Optical filter

Abstract

To provide an optical filter that is advantageous in exhibiting desired transmittance characteristics even without a near-infrared reflective film.SOLUTION: An optical filter 1a comprises a first light absorber 11 and a second light absorber 12. The first light absorber 11 contains an organic dye. The second light absorber 12 contains a copper component, and absorbs at least a portion of infrared light. The optical filter exhibits a first transmission spectrum that satisfies the following conditions: (I) an average value of a transmittance TA450-600 within a wavelength range of 450 nm to 600 nm is 76% or more; (II) a first cutoff wavelength λF is within a range of 360 nm to 450 nm; (III) a second cutoff wavelength λS is within a range of 600 nm to 700 nm; and (IV) a maximum value of the transmittance TM700-750 within a wavelength range of 700 nm to 750 nm is 5% or less.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an optical filter.

Background Art

[0002] In an imaging device including an imaging element such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor), various optical filters are arranged in front of the imaging element in order to obtain an image having good color reproducibility. The imaging element has sensitivity to light in a wide wavelength range from the ultraviolet region to the infrared region. On the other hand, human visual sensitivity exists only in the visible light region. For this reason, a technique of arranging an optical filter that shields a part of infrared or ultraviolet light in front of the imaging element is known so that the image obtained by the imaging device approaches the image recognized by humans.

[0003]

[0004] ​On the one hand, there is a known technique of using an optical filter such as a near-infrared cut filter to allow only visible light to reach the environmental sensor of an information terminal device and to match the human visual sensitivity with the brightness or color tone of a display. For example, Patent Document 2 describes an optical filter for an environmental sensor. This optical filter has a layer containing a compound (A) having an absorption maximum in the region of 650 nm or more and less than 800 nm in wavelength and a compound (B) having an absorption maximum in the region of 800 nm or more and 1850 nm or less in wavelength. The compound (A) is at least one compound selected from the group consisting of squarylium compounds, phthalocyanine compounds, and cyanine compounds. The compound (B) is at least one compound selected from the group consisting of near-infrared absorbing fine particles, squarylium compounds, phthalocyanine compounds, naphthalocyanine compounds, croconium compounds, cyanine compounds, diimonium compounds, metal dithiolate compounds, and pyrrolopyrrole compounds.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] In recent years, considering the performance required for optical filters, the technique described in Patent Document 1 may further require a device for increasing the transmittance in the visible light region. In the technique described in Patent Document 2, since an optical absorber made of an organic compound is used, when used for an optical filter, the wavelength band that shields light may be insufficient, and in order to complement it, it is necessary to also provide a near-infrared reflection film made of a dielectric multilayer film or the like. This is disadvantageous from the viewpoints of suppressing flare and ghost or reducing manufacturing costs.

[0007] In view of such circumstances, the present invention provides an optical filter that is advantageous for exhibiting desired transmittance characteristics without including a near-infrared reflection film.

Means for Solving the Problems

[0008] The present invention is an optical filter comprising a first light absorber containing an organic dye, and a second light absorber containing a copper component and absorbing at least part of infrared rays, when light in the wavelength range of 300 nm to 1200 nm is incident on the optical filter, it shows a first transmittance spectrum satisfying the following conditions (I), (II), (III), and (IV), a second transmittance spectrum which is the transmittance spectrum of the first light absorber when light in the wavelength range of 300 nm to 1200 nm is incident on the first light absorber satisfies the following conditions (i1), (i2), (i3), (i4), and (i5), and provides an optical filter. (I) The average value of the transmittance in the wavelength range of 450 nm to 600 nm is 76% or more. (II) A first cut-off wavelength, which is a wavelength showing a transmittance of 50% in the wavelength range of 350 nm to 470 nm, exists in the range of 360 nm to 450 nm. (III) A second cut-off wavelength, which is a wavelength showing a transmittance of 50% in the wavelength range of 580 nm to 720 nm, exists in the range of 600 nm to 700 nm. (IV) The maximum value of the transmittance in the wavelength range of 700 nm to 750 nm is 5% or less. (i1) The wavelength showing the minimum value of the transmittance in the wavelength range of 550 nm to 850 nm is 650 nm or more and 770 nm or less. (i2) The minimum value of the wavelength showing a transmittance of 70% in the wavelength range of 550 nm to 850 nm is 570 nm or more and 670 nm or less. (i3) The minimum value of the wavelength showing a transmittance of 50% in the wavelength range of 550 nm to 850 nm is 590 nm or more and 700 nm or less. (i4) In the wavelength range of 550 nm to 850 nm, the minimum value of the wavelength showing a transmittance of 20% is 630 nm or more and 720 nm or less. (i5) The average value of the transmittance in the wavelength range of 450 nm to 600 nm is 76% or more.

Advantages of the Invention

[0009] The above optical filter is composed of a light absorber and is advantageous for exhibiting desired transmittance characteristics. Furthermore, it is possible to transmit light in the wavelength range corresponding to the visible light region and shield light in the wavelength ranges of the ultraviolet and infrared regions without using a light reflection film in combination.

Brief Description of the Drawings

[0010]

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Mode for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the following description relates to an example of the present invention, and the present invention is not limited thereto.

[0012] As an optical filter for shielding a part of infrared or ultraviolet light, it is conceivable to use a light-reflective optical filter having a dielectric multilayer film, a light-absorbing film or a light-absorbing filter containing a light-absorbing dye, or a hybrid filter combining them. As the light-absorbing filter, it is conceivable to use an infrared-absorbing glass such as phosphate glass or phosphate glass containing a specific metal component such as Cu, and a light-absorbing glass. In addition, a cured product of a composition obtained by dissolving or dispersing an organic dye such as a cyanine-based dye compound capable of absorbing specific light in a resin and formed into a film, a film, or a sheet-like shape can also be used as the light absorber. In particular, a light absorber formed from a composition containing an organic dye and a resin can use various dye compounds having various light absorption characteristics that are on the market, is easy to adjust or modify optical characteristics, and is also advantageous from the viewpoint of manufacturing cost. However, a light-absorbing film or film formed from a resin containing an organic dye may have a narrow wavelength range of light that can be sufficiently absorbed due to the absorption spectral characteristics of the organic dye. For this reason, for example, in order to sufficiently shield infrared light in a wavelength range from 700 nm to 1000 nm, it is necessary to simultaneously use a variety of dye compounds having different absorption bands in the light-absorbing film. In addition, it may be necessary to use the light-absorbing film in combination with a light-reflecting film made of a dielectric multilayer film. Using a variety of dye compounds having different absorption bands in the light-absorbing film may not be advantageous from the viewpoint of sufficiently increasing the transmittance in the visible light region. Using the light-absorbing film and the light-reflecting film in combination requires laminating a large number of dielectric thin films by methods such as vacuum deposition and sputtering, and the manufacturing cost increases easily.

[0013] Therefore, the present inventors have repeatedly studied day and night to develop an optical filter that can exhibit desired transmittance characteristics while addressing the above problems. As a result of numerous trials and errors, the present inventors have discovered that an optical filter including a first absorber containing an organic dye and a predetermined second absorber containing a copper component can exhibit desired transmittance characteristics. Based on this new discovery, the present inventors have devised the optical filter according to the present invention.

[0014] As shown in FIGS. 1 to 4, each of the optical filters 1a, 1b, 1c, and 1d includes a first light absorber 11 and a second light absorber 12. The first light absorber 11 contains an organic dye. The second light absorber 12 contains a copper component and absorbs at least a part of infrared rays. When light in the wavelength range of 300 nm to 1200 nm is incident on the optical filters 1a to 1d, each optical filter satisfies the following first transmission spectra of conditions (I), (II), (III), and (IV). The first transmission spectrum is the transmission spectrum at an incident angle of 0°. (I) The average value T of the transmittance in the wavelength range of 450 nm to 600 nm A 450-600 is 76% or more. (II) The first cut-off wavelength λ, which is the wavelength showing a transmittance of 50% in the wavelength range of 350 nm to 470 nm F exists in the range of 360 nm to 450 nm. (III) The second cut-off wavelength λ, which is the wavelength showing a transmittance of 50% in the wavelength range of 580 nm to 720 nm is in the range of 600 nm to 700 nm. S exists in the range of 600 nm to 700 nm. (IV) The maximum value T of the transmittance in the wavelength range of 700 nm to 750 nm M 700-750 is 5% or less.

[0015] When the optical filters 1a to 1d are used for photographing digital photos such as in a digital camera or a built-in camera of a smartphone together with an imaging device such as a CCD or a CMOS, since the first transmission spectrum in the optical filters 1a to 1d satisfies the condition (I), the transmittance in the visible light region of the optical filters 1a to 1d is high, which is advantageous for obtaining a bright image. Since the first transmission spectrum satisfies the conditions (II), (III), and (IV), ultraviolet rays and It can appropriately shield a part of visible light and infrared rays, which is advantageous for shielding light unnecessary for image formation. Based on such circumstances, the optical filters 1a to 1d can exhibit desired transmittance characteristics. In addition, according to the optical filters 1a to 1d, desired transmittance characteristics can be exhibited without providing a light reflection film such as a dielectric multilayer film.

[0016] (Regarding the condition of (I), the average value T A 450-600 is desirably 78% or more.

[0017] (Regarding the condition of (II), the first cut-off wavelength λ F is desirably in the range of 370 nm to 440 nm and more desirably in the range of 380 nm to 430 nm.

[0018] (Regarding the condition of (III), the second cut-off wavelength λ S is desirably in the range of 620 nm to 680 nm.

[0019] (Regarding the condition of (IV), the maximum value T M 700-750 is desirably 3% or less, and more desirably 1.5% or less.

[0020] As shown in FIGS. 1 to 4, in the optical filters 1a to 1d, each of the first light absorber 11 and the second light absorber 12 can typically be formed as a film, a sheet, or a membrane. The first light absorber 11 and the second light absorber 12 are arranged side by side in their thickness directions, and when the optical filters 1a to 1d are viewed in plan view, the second light absorber 12 overlaps at least a part of the first light absorber 11. The first transmittance spectrum is a transmittance spectrum obtained when light in the wavelength range of 300 nm to 1200 nm passes through the first light absorber 11 and the second light absorber 12. Toru.

[0021] In the first transmittance spectrum, the absolute value Δλ of the difference between the second cut-off wavelength λ S and the first cut-off wavelength λ F ​S / F is, for example, 190 nm or more and 280 nm or less. Thereby, the optical filters 1a to 1d can more surely exhibit desired transmittance characteristics. Δλ S / F corresponds to the transmission band in the visible light region. By specifying this within the above range, the first transmission spectrum of the optical filters 1a to 1d can be easily adjusted to the human visual sensitivity. Adjusting the transmission spectrum to the human visual sensitivity means making the spectrum expressed using the ratio of the transmittance corresponding to other wavelengths with the maximum transmittance in the transmission spectrum being 1 approach the visual sensitivity (visual sensitivity curve or spectral luminous efficiency). The higher the consistency between the two, the better the adjustment is expressed. The output from the imaging element that has received the light transmitted through the optical filter well adjusted to the visual sensitivity has a spectrum that is also close to that corresponding to the visual sensitivity, and the color reproducibility of the imaging device becomes good.

[0022] The absolute value Δλ S / F is desirably 200 nm or more and 270 nm or less, and more desirably 200 nm or more and 260 nm or less.

[0023] The transmittance T at a wavelength of 350 nm in the first transmission spectrum 350 is, for example, 20% or less Thereby, the optical filters 1a to 1d can more surely exhibit desired transmittance characteristics. In particular, the condition that the transmittance T 350 is 20% or less is also one of the criteria indicating how much light belonging to the ultraviolet region can be blocked. At this time, the first transmission spectrum can be easily adjusted to the human visual sensitivity. Further, the transmittance T is desirably 16% or less. 350

[0024] The maximum value T of the transmittance in the range of wavelengths from 750 nm to 1000 nm in the first transmission spectrum M 750-1000 is, for example, 2% or less. Thereby, the optical filters 1a to 1d can more ​It can surely exhibit the desired transmittance characteristics. In particular, it becomes easier to block light belonging to the near-infrared region, and the first transmittance spectrum can be easily adjusted to the human visual sensitivity.

[0025] Desirably, the maximum value T of the transmittance in the wavelength range of 750 nm to 1100 nm of the first transmittance spectrum M 750-1100 is 1% or less, and more desirably, the wavelength of the first transmittance spectrum the maximum value T of the transmittance in the range of 750 nm to 1200 nm M 750-1200 is 1% or less .

[0026] The maximum value T of the transmittance in the wavelength range of 800 nm to 950 nm of the first transmittance spectrum M 800-950 is, for example, 1% or less. Thereby, the optical filters 1a to 1d can surely exhibit the desired transmittance characteristics. In particular, it becomes easier to further block light belonging to the near-infrared region, and the first transmittance spectrum can be easily adjusted to the human visual sensitivity. The maximum value T M 800-950 is desirably 0.7% or less, and more desirably 0.5% or less.

[0027] The absolute value ΔT of the difference between the maximum wavelength and the minimum wavelength showing a transmittance of 1% in the wavelength range of 700 nm to 1200 nm of the first transmittance spectrum 1% is, for example, 400 nm or more. Thereby, the optical filters 1a to 1d can block light belonging to the near-infrared region in a wider wavelength band, so that the desired transmittance characteristics can be surely exhibited.

[0028] The absolute value ΔT of the difference between the maximum wavelength and the minimum wavelength showing a transmittance of 0.5% in the wavelength range of 700 nm to 1200 nm of the first transmittance spectrum 0.5% is, for example, 400 nm or more.

[0029] The absolute value ΔT of the difference between the maximum wavelength and the minimum wavelength showing a transmittance of 0.3% in the wavelength range of 700 nm to 1200 nm of the first transmittance spectrum0.3% is, for example, 400 nm or more.

[0030] The transmittance characteristics of the first light absorber 11 are not limited to specific transmittance characteristics as long as the first transmittance spectrum satisfies the conditions (I), (II), (III), and (IV). The second transmittance spectrum, which is the transmittance spectrum of the first light absorber 11 when light in the wavelength range of 300 nm to 1200 nm is incident on the first light absorber 11, satisfies, for example, the following conditions (i1), (i2), (i3), (i4), and (i5). By laminating and combining the first light absorber 11 that satisfies these conditions with a predetermined second light absorber, the optical filters 1a to 1d can exhibit desired transmittance characteristics. The second transmittance spectrum is the transmittance spectrum at an incident angle of 0°. (i1) The wavelength λ showing the minimum transmittance in the wavelength range of 550 nm to 850 nm (2)M is 650 nm or more and 770 nm or less. (i2) The minimum value λ of the wavelength showing a transmittance of 70% in the wavelength range of 550 nm to 850 nm (2) 70%L is 570 nm or more and 670 nm or less. (i3) The minimum value λ of the wavelength showing a transmittance of 50% in the wavelength range of 550 nm to 850 nm (2) 50%L is 590 nm or more and 700 nm or less. (i4) The minimum value λ of the wavelength showing a transmittance of 20% in the wavelength range of 550 nm to 850 nm (2) 20%L is 630 nm or more and 720 nm or less. (i5) The average value T of the transmittance in the wavelength range of 450 nm to 600 nm (2)A 450-600 is 76 % or more.

[0031] Regarding condition (i1), the wavelength λ (2)M is preferably 650 nm or more and 750 nm or less.

[0032] Regarding condition (i2), the minimum value λ (2)70%L is desirably 590 nm or more and 660 nm or less is present.

[0033] Regarding condition (i3), the minimum value λ (2) 50%L is desirably 580 nm or more and 690 nm or less is present.

[0034] Regarding condition (i4), the minimum value λ (2) 20%L is desirably 640 nm or more and 710 nm or less is present.

[0035] Regarding condition (i5), the average value T (2)A 450-600 is desirably 80% or more, and more desirably 85% or more.

[0036] The second transmission spectrum may satisfy at least one of the following conditions (i6), (i7), and (i8). Thereby, the optical filters 1a to 1d can more reliably exhibit the desired transmittance characteristics. (i6) The absolute value Δλ of the difference between the maximum value λ (2) 70%H and the minimum value λ (2) 70%L of the wavelengths showing a transmittance of 70% in the wavelength range of 550 nm to 850 nm (2) 70% is 120 nm or more and 250 nm or less. (i7) The absolute value Δλ of the difference between the maximum value λ (2) 50%H and the minimum value λ (2) 50%L of the wavelengths showing a transmittance of 50% in the wavelength range of 550 nm to 850 nm (2) 50% is 70 nm or more and 210 nm or less. (i8) The absolute value Δλ of the difference between the maximum value λ (2) 20%H and the minimum value λ (2) 20%L of the wavelengths showing a transmittance of 20% in the wavelength range of 550 nm to 850 nm (2)20% is 30 nm or more and 160 nm or less.

[0037] The second transmission spectrum desirably satisfies the above conditions (i6), (i7), and (i8).

[0038] Regarding condition (i6), the absolute value Δλ (2) 70% is desirably 130 nm or more and 240 nm or less, more desirably 140 nm or more and 230 nm or less.

[0039] Regarding condition (i7), the absolute value Δλ (2) 50% is desirably 80 nm or more and 200 nm or less, more desirably 90 nm or more and 190 nm or less.

[0040] Regarding condition (i8), the absolute value Δλ (2) 20% is desirably 40 nm or more and 150 nm or less, more desirably 50 nm or more and 140 nm or less.

[0041] The second transmission spectrum satisfies, for example, the condition of -1.2 [% / nm] ≦ (20 - 70) / (λ (2) 20%L -λ (2) 70%L ) ≦ -0.6 [% / nm]. By combining the first light absorber 11 that satisfies such a condition with the second light absorber, the optical filters 1a to 1d can exhibit a desired transmission spectrum. (20 - 70) / (λ (2) 20%L -λ (2) 70%L ) [% / nm] represents the average slope of the second transmission spectrum in the range of the wavelength λ (2) 70%L [nm] and λ (2) 20%L [nm], and is also expressed as ΔT (2) / Δλ (2) L .

[0042] The minimum value λ (2)20%L and the minimum value λ (2) 70%L is desirably -1.1 [% / nm] ≦ (20 - 70) / (λ (2) 20%L - λ (2) 70%L ) ≦ -0.7 [% / nm], and more desirably -1.0 [% / nm] ≦ (20 - 70) / (λ (2) 20%L - λ (2) 70%L ) ≦ -0.75 [% / nm].

[0043] The organic dye contained in the first light absorber 11 is composed of an organic compound, and here, it is not distinguished as a dye or a pigment, and is not limited to a specific organic dye. The organic dye contained in the first light absorber 11 includes, for example, at least one selected from the group consisting of cyanine dyes, squarylium dyes, phthalocyanine dyes, diimonium dyes, and azo dyes. Thereby, the optical filters 1a to 1d are likely to exhibit desired transmittance characteristics.

[0044] The first light absorber 11 may contain a single type of organic dye or may contain a plurality of types of organic dyes. The organic dye has an absorption maximum wavelength in the range of, for example, 650 nm to 800 nm.

[0045] The first light absorber 11 further includes, for example, a matrix. The organic dye is typically dispersed or dissolved in the matrix. This matrix is not limited to a specific material as long as the first transmittance spectrum satisfies the conditions (I), (II), (III), and (IV). The matrix contained in the first light absorber 11 is typically a material having high transmittance at wavelengths of 400 nm to 600 nm. For example, when a layer with a thickness of 0.1 mm is formed only of that material, the transmittance of that layer at wavelengths of 400 nm to 600 nm is, for example, 70% or more, desirably 75% or more, more desirably 80% or more, and even more desirably 85% or more.

[0046] The material of the matrix contained in the first light absorber 11 is, for example, a resin. The type of resin contained in the first light absorber 11 is not limited to a specific type. The resin is, for example, a cyclic polyolefin resin, an epoxy resin, a polyimide resin, a modified acrylic resin, a silicone resin, or a polyvinyl resin such as PVB. The resin may be a curable resin that can be cured by energy irradiation such as heat or light. Note that the matrix contained in the first light absorber 11 may be an organic-inorganic hybrid material or an inorganic material formed by hydrolyzing and polycondensing an alkoxide containing a metal component according to the sol-gel method.

[0047] The first light absorber 11 may be formed as a layer, for example, on the surface of a substrate, an optical device, or an optical component. The substrate can be formed of a transparent material such as glass, resin, or crystal.

[0048] The thickness of the first light absorber 11 is, for example, 0.5 μm to 1000 μm, may be 1 μm to 250 μm, or may be 1 μm to 200 μm.

[0049] The transmittance characteristics of the second light absorber 12 are not limited to specific transmittance characteristics as long as the first transmittance spectrum satisfies the conditions of (I), (II), (III), and (IV). The third transmittance spectrum, which is the transmittance spectrum of the second light absorber 12 when light in the wavelength range of 300 nm to 1200 nm is incident on the second light absorber 12, satisfies, for example, the following conditions (ii1), (ii2), (ii3), (ii4), and (ii5). By combining the second light absorber 12 that satisfies such conditions with the above-mentioned first light absorber, the optical filters 1a to 1d are likely to exhibit desired transmittance characteristics. The third transmittance spectrum is the transmittance spectrum at an incident angle of 0°. (ii1) The wavelength λ showing a transmittance of 70% in the wavelength range of 550 nm to 750 nm (3) 70%H is 620 nm or more and 690 nm or less. (ii2) The wavelength λ that exhibits a transmittance of 50% in the wavelength range of 550 nm to 750 nm (3) 50%H is 640 nm or more and 720 nm or less. (ii3) The wavelength λ that exhibits a transmittance of 20% in the wavelength range of 550 nm to 750 nm (3) 20%H is 670 nm or more and 750 nm or less. (ii4) The transmittance T at a wavelength of 750 nm (3) 750 is 0.5% or more and 6% or less. (ii5) The average value T of the transmittance in the wavelength range of 450 nm to 600 nm (3)A 450-600 is 76% or more.

[0050] Regarding the condition of (ii1), the wavelength λ (3) 70%H is preferably 630 nm or more and 680 nm or less.

[0051] Regarding the condition of (ii2), the wavelength λ (3) 50%H is preferably 650 nm or more and 710 nm or less.

[0052] Regarding the condition of (ii3), the wavelength λ (3) 20%H is preferably 680 nm or more and 740 nm or less.

[0053] Regarding the condition of (ii4), the transmittance T (3) 750 is preferably 1% or more and 5% or less.

[0054] Regarding the condition of (ii5), the average value T (3)A 450-600 is preferably 78% or more, and more preferably 80% or more.

[0055] The maximum value T of the transmittance in the wavelength range of 750 nm to 1100 nm of the third transmittance spectrum (3)M 750-1100is, for example, 0.5% or more and 6% or less. Thereby, the optical filters 1a to 1d are likely to exhibit desired transmittance characteristics. The maximum value T (3)M 750-1100 is desirably 1% or more and 5% or less.

[0056] In the third transmittance spectrum, the wavelength λ (3) 20%H , the wavelength λ (3) 70%H , and the transmittance T (3) 750 are, for example, -0.9 [% / nm] ≦ (20 - 70) / (λ (3) 20%H - λ (3) 70%H ) ≦ -0.78 [% / nm] and -0.9 [% / nm] ≦ (T (3) 750 - 70) / (750 - λ (3) 70%H ) ≦ -0.5 [% / nm] satisfy at least one of the conditions. By combining the second light absorber 12 that satisfies such conditions with the first light absorber described above, the optical filters 1a to 1d are more likely to exhibit the desired transmittance spectrum. (20 - 70) / (λ satisfies (3) 20%H (3) - λ 70%H (3) ) [% / nm] represents the average slope of the third transmittance spectrum in the range of the wavelength λ 70%H [nm] and λ[nm], and is also expressed as ΔT (3) 20%H / Δλ (3) / Δλ (3) H and is also expressed as ΔT (3) 750 - 70) / (750 - λ (3) 70%H ) [% / nm] represents the average slope of the third transmittance spectrum in the range of the wavelength 750 nm and λ (3) 70%H nm], and is also expressed as ΔT (3) / Δλ (3) 750 and is also expressed as ΔT

[0057] ​In the third transmission spectrum, the wavelength λ (3) 20%H and the wavelength λ (3) 70%H preferably satisfy the condition of -0.88 [% / nm] ≦ (20 - 70) / (λ (3) 20%H - λ (3) 70%H ) ≦ -0.80 [% / nm], and more preferably -0.87 [% / nm] ≦ (20 - 70) / (λ (3) 20%H - λ (3) 70%H ) ≦ -0.82 [% / nm].

[0058] In the third transmission spectrum, the wavelength λ (3) 70%H and the transmittance T (3) 750 preferably satisfy the condition of -0 .85 [% / nm] ≦ (T (3) 750 - 70) / (750 - λ (3) 70%H ) ≦ -0.55 [% / nm], and more preferably -0.8 [% / nm] ≦ (T (3) 750 - 70) / (750 - λ (3) 70%H ) ≦ -0.6 [% / nm].

[0059] The third transmission spectrum satisfies at least one of the conditions (ii6), (ii7), and (ii8) below. Thereby, the optical filters 1a to 1d are likely to exhibit desired transmittance characteristics. (ii6) The wavelength λ (3) 70%L showing a transmittance of 70% in the wavelength range of 300 nm to 450 nm is 360 nm or more and 430 nm or less. (ii7) The wavelength λ (3) 50%L showing a transmittance of 50% in the wavelength range of 300 nm to 450 nm is 340 nm or more and 390 nm or less. (ii8) The wavelength λ that exhibits a transmittance of 20% in the wavelength range of 300 nm to 450 nm (3) 20%L is 330 nm or more and 380 nm or less.

[0060] The wavelength λ (3) 70%L is desirably 370 nm or more and 420 nm or less.

[0061] The wavelength λ (3) 50%L is desirably 350 nm or more and 380 nm or less.

[0062] The wavelength λ (3) 20%L is desirably 340 nm or more and 360 nm or less.

[0063] In the third transmittance spectrum, the wavelength λ (3) 70%L and the wavelength λ (3) 20%L satisfy the condition of, for example, 0.75 [% / nm] ≦ (70 - 20) / (λ (3) 70%L - λ (3) 20%L ) ≦ 1.6 [% / nm]. Thereby, the optical filters 1a to 1d can easily adjust the transmittance spectrum in the ultraviolet region and easily exhibit the desired transmittance characteristics. (70 - 20) / (λ (3) 70%L - λ (3) 20%L ) [% / nm] represents the average slope of the third transmittance spectrum in the range of λ (3) 20%L [nm] and the wavelength λ (3) 70%L [nm], and is also represented as ΔT (3) / Δλ (3) L .

[0064] The wavelength λ (3) 70%L and the wavelength λ (3) 20%L are desirably such that 0.85 [% / nm] ≦ (70 - 20) / (λ (3) 70%L-λ (3) 20%L ) satisfies the condition of ≤ 1.55 [% / nm], and more preferably, 0.9 [% / nm] ≤ (70 - 20) / (λ (3) 70%L -λ (3) 20%L ) satisfies the condition of ≤ 1.5 [% / nm].

[0065] In the third transmission spectrum, the absolute value Δλ (3) 50%H of the difference between wavelength λ (3) 50%L and wavelength λ (3) 50% is, for example, 270 nm or more and 350 nm or less. Thereby, in the wavelength range corresponding to the visible light region, a wide band with high transmittance can be secured, so the optical filters 1a to 1d are likely to exhibit desired transmittance characteristics.

[0066] The absolute value Δλ (3) 50% is preferably 290 nm or more and 340 nm or less.

[0067] As long as the first transmission spectrum satisfies the conditions of (I), (II), (III), and (IV), the mode of the copper component content in the second light absorber 12 is not limited to a specific mode. The second light absorption body 12 contains, for example, a compound containing a copper component and at least one selected from the group consisting of phosphonic acid, sulfonic acid, and carboxylic acid. These compounds are light-absorbing compounds having light-absorbing properties mainly due to the function of the copper component, and their properties contribute to realizing the required transmission spectrum of the optical filter of the present invention, and the optical filters 1a to 1d are more likely to exhibit desired transmittance characteristics with certainty.

[0068] In the second light absorber 12, the light-absorbing compound may be a complex formed by a copper component and at least one selected from the group consisting of phosphonic acid, sulfonic acid, and carboxylic acid. The light-absorbing compound may be fine particles containing a copper component and phosphonic acid. In this case, the phosphonic acid is not limited to a specific phosphonic acid. The phosphonic acid is represented by, for example, the following formula (a).

[0069] [Chemical Formula] [In the formula, R 11 is an alkyl group, an aryl group, a nitroaryl group, a hydroxyaryl group, or a halogenated aryl group in which at least one hydrogen atom in the aryl group is substituted with a halogen atom.]

[0070] In formula (a), the alkyl group has, for example, 8 or fewer carbon atoms. The aryl group is, for example, a phenyl group, a benzyl group, or a toluyl group.

[0071] In the formation of the second light absorber 12, the copper component is supplied, for example, as a copper salt. The copper salt may be an anhydride or hydrate of copper chloride, copper formate, copper stearate, copper benzoate, copper pyrophosphate, copper naphthenate, and copper citrate. For example, copper acetate monohydrate is represented as Cu(CH3 COO)2·H2O, and 1 mole of copper ions is supplied by 1 mole of copper acetate monohydrate.

[0072] The second light absorber 12 further includes, for example, a matrix. The light-absorbing compound containing the copper component is typically dispersed in the matrix. This matrix is not limited to a specific material as long as the first transmission spectrum satisfies the conditions of (I), (II), (III), and (IV). It will not occur. The matrix included in the second light absorber 12 is typically a material having high transparency at wavelengths of 400 nm to 600 nm. For example, when a layer with a thickness of 0.1 mm is formed only of this material, the transmittance of the layer at wavelengths of 400 nm to 600 nm is, for example, 70% or more, desirably 75% or more, more desirably 80% or more, and even more desirably 85% or more.

[0073] The material of the matrix included in the second light absorber 12 is, for example, a resin. The type of resin included in the second light absorber 12 is not limited to a specific type. The resin is, for example, a cyclic polyolefin-based resin, an epoxy-based resin, a polyimide-based resin, a modified acrylic resin, a silicone resin, or a polyvinyl-based resin such as PVB. The resin may be a curable resin that can be cured by energy irradiation such as heat or light. Note that the matrix included in the second light absorber 12 may be an organic-inorganic hybrid material or an inorganic material formed by hydrolyzing and polycondensing an alkoxide containing a metal component according to the sol-gel method.

[0074] The second light absorber 12 may further contain, for example, at least one selected from the group consisting of phosphate esters, metal alkoxides, hydrolysis condensates of metal alkoxides, silicon alkoxides, and hydrolysis condensates of silicon alkoxides. This makes it easier for the compound containing the copper component to be uniformly dispersed in the second light absorber 12. In the second light absorber 12, at least two selected from this group may be contained in a mixed state. For example, phosphate esters, metal alkoxides, or silicon alkoxides are mixed with components such as copper components and phosphonic acids in the preparation of the liquid composition for the second light absorber 12. In this case, a part of the phosphate ester, metal alkoxide, and silicon alkoxide may be contained in the fine particles containing the copper component due to the interaction with components such as copper components or phosphonic acids and compounds containing them in the preparation of the liquid composition for the second light absorber 12.

[0075] The phosphate ester contained in the second light absorber 12 is not limited to a specific phosphate ester. The phosphate ester has, for example, a polyoxyalkyl group. Examples of such phosphate esters include Prisurf A208N: polyoxyethylene alkyl (C12, C13) ether phosphate ester, Prisurf A208F: polyoxyethylene alkyl (C8) ether phosphate ester, Prisurf A208B: polyoxyethylene lauryl ether phosphate ester, Prisurf A219B: polyoxyethylene lauryl ether phosphate ester, Prisurf AL: polyoxyethylene styrenated phenyl ether phosphate ester, Prisurf A212C: polyoxyethylene tridecyl ether phosphate ester, or Prisurf A215C: polyoxyethylene tridecyl ether phosphate ester. All of these are products manufactured by Daiichi Kogyo Seiyaku Co., Ltd. In addition, examples of phosphate esters include NIKKOL DDP-2: polyoxyethylene alkyl ether phosphate ester, NIKKOL DDP-4: polyoxyethylene alkyl ether phosphate ester, or NIKKOL DDP-6: polyoxyethylene alkyl ether phosphate ester. All of these are products manufactured by Nikko Chemicals Co., Ltd.

[0076] The metal alkoxide contained in the second light absorber 12 or the metal alkoxide that forms a hydrolytic condensate of the metal alkoxide is, for example, an alkoxide of at least one metal selected from the group consisting of Li, Na, Mg, Ca, Sr, Ba, Ge, Sn, Pb, Al, Ga, In, Tl, Zn, Cd, Cu, Ag, Au, Ni, Pd, Pt, Co, Rh, Ir, Fe, Mn, Cr, Mo, W, V, Nb, Ta, Ti, and Zr.

[0077] These metal alkoxides contribute to the promotion of the curing reaction of the resin contained in the second light absorber 12. The amount of the component is preferably about 0.1 to 10% by mass, more preferably 0.1 to 3% by mass, based on the resin. The metal alkoxide added in such a ratio promotes the formation of the resin skeleton due to its high reactivity, enables the formation of a dense and rigid absorption film, and particularly greatly contributes to enhancing the encapsulation property into the film of the copper compound. By forming the second light absorber 12 into such a film, defects occurring in the adjacent portion when other absorption films are laminated can be suppressed. Thereby, for example, an inconvenient action such as the copper component in the second light absorber reacting with the organic dye of the first light absorber 11 to deteriorate the organic dye and reduce its light absorption ability can be suppressed, and desired optical characteristics can be obtained.

[0078] As shown in FIGS. 1 and 3, the second light absorber 12 is formed in a layer on the surface of the first light absorber 11 formed as a sheet or a film, for example. As shown in FIGS. 2 and 4, the second light absorber 12 may be formed as a sheet or a film. The second light absorber 12 may be formed as a layer on the surface of a substrate, an optical device, or an optical component. The substrate can be formed of a transparent material such as glass, resin, or crystal, for example.

[0079] The thickness of the second light absorber 12 is, for example, 20 μm to 1000 μm, may be 50 μm to 500 μm, or may be 65 μm to 350 μm.

[0080] In the second transmission spectrum and the third transmission spectrum, preferably, using the symbols defined above, λ (2) 50%L <λ (3) 50%H <λ (2) 50%H under the condition of λ (2) 70%L <λ (3) 70%H under the condition of, and and λ (2) 20%L <λ (3) 20%HThe conditions are satisfied. As a result, the optical filters 1a to 1d are more likely to reliably exhibit the desired transmittance characteristics. Specifically, in the first transmittance spectrum of the optical filter, the second cut-off wavelength is likely to depend on the characteristics including the transmittance spectrum of the first absorber.

[0081] In the second transmittance spectrum and the third transmittance spectrum, more desirably, λ (3) 50%H - λ (2) 50%L satisfies the condition that the value is 5 nm or more and 70 nm or less, and λ (2) 50%H -λ (3) 50%H of satisfies the further condition that the value is 50 nm or more and 150 nm or less. As a result, the optical filters 1a to 1d are more likely to reliably exhibit the desired transmittance characteristics. In this case, the value of λ (3) 50%H -λ (2) 50%L is desirably 15 nm or more and 60 nm or less, and the value of λ (2) 50%H -λ (3) 50%H is desirably 70 nm or more and 125 nm or less.

[0082] In the second transmittance spectrum and the third transmittance spectrum, the value of |{(20 - 70) / (λ (3) 20%H -λ (3) 70%H )}-{(20 - 70) / (λ (2) 20%L -λ (2) 70%L )}| is, for example, 0 or more and 0.10 or less, and desirably 0 or more and 0.07 or less. As a result, the optical filters 1a to 1d are more likely to reliably exhibit the desired transmittance characteristics.

[0083] In the second transmittance spectrum and the third transmittance spectrum, desirably, λ (3) 20%H -λ (3)70%H <Δλ (2) 50% The condition of 50% is satisfied, and more preferably 2×(λ (3) 20%H -λ (3) 70%H ) < Δλ (2) 50% is satisfied. Thereby, the optical filters 1a to 1d are more likely to exhibit the desired transmittance characteristics.

[0084] In the second transmittance spectrum and the third transmittance spectrum, preferably, the maximum value λ (2) 20%H is 750 nm or more, and the transmittance (2) 70%H at λ = λ T (3) λ(2)70%H in the third transmittance spectrum is 5% or less. Thereby, the optical filters 1a to 1d are more likely to exhibit the desired transmittance characteristics. The transmittance T (3) λ(2)70%H is more preferably 1% or less. The maximum value λ (2) 50%H of the transmittance T (3) λ(2)50%H at is, for example, 1% or less.

[0085] As shown in FIGS. 3 and 4, the optical filters 1c and 1d further include, for example, a third light absorber 13. The third light absorber 13 contains an ultraviolet absorber. The fourth transmittance spectrum, which is the transmittance spectrum of the third light absorber 13 when light in the wavelength range of 300 nm to 1200 nm is incident on the third light absorber 13, satisfies the following conditions (iii1), (iii2), and (iii3). Thereby, the optical filters 1c and 1d are likely to exhibit the desired transmittance characteristics. The fourth transmittance spectrum is the transmittance spectrum at an incident angle of 0°. (iii1) The wavelength λ (4) 70%L showing a transmittance of 70% in the wavelength range of 300 nm to 450 nm is 350 nm or more and 450 nm or less. (iii2) The wavelength λ that exhibits a transmittance of 50% in the wavelength range of 300 nm to 450 nm (4) 50%L is 340 nm or more and 440 nm or less. (iii3) The wavelength λ that exhibits a transmittance of 20% in the wavelength range of 300 nm to 450 nm (4) 20%L is 340 nm or more and 440 nm or less.

[0086] In the optical filters 1c and 1d, the transmittance T at a wavelength of 350 nm in the first transmittance spectrum 350 is desirably 1% or less, and more desirably 0.5% or less.

[0087] In the fourth transmittance spectrum, the wavelengths λ (4) 70%L and the wavelength λ (4) 20%L satisfy the condition of, for example, 3.0 [% / nm] ≤ (70 - 20) / (λ (4) 70%L - λ (4) 20%L ) ≤ 4.2 [% / nm]. Thereby, the optical filters 1c and 1d are likely to exhibit the desired transmittance characteristics. (70 - 20) / (λ (4) 70%L - λ (4) 20%L ) represents the average slope of the third transmittance spectrum in the range of λ (4) 20%L [nm] and the wavelength λ (4) 70%L [nm], and also represents ΔT (4) / Δλ (4) L and also represents.

[0088] The wavelengths λ (4) 70%L and the wavelength λ (4) 20%L are desirably 3.1 [% / nm] ≤ (70 - 20) / (λ (4) 70%L - λ (4) 20%L) satisfies the condition of ≤ 4.1 [% / nm], and more desirably 3.3 [% / nm] ≤ (70 - 20) / (λ (4) 70%L - λ (4) 20%L ) ≤ 4.0 [% / nm]. Thereby, the optical filters 1c and 1d are likely to exhibit desired transmittance characteristics.

[0089] The type of the ultraviolet absorber contained in the third light absorber 13 is not limited to a specific type. The ultraviolet absorber includes, for example, at least one selected from the group consisting of benzophenone compounds, benzotriazole compounds, triazine compounds, acrylonitrile compounds, and salicylic acid compounds.

[0090] The ultraviolet absorber may include at least one selected from the group consisting of 2-hydroxybenzophenone, 2,4-dioxybenzophenone, 2-oxy-4-methoxybenzophenone, 2,2’4,4’-tetraoxybenzophenone, 2,2’-dioxy-4,4’-dimethoxybenzophenone, 2-oxy-4-methoxy-4’-chlorobenzophenone, 2-oxy-4-n-octoxybenzophenone, 2,4-diloxybenzophenone, 2-oxy-4-methoxy-2’-carboxybenzophenone, 2,2’-dioxy-4-n-octoxybenzophenone, 2-oxy-5-chlorobenzophenone, 2,4-dibenzoylresorcinol, 2(2’-oxy-5’-methylphenyl)benzotriazole, 2(2’-oxy-3’,5’-dibutylphenyl)-6-chlorobenzotriazole, resorcinol monobenzoate, phenyl salicylate, 4-t-butylphenyl salicylate, p-octylphenyl salicylate, ethyl diphenylmethylene cyanoacetate, 2-ethylhexyl diphenylmethylene cyanoacetate, and 2-oxyphenyl-1,3,5-triazine.

[0091] The third light absorber 13 further includes, for example, a matrix. The ultraviolet absorber is typically dispersed in the matrix. This matrix is not limited to a specific material as long as the first transmittance spectrum satisfies the conditions of (I), (II), (III), and (IV). Third The matrix included in the third light absorber 13 is typically a material having high transmittance at wavelengths of 400 nm to 600 nm. For example, when a layer with a thickness of 0.1 mm is formed only of this material, the transmittance of the layer at wavelengths of 400 nm to 600 nm is, for example, 70% or more, desirably 75% or more, more desirably 80% or more, and even more desirably 85% or more.

[0092] The matrix included in the third light absorber 13 is, for example, a resin. The type of resin included in the third light absorber 13 is not limited to a specific type. The resin is, for example, a cyclic polyolefin-based resin, an epoxy-based resin, a polyimide-based resin, a modified acrylic resin, a silicone resin, or a polyvinyl-based resin such as PVB. The resin may be a curable resin that can be cured by energy irradiation such as heat or light. Note that the matrix included in the third light absorber 13 may be an organic-inorganic hybrid material or an inorganic material formed by hydrolyzing and polycondensing an alkoxide containing a metal component according to the sol-gel method.

[0093] The third light absorber 13 can typically be formed as a film, sheet, or membrane. The third light absorber 13 is formed in a layer on the surface of the first light absorber 11 or the second light absorber 12 formed as a film or sheet, for example. The third light absorber 13 may be formed as a sheet or a film.

[0094] The thickness of the third light absorber 13 is, for example, 2 μm to 250 μm, may be 5 μm to 200 μm, may be 10 μm to 200 μm, or may be 15 μm to 100 μm.

[0095] In the third transmittance spectrum and the fourth transmittance spectrum, for example, λ (3)50%L <λ (4) 50%L The condition of is satisfied. Desirably, λ (3) 50%L +5nm < λ (4) 50%L The condition of is satisfied, and more desirably, λ (3) 50%L +10nm < λ (4) 50%L is satisfied. Thereby, the optical filters 1c and 1d are likely to exhibit the desired transmittance characteristics.

[0096] In the third transmittance spectrum and the fourth transmittance spectrum, for example, λ (3) 20%L <λ (4) 20%L The condition of is satisfied. Desirably, λ (3) 20%L +5nm < λ (4) 20%L The condition of is satisfied, and more desirably, λ (3) 20%L +10nm < λ (4) 20%L is satisfied. Thereby, the optical filters 1c and 1d are likely to exhibit the desired transmittance characteristics.

[0097] In the third transmittance spectrum and the fourth transmittance spectrum, desirably, 2×(70 - 20) / (λ (3) 70%L - λ (3) 20%L ) < (70 - 20) / (λ (4) 70%L - λ (4) 20%L ) The condition of is satisfied, and more desirably, 2.5×(70 - 20) / (λ (3) 70%L - λ (3) 20%L ) < (70 - 20) / (λ (4) 70%L - λ (4) 20%L ) The condition of is satisfied. Thereby, the optical filters 1c and 1d are likely to exhibit the desired transmittance characteristics.

[0098] An example of a method for manufacturing the optical filters 1a to 1d will be described. As shown in FIG. 1, in the optical filters 1a and 1c, the first light absorber 11 forms, for example, a film. The first light absorber 11 can be formed, for example, by applying a composition containing an organic dye and a raw material of a matrix onto a predetermined substrate to form a coating film, and curing the coating film by a treatment such as drying or heating. The first light absorber 11 formed on the substrate is peeled off from the substrate, for example. On the other hand, a composition containing a copper component and a raw material of a matrix is applied onto the surface of the first light absorber 11 to form a coating film, and the coating film is cured by a treatment such as drying or heating to form the second light absorber 12. In this way, the optical filter 1a can be manufactured. Thereafter, a composition containing an ultraviolet absorber and a raw material of a matrix is applied onto another surface of the first light absorber 11, and cured by a treatment such as drying or heating to form the third light absorber 13. In this way, the optical filter 1c can be manufactured.

[0099] As shown in FIG. 2, in the optical filters 1b and 1d, the second light absorber 12 forms, for example, a film. The second light absorber 12 can be formed, for example, by applying a composition containing a copper component and a raw material of a matrix onto a predetermined substrate to form a coating film, and curing the coating film by a treatment such as heating. The second light absorber 12 formed on the substrate is peeled off from the substrate, for example. On the other hand, a composition containing an organic dye and a raw material of a matrix is applied onto the surface of the second light absorber 12 to form a coating film, and the coating film is cured by a treatment such as drying or heating to form the first light absorber 11. In this way, the optical filter 1b can be manufactured. Thereafter, a composition containing an ultraviolet absorber and a raw material of a matrix is applied onto another surface of the second light absorber 12, and cured by a treatment such as drying or heating to form the third light absorber 13. In this way, the optical filter 1d can be manufactured.

Example

[0100] The present invention will be described in more detail with reference to examples. Note that the present invention is not limited to the following examples.

[0101] In each example, using a UV-visible near-infrared spectrophotometer V-670 manufactured by JASCO Corporation, the transmission spectra at an incident angle of 0° of the first light absorber, the second light absorber, the optical filter, the laminate corresponding to the first light absorber, the laminate corresponding to the second light absorber, or the laminate corresponding to the third light absorber were measured. The transmission spectrum at an incident angle of 0° of the laminate corresponding to the second light absorber or the laminate corresponding to the third light absorber was measured.

[0102] <Example 1> An organic dye having an absorption maximum wavelength in the wavelength range of 660 nm to 770 nm, methyl ethyl ketone (MEK) as a solvent, and polyvinyl butyral (PVB) were mixed, and the mixture was stirred for 2 hours to obtain a liquid composition H1. The organic dye was soluble in MEK and had little absorption in the visible region. The organic dye also contained at least one selected from the group consisting of cyanine-based dye compounds, squarylium-based dye compounds, phthalocyanine-based dye compounds, diimonium-based dye compounds, and azo-based dye compounds. The solid content in PVB was 99% by weight.

[0103] 4.500 g of copper acetate monohydrate and 240 g of tetrahydrofuran (THF) were mixed, and the mixture was stirred for 3 hours to obtain a copper acetate solution. Next, 2.572 g of the phosphate ester compound Plisurf A208F manufactured by Daiichi Kogyo Seiyaku Co., Ltd. was added to the obtained copper acetate solution, and the mixture was stirred for 30 minutes to obtain Solution A. Also, 40 g of THF was added to 2.886 g of n-butylphosphonic acid and stirred for 30 minutes to obtain Solution B. Solution B was added to Solution A while stirring Solution A, and the mixture was stirred at room temperature for 1 minute. Next, 100 g of toluene was added to this solution, and the mixture was stirred at room temperature for 1 minute to obtain Solution C. This Solution C was placed in a flask and subjected to solvent removal treatment using a rotary evaporator (manufactured by Tokyo Rika Kikai Co., Ltd., model: N-1110SF) while heating with an oil bath (manufactured by Tokyo Rika Kikai Co., Ltd., model: OSB-2100). The set temperature of the oil bath was adjusted to 105°C. Thereafter, Solution D after the solvent removal treatment was taken out from the flask. In Solution D, fine particles were well dispersed, and the fine particles contained a copper complex. The copper complex contained a compound generated by the reaction of phosphonic acid and a copper component. Next, 8.91 g of a curable silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KR-300) and 0.09 g of an aluminum alkoxide compound (manufactured by Shin-Etsu Chemical Co., Ltd., product name: CAT-AC) were added to Solution D and stirred for 30 minutes. Thus, a liquid composition E1 containing a curable resin and fine particles containing a copper complex was obtained.

[0104] Liquid composition H1 was applied to an area of approximately 76 mm × 76 mm on the surface of a glass substrate (D263 T eco manufactured by SCHOTT) using a dispenser to form a coating film. After thoroughly drying this coating film at room temperature, it was placed in an oven and heat-treated at 130 °C for 1 hour to cure the liquid composition H1. A stain-resistant coating containing a fluorine component was previously applied to the surface of the glass substrate. In the stain-resistant coating, Optool DSX manufactured by Daikin Industries, Ltd. was used. A coating liquid containing Optool DSX was applied to the surface of the glass substrate to form a coating film, and the coating film was dried to form a stain-resistant coating. The cured product of the liquid composition H1 was peeled off from the glass substrate to obtain the first light absorber according to Example 1. When measuring the thickness of the first light absorber using a micrometer, the thickness was 110 μm. The transmission spectrum of the first light absorber according to Example 1 is shown in FIG. 5, and the characteristic values of this transmission spectrum are shown in Table 2.

[0105] Liquid composition E1 was applied to the surface of the first light absorber according to Example 1 using a dispenser to form a coating film, and the coating film was thoroughly dried at room temperature. Then, the first light absorber according to Example 1 was placed in an oven and heat-treated under the conditions of 45 °C for 2 hours, 85 °C for 3 hours, 125 °C for 1 hour, and 150 °C for 1 hour to cure the coating film, and the second light absorber according to Example 1 was formed on the first light absorber. The thickness of the second light absorber was 160 μm. In this way, the optical filter according to Example 1 was obtained. The transmission spectrum of the optical filter according to Example 1 is shown in FIG. 6, and the characteristic values of this transmission spectrum are shown in Table 1.

[0106] Liquid composition E1 was applied to the surface of a glass substrate having a stain-resistant coating containing a fluorine component using a dispenser to form a coating film, and this coating film was used in the production of the optical filter according to Example 1. It was dried and cured under the same conditions as the coating film of the liquid composition E1. The cured product of the coating film of the liquid composition E1 was peeled off from the glass substrate to obtain a sample for the second light absorber according to Example 1. The coating conditions of the liquid composition E1 were adjusted so that the thickness of the sample for the second light absorber according to Example 1 was almost the same as the thickness of the second light absorber in the optical filter according to Example 1. The transmission spectrum of the sample for the second light absorber according to Example 1 is shown in FIG. 7, and the characteristic values and the like of this transmission spectrum are shown in Table 3. The transmission spectrum of the sample for the second light absorber according to Example 1 can be regarded as the transmission spectrum of the second light absorber of the optical filter according to Example 1.

[0107] <Example 2> The liquid composition E1 was applied with a dispenser to an area of about 76 mm × 76 mm on the surface of a glass substrate having an antifouling coating containing a fluorine component to form a coating film. After the coating film was sufficiently dried at room temperature, it was placed in an oven and heat-treated at 45°C for 2 hours, 85°C for 3 hours, 125°C for 1 hour, and 150°C for 1 hour to be cured. The cured product of the coating film of the liquid composition E1 was peeled off from the glass substrate to obtain the second light absorber according to Example 2. When the thickness of the second light absorber according to Example 2 was measured using a micrometer, the thickness was 141 μm. The transmission spectrum of the second light absorber according to Example 2 is shown in FIG. 8, and the characteristic values and the like of this transmission spectrum are shown in Table 3.

[0108] The liquid composition H2 was prepared in the same manner as the preparation of the liquid composition H1, except for the following points. The organic dye contained in the liquid composition H2 is the same as the organic dye contained in the liquid composition H1, but the concentration of the organic dye in the liquid composition H2 is higher than the concentration of the organic dye in the liquid composition H1. The content of the solid component in PVB was 99% by weight.

[0109] Liquid composition H2 was applied to the surface of the second light absorber according to Example 2 with a dispenser to form a coating film. After sufficiently drying this coating film at room temperature, it was placed in an oven and heat-treated at 130°C for 1 hour to be cured. Thereby, the first light absorber according to Example 2 was formed on the second light absorber according to Example 2. The thickness of the first light absorber according to Example 2 was 4 μm. In this way, the optical filter according to Example 2 was obtained. The transmission spectrum of the optical filter according to Example 2 is shown in FIG. 9, and the characteristic values etc. of this transmission spectrum are shown in Table 1.

[0110] Liquid composition H2 was applied to the surface of a glass substrate with a dispenser to form a coating film. This coating film was cured under the same conditions as the coating film of liquid composition H2 in the production of the optical filter according to Example 2 to obtain a laminate 2-I corresponding to the first light absorber of the optical filter according to Example 2. The coating conditions of liquid composition H2 were adjusted so that the thickness of the cured product of the coating film of liquid composition H2 in laminate 2-I was almost the same as the thickness of the first light absorber according to Example 2. The transmission spectrum of laminate 2-I is shown in FIG. 10, and the characteristic values etc. of this transmission spectrum are shown in Table 2.

[0111] <Example 3> Liquid composition H3 was prepared in the same manner as the preparation of liquid composition H1, except for the following points. The organic dye contained in liquid composition H3 is the same as the organic dye contained in liquid composition H1, but the concentration of the organic dye in liquid composition H3 was adjusted to be slightly lower than the concentration of the organic dye in liquid composition H1. The solid content in PVB was 99% by weight.

[0112] Liquid composition H3 was applied with a dispenser over an area of about 76 mm × 76 mm on the surface of a glass substrate having an antifouling coating containing a fluorine component to form a coating film. After thoroughly drying this coating film at room temperature, it was placed in an oven and heat-treated at 130 °C for 1 hour to cure the coating film. The cured product of the coating film of liquid composition H3 was peeled off from the glass substrate to obtain the first light absorber according to Example 3. When measuring the thickness of the first light absorber according to Example 3 using a micrometer, the thickness was 160 μm. The transmission spectrum of the first light absorber according to Example 3 is shown in FIG. 11, and the characteristic values and the like of this transmission spectrum are shown in Table 2.

[0113] Liquid composition E1 was applied with a dispenser on the surface of the first light absorber according to Example 3 to form a coating film. After thoroughly drying the coating film at room temperature, it was placed in an oven and heat-treated at 45 °C for 2 hours, 85 °C for 3 hours, 125 °C for 1 hour, and 150 °C for 1 hour to cure it, and the second light absorber according to Example 3 was formed on the first light absorber. The thickness of the second light absorber according to Example 3 was 188 μm. In this way, the optical filter according to Example 3 was obtained. The transmission spectrum of the optical filter according to Example 3 is shown in FIG. 12, and the characteristic values and the like of this transmission spectrum are shown in Table 1.

[0114] Liquid composition E1 was applied on the surface of a glass substrate having an antifouling coating containing a fluorine component to form a coating film, and this coating film was dried and heated under the same conditions as the coating film of liquid composition E1 in the production of the optical filter according to Example 3 to cure it. The cured product of the coating film of liquid composition E1 was peeled off from the glass substrate to obtain a sample for the second light absorber according to Example 3. The coating conditions of liquid composition E1 were adjusted so that the thickness of the sample for the second light absorber according to Example 3 would be almost the same as the thickness of the second light absorber in the optical filter according to Example 3. The transmission spectrum of the sample for the second light absorber according to Example 3 is shown in FIG. 13, and the characteristic values and the like of this transmission spectrum are shown in Table 3. The transmission spectrum of the sample for the second light absorber according to Example 3 can be regarded as the transmission spectrum of the second light absorber of the optical filter according to Example 3.

[0115] <Example 4> Liquid composition E1 was applied with a dispenser over an area of about 76 mm × 76 mm on the surface of a glass substrate having an antifouling coating containing a fluorine component to form a coating film. After the coating film was sufficiently dried at room temperature, it was placed in an oven and heat-treated at 45°C for 2 hours, 85°C for 3 hours, 125°C for 1 hour, and 150°C for 1 hour to be cured. The cured product of the coating film of liquid composition E1 was peeled off from the glass substrate to obtain a second light absorber according to Example 4. When the thickness of the second light absorber according to Example 4 was measured using a micrometer, the thickness was 161 μm. The transmission spectrum of the second light absorber according to Example 4 is shown in FIG. 14, and the characteristic values of the transmission spectrum are shown in Table 3.

[0116] An organic dye having an absorption maximum wavelength in the wavelength range of 660 nm to 770 nm, MEK as a solvent, and PVB were mixed, and the mixture was stirred for 2 hours to obtain liquid composition H4. The organic dye was soluble in MEK and had little absorption in the visible region. Further, the organic dye contained at least one selected from the group consisting of cyanine-based dye compounds, squarylium-based dye compounds, phthalocyanine-based dye compounds, diimonium-based dye compounds, and azo-based dye compounds. The solid content in PVB was 99% by weight. The organic dye contained in liquid composition H4 was different from the organic dye contained in liquid composition H1.

[0117] Liquid composition H4 was applied with a dispenser on the surface of the second light absorber according to Example 4 to form a coating film. After this coating film was sufficiently dried at room temperature, it was placed in an oven and heat-treated at 130°C for 1 hour to be cured. Thereby, a first light absorber according to Example 4 was formed on the second light absorber according to Example 4. The thickness of the first light absorber according to Example 4 was 3 μm. In this way, an optical filter according to Example 4 was obtained. The transmission spectrum of the optical filter according to Example 4 is shown in FIG. 15, and the characteristic values of this transmission spectrum are shown in Table 1.

[0118] Liquid composition H4 was applied to the surface of a glass substrate to form a coating film. This coating film was cured under the same conditions as the coating film of liquid composition H4 in the production of the optical filter according to Example 4, and a laminate 4-I corresponding to the first light absorber of the optical filter according to Example 4 was obtained. The coating conditions of liquid composition H4 were adjusted so that the thickness of the cured product of the coating film of liquid composition H4 in laminate 4-I was substantially the same as the thickness of the first light absorber according to Example 4. The transmission spectrum of laminate 4-I is shown in Fig. 16, and the characteristic values of this transmission spectrum are shown in Table 2.

[0119] <Example 5> 5 g of the ultraviolet absorber Uvinul 3050 (manufactured by BASF, 2,2’,4,4’-tetrahydroxybenzophenone) and 95 g of ethanol were mixed and stirred for 30 minutes to obtain F1 liquid. Next, 2 g of F1 liquid and 10 g of silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KR-300) were mixed and stirred for 30 minutes to obtain liquid composition U1.

[0120] Liquid composition U1 was applied with a dispenser to the main surface of the optical filter according to Example 1 where the second light absorber was not formed to form a coating film, and this coating film was sufficiently dried at room temperature. Thereafter, the optical filter according to Example 1 was placed in an oven, and the coating film was cured by heat treatment under the conditions of 45 °C for 2 hours and 85 °C for 1 hour, and a third light absorber according to Example 5 was formed on the first light absorber. The thickness of the third light absorber according to Example 5 was 28 μm. In this way, the optical filter according to Example 5 was obtained. The transmission spectrum of the optical filter according to Example 5 is shown in Fig. 17, and the characteristic values of this transmission spectrum are shown in Table 1.

[0121] Liquid composition U1 was applied to the surface of a glass substrate to form a coating film. This coating film was cured under the same conditions as the coating film of liquid composition U1 in the production of the optical filter according to Example 5, and a laminate 5-III corresponding to the third light absorber of the optical filter according to Example 5 was obtained. The coating conditions of liquid composition U1 were adjusted so that the thickness of the cured product of the coating film of liquid composition U1 in laminate 5-III was substantially the same as the thickness of the third light absorber according to Example 5. The transmission spectrum of laminate 5-III is shown in FIG. 18, and the characteristic values of this transmittance spectrum are shown in Table 4.

[0122] <Example 6> Liquid composition U1 was applied with a dispenser onto the main surface of the optical filter according to Example 2 where the first light absorber was not formed, to form a coating film, and this coating film was sufficiently dried at room temperature. Then, the optical filter according to Example 2 was placed in an oven, and the coating film was cured by heat treatment under the conditions of 45°C for 2 hours and 85°C for 1 hour, and the third light absorber according to Example 6 was formed on the second light absorber. The thickness of the third light absorber according to Example 6 was 50 μm. In this way, the optical filter according to Example 6 was obtained. The transmittance spectrum of the optical filter according to Example 6 is shown in FIG. 19, and the characteristic values of this transmittance spectrum are shown in Table 1.

[0123] Liquid composition U1 was applied onto the surface of a glass substrate to form a coating film. This coating film was cured under the same conditions as the coating film of liquid composition U1 in the production of the optical filter according to Example 6, to obtain a laminate 6-III corresponding to the third light absorber of the optical filter according to Example 6. The coating conditions of liquid composition U1 were adjusted so that the thickness of the cured product of the coating film of liquid composition U1 in laminate 6-III would be approximately the same as the thickness of the third light absorber according to Example 6. The transmittance spectrum of laminate 6-III is shown in FIG. 20, and the characteristic values of this transmittance spectrum are shown in Table 4.

[0124] <Example 7> Liquid composition U1 was applied with a dispenser onto the main surface of the optical filter according to Example 3 where the second light absorber was not formed, to form a coating film, and this coating film was sufficiently dried at room temperature. Then, the optical filter according to Example 3 was placed in an oven, and the coating film was cured by heat treatment under the conditions of 45°C for 2 hours and 85°C for 1 hour, and the third light absorber according to Example 7 was formed on the first light absorber. The thickness of the third light absorber according to Example 7 was 20 μm. In this way, the optical filter according to Example 7 was obtained. The transmittance spectrum of the optical filter according to Example 7 is shown in FIG. 21, and the characteristic values of this transmittance spectrum are shown in Table 1.

[0125] A liquid composition U1 was applied to the surface of a glass substrate to form a coating film. This coating film was cured under the same conditions as the coating film of the liquid composition U1 in the production of the optical filter according to Example 7, and Example 7 A laminate 7-III corresponding to the third light absorber of the optical filter according to Example 7 was obtained. The coating conditions of the liquid composition U1 were adjusted so that the thickness of the cured product of the coating film of the liquid composition U1 in the laminate 7-III was substantially the same as the thickness of the third light absorber according to Example 7. The transmission spectrum of the laminate 7-III is shown in Fig. 22, and the characteristic values of this transmission spectrum are shown in Table 4.

[0126] <Example 8> The liquid composition U1 was applied with a dispenser to the main surface on which the first light absorber of the optical filter according to Example 4 was not formed to form a coating film, and this coating film was sufficiently dried at room temperature. Then, the optical filter according to Example 4 was placed in an oven, and the coating film was cured by heat treatment under the conditions of 45°C for 2 hours and 85°C for 1 hour, and the third light absorber according to Example 8 was formed on the second light absorber. The thickness of the third light absorber according to Example 8 was 28 μm. In this way, the optical filter according to Example 8 was obtained. The transmission spectrum of the optical filter according to Example 8 is shown in Fig. 23, and the characteristic values of this transmission spectrum are shown in Table 1.

[0127] A liquid composition U1 was applied to the surface of a glass substrate to form a coating film. This coating film was cured under the same conditions as the coating film of the liquid composition U1 in the production of the optical filter according to Example 8, and a laminate 8-III corresponding to the third light absorber of the optical filter according to Example 8 was obtained. The coating conditions of the liquid composition U1 were adjusted so that the thickness of the cured product of the coating film of the liquid composition U1 in the laminate 8-III was substantially the same as the thickness of the third light absorber according to Example 8. The transmission spectrum of the laminate 8-III is shown in Fig. 24, and the characteristic values of this transmission spectrum are shown in Table 4.

[0128] <Example 9> Liquid composition E1 was applied with a dispenser to an area of about 76 mm × 76 mm on the surface of a glass substrate having an antifouling coating containing a fluorine component to form a coating film. After the coating film was sufficiently dried at room temperature, it was placed in an oven and heat-treated at 45°C for 2 hours, 85°C for 3 hours, 125°C for 1 hour, and 150°C for 1 hour to be cured. The cured product of the coating film of liquid composition E1 was peeled off from the glass substrate to obtain a second light absorber according to Example 9. When the thickness of the second light absorber according to Example 9 was measured using a micrometer, the thickness was 145 μm. The transmission spectrum of the second light absorber according to Example 9 is shown in FIG. 25, and the characteristic values and the like of the transmission spectrum are shown in Table 3.

[0129] Liquid composition H5 was prepared in the same manner as the preparation of liquid composition H4, except for the following points. The organic dye contained in liquid composition H5 is of the same type as the organic dye contained in liquid composition H4, but the concentration of the organic dye in liquid composition H5 was adjusted to be slightly different from the concentration of the organic dye in liquid composition H4. The solid content in PVB was 99% by weight.

[0130] Liquid composition H5 was applied with a dispenser to the surface of the second light absorber according to Example 9 to form a coating film. After this coating film was sufficiently dried at room temperature, it was placed in an oven and heat-treated at 130°C for 1 hour to be cured. Thereby, a first light absorber according to Example 9 was formed on the second light absorber according to Example 9. The thickness of the first light absorber according to Example 9 was 4 μm. Liquid composition H5 was applied to the surface of the glass substrate to form a coating film. This coating film was cured under the same conditions as the coating film of liquid composition H5 applied to the surface of the second light absorber according to Example 9 to obtain a laminate 9-I corresponding to the first light absorber of the optical filter according to Example 9. The coating conditions of liquid composition H5 were adjusted so that the thickness of the cured product of the coating film of liquid composition H5 in laminate 9-I was substantially the same as the thickness of the first light absorber according to Example 9. The transmission spectrum of laminate 9-I is shown in FIG. 26, and the characteristic values and the like of this transmission spectrum are shown in Table 2.

[0131] On the main surface of the second light absorber according to Example 9 where the first light absorber was not formed, the liquid composition U1 was applied with a dispenser to form a coating film, and this coating film was sufficiently dried at room temperature. Then, The second light absorber according to Example 9 was placed in an oven and the coating film was cured by heat treatment under the conditions of 45 °C for 2 hours and 85 °C for 1 hour, and the third light absorber according to Example 9 was formed on the second light absorber. The thickness of the third light absorber according to Example 9 was 50 μm. In this way, the optical filter according to Example 9 was obtained. The transmission spectrum of the optical filter according to Example 9 is shown in Fig. 27, and the characteristic values of this transmission spectrum are shown in Table 1.

[0132] The liquid composition U1 was applied with a dispenser on the surface of a glass substrate to form a coating film. This coating film was cured under the same conditions as the coating film of the liquid composition U1 in the production of the optical filter according to Example 9, and the laminate 9-III corresponding to the third light absorber of the optical filter according to Example 9 was obtained. The coating conditions of the liquid composition U1 were adjusted so that the thickness of the cured product of the coating film of the liquid composition U1 in the laminate 9-III was almost the same as the thickness of the third light absorber according to Example 9. The transmission spectrum of the laminate 9-III is shown in Fig. 28, and the characteristic values of this transmission spectrum are shown in Table 4.

[0133] <Example 10> The liquid composition E1 was applied with a dispenser to a range of about 76 mm × 76 mm on the surface of a glass substrate having an antifouling coating containing a fluorine component to form a coating film. After the coating film was sufficiently dried at room temperature, it was placed in an oven and heat-treated at 45 °C for 2 hours, 85 °C for 3 hours, 125 °C for 1 hour, and 150 °C for 1 hour to be cured. The cured product of the coating film of the liquid composition E1 was peeled off from the glass substrate to obtain the second light absorber according to Example 10. When the thickness of the second light absorber according to Example 10 was measured using a micrometer, the thickness was 162 μm. The transmission spectrum of the second light absorber according to Example 10 is shown in Fig. 29, and the characteristic values of this transmission spectrum are shown in Table 3.

[0134] A liquid composition H6 was prepared in the same manner as the preparation of the liquid composition H5, except for the following points. The organic dye contained in the liquid composition H6 is of the same type as the organic dye contained in the liquid composition H5, but the concentration of the organic dye in the liquid composition H6 was adjusted to be slightly different from the concentration of the organic dye in the liquid composition H5. The content of the solid component in PVB was 99% by weight.

[0135] The liquid composition H6 was applied onto the surface of the second light absorber according to Example 10 with a dispenser to form a coating film. After the coating film was sufficiently dried at room temperature, it was placed in an oven and heat-treated at 130 °C for 1 hour to be cured. Thereby, the first light absorber according to Example 10 was formed on the second light absorber according to Example 10. The thickness of the first light absorber according to Example 10 was 2 μm. The liquid composition H6 was applied onto the surface of a glass substrate to form a coating film. This coating film was cured under the same conditions as the coating film of the liquid composition H6 applied onto the surface of the second light absorber according to Example 10, and a laminate 10-I corresponding to the first light absorber of the optical filter according to Example 10 was obtained. The coating conditions of the liquid composition H6 were adjusted so that the thickness of the cured product of the coating film of the liquid composition H6 in the laminate 10-I was substantially the same as the thickness of the first light absorber according to Example 10. The transmission spectrum of the laminate 10-I is shown in FIG. 30, and the characteristic values of this transmission spectrum are shown in Table 2.

[0136] The liquid composition U1 was applied onto the main surface of the second light absorber according to Example 10 where the first light absorber was not formed with a dispenser to form a coating film, and this coating film was sufficiently dried at room temperature. Then, the second light absorber according to Example 10 was placed in an oven, and the coating film was cured by heat treatment under the conditions of 45 °C for 2 hours and 85 °C for 1 hour, and the third light absorber according to Example 10 was formed on the second light absorber. The thickness of the third light absorber according to Example 10 was 20 μm. In this way, the optical filter according to Example 10 was obtained. The transmission spectrum of the optical filter according to Example 10 is shown in FIG. 31, and the characteristic values of this transmission spectrum are shown in Table 1.

[0137] A liquid composition U1 was applied onto the surface of a glass substrate using a dispenser to form a coating film. This coating film was hardened under the same conditions as the coating film of the liquid composition U1 in the production of the optical filter according to Example 10, and a laminate 10-III corresponding to the third light absorber of the optical filter according to Example 10 was obtained. The coating conditions of the liquid composition U1 were adjusted so that the thickness of the cured product of the coating film of the liquid composition U1 in the laminate 10-III was approximately the same as the thickness of the third light absorber according to Example 10. The transmission spectrum of the laminate 10-III is shown in Fig. 32, and the characteristic values of this transmission spectrum are shown in Table 4.

[0138] <Example 11> A liquid composition E1 was applied onto an approximately 76 mm × 76 mm area of the surface of a glass substrate having an antifouling coating containing a fluorine component using a dispenser to form a coating film. After the coating film was sufficiently dried at room temperature, it was placed in an oven and heat-treated at 45 °C for 2 hours, 85 °C for 3 hours, 125 °C for 1 hour, and 150 °C for 1 hour to be cured. The cured product of the coating film of the liquid composition E1 was peeled off from the glass substrate to obtain the second light absorber according to Example 11. When the thickness of the second light absorber according to Example 11 was measured using a micrometer, the thickness was 160 μm. The transmission spectrum of the second light absorber according to Example 11 is shown in Fig. 33, and the characteristic values of this transmission spectrum are shown in Table 3.

[0139] A liquid composition H7 was prepared in the same manner as the preparation of the liquid composition H5, except for the following points. The organic dye contained in the liquid composition H7 is of the same type as the organic dye contained in the liquid composition H5, but the concentration of the organic dye in the liquid composition H7 was adjusted to be slightly different from the concentration of the organic dye in the liquid composition H5. The solid content in PVB was 99% by weight.

[0140] Liquid composition H7 was applied to the surface of the second light absorber according to Example 11 with a dispenser to form a coating film. After the coating film was sufficiently dried at room temperature, it was placed in an oven and heat-treated at 130 °C for 1 hour to be cured. Thereby, the first light absorber according to Example 11 was formed on the second light absorber according to Example 11. The thickness of the first light absorber according to Example 11 was 3 μm. Liquid composition H7 was applied to the surface of a glass substrate to form a coating film. This coating film was cured under the same conditions as the coating film of liquid composition H7 applied to the surface of the second light absorber according to Example 11, and laminate 11-I corresponding to the first light absorber of the optical filter according to Example 11 was obtained. The coating conditions of liquid composition H7 were adjusted so that the thickness of the cured product of the coating film of liquid composition H7 in laminate 11-I was substantially the same as the thickness of the first light absorber according to Example 11. The transmission spectrum of laminate 11-I is shown in Fig. 34, and the characteristic values of this transmission spectrum are shown in Table 2.

[0141] 5 g of ultraviolet absorber Tinuvin (manufactured by BASF, 2-(2-hydroxy-5-methylphenyl)benzotriazole) and 95 g of toluene were mixed and stirred for 30 minutes to obtain F2 liquid. Next, 2 g of F2 liquid and 10 g of silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KR-300) were mixed and stirred for 30 minutes to obtain liquid composition U2 liquid.

[0142] Liquid composition U2 was applied to the main surface of the second light absorber according to Example 11 where the first light absorber was not formed with a dispenser to form a coating film, and this coating film was sufficiently dried at room temperature. Then, the second light absorber according to Example 11 was placed in an oven, and the coating film was cured by heat treatment under the conditions of 45 °C for 2 hours and 85 °C for 1 hour, and the third light absorber according to Example 11 was formed on the second light absorber. The thickness of the third light absorber according to Example 11 was 28 μm. In this way, the optical filter according to Example 11 was obtained. The transmission spectrum of the optical filter according to Example 11 is shown in Fig. 35, and the characteristic values of this transmission spectrum are shown in Table 1.

[0143] Liquid composition U2 was applied to the surface of a glass substrate with a dispenser to form a coating film. This coating film was cured under the same conditions as the coating film of liquid composition U2 in the production of the optical filter according to Example 11 to obtain a laminate 11-III corresponding to the third light absorber of the optical filter according to Example 11. The thickness of the cured product of the coating film of liquid composition U2 in laminate 11-III was adjusted so as to be approximately the same as the thickness of the third light absorber according to Example 11. The transmission spectrum of laminate 11-III is shown in Fig. 36, and the characteristic values etc. of this transmission spectrum are shown in Table 4. shown.

[0144] <Example 12> Liquid composition E1 was applied to an area of about 76 mm × 76 mm on the surface of a glass substrate having an antifouling coating containing a fluorine component with a dispenser to form a coating film. After the coating film was sufficiently dried at room temperature, it was placed in an oven and heat-treated at 45 °C for 2 hours, 85 °C for 3 hours, 125 °C for 1 hour, and 150 °C for 1 hour to be cured. The cured product of the coating film of liquid composition E1 was peeled off from the glass substrate to obtain the second light absorber according to Example 12. When the thickness of the second light absorber according to Example 12 was measured using a micrometer, the thickness was 162 μm. The transmission spectrum of the second light absorber according to Example 12 is shown in Fig. 37, and the characteristic values etc. of this transmission spectrum are shown in Table 3.

[0145] Liquid composition H8 was prepared in the same manner as the preparation of liquid composition H5, except for the following points. The organic dye contained in liquid composition H8 is of the same type as the organic dye contained in liquid composition H5, but the concentration of the organic dye in liquid composition H8 was adjusted to be slightly different from the concentration of the organic dye in liquid composition H5. The solid content in PVB was 99% by weight.

[0146] Liquid composition H8 was applied to the surface of the second light absorber according to Example 12 with a dispenser to form a coating film. After the coating film was sufficiently dried at room temperature, it was placed in an oven and heat-treated at 130 °C for 1 hour to be cured. As a result, the first light absorber according to Example 12 was formed on the second light absorber according to Example 12. The thickness of the first light absorber according to Example 12 was 2 μm. Liquid composition H8 was applied to the surface of a glass substrate to form a coating film. This coating film was cured under the same conditions as the coating film of liquid composition H8 applied to the surface of the second light absorber according to Example 12, and laminate 12-I corresponding to the first light absorber of the optical filter according to Example 12 was obtained. The coating conditions of liquid composition H8 were adjusted so that the thickness of the cured product of the coating film of liquid composition H8 in laminate 12-I was substantially the same as the thickness of the first light absorber according to Example 12. The transmission spectrum of laminate 12-I is shown in Fig. 38, and the characteristic values etc. of this transmission spectrum are shown in Table 2.

[0147] Liquid composition U2 was applied to the main surface of the second light absorber according to Example 12 where the first light absorber was not formed with a dispenser to form a coating film, and this coating film was sufficiently dried at room temperature. Then, the second light absorber according to Example 12 was placed in an oven, and the coating film was cured by heat treatment under the conditions of 45 °C for 2 hours and 85 °C for 1 hour, and the third light absorber according to Example 12 was formed on the second light absorber. The thickness of the third light absorber according to Example 12 was 20 μm. In this way, the optical filter according to Example 12 was obtained. The transmission spectrum of the optical filter according to Example 12 is shown in Fig. 39, and the characteristic values etc. of this transmission spectrum are shown in Table 1.

[0148] Liquid composition U2 was applied to the surface of a glass substrate with a dispenser to form a coating film. This coating film was cured under the same conditions as the coating film of liquid composition U2 in the production of the optical filter according to Example 12, and laminate 12-III corresponding to the third light absorber of the optical filter according to Example 12 was obtained. The thickness of the cured product of the coating film of liquid composition U2 in laminate 12-III was according to Example 12 The coating conditions of the liquid composition U2 were adjusted so that the thickness was approximately the same as that of the third light absorber. The transmission spectrum of the laminate 12-III is shown in FIG. 40, and the characteristic values ​​of this transmission spectrum are shown in Table 4. show.

[0149] Laminates 2-I, 4-I, 5-III, 6-III, 7-III, 8-III, 9-I, 9-III, 1 The gases used to prepare 0-I, 10-III, 11-I, 11-III, 12-I, and 12-III The transmission spectrum of the glass substrate is shown in FIG.

[0150] As shown in Table 1, the optical filters according to Examples 1 to 12 satisfied the above conditions (I), (II), (III), and (IV). The absolute value Δλ S / F was 190 nm or more and 280 nm or less. In optical filters, T 350 The optical fibers according to Examples 1 to 12 In Ruta, T M 750-1000 The optical filter according to Examples 1 to 12 Hey, T M 800-950 In the optical filters according to Examples 1 to 12, ΔT 1% was greater than 400 nm.

[0151] According to Table 2 and Fig. 41, it is suggested that in the optical filters according to Examples 1 to 12, the first light absorber satisfies the above conditions (i1), (i2), (i3), (i4), and (i5). In addition, it is suggested that the first light absorber satisfies the conditions (i6), (i7), and (i8). In the first light absorber, -1.2[% / nm]≦ΔT (2) / Δλ (2) L The condition of ≦-0.6[% / nm] is met It was suggested that this would be achieved.

[0152] According to Table 3, in the optical filters according to Examples 1 to 12, the second light absorber satisfied the above conditions (ii1), (ii2), (ii3), (ii4), and (ii5). In addition, the second light absorber satisfied the conditions (ii6), (ii7), and (ii8). In the second light absorber, T (3)M 750-1100 was 0.5% or more and 6% or less. In the second light absorber, -0.9 [% / nm] ≦ ΔT (3) / Δλ (3) H ≦ -0.78 [% / nm] was satisfied, and -0.9 [% / nm] ≦ ΔT (3) / Δλ (3) 750 ≦ -0.5 [% / nm] was satisfied. In the second light absorber, 0.75 [% / nm] ≦ ΔT (3) / Δλ (3) L ≦ 1.6 [% / nm] was satisfied In the second light absorber, Δλ (3) 50% was 270 nm or more and 350 nm or less.

[0153] According to Table 4 and FIG. 41, in the optical filters according to Examples 5 to 12, it was suggested that the third light absorber satisfied the above conditions (iii1), (iii2), and (iii3). In addition, in the third light absorber, 3.0 [% / nm] ≦ ΔT (4) / Δλ (4) L ≦ 4.2 [% / nm was suggested to be satisfied.

[0154]

Table 1

[0155]

Table 2

[0156]

Table 3

[0157]

Table 4

Explanation of Symbols

[0158] 1a, 1b, 1c, 1d optical filters 11 first light absorber 12 second light absorber 13 third light absorber

Claims

1. 1. An optical filter comprising: a first light absorber comprising an organic dye; A second light absorber that contains a copper component and absorbs at least a portion of infrared light; When light having a wavelength in the range of 300 nm to 1200 nm is incident on the optical filter, the optical filter exhibits a first transmission spectrum that satisfies the following conditions (I), (II), (III), and (IV): a second transmission spectrum, which is a transmission spectrum of the first light absorber when light having a wavelength in a range of 300 nm to 1200 nm is incident on the first light absorber, satisfies the following conditions (i1), (i2), (i3), (i4), (i5), and (i6), an average value of a transmittance in a wavelength range of 450 nm to 600 nm of a third transmission spectrum, which is a transmission spectrum of the second light absorber when light in a wavelength range of 300 nm to 1200 nm is incident on the second light absorber, is 76% or more; the wavelength λ (3) 70%H at which the third transmission spectrum exhibits a transmittance of 70% in the wavelength range of 550 nm to 750 nm and the transmittance T (3) 750 at a wavelength of 750 nm satisfy the condition: −0.85 [% / nm]≦(T (3) 750 −70) / (750−λ (3) 70%H )≦−0.55 [% / nm]; Optical filters. (I) The average transmittance in the wavelength range of 450 nm to 600 nm is 76% or more. (II) A first cutoff wavelength, which is a wavelength exhibiting a transmittance of 50% in the wavelength range of 350 nm to 470 nm, is in the range of 360 nm to 450 nm. (III) A second cutoff wavelength, which is a wavelength showing a transmittance of 50% in the wavelength range of 580 nm to 720 nm, is in the range of 600 nm to 700 nm. (IV) The maximum transmittance in the wavelength range of 700 nm to 750 nm is 5% or less. (i1) The wavelength at which the transmittance shows a minimum value in the wavelength range of 550 nm to 850 nm is 650 nm or more and 770 nm or less. (i2) The minimum wavelength showing a transmittance of 70% in the wavelength range of 550 nm to 850 nm is 570 nm or more and 670 nm or less. (i3) The minimum wavelength showing 50% transmittance in the wavelength range of 550 nm to 850 nm is 590 nm or more and 700 nm or less. (i4) The minimum wavelength showing a transmittance of 20% in the wavelength range of 550 nm to 850 nm is 630 nm or more and 720 nm or less. (i5) The average transmittance in the wavelength range of 450 nm to 600 nm is 76% or more. (i6) The absolute value of the difference between the maximum and minimum wavelengths showing a transmittance of 70% in the wavelength range of 550 nm to 850 nm is 120 nm or more and 250 nm or less.

2. The absolute value of the difference between the second cutoff wavelength and the first cutoff wavelength is 190 nm or more and 280 nm or less. The optical filter of claim 1 .

3. The transmittance at a wavelength of 350 nm of the first transmission spectrum is 20% or less.

3. The optical filter according to claim 1 or 2.

4. The maximum transmittance of the first transmission spectrum in a wavelength range of 750 nm to 1000 nm is 2% or less. The optical filter according to any one of claims 1 to 3.

5. The maximum transmittance in the wavelength range of 800 nm to 950 nm of the first transmission spectrum is 1% or less; The optical filter according to claim 4 .

6. The absolute value of the difference between the maximum wavelength and the minimum wavelength showing a transmittance of 1% in the wavelength range of 700 nm to 1200 nm of the first transmission spectrum is 400 nm or more. The optical filter according to any one of claims 1 to 5.

7. The minimum wavelength λ at which the second transmission spectrum exhibits a transmittance of 20% in the wavelength range of 550 nm to 850 nm (2) 20%L and the minimum wavelength λ at which the second transmission spectrum exhibits a transmittance of 70% in the wavelength range of 550 nm to 850 nm. (2) 70%L -1.2 [% / nm] ≦ (20-70) / (λ (2) 20%L -λ (2) 70%L )≦−0.6 [% / nm] is satisfied, The optical filter according to any one of claims 1 to 6.

8. The organic dye includes at least one selected from the group consisting of a cyanine dye, a squarylium dye, a phthalocyanine dye, a diimmonium dye, and an azo dye. The optical filter according to any one of claims 1 to 7.

9. In the third transmission spectrum, a wavelength λ that exhibits a transmittance of 50% within a wavelength range of 550 nm to 750 nm (3) 50%H and a wavelength λ that exhibits 50% transmittance within the wavelength range of 300 nm to 450 nm. (3) 50%L The absolute value of the difference between the The optical filter according to any one of claims 1 to 8.

10. The wavelength λ at which the third transmission spectrum exhibits a transmittance of 20% in the wavelength range of 550 nm to 750 nm (3) 20%H and the wavelength λ (3) 70%H is -0.9 [% / nm] ≦ (20-70) / (λ (3) 20%H -λ (3) 70%H 10. The optical filter according to claim 1, wherein the condition of 0.78% / nm is satisfied.

11. The third transmission spectrum satisfies the following condition (ii6): The optical filter according to any one of claims 1 to 10. (ii6) Wavelength λ showing 70% transmittance in the wavelength range of 300 nm to 450 nm (3) 70%L is 360 nm or more and 430 nm or less.

12. The third transmission spectrum satisfies the following condition (ii7): The optical filter according to any one of claims 1 to 11. (ii7) Wavelength λ showing 50% transmittance in the wavelength range of 300 nm to 450 nm (3) 50%L is 340 nm or more and 390 nm or less.

13. The third transmission spectrum satisfies the following condition (ii8): The optical filter according to any one of claims 1 to 12. (ii8) Wavelength λ showing 20% ​​transmittance in the wavelength range of 300 nm to 450 nm (3) 20%L is 330 nm or more and 380 nm or less.

14. Further comprising a third light absorber including an ultraviolet absorber; The optical filter according to any one of claims 1 to 13, wherein a fourth transmission spectrum which is a transmission spectrum of the third light absorber when light having a wavelength in a range of 300 nm to 1200 nm is incident on the third light absorber satisfies the following conditions (iii1), (iii2), and (iii3): (iii1) Wavelength λ showing 70% transmittance in the wavelength range of 300 nm to 450 nm (4) 70%L is 350 nm or more and 450 nm or less. (iii2) Wavelength λ showing 50% transmittance in the wavelength range of 300 nm to 450 nm (4) 50%L is 340 nm or more and 440 nm or less. (iii3) Wavelength λ showing 20% ​​transmittance in the wavelength range of 300 nm to 450 nm (4) 20%L is 340 nm or more and 440 nm or less.

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