JP2013065052A - Optical article for infrared communication and light receiving unit for infrared communication - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical article for infrared communication and a light receiving unit for infrared communication, capable of specifically largely transmitting only a wavelength range in an infrared communication band and visually showing white by scattering and reflecting light in a visible light region.SOLUTION: A scattering reflection layer 23 is formed by uniformly dispersing fine particles in transparent binder resin, where the fine particles has a refractive index different from that of the binder resin. Diameter D of a fine particle of a part of or the whole of the fine particles has size represented by following formula D<0.4*λ/π. D represents particle diameter and λ represents wavelength in an infrared communication band. The fine particles is allowed to scatter and reflect light in a visible light region to develop white color, and transmittance in a wavelength region of the infrared communication band is set to not less than 12%. The scattering reflection layer 23 is formed on an outer surface of a substrate 21 to fabricate a light receiving unit 15 for infrared communication.

Description

  The present invention relates to an infrared communication optical article used for infrared communication and control ports of various electronic devices, and an infrared communication light receiving unit using the optical article.

An infrared communication system using infrared rays is generally used in various electronic devices such as personal computers, PDAs (Personal Digital Assistants) and portable information terminals such as electronic notebooks, digital cameras, and cellular phones. A device capable of infrared communication is equipped with a predetermined (for example, IrDA standard) infrared communication port. In order to prevent malfunctions due to disturbance light of the light receiving element that is sensitive to visible light in the window part of such an infrared communication port, only infrared is used as a light receiving part for infrared communication in order to prevent the inside of the device from being seen. A transparent dark plastic plate is arranged.
However, the infrared communication light receiving unit using such a plate has a black appearance color, and therefore may not match the entire device or a component to be combined due to the design of the electronic device. There was a problem. Although it is possible in principle to color the appearance of the infrared communication light-receiving part in any color by adding a colorant to the transparent plastic substrate or painting, it is possible to maintain transparency in the infrared region. It is extremely difficult to adjust the appearance color to various colors.
Therefore, the applicant has developed a light receiving part for infrared communication having a dielectric multilayer film that transmits infrared light on a substrate as disclosed in Patent Document 1. In such infrared communication light receiving parts, it is possible to design various appearance colors using dielectric multilayer films while maintaining infrared transparency, providing electronic devices with an increased degree of design freedom I was able to do that.

JP 2006-165493 A

Although the light receiving part for infrared communication using the dielectric multilayer film as in Patent Document 1 has a greater degree of freedom in design than the conventional case where a dark plastic plate is used, the dielectric multilayer film is used. Since a metal color is inevitably associated with color development, for example, a relatively large amount of white (as a matter of course, not necessarily limited to white) as a color of the housing of the device is not necessarily disclosed in Patent Document 1. Even such a light receiving part may not be suitable as a design. For this reason, in particular, a white light receiving part for infrared communication has been demanded from a request for further design freedom.
However, white means that external light is diffusely reflected, so even if a white pigment is applied to the substrate, for example, the wavelength range of the visible light range to the infrared communication band is scattered almost over the entire area. Therefore, it was not possible to transmit only the wavelength band of the infrared communication band required. Further, even if a thin color such as frosted glass that allows transmission through the wavelength band of the infrared communication band is applied, the visible light range is received and there is a risk of malfunction of the device due to ambient light. In addition, when the white coloring is not sufficient, there is a possibility that an unfavorable state may occur in terms of design in which the inside of the device can be seen through.
The present invention has been made in order to solve the above-described problems, and the object thereof is to allow only a large amount of light to pass through only the wavelength band of the infrared communication band, and to visually observe light in the visible light range. An object of the present invention is to provide an infrared communication optical article and a light receiving part for infrared communication that are scattered and reflected to exhibit white color.

  In order to achieve the above object, according to the first aspect of the present invention, there is provided an optical article for infrared communication formed by uniformly dispersing fine particles having a refractive index different from that of a binder resin in a transparent binder resin. The average particle size of the fine particles is set to have a wavelength dependency that increases the transmittance of light on the long wavelength side while causing the fine particles to scatter and reflect light in the visible light range to develop a predetermined color. The gist is that the transmittance in the wavelength band of the infrared communication band is set to 12% or more.

  The gist of the invention described in claim 2 is that, in the invention described in claim 1, the diameter D of some or all of the fine particles is set to a size represented by the following formula.

  The gist of the invention described in claim 3 is that, in the invention described in claim 1, the diameter D of some or all of the fine particles is set to a size represented by the following formula.

The invention according to claim 4 is an optical article for infrared communication in which a surface of a transparent substrate is roughened to form a fine uneven shape and a white scattering layer is formed on the surface of the transparent substrate. The average irregularity diameter of the fine irregularities of the scattering layer is set so as to have a wavelength dependency that increases the transmittance of light on the long wavelength side, and the transmittance in the wavelength band of the infrared communication band is 12% or more The gist of this is
The gist of the invention described in claim 5 is that, in the invention described in claim 4, the diameter D of a part or all of the fine concavo-convex shape is set to the size indicated by the above equation (1).
The gist of the invention described in claim 6 is that, in the invention described in claim 4, the diameter D of a part or all of the fine concavo-convex shape is set to the size indicated by the formula 2.

  In invention of Claim 7, in invention in any one of Claims 1-6, in the said binder resin or the said transparent base material, 1 or more types of color materials which absorb a part of visible region were contained. This is the gist. In invention of Claim 8, in the invention in any one of Claims 1-7, in the said binder resin or the said transparent base material, the dye which permeate | transmits infrared rays and absorbs a part of visible region is contained. The gist of this is The gist of the invention according to claim 9 is that, in the invention according to any one of claims 1 to 8, the binder resin or the transparent substrate contains an ultraviolet absorber.

In such a configuration, the optical article for infrared communication has a white appearance due to scattering and reflection of light in the visible light range by the scattering layer formed by finely concavo-convex shapes by uniformly dispersed fine particles or rough surface treatment. It becomes possible. The term “white” refers to the state where the wavelength of visible light is scattered and clouded, but in the case where fine particles are dispersed in the binder resin, all visible light depends on the wavelength dependency when the fine particles are formed. Does not scatter uniformly and may have some saturation. Here, it is necessary to set the average particle size of the fine particles so that the fine particles to be dispersed have a wavelength dependency that increases the light transmittance on the long wavelength side. The transmittance in the wavelength band of the infrared communication band is 12% or more. Accordingly, it is possible to provide an optical article suitable for infrared communication having high infrared transmission performance and low visible light transmission performance.
Here, "infrared communication optical article" means that fine particles are uniformly dispersed in a transparent binder resin, or a fine uneven shape is formed on the surface of a transparent base material by roughening the surface to form a white scattering layer on the substrate surface. An article that is molded to transmit light in the wavelength band of at least the infrared communication band used at the position of the formed infrared communication port, and broadly refers to the presence or absence of flexibility, thickness, shape, The material is not a question.
Here, the “rough surface treatment” can be executed by means such as sand blasting, plasma treatment, chemical treatment, or roughening the die surface when forming a molded product with a die.
Here, sandblasting is a technique in which high-pressure fine particles are sprayed on the surface of a transparent substrate to make it rough. In the plasma processing, a processing gas is introduced into a processing chamber evacuated to a vacuum, and a high frequency voltage is applied to an electrode provided in the processing chamber to generate plasma and perform processing. Here, the surface of the transparent substrate is etched to be roughened by ions or radicals of the processing gas generated by the plasma. Examples of the chemical treatment include a plastic dissolution treatment with an organic solvent.

In addition, the wavelength dependency of the fine particles that increases the light transmittance on the long wavelength side is remarkably increased in the particle diameters that satisfy the equations (1) and (3). This is because the particle size corresponding to the formulas 1 and 3 is Rayleigh scattering, and the fine particles having such a particle size are particularly suitable as the particle size of the fine particles in the optical article for infrared communication. In addition, although the particle size corresponding to the formulas (2) and (4) is slightly larger than those of the formulas (1) and (3), the wavelength dependency of the fine particles is high, which is preferable in the optical article for infrared communication. It can be said.
The relationship between wavelength and particle diameter in scattering can be generally expressed by the following mathematical formula.

In this equation, if a <0.4, the region to which Rayleigh scattering is applied is used, 0.4 <a <3 is the region to which Mie scattering is applied, and a> 3 is the region to which diffraction scattering is applied. In Rayleigh scattering, the amount of scattering is determined by the size and wavelength of the particles. The scattering coefficient Ks of Rayleigh scattering is expressed by the following formula. In Rayleigh scattering, the transmittance varies depending on the wavelength, and the transmittance in a relatively long wavelength region tends to be relatively high.
On the other hand, in large particle size scattering such as Mie scattering and diffraction scattering, the directivity to the front is increased regardless of the wavelength, and the scattering specificity due to the wavelength is reduced, so it is difficult to adjust the transmittance. is there.

Therefore, by changing the blending ratio of different particle diameters and particle types as appropriate, at least the wavelength of the infrared communication band is Rayleigh scattered to give a predetermined transparency to this wavelength region, and the wavelength of the visible light region is relatively It becomes easy to make it scatter greatly, and it becomes possible to make the optical article for infrared communication exhibit a white color.
Here, particles whose particle size in the above formula 1 is the threshold value in the vicinity of the boundary between Rayleigh scattering and Mie scattering at the wavelength of the infrared communication band (around 100 nm when the wavelength of the infrared communication band is 800 to 900 nm) Is a particle that becomes Mie scattering in the visible light region. If this particle diameter is gradually reduced, the visible light wavelength band that shifts to Rayleigh scattering increases. Further, if the particle diameter is smaller than 50 nm, all wavelengths in the visible to infrared communication band are Rayleigh scattered. It is preferable to adjust the optimal transmittance at the wavelength of the infrared communication band and the color of the optical article for infrared communication by utilizing such a difference in scattering action.
In the case of the following particle size, for example, when “particle size is 100 nm”, the particle is not a perfect sphere, so the particle size is the average and the average obtained by calculation of, for example, the triaxial average diameter of each particle. Means a statistical value. Similarly, it does not mean that the particle group as a whole does not include a diameter of 100 nm or less and a diameter of 100 nm or more, but means that the particle group is statistically composed mainly of 100 nm.

  The binder resin is not particularly limited as long as it is substantially transparent at least in the infrared wavelength region and is different from the refractive index of the particles. Examples thereof include polyester, polycarbonate, urethane resin, acrylic resin, methacrylic resin, organosilicon resin, and fluorine resin. More specifically, for example, an ester of polyhydric alcohol and (meth) acrylic acid or a copolymer of a fluorine-based monomer and another monomer (other monomers include, for example, olefins (ethylene, propylene, isoprene, Vinyl chloride, vinylidene chloride, etc.), acrylic esters (methyl acrylate, methyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate), methacrylic esters (methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylene) Glycol dimethacrylate), vinyl ethers (methyl vinyl ether, etc.), vinyl esters (vinyl acetate, vinyl propionate, vinyl cinnamate etc.), acrylamides (N-tert-butylacrylamide, N-cyclohexylacrylamide, etc.), Ruamido acids, can be mentioned acrylonitrile derivatives. Further, the transparent substrate can be used glass, either plastic.

In addition, as the particles, metals, metal oxides, resins, bubbles, or the like can be widely used. These may be used alone or in combination. Examples of the metal include zirconium, aluminum, tantalum, titanium, tin, indium, and the like, and examples of the metal oxide include those oxides. Examples of the resin include silica / acrylic compound, methacrylic compound, melamine / formaldehyde condensate, and silicone resin.
The transparent base material on which a white scattering layer is formed by sandblasting on the binder resin or the surface can change the transmission characteristics by containing a coloring material that absorbs part of the visible range such as a pigment, a dye or a fluorescent agent. . That is, the scattered light can be scattered when the scattered light is colored by the coloring material or visible light is transmitted.
The transmission characteristics can be changed by incorporating a dye that transmits infrared rays and absorbs part of the visible range into a binder resin or a transparent substrate on which a white scattering layer is formed by sandblasting.
The transmission characteristics can be changed by adding an ultraviolet absorber to a binder resin or a transparent substrate on which a white scattering layer is formed by sandblasting. Depending on the material of the binder resin and the transparent base material, deterioration due to ultraviolet rays may cause a reduction in deterioration such as yellowing. Therefore, the object is to prevent this and increase the durability of the material. Examples of the UV absorber include 2-methoxyhexyl paramethoxycinnamate and 2-ethylhexyl paradimethylaminobenzoate as organic compounds, and fine particles of titanium oxide and zinc oxide as inorganic compounds.

The invention according to claim 10 is the invention according to any one of claims 1 to 9, wherein the infrared communication optical article according to claim 1 is arranged on at least the outer surface or the inner surface of a substrate that transmits infrared rays. The gist.
In such a configuration, the optical article for infrared communication has a white appearance as in any one of claims 1 to 9, and is 12% or more in the wavelength band of the infrared communication band required for the infrared communication system. The transmittance will be ensured. Here, the “outer surface of the substrate” means the surface facing the outside of the casing of the device to which the infrared communication light receiving unit is mounted, and the “inner surface” means the surface facing the inner side of the casing. is there.
The “substrate” is, for example, an optical article for infrared communication that is formed into a close contact when the optical article is thin or flexible, and the shape and thickness thereof are not limited. Specifically, for example, a transparent and hard plate-like body made of a resin material such as glass, polycarbonate, or acrylic resin is assumed.

According to an eleventh aspect of the present invention, in the invention according to the tenth aspect, the substrate transmits infrared rays and is prevented from transmitting visible light, and the optical article for infrared communication is disposed on an outer surface of the substrate. The gist of this is.
In the invention of claim 12, in the invention of claim 10, the base is made of a transparent material, and the infrared communication optical article is arranged on the inner surface of the base, and the optical article apparatus is provided. The gist of the invention is that a visible light absorbing layer that transmits infrared light and blocks visible light transmission is disposed on the inner surface side.
According to a thirteenth aspect of the invention, in the tenth aspect of the invention, the base is made of a transparent material, and the infrared communication optical article is disposed on the outer surface of the base, and the base and the optical The gist of the invention is that a visible light absorbing layer that transmits infrared rays and blocks visible light transmission is disposed between articles or on the inner surface side of the substrate.
By adopting the configuration in which visible light transmission is blocked on the inner surface side of the infrared communication optical article as described above, the visible light absorbing layer is darkened by the visible light transmitted through the infrared communication optical article. Therefore, even if the cloudiness value (generally evaluated as a haze amount) is white in the optical article for infrared communication, the inside of the infrared port can be prevented from being visually observed from the outside.
Here, the “visible light absorbing layer” includes, for example, a layer structure in which visible light is absorbed to exhibit a dark color (black) and a visible light absorbing dye that transmits infrared rays is uniformly dispersed in a binder resin. . It is also possible to configure with a dielectric multilayer film. The “visible light absorbing layer” does not necessarily need to exist only in a thin form such as a film body, and includes a case where it has a sufficient thickness.

The invention according to claim 14 is the invention according to claim 10, wherein the base is made of a transparent material, the optical article for infrared communication is arranged on the inner surface of the base, and an apparatus for the optical article is provided. The gist is that a reflective layer that transmits infrared rays and reflects part or all of visible light is disposed on the inner surface side.
According to a fifteenth aspect of the invention, in the tenth aspect of the invention, the base is made of a transparent material, and the infrared communication optical article is disposed on the outer surface of the base, and the base and the optical are the same. The gist of the invention is that a reflective layer that transmits infrared light between the articles or on the inner surface of the apparatus on the same substrate and reflects part or all of visible light toward the optical article for infrared communication is disposed.
Since the reflective layer is disposed on the inner surface side of the optical article for infrared communication as described above, visible light transmitted through the optical article for infrared communication is reflected by the reflective layer and again collides with particles in the optical article for infrared communication to cause irregular reflection. As a result, the haze value of the optical article for infrared communication increases. That is, whiteness is further improved. The “reflective layer” does not necessarily need to exist only in a thin form such as a film body, and includes a case where it has a sufficient thickness.

For this purpose, it is most preferable to use a dielectric multilayer film as the reflective layer. This is because if the dielectric multilayer film is used, the reflection layer itself can be set to a high reflectance without being scattered and reflected, and all visible light can be reflected again toward the optical article for infrared communication. A dielectric multilayer film is a film that selectively transmits and reflects light in a predetermined wavelength range. Generally, a multilayer film itself has a multilayer film structure. It is possible to freely control the transmitted light (that is, reflected light) by designing the number of dielectric multilayer films, the film material, and the film thickness. Each constituent film layer of the multilayer film is a dielectric made of a metal oxide, metal nitride, metal fluoride, or the like. For example, TiO ₂ (titanium dioxide), Ta ₂ O ₅ (tantalum pentoxide), ZrO ₂ (oxidation) Zircon), Al ₂ O ₃ (aluminum oxide), Nb ₂ O ₅ (niobium pentoxide), SiO ₂ (silicon oxide), MgF ₂ (magnesium fluoride), ZnO ₂ (zinc oxide) HfO ₂ (hafnium oxide), Examples thereof include CaF ₂ (calcium fluoride) and SiN (silicon nitride). The dielectric multilayer film is preferably composed of alternating layers in which a low refractive index material and a high refractive index material are alternately laminated in a light transmitting direction through at least two kinds of dielectrics.

In the invention of claim 16, a visible light absorbing layer that transmits infrared light and blocks visible light transmission is disposed on the inner surface side of the optical article for infrared communication according to any one of claims 1 to 9. The gist.
As a result, the inside of the infrared port can be prevented from being visually observed from the outside even when the color of the optical article for infrared communication is a low cloudiness value. Claim 8 assumes a case where the optical article for infrared communication itself has sufficient rigidity and does not require a base as described above. The definition of “visible light absorbing layer” is the same as described above.
In invention of Claim 17, infrared rays are permeate | transmitted to the apparatus inner surface side of the optical article for infrared communication in any one of Claims 1-9, and a part or all of visible light is in the said optical article for infrared communication. The gist of the invention is that a reflective layer for reflection is disposed.
As described above, the visible light transmitted through the infrared communication optical article is reflected by the reflective layer and collides with particles in the infrared communication optical article to be scattered and reflected. As a result, the infrared communication optical article The haze value increases. That is, whiteness is further improved.

The gist of the invention according to claim 18 is that, in the invention according to any one of claims 10 to 17, the protective layer is disposed at the outermost layer position.
Thereby, it is possible to prevent deterioration due to dirt such as scratches and sebum accompanying use of the device.
The protective layer can be hardened with a hard coat, etc., and can be formed by spraying, dipping, sputtering, vacuum deposition, etc. with a combination of antifouling properties and slipperiness such as a water repellent coat. it can. In particular, when an organic silicon-based water repellent treatment is performed by a vacuum deposition method, it has excellent slipperiness and antifouling properties, and there is an advantage that the coating agent does not accumulate in detail by an immersion method or a spray method. In addition, since the film thickness can be reduced (for example, 10 nm or less) in the vacuum deposition method, the influence on the generation of interference colors and the spectral characteristics of the dielectric multilayer film can be extremely reduced.

  According to the inventions described in the above claims, there are provided an optical article for infrared communication and a light receiving section for infrared communication that can transmit only a large number of wavelengths in the infrared communication band, and that are visually observable white. As a result, the degree of freedom in designing the design of a device equipped with an infrared port is expanded.

The schematic block diagram which has arrange | positioned the light-receiving part for infrared communication which is embodiment of this invention in the infrared port. Explanatory drawing explaining infrared light being permeate | transmitted while external light is scattered and reflected in a scattering reflection layer in the infrared communication light-receiving part of Embodiment 1. FIG. In the infrared communication light receiving unit according to the second embodiment, it will be described that visible light is scattered and reflected by the scattering reflection layer, a part of the visible light is absorbed by the visible light absorption layer, and only infrared light is transmitted. Illustration. Explanatory drawing explaining that visible light is scattered and reflected by the scattering reflection layer, a part of visible light is reflected by the reflection layer, and only infrared rays are transmitted in the infrared communication light receiving section of the third embodiment. . Explanatory drawing explaining that external light is scattered and reflected by the scattering reflection layer, only infrared rays are transmitted, and the substrate is protected by the hard coat layer in the infrared communication light receiving section of the fourth embodiment. 10 is a graph for explaining spectral reflection characteristics of a reflective layer according to Embodiment 3. Explanatory drawing explaining infrared light being permeate | transmitted while external light is scattered and reflected by a scattering reflection layer in the infrared communication light-receiving part of Embodiment 5. FIG. In the infrared communication light receiving unit according to the sixth embodiment, external light is scattered and reflected by the scattering reflection layer, a part of the visible light is reflected by the reflection layer, and a part of the visible light is absorbed by the visible light absorption layer. Explanatory drawing explaining that only infrared rays are transmitted. Explanatory drawing explaining that external light is scattered and reflected by the scattering reflection layer, a part of visible light is reflected by the reflection layer, and only infrared rays are transmitted in the infrared communication light receiving unit of the seventh embodiment. . Explanatory drawing explaining that external light is scattered and reflected by a scattering reflection layer and infrared rays are transmitted in the infrared communication light receiving unit of the eighth embodiment. The graph explaining the spectral transmission characteristic of the reflection layer of Examples 1-7 and the comparative example 1 which made the vertical axis | shaft the transmittance | permeability. The graph explaining the spectral transmission characteristic of Example 8 and 9 which made the vertical axis | shaft the transmittance | permeability. The graph explaining the spectral transmission characteristic of Example 10 which made the vertical axis | shaft the transmittance | permeability. The graph explaining the spectral reflection characteristic of Examples 11-13 which made the vertical axis | shaft the reflectance. The graph explaining the spectral transmission characteristic of Examples 11-13 which made the vertical axis | shaft the transmittance | permeability. The graph explaining the spectral transmission characteristic of Example 13 which made the vertical axis | shaft the transmittance | permeability. The graph explaining the spectral transmission characteristic of dye itself for the comparison with Example 17 and 18 which made the vertical axis | shaft the transmittance | permeability. The graph explaining the spectral transmission characteristic of Examples 17 and 18 which made the vertical axis | shaft the transmittance | permeability. The graph explaining the spectral transmission characteristic of Example 19 which made the vertical axis | shaft the transmittance | permeability. The graph explaining the spectral transmission characteristic of Example 20 which made the vertical axis | shaft the transmittance | permeability.

As shown in FIG. 1, the case body 12 of the portable information terminal is provided with a port 13 for infrared communication and infrared control. A light receiving unit 14 including a light emitting element, a light receiving element, and the like is disposed inside the case body 12 so as to face the port 13. The port 13 is assumed to be fitted with infrared communication light receiving portions (hereinafter simply referred to as light receiving portions) 15 to 18 and 30 to 33 according to the first to fourth embodiments. In the following embodiments, the same components are denoted by the same reference numerals and description thereof is omitted. Further, description of a condensing optical system that is not directly related to the present invention and a composite element that performs light projection and reception with one element is omitted.
(Embodiment 1)
First, the light receiving unit 15 according to the first embodiment will be described with reference to FIG. The light receiving unit 15 includes a transparent acrylic substrate 21 that transmits infrared rays, and a scattering reflection layer 23 that is an optical article for infrared communication formed on the outer surface of the substrate 21. In the first embodiment, the substrate 21 has a thickness of several mm. The scattering reflection layer 23 is a thin film formed by uniformly dispersing fine particles in a binder resin made of an acrylic resin. The fine particles have a part or all of the particle diameter satisfying the above formula 1 and are white by visible light.
In such a light receiving unit 15, the following optical action occurs with respect to external light.
First, visible light of the external light is scattered and reflected by the fine particles of the scattering reflection layer 23, so that the amount of visible light transmitted is attenuated to the extent that the light receiving element of the light receiving unit 14 is not affected by malfunction or the like. The scattering reflection layer 23 is white due to the visible light scattered and reflected by the fine particles.
On the other hand, although some infrared rays may be scattered and reflected by the scattering reflection layer 23, a predetermined transmission amount is secured, so that the infrared transmission light passes through the scattering reflection layer 23 and further passes through the substrate 21 and reaches the light receiving unit 14. It will be. Therefore, data communication using infrared rays in the light receiving unit 15 is possible.

(Embodiment 2)
Next, the light receiving unit 16 according to the second embodiment will be described with reference to FIG. The light receiving unit 16 includes a transparent acrylic substrate 21 that transmits infrared rays, a scattering reflection layer 23 formed on the outer surface of the substrate 21, and a visible light absorption layer 26 formed on the inner surface of the substrate 21. Yes. The visible light absorption layer 26 is a thin film.
In such a light receiving unit 16, the following optical action occurs with respect to external light.
First, visible light of the external light is scattered and reflected by the fine particles of the scattering reflection layer 23, and the scattering reflection layer 23 exhibits white.
Here, when a part of the visible light is scattered and reflected or reaches the visible light absorbing layer 26 without colliding with the fine particles, the visible light is absorbed and the visible light absorbing layer 26 is darkened. Therefore, even if the cloudiness value in the scattering reflection layer 23 is small, the inside of the substrate 21 is not visually observed due to the blinding effect by the visible light absorption layer 26. Further, visible light can be prevented from reaching the light receiving unit 14. On the other hand, a part of infrared rays is scattered and reflected by the scattering reflection layer 23 but passes through the scattering reflection layer 23 with a predetermined transmission amount, and further passes through the visible light absorption layer 26 and the substrate 21 to reach the light receiving unit 14. Become. Therefore, data communication using infrared rays in the light receiving unit 15 is possible. An example of the reflectance characteristic of the visible light absorbing layer 26 used in the second embodiment is shown in FIG.

(Embodiment 3)
Next, the light receiving unit 17 according to the third embodiment will be described with reference to FIG. The light receiving unit 17 includes a transparent acrylic substrate 21 as a base material that transmits infrared rays, a scattering reflection layer 23 formed on the outer surface of the substrate 21, and a reflection layer 27 made of a dielectric multilayer thin film formed on the inner surface of the substrate 21. And.
In such a light receiving unit 17, the following optical action occurs with respect to external light.
First, visible light of the external light is scattered and reflected by the fine particles of the scattering reflection layer 23, and the scattering reflection layer 23 exhibits white.
Here, when a part of the visible light is scattered and reflected or reaches the reflection layer 27 without colliding with the fine particles, the visible light is reflected, and a part of the visible light is scattered and reflected by the fine particles of the scattering reflection layer 23. Accordingly, in the third embodiment, the haze value of the scattering reflection layer 23 is larger than that in the above embodiment. In the present embodiment, since the reflection layer 27 has a characteristic of mainly reflecting the blue wavelength band, the scattering reflection layer 23 is colored pale. A design example of the reflective layer 27 is shown in Table 1 below. The reflectance characteristics of the reflective layer 27 are shown in FIG.

(Embodiment 4)
Next, the light receiving unit 18 according to the fourth embodiment will be described with reference to FIG. The light-receiving unit 18 includes a transparent acrylic substrate 21 that transmits infrared rays, a scattering reflection layer 23 formed on the inner surface of the substrate 21, and a hard coat layer 28 as a protective layer formed on the outer surface of the substrate 21. I have. In addition, when a hard coat process is performed on the outer surface of such an acrylic substrate 21, a base treatment layer is required. However, the base treatment layer is not shown in FIG. In such a configuration, the hard coat layer 28 can prevent deterioration of the substrate 21 due to scratches, sebum, and the like.

(Embodiment 5)
Next, the light receiving unit 30 according to the fifth embodiment will be described with reference to FIG. The light receiving unit 30 according to the fifth embodiment has a configuration in which the base body is not provided, and the scattering reflection layer 23 is not a thin film but has a thickness similar to that of the substrate 21. A reflection layer 27 made of a dielectric multilayer film is formed on the inner surface of the scattering reflection layer 23. The reflectance characteristics of the reflective layer 27 are the same as described above.
In such a light receiving unit 30, the following optical action occurs with respect to external light.
First, visible light of the external light is scattered and reflected by the fine particles of the scattering reflection layer 23, and the scattering reflection layer 23 exhibits white.
Here, when a part of the visible light is scattered and reflected or reaches the reflection layer 27 without colliding with the fine particles, the visible light is reflected, and a part of the visible light is scattered and reflected by the fine particles of the scattering reflection layer 23. Therefore, in the fifth embodiment, the cloudiness value of the scattering reflection layer 23 is increased as in the third embodiment.

(Embodiment 6)
Next, the light receiving unit 31 according to the sixth embodiment will be described with reference to FIG. The light receiving unit 31 includes a transparent acrylic substrate 21 that transmits infrared rays, a reflection layer 27 formed on the outer surface of the substrate 21, and a scattering reflection layer 23 formed on the outer surface of the reflection layer 27, that is, the outermost surface. And a visible light absorbing layer 26 formed on the inner surface of the substrate 21. That is, the order is the scattering reflection layer 23, the reflection layer 27, the substrate 21, and the visible light absorption layer 26 in order from the outermost layer. The reflectance characteristics of the visible light absorption layer 26 and the reflection layer 27 are the same as described above.
In such a light receiving unit 31, the following optical action occurs with respect to external light.
First, visible light of the external light is scattered and reflected by the fine particles of the scattering reflection layer 23, and the scattering reflection layer 23 exhibits white.
Here, when a part of the visible light is scattered and reflected or reaches the reflection layer 27 without colliding with the fine particles, the visible light is reflected, and a part of the visible light is scattered and reflected by the fine particles of the scattering reflection layer 23. Accordingly, in the sixth embodiment, the haze value of the scattering reflection layer 23 is increased as in the third embodiment.
Further, when the visible light transmitted through the reflective layer 27 reaches the visible light absorbing layer 26, the visible light is absorbed and the visible light absorbing layer 26 is darkened. Therefore, even if the cloudiness value in the scattering reflection layer 23 is small, the inside of the substrate 21 is not visually observed due to the blinding effect by the visible light absorption layer 26. Further, visible light can be prevented from reaching the light receiving unit 14. On the other hand, a part of infrared rays is scattered and reflected by the scattering reflection layer 23 but passes through the scattering reflection layer 23 with a predetermined transmission amount, and further passes through the visible light absorption layer 26 and the substrate 21 to reach the light receiving unit 14. Become. Therefore, data communication by infrared rays in the light receiving unit 31 is possible.

(Embodiment 7)
Next, the light receiving unit 32 according to the seventh embodiment will be described with reference to FIG. The light receiving section 32 of the seventh embodiment has a structure in which the visible light absorption layer 26 is not thin but has a thickness comparable to that of the substrate 21 without having a base. A reflective layer 27 made of a dielectric multilayer film is formed on the outer surface of the visible light absorbing layer 26, and a scattering reflection layer 23 is formed on the outer surface of the reflective layer 27, that is, the outermost surface. The reflectance characteristics of the visible light absorption layer 26 and the reflection layer 27 are the same as described above.
In such a light receiving section 32, the following optical action occurs with respect to external light.
First, visible light of the external light is scattered and reflected by the fine particles of the scattering reflection layer 23, and the scattering reflection layer 23 exhibits white.
Here, when a part of the visible light is scattered and reflected or reaches the reflection layer 27 without colliding with the fine particles, the visible light is reflected, and a part of the visible light is scattered and reflected by the fine particles of the scattering reflection layer 23. Accordingly, in the seventh embodiment as well, the haze value of the scattering reflection layer 23 is increased as in the third embodiment.
Further, when the visible light further transmitted through the reflection layer 27 reaches the visible light absorption layer 26, the visible light is absorbed and the visible light absorption layer 26 is darkened. Therefore, even if the cloudiness value in the scattering reflection layer 23 is small, the inside of the light receiving unit 32 is not visually observed due to the blinding effect by the visible light absorption layer 26. Further, visible light can be prevented from reaching the light receiving unit 14. On the other hand, a part of infrared rays is scattered and reflected by the scattering reflection layer 23, but passes through the scattering reflection layer 23 with a predetermined transmission amount, and further passes through the reflection layer 27 and the visible light absorption layer 26 to reach the light receiving unit 14. It becomes. Therefore, data communication by infrared rays in the light receiving unit 32 is possible.
(Embodiment 8)
Next, the light receiving unit 33 according to the eighth embodiment will be described with reference to FIG. The light receiving unit 33 of the eighth embodiment has a structure in which the base body is not provided and the scattering reflection layer 23 is not a thin film but has a thickness comparable to that of the substrate 21. That is, the light receiving unit 33 has a more basic configuration without the reflective layer 27 in the seventh embodiment.
In such a light receiving section 33, the following optical action occurs with respect to external light.
First, visible light of the external light is scattered and reflected by the fine particles of the scattering reflection layer 23, so that the amount of visible light transmitted is attenuated to the extent that the light receiving element of the light receiving unit 14 is not affected by malfunction or the like. The scattering reflection layer 23 is white due to the visible light scattered and reflected by the fine particles. On the other hand, although a part of infrared rays is scattered and reflected by the scattering reflection layer 23, it passes through the scattering reflection layer 23 with a predetermined transmission amount and reaches the light receiving unit 14. Therefore, data communication by infrared rays in the light receiving unit 33 is possible.

(Other embodiments)
-Although the example which uses the scattering reflection layer 23 as an infrared communication optical article was given in the said embodiment, the optical for infrared communication which formed the scattering reflection layer which carried out the sandblast process on the outer surface of the transparent base material made from transparent acrylic, for example An article may be used instead of the scattering reflection layer 23. It is possible to replace with such a configuration in the first to seventh embodiments.
In the fifth embodiment, the visible light absorbing layer 26 may be formed at the same position instead of the reflective layer 27. Further, the visible light absorbing layer 26 may be disposed outside the reflective layer 27.
In the fifth embodiment, the visible light absorbing layer 26 may be formed on the inner surface of the reflective layer 27. That is, an arrangement configuration in which the reflection layer 27 is sandwiched between the scattering reflection layer 23 and the visible light absorption layer 26 of the fifth embodiment may be employed.
In the sixth embodiment, the visible light absorbing layer 26 on the inner surface of the substrate 21 may be omitted.
In the seventh embodiment, the reflection layer 27 may not be formed, that is, the visible light absorption layer 26 may be directly formed with the scattering reflection layer 23.
-You may make it apply the hard-coat layer 28 of Embodiment 4 to the other Embodiment 2. FIG.
In Embodiment 3, the reflective layer 27 is disposed on the inner surface (apparatus side) than the diffuse reflective layer 23. However, the reflective layer 27 may be disposed on the outer side of the scattering reflective layer 23. In this case, the reflective layer 27 needs to have not only infrared rays but also visible light transmission performance.
In the above description, the transparent acrylic resin is used as the material for the substrate 21. However, other plastics may be used.

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples.
<Example 1>
The embodiment is a light receiving section that can be used in the first to fourth embodiments. The same applies to Examples 2 to 9 below.
(Preparation of solution for diffuse reflection layer)
An acrylic urethane resin paint (manufactured by Rock Paint Co., Ltd., product name: 088-0201 opal white) was used as the binder and fine particles constituting the layer. In the present paint, 10 to 15% by weight of titanium dioxide fine particles (particle size: about 20 nm) are dispersed. This paint was diluted with toluene to adjust the solid content to 5 to 7.5% by weight.
(Formation of diffuse reflection layer)
A film was formed on the surface of a plate-like glass substrate having a thickness of 2 mm and a refractive index of 1.54 by the spin coating method under the following conditions. As spin coating conditions, the rotation speed was 1500 rpm and the rotation time was 90 seconds. After film formation, the film was naturally dried at room temperature and normal pressure. As a result, the light-receiving part of Example 1 having a haze of 22 was obtained. The optical characteristics of Example 1 are shown in FIG. FIG. 11 is a graph of spectral transmittance characteristics with the vertical axis representing transmittance and the horizontal axis representing wavelength. The same applies to FIGS. 12 to 20 (except for FIG. 14).

<Example 2>
The solution for the irregular reflection layer was prepared in the same manner as in Example 1, and the solution was diluted with toluene so as to have a solid content of 6.7 to 10%. With the obtained solution, the light receiving part of Example 2 having a haze of 42 was obtained by spin coating under the same conditions as described above. The optical characteristics of Example 2 are shown in FIG.
<Example 3>
The solution for the irregular reflection layer was prepared in the same manner as in Example 1, and the solution was diluted with toluene so as to have a solid content of 6.7 to 10%. With the obtained solution, a light receiving part of Example 3 having a haze as a coating film of 43 was obtained by spin coating under the same conditions with a slightly larger amount than Example 2. The optical characteristics of Example 3 are shown in FIG.
<Example 4>
In the same manner as in Example 1, a solution for the irregular reflection layer was prepared, and the solution was diluted with toluene so as to have a solid content of 8 to 12%. Using the obtained solution, the light receiving part of Example 4 having a haze of 63 as a coating film was obtained by the spin coating method under the same conditions as in Example 1. The optical characteristics of Example 4 are shown in FIG.
<Example 5>
In the same manner as in Example 1, a solution for the irregular reflection layer was prepared, and the solution was diluted with toluene so as to have a solid content of 8 to 13%. With the obtained solution, a light receiving part of Example 5 having a haze of 65 as a coating film was obtained by spin coating under the same conditions with a slightly larger amount than Example 2. The optical characteristics of Example 5 are shown in FIG.
<Example 6>
The solution for the irregular reflection layer was prepared in the same manner as in Example 1, and the solution was diluted with toluene so as to have a solid content of 6.7 to 10%. With the obtained solution, a light receiving part of Example 6 having a haze of 82 as a coating film was obtained by spin coating under the same conditions with a slightly larger amount than Example 5. The optical characteristics of Example 6 are shown in FIG.
<Example 7>
The solution for the irregular reflection layer was prepared in the same manner as in Example 1, and the solution was diluted with toluene so as to have a solid content of 6.7 to 10%. Using the obtained solution, a light receiving portion of Example 7 having a haze as a coating film of 95 or more was obtained by spin coating under the same conditions with a slightly larger amount than Example 6. The optical characteristics of Example 7 are shown in FIG.
<Comparative Example 1>
The solution for the irregular reflection layer was prepared in the same manner as in Example 1, and the solution was diluted with toluene so as to have a solid content of 6.7 to 10%. With the obtained solution, a light receiving part of Example 8 having a haze as a coating film of 95 or more was obtained by spin coating under the same conditions with a slightly larger amount than Example 6. The optical characteristics of Comparative Example 1 are shown in FIG.

<Example 8>
The solution for the irregular reflection layer was prepared in the same manner as in Example 1, and the solution was diluted with toluene so as to have a solid content of 6.7 to 10%. With the obtained solution, a light receiving part of Example 8 having a haze as a coating film of 60 was obtained by spin coating under the same conditions with a slightly larger amount than Example 6. The optical characteristics of Example 8 are shown in FIG.
<Example 9>
On the inner surface of the white infrared communication optical article formed in Example 8, a black infrared communication optical article (so-called IR black) as the visible light absorbing layer 26 was overlaid. The optical characteristics at this time are shown in FIG.

Examples 10 to 13 are examples assuming the light receiving unit 16 as in the third embodiment.
<Example 10>
1) Calcium carbonate fine particles having a particle diameter of 100 nm (vigot-10, manufactured by Shiroishi Kogyo Co., Ltd.) for eyeglasses (material refractive index: 1.6) 1.5% by weight of the fine particles dispersed in a base material Then, 1% by weight of an ultraviolet absorber (Dynesorb T-53 manufactured by Daiwa Kasei Laboratories Co., Ltd.) was mixed and molded into a flat plate having a thickness of 0.69 (hereinafter referred to as resin material A). The haze at the stage of the resin material A was 18.5.
2) A SiO ₂ / TiO ₂ 45 layer was formed as a cold mirror film on one side of a transparent plate glass, and a SiO ₂ / TiO ₂ 5 layer was formed as an AR film on the opposite side by vacuum deposition (hereinafter referred to as mirror material A). ).
3) The resin material A was bonded to the cold mirror film 45 layer side of the mirror material A with an adhesive (SYLGARD® 184 manufactured by Dow Corning Toray). The optical characteristics of Example 10 are shown in FIG.

<Example 11>
Disperse the fine particles 1.5% by weight in a resin for spectacles (material refractive index: 1.6) prepared by adjusting calcium carbonate fine particles (vigot-10 manufactured by Shiraishi Kogyo Co., Ltd.) having a particle size of 100 nm for spectacles, A fluorescent pigment (manufactured by Epoch Co., Ltd .: fluorescent pigment blue I-02-001B) was dispersed by 0.5% by weight and molded into a flat plate having a thickness of 2 mm. The haze of Example 11 was 81.7. In Example 11, as shown in the reflection characteristics of FIG. 14, the reflectance in the wavelength region near blue is larger than that of other visible light, and bluish white is exhibited to the naked eye. The optical characteristics of Example 11 are shown in FIG.
<Example 12>
3% by weight of the above fine particles are dispersed in a base material for a spectacle resin (material refractive index: 1.6) in which calcium carbonate fine particles (vigot-10 manufactured by Shiraishi Kogyo Co., Ltd.) having a particle diameter of 100 nm are prepared for spectacles, and fluorescent pigment (Epoch Co., Ltd .: Lime l-02-001LI) was dispersed in an amount of 0.5% by weight and molded into a flat plate having a thickness of 2 mm. The haze of Example 12 was 96.7. In Example 12, as shown in the reflection characteristics of FIG. 14, the reflectance in the wavelength range near blue and yellow is larger than that of other visible light, and greenish white is exhibited to the naked eye. The optical characteristics of Example 12 are shown in FIG.
<Example 13>
3% by weight of the above fine particles are dispersed in a base material for a spectacle resin (material refractive index: 1.6) in which calcium carbonate fine particles (vigot-10 manufactured by Shiraishi Kogyo Co., Ltd.) having a particle diameter of 100 nm are prepared for spectacles, and fluorescent pigment 0.5% by weight (manufactured by Epoch Co., Ltd .: Red l-02-001R) was dispersed and molded into a flat plate having a thickness of 2 mm. The haze of Example 13 was 88.2. In Example 13, as shown in the reflection characteristics of FIG. 14, the reflectance in the wavelength region near blue and red is larger than that of other visible light, and pinkish white is exhibited to the naked eye. The optical characteristics of Example 13 are shown in FIG.

Examples 14 to 16 are examples in which the light receiving unit 33 is assumed as in the tenth embodiment, and the transmittance of 12% is maintained at a wavelength of 850 nm as an infrared band, while the transmittance in the visible region is 5 on average. It is an example of controlling to below%.
<Example 14>
3% by weight of the above-mentioned fine particles are dispersed in a base material for a spectacle resin (material refractive index: 1.6) in which calcium carbonate fine particles having a particle diameter of 150 nm (vigot-15 manufactured by Shiraishi Kogyo Co., Ltd.) are prepared for spectacles. It was molded into a 4.4 mm flat plate. The haze was 90 or more. The optical characteristics of Example 14 are shown in FIG.
<Example 15>
The above fine particles are dispersed in an amount of 0.5% by weight in a resin for spectacles (refractive index of material: 1.6) prepared by using silica having a particle size of 2.2 μm (Fine Seal manufactured by Tokuyama Co., Ltd.) for the spectacles. Molded into a 6 mm flat plate. The haze was 90 or more. The optical characteristics of Example 15 are shown in FIG. <Example 16>
2. Disperse 0.7% by weight of the fine particles in a spectacle resin (material refractive index: 1.6) base material prepared by using silica (Tokuyama U made by Tokuyama Corporation) having a particle size of 10 μm for spectacles; Molded into a 3 mm flat plate. The haze was 90 or more. The optical characteristics of Example 16 are shown in FIG.
In addition, the characteristic of the resin material A of Example 7 is illustrated on FIG. 16 as a comparison of the optical characteristics of Examples 14-16.

<Example 17>
3% by weight of the above-mentioned fine particles are dispersed in a base material for a spectacle resin (material refractive index: 1.6) in which calcium carbonate fine particles (Vigot-10 manufactured by Shiraishi Kogyo Co., Ltd.) having a particle diameter of 100 nm are prepared for spectacles, and absorbs ultraviolet rays. 1% by weight of an agent (Dynesorb T-53 manufactured by Daiwa Kasei Laboratories Co., Ltd.) was mixed and molded into a flat plate having a thickness of 1.3 mm. The haze at this stage was 53.45. Dye (Nippon Kayaku Co., Ltd .: Kayalon Polyster Yellow 5R-SE200) is added to 3 g / liter of water with a surfactant (Nippon Emulsifier Co., Ltd. New Call 210) and a carrier agent (Daiwa Chemical Industry Co., Ltd .: Die Carrier) DK-CN) was added, and the mixture was immersed in 90 ° C. for 30 minutes to obtain Example 17. Example 17 exhibits orange white color with the naked eye. For comparison, a resin (resin material B) in which only the dye under the same conditions as in Example 17 was dispersed in the above spectacle resin was prepared. Moreover, what was adjusted on the conditions which did not put only the dye in Example 17 was created for the comparison. FIG. 17 shows the transmission characteristics of the resin material B. The optical characteristics of Example 17 are shown in FIG.
<Example 18>
3% by weight of the above-mentioned fine particles are dispersed in a base material for a spectacle resin (material refractive index: 1.6) in which calcium carbonate fine particles (Vigot-10 manufactured by Shiraishi Kogyo Co., Ltd.) having a particle diameter of 100 nm are prepared for spectacles, and absorbs ultraviolet rays. 1% by weight of an agent (Dynesorb T-53 manufactured by Daiwa Kasei Laboratories Co., Ltd.) was mixed and molded into a flat plate having a thickness of 1.3 mm. The haze at this stage was 53.45. This plate material is dye (FSP BLUE AUL-S made by Futaba Sangyo Co., Ltd.) in 3 g / liter of water. Surfactant (Nippon Emulsifier Co., Ltd. New Call 210) and carrier agent (Daiwa Chemical Industry Co., Ltd .: Die Carrier DK-CN) Was added and immersed in 30 ° C. for 30 minutes to obtain Example 18. Example 18 is bluish white with the naked eye. For comparison, a resin in which only a dye was dispersed under the same conditions as in Example 18 was prepared (referred to as resin material C). FIG. 17 shows the transmission characteristics of the resin material C. The optical characteristics of Example 18 are shown in FIG.

<Example 19>
1) One side surface of quartz glass was blasted for about several tens of seconds at a pressure of 0.2 to 0.3 MPa using a sand blasting abrasive white alundum WA # 100 (hereinafter referred to as blasting material A). The haze at the stage of the blast material A was 79.
2) A SiO ₂ / TiO ₂ 49 layer was formed as a cold mirror film on one side of the transparent plate glass, and an SiO ₂ / TiO ₂ 5 layer was formed as an AR film on the opposite side by vacuum deposition (hereinafter referred to as mirror material B). ).
3) The blast material was superposed on the cold mirror film 49 layer side of the mirror material B without using an adhesive on the blast side. The optical characteristics of Example 19 are shown in FIG.

<Example 20>
1) The surface of a 1 mm thick acrylic resin substrate was lightly rubbed with a cloth containing 100% acetone, and then air-dried for 30 minutes (hereinafter referred to as acetone-treated material A). The haze was 87.
2) as a cold mirror film on one side of the glazing, SiO ₂ / TiO ₂ 49 layers was formed by a respective vacuum deposition SiO ₂ / TiO ₂ 5 layers in opposite surface (hereinafter referred to as the mirror material C).
3) The acetone-treated material A was superposed on the cold mirror film 49 layer side of the mirror material C without using an adhesive on the non-treated surface side. The optical characteristics of Example 20 are shown in FIG.

(About communication performance evaluation)
Two commercially available IrDA standard infrared communication type mobile phones were prepared, and a light receiving unit of the same example was attached to each infrared port, and an experiment was conducted to determine whether communication was possible with a distance of 20 cm. As a result, communication was possible for Examples 1 to 20, but communication was not possible in Comparative Example 1.
(About white color development)
The haze about each said Example was measured using the haze meter, and the above values were obtained. In all cases, sufficient cloudiness was obtained.

  15-18, 30-33 ... Light-receiving part for infrared communication, 23 ... Scattering reflection layer as an optical article for infrared communication.

  The present invention relates to an infrared communication optical article used for infrared communication and control ports of various electronic devices, and an infrared communication light receiving unit using the optical article.

An infrared communication system using infrared rays is generally used in various electronic devices such as personal computers, PDAs (Personal Digital Assistants) and portable information terminals such as electronic notebooks, digital cameras, and cellular phones. A device capable of infrared communication is equipped with a predetermined (for example, IrDA standard) infrared communication port. In order to prevent malfunctions due to disturbance light of the light receiving element that is sensitive to visible light in the window part of such an infrared communication port, only infrared is used as a light receiving part for infrared communication in order to prevent the inside of the device from being seen. A transparent dark plastic plate is arranged.
However, the infrared communication light receiving unit using such a plate has a black appearance color, and therefore may not match the entire device or a component to be combined due to the design of the electronic device. There was a problem. Although it is possible in principle to color the appearance of the infrared communication light-receiving part in any color by adding a colorant to the transparent plastic substrate or painting, it is possible to maintain transparency in the infrared region. It is extremely difficult to adjust the appearance color to various colors.
Therefore, the applicant has developed a light receiving part for infrared communication having a dielectric multilayer film that transmits infrared light on a substrate as disclosed in Patent Document 1. In such infrared communication light receiving parts, it is possible to design various appearance colors using dielectric multilayer films while maintaining infrared transparency, providing electronic devices with an increased degree of design freedom I was able to do that.

JP 2006-165493 A

Although the light receiving part for infrared communication using the dielectric multilayer film as in Patent Document 1 has a greater degree of freedom in design than the conventional case where a dark plastic plate is used, the dielectric multilayer film is used. Since a metal color is inevitably associated with color development, for example, a relatively large amount of white (as a matter of course, not necessarily limited to white) as a color of the housing of the device is not necessarily disclosed in Patent Document 1. Even such a light receiving part may not be suitable as a design. For this reason, in particular, a white light receiving part for infrared communication has been demanded from a request for further design freedom.
However, white means that external light is diffusely reflected, so even if a white pigment is applied to the substrate, for example, the wavelength range of the visible light range to the infrared communication band is scattered almost over the entire area. Therefore, it was not possible to transmit only the wavelength band of the infrared communication band required. Further, even if a thin color such as frosted glass that allows transmission through the wavelength band of the infrared communication band is applied, the visible light range is received and there is a risk of malfunction of the device due to ambient light. In addition, when the white coloring is not sufficient, there is a possibility that an unfavorable state may occur in terms of design in which the inside of the device can be seen through.
The present invention has been made in order to solve the above-described problems, and the object thereof is to allow only a large amount of light to pass through only the wavelength band of the infrared communication band, and to visually observe light in the visible light range. An object of the present invention is to provide an infrared communication optical article and a light receiving part for infrared communication that are scattered and reflected to exhibit white color.

In order to achieve the above object, in the invention described in claim 1, infrared communication in which a fine uneven shape is formed by roughening the surface of a transparent substrate to form a white scattering layer on the surface of the transparent substrate. An optical article for use, wherein the average uneven diameter of the fine uneven shape of the scattering layer is set so as to have a wavelength dependency such that the light transmittance becomes higher as the wavelength becomes longer, and the scattering layer allows the visible light region to be The gist is that the light is colored white and the transmittance in the infrared wavelength region where the infrared communication band is possible is set to 12% or more.

Further, the gist of the invention described in claim 2 is that, in the invention described in claim 1, the diameter D of the fine concavo-convex shape of the part or the whole is set to a size represented by the following formula.

Further, the gist of the invention described in claim 3 is that, in the invention described in claim 1, the diameter D of the fine concavo-convex shape of the part or the whole is set to a size represented by the following formula.

In invention of Claim 4 , in the invention in any one of Claims 1-3 , 1 or more types of color materials which absorb a part of visible region were contained in the said binder resin or the said transparent base material. This is the gist. In invention of Claim 5 , in invention in any one of Claims 1-4 , in the said binder resin or the said transparent base material, the dye which permeate | transmits infrared rays and absorbs a part of visible region is contained. The gist of this is The gist of the invention according to claim 6 is that, in the invention according to any one of claims 1 to 5, the binder resin or the transparent substrate contains an ultraviolet absorber.

In such a configuration, the optical article for infrared communication has a white appearance due to scattering and reflection of light in the visible light range by the scattering layer formed by finely concavo-convex shapes by uniformly dispersed fine particles or rough surface treatment. It becomes possible. The term “white” refers to the state where the wavelength of visible light is scattered and clouded, but in the case where fine particles are dispersed in the binder resin, all visible light depends on the wavelength dependency when the fine particles are formed. Does not scatter uniformly and may have some saturation. Here, it is necessary to set the average particle size of the fine particles so that the fine particles to be dispersed have a wavelength dependency that increases the light transmittance on the long wavelength side. The transmittance in the wavelength band of the infrared communication band is 12% or more. Accordingly, it is possible to provide an optical article suitable for infrared communication having high infrared transmission performance and low visible light transmission performance.
Here, "infrared communication optical article" means that fine particles are uniformly dispersed in a transparent binder resin, or a fine uneven shape is formed on the surface of a transparent base material by roughening the surface to form a white scattering layer on the substrate surface. An article that is molded to transmit light in the wavelength band of at least the infrared communication band used at the position of the formed infrared communication port, and broadly refers to the presence or absence of flexibility, thickness, shape, The material is not a question.
Here, the “rough surface treatment” can be executed by means such as sand blasting, plasma treatment, chemical treatment, or roughening the die surface when forming a molded product with a die.
Here, sandblasting is a technique in which high-pressure fine particles are sprayed on the surface of a transparent substrate to make it rough. In the plasma processing, a processing gas is introduced into a processing chamber evacuated to a vacuum, and a high frequency voltage is applied to an electrode provided in the processing chamber to generate plasma and perform processing. Here, the surface of the transparent substrate is etched to be roughened by ions or radicals of the processing gas generated by the plasma. Examples of the chemical treatment include a plastic dissolution treatment with an organic solvent.

In addition, the wavelength dependency of the fine particles that increases the light transmittance on the long wavelength side is remarkably increased in the particle diameters that satisfy the equations (1) and (3). This is because the particle size corresponding to the formulas 1 and 3 is Rayleigh scattering, and the fine particles having such a particle size are particularly suitable as the particle size of the fine particles in the optical article for infrared communication. In addition, although the particle size corresponding to the formulas (2) and (4) is slightly larger than those of the formulas (1) and (3), the wavelength dependency of the fine particles is high, which is preferable in the optical article for infrared communication. It can be said.
The relationship between wavelength and particle diameter in scattering can be generally expressed by the following mathematical formula.

In this equation, if a <0.4, the region to which Rayleigh scattering is applied is used, 0.4 <a <3 is the region to which Mie scattering is applied, and a> 3 is the region to which diffraction scattering is applied. In Rayleigh scattering, the amount of scattering is determined by the size and wavelength of the particles. The scattering coefficient Ks of Rayleigh scattering is expressed by the following formula. In Rayleigh scattering, the transmittance varies depending on the wavelength, and the transmittance in a relatively long wavelength region tends to be relatively high.
On the other hand, in large particle size scattering such as Mie scattering and diffraction scattering, the directivity to the front is increased regardless of the wavelength, and the scattering specificity due to the wavelength is reduced, so it is difficult to adjust the transmittance. is there.

Therefore, by changing the blending ratio of different particle diameters and particle types as appropriate, at least the wavelength of the infrared communication band is Rayleigh scattered to give a predetermined transparency to this wavelength region, and the wavelength of the visible light region is relatively It becomes easy to make it scatter greatly, and it becomes possible to make the optical article for infrared communication exhibit a white color.
Here, particles whose particle size in the above formula 1 is the threshold value in the vicinity of the boundary between Rayleigh scattering and Mie scattering at the wavelength of the infrared communication band (around 100 nm when the wavelength of the infrared communication band is 800 to 900 nm) Is a particle that becomes Mie scattering in the visible light region. If this particle diameter is gradually reduced, the visible light wavelength band that shifts to Rayleigh scattering increases. Further, if the particle diameter is smaller than 50 nm, all wavelengths in the visible to infrared communication band are Rayleigh scattered. It is preferable to adjust the optimal transmittance at the wavelength of the infrared communication band and the color of the optical article for infrared communication by utilizing such a difference in scattering action.
In the case of the following particle size, for example, when “particle size is 100 nm”, the particle is not a perfect sphere, so the particle size is the average and the average obtained by calculation of, for example, the triaxial average diameter of each particle. Means a statistical value. Similarly, it does not mean that the particle group as a whole does not include a diameter of 100 nm or less and a diameter of 100 nm or more, but means that the particle group is statistically composed mainly of 100 nm.

  The binder resin is not particularly limited as long as it is substantially transparent at least in the infrared wavelength region and is different from the refractive index of the particles. Examples thereof include polyester, polycarbonate, urethane resin, acrylic resin, methacrylic resin, organosilicon resin, and fluorine resin. More specifically, for example, an ester of polyhydric alcohol and (meth) acrylic acid or a copolymer of a fluorine-based monomer and another monomer (other monomers include, for example, olefins (ethylene, propylene, isoprene, Vinyl chloride, vinylidene chloride, etc.), acrylic esters (methyl acrylate, methyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate), methacrylic esters (methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylene) Glycol dimethacrylate), vinyl ethers (methyl vinyl ether, etc.), vinyl esters (vinyl acetate, vinyl propionate, vinyl cinnamate etc.), acrylamides (N-tert-butylacrylamide, N-cyclohexylacrylamide, etc.), Ruamido acids, can be mentioned acrylonitrile derivatives. Further, the transparent substrate can be used glass, either plastic.

In addition, as the particles, metals, metal oxides, resins, bubbles, or the like can be widely used. These may be used alone or in combination. Examples of the metal include zirconium, aluminum, tantalum, titanium, tin, indium, and the like, and examples of the metal oxide include those oxides. Examples of the resin include silica / acrylic compound, methacrylic compound, melamine / formaldehyde condensate, and silicone resin.
The transparent base material on which a white scattering layer is formed by sandblasting on the binder resin or the surface can change the transmission characteristics by containing a coloring material that absorbs part of the visible range such as a pigment, a dye or a fluorescent agent. . That is, the scattered light can be scattered when the scattered light is colored by the coloring material or visible light is transmitted.
The transmission characteristics can be changed by incorporating a dye that transmits infrared rays and absorbs part of the visible range into a binder resin or a transparent substrate on which a white scattering layer is formed by sandblasting.
The transmission characteristics can be changed by adding an ultraviolet absorber to a binder resin or a transparent substrate on which a white scattering layer is formed by sandblasting. Depending on the material of the binder resin and the transparent base material, deterioration due to ultraviolet rays may cause a reduction in deterioration such as yellowing. Therefore, the object is to prevent this and increase the durability of the material. Examples of the UV absorber include 2-methoxyhexyl paramethoxycinnamate and 2-ethylhexyl paradimethylaminobenzoate as organic compounds, and fine particles of titanium oxide and zinc oxide as inorganic compounds.

The invention according to claim 7 is the invention according to any one of claims 1 to 6 , wherein the optical article for infrared communication according to claim 1 is arranged on at least an outer surface or an inner surface of a substrate that transmits infrared rays The gist.
In such a configuration, similarly to any one of claims 1 to 6 , the optical article for infrared communication exhibits a white appearance, and 12% or more in the wavelength band of the infrared communication band required for the infrared communication system. The transmittance will be ensured. Here, the “outer surface of the substrate” means the surface facing the outside of the casing of the device to which the infrared communication light receiving unit is mounted, and the “inner surface” means the surface facing the inner side of the casing. is there.
The “substrate” is, for example, an optical article for infrared communication that is formed into a close contact when the optical article is thin or flexible, and the shape and thickness thereof are not limited. Specifically, for example, a transparent and hard plate-like body made of a resin material such as glass, polycarbonate, or acrylic resin is assumed.

According to an eighth aspect of the present invention, in the seventh aspect of the present invention, the substrate transmits infrared rays and is prevented from transmitting visible light, and the optical article for infrared communication is disposed on the outer surface of the substrate. The gist of this is.
According to a ninth aspect of the invention, in the seventh aspect of the invention, the substrate is made of a transparent material, and the infrared communication optical article is disposed on the inner surface of the substrate, and the optical article apparatus is provided. The gist of the invention is that a visible light absorbing layer that transmits infrared light and blocks visible light transmission is disposed on the inner surface side.
In the invention of claim 7 is the invention according to claim 1 0, wherein the substrate is composed of a transparent material, as well as disposing the infrared communication optical article to an outer surface of said substrate, said same substrate The gist of the invention is that a visible light absorbing layer that transmits infrared light and blocks visible light transmission is disposed between the optical articles or on the inner surface of the substrate.
By adopting the configuration in which visible light transmission is blocked on the inner surface side of the infrared communication optical article as described above, the visible light absorbing layer is darkened by the visible light transmitted through the infrared communication optical article. Therefore, even if the cloudiness value (generally evaluated as a haze amount) is white in the optical article for infrared communication, the inside of the infrared port can be prevented from being visually observed from the outside.
Here, the “visible light absorbing layer” includes, for example, a layer structure in which visible light is absorbed to exhibit a dark color (black) and a visible light absorbing dye that transmits infrared rays is uniformly dispersed in a binder resin. . It is also possible to configure with a dielectric multilayer film. The “visible light absorbing layer” does not necessarily need to exist only in a thin form such as a film body, and includes a case where it has a sufficient thickness.

In the invention of claim 7 is the invention according to claim 1 1, wherein the substrate is composed of a transparent material, as well as disposing the infrared communication optical article to the inner surface of the substrate, the same optical article The gist is that a reflective layer that transmits infrared light and reflects part or all of visible light is disposed on the inner surface side of the device.
In the invention of claim 7 is the invention according to claim 1 2, wherein the substrate is composed of a transparent material, as well as disposing the infrared communication optical article to an outer surface of said substrate, said same substrate The gist of the invention is that a reflective layer that transmits infrared light between optical articles or on the inner surface side of the substrate and reflects part or all of visible light in the direction of the optical article for infrared communication is provided.
Since the reflective layer is disposed on the inner surface side of the optical article for infrared communication as described above, visible light transmitted through the optical article for infrared communication is reflected by the reflective layer and again collides with particles in the optical article for infrared communication to cause irregular reflection. As a result, the haze value of the optical article for infrared communication increases. That is, whiteness is further improved. The “reflective layer” does not necessarily need to exist only in a thin form such as a film body, and includes a case where it has a sufficient thickness.

For this purpose, it is most preferable to use a dielectric multilayer film as the reflective layer. This is because if the dielectric multilayer film is used, the reflection layer itself can be set to a high reflectance without being scattered and reflected, and all visible light can be reflected again toward the optical article for infrared communication. A dielectric multilayer film is a film that selectively transmits and reflects light in a predetermined wavelength range. Generally, a multilayer film itself has a multilayer film structure. It is possible to freely control the transmitted light (that is, reflected light) by designing the number of dielectric multilayer films, the film material, and the film thickness. Each constituent film layer of the multilayer film is a dielectric made of a metal oxide, metal nitride, metal fluoride, or the like. For example, TiO ₂ (titanium dioxide), Ta ₂ O ₅ (tantalum pentoxide), ZrO ₂ (oxidation) Zircon), Al ₂ O ₃ (aluminum oxide), Nb ₂ O ₅ (niobium pentoxide), SiO ₂ (silicon oxide), MgF ₂ (magnesium fluoride), ZnO ₂ (zinc oxide) HfO ₂ (hafnium oxide), Examples thereof include CaF ₂ (calcium fluoride) and SiN (silicon nitride). The dielectric multilayer film is preferably composed of alternating layers in which a low refractive index material and a high refractive index material are alternately laminated in a light transmitting direction through at least two kinds of dielectrics.

The invention described in claim 1 3, that claim 1 is transmitted through the infrared device inner surface of one of infrared communication optical article 6, and was placed visible light absorbing layer for preventing transmission of visible light Is the gist.
As a result, the inside of the infrared port can be prevented from being visually observed from the outside even when the color of the optical article for infrared communication is a low cloudiness value. Claim 8 assumes a case where the optical article for infrared communication itself has sufficient rigidity and does not require a base as described above. The definition of “visible light absorbing layer” is the same as described above.
In the invention according to claims 1 to 4, either through the infrared device inner surface side of the infrared communication optical article, and part or all of the infrared communication optical articles direction of visible light of claim 1-6 The gist of this is that a reflective layer that reflects light is disposed.
As described above, the visible light transmitted through the infrared communication optical article is reflected by the reflective layer and collides with particles in the infrared communication optical article to be scattered and reflected. As a result, the infrared communication optical article The haze value increases. That is, whiteness is further improved.

In the invention described in claim 1 5 in the invention of any one of claims 7-1 4, as its gist in that a protective layer on the outermost position.
Thereby, it is possible to prevent deterioration due to dirt such as scratches and sebum accompanying use of the device.
The protective layer can be hardened with a hard coat, etc., and can be formed by spraying, dipping, sputtering, vacuum deposition, etc. with a combination of antifouling properties and slipperiness such as a water repellent coat. it can. In particular, when an organic silicon-based water repellent treatment is performed by a vacuum deposition method, it has excellent slipperiness and antifouling properties, and there is an advantage that the coating agent does not accumulate in detail by an immersion method or a spray method. In addition, since the film thickness can be reduced (for example, 10 nm or less) in the vacuum deposition method, the influence on the generation of interference colors and the spectral characteristics of the dielectric multilayer film can be extremely reduced.

  According to the inventions described in the above claims, there are provided an optical article for infrared communication and a light receiving section for infrared communication that can transmit only a large number of wavelengths in the infrared communication band, and that are visually observable white. As a result, the degree of freedom in designing the design of a device equipped with an infrared port is expanded.

The schematic block diagram which has arrange | positioned the light-receiving part for infrared communication which is embodiment of this invention in the infrared port. Explanatory drawing explaining infrared light being permeate | transmitted while external light is scattered and reflected in a scattering reflection layer in the infrared communication light-receiving part of Embodiment 1. FIG. In the infrared communication light receiving unit according to the second embodiment, it will be described that visible light is scattered and reflected by the scattering reflection layer, a part of the visible light is absorbed by the visible light absorption layer, and only infrared light is transmitted. Illustration. Explanatory drawing explaining that visible light is scattered and reflected by the scattering reflection layer, a part of visible light is reflected by the reflection layer, and only infrared rays are transmitted in the infrared communication light receiving section of the third embodiment. . Explanatory drawing explaining that external light is scattered and reflected by the scattering reflection layer, only infrared rays are transmitted, and the substrate is protected by the hard coat layer in the infrared communication light receiving section of the fourth embodiment. 10 is a graph for explaining spectral reflection characteristics of a reflective layer according to Embodiment 3. Explanatory drawing explaining infrared light being permeate | transmitted while external light is scattered and reflected by a scattering reflection layer in the infrared communication light-receiving part of Embodiment 5. FIG. In the infrared communication light receiving unit according to the sixth embodiment, external light is scattered and reflected by the scattering reflection layer, a part of the visible light is reflected by the reflection layer, and a part of the visible light is absorbed by the visible light absorption layer. Explanatory drawing explaining that only infrared rays are transmitted. Explanatory drawing explaining that external light is scattered and reflected by the scattering reflection layer, a part of visible light is reflected by the reflection layer, and only infrared rays are transmitted in the infrared communication light receiving unit of the seventh embodiment. . Explanatory drawing explaining that external light is scattered and reflected by a scattering reflection layer and infrared rays are transmitted in the infrared communication light receiving unit of the eighth embodiment. The graph explaining the spectral transmission characteristic of the reflection layer of Examples 1-7 and the comparative example 1 which made the vertical axis | shaft the transmittance | permeability. The graph explaining the spectral transmission characteristic of Example 8 and 9 which made the vertical axis | shaft the transmittance | permeability. The graph explaining the spectral transmission characteristic of Example 10 which made the vertical axis | shaft the transmittance | permeability. The graph explaining the spectral reflection characteristic of Examples 11-13 which made the vertical axis | shaft the reflectance. The graph explaining the spectral transmission characteristic of Examples 11-13 which made the vertical axis | shaft the transmittance | permeability. The graph explaining the spectral transmission characteristic of Example 13 which made the vertical axis | shaft the transmittance | permeability. The graph explaining the spectral transmission characteristic of dye itself for the comparison with Example 17 and 18 which made the vertical axis | shaft the transmittance | permeability. The graph explaining the spectral transmission characteristic of Examples 17 and 18 which made the vertical axis | shaft the transmittance | permeability. The graph explaining the spectral transmission characteristic of Example 19 which made the vertical axis | shaft the transmittance | permeability. The graph explaining the spectral transmission characteristic of Example 20 which made the vertical axis | shaft the transmittance | permeability.

As shown in FIG. 1, the case body 12 of the portable information terminal is provided with a port 13 for infrared communication and infrared control. A light receiving unit 14 including a light emitting element, a light receiving element, and the like is disposed inside the case body 12 so as to face the port 13. The port 13 is assumed to be fitted with infrared communication light receiving portions (hereinafter simply referred to as light receiving portions) 15 to 18 and 30 to 33 according to the first to fourth embodiments. In the following embodiments, the same components are denoted by the same reference numerals and description thereof is omitted. Further, description of a condensing optical system that is not directly related to the present invention and a composite element that performs light projection and reception with one element is omitted.
(Embodiment 1)
First, the light receiving unit 15 according to the first embodiment will be described with reference to FIG. The light receiving unit 15 includes a transparent acrylic substrate 21 that transmits infrared rays, and a scattering reflection layer 23 that is an optical article for infrared communication formed on the outer surface of the substrate 21. In the first embodiment, the substrate 21 has a thickness of several mm. The scattering reflection layer 23 is a thin film formed by uniformly dispersing fine particles in a binder resin made of an acrylic resin. The fine particles have a part or all of the particle diameter satisfying the above formula 1 and are white by visible light.
In such a light receiving unit 15, the following optical action occurs with respect to external light.
First, visible light of the external light is scattered and reflected by the fine particles of the scattering reflection layer 23, so that the amount of visible light transmitted is attenuated to the extent that the light receiving element of the light receiving unit 14 is not affected by malfunction or the like. The scattering reflection layer 23 is white due to the visible light scattered and reflected by the fine particles.
On the other hand, although some infrared rays may be scattered and reflected by the scattering reflection layer 23, a predetermined transmission amount is secured, so that the infrared transmission light passes through the scattering reflection layer 23 and further passes through the substrate 21 and reaches the light receiving unit 14. It will be. Therefore, data communication using infrared rays in the light receiving unit 15 is possible.

(Embodiment 2)
Next, the light receiving unit 16 according to the second embodiment will be described with reference to FIG. The light receiving unit 16 includes a transparent acrylic substrate 21 that transmits infrared rays, a scattering reflection layer 23 formed on the outer surface of the substrate 21, and a visible light absorption layer 26 formed on the inner surface of the substrate 21. Yes. The visible light absorption layer 26 is a thin film.
In such a light receiving unit 16, the following optical action occurs with respect to external light.
First, visible light of the external light is scattered and reflected by the fine particles of the scattering reflection layer 23, and the scattering reflection layer 23 exhibits white.
Here, when a part of the visible light is scattered and reflected or reaches the visible light absorbing layer 26 without colliding with the fine particles, the visible light is absorbed and the visible light absorbing layer 26 is darkened. Therefore, even if the cloudiness value in the scattering reflection layer 23 is small, the inside of the substrate 21 is not visually observed due to the blinding effect by the visible light absorption layer 26. Further, visible light can be prevented from reaching the light receiving unit 14. On the other hand, a part of infrared rays is scattered and reflected by the scattering reflection layer 23 but passes through the scattering reflection layer 23 with a predetermined transmission amount, and further passes through the visible light absorption layer 26 and the substrate 21 to reach the light receiving unit 14. Become. Therefore, data communication using infrared rays in the light receiving unit 15 is possible. An example of the reflectance characteristic of the visible light absorbing layer 26 used in the second embodiment is shown in FIG.

(Embodiment 3)
Next, the light receiving unit 17 according to the third embodiment will be described with reference to FIG. The light receiving unit 17 includes a transparent acrylic substrate 21 as a base material that transmits infrared rays, a scattering reflection layer 23 formed on the outer surface of the substrate 21, and a reflection layer 27 made of a dielectric multilayer thin film formed on the inner surface of the substrate 21. And.
In such a light receiving unit 17, the following optical action occurs with respect to external light.
First, visible light of the external light is scattered and reflected by the fine particles of the scattering reflection layer 23, and the scattering reflection layer 23 exhibits white.
Here, when a part of the visible light is scattered and reflected or reaches the reflection layer 27 without colliding with the fine particles, the visible light is reflected, and a part of the visible light is scattered and reflected by the fine particles of the scattering reflection layer 23. Accordingly, in the third embodiment, the haze value of the scattering reflection layer 23 is larger than that in the above embodiment. In the present embodiment, since the reflection layer 27 has a characteristic of mainly reflecting the blue wavelength band, the scattering reflection layer 23 is colored pale. A design example of the reflective layer 27 is shown in Table 1 below. The reflectance characteristics of the reflective layer 27 are shown in FIG.

(Embodiment 4)
Next, the light receiving unit 18 according to the fourth embodiment will be described with reference to FIG. The light-receiving unit 18 includes a transparent acrylic substrate 21 that transmits infrared rays, a scattering reflection layer 23 formed on the inner surface of the substrate 21, and a hard coat layer 28 as a protective layer formed on the outer surface of the substrate 21. I have. In addition, when a hard coat process is performed on the outer surface of such an acrylic substrate 21, a base treatment layer is required. However, the base treatment layer is not shown in FIG. In such a configuration, the hard coat layer 28 can prevent deterioration of the substrate 21 due to scratches, sebum, and the like.

(Embodiment 5)
Next, the light receiving unit 30 according to the fifth embodiment will be described with reference to FIG. The light receiving unit 30 according to the fifth embodiment has a configuration in which the base body is not provided, and the scattering reflection layer 23 is not a thin film but has a thickness similar to that of the substrate 21. A reflection layer 27 made of a dielectric multilayer film is formed on the inner surface of the scattering reflection layer 23. The reflectance characteristics of the reflective layer 27 are the same as described above.
In such a light receiving unit 30, the following optical action occurs with respect to external light.
First, visible light of the external light is scattered and reflected by the fine particles of the scattering reflection layer 23, and the scattering reflection layer 23 exhibits white.
Here, when a part of the visible light is scattered and reflected or reaches the reflection layer 27 without colliding with the fine particles, the visible light is reflected, and a part of the visible light is scattered and reflected by the fine particles of the scattering reflection layer 23. Therefore, in the fifth embodiment, the cloudiness value of the scattering reflection layer 23 is increased as in the third embodiment.

(Embodiment 6)
Next, the light receiving unit 31 according to the sixth embodiment will be described with reference to FIG. The light receiving unit 31 includes a transparent acrylic substrate 21 that transmits infrared rays, a reflection layer 27 formed on the outer surface of the substrate 21, and a scattering reflection layer 23 formed on the outer surface of the reflection layer 27, that is, the outermost surface. And a visible light absorbing layer 26 formed on the inner surface of the substrate 21. That is, the order is the scattering reflection layer 23, the reflection layer 27, the substrate 21, and the visible light absorption layer 26 in order from the outermost layer. The reflectance characteristics of the visible light absorption layer 26 and the reflection layer 27 are the same as described above.
In such a light receiving unit 31, the following optical action occurs with respect to external light.
First, visible light of the external light is scattered and reflected by the fine particles of the scattering reflection layer 23, and the scattering reflection layer 23 exhibits white.
Here, when a part of the visible light is scattered and reflected or reaches the reflection layer 27 without colliding with the fine particles, the visible light is reflected, and a part of the visible light is scattered and reflected by the fine particles of the scattering reflection layer 23. Accordingly, in the sixth embodiment, the haze value of the scattering reflection layer 23 is increased as in the third embodiment.
Further, when the visible light transmitted through the reflective layer 27 reaches the visible light absorbing layer 26, the visible light is absorbed and the visible light absorbing layer 26 is darkened. Therefore, even if the cloudiness value in the scattering reflection layer 23 is small, the inside of the substrate 21 is not visually observed due to the blinding effect by the visible light absorption layer 26. Further, visible light can be prevented from reaching the light receiving unit 14. On the other hand, a part of infrared rays is scattered and reflected by the scattering reflection layer 23 but passes through the scattering reflection layer 23 with a predetermined transmission amount, and further passes through the visible light absorption layer 26 and the substrate 21 to reach the light receiving unit 14. Become. Therefore, data communication by infrared rays in the light receiving unit 31 is possible.

(Embodiment 7)
Next, the light receiving unit 32 according to the seventh embodiment will be described with reference to FIG. The light receiving section 32 of the seventh embodiment has a structure in which the visible light absorption layer 26 is not thin but has a thickness comparable to that of the substrate 21 without having a base. A reflective layer 27 made of a dielectric multilayer film is formed on the outer surface of the visible light absorbing layer 26, and a scattering reflection layer 23 is formed on the outer surface of the reflective layer 27, that is, the outermost surface. The reflectance characteristics of the visible light absorption layer 26 and the reflection layer 27 are the same as described above.
In such a light receiving section 32, the following optical action occurs with respect to external light.
First, visible light of the external light is scattered and reflected by the fine particles of the scattering reflection layer 23, and the scattering reflection layer 23 exhibits white.
Here, when a part of the visible light is scattered and reflected or reaches the reflection layer 27 without colliding with the fine particles, the visible light is reflected, and a part of the visible light is scattered and reflected by the fine particles of the scattering reflection layer 23. Accordingly, in the seventh embodiment as well, the haze value of the scattering reflection layer 23 is increased as in the third embodiment.
Further, when the visible light further transmitted through the reflection layer 27 reaches the visible light absorption layer 26, the visible light is absorbed and the visible light absorption layer 26 is darkened. Therefore, even if the cloudiness value in the scattering reflection layer 23 is small, the inside of the light receiving unit 32 is not visually observed due to the blinding effect by the visible light absorption layer 26. Further, visible light can be prevented from reaching the light receiving unit 14. On the other hand, a part of infrared rays is scattered and reflected by the scattering reflection layer 23, but passes through the scattering reflection layer 23 with a predetermined transmission amount, and further passes through the reflection layer 27 and the visible light absorption layer 26 to reach the light receiving unit 14. It becomes. Therefore, data communication by infrared rays in the light receiving unit 32 is possible.
(Embodiment 8)
Next, the light receiving unit 33 according to the eighth embodiment will be described with reference to FIG. The light receiving unit 33 of the eighth embodiment has a structure in which the base body is not provided and the scattering reflection layer 23 is not a thin film but has a thickness comparable to that of the substrate 21. That is, the light receiving unit 33 has a more basic configuration without the reflective layer 27 in the seventh embodiment.
In such a light receiving section 33, the following optical action occurs with respect to external light.
First, visible light of the external light is scattered and reflected by the fine particles of the scattering reflection layer 23, so that the amount of visible light transmitted is attenuated to the extent that the light receiving element of the light receiving unit 14 is not affected by malfunction or the like. The scattering reflection layer 23 is white due to the visible light scattered and reflected by the fine particles. On the other hand, although a part of infrared rays is scattered and reflected by the scattering reflection layer 23, it passes through the scattering reflection layer 23 with a predetermined transmission amount and reaches the light receiving unit 14. Therefore, data communication by infrared rays in the light receiving unit 33 is possible.

(Other embodiments)
-Although the example which uses the scattering reflection layer 23 as an infrared communication optical article was given in the said embodiment, the optical for infrared communication which formed the scattering reflection layer which carried out the sandblast process on the outer surface of the transparent base material made from transparent acrylic, for example An article may be used instead of the scattering reflection layer 23. It is possible to replace with such a configuration in the first to seventh embodiments.
In the fifth embodiment, the visible light absorbing layer 26 may be formed at the same position instead of the reflective layer 27. Further, the visible light absorbing layer 26 may be disposed outside the reflective layer 27.
In the fifth embodiment, the visible light absorbing layer 26 may be formed on the inner surface of the reflective layer 27. That is, an arrangement configuration in which the reflection layer 27 is sandwiched between the scattering reflection layer 23 and the visible light absorption layer 26 of the fifth embodiment may be employed.
In the sixth embodiment, the visible light absorbing layer 26 on the inner surface of the substrate 21 may be omitted.
In the seventh embodiment, the reflection layer 27 may not be formed, that is, the visible light absorption layer 26 may be directly formed with the scattering reflection layer 23.
-You may make it apply the hard-coat layer 28 of Embodiment 4 to the other Embodiment 2. FIG.
In Embodiment 3, the reflective layer 27 is disposed on the inner surface (apparatus side) than the diffuse reflective layer 23. However, the reflective layer 27 may be disposed on the outer side of the scattering reflective layer 23. In this case, the reflective layer 27 needs to have not only infrared rays but also visible light transmission performance.
In the above description, the transparent acrylic resin is used as the material for the substrate 21. However, other plastics may be used.

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples.
<Example 1>
The embodiment is a light receiving section that can be used in the first to fourth embodiments. The same applies to Examples 2 to 9 below.
(Preparation of solution for diffuse reflection layer)
An acrylic urethane resin paint (manufactured by Rock Paint Co., Ltd., product name: 088-0201 opal white) was used as the binder and fine particles constituting the layer. In the present paint, 10 to 15% by weight of titanium dioxide fine particles (particle size: about 20 nm) are dispersed. This paint was diluted with toluene to adjust the solid content to 5 to 7.5% by weight.
(Formation of diffuse reflection layer)
A film was formed on the surface of a plate-like glass substrate having a thickness of 2 mm and a refractive index of 1.54 by the spin coating method under the following conditions. As spin coating conditions, the rotation speed was 1500 rpm and the rotation time was 90 seconds. After film formation, the film was naturally dried at room temperature and normal pressure. As a result, the light-receiving part of Example 1 having a haze of 22 was obtained. The optical characteristics of Example 1 are shown in FIG. FIG. 11 is a graph of spectral transmittance characteristics with the vertical axis representing transmittance and the horizontal axis representing wavelength. The same applies to FIGS. 12 to 20 (except for FIG. 14).

<Example 2>
The solution for the irregular reflection layer was prepared in the same manner as in Example 1, and the solution was diluted with toluene so as to have a solid content of 6.7 to 10%. With the obtained solution, the light receiving part of Example 2 having a haze of 42 was obtained by spin coating under the same conditions as described above. The optical characteristics of Example 2 are shown in FIG.
<Example 3>
The solution for the irregular reflection layer was prepared in the same manner as in Example 1, and the solution was diluted with toluene so as to have a solid content of 6.7 to 10%. With the obtained solution, a light receiving part of Example 3 having a haze as a coating film of 43 was obtained by spin coating under the same conditions with a slightly larger amount than Example 2. The optical characteristics of Example 3 are shown in FIG.
<Example 4>
In the same manner as in Example 1, a solution for the irregular reflection layer was prepared, and the solution was diluted with toluene so as to have a solid content of 8 to 12%. Using the obtained solution, the light receiving part of Example 4 having a haze of 63 as a coating film was obtained by the spin coating method under the same conditions as in Example 1. The optical characteristics of Example 4 are shown in FIG.
<Example 5>
In the same manner as in Example 1, a solution for the irregular reflection layer was prepared, and the solution was diluted with toluene so as to have a solid content of 8 to 13%. With the obtained solution, a light receiving part of Example 5 having a haze of 65 as a coating film was obtained by spin coating under the same conditions with a slightly larger amount than Example 2. The optical characteristics of Example 5 are shown in FIG.
<Example 6>
The solution for the irregular reflection layer was prepared in the same manner as in Example 1, and the solution was diluted with toluene so as to have a solid content of 6.7 to 10%. With the obtained solution, a light receiving part of Example 6 having a haze of 82 as a coating film was obtained by spin coating under the same conditions with a slightly larger amount than Example 5. The optical characteristics of Example 6 are shown in FIG.
<Example 7>
The solution for the irregular reflection layer was prepared in the same manner as in Example 1, and the solution was diluted with toluene so as to have a solid content of 6.7 to 10%. Using the obtained solution, a light receiving portion of Example 7 having a haze as a coating film of 95 or more was obtained by spin coating under the same conditions with a slightly larger amount than Example 6. The optical characteristics of Example 7 are shown in FIG.
<Comparative Example 1>
The solution for the irregular reflection layer was prepared in the same manner as in Example 1, and the solution was diluted with toluene so as to have a solid content of 6.7 to 10%. With the obtained solution, a light receiving part of Example 8 having a haze as a coating film of 95 or more was obtained by spin coating under the same conditions with a slightly larger amount than Example 6. The optical characteristics of Comparative Example 1 are shown in FIG.

<Example 8>
The solution for the irregular reflection layer was prepared in the same manner as in Example 1, and the solution was diluted with toluene so as to have a solid content of 6.7 to 10%. With the obtained solution, a light receiving part of Example 8 having a haze as a coating film of 60 was obtained by spin coating under the same conditions with a slightly larger amount than Example 6. The optical characteristics of Example 8 are shown in FIG.
<Example 9>
On the inner surface of the white infrared communication optical article formed in Example 8, a black infrared communication optical article (so-called IR black) as the visible light absorbing layer 26 was overlaid. The optical characteristics at this time are shown in FIG.

Examples 10 to 13 are examples assuming the light receiving unit 16 as in the third embodiment.
<Example 10>
1) Calcium carbonate fine particles having a particle diameter of 100 nm (vigot-10, manufactured by Shiroishi Kogyo Co., Ltd.) for eyeglasses (material refractive index: 1.6) 1.5% by weight of the fine particles dispersed in a base material Then, 1% by weight of an ultraviolet absorber (Dynesorb T-53 manufactured by Daiwa Kasei Laboratories Co., Ltd.) was mixed and molded into a flat plate having a thickness of 0.69 (hereinafter referred to as resin material A). The haze at the stage of the resin material A was 18.5.
2) A SiO ₂ / TiO ₂ 45 layer was formed as a cold mirror film on one side of a transparent plate glass, and a SiO ₂ / TiO ₂ 5 layer was formed as an AR film on the opposite side by vacuum deposition (hereinafter referred to as mirror material A). ).
3) The resin material A was bonded to the cold mirror film 45 layer side of the mirror material A with an adhesive (SYLGARD® 184 manufactured by Dow Corning Toray). The optical characteristics of Example 10 are shown in FIG.

<Example 11>
Disperse the fine particles 1.5% by weight in a resin for spectacles (material refractive index: 1.6) prepared by adjusting calcium carbonate fine particles (vigot-10 manufactured by Shiraishi Kogyo Co., Ltd.) having a particle size of 100 nm for spectacles, A fluorescent pigment (manufactured by Epoch Co., Ltd .: fluorescent pigment blue I-02-001B) was dispersed by 0.5% by weight and molded into a flat plate having a thickness of 2 mm. The haze of Example 11 was 81.7. In Example 11, as shown in the reflection characteristics of FIG. 14, the reflectance in the wavelength region near blue is larger than that of other visible light, and bluish white is exhibited to the naked eye. The optical characteristics of Example 11 are shown in FIG.
<Example 12>
3% by weight of the above fine particles are dispersed in a base material for a spectacle resin (material refractive index: 1.6) in which calcium carbonate fine particles (vigot-10 manufactured by Shiraishi Kogyo Co., Ltd.) having a particle diameter of 100 nm are prepared for spectacles, and fluorescent pigment (Epoch Co., Ltd .: Lime l-02-001LI) was dispersed in an amount of 0.5% by weight and molded into a flat plate having a thickness of 2 mm. The haze of Example 12 was 96.7. In Example 12, as shown in the reflection characteristics of FIG. 14, the reflectance in the wavelength range near blue and yellow is larger than that of other visible light, and greenish white is exhibited to the naked eye. The optical characteristics of Example 12 are shown in FIG.
<Example 13>
3% by weight of the above fine particles are dispersed in a base material for a spectacle resin (material refractive index: 1.6) in which calcium carbonate fine particles (vigot-10 manufactured by Shiraishi Kogyo Co., Ltd.) having a particle diameter of 100 nm are prepared for spectacles, and fluorescent pigment 0.5% by weight (manufactured by Epoch Co., Ltd .: Red l-02-001R) was dispersed and molded into a flat plate having a thickness of 2 mm. The haze of Example 13 was 88.2. In Example 13, as shown in the reflection characteristics of FIG. 14, the reflectance in the wavelength region near blue and red is larger than that of other visible light, and pinkish white is exhibited to the naked eye. The optical characteristics of Example 13 are shown in FIG.

Examples 14 to 16 are examples in which the light receiving unit 33 is assumed as in the tenth embodiment, and the transmittance of 12% is maintained at a wavelength of 850 nm as an infrared band, while the transmittance in the visible region is 5 on average. It is an example of controlling to below%.
<Example 14>
3% by weight of the above-mentioned fine particles are dispersed in a base material for a spectacle resin (material refractive index: 1.6) in which calcium carbonate fine particles having a particle diameter of 150 nm (vigot-15 manufactured by Shiraishi Kogyo Co., Ltd.) are prepared for spectacles. It was molded into a 4.4 mm flat plate. The haze was 90 or more. The optical characteristics of Example 14 are shown in FIG.
<Example 15>
The above fine particles are dispersed in an amount of 0.5% by weight in a resin for spectacles (refractive index of material: 1.6) prepared by using silica having a particle size of 2.2 μm (Fine Seal manufactured by Tokuyama Co., Ltd.) for the spectacles. Molded into a 6 mm flat plate. The haze was 90 or more. The optical characteristics of Example 15 are shown in FIG. <Example 16>
2. Disperse 0.7% by weight of the fine particles in a spectacle resin (material refractive index: 1.6) base material prepared by using silica (Tokuyama U made by Tokuyama Corporation) having a particle size of 10 μm for spectacles; Molded into a 3 mm flat plate. The haze was 90 or more. The optical characteristics of Example 16 are shown in FIG.
In addition, the characteristic of the resin material A of Example 7 is illustrated on FIG. 16 as a comparison of the optical characteristics of Examples 14-16.

<Example 17>
3% by weight of the above-mentioned fine particles are dispersed in a base material for a spectacle resin (material refractive index: 1.6) in which calcium carbonate fine particles (Vigot-10 manufactured by Shiraishi Kogyo Co., Ltd.) having a particle diameter of 100 nm are prepared for spectacles, and absorbs ultraviolet rays. 1% by weight of an agent (Dynesorb T-53 manufactured by Daiwa Kasei Laboratories Co., Ltd.) was mixed and molded into a flat plate having a thickness of 1.3 mm. The haze at this stage was 53.45. Dye (Nippon Kayaku Co., Ltd .: Kayalon Polyster Yellow 5R-SE200) is added to 3 g / liter of water with a surfactant (Nippon Emulsifier Co., Ltd. New Call 210) and a carrier agent (Daiwa Chemical Industry Co., Ltd .: Die Carrier) DK-CN) was added, and the mixture was immersed in 90 ° C. for 30 minutes to obtain Example 17. Example 17 exhibits orange white color with the naked eye. For comparison, a resin (resin material B) in which only the dye under the same conditions as in Example 17 was dispersed in the above spectacle resin was prepared. Moreover, what was adjusted on the conditions which did not put only the dye in Example 17 was created for the comparison. FIG. 17 shows the transmission characteristics of the resin material B. The optical characteristics of Example 17 are shown in FIG.
<Example 18>
3% by weight of the above-mentioned fine particles are dispersed in a base material for a spectacle resin (material refractive index: 1.6) in which calcium carbonate fine particles (Vigot-10 manufactured by Shiraishi Kogyo Co., Ltd.) having a particle diameter of 100 nm are prepared for spectacles, and absorbs ultraviolet rays. 1% by weight of an agent (Dynesorb T-53 manufactured by Daiwa Kasei Laboratories Co., Ltd.) was mixed and molded into a flat plate having a thickness of 1.3 mm. The haze at this stage was 53.45. This plate material is dye (FSP BLUE AUL-S made by Futaba Sangyo Co., Ltd.) in 3 g / liter of water. Surfactant (Nippon Emulsifier Co., Ltd. New Call 210) and carrier agent (Daiwa Chemical Industry Co., Ltd .: Die Carrier DK-CN) Was added and immersed in 30 ° C. for 30 minutes to obtain Example 18. Example 18 is bluish white with the naked eye. For comparison, a resin in which only a dye was dispersed under the same conditions as in Example 18 was prepared (referred to as resin material C). FIG. 17 shows the transmission characteristics of the resin material C. The optical characteristics of Example 18 are shown in FIG.

<Example 19>
1) One side surface of quartz glass was blasted for about several tens of seconds at a pressure of 0.2 to 0.3 MPa using a sand blasting abrasive white alundum WA # 100 (hereinafter referred to as blasting material A). The haze at the stage of the blast material A was 79.
2) A SiO ₂ / TiO ₂ 49 layer was formed as a cold mirror film on one side of the transparent plate glass, and an SiO ₂ / TiO ₂ 5 layer was formed as an AR film on the opposite side by vacuum deposition (hereinafter referred to as mirror material B). ).
3) The blast material was superposed on the cold mirror film 49 layer side of the mirror material B without using an adhesive on the blast side. The optical characteristics of Example 19 are shown in FIG.

<Example 20>
1) The surface of a 1 mm thick acrylic resin substrate was lightly rubbed with a cloth containing 100% acetone, and then air-dried for 30 minutes (hereinafter referred to as acetone-treated material A). The haze was 87.
2) as a cold mirror film on one side of the glazing, SiO ₂ / TiO ₂ 49 layers was formed by a respective vacuum deposition SiO ₂ / TiO ₂ 5 layers in opposite surface (hereinafter referred to as the mirror material C).
3) The acetone-treated material A was superposed on the cold mirror film 49 layer side of the mirror material C without using an adhesive on the non-treated surface side. The optical characteristics of Example 20 are shown in FIG.

(About communication performance evaluation)
Two commercially available IrDA standard infrared communication type mobile phones were prepared, and a light receiving unit of the same example was attached to each infrared port, and an experiment was conducted to determine whether communication was possible with a distance of 20 cm. As a result, communication was possible for Examples 1 to 20, but communication was not possible in Comparative Example 1.
(About white color development)
The haze about each said Example was measured using the haze meter, and the above values were obtained. In all cases, sufficient cloudiness was obtained.

  15-18, 30-33 ... Light-receiving part for infrared communication, 23 ... Scattering reflection layer as an optical article for infrared communication.

Claims (18)

An optical article for infrared communication, which is formed by uniformly dispersing fine particles with different refractive index in a transparent binder resin, and causing the fine particles to scatter and reflect light in the visible light region to develop white color In addition, the average particle size of the fine particles is set so as to have a wavelength dependency that increases the transmittance of light on the long wavelength side, and the transmittance in the wavelength band of the infrared communication band is set to 12% or more. An optical article for infrared communication characterized by the above. 2. The optical article for infrared communication according to claim 1, wherein the diameter D of some or all of the fine particles is set to a size represented by the following formula.

2. The optical article for infrared communication according to claim 1, wherein the diameter D of some or all of the fine particles is set to a size represented by the following formula.

An optical article for infrared communication in which a fine uneven shape is formed by roughening the surface of a transparent substrate and a white scattering layer is formed on the surface of the transparent substrate, and the transmittance of light on the long wavelength side is Infrared communication characterized in that the average uneven diameter of the fine uneven shape of the scattering layer is set so as to have a wavelength dependency that increases, and the transmittance in the wavelength band of the infrared communication band is set to 12% or more Optical article. 5. The optical article for infrared communication according to claim 4, wherein the diameter D of a part or all of the fine irregularities is a size represented by the following formula.

5. The optical article for infrared communication according to claim 4, wherein the diameter D of a part or all of the fine irregularities is a size represented by the following formula.

The optical article for infrared communication according to any one of claims 1 to 6, wherein the binder resin or the transparent base material contains one or more coloring materials that absorb part of the visible range. The infrared communication optical device according to any one of claims 1 to 7, wherein the binder resin or the transparent base material contains a dye that transmits infrared light and absorbs part of the visible region. Goods. The infrared communication optical article according to any one of claims 1 to 8, wherein an ultraviolet absorber is contained in the binder resin or the transparent substrate. An infrared communication light receiving section, comprising: the infrared communication optical article according to any one of claims 1 to 9 disposed at least on an outer surface or an inner surface of a substrate that transmits infrared light. 11. The infrared communication light receiving unit according to claim 10, wherein the base body transmits infrared light and is prevented from transmitting visible light, and the infrared communication optical article is disposed on an outer surface of the base body. . The substrate is made of a transparent material, and the optical article for infrared communication is disposed on the inner surface of the substrate, and the visible light that transmits infrared light to the inner surface of the device and blocks visible light from being transmitted. The light receiving part for infrared communication according to claim 10, wherein a light absorbing layer is disposed. The base is made of a transparent material, and the infrared communication optical article is disposed on the outer surface of the base, and the infrared ray is transmitted between the base and the optical article or on the device inner side of the base, and The infrared communication light receiving unit according to claim 10, further comprising a visible light absorption layer that blocks transmission of visible light. The substrate is made of a transparent material, and the optical article for infrared communication is disposed on the inner surface of the substrate, transmits infrared light to the inner surface of the device of the optical article, and part or all of visible light is transmitted. The infrared communication light receiving unit according to claim 10, further comprising a reflective layer that reflects in the direction of the optical article for infrared communication. The base is made of a transparent material, and the infrared communication optical article is disposed on the outer surface of the base, and the infrared ray is transmitted between the base and the optical article or on the device inner side of the base, and The infrared communication light-receiving unit according to claim 10, wherein a reflection layer that reflects part or all of visible light toward the infrared communication optical article is disposed. 10. A light receiving part for infrared communication, wherein a visible light absorbing layer that transmits infrared light and blocks visible light transmission is disposed on the inner surface side of the optical article for infrared communication according to claim 1. 10. A light receiving part for infrared communication, wherein a reflection layer that transmits infrared light and reflects part or all of visible light is disposed on the inner surface side of the optical article for infrared communication according to claim 1. . 18. The infrared communication light receiving unit according to claim 10, wherein a protective layer is disposed at an outermost layer position.

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