or highest transmittance)" used in this application, unless otherwise specified, means the highest transmittance among the transmittances (measured transmittances) within a specific wavelength range, and the minimum transmittance (or lowest transmittance) means the lowest transmittance among the transmittances (measured transmittances) within a specific wavelength range, unless otherwise specified.

[0022] The term "maximum reflectance" used in this application, unless otherwise specified, means the highest reflectance among the reflectances (measured reflectances) within a specific wavelength range, and the minimum reflectance means the lowest reflectance among the reflectances (measured reflectances) within a specific wavelength range, unless otherwise specified.

[0023] The term "incident angle" used in this application is an angle with respect to the normal of the surface to be evaluated. For example, the transmittance of a filter at an incident angle of 0 degrees means the transmittance of light incident in a direction parallel to the normal of the filter surface, and the transmittance at an incident angle of 40 degrees is the transmittance of incident light that forms an angle of 40 degrees with the normal in the clockwise or counterclockwise direction. Such a definition of the incident angle is equally applicable to other optical properties measured by the incident light.

[0024] As used in this application, the term "visible light (or visible radiation)" means light having a wavelength range of about 380 to 720 nm. Also, as used in this application, the term "ultraviolet light (or ultraviolet radiation)" means light having a wavelength range of 10 nm or more and less than 380 nm. Also, as used in this application, the term "infrared light (or infrared radiation)" means light having a wavelength range of more than 720 nm and 1 mm or less, and among them, near-infrared light (or near-infrared radiation) means light having a wavelength range of more than 720 nm and 3 μm or less.

[0025] As used in this application, the term "light absorption" means absorbing light of a specific wavelength or a specific wavelength range.

[0026] A laminate according to an example of this application may include a near-infrared absorbing glass substrate and a light absorption layer.

[0027] The near-infrared absorbing glass substrate of the laminate according to an example of this application may contain Cu 2+ . It can absorb near-infrared light in at least a partial region through the Cu 2+ . Also, the near-infrared absorbing glass substrate may contain Cu 2+ in the range of 1 to 10% by weight based on the total weight. The content of the Cu 2+ may be 1.5% by weight or more, 2% by weight or more, 2.5% by weight or more, or 3% by weight or more, or 9% by weight or less, 8% by weight or less, 7% by weight or less, 6% by weight or less, or 5% by weight or less based on the total weight of the infrared absorbing glass substrate.

[0028] On the other hand, the near-infrared absorbing glass substrate of the laminate according to an example of this application may be a Cu 2+ -containing fluorophosphate glass or a Cu 2+ -containing phosphate glass. By using the near-infrared absorbing glass substrate, it may have a high transmittance for visible light and at the same time have a high shielding property for near-infrared light. Also, the Cu 2+ -containing fluorophosphate glass and the Cu 2+The phosphate-containing glass may include a phosphosilicate glass in which part of the glass skeleton is composed of SiO2.

[0029] In addition, the near-infrared absorbing glass substrate may contain P 5+ in the range of 10 to 50% by weight based on the total weight. The content of the P 5+ may be 12% by weight or more, 14% by weight or more, 16% by weight or more, 18% by weight or more, or 20% by weight or more, or 45% by weight or less, 40% by weight or less, or 35% by weight or less based on the total weight of the infrared absorbing glass substrate.

[0030] On the other hand, the near-infrared absorbing glass substrate may further contain F - in some cases. When the near-infrared absorbing glass substrate further contains F - it may contain F - in an amount of 15% by weight or less, 14% by weight or less, 13% by weight or less, 12% by weight or less, 11% by weight or less, or 10% by weight or less based on the total weight. The lower limit is not particularly limited, but it may be 0.1% by weight or more or 0.5% by weight or more.

[0031] In addition, the near-infrared absorbing glass substrate has a content of F - / content of Cu 2+ that can satisfy 0.5 or more, 0.6 or more, 0.7 or more, or 0.8 or more, or 5 or less, 4.5 or less, 4 or less, or 3.5 or less. When the content of F - / content of Cu 2+ in the near-infrared absorbing glass substrate satisfies the above range, excellent weather resistance can be ensured.

[0032] The near-infrared absorbing glass substrate of the laminate according to an example of the present application, when satisfying the content of the above configuration, is not particularly limited, but for example, CD700, CXA700 of HOYA Corporation of Japan, KF099, ZF230 of PTOT Corporation of Taiwan, BG66 of SCHOTT Corporation of Germany, etc. can be used.

[0033] The content ratio of the composition contained in the near-infrared absorbing glass substrate of the laminate according to an example of the present application can be measured by using wavelength-dispersive X-ray fluorescence (WD-XRF) spectrometry or inductively coupled plasma (ICP) spectrometry.

[0034] The near-infrared absorbing glass substrate of the laminate according to an example of the present application may have an average transmittance of 80% or more, 81% or more, 82% or more, 83% or more, 84% or more, 85% or more, 86% or more, 87% or more, or 88% or more with respect to light having a wavelength region of 400 to 550 nm. The upper limit of the average transmittance of the near-infrared absorbing glass substrate with respect to light having a wavelength region of 400 to 550 nm is not particularly limited, but may be 100% or less, 99.99% or less, 99.9% or less, or 99% or less.

[0035] The near-infrared absorbing glass substrate of the laminate according to an example of the present application may have an average transmittance of 10% or less, 9% or less, 8% or less, 7% or less, 6% or less, or 5% or less with respect to light having a wavelength region of 750 to 1,000 nm. The lower limit of the average transmittance of the near-infrared absorbing glass substrate with respect to light having a wavelength region of 750 to 1,000 nm is not particularly limited, but may be 0% or more, 0.1% or more, or 0.5% or more.

[0036] The near-infrared absorbing glass substrate of the laminate according to an example of the present application is not particularly limited, but considering the above-described optical characteristics, it may have a thickness of 0.1 mm or more, 0.125 mm or more, 0.15 mm or more, 0.175 mm or more, or 0.2 mm or more, or 0.5 mm or less, 0.4 mm or less, or 0.3 mm or less.

[0037] As described above, the laminate according to an example of the present application may include a light absorption layer. The light absorption layer can exist in a form laminated on one or both sides of the near-infrared absorbing glass substrate. Specifically, the laminate according to an example of the present application may be formed in a structure of near-infrared absorbing glass substrate / light absorption layer or light absorption layer A / near-infrared absorbing glass substrate / light absorption layer B (where the light absorption layer A and the light absorption layer B are independent of each other). As described above, when the laminate according to an example of the present application includes light absorption layers on both outermost sides, one light absorption layer can be referred to as the light absorption layer A, and the other light absorption layer can be referred to as the light absorption layer B.

[0038] The light absorption layer of the laminate according to an example of the present application can be formed of a light absorption composition. Specifically, the light absorption layer can be formed by applying the light absorption composition to one or both sides of the near-infrared absorbing glass substrate described above and drying it. At this time, the coating method is not particularly limited, and a coating method generally used in the industry such as spin coating, die coating, roll coating, gravure coating, reverse coating, dip coating, or air knife coating can be used. The light absorption layer can be obtained by appropriately drying the applied light absorption composition. For example, a coating film can be coated on one side through spin coating and dried in a drying oven within a range of room temperature to 150°C, room temperature to 120°C, or room temperature to 40°C for about 5 to 300 minutes. The light absorption composition may contain a transparent resin, a near-infrared absorber, an ultraviolet absorber, etc. contained in the light absorption layer described below.

[0039] The light absorption layer of the laminate according to an example of the present application means a layer containing a near-infrared absorber and a transparent resin, and in some cases, a layer containing a near-infrared absorber, an ultraviolet absorber, and a transparent resin. Also, the light absorption layer is a layer in which the near-infrared absorber (and in some cases, an ultraviolet absorber is further included) is uniformly dispersed in the transparent resin, and may be cured. Further, the light absorption layer can be formed by applying a light absorption composition containing a transparent resin and a near-infrared absorber (and in some cases, an ultraviolet absorber is further included) to a substrate and then drying it.

[0040] The light absorption layer of the laminate according to an example of the present application may contain a near-infrared absorber. Further, the light absorption layer of the laminate according to an example of the present application can further contain an ultraviolet absorber. Here, the light absorption layer of the laminate according to another example of the present application may contain a near-infrared absorption layer containing a near-infrared absorber and an ultraviolet absorption layer containing an ultraviolet absorber.

[0041] The term "near-infrared absorber" used in the present application means an absorber having an absorption maximum wavelength in the near-infrared region. Further, the near-infrared absorber preferably has a high transmittance in the visible light region, and the transmittance may be about 80% or more, about 81% or more, about 82% or more, about 83% or more, about 84% or more, or about 85% or more.

[0042] The near-infrared absorber contained in the light absorption layer of the laminate according to an example of the present application is not particularly limited as long as it is used in the art and can be used. For example, it may contain one or more selected from the group consisting of squarylium compounds, cyanine compounds, phthalocyanine compounds, naphthalocyanine compounds, dithiol metal complex compounds, dimonium compounds, polymethine compounds, phthalide compounds, naphthoquinone compounds, and anthraquinone compounds.

[0043] The near-infrared absorber contained in the light absorption layer of the laminate according to an example of the present application may contain three or more selected from the group consisting of a first near-infrared absorber having an absorption maximum wavelength in the range of 700 nm or more and 720 nm or less, a second near-infrared absorber having an absorption maximum wavelength in the range of more than 720 nm and 740 nm or less, a third near-infrared absorber having an absorption maximum wavelength in the range of more than 740 nm and 760 nm or less, and a fourth near-infrared absorber having an absorption maximum wavelength in the range of more than 760 nm and 800 nm or less.

[0044] Conventional optical filters were designed with a dielectric multilayer film to reflect light in the wavelength range of approximately 700 to 750 nm. However, when using this type of filter, as described above, there was a problem of the occurrence of petal-shaped red flares. To improve such problems, the dielectric multilayer film of the optical filter was redesigned to transmit light having a wavelength range of approximately 700 to 750 nm. In this case, however, the optical filter generated a second peak having a transmittance of approximately 2% with respect to light having a wavelength around approximately 750 nm (in the wavelength range of approximately 730 to 780 nm), which caused problems in the image by absorbing light unnecessary for imaging.

[0045] The laminate according to an example of the present application includes a light absorption layer containing three or more selected from the group consisting of the first near-infrared absorber, the second near-infrared absorber, the third near-infrared absorber, and the fourth near-infrared absorber. By doing so, when a dielectric multilayer film is formed on the laminate to manufacture an optical filter, the problem of the occurrence of the above-described second peak can be prevented. That is, when the dielectric multilayer film is designed to transmit light having a wavelength range of approximately 700 to 750 nm and applied to the laminate according to an example of the present application to manufacture an optical filter, the problem of the occurrence of the second peak can be prevented. Through this, unnecessary light is blocked to prevent the flare phenomenon, the transmittance of visible light is high, and while efficiently and accurately blocking ultraviolet rays near the short-wavelength region of visible light and infrared rays in the long-wavelength region of visible light, a sharp visible light transmission band can be obtained, and an image in a form similar to that of the human eye can be obtained.

[0046] The term "absorption maximum wavelength of the absorber" used in the present application means the wavelength at which the transmittance of light is the lowest when light in the range of 250 to 1,300 nm is transmitted through the layer containing the absorber. Here, the layer containing the absorber means a layer in which the absorber is dispersed in a resin. Further, the resin means a resin having a transmittance of at least 90% or more in the visible light region when cured to form a layer, and when the transmittance in the visible light region is satisfied, such as an acrylic resin or a silicone resin, it can be used without particular limitation.

[0047] The first near-infrared absorber may contain one or more selected from the group consisting of squarylium compounds, cyanine compounds, and phthalocyanine compounds whose absorption maximum wavelength is in the range of 700 nm or more and 720 nm or less. Further, the first near-infrared absorber contained in the light absorption layer may have an OD (optical density) value with respect to the light having the absorption maximum wavelength in the range of 0.5 to 1.2. In another example, the OD value of the first near-infrared absorber may be 0.55 or more, 0.6 or more, 0.65 or more, 0.7 or more, 0.75 or more, 0.8 or more, 0.85 or more, 0.9 or more, or 0.95 or more, or 1.15 or less, 1.1 or less, 1.05 or less, or 1 or less.

[0048] In the present application, the term "OD (optical density) value" means a negative value of the value obtained by taking the common logarithm of the value of the light energy E1 after transmission with respect to the light energy E2 before transmission when the light having the absorption maximum wavelength of the absorber is transmitted through the layer containing the absorber. Specifically, the OD can be measured by the following [OD formula].

[0049] [OD formula] OD (optical density) value = -log 10 (E1 / E2)

[0050] The second near-infrared absorber may contain one or more selected from the group consisting of squarylium compounds, cyanine compounds, and phthalocyanine compounds whose absorption maximum wavelength is in the range of more than 720 nm and 740 nm or less. Further, the second near-infrared absorber contained in the light absorption layer may have an OD (optical density) value with respect to the light having the absorption maximum wavelength in the range of 0.2 to 0.6. In another example, the OD value of the second near-infrared absorber may be 0.25 or more, 0.3 or more, 0.35 or more, or 0.4 or more, or 0.55 or less, 0.5 or less, or 0.45 or less.

[0051] The third near-infrared absorber may include one or more selected from the group consisting of squarylium compounds, cyanine compounds, and phthalocyanine compounds having an absorption maximum wavelength in the range exceeding 740 nm and not exceeding 760 nm. Further, the third near-infrared absorber contained in the light absorption layer may have an OD (optical density) value in the range of 0.4 to 1 with respect to the light having the absorption maximum wavelength. In another example, the OD value of the third near-infrared absorber may be 0.45 or more, 0.5 or more, 0.55 or more, or 0.6 or more, or may be 0.95 or less, 0.9 or less, 0.85 or less, 0.8 or less, 0.75 or less, 0.7 or less, or 0.65 or less.

[0052] The fourth near-infrared absorber may include one or more selected from the group consisting of squarylium compounds, cyanine compounds, and phthalocyanine compounds having an absorption maximum wavelength in the range exceeding 760 nm and not exceeding 800 nm. Further, the fourth near-infrared absorber contained in the light absorption layer may have an OD (optical density) value in the range of 0.5 to 1.1 with respect to the light having the absorption maximum wavelength.

[0053] Depending on the type, number, and / or content of the near-infrared absorber contained in the light absorption layer, the OD values of the respective near-infrared absorbers may be different. The light absorption layer of the laminate according to an example of the present application includes a light absorption layer containing three or more selected from the group consisting of a first near-infrared absorber, a second near-infrared absorber, a third near-infrared absorber, and a fourth near-infrared absorber. By satisfying the OD values of the respective near-infrared absorbers within the ranges described above, unnecessary light is blocked, a flare phenomenon is prevented, the transmittance of visible light is high, infrared rays in the long wavelength region of visible light are efficiently and accurately blocked, a sharp visible light transmission band can be obtained, and an image in a form similar to that of the human eye can be obtained.

[0054] In the light absorption layer of the laminate according to an example of the present application, the near-infrared absorber may be contained in an amount of 0.1 part by weight or more, 0.2 part by weight or more, 0.3 part by weight or more, 0.4 part by weight or more, 0.5 part by weight or more, 0.6 part by weight or more, 0.7 part by weight or more, 0.8 part by weight or more, 0.9 part by weight or more, or 1 part by weight or more, or 3 parts by weight or less, 2.8 parts by weight or less, 2.6 parts by weight or less, 2.4 parts by weight or less, 2.2 parts by weight or less, 2 parts by weight or less, 1.8 parts by weight or less, 1.6 parts by weight or less, 1.4 parts by weight or less, or 1.2 parts by weight or less, based on 100 parts by weight of the transparent resin. When the content ratio of the near-infrared absorber in the light absorption layer satisfies the above range, it is possible to efficiently and accurately block infrared light in the long wavelength region of visible light while obtaining a sharp visible light transmission band.

[0055] The total OD value of the near-infrared absorbers contained in the light absorption layer of the laminate according to an example of the present application may be in the range of 2 to 3. Here, the total OD value of the near-infrared absorbers contained in the light absorption layer may be 2.1 or more, 2.2 or more, 2.3 or more, 2.4 or more, 2.5 or more, 2.6 or more, or 2.7 or more, or 2.95 or less, 2.9 or less, 2.85 or less, 2.8 or less, or 2.75 or less. Further, as described above, the light absorption layer of the laminate according to an example of the present application contains three or more selected from the group consisting of a first near-infrared absorber, a second near-infrared absorber, a third near-infrared absorber, and a fourth near-infrared absorber. By satisfying the total OD value of the near-infrared absorbers contained in the light absorption layer within the above range, unnecessary light is blocked, the flare phenomenon is prevented, the transmittance of visible light is high, ultraviolet light near the short wavelength region of visible light and infrared light in the long wavelength region of visible light are efficiently and accurately blocked, a sharp visible light transmission band can be obtained, and an image in a form similar to the human eye can be obtained.

[0056] The term "ultraviolet absorber" used in the present application means an absorber having an absorption maximum wavelength in the ultraviolet region. Further, the ultraviolet absorber preferably has a high transmittance in the visible light region, and the transmittance may be about 80% or more, about 81% or more, about 82% or more, about 83% or more, about 84% or more, or about 85% or more.

[0057] The ultraviolet absorber contained in the light absorption layer of the laminate according to an example of the present application is not particularly limited as long as it is used in the art and can be used. For example, it may contain one or more selected from the group consisting of benzotriazole compounds, triazine compounds, benzophenone compounds, oxazole compounds, merocyanine compounds, cyanine compounds, naphthalimide compounds, oxadiazole compounds, oxazine compounds, oxazolidine compounds, naphthalic acid compounds, styryl compounds, anthracene compounds, cyclic carbonyl compounds, azomethine compounds, indole compounds, cyanoacrylate compounds, oxyanilide compounds and triazole compounds.

[0058] The ultraviolet absorber contained in the light absorption layer of the laminate according to an example of the present application may contain one or more selected from the group consisting of azomethine compounds, indole compounds, benzotriazole compounds, triazine compounds, cyanoacrylate compounds and oxyanilide compounds whose absorption maximum wavelength is in the range of 350 nm or more and 400 nm or less. By the absorption maximum wavelength of the ultraviolet absorber satisfying the above range, it is possible to efficiently and accurately block ultraviolet rays in the vicinity of the short wavelength region of visible light and obtain a sharp visible light transmission band.

[0059] In addition, the OD (optical density) value of the ultraviolet absorber contained in the light absorption layer with respect to the light having the absorption maximum wavelength may be in the range of 0.8 to 1.5. In another example, the OD value of the ultraviolet absorber may be 0.85 or more, 0.9 or more, 0.95 or more, 1 or more, 1.05 or more, 1.1 or more, 1.15 or more or 1.2 or more, or 1.45 or less, 1.4 or less, 1.35 or less, 1.3 or less or 1.25 or less. By the OD value of the ultraviolet absorber satisfying the above range, it is possible to efficiently and accurately block ultraviolet rays in the vicinity of the short wavelength region of visible light and obtain a sharp visible light transmission band.

[0060] The light absorption layer of the laminate according to an example of the present application may contain 1 part by weight or more, 1.5 parts by weight or more, 2 parts by weight or more, 2.5 parts by weight or more, or 3 parts by weight or more, or 5 parts by weight or less, 4.5 parts by weight or less, 4 parts by weight or less, or 3.5 parts by weight or less of an ultraviolet absorber with respect to 100 parts by weight of the transparent resin. When the content ratio of the infrared absorber in the light absorption layer satisfies the above range, it is possible to efficiently and accurately block ultraviolet rays in the vicinity of the short wavelength region of visible light, obtain a sharp visible light transmission band, and effectively prevent the purple fringe phenomenon (a purple band appears at the edge of the subject) caused by the change of the transmittance curve in the vicinity of the short wavelength region of visible light.

[0061] When the light absorption layer of the laminate according to an example of the present application contains both a near-infrared absorber and an ultraviolet absorber, the combined OD value OD of the near-infrared absorber contained in the light absorption layer NIR and the combined OD value OD of the ultraviolet absorber contained in the light absorption layer UV The ratio OD NIR / OD UV may be within the range of 1 to 3. The ratio OD NIR / OD UV can satisfy 1.2 or more, 1.4 or more, 1.6 or more, 1.8 or more, 2 or more, or 2.2 or more, or 2.9 or less, 2.8 or less, 2.7 or less, or 2.6 or less. When the light absorption layer satisfies the ratio OD NIR / OD UV within the above range, unnecessary light can be blocked to prevent the flare phenomenon, the transmittance of visible light is high, ultraviolet rays in the vicinity of the short wavelength region of visible light and infrared rays in the long wavelength region of visible light can be efficiently and accurately blocked, a sharp visible light transmission band can be obtained, and an image in a form similar to that of the human eye can be obtained. Further, the combined OD value of the near-infrared absorber contained in the light absorption layer of the laminate according to an example of the present application is within the range of 2 to 3, and the ratio OD NIR / OD UV can satisfy the above range, and in this case, the flare phenomenon can be prevented.

[0062] Here, when the number of compounds contained in each of the near-infrared absorber and the ultraviolet absorber is 1, the OD value means the respective OD values for the compounds, and when various compounds are contained, it means the total OD value of all the contained compounds.

[0063] As described above, the light absorption layer of the laminate according to an example of the present application may contain a transparent resin. The refractive index of the transparent resin measured when cured may be 1.4 or more, 1.45 or more, 1.5 or more, 1.55 or more, or 1.6 or more, or may be 2.5 or less, 2.4 or less, 2.3 or less, 2.2 or less, 2.1 or less, or 2 or less.

[0064] The light absorption layer of the laminate according to an example of the present application may contain 90% by weight or more, 91% by weight or more, 92% by weight or more, 93% by weight or more, 94% by weight or more, 95% by weight or more, 96% by weight or more, 97% by weight or more, 98% by weight or more, or 99% by weight or more of the transparent resin based on the total weight.

[0065] Further, as the transparent resin, one or more selected from the group consisting of polyacrylic resin, epoxy resin, ene-thiol resin, polycarbonate resin, polyether resin, polyarylate resin, polysulfone resin, polyethersulfone resin, polyphenylene resin, polyarylene ether phosphine oxide resin, polyimide resin, polyamideimide resin, polyolefin resin, cyclic olefin resin, and polyester resin may be included, or a resin having transparent properties in the art can be used without limitation.

[0066] Further, the transparent resin has a glass transition temperature T gis 100 °C or higher, 110 °C or higher, 120 °C or higher, 130 °C or higher, or 140 °C or higher, or may be 400 °C or lower, 380 °C or lower, 360 °C or lower, or 340 °C or lower. The glass transition temperature can be measured through DSC (differential scanning calorimetry). When the transparent resin has the glass transition temperature described above, deformation due to the deposition temperature in the deposition process for forming the dielectric multilayer film described later can be prevented.

[0067] Further, the transmittance of the transparent resin at a thickness of 0.1 mm may be 70% or higher, 75% or higher, 80% or higher, or 85% or higher, or may be 99% or lower or 95% or lower. When the transparent resin satisfies the transmittance described above, good transparency can be ensured as an optical filter described later.

[0068] As described above, the light absorption composition according to an example of the present application may contain a near-infrared absorber, and may further contain a transparent resin and / or an ultraviolet absorber. Further, the light absorption composition may optionally further contain a solvent.

[0069] The light absorption composition may contain the transparent resin in an amount of 90% by weight or more, 91% by weight or more, 92% by weight or more, 93% by weight or more, 94% by weight or more, or 95% by weight or more, or 99% by weight or less, 98% by weight or less, 97% by weight or less, or 96% by weight or less, based on the total weight of the remaining components (solid content basis) excluding the solvent.

[0070] The light absorption composition may contain the near-infrared absorber in an amount of 0.1 part by weight or more, 0.2 part by weight or more, 0.3 part by weight or more, 0.4 part by weight or more, 0.5 part by weight or more, 0.6 part by weight or more, 0.7 part by weight or more, 0.8 part by weight or more, 0.9 part by weight or more, or 1 part by weight or more, or 3 parts by weight or less, 2.8 parts by weight or less, 2.6 parts by weight or less, 2.4 parts by weight or less, 2.2 parts by weight or less, 2 parts by weight or less, 1.8 parts by weight or less, 1.6 parts by weight or less, 1.4 parts by weight or less, or 1.2 parts by weight or less, based on 100 parts by weight of the transparent resin.

[0071] Further, the light absorption composition may contain an ultraviolet absorber in an amount of 1 part by weight or more, 1.5 parts by weight or more, 2 parts by weight or more, 2.5 parts by weight or more, or 3 parts by weight or more, or 5 parts by weight or less, 4.5 parts by weight or less, 4 parts by weight or less, or 3.5 parts by weight or less, based on 100 parts by weight of the transparent resin.

[0072] The light absorption composition can use a ketone compound as a solvent. Through the ketone compound, the absorbent contained in the light absorption composition can be uniformly dispersed or dissolved in the transparent resin to form a light absorption layer with little difference in optical properties depending on the position. As the ketone compound, methyl ethyl ketone or methyl isobutyl ketone can be used. The light absorption composition may contain a solvent in an amount of 100 parts by weight or more, 150 parts by weight or more, 200 parts by weight or more, 250 parts by weight or more, 300 parts by weight or more, 350 parts by weight or more, 400 parts by weight or more, 450 parts by weight or more, or 500 parts by weight or more, or 5,000 parts by weight or less, 4,000 parts by weight or less, 3,000 parts by weight or less, 2,000 parts by weight or less, 1,000 parts by weight or less, 900 parts by weight or less, 800 parts by weight or less, 700 parts by weight or less, or 600 parts by weight or less, based on 100 parts by weight of the transparent resin, but is not particularly limited thereto.

[0073] The light absorption layer of the laminate according to an example of the present application may have a thickness of 1 μm or more, 1.2 μm or more, 1.4 μm or more, 1.6 μm or more, 1.8 μm or more, 2 μm or more, 2.2 μm or more, 2.4 μm or more, 2.6 μm or more, 2.8 μm or more, or 3 μm or more, or 10 μm or less, 9.5 μm or less, 9 μm or less, 8.5 μm or less, 8 μm or less, 7.5 μm or less, 7 μm or less, 6.5 μm or less, 6 μm or less, 5.5 μm or less, 5 μm or less, 4.5 μm or less, 4 μm or less, or 3.5 μm or less.

[0074] The light absorption layer of the laminate according to an example of the present application may have one or more of the optical properties listed below. The optical properties of the light absorption layer can be achieved by the combination of the transparent resin, near-infrared absorber, and ultraviolet absorber described above.

[0075] The light absorption layer of the laminate according to an example of the present application may have an average transmittance of 80% or more, 80.5% or more, 81% or more, 81.5% or more, 82% or more, 82.5% or more, 83% or more, 83.5% or more, or 84% or more with respect to light in the wavelength range of 400 to 550 nm. When the average transmittance of the light absorption layer of the laminate satisfies the above range within the wavelength range, a high transmittance for visible light can be ensured, and excellent color reproducibility can be obtained.

[0076] The light absorption layer of the laminate according to an example of the present application may have an average transmittance of 20% or less, 19% or less, 18% or less, 17% or less, 16% or less, or 15% or less with respect to light in the wavelength range of 700 to 800 nm. When the average transmittance of the light absorption layer of the laminate satisfies the above range within the wavelength range, the problem of the occurrence of a secondary peak can be prevented, the flare phenomenon can be prevented, and an image in a form similar to that of a human eye can be obtained.

[0077] The light absorption layer of the laminate according to an example of the present application may have an average transmittance of 15% or less, 14.5% or less, 14% or less, 13.5% or less, 13% or less, 12.5% or less, or 12% or less with respect to light in the wavelength range of 720 to 780 nm. When the average transmittance of the light absorption layer of the laminate satisfies the above range within the wavelength range, the problem of the occurrence of a secondary peak can be prevented, the flare phenomenon can be prevented, and an image in a form similar to that of a human eye can be obtained.

[0078] The light absorption layer of the laminate according to an example of the present application may have a transmittance of 15% or less, 14.5% or less, 14% or less, 13.5% or less, 13% or less, 12.5% or less, or 12% or less with respect to light at 750 nm. When the transmittance of the light absorption layer of the laminate in the above wavelength range satisfies the above range, the problem of the occurrence of a secondary peak can be prevented, the flare phenomenon can be prevented, and an image in a form similar to that of a human eye can be obtained.

[0079] The light absorption layer of the laminate according to an example of the present application may have an absorption half-width (FWHM, full width half maximum) in the range of 120 nm to 200 nm with respect to light in the wavelength range of 300 to 1,200 nm. In another example, the absorption half-width of the light absorption layer is 125 nm or more, 130 nm or more, 135 nm or more, or 140 nm or more, or 190 nm or less, 185 nm or less, 180 nm or less, 175 nm or less, 170 nm or less, 165 nm or less, 160 nm or less, 155 nm or less, 150 nm or less, or 145 nm or less. When the absorption half-width of the light absorption layer is controlled within the above range, the problem of the generation of secondary peaks can be prevented, the flare phenomenon can be prevented, and an image in a form similar to that of the human eye can be obtained.

[0080] The laminate according to an example of the present application may have one or more of the following listed optical properties. The optical properties of the laminate can be achieved by a combination of a near-infrared absorbing glass substrate and a light absorption layer.

[0081] The laminate according to an example of the present application may have an average transmittance of 1% or less, 0.95% or less, 0.9% or less, 0.85% or less, 0.8% or less, 0.75% or less, 0.7% or less, or 0.65% or less with respect to light in the wavelength range of 720 to 780 nm. The lower limit of the average transmittance with respect to light in the wavelength range of 720 to 780 nm corresponds to better physical properties the closer it is to 0%, and may be 0% or more, 0.01% or more, or 0.1% or more. When the average transmittance of the laminate with respect to light in the wavelength range of 720 to 780 nm satisfies the above range, when a dielectric multilayer film is formed on the laminate to manufacture an optical filter, the problem of the generation of the above-described secondary peaks can be prevented. As a result, unnecessary light can be blocked, the flare phenomenon can be prevented, the transmittance of visible light is high, ultraviolet rays near the short wavelength region of visible light and infrared rays in the long wavelength region of visible light can be efficiently and accurately blocked, a sharp visible light transmission band can be obtained, and an image in a form similar to that of the human eye can be obtained.

[0082] The laminate according to an example of the present application may have a transmittance of 1% or less, 0.95% or less, 0.9% or less, 0.85% or less, 0.8% or less, 0.75% or less, 0.7% or less, 0.65% or less, 0.6% or less, 0.55% or less, 0.5% or less, 0.45% or less, 0.4% or less, or 0.35% or less with respect to light of 750 nm. The lower limit of the transmittance with respect to the light of 750 nm corresponds to better physical properties the closer it is to 0%, and may be 0% or more, 0.01% or more, or 0.1% or more. When the transmittance of the laminate with respect to the light of 750 nm satisfies the above range, when a dielectric multilayer film is formed on the laminate to manufacture an optical filter, the problem of the occurrence of the secondary peak described above can be prevented. As a result, unnecessary light can be blocked, the flare phenomenon can be prevented, the transmittance of visible light is high, and ultraviolet rays near the short wavelength region of visible light and infrared rays in the long wavelength region of visible light can be efficiently and accurately blocked while obtaining a sharp visible light transmission band, and an image in a form similar to the human eye can be obtained.

[0083] The laminate according to an example of the present application may have an average transmittance of 70% or more, 71% or more, 72% or more, 73% or more, 74% or more, 75% or more, 76% or more, 77% or more, 78% or more, or 79% or more with respect to light in the wavelength range of 400 to 550 nm. The upper limit of the average transmittance with respect to the light in the wavelength range of 400 to 550 nm corresponds to better physical properties the closer it is to 100%, and may be 100% or less, 99% or less, or 98% or less. When the average transmittance of the laminate with respect to the light in the wavelength range of 400 to 550 nm satisfies the above range, a high transmittance with respect to visible light can be ensured, and excellent color reproducibility can be obtained.

[0084] The laminate according to an example of the present application may have an average transmittance of 5% or less, 4.9% or less, 4.8% or less, 4.7% or less, 4.6% or less, 4.5% or less, 4.4% or less, 4.3% or less, or 4.2% or less with respect to light in the wavelength range of 750 to 1,000 nm. The lower limit of the average transmittance with respect to light in the wavelength range of 750 to 1,000 nm corresponds to better physical properties the closer it is to 0%, and it may be 0% or more, 0.01% or more, or 0.1% or more. When the average transmittance of the laminate with respect to light in the wavelength range of 750 to 1,000 nm satisfies the above range, it is possible to efficiently and accurately block infrared rays in the long wavelength region of visible light while obtaining a sharp visible light transmission band, and it is possible to obtain an image in a form similar to that of a human eye.

[0085] The laminate according to an example of the present application has T according to the following general formula 1 s1 The absolute value of may be 1% or less, 0.95% or less, 0.9% or less, 0.85% or less, 0.8% or less, 0.75% or less, 0.7% or less, 0.65% or less, or 0.6% or less. When the absolute value of T of the laminate according to the general formula 1 s1 satisfies the above range, when a dielectric multilayer film is formed on the laminate to manufacture an optical filter, it is possible to prevent the occurrence problem of the secondary peak described above. As a result, unnecessary light is blocked, the flare phenomenon is prevented, the transmittance of visible light is high, and ultraviolet rays near the short wavelength region of visible light and infrared rays in the long wavelength region of visible light are efficiently and accurately blocked while obtaining a sharp visible light transmission band, and it is possible to obtain an image in a form similar to that of a human eye.

[0086] [General formula 1] T s1 =(T 780- T 720 ) / (780 - 720)×100

[0087] In general formula 1, T 780 means the transmittance with respect to light having a wavelength of 780 nm, and T 720 means the transmittance with respect to light having a wavelength of 720 nm.

[0088] The laminate according to an example of the present application has a light wavelength λ with a transmittance of 50% for light in the wavelength range of 500 to 750 nm. cutoff It may be in the range of 600 to 640 nm. The light wavelength λ with a transmittance of 50% for light in the wavelength range of 500 to 750 nm. cutoff May be 605 nm or more, 610 nm or more, or 615 nm or more, or may be 635 nm or less, 630 nm or less, 625 nm or less, or 620 nm or less. When the light wavelength λ of the laminate has a transmittance of 50% for light in the wavelength range of 500 to 750 nm satisfies the above range, it is possible to efficiently and accurately block infrared rays in the long wavelength region of visible light while obtaining a sharp visible light transmission band, and it is possible to obtain an image in a form similar to that of a human eye. cutoff When the light wavelength λ of the laminate has a transmittance of 50% for light in the wavelength range of 500 to 750 nm satisfies the above range, it is possible to efficiently and accurately block infrared rays in the long wavelength region of visible light while obtaining a sharp visible light transmission band, and it is possible to obtain an image in a form similar to that of a human eye.

[0089] The laminate according to an example of the present application has a light wavelength λ with a transmittance of 50% for light in the wavelength range of 300 to 450 nm. cuton It may be in the range of 390 to 430 nm. The light wavelength λ with a transmittance of 50% for light in the wavelength range of 300 to 450 nm. cuton May be 395 nm or more, 400 nm or more, 405 nm or more, or 410 nm or more, or may be 425 nm or less, 420 nm or less, or 415 nm or less. When the light wavelength λ of the laminate has a transmittance of 50% for light in the wavelength range of 300 to 450 nm satisfies the above range, it is possible to efficiently and accurately block ultraviolet rays near the short wavelength region of visible light while obtaining a sharp visible light transmission band, and it is possible to obtain an image in a form similar to that of a human eye. cuton When the light wavelength λ of the laminate has a transmittance of 50% for light in the wavelength range of 300 to 450 nm satisfies the above range, it is possible to efficiently and accurately block ultraviolet rays near the short wavelength region of visible light while obtaining a sharp visible light transmission band, and it is possible to obtain an image in a form similar to that of a human eye.

[0090] The optical filter according to an example of the present application may include a near-infrared absorbing glass substrate, a light absorbing layer, and a dielectric multilayer film. Here, since the near-infrared absorbing glass substrate and the light absorbing layer are the same as those described in the laminate according to an example of the present application described above, detailed content will be omitted.

[0091] Conventional optical filters were designed with a dielectric multilayer film to reflect light having a wavelength range of approximately 700 to 750 nm. However, when using this, as described above, there was a problem of the occurrence of petal-shaped red flares. In order to improve such a problem, the dielectric multilayer film of the optical filter was redesigned to transmit light having a wavelength range of approximately 700 to 750 nm. In this case, however, the optical filter generated a second peak having a transmittance of approximately 2% with respect to light having a wavelength around approximately 750 nm (in the wavelength range of approximately 730 to 780 nm), and by absorbing light unnecessary for imaging, it caused problems in the image.

[0092] An optical filter according to an example of the present application is designed such that a dielectric multilayer film transmits light in a related wavelength range so that no red flare occurs, and by forming the dielectric multilayer film on the laminate according to an example of the present application described above, a second peak that may be generated by the design of the dielectric multilayer film is also prevented, and an image in a form similar to that of a human eye can be obtained.

[0093] In an optical filter according to an example of the present application, a light absorption layer may be located on one or both sides of a near-infrared absorbing glass substrate. Further, dielectric multilayer films may be located on both outermost surfaces of the optical filter, respectively, one of which may be a first dielectric multilayer film and the other may be a second dielectric multilayer film. In particular, when a light absorption layer is located on one side of the near-infrared absorbing glass substrate of the optical filter, the dielectric multilayer film in contact with the near-infrared absorbing glass substrate may be the first dielectric multilayer film, and the dielectric multilayer film in contact with the light absorption layer may be the second dielectric multilayer film. Here, the first dielectric multilayer film is called a so-called IR (infrared) reflection layer, and the second dielectric multilayer film is called a so-called AR (Anti-reflection) layer.

[0094] The first dielectric multilayer film according to an example of the present application has a light wavelength λ with a reflectance of 50% with respect to light in the wavelength range of 600 to 850 nm R、cutoffmay also be in the range of 750 to 780 nm. By making the wavelength λ of the first dielectric multilayer film satisfy within the above range, near-infrared light that generates red flare can be transmitted. R、cutoff

[0095] Also, the first dielectric multilayer film has a reflectance of 50% with respect to light having an incident angle of n degrees (where n is 30 or 40) in the wavelength range of 600 to 850 nm, and the wavelength λ R、n / cutoff may be in the range of 700 to 760 nm. By making the wavelength λ of the first dielectric multilayer film satisfy within the above range, near-infrared light that generates red flare with respect to light having a changed incident angle can be transmitted. R、n / cutoff

[0096] Also, the average transmittance of the first dielectric multilayer film with respect to light in the wavelength range of 750 to 1,000 nm may be 10% or less, 9.5% or less, 9% or less, 8.5% or less, 8% or less, or 7.5% or less. The lower limit of the average transmittance with respect to light in the wavelength range of 750 to 1,000 nm corresponds to better physical properties the closer it is to 0%, and may be 0% or more, 0.01% or more, or 0.1% or more. Such characteristics of the first dielectric multilayer film can be said to be the characteristics of an IR (infrared) reflective layer. Also, the average transmittance of the first dielectric multilayer film with respect to light having an incident angle of n degrees (where n is 30 or 40) in the wavelength range of 750 to 1,000 nm may be 5% or less, 4.5% or less, 4% or less, 3.5% or less, 3% or less, or 2.5% or less. The lower limit of the average transmittance with respect to light having an incident angle of n degrees (where n is 30 or 40) in the wavelength range of 750 to 1,000 nm corresponds to better physical properties the closer it is to 0%, and may be 0% or more, 0.01% or more, or 0.1% or more.

[0097] In addition, the first dielectric multilayer film may have an average transmittance of 50% or more, 52% or more, 54% or more, 56% or more, 58% or more, 60% or more, 62% or more, or 64% or more with respect to light in the wavelength range of 700 to 750 nm. The closer the upper limit of the average transmittance with respect to light in the wavelength range of 700 to 750 nm is to 100%, the better the physical properties, and it may be 100% or less, 99% or less, or 98% or less. By making the average transmittance of the first dielectric multilayer film with respect to light in the wavelength range of 700 to 750 nm satisfy the above range, near-infrared light that generates red flare can be transmitted.

[0098] In addition, the first dielectric multilayer film may include a dielectric multilayer film in which a first dielectric layer having a refractive index in the range of 1.8 to 3.5 and a second dielectric layer having a refractive index in the range of 1.1 to 1.7 are alternately laminated. The refractive index of the first dielectric layer may be about 1.9 or more, 2 or more, 2.2 or more, 2.4 or more, 2.5 or more, or 2.55 or more, or 3.5 or less, 3.3 or less, 3.1 or less, 2.9 or less, or 2.7 or less. Also, the refractive index of the second dielectric layer may be about 1.1 or more, 1.2 or more, 1.3 or more, or 1.4 or more, or 1.7 or less, 1.65 or less, 1.6 or less, 1.55 or less, or 1.5 or less. Further, the ratio n1 / n2 of the refractive index n1 of the first dielectric layer to the refractive index n2 of the second dielectric layer may be about 1.4 or more, 1.45 or more, 1.5 or more, 1.55 or more, 1.6 or more, or 1.65 or more, or 1.7 or more, or 2 or less, 1.95 or less, 1.9 or less, 1.85 or less, 1.8 or less, 1.75 or less, or 1.7 or less.

[0099] In addition, in the first dielectric multilayer film, appropriate materials can be selected for the first dielectric layer and the second dielectric layer so as to satisfy the above ranges in consideration of the refractive indices of the near-infrared absorbing glass substrate and the light absorbing layer. TiO2, Ta2O5, Nb2O5, ZnS, or ZnSe can be applied as the first dielectric layer, and SiO2 or Na5Al3F can be used as the second dielectric layer. 14, fluorides such as Na3AlF6 or MgF2 can be applied, but there is no particular limitation as long as it is used in the art.

[0100] Further, when the first dielectric multilayer film is in contact with the near-infrared absorbing glass substrate, in the dielectric layer of the first dielectric multilayer film that contacts the substrate, Na5Al3F 14 , it may include a fluoride layer containing Na3AlF6 and / or MgF2, etc., and include a dielectric multilayer film in which the above-mentioned first dielectric layer and second dielectric layer are alternately laminated on the fluoride layer. By introducing the fluoride layer, the adhesion between the first dielectric multilayer film and the near-infrared absorbing glass substrate can be further improved, and the durability of the optical filter can be enhanced.

[0101] Also, in the first dielectric multilayer film, the thicknesses of the first and second dielectric layers can be adjusted according to the purpose, but each independently is 10 nm or more, 15 nm or more, 20 nm or more, 25 nm or more, 30 nm or more, 35 nm or more, 40 nm or more, 45 nm or more, 50 nm or more, 55 nm or more, 60 nm or more, 65 nm or more, 70 nm or more, 75 nm or more, 80 nm or more, or 200 nm or less, 190 nm or less, 180 nm or less, 170 nm or less, 160 nm or less, 150 nm or less, 140 nm or less, 130 nm or less, 120 nm or less, 110 nm or less, 100 nm or less, 90 nm or less, 80 nm or less, 70 nm or less, 60 nm or less, 50 nm or less, 40 nm or less, 30 nm or less, 20 nm or less, or 15 nm or less.

[0102] Also, in the first dielectric multilayer film, the dielectric multilayer film may have a number of layers within the range of 15 to 35 layers or 40 to 100 layers. Specifically, the dielectric multilayer film can be controlled such that the first and second dielectric layers are alternately laminated and the total number of all the layers of the first and second dielectric layers is 15 to 35 layers or 40 to 100 layers. When the first dielectric multilayer film is controlled within the above range, the above-described optical characteristics can be satisfied. In the first dielectric multilayer film, the dielectric multilayer film may be within the range of 18 to 25 layers, or in another example, within the range of 40 to 50 layers.

[0103] In an example of the present application, the second dielectric multilayer film may have an average transmittance of 90% or more, 91% or more, 92% or more, or 93% or more with respect to light in the wavelength range of 750 to 1,000 nm. The upper limit of the average transmittance with respect to light in the wavelength range of 750 to 1,000 nm corresponds to better physical properties the closer it is to 100%, and may be 100% or less, 99% or less, or 98% or less. Such characteristics of the second dielectric multilayer film can be said to be the characteristics of an AR (Anti-reflection) layer. Also, the second dielectric multilayer film may have an average transmittance of 90% or more, 91% or more, 92% or more, or 93% or more with respect to light having an incident angle of n degrees (where n is 30 or 40) in the wavelength range of 750 to 1,000 nm. The upper limit of the average transmittance with respect to light having an incident angle of n degrees (where n is 30 or 40) in the wavelength range of 750 to 1,000 nm corresponds to better physical properties the closer it is to 100%, and may be 100% or less, 99% or less, or 98% or less.

[0104] The second dielectric multilayer film according to an example of the present application may include a dielectric multilayer film in which a first dielectric layer having a refractive index in the range of 1.8 to 3.5 and a second dielectric layer having a refractive index in the range of 1.1 to 1.7 are alternately laminated. The refractive index of the first dielectric layer may be about 1.9 or more, 2 or more, 2.2 or more, 2.4 or more, 2.5 or more, or 2.55 or more, or 3.5 or less, 3.3 or less, 3.1 or less, 2.9 or less, or 2.7 or less. Also, the refractive index of the second dielectric layer may be about 1.1 or more, 1.2 or more, 1.3 or more, or 1.4 or more, or 1.7 or less, 1.65 or less, 1.6 or less, 1.55 or less, or 1.5 or less. Further, the ratio n1 / n2 of the refractive index n1 of the first dielectric layer to the refractive index n2 of the second dielectric layer may be about 1.4 or more, 1.45 or more, 1.5 or more, 1.55 or more, 1.6 or more, or 1.65 or more, or 1.7 or more, or 2 or less, 1.95 or less, 1.9 or less, 1.85 or less, 1.8 or less, 1.75 or less, or 1.7 or less.

[0105] Also, in the second dielectric multilayer film, appropriate materials can be selected for the first dielectric layer and the second dielectric layer so as to satisfy the above ranges in consideration of the refractive indices of the near-infrared absorbing glass substrate and the light absorbing layer. TiO2, Ta2O5, Nb2O5, ZnS, or ZnSe, etc. can be applied as the first dielectric layer, and fluorides such as SiO2 or Na5Al3F 14 , Na3AlF6, or MgF2 can be applied as the second dielectric layer, but it is not particularly limited as long as it is used in the art.

[0106] Also, in the second dielectric multilayer film, the thicknesses of the first and second dielectric layers can be adjusted according to the purpose, but each independently is 5 nm or more, 10 nm or more, 15 nm or more, 20 nm or more, 25 nm or more, 30 nm or more, 35 nm or more, 40 nm or more, 45 nm or more, 50 nm or more, 55 nm or more, 60 nm or more, 65 nm or more, 70 nm or more, 75 nm or more, or 80 nm or more, or may be 500 nm or less, 450 nm or less, 400 nm or less, 350 nm or less, 300 nm or less, 250 nm or less, 200 nm or less, 190 nm or less, 180 nm or less, 170 nm or less, 160 nm or less, 150 nm or less, 140 nm or less, 130 nm or less, 120 nm or less, 110 nm or less, 100 nm or less, 90 nm or less, 80 nm or less, 70 nm or less, 60 nm or less, 50 nm or less, 40 nm or less, 30 nm or less, 20 nm or less, or 15 nm or less.

[0107] Also, in the second dielectric multilayer film, the number of layers of the dielectric laminate film is not particularly limited and can be designed and applied as needed.

[0108] According to an example of the present application, the second dielectric multilayer film can ensure a high transmittance for visible light and obtain excellent color reproducibility by significantly reducing the reflectance in the visible light region. The average reflectance of the second dielectric multilayer film for light in the wavelength range of 450 to 750 nm may be 1% or less, 0.9% or less, 0.8% or less, 0.7% or less, 0.6% or less, 0.5% or less, or 0.4% or less. The lower limit of the average reflectance for light in the wavelength range of 450 to 750 nm corresponds to better physical properties, and it may be 0% or more, 0.01% or more, or 0.1% or more. Further, the average reflectance of the second dielectric multilayer film for light having an incident angle of n degrees (where n is 30 or 40) in the wavelength range of 450 to 750 nm may be 1% or less, 0.9% or less, 0.8% or less, 0.7% or less, 0.6% or less, 0.5% or less, 0.4% or less, 0.3% or less, or 0.2% or less. By reducing the average reflectance of the second dielectric multilayer film for light in the wavelength range of 450 to 750 nm, a high transmittance can be ensured for light with a changed incident angle, and excellent color reproducibility can be obtained.

[0109] As described above, in order to reduce the average reflectance of the second dielectric multilayer film for light in the wavelength range of 450 to 750 nm, the dielectric multilayer film may be 2 to 15 layers, 3 to 14 layers, 4 to 13 layers, 5 to 12 layers, 6 to 11 layers, or 7 to 10 layers.

[0110] In the first and second dielectric multilayer films of the optical filter according to an example of the present application, in addition to the first and second dielectric layers of the dielectric multilayer film described above, other dielectric layers may also be included. The ratio of the total number of the first and second dielectric layers to the total number of all layers of the dielectric multilayer film in the first and second dielectric multilayer films may be 80% or more, 85% or more, 90% or more, 95% or more, or it may be formed only by the first and second dielectric layers.

[0111] The method for forming the dielectric multilayer film of the optical filter according to an example of the present application is not particularly limited, and for example, a known vapor deposition method can be applied for formation.

[0112] An optical filter according to an example of the present application may have a maximum transmittance of 1% or less, 0.95% or less, 0.9% or less, or 0.85% or less for light in the wavelength range of 730 to 780 nm. By controlling the maximum transmittance of the optical filter for light in the wavelength range of 730 to 780 nm within the above range, a flare phenomenon can be prevented, and an image in a form similar to that of a human eye can be obtained.

[0113] Also, an optical filter according to an example of the present application may have an average transmittance of 0.5% or less, 0.48% or less, 0.46% or less, 0.44% or less, 0.42% or less, 0.4% or less, 0.38% or less, 0.36% or less, 0.34% or less, 0.32% or less, or 0.3% or less for light in the wavelength range of 730 to 780 nm. By controlling the average transmittance of the optical filter for light in the wavelength range of 730 to 780 nm within the above range, a flare phenomenon can be prevented, and an image in a form similar to that of a human eye can be obtained.

[0114] An optical filter according to an example of the present application can satisfy one or more, two or more, three or more, or all of the following conditions 1 to 4. When the optical filter satisfies one or more, two or more, three or more, or all of the following conditions 1 to 4, unnecessary light is blocked, a flare phenomenon is prevented, the transmittance of visible light is high, ultraviolet rays near the short wavelength region of visible light and infrared rays in the long wavelength region of visible light are efficiently and accurately blocked, a sharp visible light transmission band can be obtained, and an image in a form similar to that of a human eye can be obtained.

[0115] Condition 1: The average transmittance for light in the wavelength range of 430 to 565 nm may be 85% or more, and the minimum transmittance for light in the wavelength range of 430 to 565 nm may be 75% or more. Here, the average transmittance may be 86% or more, 87% or more, 88% or more, 89% or more, or 90% or more, and the upper limit is not particularly limited and may be 100% or less, 99.9% or less, or 99% or less. Also, the minimum transmittance may be 76% or more, 77% or more, or 77.5% or more, and the upper limit is not particularly limited and may be 100% or less, 99.9% or less, or 99% or less.

[0116] Condition 2: The average transmittance for light in the wavelength range of 700 to 725 nm may be 5% or less. Here, the average transmittance may be 4.5% or less, 4% or less, 3.5% or less, 3% or less, or 2.8% or less, and the lower limit is not particularly limited and may be 0% or more, 0.1% or more, or 0.5% or more.

[0117] Condition 3: The average transmittance for light in the wavelength range of 800 to 1,000 nm may be 3% or less. Here, the average transmittance may be 2.9% or less, 2.8% or less, 2.7% or less, or 2.6% or less, and the lower limit is not particularly limited and may be 0% or more, 0.01% or more, or 0.1% or more.

[0118] Condition 4: The wavelength λ F、cuton when the transmittance for light in the wavelength range of 350 to 450 nm is 50% is within the range of 390 to 420 nm. Here, when there are multiple wavelengths at which the transmittance for light having the wavelength range is 50%, the smallest of them is the wavelength λ F、cuton when the transmittance for light in the wavelength range of 350 to 450 nm is 50%. Also, the wavelength λ F、cutoffcan be within the range of 610 to 640 nm. Here, when there are multiple wavelengths at which the transmittance for light having the wavelength region is 50%, among them, when the largest wavelength has a transmittance of 50% for light in the wavelength region of 600 to 700 nm, the wavelength λ F、cutoff may be used.

[0119] The optical filter according to an example of the present application has λ according to the following general formula 2 d、cutoff where the absolute value of is 15 nm or less, 14.5 nm or less, 14 nm or less, 13.5 nm or less, 13 nm or less, 12.5 nm or less, 12 nm or less, 11.5 nm or less, 11 nm or less, 10.5 nm or less, 10 nm or less, 9.5 nm or less, 9 nm or less, 8.5 nm or less, 8 nm or less, 7.5 nm or less, 7 nm or less, 6.5 nm or less, 6 nm or less, 5.5 nm or less, 5 nm or less, 4.5 nm or less, 4 nm or less, 3.5 nm or less, or 3 nm or less. When the absolute value of λ according to the following general formula 2 for the optical filter satisfies the above range, excellent color reproducibility can be obtained even for light with a changed incident angle. d、cutoff

[0120] [General formula 2] λ d、cutoff =λ F、cutoff -λ F、n / cutoff

[0121] In general formula 2, λ F、cutoff is the wavelength when the transmittance is 50% for light having an incident angle of 0 degrees in the wavelength region of 600 to 700 nm, and λ F、n / cutoff is the wavelength when the transmittance is 50% for light having an incident angle of n degrees in the wavelength region of 600 to 700 nm, and the n is 30 or 40.

[0122] An optical filter according to an example of this application extracts RGB values from a photograph taken under the following shooting conditions using a Color picker tool. The absolute value of the difference between the R value at the point with the smallest R value and the R value at the point with the largest R value in the photograph may be within the range of 0 to 50, 0 to 45, 0 to 40, 0 to 35, or 0 to 30. On the other hand, when the absolute value of the difference in R values is outside the above range, it is considered that a flare phenomenon has occurred.

[0123] [Shooting conditions] Using a rear camera equipped with the optical filter, photograph a halogen LED light source with a color temperature of 3100K as the subject, set the distance between the rear camera and the light source to 50 cm, and proceed with photography in a darkroom.

[0124] The darkroom does not have to be completely black, but in the substantial sense of a darkroom. When extracting RGB values from a photograph taken under the above shooting conditions using a Color picker tool, each of the RGB values can independently satisfy the range of 0 to 50, 0 to 40, 0 to 30, 0 to 20, or 0 to 15.

[0125] On the other hand, the photograph may be taken within a range with a radius of 1 m or less centered on the light source.

[0126] Also, for the RGB values extracted from the photograph taken with the optical filter, the absolute value of the difference between the R value and the G value at the point with the largest R value is within the range of 0 to 50, 0 to 45, 0 to 40, 0 to 35, 0 to 30, 0 to 25, 0 to 20, 0 to 15, 0 to 10, or 0 to 5, and the absolute value of the difference between the R value and the B value may be within the range of 0 to 50, 0 to 45, 0 to 40, 0 to 35, 0 to 30, 0 to 25, 0 to 20, 0 to 15, 0 to 10, or 0 to 5. On the other hand, when the absolute value of the difference between the R value and the G value and the absolute value of the difference between the R value and the B value at the point with the largest R value are outside the above range, it is considered that a flare phenomenon has occurred.

[0127] When the relationship of RGB extracted from the photograph taken under the shooting conditions by the optical filter according to an example of the present application satisfies the above range, it can be seen that the flare phenomenon can be prevented.

[0128] The imaging device of the present application may include a laminate or an optical filter according to an example of the present application. Further, the imaging device may also include other known elements such as an image sensor, and known contents can be applied to the included configurations and forms without limitation.

Advantages of the Invention

[0129] The present application can provide a laminate and an imaging device that have a high transmittance of visible light, can efficiently and accurately block ultraviolet rays near the short wavelength region of visible light and infrared rays in the long wavelength region of visible light, and can obtain a sharp visible light transmission band.

[0130] In addition, the present application can provide a laminate and an imaging device that can prevent the flare phenomenon.

Brief Description of the Drawings

[0131]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7a

Figure 7b

Figure 8a

Figure 8b

Figure 9a

Figure 9b

Figure 10a

Figure 10b

Figure 11a

Figure 11b

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Mode for Carrying Out the Invention

[0132] Hereinafter, the present invention will be described based on examples and comparative examples, but the scope of the present invention is not limited by the content presented below.

[0133] <Physical Property Measurement Method> 1. Evaluation of Refractive Index The refractive index was measured at room temperature with light having a wavelength of 520 nm using an ellipsometer (M-2000 (registered trademark) Ellipsometer) device manufactured by Woollens Optics.

[0134] 2. Evaluation of Transmittance and Reflectance The transmittance and reflectance were measured for the measurement target using a spectrophotometer (manufacturer: PerkinElmer, product name: Lambda750 spectrophotometer). The transmittance was measured according to the manual of the equipment for each wavelength and each incident angle, and the reflectance was measured according to the manual of the equipment for each wavelength. The measurement target was positioned on a straight line between the measurement beam and the detector of the spectrophotometer, and the transmittance and reflectance were measured while changing the angle of the incident angle of the measurement beam from 0 degrees to 40 degrees. Here, the meaning of the incident angle being 0 degrees means a direction parallel to the surface normal direction of the measurement target.

[0135] Material 1. Near-Infrared Absorbing Glass Substrate The near-infrared absorbing glass substrate contains Cu based on the total weight 2+ in an amount of 3 to 5% by weight, and P 5+The content of is 20 to 30% by weight and F - Each cation is contained such that the content of is 1 to 10% by weight, and F - The content of / Cu 2+ The content of was about 1.43.

[0136] Also, the near-infrared absorbing glass substrate has a thickness of 0.21 mm, an average transmittance of 88% or more for light having a wavelength region of 400 to 550 nm, and an average transmittance of 5% or less for light having a wavelength region of 750 to 1,000 nm.

[0137] The optical characteristics (transmittance graph) of the near-infrared absorbing glass substrate used are shown in Fig. 3.

[0138] 2. Light Absorbing Composition (1) Manufacturing Example of Light Absorbing Composition Polyacrylic resin (manufacturer: Sumitomo Corporation, product name: SUMIPEX, refractive index of about 1.6), a squarylium compound (manufacturer: Exciton Corporation, product name: IRA705) with an absorption maximum wavelength of about 700 nm or more and 710 nm or less as the first near-infrared absorber (IA1), a cyanine compound (manufacturer: FEW CHEMICALS, product name: S2364) with an absorption maximum wavelength of about 730 nm or more and 740 nm or less as the second near-infrared absorber (IA2), a cyanine compound (manufacturer: FEW CHEMICALS, product name: S2137) with an absorption maximum wavelength of more than about 740 nm and 750 nm or less as the third near-infrared absorber (IA3), a squarylium compound (FEW CHEMICALS, product name: S2404) with an absorption maximum wavelength of about 770 nm or more and 780 nm or less as the fourth near-infrared absorber (IA4), and a benzotriazole compound (manufacturer: ZICO Corporation, product name: ZIKA-480) with an absorption maximum wavelength of about 360 nm as the ultraviolet absorber (UA) were mixed at a weight ratio of 100:0.2:0.01:0.2:0.6:3.5 (SUMIPEX:IRA705:S2364:S2137:S2404:ZIKA-480), and methyl isobutyl ketone (K) as a solvent was appropriately added to produce a light absorbing composition A.

[0139] (2) Comparative production examples of light absorption compositions A polyacrylic resin (manufacturer: Sumitomo, product name: SUMIPEX, refractive index of about 1.6), a squarylium-based compound with an absorption peak wavelength of 700 - 710 nm as the first near-infrared absorber (IA1) (manufacturer: Exciton, product name: IRA705), a cyanine-based compound with an absorption peak wavelength of 730 - 740 nm as the second near-infrared absorber (IA2) (manufacturer: FEW CHEMICALS, product name: S2364), and a benzotriazole-based compound with an absorption peak wavelength of 360 nm as the ultraviolet absorber (UA) (manufacturer: ZICO, product name: ZIKA-480) were mixed at a weight ratio of 100:1.3:1.5:4.4:450 (SUMIPEX:IRA705:S2364:ZIKA-480), and methyl isobutyl ketone (K) as a solvent was appropriately added to produce a light absorption composition B.

[0140] Manufacture of laminate (A) Example A1. A certain amount of the light absorption composition A produced according to the production example of the light absorption composition was applied to one surface of the near-infrared absorbing glass substrate and dried at 140°C for 60 minutes to form a light absorption layer having a thickness of 3 μm, thereby manufacturing a laminate.

[0141] In the light absorption layer, the OD value of the first near-infrared absorber (IA1) was approximately 0.96, the OD value of the second near-infrared absorber (IA2) was approximately 0.41, the OD value of the third near-infrared absorber (IA3) was approximately 0.64, the OD value of the fourth near-infrared absorber (IA4) was approximately 0.7, and the OD value of the ultraviolet absorber (UA) was approximately 1.22. From FIG. 4, the transmittance graph for each absorber contained in the light absorption composition (the light absorption composition A) according to an example of the present application can be confirmed. Further, from FIG. 6, the transmittance graph of the light absorption layer formed of the light absorption composition (the light absorption composition A) according to an example of the present application can be confirmed. The light absorption layer had an average transmittance of approximately 84.9% for light in the wavelength range of 400 to 550 nm, an average transmittance of approximately 14.4% for light in the wavelength range of 700 to 800 nm, an average transmittance of 11.6% for light in the wavelength range of 720 to 780 nm, a transmittance of 9.17% for light with a wavelength of 750 nm, and an absorption half-value width (FWHM) of approximately 139 nm.

[0142] Comparative Example A1. A certain amount of the light absorption composition B produced by the comparative production example of the light absorption composition was applied to one surface of the near-infrared absorbing glass substrate and dried at 140° C. for 60 minutes to form a light absorption layer having a thickness of 3 μm, thereby manufacturing a laminate.

[0143] In the light absorption layer, the OD value of the first near-infrared absorber (IA1) was about 1.52, the OD value of the second near-infrared absorber (IA2) was about 0.93, and the OD value of the ultraviolet absorber was about 1.22. Figure 5 shows the transmittance graphs for each absorber contained in the light absorption layer produced from the light absorption composition (the light absorption composition B) according to the comparative production example. Further, from Figure 6, the transmittance graph of the light absorption layer formed from the light absorption composition (the light absorption composition B) according to the comparative production example can be confirmed. The light absorption layer had an average transmittance of about 85.5% for light in the wavelength range of 400 to 550 nm, an average transmittance of about 38.8% for light in the wavelength range of 700 to 800 nm, an average transmittance of 34.2% for light in the wavelength range of 720 to 780 nm, a transmittance of 19.9% for light with a wavelength of 750 nm, and an absorption half-value width (FWHM) of about 104 nm.

[0144] The transmittance characteristic graphs for the laminates produced in Example A1 and Comparative Example A1 are shown in Figures 7a and 7b.

[0145] Also, the optical properties of the laminates produced in Example A1 and Comparative Example A1 are summarized in Table 1 below. In Table 1 below, λ means the wavelength of the incident light.

[0146]

Table 1

[0147] Manufacture of Optical Filter (B) An optical filter (B) was manufactured by forming dielectric multilayer films on both outermost surfaces of the produced laminate (A). The dielectric multilayer film in contact with the near-infrared absorbing glass substrate of the laminate (A) is the first dielectric multilayer film, and the dielectric multilayer film in contact with the light absorption layer of the laminate (A) is the second dielectric multilayer film.

[0148] The first and second dielectric multilayer films were formed while depositing by an ion-beam assisted deposition method. The deposition was carried out at 5×10-5 Torr and 120°C, and the conditions were set to an IBS (ion beam sputtering) source voltage of 350 V and a current of 850 mA. By alternately forming a TiO2 layer, which is a high refractive index layer (refractive index for light having a wavelength of 520 nm is about 2.61), and a SiO2 layer, which is a low refractive index layer (refractive index for light having a wavelength of 520 nm is about 1.46), the first and second dielectric multilayer films were formed respectively.

[0149] For the first dielectric multilayer film, the first dielectric multilayer film according to Production Example 1 was produced in the stacking order as shown in Table 2 below, the first dielectric multilayer film according to Production Example 2 was produced in the stacking order as shown in Table 3 below, and the first dielectric multilayer film according to the Comparative Production Example was produced in the stacking order as shown in Table 4 below. In Tables 2 to 4 below, the layer with a stacking order of 1 is the layer in contact with the near-infrared absorbing glass substrate of the laminate (A).

[0150]

Table 2

[0151]

Table 3

[0152]

Table 4

[0153] The transmittance graph of the first dielectric multilayer film according to Production Example 1 manufactured in the stacking order as shown in Table 2 above is shown in FIG. 8a, and the reflectance graph is shown in FIG. 8b. Further, the transmittance graph of the first dielectric multilayer film according to Production Example 2 manufactured in the stacking order as shown in Table 3 above is shown in FIG. 9a, and the reflectance graph is shown in FIG. 9b. Further, the transmittance graph of the first dielectric multilayer film according to the Comparative Example manufactured in the stacking order as shown in Table 4 above is shown in FIG. 10a, and the reflectance graph is shown in FIG. 10b.

[0154] The optical properties of the first dielectric multilayer films according to Production Examples 1 and 2 and the first dielectric multilayer film according to the Comparative Example are summarized in Table 5 below. In Table 5 below, λ means the wavelength of incident light.

[0155]

Table 5

[0156] Referring to Table 5 above, for the first dielectric multilayer film according to the Comparative Example, since the values of λ R、cutoff and λ R、n / cutoff are not included within the specified range, near-infrared light that generates red flare is reflected, thereby generating red flare.

[0157] Further, the second dielectric multilayer film is a second dielectric multilayer film according to a production example, and is manufactured in the stacking order as shown in Table 6 below. In Table 6 below, the layer with a stacking order of 1 is the layer in contact with the light absorption layer of the laminate (A).

[0158]

Table 6

[0159] The transmittance graph of the second dielectric multilayer film according to the production example manufactured in the stacking order as shown in Table 6 above is shown in FIG. 11a, and the reflectance graph is shown in FIG. 11b.

[0160] Further, the optical properties of the second dielectric multilayer film according to the production example are summarized in Table 7 below. In Table 7 below, λ means the wavelength of incident light.

[0161]

Table 7

[0162] Example B1. A first dielectric multilayer film was formed on the laminate manufactured according to Example A1 according to Production Example 1, and a second dielectric multilayer film was formed according to the production example to manufacture an optical filter. The transmittance graph of the optical filter manufactured according to Example B1 is shown in FIG. 12.

[0163] Example B2. A first dielectric multilayer film was formed on the laminate manufactured according to Example A1 according to Production Example 2, and a second dielectric multilayer film was formed according to the production example to manufacture an optical filter. The transmittance graph of the optical filter manufactured according to Example B2 is shown in FIG. 13. Also, the photograph taken under the following shooting conditions is shown in FIG. 14.

[0164] [Shooting Conditions] Using a rear camera equipped with the optical filter, a halogen LED light source with a color temperature of 3100 K is used as the subject, and the distance between the rear camera and the light source is set to 50 cm, and photographing is carried out in a dark room.

[0165] The RGB values for the dark room were 11, 11, and 9, respectively. Also, in the photograph according to FIG. 14, the RGB values at the point where the R value was the smallest were 9, 11, and 8, respectively, and the RGB values at the point where the R value was the largest were 39, 40, and 42, respectively. Since the absolute value of the difference in the R values between the point where the R value was the largest and the point where the R value was the smallest was about 30, it can be seen that no flare phenomenon occurred. Also, since the absolute values of the difference between the R value and the G value and the difference between the R value and the B value at the point where the R value was the largest were about 1 and about 3, respectively, it can be seen that no flare phenomenon occurred. Referring to FIG. 14, it can be confirmed that the flare phenomenon was prevented.

[0166] On the other hand, the photograph was taken within a range of 1 m in radius centered on the light source.

[0167] Comparative Example B1. A first dielectric multilayer film was formed on the laminate produced according to Example A1 according to the comparative example, and a second dielectric multilayer film was formed according to the production example to produce an optical filter. The photograph taken under the following photographing conditions using the optical filter produced according to Comparative Example B1 is shown in FIG. 15.

[0168] [Photographing Conditions] Using a rear camera equipped with the optical filter, a halogen LED light source with a color temperature of 3100 K is used as the subject, and the distance between the rear camera and the light source is set to 50 cm, and photographing is carried out in a dark room.

[0169] The RGB values for the dark room were 11, 11, and 9, respectively. Also, in the photograph according to FIG. 15, the RGB values at the point where the R value was the smallest were 10, 12, and 9, respectively, and the RGB values at the point where the R value was the largest were 136, 43, and 28, respectively. Since the absolute value of the difference in the R value between the point where the R value was the largest and the point where the R value was the smallest exceeded 100, it can be seen that a flare phenomenon occurred. Also, since the absolute values of the difference between the R value and the G value and the difference between the R value and the B value at the point where the R value was the largest were approximately 93 and approximately 108, respectively, it can be seen that a flare phenomenon occurred. Referring to FIG. 15, it can be confirmed that a flare phenomenon occurred.

[0170] On the other hand, the photograph was taken within a range of 1 m in radius centered on the light source.

[0171] Comparative Example B2. A first dielectric multilayer film was formed on the laminate produced according to Comparative Example A1 according to Production Example 1, and a second dielectric multilayer film was formed according to the production example to produce an optical filter. The transmittance graph of the optical filter produced according to Comparative Example B2 is shown in FIG. 16.

[0172] Comparative Example B3. A first dielectric multilayer film was formed on the laminate produced by the comparative example A1, and a second dielectric multilayer film was formed according to the production example to manufacture an optical filter. The transmittance graph of the optical filter produced by the comparative example B3 is shown in FIG. 17.

[0173] The optical characteristics of the optical filters according to the examples B1 and B2 and the optical filters according to the comparative examples B2 and B3 are summarized in Tables 8 and 9 below, respectively. In Tables 8 and 9 below, λ means the wavelength of the incident light.

[0174] [Table 8]

[0175] [Table 9]

[0176] Referring to Table 8 above, in both Examples B1 and B2, the maximum transmittance with respect to light in the wavelength range of 730 to 780 nm did not exceed 1%, and the average transmittance with respect to light in the wavelength range of 730 to 780 nm also did not exceed 0.5%. On the other hand, referring to Table 9 above, in both Comparative Examples B2 and B3, the maximum transmittance with respect to light in the wavelength range of 730 to 780 nm exceeded 1%, and in Comparative Example B2, the average transmittance with respect to light in the wavelength range of 730 to 780 nm also exceeded 0.5%.

[0177] Therefore, it can be seen that Examples B1 and B2 can prevent the flare phenomenon and obtain an image in a form similar to that of a human eye, and it can be seen that problems occur in the images due to the second peak in Comparative Examples B2 and B3.

Claims

1. comprising a near-infrared absorbing glass substrate and a light absorption layer, wherein the light absorption layer contains a near-infrared absorber, the near-infrared absorber includes a first near-infrared absorber having an absorption peak wavelength in the range of 700 nm or more and 720 nm or less, a second near-infrared absorber having an absorption peak wavelength in the range of more than 720 nm and 740 nm or less, a third near-infrared absorber having an absorption peak wavelength in the range of more than 740 nm and 760 nm or less, and a fourth near-infrared absorber having an absorption peak wavelength in the range of more than 760 nm and 800 nm or less, the light absorption layer has an absorption half-width (full width half maximum) of 120 nm or more with respect to light in the wavelength range of 300 to 1,200 nm, a laminate having an average transmittance of 1% or less with respect to light in the wavelength range of 720 to 780 nm.

2. The laminate according to claim 1, wherein the transmittance with respect to light having a wavelength of 750 nm is 1% or less.

3. T represented by the following general formula 1 ｓ１ The laminate according to claim 1, wherein the absolute value of is 1% or less. [General formula 1] T ｓ１ = (T ７８０ - T ７２０ ) / (780 - 720) × 100 In General Formula 1, T ７８０ means the transmittance with respect to light having a wavelength of 780 nm, and T ７２０ means the transmittance with respect to light having a wavelength of 720 nm.

4. The laminate according to claim 1, having an average transmittance of 70% or more with respect to light in the wavelength range of 400 to 550 nm and an average transmittance of 5% or less with respect to light in the wavelength range of 750 to 1,000 nm.

5. The wavelength λ of light with a transmittance of 50% for light in the wavelength range of 500 to 750 nm ｃｕｔｏｆｆ is within the range of 600 to 640 nm, the laminate according to claim 1.

6. The near-infrared absorbing glass substrate contains Cu in the range of 1 to 10% by weight based on the total weight. ２＋ The laminate according to claim 1, comprising ２＋ in the range of 1 to 10% by weight.

7. The laminate according to claim 1, wherein the near-infrared absorbing glass substrate has an average transmittance of 80% or more with respect to light in the wavelength range of 400 to 550 nm and an average transmittance of 10% or less with respect to light in the wavelength range of 750 to 1,000 nm.

8. The laminate according to claim 1, wherein the light absorption layer has an average transmittance of 20% or less with respect to light in the wavelength range of 700 to 800 nm.

9. The laminate according to claim 1, wherein the OD (optical density) value of the first near-infrared absorber contained in the light absorption layer is in the range of 0.5 to 1.2, the OD value of the second near-infrared absorber is in the range of 0.2 to 0.6, the OD value of the third near-infrared absorber is in the range of 0.4 to 1, and the OD value of the fourth near-infrared absorber is in the range of 0.5 to 1.

1.

10. The laminate according to claim 1, wherein the total OD value of the near-infrared absorbers contained in the light absorption layer is in the range of 2 to 3.

11. The near-infrared absorber in the laminate according to claim 1 contains one or more selected from the group consisting of squarylium compounds, cyanine compounds, phthalocyanine compounds, naphthalocyanine compounds, dithiol metal complex compounds, dimonium compounds, polymethine compounds, phthalide compounds, naphthoquinone compounds, and anthraquinone compounds.

12. The light absorption layer in the laminate according to claim 1 further contains an ultraviolet absorber.

13. The ultraviolet absorber in the laminate according to claim 12 contains at least one absorber having an absorption maximum wavelength in the range of 350 nm or more and 400 nm or less.

14. The ultraviolet absorber in the laminate according to claim 12 contains one or more selected from the group consisting of benzotriazole compounds, triazine compounds, benzophenone compounds, oxazole compounds, merocyanine compounds, cyanine compounds, naphthalimide compounds, oxadiazole compounds, oxazine compounds, oxazolidine compounds, naphthalic acid compounds, styryl compounds, anthracene compounds, cyclic carbonyl compounds, azomethine compounds, indole compounds, cyanoacrylate compounds, oxyanilide compounds, and triazole compounds.

15. An optical filter comprising the laminate according to claim 1 and a dielectric multilayer film, extracting RGB values with a Color picker tool for a photograph taken under the following photographing conditions, and the absolute value of the difference in R values between the point with the smallest R value and the point with the largest R value in the photograph is in the range of 0 to 50. [Photographing conditions] Using a rear camera equipped with the optical filter, a halogen LED light source with a color temperature of 3100 K is used as the subject, the distance between the rear camera and the light source is 50 cm, and photographing is carried out in a darkroom.

16. For the RGB values extracted for the photographed photograph, the absolute value of the difference between the R value and the G value at the point with the largest R value is in the range of 0 to 50, and the absolute value of the difference between the R value and the B value is in the range of 0 to 50. The optical filter according to claim 15.

17. An optical filter comprising the laminate according to claim 1 and a dielectric multilayer film, The dielectric multilayer film includes a first dielectric multilayer film and a second dielectric multilayer film. The first dielectric multilayer film is located on one of the outermost surfaces of the optical filter, and the second dielectric multilayer film is located on the other of the outermost surfaces of the optical filter. The first dielectric multilayer film has a light wavelength λ at which the reflectance with respect to light in the wavelength range of 600 to 850 nm is 50%. Ｒ、ｃｕｔｏｆｆ The wavelength λ is in the range of 750 to 780 nm, and the average transmittance with respect to light in the wavelength range of 750 to 1,000 nm is 10% or less. The second dielectric multilayer film has an average transmittance of 90% or more for light in the wavelength range of 750 to 1,000 nm. An optical filter having a maximum transmittance of 1% or less for light in the wavelength range of 730 to 780 nm.

18. The optical filter according to claim 17, wherein the first dielectric multilayer film has an average transmittance of 50% or more for light in the wavelength range of 700 to 750 nm.

19. The optical filter according to claim 17, wherein the second dielectric multilayer film has an average reflectance of 1% or less for light in the wavelength range of 450 to 750 nm.

20. The optical filter according to claim 17, having an average transmittance of 0.5% or less for light in the wavelength range of 730 to 780 nm.

Images