JP6476812B2 - Reflective screen, video display system - Google Patents

Description

  The present invention relates to a reflection screen and an image display system for displaying an image by reflecting projected image light.

  Conventionally, reflective screens having various configurations have been developed and used in video display systems. In recent years, short focus type video projection devices (projectors) that project a video light at a relatively large projection angle from a close distance to a reflective screen to realize a large screen display have been widely used. Reflective screens and the like have also been developed for satisfactorily displaying video light projected by a short focus type video projector.

The short focus type image projection apparatus can project image light at a larger projection angle than the conventional image source from above or below the reflection screen, and the distance in the depth direction between the image projection apparatus and the reflection screen. Therefore, it is possible to 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, a lens layer having a linear Fresnel lens shape or a circular Fresnel lens shape formed by arranging a plurality of unit lenses. Various reflective screens having a reflective layer formed on the surface have been developed (for example, see Patent Document 1).

The reflective screen of Patent Document 1 includes a lens layer having a circular Fresnel lens shape. Since such a lens layer is formed on a sheet-like base material with an ultraviolet curable resin or the like, it is necessary to manufacture each lens layer one by one, and it is not possible to improve the manufacturing efficiency, and the manufacturing cost is also expensive. There was a case.
Here, a linear Fresnel lens shape is applied to the lens layer, and the lens layer is sequentially formed on the wound substrate, so that the lens layer is formed by a so-called roll conveyance method, thereby improving the manufacturing efficiency and reducing the manufacturing cost. However, in this case, there arises a problem that the luminance distribution in the screen surface of the reflective screen becomes non-uniform as compared with the circular Fresnel lens shape.

JP 2008-76523 A

  An object of the present invention is to provide a reflective screen and an image display system that can improve the manufacturing efficiency, reduce the manufacturing cost, and make the luminance distribution in the screen surface uniform.

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 according to claim 1 is a reflective screen (20) for reflecting video light projected from a video source (LS) arranged above or below the screen in the vertical direction and displaying it on the screen, on the video source side A lens layer (23) which is convex on the back side opposite to the surface and extends in the vertical direction of the screen, and a plurality of unit optical shapes (231) arranged in the horizontal direction of the screen along the screen surface, and the back side of the lens layer A reflection layer (22) for reflecting light, a first light transmission part (252) and a second light transmission part (253) provided on the image source side of the lens layer for transmitting light, Light control layers (25) alternately arranged in the vertical direction of the screen along the screen surface, and the second light transmission part (253) is in a cross section parallel to the thickness direction and parallel to the vertical direction of the screen. The cross-sectional shape is wide at the edge of the image source side, Only in that it is formed in a wedge shape whose width gradually becomes narrow, a reflective screen according to claim.
According to a second aspect of the present invention, in the reflective screen (20) according to the first aspect, the refractive index of the second light transmission part (253) is smaller than the refractive index of the first light transmission part (252). The reflective screen characterized by these.
According to a third aspect of the present invention, in the reflective screen (20) according to the first or second aspect, the second light transmission part (253) forms an interface with the first light transmission part (252). Of the slopes, an angle α formed by a slope (253a) on the same side as the side where the image source is arranged in the screen vertical direction and a plane parallel to the screen surface is formed in a range of 60 ° ≦ α ≦ 80 °. It is the reflective screen characterized by being made.
According to a fourth aspect of the present invention, there is provided a video display comprising the reflective screen (20) according to any one of the first to third aspects and a video source (LS) that projects video light onto the reflective screen. System (1).

  According to the present invention, it is possible to provide a reflective screen and an image display system that can improve the manufacturing efficiency, reduce the manufacturing cost, and make the luminance distribution in the screen surface uniform.

It is a figure explaining the video display system of an embodiment. It is a figure explaining the layer structure of the reflective screen of embodiment. It is a figure explaining the lens layer of embodiment. It is a figure explaining the detail of the light control layer of embodiment. It is a figure explaining the manufacturing method of the reflective screen of an embodiment. It is a figure explaining the manufacturing method of the reflective screen of an embodiment. It is a figure which shows the reflective screen of a deformation | transformation form.

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, words such as plate and sheet are used, but these are generally used in the order of thickness, plate, sheet, and film in order of increasing thickness. I use it. However, there is no technical meaning in such proper use, so these terms 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.

(First 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 unit 10 including a reflective screen 20, a video source LS, and the like. In the video display system 1 of the present embodiment, the reflective screen 20 reflects the video light L projected from the video source LS, and displays the video on the screen.
The video display system 1 can be used as, for example, a front projection television system that projects video light L from a video source LS.

The video source LS is a video light projection device that projects the video light L onto the reflection screen 20. The video source LS of this embodiment is a general-purpose short focus projector. When the image source LS is in use and the screen of the reflection screen 20 is viewed from the normal direction (normal direction of the screen surface), the image source LS is the center in the horizontal direction of the screen of the reflection screen 20 and the image of the reflection screen 20 It is arranged at a position below the (display area).
The screen surface refers to a surface that is the planar direction of the reflective screen 20 when viewed as the entire reflective screen 20.
The video source LS can project the video light L from a position where the distance from the reflective screen 20 in a direction orthogonal to the screen of the reflective screen 20 (thickness direction of the reflective screen 20) 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 20 and a larger incident angle of the image light L with respect to the screen surface of the reflection screen 20 than a conventional general-purpose projector.

The reflection screen 20 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 20 has a substantially rectangular shape with the long side direction being the horizontal direction of the screen when viewed from the observer O side.
In the following description, the screen vertical direction, the screen horizontal direction, and the thickness direction are the screen vertical direction (vertical direction), the screen horizontal direction (horizontal direction), and thickness when the reflective screen 20 is used unless otherwise specified. The direction (depth direction) is assumed.
The reflective screen 20 has a large screen (display area) such as a diagonal of 80 inches, 100 inches, or 120 inches.

  The video display system 1 of the present embodiment includes a video source LS that is a short focus type projector, and a reflective screen 20 that displays video by reflecting video light projected from the video source LS. However, the present invention is not limited to this, and the image source LS is a conventional general-purpose projector having a long projection distance and a small image light projection angle (that is, an incident angle of the image light on the screen), and the reflection screen 20 is such a projector. It may correspond to the video source LS.

  The reflective screen unit 10 includes a reflective screen 20, a flat support plate 30 disposed on the back side thereof, and a bonding layer 40. The reflection screen 20 and the support plate 30 are integrally bonded via a bonding layer 40.

The support plate 30 is not particularly limited as long as it is a member having high rigidity. For example, a metal plate material such as aluminum or a resin plate material such as acrylic resin is preferably used. . Also, a metal plate material (so-called honeycomb panel) that reduces the overall weight of the plate material by providing a honeycomb structure formed of a thin plate of aluminum or the like on the front and back surfaces and a thin plate of aluminum or the like as an internal core material. Etc. may be used. Moreover, it is preferable that the support plate 30 is a member which does not have a light transmittance from a viewpoint of preventing the reflection of external light, the contrast fall by external light, etc.
In many cases, the reflective screen 20 is thin and does not have sufficient rigidity to maintain flatness by itself. For this reason, the reflection screen 20 maintains the flatness of the screen by being integrally joined to the support plate 30.

  The bonding layer 40 is a layer having a function of bonding the reflective screen 20 and the support plate 30 together. The bonding layer 40 is formed of a pressure sensitive adhesive, an adhesive, or the like.

FIG. 2 is a diagram illustrating the layer configuration of the reflective screen 20 of the present embodiment.
In FIG. 2A, it passes through a point A (see FIGS. 1A and 1B) that is the geometric center (center of the screen) of the observation screen (display area) of the reflection screen 20, and is parallel to the vertical direction of the screen. However, a part of a cross section perpendicular to the screen surface (parallel to the thickness direction) is shown enlarged. FIG. 2B shows a bb cross section of FIG.
As shown in FIG. 2, the reflective screen 20 has a surface layer 26, a light control layer 25, a base material layer 24, a lens layer 23, a reflective layer 22, in order from the image source side (observer side) in the thickness direction. A protective layer 21 and the like are provided.

The base material layer 24 is a sheet-like member that serves as a base of the reflective screen 20. A light control layer 25 is formed on the image source side of the base material layer 24, and a lens layer 23 is formed on the back side (back side).
The base material layer 24 has a light diffusing layer 241 containing a diffusing material and a colored layer 242 containing a coloring material such as a pigment or a dye. The base material layer 24 of this embodiment is formed by integrally laminating a light diffusion layer 241 and a colored layer 242 by coextrusion molding.
In the present embodiment, as shown in FIG. 2, in the base material layer 24, the light diffusion layer 241 is on the back side and the coloring layer 242 is positioned on the image source side. The diffusion layer 241 may be positioned on the video source side and the colored layer 242 may be positioned on the back side.

The light diffusion layer 241 is a layer that contains a light transmissive resin as a base material and contains a light diffusing material. The light diffusion layer 241 has a 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 241 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 material contained in the light diffusion layer 241, particles made of resin such as acrylic resin, epoxy resin, or silicon resin, inorganic particles, and the like are preferably used. Note that the diffusion material may be a combination of an inorganic diffusion material and an organic diffusion material. This diffusing material is preferably substantially spherical and has an average particle diameter of about 1 to 50 μm. Moreover, it is preferable that the range of the particle size of the diffusing material suitable for use is 5 to 30 μm.
The thickness of the light diffusion layer 241 is preferably about 50 to 1000 μm, although it depends on the screen size of the reflection screen 20 and the like. The light diffusion layer 241 preferably has a haze value in the range of 85 to 99%. The thickness of the light diffusion layer 241 of this embodiment is formed to be about 150 μm.

The colored layer 242 is a layer colored with a dark colorant such as black so as to have a predetermined light transmittance. The colored layer 242 has a function of improving the contrast of an image by absorbing unnecessary external light such as illumination light incident on the reflective screen 20 and reducing the black luminance of the displayed image.
As the colorant of the colored layer 242, a dark dye such as gray or black, a pigment, a metal salt such as carbon black, graphite, black iron oxide, or the like is preferably used.
As a resin which is a base material of the coloring layer 242, a PET resin, a PC resin, an MS resin, an MBS resin, a TAC resin, a PEN resin, an acrylic resin, or the like can be used.
The colored layer 242 preferably has a thickness of about 30 to 2000 μm, although it depends on the screen size of the reflective screen 20 and the like. The thickness of the colored layer 242 of the present embodiment is about 70 μm.

FIG. 3 is a diagram illustrating the lens layer 23 of the present embodiment.
FIG. 3A shows a state in which the lens layer 23 and the reflective layer 22 are observed from the front side on the back side, and the protective layer 21 and the like are omitted for easy understanding. FIG. 3B shows a part of the cross section shown in FIG. 2B in an enlarged manner, and in order to facilitate understanding, the base material layer 24 positioned on the image source side, the light control layer 25, The surface layer 26 is omitted.

The lens layer 23 is a layer integrally formed on the back side of the base material layer 24, and is a layer that imparts a predetermined shape to the reflection surface of the reflection layer 22 described later.
The lens layer 23 has optical transparency, and a plurality of unit optical shapes 231 are arranged on the back surface thereof. As shown in FIG. 3, the unit optical shape 231 of the present embodiment is a partial shape of an elliptical column shape or a cylindrical shape that is convex on the back side, and is a cross section parallel to the horizontal direction of the screen and the thickness direction. The cross-sectional shape of each extends in the vertical direction of the screen while maintaining the same shape, and a plurality of cross-sectional shapes are arranged in the horizontal direction of the screen. Therefore, a so-called lenticular lens shape is formed on the back surface of the lens layer 23.

The lens layer 23 is integrally formed on the back surface side of the light diffusion layer 241 of the base material layer 24 by using a UV molding method or the like with an ultraviolet curable resin such as urethane acrylate or epoxy acrylate. The lens layer 23 may be formed of another ionizing radiation curable resin such as an electron beam curable resin, or may be a thermoplastic resin.
As shown in FIG. 3B, the arrangement pitch of the unit optical shapes 231 with the adjacent unit optical shapes is P1, and the unit optical shape is closest to the point b closest to the observer in the thickness direction of the lens layer 23. The distance (lens height) from the point t on the back side is h1. The lens layer 23 of the present embodiment is formed so that the unit optical shape 231 has an arrangement pitch P1 of 65 μm and a height h1 of 12 μm. Since the unit optical shapes 231 are arranged adjacent to each other in the horizontal direction of the screen, the arrangement pitch P1 is equal to the width dimension of the unit optical shapes 231 in the horizontal direction of the screen.

The reflection layer 22 is a layer having an action of reflecting the image light and returning it to the image source LS side (observer O side). The reflection layer 22 is provided on the back side of the lens layer 23, that is, on the surface of the unit optical shape 231 and has a function of reflecting light. Therefore, the reflecting surface of the present embodiment has a shape that follows the shape of the lenticular lens on the back surface of the lens layer 23.
The reflective layer 22 is preferably formed by depositing a metal having high light reflectivity such as aluminum, silver, or chromium, sputtering, or transferring a metal foil. The reflective layer 22 is not limited to this, and the reflective layer 22 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 reflection surface of the reflection layer 22 into a lenticular lens shape, the diffusion effect in the horizontal direction of the screen on the reflection surface can be made larger than the diffusion effect in the vertical direction of the screen. In comparison, it is possible to widen the viewing angle in the horizontal direction of the screen while maintaining the front luminance.
In addition, since the shape of the reflecting surface can be controlled by the shape of the lens layer 23 on the back side, the viewing angle in the horizontal direction of the screen can be controlled more finely.

The protective layer 21 is a layer provided on the most back side (back side) of the reflective screen 20, and is a layer that protects the back surface of the reflective screen 20 from scratches and the like. It is a layer that protects against oxidation or the like that easily occurs when it is made of metal.
The protective layer 21 is a reflective layer 22 formed of a sheet-like member made of PET resin or the like containing a dark pigment such as black, or a dark-colored fabric such as black via a bonding layer (not shown). It may be provided by being bonded to the back surface side, or may be formed by applying and curing an ultraviolet curable resin containing a black pigment or the like on the back surface side of the reflective layer 22. Thus, by providing the protective layer 21 with a light absorbing action, it is possible to prevent the incidence of external light from the back side of the reflective screen 20.
Note that the protective layer 21 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 22, and the like.
The protective layer 21 may have a form having a hard coat function, an antistatic function, an antifouling function, an ultraviolet absorbing function, or the like.

  FIG. 4 is a diagram illustrating the light control layer 25 of the present embodiment. FIG. 4A shows the cross section shown in FIG. 2A further enlarged, and in order to facilitate understanding, the protective layer 21, the reflective layer 22, the lens layer 23, the base material layer 24, and the surface layer 26 are illustrated. Is omitted. FIG. 4B shows an enlarged part of the light control layer 25 as viewed from the front direction on the image source side (observer side).

The light control layer 25 includes a base material portion 251 and an optical shape portion 254, and is laminated on the viewer side of the base material layer 24 via a bonding layer (not shown) as shown in FIG. Has been.
The base material portion 251 is formed from a transparent member having light permeability, and is a layer that serves as a base of the light control layer 25. The base material portion 251 uses a sheet-like member.
Examples of the material for forming the base portion 251 include PC resin, PET resin, triacetyl cellulose (TAC) resin, ABS resin, MBS resin, and MS resin. Moreover, it is preferable that the thickness of the base material part 251 shall be 38-250 micrometers.

The optical shape portion 254 is integrally laminated on the surface of the base material portion 251 on the viewer side, and includes a plurality of first light transmission portions 252 and second light transmission portions 253.
The first light transmission part 252 is formed of a transparent member having light transmittance, and extends in the left-right direction of the screen as shown in FIG. Are arranged in the vertical direction along the screen. As shown in FIG. 4A, the cross-sectional shape parallel to the arrangement direction (the screen vertical direction) of the first light transmission parts 252 and parallel to the thickness direction of the reflection screen 20 It is a substantially trapezoidal shape in which the back side is a lower base having a size larger than that of the upper base.
The first light transmission part 252 of the present embodiment is integrally formed on the back side surface of the base part 251 with an ultraviolet curable resin such as urethane acrylate. However, the present invention is not limited to this, and an electron beam curable resin or the like. Other ionizing radiation curable resins may be used.
Further, the first light transmission part 252 may be formed by hot melt extrusion using a thermoplastic resin such as a PET resin.
The first light transmission part 252 may be provided directly on the surface on the viewer side of the base material layer 24 without being provided on the base material part 251 described above. In this case, the layer configuration of the reflective screen can be reduced, and the manufacturing process and manufacturing cost of the reflective screen can be reduced.

The second light transmission part 253 is formed of a transparent member having light transmittance, and is formed in a valley-like portion between the adjacent first light transmission parts 252 as shown in FIG. , A portion having an action of transmitting light. Here, the term “transparent” means not only a state where the transparency is high and completely transparent, but also a state including a substantially transparent state, in which incident light can be transmitted and emitted without being diffused. Including those having a transparency of.
As shown in FIGS. 4A and 4B, the second light transmission portion 253 extends in the horizontal direction of the screen and extends in the vertical direction of the screen along the surface of the light control layer 25 on the image source side. The first light transmission unit 252 and the first light transmission unit 252 are alternately arranged. Therefore, in this embodiment, the image source side surface of the light control layer 25 is formed by the image source side surface of the first light transmission unit 252 and the image source side surface of the second light transmission unit 253.
The second light transmission portion 253 has a wedge-shaped cross section in a cross section parallel to the arrangement direction (up and down direction of the screen) and parallel to the thickness direction of the reflection screen. As used herein, the wedge shape refers to a shape in which one end is wide and gradually narrows toward the other, and includes a triangular shape, a trapezoidal shape, and the like. In the present embodiment, as shown in FIG. 4A, the second light transmission portion 253 has a cross-sectional shape that is a substantially triangular shape with the video source side as a base.

The second light transmission part 253 is formed so that its refractive index is smaller than the refractive index of the first light transmission part 252. In the present embodiment, for example, the refractive index of the first light transmission part 252 is 1.56, and the refractive index of the second light transmission part is 1.49.
The second light transmission part 253 is formed, for example, by wiping (squeezing) the resin between the first light transmission parts 252 with a light transmissive resin, filling the valley, and curing the resin.
As the resin having optical transparency used for the second light transmission part 253, an ionizing radiation curable resin such as an ultraviolet curable resin such as urethane acrylate or epoxy acrylate or an electron beam curable resin is preferably used. In addition, in order to make the refractive index of the 2nd light transmission part 253 smaller than the refractive index of the 1st light transmission part 252, the resin which has the light transmittance used for the 2nd light transmission part 253 is the 1st light transmission part. It is preferable to select a resin having a refractive index smaller than that of the resin forming 252.
In this embodiment, an epoxy acrylate resin is selected for the first light transmission part 252 and a urethane acrylate resin is selected for the second light transmission part 253, and the refractive index difference is provided as described above.

As shown in FIG. 4A, the arrangement pitch of the first light transmission parts 252 (second light transmission parts 253) is P2, and the thickness of the optical shape part 254 (thickness of the first light transmission part 252). Is D, the dimension of the upper base of the first light transmission part 252 in the arrangement direction of the first light transmission part 252 and the second light transmission part 253 is W2, and the dimension of the bottom side of the second light transmission part 253 is W1.
In addition, the dimension (thickness) of the second light transmission portion 253 in the thickness direction of the reflective screen 20 is H. Of the interface between the first light transmission part 252 and the second light transmission part 253, the slope 253a on the lower side of the screen in the vertical direction of the second light transmission part 253 (the side on which the video source LS is arranged) is the screen surface. The angle formed is α, and the angle formed by the inclined surface 253b on the upper side in the vertical direction of the screen of the second light transmitting portion 253 (the side opposite to the side where the video source LS is disposed) with the screen surface is β.

With the above configuration, the reflection screen 20 of the present embodiment allows a part of the light incident on the first light transmission unit 252 out of the image light projected from the video source LS to be inclined by the inclined surface 253a of the second light transmission unit 253. It can be totally reflected toward the lens layer 23, reflected by the reflecting layer 22, and emitted from the screen surface (see L1 and L2 in FIG. 2A).
Further, the light incident on the second light transmission part among the light reflected by the reflection layer 22 is refracted at the interface (slope 253a) between the first light transmission part 252 and the second light transmission part 253, so that the observer It can radiate | emit to the side (refer L1 of Fig.2 (a)).
Thereby, the light control layer 25 reflects the light projected from the video source LS disposed on the lower side of the reflective screen 20 in a direction substantially parallel to the thickness direction of the reflective screen 20 on the viewer side. Can do.

Here, the angle α is formed in the range of 60 ° ≦ α ≦ 80 ° from the viewpoint of efficiently totally reflecting the image light projected from the image source toward the lens layer 23 side in the second light transmitting portion 253. Is desirable.
If the angle α is less than 60 °, it is not desirable because the image light hardly enters the inclined surface 253a and the light use efficiency decreases. Even if the light is totally reflected, the degree of change in the angle of the totally reflected light is so small that the image light cannot be properly reflected to the observer side, which is not desirable.
On the other hand, when the angle α is larger than 80 °, it is difficult to totally reflect the image light projected from the image source, which is not desirable. Even if the light is totally reflected, the degree of change in the angle of the totally reflected light is so large that the image light may not be properly reflected to the viewer side, which is not desirable.

In the present embodiment, the arrangement pitch P2 of the second light transmission parts 253 is 100 μm, the thickness D of the optical shape part 254 is 130 μm, the dimension W2 of the upper base of the first light transmission part 252 is 70 μm, The dimension W1 of the bottom side of the two light transmission parts 253 is 30 μm. The height H of the second light transmission part is 100 μm, the angle α formed between the inclined surface 253a of the second light transmission part 253 and the screen surface is 73 °, and the angle β formed between the inclined surface 253b and the screen surface. Is 90 °.
In the present embodiment, the values of P2, D, W1, W2, H, α, and β are constant. However, the present invention is not limited to this, and each value depends on the position of the screen surface. It may be changed as appropriate.

The surface layer 26 is a layer provided on the image source side (observer side) of the light control layer 25. The surface layer 26 of the present embodiment forms the outermost surface of the reflection screen 20 on the image source side.
The surface layer 26 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 provided on the surface of the light control layer 25 on the image source side. The ionizing radiation curable resin is applied so that the film thickness of the coating film is about 10 to 100 μm, and the fine uneven shape (mat shape) is cured by transferring it to the surface of the resin film. Is shaped and formed. In the present embodiment, the surface layer 26 has a surface roughness in the range of 0.1 to 3 μm and a haze value in the range of 5 to 20%. The surface layer 26 of the present embodiment is formed with a film thickness of about 30 μm.

The surface layer 26 is not limited to the above example, and one or more necessary functions such as an antireflection function, an antiglare function, a hard coat function, an ultraviolet absorption function, an antifouling function, and an antistatic function are appropriately selected. Can be provided. Further, a touch panel layer or the like may be provided as the surface layer 26.
Further, the surface layer 26 may be provided with a layer having an antireflection function, an ultraviolet absorption function, an antifouling function, an antistatic function, or the like as a separate layer between the surface layer 26 and the light control layer 25.
Further, the surface layer 26 may be a layer separate from the light control layer 25 and bonded to the light control layer 25 by an adhesive material (not shown), or on the image source side surface of the light control layer 25. You may form directly.

Returning to FIG. 2A, the state of image light and external light incident on the reflection screen 20 of this embodiment will be described. In FIG. 2A, for easy understanding, it is assumed that the refractive index of the surface layer 26, the colored layer 242, the light diffusion layer 241, and the lens layer 23 is the same, and the light diffusion layer 241 with respect to the image lights L1 and L2 The light diffusing action and the like are omitted.
As shown in FIG. 2A, most of the image light L (L1, L2) projected from the image source LS is incident from below the reflection screen 20, and the surface layer 26, the light control layer 25, the base material The light passes through the layer 24 and enters the lens layer 23.

Then, the image light enters the unit optical shape 231, is reflected by the reflection layer 22, and exits to the observer O side. Therefore, since the image light L is efficiently reflected and reaches the observer O side, a bright image can be displayed.
At this time, of the image light projected from the image source LS, a part of the light L1 and L2 incident on the first light transmitting portion 252 of the light control layer 25 is the second as shown in FIG. The light is totally reflected at the inclined surface 253 a of the light transmitting portion 253 and enters the lens layer 23.
Then, the light is reflected by the reflection layer 22 provided on the back side of the lens layer 23, and a part L 1 of the reflected light is transmitted through the first light transmission part 252 and enters the second light transmission part 253. At this time, the light L1 is refracted at the interface (inclined surface 253a) between the first light transmission unit 252 and the second light transmission unit 253 and then enters the second light transmission unit 253. The reflection screen 20 is substantially parallel to the thickness direction. In addition, the other part of the light L2 reflected from the reflective layer 22 is transmitted only through the first light transmission part 252 and is emitted from the screen surface.
Thereby, the reflection screen 20 can reflect the light projected from the video source LS disposed on the lower side of the reflection screen 20 toward the viewer in a direction substantially parallel to the thickness direction of the reflection screen 20. it can.
Further, since the reflection screen 20 is provided with the unit optical shape 231 in the lens layer 23, the image light can be reflected not only in the front direction of the screen surface but also in the left-right direction of the screen. The luminance distribution can be made uniform.

Next, the manufacturing method of the reflective screen 20 of this embodiment is demonstrated.
FIG. 5 is a diagram illustrating a method for manufacturing the reflective screen 20 of the present embodiment.
FIG. 6 is a diagram illustrating a method for manufacturing the reflective screen 20 of the present embodiment.
Here, each figure of FIG.5 and FIG.6 shows a cross section parallel to the thickness direction of a reflective screen, and parallel to a screen up-down direction.

First, a base material portion 251 made of a web-like PC resin sheet is prepared, and an optical shape portion 254 is formed on the surface of the base material portion 251 on the viewer side by a roll conveyance method to constitute the light control layer 25. .
Specifically, as shown in FIG. 5A, an epoxy acrylate-based ultraviolet curable resin is applied to the surface of the base member 251 on the image source side, and the first light transmission part 252 is shaped. A plurality of first light transmission parts 252 are sequentially formed on the base part 251 by pressing the mold roll and curing it by irradiating ultraviolet rays and then releasing the mold roll from the mold roll.
Next, as shown in FIG. 5B, the surface of the first light transmission part 252 formed on the base part 251 (the surface on the back side) is filled with a urethane acrylate-based ultraviolet curable resin, A two-light transmission part 253 is formed. Specifically, the second light transmission portion 253 is formed by filling a valley portion between adjacent first light transmission portions 252 with an ultraviolet curable resin by a doctor blade and irradiating and curing with ultraviolet rays. Thus, the light control layer 25 is formed.
As described above, the light control layer 25 is produced by sequentially forming a plurality of first light transmission parts 252 and second light transmission parts 253 on the web-shaped base material part 251, The manufacturing efficiency of the control layer 25 can be improved.

Next, as shown in FIG. 5C, an ultraviolet curable resin such as urethane acrylate is applied on the surface of the light control layer 25 on the image source side, and a fine uneven shape (mat shape) is formed on the resin. The surface layer 26 having fine unevenness on the surface is formed by curing the film by transferring it to the film surface.
Note that a masking material (not shown) may be bonded to the surface layer 26 so as to be peeled off and then flowed to the next step. As this masking material, for example, a transparent or substantially transparent sheet-like member can be used, and has a function of preventing the surface layer 26 from being stained or damaged in the subsequent manufacturing process.
Next, as shown in FIG. 5D, a light diffusing layer 241 and a colored layer 242 are formed by coextruding a resin containing a diffusing material and a resin containing a coloring material with a predetermined thickness, respectively. Are integrally formed to form a web-like base material layer 24, and the surface of the base material layer 24 on the colored layer 242 side and the surface of the light control layer 25 on the base material portion 251 side are joined.

Subsequently, as illustrated in FIG. 6A, the lens layer 23 is formed on the back surface of the base material layer 24 (in this embodiment, the surface on the light diffusion layer 241 side) by a roll conveyance method.
Specifically, the lens layer 23 is coated with an ultraviolet curable resin such as urethane acrylate on the back surface of the base material layer 24, pressed by a mold roll that shapes the unit optical shape 231, and irradiated with ultraviolet rays. It is formed by releasing from a mold roll with a peeling roll after curing.
Next, as shown in FIG. 6B, the reflective layer 22 is formed by vapor-depositing aluminum on the back surface (surface on the unit optical shape 231 side) of the lens layer 23 by a vacuum vapor deposition method. The reflective layer 22 may be formed by applying a paint containing a light reflective material such as a metal thin film.

Subsequently, as shown in FIG. 6C, the protective layer 21 is formed by applying an ultraviolet curable resin containing a dark color material to the back surface of the lens layer 23 on which the reflective layer 22 is formed. Form.
As described above, a laminate in which the protective layer 21, the reflective layer 22, the lens layer 23, the base material layer 24, the light control layer 25, and the surface layer 26 are sequentially laminated is completed. Finally, the laminate is formed into a predetermined size. The reflective screen 20 is completed by cutting into (see FIG. 2).

In addition, as above-mentioned, the light-control layer 25 can abbreviate | omit the base material part 251, In this case, a reflective screen can be manufactured with the following flows.
First, the web-shaped base material layer 24 is produced by coextrusion molding of the light diffusion layer 241 and the colored layer 242 and then the first light transmission layer 252 is directly formed on the surface of the base material layer 24 on the viewer side. To do. Then, the second light transmission layer 253 is formed in the valley portion of the first light transmission portion 252 to produce the light control layer 25, and the surface layer 26 is formed on the surface of the light control layer 25 on the image source side. Formation of the lens layer 23 on the back side of the base material layer 24, the reflective layer 22, and the protective layer 21 is the same as in the above-described manufacturing method (see FIG. 6).
Thus, by omitting the base material portion 251 of the light control layer 25, the manufacturing process of the reflective screen can be simplified and the manufacturing cost can be reduced.

As described above, the reflective screen 20 of the present embodiment is provided on the back side of the lens layer 23 having the lens layer 23 in which a plurality of unit optical shapes 231 extending in the vertical direction of the screen are arranged in the horizontal direction of the screen along the screen surface. The reflection layer 22 and the first light transmission unit 252 and the second light transmission unit 253 that are provided on the image source side of the lens layer 23 and transmit light are alternately arranged in the vertical direction of the screen along the screen surface. The light control layer 25 is provided. Therefore, the reflection screen 20 causes the light control layer 25 to totally reflect the image light projected from the image source to the lens layer 23 side, and the unit optical shape 231 of the lens layer 23 not only in the front direction but also in the horizontal direction of the screen. Can also be reflected in the left and right directions. Thereby, the reflective screen 20 can make the luminance distribution in the screen surface uniform.
Moreover, the reflective screen 20 of this embodiment can manufacture a several reflective screen sequentially by the system of roll conveyance, and while being able to improve the manufacture efficiency of the reflective screen 20, manufacturing cost can be made cheap. .

In the reflective screen 20 of this embodiment, since the refractive index of the second light transmission unit 253 is smaller than the refractive index of the first light transmission unit 252, the image light incident from the image source is efficiently transmitted by the light control layer 25. Total reflection can be performed on the lens layer 23 side.
In the reflective screen 20 of the present embodiment, the angle α formed by the inclined surface 253a of the second light transmission portion and a plane parallel to the screen surface is formed in the range of 60 ° ≦ α ≦ 80 °. The projected image light can be efficiently totally reflected on the light control layer 25 by the lens layer 23 side.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and changes can be made as in the modifications described later, and these are also included in the present invention. Within the technical scope. In addition, the effects described in the embodiments are merely a list of the most preferable effects resulting from the present invention, and the effects of the present invention are not limited to those described in the embodiments. It should be noted that the above-described embodiment and modifications described later can be used in appropriate combination, but detailed description thereof is omitted.

(Deformation)
FIG. 7 is a diagram for explaining a modified reflective screen, FIG. 7 (a) is a cross-sectional view corresponding to FIG. 2 (a), and FIG. 7 (b) corresponds to FIG. 2 (b). FIG.
(1) In the above-described embodiment, the example in which the light control layer 25 is provided on the image source side with respect to the lens layer 23 and the base material layer 24 has been described, but the present invention is not limited thereto. For example, the light control layer 25 may be provided on the image source side of the lens layer 23 and between the base material layer 24 and the lens layer 23 as shown in FIG.

(2) In the above-described embodiment, the base material layer 24 includes the colored layer 242 and the light diffusion layer 241. However, the present invention is not limited thereto. For example, the base material layer 24 includes the colored layer 242. Instead, the light diffusing layer 241 alone may be provided. In this case, the light diffusion layer 241 may further include a coloring material in addition to the diffusion material.
Further, the base material layer 24 may include only the colored layer 242 and the colored layer 242 may further include a light diffusing material in addition to the colorant.
Furthermore, the light diffusing layer 241 and the colored layer 242 may be formed as a base material layer 24 by bonding the light diffusing layer 241 and the colored layer 242 that are separately formed with an adhesive or the like.

(3) In the above embodiment, the video source LS is positioned below the reflective screen 20 (the reflective screen unit 10) in the vertical direction, and the video light L is projected obliquely from below the reflective screen 20. However, the present invention is not limited to this. For example, the video source LS may be positioned above the reflective screen 20 in the vertical direction, and the video light L may be projected obliquely from above the reflective screen 20. In this case, the reflection screen needs to be used with the screen up-down direction of the reflection screen 20 of the above-described embodiment reversed.

DESCRIPTION OF SYMBOLS 1 Image display system 20 Reflective screen 21 Protective layer 22 Reflective layer 23 Lens layer 231 Unit optical shape 24 Base material layer 25 Light control layer 251 Base material part 252 First light transmission part 253 Second light transmission part 253a, 253b Slope 26 Surface Layer LS video source

Claims (4)

A reflective screen that reflects video light projected from a video source arranged above or below the screen in the vertical direction and displays it on the screen,
A lens layer that is convex on the back side opposite to the image source side and has a plurality of unit optical shapes that extend in the screen vertical direction along the screen surface in the screen horizontal direction,
A reflective layer that is provided on the back side of the lens layer and reflects light;
A light control layer provided on the image source side of the lens layer, the first light transmission part and the second light transmission part that transmit light are alternately arranged in the vertical direction of the screen along the screen surface;
The second light transmission portion has a wedge-shaped shape in which a cross-sectional shape in a cross-section parallel to the thickness direction and parallel to the vertical direction of the screen has a wide end at the image source side and gradually narrows toward the back side. Is formed ,
The first light transmission portion has a cross-sectional shape in a cross section parallel to the thickness direction and parallel to the vertical direction of the screen, the image source side being an upper base, and the back side being a lower base having a size larger than the upper base. Formed in a trapezoidal shape,
The image source side surface of the light control layer is flat and formed by the image source side surface of the first light transmission unit and the image source side surface of the second light transmission unit,
Reflective screen featuring. The reflective screen according to claim 1.
The refractive index of the second light transmission part is smaller than the refractive index of the first light transmission part;
Reflective screen featuring. The reflective screen according to claim 1 or 2,
The second light transmission part includes an inclined surface that forms an interface with the first light transmission part, an inclined surface on the same side as the side on which the image source is arranged in the vertical direction of the screen, and a surface parallel to the screen surface. Is formed in the range of 60 ° ≦ α ≦ 80 °,
Reflective screen featuring. The reflective screen according to any one of claims 1 to 3,
An image source for projecting image light onto the reflective screen;
A video display system comprising:

Images