At present, the so-called rear projection type transmission type screen in which an image projected from a projector is projected on a screen and it is visually recognized from an opposite side of the projector from the screen is now spreading in place of the past advertising media such as a poster, a sign, a signboard, etc. In recent years, a transmission type screen has been extremely attracted attention as a digital signage since it requires no replacement, is capable of changing the content of the image immediately, and can project digital contents including not only a static image but also dynamic image contents with a large size.
Above all, show windows, etc., of a store are, in many cases, faced to a road on which customers pass. If the show window surface can be used as a digital signage which is used as a large sized screen, it is extremely useful as advertising media. Therefore, needs of a transmission type screen which is laminated on a show window, that is, the so-called window display are increasing.
As a rear projection type transmission type screen, those using a polarizing film, a Fresnel lens sheet, a lenticular lens sheet, etc., (for example, Patent Document 1), and a screen in which light transmissive beads are adhered on a light transmissive support (for example, Patent Document 2) have been proposed. Also, a transmission type screen in which a light diffusion layer containing porous particles is provided on a light transmissive support (for example, Patent Document 3), and a transmission type screen comprising a light diffusion layer which contains light diffusion fine particles and a resin binder and provided on a light transmissive support, wherein a part of the light diffusion fine particles is protruded from the light diffusion layer whereby making the haze value 80% or more, the total light transmittance 60% or more, and the specular glossiness of at least one of the surfaces 10% or less (for example, Patent Document 4) have been proposed.
Further, if a show window, etc., of a store can not only be used its window surface as a digital signage depending on necessity, but also have an inherent function of allowing visual recognition of the goods in the store through the window, it is extremely useful as advertising media. Therefore, needs of a transmission type screen which can be seen through and is laminated on a show window are also increasing.
In transmission type screens disclosed in Patent Documents 1, 2, 3 and 4, etc., the screen itself is opaque, and it is impossible to use these as a see-through transmission type screen. As the see-through transmission type screen, a transmission type screen (for example, Patent Documents 5 and 6) which comprises a light scattering layer containing a transparent resin binder and spherical fine particles having an average particle diameter of 1.0 to 10 μm and a relative refractive index n thereof to a refractive index of the transparent resin binder of 0.91<n<1.09 (provided that n≠1) provided on a light transmissive support has been proposed.
USPTO Backgrounds
USPTO Backgrounds