JP7380991B2 - Transparent screen and projection system using this transparent screen or its applied equipment - Google Patents

Description

The present invention is a transparent screen that displays an image by forming an image of light projected from a projector, and that prevents light transmitted through the screen from forming an image on a place other than the screen, such as a floor surface. The present invention relates to a screen, a projection system using the transparent screen, and its applied equipment.

Transmissive screens and reflective screens are used as transparent screens that form and project light projected from a projector. Among these, in the case of a transmissive transparent screen, a transparent screen is installed between the projection lens of the projector and the viewer's eyes, and the light projected from the projector is formed into an image to display an image on the transparent screen. In the case of a reflective transparent screen, the projection lens of the projector is placed on the same side of the viewer's eyes as the transparent screen, and images are displayed on the transparent screen. At this time, since the screen is transparent, objects behind it can be seen through the screen, making it appear as if an image is being formed in space.

At this time, since the screen is transparent and objects behind it are visible, if the projector is placed behind the screen, the projector behind the screen will be visible to the viewer. In addition, the light from the projector may directly enter the eyes of the viewer, causing the viewer to feel glare. To prevent this, it is possible to place the projector diagonally above or below the screen and project at an angle to the screen so that the optical axis of the projected light from the projector is shifted from the viewer's line of sight. It is being done.

However, when the angle is set in this way, the light that passes through the screen is projected onto areas other than the screen, such as the floor and ceiling on the viewer's side, causing a phenomenon in which images other than those formed on the screen are visible. It happens and the effect of the screen is spoiled.
As a countermeasure to this phenomenon, it is possible to install a blinding wall to hide the images transmitted through the screen and formed on areas other than the screen, such as the floor or ceiling, but this requires large-scale construction and complicated construction. In addition to requiring the provision of a unique structure, the space becomes narrower, and the effect as a transparent screen is impaired.
Further, although the description is given using a transmissive transparent screen, a similar phenomenon occurs in a reflective transparent screen as well, in which light transmitted through the transparent screen forms an image at a location other than the screen and an image is visible.
Note that although the installation positions for shifting the optical axis of the projector are expressed as diagonally above and diagonally below, the same applies to diagonally to the side.

Patent Document 1 describes an example in which a projector is arranged diagonally with respect to the screen and the optical axis of the projected light is angled with respect to the screen in a transmissive screen as in the above-mentioned prior art. . However, even in this case, there is a risk that the image transmitted through the screen may form an image on the viewer's side of the floor, ceiling, or other location other than the screen.

Unexamined Japanese Patent Publication No. 2016-65999

The problem to be solved by the present invention is to prevent the light projected from the projector from passing through the transparent screen and forming an image on a place other than the screen, such as the floor, and to improve the visibility of the image formed on the screen. An object of the present invention is to provide a transparent screen, a projection system using this transparent screen, and its application equipment.

In order to solve the above problems, the transparent screen of the present invention has an incident angle dependent function in the light diffusion intensity for incident light from a specific angle range, so that the light that has passed through the transparent screen can be transmitted to other than the screen. It is characterized by not forming an image on the location.
Here, the expression "not to form an image anywhere other than the screen" means that the image formed on the transparent screen cannot be clearly recognized anywhere other than the transparent screen.

The transparent screen includes a screen layer that forms an image and a light control layer whose light diffusion intensity is dependent on the angle of incidence, and the screen layer and the light control layer are separate bodies and are bonded to each other.
Further, the light control layer may be coated with a screen layer, or the screen layer may be coated with a light control layer. Furthermore, the light control layer may be configured to include the function of a screen layer.
The thickness of the light control layer is preferably 10 to 200 μm. It may also be used by bonding it to a transparent material such as resin or glass.
Any of the transparent screens described above may be used as a projection system or its application equipment.

According to the present invention, light incident at a specific angle forms an image on the screen, but unnecessary images are projected on areas other than the screen such as the floor and ceiling due to the light that passes through the transparent screen. Never.
At this time, since light incident at an angle smaller or larger than a specific angle is not diffused, objects behind the transparent screen can be viewed from angles other than the specific angle.

FIG. 1 is a sectional view of a transparent screen showing an embodiment of the present invention. FIG. 2 is a diagram showing details of the configuration of the transparent screen shown in FIG. 1; It is a figure showing another composition of a transparent screen. It is a figure showing still another composition of a transparent screen. FIG. 1 is a cross-sectional view of a transparent screen in use, showing an embodiment of the present invention. FIG. 2 is a schematic diagram of the apparatus used in Experiment 1. 3 is a diagram showing the state of the test target T used in Experiment 1. FIG. 3 is a diagram showing a waveform after passing through a transparent screen 1 in Experiment 1. FIG. FIG. 3 is a diagram showing an image when the incident angle is 90° in Experiment 1. FIG. 3 is a diagram showing an image when the incident angle is 80° in Experiment 1. FIG. 4 is a diagram showing an image when the incident angle is 70° in Experiment 1. FIG. 4 is a diagram showing an image when the incident angle is 60° in Experiment 1. FIG. 4 is a diagram showing an image when the incident angle is 50° in Experiment 1. FIG. 4 is a diagram showing an image when the incident angle is 40° in Experiment 1. FIG. 3 is a diagram showing an image when the incident angle is 30° in Experiment 1. FIG. 4 is a diagram showing an image when the incident angle is 20° in Experiment 1. FIG. 3 is a diagram showing an image when the incident angle is 10° in Experiment 1. FIG. 3 is a diagram showing MTF values and image determination results for each incident angle of light in Experiment 1. FIG. 2 is a perspective view of the apparatus used in Experiment 2. FIG. 6 is a diagram showing an image seen from the front in Experiment 2. FIG. 6 is a diagram showing an image viewed diagonally from the left side in Experiment 2. FIG. 6 is a diagram showing an image viewed diagonally from the right side in Experiment 2. FIG. 6 is a diagram showing an image viewed from the front and lower side in Experiment 2. FIG. 7 is a diagram showing an image viewed from the front and above in Experiment 2. It is a figure showing the relationship between a diffusion angle and a haze value. FIG. 3 is a diagram showing a method of measuring declination haze. FIG. 3 is a diagram showing a reflective transparent screen in an embodiment of the present invention.

Embodiments of the present invention will be described below. FIG. 1 is a sectional view of a transparent screen 1 according to an embodiment of the present invention.
As shown in FIG. 1, the transparent screen 1 includes a screen layer 2, a light control layer 3 laminated on one side of the screen layer 2, and an anti-warping film 4 laminated on the other side of the screen layer 2. Equipped with

FIG. 2 is a diagram showing details of the structure of the transparent screen shown in FIG. 1. The screen layer 2 is formed of a plate material or a film made of a transparent resin mixed with particles 10. The thickness was 3.0 mm and the hardness was 2H on a pencil scale, but the thickness and hardness can be changed as appropriate, such as making the thickness thinner, lowering the hardness, or increasing the hardness. It is also possible.

For the transparent resin, PMMA was used as a base material. Specifically, MMA (methyl methacrylate) is used and polymerized to form PMMA (polymethyl methacrylate). As the particles 10 to be mixed, silicon beads, acrylic beads, MS beads, inorganic fine particles, glass beads, nanodiamonds, etc. can be used. Among these particles, nanodiamonds are more preferred. The base material may be any other material as long as it is a light-transmitting material, such as polyester such as PET (polyethylene terephthalate), polybutylene terephthalate, and polyethylene naphthalate, polyolefin, polyvinyl alcohol, polycarbonate, polystyrene, vinyl chloride, and fluorine. It is possible to use resin, polyamide, acrylic resin, polyurethane resin, fluororesin, etc. Furthermore, it is also possible to add dyes or pigments to the disimpaction to color it.

As the colorant, it is possible to use known colorants such as inorganic pigments, organic pigments, and organic dyes. Examples of inorganic pigments that can be used include carbon black, cobalt pigments, iron pigments, chromium pigments, titanium pigments, vanadium pigments, zirconium pigments, molybdenum pigments, and platinum pigments.
Examples of organic pigments and organic dyes include aluminum dyes, cyanine dyes, merocyanine dyes, phthalocyanine dyes, azo dyes, indigo dyes, metal complex dyes (metal complex salt dyes), triallylmethane dyes, and anthraquinones. It is possible to use colorants such as coloring matter and coloring matter. In addition, these pigments or dyes can be used in an appropriate mixture in order to adjust the desired hue.

In this embodiment, the resin constituting the screen layer 2 is an acrylic resin produced by a cell-casting method. This makes it possible to increase variations in thickness and color. However, the manufacturing method is not limited to the cell-casting method; it is also possible to create pellets into which scatterers and dyes are kneaded and then use an extrusion method or an injection molding method. The resin used in this case is not particularly limited, as long as it is a transparent resin, and polycarbonate, polystyrene, etc. are preferably used. Further, in order to improve the adhesion of a layer provided on the surface, the surface can be subjected to surface treatment by a primer treatment, an oxidation method, a roughening method, etc.

Furthermore, it is also possible to form an image by providing irregularities on the surface of the resin and using the difference in refractive index between the resin and the air. At this time, by providing unevenness on one side and laminating a diffusion plate on the other side, or by providing unevenness on both sides and providing a diffusion layer inside so that it is parallel to the unevenness on the surface, It is possible to prevent (actively) the light that has passed through the screen from forming an image on a floor, ceiling, or other location other than the screen.

It is also possible to manufacture the binder by kneading scatterers or dyes into the binder to give it a screen function and applying it to the surface of a film or plate material. As the binder, general binders can be used, and oligomers, amino alkyd resins, epoxy resins, polyurethane resins, acrylic resins, polyurethane resins, fluororesins, polyolefin resins, phenolic resins, etc. can be used. be.

The light control layer 3 has an incident angle dependence on light diffusion intensity. Specifically, it is a layer that controls the diffusion intensity of light incident from a projector, and its haze value depends on the incident angle of light. In this embodiment, a directional light diffusion film is used. That is, the light control layer 3 has a function of selectively diffusing only incident light from a specific angle range and transmitting incident light from other angles. The thickness is approximately 10 to 200 μm.

The haze value of the light control layer 3 is generally determined by measuring the total light transmittance and diffuse transmittance of the light control layer 3 using an integrating sphere type light transmittance measuring device, and using the following equation.
Haze value (%) = Diffuse transmittance (%) / Total light transmittance (%) x 100
Here, the diffuse transmittance is the value obtained by subtracting the parallel light transmittance from the total light transmittance.
A method for measuring the declination haze, which is the haze value in this embodiment, will be explained later. Furthermore, as the difference in light diffusion intensity increases, the difference in haze value also increases.

The method of measuring the state in which the light transmitted through the transparent screen does not form an image on a place other than the screen, such as the floor surface, is expressed by a numerical value called MTF, as will be described later.

The light control layer 3 can be formed as a single layer on the surface of the support substrate, and is formed by forming a composition containing two or more types of photopolymerizable compounds having different refractive indexes into a film. It can be manufactured by irradiating light from a specific direction and curing it. Urethane and the like are used as the compound, but various other monomers and oligomers can also be used. When urethane is used, it will have rubber elasticity. In this case, there is a diffusion film whose center angle of each light scattering angle range is different, for example, a diffusion film whose axis is tilted 35 degrees in one direction from the normal direction of the film, and a diffusion film whose axis is tilted 35 degrees in one direction from the normal direction of the film, and a diffusion film whose axis is tilted 35 degrees in one direction from the normal direction of the film. By stacking diffusion films with different axes, it is possible to control the image formation on the floor or ceiling of the image transmitted through the screen at a wider range of angles than when each diffusion film is used as a single layer. Become.

A region that scatters light is formed by irradiating light from a predetermined direction onto a composition obtained by mixing at least two types of photopolymerizable compounds having different refractive indexes and curing the composition. Haze appears due to the solubility and refractive index difference between these two types of compounds, and at the same time, light diffusion intensity develops dependence on the angle of incidence.
As the light used for curing, any light can be used as long as it cures the composition, and visible light, ultraviolet light, etc. can be used. Ultraviolet light is emitted using a mercury lamp, metal halide lamp, or the like. The degree of diffusion and the angle of selectively scattered incident light can be adjusted depending on the composition used and the irradiation conditions, and by changing the direction of incidence of the irradiated light, the light that enters the cured sheet can be emitted from the sheet. It is possible to control the angular range of diffuse or straight transmission.

The light control layer 3 can be laminated by laminating a plurality of films together. At that time, they may be bonded together using a pressure-sensitive adhesive or an adhesive. The adhesive is made of a sticky resin, and for example, acrylic, rubber, silicone, or other sticky resins can be used. As the acrylic adhesive resin, it is possible to use an acrylic acid ester copolymer or the like. At this time, it is also possible to add dyes, pigments, particles, etc. to the pressure-sensitive adhesive or adhesive resin to color the disimpaction or control the dispersibility.
In addition, by using one film as a base material, by coating and curing the photocurable composition, the light control layer 3 can be laminated, or the light control layer 3 can be used as a base material and the photocurable composition can be applied and cured. It is also possible to laminate the screen layer 2 by coating and curing. In the case of this method, a device for bonding is not required.

The screen layer 2 and the light control layer 3 are bonded together with an adhesive 6. As the adhesive 6, a general adhesive can be used, but it is preferable to use one that has good adhesion to urethane, which is the material of the light control layer 3 in this embodiment.

A surface protection layer 5 is provided on the surface of the light control layer 3 for surface protection. As the surface protection layer 5, a polyester film (PET) or the like is used. The surface protective layer 5 is provided to protect the surface of the light control layer, but from the viewpoint of light diffusion, etc., it is not necessarily necessary, and the same function can be achieved without the surface protective layer 5. . Furthermore, since the material currently used for the light control layer 3 has low hardness, providing the surface protective layer 5 also makes it possible to ensure the hardness. In this embodiment, the pencil hardness is 2H, but it is also possible to change the hardness as appropriate, such as lowering the hardness or increasing the hardness. Note that when a material having sufficient hardness is used as the light control layer 3, there is no need to provide a surface protective layer for the purpose of ensuring hardness.

The anti-warp film 4 is attached to the surface of the screen layer 2 opposite to the light control layer 3 via an adhesive 6. The anti-warpage film 4 is made of a polyester film (PET) or the like similarly to the surface protection layer 5. If the surface protection layer 5 is attached only to the surface of the light control layer 3, warpage will occur, so by attaching a film made of the same material to the opposite side, it is possible to prevent warpage. Specifically, as the warpage prevention film 4, OPTERIA-HA116-75J5P manufactured by Lintec Corporation was used. It is also possible to reduce the light reflectance by providing an antireflection film on the surface of the film. Furthermore, instead of using the anti-warp film 4, the surface of the screen layer 2 may be treated for anti-reflection to reduce the reflectance of light.

Moreover, the transparent screen of this embodiment can also be configured as a reflective transparent screen. FIG. 15 is a diagram showing a configuration as a reflective transparent screen. FIG. 15(a) shows a part of the cross-sectional configuration of a reflective transparent screen, in which an uneven surface 18 is formed on one surface (the right side in the figure) of a transparent base material 17, and the uneven surface 18 has a high height. A reflective layer 20 made of a refractive index material 21 is provided. FIG. 15(b) shows an enlarged schematic cross-sectional view of the uneven surface 18 of the transparent base material 17. As shown in the figure, a high refractive index material 18 is applied to the uneven surface 11 of the transparent base material 17 to form a thin film, thereby forming a reflective layer 20. Instead of the screen layer 2 of the transmissive transparent screen described above, it is possible to use these reflective transparent screens.

FIG. 3 is a diagram showing another configuration of the transparent screen. In the structure shown in FIG. 3, the screen layer 2 is made of a binder mixed with particles 11, and is formed by coating on the light control layer 3 similar to that shown in FIG. With such a configuration, a device for bonding the screen layer 2, the light control layer 3, etc. together becomes unnecessary. Alternatively, it is also possible to use the same screen layer 2 as shown in FIG. 2 as the screen layer 2 and form the light control layer 3 by coating. With these configurations, it is possible to have the same function as the transparent screen shown in FIG. 2.

FIG. 4 is a diagram showing still another configuration of the transparent screen. In the configuration of FIG. 4, particles 12 are mixed into the base material of the light control layer 3 similar to that of FIG. As the particles 12 to be mixed, silicon beads, acrylic beads, MS beads, inorganic fine particles, glass beads, nanodiamonds, etc. can be used. With such a structure, it becomes possible to have the functions of a screen layer and a light control layer in one layer, and there is no need to bond or coat the two layers. With these configurations, it is possible to have the same function as the transparent screen shown in FIG. 2. Further, for the purpose of surface protection, it is also possible to use a surface protection layer 5 attached to the surface of the light control layer 3 shown in FIG. 4.

In the configuration of these transparent screens, it is also possible to provide a half mirror layer on the surface of the outermost layer or any arbitrary layer inside by vapor deposition or sputtering. Furthermore, weather resistance can be improved by adding an antioxidant, a heat ray absorber, an ultraviolet absorber, etc. to the outermost layer or any internal layer. As the ultraviolet absorber, compounds such as benzophenone, benzotriazole, benzoate, and nickel complex salts can be used. It is also possible to use a combination of two or more of these.

As shown in FIG. 5, when using a general projector A with a ratio of projection distance to image width (hereinafter referred to as "projection ratio") of about 1.0 or more, the transparent screen 1 has a When α is narrower than 20° to 50° (angle of view β = 30°), objects on the back of the screen become invisible (this state is expressed as "haze appears". (refers to a state in which the haze value measured by the angular haze measurement method is 60% or more). In this case, since the necessary diffusion angle range is narrow, it is sufficient to use one directional light diffusion film as the light control layer 3.
On the other hand, when using projector B with a projection ratio smaller than 1.0 (specifically, a projection ratio of 0.39), for example, It is necessary to be unable to see the other side within the range (haze appears). In this case, since the necessary diffusion angle range is wide, the light control layer 3 is formed by laminating a plurality of directional light diffusion films having different diffusion angles.

A method for measuring the diffusion angle, the haze value, and the declination haze, which is the haze value in this embodiment, will be described with reference to FIGS. 13 and 14.
FIG. 13 is a diagram showing the diffusion angle and haze value. When a light source is placed at a predetermined location a predetermined distance from the screen and light with a predetermined spread is incident, the respective ends are the minimum incident angle (angle a) and the maximum incident angle (angle c). Become. In addition, the intermediate value between the two is defined as the center of the optical axis (angle b), and the spread of light is 10 to 35 degrees on one side and 20 to 70 degrees on both sides, preferably on both sides, with respect to the center of the optical axis. The angle should be between 30° and 60°. The haze value at that time is set to 60% or more.

FIG. 13 is a diagram showing a method for measuring the declination haze, which is the haze value in this embodiment. The haze value measurement in this embodiment is performed by changing the screen to an arbitrary angle at a position 62 mm away from the integrating sphere, as shown in FIG. The haze value at the maximum incident angle (angle c) is measured so that the measured value is 60% or more.

Since the light control layer 3 turns yellow due to ultraviolet rays contained in external light, it is desirable to dispose it facing the projector A installed on the back side of the screen when viewed from the viewer. However, if an ultraviolet absorbing layer is provided on the surface of the light control layer 3, it may be placed so as to face the viewer. The ultraviolet absorbing layer is made of a transparent resin such as an acrylic resin or a silicone resin containing an ultraviolet absorber such as a benzophenone compound or a benzotriazate compound.

Next, in Experiment 1, transparent screen 1 was used to detect that light projected from a projector placed on the back of the screen was transmitted through the transparent screen and an image was formed on a place other than the screen, such as the floor or ceiling on the viewer's side. Verify the functionality to prevent.
As a verification method, a projector, a transparent screen, and an imaging camera are arranged in this order on a single horizontal axis with a space between them. Then, a test target is projected from a projector onto a transparent screen. The transparent screen 1 shown in FIG. 2 was used as the transparent screen, and was installed so as to be rotatable about a vertical axis.

The test target used was one in which white lines and black lines having a constant width and length were arranged alternately, as shown in FIG. This test pattern is projected onto a transparent screen via a projector, and the image transmitted through the transparent screen is formed on a transmissive screen placed opposite the projector. A specific state of the test target T is shown in FIG. Then, the image was captured with a CCD camera, and as shown in Fig. 8, the upper and lower limits of the waveform obtained from the gradation changes of the camera sensor were set as Imax and Imin, respectively, and the MTF was calculated using the following formula. .
MTF = (Imax-Imin)/(Imax+Imin)

At this time, the image reflected on the transmissive screen on which the test pattern is finally projected is not directed in the normal direction of the back of the screen, but in the upward or downward direction to prevent the light source from directly hitting the viewer's eyes. The image is projected by a projector at a certain angle, passes through the screen, and forms a reproduction of the image formed at a different location than the screen, such as on the floor or ceiling.

9-1 to 9-9 are diagrams in which the transparent screen 1 is rotated by 10 degrees from an angle orthogonal to the horizontal axis, and images projected on the screen B at each angle are photographed by a CCD camera C.
Then, the path of light traveling straight from projector A, which is one end of the image range (angle of view), toward screen B in parallel with the horizontal axis is made to coincide with one end of screen B, and this one end The MTF was evaluated as the clarity of the image using the evaluation position.

As shown in Figures 9-1, 9-2, and 9-3, when the incident angle of light is 90°, 80°, and 70°, the image at the evaluation position of screen B is clear; -4, when the incident angle of light is 60°, the image becomes somewhat unclear.
Furthermore, as shown in FIGS. 9-5 and 9-6, when the incident angle of light is 50° and 40°, the image becomes unclear. As shown in FIG. 9-7, when the incident angle of light is 30°, the image at the evaluation position of screen B is somewhat recovered, although it is unclear. Further, by changing the incident angle of light, as shown in FIGS. 9-8 and 9-9, as the incident angle of light increases to 20° and 10°, the blurring of the image is recovered.

FIG. 10 is a diagram showing MTF values and image determination results for each incident angle of light. As a result of the judgment, × indicates a clear image, △ indicates a somewhat unclear image, and ○ indicates an unclear image. When the incident angle of light is 90° to 80° or 10°, the MTF value is high and the image is clear, whereas when the incident angle is 70° or 20°, the MTF value is low. The image becomes somewhat unclear. Furthermore, when the incident angle is 60° or 30°, the image becomes even more unclear.
From the results of Experiment 1, it was confirmed that a clear image was not formed (development of image obscurity) when the incident angle of light was within a predetermined range.

Furthermore, in Experiment 2, the visibility of images by laminating the light control layer 3 on the screen layer 2 was verified.
As shown in FIG. 11, a transparent screen 1 similar to that used in Experiment 1 and a comparison screen D in which a light control layer 3 is bonded to a transparent acrylic plate are placed side by side on the left and right, and the back side of the boundary between the two is placed side by side. An image was projected diagonally upward from projector A installed at the lower side. Note that the screen layer 2 of the transparent screen 1 and the transparent acrylic plate of the comparative screen D were both 2 mm thick.

12-1 to 12-5 are images of the front side of the transparent screen 1 and comparison screen D taken from various angles, and FIG. 12-1 is a view seen from the front, and FIG. 12-2 12-3 is a diagram seen diagonally from the left side, FIG. 12-3 is a diagram seen diagonally from the right side, FIG. 12-4 is a diagram seen from the lower front, and FIG. 12-5 is a diagram seen from the upper front.
As is clear from these figures, the image on the transparent screen 1 is clearer than the image on the comparison screen D no matter what angle it is viewed from.
From the results of Experiment 2, it was confirmed that by laminating the light control layer 3 on the screen layer 2, the clarity of the image was increased and the viewing angle was wider than when the light control layer was simply laminated on a transparent plate. Ta.

Next, in Experiment 3, it was verified that by transmitting the light through the transparent screen 1, the color was not changed and there was little change in the chromaticity of the light even after passing through the transparent screen 1.
The following method was used for the experiment. A radiance meter manufactured by Topcon was used as a measuring device, and measurements were made in an angular range of -80° to 80° with respect to the normal direction of the transparent screen. That is, the direction perpendicular to the surface of the transparent screen is 0°, the tilt in a specific direction from there is a positive angle, and the tilt in the opposite direction is a negative angle.

A transparent screen with a light control layer was used as a measurement sample. Since such a transparent screen has directionality, by taking into account the influence of directionality, measurements are taken in a predetermined direction and in a direction rotated 90 degrees from that direction, and compared with the light source data. , it was verified that there was little change in chromaticity regardless of directionality.
As a light source, a white diffusion plate DR-65CX manufactured by Nitto Jushi Kogyo was placed on an LED lamp and used as a planar light source. Moreover, chromaticity data x, y was used as the measurement data.

The results are shown in Table 1. At any angle, whether the transparent screen is in a predetermined orientation or in a direction rotated 90 degrees from that orientation, there is no significant change in either the chromaticity data x or y, and the transmission of the transparent screen 1 is It was confirmed that color was developed without any major color change between before and after.

The transparent screen of the present invention can stand alone or can be supported by being attached to a transparent body made of resin or glass.
Furthermore, the projection system using the transparent screen of the present invention can be applied to window displays and the like.

Although the explanation has been made so far using a transmissive transparent screen, the present invention is also applicable to a reflective transparent screen. The basic configurations of reflective transparent screens include those that use diffusion, those that have an uneven surface to create a reflective type, and those that have unevenness on the inside and a high refractive index layer that is then flattened with transparent resin. There are also those in which a polymer liquid crystal layer is provided on the irregularities. In the reflective transparent screen of any configuration, like the transmissive transparent screen described above, a single layer or multiple compositions are formed into a film and irradiated with light from a specific direction to cure the light. Created by providing a control layer on the surface. As a result, even in a reflective transparent screen, it is possible to prevent a clear image from being formed on the floor or ceiling surface on the back side of the screen.
Further, although the light control layer is provided on the surface of the transparent screen, it can be provided not only on the surface but also inside the transparent screen, and the arrangement position can be changed as desired.

1 Transparent screen 2 Screen layer 3 Light control layer 4 Anti-warp film 5 Surface protection layer 6 Adhesive 10, 11, 12 Particles A Projector B Screen C Camera D Comparison screen T Test target

Claims (14)

In a transparent screen that displays an image by forming an image of the light projected from a projector,
By having a light control layer that is composed of a single layer containing two or more types of photopolymerizable compounds with different refractive indexes and further mixed with particles, the light diffusion intensity of which has a function that depends on the angle of incidence. , has an incident angle dependent function in which there is a difference of at least a predetermined amount between the light diffusion intensity for light incident on the transparent screen from the normal direction and the light diffusion intensity for light incident from a specific angular range. A transparent screen characterized in that image light incident from the specific angle range and transmitted through the transparent screen does not form an image anywhere other than the screen. selectively and strongly diffusing incident light from the specific angular range;
2. The transparent screen according to claim 1, wherein the emitted light has a polarization haze value of 60% or more. 2. The transparent screen according to claim 1, wherein the difference in polarization haze value between the incident light in the normal direction and the incident light from the specific angular range is 30% or more. 2. The MTF of an image formed at a location other than the screen after the image light incident from the specific angle range passes through the transparent screen is smaller than 9.0%. transparent screen. The transparent screen according to claim 1, wherein the transparent screen selectively diffuses incident light from the specific angle range, and the incident angle range of the incident light is 20° to 70°. Equipped with a screen layer that forms images,
The transparent screen according to any one of claims 1 to 5, wherein the screen layer and the light control layer are separately bonded to each other. Equipped with a screen layer that forms images,
6. The transparent screen according to claim 1, wherein the light control layer is coated with the screen layer. Equipped with a screen layer that forms images,
6. The transparent screen according to claim 1, wherein the screen layer is coated with the light control layer. 6. The transparent screen according to claim 1, wherein the light control layer includes an image forming function. The transparent screen according to any one of claims 6 to 8, characterized in that the thickness of the screen layer is 3 mm or less. The transparent screen according to any one of claims 6 to 9, wherein the light control layer has a thickness of 10 to 200 μm. The transparent screen according to any one of claims 1 to 9, having a non-reflective function on at least one surface. The transparent screen according to any one of claims 1 to 12, characterized in that it is formed by laminating a transparent base material on at least one surface. A projection system using the transparent screen according to any one of claims 1 to 13 or applied equipment thereof.

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