Bokeh filter membrane, imaging optical lens assembly, imaging apparatus and electronic device

Abstract

This disclosure provides a bokeh filter film disposed on a surface of a substrate and comprising a gradient thickness absorption film and an anti-reflective film. The anti-reflective film includes a high- and low-refractive-index film and a gradient-refractive-index film. The light transmittance of the substrate at its center is greater than that at its periphery. The gradient-refractive-index film has a plurality of pores, with the pores farther from the substrate being relatively larger than those closer to the substrate. The main material of the gradient-refractive-index film is a metal oxide. This helps to control the amount of light entering at the periphery to achieve a soft-edged effect for out-of-focus scenes.

Description

Bokeh filter film, imaging optical lens, imaging device and electronic device The present disclosure relates to an imaging optical lens, an imaging device, and an electronic device, and more particularly to an imaging optical lens, an imaging device, and an electronic device having a bokeh filter film to reduce reflected light. In recent years, the use of micro-optical lenses in mobile devices for photography has become increasingly popular. While the pursuit of large aperture lenses provides a brighter and clearer photography experience, the shallower depth of field leads to greater defocusing of the scene. This fails to address the problem of bilinear aberration caused by out-of-focus images, easily resulting in clear and excessive overlapping light spots, causing interference, making it difficult to highlight the subject and reducing image quality. Conventional technology uses a light-absorbing metal film coated on the surface of optical lenses or optical elements to soften peripheral bokeh and eliminate stray light. Although this can improve optical imaging quality, it is still not enough to eliminate the problem of high reflection in some areas. The bokeh filter film, imaging optical lens, imaging device, and electronic device disclosed herein utilize a multi-layer coating design, in which a gradient-thickness absorption film capable of absorbing visible light is added to the multi-layer coating. By distributing the gradient-thickness absorption film in a concentric circular pattern with varying film thicknesses at different locations on the substrate, the transmittance gradually decreases from the center to the periphery of the substrate. This helps control the amount of light entering the periphery to achieve a soft-edge effect for out-of-focus scenes, creating a greater contrast between the subject and the soft bokeh, making the subject stand out more clearly. According to one embodiment of the present disclosure, a bokeh filter film is provided. The bokeh filter film is disposed on a surface of a substrate and includes a gradient thickness absorption film and an anti-reflection film. The anti-reflection film includes a high- and low-refractive-index film and a gradient refractive-index film. The light transmittance at the center of the substrate is greater than the light transmittance at the periphery. The high- and low-refractive-index films include a first high- and low-refractive-index film and a second high- and low-refractive-index film. The gradient thickness absorption film is further away from the substrate than the first high- and low-refractive-index film, the second high- and low-refractive-index film is further away from the substrate than the gradient thickness absorption film, and the gradient refractive-index film is further away from the substrate than the second high- and low-refractive-index film. The gradient refractive-index film has a plurality of pores, with the pores farther away from the substrate being larger than those closer to the substrate. The primary material of the gradient refractive-index film is a metal oxide. The thickness of the gradient refractive-index film is TNG, which satisfies the following conditions: 115.0 nm ≤ TNG ≤ 1000.0 nm. According to another embodiment of the present disclosure, an imaging optical lens is provided, comprising the bokeh filter film described above, at least one optical lens, and at least one optical element. The bokeh filter film is formed on at least one surface of the at least one optical lens and the at least one optical element. According to another embodiment of the present disclosure, an imaging device is provided, comprising the imaging optical lens described above and an electronic photosensitive element. The electronic photosensitive element is disposed on an imaging surface of the imaging optical lens. According to another embodiment of the present disclosure, an electronic device is provided, comprising the imaging device described in the preceding paragraph. According to another embodiment of the present disclosure, a bokeh filter film is provided. The bokeh filter film is disposed on a surface of a substrate, and the bokeh filter film includes a gradient thickness absorption film and an anti-reflection film. The anti-reflection film includes a high-low refractive index film and a gradient refractive index film. The transmittance of the substrate at the center is greater than the transmittance of the substrate at the periphery. The gradient thickness absorption film includes a first gradient thickness absorption film and a second gradient thickness absorption film, the second gradient thickness absorption film being further away from the substrate than the first gradient thickness absorption film, and the gradient refractive index film being further away from the substrate than the second gradient thickness absorption film. The gradient refractive index film has a plurality of holes, and the holes farther away from the substrate are relatively larger than the holes closer to the substrate. The primary material of the gradient refractive index film is metal oxide. The thickness of the first gradient-thickness absorption film at the maximum effective diameter is Tab1, the thickness of the second gradient-thickness absorption film at the maximum effective diameter is Tab2, and the total thickness of the bokeh filter film at the maximum effective diameter is TKP, which satisfies the following conditions: 0.60 ≤ Tab1 / Tab2 ≤ 1.80; and 1250.0 nm < TKP. According to another embodiment of the present disclosure, an imaging optical lens is provided, comprising the bokeh filter film as described above, at least one optical lens, and at least one optical element. The bokeh filter film is formed on at least one surface of the at least one optical lens and the at least one optical element. One embodiment of the present disclosure provides a bokeh filter film, which is disposed on a surface of a substrate and includes a gradient thickness absorption film and an anti-reflection film. The anti-reflection film includes a high-low refractive index film and a gradient refractive index film. The transmittance of the substrate at the center is greater than the transmittance of the substrate at the periphery. The high-low refractive index film includes a first high-low refractive index film and a second high-low refractive index film. The gradient thickness absorption film is farther away from the substrate than the first high-low refractive index film, the second high-low refractive index film is farther away from the substrate than the gradient thickness absorption film, and the gradient refractive index film is farther away from the substrate than the second high-low refractive index film. The gradient refractive index film has a plurality of holes, and the holes farther away from the substrate are relatively larger than the holes closer to the substrate. The main material of the gradient refractive index film is metal oxide. The present invention develops a bokeh filter film using a multi-layer coating design. This multi-layer coating incorporates a graded-thickness absorber film that absorbs visible light. By distributing the film layers in a concentric circular pattern, the thickness of the graded-thickness absorber film varies at different locations on the substrate, creating a gradual decrease in transmittance from the center to the periphery. This helps control the amount of light entering the periphery, achieving a soft edge effect for out-of-focus scenes, creating a greater contrast between the subject and the soft bokeh, making the subject stand out more clearly. Furthermore, stray light generation can be further reduced to enhance optical imaging quality. By alternating multiple high- and low-refractive-index layers, light interacts destructively on the film surfaces, reducing reflected light. Furthermore, by controlling the graded-index film's pore structure and gradient refractive index to meet minimum film thickness requirements, the film maintains an optimal pore structure and a relatively continuous refractive index variation, effectively achieving ultra-low reflectivity across all regions of the visible light spectrum. Another embodiment of the present disclosure provides a bokeh filter film, which is disposed on a surface of a substrate and includes a gradient thickness absorption film and an anti-reflection film. The anti-reflection film includes a high-low refractive index film and a gradient refractive index film. The transmittance of the substrate at the center is greater than the transmittance of the substrate at the periphery. The gradient thickness absorption film includes a first gradient thickness absorption film and a second gradient thickness absorption film, the second gradient thickness absorption film being further away from the substrate than the first gradient thickness absorption film, and the gradient refractive index film being further away from the substrate than the second gradient thickness absorption film. The gradient refractive index film has a plurality of holes, and the holes farther away from the substrate are relatively larger than the holes closer to the substrate. The main material of the gradient refractive index film is metal oxide. By adding an absorbing film capable of absorbing visible light to the multi-layer coating and adjusting the thickness of the first and second gradient-thickness absorbing films to maintain consistency, this helps balance the absorption levels of all wavelengths in the visible light range. Furthermore, by distributing the bokeh filter film's thickness in a concentric circle pattern at different locations on the substrate, the transmittance gradually decreases from the center to the periphery of the substrate, helping to control the amount of light entering the periphery and achieve a soft-edge effect for out-of-focus scenes. The thickness of the graded refractive index film is TNG, which satisfies the following conditions: 115.0 nm ≤ TNG ≤ 1000.0 nm. By controlling the thickness of the graded refractive index film, an optimal pore structure is maintained, effectively avoiding a reduction in anti-reflection effect due to insufficient film thickness. Alternatively, the film may satisfy the following conditions: 116.0 nm ≤ TNG ≤ 800.0 nm. Alternatively, the film may satisfy the following conditions: 116.0 nm ≤ TNG ≤ 600.0 nm. Alternatively, the film may satisfy the following conditions: 116.0 nm ≤ TNG ≤ 500.0 nm. Alternatively, the film may satisfy the following conditions: 117.0 nm ≤ TNG ≤ 500.0 nm. Alternatively, the film may satisfy the following conditions: 118.0 nm ≤ TNG ≤ 400.0 nm. Alternatively, the film may satisfy the following conditions: 118.0 nm ≤ TNG ≤ 350.0 nm. The first graded-thickness absorption film has a thickness of Tab1 at its maximum effective diameter, and the second graded-thickness absorption film has a thickness of Tab2 at its maximum effective diameter. These films may satisfy the following condition: 0.60 ≤ Tab1 / Tab2 ≤ 1.80. By adjusting the thicknesses of the first and second graded-thickness absorption films to maintain consistency, this helps balance the absorption levels across all wavelengths in the visible light range. Alternatively, these films may satisfy the following condition: 0.70 ≤ Tab1 / Tab2 ≤ 1.60. Alternatively, these films may satisfy the following condition: 0.80 ≤ Tab1 / Tab2 ≤ 1.40. Alternatively, these films may satisfy the following condition: 0.85 ≤ Tab1 / Tab2 ≤ 1.30. Alternatively, these films may satisfy the following condition: 0.90 ≤ Tab1 / Tab2 ≤ 1.20. Alternatively, these films may satisfy the following condition: 0.95 ≤ Tab1 / Tab2 ≤ 1.10. The total film thickness of the bokeh filter at its maximum effective diameter is TKP, which can meet the following conditions: 1250.0 nm < TKP. This maintains the integrity of the film layer at the periphery, helping to control the amount of low-beam light at the periphery to achieve low penetration. Alternatively, it can meet the following conditions: 1260.0 nm ≤ TKP ≤ 5000.0 nm. Alternatively, it can meet the following conditions: 1265.0 nm ≤ TKP ≤ 3000.0 nm. Alternatively, it can meet the following conditions: 1270.0 nm ≤ TKP ≤ 2500.0 nm. Alternatively, it can meet the following conditions: 1275.0 nm ≤ TKP ≤ 2000.0 nm. Alternatively, it can meet the following conditions: 1280.0 nm ≤ TKP ≤ 1600.0 nm. The graded-thickness absorbing film may include a first graded-thickness absorbing film and a second graded-thickness absorbing film. The second graded-thickness absorbing film may be further away from the substrate than the first graded-thickness absorbing film. The refractive index of the first graded-thickness absorbing film is Nab1, and the refractive index of the second graded-thickness absorbing film is Nab2, which may satisfy the following condition: Nab1 > Nab2. Adjusting the refractive index configuration of the graded-thickness absorbing film layers helps reduce reflected light. The first high-low refractive index film may include an adjacent film layer. The adjacent film layer may be the film layer closest to the first graded-thickness absorbing film within the first high-low refractive index film. The refractive index of the first graded-thickness absorbing film is Nab1, and the refractive index of the adjacent film layer is Narn. The conditions may be satisfied: 1.32 ≤ Nab1 / Narn ≤ 2.00. Maintaining the refractive index difference between the graded-thickness absorbing film and the adjacent film layer helps reduce reflected light through destructive interference between the film layers. Alternatively, the conditions may be satisfied: 1.32 ≤ Nab1 / Narn ≤ 1.90. Alternatively, the conditions may be satisfied: 1.34 ≤ Nab1 / Narn ≤ 1.85. Alternatively, the conditions may be satisfied: 1.35 ≤ Nab1 / Narn ≤ 1.80. Alternatively, the conditions may be satisfied: 1.36 ≤ Nab1 / Narn ≤ 1.75. Alternatively, it may satisfy the following condition: 1.38 ≤ Nab1 / Narn ≤ 1.70. The total thickness of the first high- and low-refractive-index films is Tar1, which can satisfy the following conditions: 105.0 nm ≤ Tar1 ≤ 200.0 nm. By controlling the first high- and low-refractive-index films to a specific thickness, reflected light can more easily generate destructive interference on the surfaces of the intervening film layers, thereby enhancing the anti-reflection effect. Alternatively, the thickness can satisfy the following conditions: 110.0 nm ≤ Tar1 ≤ 180.0 nm. Alternatively, the thickness can satisfy the following conditions: 112.0 nm ≤ Tar1 ≤ 170.0 nm. Alternatively, the thickness can satisfy the following conditions: 115.0 nm ≤ Tar1 ≤ 160.0 nm. Alternatively, the thickness can satisfy the following conditions: 118.0 nm ≤ Tar1 ≤ 155.0 nm. Alternatively, the thickness can satisfy the following conditions: 120.0 nm ≤ Tar1 ≤ 150.0 nm. The total thickness of the second high- and low-refractive-index films is Tar2, which can satisfy the following conditions: 38.0 nm ≤ Tar2 ≤ 150.0 nm. By controlling the thickness of the second high- and low-refractive-index films to a specific value, reflected light is more likely to undergo destructive interference on the surfaces of the intervening film layers, thereby enhancing the anti-reflection effect. Alternatively, the thickness can satisfy the following conditions: 38.5 nm ≤ Tar2 ≤ 130.0 nm. Alternatively, the thickness can satisfy the following conditions: 38.8 nm ≤ Tar2 ≤ 110.0 nm. Alternatively, the thickness can satisfy the following conditions: 39.0 nm ≤ Tar2 ≤ 90.0 nm. Alternatively, the thickness can satisfy the following conditions: 39.2 nm ≤ Tar2 ≤ 70.0 nm. Alternatively, the thickness can satisfy the following conditions: 39.5 nm ≤ Tar2 ≤ 50.0 nm. At the center of the substrate, the average reflectivity of the bokeh filter film at wavelengths between 400 nm and 700 nm is R4070-c, which can meet the following conditions: 0% ≤ R4070-c ≤ 3.00%. This effectively controls the reflection of wide-band light at the center, helping to improve image quality at the center. Alternatively, the bokeh filter film can meet the following conditions: 0% ≤ R4070-c ≤ 2.00%. Alternatively, the bokeh filter film can meet the following conditions: 0% ≤ R4070-c ≤ 1.50%. Alternatively, the bokeh filter film can meet the following conditions: 0% ≤ R4070-c ≤ 1.00%. Alternatively, the bokeh filter film can meet the following conditions: 0% ≤ R4070-c ≤ 0.50%. Alternatively, the bokeh filter film can meet the following conditions: 0.01% ≤ R4070-c ≤ 0.40%. At the substrate's maximum effective diameter, the average reflectivity of the bokeh filter coating at wavelengths between 400 nm and 700 nm is R4070-p, which can meet the following conditions: 0% ≤ R4070-p ≤ 3.00%. This effectively controls the reflection of broad-band light at the maximum effective diameter, helping to reduce peripheral stray light. Alternatively, the bokeh filter coating can meet the following conditions: 0% ≤ R4070-p ≤ 2.00%. Alternatively, the bokeh filter coating can meet the following conditions: 0% ≤ R4070-p ≤ 1.50%. Alternatively, the bokeh filter coating can meet the following conditions: 0% ≤ R4070-p ≤ 1.00%. Alternatively, the bokeh filter coating can meet the following conditions: 0% ≤ R4070-p ≤ 0.50%. Alternatively, the bokeh filter coating can meet the following conditions: 0.01% ≤ R4070-p ≤ 0.30%. When the total thickness of the graded-thickness absorber film is 40 nm to 60 nm, the average reflectivity of the bokeh filter film at wavelengths between 400 nm and 500 nm is R4050-5, which can meet the following conditions: 0% ≤ R4050-5 ≤ 0.70%. This helps reduce short-wavelength reflections in the area located at half the maximum effective diameter by maintaining the low reflectivity of the graded-thickness absorber film within the thinner thickness range. Alternatively, the bokeh filter film can meet the following conditions: 0% ≤ R4050-5 ≤ 0.65%. Alternatively, the bokeh filter film can meet the following conditions: 0% ≤ R4050-5 ≤ 0.62%. Alternatively, the bokeh filter film can meet the following conditions: 0% ≤ R4050-5 ≤ 0.60%. Alternatively, the bokeh filter film can meet the following conditions: 0% ≤ R4050-5 ≤ 0.58%. Alternatively, it may satisfy the following conditions: 0.01% ≤ R4050-5 ≤ 0.55%. When the total thickness of the graded-thickness absorber film is 85 nm to 115 nm, the average reflectivity of the bokeh filter film at wavelengths of 450 nm to 550 nm is R4555-10, which can meet the following conditions: 0% ≤ R4555-10 ≤ 0.82%. By maintaining the low reflectivity of the graded-thickness absorber film within a specific thickness range, it helps reduce short-wavelength reflected light from the periphery. Alternatively, it can meet the following conditions: 0% ≤ R4555-10 ≤ 0.75%. Alternatively, it can meet the following conditions: 0% ≤ R4555-10 ≤ 0.72%. Alternatively, it can meet the following conditions: 0% ≤ R4555-10 ≤ 0.65%. Alternatively, it can meet the following conditions: 0% ≤ R4555-10 ≤ 0.62%. Alternatively, it may satisfy the following conditions: 0.01% ≤ R4555-10 ≤ 0.60%. When the total thickness of the graded-thickness absorber film is 180 nm to 220 nm, the average reflectivity of the bokeh filter film at wavelengths between 550 nm and 700 nm is R5570-20, which can meet the following conditions: 0% ≤ R5570-20 ≤ 1.10%. This helps reduce long-wavelength reflected light from the periphery by maintaining the low reflectivity of the graded-thickness absorber film within the thicker thickness range. Alternatively, the bokeh filter film can meet the following conditions: 0% ≤ R5570-20 ≤ 1.05%. Alternatively, the bokeh filter film can meet the following conditions: 0.10% ≤ R5570-20 ≤ 1.05%. Alternatively, the bokeh filter film can meet the following conditions: 0.10% ≤ R5570-20 ≤ 1.00%. Alternatively, the bokeh filter film can meet the following conditions: 0.15% ≤ R5570-20 ≤ 0.98%. Alternatively, it may satisfy the following conditions: 0.20% ≤ R5570-20 ≤ 0.98%. When the total thickness of the graded-thickness absorber film is 450 nm to 550 nm, the average reflectivity of the bokeh filter film at wavelengths of 400 nm to 700 nm is R4070-50, which can meet the following conditions: 0% ≤ R4070-50 ≤ 1.00%. This helps reduce stray light generated at the periphery by maintaining low reflection at the periphery. Alternatively, the bokeh filter film can meet the following conditions: 0% ≤ R4070-50 ≤ 0.90%. Alternatively, the bokeh filter film can meet the following conditions: 0% ≤ R4070-50 ≤ 0.75%. Alternatively, the bokeh filter film can meet the following conditions: 0% ≤ R4070-50 ≤ 0.60%. Alternatively, the bokeh filter film can meet the following conditions: 0% ≤ R4070-50 ≤ 0.50%. Alternatively, the bokeh filter film can meet the following conditions: 0.01% ≤ R4070-50 ≤ 0.35%. At the maximum effective diameter of the substrate, the average transmittance of the bokeh filter film at wavelengths between 400 nm and 700 nm is T4070-p, which may meet the following conditions: T4070-p ≤ 3.00%. Maintaining a lower transmittance at the maximum effective diameter helps reduce edge sharpness, creating a soft-edge effect. Alternatively, the bokeh filter film may meet the following conditions: 0% ≤ T4070-p ≤ 2.50%. Alternatively, the bokeh filter film may meet the following conditions: 0% ≤ T4070-p ≤ 2.00%. Alternatively, the bokeh filter film may meet the following conditions: 0.10% ≤ T4070-p ≤ 1.50%. Alternatively, the bokeh filter film may meet the following conditions: 0.30% ≤ T4070-p ≤ 1.20%. Alternatively, the bokeh filter film may meet the following conditions: 0.50% ≤ T4070-p ≤ 1.00%. At the maximum effective diameter of the substrate, the average transmittance of the bokeh filter film at wavelengths of 400 nm to 700 nm is T4070-p; at the center of the substrate, the average transmittance of the bokeh filter film at wavelengths of 400 nm to 700 nm is T4070-c; when the total film thickness of the graded thickness absorber film is 40 nm to 60 nm, the average transmittance of the bokeh filter film at wavelengths of 400 nm to 700 nm is T4070-5; when the total film thickness of the graded thickness absorber film is 180 nm to 220 nm, the average transmittance of the bokeh filter film at wavelengths of 400 nm to 700 nm is T4070-20, which can meet the following conditions: 100 × (T4070-p / T4070-c) ≤ 3.00; T4070-5 / T4070-c ≤ 1.20; and T4070-20 / T4070-c ≤ 0.80. By designing a configuration where the transmittance gradually decreases from the center to the periphery of the substrate, a more natural gradient dimming effect can be created. Alternatively, the following conditions can be met: 0 ≤ 100 × (T4070-p / T4070-c) ≤ 2.50; 0 ≤ T4070-5 / T4070-c ≤ 1.10; and 0 ≤ T4070-20 / T4070-c ≤ 0.70. Alternatively, the following conditions can be met: 0 ≤ 100 × (T4070-p / T4070-c) ≤ 2.00; 0.10 ≤ T4070-5 / T4070-c ≤ 1.05; and 0.01 ≤ T4070-20 / T4070-c ≤ 0.65. Alternatively, it may satisfy the following conditions: 0.10 ≤ 100 × (T4070-p / T4070-c) ≤ 1.50; 0.20 ≤ T4070-5 / T4070-c ≤ 1.00; and 0.10 ≤ T4070-20 / T4070-c ≤ 0.60. Alternatively, it may satisfy the following conditions: 0.30 ≤ 100 × (T4070-p / T4070-c) ≤ 1.20; 0.30 ≤ T4070-5 / T4070-c ≤ 0.95; and 0.20 ≤ T4070-20 / T4070-c ≤ 0.55. Alternatively, it may satisfy the following conditions: 0.50 ≤ 100 × (T4070-p / T4070-c) ≤ 1.00; 0.40 ≤ T4070-5 / T4070-c ≤ 0.90; and 0.30 ≤ T4070-20 / T4070-c ≤ 0.50. The various technical features of the bokeh filter film disclosed above can be configured in combination to achieve corresponding effects. Another embodiment of the present disclosure provides an imaging optical lens, comprising the bokeh filter film described above, at least one optical lens, and at least one optical element. The bokeh filter film is formed on at least one surface of the at least one optical lens and at least one optical element. The imaging optical lens according to the present disclosure may further include an aperture, wherein an optical element is located on the object side or image side of the aperture, and at least one surface of the optical element is coated with a bokeh filter. Thus, by coating the optical element with a bokeh filter and placing it within the imaging optical lens, the need for photographic accessories can be reduced. According to the imaging optical lens disclosed herein, the at least one optical element comprises a first optical element and a second optical element. The first optical element is located on the object side of the aperture, and the second optical element is located on the image side of the aperture. At least one surface of the first optical element and at least one surface of the second optical element are coated with a bokeh filter. By placing optical elements on both the object and image sides of the aperture and coating the surfaces with bokeh filters, a soft-edge effect is achieved at all edges of the bokeh image. In the imaging optical lens disclosed herein, the distance on the optical axis between the surface of the first optical element with the bokeh filter coating and the aperture is equal to the distance on the optical axis between the aperture and the surface of the second optical element with the bokeh filter coating. This arrangement, with the bokeh filter coating surfaces of both optical elements at the same distance from the aperture, helps maintain a consistent glare reduction effect on peripheral light across all fields of view. The imaging optical lens according to the present disclosure may further include an aperture, wherein at least one surface of the optical element has a bokeh filter coating, and the at least one surface is positioned at the aperture. Thus, by placing the optical element with the bokeh filter coating at the aperture, it helps achieve an optimal soft-edge effect for light of varying incident angles. The imaging optical lens according to the present disclosure may further include an aperture, wherein the optical lens is located on the object side or the image side of the aperture, and at least one surface of the optical lens is coated with a bokeh filter. Thus, by coating the bokeh filter on the surface of the optical lens and disposing it within the imaging optical lens, the overall volume of the imaging optical lens can be reduced. According to the imaging optical lens disclosed herein, the at least one optical lens comprises a first optical lens and a second optical lens. The first optical lens is located on the object side of the aperture, and the second optical lens is located on the image side of the aperture. At least one surface of the first optical lens and at least one surface of the second optical lens are coated with a bokeh filter. Thus, by coating the bokeh filter on the optical lens surfaces on the object and image sides of the aperture, a soft-edge effect is achieved at all edges of the bokeh image. In the imaging optical lens disclosed herein, the distance on the optical axis between the surface of the first optical lens with the bokeh filter coating and the aperture is equal to the distance on the optical axis between the aperture and the surface of the second optical lens with the bokeh filter coating. This arrangement, with the bokeh filter coating surfaces of both optical lenses at the same distance from the aperture, helps maintain a consistent glare reduction effect on peripheral light across all fields of view. The various technical features of the imaging optical lens disclosed above can be combined and configured to achieve corresponding effects. The substrate described in the present disclosure can be an optical lens or an optical element. The optical element can be a filter, cover glass, a light path deflection element, a diffraction element (such as a Fresnel lens), a shading element, an annular spacer, a lens barrel element, or a microlens disposed on a photosensitive element. The filter element can include blue glass, an IR cut filter, an absorptive color filter, a bandpass interference filter, or an optical low-pass filter. The flat glass can include a protective lens at the object side of an imaging optical lens, a glass sheet around a photosensitive element substrate, or a glass sheet used to protect a photosensitive element. The light path deflection element can include a prism or a reflector. The shading element, the annular spacer, and the lens barrel element can be provided with a flat plate of glass or plastic material in the optical effective diameter area, and an anti-reflection film can be provided on at least one surface of the flat plate. The material of the absorption film described in the present disclosure may be selected from at least one of the following materials, including: aluminum, gold, silver, chromium, nickel, copper, iron, zinc, tin, aluminum oxide, calcium oxide, chromium oxide, indium oxide, magnesium oxide, nickel oxide, lead oxide, tin oxide, titanium oxide, niobium oxide, tantalum oxide, zirconium oxide, molybdenum oxide, rubidium oxide, thorium oxide, sulfide or phosphide; or selected from at least one of the following ions, including: manganese ion, chromium ion, vanadium ion, copper ion, cobalt ion, nickel ion, iron ion, tungsten ion or molybdenum ion. All of the above materials may include multiple different oxidation states, wherein the first graded thickness absorption film may include a film layer composed of tantalum oxide, and the second graded thickness absorption film may include a film layer composed of titanium oxide. The absorber film described in the present disclosure can be any of the following three designs, including a gradient thickness absorber film, a gradient concentration absorber film, and a color-changing absorber film. In the gradient thickness absorber film, the film thickness of the gradient thickness absorber film can be configured to vary at different locations on the substrate in a concentric circle distribution with the center as the center. The film thickness of the gradient thickness absorber film at the periphery is designed to be greater than the film thickness of the gradient thickness absorber film at the center. The film thickness of the gradient thickness absorber film can be further designed to change from the center to the periphery of the substrate using a linear function, a polynomial function, an exponential function, or a logarithmic function. Alternatively, the area from the center to the periphery can be divided into multiple regions, and the film thickness variation in each region can be represented by any of the above functions, resulting in a transmittance that gradually decreases from the center to the periphery of the substrate. In the gradient concentration absorption film, the thickness of the film layer of the gradient concentration absorption film at the center and the periphery can be relatively uniform, and it contains at least one material of the absorption film. The content ratio of the absorption film material gradually increases from the center to the periphery of the substrate, and the absorption film material is evenly distributed everywhere. The gradient concentration absorption film can be further designed so that the change in the content ratio of the absorption material from the center to the periphery of the substrate can be a linear function, a polynomial function, an exponential function or a logarithmic function, or the center to the periphery can be divided into multiple regions, and the content ratio change of each region can be represented by any of the above functions, so that the transmittance gradually decreases from the center to the periphery of the substrate. In the color-changing absorption film, the color-changing absorption film can be an electrochromic composite film, which can contain at least one material of the absorption film or an organic matter, which can be further selected from inorganic transition metal oxides, and can include: tungsten trioxide (WO 3) Nickel oxide (NiO) or titanium dioxide (TiO 2) The color-shifting absorber film undergoes a reversible electrochemical reaction through an applied electric field. Ions are forced into or out of the material's crystal structure by the applied electric field, causing the film to change color and absorb visible and infrared light, thereby altering the bokeh filter's transmittance. The range of total thickness of the gradient thickness absorption film described in the present disclosure, as well as the average reflectivity and average transmittance within the wavelength range, can be changed according to design requirements and are not limited to the definition of the conditions. The object side of the imaging optical lens described in this disclosure is the side where light enters the imaging optical lens, and the image side is the side where light is imaged onto the imaging surface. The optical axis refers to an axisymmetric optical system, including at least two rotationally symmetric reflective or refractive surfaces, shared by the lens. The center refers to a relatively narrow region near the optical axis that contains the optical axis. The periphery refers to a region within the optical effective diameter that is not at the center. The bokeh filter described in this disclosure is positioned within an imaging optical lens. The imaging optical lens may include a first bokeh filter, a second bokeh filter, and an aperture. The first and second bokeh filters are disposed on separate substrates, with the first filter positioned on the object side of the aperture and the second filter positioned on the image side. The distance on the optical axis from the aperture to the first bokeh filter is SDE1, and the distance on the optical axis from the aperture to the second bokeh filter is SDE2, satisfying the following condition: 0.5 < |SDE1 / SDE2| < 2.0. The thickness of the first and second bokeh filters can be adjusted from the center to the periphery based on the difference in distance between the first and second bokeh filters and the aperture, the change in substrate curvature from the center to the maximum effective diameter, and the difference in incident light angle. The relative positional relationship of each film layer described in the present disclosure is based on the relative relationship in the direction perpendicular to the tangent line of the substrate surface when the layers are at the same position. The transmittance described in the present disclosure may be Gaussian in distribution from the center to the periphery, which can be further represented by the equation: Tm = exp(-αx 2 ), where Tm is the transmittance, α is a constant, and x is the vertical distance between a point on the substrate surface curve and the optical axis. The refractive index and extinction coefficient described in this disclosure are all based on a wavelength of 555 nm. The reflectivity described in this disclosure is measured using a single lens, and the reflectivity is based on data at an incident angle of 0 degrees as a comparison benchmark. The main material mentioned in the present disclosure may mean that the material accounts for at least 50% of the total weight. The surface pore-forming process described herein can effectively improve surface pore distribution, increasing surface pore spacing, creating a sponge-like structure, or varying pore density. The pore-forming effect can also vary with depth, such as larger pores on the outer side exposed to air and smaller pores on the deeper inner side. These pores are composed of spaces between irregular nanofiber structures, allowing air to entrap or connect between them. In cross-sectional and schematic diagrams, the outer side represents the side exposed to air, while the inner side represents the side closer to the substrate. Clearly, the pores / gaps on the outer side are larger than those on the inner side. This can also be explained by the sparser distribution of the irregular branched structures on the outer side and the denser distribution of the irregular branched structures on the inner side within the same plane. The process can be achieved using plasma etching, chemical reaction etching, time-controlled crystallization techniques, or high-temperature solution treatment, such as immersion in alcohol or water at temperatures above 50°C. The gradient refractive index film described in the present disclosure can be subjected to a surface pore forming process from the outside to the inside of the gradient refractive index film, forming a design in which the refractive index gradually changes from the outside to the inside, which helps to reduce the reflected light generated by the excessive difference in refractive index between the film layers. The film thickness of the gradient refractive index film can be measured by selecting at least the first three highest vertices in the cross-sectional view and measuring the height of the vertices in the direction perpendicular to the tangent line of the inner film surface, and calculating the average value. The main material of the gradient refractive index film is a metal oxide, which can be aluminum oxide, or aluminum nitride (AlN), aluminum hydroxide (Al(OH) 3) or aluminum-containing mixtures. The high- and low-refractive-index films described in this disclosure may include a high- and low-refractive-index films, wherein the refractive index of the high- and low-refractive-index films is greater than 2.0 and the refractive index of the low- and high-refractive-index films is less than 1.8. The high- and low-refractive-index film coating materials (the values ​​in brackets are the refractive indices at a wavelength of 587.6 nm) may be: MgF 2(1.3777), SiO 2(1.4585),Al 2O 3(1.7682), HfO 2(1.8935), ZnO (1.9269), Sc 2O 3(1.9872), AlN (2.0294), Si 3N 4(2.0381), Ta 2O 5(2.1306), ZrO 2(2.1588), ZnS (2.2719), Nb 2O 5(2.3403), TiO 2 (2.6142) or TiN (3.1307), the refractive index stated is based on a wavelength of 587.6 nm and applies only to this paragraph. The first coating layer close to the substrate surface described in this disclosure may be made of TiO 2. AlN, Al 2O 3. Al(OH) 3 or an aluminum-containing mixture, or zinc oxide, magnesium oxide; or a mixture of at least one of the above aluminum oxide, zinc oxide, and magnesium oxide and other metal oxides. It has a dense structure and can enhance the adhesion between the material and the substrate surface to prevent the coating from falling off, thereby achieving the effect of protecting the substrate surface during the coating process and effectively enhancing the environmental weather resistance of the substrate. The anti-reflective coatings described herein are based on the principle of constructive interference. For typical lens surface coatings, single or multi-layer thin films can be deposited on plastic substrates using physical vapor deposition (PVD), such as evaporation or sputtering, or chemical vapor deposition (CVD), such as ultra-high vacuum CVD, microwave plasma-assisted CVD, plasma-enhanced CVD, or atomic layer deposition (ALD). Using ALD to create these coatings offers optimal value, striking a balance between cost and quality. When applied to lens materials with the most appropriate refractive index, these coatings can achieve the best anti-reflective effect. The full field of view described in this disclosure is the range from the central field of view (0 Field) to the maximum image height field of view (1.0 Field), and the full field of view covers the optically effective area of ​​the lens surface. The tangent slope of the lens surface described in this disclosure is calculated with the optical axis as the horizontal direction. The tangent slope is infinite (INF, ∞) near the optical axis. The correction lenses described in this disclosure, especially plastic lenses, can cause large surface shape errors due to thickness and high temperatures. The greater the number of coating layers, the more significant the effect of temperature on surface accuracy. Lens correction technology effectively solves the temperature effect problem during plastic surface coating, helping to maintain the integrity of the lens coating and the high precision of the plastic lens, which is a key technology for achieving high-quality imaging optical lenses. The lens correction techniques described in this reveal are not limited to such as applied mold flow (Moldflow) analysis methods, curve fitting function methods or wavefront error methods. Among them, the modulo flow analysis method finds the stereoscopic profile node of the lens surface shrinkage in the Z-axis by modulo flow analysis, converts it into an aspherical curve and then compares the difference with the original curve, while considering the material shrinkage rate and face shape deformation trend calculation to obtain the correction value. Among them, the curve fitting function method resorts to measuring the surface profile error of the element. Functions such as Exponential or Polynomial, algorithms such as Gauss Newton, Simplex Algorithm or Steepest Descent Method. The wavefront error method uses an interferometer to measure the wavefront error (imaging error) data of the optical system, comprehensively analyze the wavefront error generated by manufacturing assembly with the original design value wavefront error, and then obtain the correction value by optical software optimization. The imaging optical lens provided in this reveal can be designed as a miniature lens and can be applied in many ways in electronic devices such as mobile products, digital tablets, three-dimensional (3D) image capture, digital cameras, smart TVs, network surveillance equipment, body sensing game consoles, driving recorders, reversing development devices, wearable products or aerial cameras. Another embodiment of the present disclosure provides an imaging device comprising an imaging optical lens as described in the preceding paragraph as well as an electronic sensor. The electronic sensor is disposed on an imaging plane of the imaging optical lens. The imaging device is a camera module comprising an imaging optical lens, a driving device group, and an electronic sensor, wherein the camera module comprises the imaging optical lens of the present content and a lens barrel bearing the imaging optical lens. The imaging device utilizes an imaging optical lens to focus and photograph the subject and cooperates with the driving device group for image focusing, and finally images on the electronic sensor and outputs the image data. The imaging device may be a wide-angle imaging device, an ultra-wide-angle imaging device, a telescopic imaging device (which may contain an optical path turning element) or a TOF module (Time-Of-Flight; flight time rangefinder module), but is not limited to this configuration. In addition, the connection relationship between the imaging device and other members may be adaptively adjusted according to the type of the imaging device and will not be drawn and detailed herein. The imaging device can be equipped with an electronic photosensitive element (such as a CMOS or CCD) with high sensitivity and low noise, which is placed on the imaging surface of the imaging optical lens to truly present the excellent imaging quality of the imaging optical lens. In addition, the imaging device can also include an image stabilization module, which can be a kinetic energy sensing element such as an accelerometer, gyroscope, or Hall Effect Sensor, but is not limited to these. By adjusting the changes in different axes of the imaging optical lens to compensate for the blurred image caused by shaking at the moment of shooting, the imaging quality of dynamic and low-light scenes is further improved, and advanced image compensation functions such as optical image stabilization (OIS) and electronic image stabilization (EIS) are provided. The imaging device can capture images corresponding to a non-circular opening on the outer side of the electronic device. The drive assembly can be an autofocus module, using a drive system such as a voice coil motor, micro-electromechanical system, piezoelectric system, or memory metal. The drive assembly allows the imaging optical lens to achieve an optimal imaging position, providing clear images of the subject at various object distances. Another embodiment of the present disclosure provides an electronic device comprising the imaging device described in the preceding paragraph. This improves imaging quality. Preferably, the aforementioned electronic device further comprises a control unit, a display unit, a storage unit, a temporary storage unit, or a combination thereof. The present disclosure provides an electronic device, which is a mobile device, and includes the aforementioned imaging device. The electronic device is a smartphone, comprising an imaging device, a flash module, a focus assist module, an image signal processor (ISP), a user interface, and an image software processor. The imaging device may be a front-facing lens or a rear-facing lens. When a user photographs a subject through the user interface, the electronic device uses the imaging device to focus light, activates the flash module for fill light, and uses the subject distance information provided by the focus assist module for rapid focus. The image signal processor and the image software processor then perform image optimization processing to further enhance the image quality produced by the imaging lens. The focus assist module may utilize an infrared or laser focus assist system to achieve rapid focus. The user interface may utilize a touch screen or a physical capture button, in conjunction with the diverse functions of the image processing software for image capture and image processing. According to the above-mentioned embodiments, specific embodiments are presented below and described in detail with reference to the drawings. <First Comparative Example> The bokeh filter film of the first comparative example is disposed on a surface of a substrate. The bokeh filter film comprises a gradient thickness absorption film and an anti-reflection film. The gradient thickness absorption film comprises a first gradient thickness absorption film and a second gradient thickness absorption film, while the anti-reflection film comprises a high-low refractive index film and a gradient refractive index film. The high-low refractive index film comprises a first high-low refractive index film and a second high-low refractive index film. The first high-low refractive index film comprises an adjacent film layer, which is the film layer of the first high-low refractive index film closest to the first gradient thickness absorption film. The details of each layer of the bokeh filter film of the first comparative example are shown in Table 1A. Please refer to Table 1B, which shows the parameters of different film layers of the bokeh filter film of the first comparative example, wherein TNG is the film thickness of the gradient refractive index film, Nab1 is the refractive index of the first gradient thickness absorption film, Nab2 is the refractive index of the second gradient thickness absorption film, Narn is the refractive index of the adjacent film layer, Tab1 is the film thickness of the first gradient thickness absorption film at the maximum effective diameter, Tab2 is the film thickness of the second gradient thickness absorption film at the maximum effective diameter, Tar1 is the total film thickness of the first high- and low-refractive index films, Tar2 is the total film thickness of the second high- and low-refractive index films, and TKP is the total film thickness of the bokeh filter film at the maximum effective diameter. Please refer to Table 1C, which shows the parameters of the bokeh filter film of the first comparative example, wherein R4070-c is the average reflectivity of the bokeh filter film at the center of the substrate at a wavelength of 400 nm to 700 nm; R4050-5 is the average reflectivity of the bokeh filter film at a wavelength of 400 nm to 500 nm when the total thickness of the graded thickness absorption film is 40 nm to 60 nm; R4555-10 is the average reflectivity of the bokeh filter film at a wavelength of 450 nm to 550 nm when the total thickness of the graded thickness absorption film is 85 nm to 115 nm; R5570-20 is the average reflectivity of the bokeh filter film at a wavelength of 550 nm to 700 nm when the total thickness of the graded thickness absorption film is 180 nm to 220 nm; R4070-50 is the average reflectivity of the bokeh filter film at a wavelength of 400 nm to 550 nm when the total thickness of the graded thickness absorption film is 450 nm to 550 nm. R4070-p is the average reflectivity of the bokeh filter film at wavelengths of 400 nm to 700 nm at the maximum effective diameter of the substrate. If the definitions of the data in the tables of the following embodiments are the same as those in Tables 1A to 1C, they will not be repeated here. <First embodiment> The bokeh filter film of the first embodiment is disposed on a surface of a substrate. The bokeh filter film comprises a gradient thickness absorption film and an anti-reflection film. The gradient thickness absorption film comprises a first gradient thickness absorption film and a second gradient thickness absorption film, while the anti-reflection film comprises a high-low refractive index film and a gradient refractive index film. The high-low refractive index film comprises a first high-low refractive index film and a second high-low refractive index film. The first high-low refractive index film comprises an adjacent film layer, which is the film layer of the first high-low refractive index film closest to the first gradient thickness absorption film. The details of each layer of the bokeh filter film of the first embodiment are shown in Table 2A, wherein ab1 represents that the film layer is composed of tantalum oxide, and ab2 represents that the film layer is composed of titanium oxide. Please refer to Table 2B again, which shows the values ​​of TNG, Nab1, Nab2, Nab1 / Narn, Tab1 / Tab2, Tar1, Tar2 and TKP of the first embodiment. Please refer to Table 2C again, which shows the values ​​of R4070-c, R4050-5, R4555-10, R5570-20, R4070-50, and R4070-p of the bokeh filter film of the first embodiment. Please refer to FIG. 1 and Table 2D simultaneously. FIG. 1 illustrates the relationship between the reflectivity and wavelength of the bokeh filter film according to the first embodiment of the present disclosure when the gradient-thickness absorber film has different total film thicknesses. Table 2D shows the reflectivity values ​​of the bokeh filter film according to the first embodiment at wavelengths of 400 nm to 700 nm when the gradient-thickness absorber film has different total film thicknesses. Please refer to Table 2E, which shows the parameters of the bokeh filter film of the first embodiment, where T4070-p is the average transmittance of the bokeh filter film at wavelengths of 400 nm to 700 nm at the maximum effective diameter of the substrate; T4070-c is the average transmittance of the bokeh filter film at wavelengths of 400 nm to 700 nm at the center of the substrate; T4070-5 is the average transmittance of the bokeh filter film at wavelengths of 400 nm to 700 nm when the total thickness of the graded-thickness absorber film is 40 nm to 60 nm; and T4070-20 is the average transmittance of the bokeh filter film at wavelengths of 400 nm to 700 nm when the total thickness of the graded-thickness absorber film is 180 nm to 220 nm. Please refer to FIG. 2 and Table 2F simultaneously. FIG. 2 illustrates the relationship between transmittance and wavelength for the bokeh filter film according to the first embodiment of the present disclosure when the gradient-thickness absorber film has different total film thicknesses. Table 2F presents the transmittance values ​​of the bokeh filter film according to the first embodiment at wavelengths of 400 nm to 700 nm when the gradient-thickness absorber film has different total film thicknesses. <Second embodiment> The bokeh filter film of the second embodiment is disposed on a surface of a substrate. The bokeh filter film comprises a gradient thickness absorption film and an anti-reflection film. The gradient thickness absorption film comprises a first gradient thickness absorption film and a second gradient thickness absorption film, while the anti-reflection film comprises a high-low refractive index film and a gradient refractive index film. The high-low refractive index film comprises a first high-low refractive index film and a second high-low refractive index film. The first high-low refractive index film comprises an adjacent film layer, which is the film layer of the first high-low refractive index film closest to the first gradient thickness absorption film. The details of each layer of the bokeh filter film of the second embodiment are shown in Table 3A, wherein ab1 represents that the film layer is composed of tantalum oxide, and ab2 represents that the film layer is composed of titanium oxide. Please refer to Table 3B again, which shows the values ​​of TNG, Nab1, Nab2, Nab1 / Narn, Tab1 / Tab2, Tar1, Tar2 and TKP of the second embodiment. Please refer to Table 3C again, which shows the values ​​of R4070-c, R4050-5, R4555-10, R5570-20, R4070-50, and R4070-p of the bokeh filter film of the second embodiment. Please refer to Table 3D, which shows the reflectivity values ​​of the bokeh filter film of the second embodiment at wavelengths of 400 nm to 700 nm when the gradient thickness absorption film has different total film thicknesses. <Third embodiment> The bokeh filter film of the third embodiment is disposed on a surface of a substrate. The bokeh filter film comprises a gradient thickness absorption film and an anti-reflection film. The gradient thickness absorption film comprises a first gradient thickness absorption film and a second gradient thickness absorption film, while the anti-reflection film comprises a high-low refractive index film and a gradient refractive index film. The high-low refractive index film comprises a first high-low refractive index film and a second high-low refractive index film. The first high-low refractive index film comprises an adjacent film layer, which is the film layer of the first high-low refractive index film closest to the first gradient thickness absorption film. The details of each layer of the bokeh filter film of the third embodiment are shown in Table 4A, wherein ab1 represents that the film layer is composed of tantalum oxide, and ab2 represents that the film layer is composed of titanium oxide. Please refer to Table 4B again, which shows the values ​​of TNG, Nab1, Nab2, Nab1 / Narn, Tab1 / Tab2, Tar1, Tar2 and TKP of the third embodiment. Please refer to Table 4C, which shows the values ​​of R4070-c, R4050-5, R4555-10, R5570-20, R4070-50, and R4070-p of the bokeh filter film of the third embodiment. Please refer to Table 4D, which shows the reflectivity values ​​of the bokeh filter film of the third embodiment at wavelengths of 400 nm to 700 nm when the gradient thickness absorption film has different total film thicknesses. <Fourth embodiment> A bokeh filter film of the fourth embodiment is disposed on a surface of a substrate. The bokeh filter film comprises a gradient thickness absorption film and an anti-reflection film. The gradient thickness absorption film comprises a first gradient thickness absorption film and a second gradient thickness absorption film, while the anti-reflection film comprises a high-low refractive index film and a gradient refractive index film. The high-low refractive index film comprises a first high-low refractive index film and a second high-low refractive index film. The first high-low refractive index film comprises an adjacent film layer, which is the film layer of the first high-low refractive index film closest to the first gradient thickness absorption film. The details of each layer of the bokeh filter film of the fourth embodiment are shown in Table 5A, wherein ab1 represents that the film layer is composed of tantalum oxide, and ab2 represents that the film layer is composed of titanium oxide. Please refer to Table 5B again, which shows the values ​​of TNG, Nab1, Nab2, Nab1 / Narn, Tab1 / Tab2, Tar1, Tar2 and TKP of the fourth embodiment. Please refer to Table 5C again, which shows the values ​​of R4070-c, R4050-5, R4555-10, R5570-20, R4070-50, and R4070-p of the bokeh filter film of the fourth embodiment. Please refer to Table 5D, which shows the reflectivity values ​​of the bokeh filter film of the fourth embodiment at wavelengths of 400 nm to 700 nm when the gradient thickness absorption film has different total film thicknesses. <Fifth embodiment> The fifth embodiment of the bokeh filter film is disposed on a surface of a substrate. The bokeh filter film comprises a gradient thickness absorption film and an anti-reflection film. The gradient thickness absorption film comprises a first gradient thickness absorption film and a second gradient thickness absorption film, while the anti-reflection film comprises a high-low refractive index film and a gradient refractive index film. The high-low refractive index film comprises a first high-low refractive index film and a second high-low refractive index film. The first high-low refractive index film comprises an adjacent film layer, which is the film layer of the first high-low refractive index film closest to the first gradient thickness absorption film. The details of each layer of the bokeh filter film of the fifth embodiment are shown in Table 6A, wherein ab1 represents that the film layer is composed of tantalum oxide, and ab2 represents that the film layer is composed of titanium oxide. Please refer to Table 6B again, which shows the values ​​of TNG, Nab1, Nab2, Nab1 / Narn, Tab1 / Tab2, Tar1, Tar2 and TKP of the fifth embodiment. Please refer to Table 6C again, which shows the values ​​of R4070-c, R4050-5, R4555-10, R5570-20, R4070-50, and R4070-p of the bokeh filter film of the fifth embodiment. Please refer to Table 6D, which shows the reflectivity values ​​of the bokeh filter film of the fifth embodiment at wavelengths of 400 nm to 700 nm when the gradient thickness absorption film has different total film thicknesses. <Sixth embodiment> The sixth embodiment of a bokeh filter film is disposed on a surface of a substrate. The bokeh filter film comprises a gradient thickness absorption film and an anti-reflection film. The gradient thickness absorption film comprises a first gradient thickness absorption film and a second gradient thickness absorption film, while the anti-reflection film comprises a high-low refractive index film and a gradient refractive index film. The high-low refractive index film comprises a first high-low refractive index film and a second high-low refractive index film. The first high-low refractive index film comprises an adjacent film layer, which is the film layer of the first high-low refractive index film closest to the first gradient thickness absorption film. The details of each layer of the bokeh filter film of the sixth embodiment are shown in Table 7A, wherein ab1 represents that the film layer is composed of tantalum oxide, and ab2 represents that the film layer is composed of titanium oxide. Please refer to Table 7B again, which shows the values ​​of TNG, Nab1, Nab2, Nab1 / Narn, Tab1 / Tab2, Tar1, Tar2 and TKP of the sixth embodiment. Please refer to Table 7C again, which shows the values ​​of R4070-c, R4050-5, R4555-10, R5570-20, R4070-50, and R4070-p of the bokeh filter film of the sixth embodiment. Please refer to Table 7D, which shows the reflectivity values ​​of the bokeh filter film of the sixth embodiment at wavelengths of 400 nm to 700 nm when the gradient thickness absorption film has different total film thicknesses. <Seventh embodiment> The seventh embodiment of a bokeh filter film is disposed on a surface of a substrate. The bokeh filter film comprises a gradient thickness absorption film and an anti-reflection film. The gradient thickness absorption film comprises a first gradient thickness absorption film and a second gradient thickness absorption film, while the anti-reflection film comprises a high-low refractive index film and a gradient refractive index film. The high-low refractive index film comprises a first high-low refractive index film and a second high-low refractive index film. The first high-low refractive index film comprises an adjacent film layer, which is the film layer of the first high-low refractive index film closest to the first gradient thickness absorption film. The details of each layer of the bokeh filter film of the seventh embodiment are shown in Table 8A, wherein ab1 represents that the film layer is composed of tantalum oxide, and ab2 represents that the film layer is composed of titanium oxide. Please refer to Table 8B again, which shows the values ​​of TNG, Nab1, Nab2, Nab1 / Narn, Tab1 / Tab2, Tar1, Tar2 and TKP of the seventh embodiment. Please refer to Table 8C, which shows the values ​​of R4070-c, R4050-5, R4555-10, R5570-20, R4070-50, and R4070-p of the bokeh filter film of the seventh embodiment. Please refer to Table 8D, which shows the reflectivity values ​​of the bokeh filter film of the seventh embodiment at wavelengths of 400 nm to 700 nm when the gradient thickness absorption film has different total film thicknesses. <Eighth embodiment> The eighth embodiment of the bokeh filter film is disposed on a surface of a substrate. The bokeh filter film comprises a gradient thickness absorption film and an anti-reflection film. The gradient thickness absorption film comprises a first gradient thickness absorption film and a second gradient thickness absorption film, while the anti-reflection film comprises a high-low refractive index film and a gradient refractive index film. The high-low refractive index film comprises a first high-low refractive index film and a second high-low refractive index film. The first high-low refractive index film comprises an adjacent film layer, which is the film layer of the first high-low refractive index film closest to the first gradient thickness absorption film. Please refer to Table 9A for details of each layer of the bokeh filter film of the eighth embodiment, wherein ab1 represents that the film layer is composed of tantalum oxide, and ab2 represents that the film layer is composed of titanium oxide. Please refer to Table 9B again, which shows the values ​​of TNG, Nab1, Nab2, Nab1 / Narn, Tab1 / Tab2, Tar1, Tar2 and TKP of the eighth embodiment. Please refer to Table 9C, which shows the values ​​of R4070-c, R4050-5, R4555-10, R5570-20, R4070-50, and R4070-p of the bokeh filter film of the eighth embodiment. Please refer to Table 9D, which shows the reflectivity values ​​of the bokeh filter film of the eighth embodiment at wavelengths of 400 nm to 700 nm when the gradient thickness absorption film has different total film thicknesses. Ninth embodiment The ninth embodiment of the bokeh filter film is disposed on a surface of a substrate. The bokeh filter film comprises a gradient thickness absorption film and an anti-reflection film. The gradient thickness absorption film comprises a first gradient thickness absorption film and a second gradient thickness absorption film, while the anti-reflection film comprises a high-low refractive index film and a gradient refractive index film. The high-low refractive index film comprises a first high-low refractive index film and a second high-low refractive index film. The first high-low refractive index film comprises an adjacent film layer, which is the film layer of the first high-low refractive index film closest to the first gradient thickness absorption film. The details of each layer of the bokeh filter film of the ninth embodiment are shown in Table 10A, wherein ab1 represents that the film layer is composed of tantalum oxide, and ab2 represents that the film layer is composed of titanium oxide. Please refer to Table 10B again, which shows the values ​​of TNG, Nab1, Nab2, Nab1 / Narn, Tab1 / Tab2, Tar1, Tar2 and TKP of the ninth embodiment. Please refer to Table 10C again, which shows the values ​​of R4070-c, R4050-5, R4555-10, R5570-20, R4070-50, and R4070-p of the bokeh filter film of the ninth embodiment. Please refer to Table 10D, which shows the reflectivity values ​​of the bokeh filter film of the ninth embodiment at wavelengths of 400 nm to 700 nm when the gradient thickness absorption film has different total film thicknesses. <Tenth embodiment> The tenth embodiment of a bokeh filter film is disposed on a surface of a substrate. The bokeh filter film comprises a gradient thickness absorption film and an anti-reflection film. The gradient thickness absorption film comprises a first gradient thickness absorption film and a second gradient thickness absorption film, while the anti-reflection film comprises a high-low refractive index film and a gradient refractive index film. The high-low refractive index film comprises a first high-low refractive index film and a second high-low refractive index film. The first high-low refractive index film comprises an adjacent film layer, which is the film layer of the first high-low refractive index film closest to the first gradient thickness absorption film. The details of each layer of the bokeh filter film of the tenth embodiment are shown in Table 11A, wherein ab1 represents that the film layer is composed of tantalum oxide, and ab2 represents that the film layer is composed of titanium oxide. Please refer to Table 11B again, which shows the values ​​of TNG, Nab1, Nab2, Nab1 / Narn, Tab1 / Tab2, Tar1, Tar2, and TKP of the tenth embodiment. Please refer to Table 11C again, which shows the values ​​of R4070-c, R4050-5, R4555-10, R5570-20, R4070-50, and R4070-p of the bokeh filter film of the tenth embodiment. Please refer to Table 11D, which shows the reflectivity values ​​of the bokeh filter film of the tenth embodiment at wavelengths of 400 nm to 700 nm when the gradient thickness absorption film has different total film thicknesses. <Eleventh Example> Please refer to FIG. 3 , which is a schematic diagram illustrating an imaging optical lens 1 according to an eleventh embodiment of the present disclosure. The imaging optical lens 1 includes, from the object side to the image side of the optical path, a first optical lens E1, a second optical lens E2, a third optical lens E3, an aperture ST, a first filter E6, a fourth optical lens E4, a fifth optical lens E5, a second filter E7, and an imaging surface IMG. The electronic photosensitive element IS is disposed on the imaging surface IMG of the imaging optical lens 1. The first optical lens E1, the second optical lens E2, the third optical lens E3, the fourth optical lens E4, and the fifth optical lens E5 each have an object-side surface and an image-side surface. The aperture ST is located between the third optical lens E3 and the fourth optical lens E4. The first filter element E6 is located between the aperture ST and the fourth optical lens E4. The object-side surface of the first filter element E6 includes a bokeh filter film C1. The bokeh filter film C1 can be the bokeh filter film described in the first to tenth embodiments, and the structure and details thereof are identical and are not further described herein. <Twelfth embodiment> Please refer to FIG. 4 , which is a schematic diagram illustrating an imaging optical lens 2 according to a twelfth embodiment of the present disclosure. The imaging optical lens 2 includes, from the object side to the image side of the optical path, a first optical lens E1, a second optical lens E2, a third optical lens E3, a first filter E6, an aperture ST, a second filter E7, a fourth optical lens E4, a fifth optical lens E5, a third filter E8, and an imaging surface IMG. The electronic photosensitive element IS is disposed on the imaging surface IMG of the imaging optical lens 2. The first optical lens E1, the second optical lens E2, the third optical lens E3, the fourth optical lens E4, and the fifth optical lens E5 each have an object-side surface and an image-side surface. The aperture ST is located between the third optical lens E3 and the fourth optical lens E4. The image-side surface of the first filter element E6 includes a bokeh filter film C1, and the object-side surface of the second filter element E7 includes a bokeh filter film C2. The distance on the optical axis between the image-side surface of the first filter element E6 and the aperture ST is the same as the distance on the optical axis between the aperture ST and the object-side surface of the second filter element E7. The bokeh filter films C1 and C2 can be the bokeh filter films described in the first to tenth embodiments above, and their structures and details are identical and will not be further described here. <Thirteenth embodiment> Please refer to FIG5 , which is a schematic diagram illustrating an imaging optical lens 3 according to a thirteenth embodiment of the present disclosure. The imaging optical lens 3 includes, from the object side to the image side of the optical path, a first optical lens E1, a second optical lens E2, a third optical lens E3, an aperture ST, a first filter E6, a fourth optical lens E4, a fifth optical lens E5, a second filter E7, and an imaging surface IMG. The electronic photosensitive element IS is disposed on the imaging surface IMG of the imaging optical lens 3. The first optical lens E1, the second optical lens E2, the third optical lens E3, the fourth optical lens E4, and the fifth optical lens E5 each have an object-side surface and an image-side surface. The aperture ST is located between the third optical lens E3 and the fourth optical lens E4. The object-side surface of the first filter element E6 includes a bokeh filter film C1, and this surface and the aperture ST are located at the same position on the optical axis. The bokeh filter film C1 can be the bokeh filter film described in the first to tenth embodiments above, and the structure and details are identical and will not be further described here. <Fourteenth embodiment> Please refer to FIG6 , which is a schematic diagram illustrating an imaging optical lens system 4 according to a fourteenth embodiment of the present disclosure. The imaging optical lens system 4 includes, from the object side to the image side of the optical path, a first optical lens E1, a second optical lens E2, a third optical lens E3, an aperture ST, a fourth optical lens E4, a fifth optical lens E5, a first filter element E6, and an imaging surface IMG. The electronic photosensitive element IS is disposed on the imaging surface IMG of the imaging optical lens system 4. The first optical lens E1, the second optical lens E2, the third optical lens E3, the fourth optical lens E4, and the fifth optical lens E5 each have an object-side surface and an image-side surface, with an aperture ST located between the third optical lens E3 and the fourth optical lens E4. The image-side surface of the third optical lens E3 includes a bokeh filter C1, and the object-side surface of the fourth optical lens E4 includes a bokeh filter C2. The bokeh filter C1 and the bokeh filter C2 can be the same as those described in the first to tenth embodiments above, and their structures and details are not further described here. <Fifteenth embodiment> Please refer to FIG7 , which is a schematic diagram illustrating an electronic device 100 according to a fifteenth embodiment of the present disclosure. The electronic device 100 of the fifteenth embodiment is a smart phone, and includes imaging devices 110 , 120 , 130 and a flash module 101 . The imaging devices 110, 120, and 130 in the electronic device 100 of the fifteenth embodiment may all include the imaging optical lenses of the present disclosure, and may all be the same as or have similar structures to the imaging optical lenses 1, 2, 3, and 4 in the aforementioned eleventh to fourteenth embodiments, and are not further described herein. Specifically, the imaging device 110 may be an ultra-wide-angle imaging device, the imaging device 120 may be a wide-angle imaging device, the imaging device 130 may be a telephoto imaging device (may include an optical path turning element), or may be other types of imaging devices, and is not limited to this configuration. <Sixteenth embodiment> Please refer to FIG8 , which is a schematic diagram illustrating an electronic device 200 according to a sixteenth embodiment of the present disclosure. As shown in FIG8 , the electronic device 200 of the sixteenth embodiment is a smartphone. The electronic device 200 includes imaging devices 210 , 220 , 230 , 240 , 250 , 260 , 270 , 280 , and 290 , and a flash module 201 . The imaging devices 210, 220, 230, 240, 250, 260, 270, 280, and 290 in the electronic device 200 of the sixteenth embodiment may all include the imaging optical lenses disclosed herein, and may all be identical to or have similar structures to the imaging optical lenses 1, 2, 3, and 4 in the aforementioned eleventh to fourteenth embodiments, and are not further described herein. In detail, the imaging devices 210 and 220 can be ultra-wide-angle imaging devices, respectively; the imaging devices 230 and 240 can be wide-angle imaging devices, respectively; the imaging devices 250 and 260 can be telephoto imaging devices, respectively; the imaging devices 270 and 280 can be telephoto imaging devices (which can include optical path turning elements), respectively; the imaging device 290 can be a TOF module, or can be another type of imaging device, and is not limited to this configuration. <Seventeenth embodiment> Referring to Figures 9A and 9B, Figure 9A illustrates a schematic diagram of one side of an electronic device 300 according to a seventeenth embodiment of the present disclosure, while Figure 9B illustrates a schematic diagram of the other side of the electronic device 300 according to Figure 9A. As can be seen from Figures 9A and 9B, the electronic device 300 of the seventeenth embodiment is a smartphone and includes imaging devices 310, 320, 330, and 340, and a user interface 304. The imaging devices 310, 320, 330, and 340 in the electronic device 300 of the seventeenth embodiment may all include the imaging optical lenses disclosed herein, and may all be identical to or have similar structures to the imaging optical lenses 1, 2, 3, and 4 in the aforementioned eleventh to fourteenth embodiments, and are not further described herein. Specifically, the imaging device 310 can capture images corresponding to a non-circular opening on the outside of the electronic device, and the imaging devices 320, 330, and 340 are respectively a telephoto imaging device, a wide-angle imaging device, and an ultra-wide-angle imaging device, or can be other types of imaging devices, and are not limited to this configuration. Although the present disclosure has been disclosed above with reference to the embodiments, it is not intended to limit the present disclosure. Anyone skilled in the art may make various changes and modifications without departing from the spirit and scope of the present disclosure. Therefore, the scope of protection of the present disclosure shall be determined by the scope of the appended patent applications. 1,2,3,4: Imaging optical lens E1: First optical lens E2: Second optical lens E3: Third optical lens E4: Fourth optical lens E5: Fifth optical lens E6: First filter element E7: Second filter element E8: Third filter element ST: Aperture IMG: Imaging surface IS: Electronic photosensitive element C1, C2: Bokeh filter 100,200,300: Electronic device 110,120,130,210,220,230,240,250,260,270,280,290,310,320,330,340: Imaging device 101,2 01: Flash module 304: User interface TNG: Thickness of the gradient refractive index film TKP: Total thickness of the bokeh filter film at the maximum effective diameter Tab1: Thickness of the first gradient thickness absorption film at the maximum effective diameter Tab2: Thickness of the second gradient thickness absorption film at the maximum effective diameter Tar1: Total thickness of the first high- and low-refractive index films Tar2: Total thickness of the second high- and low-refractive index films Nab1: Refractive index of the first gradient thickness absorption film Nab2: Refractive index of the second gradient thickness absorption film Narn: Refractive index of the adjacent film layer R4070-c: At the center of the substrate, the bokeh filter film has a wavelength of 400 R4070-p: Average reflectivity of the bokeh filter film at wavelengths of 400 nm to 700 nm at the maximum effective diameter of the substrate. R4050-5: Average reflectivity of the bokeh filter film at wavelengths of 400 nm to 500 nm when the total thickness of the graded thickness absorber film is 40 nm to 60 nm. R4555-10: Average reflectivity of the bokeh filter film at wavelengths of 450 nm to 550 nm when the total thickness of the graded thickness absorber film is 85 nm to 115 nm. R5570-20: Average reflectivity of the bokeh filter film at wavelengths of 550 nm to 700 nm when the total thickness of the graded thickness absorber film is 180 nm to 220 nm. R4070-50: Average reflectivity of the bokeh filter film at wavelengths of 400 nm to 700 nm when the total thickness of the graded thickness absorber film is 450 nm to 550 nm. T4070-c: Average transmittance of the bokeh filter film at wavelengths of 400 nm to 700 nm at the center of the substrate. T4070-p: Average transmittance of the bokeh filter film at wavelengths of 400 nm to 700 nm at the maximum effective diameter of the substrate. T4070-5: Average transmittance of the bokeh filter film at wavelengths of 400 nm to 700 nm when the total thickness of the graded thickness absorber film is 40 nm to 60 nm. T4070-20: Average transmittance of the bokeh filter film at wavelengths of 400 nm to 700 nm when the total thickness of the graded thickness absorber film is 180 nm to 220 nm. To make the above and other objects, features, advantages and embodiments of the present disclosure more apparent and understandable, the accompanying drawings are described as follows: FIG1 is a diagram illustrating the relationship between the reflectivity and wavelength of a bokeh filter film according to the first embodiment of the present disclosure when its gradient thickness absorption film has different total film thicknesses; FIG2 is a diagram illustrating the relationship between the transmittance and wavelength of a bokeh filter film according to the first embodiment of the present disclosure when its gradient thickness absorption film has different total film thicknesses; FIG3 is a schematic diagram of an imaging optical lens according to the eleventh embodiment of the present disclosure; FIG4 is a schematic diagram of an imaging optical lens according to the twelfth embodiment of the present disclosure; FIG5 is a schematic diagram of an imaging optical lens according to the thirteenth embodiment of the present disclosure; FIG6 is a schematic diagram of an imaging optical lens according to the fourteenth embodiment of the present disclosure; FIG7 is a schematic diagram of an electronic device according to the fifteenth embodiment of the present disclosure; FIG8 is a schematic diagram of an electronic device according to the sixteenth embodiment of the present disclosure; FIG9A is a schematic diagram of one side of an electronic device according to the seventeenth embodiment of the present disclosure; and FIG9B is a schematic diagram of the other side of the electronic device according to FIG9A.

Claims

1. A bokeh filter film disposed on a surface of a substrate, the bokeh filter film comprising: a gradient thickness absorption film including a first gradient thickness absorption film and a second gradient thickness absorption film, the second gradient thickness absorption film being farther away from the substrate than the first gradient thickness absorption film; and an anti-reflection film including a high-low refractive index film and a gradient refractive index film; wherein, The light transmittance of the substrate with the bokeh filter film at its center is greater than that at its periphery; wherein, the high and low refractive index film comprises a first high and low refractive index film and a second high and low refractive index film, the gradient thickness absorption film is farther from the substrate than the first high and low refractive index film, the second high and low refractive index film is farther from the substrate than the gradient thickness absorption film, and the gradient refractive index film is farther from the substrate than the second high and low refractive index film; wherein, the gradient refractive index film has a plurality of pores, and the pores farther from the substrate are relatively larger than the pores closer to the substrate; wherein, the main material of the gradient refractive index film is aluminum oxide; wherein, the film thickness of the gradient refractive index film is TNG, which satisfies the following condition: 115.0 nm ≤ TNG ≤ 1000.0 nm.

2. The bokeh filter film as claimed in claim 1, wherein the thickness of the gradient refractive index film is TNG, which satisfies the following condition: 118.0 nm ≤ TNG ≤ 350.0 nm.

3. The bokeh filter film as claimed in claim 1, wherein the refractive index of the first graded thickness absorption film is Nab1 and the refractive index of the second graded thickness absorption film is Nab2, which satisfies the following condition: Nab1 > Nab2.

4. The bokeh filter film as claimed in claim 3, wherein the first high-low refractive index film includes an adjacent film layer, the adjacent film layer being the film layer closest to the first graded thickness absorption film in the first high-low refractive index film, the refractive index of the first graded thickness absorption film being Nab1, and the refractive index of the adjacent film layer being Narn, which satisfies the following condition: 1.32 ≤ Nab1 / Narn ≤ 2.

00.

5. The bokeh filter film as claimed in claim 1, wherein the gradient thickness absorption film comprises a first gradient thickness absorption film and a second gradient thickness absorption film, the second gradient thickness absorption film being farther away from the substrate than the first gradient thickness absorption film, the thickness of the first gradient thickness absorption film at its maximum effective diameter being Tab1, and the thickness of the second gradient thickness absorption film at its maximum effective diameter being Tab2, which satisfies the following condition: 0.60 ≤ Tab1 / Tab2 ≤ 1.

80.

6. The bokeh filter film as claimed in claim 5, wherein the total thickness of the first high and low refractive index film is Tar1, which satisfies the following condition: 105.0 nm ≤ Tar1 ≤ 200.0 nm.

7. The bokeh filter film as claimed in claim 5, wherein the total thickness of the second high-low refractive index film is Tar2, which satisfies the following condition: 38.0 nm ≤ Tar2 ≤ 150.0 nm.

8. The bokeh filter as claimed in claim 1, wherein at the center of the substrate, the bokeh filter has an average reflectance of R4070-c at wavelengths from 400 nm to 700 nm, which satisfies the following condition: 0% ≤ R4070-c ≤ 3.00%.

9. The bokeh filter as claimed in claim 1, wherein at the maximum effective diameter of the substrate, the average reflectance of the bokeh filter at wavelengths from 400 nm to 700 nm is R4070-p, which satisfies the following condition: 0% ≤ R4070-p ≤ 3.00%.

10. The bokeh filter as claimed in claim 1, wherein when the total thickness of the gradient thickness absorption film is 40 nm to 60 nm, the average reflectance of the bokeh filter at wavelengths of 400 nm to 500 nm is R4050-5, which satisfies the following condition: 0% ≤ R4050-5 ≤ 0.70%.

11. The bokeh filter as claimed in claim 1, wherein when the total thickness of the gradient thickness absorption film is 85 nm to 115 nm, the average reflectance of the bokeh filter at wavelengths from 450 nm to 550 nm is R4555-10, which satisfies the following condition: 0% ≤ R4555-10 ≤ 0.82%.

12. The bokeh filter as claimed in claim 1, wherein when the total thickness of the gradient thickness absorption film is 180 nm to 220 nm, the average reflectance of the bokeh filter at wavelengths from 550 nm to 700 nm is R5570-20, which satisfies the following condition: 0% ≤ R5570-20 ≤ 1.10%.

13. The bokeh filter as claimed in claim 1, wherein when the total thickness of the gradient thickness absorption film is 450 nm to 550 nm, the average reflectance of the bokeh filter at wavelengths from 400 nm to 700 nm is R4070-50, which satisfies the following condition: 0% ≤ R4070-50 ≤ 1.00%.

14. The bokeh filter as claimed in claim 1, wherein at the maximum effective diameter of the substrate, the average transmittance of the bokeh filter at wavelengths from 400 nm to 700 nm is T4070-p, which satisfies the following condition: T4070-p ≤ 3.00%.

15. A bokeh filter as claimed in claim 1, wherein at the maximum effective diameter of the substrate, the average transmittance of the bokeh filter at wavelengths from 400 nm to 700 nm is T4070-p; at the center of the substrate, the average transmittance of the bokeh filter at wavelengths from 400 nm to 700 nm is T4070-c; when the total thickness of the gradient thickness absorption film is 40 nm to 60 nm, the average transmittance of the bokeh filter at wavelengths from 400 nm to 700 nm is T4070-5; when the total thickness of the gradient thickness absorption film is 180 nm to 220 nm, the average transmittance of the bokeh filter at wavelengths from 400 nm to 700 nm is T4070-20, which satisfies the following conditions: 100 × (T4070-p / T4070-c) ≤ 3.00; T4070-5 / T4070-c ≤ 1.20; and T4070-20 / T4070-c ≤ 0.

80.

16. An imaging optical lens, comprising: a bokeh filter as described in claim 1; at least one optical lens; and at least one optical element; wherein, The at least one optical lens and the at least one surface of the at least one optical element have the bokeh filter film.

17. The imaging optical lens of claim 16 further comprises: an aperture, wherein the optical element is located on the object side or image side of the aperture, and at least one surface of the optical element has the bokeh filter.

18. The imaging optical lens of claim 17, wherein the at least one optical element comprises a first optical element and a second optical element, the first optical element being located on the object side of the aperture, the second optical element being located on the image side of the aperture, and at least one surface of the first optical element and at least one surface of the second optical element having the bokeh filter.

19. The imaging optical lens of claim 18, wherein the distance from the surface of the first optical element having the bokeh filter to the aperture on the optical axis is equal to the distance from the aperture to the surface of the second optical element having the bokeh filter on the optical axis.

20. The imaging optical lens of claim 16 further comprises: an aperture, wherein at least one surface of the optical element has the bokeh filter, and the at least one surface is disposed at the position of the aperture.

21. The imaging optical lens of claim 16 further comprises: an aperture, wherein the optical lens is located on the object side or image side of the aperture, and at least one surface of the optical lens has the bokeh filter.

22. The imaging optical lens of claim 21, wherein the at least one optical lens comprises a first optical lens and a second optical lens, the first optical lens being located on the object side of the aperture, the second optical lens being located on the image side of the aperture, and at least one surface of the first optical lens and at least one surface of the second optical lens having the bokeh filter.

23. The imaging optical lens of claim 22, wherein the distance from the surface of the first optical lens having the bokeh filter to the aperture on the optical axis is equal to the distance from the aperture to the surface of the second optical lens having the bokeh filter on the optical axis.

24. An image capturing device comprising: an imaging optical lens as described in claim 16; and an electronic photosensitive element disposed on an imaging surface of the imaging optical lens.

25. An electronic device comprising: an image capturing device as described in claim 24.

26. A bokeh filter film disposed on a surface of a substrate, the bokeh filter film comprising: a gradient thickness absorption film; and an anti-reflection film comprising a high- and low-refractive-index film and a gradient refractive-index film; wherein, The light transmittance of the substrate with the bokeh filter film at its center is greater than that at its periphery; wherein, the gradient thickness absorption film comprises a first gradient thickness absorption film and a second gradient thickness absorption film, the second gradient thickness absorption film being farther away from the substrate than the first gradient thickness absorption film, and the gradient refractive index film being farther away from the substrate than the second gradient thickness absorption film; wherein, the gradient refractive index film has a plurality of pores, and the pores farther away from the substrate are relatively larger than the pores closer to the substrate; wherein, the main material of the gradient refractive index film is a metal oxide; wherein, the film thickness of the first gradient thickness absorption film at its maximum effective diameter is Tab1, the film thickness of the second gradient thickness absorption film at its maximum effective diameter is Tab2, and the total film thickness of the bokeh filter film at its maximum effective diameter is TKP, which satisfies the following conditions: 0.60 ≤ Tab1 / Tab2 ≤ 1.80; and 1250.0 nm < TKP.

27. The bokeh filter as claimed in claim 26, wherein the thickness of the gradient refractive index film is TNG, which satisfies the following condition: 115.0 nm ≤ TNG ≤ 1000.0 nm.

28. The bokeh filter as claimed in claim 27, wherein the thickness of the gradient refractive index film is TNG, which satisfies the following condition: 118.0 nm ≤ TNG ≤ 350.0 nm.

29. The bokeh filter film as claimed in claim 26, wherein the first graded thickness absorption film has a refractive index of Nab1 and the second graded thickness absorption film has a refractive index of Nab2, which satisfy the following condition: Nab1 > Nab2.

30. The bokeh filter as claimed in claim 26, wherein when the total thickness of the gradient thickness absorption film is 40 nm to 60 nm, the average reflectance of the bokeh filter at wavelengths of 400 nm to 500 nm is R4050-5, which satisfies the following condition: 0% < R4050-5 < 0.70%.

31. The bokeh filter as claimed in claim 26, wherein when the total thickness of the gradient thickness absorption film is 85 nm to 115 nm, the average reflectance of the bokeh filter at wavelengths from 450 nm to 550 nm is R4555-10, which satisfies the following condition: 0% < R4555-10 < 0.82%.

32. The bokeh filter as claimed in claim 26, wherein when the total thickness of the gradient thickness absorption film is 180 nm to 220 nm, the average reflectance of the bokeh filter at wavelengths from 550 nm to 700 nm is R5570-20, which satisfies the following condition: 0% < R5570-20 < 1.10%.

33. The bokeh filter as claimed in claim 26, wherein when the total thickness of the gradient thickness absorption film is 450 nm to 550 nm, the average reflectance of the bokeh filter at wavelengths from 400 nm to 700 nm is R4070-50, which satisfies the following condition: 0% < R4070-50 < 1.00%.

34. An imaging optical lens, comprising: a bokeh filter as described in claim 26; at least one optical lens; and at least one optical element; wherein, The at least one optical lens and the at least one surface of the at least one optical element have the bokeh filter film.

Images