Stacked optical member and optical device

Abstract

A laminated optical member has, in order, an optical element, a low refractive index layer having a refractive index of 1.25 or less, and a light absorbing layer that absorbs light from a light source.

Description

Technical Field

[0001] This disclosure relates to a stacked optical component and an optical device. Background Technology

[0002] Super telephoto camera modules typically have a long focal length, making them ideal for capturing distant landscapes and subjects. In recent years, there has been a growing demand for super telephoto camera modules in small electronic devices such as smartphones, tablets, and wearable devices.

[0003] To achieve super telescopes, it is usually necessary to lengthen the optical path. However, in small electronic devices, it is difficult to ensure the space available for achieving a long optical path. Therefore, currently, the optical path length is lengthened by utilizing a folding optical system called a periscope lens, and miniaturization is achieved by reducing the thickness of the electronic device (for example, see Patent Document 1).

[0004] Periscope lenses use optical elements such as prisms to refract light at 90°, allowing the lens and image sensor to be configured at right angles rather than horizontally, enabling high-magnification optical zoom even in thin electronic devices such as smartphones.

[0005] However, to achieve total internal reflection within the optical element, a light-reflecting layer is required on the reflective surface of the optical element. To attach this layer, an adhesive layer is typically placed between the optical element and the reflective layer. However, because light transmits through the adhesive layer, the total reflectivity on the reflective surface of the optical element decreases.

[0006] On the other hand, it is proposed to stack the light guide plate and the reflector plate in the optical component with a low refractive index layer in between, thereby improving the light utilization efficiency (see Patent Document 2).

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: US Patent No. 11,762,174

[0010] Patent Document 2: Japanese Invention No. 7425857 Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] The purpose of this disclosure is to provide a stacked optical component that solves the aforementioned problems, can be used on a reflective surface with excellent reflectivity, and can prevent stray light.

[0013] Solution for solving the problem

[0014] This disclosure discloses a stacked optical component, characterized in that it comprises, in sequence: an optical element; a low refractive index layer having a refractive index of 1.25 or less; and a light-absorbing layer for absorbing light from a light source.

[0015] Invention Effects

[0016] According to this disclosure, a stacked optical component can be provided that solves the aforementioned problems, can be used on a reflective surface with excellent reflectivity, and can prevent stray light. Attached Figure Description

[0017] Figure 1 This is a schematic cross-sectional view illustrating an example of a stacked optical component according to a first embodiment of the present disclosure.

[0018] Figure 2A This is a schematic cross-sectional view illustrating an example of a stacked optical component according to a second embodiment of the present disclosure.

[0019] Figure 2B This is a schematic cross-sectional view illustrating another example of a stacked optical component according to a second embodiment of the present disclosure.

[0020] Figure 3 This is a schematic cross-sectional view illustrating an example of a stacked optical component according to a third embodiment of the present disclosure.

[0021] Figure 4 This is a schematic cross-sectional view showing an example of a stacked optical component according to the fourth embodiment of this disclosure.

[0022] Figure 5 This is a schematic cross-sectional view showing an example of a stacked optical component according to the fifth embodiment of this disclosure.

[0023] Figure 6 This is a schematic cross-sectional view showing an example of a stacked optical component according to the sixth embodiment of this disclosure.

[0024] Figure 7 This is a schematic cross-sectional view showing an example of a stacked optical component according to the seventh embodiment of the present disclosure.

[0025] Figure 8 This is a schematic cross-sectional view illustrating an example of an optical device according to an embodiment of the present disclosure.

[0026] Figure 9 This is a schematic diagram illustrating the method for evaluating the external reflection of the stacked optical component of Example 1.

[0027] Figure 10This is a graph showing the evaluation results of external reflection for Example 1 and Comparative Example 1. The vertical axis represents the visual reflectance Y (%), and the horizontal axis represents the angle of incidence (°).

[0028] Figure 11 This is a schematic cross-sectional view showing the layered structure of the stacked optical component in Embodiment 2.

[0029] Figure 12 This is a schematic cross-sectional view showing the layered structure of the stacked optical component in Embodiment 3.

[0030] Figure 13 This is a schematic cross-sectional view showing the layered structure of the optical component in Comparative Example 3.

[0031] Figure 14 This is a schematic diagram illustrating the method for evaluating the external reflection of the stacked optical components of Example 2.

[0032] Figure 15 This is a graph showing the evaluation results of internal reflection in Examples 2 and 3, and Comparative Examples 2 and 3. The vertical axis represents specular reflectivity (%), and the horizontal axis represents wavelength (nm). Detailed Implementation

[0033] The embodiments of this disclosure will now be described in detail. It should be noted that the embodiments are not limited to the following content and can be appropriately modified without departing from the spirit of this disclosure. Furthermore, unless otherwise stated, the "~" signifying a numerical range in this disclosure means that the values ​​described before and after it are included as a lower limit and an upper limit.

[0034] Unless otherwise explicitly stated, the dimensions, materials, shapes, and relative arrangements of the components described in the embodiments are not intended to limit the scope of this disclosure, but are merely illustrative examples. It should be noted that, for clarity, the sizes and positional relationships of the components shown in the figures are sometimes exaggerated. Furthermore, in the following description, the same names and reference numerals denote the same or similar components, and detailed descriptions are appropriately omitted. To avoid making the figures overly complex, sometimes schematic diagrams with some elements omitted are used, or end views showing only the cross-section are used as sectional views.

[0035] Furthermore, in this disclosure, the term "polygon" refers to shapes that have undergone processing such as rounding, chamfering, beveling, or arcing at the corners, including rectangles, triangles, and quadrilaterals. Moreover, shapes that have been processed in the middle portions of the sides, not limited to the corners (the ends of the sides), are also called polygons. That is to say, shapes that retain the basic characteristics of a polygon but have undergone localized processing are included in the interpretation of "polygon" as described in this disclosure.

[0036] Furthermore, this terminology is not limited to polygons; it also applies to terms describing specific shapes such as trapezoids, circles, and concave / convex shapes. Moreover, it applies when dealing with the edges that form the shape. That is, even if the corners or middle portions of an edge are modified, the interpretation of "edge" still includes the modified portion. It should be noted that when distinguishing between unmodified "polygons" or "edges" and the modified shape, the term "strict" is used, such as "strict quadrilateral."

[0037] Furthermore, in the following description, terms indicating specific directions and positions (e.g., "upper," "lower," "X," "Y," "Z," and other terms containing these terms) will be used as needed. However, the use of these terms is for the purpose of facilitating understanding of the invention with reference to the accompanying drawings and will not unduly limit the scope of the technology disclosed herein due to the meaning of these terms. For example, when referred to as "upper surface," it does not mean that the invention must always be used facing upwards. In addition, the same reference numerals appearing in multiple drawings indicate the same or equivalent parts or components.

[0038] Furthermore, in this specification or claims, when there are multiple constituent elements and they need to be described separately, sometimes "first," "second," etc., are added at the beginning of the constituent element for distinction.

[0039] (Layered optical components)

[0040] The stacked optical component of the embodiments of this disclosure sequentially comprises: an optical element; a low refractive index layer with a refractive index of 1.25 or less; and a light-absorbing layer for absorbing light from a light source. The stacked optical component of the embodiments of this disclosure may further include other layers as needed.

[0041] Other layers include, for example, adhesive layers, primer layers, and substrates. When the stacked optical component of the embodiments of this disclosure has other layers, they are arranged in a manner that does not change the stacking order of the optical element, the low-refractive-index layer, and the light-absorbing layer. For example, the other layers are arranged between the optical element and the low-refractive-index layer, and between the low-refractive-index layer and the light-absorbing layer. Therefore, when the stacked optical component of the embodiments of this disclosure has other layers, it is preferable to arrange them such that at least one side of the optical element and one side of the light-absorbing layer are exposed.

[0042] When the technology of Patent Document 2 is applied to a periscope lens, total internal reflection can be appropriately obtained inside the lens, thus enabling suitable image acquisition when applied to a camera module. However, in the configuration where the lens and low-refractive-index layer are bonded together with an adhesive layer, stray light intrusion occurs, resulting in poor image quality.

[0043] To address this problem, the stacked optical component of the present disclosure, having the above-described configuration, can be used as a reflective surface, exhibits excellent reflectivity on the reflective surface, and prevents stray light. Specifically, when the stacked optical component of the present disclosure is applied to a periscope lens such as a camera module, light incident into the lens is appropriately reflected by the low-refractive-index layer. Furthermore, stray light is appropriately absorbed by the light-absorbing layer, thus preventing stray light from intruding into the optical element.

[0044] [First Implementation Method]

[0045] Figure 1 This is a schematic cross-sectional view illustrating an example of a stacked optical component according to a first embodiment of the present disclosure. The stacked optical component 100 of the first embodiment includes: a light guide plate 10A as an optical element 10, a low refractive index layer 20, and a light-absorbing layer 30. The stacked optical component 100 has a first surface 100a and a second surface 100b. The first surface 100a is formed by one surface of the light-absorbing layer 30, and the second surface 100b is formed by one surface of the optical element. In the stacked optical component 100 of the first embodiment, the second surface 100b side may serve as a reflective surface.

[0046] The average thickness of the stacked optical component 100 is not particularly limited and can be appropriately selected according to the purpose, but it is preferably 0.3 mm to 20 mm, more preferably 0.5 mm to 15 mm, and even more preferably 0.7 mm to 10 mm.

[0047] In this disclosure, "thickness of the stacked optical component" refers to the total thickness from the outermost layer on one side to the outermost layer on the other side of the stacked optical component 100. For example, in the stacked optical component 100 of the first embodiment, the thickness of the stacked optical component 100 is the thickness from one surface of the optical element 10, namely the first surface 100a, to one surface of the light-absorbing layer 30, namely the second surface 100b. Furthermore, "average thickness of the stacked optical component" refers to the sum of the average thicknesses of all the layers of the stacked optical component 100 (total thickness).

[0048] Furthermore, in the stacked optical component 100 of the first embodiment, the total average thickness of the low refractive index layer 20 and the light absorption layer 30 is not particularly limited and can be appropriately selected according to the purpose, but it is preferably 1 μm to 500 μm, more preferably 1.1 μm to 200 μm, and even more preferably 1.2 μm to 150 μm.

[0049] <Optical Components (Light Guide Plate)>

[0050] The light guide plate 10A has: an end face 10a for light from a light source to be incident on; an exit face 10b for the incident light to exit; and a light extraction pattern 10c disposed on the side opposite to the exit face 10b. That is, the light guide plate 10A is a typical edge-light type where light is incident from the end face 10a. More specifically, the light guide plate 10A guides light from the light source incident on the end face 10a to the end face opposite to the end face 10a while undergoing internal reflection, etc., and gradually allows the light to exit from the exit face 10b during this light guiding process. The light extraction pattern 10c can facilitate reflection during light guiding.

[0051] Examples of light-extracting patterns 10c include white dots and raised or recessed shapes. The light-extracting pattern 10c can be formed, for example, by screen printing, injection molding, laser processing, or embossing.

[0052] An emission pattern is typically provided on the emission surface 10b. Examples of emission patterns include concave and convex shapes.

[0053] The material constituting the light guide plate 10A is not particularly limited as long as it can efficiently guide light emanating from the light source. It can be appropriately selected from known materials, such as (meth)acrylic resins like polymethyl methacrylate (PMMA), polycarbonate (PC) resins, polyethylene terephthalate (PET) resins, styrene resins, and glass. It should be noted that in this disclosure, "(meth)acrylic acid" refers to "acrylic acid" or "methacrylic acid".

[0054] <Low Refractive Index Layer>

[0055] In the stacked optical component 100, the low refractive index layer 20 is mainly configured to improve the reflectivity of the reflecting surface.

[0056] The refractive index of the low-refractive-index layer 20 is 1.25 or less, but preferably 1.05 or more and 1.25 or less, more preferably 1.08 or more and 1.20 or less, and even more preferably 1.10 or more and 1.18 or less. When the refractive index of the low-refractive-index layer 20 exceeds 1.25, the reflectivity on the reflective surface of the stacked optical component 100 decreases. On the other hand, when the refractive index is 1.25 or less, the reflectivity on the reflective surface of the stacked optical component 100 can be improved.

[0057] In this disclosure, unless otherwise stated, "refractive index" means the refractive index measured at a wavelength of 550 nm. In this disclosure, the refractive index is a value measured by the method described in the embodiments described later.

[0058] The low-refractive-index layer 20 preferably has internal voids. The porosity of the low-refractive-index layer 20 is not particularly limited, but is preferably 30% by volume or more and 90% by volume or less, more preferably 35% by volume or more and 90% by volume or less, further preferably 40% by volume or more and 75% by volume or less, and particularly preferably 50% by volume or more and 70% by volume or less. When the porosity of the low-refractive-index layer 20 is 30% by volume or more, a low-refractive-index layer 20 with a low refractive index can be formed. Furthermore, when the porosity of the low-refractive-index layer 20 is 90% by volume or less, a low-refractive-index layer 20 with excellent strength can be formed.

[0059] In this disclosure, the "porosity" of the low refractive index layer 20 is a value obtained by measuring the refractive index using an ellipsometer and calculating it based on the Lorentz-Lorenz formula.

[0060] In this disclosure, the size of the voids (holes) on the low refractive index layer 20 refers to the diameter of the major axis of the void (hole) and the diameter of its minor axis. The size of the voids (holes) on the low refractive index layer 20 is not particularly limited and can be appropriately selected according to the purpose, but is preferably 2 nm or more and 500 nm or less, more preferably 5 nm or more and 500 nm or less, further preferably 10 nm or more and 200 nm or less, and particularly preferably 20 nm or more and 100 nm or less.

[0061] In this disclosure, the size of the pores (voids) in the low-refractive-index layer 20 is a value quantified by the BET test method. Specifically, 0.1 g of the low-refractive-index layer 20 is introduced into the capillary of a surface area measuring device (e.g., trade name: ASAP2020, manufactured by McMurray-Tec Corporation), and then dried under reduced pressure at room temperature (25°C ± 5°C) for 24 hours to degas the gas within the pore structure. Then, by adsorbing nitrogen gas into the low-refractive-index layer 20, an adsorption isotherm is plotted to determine the pore size distribution. This allows for the evaluation of the pore size.

[0062] There is no particular limitation on the total light transmittance of the low refractive index layer 20, but it is preferably 85% to 99%, more preferably 87% to 98%, and even more preferably 89% to 97%. When the total light transmittance of the low refractive index layer 20 is 85% to 99%, excellent transparency can be ensured while maintaining the function of the low refractive index layer 20.

[0063] In this disclosure, the total light transmittance was measured according to JIS K 7136:2000 using a commercially available transmittance meter (e.g., trade name: HM-150, manufactured by Murakami Color Technology Research Institute Co., Ltd.).

[0064] There are no particular limitations on the haze of the low refractive index layer 20, but it is preferably 0.1% or more and less than 5%, more preferably 0.2% or more and less than 3%. When the haze of the low refractive index layer 20 is 0.1% or more and less than 5%, excellent transparency can be ensured while maintaining the function of the low refractive index layer 20.

[0065] In this disclosure, the "haze" of the low-refractive-index layer 20 is calculated as follows: The low-refractive-index layer 20 is cut into a size of 50mm in length and 50mm in width, and the haze is measured using a haze meter (e.g., trade name: HM-150, manufactured by Murakami Color Technology Research Institute Co., Ltd.). It should be noted that the haze value is calculated using the following formula 1.

[0066] [Equation 1]

[0067] Haze (%) = [Diffusion transmittance (%) / Total light transmittance (%)] × 100 (%)

[0068] The average thickness of the low-refractive-index layer 20 is not particularly limited and can be appropriately selected according to the purpose, but it is preferably 0.1 μm or more, more preferably 0.1 μm or more and 5 μm or less, further preferably 0.3 μm or more and 5 μm or less, and particularly preferably 0.5 μm or more and 3 μm or less. When the average thickness of the low-refractive-index layer 20 is less than 0.1 μm, the reflectivity on the reflecting surface of the stacked optical component 100 may decrease. In addition, when the average thickness of the low-refractive-index layer 20 is 5 μm or less, the stacked optical component 100 can be made thinner.

[0069] In this disclosure, "average thickness" refers to the average thickness of three points arbitrarily selected from each layer. The thickness of each layer can be measured using a known film thickness measuring device (e.g., R1-205, PEACOCK (registered trademark), manufactured by Ozaki Manufacturing Co., Ltd.).

[0070] As materials constituting the low refractive index layer 20, materials described in, for example, International Patent Publication No. 2004 / 113966, Japanese Patent Application Publication No. 2013-254183, and Japanese Patent Application Publication No. 2012-189802 may be used. These publications are incorporated herein by reference to their entirety. Specific examples of materials constituting the low refractive index layer 20 include silicon compounds, organic polymers, polymerizable monomers, and curable resins. These may be used alone or in combination of two or more. Among these, the material constituting the low refractive index layer 20 preferably contains a silicon compound.

[0071] Examples of silicon compounds include: silica-based compounds; hydrolyzable silanes and their partial hydrolysates and dehydration condensates; silicon compounds containing silanol groups; and active silica obtained by contacting silicates with acids or ion exchange resins. These can be used individually or in combination with two or more.

[0072] Examples of polymerizable monomers include (meth)acrylic acid monomers and styrene monomers.

[0073] Examples of curable resins include (meth)acrylic resins, fluorinated resins, and urethane resins.

[0074] The low refractive index layer 20 may further comprise aerogel or particles. The low refractive index layer 20 is preferably a nanoporous layer. In this disclosure, a nanoporous layer refers to a layer in which more than 90% of the micropores have a diameter of 10 nm. -1 nm~10 3 Low refractive index layer 20 in the nm range.

[0075] There are no particular restrictions on the particles used; any suitable particles can be employed. As a specific example of a particle, microporous particles selected from the group consisting of hollow microparticles and porous particles are preferred.

[0076] These microporous particles can be, for example, sol-gel beads, nanoparticles (hollow silica nanoparticles / hollow sphere nanoparticles), and nanofibers. The microporous particles preferably contain inorganic materials. Specific examples of inorganic materials include silicon (Si), magnesium (Mg), aluminum (Al), titanium (Ti), zinc (Zn), and zirconium (Zr). These can be used alone or in combination.

[0077] There are no particular limitations on the shape of the particles; examples include spherical, plate-like, needle-like, chain-like, and grape-like particles. Chain-like particles include, for example, particles consisting of multiple particles with spherical, plate-like, or needle-like shapes linked together to form a beaded structure, short fibrous particles (e.g., the short fibrous particles described in Japanese Patent Application Publication No. 2001-188104), and combinations thereof. Chain-like particles can be linear or branched. Grape-like particles include, for example, particles formed by the aggregation of multiple spherical, plate-like, and needle-like particles. The shape of the particles can be confirmed, for example, by observation using a transmission electron microscope.

[0078] The following describes an example of the specific structure of the low refractive index layer 20. In one embodiment, the low refractive index layer 20 is composed of one or more constituent units forming a microporous structure, which are chemically bonded to each other via catalysis. Examples of the shapes of the constituent units include particle-like, fibrous, rod-like, and plate-like shapes. The constituent units may have only one shape or may combine two or more shapes.

[0079] In another embodiment of the low-refractive-index layer 20, the low-refractive-index layer 20 is a porous layer in which microporous particles are chemically bonded to each other. This low-refractive-index layer 20 can be formed, for example, by chemically bonding the microporous particles to each other. In another embodiment, the microporous particles are, for example, microporous particles of a silicon compound, and the porous body is, for example, an organosilicon porous body. The microporous particles of the silicon compound include, for example, pulverized gel-like silica compounds.

[0080] Furthermore, as another embodiment of the low-refractive-index layer 20, for example, the low-refractive-index layer 20 is composed of fibrous materials such as nanofibers, which are intertwined to form voids and thus form a layer. The manufacturing method of this low-refractive-index layer 20 is not particularly limited; for example, it can be the same as a layer of porous bodies where microporous particles are chemically bonded to each other.

[0081] Furthermore, as another embodiment of the low-refractive-index layer 20, examples of low-refractive-index layer 20 include layers using hollow nanoparticles, nano-clay, and layers formed using hollow nanospheres or magnesium fluoride. The low-refractive-index layer 20 can be a layer composed of a single constituent material or a layer composed of multiple constituent materials. Furthermore, the low-refractive-index layer 20 can be composed of a single of the above-described forms or can include multiple of the above-described forms.

[0082] In the first embodiment, the porous structure of the porous body can be, for example, a continuous interconnected bubble structure. In the case of an organosilicon porous body, an interconnected bubble structure refers to a three-dimensional interconnected pore structure, or a state where the internal voids of the pore structure are continuous. The porous body has an interconnected bubble structure, thereby increasing the porosity. However, when using individual bubble particles (particles each having a pore structure) such as hollow silica, an interconnected bubble structure cannot be formed. On the other hand, when using silica sol particles (a pulverized gel-like silicon compound forming a sol), since these particles have a three-dimensional dendritic structure, an interconnected bubble structure can be easily formed by the sedimentation and accumulation of these dendritic particles in a coating film (a coating film containing a sol of pulverized gel-like silicon compounds). The low refractive index layer 20 is more preferably a monolithic structure with an interconnected bubble structure and multiple pore size distributions. A monolithic structure refers, for example, a hierarchical structure including a structure with nanoscale micropores and interconnected bubble structures formed by the aggregation of these nanoscale micropores. When forming a monolithic structure, for example, membrane strength is imparted through fine pores, and high porosity is imparted through large interconnected pores, thereby achieving a balance between membrane strength and high porosity. Preferably, this monolithic structure can be formed by controlling the pore size distribution of the generated void structure in the gel (gel-like silicon compound) before it is pulverized into silica sol particles. Furthermore, for example, when pulverizing the gel-like silicon compound, a monolithic structure can be formed by controlling the particle size distribution of the pulverized silica sol particles to the desired size.

[0083] The low-refractive-index layer 20 may contain, for example, fragments of a gel-like compound that are chemically bonded to each other. There are no particular limitations on the manner in which the fragments in the low-refractive-index layer 20 are chemically bonded to each other; for example, cross-linking, covalent bonds, and hydrogen bonds may be included.

[0084] There are no particular limitations on the types of gel-like compounds; for example, gel-like silicon compounds can be listed.

[0085] Furthermore, in the low refractive index layer 20, the silicon atoms contained therein preferably form siloxane bonds. As a specific example, the proportion of unbonded silicon atoms (i.e., residual silanols) in all the silicon atoms contained in the low refractive index layer 20 is not particularly limited, but is preferably less than 50 at%, more preferably less than 30 at%, and even more preferably less than 15 at%.

[0086] <<Methods for forming low refractive index layers>>

[0087] There are no particular limitations on the method for forming the low-refractive-index layer 20, and it can be appropriately selected according to the purpose. Hereinafter, an example of a method for forming the low-refractive-index layer 20 on one surface of the optical element 10 will be described.

[0088] The low refractive index layer 20 can be formed, for example, by a method comprising: a precursor formation step, forming a void structure as a precursor of the low refractive index layer 20 on one side of the optical element 10; and a crosslinking reaction step, after the precursor formation step, causing a crosslinking reaction to occur inside the precursor. The method for forming the low refractive index layer 20 may further include a step of preparing a coating liquid for forming a low refractive index layer containing microporous particles (hereinafter sometimes referred to as a "coating liquid for forming a low refractive index layer").

[0089] It should be noted that the following description mainly focuses on the case where the microporous particles are pulverized gel-like compounds and the low-refractive-index layer 20 is a porous body (preferably an organosilicon porous body) containing pulverized gel-like compounds. However, the low-refractive-index layer 20 can also be formed in cases where the microporous particles are not pulverized gel-like compounds.

[0090] - Process for preparing coating solution for forming low refractive index layer -

[0091] The process of preparing a coating liquid for forming a low refractive index layer is a process of producing a coating liquid for forming a low refractive index layer. There are no particular limitations on the method for manufacturing the coating liquid for forming a low refractive index layer, but it is preferable to include: a treatment to prepare a pulverized material as a raw material for microporous particles; a treatment to mature the pulverized material (hereinafter, sometimes also called "maturation treatment"); a treatment to pulverize the pulverized material (hereinafter, sometimes also called "pulverization treatment"); and a treatment to replace the hydrophilic medium with a dispersion medium (hereinafter, sometimes also called "displacement treatment"). In this way, when the solvent is replaced after the pulverized material is pulverized, the dispersibility of the microporous particles can be maintained.

[0092] --Preparation of the material to be pulverized--

[0093] As a method for preparing the pulverized material, the method described in Japanese Patent Application Publication No. 2017-25277 can be cited as an example. This publication is incorporated herein by reference to its entirety. More specifically, in the process of preparing the pulverized material, the precursor of the microporous particles, preferably a silicon compound, is gelled in a hydrophilic medium.

[0094] There are no particular limitations on the hydrophilic medium; examples include isopropanol (IPA), ethanol, methanol, butanol, acetone, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), or mixtures of these hydrophilic media with water. These can be used individually or in combination. Among these, IPA and DMSO are preferred.

[0095] --Aging process--

[0096] In the aging process, the pulverized material obtained in the preparation of the pulverized material is aged. There are no particular limitations on the method of aging the pulverized material, but it is preferable to incubate the pulverized material in a hydrophilic medium at 20°C to 50°C for more than 10 hours.

[0097] --Grinding process--

[0098] In the pulverization process, the material to be pulverized in the curing process is pulverized in a hydrophilic medium. This allows for the preparation of a sol solution in which microporous particles are dispersed in a hydrophilic medium.

[0099] There are no particular limitations on the method of pulverizing the material in a hydrophilic medium; pulverization can be carried out by any suitable method. When the material to be pulverized is a gel-like silicon compound, high-pressure medialess pulverization using a homogenizer is preferred. It should be noted that the hydrophilic medium used in the pulverization process can be a mixture of a hydrophilic medium and water.

[0100] --Replacement Process--

[0101] In the displacement treatment, the hydrophilic medium contained in the sol obtained from the pulverization process is replaced with a dispersion medium by any suitable method. This yields a coating solution for forming a low-refractive-index layer containing microporous particles and a dispersion medium.

[0102] There are no particular limitations on the solvent displacement method; examples include decantation, cross-flow filtration, and dynamic filtration. These displacement methods are preferably performed multiple times. It should be noted that the concentration of microporous particles can be adjusted to the desired range using a dispersion medium as needed.

[0103] Furthermore, when using a mixture of a hydrophilic medium and water, the mixture can be replaced with a hydrophilic medium, preferably an alcohol with 3 or fewer carbon atoms, and then the hydrophilic medium can be further replaced with a dispersion medium.

[0104] There are no particular limitations on the dispersion medium in the coating liquid for forming the low refractive index layer, and it can be appropriately selected according to the purpose, but it is preferred to include a first dispersion medium with a boiling point of less than 150°C. The boiling point of the first dispersion medium is the boiling point at 1 atmosphere.

[0105] The boiling point of the first dispersion medium is less than 150°C, but preferably 80°C or higher and less than 150°C, more preferably 80°C or higher and less than 130°C, and even more preferably 90°C or higher and less than 110°C. Specific examples of the first dispersion medium include: alcohols such as ethanol, isopropanol, butanol, tert-butanol, isobutanol, and 2-methoxyethanol (methyl cellosolve); esters such as ethyl acetate and butyl acetate; ethers such as diisopropyl ether and propylene glycol monomethyl ether; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; and aromatic hydrocarbons such as toluene. One of these can be used alone, or two or more can be used in combination. Among these, the first dispersion medium is preferably an alcohol or a ketone, more preferably isopropanol, isobutanol, or methyl ethyl ketone.

[0106] The content of the first dispersion medium in the coating liquid for forming a low refractive index layer is not particularly limited and can be appropriately selected according to the purpose. However, from the viewpoint that the viscosity of the coating liquid for forming a low refractive index layer can be stably adjusted to a suitable range for spraying, it is preferable to be 5% by mass or more and 100% by mass or less relative to the total mass of the coating liquid for forming a low refractive index layer, more preferably 30% by mass or more and 95% by mass or less, and even more preferably 40% by mass or more and 60% by mass or less.

[0107] The dispersion medium in the coating liquid for forming a low refractive index layer may consist solely of a first dispersion medium, or it may contain a second dispersion medium with a boiling point of 150°C or higher in addition to the first dispersion medium. The boiling point of the second dispersion medium is the boiling point at 1 atmosphere.

[0108] The boiling point of the second dispersion medium is above 150°C, but preferably above 150°C and below 200°C, more preferably above 155°C and below 200°C, and even more preferably above 165°C and below 190°C. Specific examples of the second dispersion medium include: dimethyl sulfoxide (DMSO); esters such as ethylene glycol monoethyl ether acetate and ethyl lactate; and ethers such as diethylene glycol ethyl methyl ether, diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol monomethyl ether, diethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol butyl methyl ether, tripropylene glycol dimethyl ether, triethylene glycol dimethyl ether, diethylene glycol monobutyl ether, ethylene glycol monophenyl ether, triethylene glycol monomethyl ether, diethylene glycol dibutyl ether, triethylene glycol butyl methyl ether, polyethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, and polyethylene glycol monomethyl ether. These can be used alone or in combination with two or more. Among these, the second dispersion medium is preferably dimethyl sulfoxide (DMSO) or diethylene glycol ethyl methyl ether.

[0109] The content of the second dispersion medium in the coating liquid for forming a low refractive index layer is not particularly limited and can be appropriately selected according to the purpose. However, from the viewpoint that the viscosity of the coating liquid for forming a low refractive index layer can be stably adjusted to a suitable range for spraying, it is preferable to be 95% by mass or less relative to the total mass of the coating liquid for forming a low refractive index layer, more preferably 5% by mass or more and 95% by mass or less, even more preferably 5% by mass or more and 70% by mass or less, and particularly preferably 40% by mass or more and 60% by mass or less.

[0110] -Precursor Formation Process-

[0111] The precursor formation process is a process of forming a void structure as a precursor of the low refractive index layer 20 on one side of the optical element 10. The precursor formation process includes applying a coating liquid for forming the low refractive index layer to the optical element 10.

[0112] There are no particular limitations on the coating method for the coating liquid used to form a low refractive index layer. Examples include coating methods using a slit die, coating methods using various gravure coating machines, coating methods using a bar coater, coating methods using a spit coater, and coating methods using a sprayer or similar spraying method. Among these, the coating method using a sprayer (hereinafter sometimes simply referred to as "spraying method" or "spraying") is preferred as the coating method for the coating liquid used to form a low refractive index layer. As a spraying method, for example, the method described in International Publication No. 2023 / 190022 can be used. This publication is incorporated herein by reference to its entirety.

[0113] There are no particular limitations on the conditions for spraying the coating liquid for forming a low-refractive-index layer, but it is preferable to spray the target layer to form a coating film in such a way that the rate of change of solid component concentration satisfies the following formula 2. When the rate of change of solid component concentration satisfies formula 2, the state of the coating film formed by the coating liquid for forming a low-refractive-index layer on the target layer can be stabilized, which is therefore preferred. Therefore, surface wobbling of the coating film caused by the effect of spraying can be suppressed, and the generation of large voids in the coating film can be suppressed. As a result, the thickness unevenness of the low-refractive-index layer 20 can be reduced. In addition, the transparency of the low-refractive-index layer 20 can be improved. The rate of change of solid component concentration is more preferably 1.5 or more and 55 or less.

[0114] [Equation 2]

[0115] 1.3≤Solid component concentration change rate≤60

[0116] In Equation 2 above, the solid component concentration change rate represents the ratio of the solid component concentration in the coating film at a time point 10 seconds after spraying to the solid component concentration in the coating liquid used to form the low refractive index layer before spraying.

[0117] There is no particular limitation on the concentration of solid components in the coating liquid for forming the low refractive index layer before spraying, but it is preferably 0.1% by mass or more and 6.0% by mass or less, more preferably 1.0% by mass or more and 6.0% by mass or less, and even more preferably 2.0% by mass or more and 3.5% by mass or less.

[0118] There is no particular limitation on the concentration of solid components in the coating at 10 seconds after spraying, but it is preferably 3.7% by mass or more and 6.5% by mass or less, more preferably 4.5% by mass or more and 6.5% by mass or less.

[0119] The concentration of solid components in the coating liquid for forming a low refractive index layer before spraying, and the concentration of solid components in the coating film at a time point of 10 seconds after spraying, can be measured, for example, by spraying the coating liquid for forming a low refractive index layer onto the target coating layer, and the mass before and after drying can be determined, and the mass change before and after drying can be quantified.

[0120] Furthermore, the viscosity of the coating liquid for forming the low refractive index layer before spraying is not particularly limited, but it is preferably 0.1 mPa·s or more and 2000 mPa·s or less, more preferably 1.0 mPa·s or more and 200 mPa·s or less. In this disclosure, the viscosity of the coating liquid for forming the low refractive index layer can be measured by a rheometer (e.g., manufactured by Anton-Paar).

[0121] Furthermore, there is no particular limitation on the viscosity of the coating at the time point 10 seconds after spraying, but from the viewpoint of improving the transparency of the low refractive index layer 20 and reducing the thickness unevenness of the low refractive index layer 20, it is preferable to satisfy the following formula 3.

[0122] [Equation 3]

[0123] 0.0549e 1.2x The viscosity of the coating at a time point 10 seconds after spraying is ≤0.0549e. 3.3x

[0124] In the above formula 3, e represents the Napier number, and x represents the concentration of solid components in the coating at a time point of 10 seconds after spraying.

[0125] The viscosity of the coating at 10 seconds after spraying is preferably satisfied by Formula 3, but is preferably 30 mPa·s or more and 4500 mPa·s or less, more preferably 100 mPa·s or more and 4500 mPa·s or less, even more preferably 300 mPa·s or more and 3000 mPa·s or less, even more preferably 400 mPa·s or more and 1000 mPa·s or less, and particularly preferably 500 mPa·s or more and 700 mPa·s or less.

[0126] In spraying, the distance (coating distance) between the nozzle spraying the coating liquid for forming the low refractive index layer and one surface of the optical element 10 is not particularly limited and can be adjusted appropriately, but is preferably 50 mm or more and 500 mm or less, more preferably 100 mm or more and 300 mm or less. If the distance between the nozzle and one surface of the optical element 10 increases, the rate of change of solid component concentration will increase; if the distance between the nozzle and one surface of the optical element 10 decreases, the rate of change of solid component concentration may decrease.

[0127] Spraying refers to the process of spraying a coating liquid for forming a low refractive index layer while moving the nozzle along one surface of the optical element 10. The atomization pressure of the spraying is, for example, 100 kPa to 1000 kPa, the coating amount is, for example, 0.1 mL / min to 20 mL / min, and the moving speed of the nozzle during spraying is, for example, 1 mm / s to 1000 mm / s.

[0128] Thus, a coating is formed on one surface of the optical element 10 to form a void structure that serves as a precursor to the low refractive index layer 20.

[0129] It should be noted that, here, an example is given using one side of the optical element 10 as the side on which the low refractive index layer 20 is formed. However, the layers adjacent to the low refractive index layer 20 can be appropriately selected. Even if the target layer of the coating liquid for forming the low refractive index layer is changed to another layer, a coating film for forming the void structure that serves as the precursor of the low refractive index layer 20 can be formed in the same way.

[0130] - Crosslinking reaction process -

[0131] The crosslinking reaction process is a process that causes a crosslinking reaction within the precursor after the precursor formation process. In the crosslinking reaction process, crosslinking occurs between multiple particles contained in the coating film. Furthermore, the dispersion medium in the coating solution for forming the low-refractive-index layer is also dried through the crosslinking reaction process.

[0132] There are no particular restrictions on the reaction conditions for the crosslinking reaction, and they can be appropriately selected according to the purpose, but heating is preferable. Furthermore, the dispersion medium in the coating solution for forming the low-refractive-index layer is also dried as a result.

[0133] There are no particular limitations on the heating temperature, which can be appropriately selected according to the purpose, but it is preferably above 60°C and below 200°C, more preferably above 70°C and below 120°C, and even more preferably above 80°C and below 100°C.

[0134] There is no particular limit to the heating time, as long as the coating is fully dried.

[0135] According to the method described above, for example, a low-refractive-index layer 20 with a very low refractive index is formed. The reasons for this are speculated, for example, as follows. However, the following speculation does not limit the method of forming the low-refractive-index layer 20.

[0136] The pulverized material is obtained by pulverizing a gel-like silicon compound, thus the three-dimensional structure of the gel-like silicon compound before pulverization is dispersed into a three-dimensional basic structure. Furthermore, in the method for forming the low-refractive-index layer 20, by coating the pulverized gel-like silicon compound onto one surface of the optical element 10, a precursor of a porous structure based on the three-dimensional basic structure is formed. That is, according to the method for forming the low-refractive-index layer 20, a new porous structure (three-dimensional basic structure) based on the coating of pulverized material, different from the three-dimensional structure of the gel-like silicon compound, is formed. Therefore, the final low-refractive-index layer 20 can achieve, for example, a low refractive index that functions to the same extent as that in air. Moreover, in the method for forming the low-refractive-index layer 20, the three-dimensional basic structure is fixed by chemically bonding the pulverized material together. Therefore, the final low-refractive-index layer 20, despite having a porous structure, maintains sufficient strength and flexibility.

[0137] <Light Absorption Layer>

[0138] In the stacked optical component 100, the light-absorbing layer 30 is primarily configured to prevent stray light. By configuring the light-absorbing layer 30 as the layer closest to the light source in the stacked optical component 100, stray light can be prevented.

[0139] The absorption spectrum of the light-absorbing layer 30 is not particularly limited and can be appropriately selected depending on the optical device using the stacked optical component 100, but is preferably in the range of 380 nm to 2500 nm. For example, when the absorption spectrum of the light-absorbing layer 30 is in the visible light region, it is suitable for use in optical devices with image sensors corresponding to the visible light region. Furthermore, when the absorption spectrum of the light-absorbing layer 30 is in the near-infrared region, it is suitable for use in optical devices with image sensors corresponding to the near-infrared region.

[0140] The definition of near-infrared radiation varies depending on the technical field, but in the embodiments of this disclosure, "near-infrared radiation" refers to light (electromagnetic waves) that includes a wavelength range of at least 760 nm and below 2000 nm. Furthermore, in the embodiments of this disclosure, "visible light" refers to light with a wavelength range of 400 nm and below 760 nm.

[0141] The light-absorbing layer 30 may be a decorative layer with a predetermined design, or it may be a fully coated coloring layer. The light-absorbing layer 30 is preferably a fully coated coloring layer, and more preferably a black coloring layer.

[0142] The total light transmittance of the light absorption layer 30 is not particularly limited, but it is preferably 0.01% or less, more preferably 0.008% or less. A lower total light transmittance of the light absorption layer 30 is more preferred, and there is no particular limitation on its lower limit; for example, 0.001% or more can be listed. When the total light transmittance of the light absorption layer 30 is 0.01% or less, superior light absorption and blocking functions can be achieved.

[0143] The average thickness of the light-absorbing layer 30 is not particularly limited and can be appropriately selected according to the purpose, but it is preferably 0.1 μm to 300 μm. When the average thickness of the light-absorbing layer 30 is 0.1 μm to 300 μm, the required total light transmittance can be easily achieved, thereby enabling better light absorption and blocking functions.

[0144] There are no particular limitations on the method of forming the light-absorbing layer 30. For example, methods using any suitable ink or coating and any suitable printing method can be listed. Specific examples of printing methods include inkjet printing, gravure printing, offset printing, screen printing, and transfer printing from a transfer sheet.

[0145] There are no particular restrictions on the inks or coatings used to form the light-absorbing layer 30. They can be appropriately selected according to the purpose, for example, containing binders, colorants and solvents, and may further contain any suitable additives as needed.

[0146] There are no particular limitations on the adhesives used; examples include chlorinated polyolefins (e.g., chlorinated polyethylene, chlorinated polypropylene, etc.), polyester resins, urethane resins, acrylic resins, vinyl acetate resins, vinyl chloride-vinyl acetate copolymers, and cellulose resins. These can be used individually or in combination.

[0147] The adhesive can be a thermopolymerizable resin or a photopolymerizable resin. Among these, the adhesive is preferably a (meth)acrylic resin, more preferably a (meth)acrylic resin containing a polyfunctional monomer (e.g., pentaerythritol triacrylate, etc.) as a copolymer component.

[0148] There are no particular restrictions on colorants; any suitable colorant may be used depending on the purpose. Specific examples of colorants include: inorganic pigments such as titanium dioxide, zinc dioxide, carbon black, iron black, iron oxide red, chrome vermilion, ultramarine, cobalt blue, lead yellow, and titanium yellow; organic pigments or dyes such as phthalocyanine blue, indanthrene blue, isoindolinone yellow, benzidine yellow, quinacridone red, polyazo red, perylene red, and aniline black; metallic pigments composed of flake-like foils such as aluminum and brass; and pearlescent pigments (pearl pigments) composed of flake-like foils such as mica coated with titanium dioxide and basic lead carbonate.

[0149] When the light-absorbing layer 30 is made black, carbon black, iron black, and aniline black are suitable materials. In this case, it is preferable to use a colorant as well. This is because it can absorb visible light over a wide range and uniformly, thereby forming a colorless (i.e., pure black) light-absorbing layer 30.

[0150] When the light-absorbing layer 30 is made black, in addition to the aforementioned colorant, azo compounds and / or quinone compounds may also be used. There are no particular limitations on the colorant; it can be appropriately selected according to the purpose. For example, it may contain carbon black as a main component and other colorants (e.g., azo compounds and / or quinone compounds). With this configuration, a black layer free of impurities and exhibiting excellent stability over time can be formed.

[0151] When the light-absorbing layer 30 is a black layer, there is no particular limitation on the content of colorant in the ink or coating, but it is preferable that the colorant is 1 to 200 parts by mass relative to 100 parts by mass of the binder. In this case, the content of carbon black in the colorant is preferably 1% to 100% by mass. By using the colorant (especially carbon black) in this proportion, a light-absorbing layer 30 with very low total light transmittance and excellent stability over time can be formed.

[0152] [Second Implementation]

[0153] Figure 2A This is a schematic cross-sectional view illustrating an example of a stacked optical component according to a second embodiment of the present disclosure. Figure 2B This is a schematic cross-sectional view showing another example of a stacked optical component according to a second embodiment of the present disclosure. The stacked optical component 100 of the second embodiment includes: a prism 10B as an optical element 10, a low refractive index layer 20, and a light-absorbing layer 30. The stacked optical component 100 of the second embodiment has the same configuration as the stacked optical component 100 of the first embodiment, except that the optical element 10 is a prism 10B.

[0154] <Optical Components (Prisms)>

[0155] As for the shape of prism 10B, there are no particular restrictions as long as it does not impair the effect of this disclosure, and any suitable shape can be appropriately selected. The cross-sectional shape of prism 10B in the stacking direction of the stacked optical component 100, i.e., the Y-axis direction, can be a polygon such as a triangle or a quadrilateral. In addition, one or two inclined planes of a triangle can also be the shape of multiple flat planes with different tilt angles.

[0156] When the cross-sectional shape of the prism 10B in the Y-axis direction is triangular, it can be an asymmetrical shape (e.g., a scalene triangle) that passes through the vertex of the prism 10B and is symmetrical with respect to the stacking direction of the stacked optical component 100, or it can be an isosceles triangle. Moreover, the vertex of the prism 10B can be a chamfered curved surface, or the top can be cut into a flat surface to make the cross-section trapezoidal.

[0157] As for the material constituting the prism 10B, there are no particular restrictions as long as it can efficiently guide the light irradiated from the light source. It can be appropriately selected from known materials, such as (meth)acrylic resins such as polymethyl methacrylate (PMMA), polycarbonate (PC) resins, polyethylene terephthalate (PET) resins, styrene resins, and glass.

[0158] [Third Implementation Method]

[0159] Figure 3 This is a schematic cross-sectional view showing an example of a stacked optical component according to a third embodiment of the present disclosure. The stacked optical component 100 of the third embodiment sequentially includes: a light guide plate 10A as an optical element 10, a low refractive index layer 20, an adhesive layer 40, and a light absorption layer 30. The stacked optical component 100 of the third embodiment has the same structure as the stacked optical component 100 of the first embodiment, except that it has the adhesive layer 40.

[0160] It should be noted that in the stacked optical component 100 of the third embodiment, the light guide plate 10A can also be replaced with the prism 10B in the stacked optical component 100 of the second embodiment.

[0161] <Adhesive layer>

[0162] Adhesive layer 40 is configured to bond the two layers together. Figure 3 In this configuration, the adhesive layer 40 is disposed between the low refractive index layer 20 and the light absorption layer 30, but the adhesive layer 40 may also be disposed between the optical element 10 and the low refractive index layer 20.

[0163] Preferably, the adhesive layer 40 has a hardness sufficient to prevent the adhesive constituting the adhesive layer 40 from penetrating into the voids of the low refractive index layer 20 under normal conditions. Therefore, the storage modulus of the adhesive layer 40 at 23°C is not particularly limited, but is preferably 0.2 × 10⁻⁶. 5 Pa or higher and 5.0 × 10 7 Pa or less, more preferably 0.4 × 10 Pa. 5 Pa or higher and 4.0 × 10 7 Pa is below, and more preferably 0.6 × 10 Pa. 5 Pa or higher and 3.0 × 107 Pa or less, and more preferably 0.8 × 10 Pa. 5 Pa or higher and 2.0 × 10 7 Pa below, particularly preferably 1.0 × 10 Pa 5 Pa or higher and 1.0 × 10 7 Below Pa. The storage modulus of adhesive layer 40 at 23°C is 0.2 × 10⁻⁶. 5 At a pressure above Pa, it possesses a hardness sufficient to prevent penetration into the voids of the low-refractive-index layer 20. Furthermore, the adhesive layer 40 has a storage modulus of 5.0 × 10⁻⁶ at 23°C. 7 When Pa is below, it has a cushioning function against external forces and a softness that can suppress the breakage of other layers such as optical element 10 and low refractive index layer 20.

[0164] In this disclosure, the storage modulus of the adhesive layer 40 at 23°C is obtained by reading the value at 23°C according to the method described in JIS K 7244-1:1988 "Plastics - Test method for dynamic mechanical properties" at a frequency of 1 Hz and a heating rate of 5°C / min in the range of -50°C to 150°C.

[0165] As the adhesive constituting the adhesive layer 40, any suitable adhesive can be used as long as it has the properties described above. Examples of adhesives include (meth)acrylic adhesive compositions. Preferably, the (meth)acrylic adhesive composition contains a (meth)acrylic polymer as the base polymer.

[0166] There is no particular limitation on the content of (meth)acrylic polymers, but it is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more in the solid components of the (meth)acrylic adhesive composition.

[0167] The (meth)acrylic polymer contains alkyl (meth)acrylates as monomer units as a major component. Examples of alkyl groups that are linear or branched alkyl groups having 1 to 18 carbon atoms are cited. The average number of carbon atoms in the alkyl group is not particularly limited, but is preferably 3 to 9. It should be noted that in this disclosure, "(meth)acrylate" refers to "acrylate" or "methacrylate".

[0168] In addition to alkyl methacrylates, the monomers constituting (meth)acrylate polymers may also include: monomers containing carboxyl groups, monomers containing hydroxyl groups, monomers containing amide groups, (meth)acrylates containing aromatic rings, and (meth)acrylates containing heterocyclic rings, etc., as comonomers. These may be used alone or in combination of two or more. Among these, hydroxyl-containing monomers and / or (meth)acrylates containing heterocyclic rings are preferred as comonomers, and N-acryloylmorpholine is more preferred.

[0169] The (meth)acrylic acid-based adhesive composition may further contain a silane coupling agent and / or a crosslinking agent. There are no particular limitations on the silane coupling agent; examples include silane coupling agents containing epoxy groups. There are no particular limitations on the crosslinking agent; examples include isocyanate-based crosslinking agents, peroxide-based crosslinking agents, etc. These can be used alone or in combination of two or more.

[0170] Details of this adhesive layer 40 and the acrylic adhesive composition are described, for example, in Japanese Patent No. 4140736, which is incorporated herein by reference to its entirety.

[0171] There are no particular limitations on the method of forming the adhesive layer 40, and a suitable method can be selected from known methods. For example, the following methods can be listed: applying the monomer of the material constituting the adhesive layer 40, and then, as needed, an adhesive composition containing a silane coupling agent and / or crosslinking agent, a polymerization solvent, etc., preferably a (meth)acrylic adhesive composition, onto a release liner, etc., after drying to remove the polymerization solvent, etc., to form the adhesive layer 40, and then transferring it to a layer adjacent to the adhesive layer 40 (e.g., low refractive index layer 20, light absorption layer 30, optical element 10, etc.); and applying the adhesive composition, preferably a (meth)acrylic adhesive composition, onto a layer adjacent to the adhesive layer 40 (e.g., low refractive index layer 20, light absorption layer 30, optical element 10, etc.), drying to remove the polymerization solvent, etc., to form the adhesive layer 40 on the adjacent layer, etc.

[0172] Furthermore, an anchoring layer can be formed on the surface of the layer adjacent to the adhesive layer 40, on the surface where the adhesive layer 40 is formed, or the adhesive layer 40 can be formed after various easy-bonding treatments such as corona treatment or plasma treatment. Additionally, the surface of the adhesive layer 40 can be treated for easy bonding.

[0173] Examples of coating methods for the adhesive composition used to form the adhesive layer 40 include coating methods using a slit die, coating methods using various gravure coating machines, coating methods using a bar coater, coating methods using a kiss coater, and coating methods using a sprayer or similar spraying method.

[0174] There are no particular restrictions on the materials used to construct the separator. Examples include: plastic film; porous materials such as paper, cloth, and non-woven fabric; mesh; foam sheets; metal foil; and appropriately selected thin sheets such as laminates of these materials. Among these, plastic film is suitable as a material for the separator from the viewpoint of excellent surface smoothness.

[0175] As for plastic films, there are no particular restrictions as long as they can protect the adhesive layer 40. Examples include polyethylene films, polypropylene films, polybutene films, polybutadiene films, polymethylpentene films, polyvinyl chloride films, vinyl chloride copolymer films, polyethylene terephthalate films, polybutylene terephthalate films, polyurethane films, and ethylene-vinyl acetate copolymer films.

[0176] The average thickness of the separator is not particularly limited, but is preferably 5 μm to 200 μm, more preferably 5 μm to 100 μm. As needed, the separator can be subjected to demolding and anti-fouling treatments, antistatic treatments, etc. Examples of demolding and anti-fouling treatments include treatments using silicone-based, fluorine-based, long-chain alkyl-based, or fatty acid amide-based release agents; and treatments using silica powder, etc. Furthermore, examples of antistatic treatments include coating, compounding, and vapor deposition treatments. In particular, by appropriately treating the surface of the separator with silicone-based release agents, long-chain alkyl-based release agents, or fluorine-based release agents, the peelability from the adhesive layer 40 can be further improved.

[0177] The average thickness of the adhesive layer 40 is not particularly limited and can be appropriately selected according to the purpose, but it is preferably 3 μm or more and 30 μm or less, more preferably 5 μm or more and 20 μm or less. When the average thickness of the adhesive layer 40 is 3 μm or more and 30 μm or less, it can suppress damage to other layers such as the optical element 10 and the low refractive index layer 20.

[0178] [Fourth Implementation Method]

[0179] Figure 4 This is a schematic cross-sectional view illustrating an example of a stacked optical component according to a fourth embodiment of the present disclosure. The stacked optical component 100 of the fourth embodiment sequentially includes: an optical element 10, a base coating 50, a low refractive index layer 20, and a light-absorbing layer 30. The stacked optical component 100 of the fourth embodiment has the same configuration as the stacked optical component 100 of the first embodiment, except that it has a base coating 50.

[0180] It should be noted that in the stacked optical component 100 of the fourth embodiment, the light guide plate 10A can also be replaced with the prism 10B in the stacked optical component 100 of the second embodiment.

[0181] <Undercoat>

[0182] The undercoat layer 50 is configured to improve the adhesion between the optical element 10 and the low refractive index layer 20. Therefore, the undercoat layer 50 is suitable for being disposed between the optical element 10 and the low refractive index layer 20.

[0183] The primer layer 50 can be formed by applying a primer. Ideally, the primer material should exhibit good adhesion to both the optical element 10 and the low refractive index layer 20, and form a film with excellent cohesiveness. Examples include silane coupling agents, urethane polymers, etc. Among these, the primer is preferably prepared by hydrolyzing a silane coupling agent to form an aqueous solution, and then mixing it with an organic solvent that is miscible with water in any way.

[0184] There are no particular limitations on the silane coupling agent; examples include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-phenyl-aminopropyltrimethoxysilane, and 3-acryloyloxypropyltrimethoxysilane. These can be used alone or in combination. Among these, 3-aminopropyltrimethoxysilane is preferred. Furthermore, a commercially available example is "KBM-903" (manufactured by Shin-Etsu Chemical Co., Ltd.).

[0185] There are no particular restrictions on the application method of the primer when forming the base coating layer 50. For example, the application method can be carried out by a slit die, the application method using various gravure coating machines, the application method using a bar coater, the application method using a kiss coater, and the application method by spraying using a sprayer, etc.

[0186] The average thickness of the base coating 50 is not particularly limited and can be appropriately selected according to the purpose, but it is preferably 1 nm or more and 50 nm or less, more preferably 2 nm or more and 30 nm or less, and even more preferably 3 nm or more and 20 nm or less.

[0187] [Fifth Implementation]

[0188] Figure 5 This is a schematic cross-sectional view illustrating an example of a stacked optical component according to a fifth embodiment of the present disclosure. The stacked optical component 100 of the fifth embodiment sequentially comprises: an optical element 10, a base coating layer 50, a low refractive index layer 20, an adhesive layer 40, and a light-absorbing layer 30. The stacked optical component 100 of the fifth embodiment has the same configuration as the stacked optical component 100 of the first embodiment, except for the base coating layer 50 and the adhesive layer 40.

[0189] The base coating layer 50 is as described in the laminated optical component 100 of the fourth embodiment. Furthermore, the adhesive layer 40 is as described in the laminated optical component 100 of the third embodiment.

[0190] It should be noted that in the stacked optical component 100 of the fifth embodiment, the light guide plate 10A can also be replaced with the prism 10B in the stacked optical component 100 of the second embodiment.

[0191] [Sixth Implementation Method]

[0192] Figure 6 This is a schematic cross-sectional view illustrating an example of a stacked optical component according to a sixth embodiment of the present disclosure. The stacked optical component 100 of the sixth embodiment sequentially comprises: an optical element 10, a base coating layer 50, a low refractive index layer 20, a substrate 60, an adhesive layer 40, and a light-absorbing layer 30. The stacked optical component 100 of the sixth embodiment has the same configuration as the stacked optical component 100 of the fifth embodiment, except for the substrate 60.

[0193] It should be noted that in the stacked optical component 100 of the sixth embodiment, the light guide plate 10A can also be replaced with the prism 10B in the stacked optical component 100 of the second embodiment.

[0194] <Substrate>

[0195] The substrate 60 is primarily configured to enhance the strength of the stacked optical component 100. Preferably, the substrate 60 is disposed between the low refractive index layer 20 and the light-absorbing layer 30. It should be noted that, in this case, an adhesive layer 40 is preferably disposed between the substrate 60 and the light-absorbing layer 30.

[0196] There are no particular limitations on the Young's modulus of the substrate 60, and it can be appropriately selected according to the purpose, but it is preferably 2 GPa or more and 10 GPa or less, more preferably 2.5 GPa or more and 9 GPa, and even more preferably 3 GPa or more and 8 GPa or less. When the Young's modulus of the substrate is 2 GPa or more and 10 GPa or less, it can suppress the damage of other layers such as the optical element 10 and the low refractive index layer 20.

[0197] The material of the substrate 60 is not particularly limited, but a resin film is preferred. Examples of resin film forming materials include: (meth)acrylic resins, cellulose resins such as diacetylcellulose and triacetylcellulose; cycloolefin resins such as norbornene resins; olefin resins such as polypropylene and ester resins such as polyethylene terephthalate resins; polyamide resins; polycarbonate resins; and copolymers of these resins. It should be noted that in this disclosure, "(meth)acrylic resin" refers to either "acrylic resin" or "methacrylic resin".

[0198] There are no particular limitations on the moisture permeability of the substrate 60, and it can be appropriately selected according to the purpose, but 0.1 g / m² is preferred. 2 / 24hr~1000g / m 2 / 24hr, more preferably 0.5g / m 2 / 24hr~800g / m 2 / 24hr, further preferably 1g / m 2 / 24hr~500g / m 2 / 24hr. The moisture permeability of substrate 60 is 0.1g / m³. 2 / 24hr~1000g / m 2 At 24hr, it can further suppress the damage of other layers such as optical element 10 and low refractive index layer 20.

[0199] The average thickness of the substrate 60 is not particularly limited and can be appropriately selected according to the purpose, but it is preferably 20 μm or more and 50 μm or less, more preferably 25 μm or more and 40 μm or less. When the average thickness of the substrate 60 is 20 μm or more and 50 μm or less, damage to other layers such as the optical element 10 and the low refractive index layer 20 can be suppressed.

[0200] [Seventh Implementation Method]

[0201] Figure 7 This is a schematic cross-sectional view showing an example of a stacked optical component according to the seventh embodiment of the present disclosure. The stacked optical component 100 of the seventh embodiment includes: an optical element 10, a low refractive index layer 20, a light absorption layer 30, an incident portion 70, and an exit portion 80. The stacked optical component 100 of the seventh embodiment is formed by sequentially stacking the low refractive index layer 20 and the light absorption layer 30 around the optical element 10. The stacked optical component 100 of the seventh embodiment has the same configuration as the stacked optical component 100 of the first embodiment, except for the shape of the optical element 10, the arrangement of the low refractive index layer 20 and the light absorption layer 30 around the optical element 10, and the presence of the incident portion 70 and the exit portion 80.

[0202] In the stacked optical component 100 of the seventh embodiment, the optical element 10 may be a light guide plate 10A or a prism 10B. Figure 7 The shape of the optical element 10 is an example, and it is not limited to a quadrilateral. As long as it can achieve the effect of this disclosure, it can be set to a rectangle, triangle, or other polygonal shapes.

[0203] It should be noted that the stacked optical component 100 of the second to sixth embodiments can also be configured to have the shape of the stacked optical component 100 of the seventh embodiment.

[0204] In the stacked optical component 100 of the seventh embodiment, light L from the light source is incident from the incident portion 70 onto the optical element 10, and is sequentially reflected by the first inner surface 20-1, the second inner surface 20-2, and the third inner surface 20-3 of the low refractive index layer 20 before exiting from the exit portion 80. On the other hand, light L from the light source that irradiates the light absorption layer 30 is absorbed by the light absorption layer 30, thereby preventing stray light within the optical element 10.

[0205] <Incidence Section>

[0206] The incident section 70 is a component that allows light L from the light source to enter. As for the shape of the incident section 70, it is not particularly limited as long as it can allow light L to enter the optical element 10. It can be appropriately selected according to the purpose, for example, a polygonal shape such as a triangle or a quadrilateral can be listed.

[0207] The size of the incident portion 70 is not particularly limited and can be appropriately selected depending on the other components when the stacked optical component 100 is applied. For example, when applied to the optical device disclosed later, it can be appropriately selected based on the size of the multiple lenses, the size of the image sensor, and the width of the optical path. However, from the viewpoint of preventing stray light, it is preferable to cover 10% or more of the area of ​​the light-incident surface of the incident portion 70, more preferably 30% or more, and even more preferably 50% or more.

[0208] Furthermore, in the cross-sectional view of the stacked optical component 100 of the incident portion 70 in the stacking direction, i.e. the XY plane, the length of the incident portion 70 in the stacking direction of the stacked optical component 100, i.e. the length in the Y-axis direction, can be the same as the combined thickness of the average thickness of the low refractive index layer 20 and the average thickness of the light absorption layer 30, or it can be shorter than the combined thickness of the average thickness of the low refractive index layer 20 and the average thickness of the light absorption layer 30.

[0209] As for the material constituting the incident section 70, there are no particular restrictions as long as it can efficiently incident light irradiated from the light source. It can be appropriately selected from known materials, such as (meth)acrylic resins such as polymethyl methacrylate (PMMA), polycarbonate (PC) resins, polyethylene terephthalate (PET) resins, styrene resins, and glass.

[0210] <Exit part>

[0211] The exit section 80 is a component for emitting light L incident on the optical element 10. As for the shape of the exit section 80, it is not particularly limited as long as it can emit light L incident on the optical element 10. It can be appropriately selected according to the purpose. For example, polygonal shapes such as triangles and quadrilaterals can be listed.

[0212] The size of the emitting portion 80 is not particularly limited and can be appropriately selected depending on the other components when the stacked optical component 100 is applied. For example, when applied to the optical device disclosed later, it can be appropriately selected based on the size of the multiple lenses, the size of the image sensor, and the width of the optical path. However, from the viewpoint of preventing stray light, it is preferable to cover 10% or more of the area of ​​the emitting surface of the emitting portion 80, more preferably 30% or more, and even more preferably 50% or more.

[0213] Furthermore, in the cross-sectional view of the stacked optical component 100 of the emission section 80 in the stacking direction, i.e. the XY plane, the length of the emission section 80 in the stacking direction of the stacked optical component 100, i.e. the length in the Y-axis direction, can be the same as the combined thickness of the average thickness of the low refractive index layer 20 and the average thickness of the light absorption layer 30, or it can be shorter than the combined thickness of the average thickness of the low refractive index layer 20 and the average thickness of the light absorption layer 30.

[0214] As for the material constituting the emission section 80, there are no particular restrictions as long as it can efficiently incident light irradiated from the light source. It can be appropriately selected from known materials. For example, (meth)acrylic resins such as polymethyl methacrylate (PMMA), polycarbonate (PC) resins, polyethylene terephthalate (PET) resins, styrene resins, and glass can be listed.

[0215] <Uses>

[0216] The stacked optical components of the present disclosure can be used as reflective surfaces, and have excellent reflectivity on the reflective surfaces, and can prevent stray light. Therefore, they are suitable for use as optical components for optical filters, optical components for imaging devices, and optical components for optical sensor devices. As specific examples, they can be used as optical components for camera modules, televisions, vehicle navigation systems, portable information terminals, video game consoles, portable game consoles, fingerprint authentication systems, and digital music players.

[0217] The stacked optical components of the embodiments of this disclosure are particularly suitable for use as optical components in camera modules with telescopic functions. Examples of camera modules include digital cameras, smartphone cameras, mobile phone cameras, digital camcorders, wearable device cameras, PC cameras, surveillance cameras, and vehicle cameras.

[0218] (Optical device)

[0219] The optical device of the embodiments of this disclosure includes multiple lenses, an image sensor, and stacked optical components of the embodiments of this disclosure. The optical device of the embodiments of this disclosure may further include other components as needed.

[0220] Figure 8This is a schematic cross-sectional view illustrating an example of an optical device 200 according to an embodiment of the present disclosure. The optical device 200 is a camera module having a plurality of lenses 90, an image sensor 95, and stacked optical components 100.

[0221] Light L from the subject passes through multiple lenses 90, consisting of a first lens 90a, a second lens 90b, a third lens 90c, and a fourth lens 90d, and then through the stacked optical components 100 before being captured by the image sensor 95 for imaging.

[0222] Multiple lenses 90 Figure 8 Four lenses are shown, and there is no particular limit to the number of lenses 90; they can be selected appropriately according to the purpose.

[0223] There are no particular limitations on the image sensor 95; it can be appropriately selected from known image sensors.

[0224] The optical devices of the embodiments of this disclosure are suitable for use in handheld devices, vehicle-mounted devices, wearable devices, computing devices, and other processing devices connected to wireless modems. Specific examples of the optical devices of the embodiments of this disclosure include cellular phones, smartphones, portable information terminal PDAs (personal digital assistants), tablet computers, laptop computers, cameras, video recorders, smartwatches, smart bracelets, vehicle-mounted computers, and other electronic devices with imaging capabilities.

[0225] The optical device of the present disclosure can be used on a reflective surface. Since the stacked optical component of the present disclosure has excellent reflectivity on the reflective surface and can prevent stray light, especially when applied to a camera module, it can be miniaturized and thinned, and high-quality images can be obtained.

[0226] [Example]

[0227] The following preparation examples, embodiments, and comparative examples are provided to illustrate this disclosure in detail, but this disclosure is not limited by these preparation examples, embodiments, and comparative examples. It should be noted that, in the preparation examples, embodiments, and comparative examples, unless otherwise stated, "%" means "mass %" and "parts" means "parts by mass".

[0228] [Methods for determining the refractive index of low-refractive-index layers]

[0229] In Examples 1-3 below, the refractive index of the low-refractive-index layer was determined by the following method. A coating liquid for forming a low-refractive-index layer (Preparation Example 1) was applied to an acrylic film using the method and conditions described in Example 1 via spraying. The resulting coating was treated at 100°C for 1 minute and dried to form a low-refractive-index layer with an average thickness of 2.0 μm. This was then cut into dimensions of 50 mm x 50 mm. Furthermore, the adhesive layer formed in Preparation Example 2 was transferred onto one side of a glass plate (glass type: S-BSL7, product number: 516641, manufactured by OHARA Corporation, average thickness: 2 mm). The side of the adhesive layer opposite to the side of the glass plate was then attached to the side of the low-refractive-index layer opposite to the side of the acrylic film. A 20 mm diameter area in the center of the exposed surface of the glass plate was filled with black marker to create a sample that would not reflect off the back of the glass plate. The prepared sample was placed on an ellipsometry (trade name: VASE (registered trademark), manufactured by JAWoollam Japan Co., Ltd.) and the refractive index was measured under the conditions of wavelength 550 nm and incident angle 50° to 80°.

[0230] [Methods for determining the porosity of low-refractive-index layers]

[0231] In the method for determining the refractive index of the low-refractive-index layer, the refractive index of the low-refractive-index layer in Examples 1 to 3 below is calculated based on the refractive index value measured by an ellipsometer and the Lorentz-Lorenz formula.

[0232] [Method for determining the solid component concentration of coating solution used for forming low refractive index layers]

[0233] In Examples 1 to 3 below, the solid content concentration of the coating liquid for forming the low refractive index layer before application was calculated based on the amount of material added. Furthermore, in Examples 1 to 3 below, the solid content concentration in the coating film at a time point 10 seconds after spraying the coating liquid for forming the low refractive index layer was taken as the solid content concentration at the time of application, and calculated using the following formula 4.

[0234] [Equation 4]

[0235] The concentration of solid components (mass%) during application = (A / B) × 100 = {(C-D) / (E-D)} × 100

[0236] In the above formula 4, A to E represent the following contents.

[0237] A: The mass of the solid components of the coating liquid used to form the low refractive index layer applied to the target layer.

[0238] B: Total mass of coating liquid used to form a low refractive index layer on the target layer.

[0239] C: The total mass of the target layer and the coating after drying (referring to the mass of the coating on the target layer after continuous drying at 90°C until no solvent evaporation causes mass change).

[0240] D: The quality of the target layer before the coating liquid for forming the low refractive index layer is applied.

[0241] E: The sum of the mass of the target layer and the coating at 10 seconds after spraying.

[0242] The target layers in A to E are: acrylic films in the determination of the refractive index of the low refractive index layer 20, base layer 50 in Example 1, and substrate 60 in Examples 2 to 4.

[0243] Furthermore, the ratio of the change in solid component concentration of the coating liquid before application to that during application is calculated using the following formula 5.

[0244] [Equation 5]

[0245] Change rate = Solid concentration at application (mass%) / Solid concentration before application (mass%)

[0246] [Method for determining the viscosity of coating solutions used to form low-refractive-index layers]

[0247] In Examples 1 to 3 below, the viscosity of the coating liquid for forming a low refractive index layer before and after coating was measured by a rheometer (manufactured by Anton-Paar).

[0248] (Preparation Example 1: Preparation of Coating Solution for Forming Low Refractive Index Layer)

[0249] <Gelation of Silicon Compounds>

[0250] Dissolve 0.95 g of methyltrimethoxysilane (MTMS), a precursor of silicon compounds, in 2.2 g of dimethyl sulfoxide (DMSO) to prepare mixture A. Add 0.5 g of 0.01 mol / L oxalic acid aqueous solution to mixture A and stir at room temperature (25℃±5℃) for 30 minutes to hydrolyze MTMS, preparing mixture B containing tri(hydroxy)methylsilane.

[0251] Add 0.38g of 28% ammonia and 0.2g of pure water to 5.5g of DMSO, then add mixture B and stir at room temperature for 15 minutes to gel the tris(hydroxy)methylsilane, resulting in mixture C containing gel-like silicon compounds.

[0252] <Aging Process>

[0253] The prepared mixture C containing gel-like silicon compounds was incubated at 40°C for 20 hours for aging treatment.

[0254] <Pulverization Processing>

[0255] The gel-like silicon compound in the cured mixture C was broken into particles of several mm to several cm in size using a scraper. Next, 40 g of isopropanol (IPA) was added to mixture C, and after gentle stirring, it was allowed to stand at room temperature (25℃±5℃) for 6 hours. The solvent and catalyst in the gel were then removed by decantation. Solvent replacement was performed three times using the same decantation process to obtain mixture D.

[0256] Next, the gel-like silicon compound in mixture D was subjected to a pulverization process (high-pressure, media-free pulverization). The pulverization process (high-pressure, media-free pulverization) was performed as follows: using a homogenizer (trade name: UH-50, manufactured by SMT Co., Ltd.), 1.85 g of the gel-like compound and 1.15 g of IPA in mixture D were weighed into a 5 mL screw-top bottle, and then pulverized for 2 minutes at 50 W and 20 kHz. Through this pulverization process, the gel-like silicon compound in mixture D was pulverized, thus mixture D became a sol solution E of the pulverized material.

[0257] <Displacement Treatment>

[0258] To the sol solution E of the pulverized material, a mixed solvent of isobutanol (IBA; boiling point 108°C, manufactured by Tokyo Chemical Industry Co., Ltd.) and diethylene glycol ethyl methyl ether (EDM; boiling point 176°C, manufactured by Toho Chemical Industry Co., Ltd.) (mass ratio IBA:EDM = 1:1) was added. After gentle stirring, the mixture was allowed to stand at room temperature for 6 hours, and then decanted to remove the dispersion medium and catalyst from the gel. This same decantation process was performed three times to replace the solvent in sol solution E.

[0259] The volume average particle size, which indicates the uneven particle size distribution of the pulverized material contained in the sol solution E, was confirmed using a dynamic light scattering nanoparticle size analyzer (UPA-EX150, manufactured by Microtrac BEL Co., Ltd.), and the result was 0.50 to 0.70.

[0260] Furthermore, relative to 0.75g of sol solution E, a coating solution for forming a low refractive index layer was obtained by adding 0.062g of MEK (methyl ethyl ketone) solution containing 1.5% photoalkali generator (trade name: WPBG266, manufactured by Fujifilm and Koujun Pharmaceutical Co., Ltd.) and 0.036g of MEK solution containing 5% bis(trimethoxysilyl)ethane.

[0261] (Preparation Example 2: Coating liquid for forming adhesive layer)

[0262] A four-necked flask equipped with a stirring blade, thermometer, nitrogen inlet pipe, and cooler was filled with 90.7 parts of butyl acrylate, 6 parts of N-acryloylmorpholine, 3 parts of acrylic acid, 0.3 parts of 2-hydroxybutyl acrylate, and 0.1 parts of 2,2'-azobisisobutyronitrile (2,2'-azobisisobutyronitrile) as a polymerization initiator, along with 100 parts of ethyl acetate. Then, while slowly stirring, nitrogen was introduced for nitrogen purging. The liquid temperature in the flask was maintained at approximately 55°C for 8 hours to prepare an acrylic polymer solution. To a solid content of 100 parts relative to the obtained acrylic polymer solution, 0.2 parts of an isocyanate-based crosslinking agent (Coronate L, manufactured by Nippon Polyurethane Kogyo Co., Ltd., an adduct of trimethylolpropane and toluene diisocyanate), 0.3 parts of benzoyl peroxide (NYPER (registered trademark) BMT, manufactured by Nippon Yuko Co., Ltd.), and 0.2 parts of a silane coupling agent (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd., γ-glycidyl ether oxypropyl methoxysilane) were added to obtain a coating solution for forming an adhesive layer containing an acrylic adhesive. Next, the coating solution for forming the adhesive layer was applied to one side of a silicone-treated polyethylene terephthalate (PET) film (manufactured by Mitsubishi Chemical Holdings Group (Mitsubishi Chemical Corporation), thickness: 38.0 μm), so that the average thickness of the dried adhesive layer was 10.0 μm. The film was then dried at 150°C for 3 minutes to form an adhesive layer.

[0263] (Example 1)

[0264] Make using the following methods Figure 5 The stacked optical component shown comprises, in sequence, an optical element 10 with an average thickness of 2.0 mm, a base coating layer 50 with an average thickness of 5.0 nm, a low refractive index layer 20 with an average thickness of 2.0 μm, an adhesive layer 40 with an average thickness of 10.0 μm, and a light absorption layer 30 with an average thickness of 18.0 μm.

[0265] The adhesive layer formed in Preparation Example 2 is transferred onto one side of the black film (trade name: CARBONFEATHER, model: 6X4LGB, manufactured by KIMOTO Corporation, average thickness: 18.0 μm) which serves as the light absorption layer 30.

[0266] As optical element 10, a plate glass (glass type: S-BSL7, product number: 516641, manufactured by OHARA Corporation, average thickness: 2.0 mm) is used as light guide plate 10A. A silane coupling agent (KBM-903, manufactured by Shin-Etsu Chemical Industry Co., Ltd., 3-aminopropyltrimethoxysilane) is coated on the plate glass to form an undercoat 50 with an average thickness of 5.0 nm after drying. Next, the light guide plate 10A with the undercoat 50 formed and the low refractive index layer forming coating liquid obtained in Preparation Example 1 are placed in a spraying machine (product name: API-240 series, manufactured by Apeiros). The distance (coating distance) between the nozzle and the surface of the light guide plate 10A with the base coating 50 is set to 100 mm. Under the following coating conditions, a low refractive index layer forming coating liquid is sprayed onto the base coating 50, forming a coating film on the surface of the base coating 50 (the side of the base coating 50 opposite to the surface of the glass plate). Spraying is performed by repeating the following steps: in the first step, the nozzle moves along the X-axis direction of the base coating 50 and sprays the low refractive index layer forming coating liquid; and in the second step, the nozzle moves along the Z-axis direction of the base coating 50. Then, the coating film is treated at a temperature of 100°C for 1 minute and dried to form a low refractive index layer 20 with an average thickness of 2.0 μm. Next, on the low refractive index layer 20 (the side of the low refractive index layer 20 opposite to the side where the base layer 50 is disposed), the adhesive layer 40 transferred to the light absorption layer 30 is laminated in such a way that the side of the adhesive layer 40 opposite to the side where the light absorption layer 30 is disposed is in contact, and the laminated optical component 100 is fabricated by using a manual roller.

[0267] - Coating conditions -

[0268] • Atomization pressure: 100 kPa.

[0269] • Coating amount: 7 mL / min.

[0270] • Nozzle speed in the first process: 300 mm / second.

[0271] • Nozzle movement distance in the second process: 15mm.

[0272] The solid content concentration of the coating liquid for forming the low refractive index layer before application, as measured by the above method, was 3.0% by mass, and the solid content concentration during application was 5.3% by mass, with a change ratio of 1.8. Furthermore, in Example 1, the viscosity of the coating liquid for forming the low refractive index layer before application, as measured by the above method, was 10.0 mPa·s, and the viscosity after application was 522 mPa·s. It should be noted that the sample used to determine the refractive index of the low refractive index layer 20 was formed using the same method as in Example 1. Therefore, the solid content concentration of the coating liquid for forming the low refractive index layer before application, the solid content concentration during application, the viscosity before application, and the viscosity after application of the coating liquid for forming the low refractive index layer 20 in the sample used to determine the refractive index of the low refractive index layer 20 were the same as in Example 1.

[0273] Furthermore, in the stacked optical component 100 of Example 1, the refractive index of the low refractive index layer 20, as measured by the above method, is 1.18, and the porosity is 60% by volume.

[0274] (Comparative Example 1)

[0275] A single layer consisting only of a black thin film (trade name: CARBONFEATHER, model: 6X4LGB, manufactured by KIMOTO Co., Ltd., average thickness: 18.0 μm) serving as the light absorption layer 30 was used as the optical component of Comparative Example 1.

[0276] The layer composition of Example 1 and Comparative Example 1, as well as the refractive index and porosity of the low refractive index layer 20 measured by the above method, are shown in Table 1 below.

[0277] [Table 1]

[0278]

[0279] [Evaluation of external reflection]

[0280] Using the stacked optical component 100 of Example 1 and the optical component consisting only of the light-absorbing layer of Comparative Example 1, the external reflection with the exposed surface of the light-absorbing layer as the outside was evaluated by the following method. Figure 9 This is a schematic diagram illustrating the method for evaluating the external reflection of the stacked optical component 100 of Embodiment 1.

[0281] On the first surface 100a of the light-absorbing layer 30 of the stacked optical component 100 of Example 1, or on one surface of the light-absorbing layer 30 of the optical component of Comparative Example 1, a UV-Vis-NIR spectrophotometer (trade name: UH4150, manufactured by Hitachi High Technology Co., Ltd.) was used to illuminate light by varying the incident angle R1 from 10° to 70° in 10° intervals, and a detector 150 was set at the angle where positive reflection would occur for measurement. The resulting reflectance spectrum in the visible light region with wavelengths from 380 nm to 780 nm was converted into visual reflectance Y values ​​and plotted.

[0282] The plotting results of the relationship between the incident angle and the visual reflectance Y value are shown in... Figure 10 Therefore, it can be seen that the apparent reflectance Y value of the stacked optical component 100 of Example 1 is approximately the same as the apparent reflectance Y value of the optical component composed only of the light absorption layer of Comparative Example 1, and the external reflection of the first surface 100a on the side of the light absorption layer 30 maintains a low reflectance.

[0283] (Example 2)

[0284] Make using the following methods Figure 11 The stacked optical component 100 shown comprises, in sequence, an equilateral triangular prism 10B with one side having a size of 5.0 mm, an adhesive layer 40 with an average thickness of 10.0 μm, a low refractive index layer 20 with an average thickness of 2.0 μm, a substrate 60 with an average thickness of 30.0 μm, an adhesive layer 40 with an average thickness of 10.0 μm, and a light absorption layer 30 with an average thickness of 18.0 μm.

[0285] A substrate 60 (acrylic film, average thickness: 30.0 μm) and the low refractive index layer forming coating liquid obtained in Preparation Example 1 were placed in a sprayer (product name: API-240 series, manufactured by Apeiros). The distance between the nozzle and one side of the substrate 60 (coating distance) was set to 100 mm. Under the coating conditions described in Example 1, the low refractive index layer forming coating liquid was sprayed onto the substrate 60, forming a coating film on one side of the substrate 60. Spraying was performed by repeating the following steps: in the first step, the nozzle was moved along the X-axis direction of the substrate 60 and sprayed the low refractive index layer forming coating liquid; and in the second step, the nozzle was moved along the Z-axis direction of the substrate 60. Then, the coating film was treated at a temperature of 100°C for 1 minute and dried to form a low refractive index layer 20 with an average thickness of 2.0 μm.

[0286] The adhesive layer 40 formed in Preparation Example 2 is transferred onto one side of the black film (trade name: CARBONFEATHER, model: 6X4LGB, manufactured by KIMOTO Corporation, average thickness: 18.0 μm) which serves as the light absorption layer 30.

[0287] On the side of the substrate 60 opposite to the side where the low refractive index layer 20 is disposed, the adhesive layer 40 of the light-absorbing layer 30 is transferred to the substrate 60 in such a way that the side opposite to the side where the light-absorbing layer 30 is disposed is in contact, and the bonding is performed using a manual roller.

[0288] On the side of the low-refractive-index layer 20 opposite to the side of the substrate 60, the adhesive layer 40 formed in Preparation Example 2 is transferred. Next, on the side of the adhesive layer 40 opposite to the side of the low-refractive-index layer 20, the prism 10B (TS equilateral triangular prism 5.0mm, product number: #49-430, manufactured by Edmund Optics Japan Co., Ltd., the size of one side of the triangle: 5.0mm), which serves as the optical element 10, is laminated using a manual roller to fabricate the laminated optical component 100.

[0289] In Example 2, the solid content concentration of the coating liquid for forming the low refractive index layer before application, as measured by the above method, was 3.0% by mass, and the solid content concentration during application was 5.3% by mass, with a change ratio of 1.8. Furthermore, in Example 2, the viscosity of the coating liquid for forming the low refractive index layer before application, as measured by the above method, was 10.0 mPa·s, and the viscosity after application was 522 mPa·s. It should be noted that the sample used to determine the refractive index of the low refractive index layer 20 was formed using the same method as in Example 2. Therefore, the solid content concentration of the coating liquid for forming the low refractive index layer before application, the solid content concentration during application, the viscosity before application, and the viscosity after application of the coating liquid for forming the low refractive index layer 20 in the sample used to determine the refractive index of the low refractive index layer 20 were the same as in Example 2.

[0290] (Example 3)

[0291] Make using the following methods Figure 12 The stacked optical component 100 shown comprises, in sequence, an equilateral triangular prism 10B with one side dimension of 5.0 mm, a base coating layer 50 with an average thickness of 5.0 nm, a low refractive index layer 20 with an average thickness of 2.0 μm, an adhesive layer 40 with an average thickness of 10.0 μm, and a light absorption layer 30 with an average thickness of 18.0 μm.

[0292] On one side of the prism 10B (TS equilateral triangular prism 5.0 mm, product number: #49-430, manufactured by Edmund Optics Japan Co., Ltd., the size of one side of the triangle: 5 mm), which serves as optical element 10, a silane coupling agent (KBM-903, manufactured by Shin-Etsu Chemical Industry Co., Ltd., 3-aminopropyltrimethoxysilane) is coated to form a base coating 50 with an average thickness of 5.0 nm after drying. On the base coating 50 (the side opposite to the face of the prism on which the base coating is arranged), the coating liquid for forming the low refractive index layer obtained in Example 1 is sprayed using the same method and conditions as in Example 1. The coating is treated at 100°C for 1 minute and dried to form a low refractive index layer 20 with an average thickness of 2.0 μm. On the low refractive index layer 20 (the side of the low refractive index layer 20 opposite to the side where the base layer 50 is disposed), the adhesive layer 40 transferred to the light absorption layer 30 is laminated in such a way that the side opposite to the side where the light absorption layer 30 is disposed is in contact, and the laminated optical component 100 is fabricated by using a manual roller.

[0293] In Example 3, the solid content concentration of the coating liquid for forming the low refractive index layer before application, as measured by the above method, was 3.0% by mass, and the solid content concentration during application was 5.3% by mass, with a change ratio of 1.8. Furthermore, in Example 3, the viscosity of the coating liquid for forming the low refractive index layer before application, as measured by the above method, was 10.0 mPa·s, and the viscosity after application was 522 mPa·s. It should be noted that the sample used to determine the refractive index of the low refractive index layer 20 was formed using the same method as in Example 3. Therefore, the solid content concentration of the coating liquid for forming the low refractive index layer before application, the solid content concentration during application, the viscosity before application, and the viscosity after application of the coating liquid for forming the low refractive index layer 20 in the sample used to determine the refractive index of the low refractive index layer 20 were the same as in Example 3.

[0294] (Comparative Example 2)

[0295] A single layer consisting only of a prism (TS equilateral triangular prism 5.0mm, product number: #49-430, manufactured by Edmund Optics Japan Co., Ltd., the size of one side of the triangle: 5.0mm) was used as the optical component of Comparative Example 2.

[0296] (Comparative Example 3)

[0297] Make using the following methods Figure 13The stacked optical component 100A shown has a 5.0 mm equilateral triangular prism, an adhesive with an average thickness of 10 μm, and a light absorption layer 30 with an average thickness of 18.0 μm stacked on top of each other in sequence.

[0298] On one side of the black thin film (trade name: CARBONFEATHER, model: 6X4LGB, manufactured by KIMOTO Co., Ltd., average thickness: 18.0 μm) serving as the light-absorbing layer 30, the adhesive layer 40 formed in Preparation Example 2 is transferred. On one side of the prism 10B (TS equilateral triangular prism 5.0 mm, product number: #49-430, manufactured by Edmund Optics Japan Co., Ltd., the size of one side of the triangle: 5.0 mm) serving as the optical element 10, the adhesive layer 40 transferred to the light-absorbing layer 30 is laminated in such a way that the side opposite to the side where the light-absorbing layer 30 is disposed is in contact with the adhesive layer 40, and the lamination is performed using a manual roller to fabricate the laminated optical component 100A.

[0299] The layer composition of Examples 2, 3, Comparative Examples 2 and 3, and the refractive index and porosity of the low refractive index layer 20 measured by the above method are shown in Table 2 below.

[0300] [Table 2]

[0301]

[0302] [Evaluation of internal reflection]

[0303] Using the stacked optical components 100 of Examples 2 and 3, the stacked optical component 100A of Comparative Example 3, and the optical component consisting only of the prism 10B of Comparative Example 2, the internal reflection with the exposed surface of the optical element 10 inside is evaluated by the following method. Figure 14 This is a schematic diagram illustrating the method for evaluating the external reflection of the stacked optical component 100 in Embodiment 2.

[0304] A surface 10d of the prism 10B of the stacked optical component 100 of Examples 2 and 3, a surface 10d of the prism 10B of the stacked optical component 100A of Comparative Example 3, and a surface of the prism 10B of Comparative Example 2 were illuminated with light L at an angle R2 of 60° relative to the reflecting surface. A detector 151 was placed at a position of 120° where positive reflection would occur, and measurements were taken under the following conditions.

[0305] - Measurement conditions -

[0306] • Measurement start wavelength: 1200nm.

[0307] • End wavelength: 300nm.

[0308] • Light source switching wavelength: 340nm and 850nm.

[0309] • Scanning speed (1): 300nm~850nm, 300nm / minute, sampling interval 5nm.

[0310] • Scanning speed (2): 850nm~1200m, 750nm / minute, sampling interval 5nm.

[0311] The plotting results of the relationship between wavelength and specular reflectivity are shown below. Figure 15 Therefore, it can be seen that the specular reflectivity of the stacked optical component 100 of Embodiments 2 and 3 is approximately the same as that of the optical component composed solely of the prism 10B of Comparative Example 2, thus maintaining the reflectivity of internal reflections on the prism 10B side. On the other hand, the stacked optical component 100A of Comparative Example 3 cannot obtain internal reflections from the prism 10B, which is an optical element 10.

[0312] As examples of the solutions disclosed herein, the following solutions may be cited.

[0313] <1> A stacked optical component, characterized in that it comprises, in sequence:

[0314] Optical components;

[0315] Low refractive index layer, with a refractive index below 1.25; and

[0316] The light-absorbing layer absorbs light from the light source.

[0317] <2> According to the stacked optical component described in <1> above, the optical element is a light guide plate or a prism.

[0318] <3> According to the stacked optical component described in <1> above, the absorption spectrum of the light absorption layer is 380nm to 2500nm.

[0319] <4> According to the stacked optical component described in <1> or <2> above, the low refractive index layer has voids inside.

[0320] <5> According to the stacked optical component described in <4> above, the porosity of the low refractive index layer is 30% or more of the total volume of the low refractive index layer.

[0321] <6> The stacked optical component according to any one of <1> to <5> above, wherein the average thickness of the low refractive index layer is 0.1 μm or more.

[0322] <7> The stacked optical component according to any one of <1> to <6> above, wherein,

[0323] The stacked optical component has: an incident portion for light from a light source to enter; and an exit portion for light incident on the optical component to exit.

[0324] The low refractive index layer is disposed in a reflective portion that causes light incident from the incident portion to be reflected inside the optical element.

[0325] The light-absorbing layer is disposed on the side of the low-refractive-index layer opposite to the optical element.

[0326] <8> The stacked optical component according to any one of <1> to <7> above, wherein the stacked optical component is used in a camera device.

[0327] <9> An optical device, characterized in that it comprises: a plurality of lenses; an image sensor; and a stacked optical component as described in any one of <1> to <8> above.

[0328] <10> A camera device, characterized in that it comprises, in sequence:

[0329] Optical components;

[0330] Low refractive index layer, with a refractive index below 1.25; and

[0331] The light-absorbing layer absorbs light from the light source.

[0332] As described above, this disclosure has been illustrated based on specific implementation methods and embodiments, but these implementation methods and embodiments are merely examples, and this disclosure is not limited to the above implementation methods and embodiments. The above implementation methods can be implemented in various other ways, and various combinations, omissions, substitutions, additions, and modifications can be made without departing from the spirit of the invention. These implementation methods and their variations are included in the scope and spirit of the invention, and are included within the scope of the invention as described in the claims and its equivalents.

[0333] [Industry availability]

[0334] The stacked optical components of the present disclosure are suitable for use as optical components for optical filters, optical components for imaging devices, optical components for optical sensor devices, etc. As specific examples, they can be used as optical components for camera modules, televisions, vehicle navigation systems, portable information terminals, video game consoles, portable game consoles, fingerprint authentication systems, and digital music players.

[0335] This international application claims priority based on Japanese Invention Application No. 2024-055971, filed on March 29, 2024, which is incorporated herein by reference in its entirety.

[0336] Explanation of reference numerals in the attached figures

[0337] 10: Optical element; 10A: Light guide plate; 10B: Prism; 10a: End face; 10b: Exit surface; 10c: Light extraction pattern; 10d: Exposed surface of prism 10B; 20: Low refractive index layer; 20-1: First inner surface; 20-2: Second inner surface; 20-3: Third inner surface; 30: Light absorption layer; 40: Adhesive layer; 50: Undercoat layer; 60: Substrate; 70: Incident part; 80: Exit part; 90: Multiple lenses; 90a: First lens; 90b: Second lens; 90c: Third lens; 90d: Fourth lens; 95: Image sensor; 100: Stacked optical components; 100a: First surface; 100b: Second surface; 150: Detector; 151: Detector; 200: Optical device; L: Light.

Claims

1. A stacked optical component, characterized in that, It has the following characteristics in sequence: Optical components; Low refractive index layer, with a refractive index below 1.25; and The light-absorbing layer absorbs light from the light source.

2. The stacked optical component according to claim 1, wherein, The optical element is a light guide plate or a prism.

3. The stacked optical component according to claim 1 or 2, wherein, The absorption spectrum of the light-absorbing layer is 380nm to 2500nm.

4. The laminated optical component according to any one of claims 1 to 3, wherein, The low-refractive-index layer has voids inside.

5. The stacked optical component according to claim 4, wherein, The porosity of the low-refractive-index layer is more than 30% by volume relative to the total volume of the low-refractive-index layer.

6. The laminated optical component according to any one of claims 1 to 5, wherein, The average thickness of the low-refractive-index layer is greater than 0.1 μm.

7. The laminated optical component according to any one of claims 1 to 6, wherein, The stacked optical component has: an incident portion for light from a light source to enter; and an exit portion for light incident on the optical component to exit. The low-refractive-index layer is disposed in a reflective portion that causes light incident from the incident portion to be reflected inside the optical element. The light-absorbing layer is disposed on the side of the low-refractive-index layer opposite to the optical element.

8. The stacked optical component according to claim 1, wherein, The stacked optical components are used in the camera device.

9. An optical device, characterized in that, have: Multiple lenses; an image sensor; and a stacked optical component as claimed in any one of claims 1 to 8.

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