Optical filter, imaging device, and method for manufacturing optical filter

Abstract

The optical filter (1) includes a frame (10) and a light-absorbing film (20). The frame (10) has a through-hole (12). The light-absorbing film (20) is disposed so as to close the through-hole (12) and contains a light-absorbing compound. The average value of the Young's modulus of the light-absorbing film (20) measured by a continuous stiffness measurement method is 2.5 GPa or less.

Description

Technical Field

[0001] This invention relates to filters, imaging devices, and methods for manufacturing filters. Background Technology

[0002] In imaging devices using solid-state imaging elements such as CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor), various filters are placed in front of the solid-state imaging element to obtain images with good color reproduction. Typically, solid-state imaging elements have spectral sensitivity over a wide wavelength range, from the ultraviolet to the infrared region. On the other hand, human vision is only sensitive in the visible light region. Therefore, to make the spectral sensitivity of the solid-state imaging element in the imaging device approach human visual sensitivity, techniques are known to involve placing filters in front of the solid-state imaging element that block a portion of infrared or ultraviolet light.

[0003] Traditionally, such filters typically utilize light reflection based on dielectric multilayer films to block infrared or ultraviolet rays. However, in recent years, filters incorporating films containing light-absorbing compounds have attracted attention. The transmittance characteristics of filters with light-absorbing compounds are less affected by the angle of incidence; therefore, even when light is incident obliquely on the filter in the imaging device, good images with minimal tonal variation can be obtained. Furthermore, light-absorbing filters that do not use reflective films can suppress ghosting or glare caused by multiple reflections based on reflective films, thus making it easier to obtain good images in backlit conditions or night scene shooting. In addition, filters with films containing light-absorbing agents are also advantageous for miniaturizing and thinning imaging devices.

[0004] As such light-absorbing compounds, those formed from phosphonic acid and copper ions are known. For example, Patent Document 1 describes a filter having a UV-IR absorbing layer capable of absorbing infrared and ultraviolet light. The UV-IR absorbing layer contains a UV-IR absorber formed from phosphonic acid and copper ions. Patent Document 2 describes a method for manufacturing a filter having a light-absorbing layer containing a light-absorbing compound formed from phosphonic acid and copper ions. According to this manufacturing method, a coating is formed on a substrate having a surface containing an organofluorine compound, and the coating is cured to form a light-absorbing layer. Subsequently, the light-absorbing layer is peeled off from the substrate to obtain the filter.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent No. 6232161

[0008] Patent Document 2: Japanese Patent No. 6543746 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] Patent documents 1 and 2 do not provide any research on articles with a light-absorbing film mounted on a frame. Therefore, this disclosure provides a filter that includes a frame and a light-absorbing film, exhibiting good resistance to changes in environmental conditions such as temperature variations.

[0011] Methods for solving problems

[0012] This invention provides a filter comprising:

[0013] A frame with through holes; and

[0014] A light-absorbing film containing a light-absorbing compound is configured to seal the aforementioned through-holes.

[0015] The average Young's modulus of the above-mentioned light-absorbing film, as determined by the continuous rigidity measurement method, is below 2.5 GPa.

[0016] In addition, the present invention provides a camera device comprising:

[0017] Camera components;

[0018] A lens that allows light from the subject to pass through and converge onto the imaging element; and

[0019] The aforementioned filter.

[0020] In addition, the present invention provides a method for manufacturing a filter, which comprises:

[0021] A resin composition containing a light-absorbing compound is supplied in such a manner as to seal the through-hole of a frame having a through-hole; and

[0022] The above resin composition is cured to form a light-absorbing film.

[0023] The average Young's modulus of the above-mentioned light-absorbing film, as determined by the continuous rigidity measurement method, is below 2.5 GPa.

[0024] Invention Effects

[0025] The aforementioned filters exhibit good resistance to changes in environmental conditions such as temperature variations. Attached Figure Description

[0026] Figure 1AThis is a top view illustrating an example of the filter of the present invention.

[0027] Figure 1B It is Figure 1A The diagram shows a cross-sectional view of a filter with the IB-IB line as the cutting line.

[0028] Figure 2A This is a top view showing another example of the frame of the filter of the present invention.

[0029] Figure 2B It is Figure 2A The cross-sectional view of the frame with the IIB-IIB line as the cutting line is shown.

[0030] Figure 3A This is a cross-sectional view showing another example of the frame of the filter of the present invention.

[0031] Figure 3B This is a cross-sectional view showing another example of the frame of the filter of the present invention.

[0032] Figure 3C This is a cross-sectional view showing another example of the frame of the filter of the present invention.

[0033] Figure 3D This is a cross-sectional view showing another example of the frame of the filter of the present invention.

[0034] Figure 3E This is a cross-sectional view showing another example of the frame of the filter of the present invention.

[0035] Figure 3F This is a cross-sectional view showing another example of the frame of the filter of the present invention.

[0036] Figure 3G This is a cross-sectional view showing another example of the frame of the filter of the present invention.

[0037] Figure 3H This is a cross-sectional view showing another example of the frame of the filter of the present invention.

[0038] Figure 3I This is a cross-sectional view showing another example of the frame of the filter of the present invention.

[0039] Figure 3J This is a cross-sectional view showing another example of the filter of the present invention.

[0040] Figure 3K This is a cross-sectional view showing yet another example of the filter of the present invention.

[0041] Figure 3L This is a cross-sectional view showing yet another example of the filter of the present invention.

[0042] Figure 3MThis is a cross-sectional view showing yet another example of the filter of the present invention.

[0043] Figure 3N This is a cross-sectional view showing yet another example of the filter of the present invention.

[0044] Figure 3O This is a cross-sectional view showing yet another example of the filter of the present invention.

[0045] Figure 3P This is a cross-sectional view showing yet another example of the filter of the present invention.

[0046] Figure 4 This is a diagram illustrating an example of a method for manufacturing the filter of the present invention.

[0047] Figure 5 This is a schematic diagram illustrating the camera device of the present invention.

[0048] Figure 6 This is the transmission spectrum of the filter in Example 1.

[0049] Figure 7 This is the transmission spectrum of the filter in Example 2.

[0050] Figure 8 This is the transmission spectrum of the filter in Example 3.

[0051] Figure 9 This is the transmission spectrum of the filter in Example 4.

[0052] Figure 10 This is the transmission spectrum of the filter in Example 5.

[0053] Figure 11 This is the transmission spectrum of the filter in Example 6.

[0054] Figure 12 The transmission spectrum is that of the filter in Comparative Example 1.

[0055] Figure 13 It is a graph showing the relationship between the energy storage modulus E' and the loss modulus E” and temperature, as well as the relationship between the loss tangent tanδ and temperature. Detailed Implementation

[0056] The filters described in Patent Documents 1 and 2 are plate-shaped or film-shaped. Therefore, it is understood that, for example, when mounting these filters on a camera module, the filters first need to be cut to the desired size. In this case, it is considered to manufacture framed filters by bonding the cut filters to a specified frame, and then assemble the framed filters by bonding them to the camera module. Such filter cutting or bonding requires large-scale equipment or complex and meticulous work. Furthermore, in the manufacturing process of such framed filters, the yield rate is difficult to improve, and productivity is prone to problems. In particular, due to the difference between the frame material and the filter material, when environmental changes occur, such as temperature changes, a difference can easily arise between the expansion and contraction of the filter and the frame. As a result, there is a possibility that the filter may break or detach from the frame.

[0057] Therefore, the inventors conducted in-depth research on a structure that includes a frame and a light-absorbing film, and exhibits good resistance to changes in environmental conditions such as temperature variations. Through extensive trial and error, the inventors finally developed the filter of this invention.

[0058] The following describes embodiments of the present invention. It should be noted that the following description relates to one example of the present invention, and the present invention is not limited to these descriptions.

[0059] Figure 1A This is a top view of an example of the filter of the present invention. Figure 1B Through Figure 1A The IB-IB line and the cross-sectional view of the filter along the plane perpendicular to the paper.

[0060] like Figure 1A and Figure 1B As shown, the filter 1 includes a frame 10 and a light-absorbing film 20. The frame 10 has a through-hole 12. The light-absorbing film 20 is configured to seal the through-hole 12 and contains a light-absorbing compound. The average value of the Young's modulus of the light-absorbing film 20, measured by the continuous rigidity measurement method, is 2.5 GPa or less. Therefore, the filter 1 can exhibit good resistance to environmental changes such as temperature variations. Thus, even if the ambient temperature of the filter 1 changes, the light-absorbing film 20 is not easily broken, nor is it easily detached from the frame 10. The average value of the Young's modulus of the light-absorbing film 20 is determined, for example, by the method described in the embodiment. For details on the nanoindentation method (continuous rigidity measurement method), please refer to International Publication No. 2019 / 044758 and Japanese Patent Application Publication No. 2015-174270.

[0061] The average value of the Young's modulus of the light-absorbing film 20 is preferably 2.4 GPa or less, more preferably 2.2 GPa or less. The Young's modulus of the light-absorbing film 20 is, for example, 0.1 GPa or more, or 0.4 GPa or more.

[0062] The average hardness of the light-absorbing film 20, measured by the continuous rigidity test method, is not limited to a specific value. For example, the average hardness of the light-absorbing film 20 is 0.06 GPa or less. The average hardness can be between 0.005 GPa and 0.06 GPa.

[0063] The material of the frame 10 is not limited to a specific material. The frame 10 can be made of metals such as stainless steel, iron, and aluminum, resin, composite materials, or ceramics. Metals can be alloys such as aluminum alloys. Examples of resins include nylon, polyphenylene sulfide (PPS), polyethylene terephthalate (PET), vinyl chloride resin (PVC), acrylic resins, acrylonitrile-butadiene-styrene resin (ABS), polyethylene, polyester, polypropylene, polyolefins, polyvinyl alcohol (PVA), polyvinyl butyral (PVB), polyimide, and epoxy resin. Composite materials, for example, are materials in which fillers or fibers are dispersed in the base resin. Ceramic materials include, for example, alumina or zirconium oxide.

[0064] The average coefficient of linear expansion of the material constituting the frame 10 is not limited to a specific range from 0°C to 60°C. For example, this average coefficient of linear expansion is 0.2 × 10⁻⁶. -5 [℃]~25×10 -5 [ / ℃]. Therefore, the filter 1 can more reliably exhibit good resistance to environmental changes such as temperature variations. The material constituting the frame 10 preferably has an average coefficient of linear expansion of 1.0 × 10⁻⁶ °C between 0℃ and 60℃. -5 [℃]~25×10 -5 [ / ℃], more preferably 4.0×10 -5 [℃]~16×10 -5 [ / ℃].

[0065] When the frame 10 is made of metal, the average coefficient of linear expansion of the metal is, for example, 1.0 × 10⁻⁶ within a temperature range of 0°C to 60°C. -5 [℃]~3.0×10 -5 [ / ℃]. Regarding the average linear expansion coefficient of metallic materials within the temperature range of 0℃ to 60℃, it is 2.3 × 10⁻⁶ for aluminum and aluminum alloys such as Duralumin. -5 [℃]~2.8×10 -5 [℃], when the metallic material is iron and steel, is 1.0 × 10⁻⁶. -5 [℃]~1.3×10-5 [℃], when the metal material is stainless steel, is 1.0 × 10. -5 [℃]~1.8×10 -5 [ / ℃]. The average coefficient of linear expansion of a metal frame within a specified temperature range can be measured according to Japanese Industrial Standard JIS R3251-1995.

[0066] When the frame 10 is made of resin, the average coefficient of linear expansion in the temperature range of 0℃ to 60℃ is, for example, 1.0 × 10⁻⁶. -5 [℃]~25×10 -5 [ / ℃]. Regarding the average coefficient of linear expansion of the resin within the temperature range of 0℃ to 60℃, it is 10 × 10⁻⁶ when the resin is polyethylene (PE). -5 [℃]~22×10 -5 [℃], when the resin is polypropylene (PP), it is 5×10. -5 [℃]~11×10 -5 [℃], when the resin is acrylonitrile-butadiene-styrene (ABS), it is 6×10. -5 [℃]~13×10 -5 [℃], when the resin is polymethyl methacrylate (PMMA), it is 5×10. -5 [℃]~10×10 -5 [℃], when the resin is polyamide (PA), it is 5×10 -5 [℃]~15×10 -5 [℃], when the resin is epoxy resin (EP), it is 4×10. -5 [℃]~7×10 -5 [℃], when the resin is polyetheretherketone (PEEK), it is 3.6 × 10⁻⁶. -5 [℃]~5×10 -5 [℃], when the resin is polyetherimide (PEI), it is 4.2 × 10⁻⁶. -5 [℃]~5.9×10 -5 [℃], when the resin is polyethylene terephthalate (PET), it is 5×10 -5 [℃]~7×10 -5 [℃], when the resin is polyphenylene sulfide (PPS), it is 4×10. -5 [℃]~6×10 -5 [ / ℃]. Additionally, the frame 10 can be formed from engineering plastics derived from these resins. The average coefficient of thermal expansion of the frame over a temperature range of 0℃ to 60℃ can be 3.5 × 10⁻⁶. -5 [℃]~15×10 -5[ / ℃]. The average coefficient of linear expansion of the resin frame within a specified temperature range can be determined according to JIS R3251-1995.

[0067] The frame 10 can be made of ceramic, as needed. Regarding the average linear expansion coefficient of ceramics in the temperature range of 0℃ to 60℃, it is 0.55 × 10⁻⁶ when the ceramic is Al₂O₃ (alumina). -5 [℃]~0.7×10 -5 [℃], when the ceramic is ZrO2 (zirconia), it is 0.7 × 10⁻⁶. -5 [℃]~0.8×10 -5 [℃], when the ceramic is SiC (silicon carbide), it is 0.28 × 10⁻⁶. -5 [℃]~0.3×10 -5 [ / ℃]. The average coefficient of linear expansion of the ceramic frame within a specified temperature range can be determined according to JIS R3251-1995.

[0068] The method for determining the average linear expansion coefficient of the frame 10 is not limited to a specific method. For example, the average linear expansion coefficient of the frame 10 can be determined using a LIX-2L laser dilatometer manufactured by Advance Riko, according to JISR 3251-1995. In this case, the test sample is prepared by clamping the frame from both ends with a pair of quartz plates. The environment for the test sample is filled with low-pressure, high-purity He gas, and the change in the length of the sample is measured using a Michelson laser interferometer while changing the temperature of the environment. The average thermal expansion coefficient of the frame from 0°C to 60°C can then be determined. In this case, the heating rate is set, for example, to 2°C / minute. It should be noted that the diameter of the test sample clamped by the quartz plates is, for example, 3 mm to 6 mm, and the length of the sample is, for example, 10 mm to 15 mm.

[0069] The dimensions of the frame 10 in the thickness direction of the light-absorbing film 20 are not limited to a specific value. For example, its dimensions are 0.2 mm to 2 mm.

[0070] The number of through holes 12 in the frame 10 is not limited to a specific value. The number can be 1 or more.

[0071] The size and shape of the through-hole 12 of the filter 1 when viewed from above are not limited to a specific manner. For example, when the filter 1 is used with an imaging element, the size of the through-hole 12 of the filter 1 when viewed from above can be determined according to the size of the imaging element or the size of the image circle.

[0072] Examples of the shape of the through-hole 12 of the filter 1 when viewed from above include a circle, a near-circular shape, an ellipse, a near-ellipse shape, a triangle, a square, a rectangle, and a quadrilateral such as a rhombus, or other polygons such as pentagons and hexagons. For example, when the filter 1 is used with an imaging element, the shape of the through-hole 12 of the filter 1 when viewed from above can be adjusted to correspond to the shape of the imaging element.

[0073] like Figure 1B As shown, the frame 10 has a first surface 14. The first surface 14 is in contact with the through hole 12 and is formed along a surface parallel to the main surface of the light-absorbing film 20. The first surface 14 is formed, for example, in a ring shape.

[0074] The frame 10, for example, has at least one of a protrusion and a recess that engage with the through hole 12. Figure 1B As shown, the frame 10, for example, has a protrusion 16 that connects to the through hole 12. The protrusion 16 protrudes toward the center of the through hole 12 in a direction parallel to the main surface of the light-absorbing film 20. For example, a first surface 14 is formed by the end face of the protrusion 16 in the thickness direction of the light-absorbing film 20. For example, one end of the protrusion 16 in the thickness direction of the light-absorbing film 20 is located on the same plane as one end of the frame 10 in the thickness direction of the light-absorbing film 20.

[0075] It should be noted that, regarding the main surface, when the object with the main surface is a plate-like body, it refers to the "main surface" that has a larger area than other surfaces, and this surface is called the main surface.

[0076] In the frame 10, a through hole 12 is formed by connecting a prism-shaped space with a volume of A×B×(t1-t2) with a prism-shaped space with a volume of a×b×t2. It should be noted that when the through hole 12 is square in top view, A=B and a=b. t1 is the dimension of the frame 10 in the thickness direction of the light-absorbing film 20, and t2 is the distance between one end of the frame 10 and the first surface 14 in the thickness direction of the light-absorbing film 20. A and B are, for example, 5~30mm, and a and b are, for example, 3~25mm. t1 is, for example, 0.2~2mm, 0.2~1.5mm, or 0.3~0.9mm. t2 is, for example, 0.1~0.5mm, or 0.1~0.25mm.

[0077] The ratio of the thickness of the light-absorbing film 20 to t1 (the value obtained by dividing the thickness of the light-absorbing film 20 by t1) is not limited to a specific value. This ratio can be 0.6 or more, or 1 or more. The ratio of the thickness of the light-absorbing film 20 to t1 can be 2 or less, or 1.5 or less. Furthermore, the ratio of the thickness of the light-absorbing film 20 to t1 can be 0.3 to 0.6, and further, 0.39 to 0.44.

[0078] The ratio of the thickness of the light-absorbing film 20 to t2 (the value obtained by dividing the thickness of the light-absorbing film 20 by t2) can be greater than 1 and less than 2, and can be 1.2 to 1.6, or even 1.3 to 1.46. When the thickness of the light-absorbing film 20 is in this relationship with t2, the contact area between the light-absorbing film 20 and the inner surface of the through hole 12 can be increased, thereby improving the adhesion between the light-absorbing film 20 and the frame 10.

[0079] It is important to note that Figure 1B This is a (cross-sectional) view illustrating one embodiment of the filter 1 of this application. Using Figure 1B A more detailed description of an embodiment of filter 1 of this application will be given. Figure 1B In the frame 10, the frame body 10 is a flat plate having a first end face 25 and a second end face 26 in the thickness direction. The first end face 25 is the upper end face, and the second end face 26 is the lower end face. The first end face 25 and the second end face 26 are both planar. A through hole 12 penetrates the frame body 10 in the thickness direction. The thickness of the frame body 10 is t1. The through hole 12 includes a protrusion 16 protruding toward the interior of the through hole 12. The protrusion 16 includes a first surface 14 and a surface 17. The first surface 14 is a surface that is substantially parallel to the second end face 26. The surface 17 is a surface that is perpendicular to the second end face 26 and the first surface 14. Between the second end face 26 and the first surface 14, the length of the frame body 10 in the thickness direction is t2. A light-absorbing film 20 is formed inside the through hole 12. The light-absorbing film 20 is a flat plate having a first main surface 22 and a second main surface 24 that are formed separately and parallel to each other in the thickness direction. The first main surface 22 is the upper main surface, and the second main surface 24 is the lower main surface. Both the first main surface 22 and the second main surface 24 are planar. The second main surface 24 of the light-absorbing film 20 is approximately flush with the second end surface 26 of the frame 10. "Flush" means that two or more surfaces are connected flatly without any step difference. The thickness of the light-absorbing film 20 is the length of the light-absorbing film 20 between the first main surface 22 and the second main surface 24 in the thickness direction. Furthermore, the first main surface 22 of the light-absorbing film 20 is formed closer to the first end surface 25 than the first surface 14 of the frame 10, and the thickness of the light-absorbing film 20 is greater than its length t2. Additionally, the light-absorbing film 20 is in contact with the surfaces 17 and 14 that constitute the protrusion 16.

[0080] In the filter of this application, regardless of the specific configuration of the above embodiments, when the interior of the through-hole of the light-absorbing film has a protrusion or a recess, the light-absorbing film can be in contact with a portion or all of the protrusion or recess. Alternatively, the light-absorbing film can be in contact with at least two of the surfaces constituting the protrusion or recess.

[0081] The color of the surface of the frame 10 is not limited to a specific color. For example, the portion of the frame 10 that connects to the through hole 12 may be black, or the entire surface of the frame 10 may be black. In this case, for example, when the filter 1 is used in a camera device, the re-reflection of light in the frame 10 can be suppressed. The frame 10 may also be colored in a color that suppresses the re-reflection of light.

[0082] The surface of the frame 10 can be a matte surface with suppressed gloss, and minute irregularities can be formed on the surface of the frame 10 in a manner that diffuses light. This allows light reflected from the surface of the frame 10 to diffuse. As a result, when the filter 1 is used in a camera device, it is easy to suppress ghosting or glare caused by direct reflection of light.

[0083] Frame 10 can be as follows Figure 2A and Figure 2B The diagram shows a modification of frame 10x. Frame 10x is constructed in the same manner as frame 10, except where specifically stated. Elements of frame 10x that are identical or corresponding to those of frame 10 are assigned the same symbols. The through-hole 12 in frame 10x, viewed from above, is elliptical. In frame 10x, the through-hole 12 is formed by connecting an elliptical cylindrical space with a volume of π(S1 / 2)×(S2 / 2)×(t3-t4) with an elliptical cylindrical space with a volume of π(s1 / 2)×(s2 / 2)×t4. S1 and s2 are the lengths of the major axis of the ellipse, and S2 and s2 are the lengths of the minor axis of the ellipse. It should be noted that when the through-hole 12 is circular in view from above, S1 = S2 and s1 = s2. t3 is the dimension of the frame 10x in the thickness direction of the light-absorbing film 20, and t4 is the distance between one end of the frame 10x in the thickness direction of the light-absorbing film 20 and the first surface 14. S1 and S2 are, for example, 5 to 30 mm, and s1 and s2 are, for example, 3 to 25 mm. t3 is, for example, 0.2 to 2 mm, 0.2 to 1.5 mm, or 0.3 to 0.9 mm. t4 is, for example, 0.1 to 0.5 mm, or 0.1 to 0.25 mm.

[0084] The ratio of the thickness of the light-absorbing film 20 to t3 (the value obtained by dividing the thickness of the light-absorbing film 20 by t3) is not limited to a specific value. This ratio can be 0.6 or more, or 1 or more. Furthermore, the ratio of the thickness of the light-absorbing film 20 to t3 can be 2 or less, or 1.5 or less. The ratio of the thickness of the light-absorbing film 20 to t3 can be 0.3 to 0.6, and further, 0.39 to 0.44.

[0085] The ratio of the thickness of the light-absorbing film 20 to t4 (the value obtained by dividing the thickness of the light-absorbing film 20 by t4) is greater than 1. This ratio can be less than 2, or it can be 1.2 to 1.6, and further, it can be 1.3 to 1.46. When the thickness of the light-absorbing film 20 and t4 are in this relationship, the contact area between the light-absorbing film 20 and the inner surface of the through hole 12 can be increased, thereby improving the adhesion between the light-absorbing film 20 and the frame 10x.

[0086] The frame 10 is not limited to any particular method as long as it has a through hole 12. For example, the frame 10 can be as follows: Figures 3A to 3I The changes shown are made according to frames 10a to 10i. Frames 10a to 10i are constructed in the same manner as frame 10, except where specifically described. The constituent elements of frames 10a to 10i that are the same as or correspond to the constituent elements of frame 10 are assigned the same symbols. Figures 3A to 3I Cross sections of the frame 10a to 10i, formed along a plane containing the through hole 12 and parallel to the axis, are shown respectively.

[0087] exist Figure 3A In the frame 10a shown, the through hole 12 is formed by the inner surface extending along a direction perpendicular to the main surface of the light-absorbing film 20 (not shown). Figure 3B In the frame 10b shown, the through hole 12 is formed in the form of a tapered hole. Figure 3C In the frame 10c shown, the through hole 12 has a portion formed in the form of a tapered hole and a portion formed by an inner surface extending along a direction perpendicular to the main surface of the light-absorbing film 20. Figure 3D The frame 10d shown and Figure 3E The frame 10e shown has a protrusion 16 that connects to the through hole 12. The protrusion 16 is formed in an annular shape around the through hole 12. The protrusion 16 in the frame 10d has, for example, a pair of side surfaces parallel to the main surface of the light-absorbing film 20, and an end surface connecting these side surfaces. For example, one of the pair of side surfaces of the protrusion 16 constitutes the first surface 14. The protrusion 16 in the frame 10e has a pointed shape.

[0088] Figure 3F The frame 10f shown and Figure 3G The frame 10g shown has a recess 18 that connects to the through hole 12. The recess 18 is formed in annular shape and is included in a portion of the through hole 12. The recess 18 of the frame 10g has, for example, a pair of side surfaces that are parallel to the main surface of the light-absorbing film 20 and opposite to each other. One of the pair of side surfaces can form the first surface 14. The recess 18 in the frame 10g forms a wedge-shaped groove.

[0089] Figure 3HIn the frame 10h shown, a pair of inner surfaces extending in mutually orthogonal directions and connected to the through hole 12 can be connected using surfaces inclined relative to these inner surfaces. For example, in a cross-section of the frame 10h formed along a plane containing the axis of the through hole 12 and parallel to that axis, the contours of the pair of inner surfaces extending in mutually orthogonal directions are connected using contours inclined at an angle of 45° relative to these two contours. The pair of inner surfaces extending in mutually orthogonal directions and connected to the through hole 12 can be connected using curved surfaces with rounded corners. The above-described shape of the frame 10h can be described as... Figure 1B The filter shown has a frame in which a portion of the inner surface of the through-hole forming the protrusion 16 is chamfered by an appropriate amount of C or R chamfer. The size of the C surface can be C0.01 to C0.25 or C0.025 to C0.1. The size of the R surface can be R0.01 to R0.25 or R0.025 to R0.1. It should be noted that the filter can also be formed by chamfering the portion of the through-hole forming the protrusion 16. Figures 3A to 3G A portion of the inner surface of the through hole in the frame is chamfered in this way.

[0090] Figure 3I The frame 10i shown has a protrusion 16 that connects to the through hole 12. The protrusion 16 has a tapered surface formed from both ends of the frame 10i in a direction perpendicular to the main surface of the light-absorbing film 20 (not shown).

[0091] like Figure 1B As shown, the light-absorbing film 20 has a thickness smaller than that of the frame 10 in the thickness direction of the light-absorbing film 20. In this case, even if the thickness of the light-absorbing film 20 is small, the operation of the filter 1 is easy since the light-absorbing film 20 and the frame 10 are integrally formed.

[0092] The thickness of the light-absorbing film 20 is not limited to a specific thickness. For example, the light-absorbing film 20 has a thickness of 1 μm to 1000 μm.

[0093] The thickness of the light-absorbing film 20 can be 10μm to 500μm or 50μm to 300μm.

[0094] like Figure 1B As shown, the light-absorbing film 20, for example, has a first main surface 22. The first main surface 22 is formed in the thickness direction of the light-absorbing film 20 between one end and the other end of the frame 10. In this case, the filter 1 can be moved without contacting the first main surface 22, which easily improves the yield of products equipped with the filter 1. The first main surface 22 is formed, for example, in the thickness direction of the light-absorbing film 20 in a manner that covers the first surface 14. The first main surface 22 can be formed in a manner that forms the same plane as the first surface 14.

[0095] like Figure 1B As shown, the light-absorbing film 20, for example, has a second main surface 24. The second main surface 24 is formed, for example, in a manner that it forms a plane with one end of the frame 10 in the thickness direction of the light-absorbing film 20. In this case, no step difference is formed in the filter 1 due to the second main surface 24 of the light-absorbing film 20, and damage to the light-absorbing film 20 from contact with other components can be prevented during the transport of the filter 1. As a result, the yield rate of products equipped with the filter 1 is easily improved. Furthermore, since the light-absorbing film 20 is present at one end of the through-hole 12 in the thickness direction of the light-absorbing film 20, direct light irradiation to the inner surface of the frame 10 connected to the through-hole 12 can be prevented. The second main surface 24 can be formed between one end and the other end of the frame 10 in the thickness direction of the light-absorbing film 20.

[0096] like Figure 1B As shown, the light-absorbing film 20 overlaps with the protrusion 16 in the thickness direction of the light-absorbing film 20. Figures 3J to 3P As shown, for example, the light-absorbing film 20 may overlap with at least a portion of the protrusion or at least a portion of the concave portion formed inside the through hole of the frame in the thickness direction of the light-absorbing film 20.

[0097] Figure 3J and Figure 3K They are shown respectively in Figure 3D A filter is obtained by forming a light-absorbing film 20 inside the through hole 12 of the frame 10d shown. Figure 3J In the filter shown, the light absorption film 20 overlaps the protrusion 16 entirely in the thickness direction of the light absorption film 20. Figure 3K In the filter shown, the light absorption film 20 overlaps with a portion of the protrusion 16 in the thickness direction of the light absorption film 20.

[0098] Figure 3J In the filter shown, the light-absorbing film 20 is in contact with the three surfaces of the protrusion 16 inside the through hole of the frame 10d (two surfaces parallel to the end face of the frame 10d and one surface perpendicular to the protrusion). Figure 3K In the filter shown, the light-absorbing film 20 is in contact with two surfaces of the protrusion 16 inside the through hole of the frame 10d (one surface parallel to the end face of the frame 10d and the other surface perpendicular to that surface).

[0099] Figure 3L It shows in Figure 3E A filter is obtained by forming a light-absorbing film 20 inside the through hole 12 of the frame 10e shown. Figure 3L In the filter shown, the light absorption film 20 overlaps the protrusion 16 entirely in the thickness direction of the light absorption film 20. Figure 3L In the filter shown, the light absorption film 20 can overlap with a portion of the protrusion 16 in the thickness direction of the light absorption film 20.

[0100] Figure 3L In the filter shown, the light-absorbing film 20 is in contact with two surfaces of the triangular protrusion protruding towards the center of the through-hole in the frame 10e. Additionally, in Figure 3L The filter shown includes a frame 10e, which, although having a protrusion inside the through-hole, does not resemble... Figure 1B The filter, for example, has a frame with a surface parallel to one end face of the frame. Such a configuration is also included in this invention.

[0101] Figure 3M and Figure 3N They are shown respectively in Figure 3F A filter is obtained by forming a light-absorbing film 20 inside the through hole 12 of the frame 10f shown. Figure 3M In the filter shown, the light absorption film 20 overlaps entirely with the recess 18 in the thickness direction of the light absorption film 20. Figure 3N In the filter shown, the light absorption film 20 overlaps with a portion of the recess 18 in the thickness direction of the light absorption film 20.

[0102] exist Figure 3M In the filter shown, the light-absorbing film 20 is in contact with the three surfaces (two surfaces parallel to the end face of the frame 10f and one surface perpendicular to the end face) of the recess 18 inside the through hole of the frame 10f. Figure 3N In the filter shown, the light-absorbing film 20 is in contact with two surfaces of the recess 18 inside the through hole of the frame 10f (one surface parallel to the end face of the frame 10d and the other surface perpendicular to that surface).

[0103] Figure 3O It shows in Figure 3G A filter is obtained by forming a light-absorbing film 20 inside the through hole 12 of the frame 10g shown. Figure 3O In the filter shown, the light absorption film 20 overlaps entirely with the recess 18 in the thickness direction of the light absorption film 20. Figure 3O In the filter shown, the light absorption film 20 can overlap with a portion of the recess 18 in the thickness direction of the light absorption film 20.

[0104] Figure 3O In the filter shown, the light-absorbing film 20 is in contact with two surfaces of the triangular recess inside the through-hole of the frame 10g, which faces outward from the through-hole. Furthermore, Figure 3O The filter shown includes a frame of 10g, which, although having a recess inside the through-hole, is not like... Figure 1B The filter, for example, has a frame with a surface parallel to one end face of the frame. Such a configuration is also included in this invention.

[0105] Figure 3P It shows in Figure 3I A filter is obtained by forming a light-absorbing film 20 inside the through hole 12 of the frame 10i shown. Figure 3P In the filter shown, the light absorption film 20 overlaps with a portion of the protrusion 16 in the thickness direction of the light absorption film 20. Figure 3P In the filter shown, the light absorption film 20 can overlap the entire protrusion 16 in the thickness direction of the light absorption film 20.

[0106] Figure 3P In the filter shown, the light-absorbing film 20 is in contact with three surfaces of the trapezoidal protrusion that protrudes towards the center of the through-hole inside the frame 10i. Additionally, in Figure 3P The filter shown includes a frame 10i, which, although having a protrusion inside the through-hole, does not resemble... Figure 1B The filter, for example, has a frame with a surface parallel to one end face of the frame. Such a configuration is also included in this invention.

[0107] Thus, in Figure 1B , Figures 3J to 3P In the filter, at least two surfaces of the surface constituting the protrusion or recess inside the through hole of the frame included in the filter are in contact with the light-absorbing film.

[0108] The light-absorbing film 20 is not limited to a specific film as long as it can absorb light of a specified wavelength. For example, the light-absorbing film 20 has a transmission spectrum that satisfies the following conditions (I), (II), (III), (IV), (V), (VI), and (VII).

[0109] (I) There is a first cutoff wavelength in the wavelength range of 380 nm to 440 nm that shows 50% transmittance.

[0110] (II) There is a second cutoff wavelength in the wavelength range of 600 nm to 720 nm that shows 50% transmittance.

[0111] (III) The maximum transmittance in the wavelength range of 300nm to 350nm is less than 1%.

[0112] (IV) The average transmittance within the wavelength range of 450nm to 600nm is over 75%.

[0113] (V) The maximum transmittance in the wavelength range of 750nm to 1000nm is less than 5%.

[0114] (VI) The maximum transmittance in the wavelength range of 800nm ​​to 950nm is less than 4%.

[0115] (VII) The transmittance at a wavelength of 1100 nm is less than 20%.

[0116] In this specification, "the maximum transmittance in the wavelength range of Xnm to Ynm is less than A%" has the same meaning as "the transmittance is less than A% in the entire wavelength range of Xnm to Ynm".

[0117] Regarding the above condition (I), the first cutoff wavelength is preferably in the range of wavelength 385nm to 435nm, and more preferably in the range of wavelength 390nm to 430nm.

[0118] Regarding the above condition (II), the second cutoff wavelength is preferably in the range of wavelength 610nm to 700nm, and more preferably in the range of wavelength 620nm to 680nm.

[0119] Regarding the above conditions (IV), the average transmittance within the wavelength range of 450 nm to 600 nm is preferably 78% or more, and more preferably 80% or more.

[0120] Regarding the above conditions (V), the maximum transmittance in the wavelength range of 750 nm to 1000 nm is preferably 3% or less, more preferably 1% or less.

[0121] Regarding the above condition (VI), the maximum transmittance in the wavelength range of 800 nm to 950 nm is preferably 2% or less, more preferably 0.5% or less.

[0122] Regarding the above condition (VII), the transmittance at a wavelength of 1100 nm is preferably 15% or less, more preferably 10% or less.

[0123] The light-absorbing film 20 is fixed to the frame 10, for example, by direct contact with the inner surface of the frame 10. In other words, there is no adhesive layer between the light-absorbing film 20 and the frame 10. The light-absorbing film 20 can be fixed to the frame 10 using an adhesive.

[0124] The light-absorbing compound in the light-absorbing film 20 is not limited to a specific compound as long as it can absorb light of a specified wavelength. For example, the light-absorbing compound may include phosphonic acid and copper components represented by the following formula (a).

[0125] [Chemistry 1]

[0126]

[0127] [In the formula, R] 11 A haloaryl group is formed by substituting at least one hydrogen atom of an alkyl, aryl, nitroaryl, hydroxyaryl, or aryl group with a halogen atom.

[0128] In the light-absorbing film 20, a light-absorbing compound is formed, for example, by coordinating a phosphonic acid represented by formula (a) onto a copper component. For example, particles containing at least the light-absorbing compound are formed in the light-absorbing film 20. In this case, the particles do not aggregate but are dispersed within the light-absorbing film 20. The average particle size is, for example, 5 nm to 200 nm. When the average particle size is 5 nm or more, no special process for micronization of the particles is required, and the possibility of damage to the structure of the particles containing at least the light-absorbing compound is small. Furthermore, the particles are well dispersed in the light-absorbing film 20. Additionally, when the average particle size is 200 nm or less, the influence of Mie scattering can be reduced, the transmittance of visible light in the light-absorbing film 20 can be improved, and the reduction in contrast and haze characteristics of images captured by the imaging device can be suppressed. The average particle size is preferably 100 nm or less. In this case, the influence of Rayleigh scattering is reduced, thus improving the transparency of the light-absorbing film 20 to visible light. Furthermore, the average particle size is more preferably 75 nm or less. In this case, the light-absorbing film 20 exhibits particularly high transparency to visible light. It should be noted that the average particle size can be determined using dynamic light scattering in the composition used for the light-absorbing film 20.

[0129] The light-absorbing film 20 contains, for example, a hydrolysis condensate of an alkoxysilane. In this case, the light-absorbing film 20 forms a robust framework with siloxane bonds (-Si-O-Si-).

[0130] The light-absorbing film 20 contains hydrolysis condensates of alkoxysilanes, such as those containing dialkoxysilanes. This forms a robust framework with siloxane bonds in the light-absorbing film 20, and the organic functional groups from the dialkoxysilanes readily impart the desired flexibility to the film. Therefore, cracks and chipping are less likely to occur when the light-absorbing film 20 is cut. Furthermore, the light-absorbing film 20 is less prone to breakage when subjected to external force in a bending manner. Additionally, even if the difference between the coefficient of thermal expansion of the frame 10 and the coefficient of thermal expansion of the light-absorbing film 20 is large, the light-absorbing film 20 can deform flexibly with the expansion and contraction of the frame 10. Therefore, it is less susceptible to thermal stress, and problems such as cracking or peeling of the light-absorbing film 20 from the frame 10 are less likely to occur during thermal cycling tests.

[0131] The hydrolysis condensate of dialkoxysilanes is not limited to hydrolysis condensates of a specific dialkoxysilane. Such hydrolysis condensates, for example, originate from dialkoxysilanes containing a hydrocarbon group having 1 to 6 carbon atoms bonded to a silicon atom. The dialkoxysilane may have a haloalkyl group. In the haloalkyl group, at least one hydrogen atom in the hydrocarbon group having 1 to 6 carbon atoms bonded to the silicon atom is replaced by a halogen atom.

[0132] Hydrolysis condensates of dialkoxysilanes, for example, are derived from alkoxysilanes represented by formula (b) below. In this case, the desired flexibility can be more easily and reliably imparted to the light-absorbing film 20.

[0133] (R2)2-Si-(OR3)2(b)

[0134] [In the formula, R2 is an alkyl group having 1 to 6 carbon atoms, and R3 is an alkyl group having 1 to 8 carbon atoms.]

[0135] Hydrolysis condensates of dialkoxysilanes can be, for example, hydrolysis condensates of dimethyldiethoxysilane, dimethyldimethoxysilane, diethyldiethoxysilane, diethyldimethoxysilane, 3-epoxypropoxypropylmethyldimethoxysilane, or 3-epoxypropoxypropylmethyldiethoxysilane.

[0136] The hydrolysis condensate of alkoxysilanes may further include hydrolysis condensates of at least one of tetraalkoxysilanes and trialkoxysilanes. Thus, a dense structure is readily formed in the light-absorbing film 20 by siloxane bonds.

[0137] The hydrolysis condensate of alkoxysilanes can further include hydrolysis condensates of tetraalkoxysilanes and trialkoxysilanes. This facilitates a more reliable and compact structure formed by siloxane bonds within the light-absorbing film 20.

[0138] The tetraalkoxysilane or trialkoxysilane used for the hydrolysis condensation of the alkoxysilane contained in the light absorption membrane 20 is not limited to a specific alkoxysilane. For example, the tetraalkoxysilane or trialkoxysilane used for the hydrolysis condensation of the alkoxysilane contained in the light absorption membrane 20 may be selected from tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3-epoxypropoxypropyltrimethoxysilane, 3-epoxypropoxypropyltriethoxysilane, n-propyltriethoxysilane, n-propyltrimethoxysilane, hexyltriethoxysilane, etc. At least one of the group consisting of oxysilane, hexyltrimethoxysilane, trifluoropropyltriethoxysilane, trifluoropropyltrimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanopropyltriethoxysilane, and 3-isocyanopropyltrimethoxysilane.

[0139] The proportion of dialkoxysilane and dialkoxysilane hydrolysis condensates in the alkoxysilane and alkoxysilane hydrolysis condensates contained in the light-absorbing membrane 20 is not limited to a specific value. The ratio of the content of dialkoxysilane and dialkoxysilane hydrolysis condensates in the light-absorbing membrane 20 to the total amount of alkoxysilane and alkoxysilane hydrolysis condensates contained in the light-absorbing membrane 20, calculated based on the mass of these converted to fully hydrolyzed condensates, is, for example, 6 to 48%. This allows for a more reliable adjustment of the average Young's modulus of the light-absorbing membrane 20, as measured by the continuous rigidity determination method, to the desired range. This ratio is preferably 8 to 35%, more preferably 10 to 30%. In this case, the light-absorbing membrane 20 tends to have high moisture resistance. This is because the dense structure formed by siloxane bonds prevents the light-absorbing compounds from agglomerating under high humidity conditions.

[0140] The light-absorbing film 20 may further contain, for example, a phosphate ester. Through the action of the phosphate ester, the light-absorbing compound is readily and well dispersed in the light-absorbing film 20. In the light-absorbing film 20, compared to the phosphate ester, compounds derived from alkoxysilanes can impart high moisture resistance to the light-absorbing film 20 while also appropriately dispersing the light-absorbing compound. Therefore, by including alkoxysilanes in the light-absorbing film 20, the amount of phosphate ester used can be reduced. During the formation of the light-absorbing film 20, the alkoxysilanes surrounding the light-absorbing compound react with dialkoxysilanes, thereby easily making the light-absorbing film 20 homogeneous and highly dense. It should be noted that the light-absorbing film 20 may also not contain a phosphate ester.

[0141] Phosphate esters, for example, are phosphate esters containing polyoxyalkyl groups. Phosphate esters containing polyoxyalkyl groups are not limited to specific phosphate esters. Examples of phosphate esters containing polyoxyalkyl groups include Plysurf A208N: polyoxyethylene alkyl (C12, C13) ether phosphate, Plysurf A208F: polyoxyethylene alkyl (C8) ether phosphate, Plysurf A208B: polyoxyethylene lauryl ether phosphate, Plysurf A219B: polyoxyethylene lauryl ether phosphate, Plysurf AL: polyoxyethylene styrene phenyl ether phosphate, Plysurf A212C: polyoxyethylene tridecyl ether phosphate, or Plysurf A215C: polyoxyethylene tridecyl ether phosphate. These are all products manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd. Alternatively, the phosphate esters may be, for example, NIKKOL DDP-2: polyoxyethylene alkyl ether phosphate, NIKKOL DDP-4: polyoxyethylene alkyl ether phosphate, or NIKKOL DDP-6: polyoxyethylene alkyl ether phosphate. These are all products manufactured by Nikkol Chemicals.

[0142] The light-absorbing membrane 20 may further comprise a resin, for example. The resin is not limited to a specific resin. For example, the resin is an organosilicon resin. Organosilicon resins are compounds having siloxane bonds within their structure. In this case, since the hydrolytic condensate of alkoxysilanes also has siloxane bonds, the hydrolytic condensate of alkoxysilanes has good compatibility with the resin in the light-absorbing membrane 20.

[0143] The resin is preferably a silicone resin containing aryl groups such as phenyl groups. If the resin contained in the light-absorbing film 20 is rigid, cracks are easily generated during the manufacturing process of the light-absorbing film 20 due to curing shrinkage as the thickness of the light-absorbing film 20 increases. If the resin is a silicone resin containing aryl groups, the light-absorbing film 20 tends to have good crack resistance. In addition, silicone resins containing aryl groups have high compatibility with the phosphonic acid represented by formula (a), and the light-absorbing compound is less likely to aggregate. Specific examples of silicone resins used as resins include KR-255, KR-300, KR-2621-1, KR-211, KR-311, KR-216, KR-212, KR-251, and KR-5230. These are all silicone resins manufactured by Shin-Etsu Chemical Co., Ltd.

[0144] An example of a method for manufacturing filter 1 is shown. The method for manufacturing filter 1 includes, for example, the following steps (i) and (ii).

[0145] (i) A resin composition containing a light-absorbing compound is supplied in such a way that the through hole 12 of the frame 10 is sealed.

[0146] (ii) The resin composition supplied in (i) is cured to form a light-absorbing film 20.

[0147] Figure 4 This is a flowchart illustrating a manufacturing example of filter 1 in this embodiment. As an example, the manufacturing process is described... Figure 1A and Figure 1B The method for using filter 1 will be described. It should be noted that this description, as well as the methods used for illustration, are... Figure 4 The main parts of the manufacturing method of the filter of the present invention are described, but the specific and defined structure is not reflected.

[0148] Filter 1 can be Figure 4 The method shown is used to manufacture the substrate. In this method, a substrate 30 is first provided. The substrate 30 is not limited to a specific substrate. The substrate 30 can be a glass substrate, a substrate made of metals such as stainless steel and aluminum, a substrate made of ceramics such as alumina and zirconium oxide, or a substrate made of resin. The substrate 30 is preferably a glass substrate. In this case, a smooth surface can be easily and cost-effectively obtained.

[0149] Depend on Figure 4 Understandably, the substrate 30 has at least one flat main surface.

[0150] Next, a coating 32 is formed on the main surface of the substrate 30. The coating 32 is formed in a manner that facilitates the peeling off of the light-absorbing film 20 in subsequent processes. The coating 32 may be hydrophobic or waterproof, for example. The coating 32 may contain, for example, a fluorinated compound. The substrate 30 can undergo surface treatment other than the formation of the coating 32 to facilitate the peeling off of the light-absorbing film 20 in subsequent processes. If the main surface of the substrate 30 has the characteristic of facilitating the peeling off of the light-absorbing film 20, the formation of the coating 32 and other surface treatments can be omitted. For example, if the substrate 30 is a substrate made of fluororesin, the formation of the coating 32 and other surface treatments can be omitted.

[0151] Next, a frame 10 is provided on the coating 32. In this case, the frame 10 is fixed to the substrate 30 using a clamp (not shown). Two or more frames 10 can be provided on one substrate 30. Preferably, the frames 10 are provided in a way that a portion of the surface of the frame 10 does not create a gap with the surface of the coating 32, and the frames 10 are provided in this sealed state.

[0152] Regarding frame 10, according to Figure 4 As can be understood from the cross-sectional view shown in the third image from the top, it is a flat plate shape with two parallel flat main surfaces and a through hole 12 extending through the thickness direction. One of the main surfaces of the frame 10 is in surface contact with the flat main surface of the substrate 30, or with the coating 32 formed on the main surface of the substrate 30. The frame 10 includes a protrusion 16 inside the through hole 12. In addition, the protrusion 16 includes a first surface 14 parallel to the main surface of the frame 10.

[0153] Next, a predetermined amount of light-absorbing composition 20a is supplied to seal the through-hole 12 of the frame 10. The amount of light-absorbing composition 20a supplied is adjusted such that the light-absorbing film 20 obtained by curing the light-absorbing composition 20a has a thickness that enables it to exhibit the desired optical properties, such as the desired transmission spectrum.

[0154] At this time, according to Figure 4 (Especially the fourth or fifth image from the top) it can be understood that one end face of the light-absorbing film 20 in the thickness direction is in close contact with the flat main surface of the substrate 30, or the surface of the coating 32 formed on the main surface of the substrate 30. Thus, it is expected that one main surface of the light-absorbing film 20 in the thickness direction is approximately flush with one main surface of the frame 10.

[0155] In addition, according to Figure 4(Especially the fourth or fifth image above) It can be understood that the end face of the light-absorbing film 20 on the opposite side of the substrate 30 is formed by supplying the light-absorbing composition 20a in a manner that exceeds the height of the first surface 14.

[0156] Next, the light-absorbing composition 20a is cured to form a light-absorbing film 20. For example, the light-absorbing composition 20a can be cured by heating it inside a heating furnace or oven. The curing conditions of the light-absorbing composition 20a can be adjusted, for example, according to the curing conditions of the curable resin contained in the light-absorbing composition 20a. The curing conditions may include the ambient temperature of the light-absorbing composition 20a and the time.

[0157] according to Figure 4 It can be understood that the ratio of the thickness of the light-absorbing film 20 to its length t2 is greater than 1. The length t2 corresponds to the distance in the thickness direction of the light-absorbing film 20 between one end face of the frame 10 and the first surface 14.

[0158] Next, the light-absorbing film 20 is peeled off from the substrate 30 together with the frame 10. This yields the filter 1. When the light-absorbing film 20 contains an alkoxysilane or its hydrolysate, the formation of siloxane bonds in the light-absorbing film 20 can be promoted by exposing it to a temperature of approximately 60°C to 90°C and an atmosphere with a specified relative humidity of less than 90%. This makes the substrate of the light-absorbing film 20 more robust.

[0159] The light-absorbing composition 20a is not limited to a specific composition, as long as the light-absorbing film 20 can be formed. The light-absorbing composition 20a may contain, for example, components contained in the light-absorbing film 20 or precursors of components contained in the light-absorbing film 20. An example of a method for preparing the light-absorbing composition 20a will be described, taking the case where the light-absorbing compound contains the aforementioned phosphonic acid and copper components as an example.

[0160] For example, the light-absorbing composition 20a contains R in formula (a). 11In the case of aryl, nitroaryl, hydroxyaryl, or haloaryl phosphonic acids (aryl phosphonic acids), solution D is prepared as follows. A copper salt, such as copper acetate monohydrate, is added to a specified solvent, such as tetrahydrofuran (THF), and stirred to prepare solution A as a copper salt solution. Next, an aryl phosphonic acid is added to a specified solvent, such as THF, and stirred to prepare solution B. When using two or more aryl phosphonic acids as the phosphonic acid represented by formula (a), each aryl phosphonic acid can be added to a specified solvent, such as THF, and stirred to mix the two or more preparative solutions prepared according to the type of aryl phosphonic acid to prepare solution B. For example, an alkoxysilane is added to the preparation of solution B. Solution B is added to solution A while stirring, and the stirring is continued for a specified time. Next, a specified solvent, such as toluene, is added to the solution and stirred to obtain solution C. Next, solution C is heated and subjected to a solvent removal treatment for a specified time to obtain solution D. This process removes solvents such as THF and components generated through the dissociation of copper salts, such as acetic acid (boiling point: approximately 118°C), and generates a light-absorbing compound by reacting the phosphonic acid represented by formula (a) with the copper component. The heating temperature of liquid C is determined based on the boiling point of the components that should be removed after dissociation from the copper salt. It should be noted that solvents such as toluene (boiling point: approximately 110°C) used to obtain liquid C during the desolventizing process will also evaporate. It is preferable that this solvent leaves a certain degree of residue in the light-absorbing composition 20a, and the amount of solvent added and the time of the desolventizing process can be determined from this perspective. It should be noted that o-xylene (boiling point: approximately 144°C) can also be used instead of toluene to obtain liquid C. In this case, since the boiling point of o-xylene is higher than that of toluene, its amount added can be reduced to about one-quarter of the amount of toluene added.

[0161] The light-absorbing composition 20a contains R in formula (a). 11In the case of alkyl phosphonic acids (alkyl-based phosphonic acids), solution H is further prepared, for example, as follows: First, copper salts such as copper acetate monohydrate are added to a specified solvent such as tetrahydrofuran (THF), and the mixture is stirred to obtain solution E, which is a copper salt solution. Then, an alkyl-based phosphonic acid is added to a specified solvent such as THF, and the mixture is stirred to prepare solution F. When using two or more phosphonic acids as alkyl-based phosphonic acids, each alkyl-based phosphonic acid can be added to a specified solvent such as THF, and the mixture is stirred to combine the two or more preparative solutions prepared according to the type of alkyl-based phosphonic acid to prepare solution F. For example, an alkoxysilane is further added to the preparation of solution F. While stirring solution E, solution F is added to solution E, and the mixture is stirred for a specified time. Next, a specified solvent such as toluene is added to this solution and the mixture is stirred to obtain solution G. Next, solution G is heated and simultaneously subjected to a solvent removal treatment for a specified time to obtain solution H. This removes solvents such as THF and components such as acetic acid generated through the dissociation of the copper salt. The heating temperature for liquid G is determined in the same way as for liquid C, and the solvent used to obtain liquid G is also determined in the same way as for liquid C.

[0162] For example, by mixing liquid D and liquid H in a prescribed ratio and adding alkoxysilane, and adding curable resins such as organosilicon resin as needed, a light-absorbing composition 20a can be prepared. In this case, the dialkoxysilane can be added after mixing liquid D and liquid H. In the light-absorbing composition 20a, aryl phosphonic acids and alkyl phosphonic acids can react with the copper component to form complexes. In addition, a portion of the added phosphate ester can react with the copper component to form complexes, and a portion of the phosphate ester can react with phosphonic acid or copper component to form complexes. The light-absorbing film 20 formed by curing the light-absorbing composition 20a can exert the desired light absorption performance through the action of the various materials, especially copper components such as copper ions.

[0163] The filter 1 can have other functional films on one or both main surfaces of the light-absorbing film 20. These functional films are, for example, anti-reflective films that prevent or reduce reflection. The anti-reflective film can be designed or manufactured in a way that reduces light reflection in the visible light region where transmission is desired in the light-absorbing film 20. This increases the transmittance of light in the visible light region, making it easier to obtain a bright image when the filter 1 is used in a camera device. The anti-reflective film is obtained by forming a dielectric film of appropriate thickness on the main surface of the light-absorbing film 20. Examples of dielectrics are SiO2, TiO2, Ti3N4, Al2O3, and MgO. The anti-reflective film can be a single-layer dielectric film or a multilayer film of different types of dielectrics. For example, when using a material with a low refractive index to form the anti-reflective film, the anti-reflective film can achieve good anti-reflective function with fewer layers. For example, when encapsulating a material containing hollow particles or its sol using a resin or other material as a base, since the hollow particles have a low apparent refractive index, a low-refractive-index film or layer can be formed as a whole. Hollow particles composed of SiO2 or TiO2 are commercially available. Additionally, curable resins or silane compounds with low refractive indices that can be cured via sol-gel methods are suitable as the base material for antireflective films.

[0164] The functional film can be a reflective film capable of reflecting a portion of light. Like the light-absorbing film 20, the reflective film also has the function of shielding a portion of light. Through the cooperation of the light-absorbing film 20 and the reflective film, light of a specified wavelength can be shielded. The reflective film can, for example, be formed in the form of a multilayer dielectric film. In this case, the design of the wavelength characteristics of the reflective film has a high degree of freedom, thus allowing for more precise adjustment of light shielding. Furthermore, since the reflective function can shield a portion of the light that should be shielded by the filter 1, the required reduction in absorbance of the light-absorbing film 20 can be achieved. As a result, the thickness of the light-absorbing film 20 can be reduced, or the concentration of the light-absorbing compound contained in the light-absorbing film 20 can be decreased. The reflective film is formed by forming a dielectric film of appropriate thickness on the main surface of the light-absorbing film 20. Examples of dielectrics are SiO2, TiO2, Ti3N4, Al2O3, and MgO. The reflective film can be a single-layer dielectric film or a multilayer dielectric film.

[0165] The functional membrane can be formed in such a way that it covers a portion of the surface of the frame 10 in addition to the surface covering the light-absorbing membrane 20.

[0166] A camera device equipped with filter 1 can be provided. For example... Figure 5 As shown, the imaging device 5 includes an imaging element 2, a lens 3, and a filter 1. The lens 3 allows light from the subject to pass through and converge onto the imaging element 2.

[0167] The filter 1 is disposed, for example, between the lens 3 and the imaging element 2 in the optical path of light from the subject. The imaging element 2 is disposed, for example, on the circuit board 50. In the imaging device 5, for example, the main surface of the light-absorbing film 20 of the filter 1 is separate from the light-receiving surface of the imaging element 2 and does not directly contact it. Therefore, the difficulty of manufacturing the imaging device 5 can be easily reduced, and the manufacturing time can be reduced or the yield of the imaging device 5 can be increased.

[0168] Example

[0169] The present invention will be described in more detail through embodiments. It should be noted that the present invention is not limited to the following embodiments.

[0170] <Example 1>

[0171] 4.500 g of copper acetate monohydrate and 240 g of tetrahydrofuran (THF) were mixed and stirred for 3 hours to obtain a copper acetate solution. Next, 1.646 g of Plysurf A208N (manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd.), a phosphate ester compound, was added to the obtained copper acetate solution, and the mixture was stirred for 30 minutes to obtain solution A1. 40 g of THF was added to 0.706 g of phenylphosphonic acid, and the mixture was stirred for 30 minutes to obtain solution B1α. 40 g of THF was added to 4.230 g of 4-bromophenylphosphonic acid, and the mixture was stirred for 30 minutes to obtain solution B1β. Next, solutions B1α and B1β were mixed and stirred for 1 minute. Then, 8.664 g of methyltriethoxysilane (MTES) (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KBE-13) and 2.840 g of tetraethoxysilane (TEOS) (premium grade manufactured by Kishida Chemical Co., Ltd.) were added to this mixture, and the mixture was stirred for another 1 minute to obtain solution B1. While stirring solution A1, solution B1 was added, and the mixture was stirred for 1 minute at room temperature. Next, 100g of toluene was added to the solution, and the mixture was stirred for 1 minute at room temperature to obtain solution C1. Solution C1 was transferred to a flask and desolventized using a rotary evaporator (Tokyo Rikagi Co., Ltd., model: OSB-2100) while heated in an oil bath. The oil bath temperature was set to 105°C. Solution D1, after desolventization, was then removed from the flask. This yielded solution D1, a liquid composition containing aryl phosphonic acid and copper.

[0172] 1.800 g of copper acetate monohydrate and 100 g of THF were mixed and stirred for 3 hours to obtain a copper acetate solution. Next, 1.029 g of Plysurf A208N (a phosphate ester compound) was added to the obtained copper acetate solution, and the mixture was stirred for 30 minutes to obtain solution E1. Separately, 40 g of THF was added to 1.154 g of n-butylphosphonic acid, and the mixture was stirred for 30 minutes to obtain solution F1. Solution F1 was added to solution E1 while stirring, and the mixture was stirred for 1 minute at room temperature. Next, 30 g of toluene was added to this solution, and the mixture was stirred for 1 minute at room temperature to obtain solution G1. Solution G1 was transferred to a flask and desolventized using a rotary evaporator while heating in an oil bath. The oil bath temperature was set to 105°C. Then, the desolventized solution H1 was removed from the flask. Thus, solution H1 was obtained as a liquid composition containing n-butylphosphonic acid and copper.

[0173] The following liquids were mixed as a liquid composition: D1 liquid, H1 liquid, 8.800 g of silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KR-300), 0.090 g of aluminum alkoxide compound (manufactured by Shin-Etsu Chemical Co., Ltd., product name: CAT-AC), 10.840 g of methyltriethoxysilane (MTES) (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KBE-13), 5.660 g of tetraethoxysilane (TEOS) (manufactured by Kishida Chemical Co., Ltd., premium grade), and 4.896 g of dimethyldiethoxysilane (DMDES) (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KBE-22). The mixture was stirred for 30 minutes to obtain J1 liquid as a light-absorbing composition.

[0174] 0.1 g of surface antifouling coating agent (manufactured by Daikin Industries, product name: OPTOOL DSX, active ingredient concentration: 20% by mass) was mixed with 19.9 g of a solution containing hydrofluoroether (manufactured by 3M, product name: Novec 7100), and stirred for 5 minutes to prepare a fluorine treatment agent (active ingredient concentration: 0.1% by mass).

[0175] Prepare a borosilicate glass substrate (manufactured by SCHOTT, product name: D263 Teco) with dimensions of 136mm × 108mm × 0.70mm. Overflow the aforementioned fluorine treatment agent onto one main surface of the glass substrate. Then, place the glass substrate at room temperature for 24 hours to allow the fluorine treatment agent coating to dry. Afterward, gently wipe the glass surface with a lint-free cloth containing Novec 7100 to remove excess fluorine treatment agent. This produces a fluorinated substrate coated with a fluorine compound.

[0176] Prepare nine types of frames with the dimensions shown in Table 5. In Table 5, A, B, a, b, t1, and t2 correspond to... Figure 1Aand Figure 1B The dimensions are shown. Frames α-1, α-2, and α-3 are made of MC Nylon. MC Nylon has an average coefficient of linear expansion of 10.1 × 10⁻⁶ C / L from 0°C to 60°C. -5 [℃]. MC Nylon is a registered trademark. Frames β-1, β-2, and β-3 are made of high-strength nylon. The average coefficient of linear expansion of high-strength nylon is 12.5 × 10⁻⁶ °C between 0℃ and 60℃. -5 [℃]. Frames γ-1, γ-2, and γ-3 are made of PPS. The average coefficient of linear expansion of PPS between 0℃ and 60℃ is 4.7 × 10⁻⁶. -5 [ / ℃]. Each frame is positioned on the fluorinated substrate. At this point, a portion of the main surface of the fluorinated substrate is exposed through the through-holes in the frames.

[0177] The light-absorbing composition J1 liquid was injected into the through-holes of each frame using a dispenser. Then, it was dried at 45°C for 3 hours, and the ambient temperature was slowly raised to 85°C over 10 hours to evaporate the solvent in J1 liquid, promoting the reaction of the components in J1 liquid and curing the light-absorbing composition. Subsequently, the curing light-absorbing composition was placed in an environment of 85°C and 85% relative humidity for 8 hours to complete the curing reaction. Thus, the light-absorbing film of Example 1 was formed by sealing the through-holes of the frame. The thickness of the light-absorbing film, which determines the optical properties such as the transmission spectrum of the fully cured light-absorbing composition, was predetermined, and the injection amount of the light-absorbing composition was controlled to achieve this thickness. Next, the frame with the light-absorbing film formed in the through-holes and the light-absorbing film were slowly peeled off from the fluorine-treated substrate. This yielded the filter of Example 1.

[0178] In the filter of Example 1, the thickness of the light absorption film is 207 μm, and the t1 and t2 of the frame are 0.5 mm (500 μm) and 0.15 mm (150 μm) respectively. Therefore, the ratio of the thickness of the light absorption film to t1 and t2 is 0.414 and 1.38 respectively.

[0179] <Example 2>

[0180] As a light-absorbing composition, liquid J2, prepared under the following conditions, was used instead of liquid J1, and the filter of Example 2 was prepared in the same manner as in Example 1.

[0181] In the filter of Example 2, the thickness of the light absorption film is 204 μm, and the ratio of the thickness of the light absorption film to t1 and t2 is 0.408 and 1.36, respectively.

[0182] The D1 solution, H1 solution, 8.800 g of silicone resin (manufactured by Shin-Etsu Chemical Industry Co., Ltd., product name: KR-300), 0.090 g of aluminum alkoxide compound (manufactured by Shin-Etsu Chemical Industry Co., Ltd., product name: CAT-AC), 5.420 g of methyltriethoxysilane (MTES) (manufactured by Shin-Etsu Chemical Industry Co., Ltd., product name: KBE-13), 2.830 g of tetraethoxysilane (TEOS) (manufactured by Kishida Chemical Co., Ltd., premium grade), and 2.448 g of dimethyldiethoxysilane (DMDES) (manufactured by Shin-Etsu Chemical Industry Co., Ltd., product name: KBE-22) were mixed and stirred for 30 minutes to obtain the J2 solution as a light-absorbing composition.

[0183] <Example 3>

[0184] As a light-absorbing composition, liquid J3, prepared under the following conditions, was used instead of liquid J1, and the filter of Example 3 was prepared in the same manner as in Example 1.

[0185] In the filter of Example 3, the thickness of the light-absorbing film is 195 μm, and the ratio of the thickness of the light-absorbing film to t1 and t2 is 0.390 and 1.30, respectively.

[0186] The D1 solution, H1 solution, 8.800 g of silicone resin (manufactured by Shin-Etsu Chemical Industry Co., Ltd., product name: KR-300), 0.090 g of aluminum alkoxide compound (manufactured by Shin-Etsu Chemical Industry Co., Ltd., product name: CAT-AC), 2.710 g of methyltriethoxysilane (MTES) (manufactured by Shin-Etsu Chemical Industry Co., Ltd., product name: KBE-13), 1.415 g of tetraethoxysilane (TEOS) (manufactured by Kishida Chemical Co., Ltd., premium grade), and 1.224 g of dimethyldiethoxysilane (DMDES) (manufactured by Shin-Etsu Chemical Industry Co., Ltd., product name: KBE-22) were mixed and stirred for 30 minutes to obtain the J3 solution as a light-absorbing composition.

[0187] <Example 4>

[0188] As a light-absorbing composition, liquid J4, prepared under the following conditions, was used instead of liquid J1, and the filter of Example 4 was prepared in the same manner as in Example 1.

[0189] In the filter of Example 4, the thickness of the light-absorbing film is 220 μm, and the ratio of the thickness of the light-absorbing film to t1 and t2 is 0.440 and 1.47, respectively.

[0190] D1 solution, H1 solution, 8.800 g of silicone resin (manufactured by Shin-Etsu Chemical Industry Co., Ltd., product name: KR-300), 0.090 g of aluminum alkoxide compound (manufactured by Shin-Etsu Chemical Industry Co., Ltd., product name: CAT-AC), 9.756 g of methyltriethoxysilane (MTES) (manufactured by Shin-Etsu Chemical Industry Co., Ltd., product name: KBE-13), 5.732 g of tetraethoxysilane (TEOS) (manufactured by Kishida Chemical Co., Ltd., premium grade), and 5.957 g of dimethyldiethoxysilane (DMDES) (manufactured by Shin-Etsu Chemical Industry Co., Ltd., product name: KBE-22) were mixed and stirred for 30 minutes to obtain J4 solution as a light-absorbing composition.

[0191] <Example 5>

[0192] As a light-absorbing composition, liquid J5, prepared under the following conditions, was used instead of liquid J1, and the filter of Example 5 was prepared in the same manner as in Example 1.

[0193] In the filter of Example 5, the thickness of the light absorption film is 218 μm, and the ratio of the thickness of the light absorption film to t1 and t2 is 0.436 and 1.45, respectively.

[0194] 4.500 g of copper acetate monohydrate and 240 g of tetrahydrofuran (THF) were mixed and stirred for 3 hours to obtain a copper acetate solution. Next, 6.000 g of Plysurf A219B (manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd.), a phosphate ester compound, was added to the obtained copper acetate solution, and the mixture was stirred for 30 minutes to obtain solution A5. 40 g of THF was added to 0.710 g of phenylphosphonic acid, and the mixture was stirred for 30 minutes to obtain solution B5α. 40 g of THF was added to 4.290 g of 4-bromophenylphosphonic acid, and the mixture was stirred for 30 minutes to obtain solution B5β. Next, solutions B5α and B5β were mixed and stirred for 1 minute. Then, 8.664 g of methyltriethoxysilane (MTES) (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KBE-13) and 2.840 g of tetraethoxysilane (TEOS) (premium grade manufactured by Kishida Chemical Co., Ltd.) were added to this mixture, and the mixture was stirred for another 1 minute to obtain solution B5. While stirring solution A5, solution B5 was added, and the mixture was stirred for 1 minute at room temperature. Next, 60g of cyclopentanone was added to the solution, and the mixture was stirred for 1 minute at room temperature to obtain solution C5. Solution C5 was transferred to a flask and desolventized using a rotary evaporator (Tokyo Rikagi Co., Ltd., model: OSB-2100) while heated in an oil bath. The oil bath temperature was set to 105°C. Solution D5, after desolventization, was then removed from the flask. This yielded solution D5, a liquid composition containing aryl phosphonic acid and copper.

[0195] D5 solution, 7.040 g of silicone resin (manufactured by Shin-Etsu Chemical Industry Co., Ltd., product name: KR-300), 0.070 g of aluminum alkoxide compound (manufactured by Shin-Etsu Chemical Industry Co., Ltd., product name: CAT-AC), 5.420 g of methyltriethoxysilane (MTES) (manufactured by Shin-Etsu Chemical Industry Co., Ltd., product name: KBE-13), 2.830 g of tetraethoxysilane (TEOS) (manufactured by Kishida Chemical Co., Ltd., premium grade), and 2.448 g of dimethyldiethoxysilane (DMDES) (manufactured by Shin-Etsu Chemical Industry Co., Ltd., product name: KBE-22) were mixed and stirred for 30 minutes to obtain J5 solution as a light-absorbing composition.

[0196] <Example 6>

[0197] As a light-absorbing composition, liquid J6, prepared under the following conditions, was used instead of liquid J1, and the filter of Example 6 was prepared in the same manner as in Example 1.

[0198] In the filter of Example 6, the thickness of the light absorption film is 220 μm, and the ratio of the thickness of the light absorption film to t1 and t2 is 0.440 and 1.47, respectively.

[0199] 4.500 g of copper acetate monohydrate and 240 g of tetrahydrofuran (THF) were mixed and stirred for 3 hours to obtain a copper acetate solution. Next, 3.000 g of Plysurf A212C (manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd.), a phosphate ester compound, was added to the obtained copper acetate solution, and the mixture was stirred for 30 minutes to obtain solution A6. 40 g of THF was added to 0.750 g of phenylphosphonic acid, and the mixture was stirred for 30 minutes to obtain solution B6α. 40 g of THF was added to 4.490 g of 4-bromophenylphosphonic acid, and the mixture was stirred for 30 minutes to obtain solution B6β. Next, solutions B6α and B6β were mixed and stirred for 1 minute. Then, 8.664 g of methyltriethoxysilane (MTES) (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KBE-13) and 2.840 g of tetraethoxysilane (TEOS) (premium grade manufactured by Kishida Chemical Co., Ltd.) were added to this mixture, and the mixture was stirred for another 1 minute to obtain solution B6. While stirring solution A6, solution B6 was added, and the mixture was stirred for 1 minute at room temperature. Next, 60 g of cyclopentanone was added to the solution, and the mixture was stirred for 1 minute at room temperature to obtain solution C6. Solution C6 was transferred to a flask and desolventized using a rotary evaporator (Tokyo Rikagi Co., Ltd., model: OSB-2100) while heated in an oil bath. The oil bath temperature was set to 105°C. Solution D6, after desolventizing, was then removed from the flask. This yielded solution D6, a liquid composition containing aryl phosphonic acid and copper.

[0200] D6 solution, 7.040 g of silicone resin (manufactured by Shin-Etsu Chemical Industry Co., Ltd., product name: KR-300), 0.070 g of aluminum alkoxide compound (manufactured by Shin-Etsu Chemical Industry Co., Ltd., product name: CAT-AC), 5.420 g of methyltriethoxysilane (MTES) (manufactured by Shin-Etsu Chemical Industry Co., Ltd., product name: KBE-13), 2.830 g of tetraethoxysilane (TEOS) (manufactured by Kishida Chemical Co., Ltd., premium grade), and 2.448 g of dimethyldiethoxysilane (DMDES) (manufactured by Shin-Etsu Chemical Industry Co., Ltd., product name: KBE-22) were mixed and stirred for 30 minutes to obtain J6 solution as a light-absorbing composition.

[0201] <Comparative Example 1>

[0202] As a light-absorbing composition, liquid J7, prepared under the following conditions, was used instead of liquid J1, and the filter of Comparative Example 1 was prepared in the same manner as in Example 1.

[0203] In the filter of Comparative Example 1, the thickness of the light-absorbing film is 201 μm, and the ratio of the thickness of the light-absorbing film to t1 and t2 is 0.402 and 1.34, respectively.

[0204] Add D1 solution, H1 solution, 8.800g of silicone resin (manufactured by Shin-Etsu Chemical Industry Co., Ltd., product name: KR-300), and 0.090g of aluminum alkoxide compound (manufactured by Shin-Etsu Chemical Industry Co., Ltd., product name: CAT-AC) and stir for 30 minutes to obtain J7 solution as a light-absorbing composition.

[0205] The compounds and their amounts added in the preparation of the light-absorbing compositions of Examples 1-6 and Comparative Example 1 are shown in Tables 1 and 2. As shown in these tables, toluene was used as the solvent in Examples 1-4. On the other hand, cyclopentanone was used as the solvent in Examples 5 and 6. When the solvent is changed, it is necessary to change the type of phosphate ester used as a dispersant according to the type of solvent, since it is necessary to prevent the coating liquid from agglomerating. Therefore, in Examples 5 and 6, phosphate esters different from those used in Examples 1-4 were used. It is understood that it is preferable to select the solvent and the corresponding phosphate ester according to the chemical resistance of the frame used in the filter.

[0206] Table 3 shows the alkoxysilanes used in preparing the light-absorbing compositions of Examples 1-6 and Comparative Example 1, their total addition amount, the amount of solids content assuming complete hydrolysis and polycondensation of the alkoxysilanes, and their proportions.

[0207] <Determination of Transmission Spectroscopy and Thickness of Light Absorption Film>

[0208] For the light-absorbing films in the filters of Examples 1-6 and Comparative Example 1, the transmission spectra at an incident angle of 0° were measured using a UV-Vis-NIR spectrophotometer V-670 manufactured by Nippon Spectrophotometer Co., Ltd. The thickness of the light-absorbing film in each filter was measured using a laser displacement meter LK-H008 manufactured by Keyence Co., Ltd. In each example and Comparative Example 1, the thickness of the light-absorbing film in the filter having the frame α-1 was used as a representative for measurement. The transmission spectra of the filters of Examples 1-6 and Comparative Example 1 are shown below. Figures 6-12 Furthermore, the transmission characteristics observed from these transmission spectra are shown in Table 4. Additionally, the thickness of the light-absorbing film in each filter is shown in Table 4.

[0209] <Thermal Cycling Test>

[0210] For the filters of Examples 1-6 and Comparative Example 1, five samples were selected according to the type of frame. A thermal cycling test of 144 cycles was performed on the selected five samples. Each cycle included a period of 30 minutes at 85°C and 30 minutes at -40°C, with a heating and cooling time of 5 minutes per cycle. The thermal cycling test was conducted using a TSA-103ES thermal shock testing machine manufactured by ESPEC. Among the five samples, a sample with only one crack or peel was rated "B", a sample with two or more cracks or peels was rated "C", and a sample with no cracks or peels was rated "A". The results are shown in Table 6.

[0211] Young's modulus and hardness

[0212] The surface hardness of the light-absorbing film of each filter was measured using the Nano Indenter XP manufactured by MTS Systems, employing a nanoindentation method (continuous rigidity measurement method). A diamond triangular pyramid indenter was used as the indenter, and measurements were performed at room temperature (approximately 23°C) and in atmospheric conditions. The average hardness of each filter surface was determined by averaging the hardness values ​​within an indentation depth range of 5–10 μm in the hardness-indentation depth graph obtained from this measurement. Similarly, the average Young's modulus of each light-absorbing film was determined by averaging the Young's modulus values ​​within an indentation depth range of 5–10 μm in the Young's modulus-indentation depth graph obtained from this measurement. It should be noted that, considering the main component of the light-absorbing film is silicone resin, the Poisson's ratio of the light-absorbing film was determined to be 0.4. The results are shown in Table 4.

[0213] <Glass transition point>

[0214] For the light-absorbing film of Example 1, dynamic viscoelasticity (DMA) was measured by forced vibration stretching. This measurement was performed using a Rheovibron DDV-01FP manufactured by ORIENTEC under the following conditions.

[0215] Test method: Forced vibration tensile method (temperature scan)

[0216] Measurement temperature: -40℃~95℃

[0217] Heating rate: 2℃ / minute

[0218] Vibration frequency: 1Hz

[0219] Chuck spacing: 30mm

[0220] Added vibration amplitude: 10μm

[0221] Preload: 4.9mN

[0222] Based on the DMA results, the temperature dependence of the storage modulus E' and loss modulus E'" of the light-absorbing film of Example 1 was determined. The results are shown below. Figure 13 The temperature at which the storage modulus E' decreases is 50.8°C, which represents the temperature at which the hardness begins to decrease. The loss modulus E' represents the energy loss caused by the micro-Brownian motion accompanying the transfer, and its peak temperature is 55.4°C. From these results, it can be seen that the glass transition point of the light-absorbing film of Example 1 is in the range of 50–60°C. It is understood that having a glass transition point in such a temperature range is effective because when the filter is exposed to high temperatures or subjected to thermal cycling, the increased flexibility associated with the change in the state of the light-absorbing film can prevent the film from cracking due to thermal expansion or contraction. The glass transition point of the light-absorbing film is preferably in the range of room temperature to 80°C, more preferably in the range of 35°C to 70°C, and even more preferably in the range of 40°C to 60°C.

[0223] As shown in Table 4, the average Young's modulus of the light-absorbing films in the filters of Examples 1-6 ranged from 0.56 GPa to 2.0 GPa. On the other hand, the average Young's modulus of the light-absorbing film in the filter of Comparative Example 1 was 2.6 GPa. These results suggest that the light-absorbing films of the filters of Examples 1-6 possess the desired flexibility, but the light-absorbing film of the filter of Comparative Example 1 exhibits poor flexibility. Based on the comparison between Examples 1-6 and Comparative Example 1, it can be understood that by adding specific alkoxysilanes to the light-absorbing composition, the desired flexibility can be readily imparted. For example, as the amount of DMDES added increases, the flexibility of the light-absorbing film is easily improved. The amount of DMDES added, converted to solid components by mass, is preferably 10% or more of the total solid components of the alkoxysilanes. It can be understood that by increasing the proportion in the range of 10% to 24%, the flexibility of the light-absorbing film can be improved. On the other hand, in the light-absorbing film of each filter, the amount of TEOS added, converted to solid content by weight, is approximately 20% of the total solid content of alkoxysilane. TEOS imparts strength to the light-absorbing film; however, increasing the proportion of TEOS in the light-absorbing film can sometimes lead to cracking or breakage during or after the film's fabrication. Therefore, the amount of TEOS added, converted to solid content by weight, is preferably 50% or less, more preferably 35% or less of the total solid content of alkoxysilane. Increasing the amount of phosphate ester added, which is a component other than the silane monomer, can also improve flexibility. The phosphate ester content in the light-absorbing film of the filters of Examples 5 and 6 is higher than that in the light-absorbing film of the filters of Examples 1-4. This is understandably one reason for the decrease in the Young's modulus of the light-absorbing film.

[0224] As shown in Table 6, peeling or cracking of the light-absorbing film was confirmed in some samples. The filters of Examples 1-6 showed good results in the thermal cycling test. On the other hand, the filter of Comparative Example 1 exhibited problems such as peeling or cracking of the light-absorbing film in the thermal cycling test. The light-absorbing composition for the light-absorbing film of the filters of Examples 1-6 contains DMDES with two organic functional groups bonded to one silicon atom, therefore it is presumed that the thermal expansion coefficient of this light-absorbing film is relatively large. However, it is believed that due to its flexibility in resisting strain based on the difference between the thermal expansion coefficient of the frame and the thermal expansion coefficient of the light-absorbing film, it showed good results in the thermal cycling test. On the other hand, although Comparative Example 1 is presumed to have a higher Young's modulus and greater rigidity, its durability against strain caused by temperature changes is considered insufficient.

[0225] It is believed that by making the thermal expansion coefficient of the frame close to that of the light-absorbing film, the cracking and peeling of the light-absorbing film can be prevented. However, it is known that when the periphery of the light-absorbing film is completely fixed to the frame, it is necessary to adjust the properties of the light-absorbing film, rather than adjusting the difference between the thermal expansion coefficients of the frame and the light-absorbing film. This is suggested by the fact that in thermal cycling tests using filters with three frames having different expansion coefficients, the type of frame had almost no effect on the test results.

[0226] Based on the results from the filters described in the embodiments, it is understood that controlling the average Young's modulus of the light-absorbing film within the range of 0.56 GPa to 2.0 GPa is particularly effective in achieving high tolerance to temperature changes. Furthermore, it is understood that using an average linear expansion coefficient of 4.7 × 10⁻⁶ for temperatures ranging from 0°C to 60°C is also beneficial. -5 ~12.5×10 -5 The frame formed by the material [ / ℃] is particularly important in obtaining filters that are highly resistant to temperature changes.

[0227]

[0228]

[0229]

[0230]

[0231]

[0232] [Table 6]

[0233] frame Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example 1 α-1 A A A A A A C α-2 A A A A A A C α-3 A A A A A A C β-1 A A A A A A C β-2 A A A A A A C β-3 A A A A A A B γ-1 A A A A A A C γ-2 A A A A A A C γ-3 A A A A A A C

Claims

1. A filter comprising: A frame with through holes, and A light-absorbing film containing a light-absorbing compound is configured to seal the through-holes. The average Young's modulus of the light-absorbing film, as determined by the continuous rigidity measurement method, is below 2.5 GPa. The light-absorbing film is integrally formed with the frame by curing a light-absorbing composition supplied to the through-hole within the through-hole.

2. The filter as claimed in claim 1, wherein, The material constituting the frame has an average coefficient of linear expansion of 0.2 × 10⁻⁶ at temperatures ranging from 0°C to 60°C. -5 [℃]~25×10 -5 [ / ℃].

3. The filter as claimed in claim 1, wherein, The frame has a first surface that is in contact with the through hole and is formed along a surface parallel to the main surface of the light-absorbing film.

4. The filter as claimed in claim 1, wherein, The light-absorbing film has a thickness smaller than the size of the frame in the thickness direction of the light-absorbing film.

5. The filter as claimed in claim 1, wherein, The light-absorbing film has a first main surface formed in the thickness direction of the light-absorbing film between one end and the other end of the frame.

6. The filter as claimed in claim 1, wherein, The light-absorbing film has a second main surface formed in such a way that it is coplanar with one end of the frame in the thickness direction of the light-absorbing film.

7. The filter as claimed in claim 1, wherein, The frame includes at least one of a protrusion and a recess inside.

8. The filter as claimed in claim 7, wherein, The light-absorbing film is in contact with at least a portion of the protrusion or at least a portion of the concave portion in the thickness direction of the light-absorbing film.

9. The filter as claimed in claim 7, wherein, The light-absorbing film is in contact with at least two of the surfaces inside the through hole that form the protrusion or the recess.

10. The filter as claimed in claim 1, wherein, The frame is a flat plate with a first end face and a second end face as its main surfaces, and has a through hole extending through the thickness of the frame. The frame includes a protrusion that projects inward toward the interior of the through hole. The protrusion includes a first surface that is substantially parallel to either the first end face or the second end face. The light-absorbing film has a first main surface and a second main surface. The second main surface is flatly connected to either the first end surface or the second end surface. When the length in the thickness direction of the frame between the first end face and the second end face, which are flatly connected to the second main surface of the light-absorbing film, and the first surface is defined as t2, the ratio of the thickness of the light-absorbing film to t2 is greater than 1 and less than 2.

11. The filter as claimed in claim 1, wherein, The light-absorbing film has a transmission spectrum that satisfies the following conditions (I), (II), (III), (IV), (V), (VI) and (VII). (I) There is a first cutoff wavelength in the wavelength range of 380 nm to 440 nm that shows 50% transmittance; (II) A second cutoff wavelength with 50% transmittance exists in the wavelength range of 600 nm to 720 nm; (III) The maximum transmittance in the wavelength range of 300nm to 350nm is less than 1%; (IV) The average transmittance within the wavelength range of 450nm to 600nm is over 75%; (V) The maximum transmittance in the wavelength range of 750nm to 1000nm is less than 5%; (VI) The maximum transmittance in the wavelength range of 800nm ​​to 950nm is less than 4%; (VII) The transmittance at a wavelength of 1100 nm is less than 20%.

12. The filter as claimed in claim 1, wherein, The light-absorbing film has a thickness of 1 μm to 1000 μm.

13. A camera device comprising: Camera components; A lens that allows light from the subject to pass through and converge onto the imaging element; and The filter according to any one of claims 1 to 12.

14. A method for manufacturing a filter, comprising: Provide substrate; The frame with through holes is fixed to the substrate; A light-absorbing composition containing a light-absorbing compound is supplied in such a manner as to seal the through hole; The light-absorbing composition is cured to form a light-absorbing film while the through-hole of the frame is sealed; and The light-absorbing film and the frame are peeled off from the substrate to obtain the filter. The average value of the Young's modulus of the light-absorbing film, as determined by the continuous rigidity measurement method, is below 2.5 GPa.

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