JP2013213882A - Reflection screen, video display system - Google Patents

Abstract

A reflection screen for displaying a good image with high contrast and an image display system including the same are provided.
A reflective screen 10 is provided on the back side, is provided with a reflective layer 16 that reflects light, and is provided on the image source side with respect to the reflective layer 16, and a plurality of unit optical shapes 111 are arranged on the image source side surface. The optical shape layer 11 that deflects the image light toward the reflection layer 16, the back surface side of the optical shape layer 11, and the image source side of the reflection layer 16, and the light transmission unit 131 and the light absorption unit 132 Are arranged alternately in the vertical direction of the screen along the screen surface, and the unit optical shape 111 has a cross-sectional shape in a direction parallel to the array direction and perpendicular to the screen surface, It was assumed to be a substantially triangular shape that is convex to the side.
[Selection] Figure 2

Description

  The present invention relates to a reflection screen that reflects image light projected from an image source and displays the image light so as to be observable, and an image display system including the same.

In recent years, as a video source for projecting an image on a reflective screen, a short focus type video projection device (projector) that projects a video light at a relatively large incident angle from a close distance to realize a large screen display has been widely used. Yes.
Such a short focus type image projection device can project the reflection screen from above or below at a larger incident angle than the conventional image source, and the distance between the image projection device and the reflection screen in the depth direction. Can be shortened, and can contribute to space saving of an image display system using a reflective screen.
In order to satisfactorily display the image light projected by such a short focus type image projection device, the surface of the lens layer having a linear Fresnel lens shape or a circular Fresnel lens shape formed by arranging a plurality of unit lenses is used. Various reflective screens and the like on which a reflective layer is formed have been developed (for example, Patent Document 1).

JP 2008-76523 A

For a reflective screen, it is required to display a bright and high-contrast image. In general, the contrast is displayed by the ratio of the luminance at the time of white display (white luminance) and the luminance at the time of black display (black luminance). In order to display a good image with high contrast, illumination light, etc. It is effective to suppress an increase in black luminance due to external light.
For example, in the reflective screen shown in Patent Document 1, an increase in black luminance due to external light such as illumination light is suppressed by providing a colored layer colored in a dark color system (black or the like) with a density of a predetermined color material. . However, in such a colored layer, the image light is uniformly absorbed together with the external light, so that there is a problem that the brightness of the image is lowered and the contrast is lowered.

  An object of the present invention is to provide a reflective screen that displays a good image with high contrast, and an image display system including the same.

The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected and demonstrated, it is not limited to this.
The invention of claim 1 is a reflective screen that reflects image light projected from an image source and displays the image light so as to be observable. The reflective screen is provided on the back side and reflects light, and the reflective layer. A plurality of unit optical shapes (111) arranged on the image source side surface, and an optical shape layer (11) for deflecting image light toward the reflective layer, and more than the optical shape layer A light control layer (on the back side, provided closer to the image source than the reflective layer), in which light transmitting portions (131) and light absorbing portions (132) are alternately arranged along the screen surface in the vertical direction of the screen ( 13), and the unit optical shape is a substantially triangular shape in which a cross-sectional shape in a direction parallel to the arrangement direction and orthogonal to the screen surface is convex toward the image source side. A reflective screen (10).
According to a second aspect of the present invention, in the reflective screen according to the first aspect, the shaping layer is provided on the image source side of the reflective layer (16) and shapes the shape of the surface of the reflective layer on the image source side. 15), and the shaping layer is a reflection screen (10) characterized in that a plurality of unit surface shapes (151) are arranged on the surface on the reflection layer side.
According to a third aspect of the present invention, in the reflective screen according to the second aspect, the unit surface shape (111) is convex on the back side, and a plurality of unit surface shapes are arranged in the horizontal direction of the screen with the vertical direction of the screen as the longitudinal direction. This is a reflective screen (10).
According to a fourth aspect of the present invention, in the reflective screen according to any one of the first to third aspects, the unit optical shape (111) includes an incident surface (112) on which light is incident and the incident surface. And a total reflection surface (113) that totally reflects at least a part of the light from the light and directs it toward the back side.
According to a fifth aspect of the present invention, in the reflective screen according to any one of the first to fourth aspects, the light absorbing portion (132) is parallel to the arrangement direction and is a cross section perpendicular to the screen surface. The reflecting screen (10) is characterized in that the cross-sectional shape in is substantially wedge-shaped.
A sixth aspect of the present invention is the reflective screen according to any one of the first to fifth aspects, wherein the light transmitting portion (131) is a cross section that is parallel to the arrangement direction and orthogonal to the screen surface. The reflective screen (10) is characterized in that the cross-sectional shape in FIG. 1 is a substantially trapezoidal shape, and the width on the image source side is larger than the width on the back side.
A seventh aspect of the present invention is a video display comprising the reflective screen (10) according to any one of the first to sixth aspects, and a video source (LS) that projects video light onto the reflective screen. System (1).

  ADVANTAGE OF THE INVENTION According to this invention, the reflective screen which displays a favorable high contrast image | video, and an image display system provided with the same can be provided.

It is a figure explaining video display system 1 of an embodiment. It is a figure which shows the layer structure of the reflective screen 10 of embodiment. It is a figure explaining the unit optical shape 111 of embodiment. It is a figure explaining the light control layer 13 of embodiment. It is a figure explaining the shaping layer 15, the reflective layer 16, and the back surface protective layer 17 of embodiment. It is a figure explaining the reflective screen 10 of other embodiment. It is a figure explaining the optical shape layer 61 of a deformation | transformation form. It is a figure explaining the example of the other shape of the shaping layer.

Embodiments of the present invention will be described below with reference to the drawings.
In addition, each figure shown below including FIG. 1 is the figure shown typically, and the magnitude | size and shape of each part are exaggerated suitably for easy understanding.
In addition, the terms “plate”, “sheet”, “film” and the like are used, but these are generally used in the order of thickness, “plate”, “sheet”, “film”. I am using it. However, such proper use has no technical meaning and can be replaced as appropriate.
Furthermore, numerical values such as dimensions and material names of each member described in the present specification are examples of the embodiment, and the present invention is not limited thereto, and may be appropriately selected and used.

(Embodiment)
FIG. 1 is a diagram illustrating a video display system 1 according to the present embodiment. FIG. 1A is a perspective view of the video display system 1, and FIG. 1B is a side view of the video display system 1.
The video display system 1 includes a reflective screen 10, a video source LS, and the like. The video display system 1 according to the present embodiment is a general video display system in which video light L projected from a video source LS is reflected by a reflective screen 10 and a video is displayed on the screen.
The video display system 1 is not limited to this, and may be, for example, a front projection television system that projects video light from the video source LS, or an input on the observation screen of the reflective screen 10, the video source LS, and the reflective screen. An interactive board system including a position detection unit for detecting the position of the unit and a personal computer may be used.

The video source LS is a device that projects the video light L onto the reflective screen 10, and a general-purpose short focus projector or the like can be used. This image source LS is in the center in the left-right direction of the reflection screen 10 when the screen of the reflection screen 10 is viewed from the normal direction (normal direction of the screen surface) in the use state. It is arranged at a position below the screen (display area).
Note that the screen surface indicates a surface in the planar direction of the reflection screen when viewed as the entire reflection screen, and is used as the same definition in this specification and in the claims. Yes.
The video source LS can project the video light L from a position where the distance from the reflective screen 10 in a direction orthogonal to the screen of the reflective screen 10 (thickness direction of the reflective screen 10) is much closer than that of a conventional general-purpose projector. . That is, the image source LS has a shorter projection distance to the reflection screen 10 and a larger incident angle of the image light L with respect to the reflection screen 10 than a conventional general-purpose projector.

The reflection screen 10 is a screen that displays the image by reflecting the image light L projected by the image source LS toward the observer O side. In the use state, the observation screen of the reflection screen 10 has a substantially rectangular shape with the long side direction being the left-right direction of the screen when viewed from the observer O side.
In the following description, unless otherwise specified, the screen vertical direction, screen horizontal direction, and thickness direction are the screen vertical direction (vertical direction) and screen horizontal direction (horizontal direction) when the reflective screen 10 is used. The thickness direction (depth direction) is assumed.

The reflective screen 10 is provided with a flat plate-like support plate 70 on the back side thereof via a bonding layer (not shown) made of an adhesive material or the like, and the flatness is maintained by the support plate 70. . However, the present invention is not limited thereto, and the reflective screen 10 may be supported by a frame member (not shown) or the like and maintain its flatness.
The reflective screen 10 has a large screen (display area) such as a diagonal of 80 inches or 100 inches.
In the reflective screen 10 of the present embodiment, for example, the screen size is a diagonal size of 80 inches (1771 × 996 mm).

FIG. 2 is a diagram showing a layer configuration of the reflective screen 10 of the present embodiment. In FIG. 2, it passes through the point A (see FIGS. 1A and 1B) which is the geometric center of the observation screen (display area) of the reflection screen 10, is parallel to the vertical direction of the screen, and is on the screen surface. A part of a cross section orthogonal (parallel to the thickness direction) is shown enlarged.
The reflective screen 10 has an optical shape layer 11, a base material layer 12, a light control layer 13, a light diffusion layer 14, a shaping layer 15, a reflective layer 16, and a back surface protective layer 17 in order from the image source side (observer side). Etc.

The optical shape layer 11 is a layer arranged closest to the video source. The optical shape layer 11 has a plurality of unit optical shapes 111 arranged on the image source side surface, and is integrally formed on the image source side surface of the base layer 12.
FIG. 3 is a diagram illustrating the unit optical shape 111 of the present embodiment. FIG. 3A is a diagram of the optical shape layer 11 viewed from the image source side front direction. FIG. 3B is a diagram showing one unit optical shape 111 and an example of image light passing through the unit optical shape 111. FIG. 3B is an enlarged view of the unit optical shape 111 similar to FIG. The layers other than the reflective layer 16 are omitted.
The unit optical shape 111 is convex toward the image source side, and the cross-sectional shape in a cross section parallel to the arrangement direction and the thickness direction (a cross section parallel to the arrangement direction and perpendicular to the sheet surface) is a substantially triangular shape.
The unit optical shape 111 of the present embodiment includes an incident surface 112 on which the projected image light is incident, and a total reflection surface 113 that totally reflects at least part of the light from the incident surface. The unit optical shapes 111 are arranged concentrically around the point C as shown in FIG. This point C is outside the screen of the reflective screen 10 (outside the display area), and is located below the reflective screen 10 and at the center of the screen in the left-right direction. That is, the optical shape layer 11 has a circular Fresnel lens shape including a so-called total reflection type unit lens (unit optical shape 111) on the image source side.
The unit optical shape 111 is not limited to this, and is a substantially triangular prism shape having an incident surface 112 and a total reflection surface 113. The unit optical shape 111 has a shape in which the horizontal direction of the screen is the longitudinal direction and is arranged in the vertical direction of the screen (so-called all-round shape). A reflection type unit lens (linear Fresnel lens shape including unit optical shape 111) may be used.

In the unit optical shape 111, the light L1 from the video source LS is incident on the incident surface 112 and refracted toward the total reflection surface 113 as shown in FIGS. It is totally reflected and goes to the back side (the reflective layer 16 side).
The optical shape layer 11 is provided with the unit optical shape 111 as described above, so that the light beam of the image light projected so as to spread from the obliquely lower side to the reflection screen 10 can be incident on the incident surface 112 and the total reflection surface of the unit optical shape 111. Due to refraction and total reflection at 113, a substantially parallel light beam traveling toward the back side can be obtained.

Each angle (°) shown in FIG. 3B is as follows. Both are in a cross section parallel to the vertical direction of the screen passing through the point A which is the center of the screen and parallel to the thickness direction. Also, the image light L3 shown in FIG. 3B is an example of image light passing through the unit optical shape 111.
Α: angle formed by the image light L3 from the image source LS and the normal direction of the screen surface β: incident angle of the image light L3 on the incident surface 112 γ: refraction angle of the image light L3 on the incident surface 112 Δ: incident angle and reflection angle of the image light L3 on the total reflection surface 113 ε: angle formed by the image light L3 reflected by the total reflection surface 113 and the normal direction of the screen surface ζ: all functioning as an exit surface Incident angle of the image light L3 to the reflection surface 113 η: an emission angle of the image light L3 from the total reflection surface 113 functioning as an emission surface λ: an angle formed by the emitted image light L3 with the normal direction of the screen surface φ: angle formed by the incident surface 112 and the normal direction of the screen surface θ: angle formed by the total reflection surface 113 and the direction parallel to the screen surface

At each angle as described above, the following relational expressions (1) to (7) hold. Here, the refractive index of the unit optical shape 111 is n.
β = 90 ° − (α + φ) (1)
γ = sin ⁻¹ ((sin β) / n) (2)
δ = θ− (γ + φ) (3)
ε = 90 ° − (δ + θ) (4)
ζ = θ−ε (5)
η = sin ⁻¹ (n × sin ζ) (6)
λ = 90 ° − (θ + η) (7)
Therefore, in the cross section shown in FIG. 3B, based on the refractive index n and the angle α, the image light from the image source LS is directed toward the viewer, that is, the angle λ is close to 0 °. , Angles θ and φ are set.
Note that λ can be arbitrarily set in the intended direction. For example, on the line passing through point A and parallel to the screen vertical direction so as to condense to the viewer O side, the screen upper side is the lower side in the screen vertical direction, the center is the horizontal direction (normal direction of the screen surface), and the lower part is The angles θ and φ may be set so that the image light is emitted upward in the vertical direction of the screen.

For easy understanding, FIG. 2 shows an example in which the arrangement pitch and the angles θ and φ of the unit optical shapes 111 are constant in the arrangement direction of the unit optical shapes 111. However, in the arrangement direction of the unit optical shapes 111, the arrangement pitch of the unit optical shapes 111 may be changed, or the angles θ and φ may be changed.
Further, the arrangement pitch of the unit optical shapes 111 is the size of a pixel of the video source LS that projects the video light, the projection angle of the video source LS (the incident angle of the video light on the screen surface of the reflective screen 10), It can be appropriately set according to the screen size of the reflective screen 10, the refractive index of each layer, and the like.
In this embodiment, the unit optical shape 111 has an example in which the cross-sectional shape is a substantially triangular shape. However, the unit optical shape 111 has a function as an image light incident surface and a total reflection surface, and a function as an image light output surface. It is preferable that it is a shape having both, and a shape other than a triangular shape (for example, a substantially trapezoidal shape or the like) may be used.

The optical shape layer 11 may use an ionizing radiation curable resin such as an ultraviolet curable resin such as epoxy acrylate or urethane acrylate, or an electron beam curable resin, an acrylic resin, a styrene resin, a PC (polycarbonate) resin, It can be formed using a thermoplastic resin such as a PET (polyethylene terephthalate) resin.
The optical shape layer 11 is preferably made of a material that is excellent in optical characteristics, mechanical characteristics, stability, workability, and the like and can be obtained at low cost.

Returning to FIG. 2, the base material layer 12 is a layer serving as a base material (base) of the optical shape layer 11 and the light control layer 13, and a sheet-like member having light transmittance is used. An optical shape layer 11 is formed on the image source side of the base material layer 12, and a light control layer 13 is formed on the back side.
The resin for forming the base layer 12 is PET resin, PC resin, MBS (methyl methacrylate / butadiene / styrene) resin, MS (methyl methacrylate / styrene) resin, acrylic resin, TAC (triacetyl cellulose) resin, PEN ( Polyethylene naphthalate) resin and the like. Moreover, the thickness of the base material layer 12 can use about 38-250 micrometers.
In the present embodiment, for example, a sheet-like member made of PET resin having a thickness of 100 μm is used as the base material layer 12.
In addition, the base material layer 12 is good also as a form containing the diffusing material which diffuses light, for the purpose of expanding the viewing angle and improving the uniformity of the luminance in the screen, and adjusting the color tone of the video and improving the contrast. For the purpose, it is good also as a form containing colorants, such as a pigment and dye.

The light control layer 13 is a layer that has a function of controlling a light path of image light and absorbing part of stray light or external light. The light control layer 13 is formed on the back side of the base material layer 12.
The light control layer 13 includes a light transmission part 131 and a light absorption part 132. The light transmission part 131 and the light absorption part 132 extend in parallel in the horizontal direction of the screen, and are alternately arranged in the vertical direction of the screen along a plane parallel to the screen surface (a surface on the back side of the light control layer 13). ing.

FIG. 4 is a diagram illustrating the light control layer 13 of the present embodiment. In FIG. 4, a part of a cross section (cross section parallel to the screen vertical direction and orthogonal to the screen surface) parallel to the screen vertical direction and thickness direction of the light control layer 13 is shown in an enlarged manner.
The light transmission part 131 is an element having a function of transmitting light, and the cross-sectional shape shown in FIG. 4 is a substantially trapezoidal shape. In the light transmission part 131, the dimension W1 of the rear side end in the vertical direction of the screen is smaller than the width W3 of the video source side end.
The light transmission part 131 is formed on the back side of the base material layer 12 with an ionizing radiation curable resin such as an ultraviolet curable resin, a photocurable resin, or the like.

The light absorption part 132 is an element having an action of absorbing light, which is formed in a valley between the light transmission parts 131, and has an action of absorbing external light, stray light, and the like. The light absorbing portion 132 has a substantially wedge shape in cross section as shown in FIG. The wedge shape means a shape that is wide at one end and gradually narrows toward the other end, and includes a triangle shape and a trapezoidal shape.
In the present embodiment, the light absorbing section 132 has a substantially trapezoidal cross-sectional shape as shown in FIG. 4, and the dimension W4 of the image source side end in the vertical direction of the screen is smaller than the dimension W2 of the back side end. In addition, the light absorption part 132 is good also as a substantially triangular shape.

The light absorbing portion 132 is filled with an ionizing radiation curable resin such as an ultraviolet curable resin containing light absorbing particles that absorbs light or a light curable resin by wiping (squeezing) between the light transmitting portions 131 and curing. Is formed.
The light-absorbing particles are preferably colored particles having light-absorbing properties such as organic fine particles colored with metal salts such as carbon black, graphite, black iron oxide, pigments, dyes, and colored glass beads. Moreover, it is good also as a colored particle which selectively absorbs a specific wavelength according to the characteristic of image light. The light absorbing particles preferably have an average particle diameter of 1.0 to 20 μm. If it is smaller than this range, scraping by wiping becomes difficult, and light absorbing particles are likely to remain on the light transmission part 131. If it is larger than this range, it becomes difficult to fill the gaps between the light transmission parts 131.
In addition, the light absorption part 132 is good also as a form which colors the light absorption part 132 whole with a pigment.

  The interface 133 between the light transmitting portion 131 and the light absorbing portion 132 forms an angle of 0 ° or more and 20 ° or less with respect to the normal direction (thickness direction) of the screen surface in the cross section shown in FIG. The interface 133 may be a bent surface formed of a plurality of surfaces in the thickness direction, or may be a curved surface.

When the refractive index of the light transmitting portion 131 is Np and the refractive index of the light absorbing portion 132 is Nb, the magnitude relationship between these refractive indexes can be appropriately set according to the desired optical performance.
For example, in the case of Np> Nb, the image light incident on the interface 133 between the light transmission unit 131 and the light absorption unit 132 at an angle equal to or greater than the critical angle can be totally reflected at the interface 133. Therefore, when Np> Nb, the amount of image light absorbed by the light absorption unit 132 can be reduced, the luminance can be increased, and a bright image can be displayed.
In addition, when Np ≦ Nb, compared with the case where Np> Nb, the light absorbing unit 132 does not totally reflect light incident on the interface between the light transmitting unit 131 and the light absorbing unit 132. Light and stray light can be absorbed efficiently. In particular, when Np> Nb, a part of the external light is incident on the top of the light absorbing unit 132 on the image source side, and the region where the light absorbing particles on the top do not exist or between the light absorbing particles. In the case where Np <Nb, such external light is totally reflected at the interface 133 and confined in the light absorption unit 132, and the light transmission unit 131 is transmitted. The light can be prevented from being emitted to 131. Therefore, when Np ≦ Nb (particularly Np <Nb), the contrast improvement effect can be further enhanced.
In the present embodiment, it is preferable that Np ≦ Np from the viewpoint of enhancing the contrast improvement effect.

As shown in FIG. 4, the arrangement pitch of the light absorption sections 132 (the arrangement pitch of the light transmission sections 131) is P (P = W1 + W2 = W3 + W4). Moreover, the height (dimension in the thickness direction) of the light absorption part 132 is h.
The ratio h / P between the arrangement pitch P and the height h preferably satisfies 0.3 ≦ h / P ≦ 0.8 from the viewpoint of displaying a bright and high-contrast image.
When h / P <0.3, the light absorbing portion 132 provided in the light control layer 13 is sparse, the amount of external light absorbed by the light absorbing portion 132 is reduced, and the contrast improvement effect cannot be obtained. . Further, when h / P> 0.8, the image light absorbed by the light absorbing unit 132 increases, which is not preferable because the image becomes dark. Therefore, the ratio h / P preferably satisfies 0.3 ≦ h / P ≦ 0.8.

The image light incident on the reflection screen 10 is deflected by the optical shape layer 11 in a direction parallel to the normal direction of the screen surface or at a small angle with respect to the normal direction, and is incident on the light transmission portion 131.
In order to display a bright image by transmitting more image light through the light transmission unit 131, the image light can be transmitted through the light transmission unit 131 without reaching the light absorption unit 132. Is preferred. When the light control layer 13 is viewed from the front side on the back side, the ratio of the light absorbing portion 132 to the back side surface of the light control layer 13 is preferably 2% or more and 50% or less, and about 20%. It is preferable that

Returning to FIG. 2, the light diffusion layer 14 has a function of diffusing light, and is integrally laminated on the back side of the light control layer 13. As an example, the light diffusion layer 14 of the present embodiment is laminated on the back side of the light control layer 13 via a light-transmitting bonding layer (not shown).
The light diffusing layer 14 may be a sheet-like member containing a light transmissive resin as a base material and containing a light diffusing material.
The light diffusion layer 14 has a function of widening the viewing angle and improving the in-plane uniformity of brightness.
For example, a PET resin, a PC resin, an MS resin, an MBS resin, an acrylic resin, a TAC resin, a PEN resin, or the like can be used as the resin serving as a base material of the light diffusion layer 14. The thickness of the light diffusion layer 14 is preferably 100 to 500 μm, and more preferably 100 to 250 μm. Further, as the diffusing material, acrylic resin, epoxy resin, silicon-based resin particles, inorganic particles, and the like, and those having an average particle diameter of about 1 to 50 μm can be used.

FIG. 5 is a diagram illustrating the shaping layer 15, the reflective layer 16, and the back surface protective layer 17 according to this embodiment. 5A is a perspective view of the shaping layer 15 and the reflective layer 16 as viewed from the back side, and FIG. 5B is a screen left-right direction of the shaping layer 15, the reflective layer 16, and the back surface protective layer 17. In addition, a part of a cross section parallel to the thickness direction is enlarged.
The shaping layer 15 is a layer integrally formed on the back side of the light diffusion layer 14 and is a layer that imparts a predetermined shape to the reflection surface of the reflection layer 16 described later.
The shaping layer 15 has light transmittance, and a plurality of unit surface shapes 151 are arranged on the surface on the back side. The unit surface shape 151 of the present embodiment is a partial shape of an elliptical cylinder shape that is convex on the back side or a partial shape of a cylindrical shape, and the cross-sectional shape of the cross section parallel to the horizontal direction of the screen and the thickness direction is the same shape. Are extended in the vertical direction, and a plurality are arranged in the horizontal direction of the screen. Therefore, a so-called lenticular lens shape is formed on the back surface of the shaping layer 15.
The shaping layer 15 of the present embodiment is formed on one side (the surface on the back side) of the light diffusion layer 14 by using an UV molding method or the like with an ultraviolet curable resin. For example, the shaping layer 15 may be formed by co-extrusion with the light diffusion layer 14 using a thermoplastic resin such as an acrylic resin or a PET resin.

The reflection layer 16 is a layer having an action of reflecting the image light and returning it to the image source LS side (observer O side). The reflective layer 16 is provided on the back side of the shaping layer 15, that is, on the surface of the unit surface shape 151, and has a function of reflecting light. Therefore, the reflective surface of the present embodiment has a shape along the shape of the lenticular lens on the back surface of the shaping layer 15.
The reflective layer 16 is preferably formed by depositing a metal having high light reflectivity such as aluminum, silver, or chromium, sputtering, or transferring a metal foil. However, the reflective layer 16 is not limited to this, and the reflective layer 16 is an ultraviolet curable resin or thermosetting resin containing a highly reflective white or silver pigment or bead, a metal vapor deposition film such as silver or aluminum, or a metal foil. A coating material containing finely pulverized particles, fine flakes, and the like may be appropriately selected and used, and the forming method may be spray coating, gravure reverse coating, screen printing, inkjet coating, or the like.

Thus, by making the reflective surface of the reflective layer 16 into a lenticular lens shape, the diffusion effect in the horizontal direction of the screen on the reflective surface can be made larger than the diffusion effect in the vertical direction of the screen, and the viewing angle in the horizontal direction of the screen. Can be spread.
In addition, since the shape of the reflecting surface can be controlled by the shape of the shaping layer 15 on the back side, the viewing angle in the horizontal direction of the screen can be controlled more finely.
Note that the arrangement direction of the unit surface shapes 151 may be a direction that forms a predetermined angle with respect to the horizontal direction of the screen depending on the environment in which the reflective screen 10 is used, the desired optical performance, and the like.

The back surface protection layer 17 is a layer provided on the most back surface side (back surface side) of the reflection screen 10, and is a layer that protects the back surface of the reflection screen 10 from scratches and the like. This is a layer that protects against oxidation or the like that is likely to occur when the metal is made of metal.
The back surface protective layer 17 is a reflective layer formed of a sheet-like member made of a PET resin or the like containing a dark pigment such as black, or a dark color fabric such as black via a bonding layer (not shown). 16 may be bonded to the back side of the reflective layer 16 or may be formed by applying and curing an ultraviolet curable resin containing a black pigment or the like on the back side of the reflective layer 16. In this way, by providing the back surface protective layer 17 with a light absorbing action, it is possible to prevent external light from entering from the back side of the reflective screen 10.
Note that the back surface protective layer 17 may have another color, or may be transparent or substantially transparent as long as it can suppress the incidence of external light from the back side, oxidation of the reflective layer 16, and the like.
Further, the back surface protective layer 17 may have a hard coat function, an antistatic function, an antifouling function, an ultraviolet absorption function, or the like.

  Next, the path of external light such as video light and illumination light incident on the reflective screen 10 will be described using the video light L1 and the external light G1 shown in FIG. 2 as an example. However, the optical path examples of the image light L1 and the external light G1 shown in the drawing conceptually represent the path of light, and do not accurately represent the degree of refraction or the angle of reflection. In FIG. 1, the optical shape layer 11, the base material layer 12, the light transmission part 131, the light diffusion layer, and the shaping layer 15 are assumed to have the same refractive index, and the light diffusion layer 14 with respect to the image light L1 and the external light G1. The diffusion action and the like are omitted.

The image light L1 emitted from the image source LS is refracted by being incident from the incident surface 112 of the optical shape layer 11 while spreading radially, and is totally reflected by the total reflection surface 113, and its direction is the normal direction of the screen surface. It is deflected so as to approach, and proceeds to the reflective layer 16 side.
A part of the image light totally reflected by the total reflection surface 113 is transmitted through the base material layer 12 and the light transmission part 131 like the image light L1, and is further transmitted through the light diffusion layer 14 and the shaping layer 15. It reaches the reflection layer 16 and is reflected there.

The image light L1 reflected by the reflection layer 16 changes its direction toward the image source side, passes through the shaping layer 15, the light diffusion layer 14, the light transmission part 131, and the base material layer 12, and is unit optical of the optical shape layer 11. The light is emitted from the total reflection surface 113 that passes through the shape 111 and functions as an emission surface, in the normal direction of the screen surface or in a direction with a small angle with the normal direction. Further, when exiting from the total reflection surface 113, a part of the image light exits in a direction (front direction) closer to the normal direction of the screen surface due to refraction at the interface between the total reflection surface 111b and air. .
Therefore, the reflecting screen 10 efficiently deflects the image light from the image source LS to be incident on the inside of the reflecting screen 10 and deflects the image light reflected by the reflecting layer 16 by the optical shape layer 11. Can be emitted. Therefore, according to the reflective screen 10 of the present embodiment, the light from the video source LS can be appropriately directed toward the observer O in both the screen vertical direction and the screen horizontal direction of the image light, and a bright image can be obtained. Can be displayed.

Further, in the reflection screen 10, unnecessary external light (illumination light, sunlight from a window, etc.) other than the image light is incident mainly from obliquely above the reflection screen 10. Such external light G1 is incident on the interface 133 between the light absorbing portion 132 and the light transmitting portion 131 at an angle less than the critical angle, and is thus absorbed by the light absorbing portion 132. Therefore, according to the reflective screen 10 of the present embodiment, external light can be efficiently absorbed, the black luminance can be reduced, and the contrast of the image displayed on the screen surface can be improved.
From the above, according to the present embodiment, it is possible to display a bright and good video with high contrast.

  Furthermore, according to the present embodiment, the shaping layer 15 and the reflection layer 16 cause the reflection surface to have a strong diffuse reflection effect in the horizontal direction of the screen as compared with the vertical direction of the screen. The viewing angle in the horizontal direction of the screen, which is regarded as important in a display system or the like, can be widened, and a good image can be displayed.

  In addition, when using a conventional reflective screen or short-focus image source LS, or when projecting an image on a large-screen reflective screen, a portion of the image light is reflected on the image source side surface. Due to this, the brightness of the image was lowered, and the image was reflected on the ceiling due to the reflected image light. However, according to the present embodiment, the image light can be efficiently incident on the reflection screen 10 from the incident surface 112, the luminance is improved by improving the use efficiency of the image light, and the reflection of the image light on the ceiling is suppressed. Can be realized.

(Other embodiments)
FIG. 6 is a diagram illustrating a reflective screen 10 according to another embodiment. 6 shows a cross section corresponding to the cross section shown in FIG.
Further, as shown in FIG. 6A, the reflective layer is a reflective layer 26 formed on the back side of the light diffusing layer 14 so that the reflective surface is substantially planar, and includes a shaping layer 15. There may be no form.
In the case of such a form, the viewing angle in the left-right direction of the screen may be narrowed. Therefore, when using such a reflective layer 26, the optical shape layer is preferably the optical shape layer 11 in which the unit optical shapes 111 are arranged concentrically as in the above-described embodiment.

Further, as shown in FIG. 6B, the light absorption unit 332 and the light transmission unit 331 may be alternately arranged along the image source side surface of the light control layer 33. At this time, as shown in FIG. 6B, the light absorbing portion 332 has a configuration in which the size of the end portion on the video source side is larger than the size of the end portion on the back side.
In the case of such a configuration, for example, the light transmission portion 331 is integrally formed on the image source side with the light diffusion layer 14 as a base material (base), and the light control layer 33 and the base material layer 12 are It can be manufactured by bonding with a bonding layer (not shown). Further, in the case of such a configuration, the optical shape layer 11 can be formed on the image source side of the light control layer 33, and the substrate layer 12 is omitted to reduce the thickness, reduce the production cost, and the like. be able to.

Further, as shown in FIG. 6C, the shaping layer 45 has a Fresnel lens shape in which a plurality of unit lenses 451 each having a lens surface 452 and a non-lens surface 453 are arranged, and is reflected by the lens surface 452. The layer 46 may be formed. At this time, as shown in FIG. 6C, it is preferable from the viewpoint of improving the contrast that the non-lens surface 453 is colored with black or the like and covered with the back surface protective layer 47 having a light absorption function.
The Fresnel lens shape of the shaping layer 45 is a circular Fresnel lens shape in which the unit optical shapes 111 are concentrically arranged on the optical shape layer 11 from the viewpoints of in-plane brightness uniformity, image clarity, and the like. In this case, it is preferable that the unit lenses 451 have a circular Fresnel lens shape arranged concentrically, and a plurality of unit optical shapes 111 extend in the horizontal direction of the screen and are arranged in the vertical direction of the screen. In the case of a linear Fresnel lens shape, it is preferable that the unit lens 451 has a linear Fresnel lens shape that extends in the horizontal direction of the screen and is arranged in the vertical direction of the screen.
The shaping layer 45 can be formed on the back side of the light diffusion layer 14 by using an ionizing radiation curable resin such as an ultraviolet curable resin having light permeability.

In the Fresnel lens shape of the shaping layer 45, the arrangement pitch of the unit lenses 451, the angle formed by the lens surface 452 with the plane parallel to the screen surface, or the like may be constant or may vary in the arrangement direction of the unit lenses 451. Also good. The arrangement pitch of the unit lenses 451 can be appropriately changed according to the size of the picture element (pixel) of the video source LS that projects the video light, the screen size of the reflective screen 10, the refractive index of each layer, and the like.
In addition, you may combine each above-mentioned embodiment suitably, respectively.

(Deformation)
The present invention is not limited to the embodiment described above, and various modifications and changes are possible, and these are also within the scope of the present invention.
(1) In this embodiment, the unit optical shape 111 of the optical shape layer 11 has the incident surface 112 and the total reflection surface 113. However, the present invention is not limited to this, and the optical shape layer is not a lens surface. An optical shape layer having a Fresnel lens shape (refractive Fresnel lens shape) in which a plurality of unit lenses having a lens surface are arranged may be used. When such an optical shape layer is provided, the image light is deflected so as to enter the lens surface and travel toward the back side by refraction at the lens surface.

(2) In the present embodiment, the unit optical shape 111 formed in the optical shape layer 11 is one type. However, the present invention is not limited to this. Different types may be used in combination.
In the present embodiment, the unit optical shape 111 has an example including only the incident surface 112 and the total reflection surface 113. For example, the unit optical shape 611 of the optical shape layer 61 of the modified form shown in FIG. It is good.
FIG. 7 is a diagram showing a modified optical shape layer 61.
The unit optical shape 611 of the optical shape layer 61 of this modification is a hybrid unit optical shape having a first shape 611A and a second shape 611B.
The first shape 611A includes an incident surface 612 and a total reflection surface 613, and is a part of the shape of the unit optical shape 111 shown in the above-described embodiment.
The second shape 611B is adjacent to the lower side in the vertical direction of the screen of the first shape 611A, faces the incident surface 612, and has a third surface 614 that is an incident surface on which light is incident, and the third surface 614 and a convex shape. And a part of the shape of a so-called refractive Fresnel lens unit lens.
By using such an optical shape layer 61, the light L5 incident on the third surface 614 can be refracted at the interface (third surface 614) and directed toward the back side.

(3) In the present embodiment, the light diffusion layer 14 has been described with reference to an example in which the light diffusion layer 14 is disposed between the light control layer 13 and the shaping layer 15. 13 may be arranged, and the position is not particularly limited. Moreover, when the base material layer 12 contains a diffusing material, the light diffusing layer 14 may not be provided.

(4) In the present embodiment, the light absorbing unit 132 has an example in which the cross-sectional shape in the cross section parallel to the screen vertical direction and the thickness direction is a symmetric shape in the screen vertical direction. The shape may be asymmetric in the vertical direction. For example, the light absorber 132 may be configured such that the angle formed by the upper interface 133 with the normal direction of the screen surface in the vertical direction of the screen is different from the angle formed by the lower interface 133 with the normal direction of the screen surface. Alternatively, one interface 133 may be a folded surface.
Further, the angle formed by the interface 133 between the light transmission part 131 and the light absorption part 132 and the normal direction of the screen surface may be changed gradually or stepwise along the vertical direction of the screen. The arrangement pitch of the light transmission part 131 and the light absorption part 132 may be changed gradually or stepwise along the vertical direction of the screen.

  Further, in the present embodiment, the light transmission part 131 and the light absorption part 132 both show an example in which the cross-sectional shape is a trapezoidal shape. However, the present invention is not limited thereto, and for example, the light transmission part 131 and the light absorption part 132. May have a substantially rectangular cross-sectional shape. When the cross-sectional shape is rectangular, the angle formed by the interface between the light transmitting portion and the light absorbing portion with the normal direction of the screen surface may be 0 °, and the back side end of the light absorbing portion is the image source side end. It may have an inclination that is located on the upper side in the vertical direction of the screen. In this case, the angle formed by the interface between the light transmission part and the light absorption part with the normal direction of the screen surface is preferably 0 ° or more and 10 ° or less.

(5) In the present embodiment, the example in which the light control layer 13 is only one layer has been described. However, the present invention is not limited to this. For example, the light transmission unit and the light absorption unit have the vertical direction of the screen as the longitudinal direction, A second light control layer arranged in the direction may be further stacked. The arrangement direction of the light transmission part and the light absorption part of the second light control layer is orthogonal to the arrangement direction of the light transmission part 131 and the light absorption part 132 of the light control layer as seen from the normal direction of the screen surface. .
By setting it as such a form, the light beam control effect | action in a screen up-down direction and a screen left-right direction can be exhibited, and effects, such as a reduction of stray light and a contrast improvement, can be show | played.

(6) In the present embodiment, the shaping layer 15 has been described by taking an example having a lenticular lens shape, but the present invention is not limited to this, and the following form may be employed.
FIG. 8 is a diagram for explaining an example of another shape of the shaping layer 15. FIG. 8 shows a cross section orthogonal to the screen surface of the shaping layer 15 and parallel to the horizontal direction of the screen. In each of FIGS. 8A to 8D, the lower side in the figure is the image source LS side. Yes, the upper side in the figure is the back side (back side protective layer 17 side).
For example, as shown in FIG. 8A, the unit surface shape formed on the surface on the back side of the shaping layer 15 may be a substantially sinusoidal shape, or as shown in FIG. It is good also as a shape which consists of two curved surfaces from which. Moreover, as shown in FIG.8 (c), it is good also as a shape asymmetrical in a screen left-right direction, and it is good also as a shape which combined the plane and the curved surface as shown in FIG.8 (d). Furthermore, although not shown, the unit surface shape may be a shape obtained by combining a plurality of curved surfaces or a plurality of planes.
By appropriately selecting the shape on the back side of the shaping layer 15, the diffusibility in the left-right direction of the screen can be made more preferable according to the position of the video source LS, the position of the observer O, and the like. For example, in the case of the shape shown in FIG. 8C, the diffusibility in the horizontal direction of the screen can be highly directional.

(7) The reflective screen 10 of this embodiment may be provided with a colored layer. This colored layer is a layer containing a colorant such as a pigment or a dye, and has an effect of improving the contrast or adjusting the color tone. Such a colored layer may be formed integrally with the light diffusion layer 14 by, for example, co-extrusion molding with the light diffusion layer 14 and disposed on the image source side of the light diffusion layer.
In addition, the position of the colored layer, the formation method, and the like are not limited to the above examples, and can be selected as appropriate.

  In addition, although this embodiment and modification can also be used in combination as appropriate, detailed description is abbreviate | omitted. Further, the present invention is not limited by the embodiments described above.

DESCRIPTION OF SYMBOLS 1 Image display system 10 Reflective screen 11 Optical shape layer 111 Unit optical shape 111a Incident surface 111b Total reflection surface 12 Base material layer 13,33 Light control layer 131,331 Light transmission part 132,332 Light absorption part 14 Light diffusion layer 15, 45 Shaped layer 16, 26 Reflective layer LS Image source

Claims (7)

A reflection screen that reflects image light projected from an image source and displays the image light so as to be observable;
A reflective layer provided on the back side and reflecting light;
An optical shape layer that is provided closer to the image source than the reflective layer, a plurality of unit optical shapes are arranged on the surface of the image source, and deflects image light toward the reflective layer;
A light control layer provided on the back side of the optical shape layer and on the image source side of the reflective layer, wherein light transmitting portions and light absorbing portions are alternately arranged in the vertical direction of the screen along the screen surface; ,
With
The unit optical shape is a substantially triangular shape in which a cross-sectional shape in a direction parallel to the arrangement direction and orthogonal to the screen surface is convex toward the image source side,
Reflective screen featuring. The reflective screen according to claim 1.
Provided on the image source side of the reflective layer, comprising a shaping layer that shapes the shape on the image source side of the reflective layer,
The shaping layer has a plurality of unit surface shapes arranged on the surface on the reflective layer side,
Reflective screen featuring. The reflective screen according to claim 2,
The unit surface shape is convex on the back side, the screen vertical direction is a longitudinal direction, and a plurality of unit surface shapes are arranged in the screen horizontal direction,
Reflective screen featuring. The reflective screen according to any one of claims 1 to 3,
The unit optical shape has an incident surface on which light is incident, and a total reflection surface that totally reflects at least a part of the light from the incident surface toward the back side,
Reflective screen featuring. The reflective screen according to any one of claims 1 to 4, wherein:
The light absorbing portion has a substantially wedge-shaped cross section in a cross section that is parallel to the arrangement direction and orthogonal to the screen surface;
Reflective screen featuring. The reflection screen according to any one of claims 1 to 5,
The light transmission part has a substantially trapezoidal cross-sectional shape in a cross section that is parallel to the arrangement direction and orthogonal to the screen surface, and the width on the image source side is larger than the width on the back side,
Reflective screen featuring. The reflective screen according to any one of claims 1 to 6,
An image source for projecting image light onto the reflective screen;
A video display system comprising:

Images