JP7201115B1 - Reflective screen, image display device - Google Patents

Abstract

A reflective screen and an image display device capable of suppressing reflection of an image on a ceiling or the like and capable of displaying a good image are provided. SOLUTION: The screen 10 is a reflective screen. and a non-lens surface 133, and a lens layer 13 having a Fresnel lens shape on the second surface side in which unit lenses 131 convex on the second surface side are arranged, and formed on the unit lenses 131 to reflect light and a reflective layer 14 for The non-lens surface 133 has a curved first curved surface portion 134 at the end on the first surface side. The ratio of the dimension of the lens surface 132 in the arrangement direction of the unit lenses 131 to the arrangement pitch of the unit lenses 131 is 60% or more and 95% or less. [Selection drawing] Fig. 2

Description

The present invention relates to a reflective screen and an image display device.

2. Description of the Related Art Conventionally, various developments have been made in order to display good images in a reflective screen and an image display device including the same (for example, Patent Document 1, etc.).
In recent years, short-focus image sources have been widely used in image display devices equipped with reflective screens. Such a short-focus image source can project image light onto the reflective screen from a short distance at a large incident angle, and can reduce the size of the image display device in the depth direction.

JP 2008-076522 A

However, when such an image source is used, the incident angle of the image light with respect to the reflective screen is large, and a part of the image light is reflected on the surface of the reflective screen, resulting in a phenomenon in which the image is reflected on the ceiling or the like. may occur. Such reflection of the image on the ceiling or the like becomes an eyesore especially when viewing the image in a dark room or the like, and interferes with comfortable viewing of the image.

SUMMARY OF THE INVENTION An object of the present invention is to provide a reflective screen and an image display device capable of suppressing reflection of an image on a ceiling or the like and displaying a good image.

The present invention solves the above problems by means of the following solutions. In order to facilitate understanding, reference numerals corresponding to the embodiments of the present invention are used for description, but the present invention is not limited to these.
A first aspect of the present invention is a reflective screen that reflects and displays image light projected from an image source, and in the thickness direction of the reflective screen, the surface on which the image light is projected is defined as the first surface side. A Fresnel lens shape in which unit lenses (131) having a lens surface (132) and a non-lens surface (133) and convex to the second surface side are arranged with the rear surface side as the second surface side. A lens layer (13) provided on the second surface side, and a reflecting layer (14) formed on the unit lens and reflecting light, wherein the non-lens surface is curved at the end on the first surface side. The first curved surface portion (134) is located on the non-lens surface in a region adjacent to the lens surface of the adjacent unit lens, and is aligned with the arrangement pitch of the unit lenses. On the other hand, the reflective screen (10) is characterized in that the ratio of the dimensions of the lens surfaces in the arrangement direction of the unit lenses is 60% or more and 95% or less.
A second aspect of the present invention is the reflective screen of the first aspect, wherein the screen of the reflective screen is divided into three in the vertical direction of the screen and in the horizontal direction of the screen in the state of use to form a total of nine areas, and with respect to the scintillation value S is 1.38 or less.
A third invention is the reflective screen according to the first invention or the second invention, wherein the non-lens surface (133) has a curved second curved surface portion (135) at the end on the second surface side. and wherein the radius of curvature of the first curved surface portion (134) is larger than the radius of curvature of the second curved surface portion.
A fourth invention is the reflective screen according to the third invention, wherein the non-lens surface (133) is a flat area between the first curved surface portion (134) and the second curved surface portion (135). (136), and an angle (γ) at which the extension direction of the lens surface and the extension direction of the planar region intersect, which corresponds to the apex angle of the unit lens, is an acute angle. It is a reflective screen (10).
A fifth invention is the reflective screen according to the first invention or the second invention, in which the unit lenses (131) are arranged in a cross section parallel to the direction of arrangement of the unit lenses (131) and the thickness direction of the reflective screen. A point (t1) closest to the first surface and a point (t2) closest to the second surface in the extending direction of the lens surface (132) and the non-lens surface (133) corresponding to the vertical angle. A reflective screen (10) characterized in that the angle (γ) intersected by a tangential direction at a point (t3) equidistant to and is an acute angle.
A sixth aspect of the invention is the reflective screen according to any one of the first to fifth aspects, wherein the lens layer (13) has the unit lenses (131) outside the display area of the reflective screen. A reflective screen (10) characterized by having a circular Fresnel lens shape arranged concentrically with one point (C) as the center (C).
A seventh invention is the reflective screen according to any one of the first invention to the sixth invention, wherein a colored layer ( 122).
In an eighth invention, in the reflective screen according to any one of the first invention to the seventh invention, a light diffusion layer ( 121).
A ninth invention is an image display device comprising a reflective screen (10) according to any one of the first invention to the eighth invention and an image source (LS) for projecting image light onto the reflective screen. (1).

Advantageous Effects of Invention According to the present invention, it is possible to provide a reflective screen and an image display device capable of suppressing reflection of an image on a ceiling or the like and displaying a good image.

It is a figure which shows the video display apparatus 1 of embodiment. It is a figure which shows the layer structure of the screen 10 of embodiment. It is a figure explaining the lens layer 13 and the unit lens 131 of embodiment. 4 is a diagram illustrating the unit lens 131 in more detail; FIG. 4A and 4B are diagrams showing an example of image light and external light incident on a unit lens 131 of the embodiment; FIG. FIG. 10 is a diagram schematically showing the cross-sectional shape of the unit lens at the screen center of the screens of Measurement Examples 1 to 8; FIG. 10 is a diagram showing each area of the screen when obtaining the standard deviation σ of the speckle values. FIG. 10 is a diagram showing a table summarizing evaluation results of image reflection on the ceiling of the screen and image glare in Measurement Examples 1 to 8. FIG. 3 is a diagram for explaining an angle γ corresponding to the apex angle of a unit lens 131; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, each figure shown below including FIG. 1 is a schematic diagram, and the size and shape of each part are appropriately exaggerated for easy understanding.
In this specification, terms specifying shapes and geometrical conditions, such as parallel and orthogonal terms, have strict meanings, as well as similar optical functions to the extent that they can be regarded as parallel or orthogonal. It also includes states with errors.
In addition, numerical values such as dimensions and material names of each member described in this specification are examples as an embodiment, and are not limited to these, and may be appropriately selected and used.

In addition, in this specification, terms such as plate and sheet are used, but these are generally used in the order of thickness, plate, sheet, and film. I use it in my book as well. However, since there is no technical meaning in such proper use, these words can be replaced as appropriate.
Further, the screen surface indicates a surface in the planar direction of the reflective screen when viewed as a whole reflective screen, and the screen of the reflective screen is assumed to be parallel to this screen surface.

(embodiment)
FIG. 1 is a diagram showing a video display device 1 of this embodiment. 1(a) is a perspective view of the image display device 1, and FIG. 1(b) is a view of the image display device 1 viewed from the side (+X side, which will be described later).
The video display device 1 has a screen 10, a video source LS, and the like. The screen 10 of this embodiment is a reflective screen that reflects the image light L projected from the image source LS to display an image on the screen. The details of this screen 10 will be described later.

Here, in order to facilitate understanding, an XYZ orthogonal coordinate system is appropriately provided and shown in each figure shown below including FIG. In this coordinate system, in the video display device 1, the vertical direction is the Y direction, the horizontal direction is the X direction, and the depth direction is the Z direction. When the screen 10 is in use, the X direction is parallel to the horizontal direction of the screen, the Y direction is parallel to the vertical direction of the screen, and the Z direction is parallel to the thickness direction of the screen 10 . The screen of the screen 10 is parallel to the XY plane, and the thickness direction (Z direction) of the screen 10 is orthogonal to the screen of the screen 10 .

When the screen 10 of the present embodiment is used, the screen (display area) of the screen is parallel to the XY plane, the vertical direction of the screen (Y direction) is the vertical direction, and the horizontal direction of the screen (X direction) is the horizontal direction. are arranged so that In the thickness direction of the screen 10, the surface on the back side (−Z side) is the second surface 10b, and the surface on the viewer side (+Z side) is the first surface 10a.
The +X direction is the direction toward the right side in the horizontal direction of the screen when viewed from the observer O positioned in the front direction of the screen 10, the +Y direction is the direction toward the upper side in the vertical direction of the screen, and the second surface side (back surface) in the thickness direction of the screen 10. The direction from the first surface side (observer side, image source side) to the +Z direction.
In the following description, the up-down direction of the screen, the left-right direction of the screen, and the thickness direction refer to the up-down direction of the screen (vertical direction), the left-right direction of the screen (horizontal direction), and the thickness direction, unless otherwise specified. (depth direction).

The image source LS is an image projection device that projects the image light L onto the screen 10, and is, for example, a short-focus projector. As an example, the image source LS of this embodiment uses a laser light source as a light source.
The image source LS is positioned outside the display area of the screen 10 when the screen (display area) of the screen 10 is viewed from the front (normal direction of the screen surface) in the use state of the image display device 1, It is located at the center of the screen 10 in the horizontal direction (X direction) of the screen and vertically downward (-Y side) of the screen 10 .

The image source LS can obliquely project the image light L from a position much closer to the surface of the screen 10 in the depth direction (Z direction) of the image display device 1 than a conventional general-purpose projector. Therefore, compared with conventional general-purpose projectors, the image source LS has a short projection distance of the image light L to the screen 10 and a large incident angle of the projected image light L on the screen 10 .

The screen 10 is a reflective screen that reflects the image light L projected by the image source LS toward the observer O to display an image.
The screen (display area) of the screen 10 has a substantially rectangular shape when viewed from the observer O side, and the long side direction is the horizontal direction (X direction) of the screen when in use.
The screen 10 has a large screen size of about 40 to 100 inches diagonally, and the aspect ratio of the screen is 16:9. Note that the screen size is not limited to this, and for example, the screen size may be less than 40 inches, and the size and shape can be appropriately selected according to the purpose of use, the environment of use, and the like.
In this embodiment, as an example, the screen size of the screen is 80 inches.

FIG. 2 is a diagram showing the layer structure of the screen 10 of this embodiment. In FIG. 2, the point A (see FIG. 1) which is the center of the screen (the geometric center of the screen) of the screen 10 is parallel to the vertical direction of the screen (Y direction) and perpendicular to the screen surface (in the Z direction). Parallel) is shown by enlarging a part of the cross section.
As shown in FIG. 2, the screen 10 includes a surface layer 11, a substrate layer 12, a lens layer 13, a reflective layer 14, and a back protective layer 15 in order from the first surface side (+Z side). is laminated to

The surface layer 11 is a layer provided on the first surface side (+Z side) of the base material layer 12 . The surface layer 11 of the present embodiment forms the outermost surface (first surface 10a) of the screen 10 on the viewer side.
The surface layer 11 of the present embodiment has a hard coat function and an antiglare function, and an ultraviolet curable resin (for example, urethane acrylate) having a hard coat function is applied to the first surface side surface of the base material layer 12 . An ionizing radiation curable resin such as is applied so that the coating film has a thickness of about 10 to 100 μm, and the fine uneven shape (mat shape) is cured by transferring it to the resin film surface. The shape is molded and formed. Therefore, the surface of the surface layer 11 facing the viewer is rough.

The surface layer 11 is not limited to the above examples, and may be provided with one or a plurality of appropriately selected functions such as an antireflection function, an antiglare function, a hard coat function, an ultraviolet absorption function, an antifouling function, and an antistatic function. may
The surface layer 11 may be bonded to the base material layer 12 with an adhesive (not shown) or the like, or may be directly attached to the surface of the base material layer 12 opposite to the lens layer 13 (first surface side). may be formed.

The base material layer 12 is a layer having optical transparency, and is a sheet-like member that serves as a base material for forming the lens layer 13 . A surface layer 11 is integrally formed on the first surface side (+Z side) of the base material layer 12, and a lens layer 13 is integrally formed on the second surface side (−Z side).
The base material layer 12 has a light diffusion layer 121 containing a diffusing agent and a colored layer 122 containing a colorant such as a pigment or dye. The base material layer 12 of the present embodiment is formed by integrally laminating the light diffusion layer 121 and the colored layer 122 by co-extrusion molding. Note that the present invention is not limited to this, and these layers may be integrally laminated via a bonding layer (not shown) made of a light-transmitting pressure-sensitive adhesive or adhesive.
In this embodiment, as shown in FIG. 2, in the base layer 12, the light diffusion layer 121 is located on the first surface side (+Z side), and the colored layer 122 is located on the second surface side (−Z side). ing.

The light diffusion layer 121 is a layer containing a light-transmitting resin as a base material and a diffusion agent that diffuses light. The light diffusion layer 121 has the function of widening the viewing angle and improving the in-plane uniformity of brightness.
Examples of the resin used as the base material of the light diffusion layer 121 include PET (polyethylene terephthalate) resin, PC (polycarbonate) resin, MS (methyl methacrylate/styrene) resin, MBS (methyl methacrylate/butadiene/styrene) resin, TAC ( Triacetyl cellulose) resin, PEN (polyethylene naphthalate) resin, acrylic resin, and the like are preferably used.

As the diffusing agent contained in the light diffusing layer 121, particles made of resin such as acrylic resin, epoxy resin, or silicon resin, inorganic particles, or the like are preferably used. As the diffusing agent, an inorganic diffusing agent and an organic diffusing agent may be used in combination. The diffusing agent preferably has a substantially spherical shape and an average particle size of about 1 to 50 μm, more preferably 5 to 30 μm.
The thickness of the light diffusion layer 121 depends on the screen size of the screen 10, etc., but is preferably about 100 to 2000 μm. The light diffusion layer 121 preferably has a haze value in the range of 1 to 50%.

In order to improve the front brightness of a reflective screen such as that of the present embodiment, it is conceivable to reduce the content of the diffusing agent in the light diffusing layer. However, if the content of the diffusing agent is reduced while the reflective layer and the light diffusing layer are provided close to each other in the thickness direction of the screen, the position of the diffusing agent in the light diffusing layer becomes localized. , the image may glare (scintillation) and may not be able to display a good image.
Therefore, in the screen 10 of the present embodiment, the light diffusion layer 121 and the colored layer 122 are arranged in order from the first surface side (+Z side) on the base layer 12, and the light diffusion layer 121 and the color layer 122 are arranged in the thickness direction of the screen 10. It is separated from the layer 14 by a predetermined distance. As a result, the screen 10 of the present embodiment improves the front luminance and suppresses the occurrence of image glare even when the position of the diffusing agent in the light diffusion layer is localized as described above. can do.

In the screen 10, the shortest distance between the light diffusion layer 121 and the reflective layer 14 in the thickness direction of the screen is desirably 450 μm or more and 1370 μm or less. The shortest distance means the distance from the point closest to the first surface (+Z side) of the reflective layer 14 in the normal direction (thickness direction) of the screen surface to the surface of the light diffusion layer 121 on the second surface side. . The point closest to the first surface of the reflective layer 14 corresponds to point t1 shown in FIG.

If the shortest distance between the light diffusing layer 121 and the reflective layer 14 in the thickness direction is less than 450 μm, the light diffusing layer 121 and the reflective layer 14 are too close to each other, causing image glare (also called scintillation, speckle, etc.). is not desirable because the effect of suppressing the Moreover, if the shortest distance is larger than 1370 μm, the thickness of the screen is increased, which is undesirable because the weight of the screen is excessively increased. Therefore, the shortest distance between the light diffusion layer 121 and the reflective layer 14 is preferably within the above range.

The colored layer 122 is a layer colored with a dark colorant such as black so as to have a predetermined light transmittance. The colored layer 122 has a function of absorbing unnecessary external light such as illumination light incident on the screen 10 and reducing the black brightness of the displayed image to improve the contrast of the image.
As the coloring agent for the colored layer 122, dark dyes and pigments such as gray and black, metal salts such as carbon black, graphite, black iron oxide, and the like are preferably used.
As the resin that serves as the base material of the colored layer 122, PET resin, PC resin, MS resin, MBS resin, TAC resin, PEN resin, acrylic resin, or the like can be used.
The colored layer 122 preferably has a thickness of about 430 to 1350 μm, depending on the screen size of the screen 10 and the like.

FIG. 3 is a diagram illustrating the lens layer 13 and the unit lenses 131 of this embodiment.
FIG. 3A shows the lens layer 13 observed from the front direction on the second surface side (−Z side), and the reflective layer 14 and the back protective layer 15 are omitted for easy understanding. is shown. FIG. 3(b) further enlarges a part of the cross section of the screen 10 shown in FIG. 2, and shows only the lens layer 13 and the reflective layer 14 for easy understanding.

The lens layer 13 is a layer having optical transparency provided on the second surface side (−Z side) of the base material layer 12 . As shown in FIG. 3A and the like, the lens layer 13 has a circular Fresnel lens shape in which a plurality of unit lenses 131 are concentrically arranged around a point C on the surface on the second surface side. . Therefore, when the lens layer 13 is viewed from the front direction of the second surface side (−Z side), it is observed that the unit lenses 131 having a partial perfect circle shape (arcuate shape) are arranged.

This point C is outside the screen (outside the display area) of the screen 10, and is positioned below the screen 10 at the center of the screen 10 in the horizontal direction of the screen, like the image source LS. Therefore, as shown in FIG. 3A, when viewed from the normal direction of the screen surface of the screen 10, the points A and C are positioned on a straight line parallel to the vertical direction of the screen.
In this embodiment, the lens layer 13 will be described with an example having a circular Fresnel lens shape on its second surface side (−Z side). may have a linear Fresnel lens shape arranged in the vertical direction of the screen or the like.

As shown in FIGS. 2 and 3B, the unit lens 131 has a lens surface 132 and a non-lens surface in a cross section passing through the point A and parallel to the direction in which the unit lenses 131 are arranged and parallel to the thickness direction of the screen 10. 133. In the unit lens 131 of this embodiment, the non-lens surface is located below the lens surface 132 in the vertical direction of the screen (-Y side) in the cross sections shown in FIGS.
The lens surface 132 has a linear shape in the cross section shown in FIG. 2 or FIG. It is inclined so that it is closer to the first surface side (+Z side) than the end on the closer side (the lower side in the vertical direction of the screen). This lens surface 132 is a surface that exerts a lens action of the Fresnel lens shape formed on the lens layer 13 .

As shown in FIG. 3B, the non-lens surface 133 is a portion that is located between adjacent lens surfaces 132 in the arrangement direction of the unit lenses 131 and connects the adjacent lens surfaces 132 . This non-lens surface 133 is smoothly continuous with the adjacent lens surface 132 .
The non-lens surface 133 has a point t2 that is a vertex of a convex shape on the second surface side (−Z side) and a point t1 that is a vertex of a convex shape on the first surface side (+Z side). ing. The point t1 is the bottom of the valley between the adjacent unit lenses 131 when the point t2 is the vertex of the unit lens 131, and is positioned in a curved area corresponding to the valley between the unit lenses 131. there is

The non-lens surface 133 has a curved surface shape in which a region including at least the point t1 is convex toward the first surface. Further, in the present embodiment, the area including the point t2 of the non-lens surface 133 has a curved surface shape that is convex toward the second surface side, and this area is referred to as a second curved surface portion 135 . Further, in this embodiment, as shown in FIG. 3B, the non-lens surface 133 has a substantially planar region 136 between the first curved surface portion 134 and the second curved surface portion 135. The first curved surface portion 134 and the second curved surface portion 135 are connected via this planar region 136 .
Note that the unit lens 131 may have a form in which the first curved surface portion 134 and the second curved surface portion 135 are directly connected without the planar region 136 interposed therebetween, without being limited to the above example. In addition to the above example, the region including the point t2 may not have the second curved surface portion 135 and may be configured by a plane extending from the lens surface 132 and a planar region 136 .

In the present embodiment, the cross-sectional shape of the first curved surface portion 134 and the second curved surface portion 135 shown in FIG. greater than the radius of curvature of
In addition, the first curved surface portion 134 and the second curved surface portion 135 of the non-lens surface 133 may have, for example, a partial elliptical shape or other curved shape in the cross section shown in FIG. good too.

As shown in FIG. 3B, the arrangement pitch of the unit lenses 131 is P, and the lens height of the unit lenses 131 (dimension from point t2 to point t1 in the thickness direction of the screen 10) is h. .
In this embodiment, the angle formed by the lens surface 132 with the plane parallel to the screen surface is α, and the angle formed by the planar region 136 in the non-lens surface 133 with the surface parallel to the screen surface is β. If the non-lens surface 133 does not have a planar region 136, the tangent line at a point equidistant from the points t1 and t2 on the non-lens surface 133 and the surface parallel to the screen surface are Let the angle to form be the angle β. This angle β is greater than the angle α.

For easy understanding, in FIG. 2 and the like, the arrangement pitch P, the angle α, etc. of the unit lenses 131 are shown to be constant in the arrangement direction of the unit lenses 131 . However, although the unit lenses 131 of this embodiment actually have a constant arrangement pitch P, the angle α gradually increases as the distance from the point C in the arrangement direction of the unit lenses 131 increases. h is also larger.

In this embodiment, the array pitch P is preferably 50 to 200 μm. Also, the angle α of the lens surface 132 is formed within the range of 0.5 to 35°.
In addition, the arrangement pitch P is not limited to this, and may be configured such that the arrangement pitch P gradually changes along the arrangement direction of the unit lenses 131 . It can be changed as appropriate according to the projection angle of the LS (the incident angle of the image light onto the screen surface of the screen 10), the screen size of the screen 10, the refractive index of each layer, and the like.

The lens layer 13 is formed on the surface on the second surface side (−Z side) of the base material layer 12 (in this embodiment, the surface on the back side of the colored layer 122) with an ultraviolet curable resin such as urethane acrylate or epoxy acrylate. , are integrally formed by an ultraviolet molding method. The lens layer 13 may be made of other ionizing radiation-curable resin such as electron beam-curable resin, or may be made of thermoplastic resin.
Also, the material and molding method for forming the lens layer 13 can be appropriately selected according to the shape and material of the Fresnel lens on the second surface side of the lens layer 13 .

The reflective layer 14 is a layer having a function of reflecting incident light. The reflective layer 14 is formed on at least part of the lens surface 132 . The reflective layer 14 of this embodiment is formed on the lens surface 132 and the non-lens surface 133 as shown in FIGS. 2 and 3B.
The reflective layer 14 is made of a highly light-reflective metal such as aluminum, silver, nickel, or chromium. The reflective layer 14 of this embodiment is formed by vapor-depositing aluminum, and the thickness of the reflective layer 14 is about 800 Å.

The reflective layer 14 is not limited to this, and may be formed by, for example, sputtering a highly reflective metal, transferring a metal foil, or applying a paint containing a metal thin film or the like. For example, it may be formed by depositing a dielectric multilayer film or a dielectric single layer film.
In addition, the reflective layer 14 is formed by spray coating, die coating, screen printing, wiping, or the like using a white or silver paint, an ultraviolet curable resin or a thermosetting resin containing white or silver pigments, beads, or the like. It may be formed by coating and curing by various coating methods such as groove filling.

The back protective layer 15 is a layer provided on the second surface side (−Z side) of the reflective layer 14 to protect the reflective layer 14 and the back side (back side) of the screen 10 .
As shown in FIG. 2, the back protective layer 15 of the present embodiment covers the reflective layer 14, fills the irregularities of the unit lenses 131, and flattens the second surface 10b of the screen 10. As shown in FIG.
In addition, since the back surface protective layer 15 has a function of absorbing light, it absorbs unnecessary external light such as sunlight and illumination light incident on the screen 10 from the second surface side (−Z side), from the viewpoint of improving the contrast of the

The back surface protective layer 15 of the present embodiment has a function of absorbing light, and a light-absorbing layer such as a dark-colored paint such as black, a dark-colored pigment or dye such as black, and beads having a light-absorbing function. It is formed by, for example, applying a resin containing a material to the second surface side of the reflective layer 14 and curing the resin. As such resins, thermosetting resins such as epoxy resins and urethane resins, thermoplastic resins such as acrylic resins, ultraviolet curable resins such as urethane acrylates and epoxy acrylates, and the like are preferable.
Moreover, from the viewpoint of protecting the reflective layer 14 and the lens layer 13, the back protective layer 15 may have an ultraviolet absorption function, a hard coat function, and the like.

Here, the shape of the unit lens 131 of this embodiment will be described in more detail.
FIG. 4 is a diagram illustrating the unit lens 131 in more detail. 4(a) shows a cross section of the unit lens 131 of this embodiment, and FIG. 4(b) shows a cross section of a conventional unit lens 531. FIG. 4(a) and 4(b) show only the lens layer 13 of the present embodiment and the conventional lens layer 53, respectively, for easy understanding. A part of the cross section parallel to the thickness direction of is shown enlarged.
The unit lens 131 of this embodiment shown in FIG. 4A and the conventional unit lens 531 shown in FIG. are located on the upper side of the screen in the vertical direction and are at the same distance from the point C.

A conventional unit lens 531 has a lens surface 532 and a non-lens surface 533 . In addition, the conventional unit lens 531 is the same as the unit lens 131 of the present embodiment except that the first curved surface portion 134 and the second curved surface portion 135 are not provided, and the non-lens surface 533 is planar. The pitch P and the angle α are the same, and the incident angle of the image light on the lens surface 532 is also the same.
As shown in FIG. 4B, the image light La projected from the image source LS is incident on the lens surface 532 of the conventional unit lens 531 at a predetermined incident angle. At this time, the lens surface 532 has a reflective area 532A, which is an area where the image light La is incident, and a non-reflective area 532B, which is an area where the image light La is not incident.
Wa/P is the ratio of the dimension of the reflection area 532A in the arrangement direction of the unit lenses 531 to the arrangement pitch P. As shown in FIG.

In contrast, in the unit lens 131 of this embodiment, the second curved surface portion 135 of the non-lens surface 133 is formed in a region corresponding to the non-reflecting region of the lens surface 132 . As a result, the non-reflecting area of the lens surface 132 is made much smaller than that of the conventional unit lens 531 while ensuring the same reflective area occupying the lens surface 132 as that of the conventional unit lens 531 . Therefore, in this embodiment, the ratio of the dimension of the lens surface 132 to the arrangement pitch P in the arrangement direction of the unit lenses 131 (hereinafter referred to as the ratio of the lens surface 132 to the arrangement pitch) W1/P is is equal to or substantially equal to the ratio Wa/P of the reflection area 532A of the unit lens 531 with respect to the arrangement pitch.
Further, the image light La is incident on this unit lens 131 at a predetermined incident angle, like the unit lens 531 of the comparative example.
Therefore, the unit lens 131 of the present embodiment has the same reflected light amount of the image light La as that of the conventional unit lens 531 .

Next, as shown in FIG. 4B, in the conventional unit lens 531, part of the image light (image light Lb) is incident on a point t1 that is convex toward the first surface side (+Z side), The light is reflected by the reflective layer 14 and emitted upward on the first surface side of the screen. The amount of such image light Lb is very small. Therefore, even if the image light Lb reaches the ceiling or the like, it is not possible to reduce the reflection of the image due to the image light reflected on the viewer-side surface of the screen.
On the other hand, in the unit lens 131 of the present embodiment, as shown in FIG. 4A, part of the image light (image light Lc, Ld, Le) enters the first curved surface portion 134 and The light is diffusely reflected by the curved surface shape and the reflective layer 14 . A portion of the image light Lc and Ld is emitted upward on the first surface side of the screen 10, and a portion of the image light Le is totally reflected at the interface on the first surface side of the screen 10 and passes through the inside of the screen 10. It propagates upward and eventually attenuates.

Since the image lights Lc and Ld emitted upward from the screen 10 are diffusely reflected, the image reflected on the surface of the screen 10 (first surface 10a) and reflected on the ceiling or the like is blurred and unclear. It has the effect of becoming Thereby, the screen 10 of the present embodiment can suppress reflection of images on the ceiling or the like. In addition, a small amount of the image light Lc diffusely reflected reaches the observer O, which has the effect of reducing glare in the image.

The ratio W1/P of the dimension of the lens surface 132 to the arrangement pitch P in the arrangement direction of the unit lenses 131 is preferably 60% or more and 95% or less.
If the ratio W1/P is less than 60%, the lens surface 132 becomes smaller than the array pitch P, which reduces the reflection area and reduces the front luminance of the image, which is not preferable. Further, if the ratio W1/P is greater than 95%, the first curved surface portion 134 becomes too small, and the above effect of suppressing reflection of images on the ceiling or the like cannot be sufficiently obtained. Therefore, the ratio W1/P is preferably within the above range.

In the present embodiment, since the arrangement pitch P is constant, the ratio W1/P gradually decreases along the arrangement direction of the unit lenses 131 within the preferred range as the distance from the point C (image source LS) increases. ing.
In a region near point C in the arrangement direction of the unit lenses 131 (for example, the bottom side of the screen in the vertical direction in this embodiment), the angle α is small and the lens height h is small. The radius becomes small and the ratio W1/P is large. On the other hand, in a region far from the point C in the arrangement direction of the unit lenses 131 (in this embodiment, for example, the upper side in the vertical direction of the screen), the angle α is large and the lens height h is also large. The radius of curvature increases and the ratio W1/P decreases.
Note that this ratio W1/P is not limited to this, and the ratio W1/P may decrease stepwise within the above preferable range along the direction of arrangement of the unit lenses 131 as it moves away from the point C (image source LS). , may be constant in the arrangement direction of the unit lenses 131 .

In addition, since the non-lens surface 133 has the first curved surface portion 134, in addition to the effect of suppressing the reflection of the image on the ceiling or the like, glare (also referred to as scintillation, speckle, etc.) of the displayed image is reduced. It was found that the effect of
Regarding the glare of this image, the screen of the screen 10 is divided into three areas in the vertical direction and the horizontal direction of the screen, and a total of nine areas are provided, and the speckle value at the geometric center of each area ( Speckle contrast) was measured and defined by the standard deviation σ of the speckle values of the 9 regions. From the viewpoint of reducing image glare, the standard deviation σ of the speckle values of the nine regions is preferably as small as possible, and particularly preferably less than 1.38.

FIG. 9 is a diagram for explaining the angle γ corresponding to the apex angle of the unit lens 131. As shown in FIG. As in FIG. 2 and the like, FIG. 9 shows a section parallel to the arrangement direction of the unit lenses 131 through the thickness direction of the screen 10 and the point A, and shows only a part of the unit lenses 131 in an enlarged manner. 9A shows a unit lens 131 whose non-lens surface 133 has a planar region 136, and FIG. 9B shows a unit lens 131 whose non-lens surface 133 does not have a planar region 136. is shown.

In the cross section shown in FIG. 9(a), the angle γ formed by the extending direction of the lens surface 132 and the extending direction of the planar region 136 of the non-lens surface 133, which corresponds to the apex angle of the unit lens 131, is an acute angle, That is, it is preferable that 0°<γ<90°.
When the angle γ is 90° or more, the ratio of the dimensions of the non-lens surfaces 133 to the arrangement pitch P in the arrangement direction of the unit lenses 131 becomes large, and the ratio W1/P becomes small. Therefore, the area of the lens surface 132 that reflects the image light (the area of the reflection area) is reduced. In addition, the amount of image light incident on the non-lens surface 133 increases. For these reasons, the amount of image light reflected toward the observer is reduced, and the image becomes dark.

Further, when the angle γ is 90° or more, as described above, the image light incident on the non-lens surface 133 and reflected by the reflective layer 14 becomes stray light. lowers the
Moreover, if the angle γ is 90° or more, unnecessary external light or the like enters the non-lens surface 133 and is likely to be reflected toward the observer, thereby lowering the contrast of the image.
From the above, the angle γ is preferably an acute angle (0°<γ<90°).

In addition, as shown in FIG. 9B, in the case of the unit lens 131 in which the non-lens surface 133 does not have a planar region 136, the point t1 on the non-lens surface 133 and on the first curved surface portion 134 and the first Let γ be the angle formed by the tangential line at a point equidistant from the point t2 on the two-curved surface portion 135 (the point t3 shown in FIG. 9B) and the extending direction of the lens surface 132 .

FIG. 5 is a diagram showing an example of image light and external light incident on the screen 10 of this embodiment. The cross section of the screen 10 shown in FIG. 5 is the same as the cross section of the screen 10 shown in FIG. 2 described above. In FIG. 5, for ease of understanding, it is assumed that the refractive indices between the surface layer 11 and the base layer 12 and between the base layer 12 and the lens layer 13 are the same, and the image light and the external light are The light diffusing action of the diffusion layer 121 is omitted.
As shown in FIG. 5, most of the image light L1 projected from the image source LS is incident on the screen 10 like the image light L2, and the surface layer 11 and the base layer 12 (light diffusion layer 121, It passes through the colored layer 122) and goes to the lens layer 13.

However, part of the image light L1 projected from the image source LS (image light L3) is reflected by the surface of the screen 10 and directed upward on the side of the first surface of the screen 10 to project the image onto the ceiling or the like. It may cause glare. However, the surface of the surface layer 11 of the present embodiment is formed with fine irregularities, and the image light L3 reflected toward the ceiling or the like is diffused to reduce the reflection of the image on the ceiling or the like.

Most of the image light L2 incident on the screen is incident on the lens surface 132 of the unit lens 131, reflected by the reflective layer 14, and emitted from the screen 10 toward the substantially front direction of the first surface side for observation. Reach person O. Thereby, the screen 10 can display a bright image.
At this time, since the screen 10 has a sufficient distance between the reflective layer 14 and the light diffusion layer 121 in the thickness direction, the brightness of the image light can be made uniform without significantly lowering the front luminance. , can suppress the glare of the image.

In addition, since the image light L1 is projected from below the screen 10 and the angle β is larger than the incident angle of the image light L1 at each point in the vertical direction of the screen of the screen 10, the image light L1 is projected onto the non-lens surface 133. The light does not directly enter a region other than the first curved surface portion 134 (for example, the second curved surface portion 135, etc.).
In addition, since the first curved surface portion 134 of the non-lens surface 133 does not greatly block the image light L2 incident on the lens surface 132 in the unit lens 131, the front luminance of the image is maintained, and the screen 10 displays a bright image. can.

Further, the first curved surface portion 134 and the reflective layer 14 diffusely reflect part of the image light L2 (image light L4) upward of the screen, and part of the image light L2 is emitted upward on the first surface side of the screen 10 . As a result, it is possible to obscure the reflection of the image on the ceiling or the like, and it is possible to suppress the reflection of the image. Further, part of the image light L4 is diffused and partly directed toward the observer as shown by the image light Lc in FIG. 4A, thereby reducing image glare.

On the other hand, unnecessary external lights G1 and G2 such as illumination light mainly enter the screen 10 from above, as shown in FIG. Some of the external lights G1 and G2 (not shown) are reflected by the surface of the screen and travel downwards of the screen 10 . Also, most of the external light G1 and G2 enters the screen 10 , passes through the surface layer 11 and the base layer 12 , and enters the unit lenses 131 of the lens layer 13 .
The external light G1 enters the non-lens surface 133, is reflected by the reflective layer 14, is reflected by the lens surface 132, and so on, and travels upward on the first surface side of the screen 10. The amount of light reaching to is significantly smaller than that of the image light L1. In addition, since the external light G2 is reflected by the lens surface 132 and travels mainly downward on the first surface side of the screen 10, it does not directly reach the observer O side. Significantly less than the light L1. Furthermore, some external light (not shown) is absorbed by the colored layer 122 . Therefore, in the screen 10, it is possible to greatly suppress the deterioration of the image contrast due to the external light G1, G2, and the like.

As described above, according to the screen 10 of the present embodiment, it is possible to display a high-contrast, bright and favorable image, and to suppress reflection of the image on the ceiling or the like. In addition, according to this embodiment, it is possible to reduce the glare of the image.
Further, according to the present embodiment, the surface of the surface layer 11 is formed with fine irregularities, and the irregularities can diffuse the image light reflected toward the ceiling or the like, thereby preventing the image from being reflected on the ceiling or the like. It is possible to further enhance the effect of suppressing congestion.

Here, the screens of measurement examples 1 to 8 with different ratios W1/P of the lens surface 132 to the array pitch P and the presence or absence of the first curved surface portion 134 are prepared. evaluated.
The screens of Measurement Examples 1 to 8 have the same configuration except that the ratio of the lens surface 132, the presence or absence of curved surface portions, and the shape thereof are different.
The screens of Measurement Examples 1 to 8 have a horizontally long rectangular screen with a screen size of 80 inches. The image source LS (manufactured by Hisense 75L9S) that projects image light onto the screens of measurement examples 1 to 8 is 741 mm below the screen in the vertical direction of the screen of each measurement example (the screen in the horizontal direction of the screen Image light is projected from a point 236 mm below the bottom of the screen at the center and 447 mm away from the observer side (+Z side) along the normal direction of the screen surface. The angle α at the lower end of the screen in the vertical direction of the screen is 5.2°, and the angle α at the upper end thereof is 21.8°. In the screen of each measurement example, the incident angle of the image light in the vertical direction of the screen at the point A is 58.9°.

FIG. 6 is a diagram schematically showing the cross-sectional shape of the unit lens 131 at the point A which is the center of the screen in the screens of Measurement Examples 1 to 8. As shown in FIG. FIG. 6 shows the unit lens 131 in the same cross section as in FIG. 3B, and shows only the lens layer 13 for easy understanding.
FIG. 6(a) corresponds to the unit lens 131 of the screens of Measurement Examples 1 to 3, FIG. 6(b) corresponds to the unit lens 131 of the screen of Measurement Example 4, and FIG. 6(c) is the measurement example. 6(d) corresponds to the unit lens 131 of the screens of measurement examples 7 and 8. FIG.

In the screens of Measurement Examples 1 to 3, the non-lens surface 133 has the first curved surface portion 134 and the planar area 136 but does not have the second curved surface portion 135 . The screen of Measurement Example 1 has a ratio W1/P of 60%, the screen of Measurement Example 2 has a ratio W1/P of 80%, and the screen of Measurement Example 3 has a ratio W1/P of 95%. .
In the screen of Measurement Example 4, the non-lens surface 133 has the first curved surface portion 134 and the second curved surface portion 135, and the ratio W1/P is 95%.
The screens of Measurement Examples 1 to 4 described above correspond to the screens of Examples of this embodiment.

In the screens of Measurement Examples 5 and 6, the non-lens surface 133 does not have the first curved surface portion 134 but has a planar region 136 and a second curved surface portion 135 . The screen of Measurement Example 5 has a W1/P of 80%, and the screen of Measurement Example 6 has a W1/P of 95%.
The screens of Measurement Examples 7 and 8 have a flat non-lens surface 133 and do not have the first curved surface portion 134 and the second curved surface portion 135 . The screen of measurement example 7 has a ratio W1/P of 98%, and the screen of measurement example 8 has a ratio W1/P of 99%.
The screens of measurement examples 5 to 8 described above correspond to screens of comparative examples of the present embodiment.

Further, for the screens of Measurement Examples 1 to 8, the speckle value was measured at the geometric center of nine regions obtained by dividing the screen into three in the vertical direction and the horizontal direction of the screen, respectively. A standard deviation σ of the speckle values of the nine regions was obtained.
FIG. 7 is a diagram showing each area of the screen when obtaining the standard deviation σ of the speckle values. FIG. 7 shows a view of the screen viewed from the normal direction of the screen, and nine areas are denoted by reference numerals S1 to S9.
In each of the screens of Measurement Examples 1 to 8, the lens layer 13 is a circular Fresnel lens in which the unit lenses 131 are concentrically arranged around the point C (see FIG. 3(a)) outside the display area of the screen. have a shape. In such a screen, the regions S3 and S9 shown in FIG. 7 may have a small contribution to the reduction of image reflection on the ceiling or the like from the viewpoint of the arrangement direction of the unit lenses 131, etc. Since it is expected to be effective in reducing glare, the standard deviation σ is used for all nine regions.

Here, the speckle value is a value that serves as an index for evaluation of image glare, and is a value obtained by the following formula (1).
Formula (1) S[%]=100×σa[cd/m ² ]/M[cd/m ² ]
Here, σa in equation (1) is an intersection point obtained by setting a predetermined measurement area centered on the geometric center of each area of the screen and drawing a line segment in the measurement area at a predetermined pitch. is the standard deviation of luminance at each measurement point when a white image is displayed on the screen. The measurement area is 40 mm in the vertical direction of the screen and 60 mm in the horizontal direction of the screen. In addition, the line segments are arranged at a pitch of 255 μm in the vertical direction of the screen and in the horizontal direction of the screen. Also, M indicates the average value of the respective luminance values of the above measurement points.

This speckle value is measured in a darkroom environment with a measuring instrument (Dr. SPECKLE/SM01VS09 manufactured by Oxide Co., Ltd.) from point A, which is the screen center (geometric center of the screen) of each measurement example, to the screen surface method. The speckle contrast Cs was obtained by arranging at a position 1.0 m away from the observer side (+Z side) in the linear direction and measuring the speckle contrast Cs.
Also, at this time, the image source LS (75L9S manufactured by Hisense Co., Ltd.) was observed along the normal direction of the sheet surface by 741 mm from the point A on the screen of the screen of each measurement example to the lower side of the screen in the vertical direction (-Y side). It was arranged at a position 447 mm away from the user side (+Z side).

FIG. 8 is a diagram showing a table summarizing evaluation results of image reflection on the screen ceiling and image glare in Measurement Examples 1 to 8. In FIG.
Regarding the reflection of the image on the ceiling and the glare of the image, in a darkroom environment, the observer moves from point A, which is the center of each screen, to the observer side (+Z side) along the normal direction of the screen surface. At a position of .2 m, the ceiling and the display surface of the screen were visually observed and evaluated.
In the table shown in FIG. 8, the image reflection on the ceiling is evaluated as "weak" when the reflection on the ceiling is weak and unclear, and when it can be used well, and "weak" when the reflection on the ceiling is ""Medium" indicates that it is stronger than "weak" but usable, and "strong" indicates that the reflection on the ceiling is strong and clear and is not suitable for use.
In addition, the evaluation of image glare (visibility of speckle) was evaluated as "weak" when the image glare is weak and hardly visible and can be used satisfactorily. "Medium" indicates that the image is strong but can be used, and "Strong" indicates that the image is highly glaring and is not suitable for use.

As shown in the table of FIG. 8, in the screens of Measurement Examples 1 to 4 having the first curved surface portion 134, the reflection of the image on the ceiling is higher than that of Measurement Examples 5 to 8, which does not have the first curved surface portion 134. was weak and reduced. On the other hand, the screens of Measurement Examples 5 and 6, which do not have the first curved surface portion 134 on the non-lens surface 133 and have the second curved surface portion 135, and the screens having the first curved surface portion 134 and the second curved surface portion 135, The screens of Measurement Examples 7 and 8, which had neither of them, had a strong and clear reflection on the ceiling.
Also, in measurement example 1, where the ratio W1/P of the lens surface 132 to the array pitch P is smaller than the screens of the other measurement examples, a bright image is displayed satisfactorily. The image was displayed with sufficient brightness.
Therefore, in the screen 10, the unit lens 131 has the first curved surface portion 134 that is convex on the first surface side, and the ratio W1/P is 60% or more and 95% or less. This is preferable from the viewpoint of reduction of reflection.

Further, as shown in the table of FIG. 8, the screens of Measurement Examples 1 to 4, in which the standard deviation σ of the speckle values was 1.38 or less, had reduced image glare (speckle). On the other hand, on the screens of Measurement Examples 5 to 8, in which the standard deviation σ of the speckle value was larger than 1.38, glare in the image was visually recognized.

As described above, according to the present embodiment, the non-lens surface 133 has the first curved surface portion 134, and the ratio W1/P of the lens surface 132 to the array pitch P is 60% to 95%. Since it is below, it is possible to suppress reflection of the image on the ceiling while displaying a bright and favorable image.
Further, according to the present embodiment, the screen has a standard deviation σ of the speckle values of 1.38 or less in each area obtained by dividing the screen into nine areas, so that image glare can be reduced.

(deformed form)
Various modifications and changes are possible without being limited to the embodiments described above, and they are also within the scope of the present invention.

(1) In the embodiment, the surface layer 11 has a hard coat function and an antiglare function. A layer having one or a plurality of various functions such as an antifouling function and an antistatic function may be used, or a plurality of layers having desired functions may be laminated. Also, a touch panel layer or the like may be provided as the surface layer 11 .

(2) In the embodiment, the lens surface 132 may be configured with a plurality of flat surfaces (a so-called bent surface shape), or may be a curved surface shape that is convex toward the second surface side (−Z side). good.

(3) In the embodiment, the screen 10 may be provided with a highly rigid transparent substrate layer made of glass or resin having optical transparency from the viewpoint of improving the flatness of the screen.
Further, a support plate (not shown) having high rigidity may be integrally laminated on the second surface side (−Z side) to improve the flatness of the screen.

(4) In the embodiment, the screen 10 may be flexible and can be rolled up for storage when not in use.

(5) In the embodiment, the screen 10 has an example in which the back protective layer 15 has light absorption properties, but is not limited to this, and the back protective layer 15 does not have light absorption properties, and the second surface of the screen 10 A light-shielding curtain made of cloth or resin that does not easily transmit light, a layer that improves scratch resistance, or the like may be laminated on the side (−Z side). In addition, in the environment where the screen is used, in the case where deterioration of contrast due to external light from the second surface side is unlikely to occur, the screen 10 has a form in which the back surface protective layer 15 does not have light absorption properties, and the above-described A configuration without a light shielding curtain or the like may be used.
Alternatively, the back surface protective layer 15 may be made of paper, non-woven fabric, resin sheet, or the like, and may be laminated on the second surface side of the reflective layer 14 via a bonding layer formed of an adhesive or an adhesive (not shown). good.

(6) In the embodiment, an example in which the image source LS is arranged below the screen 10 (on the -Y side) in the vertical direction is shown, but the present invention is not limited to this. It may be positioned above the screen 10 (on the +Y side). In this case, like the image source LS, the screen 10 is used with its vertical direction reversed so that the point C, which is the Fresnel center, is located on the upper side in the vertical direction.

(7) In the embodiment, the surface layer 11 may have a shape in which unit optical shapes (not shown) that are convex on the first surface side are arranged in the horizontal direction of the screen with the vertical direction of the screen as the longitudinal direction. The unit optical shape has, for example, a shape in which the cross-sectional shape of the cross section parallel to the arrangement direction and the thickness direction of the screen is a partial circular shape, and the surface layer 11 has a so-called lenticular lens shape on the first surface side. may be In addition, the unit optical shape may have a cross-sectional shape that is, for example, a partial elliptical shape, or a shape that combines a plurality of curved lines.
Moreover, the unit optical shape of the surface layer 11 is not limited to the above example, and the cross-sectional shape of the surface layer 11 parallel to the arrangement direction and the thickness direction of the screen may be a triangular shape that is convex toward the first surface.
By providing such a surface layer 11, the image light L is diffused in the horizontal direction of the screen by the unit optical shape, and the screen 10 can sufficiently secure a viewing angle in the horizontal direction (X direction) of the screen.

(8) In the embodiment, the image source LS is an example of using a laser light source. A DLP projector using a mercury lamp may be used, or an image source using another light source such as an LED may be used.

Although the present embodiment and modifications can be used in combination as appropriate, detailed description thereof will be omitted. Moreover, the present invention is not limited to each embodiment described above.

REFERENCE SIGNS LIST 1 image display device 10 screen 11 surface layer 12 base material layer 121 light diffusion layer 122 colored layer 13 lens layer 131 unit lens 132 lens surface 133 non-lens surface 134 first curved surface portion 135 second curved surface portion 136 planar area 14 reflection Layer 15 Back protective layer LS Image source

Claims (11)

A reflective screen that reflects and displays image light projected from an image source,
In the thickness direction of the reflective screen, the surface on which image light is projected is defined as the first surface side, and the back surface side is defined as the second surface side,
a lens layer having, on the second surface side, a Fresnel lens shape in which unit lenses having a lens surface and a non-lens surface and convex to the second surface side are arranged;
a reflective layer formed on the unit lens and reflecting light;
a light diffusion layer provided closer to the first surface than the reflection layer, containing a diffusing agent for diffusing light, and diffusing incident light;
a back protective layer provided closer to the second surface than the reflective layer, containing a dark-colored light-absorbing material and having light-absorbing properties;
with
The non-lens surface has a curved first curved surface portion at an end portion on the first surface side, and has a curved second curved surface portion at an end portion on the second surface side,
the first curved surface portion is located in a region adjacent to the lens surface of the adjacent unit lens on the non-lens surface;
the radius of curvature of the first curved surface portion is greater than the radius of curvature of the second curved surface portion;
The ratio of the dimension of the lens surface in the arrangement direction of the unit lenses to the arrangement pitch of the unit lenses is 60% or more and 95% or less;
A reflective screen characterized by a The reflective screen according to claim 1,
In the reflective screen, the screen is divided into three in the vertical direction and the horizontal direction of the screen in the state of use to form a total of 9 regions, and the standard deviation σ of the speckle value S of the 9 regions is 1.38 or less. to be,
A reflective screen characterized by a In the reflective screen according to claim 1 or claim 2 ,
the non-lens surface has a planar region between the first curved surface portion and the second curved surface portion;
The angle at which the direction of extension of the lens surface and the direction of extension of the planar region intersect, which corresponds to the apex angle of the unit lens, is an acute angle;
A reflective screen characterized by a In the reflective screen according to claim 1 or claim 2 ,
that the first curved surface portion and the second curved surface portion are directly continuous on the non-lens surface;
A reflective screen characterized by a In the reflective screen according to any one of claims 1 to 4 ,
The lens layer has a circular Fresnel lens shape in which the unit lenses are arranged concentrically around a point located outside the display area of the reflective screen;
A reflective screen characterized by a In the reflective screen according to any one of claims 1 to 5 ,
A colored layer colored to a predetermined density is provided on the first surface side of the reflective layer,
A reflective screen characterized by a In the reflective screen according to any one of claims 1 to 6 ,
The back surface protective layer is provided on the second surface side of the reflective layer, and fills the irregularities of the unit lenses to flatten the second surface;
A reflective screen characterized by a In the reflective screen according to any one of claims 1 to 7 ,
the shortest distance between the light diffusion layer and the reflective layer in the thickness direction of the reflective screen is 450 μm or more and 1370 μm or less;
A reflective screen characterized by a In the reflective screen according to any one of claims 1 to 8 ,
The reflective layer is not light transmissive;
A reflective screen characterized by a In the reflective screen according to any one of claims 1 to 9 ,
the reflective screen not having transparency;
A reflective screen characterized by a a reflective screen according to any one of claims 1 to 10 ;
an image source that projects image light onto the reflective screen;
A video display device.

Images