JP6736958B2 - Transmissive transparent screen, video display system and video display method - Google Patents

Description

The present invention is a transmissive transparent screen that visually displays image light projected from a projector as an image to an observer on the opposite side of the projector, and the tint of the scene seen through the transparent screen. The present invention relates to a transmissive transparent screen that suppresses changes in the tint of a projected image, and a video display system and a video display method using the same.

The following have been proposed as transparent members used for showcases of products and the like; display cases of art and the like; windows of buildings, showrooms, vehicles, etc.; glass doors;

You can see through the scene that is visible to the other side of the transparent member from the observer's side, and when transmitting information such as product description, various equipment status, destination guidance, and information to be transmitted to the observer. On the other hand, when displaying the operation screens of various devices, or when making it impossible to see through the transparent member to the observer for privacy protection, security, etc., the image projected from the projector An image display transparent member (so-called transparent screen) that visually displays light as an image for an observer.

The transparent screen has a reflective transparent screen that visually displays the image light projected from the projector as an image to an observer on the same side as the projector; the image light projected from the projector is opposite to the projector. There is a transmissive transparent screen that is visually displayed as an image for an observer on the side.

As the transmissive transparent screen, for example, as shown in FIG. 15, a transparent resin 132 and a light scattering material 133 (for example, hollow beads) are provided between a first transparent base material 110 and a second transparent base material 120. A transmissive transparent screen 101 having a light scattering layer 134 containing is proposed (see Patent Document 1).

In the transmissive transparent screen 101, the image light L projected from the projector 200 and incident from the surface (first surface A) on the first transparent base material 110 side is scattered by the light scattering layer 134 and is thus combined. The image is displayed so that it can be visually recognized as an image by an observer X on the opposite side of the projector 200.

Further, in the transmissive transparent screen 101, after the light of the scene on the first surface A side is incident on the transmissive transparent screen 101 from the first surface A, a part of the light is scattered in the light scattering layer 134 and remains. Is transparent. Thereby, when the image light L is not projected from the projector 200 onto the transmissive transparent screen 101, the observer X on the second surface B side can see through the scene on the first surface A side. Similarly, after the light of the scene on the second surface B side is incident on the transmissive transparent screen 101 from the second surface B, a part of the light is scattered in the light scattering layer 134 and the rest is transmitted. Thereby, when the image light L is not projected from the projector 200 onto the transmissive transparent screen 101, the observer on the first surface A side can see through the scene on the second surface B side.

However, in the transmissive transparent screen 101, the light L1 of the scene on the first surface A side is scattered in the scattering layer 134 as shown in FIG. 16, but the scattering method differs depending on the size of the particles contained in the scattering layer. .. Generally, when the particle size is sufficiently smaller than the wavelength of light, the scattering intensity is said to increase as the wavelength decreases (Rayleigh scattering). When the particle size is about the same as the wavelength of light, the scattering intensity is about the same regardless of the wavelength (Mie scattering). When particles having a median diameter of 0.1 to 50 nm and a maximum particle diameter of 10 to 500 nm disclosed in Patent Document 1 are used for the scattering layer 134, Rayleigh scattering becomes dominant and the scattering ratio of the blue wavelength is reduced. The number of scenes increases and the color of the scene looks yellowish. In addition, the projected image is emphasized in blue and has a different color tone from the image to be displayed, and it is necessary to adjust the projection device or the original image. For example, when a projector is used as the projector, it is necessary to reduce the blue output in accordance with the green and red that are less likely to be scattered, and as a result, the brightness (lumen) originally possessed by the projector will not be exhibited. As a result, there is a problem that the image becomes darker than expected. In addition, a complicated process is also required when adjusting on the original image side. On the other hand, in applications related to safety and design, such as head-up displays and show windows, it is considered necessary to show the colors of the scene as much as the actual colors. Further, if the particle size is increased for the purpose of solving the problem of yellowing, the transparency tends to be impaired (Comparative Example 3 of Patent Document 1).

Japanese Patent No. 575834

INDUSTRIAL APPLICABILITY The present invention is excellent in the see-through property of the scene on the other side of the transparent screen when seen from the observer in the state where the image light is not projected from the projector, and is seen from the observer when the image light is projected from the projector. The transparency of the image displayed on the transparent screen is excellent, and the tint of the scene seen through the translucent transparent screen and the tint of the projected image change while maintaining transparency. Provided are a transmissive transparent screen, a video display system and a video display method using the same.

The present invention has the following configurations .
[ 1] A transmission type transparent screen having a light-scattering layer containing a transparent resin and a light-scattering material, wherein the light-scattering material is inorganic fine particles having an average primary particle diameter of 100 to 400 nm, and a part of the inorganic fine particles. Includes aggregated particles in which 20 or less of the primary particles are aggregated, and the number of the aggregated particles composed of more than 20 primary particles is 10% of the total number of the aggregated particles. The difference between the refractive index of the transparent resin and the refractive index of the inorganic fine particles is 0.15 or more, and the content ratio of the inorganic fine particles is 0. A transmissive transparent screen having a content of 01 to 10% by mass, a haze of 5 to 45%, and a total light transmittance of 40% or more. [2] The transmissive transparent screen according to [1], wherein the content of the inorganic fine particles in the light scattering layer is 0.01 to 10 mass% with respect to 100 mass% of the light scattering layer . [3 ] The transmissive transparent screen according to [1] or [2], wherein the light scattering material is one or more selected from the group consisting of titanium oxide and zirconium oxide. [ 4 ] The ratio of the blue light scattering intensity (A) having a wavelength of 400 nm to 480 nm and the visible light scattering intensity (B) having a wavelength of 400 nm to 700 nm, A/B is 0.75 to 1.25. The transparent transparent screen according to any one of [1] to [ 3 ]. [ 5 ] The transmissive transparent screen according to any one of [1] to [ 4 ], wherein the transparent resin is a thermoplastic resin. [ 6 ] The transparent transparent screen according to any one of [1] to [ 5 ], wherein the transparent resin is one or more selected from the group consisting of polyvinyl butyral, polyvinyl acetal, and ethylene-vinyl acetate copolymer. [ 7 ] The transparent transparent screen according to [ 5 ] or [ 6 ], wherein the transparent resin has a molecular weight of 5,000 to 1,000,000. [ 8 ] A video display system comprising the transmissive transparent screen according to any one of [1] to [ 7 ] and a projector installed on the first surface side of the transmissive transparent screen.

The transmissive transparent screen of the present invention is excellent in the visibility of the scene on the other side of the transparent screen as seen from the observer in the state where the image light is not projected from the projector, and in the state where the image light is projected from the projector. A transparent type transparent screen having excellent visibility of an image displayed on the transparent screen from an observer's side, and a tint of a scene seen through the transparent type transparent screen while maintaining transparency and a tint of a projected image. (EN) Provided are a transmissive transparent screen which suppresses the change of the image, a video display system and a video display method using the same.

According to the image display system and the image display method of the present invention, in the state where the image light is not projected from the projector, the sight on the other side of the transparent screen is excellent in seeing from the observer, and the image light is projected from the projector. In this state, the visibility of the image displayed on the transparent screen is excellent to the observer, and the tint of the scene seen through the transmissive transparent screen is suppressed while maintaining the transparency.

FIG. 1 is a schematic configuration diagram showing an example of aspects of a video display system of the present invention and a layer configuration diagram showing an example of aspects of a transmissive transparent screen of the present invention. It is a figure which shows the state which does not project an image light on a transmissive transparent screen from a projector in the image display system of FIG. It is a layer block diagram which shows the other example of the aspect of the transmissive transparent screen of this invention. It is a layer block diagram which shows the other example of the aspect of the transmissive transparent screen of this invention. It is a layer block diagram which shows the other example of the aspect of the transmissive transparent screen of this invention. It is a layer block diagram which shows the other example of the aspect of the transmissive transparent screen of this invention.

FIG. 1 is a schematic configuration diagram showing an example of aspects of a video display system of the present invention and a layer configuration diagram showing an example of aspects of a transmissive transparent screen of the present invention. FIG. 9 is a diagram showing a state in which image light is not projected from a projector onto a transmissive transparent screen in the image display system of FIG. 7. It is a layer block diagram which shows the other example of the aspect of the transmissive transparent screen of this invention. It is a layer block diagram which shows the other example of the aspect of the transmissive transparent screen of this invention. It is a layer block diagram which shows the other example of the aspect of the transmissive transparent screen of this invention. It is a layer block diagram which shows the other example of the aspect of the transmissive transparent screen of this invention. It is a layer block diagram which shows the other example of the aspect of the transmissive transparent screen of this invention. It is a layer block diagram which shows the other example of the aspect of the transmissive transparent screen of this invention. FIG. 1 is a schematic configuration diagram showing an example of a conventional video display system and a layer configuration diagram showing an example of a conventional transmissive transparent screen. FIG. 16 is a diagram showing a state in which image light is not projected from a projector onto a transmissive transparent screen in the image display system of FIG. 15.

The following definitions of terms apply throughout the specification and claims.

The “first surface” means the outermost surface of the transmissive transparent screen, which is the surface on the side where the image light is projected from the projector.

The “second surface” means the outermost surface of the transmissive transparent screen and the surface opposite to the first surface.

The "view on the first surface side (second surface side)" means the other side of the transmission type transparent screen when viewed from the observer on the second surface side (first surface side) of the transmission type transparent screen. It means an image that can be seen on the side (main objects (articles, artworks, people, etc.) and their backgrounds, and scenery). The scene does not include the image displayed by the image light projected from the projector on the transmissive transparent screen.

The “bonding layer” is a layer having a function of bonding two surfaces and is a layer formed of an adhesive or a pressure-sensitive adhesive. At least one of the two surfaces to be joined is a surface made of a heat-fusible material, and when the two surfaces are joined by heat-sealing, at least one of the two surfaces to be joined is a curable resin material. A surface formed from a cured product of, and in the case where the two surfaces are bonded together with the curing of the curable resin material, the bonding function is provided by the surfaces to be bonded, and thus there is no bonding layer. And

"Thermal-fusible resin" means a thermoplastic resin which exhibits bondability by thermal fusion and softens at a relatively low temperature.

"Arithmetic mean roughness (Ra)" is an arithmetic mean roughness measured based on JIS B 0601:2013 (ISO 4287:1997, Amd.1:2009). The reference length lr (cutoff value λc) for the roughness curve was 0.8 mm.

“Haze” is the front of the transmitted light that is incident from the first surface side (or second surface side) of the transmissive transparent screen and is transmitted to the second surface side (or first surface side). It means the percentage of transmitted light that deviates from the incident light by 0.044 rad (2.5°) or more due to scattering. That is, it is a normal haze measured by the method described in JIS K 7136:2000 (ISO 14782:1999). The haze is a value measured according to the method described above at room temperature using a CIE standard D65 light source defined in ISO/CIE10526.

The "total light transmittance" is the second surface side (or the first surface side) with respect to the incident light that is incident from the first surface side (or the second surface side) of the transmissive transparent screen at an incident angle of 0°. ) Means the ratio (percentage) of the total transmitted light. That is, it is a normal total light transmittance measured by the method described in JIS K 7361:1997 (ISO 13468-1:1996), and is a value measured by a D65 light source.

The “diffuse reflectance” is the first surface side (or second surface side) with respect to the incident light incident at an incident angle of 0° from the first surface side (or second surface side) of the transmissive transparent screen. It means the ratio (percentage) of the reflected light deviated by 0.044 rad (2.5°) or more from the specularly reflected light reflected by. When measuring the diffuse reflectance, from the second surface side (or the first surface side) opposite to the first surface side (or the second surface side) of the measurement target to the transmissive transparent screen. Cover the opposite surface with a blackout curtain so that light does not enter. Further, an aperture having the same size as the diameter of the incident light is set in close contact with the measurement target.

The diffuse reflectance and the refractive index are values measured at room temperature using the d-line (wavelength 589 nm) of a sodium lamp.

In this specification, unless otherwise specified, the film includes a sheet having a thickness.
<Video display system>
FIG. 1 is a schematic configuration diagram showing an example of an aspect of a video display system of the present invention.

The video display system includes a transmissive transparent screen 1 (hereinafter, also referred to as screen 1) and a projector 200 installed in a space on the first surface A side of the screen 1.
<Transparent transparent screen>
An aspect of the transmissive transparent screen of the present invention has a first surface and a second surface opposite to the first surface, and allows a scene on the first surface side to be seen through by an observer on the second surface side. The image light projected through the first surface side is transmitted as an image to the second surface side observer, and the image light projected from the first surface side is transmitted as an image to the second surface side observer. A transmissive transparent screen which is visibly displayed and has a light scattering layer containing a transparent resin and a light scattering material.

FIG. 1 is a layer configuration diagram showing an example of the aspect of the transmissive transparent screen of the present invention.

The screen 1 is one in which a light scattering sheet 30 is arranged between a first transparent base material 10 and a second transparent base material 20.

The first transparent base material 10 and the light scattering sheet 30 are bonded by the bonding layer 12, and the second transparent base material 20 and the light scattering sheet 30 are bonded by the bonding layer 22.

(Transparent substrate)
Examples of the material of the first transparent base material 10 and the second transparent base material 20 (hereinafter collectively referred to as a transparent base material) include glass and transparent resin. The material of each transparent substrate may be the same or different.

Examples of the glass constituting the transparent substrate include soda lime glass, non-alkali glass, borosilicate glass, aluminosilicate glass and the like. The transparent base material made of glass may be subjected to chemical strengthening, physical strengthening, hard coating or the like in order to improve durability.

Examples of the transparent resin constituting the transparent substrate include a cured product of a curable resin and a thermoplastic resin, and the thermoplastic resin is preferable. Examples of the thermoplastic resin include polycarbonate, thermoplastic polyester (polyethylene terephthalate, polyethylene naphthalate, etc.), triacetyl cellulose, cycloolefin polymer, polymethylmethacrylate, ethylene-tetrafluoroethylene copolymer (ETFE), and the like. From the viewpoint of transparency, polycarbonate, thermoplastic polyester, and cycloolefin polymer are preferable.

As the transparent substrate, one having no birefringence is preferable.

The transparent substrate may have any thickness as long as the durability of the substrate is maintained. The transparent substrate may have a thickness of, for example, 0.01 mm or more, 0.05 mm or more, and 0.1 mm or more. The thickness of the transparent base material may be, for example, 10 mm or less, 5 mm or less, 0.5 mm or less, 0.3 mm or less, and 0.15 mm or less. You may

The arithmetic average roughness Ra of the surface of the first transparent base material 10 (first surface A) and the surface of the second transparent base material 20 (second surface B) is preferably 0.3 μm or less, and 0. The thickness is more preferably 05 μm or less, and further preferably 0.01 μm or less when the surface of the transparent substrate 10 is the outermost layer. If the arithmetic average roughness Ra is 0.3 μm or less, the image light L projected from the projector 200 is less likely to scatter on the first surface A and the second surface B, so that the first surface A and the second surface B are not scattered. It is difficult to form an image on the second surface B. As a result, formation of a double image can be suppressed. The lower the arithmetic average roughness Ra of the surface of the first transparent base material 10 (first surface A) and the surface of the second transparent base material 20 (second surface B), the lower the point of inspection and transparency. However, the thickness may be 0.001 μm or more from the viewpoint of the ease of manufacturing the transparent substrate and the cost.

Even when the outermost layer of the transmissive transparent screen is not a transparent substrate (for example, a transparent film, a light scattering layer, a light absorbing layer, etc.), the first surface of the transmissive transparent screen and the The preferable range of the arithmetic average roughness Ra on the surface of No. 2 is the same as when the outermost layer is a transparent substrate.
The arithmetic mean roughness Ra of each layer of the transmissive transparent screen is preferably 0.001 μm or more. By doing so, there is an effect of suppressing haze increase due to the difference in refractive index between the bonding layer and the base material.

(Bonding layer)
The bonding layer 12 and the bonding layer 22 (hereinafter, also collectively referred to as a bonding layer) are layers formed of an adhesive or a pressure-sensitive adhesive. The adhesive or the pressure-sensitive adhesive may be a liquid substance containing a solvent. In the case of a liquid containing a solvent, it is applied to at least one of the joint surfaces and then the solvent is removed for adhesion or adhesion. In the case of a pressure-sensitive adhesive or an adhesive composed of a heat-fusible resin, the film can be used.

In the case of an adhesive made of a curable resin, the bonding layer 12 is formed by curing the curable resin between the transparent substrate 10 and the transparent film 31. In the case of an adhesive made of a heat-fusible resin, the bonding layer 12 is formed by heating and softening the heat-fusible resin between the transparent base material 10 and the transparent film 31 and cooling. In the case of a pressure-sensitive adhesive, the bonding layer 12 is formed by pressure-bonding a pressure-sensitive adhesive layer between the transparent substrate 10 and the transparent film 31.

Examples of the material of the adhesive include a heat-fusible resin, a photocurable resin, and a thermosetting resin, and examples of the adhesive include an acrylic adhesive and a silicone adhesive. The material of each bonding layer may be the same or different.

Examples of the heat-fusible resin include ethylene-vinyl acetate copolymer, polyvinyl butyral, plasticized polyvinyl acetal, plasticized polyvinyl chloride, plasticized thermoplastic polyester, thermoplastic polyurethane, ethylene-ethyl acrylate copolymer and the like.

Examples of the photocurable resin include an acrylic photocurable resin and a photocurable epoxy resin, and examples of the thermosetting resin include an acrylic thermosetting resin, a thermosetting epoxy resin, and a polyurethane curable resin. Can be mentioned.

The thickness of the bonding layer may be such that the function as the bonding layer is maintained, and for example, 0.01 to 1.5 mm is preferable, and 0.05 to 1 mm is more preferable.

(Light scattering sheet)
The light-scattering sheet 30 includes a first transparent film 31, a second transparent film 35, and light-scattering inside a transparent resin 32 provided between the first transparent film 31 and the second transparent film 35. The light scattering layer 34 in which the material 33 is dispersed. The light scattering sheet preferably has a light absorbing material. Further, a second transparent film may be provided so as to sandwich the light scattering layer 34 between the first transparent film 31 and the second transparent film 35.

(Transparent film)
The first transparent film 31 and the second transparent film 35 (hereinafter, also collectively referred to as a transparent film) may be resin films or thin glass films. The material of each transparent film may be the same or different.

Examples of the transparent resin forming the transparent film include polycarbonate, thermoplastic polyester, triacetyl cellulose, cycloolefin polymer, polymethylmethacrylate and the like.

The thickness of the transparent film is preferably such that a roll-to-roll process can be applied, for example, 0.01 to 0.5 mm is preferable, 0.05 to 0.3 mm is more preferable, and 0.2 mm or less is further preferable.

(Light scattering layer)
The light scattering layer 34 includes a transparent resin 32 and a light scattering material 33.

As the transparent resin 32, a cured product of a photocurable resin (a photocurable acrylic resin, a photocurable epoxy resin or the like), a cured product of a thermosetting resin (a thermosetting acrylic resin, a thermosetting epoxy resin or the like), Thermoplastic resin (polycarbonate, thermoplastic polyester, triacetyl cellulose, cycloolefin polymer, polymethylmethacrylate, etc., as well as polyolefin resin, thermoplastic polyimide resin, thermoplastic urethane, ionomer resin, ethylene-vinyl acetate copolymer, polyvinyl butyral, polyvinyl Acetal, ETFE, thermoplastic silicone, etc. are preferred). Further, in addition to haze and transmittance, it is easy to manufacture a light scattering layer 34 having good optical performance (transparency, visibility of a projected image), and therefore a thermoplastic resin is preferable, and an ethylene/vinyl acetate copolymer, polyvinyl butyral, Polyvinyl acetal is more preferred. The yellow index of the transparent resin is preferably 10 or less, more preferably 5 or less, and further preferably 2 or less, from the viewpoint of maintaining a transparent feeling so that the function as the window in the screen 1 is not impaired.

The molecular weight of the thermoplastic resin is preferably 5,000 to 1,000,000, more preferably 10,000 to 500,000. Within this molecular weight range, the dispersibility of the light-scattering material tends to be good. Further, since the light scattering layer 34 does not easily flow even when the temperature is high, the dispersed state of the light scattering particles can be set in a preferable state, and the generation of aggregates in which 20 or more primary particles of the light scattering particles are aggregated can be suppressed.

The glass transition temperature (Tg) of the thermoplastic resin is preferably 50°C to 200°C, more preferably 60°C to 150°C. When it is in the range of Tg, when other layers (the second transparent film 35, the bonding layer 22, the transparent substrate 20, etc.) are laminated in contact with the light scattering layer 34 at a high temperature (for example, 80 to 150° C.). In addition, it is possible to prevent the surface shapes of other layers from being transferred to the light scattering layer 34.

Light-scattering material 33, average primary particle diameter of inorganic fine particles of 100 to 400 nm, a part of the inorganic fine particles containing the agglomerated particles below 20 primary particles is in the aggregate aggregated. The average primary particle diameter is obtained by observing an SEM or TEM photograph of the inorganic fine particles in a method of measuring the particle diameter of the primary particles to obtain an average value, or in an arbitrary 10 cm square range of the transmissive transparent screen. It can be obtained by measuring the particle size of primary particles and obtaining an average value in a photograph obtained by observing 9 locations with SEM or TEM. The average particle size can be determined by a dynamic light scattering method (general name such as JIS or dynamic light scattering method) using a particle size analyzer FPAR-1000 (manufactured by Otsuka Electronics Co., Ltd.).
The average primary particle diameter of the light scattering material 33 is preferably 150 to 400 nm, more preferably 200 to 400 nm. When the average primary particle diameter is 100 nm or more, it is possible to suppress the color of the scene transmitted through the transmissive transparent screen from becoming yellowish. It is considered that when the average primary particle diameter is within this range, the number of aggregated particles tends to be 20 or less.
The light-scattering material 33 includes aggregated particles in which 20 or less of the primary particles are aggregated in the light-scattering layer 34. The aggregated particles are aggregates of 20 or less of the primary particles, preferably 15 or less, more preferably 10 or less. Further, in the case of forming a light scattering layer by applying a liquid material containing a transparent resin and a light scattering material, it is preferable that the number is in the above range because the dispersion stability is good.
The agglomerated particles can be confirmed by observing an arbitrary 10 cm square area of the transmission type transparent screen at 9 locations by SEM or TEM. The aggregated particles are particles in which 20 or less of the primary particles are aggregated, and as a result of observation by the above method, the number of aggregated particles composed of more than 20 primary particles is 9 in all 9 locations. It means 10% or less of the total number of aggregated particles. Examples of the aggregated form of the aggregated particles include a form in which primary particles are connected in one row or two rows, and a shape in which primary particles are aggregated in a spherical shape. In order to control the number of agglomerated particles to fall within the above range, it is possible to control the light scattering material 33 by a method of dispersing it in the transparent resin 32 in a solution state.

As the light scattering material 33, titanium oxide (refractive index: 2.5 to 2.7), zirconium oxide (refractive index: 2.4), aluminum oxide (refractive index: 1.76), zinc oxide (refractive index: 2.0), fine particles of high refractive index material such as barium sulfate (refractive index: 1.64), zinc sulfide (refractive index: 2.2); porous silica (refractive index: 1.3 or less), hollow silica ( Fine particles of a low refractive index material such as a refractive index: 1.3 or less); a resin material having a low compatibility with the transparent resin 32 and having a different refractive index; a crystallized resin material and the like. The light-scattering material is a material that has a function of scattering light because it has a refractive index different from that of the resin material serving as a binder. Since many resin materials have a refractive index of 1.45 to 1.65, it is preferable that the resin materials have a refractive index different by 0.15 or more, more preferably 0.25 or more, Preferably, the difference is 0.5 or more. Therefore, the refractive index of the light scattering material is preferably 1.6 or more, preferably 1.7 or more, and more preferably 1.95 or more. The light-scattering material preferably has a refractive index of 1.5 or less, preferably 1.4 or less, and a part of the light-scattering material has a refractive index of 1.1 to 1.0 nm. It is more preferable to include the above voids. As the light scattering material 33, titanium oxide and zirconium oxide are particularly preferable because they have a high refractive index. Further, two or more kinds of light scattering materials may be mixed. Furthermore, materials of the same kind having different average primary particle diameters may be used. Further, the light-scattering material 33 may contain fine particles having an average primary particle diameter of 100 nm or less within a range that does not impair the effects of the present invention.

The content ratio of the light-scattering material 33 is preferably 0.01 to 10 mass% and more preferably 0.05 to 5 mass% in 100 mass% of the light-scattering layer 34. In order to increase the total light transmittance of the light scattering layer 34 and adjust the degree to which the scene seen through the screen turns yellow, the content ratio of the light scattering material 33 is calculated using titanium oxide as the light scattering material. It is preferable to set it to 0.1 to 2% by mass in 100% by mass of the light scattering layer 34. Within this range, stray light due to internal scattering is reduced, so that it is possible to suppress deterioration in contrast due to external light.
(Light absorbing material)
In order to improve the contrast of an image, it is preferable that the transmissive transparent screen 1 contains a light absorbing material. The light absorbing material 33 may be contained in any of the transparent substrate 10, the transparent substrate 20, the transparent film 31, the transparent film 35, the bonding layer 12, the bonding layer 22, and the light scattering layer 34. It is preferably included in the scattering layer 34. The light-absorbing material absorbs light that is scattered and propagated by the light-scattering material in the in-plane direction of the substrate, thereby preventing light from being emitted from a region that is not illuminated by a projector or the like. This increases the contrast of the image. Further, due to the action, even when the light from the illumination normally arranged above is incident, the light emitted from the transparent screen member due to multiple scattering can be suppressed, and the transparency can be improved.

As the light absorbing material, a carbon-based material (carbon black, nanodiamond, fullerene, carbon nanotube, carbon nanohorn, graphene, etc.) as an inorganic coloring material, titanium black, black silica, and a fine particle material mainly containing silver (for example, silver) , Nitrides, sulfides, and oxides thereof) and the like. Examples of organic coloring materials include organic pigments and organic dyes. The tint may be adjusted by mixing two or more light absorbing materials. From the viewpoint of durability, it is preferable to use an inorganic coloring material or an organic pigment as the light absorbing material. Inorganic and organic coloring materials are usually particles.

When the light-scattering layer contains a light-scattering material, the proportion of the light-absorbing material is preferably 0.01 to 10 mass% and more preferably 0.05 to 5 mass% in 100 mass% of the light-scattering layer 34. Further, it is preferable that the film thickness of the transparent resin is also adjusted so that the optical density is between 0.05 and 1. When the light-scattering layer contains a light-absorbing material, the light-scattering material-containing layer and the light-absorbing material-containing layer may be laminated.
The average primary particle diameter of the light absorbing material is preferably equal to or less than the average primary particle diameter of the light scattering material. The ratio of the average primary particle diameter of the light absorbing material and the average primary particle diameter of the light scattering material (average primary particle diameter of the light absorbing material/average primary particle diameter of the light scattering material) is 0.001 to 1. Is preferred. When the average primary particle diameter of the light absorbing material/the average primary particle diameter of the light scattering material is within the above range, light can be efficiently extracted in the forward scattering direction, and the screen gain can be increased while maintaining the transparency. Can be raised.

From the viewpoint of easily obtaining the balance of haze, total light transmittance and transparency, the light absorbing material is preferably a carbon-based material and titanium black, more preferably carbon black and titanium black.

1-200 micrometers is preferable, as for the thickness of the light-scattering layer 34, 1-100 micrometers is preferable and 1-10 micrometers is more preferable. When the thickness of the light scattering layer 34 is 1 μm or more, the light scattering effect is sufficiently exerted. When the thickness of the light scattering layer 34 is 200 μm or less, it is easy to form the light scattering layer 34 by the roll-to-roll process. When the surface of the light scattering layer 34 is not the outermost layer of the transmissive transparent screen, the surface of the light scattering layer 34 may be flat or may have irregularities, and if Ra is 10 μm or less. Good. As the unevenness, random unevenness having no periodicity is preferable. The uneven shape may be a similar shape. When it has unevenness, the scattering characteristics of the light scattering layer 34 can be controlled by two of the unevenness and the light scattering material.
When the light-scattering layer 34 is formed by laminating a layer containing a light-scattering material and a layer containing a light-absorbing material, the thickness of each layer is arbitrary within the range of the preferable thickness of the light-scattering layer 34. Can be set to.

(Method of manufacturing light scattering sheet)
The light-scattering sheet 30 can be manufactured by the following procedure, for example.

A paste containing the photocurable resin and the light scattering material 33 is prepared. The paste is applied to the surface of the first transparent film 31, and the second transparent film 35 is overlaid on the paste.

The paste is irradiated with light (ultraviolet rays or the like) from the first transparent film 31 side or the second transparent film 35 side to cure the photocurable resin, and the light scattering material 33 is dispersed in the transparent resin 32. By forming the light scattering layer 34, the light scattering sheet 30 is obtained.

The light scattering sheet 30 can also be manufactured by the following procedure.

A solution containing a solvent, a thermoplastic resin, and the light scattering material 33 is prepared. The light-scattering sheet 30 is obtained by applying a solution to the surface of the first transparent film 31 and drying it, then stacking the second transparent film 35 thereon, and then heating and softening and cooling the thermoplastic resin. The solvent medium can be used without particular limitation as long as it is a solvent capable of dissolving the thermoplastic resin, but a solvent that is easily dried is preferable. Further, it is preferable to select a solvent that can appropriately control the number of primary particles constituting the aggregated particles. If the thermoplastic resin is polyvinyl butyral or polyvinyl acetal, a solvent having a boiling point of 150° C. or lower can be preferably used, but in order to easily control the number of primary particles constituting aggregated particles to 20 or less, a solvent with high polarity is used. preferable. As the highly polar solvent, a solvent having a hydroxyl group or water can be used, and alcohols are preferable.
Further, the solution preferably contains a dispersant. The dispersant can be used to assist the dispersibility of the light scattering material or the light absorbing material in the transparent resin. As the dispersant, polyacrylate type, phosphoric acid ester type, polyamine type, polyurethane type and the like can be used.

The light scattering sheet 30 can also be manufactured by the following procedure.

The light scattering layer 34 is formed by extruding the thermoplastic resin, the light scattering material 33, and the light absorbing material. For example, the light-scattering sheet 30 is obtained by three-layer extrusion molding together with the thermoplastic resin for forming the transparent films 31 and 35. The light scattering layer may be formed using a masterbatch method. That is, a thermoplastic resin, a light-scattering material and a light-absorbing material are melt-kneaded in advance to produce a masterbatch, and during extrusion molding, the masterbatch and the thermoplastic resin are melt-kneaded and extruded to form a light-scattering layer. be able to.

(Method for manufacturing a transparent transparent screen)
The screen 1 is manufactured by laminating the light-scattering sheet 30 and the transparent base materials 10 and 20 via the bonding layers 12 and 22. The joining of the light scattering sheet 30 and the transparent base material 10 and the joining of the light scattering sheet 30 and the transparent base material 20 may be performed simultaneously or sequentially. For example, when the bonding layer is made of a cured product of a curable resin, a curable resin layer is formed between the surface of the transparent film 31 which is the bonding surface of the light scattering sheet 30 and the surface of the transparent substrate 10, and the curing thereof is performed. The resin is cured and bonded. Bonding between the surface of the transparent film 35 and the surface of the transparent substrate 20 can be performed in the same manner. When the bonding layer is made of a heat-fusible resin, a heat-fusible resin layer is formed between the transparent film surface of the light-scattering sheet and the surface of the transparent substrate, and the heat-fusible resin layer is heated. Press to fuse and cool to join. When the bonding layer is an adhesive resin, an adhesive layer is formed between the surface of the transparent film of the light scattering sheet and the surface of the transparent substrate, and the adhesive layer is pressed to bond.

(Optical characteristics of transmissive transparent screen)
The haze of the screen 1 is 5 to 45%, preferably 7 to 35%. If the haze is 5% or more, the screen gain and the viewing angle can be secured. When the haze is 45% or less, the phenomenon in which the entire screen 1 looks cloudy can be suppressed. When the haze is 35% or less, internal scattering is suppressed. As a result, the contrast of the scene seen from the side of the screen 1 viewed from the observer X side is improved, and the transparency of the scene is improved. Further, the contrast of the image displayed on the screen 1 is improved, and the visibility of the image is improved. The haze of the screen 1 is measured with respect to the light that is incident from the first surface A side and is transmitted to the second surface B side.

The haze of the screen 1 can be adjusted to the above range by adjusting the content ratio of the light scattering material 33 or adjusting the layer thickness of the light scattering layer 34 containing the light scattering material 33. Further, the haze can be adjusted within the above range by setting the number of primary particles forming the aggregate of the light scattering material 33 to 20 or less or by setting the shape of the aggregate to an aspect ratio of 2 or less.

The total light transmittance of the screen 1 is 40% or more, preferably 50 to 95%, more preferably 60 to 90%. When the total light transmittance is 40% or more, the visibility of the scene seen from the side of the screen 1 viewed from the observer X side is excellent, and therefore it is suitable for use in a show window or the like. The total light transmittance is preferably 95% or less, and when it is 85% or less, the phenomenon in which the entire screen 1 appears cloudy can be suppressed. As a result, the contrast of the scene seen from the side of the screen 1 viewed from the observer X side is improved, and the transparency of the scene is improved. Further, the contrast of the image displayed on the screen 1 is improved, and the visibility of the image is improved. The total light transmittance of the screen 1 is measured with respect to the light which is incident from the first surface A side and is transmitted to the second surface B side.

The total light transmittance of the screen 1 is mainly adjusted by adjusting the content ratio of the light absorbing material, adjusting the layer thickness of the layer containing the light absorbing material, or adjusting the type of the light absorbing material. The above range can be used.

The diffuse reflectance of the screen 1 is 0.1 to 5%, preferably 0.1 to 2.4%, more preferably 0.1 to 1.7%. If the diffuse reflectance is 0.1% or more, the screen gain and the viewing angle can be secured, and if it is 1.0% or more, the screen gain and the viewing angle are more preferable. When the diffuse reflectance is 5% or less, unnecessary scattering light is sufficiently absorbed by adding the light absorbing material, and the phenomenon in which the entire screen 1 appears cloudy can be suppressed. As a result, the contrast of the scene seen from the side of the screen 1 viewed from the observer X side is improved, and the transparency of the scene is improved. Further, the contrast of the image displayed on the screen 1 is improved, and the visibility of the image is improved. The diffuse reflectance of the screen 1 is measured with respect to the light that is incident from the second surface B side and reflected on the second surface B side.

The diffuse reflectance of the screen 1 is easily adjusted to the above range when the light-scattering particles of the present invention are included, and the ratio of the light-scattering material 33 is further adjusted, or the layer thickness of the light-scattering layer 34 including the light-scattering material 33. Can be controlled within the above range by adjusting the above, adjusting the ratio of the light absorbing material, adjusting the film thickness of the layer containing the light absorbing material, or forming an antireflection film.

The screen 1 has a ratio of blue light scattering intensity (A) having a wavelength of 400 to 480 nm to visible light scattering intensity (B) having a wavelength of 400 to 700 nm, and A/B is preferably 0.7 to 1.25. , 0.8 to 1.2 are more preferable. Within this range, the color change of the background image is small and the color reproduction of the projected image is good.

The difference in the refractive index between adjacent layers in the screen 1 is preferably 0.2 or less from the viewpoint that the reflectance at the interface between the layers can be suppressed within 0.5%, and the reflectance at the interface between the layers is about 0.1%. From the viewpoint of the above, 0.1 or less is more preferable.
<Projector>
The projector 200 may be any one that can project the image light L on the screen 1. The projector 200 may be a known projector or the like. The projector can project the image light L from a close range of 10 to 90 cm, save space in the image display system, and project the image light L with a large incident angle. A short focus projector is preferable because it is difficult for a person to cross between 200 and the screen 1.
<Video display method>
On the screen 1, as shown in FIG. 1, the image light L projected from the projector 200 and incident from the first surface A of the screen 1 is imaged by being scattered by the light scattering layer 34 to form an image. The image is visually displayed as a video image for the observer X on the opposite side of 200.

After the light of the scene on the first surface A side is incident on the screen 1 from the first surface A, a part of the light is scattered in the light scattering layer 34 and the rest is transmitted. Thereby, when the image light L is not projected from the projector 200 on the screen 1, the observer X on the second surface B side can see through the scene on the first surface A side. Similarly, after the light of the scene on the second surface B side is incident on the screen 1 from the second surface B, a part of the light is scattered in the light scattering layer 34 and the rest is transmitted. Thereby, when the image light L is not projected from the projector 200 onto the screen 1, the observer on the first surface A side can see through the scene on the second surface B side.

In addition, in the screen 1, as shown in FIG. 2, the light L1 of the scene on the first surface A side, the light L2 emitted from the illumination 202 (or the sun) on the second surface B side, and the like are light scattering layers. Scatter at 34. However, since the particle diameter of the light-scattering material 33 contained in the light-scattering layer 34 is controlled as described above, when the observer X observes the scene on the other side of the screen 1, the scene color changes to yellow. It is possible to suppress the occurrence of color change, and it is possible to suppress the color of the projected image from changing to blue.

<Mechanism of action>
In the screen 1 described above, the light-scattering particles contained in the light-scattering layer 34 have an average primary particle diameter of 100 to 400 nm, and the number of primary particles forming aggregated particles is 20 or less. It is possible to prevent the color of the scene seen through the screen 1 from changing to yellow, and it is possible to prevent the projected image from changing to blue.

<Other Embodiments>
The aspect of the screen of the present invention is a screen having a light-scattering layer having a first surface and a second surface opposite to the first surface, the light-scattering layer containing a transparent resin and a light-scattering material. The haze is 5 to 45% and the total light transmittance is 40% or more, and is not limited to the screen 1 of FIG. Hereinafter, the same components as those of the screen 1 of FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 3, the transmissive transparent screen may be a screen 1a in which the light scattering layer 34 is formed on the surface of the second transparent substrate 20. In the case where the transparent resin 32 is a cured product of a curable resin, a layer of the uncured curable resin composition to be the light scattering layer 34 is formed on one surface of the second transparent base material 20, and the second transparent base material is formed. 20 can be manufactured by curing the curable resin composition on the surface. Alternatively, a solution in which a thermoplastic resin and a light-scattering material are dispersed in a solvent is applied to one surface of the second transparent base material 20, and the solvent can be removed by heating or the like for production. When the transparent resin 32 is a thermoplastic resin, a film to be the light scattering layer 34 is produced by extrusion molding or the like from a thermoplastic resin composition to be the light scattering layer 34, and the film and the second transparent base material. 20 is a method of laminating and heat-sealing, and when the transparent resin 32 and the transparent base material 20 are thermoplastic resins, a thermoplastic resin composition which becomes the light scattering layer 34 and a thermoplastic resin which becomes the transparent base material 20. Can be manufactured by a two-layer extrusion molding method.

Further, as shown in FIG. 4, the screen 1b may be a screen 1b in which the first transparent base material 10 is attached to the surface of the screen 1a on the light scattering layer 34 side via the bonding layer 12. The screen 1b shown in FIG. 4 can be manufactured by, for example, joining the screen 1a shown in FIG. 3 and the second transparent substrate 10 with an adhesive or a pressure-sensitive adhesive. For example, the screen 1a shown in FIG. 3 and the second transparent substrate 10 are laminated with a film of a heat-fusible resin sandwiched therebetween, and the laminate is thermocompression bonded to form a bonding layer 12, thereby producing a screen 1b. can do. Note that FIG. 4 shows an embodiment in which the light scattering layer 34 contains a light absorbing material.

As shown in FIG. 5, the embodiment of the transmissive transparent screen is such that the first transparent base material 10 and the second transparent base material 20 are provided with a light scattering layer 34 using a bonding material as the transparent resin 32. It is also possible to use the screen 1c that is attached by bonding.
The screen 1c is obtained, for example, by filling an uncured curable resin composition which will be the light scattering layer 34 between the transparent base material 10 and the second transparent base material 20, and then curing the curable resin composition. It can be manufactured. Alternatively, a solution in which a thermoplastic resin and a light-scattering material are dispersed in a solvent is applied to one surface of the second transparent base material 20, and the solvent can be removed by heating or the like for production. When the transparent resin 32 is a heat-fusible resin such as polyvinyl butyral, a film to be the light-scattering layer 34 is manufactured by extrusion molding from a thermoplastic resin composition to be the light-scattering layer 34, and then heat-sealed. The obtained film is sandwiched between the first transparent base material 10 and the second transparent base material 20 which are made of a transparent base material (glass plate or the like) made of a material having no or low property, and heated and pressed for fusion bonding. It can be manufactured.
Further, it can be produced by three-layer extrusion molding from a thermoplastic resin which becomes the first transparent base material 10, a thermoplastic resin which becomes the second transparent base material 20 and a thermoplastic resin composition which becomes the light scattering layer 34. .. Note that FIG. 5 shows a mode in which the light scattering layer 34 contains a light absorbing material.

As shown in FIG. 6, the transmissive transparent screen may be a screen 1d in which the first transparent base material 10 and the second transparent base material 20 are omitted, that is, the light scattering sheet 30 itself. In this case, the surface of the first transparent film 31 becomes the first surface and the surface of the second transparent film 35 becomes the second surface. Note that FIG. 6 shows an embodiment in which the light scattering layer 34 contains a light absorbing material. Further, although not shown, a film or sheet composed only of the light scattering layer 34 can be used as a transmissive transparent screen.

The transparent films 31 and 35 are peeled off from the sheet having the structure shown in FIG. 6 to produce a film consisting of only the light scattering layer 34, and two transparent substrates are provided on both sides of the film with a heat-fusible resin film interposed therebetween. By stacking, a laminated body having a structure of transparent substrate/heat-fusible resin layer/light-scattering layer 34/heat-fusible resin layer/transparent substrate is manufactured, and the laminated body is thermocompression-bonded to form transparent substrate 10/bonding. The transmissive transparent screen of the present invention having the structure of layer 12, light scattering layer 34, bonding layer 22, and transparent substrate 20 can be manufactured.

When the transmissive transparent screen of the present invention contains a light absorbing material, as shown in FIG. 7, a light scattering layer 34 containing a transparent resin and a light scattering material, and a second surface side of the light scattering layer are provided. And a light absorbing layer 36 including a transparent material and a light absorbing material.
The light absorption layer 36 includes a transparent resin and a light absorption material, and does not include the light scattering material 33.

The transparent resin of the light absorption layer 36 may be the same as the transparent resin 32. In this embodiment, the matrix component of the light absorption layer may be any transparent material and is not limited to a transparent resin. Examples of the transparent material include glass and the like in addition to the transparent resin.

The thickness of the light absorption layer 36 is preferably 1 to 200 μm. When the thickness of the light absorption layer 36 is 1 μm or more, the light absorption effect is sufficiently exhibited. When the thickness of the light absorption layer 36 is 200 μm or less, it is easy to form the light absorption layer 36 by a roll-to-roll process.

The light absorption layer 36 may be an inorganic thin film or an organic thin film containing no matrix component. Examples of the material of the inorganic thin film include metals such as Cr, Mo, Ti, Ta, NiCr, and Zn, oxides or nitrides such as Cr, Mo, and Ta, and carbon materials such as graphene.

In the embodiment having the light scattering layer and the absorption layer provided on the second surface side with respect to the light scattering layer, as shown in FIG. 7, as shown in FIG. The light L1 of the scene, the light L2 emitted from the illumination 202 (or the sun) on the second surface B side, and the like are scattered in the light scattering layer 34. However, since the light absorbing layer 36 provided on the second surface B side of the light scattering layer 34 includes the light absorbing material, unnecessary scattered light is absorbed by the light absorbing material, and the entire screen 1 appears clouded. The phenomenon is suppressed.

Further, as shown in FIG. 9, the aspect of the transmissive transparent screen may be a screen 1e in which a light absorbing layer 36 and a light scattering layer 34 are sequentially formed on the surface of the second transparent substrate 20.

Further, as shown in FIG. 10, the screen 1f may be a screen 1e in which the first transparent base material 10 is attached to the surface of the screen 1e on the light scattering layer 34 side via the bonding layer 12.

As shown in FIG. 11, the mode of the transmissive transparent screen is such that the first transparent base material 10 and the second transparent base material 20 are made of a light-scattering layer 34 and a light-absorbing layer which are made of a bonding material as a transparent resin. It may be a screen 1g that is bonded via the layer 36.

As shown in FIG. 12, the transmissive transparent screen may be a screen 1h in which the first transparent base material 10 and the second transparent base material 20 are omitted, that is, the light scattering sheet 30 itself.

As shown in FIG. 13, the aspect of the transmissive transparent screen is such that the first transparent base material 10 and the second transparent base material 20 are attached via a light absorbing layer 36 using a bonding material as a transparent resin. The screen 1i may have the light-scattering layer 34 formed on the first surface side of the laminated glass.

As shown in FIG. 14, the aspect of the transmissive transparent screen is that the first transparent base material 10 and the second transparent base material 24 containing a light absorbing material are used as a transparent resin using a bonding material. It may be the screen 1j which is attached via the scattering layer 34.

Further, in the above-described aspect, the positional relationship between the light absorbing layer and the light scattering layer or the positional relationship between the light scattering sheet and the transparent base material may be reversed.
In the case of the transmissive transparent screen, the image light from the projector may be projected on the second transparent substrate side (or the second transparent film side). In this case, the surface on the second transparent substrate side (or the second transparent film side) becomes the first surface A.

A film having only a light scattering layer, a sheet having a transparent film on one side or both sides of the light scattering layer (for example, a sheet having a structure shown in FIG. 6), and a film or sheet having a two-layer structure having only a light scattering layer and a light absorbing layer. Further, a film or sheet having a transparent film layer on one side or both sides (for example, a sheet having a structure shown in FIG. 12), etc. is attached to an existing window glass or the like by using an adhesive or a pressure-sensitive adhesive, and a transparent transparent screen. Can be formed. Further, among them, a relatively thin one can be deformed, and is suitable for forming a transmissive transparent screen having a curved surface.

Further, in a double-layered glass having two glass plates and a frame-shaped spacer interveningly arranged at the peripheral edge of the glass plates so that a gap is formed between the glass plates, on one inner surface of the glass plate, It is also possible to form a transmissive transparent screen by sticking a film consisting of only the light scattering layer.

INDUSTRIAL APPLICABILITY The transmissive transparent screen of the present invention is useful as a transparent member used for showcases of products and the like; display cases for art objects and the like; windows of buildings, showrooms, vehicles and the like; glass doors; Specifically, it is possible to see through the sight seen from the side of the transparent member from the observer's side, and to convey information such as description of products, state of various devices, destination guidance, and matters to be transmitted to the observer. At the time of displaying the operation screens of various devices for the observer, or for obscuring the view of the other side of the transparent member from the observer for privacy protection, security, etc. It is useful as a transparent screen for visually displaying the image light projected from the viewer as an image. It is especially useful for applications where color reproduction of the scene seen through the screen is required.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Examples 1 to 4 are examples, and Example 5 is a comparative example.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.
(Example 1)
Polyvinyl butyral (Sekisui Chemical: S-REC BM-2) in 1-butanol solution (solid content: 10% by mass, viscosity: 300 MPa·s) in 10 g, light scattering particles (titanium oxide particles, average primary particle size: 160 nm) 0.01 g was added and kneaded for 5 minutes while deaerating to prepare a paste. The paste prepared on the surface of a transparent polyethylene terephthalate (hereinafter referred to as PET) film (manufactured by Toyobo Co., Ltd., Cosmoshine (registered trademark) A4300, thickness: 250 μm) was applied by spin coating (1000 rpm, 15 seconds), The paste was dried at room temperature for 30 minutes to form a light-scattering layer having a thickness of 4 μm to obtain a transparent transparent screen. The evaluation results are shown in Table 1. The blue scattering intensity (A) was 6.94, the visible light scattering intensity (B) was 5.96, and A/B was 1.18.

(Example 2)
A transmissive transparent screen was obtained in the same manner as in Example 1 except that light scattering particles (titanium oxide particles, average primary particle diameter: 200 nm) were used instead of the light scattering particles of Example 1. The evaluation results are shown in Table 1. The blue scattering intensity (A) was 7.46, the visible light scattering intensity (B) was 6.39, and A/B was 1.17.
(Example 3)
A transmissive transparent screen was obtained in the same manner as in Example 1 except that light scattering particles (titanium oxide particles, average primary particle diameter: 290 nm) were used instead of the light scattering particles of Example 1. The evaluation results are shown in Table 1. The blue scattering intensity (A) was 7.11, the visible light scattering intensity (B) was 6.67, and A/B was 1.07.
(Example 4)
A transmissive transparent screen was obtained in the same manner as in Example 1 except that light scattering particles (titanium oxide particles, average primary particle diameter: 400 nm) were used instead of the light scattering particles of Example 1. The evaluation results are shown in Table 1. The blue scattering intensity (A) was 7.02, the visible light scattering intensity (B) was 7.54, and A/B was 0.93.
(Example 5)
An example transmission type transparent screen was obtained in the same manner as in Example 1 except that light scattering particles (titanium oxide particles, average primary particle diameter: 15 nm) were used in place of the light scattering particles of Example 1. The evaluation results are shown in Table 1. The blue scattering intensity (A) was 8.91, the visible light scattering intensity (B) was 6.84, and A/B was 1.32.

The total light transmittance, the total light reflectance, and the transmitted color tone YI value of the produced light-scattering sheet were measured with a spectrophotometer using a D65 light source described in Japanese Industrial Standards (JIS Z8720:2012). The haze value was measured using a haze meter in accordance with Japanese Industrial Standards (JIS K7136) and a D65 light source described in Japanese Industrial Standards (JIS Z8720:2012). The straight light transmission color (YI) in the table represents the tint of the scene seen through the screen.
(Screen color evaluation)
The color of the screen was judged by observing a white background through the screen in the daytime environment.
(Color evaluation)
A white background was observed through the screen in the daytime environment and compared to the color of the non-screen background.
1: Screen color and background color are similar
2: Screen color and background color are close
3: Screen color and background color are different

As shown in Table 1 and Table 2, the average primary particle diameter of the light scattering material is 100 to 400 nm, the number of primary particles forming aggregated particles is 20 or less, and the haze is 5 to 45%, It can be seen that in Examples 1 to 4 in which the total light transmittance is 40% or more, the YI is small and the yellow discoloration of the scene seen through the screen is small. Also, it can be seen that the color of the screen is white to light blue and the discoloration of blue is small.

In Example 5 in which the average primary particle size of the light-scattering material is smaller than 100 nm, the haze is 18.7% and the total light transmittance is 92.4%, but the YI is large and the screen color is blue, causing discoloration. It was observed.

1 transparent type transparent screen, 1a transparent type transparent screen, 1b transparent type transparent screen, 1c transparent type transparent screen, 1d transparent type transparent screen, 1e transparent type transparent screen, 1f transparent type transparent screen, 1g transparent type transparent screen, 1h transparent type Type transparent screen, 1i transmissive transparent screen, 1j transmissive transparent screen, 10 first transparent base material, 12 bonding layer, 20 second transparent base material, 22 bonding layer, 24 second transparent base material, 30 light Scattering sheet, 31 first transparent film, 32 transparent resin, 33 light scattering material, 34 light scattering layer, 35 second transparent film, 101 transmissive transparent screen, 110 first transparent substrate, 120 second transparent Base material, 132 transparent resin, 133 light scattering material, 134 light scattering layer, 200 projector, 202 illumination, A first surface, B second surface, L image light, L1 light, L2 light, X Observer

Claims (8)

A transparent transparent screen having a light-scattering layer containing a transparent resin and a light-scattering material,
The light-scattering material is inorganic fine particles having an average primary particle diameter of 100 to 400 nm, and some of the inorganic fine particles include aggregated particles in which 20 or less of the primary particles are aggregated ,
The number of the agglomerated particles composed of more than 20 primary particles is 10% or less of the total number of the agglomerated particles,
The difference between the refractive index of the transparent resin and the refractive index of the inorganic fine particles is 0.15 or more,
The content ratio of the inorganic fine particles is 0.01 to 10 mass% with respect to 100 mass% of the light scattering layer,
Haze is 5 to 45%,
A transmissive transparent screen having a total light transmittance of 40% or more. The transmissive transparent screen according to claim 1, wherein the content of the inorganic fine particles in the light scattering layer is 0.01 to 10 mass% with respect to 100 mass% of the light scattering layer. The transmissive transparent screen according to claim 1, wherein the light-scattering material is one or more selected from the group consisting of titanium oxide and zirconium oxide. The blue light scattering intensity (A) having a wavelength of 400 nm to 480 nm and the visible light scattering intensity (B) having a wavelength of 400 nm to 700 nm, A/B is 0.75 to 1.25. transmissive transparent screen according to any one of 1-3. The transparent resin is a thermoplastic resin, a transmissive transparent screen according to any one of claims 1-4. Wherein the transparent resin is polyvinyl butyral, polyvinyl acetal, at least one member selected from the group consisting of ethylene-vinyl acetate copolymer, transmissive transparent screen according to any one of claims 1-5. The molecular weight of the transparent resin is 5000 to 1000000, transmissive transparent screen according to claim 5 or 6. Billing transmissive transparent screen according to any one of claims 1-7, and a said transmissive transparent screen first placed on the side projection machines, video display system.