Reflective screen, image display device

Abstract

To provide a reflective screen which is easy to manufacture and is capable of displaying good images, and image display device.SOLUTION: A screen 10 provided herein is a reflective screen configured to reflectively display projected image light and has reflective surfaces 13 therein for reflecting at least a portion of the image light arrayed in one direction along a screen surface. The screen 10 is curved in a direction crossing an array direction of the reflective surfaces 13 so as to be convex on the rear side.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a reflective screen and an image display device. [Background technology]

[0002] BACKGROUND ART Various reflective screens have been developed to display images by reflecting image light projected from an image source (for example, Patent Document 1). A widely known reflective screen has a reflective layer formed on a lens surface of a circular Fresnel lens, etc., in order to efficiently direct image light toward an observer positioned in front of the screen. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-169006 [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-26759 Summary of the Invention [Problem to be solved by the invention]

[0004] Such reflective screens have a reflective layer formed on the lens surface of a circular Fresnel lens, and can efficiently direct image light toward the viewer. However, since they are manufactured in sheet form, mass production is difficult, and manufacturing is also difficult.

[0005] An object of the present invention is to provide a reflective screen and an image display device that are easy to manufacture and capable of displaying good images. [Means for solving the problem]

[0006] The present invention solves the above-mentioned problems by the following means: For ease of understanding, the following description will be given with reference to the corresponding embodiments of the present invention, but the present invention is not limited to these. The first invention is a reflective screen (10, 20, 30) that displays projected image light (L) by reflecting it, characterized in that reflective surfaces (13, 23, 33) that reflect at least a portion of the image light are arranged in one direction along the screen surface inside the reflective screen, and the reflective screen is curved so as to be convex toward the back side in a direction that intersects the direction in which the reflective surfaces are arranged. The second invention is a reflective screen (10) characterized in that, in the reflective screen of the first invention, the angle that the reflective surface (13) makes with a plane parallel to the screen surface of the reflective screen changes in one direction along the arrangement direction. The third invention is a reflective screen (10, 20, 30) characterized in that, in the reflective screen of the first or second invention, the reflective surfaces (13, 23, 33) extend in a direction intersecting the arrangement direction. The fourth invention is a reflective screen (10, 20, 30) characterized in that, in any of the reflective screens of the first to third inventions, the reflective surfaces (13, 23, 33) extend in a direction intersecting the arrangement direction, and the reflective screen is curved along the extension direction of the reflective surfaces. The fifth invention is a reflective screen (20, 30) characterized in that, in the reflective screen of any of the first to fourth inventions, it has a light control layer (26) on the image source side of the reflective surface (23, 33) that diffuses light incident within a specific incident angle range (R1) more than light incident at other incident angles. A sixth aspect of the present invention is the reflective screen (20, 30) of the fifth aspect of the present invention, characterized in that the specific angle range (R1) does not include an incident angle of 0°. The seventh invention is a reflective screen (10, 20, 30) characterized in that, in the reflective screen of any of the first to sixth inventions, it comprises a first resin layer (121, 221) on the rear surface of which are arranged unit optical shapes (121a, 221a) formed by first surfaces (121b, 221b) at least a part of which is the reflective surface (13, 23, 33) and second surfaces (121c, 221c) which are arranged alternately with the first surfaces along the arrangement direction of the reflective surfaces and intersect with the first surfaces, and the angle (β) which the second surfaces make with a plane parallel to the screen surface is larger than the angle (α) which the first surfaces make with a plane parallel to the screen surface. The eighth invention is a reflective screen (10, 20, 30) characterized in that, in the reflective screen of the seventh invention, it is provided with a second resin layer (122, 222) that is provided on the back side of the first resin layer (121, 221) and fills in and flattens the valleys between the unit optical shapes (121a, 221a), and the first resin layer and the second resin layer are light-transmitting and have no refractive index difference or a refractive index difference that is so small that it can be considered to have no refractive index difference. The ninth invention is a reflective screen (10, 20) characterized in that in the reflective screen of the seventh or eighth invention, the reflective surface (13, 23) is formed by providing a reflective layer on the first surface (121b, 221b) made of a material including at least one of a metal film and a dielectric film having light reflectivity. A tenth aspect of the present invention is the reflective screen (10, 20) of the ninth aspect of the present invention, characterized in that the reflective screen (10, 20) is transparent, and the reflective surface (13, 23) is provided by a semi-transparent reflective layer that reflects a portion of incident light and transmits at least a portion of the remaining light. An eleventh invention is an image display device (1) comprising a reflective screen (10, 20, 30) according to any one of the first to tenth inventions, and an image source (LS) that projects image light onto the reflective screen. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a reflective screen and an image display device that are easy to manufacture and capable of displaying good images. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an image display device 1 according to a first embodiment. [Figure 2] FIG. 1 is a diagram illustrating an image display device 1 according to a first embodiment. [Figure 3] 2A to 2C are diagrams illustrating a state in which the screen 10 of the first embodiment is used and a base 50. FIG. [Figure 4] 2 is a diagram illustrating a layer structure of the screen 10 according to the first embodiment. FIG. [Figure 5] 3A to 3C are diagrams illustrating the light control action in the left-right direction of the screen of the screen 10 of the first embodiment. [Figure 6] 2 is a diagram showing an example of image light and external light incident on the screen 10 of the first embodiment. FIG. [Figure 7] 10A and 10B are diagrams illustrating a layer structure of a screen 20 according to a second embodiment. [Figure 8] 3A and 3B are diagrams illustrating the light control effect of the light control layer 26. FIG. [Figure 9] 10A and 10B are diagrams illustrating an example of image light and external light incident on a screen 20 according to a second embodiment. [Figure 10] 10A and 10B are diagrams illustrating a layer structure of a screen 30 according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings, etc. Note that the drawings shown below, including Fig. 1, are schematic diagrams, and the size and shape of each part are appropriately exaggerated to facilitate understanding. In this specification, the terms plate, sheet, film, etc. are used, but in general, they are used in order of thickness, that is, plate, sheet, film, and so on, and this specification follows suit. However, since there is no technical significance in this distinction, these terms can be used interchangeably as appropriate.

[0010] Furthermore, in this specification, terms specifying shapes or geometric conditions, such as parallel and orthogonal, are intended to include not only their strict meanings but also states that perform similar optical functions and have an error that can be considered as parallel or orthogonal. Furthermore, the numerical values ​​such as dimensions of each component and the names of materials described in this specification are examples of embodiments, and are not limited to these, and may be selected and used as appropriate.

[0011] (First embodiment) 1 and 2 are diagrams illustrating an image display device 1 according to a first embodiment. Fig. 1 is a perspective view of an image display device 1. Fig. 2 is a plan view of the image display device of the first embodiment as seen from above in the vertical direction (the +Y side described later), and Fig. 2(b) is a cross-sectional view of the image display device 1 taken along a plane that passes through the center of the screen of the screen 10 and is parallel to the vertical direction and the depth direction of the image display device 1. The image display device 1 includes a screen 10, an image source LS, etc. The screen 10 is a reflective screen that reflects a portion of the image light L projected from the image source LS to display an image on the screen. Details of the screen 10 will be described later.

[0012] For ease of understanding, an XYZ Cartesian coordinate system is provided as appropriate in each of the following figures, including Figure 1. In this coordinate system, the horizontal direction is the X direction, the vertical direction is the Y direction, and the depth direction of the image display device 1 is the Z direction. Furthermore, the direction toward the right in the left-right direction (horizontal direction) as viewed from an observer O1 positioned directly in front of the image source side of the screen 10 is the +X direction, the direction toward the upper side in the up-down direction (vertical direction) is the +Y direction, and the direction in the depth direction from the back side (rear side) of the screen 10 toward the image source side is the +Z direction. 1 etc., the screen surface (display surface) of this screen 10 has a curved shape, with the up-down direction of the screen parallel to the Y direction, but the left-right direction of the screen curved so as to be convex toward the rear side in the thickness direction of the screen 10. Furthermore, the thickness direction of the screen 10 at point A, which is the center of the screen (the normal direction to the screen surface at point A), is parallel to the Z direction. In this specification, the screen surface refers to the surface that faces the screen when viewed as a whole. In this embodiment, as described above, the screen surface of the screen 10 is curved in the left-right direction of the screen.

[0013] The image source LS is an image projection device that projects image light L onto the screen 10, and is, for example, a short-focus projector. When the image display device 1 is in use, the image source LS is located at the center of the screen 10 in the horizontal direction and below (to the -Y side of) the screen (display area) of the screen 10 when viewed from the normal direction of the screen surface at point A, which is the screen center of the screen 10. In other words, when viewed from the normal direction of the screen 10 at point A, the image source LS is located outside the display area. The image source LS can project the image light L obliquely from a position in the depth direction (Z direction) of the image display device 1 that is much closer to the surface of the screen 10 than a conventional general-purpose projector that is positioned directly in front of the screen's image plane. Therefore, compared to a conventional general-purpose projector that is positioned directly in front of the screen, the image source LS has a shorter projection distance to the screen 10, a larger incident angle at which the projected image light L is incident on the screen 10, and a larger amount of change in the incident angle (amount of change from minimum to maximum).

[0014] The screen 10 is a semi-transmissive reflective screen that reflects a portion of the image light L projected by the image source LS toward an observer O1 positioned in front of the image source (+Z side), thereby displaying an image to the observer O1, and transmits a portion of the image light L. The screen 10 is transparent, allowing the observer O1 to view the scenery on the other side (-Z side) through the screen 10. If the screen 10 is flat and not curved, the screen (display area) of the screen 10 is rectangular with its longer side aligned left to right as viewed from the observer O1 side, with a diagonal screen size of approximately 40 to 130 inches and an aspect ratio of 16:9. However, the screen 10 is not limited to this and may have other shapes, and the screen size may be less than 40 inches or greater than 130 inches, and the size and shape can be selected appropriately depending on the purpose of use, the environment in which it is used, etc.

[0015] FIG. 3 is a diagram illustrating the use state of the screen 10 and the base 50 according to the first embodiment. FIG. 3(a) is a perspective view of the screen 10 in use, and FIG. 3(b) is a view of the base 50 as seen from the normal direction of the upper surface 51 thereof. In the above-mentioned Figure 1 etc., for ease of understanding, the screen 10 is shown without any support members etc., but in reality, the curved shape of the screen 10 is supported by a base 50. 3(a), the screen 10 is erected in the vertical direction (Y direction) of the screen while maintaining a curved shape in the horizontal direction of the screen by inserting the lower end of the screen in the vertical direction into a groove 52 formed in an upper surface 51 of a base 50. In other words, the screen 10 has enough rigidity to be able to stand on its own with the lower end inserted into the groove 52.

[0016] 3, the base 50 is described taking an example in which it has a rectangular parallelepiped shape. The shape and size of the base 50 are not particularly limited, but it is preferable that the base 50 has a size that can sufficiently hold the screen 10 with the lower end inserted into the groove 52. 3(b), the groove 52 is curved in its longitudinal direction when viewed from the top surface 51. This curved shape corresponds to the curved shape of the screen 10. The width, length, and depth of the groove 52 are sized so that the bottom end of the screen 10 can be inserted therein and the screen 10 can be held upright in the left-right direction.

[0017] It is preferable that the screen 10 has an insertion portion (not shown) at the lower end of its display area that is inserted into the groove 52. By adopting such a configuration, the display area of ​​the screen 10 is not blocked by the groove 52, and a sufficient display area can be secured. This insertion portion has the same thickness as the display area of ​​the screen 10, and is an area that does not contribute to image display. However, without being limited to this, the screen 10 may be in a form in which it is grounded to the floor or the like and stands on its own while maintaining its curved shape, or in a form in which at least both ends of the screen in the vertical direction are supported by a frame member or the like (not shown) and the curved shape is maintained, or in a form in which it is joined (or partially fixed) to a light-transmitting support body having a curved shape. Furthermore, when the screen 10 is mainly made of a thermoplastic material, it may be given a curved shape by heating and deforming it. The image display device 1 of this embodiment can be applied to, for example, image displays at exhibitions, indoor partitions, show windows of stores, and the like.

[0018] In this embodiment, the curved shape of the screen 10 is, for example, symmetrical in the left-right direction of the screen, and as shown in Figure 2(a), the angles θ1 and θ2 formed by the normal direction of the screen surface at both ends of the display area of ​​the screen 10 in the left-right direction with respect to the depth direction (Z direction) of the image display device 1 are equal. Furthermore, as shown in FIG. 2(a), the curved shape of the screen 10 does not have an inflection point. In this embodiment, an example will be described in which the screen size of the screen 10 is 40 inches, the angles θ1 and θ2 are approximately 5 to 20°, and the total thickness of the screen 10 is approximately 1 mm. The angles θ1 and θ2 can be set appropriately depending on the screen size of the screen 10, the optical performance of the image source LS, etc.

[0019] Fig. 4 is a diagram illustrating the layer structure of the screen 10 of the first embodiment. Fig. 4 shows an enlarged portion of a cross section that passes through point A (see Fig. 1) which is the center of the screen (the geometric center of the screen) of the screen 10 and is parallel to the vertical direction (Y direction) and the depth direction (Z direction). 4, the screen 10 includes, in order from the image source side in the thickness direction, a first base material layer 11, a resin layer 12, a second base material layer 15, etc., which are laminated together. The resin layer 12 has reflective surfaces 13 arranged inside it along the vertical direction of the screen.

[0020] The first base material layer 11 is a sheet-like member having optical transparency, and a resin layer 12 (first resin layer 121) is integrally formed on the back surface side thereof. This first base material layer 11 is a layer that serves as a base for forming the first resin layer 121, which will be described later. The first base layer 11 is formed from, for example, a polyester resin such as PET (polyethylene terephthalate) having high light transmittance, an acrylic resin such as PMMA (polymethyl methacrylate resin), a styrene resin, an acrylic-styrene resin, a PC (polycarbonate) resin, an alicyclic polyolefin resin, a TAC (triacetyl cellulose) resin, or the like.

[0021] The resin layer 12 is a light-transmitting layer formed on the back surface side of the first base layer 11. The resin layer 12 has a plurality of reflective surfaces 13 arranged therein. The resin layer 12 of this embodiment is formed of an ultraviolet-curable resin having high optical transparency, such as a urethane acrylate, polyester acrylate, epoxy acrylate, polyether acrylate, polythiol, or butadiene acrylate resin. However, the resin layer 12 is not limited to this, and may be formed of other ionizing radiation-curable resins, such as an electron beam-curable resin.

[0022] The reflective surface 13 is a reflective surface that reflects at least a portion of incident light. The reflective surface 13 of this embodiment is provided inside the resin layer 12, extends in the left-right direction of the screen, and is arranged in plurality in the up-down direction of the screen along the screen surface at an arrangement pitch of P. Furthermore, the reflective surface of this embodiment reflects a portion of the incident light and transmits a portion of it. In this embodiment, for ease of understanding, the reflective surface 13 will be described as being linear in the cross section shown in Figure 4, but it may also be in a form in which at least a portion is curved in the cross section shown in Figure 4 (i.e., a form in which a portion is curved in the thickness direction of the screen 10).

[0023] 4, reflecting surface 13 of this embodiment is inclined so that its rear end is closer to image source LS (lower in the vertical direction of the screen) than its image source end in the arrangement direction (vertical direction of the screen) of reflecting surface 13. The angle between reflecting surface 13 and a plane parallel to the screen surface (plane S indicated by the dashed line in FIG. 4) is α. 4, the angle formed by a plane (hereinafter referred to as a connecting plane) connecting the rear end (point t1) of reflecting surface 13 with the image source end (point t2) of the reflecting surface 13 adjacent to that reflecting surface 13 below it in the arrangement direction of reflecting surfaces 13, and a plane parallel to the screen surface is β. In Fig. 4, the connecting plane is shown by a dashed line to make it easier to understand, but in reality it is difficult to see. Angle β is larger than angle α, α<β. Furthermore, angle α increases toward the side away from image source LS (upward along the vertical direction of the screen) along the arrangement direction of reflecting surfaces 13. In this embodiment, an example will be described in which angle α is 8° at the bottom edge of the screen in the vertical direction and 22° at the top edge. The angles α, β, array pitch P, etc. may be set appropriately depending on the projection angle of the image light from the image source LS (the incident angle of the image light onto the screen 10), the size of the pixels of the image source LS, the screen size of the screen 10, the refractive index of each layer, etc.

[0024] Furthermore, minute irregular concave-convex shapes (not shown) are formed on the surface of the reflecting surface 13. These concave-convex shapes are formed by irregularly arranging convex shapes and concave shapes in two dimensions, and the convex shapes and concave shapes are irregular in size, shape, height, etc. With such a shape, the reflecting surface 13 of this embodiment has the function of diffusing and reflecting at least a part of the incident light.

[0025] As shown in Figure 4, in a cross section parallel to the arrangement direction of the reflecting surfaces 13 and the thickness direction of the screen 10, the reflecting surfaces 13 and the connecting surface intersect at point t1, thereby forming a unit optical shape that is convex toward the back side with point t1 as its vertex. That is, the resin layer 12 of this embodiment has a first resin layer 121 located on the first base material layer side and a second resin layer 122 located on the second base material layer 15 side, and is formed in such a manner that a plurality of unit optical shapes 121a and reflecting surfaces 13 are arranged at the boundary surface between the first resin layer 121 and the second resin layer 122.

[0026] The resin layer 12 of this embodiment can be produced, for example, by molding a first resin layer 121 having a plurality of unit optical shapes 121a as described above arranged on one side, forming a layer (reflective layer) for forming a reflective surface 13 on the first surface 121b of the unit optical shapes 121a, and then forming a second resin layer 122 on top of that so as to fill in the unevenness caused by the unit optical shapes 121a. In this embodiment, as shown in FIG. 4, in a cross section parallel to the arrangement direction of the reflecting surfaces 13 (unit optical shapes 121a) and the thickness direction of the screen 10, the cross section of the unit optical shapes 121a is triangular.

[0027] The first resin layer 121 is a layer formed on the rear surface side of the first base material layer 11, which serves as a base material (base), and has unit optical shapes 121a arranged on the rear surface side. The unit optical shapes 121a are arranged in the vertical direction of the screen with the longitudinal direction being the horizontal direction of the screen. The first resin layer 121 of this embodiment has a linear Fresnel lens shape with the unit optical shapes 121a arranged on its rear surface.

[0028] 4, each unit optical shape 121a has a first surface 121b located above (on the +Y side of) point t1, which is the vertex, and a second surface 121c that intersects with the first surface 121b at point t1 and is located below (on the -Y side of) point t1. The first surfaces 121b and the second surfaces 121c are arranged alternately. The angle between the first surface 121b and a plane parallel to the screen surface (plane S indicated by the broken line in FIG. 4) is α, and the angle between the second surface 121c and a plane parallel to the screen surface is β. The unit optical shapes 121a extend in the left-right direction of the screen along the screen surface while maintaining the cross-sectional shape shown in Fig. 4. The arrangement pitch of the unit optical shapes 121a is P.

[0029] Furthermore, minute irregular concave-convex shapes are formed on the first surface 121b and the second surface 121c of the unit optical shape 121a. These concave-convex shapes are formed by irregularly arranging convex shapes and concave shapes in two dimensions, and the convex shapes and concave shapes are irregular in size, shape, height, etc. The unit optical shapes 121 a of this embodiment have an arrangement pitch P in the arrangement direction and an angle α that are the same as the arrangement pitch P and angle α of the reflecting surface 13 .

[0030] The reflective performance of the reflective surface 13 and the means for reflecting the image light on the reflective surface 13, i.e., the means for providing the reflective surface 13, can be selected depending on the desired environment in which the screen 10 is used and the desired optical performance, etc. In this embodiment, the reflecting surface 13 is formed by a semi-transmissive reflecting layer that reflects part of the incident light and transmits part of it, that is, a so-called half mirror. The reflective layer is provided adjacent to and between the first resin layer 121 and the second resin layer 122 in the thickness direction of the screen 10. In this embodiment, the reflective layer is formed on the first surface 121b of the unit optical shape 121a. The reflective layer may be formed on at least a part of the first surface 121b, or may also be formed on the second surface 121c, which is the connecting surface.

[0031] The reflective layer has a rough surface with fine irregular concaves and convexes on the surface on the image source side (surface on the first resin layer 121 side) and the surface on the back side (surface on the second resin layer 122 side). This is because, as described above, a fine concave-convex shape is formed on the first surface 121b, the reflective layer is formed to follow this fine concave-convex shape, and the thickness of the reflective layer is sufficiently thinner than the concave-convex shape of this fine concave-convex shape. As a result, the reflective layer diffuses and reflects a portion of the incident light due to the fine irregular unevenness, and transmits at least a portion of the remaining light that is not reflected without diffusing it.

[0032] The reflectance and transmittance of the reflective surface 13 can be appropriately set according to the desired optical performance. From the viewpoint of favorably reflecting the image light and favorably transmitting light other than the image light (for example, light from the outside world such as sunlight), the reflectance and transmittance of the reflective surface 13 are preferably about 30 to 80% for transmittance and about 5 to 60% for reflectance.

[0033] The reflective layer that forms the reflective surface 13 is made of a metal with high light reflectivity, such as aluminum, silver, nickel, chromium, etc. The reflective layer is not limited to this, and may be formed, for example, by sputtering the above-mentioned metal with high light reflectivity, transferring a metal foil, or applying paint containing a thin metal film. The reflective layer may also be formed by vapor deposition of a dielectric film (that is, a dielectric multilayer film or a dielectric single layer film) that has high transparency, small light absorption loss, and can achieve high reflectance. Furthermore, the reflective layer that forms the reflective surface may be formed by laminating a plurality of layers including any of the above-mentioned metal material films and dielectric films. The reflective layer of this embodiment is formed by vapor deposition of chromium, and the reflective layer alone has a reflectance of approximately 5% and a transmittance of approximately 50%.

[0034] The second resin layer 122 is filled so as to sufficiently fill the valleys between adjacent unit optical shapes 121a, and the surface on the rear side of the second resin layer 122 is a parallel flat surface. By providing such a second resin layer 122, the light transmittance of the screen 10 can be improved and the reflective surface 13 (reflective layer) can be protected.

[0035] From the viewpoint of improving the transparency of the screen 10, it is preferable that the refractive index of the second resin layer 122 is equal to that of the first resin layer 121, or that the difference in refractive index is small enough to be considered equal. The second resin layer 122 may be formed using the same resin as that of the first resin layer 121, or may be formed using a different resin. The second resin layer 122 of this embodiment is made of the same ultraviolet curable resin as the first resin layer 121, and has the same refractive index as the first resin layer 121.

[0036] The second base layer 15 is a sheet-like member having optical transparency, and is laminated integrally on the back surface side of the resin layer 12. Like the first base layer 11, the second base layer 15 is formed from, for example, a polyester resin such as PET having high optical transparency, an acrylic resin such as PMMA, a styrene resin, an acrylic-styrene resin, a PC resin, an alicyclic polyolefin resin, a TAC resin, or the like. In this embodiment, the second base material layer 15 is made of the same material as the first base material layer 11.

[0037] Fig. 5 is a diagram illustrating the light control action in the left-right direction of the screen 10 of the first embodiment. Fig. 5(a) is a diagram of the screen 10 of this embodiment as viewed from above in the vertical direction (+Y side), and Fig. 5(b) is a diagram of the screen 10B of the comparative example as viewed from above in the vertical direction (+Y side). The screen 10B of the comparative example has a layered structure similar to that of the screen 10 of this embodiment, but differs in that it is flat and not curved. 2(a) and 5(a), the screen 10 is curved so that the left-right direction of the screen is convex toward the rear side. This curvature direction is perpendicular to the arrangement direction (vertical direction of the screen) of the reflective surfaces 13 (unit optical shapes 121a), and is the extension direction (longitudinal direction) of the reflective surfaces 13 (unit optical shapes 121a).

[0038] Generally, in the comparative example screen 10B, which is flat and has reflective surfaces (unit optical shapes) arranged in the vertical direction of the screen with their longitudinal direction (extension direction) running in the horizontal direction of the screen, the screen has a light control effect of directing image light toward the observer O1 in the vertical direction of the screen, but has almost no such light control effect in the horizontal direction of the screen. 5(b), at the left and right edges of the screen 10B, the image light is reflected outside the range visible to the observer O1. Therefore, when the observer O1 looks at the screen 10B of the comparative example, the image becomes darker and unclear as it approaches the left and right edges of the screen.

[0039] However, the screen 10 of this embodiment is curved in the direction perpendicular to the arrangement direction (vertical direction of the screen) of the reflective surfaces 13 (unit optical shapes 121a), that is, in the extension direction (longitudinal direction) of the reflective surfaces 13 (unit optical shapes 121a). As a result, as shown in Fig. 5(a), the screen 10 can also reflect image light incident on the left and right ends of the screen toward the viewer O1. This makes it possible to provide a screen 10 and an image display device 1 that can display good images with uniform brightness and the like within the screen.

[0040] Fig. 6 is a diagram showing an example of image light and external light incident on the screen 10 of the first embodiment. Fig. 6 shows an enlarged portion of a cross section similar to the cross section of the screen 10 shown in Fig. 4. For ease of understanding, Fig. 6 also shows the case where there is no difference in refractive index between the first base material layer 11 and the resin layer 12 (first resin layer 121) and between the resin layer 12 (second resin layer 122) and the second base material layer 15. Hereinafter, with reference to Fig. 6, the state of image light and external light incident on the screen 10 in the vertical direction (Y direction) of the screen will be described. Image light L11 projected from an image source LS located below the screen 10 passes through the first base material layer 11 and enters the resin layer 12. Then, image light L12, which is a part of the image light L11, is diffusely reflected by the reflecting surface 13, and is emitted toward the image source side (+Z side) and reaches the viewer O1 side. Because the image light L12 is diffusely reflected by the reflecting surface 13, the screen 10 can display an image with a sufficient viewing angle.

[0041] It should be noted that part of the image light L11 is reflected from the surface of the screen 10 when it is incident on the screen 10, but since it travels upwards on the screen 10, it does not reach the viewer O1. Furthermore, since the image light L11 is projected from below the screen 10 and the angle β (see Figure 2) is greater than the angle of incidence of the image light L11 at each point in the vertical direction (Y direction) of the screen 10, the image light L11 does not directly enter the second surface 121c. Furthermore, image light L13, which is a part of the image light L11, passes through the reflecting surface 13 (reflecting layer) toward the rear side, passes through the second resin layer 122 and the second base material layer 15, and is emitted upward on the rear side of the screen 10. This image light L13 does not reach the viewer O2 who is positioned in front of the rear side of the screen 10.

[0042] Next, external light such as sunlight and illumination light other than image light incident on the screen 10 will be described. External light G11 and G12, which make up the majority of external light having a small angle of incidence on the screen 10, enter the screen 10, pass through the reflective surface 13 (reflective layer), and exit toward the back side and the image source side, respectively. The screen 10 does not have a layer (light diffusion layer) containing a diffusing material such as particles that diffuse light, and most of the external light G11 and G12 passes through the reflective surface 13 without being diffused and exits toward the back side and the image source side of the screen 10. Furthermore, some of the external light G11 and G12 (not shown) is reflected by the reflective surface 13, but the amount of light is small and the light exits outside the range visible to the observers O1 and O2 (below the screen 10) or is attenuated within the screen, so its effect on the transparency of the screen 10 is small. Therefore, when observers O1 and O2 observe the scenery on the other side of the screen 10 through the screen 10, the scenery on the other side of the screen 10 can be observed without being blurred or white-out, and the screen 10 can exhibit high transparency.

[0043] Of the external light G13 incident on the screen 10 from above on the image source side, a portion of the external light (not shown) is reflected from the surface of the screen 10 and heads downward on the screen, and does not reach the observers O1 and O2. Furthermore, a portion of the external light G13, external light G14, is reflected from the reflecting surface 13 and heads downward on the image source side of the screen 10, and then exits downward on the image source side of the screen 10, or is totally reflected by the surface of the screen 10 on the image source side and heads downward again inside the screen 10, where it is attenuated. Furthermore, a portion of the external light G13, external light G15, is transmitted through the reflecting surface 13 and heads downward on the rear side of the screen 10, and does not reach the observers O1 and O2.

[0044] Of the external light G16 incident on the screen 10 from above on the rear side, a portion of the external light (not shown) is reflected by the surface of the screen 10 and directed downward on the screen, and does not reach the observers O1 and O2. Furthermore, a portion of the external light G16, external light G17, is incident on the screen 10 and is diffusely reflected by the reflecting surface 13, but exits upward on the rear side and does not reach the observers O1 and O2. Furthermore, a portion of the external light G16, external light G18, is transmitted through the reflecting surface 13 and exits downward on the image source side, and does not reach the observers O1 and O2. Therefore, the screen 10 can suppress a decrease in image contrast caused by external light entering from above the image source side or from above the rear side.

[0045] As described above, much of the external light passes through the screen 10 without being diffused, and even if it is diffused, it is emitted outside the range visible to the observers O1 and O2 as shown in Figure 6, so the transparency of the screen 10 can be maintained and the decrease in image contrast due to the diffusion of external light can be significantly suppressed.

[0046] As described above, according to this embodiment, it is possible to provide a screen 10 and an image display device 1 that are highly transparent and capable of displaying bright and good images. Furthermore, according to this embodiment, the screen 10 is curved so as to be convex toward the rear side in a direction intersecting the arrangement direction of the reflective surfaces 13, particularly in the left-right direction of the screen, which is the extension direction (longitudinal direction) of the reflective surfaces 13. Therefore, image light can be efficiently directed toward the observer O1 even at the left-right ends of the screen, and bright, good images can be displayed even at the left-right ends of the screen. Furthermore, according to this embodiment, the unit optical shapes 121a on which the reflective surfaces 13 are provided are arranged in the vertical direction of the screen with the longitudinal direction being the horizontal direction of the screen, and therefore are easy to manufacture, and as a result, the screen 10 can be continuously produced in roll form, facilitating mass production. Furthermore, according to this embodiment, the unit optical shapes 121a on which the reflective surfaces 13 are provided are arranged in the vertical direction of the screen with their longitudinal direction aligned with the left-right direction of the screen, making it easier to increase the screen size and facilitate the manufacture of large-screen screens compared to screens in which the unit optical shapes are arranged concentrically.Furthermore, according to this embodiment, the unit optical shapes 121a on which the reflective surfaces 13 are provided are arranged in the vertical direction of the screen with their longitudinal direction aligned with the left-right direction of the screen, making it easy to connect screens to make them even larger.

[0047] (Second embodiment) FIG. 7 is a diagram illustrating the layer structure of the screen 20 according to the second embodiment. FIG. 7 shows a part of a cross section of a screen 20 of the second embodiment, which corresponds to the cross section of the screen 10 of the first embodiment shown in FIG. The screen 20 shown in the second embodiment differs from the screen 10 of the first embodiment in that it is provided with a light control layer 26 that selectively diffuses light within a specific range of incident angles, but otherwise has the same configuration as the screen 10 of the first embodiment. Therefore, parts that perform the same functions as those in the first embodiment described above are given the same reference numerals or reference numerals with the same suffixes, and duplicate explanations will be omitted as appropriate.

[0048] The screen 20 of the second embodiment includes, in order from the image source side, a light control layer 26, a bonding layer 27, a first base material layer 11, a resin layer 22 (a first resin layer 221, a reflective surface 23, a second resin layer 222), and a second base material layer 15, which are laminated together. The first base material layer 11 and the second base material layer 15 are the same as those in the first embodiment. This screen 20 can be used in place of the screen 10 in the image display device 1 of the first embodiment described above.

[0049] The resin layer 22 has a form similar to that of the resin layer 12 of the first embodiment, but the unit optical features 221a do not have fine irregular concave-convex shapes on their first and second surfaces 221b and 221c. Therefore, the reflecting surface 23 also does not have fine irregular shapes on its surface. Therefore, light incident on the reflecting surface 23 is partially specularly reflected and partially transmitted. Furthermore, the reflecting surfaces 23 (unit optical shapes 221a) of this embodiment have a constant arrangement pitch P and angle α in the arrangement direction of the reflecting surfaces 23 (unit optical shapes 221a) (in this embodiment, the vertical direction of the screen). In this embodiment, an example in which the angle α is 10° will be described.

[0050] However, the present invention is not limited to this, and the reflective surfaces 23 may have a configuration in which the arrangement pitch P is constant in the arrangement direction of the reflective surfaces 23, similar to the reflective surfaces 13 in the first embodiment described above, but the angle α increases with increasing distance from the image source (toward the upper side in the up-down direction of the screen). In other words, the unit optical shapes 221a may have a configuration in which the angle α changes to increase with increasing distance from the image source LS in the arrangement direction, similar to the unit optical shapes 121a shown in the first embodiment.

[0051] The bonding layer 27 is a layer that functions to integrally bond the light control layer 26 and the first base material layer 11. The bonding layer 27 can be made of an adhesive or sticky material that has high light transparency. The light control layer 26 is a layer located closer to the image source than the first base layer 11 in the thickness direction of the screen 20, and has the function of selectively diffusing and transmitting light incident from a specific angle range. The light control layer 26 is provided integrally with the first base layer 11 on the image source side via a bonding layer 27.

[0052] The light control layer 26 is a portion that selectively diffuses image light. The light control layer 26 has a greater diffusion effect on light incident from a specific angle range than on light incident from other angle ranges. This specific angle range is an angle range in which light is obliquely incident at an angle greater than or equal to 0° in the vertical direction of the screen relative to any point on the surface of the light control layer 26. In other words, the light control layer 26 has the function of diffusing and transmitting light that is obliquely incident on any point on its surface in the vertical direction of the screen more than light that is incident at an incident angle of 0°. The specific angle range in which the light control layer 26 exhibits a diffusing effect can be appropriately set depending on the position of the image source LS relative to the screen 20, i.e., the incident angle of the main image light, etc.

[0053] Fig. 8 is a diagram illustrating the light control effect of the light control layer 26. Fig. 8 shows a cross section parallel to the vertical direction of the screen and the thickness direction of the light control layer 26. In Fig. 8, a dashed line H is a line that is perpendicular to the image source side surface and the back side surface of the light control layer 26 in the cross section shown in Fig. 8.

[0054] 8, the light control layer 26 has the function of diffusing light incident from the air on the image source side at an incident angle within a first incident angle range R1 and emitting it to the rear side, and transmitting light incident at an incident angle within a second incident angle range R2, which is an incident angle outside the first incident angle range R1, to the rear side without diffusing or with only a small amount of diffusion. The degree of diffusion of light incident at an incident angle within the second incident angle range R2 in the light control layer 26 is significantly smaller than the degree of diffusion of light incident at an incident angle within the angle range of the first incident angle range R1. 8, the light control layer 26 has the function of diffusing light incident from the air on the rear side at an incident angle within the third incident angle range R3 and outputting it toward the image source side, and transmitting light incident at an incident angle within a fourth incident angle range R4, which is an incident angle outside the third incident angle range R3, to the image source side without diffusing or with only a small amount of diffusion. The degree of diffusion of light incident at an incident angle within the fourth incident angle range R4 in the light control layer 26 is significantly smaller than the degree of diffusion of light incident at an incident angle within the third incident angle range R3.

[0055] The first incident angle range R1 includes the main incident angle range of the image light L that is projected from the image source LS and enters the screen 20 (light control layer 26). The first incident angle range R1 is a range from 25° to 55° below (to the -Y side of) the line H on the image source side. The second incident angle range R2 is an angle other than the first incident angle range R1 on the image source side of the light control layer 26. The third incident angle range R3 is a range on the back surface side (-Z side) that is 25° or more and 55° or less above (to the +Y side) the line H. The fourth incident angle range R4 is an angle on the back surface side of the light control layer 26 that is outside the third incident angle range R3.

[0056] Therefore, the light control layer 26 selectively diffuses and transmits light incident at any point on the surface on the image source side from the lower side in the vertical direction of the screen at an incident angle of 25° or more and 55° or less, and transmits light incident from other angle ranges to the rear side without diffusing it or diffusing it with a much weaker degree than the above angle range. Furthermore, the light control layer 26 selectively diffuses and transmits light incident at any point on the rear surface from the upper side of the screen in the vertical direction at an incident angle of 25° or more and 55° or less, and transmits light incident from angles other than this range to the image source side without diffusing it or diffusing it with a much weaker degree than the above angle range.

[0057] A suitable example of such a light control layer 26 is a visibility control film (for example, visibility control film Y-2555 manufactured by Lintec Corporation) formed by laminating multiple layers of transparent resin with different refractive indices in a predetermined direction at a predetermined thickness, and changing the direction of ultraviolet light irradiation when curing each layer.

[0058] Fig. 9 is a diagram showing an example of image light and external light incident on the screen 20 of the second embodiment. Fig. 9 shows an enlarged portion of a cross section similar to the cross section of the screen 20 shown in Fig. 7. In Fig. 9 and the following description thereof, for ease of understanding, it is assumed that there is no difference in refractive index at the interface between the light control layer 26 and the bonding layer 27, the interface between the bonding layer 27 and the first base material layer 11, the interface between the first base material layer 11 and the resin layer 22 (first resin layer 221), and the interface between the resin layer 22 (second resin layer 222) and the second base material layer 15.

[0059] Hereinafter, the state of the image light and external light incident on the screen 20 in the vertical direction of the screen (Y direction) will be described with reference to Fig. 9. Note that the light control action on the image light in the horizontal direction of the screen 20 is the same as that of the screen 10 of the first embodiment described above. In the following description, the same parts as those in the first embodiment will be omitted as appropriate. Most of the image light L21 projected from the image source LS located below the screen 20 enters the light control layer 26 at an incident angle within the first incident angle range R1 and is diffused, then passes through the bonding layer 27 and the first base material layer 11 and enters the resin layer 22.

[0060] A portion of the image light L21 (image light L22) is reflected by the reflecting surface 23, is incident on the light control layer 26 at an angle within the fourth incident angle range R4, is transmitted without being diffused, and is emitted toward the observer O1 positioned in front of the image source side of the screen 20. This allows the screen 20 to have a sufficient viewing angle for the observer O1 positioned in front of the image source side, and to display a bright, high-quality image. Furthermore, a portion of the image light L21 (image light L23) is transmitted through the reflecting surface 23 and heads upward toward the rear side of the screen 20, similar to the image light L13 in the first embodiment described above.

[0061] Next, we will explain external light G21 and G22 that are incident on the screen 20 at a small incident angle, such as an incident angle of 0°. The external light G21 is incident on the light control layer 26 from the image source side (+Z side) at an incident angle within the second incident angle range R2, and the external light G22 is incident on the light control layer 26 from the back side (-Z side) at an incident angle within the fourth incident angle range R4. Therefore, most of the external light G21 and G22 are not diffused by the light control layer 26 and are transmitted through the screen 20.

[0062] Next, external light G23 incident on the screen 20 from above on the image source side is incident on the light control layer 26 from the image source side at an incident angle within the second incident angle range R2, and therefore travels through the screen 20 toward the rear side without being diffused by the light control layer 26. Thereafter, similar to the external light G13 shown in FIG. 6 of the first embodiment described above, part of the external light (external light G24) is reflected by the reflecting surface 23 and travels downward on the image source side of the screen 20, and part of the external light (external light G25) is transmitted through the reflecting surface 23 and travels downward on the rear side of the screen 20.

[0063] 6 of the first embodiment, part of the light (external light G27) is reflected by the reflecting surface 23 and travels toward the upper rear side of the screen 20, and part of the light (external light G28) passes through the reflecting surface 23 and travels toward the image source side within the screen 20. The external light G28 is incident on the light control layer 26 at an incident angle within the fourth incident angle range R4, and is therefore not diffused by the light control layer 26 and travels downward toward the image source side of the screen 20.

[0064] In this way, most of the external light that enters the screen 20 from above on the image source side or rear side is not diffused by the light control layer 26, but instead heads downward toward the image source side or rear side of the screen 20, and the amount of light that reaches the observers O1 and O2 is significantly small. Therefore, the screen 20 can suppress a decrease in image contrast caused by external light.

[0065] As described above, according to this embodiment, similar to the first embodiment, it is possible to provide a screen 20 and an image display device 1 that are highly transparent, easy to manufacture, and capable of displaying good images. Furthermore, according to this embodiment, the screen 20 selectively diffuses a large amount of image light by the light control layer 26, and most of the external light passes through the screen 20 without being diffused or exits outside the range visible to the observers O1 and O2. Therefore, according to this embodiment, the transparency of the screen 20 can be maintained and a decrease in image contrast due to the diffusion of external light can be significantly suppressed.

[0066] Furthermore, according to this embodiment, since the image light is selectively diffused by the light control layer 26, it is not necessary to form a fine irregular uneven shape on the surface of the reflecting surface 23, and the screen 20 can be manufactured more easily. Furthermore, according to this embodiment, since the light control layer 26 is provided and the angle α of the reflecting surface 23 can be made constant, the screen 30 can be manufactured more easily. Furthermore, according to this embodiment, the angle α of the reflecting surface 23 is constant, so that it is easier to achieve a larger screen by connecting screens together.

[0067] (Another form of the second embodiment) In the second embodiment described above, an example in which the screen 20 includes the light control layer 26 has been shown, but this is not limiting, and for example, a light diffusion layer (not shown) containing particles that diffuse light may be provided on the image source side of the first base layer 11 via the bonding layer 27. In this case, it is preferable that the particles have transparency from the viewpoint of maintaining the transparency of the screen. Furthermore, by configuring the screen 20 in this manner, it is possible to obtain the effect of reducing glare (scintillation) in the image. Glare in the image is particularly likely to occur when the image source LS uses a laser light source or the like, and this is effective in an image display device equipped with such an image source.

[0068] Furthermore, in the second embodiment described above, an example was shown in which the reflective surface 23 does not have fine and irregular unevenness on its surface, but this is not limited thereto, and the reflective surface 23 may have fine and irregular unevenness on its surface, similar to the reflective surface 13 of the first embodiment, and may have a form that diffuses and reflects a portion of the incident light and transmits at least a portion of the other incident light.

[0069] (Third embodiment) FIG. 10 is a diagram illustrating the layer structure of the screen 30 according to the third embodiment. FIG. 10 shows a part of a cross section of a screen 30 of the third embodiment, which corresponds to the cross section of the screen 10 of the first embodiment shown in FIG. The screen 30 shown in the third embodiment differs from the screen 10 of the first embodiment in that it is not transparent, but otherwise has the same configuration as the screen 10 of the first embodiment. Therefore, parts that perform the same functions as those in the first embodiment described above are given the same reference numerals or reference numerals with the same suffixes, and duplicated explanations will be omitted as appropriate. The screen 30 of the third embodiment can be used in place of the screen 10 in the image display device 1 of the first embodiment described above, when transparency as a screen is not required.

[0070] The screen 30 includes, in order from the image source side, a light control layer 26, a bonding layer 27, a first base material layer 11, a resin layer 32 (a first resin layer 221, a reflecting surface 33, a second resin layer 322), and a second base material layer 35. The first base material layer 11 is the same as that shown in the first embodiment, and the light control layer 26, the bonding layer 27, and the first resin layer 221 are the same as those shown in the second embodiment.

[0071] The reflecting surface 33 of this embodiment has high light reflectivity and very little light transmittance. Most of the light incident on the reflecting surface 33 is reflected, and very little light is transmitted through the reflecting surface 33. The reflective layer that forms the reflective surface 33 of this embodiment is formed on the first surface 221b by vapor deposition or sputtering of a metal such as aluminum, silver, or nickel, or by transferring a metal foil. The reflective layer may also be formed by applying and curing a silver-colored paint, an ultraviolet-curable resin or a thermosetting resin containing a silver-colored pigment or beads, or a paint containing a thin metal film such as silver or aluminum. The application method may be appropriately selected from various application methods such as spray coating, die coating, screen printing, and groove filling by wiping. In this embodiment, an example will be described in which the reflective surface 33 is provided by forming a reflective layer by spray coating silver-based paint on the first surface 221b.

[0072] The second resin layer 322 is provided to fill in and flatten the unevenness caused by the unit optical shapes 221a, similar to the second resin layer 122 of the first embodiment. This second resin layer 322 has light absorption properties but does not have light transparency properties. The second resin layer 322 is in contact with the second surface 221c, and therefore absorbs external light such as sunlight or illumination light that is incident on the second surface 221c from the image source side, thereby improving the contrast of the image. Furthermore, since the second resin layer 322 has light absorption properties, it is possible to suppress a decrease in the contrast of the image caused by external light that is incident from the back side.

[0073] Such a second resin layer 322 is preferably formed from a dark-colored pigment or dye such as black, beads having light-absorbing properties, a thermosetting resin or an ultraviolet-curing resin containing carbon black, or a dark-colored water-based paint or organic paint such as black. Furthermore, in order to fully exert its light absorption function and protective function for the reflecting surface 33 (reflecting layer), it is preferable that the second resin layer 322 has a sufficient dimension in the thickness direction of the screen 30 from point t1, which is the vertex between the unit optical shapes 221a, to its rear surface.

[0074] The second base layer 35 is a layer provided on the back side of the second resin layer 322, and has the function of protecting the back side of the screen 30 from damage, etc. The second base layer 35 of this embodiment has light-absorbing properties from the viewpoint of suppressing a decrease in contrast due to external light from the back side. In this embodiment, the screen 30 is configured to include the second base layer 35, but if the second resin layer 322 is thick enough to sufficiently protect the reflective surface 33 (reflective layer), the screen 30 may not include the second base layer 35. Furthermore, depending on the usage environment, etc., the screen 30 may be configured such that the second resin layer 322 does not have light absorption properties and only the second base layer 35 has light absorption properties (does not have light transparency), or such that only the second resin layer 322 has light absorption properties and the second base layer 35 does not have light absorption properties.

[0075] The screen 30 of this embodiment has the same light control action on image light in the left-right direction of the screen as the first embodiment described above. The state of the image light and external light incident on the screen 30 in the vertical direction of the screen in this embodiment is as follows. Like the image light L21 in the second embodiment, the image light L31 projected from the image source LS is incident on the light control layer 26 at an incident angle within the first incident angle range R1, is diffused, and travels through the screen 30 toward the rear side. Then, like the image light L22 in the second embodiment, the image light L31 is reflected by the reflecting surface 33 and travels through the screen 30 toward the image source side, is incident on the light control layer 26 at an incident angle within the fourth incident angle range R4, is transmitted without being diffused, and travels toward the viewer O1 on the image source side. This allows the screen 30 to display a good image.

[0076] Furthermore, external light G33 incident on the screen 30 of this embodiment from the image source side is incident on the light control layer 26 at an incident angle within the second incident angle range R2 and is transmitted without being diffused. The external light G33 enters the resin layer 32, enters the second resin layer 322 from the second surface 221c and is absorbed, or is reflected by the reflective surface 33 and enters the second resin layer 322 from the second surface 221c and is absorbed, so the amount of light emitted toward the viewer O1 is small. Furthermore, external light (not shown) incident on the screen 30 from above on the rear side is absorbed by the second base layer 35 of the screen 30. Therefore, the screen 30 of this embodiment can suppress a decrease in image contrast caused by external light.

[0077] As described above, according to this embodiment, similar to the first embodiment, it is possible to provide a screen 30 and an image display device 1 that are easy to manufacture and capable of displaying good images. Furthermore, according to this embodiment, the screen 30 selectively diffuses much of the image light by the light control layer 26, while much of the external light passes through the light control layer 26 without being diffused and is absorbed by the second resin layer 322, thereby significantly suppressing the reduction in image contrast caused by the diffusion of external light. Furthermore, according to this embodiment, since the light control layer 26 is provided and the angle α of the reflecting surface 33 can be made constant, the screen 30 can be manufactured more easily. Furthermore, according to this embodiment, the angle α of the reflecting surface 33 is constant, so that it is easier to achieve a larger screen by connecting screens together.

[0078] (Another form of the third embodiment) In the third embodiment described above, the screen 30 may have a configuration in which the reflective layer is formed on the first surface 221b and the second surface 221c. In this case, the screen 30 may have a configuration in which the reflective layer is provided so as to fill the valleys between the unit optical shapes 121a. In the above-described third embodiment, the screen 30 may be configured to have a light diffusion layer (not shown) containing a diffusing material that diffuses light, instead of the light control layer 26, on the image source side of the first base material layer 11 via the bonding layer 27.

[0079] Alternatively, the reflecting surface 33 may not have the light control layer 26 or the light diffusion layer described above, but may have a fine, irregular uneven shape formed on its surface, causing the reflecting surface 33 to diffusely reflect the image light, or the reflecting surface 33 may have a fine, irregular uneven shape formed on its surface while having the light control layer 26 or the light diffusion layer described above. Furthermore, the reflecting surface 33 may be configured such that the angle α increases with increasing distance from the image source LS in the arrangement direction, similar to the reflecting surface 13 shown in the first embodiment.

[0080] (Variations) The present invention is not limited to the above-described embodiments, and various modifications and variations are possible, and these are also within the scope of the present invention.

[0081] (1) In each embodiment, the curved shape of the screen may be such that the shape of the image display device viewed from above in the vertical direction is part of an arc, part of an ellipse, or part of another curved shape. In each embodiment, the curved shape of the screen may be asymmetric in the extension direction of the reflective surface (horizontal direction of the screen) depending on the environment in which the screen and the image display device are used.

[0082] (2) In each embodiment, the screen is curved so as to be convex toward the rear side in the extension direction of the reflective surface (horizontal direction of the screen), but this is not limiting, and the screen may be curved so as to be convex toward the rear side not only in the extension direction of the reflective surface (horizontal direction of the screen) but also in the arrangement direction of the reflective surfaces (vertical direction of the screen). In this case, the curved shape in the arrangement direction of the reflective surfaces may be asymmetric in the vertical direction of the screen depending on the usage environment of the screen, etc.

[0083] (3) In each embodiment, the curvature direction of the screen is described as being perpendicular to the arrangement direction of the reflecting surfaces. However, this is not limited to this. The angle that the curvature direction makes with the arrangement direction of the reflecting surfaces may be set to 90°±10°, i.e., within the range of 80 to 100°, depending on the usage environment of the screen and the image display device, etc.

[0084] (4) In the second and third embodiments, the light control layer has a constant specific angle range (first incident angle range, third incident angle range) for diffusing and transmitting incident light in a cross section parallel to the vertical direction and thickness direction of the screen. However, the specific angle range may be changed continuously or stepwise along the vertical direction of the screen. By providing a light control layer of this type, light can be more effectively diffused in response to the incident angle of image light that changes in the vertical direction of the screen, and a good image can be displayed.

[0085] (5) In each embodiment, the screen may be provided with a light-absorbing layer (not shown) that absorbs a portion of incident light and transmits a portion of the light, located closer to the image source than the reflective surface. This light-absorbing layer is preferably a layer that is colored with a dark colorant such as black or gray so as to have a predetermined transmittance. By providing such a light-absorbing layer closer to the image source than the reflective surface, the screen can reduce the black luminance of the image and absorb external light from the image source side, thereby improving the contrast of the image. The light absorbing layer may be laminated at a position closest to the image source in the thickness direction of the screen, or at least one of the bonding layer, the first base layer, etc. may contain a coloring material, etc., to serve as the light absorbing layer. Placing the light absorbing layer closest to the image source on the screen, that is, placing the light absorbing layer at a position that forms an interface with the air on the image source side of the screen, is more effective in improving the contrast of the image.

[0086] In the first and second embodiments, the screen may have the light absorbing layer as described above on the rear side of the reflective surface. By providing such a light absorbing layer, it is possible to expect effects such as reducing the black luminance of the image, absorbing external light from the rear side, and absorbing image light transmitted through the reflective surface, thereby improving the contrast of the image and suppressing image blur. Such a light absorbing layer may be newly laminated on the back side of the second base layer, or, for example, the second base layer or the like may contain a coloring material and serve as the light absorbing layer.

[0087] (6) In the second and third embodiments, the light control layer may not have the third incident angle range R3, and may transmit light incident from the rear surface side without diffusing it, regardless of the incident angle.

[0088] (7) In each embodiment, the reflective layer for forming the reflective surface is formed continuously along the first surface of the unit optical shape in the longitudinal direction of the unit optical shape, but this is not limiting and the reflective layer may be formed intermittently in the longitudinal direction of the unit optical shape. For example, the reflective layer may be formed in a polka dot pattern along the first surface of the unit optical shape.

[0089] (8) In each embodiment, the screen may be integrally bonded to a support plate (not shown) located on the rear side or the image source side via a bonding layer. When the screen is transparent, the support plate is preferably a member with high light transmittance, such as a glass plate or a resin plate such as polycarbonate or acrylic, and has a curved shape along the left-right direction of the screen. The screen can maintain its curved shape by being bonded to the support plate. The bonding layer is preferably formed using a light-transmitting adhesive or pressure-sensitive adhesive. When the screen is not transparent, it is preferable to attach a curved, non-light-transmitting support plate to the back side of the screen, but it is also possible to join a highly light-transmitting support plate to the image source side of the screen.

[0090] (9) In each embodiment, a hard coat layer may be provided on the image source side and rear surface of the screen to prevent scratches. The hard coat layer is formed, for example, by applying an ultraviolet-curable resin (e.g., urethane acrylate) having hard coat properties to the image source side and rear surface of the screen. Furthermore, in addition to the hard coat layer, one or more layers having necessary functions, such as anti-reflection, ultraviolet absorbing, anti-fouling, anti-static, etc., may be selected and provided on the surface on the image source side and the back side of the screen depending on the environment and purpose of use of the screen. Furthermore, a touch panel layer or the like may be provided on the position of the screen closest to the image source. In particular, in the screens of the first and second embodiments, when an anti-reflection layer is provided on the surface on the image source side, it is possible to prevent the image light reflected by the reflective surface from reflecting at the interface with the air on the image source side and emitting from the rear side, which would otherwise cause the image to appear as if it is leaking to the rear side. The layers having various functions, such as the hard coat layer, may be provided on only one surface of the screen, either on the image source side or on the back side.

[0091] (10) In each embodiment, the screen may not include the first base layer if the first resin layer has sufficient thickness, rigidity, and the like. The screen may have a substrate layer made of a light-transmitting plate-like member such as a glass plate. In this case, the first resin or the like may be bonded to the glass plate or the like via a light-transmitting bonding layer or the like (not shown). The glass plate preferably has a curved shape that is convex toward the back side in the extending direction of the reflective surface.

[0092] (11) In each embodiment, the image source is located below the screen, but this is not limiting and the image source may be located above the screen. In this case, the screen will be inverted in its up-down direction (Y direction).

[0093] (12) In each embodiment, the first and second surfaces of the unit optical shape are formed by flat surfaces. However, this is not limited to this. For example, the first and second surfaces may be formed by a combination of curved and flat surfaces, or may be formed by folded surfaces. In each embodiment, the unit optical shape may be a polygon formed by three or more surfaces.

[0094] The embodiments and modifications may be used in combination as appropriate, but detailed description thereof will be omitted. The present invention is not limited to the above-described embodiments. [Explanation of symbols]

[0095] 1. Video display device 10, 20, 30 screen 11 First base layer 12, 22, 32 Resin layer 121,221 1st resin layer 122,222,322 2nd resin layer 121a, 221a Unit optical shape 121b, 221b First side 121c, 221c Second Side 13,23,33 Reflective surface 15,35 2nd base layer LS video source

Claims

1. A reflective screen that reflects and displays projected image light, Reflection surfaces that reflect at least a portion of the image light are arranged in one direction along the screen surface inside the reflective screen, the reflecting surfaces extend in a direction intersecting an arrangement direction of the reflecting surfaces, The screen surface is It is curved so that it is convex on the back side, In the arrangement direction of the reflecting surfaces, the reflecting surfaces are parallel to the arrangement direction of the reflecting surfaces, a light control layer disposed closer to the image source than the reflective surface and configured to diffuse light incident within a specific range of incident angles more than light incident at other angles; the reflective layer forming the reflective surface is made of a material containing chromium; A reflective screen featuring:

2. 2. The reflective screen according to claim 1, the angle formed by the reflecting surface and a plane parallel to the screen surface varies in one direction along the arrangement direction of the reflecting surfaces; A reflective screen featuring:

3. In the reflective screen according to claim 1 or claim 2, the specific angle range does not include an incident angle of 0°; A reflective screen featuring:

4. 4. The reflective screen according to claim 1, a first resin layer on a rear surface of which unit optical shapes are arranged, the unit optical shapes being formed by first surfaces at least a part of which is the reflecting surface and second surfaces arranged alternately with the first surfaces along an arrangement direction of the reflecting surfaces and intersecting the first surfaces; an angle formed by the second surface and a plane parallel to the screen surface is larger than an angle formed by the first surface and a plane parallel to the screen surface; A reflective screen featuring:

5. The reflective screen according to claim 4, a second resin layer provided on the rear surface side of the first resin layer, filling in valleys between the unit optical shapes to flatten the surface; the first resin layer and the second resin layer have optical transparency and have no refractive index difference or a refractive index difference that is so small that it can be considered to be nonexistent; A reflective screen featuring:

6. In the reflective screen according to claim 4 or claim 5, the reflective surface is formed by providing the reflective layer on the first surface, The reflective screen has transparency, the reflective surface is provided by the semi-transmissive reflective layer that reflects a part of incident light and transmits at least a part of the remaining light; A reflective screen featuring:

7. A reflective screen according to any one of claims 1 to 6; an image source that projects image light onto the reflective screen; A video display device comprising:

Images