KR20180039610A - Optical product for using an infrared cut-off filter included in a camera module and infrared cut-off filter including the optical product - Google Patents

Abstract

According to an optical product for a near infrared cut-off filter included in a camera module and the near infrared cut-off filter for a camera module including the same, the optical product for a near infrared cut-off filter included in a camera module includes a light transmitting substrate including an organic absorber and a near infrared ray absorbing layer formed on the light transmitting substrate and including metal-tungsten oxide. Accordingly, the present invention can maximize color reproducibility while blocking a ghost or flare.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a near-infrared cut-off filter for a near-infrared cut-off filter included in a camera module and a near infrared ray cut- PRODUCT}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a near infrared ray cut-off filter for a camera module including an optical article for a near-infrared ray cut-off filter included in a camera module, and more particularly to a near infrared ray cut-off filter for a camera module including a ghost or a flare Infrared cut-off filter included in a camera module capable of realizing high color reproducibility, and a near infrared ray cut-off filter for a camera module including the optical article.

Recently, camera modules have been increasingly used in mobile phones, notebook PCs, security cameras, and vehicles. A camera module using a solid-state image sensor such as a CMOS image sensor is used in a near-infrared region (for example, 700 nm to 1200 nm wavelength range) sensed by a sensor in order to obtain a natural- (For example, a wavelength range from 400 nm to 700 nm) to transmit the light in a visible light region (for example, a wavelength range of 400 nm to 700 nm) to approximate the human eye's sensitivity. As such an optical component, a near infrared ray cut-off filter (IRCF) is used. The near-infrared cut-off filter can be largely divided into a reflection type filter and an absorption type filter according to a method of cutting off the near-infrared rays.

The reflection type filter has a high light transmittance in the visible light wavelength region, while the visible light transmittance band is shifted toward the short wavelength side as the incident angle increases, so that the color feeling that is finally visually recognized by the observer changes, There are disadvantages. In order to solve such a problem, a fluorophosphate-based glass (also referred to as " glass ") containing a bivalent copper ion that absorbs light in a wavelength range of 630 nm to 1200 nm, which largely affects the display quality of the image, Blue glass) has been developed.

The absorption filter using blue glass can realize high color reproducibility as compared with the reflection type filter, and is used in a camera module of a high pixel area. However, since blue glass is fragile and vulnerable to shock, it is limited in use for a camera module requiring high breaking strength, and it is difficult to obtain mass productivity with a thickness of 0.2 mm or less due to the limitation of physical properties of the material . In addition, optical design in a camera module applied to a smart phone has recently been downsized and integrated, thereby minimizing the thickness of a near-infrared cut-off filter. However, there is a limitation in realizing a blue glass thickness of 0.1 mm.

Recently, in order to make the thickness of the near-infrared cut-off filter for the camera module thin to 0.1 mm, an organic dye absorbing agent is coated on the upper surface of optical glass (for example, Shot D263), or the organic dye absorbing agent is uniformly dispersed Absorbing type filter using an optical article such as a polymeric absorbing film made of a polyolefin. The absorption filter using the organic dye absorbent has an advantage that it can realize high color reproducibility as compared with the absorption filter using blue glass. However, as absorbing light in a limited wavelength range (light in a wavelength range of approximately 630 nm to 730 nm) The reflection of the near-infrared region outside the optical fiber may cause an optical problem such as a ghost or a flare phenomenon.

It is an object of the present invention to provide an optical article for a near infrared ray cut-off filter included in a camera module which absorbs light in a wide wavelength range in the near infrared region to maximize color reproducibility while blocking ghost or flare.

Another object of the present invention is to provide a near infrared ray cut-off filter for a camera module comprising the optical article.

An optical article for a near-infrared ray cut-off filter included in a camera module according to an embodiment of the present invention includes a transparent substrate including an organic absorbent, and a translucent substrate formed on the translucent substrate and having a near- Absorption layer, wherein the average transmittance in a wavelength range of 460 nm to 560 nm is 85% or more and 100% or less, and the minimum wavelength value showing a light transmittance of 50% or more at 560 nm or more appears at a wavelength of more than 625 nm and less than 650 nm, The average transmittance in the wavelength range of nm to 1200 nm is more than 40% and less than 75%.

In one embodiment, the metal-tungsten oxide may be represented by the following formula (1).

[Chemical Formula 1]

In the formula (1), 0? P / q? 1, 2.5? R / q?

M represents A _x B _y D _z ,

A, B and D are each independently selected from the group consisting of Li, Na, K, Rb, Cs, Fr, Ber, Mg, (Ca), strontium (Sr), barium (Ba), radium (Ra), zirconium (Zr), chromium (Cr), manganese (Mn), iron (Fe), ruthenium (Ru), cobalt (Ag), gold (Au), zinc (Zn), cadmium (Cd), aluminum (Au), aluminum (Al), gallium (Ga), indium (In), tallium (Tl), tin (Sn), lead (Pb), titanium (Ti), niobium (Nb), vanadium (V), molybdenum Ruthenium (Re), beryllium (Be), hafnium (Hf), osmium (Os) or bismuth (Bi)

0? X? 1, 0? Y? 1 and 0? Z? 1, and x + y + z = 1.

In one embodiment, the metal-tungsten oxide _{Na 0.11 Cs 0.22 WO 3, Na} 0.5 WO 3, K 0.33 WO 3, K 0.55 WO 3, Rb 0.33 WO 3, Cs 0.33 WO 3, Ba 0.21 WO 3, Ba 0.33 WO ₃ , Na _0.11 Cs _0.22 WO _3, and Na _0.11 Cs _0.11 Rb _0.11 WO ₃ .

In one embodiment, the metal-tungsten oxide may be cesium-tungsten oxide.

In one embodiment, the content of the metal-tungsten oxide may be 5 to 20% by weight with respect to the total weight of the near infrared absorbing layer.

In one embodiment, the light-transmitting substrate includes an organic absorbent layer including a transparent substrate and an organic absorbent formed on one surface of the transparent substrate, wherein the near-infrared absorbing layer is formed on the opposite surface of the transparent substrate, . At this time, the content of the organic absorbent may be 10 to 30% by weight based on the total weight of the organic absorbent layer.

In one embodiment, the light-transmitting substrate may be in the form of an organic absorbent dispersed in a matrix formed by the binder resin. At this time, the content of the organic absorbent may be 0.1 to 1% by weight based on the total weight of the light-transmitting substrate.

In one embodiment, the organic absorbent is a cyanine compound, a phthalocyanine compound, a naphthalocyanine compound, a porphyrin compound, a benzoporphyrin compound, a squarylium compound, an anthraquinone compound, a chromium compound, a diimonium compound And dithiol metal complexes.

In one embodiment, the organic absorbent may comprise at least one compound having an absorption maximum in the 690 nm to 730 nm wavelength range.

In one embodiment, the average transmittance of the optical article in the wavelength range of 800 nm to 1200 nm may be from 45% to 55%.

In one embodiment, the near-infrared absorption layer may have a structure in which a metal-tungsten oxide is dispersed in a matrix formed by curing a composition containing at least one selected from silica or an alkoxysilane-based compound. At this time, the near infrared absorbing layer may be prepared by a sol-gel method.

A near infrared ray cut-off filter for a camera module according to another embodiment of the present invention includes the optical article described above.

In one embodiment, the near infrared ray cut-off filter for the camera module includes a first selective wave reflection layer formed on the near infrared absorption layer on one surface of the optical article, and a second selective reflection layer formed on the other surface of the optical article on which the first selective reflection layer is formed 2 < / RTI > selective reflection layer.

In one embodiment, the first selective wave reflection layer is a near-infrared reflection layer, and the second selective reflection layer may be an anti-reflection layer.

According to the near infrared ray cut-off filter for the camera module and the optical article for the near-infrared ray cut-off filter included in the camera module of the present invention, it is possible to absorb the light in the wide wavelength range in the near- It is possible to provide a near infrared ray cut-off filter suitable for a camera module capable of maximizing color reproducibility while suppressing occurrence of ghost or flare.

1 is a view for explaining an optical article for a near-infrared ray cut-off filter according to an embodiment of the present invention.
2 is a view for explaining an optical article for a near-infrared ray cut-off filter according to another embodiment of the present invention.
FIG. 3 is a view for explaining a near-infrared ray cut-off filter including the optical article of FIG. 2. FIG.
4 is a view for explaining a camera module including the near infrared ray cut-off filter of FIG.
Fig. 5 is a graph showing graphs showing changes in transmittance of each of coated-type light-transmitting substrates 1 to 7, dispersion-type light-transmitting substrates 1 to 7, and a transparent substrate.
6 is a graph showing graphs showing changes in transmittance of the optical articles 1-1 to 1-4 and comparative articles 1-1, 1-2, 8-1, and 8-6 according to wavelengths according to the present invention.
FIG. 7 is a graph showing transmittances of respective wavelengths for the first selective reflection layer and the second selective reflection layer according to the present invention.
FIG. 8 is a graph showing changes in transmittance according to wavelengths according to IRCF 1-1 to 1-4 and Comparative Filters 1-1, 1-2, 8-1 and 8-6 according to the present invention.
9 is a view for explaining a ghost / flare measurement method for an IRCF and a comparison filter according to the present invention.
FIG. 10 is a diagram showing photographs of ghost / flare measurement results of the IRCF 4-4 and the comparative filter 1-1 according to the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention is capable of various modifications and various forms, and specific embodiments are illustrated in the drawings and described in detail in the text. It is to be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but on the contrary, is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. Like reference numerals are used for like elements in describing each drawing.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the term "comprises" or "having ", etc. is intended to specify that there is a feature, step, operation, element, part or combination thereof described in the specification, , &Quot; an ", " an ", " an "

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

Optical article

An optical article according to the present invention includes a transparent substrate including an organic absorbent and a near infrared absorbing layer formed on the transparent substrate and including a metal-tungsten oxide, for a near-infrared cut-off filter included in a camera module.

Wherein the optical article has an average transmittance in a wavelength range of 460 nm to 560 nm of 85% or more and 100% or less, and a minimum wavelength value showing a light transmittance of 50% or more at 560 nm or more and less than 650 nm and less than 650 nm, The average transmittance in the wavelength range from 1200 nm to less than 75% is more than 40%. For example, when the optical article has an average transmittance of 45% to 55% in a wavelength range of 800 nm to 1200 nm, the image quality by the near-infrared cut-off filter to which the optical article is applied may be excellent.

Hereinafter, the light-transmitting substrate and the near-infrared absorbing layer of the optical article will be described in detail with reference to Figs. 1 and 2. Fig.

1 is a view for explaining an optical article for a near-infrared ray cut-off filter according to an embodiment of the present invention.

1, an optical article 301 according to an embodiment includes a transparent substrate 101 including the organic absorbent itself and a near infrared absorbing layer 200 formed on one surface of the transparent substrate 101 .

The light-transmitting substrate 101 is a substrate capable of transmitting light in a visible light region, and has a structure in which the organic absorbent is dispersed in a matrix constituting the substrate.

The matrix of the light-transmitting substrate 101 may be formed of a transparent resin. Examples of the transparent resin include polyester resins such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT), polyolefin resins such as polyethylene, polypropylene and ethylene-vinyl acetate copolymer, norbornene resins, poly Acrylic resins such as acrylate and polymethyl methacrylate, urethane resins, vinyl chloride resins, fluororesins, polycarbonate resins, polyvinyl butyral resins, polyvinyl alcohol resins and silicone resins. These may be used alone or in combination of two or more, but the type of the transparent resin listed above is not particularly limited.

As the organic absorbent dispersed in the matrix of the light-transmitting substrate 101, at least one of various kinds of dyes, pigments or metal complex system compounds can be used. The organic absorbent may include a compound having an absorption maximum in a wavelength range of 690 nm to 730 nm, and at least one or more compounds may be used. Specific examples of the organic absorbent include a cyanine compound, a phthalocyanine compound, a naphthalocyanine compound, a porphyrin compound, a benzoporphyrin compound, a squarylium compound, an anthraquinone compound, a chromium compound, a diimonium compound, Metal complexes and the like. These may be used alone or in combination of two or more, but the type of the organic absorbent listed above is not particularly limited.

The thickness of the light-transmitting substrate 101 may be 0.05 to 0.2 mm. In view of the thinness and miniaturization of the optical article or the near-infrared cut-off filter, the thinner the thickness is, the more the glass is thinned to 0.05 mm or less. Preferably, the thickness of the light-transmitting substrate 101 may be 0.05 to 0.1 mm, and more preferably 0.08 to 0.1 mm.

The content of the organic absorbent may be 0.1 to 1% by weight with respect to the total content of the transparent resin forming the matrix of the light-transmitting substrate 101 and the organic absorbent. That is, when the sum of the content of the transparent resin forming the matrix of the light-transmitting substrate 101 and the content of the organic absorbent is 100% by weight, the content of the organic absorbent may be 0.1 to 1% by weight. At this time, the transparent resin content of the light transmitting substrate 101 may be 99 to 99.9% by weight.

The near-infrared absorbing layer 200 is a layer formed on one surface of the light transmitting substrate 101, and includes a metal-tungsten oxide. 1, the near infrared absorbing layer 200 is formed on the lower surface of the translucent substrate 101 with reference to the paper surface, but may be formed on the upper surface.

The near infrared absorbing layer 200 may have a structure in which the metal-tungsten oxide is dispersed in a matrix formed by curing a composition containing at least one species selected from silica or alkoxysilane compounds. As an example of the silica, the average particle size of the primary particles is 10 nm to 50 nm, and the surface of the silica particles may include a silanol (Si-OH) group. Examples of the alkoxysilane-based compound include methacryloxypropyltrimethoxysilane, glycidyloxypropyltrimethoxysilane, phenyltrimethoxysilane, vinyltrimethoxysilane, and methyltriethoxysilane.

In another embodiment, the near infrared absorbing layer 200 may have a structure in which the binder resin forms a matrix and the metal-tungsten oxide is dispersed in the matrix formed by the binder resin. Examples of the binder resin constituting the matrix of the near infrared ray absorbing layer 200 include a cyclic olefin resin, a polyarylate resin, a polysulfone resin, a polyether sulfone resin, a polyparaphenylene resin, a polyarylene ether phosphine oxide resin, A polyamideimide resin, an acrylic resin, a polycarbonate resin, a polyethylene naphthalate resin, a silicone resin, and various kinds of organic-inorganic hybrid resins. These may be used alone or in combination of two or more, but the kind of the binder resin listed above is not particularly limited.

The thickness of the near infrared absorbing layer 200 may be 1 to 10 탆. If it is thicker than 10 탆 thick, it may cause defects in the camera module assembling process due to severe deflection in the optical article or the near-infrared cut-off filter, and if it is thinner than 1 탆 thick, it may be difficult to secure sufficient near infrared absorption ability have. Preferably, the thickness of the near infrared absorbing layer 200 may be 2 to 5 占 퐉.

The metal-tungsten oxide included in the near infrared absorbing layer 200 may be represented by the following chemical formula (1).

[Chemical Formula 1]

In the formula (1), 0? P / q? 1, 2.5? R / q?

M represents A _x B _y D _z ,

A, B and D are each independently selected from the group consisting of Li, Na, K, Rb, Cs, Fr, Ber, Mg, (Ca), strontium (Sr), barium (Ba), radium (Ra), zirconium (Zr), chromium (Cr), manganese (Mn), iron (Fe), ruthenium (Ru), cobalt (Ag), gold (Au), zinc (Zn), cadmium (Cd), aluminum (Au), aluminum (Al), gallium (Ga), indium (In), tallium (Tl), tin (Sn), lead (Pb), titanium (Ti), niobium (Nb), vanadium (V), molybdenum Ruthenium (Re), beryllium (Be), hafnium (Hf), osmium (Os) or bismuth (Bi)

0? X? 1, 0? Y? 1 and 0? Z? 1, and x + y + z = 1.

For example, the metal-tungsten oxide may be cesium-tungsten oxide, wherein the cesium-tungsten oxide may be represented by Cs _p W _q O _r, where the relationship of p, q, 1 and 2.5? R / q? 3. As a specific example, the cesium-tungsten oxide may be represented by Cs _0.33 WO ₃ .

As another example, the metal-tungsten oxide may be selected from the group consisting of Na _0.11 Cs _0.22 WO ₃ , Na _0.5 WO ₃ , K _0.33 WO ₃ , K _0.55 WO ₃ , Rb _0.33 WO ₃ , Cs _0.33 WO ₃ , Ba _0.21 WO ₃ , Ba _0.33 WO ₃ , Na _0.11 Cs _0.22 WO ₃ , Na _0.11 Cs _0.11 Rb _0.11 WO ₃ , and the like.

The metal-tungsten oxide included in the near infrared absorbing layer 200 may be in the form of particles having a size of nanometer size. Here, the particle size is defined as the average size of the particles, and is calculated as the number average particle size measured by the dynamic light scattering method, or an arbitrary two points of the edges of each particle of the irregular shape in the projected surface are connected The longest straight line distance among the straight lines may be an arithmetic mean value of each of these particle sizes. For example, the size of the metal-tungsten oxide particles included in the near infrared absorbing layer 200 may be 100 nm or less, and preferably 70 nm or less. More preferably, the size of the metal-tungsten oxide particles may be 50 nm or less, and most preferably 1 nm to 30 nm.

In the near infrared absorbing layer 200, the content of the metal-tungsten oxide may be 5 to 20% by weight based on the total weight of the near infrared absorbing layer. That is, when the sum of the content of the matrix constituting the near infrared absorbing layer and the content of the metal-tungsten oxide is 100 weight%, the content of the metal-tungsten oxide is 5-20 weight %. ≪ / RTI > At this time, the content of the matrix of the near infrared absorbing layer 200 may be 80 to 95% by weight.

2 is a view for explaining an optical article for a near-infrared ray cut-off filter according to another embodiment of the present invention.

2, an optical article 302 according to another embodiment of the present invention includes a transparent substrate 102 and a near-infrared absorbing layer 200, wherein the transparent substrate 102 includes a transparent substrate 110 and an organic absorbing layer 120). The organic absorbing layer 120 is a layer containing an organic absorbent and is formed on one surface of the transparent substrate 110. [

The transparent substrate 110 can be used as a substrate, a plate of a film or a thin film, and can be used without particular limitation as long as it is a substrate capable of transmitting light in a visible light region.

Examples of the material for forming the transparent substrate 110 include glass, quartz, crystal of lithium niobate, sapphire and the like, polyester resin such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT), polyethylene, polypropylene , Polyolefin resins such as ethylene-vinyl acetate copolymer, norbornene resins, acrylic resins such as polyacrylate and polymethyl methacrylate, urethane resins, vinyl chloride resins, fluororesins, polycarbonate resins, polyvinyl butyral resins, Polyvinyl alcohol resins, and the like. These may be used independently or in combination of two or more, and are not limited to the kinds of the materials listed above.

Examples of specific transparent substrate 110 include ARTON of JSR Corporation (Japan), ZEONEX of ZEON Corporation (Japan), TOPAS of TOPAS Advanced Polymers Co., Ltd. (Germany), Mitsui Chemicals APRI of Mitsubishi Rayon (Japan), SOXR of NKK (Japan), VYLOMAX of TOYOBO (company name, Japan), A4100 And the like. The kind of the transparent substrate of the present invention is not particularly limited to those listed above.

The thickness of the transparent substrate 110 may be 0.05 to 0.2 mm. In view of the thinness and miniaturization of the optical article or the near-infrared cut-off filter, the thinner the thickness is, the more the glass is thinned to 0.05 mm or less. Preferably, the thickness of the transparent substrate 110 may be 0.05 to 0.1 mm, and more preferably 0.08 to 0.1 mm.

In the organic absorbent layer 120, the binder resin may form a matrix, and the organic absorbent may be dispersed in the matrix formed by the binder resin.

Examples of the binder resin include a resin such as a cyclic olefin resin, a polyarylate resin, a polysulfone resin, a polyether sulfone resin, a polyparaphenylene resin, a polyarylene ether phosphine oxide resin, a polyimide resin, a polyetherimide resin, Amide imide resins, acrylic resins, polycarbonate resins, polyethylene naphthalate resins, polyester resins, and various kinds of organic-inorganic hybrid resins. These may be used alone or in combination of two or more, but the kind of the binder resin listed above is not particularly limited. Examples of the organic absorbent are substantially the same as the organic absorbent described in Fig. Therefore, redundant detailed description will be omitted.

The thickness of the organic absorbing layer 120 may be 1 to 10 mu m. If the thickness is increased to 10 탆 or more, there is a fear that the optical article or the near-infrared cut-off filter is severely warped to cause defects in the camera module assembling process. If the thickness is reduced to 1 탆 or less, absorption at 690 nm to 730 nm It may be difficult to provide a compound having a maximum in a sufficient absorption capacity (for example, a light transmittance of an optical article of 1% or less in a wavelength range of 690 nm to 730 nm) in the above wavelength range. Preferably, the thickness of the organic absorbing layer 120 may be 2 to 5 占 퐉.

The content of the organic absorbent may be 10 to 30% by weight based on the total weight of the composition forming the organic absorbent layer 120. That is, when the content of the binder resin contained in the organic absorbent layer 120 and the content of the organic absorbent are defined as 100% by weight, the content of the organic absorbent may be 10 to 30% by weight, May be 70 to 90% by weight.

The near infrared absorbing layer 200 is formed on the opposite side of the surface on which the organic absorbing layer 120 is formed on the main surface of the transparent substrate 110. Alternatively, the near infrared absorbing layer 200 may be formed on the organic absorbing layer 120. It is preferable that the near infrared ray absorbing layer 200 is formed on the opposite surface of the surface on which the organic absorbing layer 120 is formed in that the assembly failure due to warping in the camera module assembling process can be reduced. 2, the organic absorbent layer 120 is formed on the upper surface of the transparent substrate 110 and the near infrared absorbing layer 200 is formed on the lower surface of the transparent substrate 110, Infrared absorbing layer 120 may be formed on the lower surface and the near infrared absorbing layer 200 may be formed on the upper surface.

The near infrared absorbing layer 200 includes a matrix and a metal-tungsten oxide dispersed in the matrix, wherein each of the matrix and the metal-tungsten oxide is substantially in contact with the matrix of the near infrared absorbing layer 200 and the metal- . Therefore, redundant detailed description will be omitted.

The transparent substrate 110 is first prepared and the transparent substrate 110 is coated with the organic absorbing layer 120 to prepare the transparent substrate 102. [ Next, the optical article 302 described in FIG. 2 can be manufactured by coating the near infrared ray absorbing layer 200 on the other surface of the transparent substrate 110 in the light transmitting substrate 102.

At this time, the near-infrared absorption layer 200 is formed by using a sol solution containing a composition containing at least one selected from silica or alkoxysilane compounds and a metal-tungsten oxide dispersed in the composition as a coating solution, A coating film can be formed on the other surface of the substrate 110. [ In the case where the near infrared ray absorbing layer 200 is manufactured by the sol-gel method, a low turbidity (e.g., 1% or less) required for an optical article for a near-infrared cutoff filter mounted on a camera module of a high- , The scratch resistance that can prevent scratches that may occur during the manufacturing process can be achieved while maintaining a level of 0.5% or less, more preferably 0.2% or less. Further, a thick thick film having a thickness of 2 mu m or more of the near infrared absorbing layer for obtaining the high near infrared absorption performance required for the optical article can be formed without micro-cracks. As one example, the sol-gel method is a method in which a coating layer is formed using a coating solution in a sol state including silica, alkoxysilane compound, strong acid, water and alcohol together with metal-tungsten oxide, and the solvent in the coating layer is removed . In this case, the coating solution may further comprise a hydrophilic organic polymer including a polyoxyalkylene group, and the strong acid may include sulfate ion as at least a part thereof. The process of removing the solvent from the coating layer may be performed while maintaining the temperature at 200 ° C. or less. At this time, the near infrared absorbing layer 200 having a structure in which the metal-tungsten oxide is dispersed in the silica matrix through the phase change of the sol- . In the case of the near infrared ray absorbing layer 200 having such a structure, low turbidity and excellent scratch resistance can be obtained, and the near infrared ray absorbing ability of the near infrared ray absorbing layer 200 can be improved, even though the metal-tungsten oxide is included.

Near-infrared cut-off filter

FIG. 3 is a view for explaining a near-infrared ray cut-off filter including the optical article of FIG. 2. FIG.

Referring to FIG. 3, the near-infrared cut-off filter 500 includes an optical article 302, a first selected wavelength reflective layer 410, and a second selected wavelength reflective layer 420. At this time, the optical article 302 is substantially the same as that described with reference to FIG. 2, so duplicate detailed description is omitted.

The first selective wavelength reflective layer 410 may be a first near-infrared reflective layer that transmits light in a visible light region and blocks near infrared rays in a predetermined first wavelength region as a layer disposed on the near infrared absorbing layer 200. For example, the predetermined first wavelength region may be 700 nm to 950 nm. The first selective wave reflection layer 410 may have a structure in which a dielectric layer having a first refractive index and a dielectric layer having a second refractive index are alternately laminated from 5 to 61 layers, 11 to 51 layers, or 21 to 41 layers. The first selective wave reflection layer 410 can be designed in consideration of a range of a desired transmittance, a refractive index, a region of a wavelength to be cut, and the like.

The second selective wavelength reflective layer 420 is a layer formed on the other surface of one side of the translucent substrate 102 on which the near infrared absorbing layer 200 is formed and is formed on the organic absorbing layer 120, And a second near infrared ray reflective layer for blocking near infrared rays in a predetermined second wavelength region. For example, the predetermined second wavelength region may be 950 nm to 1200 nm. The second selective reflection layer 420 may have a structure in which a dielectric layer having a first refractive index and a dielectric layer having a second refractive index are alternately laminated from 5 to 61 layers, 11 to 51 layers, or 21 to 41 layers. The second selective reflection layer 420 can be designed in consideration of a desired transmittance, a range of refractive index, an area of a wavelength to be blocked, and the like.

Alternatively, the second selective reflection layer 420 may be an anti-reflection layer that reduces the phenomenon that light incident on the near-infrared cut-off filter 500 is reflected at the interface, thereby increasing the amount of incident light to the image sensor. At this time, the second selective reflection layer 420 reduces the surface reflection, thereby increasing the outgoing efficiency and eliminating interference or scattering due to the reflected light. The antireflection layer may be formed by forming a thin dielectric film having a refractive index smaller than that of the light-transmitting substrate on the surface thereof by a method such as vacuum deposition or the like, and various commercially available materials can be formed by using no particular limitation.

Of the dielectric layers constituting each of the first and second selective wave reflection layers 410 and 420, titanium dioxide (TiO ₂ ), titanium oxide (Ti ₃ O ₅ ), aluminum oxide (Al ₂ O ₃ ) (ZrO ₂ ), tantalum pentoxide (Ta ₂ O ₅ ), niobium pentoxide (Nb ₂ O ₅ ), lanthanum oxide (La ₂ O ₃ ), yttrium oxide (Y ₂ O ₃ ), zinc oxide (ZnO) Zinc sulfide (ZnS), indium oxide (In ₂ O ₃ ) and the like may be used. In the case of indium oxide, a small amount of titanium dioxide, tin oxide, cerium oxide or the like may be further included.

Of the above dielectric layers, silicon dioxide (SiO ₂ ), lanthanum fluoride (LaF ₃ ), magnesium fluoride (MaF ₂ ), sodium hexafluoride sodium (cryolite, Na ₃ AlF ₆ ) and the like can be used as the low refractive index layer have. However, the kind of the material constituting the dielectric layer is not particularly limited to those listed above.

Each of the dielectric layers constituting the first and second selective wave reflection layers 410 and 420 is formed by a reactive sputtering method using an Ar gas as a carrier gas and a silicon target and an O ₂ gas Or an e-beam evaporation method in which a source of titanium dioxide (TiO ₂ ) or silicon dioxide (SiO ₂ ) is sublimated and deposited.

3, the near infrared ray cut-off filter 500 including the optical article 302 described with reference to FIG. 2 has been described. However, the near infrared ray cut- The near-infrared cut-off filter may be formed by forming the wavelength selective reflection layer 410 and forming the second selective reflection layer 420 on the other surface of the transparent substrate 101 on which the near infrared absorbing layer 200 is formed.

Camera module

4 is a view for explaining a camera module including the near infrared ray cut-off filter of FIG.

4, the camera module 600 includes a sensing unit including an image sensor 601, a lens unit including at least one lens 602, and a near infrared ray (IR) sensor disposed between the sensing unit and the lens unit. And a cut-off filter (IRCF).

At this time, the camera module 600 is not particularly limited, and may be a camera device mounted on a mobile device such as a mobile phone, a digital camera, a camera device mounted on a notebook PC, and a camera device for a CCTV.

The image sensor 601 may be a CMOS image sensor. The light incident on the lens portion of the camera module 600 is provided to a near infrared ray cut-off filter (IRCF) via lenses 602. Light emitted from a near infrared ray cut-off filter (IRCF) And is provided to the image sensor 601.

The near infrared ray cut-off filter IRCF of FIG. 4 includes the optical article 301 described in FIG. 1 or includes the optical article 302 described in FIG. 2, wherein the first and second choices And a wavelength reflective layer (410, 420).

When the light passing through the lenses 602 is provided to the image sensor 601, all incident light provided to the image sensor 601 is not vertically incident on the image sensor 601, but partly tilted and incident , There is a problem that the color is changed, and the color reproducibility is deteriorated.

However, by applying the near infrared ray cut-off filter (IRCF) including the optical articles 301 and 302 according to the present invention to the camera module 600, it is possible to substantially observe the change of the angle of incidence of the light incident on the image sensor 601 Color reproducibility can be exhibited without changing the color tone to such an extent that it is possible to obtain a high color reproducibility. Further, the near infrared ray cut-off filter (IRCF) including the optical articles 301 and 302 according to the present invention is a phenomenon in which unintended images are displayed on an image taken together with an artificial light including near- It is possible to minimize the occurrence of image distortion problems such as so-called ghost or flare.

Hereinafter, the present invention will be described in more detail through a characteristic evaluation of a near-infrared ray cut-off filter including a specific optical article and a manufactured optical article. The following optical article is only an example to explain the present invention specifically, and the present invention is not limited thereto.

Coated type light-transmitting substrates 1 to 7

A light emitter plate having an organic absorbent layer containing an organic absorbent on one side of a transparent substrate was prepared as follows. First, NIR700A (trade name, QCR Solutions, USA) and NIR720B (trade name, QCR Solutions, Inc., USA) having an absorption maximum in the wavelength range of 720 ± 5 nm were used as an organic absorbent having an absorption maximum in a wavelength range of 700 ± 5 nm ), 7 g of a binder resin and 210 g of a solvent were mixed and an organic absorbent having an absorption maximum in the wavelength range of 700 ± 5 nm and an organic absorbent having an absorption maximum in the wavelength range of 720 ± 5 nm were mixed at a weight ratio of 1: . Thereafter, the mixture was stirred with a stirrer for 24 hours or more to prepare a coating solution. At this time, polyethylene terephthalate (PET) resin was used as the binder resin, and cyclohexanone was used as the organic solvent.

The coating solution was coated on one side of a 0.1 mm thick polyethylene terephthalate film (PET film, available from Toyo Spinning Co., Ltd. under the trade name of A4100) as a transparent substrate and cured at 120 캜 for 50 minutes to form an organic absorbing layer having a thickness of 2 탆, A translucent substrate 1 (hereinafter referred to as a coated translucent substrate) 1 having an organic absorbent layer coated on one surface of a substrate was prepared.

The coating type light-transmitting substrates 2 to 7 were prepared through substantially the same steps as those of the coating type light-transmitting substrate 1 except for the concentration of the organic absorbent. The concentration of the organic absorbent in the organic absorbent layer for the production of the coated type light transmitting substrates 2 to 7 was prepared according to the following Table 1.

division Coated type light-transmitting substrate 1 Coated type light-transmitting substrate 2 Coated type light-transmitting substrate 3 Coated type light-transmitting substrate 4 Coated type light-transmitting substrate 5 Coated type light-transmitting substrate 6 Coated type light-transmitting substrate 7 Content of organic absorbent (unit: wt%) 24.7 22.1 20.4 17.9 16.2 14.9 13.6

The dispersion type light-transmitting substrates 1 to 7

In order to prepare a light-transmitting substrate (hereinafter, referred to as a dispersion-type light-transmitting substrate) in which an organic absorbent is dispersed in a matrix formed by a binder resin, A light-transmitting substrate 1 was prepared.

(Trade name, QCR Solutions, USA) as an organic absorbent having an absorption maximum in the wavelength range of 700 + - 5 nm and an ultraviolet absorber having a wavelength range of 720 + - 5 nm NIR720B (trade name, QCR Solutions, USA), an organic absorbent having an absorption maximum, and methylene chloride were mixed to obtain a dispersion-type light transmitting substrate preparation solution having a content of the resin of 20 wt% with respect to the total weight. At this time, an organic absorbent having an absorption maximum in the wavelength range of 700 ± 5 nm and an organic absorbent having an absorption maximum in the wavelength range of 720 ± 5 nm were mixed at a weight ratio of 1: 1. The dispersion-type light-transmitting substrate preparation solution was cast on a glass plate in a solution state and applied at a uniform thickness, dried at 20 ° C for 8 hours, and then peeled off from the glass plate. The peeled film was dried at 100 占 폚 under reduced pressure for 8 hours to prepare a dispersion type translucent substrate 1 having a thickness of 0.1 mm.

The dispersed type light transmitting substrates 2 to 7 were produced through substantially the same steps as those of the dispersion type light transmitting substrate 1 except for the concentration of the organic absorbent. The content of the organic absorbent contained in the manufactured dispersed type light transmitting substrates 1 to 7 is shown in Table 2 below.

division Coated type light-transmitting substrate 1 Coated type light-transmitting substrate 2 Coated type light-transmitting substrate 3 Coated type light-transmitting substrate 4 Coated type light-transmitting substrate 5 Coated type light-transmitting substrate 6 Coated type light-transmitting substrate 7 Content of organic absorbent (unit: wt%) 0.49 0.43 0.39 0.34 0.30 0.27 0.24

Optical property evaluation 1: Coated type  The emitter plates 1 to 7 and the dispersed emitter plates 1 to 7

Using the spectrophotometer Lambda 1050 manufactured by Perkin Elmer, the coated transparent substrates 1 to 7, the dispersed transparent substrates 1 to 7, and the transparent substrate on which the organic absorbent layer was not formed, Permeability (unit%) was measured. At this time, the measurement wavelength range was from 350 nm to 1200 nm. The results are shown in Fig.

(% T _avg @ 460-560) in the wavelength range of 460 to 560 nm, an average transmittance (% T _avg @ 800-1200) in the wavelength range of 800 to 1200 nm, and a transmittance of 560 nm or more (Cut-off T50%) at which the transmittance becomes 50% for the first time. The results are shown in Table 3 below.

division % T _avg
@ 460-560 Cut-off T50% % T _avg
@ 800-1200 Coated type light-transmitting substrate 1 89 631 92 Coated type light-transmitting substrate 2 89 634 92 Coated type light-transmitting substrate 3 90 637 92 Coated type light-transmitting substrate 4 90 640 92 Coated type light-transmitting substrate 5 90 643 92 Coated type light-transmitting substrate 6 90 645 92 Coated type light-transmitting substrate 7 90 647 92 The dispersion type light-transmitting substrate 1 89 631 92 The dispersion type light-transmitting substrate 2 89 635 92 Dispersion type light-transmitting substrate 3 90 638 92 The dispersion type light-transmitting substrate 4 90 642 92 The dispersion type light-transmitting substrate 5 90 645 92 The dispersion type light-transmitting substrate 6 90 648 92 The dispersion type light-transmitting substrate 7 90 650 92 Transparent substrate 92 - 92

Fig. 5 is a graph showing graphs showing changes in transmittance of each of coated-type light-transmitting substrates 1 to 7, dispersion-type light-transmitting substrates 1 to 7, and transparent substrate.

In FIG. 5, (a) is a graph for coated type light-transmitting substrates 1 to 7, (b) is a graph for dispersed type light-transmitting substrates 1 to 7, and (c) is a graph for a transparent substance itself.

Referring to FIG. 5 and Table 3, in the case of coated type light-transmitting substrates 1 to 7 and dispersed type light-transmitting substrates 1 to 7, the average transmittance in a wavelength range of 460 nm to 560 nm is 89% to 90% , An average transmittance of about 92% in a wavelength range of 800 nm to 1200 nm, and a minimum wavelength value showing a light transmittance of 50% at a wavelength of 560 nm or more is shown between 631 nm and 650 nm. Both of the coated type light-transmitting substrate and the dispersed type light-transmitting substrate are required to have a transmittance of 50% at a point where the light transmittance starts to decrease at the boundary between the visible light region and the near-infrared region due to the characteristic of the organic absorbent having an absorption maximum at a specific wavelength Cut-off T50% wavelength appears at the beginning of the reduction, while the cut-offT 50% wavelength does not appear for the transparent substrate not containing the organic absorbent. Further, from the above results, it can be seen that the coating type or dispersed type light transmitting substrate alone has a high average transmittance in the near infrared region of 800 nm to 1200 nm, which is higher than 90% There is a high possibility of causing deterioration of image quality such as problems such as ghost or flare and problems of color reproduction.

Optical article 1-1

(1) Preparation of near infrared absorbing layer coating liquid

In order to form a near infrared absorbing layer on one surface of a coated or dispersed type light transmitting substrate, a sol solution for near infrared ray coating was prepared as follows.

First, a colloidal silica solution (Ludox LS, 30% SiO ₂ , manufactured by Sigma-Aldrich) having an average size of silica particles of 12 nm was charged with 100 parts by weight of colloidal silica solution in ethanol and distilled water Were mixed in an amount of 100 parts by weight, respectively, and stirred for 1 hour. Thereafter, a certain amount of nitric acid (70%, Sigma-Aldrich) was added during stirring to adjust the pH of the solution to be in the range of 4 to 6. To this solution, 100 parts by weight of the silica solution (3-glycidyloxypropyltrimethoxysilane, 98%, Sigma-Aldrich) was added in an amount of 23 parts by weight, and the mixture was stirred at a temperature of 30 캜 for 24 hours. Ethylenediamine (99%, Sigma-Aldrich) as a curing accelerator was added to the stirred solution in an amount of 3 parts by weight based on 100 parts by weight of the colloidal silica, and the mixture was stirred for 1 hour.

To this solution, a dispersion solution in which Cs _0.33 WO ₃ having a mean particle size of about 20 nm as a metal-tungsten oxide was dispersed was added in a mass ratio of 8: 1 and stirred for 2 hours to prepare a near infrared absorbing layer coating solution. At this time, as a Cs _0.33 WO ₃ dispersion solution, a dispersion solution was prepared by mixing the mixture so that the mass ratio of methyl ethyl ketone to Cs _0.33 WO ₃ nanoparticles was 3: 1 and ball milling for 5 hours.

(2) Production of optical article 1-1

The prepared coating solution was coated on the opposite surface of one side of the coating type light transmitting substrate 1 having a thickness of 0.1 mm on which the organic absorbent layer was formed by using a spin coater. The coated substrate was cured at 120 캜 for 60 minutes to prepare an optical article 1-1 having an organic absorbent layer formed on one surface of a transparent substrate and a near infrared absorbing layer having a thickness of 3 탆 formed on the other surface. At this time, the Cs _{0. 0} included in the near infrared absorbing layer in the manufactured optical article 1-1 _. The content of ₃₃ WO ₃ was 7.5% by weight based on the total weight of the near infrared absorbing layer.

Production of optical articles 1-2 to 1-4

The coating solution for the production of the near infrared ray absorbing layer was prepared in the same manner as in the optical article 1-1 except for the content of Cs _0.33 WO ₃ , Optical articles 1-2 were prepared. The content of Cs _0.33 WO ₃ contained in the near infrared absorbing layer of the optical article 1-2 was 11.2% by weight based on the total weight of the near infrared absorbing layer.

In addition, the coating solution was prepared, and the optical article 1-3 produced in accordance with the optical article 1-3 and the optical article 1-4 prepared in accordance with the optical article 1-4 were prepared. The content of Cs _0.33 WO ₃ contained in the near infrared absorbing layer of the manufactured optical article 1-3 was 13.7% by weight with respect to the total weight of the near infrared absorbing layer, and the content of Cs _0.33 WO ₃ contained in the near infrared absorbing layer of the optical article 1-4 Was 18.7% by weight based on the total weight of the near infrared absorbing layer.

Production of optical articles 2-1 to 7-4

Optical articles 2-1 to 7-4 were produced substantially through the same process as optical article 1-1 except for the conditions shown in Table 4 below.

Used equipment Content of Cs _0.33 WO ₃ in the near infrared absorbing layer
(Unit: wt%) Optical article 2-1 Coated type light-transmitting substrate 2 7.5 Optical article 2-2 11.2 Optical article 2-3 13.7 Optical article 2-4 18.7 Optical article 3-1 Coated type light-transmitting substrate 3 7.5 Optical article 3-2 11.2 Optical article 3-3 13.7 Optical article 3-4 18.7 Optical article 4-1 Coated type light-transmitting substrate 4 7.5 Optical article 4-2 11.2 Optical article 4-3 13.7 Optical article 4-4 18.7 Optical article 5-1 Coated type light-transmitting substrate 5 7.5 Optical article 5-2 11.2 Optical article 5-3 13.7 Optical article 5-4 18.7 Optical article 6-1 Coated type light-transmitting substrate 6 7.5 Optical article 6-2 11.2 Optical article 6-3 13.7 Optical article 6-4 18.7 Optical article 7-1 Coated type light-transmitting substrate 7 7.5 Optical article 7-2 11.2 Optical article 7-3 13.7 Optical article 7-4 18.7

Preparation of comparative articles 1-1 to 8-6

Comparative products 1-1 to 8-6 were prepared substantially the same as Optical Article 1-1 except for the conditions shown in Table 5 below.

Used equipment Content of Cs _0.33 WO ₃ in the near infrared absorbing layer (unit: wt%) Comparative article 1-1 Coated type light-transmitting substrate 1 1.2 Comparative article 1-2 49.8 Comparative article 2-1 Coated type light-transmitting substrate 2 1.2 Comparative article 2-2 49.8 Comparative article 3-1 Coated type light-transmitting substrate 3 1.2 Comparative article 3-2 49.8 Comparative article 4-1 Coated type light-transmitting substrate 4 1.2 Comparative article 4-2 49.8 Comparative article 5-1 Coated type light-transmitting substrate 5 1.2 Comparative article 5-2 49.8 Comparative article 6-1 Coated type light-transmitting substrate 6 1.2 Comparative article 6-2 49.8 Comparative article 7-1 Coated type light-transmitting substrate 7 1.2 Comparative article 7-2 49.8 Comparative article 8-1 A transparent substrate on which an organic absorbent layer is not formed 1.2 Comparative article 8-2 7.5 Comparative article 8-3 11.2 Comparative article 8-4 13.7 Comparative article 8-5 18.7 Comparative article 8-6 49.8

Optical property evaluation 2: Optical articles 1-1 to 7-4 and comparative articles 1-1 to 8-6

The optical transmittance of each of the optical articles 1-1 to 7-4 and the comparative articles 1-1 to 8-6 was measured by substantially the same method as the optical characteristic evaluation 1. [ Among them, the transmittances of the optical articles 1-1 to 1-4 and comparative articles 1-1, 1-2, 8-1 and 8-6 for respective wavelengths are shown in Fig.

From the transmittance data by wavelength, the average transmittance (% T _avg @ 460-560) in the wavelength range of 460 to 560 nm, the average transmittance (% T _avg @ 800-1200) in the wavelength range of 800 to 1200 nm and the transmittance (Cut-off T50%) at which the transmittance becomes 50% for the first time is calculated. The results are shown in Tables 6 and 7 below.

division % T _avg @ 460-560 Cut-off T50% % T _avg @ 800-1200 Optical article 1-1 87 629 69.8 Optical article 1-2 86 628 60.8 Optical article 1-3 86 627 55.4 Optical articles 1-4 85 626 46.1 Optical article 2-1 88 632 69.8 Optical article 2-2 87 631 60.7 Optical article 2-3 86 630 55.4 Optical article 2-4 85 629 46.1 Optical article 3-1 88 634 69.7 Optical article 3-2 87 633 60.7 Optical article 3-3 86 632 55.4 Optical article 3-4 85 631 46.1 Optical article 4-1 88 638 69.7 Optical article 4-2 87 637 60.7 Optical article 4-3 86 636 55.4 Optical article 4-4 85 634 46.0 Optical article 5-1 88 641 69.7 Optical article 5-2 87 640 60.7 Optical article 5-3 87 639 55.3 Optical article 5-4 85 637 46.0 Optical article 6-1 88 643 69.7 Optical article 6-2 87 642 60.7 Optical article 6-3 87 641 55.3 Optical article 6-4 85 639 46.0 Optical article 7-1 88 645 69.7 Optical article 7-2 87 644 60.7 Optical article 7-3 87 643 55.3 Optical article 7-4 86 642 46.0

division % T _avg
@ 460-560 cut-off T50% % T _avg
@ 800-1200 Comparative article 1-1 89 631 87.9 Comparative article 1-2 77 616 14.7 Comparative article 2-1 89 634 87.9 Comparative article 2-2 78 618 14.7 Comparative article 3-1 89 636 87.9 Comparative article 3-2 78 620 14.7 Comparative article 4-1 89 640 87.8 Comparative article 4-2 78 623 14.7 Comparative article 5-1 90 643 87.8 Comparative article 5-2 78 625 14.7 Comparative article 6-1 90 645 87.8 Comparative article 6-2 78 627 14.7 Comparative article 7-1 90 647 87.8 Comparative article 7-2 78 629 14.7 Comparative article 8-1 91 - 87.6 Comparative article 8-2 90 - 69.5 Comparative article 8-3 89 - 60.5 Comparative article 8-4 88 - 55.2

6 is a graph showing graphs showing changes in transmittance of the optical articles 1-1 to 1-4 and comparative articles 1-1, 1-2, 8-1, and 8-6 according to wavelengths according to the present invention.

In Fig. 6, (a) is for optical articles 1-1 to 1-4, and (b) is for comparative articles 1-1, 1-2, 8-1 and 8-6.

Referring to Table 6 and Table 7 together with FIG. 6, in each of the optical articles 1-1 to 7-4, the average transmittance in a wavelength range of 460 nm to 560 nm is 85% or more and 100% or less, , The minimum wavelength value representing the light transmittance of 50% is greater than 625 nm and less than 650 nm, and the average transmittance is more than 40% and less than 75% in the wavelength range of 800 nm to 1200 nm. From these results, it can be seen that the optical article according to the present invention has a high transmittance characteristic of 85% or more in the visible light region suitable for application to a near-infrared cut-off filter for a camera module of a high-picture area and still has a high sensitivity in a CMOS image sensor It is possible to simultaneously provide a low transmittance characteristic of 75% or less in a near infrared wavelength range of 800 to 1200 nm. In addition, it has a cut-off T50% characteristic suitable for a commercial CMOS image sensor applied to a camera module of a high-pixel area, which is easy to apply commercially.

On the other hand, in the comparative articles 1-1 to 7-2, it can be seen that the average transmittance is a level of less than 15% or a value of 87% or more in a wavelength range of 800 nm to 1200 nm. In the comparative article, even if the average transmittance is lowered to 40% or less in the 800 nm to 1200 nm near-infrared wavelength range, the average transmittance in the visible light region is significantly lowered to 80% or less, or the average transmittance in the visible light region is 90 %, The average transmittance in a wavelength range from 800 nm to 1200 nm is also significantly increased to 87% or more, and when a commercial CMOS image sensor is used, there is a high possibility of causing deterioration of image quality, problems such as ghost and flare Able to know. In the case of comparative articles 8-1 to 8-4, it does not exhibit the minimum wavelength showing a light transmittance of 50% at 560 nm or more, that is, a cut-off T50% wavelength, off T50% wavelength is in the range of 718 ~ 934 nm, it is not suitable for application to the near-infrared ray cut-off filter which is compatible with commercial CMOS image sensor for high-resolution camera and can provide excellent color reproducibility.

The results of the optical articles 1-1 to 7-4 and the comparative articles 1-1 to 7-2 together show that the content of the metal-tungsten oxide contained in the near infrared absorbing layer does not vary with the entirety of the near infrared absorbing layer In the case of less than 5 wt% or more than 20 wt% of the weight, the average transmittance exceeds 87% or rather decreases to 15% in the wavelength range of 800 nm to 1200 nm. Therefore, It is not suitable as the application of the optical article for application to the near-infrared cut-off filter. Accordingly, it can be understood that the content of the metal-tungsten oxide included in the near infrared absorbing layer of the optical article according to the present invention to achieve the object of the present invention is preferably in the range of 5.0 wt% to 20 wt%.

Fabrication of near-infrared cut-off filter (IRCF)

For each of the optical articles 1-1 to 7-4 prepared above, the above-described first near-infrared ray reflection layer is formed as a first selective wave reflection layer on the near-infrared absorption layer, and on the opposite side of the organic absorption layer, IRCF 1-1 to 7-4 for a camera module according to the present invention were prepared by forming the second near-infrared reflecting layer described above.

Further, for each of the comparative articles 1-1 to 7-2, the first near-infrared ray reflection layer is formed as a first selective wave reflection layer on the near-infrared absorption layer, and the second near- By forming the reflective layer, each of Comparative Filters 1-1 to 7-2 was prepared. For each of the comparative articles 8-1 to 8-6, the first near-infrared reflecting layer is formed as the first selective reflection layer on the near-infrared absorbing layer, and since there is no organic absorbent layer on the opposite surface, A second near-infrared reflecting layer was formed, and comparative filters 8-1 through 8-6 were prepared.

The first selective reflection layer was designed according to the following Table 8, and the second selective reflection layer was designed according to Table 9 below. Ti ₃ O ₅ and SiO ₂ were alternately deposited using an electron beam evaporator (E-beam evaporator) to form a first selective reflection layer and a second selective reflection layer having a total thickness of 3.5 μm and 3.0 μm, respectively.

In Table 8 below, the lamination sequence 1 corresponds directly to the near infrared absorbing layer and the lamination sequence 30 corresponds to the exposed surface. In Table 9 below, the lamination sequence 1 is a layer directly contacting the organic absorbent layer or the transparent substrate, Step 23 corresponds to the surface exposed to the outside.

FIG. 7 is a graph showing transmittances of respective wavelengths for the first selective reflection layer and the second selective reflection layer according to the present invention.

In Fig. 7, (a) is for the first selective reflection layer and (b) is for the second selective reflection layer.

Stacking order material Optical Thickness (QWOT) Thickness (nm) One SiO ₂ 0.121 9.1 2 Ti ₃ O ₅ 0.299 35.4 3 SiO ₂ 1.325 99.2 4 Ti ₃ O ₅ 1.319 156.1 5 SiO ₂ 1.159 86.8 6 Ti ₃ O ₅ 1.242 147.0 7 SiO ₂ 1.114 83.4 8 Ti ₃ O ₅ 1.226 145.2 9 SiO ₂ 1.110 83.1 10 Ti ₃ O ₅ 1.217 144.0 11 SiO ₂ 1.103 82.6 12 Ti ₃ O ₅ 1.218 144.2 13 SiO ₂ 1.100 82.3 14 Ti ₃ O ₅ 1.227 145.2 15 SiO ₂ 1.102 82.5 16 Ti ₃ O ₅ 1.233 146.0 17 SiO ₂ 1.128 84.4 18 Ti ₃ O ₅ 1.259 149.0 19 SiO ₂ 1.179 88.3 20 Ti ₃ O ₅ 1.297 153.6 21 SiO ₂ 1.340 100.3 22 Ti ₃ O ₅ 1.514 179.2 23 SiO ₂ 1.524 114.1 24 Ti ₃ O ₅ 1.553 183.9 25 SiO ₂ 1.493 111.8 26 Ti ₃ O ₅ 1.557 184.3 27 SiO ₂ 1.472 110.2 28 Ti ₃ O ₅ 1.495 177.0 29 SiO ₂ 1.353 101.3 30 Ti ₃ O ₅ 0.676 80.1

Stacking order material Optical Thickness (QWOT) Thickness (nm) One SiO ₂ 0.434 37.6 2 Ti ₃ O ₅ 0.227 12.1 3 SiO ₂ 0.485 41.9 4 Ti ₃ O ₅ 2.195 116.6 5 SiO ₂ 2.109 182.6 6 Ti ₃ O ₅ 2.173 115.5 7 SiO ₂ 2.171 187.9 8 Ti ₃ O ₅ 2.205 117.2 9 SiO ₂ 2.175 188.2 10 Ti ₃ O ₅ 2.216 117.8 11 SiO ₂ 2.187 189.3 12 Ti ₃ O ₅ 2.216 117.7 13 SiO ₂ 2.181 188.8 14 Ti ₃ O ₅ 2.219 117.9 15 SiO ₂ 2.181 188.8 16 Ti ₃ O ₅ 2.208 117.3 17 SiO ₂ 2.173 188.1 18 Ti ₃ O ₅ 2.196 116.7 19 SiO ₂ 2.152 186.3 20 Ti ₃ O ₅ 2.159 114.7 21 SiO ₂ 2.097 181.6 22 Ti ₃ O ₅ 2.055 109.2 23 SiO ₂ 1.013 87.7

Optical property evaluation 3: IRCF  1-1 to 7-4 and comparison filters 1-1 to 8-6

IRCF 1-1 to 7-4 For each of the iris filters 1-1 to 8-6, the transmittance of each wavelength was measured by substantially the same method as in optical characteristic evaluation 1. [ Among them, FIG. 8 shows changes in the transmittance of the IRCF 1-1 to 1-4 irreversible filters 1-1, 1-2 and 8-1 to 8-6 for respective wavelengths.

From the transmittance data by wavelength, the average transmittance (% T _avg @ 460-560) in the wavelength range of 460 to 560 nm, the average transmittance (% T _avg @ 800-1200) in the wavelength range of 800 to 1200 nm and the transmittance (Cut-off T50%) at which the transmittance becomes 50% for the first time is calculated. The results are shown in Tables 10 and 11 below.

division % T _avg @ 460-560 Cut-off T50% % T _avg
@ 800-1200 IRCF 1-1 92 632 0.13 IRCF 1-2 91 631 0.11 IRCF 1-3 90 631 0.10 IRCF 1-4 89 629 0.08 IRCF 2-1 92 636 0.13 IRCF 2-2 91 634 0.11 IRCF 2-3 91 634 0.10 IRCF 2-4 90 632 0.08 IRCF 3-1 93 638 0.13 IRCF 3-2 92 637 0.11 IRCF 3-3 91 636 0.10 IRCF 3-4 90 635 0.08 IRCF 4-1 93 642 0.13 IRCF 4-2 92 641 0.11 IRCF 4-3 92 640 0.10 IRCF 4-4 90 638 0.08 IRCF 5-1 94 645 0.13 IRCF 5-2 93 644 0.11 IRCF 5-3 92 643 0.10 IRCF 5-4 91 641 0.08 IRCF 6-1 94 647 0.13 IRCF 6-2 93 646 0.11 IRCF 6-3 92 645 0.10 IRCF 6-4 91 644 0.08 IRCF 7-1 94 649 0.13 IRCF 7-2 93 648 0.11 IRCF 7-3 92 647 0.10 IRCF 7-4 91 646 0.08

division % T _avg
@ 460-560 Cut-off T50% % T _avg
@ 800-1200 Comparison Filter 1-1 94 634 0.16 Comparative Filter 1-2 82 621 0.03 Comparison filter 2-1 94 637 0.16 Comparison Filter 2-2 82 623 0.03 Comparison filter 3-1 94 640 0.16 Comparative Filter 3-2 82 625 0.03 Comparison filter 4-1 95 643 0.16 Comparative Filter 4-2 83 628 0.03 Comparison filter 5-1 95 646 0.16 Comparative Filter 5-2 83 630 0.03 Comparison filter 6-1 95 648 0.16 Comparison Filter 6-2 83 632 0.03 Comparison filter 7-1 96 650 0.16 Comparative Filter 7-2 84 635 0.03 Comparative Filter 8-1 98 696 0.16 Comparative Filter 8-2 97 695 0.13 Comparative Filter 8-3 96 695 0.11 Comparative Filter 8-4 95 694 0.10 Comparative Filter 8-5 94 694 0.08 Comparative Filter 8-6 86 689 0.03

FIG. 8 is a graph showing changes in transmittance according to wavelengths according to IRCF 1-1 to 1-4 and Comparative Filters 1-1, 1-2, 8-1 and 8-6 according to the present invention.

In FIG. 8, (a) shows IRCF 1-1 to 1-4, and (b) shows comparative filters 1-1, 1-2, 8-1 and 8-6.

Referring to Table 10 and Table 11 together with FIG. 8, in the case of IRCF 1-1 to 7-4 produced using the optical article according to the present invention, the minimum wavelength value indicating the light transmittance of 50% at 560 nm or more is 629 nm to 649 nm, an average transmittance in a wavelength range of 460 nm to 560 nm is 89% or more, and an average transmittance in a wavelength range of 800 nm to 1200 nm is not more than 0.13% . From these results, it can be seen that the IRCF including the optical article according to the present invention is able to provide the required optical characteristics as an IRCF compatible with a commercial CMOS image sensor and suitable for a camera module. However, in the case of Comparative Filters 1-1 to 7-2, when the content of the metal-tungsten oxide contained in the optical article according to the present invention is out of an appropriate range and is more than 20.0 wt% or less than 5 wt% The average transmittance in the wavelength range of 460 nm to 560 nm is less than 85%, which makes it unsuitable for use in a camera module of a high pixel or increases in the average transmittance in a wavelength range of 800 nm to 1200 nm, The tendency to cause image distortion such as flare is increased. On the other hand, in the case of the comparative filters 8-1 to 8-6, the cut-off T50% wavelength value was 689 nm only in the near-infrared absorbing layer containing metal-tungsten oxide without the organic absorbent layer included in the optical article according to the present invention. The wavelength shift of the visible light transmission band according to the incident angle becomes severe and it is difficult to achieve the faithful color reproducibility required in the camera module in the compatibility with the commercialized CMOS image sensor.

Image quality evaluation

In order to evaluate the image quality of the camera module according to the IRCF and the comparison filter, the IRCF 1-1 to 7-4 and the comparative filters 1-1 to 8-6 are respectively connected to a commercial smartphone Xperia Z5 (model name of Sony Corporation) It was combined with a camera module and assembled into a smartphone, and then a halogen lamp was photographed. At this time, as shown in FIG. 9, the halogen lamp was photographed while changing the angle between the halogen lamp subject and the camera module, and ghost and flare were evaluated for the photographed image. 9 is a diagram showing the positional relationship between the halogen lamp and the camera module, wherein the angle formed by the halogen lamp and the normal direction of the image sensor incident surface mounted on the camera module (or the normal direction of the IRCF or comparative filter incident surface) And a value of 0 when the halogen lamp is located in the normal direction was set to 0 degree. A halogen lamp was photographed at a position having an angle of incidence of 0 degrees, 15 degrees, 30 degrees, and 45 degrees by moving the smartphone on which the respective IRCF or the comparative filter is mounted on a predetermined plane. The evaluation results are shown in Table 12 and Table 13 below. Among them, ghost and flare results for IRCF 4-4 and Comparative Filter 1-1 are shown in Fig.

In addition, after photographing the color chart as the same subject, the image quality was evaluated using the color chart and the difference in RGB ratio included in the photographed photograph, and the results are shown in Tables 12 and 13 below.

division Ghost / Flare Image quality IRCF 1-1 △ △ IRCF 1-2 △ △ IRCF 1-3 △ △ IRCF 1-4 ○ △ IRCF 2-1 △ ○ IRCF 2-2 △ △ IRCF 2-3 △ △ IRCF 2-4 ○ △ IRCF 3-1 △ ○ IRCF 3-2 △ ○ IRCF 3-3 △ ○ IRCF 3-4 ○ △ IRCF 4-1 △ ○ IRCF 4-2 △ ○ IRCF 4-3 △ ○ IRCF 4-4 ○ ○ IRCF 5-1 △ ○ IRCF 5-2 △ ○ IRCF 5-3 △ ○ IRCF 5-4 ○ ○ IRCF 6-1 △ △ IRCF 6-2 △ △ IRCF 6-3 △ △ IRCF 6-4 ○ ○ IRCF 7-1 △ △ IRCF 7-2 △ △ IRCF 7-3 △ △ IRCF 7-4 ○ △

division Ghost / Flare Image quality Comparison Filter 1-1 × △ Comparative Filter 1-2 ○ × Comparison filter 2-1 × ○ Comparison Filter 2-2 ○ × Comparison filter 3-1 × ○ Comparative Filter 3-2 ○ × Comparison filter 4-1 × ○ Comparative Filter 4-2 ○ × Comparison filter 5-1 × △ Comparative Filter 5-2 ○ × Comparison filter 6-1 × △ Comparison Filter 6-2 ○ × Comparison filter 7-1 × × Comparative Filter 7-2 ○ × Comparative Filter 8-1 × × Comparative Filter 8-2 × × Comparative Filter 8-3 × × Comparative Filter 8-4 × × Comparative Filter 8-5 × × Comparative Filter 8-6 × ×

In Table 12 and Table 13, "o" in the ghost / flare indicates a case where ghost / flare is hardly observed and "DELTA" indicates a ghost / flare , "? &Quot; means a level at which the ghost / flare becomes severe and thus is difficult to use in the camera module. In the image quality, "? "Indicates a case where the difference in the ratio of RGB of the photographed color chart is within 5% and the image quality is excellent."? & Means that the difference in the ratio of RGB of the photographed color chart is 10% or more, which is difficult to use in the camera module.

FIG. 10 is a diagram showing photographs of ghost / flare measurement results of the IRCF 4-4 and the comparative filter 1-1 according to the present invention. In the case of IRCF 4-4, ghost / flare hardly appears, but in case of comparison filter 1-1, ghost / flare is severe.

Referring to Tables 12 and 13 and FIG. 10, in the case of IRCF 1-1 to 7-4, ghost / flare does not appear or appears to be weak, and the image quality is good, In the case of the comparative filters 1-1 to 8-6, both ghost and flare are displayed or the image quality is seriously deteriorated and it is difficult to use in the camera module.

According to the above results, it can be seen that the IRCF using the optical article according to the present invention suppresses ghost / flare as compared with the comparison filters, and exhibits excellent image quality.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention as defined by the following claims. It can be understood that it is possible.

301 and 302: optical articles
101 and 102:
110: transparent substrate
120: organic absorbent layer
200: near infrared absorbing layer
410, 420: first and second selective reflection layers
500: near infrared ray cut-off filter
600: Camera module
700: Halogen lamp

Claims (16)

The organic absorbent has a dispersed structure in which the organic absorbent is directly dispersed in the inside or a coating layer comprising an organic absorbent is coated on one surface of the transparent substrate and the organic absorbent absorbs in a wavelength range of 690 nm to 730 nm A light-transmitting substrate characterized by having a maximum; And
And a near infrared absorbing layer formed on the light transmitting substrate and including a metal-tungsten oxide, wherein the near infrared ray cut-
The wavelength at which the transmittance of the light-transmitting substrate of the dispersion type structure in which the organic absorbent is applied or the transmittance of the coating type structure is reduced to 50% appears in the wavelength range of 631 nm to 650 nm and the average transmittance in the near infrared region of 800 nm to 1200 nm 90% or more and 100% or less,
An optical article for a near infrared ray cut-off filter having a structure including both the light-transmitting substrate and the near infrared ray absorbing layer has an average transmittance of 85% or more and 100% or less in a wavelength range of 460 nm to 560 nm and a light transmittance of 50% , And the average transmittance in the wavelength range of 800 nm to 1200 nm is more than 40% and less than 75%.
Optical article for near infrared ray cut-off filter included in camera module.
The method according to claim 1,
Wherein the metal-tungsten oxide is represented by the following formula (1)
An optical article for the near-infrared ray cut-off filter included in the camera module;
[Chemical Formula 1]

In the formula (1), 0? P / q? 1, 2.5? R / q?
M represents A _x B _y D _z ,
A, B and D are each independently selected from the group consisting of Li, Na, K, Rb, Cs, Fr, Ber, Mg, (Ca), strontium (Sr), barium (Ba), radium (Ra), zirconium (Zr), chromium (Cr), manganese (Mn), iron (Fe), ruthenium (Ru), cobalt (Ag), gold (Au), zinc (Zn), cadmium (Cd), aluminum (Au), aluminum (Al), gallium (Ga), indium (In), tallium (Tl), tin (Sn), lead (Pb), titanium (Ti), niobium (Nb), vanadium (V), molybdenum Ruthenium (Re), beryllium (Be), hafnium (Hf), osmium (Os) or bismuth (Bi)
0? X? 1, 0? Y? 1 and 0? Z? 1, and x + y + z = 1.
The method according to claim 1,
The metal-tungsten oxide
Na _0.11 Cs _0.22 WO ₃ , Na _0.5 WO ₃ , K _0.33 WO ₃ , K _0.55 WO ₃ , Rb _0.33 WO ₃ , Cs _0.33 WO ₃ , Ba _0.21 WO ₃ , Ba _0.33 WO ₃ , Na _0.11 Cs _0.22 WO ₃ and Na _0.11 Cs _0.11 Rb _0.11 WO ₃ ,
Optical article for near infrared ray cut-off filter included in camera module.
The method according to claim 1,
Characterized in that the metal-tungsten oxide is cesium-tungsten oxide.
Optical article for near infrared ray cut-off filter included in camera module.
The method according to claim 1,
Characterized in that the content of the metal-tungsten oxide is 5.0 to 20.0% by weight based on the total weight of the near infrared absorbing layer.
Optical article for near infrared ray cut-off filter included in camera module.
The method according to claim 1,
The light-
Transparent substrate; And
And an organic absorbent layer comprising an organic absorbent formed on one surface of the transparent substrate,
Characterized in that the near-infrared absorbing layer is formed on the opposite surface of one side of the transparent substrate on which the organic absorbent layer is formed.
Optical article for near infrared ray cut-off filter included in camera module.
The method according to claim 6,
The content of the organic absorbent
Is 10 to 30% by weight based on the total weight of the organic absorbent layer.
Optical article for near infrared ray cut-off filter included in camera module.
The method according to claim 1,
Characterized in that the light-transmitting substrate is a form in which an organic absorbent is dispersed in a matrix formed by a binder resin.
Optical article for near infrared ray cut-off filter included in camera module.
9. The method of claim 8,
Wherein the content of the organic absorbent is 0.1 to 1% by weight based on the total weight of the light-transmitting substrate.
Optical article for near infrared ray cut-off filter included in camera module.
The method according to claim 1,
The organic absorbent
At least one of a cyanine compound, a phthalocyanine compound, a naphthalocyanine compound, a porphyrin compound, a benzoporphyrin compound, a squarylium compound, an anthraquinone compound, a chromium compound, a diimonium compound, and a dithiol metal complex compound ≪ / RTI >
Optical article for near infrared ray cut-off filter included in camera module.
The method according to claim 1,
Wherein an average transmittance of an optical article for a near-infrared cutoff filter included in the camera module in a wavelength range of 800 nm to 1200 nm is 45% to 55%.
Optical article for near infrared ray cut-off filter included in camera module.
The method according to claim 1,
Wherein the near-infrared absorbing layer has a structure in which a metal-tungsten oxide is dispersed in a matrix formed by curing a composition comprising at least one selected from silica or an alkoxysilane-
Optical article for near infrared ray cut-off filter included in camera module.
The method according to claim 1,
Characterized in that the near-infrared absorbing layer is produced by a sol-gel method.
Optical article for near infrared ray cut-off filter included in camera module.
14. An optical article according to any one of claims 1 to 13,
Near-infrared cut-off filter for camera module.
15. The method of claim 14,
A first selected wavelength reflective layer formed on the near infrared absorbing layer on one side of the optical article; And
Further comprising a second selective reflection layer formed on the other surface of one surface of the optical article on which the first selective reflection layer is formed.
Near-infrared cut-off filter for camera module.
16. The method of claim 15,
The first selective reflection layer is a near-infrared reflection layer,
And the second selective reflection layer is an antireflection layer.
Near-infrared cut-off filter for camera module.

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