Optical filter substrate, optical filter, and imaging device

Abstract

To provide an optical filter base body and an optical filter that has an excellent visible light transmittance and can prevent a ripple phenomenon in a visible light region.SOLUTION: An optical filter base body includes: an infrared ray absorption board; and a moisture resistance layer formed on one surface of both the surfaces of the board, an incident angle 0-degree ripple value at a wavelength range of 450 nm to 560 nm is equal to or less than 7%, and an absolute value of ▵TV in the following expression 1 is equal to or less than 30%: [expression 1] ▵TV=100×(TV.f-TV.i) / TV.i (in the expression 1, TV.f is average transmittance within a wavelength range of 425 nm to 560 nm of the base body after maintaining the base body at a temperature of 85°C and at a relative humidity of 85% for 120 hours, and TV.i is average transmittance within a wavelength range of 425 nm to 560 nm of the base body before maintaining in at the temperature and the humidity.)SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] This disclosure relates to optical filter substrates and optical filters. [Background technology]

[0002] Optical filters are used in imaging devices that utilize CCD (Charge-Coupled Device) or CMOS (Complementary Metal-Oxide-Semiconductor) image sensors. These optical filters are used to obtain good color reproduction and sharp images, and have the characteristic of transmitting visible light and blocking infrared light such as near-infrared light. Such optical filters are also called near-infrared cut filters.

[0003] Such optical filters are required to transmit as much visible light as possible. Therefore, the optical filters are required to exhibit a transmittance curve that transmits visible light with the highest possible transmittance while blocking ultraviolet and infrared light.

[0004] However, it is not easy to obtain a transmittance curve that accurately blocks ultraviolet light near the short wavelength region of visible light and infrared light in the long wavelength region of visible light while maintaining high transmittance of visible light.

[0005] Known optical filters include those comprising an absorbing layer containing an absorbent and a reflective layer which is a dielectric film. When the dielectric film is applied, light in the ultraviolet and / or infrared region can be blocked. However, dielectric films have the characteristic that their transmittance curve changes (shifts) depending on the angle of incidence. Therefore, to compensate for the shortcomings of the dielectric film, the conventional optical filters employ an absorbing layer containing a near-infrared absorbing dye whose transmittance has little dependence on the angle of incidence.

[0006] Optical filters that apply so-called infrared absorption glass (also called Blue glass), which has infrared absorption characteristics by itself as a substrate, are also known. Infrared absorption glass is a glass filter in which CuO or the like is added to the glass so as to selectively absorb light in the near-infrared wavelength region.

[0007] However, although conventional infrared absorption glass exhibits the absorption characteristics, since its absorption ability for long-wavelength infrared rays is low, a dielectric film or the like still has to be applied.

[0008] In recent years, infrared absorption glass that exhibits excellent absorption characteristics even for the long-wavelength infrared rays by adjusting the composition of the infrared absorption glass and the like is known. When applying such glass, it is advantageous for forming an optical filter in which the shift due to the incident angle is suppressed by not forming a dielectric film or forming it less.

[0009] However, although such glass exhibits excellent absorption characteristics even for long-wavelength infrared rays, there is a problem that it is inferior in moisture resistance and heat resistance.

[0010] FIG. 5 shows the transmittance spectrum of the glass as described above. Such glass exhibits an appropriate absorption ability even for long-wavelength infrared rays as shown by the dotted line in FIG. 5, but its characteristics are rapidly lost after being maintained under moisture / heat resistance conditions (solid line in FIG. 5).

[0011] In an optical filter, it is necessary to suppress a phenomenon called so-called ripple. The ripple phenomenon is a phenomenon in which periodic fluctuations in transmittance occur in the visible light transmission region of the optical filter. Specifically, it is a phenomenon in which the actual transmittance in a predetermined region becomes larger and smaller compared to the average transmittance of the region, and this phenomenon is periodically observed.

[0012] The imaging device senses visible light transmitted through an optical filter separately for RGB (Red, Green, Blue) using sensors. The sensitivity of each RGB sensor, etc. is adjusted in consideration of the average transmittance by wavelength. However, when a ripple phenomenon occurs, fluctuations occur in the light recognized by the sensor, and color reproducibility deteriorates.

[0013] The ripple phenomenon can generate an area where the transmittance in the visible light region instantaneously decreases (so-called bunk area), which induces a ghost phenomenon, and such a ghost phenomenon also deteriorates color reproducibility.

Summary of the Invention

Problems to be Solved by the Invention

[0014] An object of the present disclosure is to provide an optical filter substrate and an optical filter. An object of the present disclosure is to provide an optical filter substrate and an optical filter that include a moisture-resistant layer, exhibit excellent durability, and have excellent optical characteristics.

[0015] An object of the present disclosure is to provide an optical filter substrate and an optical filter that have excellent blocking characteristics for wavelength bands that need to be blocked, such as ultraviolet and infrared rays, have excellent visible light transmittance, and can prevent the ripple phenomenon in the visible light region.

[0016] An object of the present disclosure is to provide an optical filter substrate and an optical filter that can ensure the above characteristics even when an infrared absorption substrate, particularly an infrared absorption substrate such as glass known to be inferior in moisture resistance and heat resistance, is applied as a substrate.

Means for Solving the Problems

[0017] Among the physical properties mentioned in this specification, physical properties affected by the measurement temperature and / or measurement pressure are the results measured at normal temperature and / or normal pressure unless otherwise specified.

[0018] In this specification, the term "room temperature" refers to the natural temperature without heating or cooling, and may be any single temperature within the range of 10°C to 30°C, for example, approximately 23°C or approximately 25°C. Furthermore, unless otherwise specified, the unit of temperature in this specification is Celsius (°C).

[0019] In this specification, the term "atmospheric pressure" refers to the natural pressure that is not pressurized or depressurized, and typically means a pressure of approximately 740 mmHg to 780 mmHg, which is the level of atmospheric pressure.

[0020] In this specification, if the measured humidity affects the results of a physical property, the physical property is the one measured at the natural humidity without any special adjustments under normal temperature and / or atmospheric pressure conditions.

[0021] If an optical property (e.g., refractive index) referred to in this disclosure is a property that changes with wavelength, unless otherwise specified, such optical property is the result obtained for light with a wavelength of 520 nm.

[0022] In this disclosure, unless otherwise specified, the term "transmittance" means the actual transmittance (measured transmittance) confirmed at a specific wavelength.

[0023] In this disclosure, unless otherwise specified, the term "average transmittance" refers to the result of calculating the arithmetic mean of the transmittances measured at each wavelength, starting from the shortest wavelength within a given wavelength range and increasing the wavelength by 1 nm increments. For example, the average transmittance in the wavelength range of 350 nm to 360 nm is the arithmetic mean of the transmittances measured at wavelengths of 350 nm, 351 nm, 352 nm, 353 nm, 354 nm, 355 nm, 356 nm, 357 nm, 358 nm, 359 nm, and 360 nm.

[0024] In this specification, the term "maximum transmittance" refers to the highest transmittance measured at each wavelength while increasing the wavelength by 1 nm from the shortest wavelength within a given wavelength range. For example, the maximum transmittance in the wavelength range of 350 nm to 360 nm is the highest transmittance among the transmittances measured at wavelengths of 350 nm, 351 nm, 352 nm, 353 nm, 354 nm, 355 nm, 356 nm, 357 nm, 358 nm, 359 nm, and 360 nm.

[0025] In this specification, the angle of incidence is the angle relative to the normal of the surface being evaluated. For example, the transmittance of an optical filter at an angle of incidence of 0 degrees means the transmittance for light incident in a direction substantially parallel to the normal of the optical filter surface. Also, for example, an angle of incidence of 40 degrees is the value for incident light that forms a substantially 40-degree angle with the normal in a clockwise or counterclockwise direction. This definition of the angle of incidence applies equally to other properties such as transmittance.

[0026] In this specification, the term "material layer for optical filter" means an optical filter before the dielectric film is formed. The optical filter layer may include other components of an optical filter, excluding the dielectric film.

[0027] In this specification, the term "optical filter" means a structure in which a dielectric film is formed on one or both sides of the substrate.

[0028] The optical filter substrate and optical filter of this disclosure exhibit excellent durability and superior optical properties.

[0029] The optical filter substrate and / or optical filter of this disclosure can efficiently and accurately block ultraviolet light near the short-wavelength visible light region and infrared light near the long-wavelength visible light region, and can realize a visible light transmission band with high transmittance.

[0030] In this disclosure, the term "visible light" means light in the range of approximately 400 nm to 700 nm.

[0031] In this disclosure, the term "visible light transmission band" means a spectral characteristic in which the average transmittance within the wavelength range of 425 nm to 560 nm is 75% or more. In other examples, the average transmittance within the wavelength range of 425 nm to 560 nm may be approximately 77% or more, 79% or more, 81% or more, 83% or more, 85% or more, 87% or more, 89% or more, or 91% or more. The upper limit of the average transmittance is not particularly limited. For example, the average transmittance may be approximately 100% or less, 95% or less, 90% or less, 85% or less, 80% or less, or 75% or less.

[0032] In this disclosure, the term "Tn% cut on" means the shortest wavelength exhibiting n% transmittance within a predetermined wavelength range, and "Tn% cut off" means the longest wavelength exhibiting n% transmittance within a predetermined wavelength range. For example, T50% cut on means the shortest wavelength exhibiting 50% transmittance within a predetermined wavelength range, and T50% cut off means the longest wavelength exhibiting 50% transmittance within a predetermined wavelength range.

[0033] In one example, the optical filter substrate of this disclosure includes a transparent substrate, and the transparent substrate may include a moisture-resistant layer on one or both sides.

[0034] In this disclosure, the term "moisture-resistant layer" refers to the optical filter substrate or optical filter having ΔT of formula 1 described later. V This refers to a layer that shows the range of the absolute value.

[0035] The optical filter substrate or optical filter of this disclosure can exhibit a low ripple value. For example, the optical filter substrate or optical filter may have a ripple value within a predetermined range with respect to an incident angle of 0 degrees in the wavelength region of 450 nm to 560 nm.

[0036] The term "ripple value" refers to the average transmittance T in the wavelength range of 450nm to 560nm. ave.i(i = 1 to n) and the actual transmittance T i The difference T between (i = 1 to n) and it diff.i = T i - T ave.i After obtaining all of (i = 1 to n), the maximum value Max(T diff.i ) and the minimum value Min(T diff.i ) of the obtained differences are subtracted to obtain the value. The subscript i defined in the range from 1 to n above is the ordinal number indicating the wavelength. For example, when checking the ripple value in the range of 450 nm to 560 nm, 450 nm is designated as the case where i is 1, and as the wavelength increases by 1 nm, i also increases by 1. That is, 451 nm is designated as the case where i is 2, and 560 nm is designated as the case where i is 111. The said ripple value is the R value determined by the following formula A.

[0037] [Formula A] R = Max(T diff.i ) - Min(T diff.i )

[0038] In Formula A, R is the said ripple value, Max(T diff.i ) is the maximum value among the differences between the average transmittance and the actual transmittance, and Min(T diff.i ) is the minimum value among the differences between the average transmittance and the actual transmittance.

[0039] The said ripple value can be calculated by the regression equation of the cubic spline method.

[0040] The upper limits of the aforementioned ripple values ​​are approximately 7.0%, 6.8%, 6.6%, 6.4%, 6.2%, 6.0%, 5.8%, 5.6%, 5.4%, 5.2%, 5%, 4.8%, 4.6%, 4.4%, 4.2%, 4%, 3.8%, 3.6%, 3.4%, 3.2%, 3%, 2.9%, 2.8%, 2.7%, 2.6%, and 2.5%. The ripple values ​​are approximately 2.4%, 2.3%, 2.2%, 2.1%, 2.0%, 1.9%, 1.8%, 1.7%, 1.6%, or 1.5%, with the lower limit being approximately 0%, 0.2%, 0.4%, 0.6%, 0.8%, 1%, 1.2%, 1.4%, 1.6%, 1.8%, 2%, 2.2%, or 2.4%. The ripple value may be less than or equal to any one upper limit selected from the upper limits described above, or less than or equal to any one upper limit selected from the upper limits described above, while being greater than or equal to any one lower limit selected from the lower limits described above.

[0041] The ripple value is the value when the optical filter does not include a multilayer dielectric film (for example, layers known as IR or AR), i.e., the value relative to the optical filter substrate. Normally, when a multilayer dielectric film is absent, the ripple phenomenon does not occur severely. However, when the moisture-resistant layer is formed to ensure durability, the ripple phenomenon often occurs due to the properties of the moisture-resistant layer. However, this disclosure can minimize or prevent the ripple phenomenon within the aforementioned range.

[0042] The optical filter substrate of this disclosure can also exhibit excellent durability, for example, ΔT according to Equation 1 below. V The absolute value of may fall within a predetermined range.

[0043] [Formula 1] △T V =100 × (T V.f -T V.i ) / T V.i

[0044] In formula 1, T V.fThis is the average transmittance of the optical filter substrate in the wavelength range of 425 nm to 560 nm, which was confirmed after maintaining the optical filter substrate at a temperature of 85°C and a relative humidity of 85% for 120 hours. V.i This is the average transmittance of the optical filter substrate in the wavelength range of 425 nm to 560 nm before being maintained at the aforementioned temperature and humidity.

[0045] Previous △T V The upper limit of the absolute value of may be approximately 30%, 28%, 26%, 24%, 22%, 20%, 18%, 16%, 14%, 12%, 10%, 8%, 6%, 4%, 2%, 1.5%, 1%, 0.8%, 0.6%, or 0.4%. V This can be a positive or negative number. V The lower limit of the absolute value of may be, for example, around 0%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, or 5.5%. V The absolute value of can be less than or equal to any one upper limit selected from the upper limits described above, or it can be less than or equal to any one upper limit selected from the upper limits described above, but greater than or equal to any one lower limit selected from the lower limits described above.

[0046] The aforementioned characteristics may also be those of the optical filter in a state where it does not contain the multilayer dielectric film (for example, layers known as IR or AR) (optical filter substrate).

[0047] The optical filter substrate of this disclosure can exhibit overall excellent optical properties while satisfying the low ripple value and excellent durability described above.

[0048] For example, the optical filter substrate can exhibit a transmission band in which the T50% cut-on wavelength is in the range of approximately 390 nm to 430 nm. The T50% cut-on wavelength is the shortest wavelength among the wavelengths that exhibit 50% transmittance within the wavelength range of 300 nm to 700 nm. There may be one or two wavelengths exhibiting 50% transmittance within the range of 390 nm to 430 nm. If there is one such wavelength, that wavelength is the T50% cut-on wavelength; if there are two or more such wavelengths, the shortest of them is the T50% cut-on wavelength. The lower limit of the T50% cut-on wavelength is approximately 390nm, 392nm, 394nm, 396nm, 398nm, 400nm, 402nm, 404nm, 406nm, 408nm, 410nm, or 412nm, and the upper limit can be approximately 430nm, 428nm, 426nm, 424nm, 422nm, 420nm, 418nm, 416nm, 414nm, 412nm, or 410nm. The T50% cut-on wavelength can be less than or equal to any one upper limit selected from the upper limits described above, while being greater than or equal to any one lower limit selected from the lower limits described above.

[0049] The optical filter substrate can exhibit a transmission band in which the T50% cutoff wavelength is in the range of approximately 590 nm to 660 nm. The T50% cutoff wavelength is the longest wavelength among the wavelengths that exhibit 50% transmittance within the wavelength range of 500 nm to 800 nm. There may be one or more wavelengths exhibiting 50% transmittance within the range of 500 nm to 800 nm. If there is one, that wavelength is the T50% cutoff wavelength; if there are two or more, the longest wavelength is the T50% cutoff wavelength. The lower limit of the T50% cutoff wavelength can be approximately 590nm, 592nm, 594nm, 596nm, 598nm, 600nm, 602nm, 604nm, 606nm, 608nm, 610nm, 612nm, 614nm, 616nm, 618nm, 620nm, 622nm, 624nm, 626nm, 628nm, or 630nm, and the upper limit can be approximately 660nm, 658nm, 656nm, 654nm, 652nm, 655nm, 648nm, 646nm, 644nm, 642nm, 640nm, 638nm, 636nm, 634nm, 632nm, 630nm, 628nm, 626nm, 624nm, 622nm, 620nm, or 618nm. The T50% cutoff wavelength can be less than or equal to any one upper limit selected from the upper limits described above, while being greater than or equal to any one lower limit selected from the lower limits described above.

[0050] The optical filter may have a transmission band that exhibits an average transmittance within a predetermined range in the range of 425 nm to 560 nm. The lower limit of the average transmittance in the range of 425 nm to 560 nm may be approximately 75%, 77%, 79%, 81%, 83%, 85%, 87%, 89%, or 91%, and the upper limit may be approximately 98%, 96%, 94%, 92%, 90%, 88%, 86%, 84%, or 82%. The average transmittance may be greater than or greater than any one lower limit selected from the lower limits described above, or less than or equal to any one upper limit selected from the upper limits described above, while being greater than or greater than any one lower limit selected from the lower limits described above.

[0051] The optical filters of this disclosure may have a transmission band exhibiting a predetermined range of maximum transmittances in the range of 425 nm to 560 nm. The lower limit of the maximum transmittance may be in the range of 79%, 81%, 83%, 85%, 87%, 89%, 91%, 93%, or 95%, and the upper limit may be in the range of 100%, 98%, 96%, 94%, 92%, 90%, or 88%. The maximum transmittance may be greater than or greater than any one lower limit selected from the lower limits described above, or less than or equal to any one upper limit selected from the upper limits described above, while being greater than or greater than any one lower limit selected from the lower limits described above.

[0052] The optical filter substrate of this disclosure may have a transmission band exhibiting a predetermined range of average transmittance within the range of 350 nm to 390 nm. The lower limit of the average transmittance may be approximately 0%, 0.5%, 1%, 1.5%, or 2%, and the upper limit may be approximately 6%, 5.5%, 5%, 4.5%, 4%, 3.5%, 3%, or 2.5%. The average transmittance may be less than or equal to any one upper limit selected from the upper limits described above, or less than or equal to any one lower limit selected from the lower limits described above, while being greater than or equal to any one lower limit selected from the lower limits described above.

[0053] The optical filter substrate of this disclosure may have a transmission band exhibiting a predetermined range of maximum transmittance within the range of 350 nm to 390 nm. The lower limit of the maximum transmittance may be approximately 0%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, or 6.5%, and the upper limit may be approximately 10%, 9.5%, 9%, 8.5%, 8%, 7.5%, 7%, 6.5%, 6%, 5.5%, 5%, 4.5%, 4%, 3.5%, 3%, 2.5%, or 2%. The maximum transmittance may be less than or equal to any one upper limit selected from the upper limits described above, or less than or equal to any one lower limit selected from the lower limits described above, while being greater than or equal to any one lower limit selected from the lower limits described above.

[0054] The optical filter substrate of this disclosure may have a transmittance at a wavelength of 700 nm within a predetermined range. The lower limit of the transmittance may be in the range of 0%, 0.2%, 0.4%, 0.6%, or 0.8%, and the upper limit may be in the range of 4%, 3.8%, 3.6%, 3.4%, 3.2%, 3.0%, 2.8%, 2.6%, 2.4%, 2.2%, 2.0%, 1.8%, 1.6%, 1.4%, 1.2%, or 1.0%. The transmittance may be less than or equal to any one upper limit selected from the upper limits described above, or less than or equal to any one lower limit selected from the lower limits described above, while being greater than or equal to any one lower limit selected from the lower limits described above.

[0055] The optical filter substrate of this disclosure may have a transmission band exhibiting a predetermined range of average transmittance in the range of 700 nm to 800 nm. The lower limit of the average transmittance may be in the range of 0%, 0.1%, 0.3%, 0.4%, or 0.5%, and the upper limit may be in the range of 2%, 1.8%, 1.6%, 1.4%, 1.2%, 1.0%, 0.8%, or 0.6%. The average transmittance may be less than or equal to any one upper limit selected from the upper limits described above, or less than or equal to any one upper limit selected from the upper limits described above, while being greater than or equal to any one lower limit selected from the lower limits described above.

[0056] The optical filter substrate of this disclosure may have a transmission band exhibiting a predetermined range of maximum transmittance in the range of 700 nm to 800 nm. The lower limit of the maximum transmittance may be in the range of 0%, 0.2%, 0.4%, 0.6%, or 0.8%, and the upper limit may be in the range of 4%, 3.8%, 3.6%, 3.4%, 3.2%, 3.0%, 2.8%, 2.6%, 2.4%, 2.2%, 2.0%, 1.8%, 1.6%, 1.4%, 1.2%, or 1.0%. The maximum transmittance may be less than or equal to any one upper limit selected from the upper limits described above, or less than or equal to any one lower limit selected from the lower limits described above, while being greater than or equal to any one lower limit selected from the lower limits described above.

[0057] The optical filter substrate of this disclosure may have a transmission band exhibiting a predetermined range average transmittance in the range of 800 nm to 1000 nm. The lower limit of the average transmittance may be in the range of 0%, 0.1%, 0.3%, 0.4%, or 0.5%, and the upper limit may be in the range of 6%, 5.5%, 5.0%, 4.5%, 4.0%, 3.5%, 3.0%, 2.5%, 2.0%, 1.5%, 1.0%, 0.8%, 0.6%, 0.4%, or 0.2%. The average transmittance may be less than or equal to any one upper limit selected from the upper limits described above, or less than or equal to any one lower limit selected from the lower limits described above, while being greater than or equal to any one lower limit selected from the lower limits described above.

[0058] The optical filter substrate of this disclosure may have a transmission band exhibiting a predetermined range of maximum transmittance within the range of 800 nm to 1000 nm. The lower limit of the maximum transmittance may be in the range of 0%, 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 5.0%, 5.5%, or 6.0%, and the upper limit may be in the range of 10%, 9.5%, 9.0%, 8.5%, 8.0%, 7.5%, 7.0%, or 6.5%. The maximum transmittance may be less than or equal to any one upper limit selected from the upper limits described above, or less than or equal to any one lower limit selected from the lower limits described above, while being greater than or equal to any one lower limit selected from the lower limits described above.

[0059] The optical filter substrate of this disclosure may have a transmission band exhibiting a predetermined range of average transmittance within the range of 1000 nm to 1050 nm. The lower limit of the average transmittance may be around 0%, 0.5%, 1%, or 1.5%, and the upper limit may be around 12%, 11.5%, 11.0%, 10.5%, 10.0%, 9.5%, 9.0%, 8.5%, 8.0%, 7.5%, 7.0%, 6.5%, 6.0%, 5.5%, 5.0%, 4.5%, 4%, 3.5%, 3%, 2.5%, 2%, 1.5%, 1%, 0.8%, 0.6%, 0.4%, or 0.2%. The average transmittance may be less than or equal to any one upper limit selected from the upper limits described above, or it may be less than or equal to any one lower limit selected from the lower limits described above, while being greater than or equal to any one lower limit selected from the lower limits described above.

[0060] The optical filter substrate of this disclosure may have a transmission band exhibiting a predetermined range of maximum transmittance within the range of 1000 nm to 1050 nm. The lower limit of the maximum transmittance may be in the range of 0%, 0.5%, 1%, or 1.5%, and the upper limit may be in the range of 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1.5%, 1%, 0.8%, 0.6%, 0.4%, or 0.2%. The maximum transmittance may be less than or equal to any one upper limit selected from the upper limits described above, or less than or equal to any one lower limit selected from the lower limits described above, while being greater than or equal to any one lower limit selected from the lower limits described above.

[0061] The optical filter substrate of this disclosure may have a transmittance at a wavelength of 1050 nm within a predetermined range. The lower limit of the transmittance may be approximately 0%, 0.5%, 1%, or 1.5%, and the upper limit may be approximately 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1.5%, 1%, 0.5%, or 0.1%. The transmittance may be less than or equal to any one upper limit selected from the upper limits described above, or less than or equal to any one lower limit selected from the lower limits described above, while being greater than or equal to any one lower limit selected from the lower limits described above.

[0062] The optical filter substrate of this disclosure can exhibit any one or more combinations of the optical properties described above, and preferably can satisfy all of the optical properties described above.

[0063] The transmittance characteristics of the optical filter substrate are those of the optical filter substrate without the dielectric film described later. By applying such a substrate, it is possible to provide an optical filter that is suitable even with a simple and thin structure, exhibiting very precisely controlled optical properties along with excellent durability.

[0064] As mentioned above, in one example, the optical filter substrate includes a transparent substrate, and the transparent substrate includes a moisture-resistant layer on one or both sides.

[0065] Figures 1 and 2 show the case where moisture-resistant layers 200, 201, and 202 are formed on one or both sides of the transparent substrate 100.

[0066] The type of transparent substrate applied to the optical filter substrate is not particularly limited, and an appropriate type can be selected and used.

[0067] The term "transparent substrate" means a substrate having the property of transmitting visible light, for example, a substrate having an average transmittance of 70% or more in the wavelength range of approximately 425 nm to 560 nm. The lower limit of the average transmittance of the transparent substrate may be around 70%, 75%, 80%, or 85%, and the upper limit may be 95% or 90%. The average transmittance may be greater than or greater than any one lower limit selected from the lower limits described above, or less than or equal to any one upper limit selected from the upper limits described above, while being greater than or greater than any one lower limit selected from the lower limits described above.

[0068] As for the transparent substrate, any substrate made of a variety of known materials can be used, as long as it exhibits the aforementioned transmittance and appropriate physical properties such as rigidity as a substrate. For example, substrates made of inorganic materials such as glass or crystal, or organic materials such as resin can be used.

[0069] Examples of resin materials that can be used for transparent substrates include, but are not limited to, polyesters such as PET (poly(ethylene terephthalate)) or PBT (poly(butylene terephthalate)), polyolefins such as polyethylene, polypropylene or EVA (ethylene-vinyl acetate copolymer), norbornene polymers, acrylic polymers such as PMMA (poly(methyl methacrylate)), urethane polymers, vinyl chloride polymers, fluoropolymers, polycarbonates, polyvinyl butyral, polyvinyl alcohol, or polyimides.

[0070] Examples of glass materials that can be used for transparent substrates include soda-lime glass, borosilicate glass, alkali-free glass, or quartz glass.

[0071] Examples of crystalline materials that can be used for transparent substrates include birefringent crystals such as quartz, lithium niobate, or sapphire.

[0072] The thickness of the transparent substrate can be adjusted, for example, within a range of approximately 0.03 mm to 5 mm, but is not limited to this range.

[0073] As a transparent substrate, a substrate having the ability to absorb light in the near-infrared and / or near-ultraviolet region can be used. Such a substrate may be referred to as an infrared absorbing substrate in this specification.

[0074] Such substrates are well known, and for example, so-called infrared absorbing glass is known as a material that performs the functions described above. Such glass is known as an absorbing glass, which is made by adding CuO or the like to fluoride phosphate glass or phosphate glass.

[0075] In this disclosure, a CuO-containing fluorinated phosphate glass substrate or a CuO-containing phosphate glass substrate may be used as the infrared absorbing substrate which is the transparent substrate.

[0076] As mentioned above, phosphate glass also includes silicophosphate glass, in which part of the glass skeleton is composed of SiO2.

[0077] When the aforementioned absorbing glass is used as a transparent substrate, the transmittance of the absorbing glass in the near-infrared region can be reduced by adjusting the concentration of added CuO and the thickness of the substrate. This improves the light-shielding properties against near-infrared light. Such absorbing glasses are publicly known, and for example, the glass disclosed in Korean Patent Registration No. 10-2056613 and other commercially available absorbing glasses (for example, commercially available products from HOYA, SCHOTT, PTOT, etc.) can be used.

[0078] Phosphate-based glasses containing CuO are known to have excellent infrared absorption properties, and therefore, they can alone provide optical filters that exhibit the aforementioned transmittance characteristics in the wavelength range of 800 nm to 1000 nm.

[0079] However, such glass has a significant drawback: its durability is greatly reduced, and its optical properties are severely damaged when exposed to high humidity and / or high temperature conditions.

[0080] However, this disclosure can leverage the advantages of the glass while overcoming its disadvantages through the application of an appropriate moisture-resistant layer.

[0081] The thickness of the transparent substrate described above is not particularly limited, and a substrate of an appropriate thickness range can be applied depending on the purpose.

[0082] The optical filter may include a moisture-resistant layer formed on one or both sides of the transparent substrate. The definition of the moisture-resistant layer is as described above.

[0083] As the moisture-resistant layer, a layer of material that can suppress the penetration of moisture into the transparent substrate can be applied.

[0084] In one example, the moisture-resistant layer may include one or more materials selected from the group consisting of polysilazane, silica (SiOx), silane compounds, cyclic olefin polymers (COP), polysilsesquioxane, polyarylate resins, polyisocyanate resins, polyimide resins, polyetherimide resins, polyamideimide resins, polyacrylic resins, polycarbonate resins, polyethylene phthalate resins, epoxy resins, urethane resins, silicone resins, polysiloxanes, polysilanes, and fluororesins.

[0085] The moisture-resistant layer may also contain other necessary additives to the material, such as curing agents and surfactants.

[0086] The moisture-resistant layer material can be selected to exhibit excellent moisture resistance and ensure the aforementioned optical properties (e.g., low ripple value and / or transmittance characteristics).

[0087] In one example, the moisture-resistant layer may be a layer containing polysilazane and a silane compound from the aforementioned materials. The moisture-resistant layer may contain the aforementioned materials or a material formed from the aforementioned materials. In one example, the moisture-resistant layer may be a cured layer of a mixture containing the polysilazane and the silane compound. Through the application of such materials, it is possible to provide an optical filter that maintains good optical properties while ensuring the desired moisture resistance.

[0088] In one example, the polysilazane used in this disclosure may include a unit represented by the following chemical formula 1.

[0089] [Chemical formula 1] TIFF0007901886000001.tif47143

[0090] In chemical formula 1, R1, R2, and R3 may each independently be a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alkylsilyl group, an alkylamide group, or an alkoxy group.

[0091] The alkyl group described above may be an alkyl group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms. The alkyl group may be linear, branched, or cyclic. The alkyl group may be optionally substituted with one or more substituents.

[0092] The alkenyl group may be an alkenyl group having 2 to 20 carbon atoms, 2 to 16 carbon atoms, 2 to 12 carbon atoms, 2 to 8 carbon atoms, or 2 to 4 carbon atoms. The alkenyl group may be linear, branched, or cyclic, and may be optionally substituted with one or more substituents.

[0093] The alkynyl group may be an alkynyl group having 2 to 20 carbon atoms, 2 to 16 carbon atoms, 2 to 12 carbon atoms, 2 to 8 carbon atoms, or 2 to 4 carbon atoms. The alkynyl group may be linear, branched, or cyclic, and may be optionally substituted with one or more substituents.

[0094] The aryl group described above may be a monovalent residue derived from a compound or derivative thereof that contains a benzene ring or a structure in which two or more benzene rings are linked or condensed or bonded while sharing one or more carbon atoms. The range of the aryl group may include not only functional groups commonly called aryl groups, but also so-called aralkyl groups or arylalkyl groups. The aryl group may be, for example, an aryl group having 6 to 25 carbon atoms, 6 to 21 carbon atoms, 6 to 18 carbon atoms, or 6 to 12 carbon atoms. Examples of aryl groups include phenyl group, dichlorophenyl, chlorophenyl, phenylethyl group, phenylpropyl group, benzyl group, tolyl group, xylyl group, or naphthyl group.

[0095] The alkoxy group may be an alkoxy group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms. The alkoxy group may be linear, branched, or cyclic. The alkoxy group may also be substituted with one or more substituents as desired. In chemical formula 1, n is any number whose range is not particularly limited. Typically, in chemical formula 1, n is a number in the range of 10 to 100,000.

[0096] The specific types of polysilazanes are not particularly limited, as long as they include the unit represented by the aforementioned chemical formula 1.

[0097] In one example, taking into consideration the density of the modified polysilazane layer, the polysilazane of this disclosure may include a polysilazane containing a unit of chemical formula 1 in which R1 to R3 are all hydrogen atoms, such as a perhydropolysilazane.

[0098] A wide variety of such polysilazanes are known, and in this disclosure, an appropriate type can be selected and used from among these known polysilazanes.

[0099] The moisture-resistant layer may also contain a silane compound along with the polysilazane. For reasons that are not entirely clear, when applying either polysilazane or a silane compound, using only one of them tends not to produce the desired effect in the optical filter of this disclosure. Although polysilazane is generally known to be able to modify and exhibit barrier properties against moisture even when used alone, in this disclosure, a suitable moisture-resistant layer is often not formed by polysilazane alone. For reasons that are not entirely clear, it is believed that this is related to the interaction with the transparent substrate to which it is applied.

[0100] The type of silane compound is not particularly limited; for example, silane compounds known in this industry as so-called silane coupling agents can be used.

[0101] The type of silane compound is not particularly limited, but for example, a silane compound represented by the following chemical formula 2 can be used.

[0102] [Chemical formula 2] X n SiY (4-n)

[0103] In Chemical Formula 2, X is a substituent bonded to a silicon atom. Such X can be, for example, an alkenyl group, an epoxy group (e.g., a glycidyl group, a glycidoxyalkyl group, or an alicyclic epoxy group), an amino group, a (meth)acrylic group, a (meth)acryloyloxy group, a (meth)acryloyloxyalkyl group, a mercapto group, a mercaptoalkyl group, a ureido group, an isocyanate group, or an isocyanatealkyl group, or a functional group containing the above. If there are multiple X in Chemical Formula 2, the multiple Xs can be the same or different from each other. In Chemical Formula 2, Y is a substituent bonded to a silicon atom. The Y can be an alkyl group or an alkoxy group. If there are multiple Ys in Chemical Formula 2, the multiple Ys can be the same or different from each other. In Chemical Formula 2, n is a number in the range of 1 to 3.

[0104] In the definition of Chemical Formula 2, the specific types of alkyl groups, alkenyl groups, and alkoxy groups are as described in Chemical Formula 1.

[0105] The compound of chemical formula 2 may contain at least one, for example, one to three alkoxy groups as Y.

[0106] In chemical formula 2, n may be 1 or 2.

[0107] The moisture-resistant layer may be a layer containing the polysilazane and silane compound, or a layer of a reaction product of a mixture containing them.

[0108] In such cases, the lower limit of the total weight of the polysilazane and silane compound in the layer or mixture containing them is approximately 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95% by weight, based on the weight of the entire layer or mixture, and the upper limit is 100% or 99% by weight, based on the weight of the entire layer or mixture. The total weight may be greater than or greater than any one lower limit selected from the lower limits described above, or less than or equal to any one upper limit selected from the upper limits described above, while being greater than or greater than any one lower limit selected from the lower limits described above. That is, the layer or mixture may substantially contain the polysilazane and silane compound as its main components. The content of the polysilazane and silane compound is the value confirmed excluding the solvent if the layer or mixture contains a solvent.

[0109] In the aforementioned layer or mixture, the lower limit of the weight ratio (parts by weight) of the silane compound to 100 parts by weight of the polysilazane is approximately 1 part by weight, 5 parts by weight, 10 parts by weight, 15 parts by weight, 20 parts by weight, 25 parts by weight, or 30 parts by weight, and the upper limit may be approximately 100 parts by weight, 95 parts by weight, 90 parts by weight, 85 parts by weight, 80 parts by weight, 75 parts by weight, 70 parts by weight, 65 parts by weight, 60 parts by weight, 55 parts by weight, 50 parts by weight, 45 parts by weight, 40 parts by weight, 35 parts by weight, or 30 parts by weight. The weight ratio may be less than or equal to any one upper limit selected from the upper limits described above, while being greater than or equal to any one lower limit selected from the lower limits described above.

[0110] In one example, the moisture-resistant layer may be a layer containing polysiloxane from the aforementioned materials. The moisture-resistant layer may contain the aforementioned materials or a material formed from the aforementioned materials. As is known, polysiloxane is a polymer having a backbone consisting of multiple siloxane bonds composed of silicon atoms and oxygen atoms, and one or more silicon atoms in the siloxane bonds may have organic groups attached to them. As is known, such polymers can be formed by curing so-called hydrosilylation-curable materials or condensation-curable materials. Through the application of such materials, it is possible to provide an optical filter that maintains good optical properties while ensuring the desired moisture resistance.

[0111] In one example, the polysiloxane can be a polysiloxane having the average unit of the following chemical formula 3. The average unit of a polysiloxane is expressed by setting the total number of moles of silicon atoms contained in the polysiloxane as 1, and then converting the number of moles of functional groups and oxygen atoms contained in the polysiloxane to this standard. Such an average unit can be an average unit for one polysiloxane or an average unit for two or more polysiloxanes. That is, if one polysiloxane is present in the moisture-resistant layer, the average unit is for that one polysiloxane, and if two or more polysiloxanes are present in the moisture-resistant layer, the average unit is for a mixture of the two or more polysiloxanes.

[0112] [Chemical formula 3] RaSiO(4-a) / 2

[0113] In chemical formula 3, R is a functional group bonded to a silicon atom in the polysiloxane. Such a functional group may be, for example, a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alkylsilyl group, an alkylamide group, an alkoxy group, or a functional group. In the definition of chemical formula 3, the specific types of alkyl groups, alkenyl groups, alkynyl groups, aryl groups, and alkoxy groups are as described in chemical formula 1.

[0114] In chemical formula 3, examples of the functional group include epoxy groups (e.g., glycidyl groups, glycidoxyalkyl groups, or alicyclic epoxy groups), amino groups, (meth)acrylic groups, (meth)acryloyloxy groups, (meth)acryloyloxyalkyl groups, mercapto groups, mercaptoalkyl groups, ureido groups, isocyanate groups, hydroxyl groups, or isocyanate alkyl groups, or a functional group containing any one of the above functional groups.

[0115] In the aforementioned functional group, the specific type of alkyl group is as described in Chemical Formula 1.

[0116] In a polysiloxane having the average unit of chemical formula 3, R can be multiple, and these multiple Rs can be the same or different from one another.

[0117] In a polysiloxane having the average unit of chemical formula 3, R can include at least the functional group. That is, in a polysiloxane having the average unit of chemical formula 3, R can be plural, and at least one of the plural Rs can be the functional group.

[0118] In the average unit of chemical formula 3, a is the number of moles of the functional group R, calculated based on the total number of moles of silicon atoms contained in the polysiloxane being set to 1. The lower limit of a can be around 0.01, 0.05, 0.1, 0.5, 1, 1.5, or 2, and its upper limit can be around 10, 9, 8, 7, 6, 5, 4, 3, 2, 1.5, 1, 0.5, or 0.05. a can be less than or equal to any one upper limit selected from the upper limits described above, while being greater than or equal to any one lower limit selected from the lower limits described above.

[0119] Polysiloxanes having the average unit of chemical formula 3 can have a weight-average molecular weight within a predetermined range. For example, the weight-average molecular weight can be in the range of approximately 1,000 g / mol to 1,000,000 g / mol.

[0120] The polysiloxane can be formed by methods known in the industry. For example, the polysiloxane can be formed using a material selected from known polysiloxane materials so as to be able to have the average unit.

[0121] In the above-described case, the lower limit of the total weight of the polysiloxane in the moisture-resistant layer or the material forming the moisture-resistant layer is approximately 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95% by weight, based on the total weight of the moisture-resistant layer or material, and the upper limit may be 100% or 99% by weight, based on the total weight of the moisture-resistant layer or material. The total weight may be greater than or greater than any one lower limit selected from the lower limits described above, or less than or equal to any one upper limit selected from the upper limits described above, while being greater than or greater than any one lower limit selected from the lower limits described above. That is, the moisture-resistant layer or material may substantially contain the polysiloxane as its main component. The polysiloxane content is the value confirmed excluding the solvent when the moisture-resistant layer or material contains a solvent.

[0122] The method for forming a moisture-resistant layer containing such components is not particularly limited. For example, the moisture-resistant layer can be formed by coating a composition containing the material onto the transparent substrate, and if necessary, a drying process or a material modification or curing process can be carried out after the coating. In this case, the modification or curing process can be carried out using a known modification or curing method for polysilazane.

[0123] If necessary, the material in the coating process may also contain a suitable solvent. The types of solvents that can be used are not particularly limited, and for example, hydrocarbon solvents such as aliphatic hydrocarbons, alicyclic hydrocarbons, and aromatic hydrocarbons, halogenated hydrocarbon solvents, and ethers such as aliphatic ethers and alicyclic ethers can be used.

[0124] The moisture-resistant layer can be formed with an appropriate thickness depending on the purpose. For example, the lower limit of the thickness of the moisture-resistant layer is 0.01 μm, 0.03 μm, 0.05 μm, 0.07 μm, or 0.09 μm, and the upper limit is 20 μm, 18 μm, 16 μm, 14 μm, 12 μm, 10 μm, 9 μm, 8 μm, 7 μm, 6 μm, 5 μm, 4 μm, 3 μm, 2 μm, 1 μm, 0.95 μm, 0.9 μm, 0 The particle size can be approximately 0.85 μm, 0.8 μm, 0.75 μm, 0.7 μm, 0.65 μm, 0.6 μm, 0.55 μm, 0.5 μm, 0.45 μm, 0.4 μm, 0.35 μm, 0.3 μm, 0.25 μm, 0.2 μm, 0.15 μm, 0.14 μm, 0.13 μm, 0.12 μm, 0.11 μm, or 0.1 μm. The thickness may be less than or equal to any one upper limit selected from the upper limits described above, but greater than or equal to any one lower limit selected from the lower limits described above.

[0125] The aforementioned moisture-resistant layer can exhibit excellent performance within the thickness range described above.

[0126] Such moisture-resistant layer of the present disclosure may, in one example, be in contact with the transparent substrate. In this case, the moisture-resistant layer can exhibit excellent adhesion to the transparent substrate. In one example, the adhesion of the moisture-resistant layer to the transparent substrate may be 3B or higher, 4B or higher, or 5B or higher. In another example, the adhesion may be 3B to 5B, 4B to 5B, or 5B. The adhesion can be measured according to the ASTM D3359 standard, and a specific measurement method is described in the examples of this specification. The maximum value of adhesion that can be measured according to the standard is 5B.

[0127] The optical filter substrate of this disclosure may further include a variety of arbitrary layers, as long as it basically includes the transparent substrate and the moisture-resistant layer.

[0128] For example, the optical filter may further include an absorption layer formed on one or both sides of the transparent substrate and / or moisture-resistant layer. The absorption layer is a light-absorbing layer, for example, a layer that absorbs light within at least a portion of the wavelength range of the infrared and / or ultraviolet region. One or more such absorption layers may be formed on the optical filter substrate.

[0129] Figure 3 shows the case where the light-absorbing layer 300 is formed on the moisture-resistant layer 201 of the optical filter substrate shown in Figure 2.

[0130] In one example, the absorbing layer may be an infrared absorbing layer and / or an ultraviolet absorbing layer. The absorbing layer may also be a layer having both infrared and ultraviolet absorbing properties. Such a layer typically comprises an absorbent (pigment, dye, etc.) and a transparent resin, and can be applied to cut out light in the near-ultraviolet and / or near-infrared regions to realize a sharper transmittance band.

[0131] In one example, the ultraviolet absorption layer can be designed to exhibit an absorption maximum in the wavelength range of approximately 300 nm to 390 nm, and the infrared absorption layer can be designed to exhibit an absorption maximum in the wavelength range of 600 nm to 800 nm.

[0132] In one example, if the light-absorbing layer is a layer that simultaneously exhibits absorption for ultraviolet and infrared rays, the light-absorbing layer can be designed to simultaneously exhibit absorption bands in the wavelength range of approximately 300 nm to 390 nm and in the wavelength range of 600 nm to 800 nm.

[0133] The infrared absorption layer and the ultraviolet absorption layer may be composed of a single layer, or they may be composed of separate layers. For example, one layer may be designed to exhibit both the absorption maxima of the ultraviolet absorption layer and the absorption maxima of the infrared absorption layer, or two layers exhibiting the respective absorption maximas may be formed. Furthermore, multiple infrared absorption layers and / or ultraviolet absorption layers may exist.

[0134] Each absorption layer may contain only one type of absorbent, or, if necessary, two or more absorbents for proper blocking of infrared and / or ultraviolet rays.

[0135] For example, the infrared absorbing layer may contain at least a first absorbent having an absorption maximum wavelength in the range of 700 nm to 720 nm and a full width at half maximum in the range of 50 nm to 60 nm; a second absorbent having an absorption maximum wavelength in the range of 730 nm to 750 nm and a full width at half maximum in the range of 60 nm to 70 nm; and a third absorbent having an absorption maximum wavelength in the range of 760 nm to 780 nm and a full width at half maximum in the range of 90 nm to 100 nm. The ultraviolet absorbing layer may contain at least a first absorbent having an absorption maximum wavelength in the range of 340 nm to 350 nm and a second absorbent having an absorption maximum wavelength in the range of 360 nm to 370 nm.

[0136] The materials and construction methods for the absorption layer are not particularly limited, and known materials and construction methods can be applied.

[0137] Typically, the absorbent layer is formed using a material that combines an absorbent (such as a dye or pigment) with a transparent resin, allowing it to exhibit the desired absorption maximum.

[0138] For example, known absorbers that exhibit an absorption maximum in the wavelength range of approximately 300nm to 390nm can be used as UV absorbers. Examples include Exiton's ABS 407; QCR Solutions Corp's UV381A, UV381B, UV382A, UV386A, VIS404A; and HWSands' ADA1225, ADA3209, ADA3216, ADA3217, ADA3218, ADA3230, ADA5205, ADA3217, ADA2055, ADA6798, ADA3102, ADA3204, ADA3210, ADA2041, ADA3201, ADA3202, ADA3215, ADA3219, ADA3225, A Examples include, but are not limited to, DA3232, ADA4160, ADA5278, ADA5762, ADA6826, ADA7226, ADA4634, ADA3213, ADA3227, ADA5922, ADA5950, ADA6752, ADA7130, ADA8212, ADA2984, ADA2999, ADA3220, ADA3228, ADA3235, ADA3240, ADA3211, ADA3221, ADA5220, ADA7158; and CRYSTALYN's DLS 381B, DLS 381C, DLS 382A, DLS 386A, DLS 404A, DLS 405A, DLS 405C, DLS 403A, etc.

[0139] Furthermore, as an infrared absorber, suitable dyes or pigments that exhibit an absorption maximum in the wavelength range of 600 nm to 800 nm can be used. For example, squarylium-based dyes, cyanine-based compounds, phthalocyanine-based compounds, naphthalocyanine-based compounds, or dithiol metal complex-based compounds can be used, but are not limited to these.

[0140] Furthermore, the transparent resin applied to the absorbent layer can be any known resin, for example, one or more of the following can be used: cyclic olefin resins, polyarylate resins, polysulfone resins, polyethersulfone resins, poly-p-phenylene resins, polyarylen etherphosphine oxide resins, polyimide resins, polyetherimide resins, polyamideimide resins, acrylic resins, polycarbonate resins, polyethylene naphthalate resins, and various organic-inorganic hybrid resins.

[0141] In addition to the layers described above, various other necessary layers can be added to the optical filter substrate, as long as they do not impair the desired effect.

[0142] This disclosure also relates to optical filters. The optical filter may include an optical filter substrate and a dielectric film formed on one or both sides of the substrate. The dielectric film may be formed on one or both sides of a transparent substrate of the optical filter substrate.

[0143] Figure 4 shows one exemplary structure of such an optical filter, where the dielectric films 401 and 402 are formed on both sides of the optical filter substrate shown in Figure 3.

[0144] The dielectric film may have a multilayer structure including at least a first sublayer and a second sublayer having different refractive indices. In one specific example, the first and second sublayers may have different refractive indices, with the first sublayer having a higher refractive index than the second sublayer. The dielectric film may also include a structure in which the first and second sublayers are alternately stacked in a repeating manner.

[0145] Typically, dielectric films are constructed by repeatedly stacking low-refractive-index dielectric materials and high-refractive-index dielectric materials, and are used to form so-called IR reflective layers and AR (Anti-reflection) layers. In this disclosure, such known dielectric films for forming IR reflective layers and AR layers can also be applied.

[0146] In one example, the present disclosure also allows for the application of a dielectric film that is a different layer from the known dielectric films described above, and which can further improve the optical properties of the optical filter. The reason such a dielectric film can be applied is that, as mentioned above, the optical filter of the present disclosure exhibits filter properties even with only the structure including the transparent substrate and moisture-resistant layer.

[0147] In other words, by adjusting the refractive index of each sublayer of the dielectric film, the refractive index of the transparent substrate, and the number of sublayers to form layers different from those of conventional dielectric films, the excellent properties of the optical filter described above, such as the low ripple value, can be maintained at a low level even when the dielectric film is formed, while also ensuring excellent transmittance characteristics even when a substrate with relatively inferior transmittance characteristics, such as infrared absorbing glass, is used as the transparent substrate.

[0148] Such dielectric films in this disclosure differ from dielectric films used as IR reflective layers and AR layers, and consequently, their practical layer configurations also differ.

[0149] For example, the dielectric film can be formed such that the V value calculated using the following formula 2 is 17 or less.

[0150] [Formula 2] V = K × {[(n1 / n2)] 2p ×(n1 2 / n s )-1] / [(n1 / n2) 2p ×(n1 2 / n s )+1]} 2

[0151] In equation 2, n1 is the refractive index of the first sublayer, n2 is the refractive index of the second sublayer, and n s k is the refractive index of the transparent substrate, k is the total number of first and second sublayers in the dielectric film, and p is a number that satisfies K=(2p+1).

[0152] The V in Equation 2 is based on an equation used to confirm the theoretical reflectance for effectively blocking the light that the IR reflective layer and AR layer are intended to block when designing them. As can be seen through the equation, when the first and second sublayers are the same, the V value increases as the values ​​of K and p increase. Therefore, when designing conventional IR reflective layers and AR layers, in order to ensure the desired performance, the number of layers K of the first and second sublayers is set to a minimum of 20 or more, and in this case, the V value will be at least greater than 20.

[0153] However, such layer designs do not contribute to ensuring the optical properties, such as low ripple values, that are the target of this disclosure.

[0154] In other words, in order to achieve the objectives of this disclosure, it is necessary to adjust the refractive index and number of layers of each layer so that the V value in Equation 2 is 17 or less.

[0155] Although the reason is not clear, it appears that dielectric films that meet the above design requirements, when combined with the optical properties of the transparent substrate (e.g., refractive index), induce a light interference phenomenon that increases the overall transmittance of the optical filter and ensures a low ripple value.

[0156] In another example, the V value in equation 2 may be approximately 16 or less, 15 or less, 14 or less, 13 or less, 12 or less, 11 or less, 10 or less, 9 or less, 8 or less, 7 or less, or 6 or less, or it may be 1 or more, 2 or more, 3 or more, 4 or more, 5 or more, or 6 or more.

[0157] In Equation 2, the ratio n1 / n2 of the refractive index n1 of the first sublayer to the refractive index n2 of the second sublayer can be in the range of approximately 1.4 to 2.0 in one example. In another example, the ratio may be 1.45 or greater, 1.5 or greater, 1.55 or greater, 1.6 or greater, 1.65 or greater, 1.7 or greater, or 1.75 or greater, or 1.95 or less, 1.9 or less, 1.85 or less, or 1.8 or less.

[0158] In Equation 2, the refractive index n1 of the first sublayer can be in the range of approximately 1.8 to 3.5. In other examples, the refractive index n1 may be 2.0 or greater, 2.2 or greater, 2.4 or greater, 2.5 or greater, or 2.55 or greater, or 3.3 or less, 3.1 or less, 2.9 or less, or 2.7 or less.

[0159] In Equation 2, the refractive index n2 of the second sublayer can be in the range of approximately 1.1 to 1.7. In other examples, the refractive index n2 may be 1.2 or greater, 1.3 or greater, or 1.4 or greater, or approximately 1.65 or less, 1.6 or less, 1.55 or less, or 1.5 or less.

[0160] The first sublayer of the dielectric film can be defined as a layer having a refractive index within the aforementioned range, and the second sublayer can be defined as a layer having a refractive index within the aforementioned range or having a refractive index that satisfies the ratio of the refractive index of the first sublayer to the refractive index within the aforementioned range.

[0161] Equation 2 can be used to calculate structures containing alternatingly stacked first and second sublayers. In this case, if the refractive indices of two or more first sublayers are different from each other, or if the refractive indices of two or more second sublayers are different from each other, the arithmetic mean of the refractive indices of the first sublayers can be used as n1 in Equation 2, and the arithmetic mean of the refractive indices of the second sublayers can be used as n2 in Equation 2.

[0162] In Equation 2, the refractive index n1 of the first sublayer and the refractive index n of the transparent substrate are given by n s The ratio n1 / n s In one example, this can be within the range of approximately 1.4 to 2.0. In another example, the aforementioned ratio may be 1.45 or higher, 1.5 or higher, 1.55 or higher, 1.6 or higher, or 1.65 or higher, or 1.95 or lower, 1.9 or lower, 1.85 or lower, 1.8 or lower, 1.75 or lower, or 1.7 or lower.

[0163] By considering the refractive index of the transparent substrate, an appropriate material can be selected to satisfy the above-mentioned range.

[0164] In Equation 2, K, which determines p, i.e., the total number of layers of the first and second sublayers (number of layers of the first sublayer + number of layers of the second sublayer), may be approximately 17 or less, 16 or less, 15 or less, 14 or less, 13 or less, 12 or less, 11 or less, 10 or less, 9 or less, 8 or less, 7 or less, or 6 or less. In another example, it may be 2 or more, 3 or more, 4 or more, 5 or more, or 6 or more. The dielectric film may also include a repeating stacked structure of the first and second sublayers. In such a case, the number of layers of the first and second sublayers may be the same as the number of layers of the first and second sublayers, or one of them may have one or two more layers.

[0165] In the dielectric film, the thickness of each of the first and second sublayers can be adjusted according to the purpose, but may be in the range of approximately 5 nm to 200 nm. In other examples, the thickness may be approximately 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 85 nm or more, or approximately 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.

[0166] The average value (arithmetic mean) of the thickness of the first sublayer and the thickness of the second sublayer contained in the dielectric film may be in the range of approximately 5 nm to 70 nm. In other examples, the average value may be 10 nm or more, 15 nm or more, 20 nm or more, 25 nm or more, 30 nm or more, or 35 nm or more, or 65 nm or less, 60 nm or less, 55 nm or less, 50 nm or less, 45 nm or less, or 40 nm or less.

[0167] The dielectric film may include other sublayers in addition to the first and second sublayers described above. However, even in such cases, the total thickness of the sublayers must be controlled to approximately 15 layers or less, 14 layers or less, 13 layers or less, 12 layers or less, 11 layers or less, 10 layers or less, 9 layers or less, 8 layers or less, 7 layers or less, or 6 layers or less, and to approximately 2 or more layers, 3 or more layers, 4 or more layers, 5 or more layers, or 6 or more layers.

[0168] Even if the dielectric film includes other sublayers in addition to the first and second sublayers, the ratio of the total number of layers of the first and second sublayers to the total number of layers of all sublayers must be 80% or more, 85% or more, 90% or more, or 95% or more, with a maximum of 100%.

[0169] Such dielectric films may have an overall thickness in the range of approximately 100 nm to 500 nm. In another example, the thickness may be in the range of 120 nm or more, 140 nm or more, 160 nm or more, 180 nm or more, or 200 nm or more, or in the range of 480 nm or less, 460 nm or less, 440 nm or less, 420 nm or less, 400 nm or less, 380 nm or less, 360 nm or less, 340 nm or less, 320 nm or less, 300 nm or less, 280 nm or less, 260 nm or less, 240 nm or less, or 220 nm or less.

[0170] A dielectric film containing alternating first and second sublayers that satisfy equation 2 may have one surface formed of the first sublayer and the other surface formed of the second sublayer. For example, the surface of the dielectric film facing the transparent substrate may be formed of the first sublayer, and the opposite surface may be formed of the second sublayer. However, this stacking order can be changed.

[0171] By applying a dielectric film with the characteristics described above, it is possible to ensure optical properties including the desired low ripple value. Such a dielectric film can be formed on only one side of the transparent substrate, or it can be appropriately formed on both sides. Furthermore, the optical filter does not need to contain any dielectric films other than the dielectric film whose V value in Equation 2 is 17 or less. That is, when dielectric films are formed on both sides of the transparent substrate, it is preferable that the V values ​​of each dielectric film be 17 or less.

[0172] The type of material used to form the dielectric film, i.e., the material used to form each of the sublayers, is not particularly limited, and known materials can be used. Typically, SiO2 or Na5Al3F is used to produce low-refractive-index sublayers. 14 For the production of a high refractive index sublayer, fluorides such as Na3AlF6 or MgF2 can be applied, and materials such as TiO2, Ta2O5, Nb2O5, ZnS, or ZnSe can be applied, but the materials applied in this disclosure are not limited to those mentioned above.

[0173] The method for forming the dielectric film described above is not particularly limited, and can be formed, for example, by applying a known deposition method.

[0174] The optical filters of this disclosure, as described above, can exhibit excellent optical properties along with excellent durability.

[0175] For example, the optical filter can exhibit a transmission band in which the T50% cut-on wavelength is in the range of approximately 390 nm to 430 nm. The T50% cut-on wavelength is the shortest wavelength among those exhibiting 50% transmittance within the wavelength range of 300 nm to 700 nm. There may be one or more wavelengths exhibiting 50% transmittance within the range of 390 nm to 430 nm. If there is one such wavelength, that wavelength is the T50% cut-on wavelength; if there are two or more such wavelengths, the shortest of them is the T50% cut-on wavelength. The T50% cut-on wavelength can be further adjusted within the range of 392nm or higher, 394nm or higher, 396nm or higher, 398nm or higher, 400nm or higher, 402nm or higher, 404nm or higher, 406nm or higher, 408nm or higher, or 410nm or higher, and / or within the range of 428nm or lower, 426nm or lower, 424nm or lower, 422nm or lower, 420nm or lower, 418nm or lower, 416nm or lower, 414nm or lower, 412nm or lower, or 410nm or lower.

[0176] The optical filter can exhibit a transmission band in which the T50% cutoff wavelength is in the range of approximately 590 nm to 680 nm. The T50% cutoff wavelength is the longest wavelength among those that exhibit 50% transmittance within the wavelength range of 500 nm to 800 nm. The wavelengths exhibiting the aforementioned 50% transmittance may be one or more within the range of 500nm to 800nm. If one wavelength exists, that wavelength is the T50% cutoff wavelength; if two or more wavelengths exist, the longest wavelength is the T50% cutoff wavelength. The T50% cutoff wavelengths are within the range of 592nm or higher, 594nm or higher, 596nm or higher, 598nm or higher, 600nm or higher, 602nm or higher, 604nm or higher, 606nm or higher, 608nm or higher, 610nm or higher, 612nm or higher, 614nm or higher, 616nm or higher, 618nm or higher, 620nm or higher, 622nm or higher, 624nm or higher, or 626nm or higher and / or 678nm or lower, 676nm or lower, 674nm or lower, 672nm It can be further adjusted within the range of m or less, 670nm or less, 668nm or less, 666nm or less, 664nm or less, 662nm or less, 660nm or less, 658nm or less, 656nm or less, 654nm or less, 652nm or less, 650nm or less, 648nm or less, 646nm or less, 644nm or less, 642nm or less, 640nm or less, 638nm or less, 636nm or less, 634nm or less, 632nm or less, or 630nm or less.

[0177] The optical filter may have a transmission band exhibiting an average transmittance of 75% or more in the range of 425 nm to 560 nm. In another example, the average transmittance can be adjusted within the range of 77% or more, 79% or more, 81% or more, 83% or more, 85% or more, 87% or more, 89% or more, 91% or more, 92% or more, or 92.5% or more and / or within the range of 98% or less, 96% or less, 94% or less, 93% or less, or 92.5% or less.

[0178] The optical filters of this disclosure may have a transmission band exhibiting a maximum transmittance of 79% or more in the range of 425 nm to 560 nm. In other examples, the maximum transmittance can be adjusted within the range of 81% or more, 83% or more, 85% or more, 87% or more, 89% or more, 91% or more, 93% or more, or 95% or more and / or within the range of 100% or less, 98% or less, or 96% or less.

[0179] The optical filters of this disclosure may have a transmission band exhibiting an average transmittance of 2% or less in the range of 350 nm to 390 nm. In another example, the average transmittance can be further adjusted within the range of 0% or more, 0.1% or more or 0.2% or more and / or within the range of 1.8% or less, 1.6% or less, 1.4% or less, 1.2% or less, 1.0% or less, 0.8% or less, 0.6% or less, 0.4% or less, 0.35% or less or 0.3% or less.

[0180] The optical filters of this disclosure may have a transmission band exhibiting a maximum transmittance of 10% or less in the range of 300 nm to 390 nm. The maximum transmittance can be further adjusted in other examples to be within the range of 0% or more, 0.5% or more, 1% or more, 1.5% or more, 2% or more or 2.5% or more and / or within the range of 9.5% or less, 9% or less, 8.5% or less, 8% or less, 7.5% or less, 7% or less, 6.5% or less, 6% or less, 5.5% or less, 5% or less, 4.5% or less, 4% or less, 3.5% or less or 3% or less.

[0181] The optical filters of this disclosure may have a transmittance of 2% or less at a wavelength of 700 nm. In other examples, the transmittance can be further adjusted within the range of 0% or more, 0.2% or more, 0.4% or more, 0.6% or more, or 0.8% or more and / or within the range of 1.8% or less, 1.6% or less, 1.4% or less, 1.2% or less, or 1.0% or less.

[0182] The optical filters of this disclosure may have a transmission band exhibiting an average transmittance of 2% or less in the range of 700 nm to 800 nm. In another example, the average transmittance can be further adjusted within the range of 0% or more, 0.1% or more, 0.3% or more, 0.4% or more, or 0.5% or more and / or within the range of 1.8% or less, 1.6% or less, 1.4% or less, 1.2% or less, 1.0% or less, 0.8% or less, 0.6% or less, or 0.5% or less.

[0183] The optical filters of this disclosure may have a transmission band exhibiting a maximum transmittance of 2% or less in the range of 700 nm to 800 nm. In another example, the maximum transmittance can be further adjusted within the range of 0% or more, 0.2% or more, 0.4% or more, 0.6% or more, or 0.8% or more and / or within the range of 1.8% or less, 1.6% or less, 1.4% or less, 1.2% or less, or 1.0% or less.

[0184] The optical filters of this disclosure may have a transmission band exhibiting an average transmittance of 2% or less in the range of 800 nm to 1000 nm. In another example, the average transmittance can be further adjusted within the range of 0% or more, 0.01% or more, 0.03% or more, 0.05% or more, 0.07% or more, or 0.09% or more and / or within the range of 1.8% or less, 1.6% or less, 1.4% or less, 1.2% or less, 1.0% or less, 0.8% or less, 0.6% or less, 0.4% or less, 0.2% or less, 0.15% or less, or 0.1% or less.

[0185] The optical filters of this disclosure may have a transmission band exhibiting a maximum transmittance of 2% or less in the range of 800 nm to 1000 nm. In another example, the maximum transmittance can be further adjusted within the range of 0% or more, 0.2% or more, 0.4% or more, 0.6% or more, or 0.8% or more and / or within the range of 1.8% or less, 1.6% or less, 1.4% or less, 1.2% or less, 1.0% or less, 0.8% or less, 0.6% or less, or 0.4% or less.

[0186] The optical filters of this disclosure may have a transmission band exhibiting an average transmittance of 5% or less in the range of 1000 nm to 1050 nm. In another example, the average transmittance can be further adjusted within the range of 0% or more, 0.5% or more, 1% or more or 1.5% or more and / or within the range of 4.5% or less, 4% or less, 3.5% or less, 3% or less, 2.5% or less, 2% or less, 1.5% or less, 1% or less, 0.8% or less, 0.6% or less, 0.4% or less or 0.3% or less.

[0187] The optical filters of this disclosure may have a transmission band exhibiting a maximum transmittance of 5% or less in the range of 1000 nm to 1050 nm. The maximum transmittance can be further adjusted in other examples to be within the range of 0% or more, 0.5% or more, 1% or more or 1.5% or more and / or within the range of 4.5% or less, 4% or less, 3.5% or less, 3% or less, 2.5% or less, 2% or less, 1.5% or less, 1% or less, 0.8% or less, 0.6% or less, 0.4% or less or 0.3% or less.

[0188] The optical filters of this disclosure may have a transmittance of 10% or less at a wavelength of 1050 nm. In other examples, the transmittance can be further adjusted within the range of 0% or more, 0.5% or more, 1% or more or 1.5% or more and / or within the range of 9% or less, 8% or less, 7% or less, 6% or less, 5% or less, 4% or less, 3% or less, 2% or less, 1.5% or less, 1% or less, 0.5% or less or 0.1% or less.

[0189] The optical filters of this disclosure can exhibit any one or more combinations of the optical properties described above, and preferably can satisfy all of the optical properties described above.

[0190] In addition to the layers mentioned above, optical filters can be modified to include various other layers as needed, as long as they do not impair the desired effect.

[0191] The aforementioned optical filter also has a low ripple value within the range described above, and can maintain this low ripple value even when the angle of incidence changes.

[0192] In other words, the ripple value of the optical filter at an incident angle of 0 degrees, and the ripple value at an incident angle of 0 degrees and the ripple value at an incident angle of 40 degrees, can be within the range described above.

[0193] This disclosure also relates to an imaging device including the optical filter. In this case, the configuration of the imaging device and the application method of the optical filter are not particularly limited, and known configurations and application methods can be applied.

[0194] Furthermore, the optical filters of this disclosure are not limited to the imaging device described above, but can be applied to a variety of other applications requiring near-infrared filtering (for example, display devices such as PDPs). [Effects of the Invention]

[0195] This disclosure provides optical filter substrates and optical filters and their applications. This disclosure provides optical filter substrates and optical filters that include a moisture-resistant layer and exhibit excellent durability while also having excellent optical properties. This disclosure provides optical filter substrates and optical filters that have excellent blocking characteristics for wavelength bands that need to be blocked, such as ultraviolet and infrared rays, have excellent visible light transmittance, and can prevent ripple phenomena in the visible light region. This disclosure provides optical filter substrates and optical filters that can ensure the above properties even when infrared absorbing glass, particularly glass known to have poor moisture resistance and heat resistance, is used as the substrate. [Brief explanation of the drawing]

[0196] [Figure 1] This figure shows an exemplary layered structure of an optical filter substrate. [Figure 2] This figure shows an exemplary layered structure of an optical filter substrate. [Figure 3] This figure shows an example of a stacked structure for an optical filter. [Figure 4] This figure shows an example of a stacked structure for an optical filter. [Figure 5] These are the spectral spectra of the transparent substrates used in the examples and comparative examples, before and after durability testing. [Figure 6] These are the spectral spectra of the optical filter substrates of Examples 1-3 and Comparative Examples 1-3. [Figure 7] These are the spectral spectra of the optical filter substrates of Examples 4 to 7. [Figure 8] These are spectral spectra used to confirm the ripple values ​​of the optical filter substrates in Examples 4-7. [Figure 9]This is a spectral spectrum used to confirm the ripple value of the optical filter substrate in Example 4. [Figure 10] This is a spectral spectrum used to confirm the ripple value of the optical filter substrate in Example 5. [Figure 11] This is a spectral spectrum used to confirm the ripple value of the optical filter substrate in Example 6. [Figure 12] This is a spectral spectrum used to confirm the ripple value of the optical filter substrate in Example 7. [Figure 13] These are the spectral spectra of the optical filter substrates of Examples 8 and 9 and Comparative Example 4. [Figure 14] These are spectral spectra used to confirm the ripple values ​​of the optical filter substrates in Examples 10-13. [Figure 15] This diagram shows the process for confirming the ripple value of the optical filter substrate in Example 10. [Figure 16] This diagram shows the process for confirming the ripple value of the optical filter substrate in Example 11. [Figure 17] This diagram shows the process for confirming the ripple value of the optical filter substrate in Example 12. [Figure 18] This diagram shows the process for confirming the ripple value of the optical filter substrate in Example 13. [Figure 19] This is the spectral spectrum of the optical filter of Example 14. [Modes for carrying out the invention]

[0197] The present disclosure will be described in detail below based on the following examples, but the scope of the present disclosure is not limited to the following examples.

[0198] 1. Evaluation of the transmittance spectrum The transmittance spectrum was measured using a spectrophotometer (manufacturer: Perkinelmer, product name: Lambda750 spectrophotometer) on test specimens obtained by cutting the object to be measured into pieces of a certain size (10 mm in width and 10 mm in height). The transmittance spectrum was measured at different wavelengths and angles of incidence according to the manual of the equipment. The test specimen was positioned on a straight line between the measurement beam and the detector of the spectrophotometer, and the transmittance spectrum was observed while changing the angle of incidence of the measurement beam from 0 degrees to 40 degrees. Unless otherwise specified, the transmittance spectrum results in this embodiment refer to the results when the angle of incidence is 0 degrees, in which case the angle of incidence of 0 degrees is substantially parallel to the direction of the surface normal of the test specimen.

[0199] In a transmittance spectrum, the average transmittance within a predetermined wavelength range is the result of calculating the arithmetic mean of the transmittances measured at each wavelength while increasing the wavelength by 1 nm from the shortest wavelength in the wavelength range, and the maximum transmittance is the highest transmittance among the transmittances measured while increasing the wavelength by 1 nm. For example, the average transmittance in the wavelength range of 350 nm to 360 nm is the arithmetic mean of the transmittances measured at wavelengths of 350 nm, 351 nm, 352 nm, 353 nm, 354 nm, 355 nm, 356 nm, 357 nm, 358 nm, 359 nm, and 360 nm, and the maximum transmittance in the wavelength range of 350 nm to 360 nm is the highest transmittance among the transmittances measured at wavelengths of 350 nm, 351 nm, 352 nm, 353 nm, 354 nm, 355 nm, 356 nm, 357 nm, 358 nm, 359 nm, and 360 nm.

[0200] In the following table summarizing the characteristics of the examples and comparative examples, T MAX This is the maximum transmittance within the given wavelength range, and its unit is %. AVGThis represents the average transmittance within the given wavelength range, and its unit is %. In the table above, T50% cut on is the shortest wavelength (in nm) that shows a 50% transmittance within the wavelength range of 350 nm to 425 nm, and T50% cut off is the longest wavelength (in nm) that shows a 50% transmittance within the wavelength range of 560 nm to 700 nm.

[0201] 2. Evaluation of Ripple Value The ripple value is the average transmittance T in the wavelength range of 450nm to 560nm. ave.i i=1~n and the actual transmittance T i The difference between i=1 and n is T. diff.i =T i -T ave.i After calculating all (i=1~n), the maximum value of the difference found is Max(T diff.i ) and minimum value Min(T diff.i The value was obtained by subtracting the value of i. The subscript i, defined above in the range from 1 to n, is an ordinal number indicating wavelength. For example, when checking the ripple value in the range of 450nm to 560nm, 450nm is specified as i = 1, and as the wavelength increases by 1nm, i also increases by 1. That is, 451nm is specified as i = 2, and 560nm is specified as i = 111.

[0202] The aforementioned ripple value is the R value determined by the following formula A.

[0203] [Formula A] R=Max(T diff.i )-Min(T diff.i )

[0204] In equation A, R is the ripple value, and Max(T diff.i ) is the maximum value of the difference between the average transmittance and the actual transmittance, and Min( Tdiff.i ) is the minimum value of the difference between the average transmittance and the actual transmittance. The ripple value was calculated using a cubic spline regression equation.

[0205] 3. Evaluation of refractive index The refractive indices of the infrared-absorbing glass and dielectric sublayer were measured at a wavelength of 520 nm using a Weez Optics M-2000 Ellipsometer.

[0206] 4. Evaluation of adhesion strength The adhesion strength of the moisture-resistant layer was evaluated using a Cross Hatch Cutter Peel Test according to the ASTM D3359 standard. In this peel test, 11 straight cut lines were made horizontally and vertically at 1 mm intervals on the moisture-resistant layer of the substrate to form a right-angle grid pattern on the moisture-resistant layer. After applying adhesive tape to the moisture-resistant layer with the grid pattern cut lines, the test measures whether the moisture-resistant layer with the cut lines peels off together with the adhesive tape, and the percentage of peeling. 3M's 810 Scotch Magic Tape was used as the adhesive tape. The adhesive tape was peeled off the moisture-resistant layer at a peel angle of approximately 180 degrees within a time of approximately 60 to 120 seconds. The adhesion strength evaluation criteria when evaluated using the above method are as follows. <Evaluation Criteria for Adhesion Strength> 5B: If no peeling occurs in the area where a grid pattern of incisions is created during the peeling test. 4B: When the area to be peeled in the peel test is less than 5% of the total area of ​​the section where the grid-patterned incision lines are created. 3B: When the area to be peeled in the peel test is 5% or more but less than 15% of the total area of ​​the section where the grid-patterned incision lines are created. 2B: When the area to be peeled in the peel test is 15% or more but less than 35% of the total area of ​​the section where the grid-patterned incision lines are created. 1B: When the area to be peeled in the peel test is 35% or more but less than 65% of the total area of ​​the section where the grid-patterned incision lines are created. 0B: When the area to be peeled in the peel test is 65% or more of the total area of ​​the part where the grid-patterned incision lines are created.

[0207] Manufacturing Example 1. Manufacturing of moisture-resistant layer material (A) The moisture-resistant layer material (A) was prepared by mixing a 10% by weight polysilazane solution with an acrylic silane coupling agent. The polysilazane solution was prepared by mixing H Company's polysilazane solution with dibutyl ether (DBE) in a weight ratio of 1:9 (polysilazane solution:DBE). 3-{diethoxy(methyl)silyl}propyl methacrylate was used as the acrylic silane coupling agent. The mixing was performed so that the weight ratio of the polysilazane solution to the silane coupling agent (polysilazane solution:silane coupling agent) was approximately 10:3.

[0208] Manufacturing Example 2. Manufacturing of moisture-resistant layer material (B) Moisture-resistant layer material (B) was manufactured in the same manner as in Manufacturing Example 1, except that 3-isocyanate-propyltrimethoxysilane was used as the silane coupling agent.

[0209] Manufacturing Example 3. Manufacturing of moisture-resistant layer material (C) Moisture-resistant layer material (C) was prepared in the same manner as in Production Example 1, except that 3-glycidoxypropyltrimethoxysilane was used as the silane coupling agent.

[0210] Manufacturing Example 4. Manufacturing of moisture-resistant layer material (D) The moisture-resistant layer material (D) was manufactured by mixing PDMS (polydimethylsiloxane) (Dow, Sylgard 184 Silicone Elastomer Base), amino-modified polysiloxane (Dow, OFX-8040 Fluid), and a curing agent (Dow, Sylgard 184 Silicone Elastomer Curing Agent). The material was manufactured by further mixing the curing agent into a mixture of PDMS (A) and amino-modified polysiloxane (B) in a weight ratio of approximately 2:8 (A:B). At this time, the curing agent was mixed so that its ratio was approximately 10% by weight, based on the total weight of PDMS (A), amino-modified polysiloxane (B), and the curing agent.

[0211] Manufacturing Example 5. Manufacturing of moisture-resistant layer material (E) The moisture-resistant layer material (E) was prepared by mixing PDMS (polydimethylsiloxane) (Dow, Sylgard 184 Silicone Elastomer Base), hydroxy-modified polysiloxane (Dow, PMX-0930 Silanol Fluid), and a curing agent (Dow, Sylgard 184 Silicone Elastomer Curing Agent). The material was prepared by further mixing the curing agent into a mixture of PDMS (A) and hydroxy-modified polysiloxane (B) in a weight ratio of approximately 2:8 (A:B). At this time, the curing agent was mixed so that its ratio was approximately 10% by weight, based on the total weight of PDMS (A), hydroxy-modified polysiloxane (B), and the curing agent.

[0212] Manufacturing Example 6. Manufacturing of Absorbent Layer Material The absorption layer material was manufactured using the following infrared absorbents: Absorbent 1 (triazine-based dye) exhibiting an absorption maximum in the range of approximately 340 nm to 390 nm; Infrared absorbent 2 (squarylium-based dye) with an absorption maximum wavelength in the range of approximately 700 nm to 720 nm and a full width at half maximum (FWHM) of approximately 50 nm to 60 nm; Infrared absorbent 3 (squarylium-based dye) with an absorption maximum wavelength in the range of approximately 730 nm to 750 nm and a FWHM of approximately 60 nm to 70 nm; and Infrared absorbent 4 (squarylium-based dye) with an absorption maximum wavelength in the range of approximately 760 nm to 780 nm and a FWHM of approximately 90 nm to 100 nm. The material was manufactured by compounding the above absorbents 1 to 4 with a binder resin. Cycloolefin polymer (COP) was used as the binder resin.

[0213] The material was prepared by mixing approximately 5 parts by weight of absorbent 1, approximately 0.1 parts by weight of absorbent 2, approximately 0.2 parts by weight of absorbent 3, and approximately 0.4 parts by weight of absorbent 4 with toluene (toluene) per 100 parts by weight of the binder resin.

[0214] Example 1. As the infrared absorption substrate, a phosphate-based absorbing glass (manufactured by PTOT) exhibiting the transmittance spectrum shown in Figure 5 was used. In Figure 5, the dotted line shows the spectrum of the phosphate-based absorbing glass before the durability test, and the solid line shows the spectrum after the durability test. The durability test involved maintaining the glass at 85°C and 85% relative humidity for 120 hours. The spectral characteristics of the infrared absorbing glass (before the durability test) are summarized in Table 1 below.

[0215] The infrared-absorbing glass had a refractive index of approximately 1.57.

[0216] [Table 1]

[0217] The moisture-resistant layer material (A) from Manufacturing Example 1 was applied to one surface of the infrared-absorbing glass (before durability testing), and heat-treated at 130°C for about 15 minutes to form a moisture-resistant layer with a thickness of about 0.1 μm. Subsequently, the same moisture-resistant layer material (A) was used on the other surface of the infrared-absorbing glass (before durability testing) to form a moisture-resistant layer with a thickness of about 0.1 μm, thereby manufacturing the base material.

[0218] Example 2. The substrate was manufactured in the same manner as in Example 1, except that the moisture-resistant layer material (B) from Manufacturing Example 2 was used instead of the moisture-resistant layer material (A) from Manufacturing Example 1.

[0219] Example 3. The substrate was manufactured in the same manner as in Example 1, except that the moisture-resistant layer material (C) from Manufacturing Example 3 was used instead of the moisture-resistant layer material (A) from Manufacturing Example 1.

[0220] Comparative Example 1. A solution of toluene dispersed with an acrylic silane coupling agent (3-{diethoxy(methyl)silyl}propyl methacrylate) was used as the moisture-resistant layer material. The same moisture-resistant layer material was applied to one surface of the infrared-absorbing glass (before durability testing) as in Example 1, and heat-treated at 130°C for about 15 minutes to form a moisture-resistant layer with a thickness of approximately 0.1 μm. Subsequently, a moisture-resistant layer with a thickness of approximately 0.1 μm was formed on the other surface of the same infrared-absorbing glass (before durability testing) to produce a substrate.

[0221] Comparative Example 2. Only the polysilazane solution used in the production of moisture-resistant layer material (A) in Production Example 1 was applied as the moisture-resistant layer material. The moisture-resistant layer material was applied to one surface of the same infrared-absorbing glass (before durability testing) as in Example 1, and heat-treated at 130°C for about 15 minutes to form a moisture-resistant layer with a thickness of about 0.1 μm. Subsequently, a moisture-resistant layer with a thickness of about 0.1 μm was formed on the other surface of the same infrared-absorbing glass (before durability testing) to produce the substrate.

[0222] Comparative Example 3. Comparative Example 3 used infrared absorbing glass without a moisture-resistant layer as the substrate.

[0223] Durability tests were conducted on the substrates of the examples and comparative examples. The durability tests involved maintaining each substrate at 85°C and 85% relative humidity for 120 hours.

[0224] Table 2 shows the transmittance characteristics after the durability tests conducted on each substrate, and the results in Table 2 are also shown in Figure 6.

[0225] [Table 2]

[0226] The evaluation results of the adhesion strength to the moisture-resistant layer for Examples 1 to 3 and Comparative Examples 1 to 3 are summarized in Table 3 below.

[0227] [Table 3]

[0228] Example 4. The substrate was manufactured in the same manner as in Example 1, except that the thickness of the moisture-resistant layer on both sides of the infrared-absorbing glass was adjusted to approximately 0.05 μm.

[0229] Next, the absorption layer material of Manufacturing Example 6 was applied to one of the moisture-resistant layers formed on both sides of the infrared-absorbing glass, and the material was heat-treated at 135°C for 2 hours to produce a substrate with an absorption layer. At this time, the thickness of the absorption layer was formed to be about 3 μm.

[0230] Example 5. A substrate with an absorbent layer was manufactured in the same manner as in Example 4, except that the thickness of the moisture-resistant layer was changed to approximately 0.1 μm.

[0231] Example 6. Except for changing the thickness of the moisture-resistant layer to approximately 5 μm, a substrate with an absorbent layer formed in the same manner as in Example 4 was manufactured.

[0232] Example 7. Except for changing the thickness of the moisture-resistant layer to approximately 10 μm, a substrate with an absorbent layer was manufactured in the same manner as in Example 4.

[0233] Tables 4 to 7 below summarize the transmittance spectra of the substrates for Examples 4 to 7 before and after the durability test. The durability test involves maintaining the substrates at 85°C and 85% relative humidity for 120 hours. Figure 7 shows the spectral spectra of the optical filter substrates for Examples 4 to 7 (before the durability test).

[0234] [Table 4]

[0235] [Table 5]

[0236]

Table 6

[0237]

Table 7

[0238] The adhesion of the moisture-resistant layer of the substrates in Examples 4 to 7 to the substrate was evaluated in the same manner as the adhesion evaluation in Table 3 above, and the results are summarized and described in Table 8 below.

[0239]

Table 8

[0240] FIG. 8 is an enlarged view (incident angle 0 degrees) of the transmittance spectrum within the wavelength range of 450 nm to 560 nm to confirm the ripple value of the optical filter substrates in Examples 4 to 7, and FIGS. 9 to 12 are diagrams showing the process of obtaining the ripple value for Examples 4 to 7, respectively. Table 9 below summarizes the ripple values of the optical filters in Examples 4 to 7 in the wavelength region of 450 nm to 560 nm.

[0241]

Table 9

[0242] As confirmed from the drawings and the above tables, the ripple value increases from Example 4 to Example 7. Therefore, from the perspective of the ripple value, Example 4 shows the best result. However, Example 4 shows somewhat inferior results compared to Example 5 from the perspectives of the adhesion of the moisture-resistant layer and coating properties, and Examples 6 and 7 have inferior adhesion of the moisture-resistant layer compared to Example 5. Also, Example 7 shows somewhat inferior results in visible light transmittance compared to other examples.

[0243] Example 8. The substrate was manufactured in the same manner as in Example 1, except that the moisture-resistant layer material (D) from Manufacturing Example 4 was used instead of the moisture-resistant layer material (A) from Manufacturing Example 1.

[0244] Example 9. The substrate was manufactured in the same manner as in Example 1, except that the moisture-resistant layer material (E) from Manufacturing Example 5 was used instead of the moisture-resistant layer material (A) from Manufacturing Example 1.

[0245] Comparative Example 4. As the moisture-resistant layer material, only PDMS (polydimethylsiloxane) and a curing agent, which were used in the moisture-resistant layer materials of Manufacturing Examples 4 and 5, were applied. The moisture-resistant layer material was applied to one surface of the same infrared-absorbing glass (before durability testing) as in Example 1, and heat-treated at 130°C for about 15 minutes to form a moisture-resistant layer with a thickness of about 0.1 μm. Subsequently, a moisture-resistant layer with a thickness of about 0.1 μm was formed on the other surface of the same infrared-absorbing glass (before durability testing) to produce the substrate.

[0246] Durability tests were conducted on the substrates of Examples 8 and 9 and Comparative Example 4. The durability tests involved maintaining each substrate at 85°C and 85% relative humidity for 120 hours.

[0247] Table 10 shows the transmittance characteristics after the durability tests conducted on each substrate, and the results in Table 10 are also shown in Figure 13.

[0248] [Table 10]

[0249] The adhesion strength of the moisture-resistant layers in Examples 8 and 9 and Comparative Example 4 to the substrate was evaluated using the same method as described above for evaluating adhesion strength, and the results are summarized in Table 11 below.

[0250] [Table 11]

[0251] Example 10. The substrate was produced in the same manner as in Example 8, except that the thickness of the moisture-resistant layers on both sides of the infrared absorption glass was adjusted to about 0.05 μm.

[0252] Next, the absorption layer material of Production Example 6 was applied to one of the moisture-resistant layers formed on both sides of the infrared absorption glass, and heat treatment was performed at 135 °C for 2 hours to produce a substrate on which an absorption layer was formed. At this time, the thickness of the absorption layer was formed to be about 3 μm.

[0253] Example 11. A substrate on which an absorption layer was formed was produced in the same manner as in Example 10, except that the thickness of the moisture-resistant layer was changed to about 0.1 μm.

[0254] Example 12. A substrate on which an absorption layer was formed was produced in the same manner as in Example 10, except that the thickness of the moisture-resistant layer was changed to about 5 μm.

[0255] Example 13. A substrate on which an absorption layer was formed was produced in the same manner as in Example 10, except that the thickness of the moisture-resistant layer was changed to about 10 μm.

[0256] Tables 12 to 15 below show the transmittance characteristics before and after the durability test performed on the substrates of Examples 10 to 13. The durability test is a test in which each substrate is maintained at 85 °C and 85% relative humidity for 120 hours.

[0257]

Table 12

[0258]

Table 13

[0259]

Table 14

[0260] [Table 15]

[0261] The adhesion of the moisture-resistant layer of the substrates in Examples 10-13 to the substrate was evaluated using the same method as the adhesion evaluation in Table 3, and the results are summarized in Table 16 below.

[0262] [Table 16]

[0263] Figure 14 is an enlarged view (incident angle 0 degrees) of the transmittance spectrum in the wavelength range of 450 nm to 560 nm to confirm the ripple value of the optical filter substrates of Examples 10 to 13. Figures 15 to 18 show the process of determining the ripple value for Examples 10 to 13, respectively. Table 17 below summarizes the ripple values ​​of the optical filters of Examples 10 to 13 in the wavelength range of 450 nm to 560 nm.

[0264] [Table 17]

[0265] As can be seen from the drawings and the table above, the ripple value increases from Example 10 to Example 13.

[0266] Example 14. A dielectric film was formed on the substrate of Example 5. The dielectric film was formed by depositing a sublayer using the ion-beam assisted deposition method. During deposition, the vacuum and temperature conditions were set to 5.0E-5 Torr and 120°C, respectively, and the IBS (Ion Beam Sputtering) source voltage was set to 350V and the current to 850mA. Using the above method, a dielectric film was formed by alternately forming a high refractive index TiO2 layer (refractive index approximately 2.61) and a low refractive index SiO2 layer (refractive index approximately 1.46). A total of six layers were formed, consisting of the high-refractive index layer and the low-refractive index layer, which are sublayers. Specifically, a dielectric film was formed by sequentially forming a TiO2 layer (approximately 12.4 nm thick), an SiO2 layer (approximately 30.3 nm thick), a TiO2 layer (approximately 43.7 nm thick), an SiO2 layer (approximately 13 nm thick), a TiO2 layer (approximately 30.4 nm thick), and an SiO2 layer (approximately 85.3 nm thick) on the infrared absorption layer. In such a dielectric film, n1 in equation A below is approximately 2.61 (refractive index of the TiO2 layer), n2 is approximately 1.46 (refractive index of the SiO2 layer), and n s Since the refractive index of the infrared-absorbing glass is approximately 1.57 and p is 2.5 (=(6-1) / 2), the V value is approximately 5.70.

[0267] [Formula 2] V = K × {[(n1 / n2)] 2p ×(n1 2 / n s )-1] / [(n1 / n2) 2p ×(n1 2 / n s )+1]} 2

[0268] Next, by sequentially forming TiO2 layers (approximately 12.4 nm thick), SiO2 layers (approximately 30.3 nm thick), TiO2 layers (approximately 43.7 nm thick), SiO2 layers (approximately 13 nm thick), TiO2 layers (approximately 30.4 nm thick), and SiO2 layers (approximately 85.3 nm thick) on the surface of the infrared-absorbing glass where the infrared-absorbing layer was not formed, an optical filter was manufactured in which dielectric films existed on both sides and the outermost layer was an SiO2 layer (approximately 85.3 nm thick).

[0269] Table 18 below summarizes the transmittance spectral characteristics of the optical filter.

[0270] [Table 18]

[0271] Test Example 1. The transmittance spectra of the optical filter of Example 14 were evaluated at incident angles of 0, 30, and 40 degrees, respectively, and the results are shown in Figure 19. As can be seen from Figure 19, the optical filter of Example 14 showed almost the same spectrum regardless of the incident angle. Furthermore, the T10% cut-on and T10% cut-off of the visible light transmission band did not shift substantially with respect to the incident angle. [Explanation of symbols]

[0272] 100 circuit boards 200, 201, 202 Moisture-resistant layer 300 Light-absorbing layer 401, 402 Dielectric Film

Claims

1. Infrared absorbing substrate and The infrared absorbing substrate includes a moisture-resistant layer formed on one or both sides of the substrate, The ripple value at an incident angle of 0 degrees in the wavelength range of 450 nm to 560 nm is 7% or less. ΔT by equation 1 below Ｖ The absolute value of is 30% or less, The moisture-resistant layer is a layer containing a polysilazane and a silane compound that is a silane coupling agent, or a layer containing a polysiloxane having the average unit of the following chemical formula 1. An optical filter substrate having an average transmittance of 6% or less in the wavelength range of 800 nm to 1000 nm. [Formula 1] △T Ｖ =100×(T Ｖ．ｆ -T Ｖ．ｉ ) / T Ｖ．ｉ (In formula 1, T Ｖ．ｆ This is the average transmittance of the optical filter substrate in the wavelength range of 425 nm to 560 nm after maintaining the optical filter substrate at a temperature of 85°C and a relative humidity of 85% for 120 hours, and T Ｖ．ｉ This is the average transmittance of the optical filter substrate in the wavelength range of 425 nm to 560 nm before being maintained at the aforementioned temperature and humidity. [Chemical formula 1] R a SiO (4-a) / 2 (In chemical formula 1, R is a hydrogen atom, an alkyl group, an alkenyl group, or a functional group, R includes at least the functional group, a is 0.01 or more and less than 4, and the functional group includes an epoxy group, an amino group, a mercapto group, or a hydroxyl group.)

2. The optical filter substrate according to claim 1, having a transmission band in which the T50% cut-off wavelength is in the range of 590 nm to 660 nm.

3. The optical filter substrate according to claim 2, wherein the average transmittance within the wavelength range of 425 nm to 560 nm of the transmission band is 75% or more.

4. The optical filter substrate according to claim 1, wherein the moisture-resistant layer is in contact with the infrared absorbing substrate, and the adhesion strength of the moisture-resistant layer is 3B or higher according to the ASTM D3359 standard.

5. The optical filter substrate according to claim 1, wherein the infrared absorbing substrate is a CuO-containing fluorinated phosphate glass substrate or a CuO-containing phosphate glass substrate.

6. The optical filter substrate according to claim 1, wherein the moisture-resistant layer has a thickness in the range of 0.01 μm to 10 μm.

7. The optical filter substrate according to claim 1, further comprising a light-absorbing layer on one or both sides of an infrared-absorbing substrate.

8. An optical filter substrate according to any one of claims 1 to 7, An optical filter comprising a dielectric film formed on one or both sides of an infrared absorbing substrate of the optical filter base.

9. The optical filter according to claim 8, wherein the dielectric film comprises a first sublayer and a second sublayer having different refractive indices and stacked alternately.

10. The optical filter according to claim 9, wherein the first and second sublayers are formed such that the V value according to the following formula 2 is 17 or less. [Formula 2] V=K×{[(n １ / n ２ ) ２ｐ ×(n １ ２ / n ｓ )-1] / [(n １ / n ２ ) ２ｐ ×(n １ ２ / n ｓ )+1]} ２ (In formula 2, n １ n is the refractive index of the first sublayer. ２ n is the refractive index of the second sublayer. ｓ (where K is the refractive index of the transparent substrate, K is the total number of first and second sublayers in the dielectric film, and p is a number that satisfies K = (2p + 1).)

11. Refractive index n of the first sublayer １ and the refractive index n of the second sublayer ２ ratio n １ / n ２ The optical filter according to claim 10, wherein the value is in the range of 1.4 to 2.

0.

12. Refractive index n of the first sublayer １ The optical filter according to claim 11, wherein the value is in the range of 1.8 to 3.

5.

13. Refractive index n of the first sublayer １ and the refractive index n of the transparent substrate ｓ ratio n １ / n ｓ The optical filter according to claim 10, wherein the value is in the range of 1.4 to 2.

0.

14. The optical filter according to claim 10, wherein K in formula 2 is 15 or less.

15. The optical filter according to claim 10, wherein the thicknesses of the first and second sublayers are in the range of 5 nm to 200 nm, and the average value of the thickness of the first sublayer and the thickness of the second sublayer contained in the dielectric film is in the range of 5 nm to 70 nm.

16. The optical filter according to claim 8, wherein the dielectric film has a thickness in the range of 100 nm to 500 nm.

17. The optical filter according to claim 8, wherein a dielectric film is formed on both sides of the infrared absorbing substrate.

18. An imaging device comprising the optical filter described in claim 8.

Images