JP2018077323A - Image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image display device having a screen with high transparency on two surfaces opposing to each other.SOLUTION: An image display device 1 includes: a first screen 10 and a second screen 20 having transparency and reflecting part of projected image light to display an image, which are disposed, with display surfaces for displaying images opposing to each other, at a predetermined distance from each other; and a first image source LS1 and a second image source LS2 disposed on an inner side of a chassis than the first screen 10 and the second screen 20 and below the respective screens. In the image display device 1, an image displayed on the first screen 10 is visible through the second screen 20, while an image displayed on the second screen 20 is visible through the first screen 10.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a video display device that displays video.

  2. Description of the Related Art Conventionally, various types of screens and video display devices that display video light projected from a video source by reflecting or transmitting the light have been developed (see, for example, Patent Document 1). In particular, there is a demand for a screen having transparency through which the scenery beyond the screen can be seen and a video display device using the screen when it is not used without projecting image light from the standpoint of high design. It is growing.

Japanese Patent Laid-Open No. 9-11003

However, when such a screen having transparency is provided with a light diffusion layer containing diffusing particles having a function of diffusing light, the scenery on the other side of the screen may be observed as whitish and blurred. In order to reduce the designability, improvement of transparency has been an issue. Moreover, it is always required to make various screens thinner and to display good images with high contrast.
Various video display devices using a transparent screen have been developed. For example, a function that allows images to be displayed on two opposing screens, such as the front and back sides of the housing, and that the screen is transparent so that the scenery on the other side of the housing can be seen when images are not displayed. There is also a need for a video display device or the like having

  Patent Document 1 described above proposes a screen that can be used for both a transmission type and a reflection type. However, this Patent Document 1 does not disclose any measures relating to improvement of the transparency of the screen. Further, Patent Document 1 does not disclose a measure relating to the video display device as described above.

  The subject of this invention is providing the video display apparatus provided with two surfaces which oppose a highly transparent screen.

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 first aspect of the present invention is a first screen (10) that is transparent and reflects and displays a part of the projected image light, and a first screen that projects the image light on the first screen. 1 image source (LS1), a second screen (20) having transparency and reflecting a part of the projected image light, and projecting the image light onto the second screen And a second video source (LS2), wherein the first screen and the second screen face a display surface for displaying the video and leave a predetermined distance therebetween. The first video source and the second video source are arranged inside the video display device with respect to the first screen and the second screen, and the first screen A first surface (121a) having transparency and receiving image light, and the first surface (121a) A plurality of first unit optical shapes (121) having opposing second surfaces (121b) are arranged on the surface on the back side opposite to the image source side on which the first image source is disposed in the thickness direction. The formed first optical shape layer (12) and at least a part of the first surface of the first unit optical shape, and the surface on the first unit optical shape side has a rough irregular shape. A first reflective layer (13) that reflects part of incident light and transmits at least part of other incident light, wherein the second screen has light transmissivity. Then, the second unit optical shape (221) having the first surface (221a) on which the image light is incident and the second surface (221b) opposite to the first surface (221a) is arranged in the thickness direction. Second optical shapes arranged in a plurality on the back side opposite to the image source side (22) and at least part of the first surface of the second unit optical shape, and the surface on the second unit optical shape side is a rough surface having an irregular uneven shape, and incident light A second reflective layer (23) that reflects part of the incident light and transmits at least part of the other incident light, wherein the first image source is a normal of the screen surface of the first screen. The second image source is located outside the display area when viewed from the direction, and the second video source is located outside the display area when viewed from the normal direction of the screen surface of the second screen. An image displayed on the screen is visible through the second screen, and an image displayed on the display surface by the second screen is visible through the first screen. Device (1).
According to a second aspect of the present invention, in the video display device according to the first aspect, the first optical shape layer (12) of the first screen (10) includes a plurality of the first unit optical shapes (121). The second optical shape layer (22) of the second screen (20) has a Fresnel lens shape in which a plurality of the second unit optical shapes (221) are arranged, Is a video display device (1) characterized by
According to a third aspect of the present invention, in the video display device according to the first or second aspect, the first screen (10) is light transmissive, and the first optical shape layer (12) and the A first resin layer laminated on the back side of the first screen with respect to the first reflective layer (13) so as to fill the concave and convex valleys of the first unit optical shape (121); The second screen has light transmittance, and the second unit optical shape (221) is located closer to the back side of the second screen than the second optical shape layer (22) and the second reflective layer (23). And a second resin layer laminated so as to fill the concave and convex valleys of the image display device (1).
According to a fourth aspect of the present invention, in the video display device according to any one of the first to third aspects, the first screen (10) and the second screen (20) diffuse light. The image display device (1) is characterized in that it does not include a light diffusion layer containing diffusing particles having the function of:

  ADVANTAGE OF THE INVENTION According to this invention, the video display apparatus provided with two surfaces which oppose a highly transparent screen can be provided.

It is a figure showing picture display device 1 of an embodiment. It is a figure explaining the layer composition of the 1st screen 10 of an embodiment. It is a figure explaining the optical shape layer 12 of the 1st screen 10 of embodiment. It is a figure explaining the layer structure of the 2nd screen 20 of an embodiment. It is a figure explaining the optical shape layer 22 of the 2nd screen 20 of embodiment. It is a figure which shows the mode of the image light and external light in the video display apparatus 1 of embodiment.

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 this specification, terms that specify shape and geometric conditions, for example, terms such as parallel and orthogonal, are strictly meanings, have similar optical functions, and can be regarded as parallel and orthogonal It also includes a state having an error of.
In the present specification, numerical values such as dimensions and material names of each member to be described are examples of the embodiment, and are not limited thereto, and may be appropriately selected and used.

In this specification, the terms “plate”, “sheet”, and the like are used, but these are generally used in the order of thickness, “plate”, “sheet”, “film”. Above all, it uses it. However, there is no technical meaning in such proper use, so these terms can be replaced as appropriate.
In the present specification, the screen surface indicates a surface in the plane direction of the screen when viewed as the entire screen, and is assumed to be parallel to the screen (display surface) of the screen.

(Embodiment)
FIG. 1 is a diagram showing a video display device 1 of the present embodiment. FIG. 1 schematically shows the video display device 1 as viewed from the side.
The video display device 1 includes a first screen 10, a second screen 20, a first video source LS1, a second video source LS2, a housing 30, and the like. The image display device 1 displays images on a first screen 10 and a second screen 20 provided on two opposing surfaces of the housing 30.
The video display device 1 of the present embodiment will be described by taking an example of a video display device for advertising or the like placed indoors.

Here, for easy understanding, an XYZ orthogonal coordinate system is provided as appropriate in each of the following drawings including FIG. In this coordinate system, the thickness direction (depth direction) of the video display device 1 is the Z direction, the left and right screen directions of the first screen 10 and the second screen 20 are the X direction, and the vertical direction of the screen is the Y direction. The screens (screen surfaces) of the first screen 10 and the second screen 20 are parallel to the XY plane, and the thickness direction of the first screen 10 and the second screen 20 is in the thickness direction (Z direction) of the video display device 1. They are parallel and orthogonal to the screens of the first screen 10 and the second screen 20.
Further, when viewed from the viewer O1 located in the front direction on the video source side of the first screen 10 (the back side of the second screen 20), the direction toward the right side in the left-right direction of the screen is + X direction, and the upper side in the vertical direction of the screen. The direction to go is the + Y direction. Further, in the thickness direction of the video display device 1, the direction from the first screen 10 side to the second screen 20 side is defined as a + Z direction.
Further, in the following description, the screen vertical direction, the screen horizontal direction, and the thickness direction are the screen vertical direction (vertical direction) and the screen horizontal direction (horizontal direction) when the first screen 10 is used unless otherwise specified. The thickness direction (depth direction) is parallel to the Y direction, the X direction, and the Z direction, respectively.

The housing 30 forms the outer shape of the video display device 1, supports the first screen 10 and the second screen 20, and can arrange the first video source LS1 and the second video source LS2 at predetermined positions inside the case 30. . The housing 30 of the present embodiment has a rectangular tube shape with a hollow inside, and a cross section parallel to the XZ plane has a quadrangular shape. Moreover, the housing | casing 30 has two opening parts which oppose to a Z direction, and the 1st screen 10 and the 2nd screen 20 are arrange | positioned at the opening part. The upper side of the casing 30 in the vertical direction is closed, and external light or the like does not enter.
It is preferable from the viewpoint of suppressing unnecessary stray light that the inside of the housing 30 has a light absorption property such as black or has a low reflectance.

The first video source LS1 is a video projection device (projector) that projects the video light L1 onto the first screen 10. The second video source LS <b> 2 is a video projection device (projector) that projects the video light L <b> 2 onto the second screen 20. The first video source LS1 and the second video source LS2 of the present embodiment are short focus projectors.
The first video source LS1 displays the left and right sides of the first screen 10 when the screen (display area) of the first screen 10 is viewed from the Z direction (normal direction of the screen surface) when the video display device 1 is in use. It is the center of the direction (X direction) and is located on the lower side (−Y side) than the screen of the first screen 10.

In addition, the second video source LS2 is configured so that when the screen (display area) of the second screen 20 is viewed from the Z direction (normal direction of the screen surface) when the video display device 1 is in use, It is the center in the left-right direction (X direction) of the screen and is located on the lower side (−Y side) than the screen of the second screen 20.
In the present embodiment, the first screen 10 and the first video source LS1, and the second screen 20 and the second video source LS2 pass through the center in the thickness direction (Z direction) of the video display device 1 and are parallel to the XY plane. In a symmetrical position with respect to the plane. Accordingly, when the video display device 1 is viewed from the Z direction, the positions of the first video source LS1 and the second video source LS2 coincide.

Compared with the conventional general-purpose projector, the first video source LS1 and the second video source LS2 are obliquely arranged from a position where the distance in the depth direction (Z direction) from the surfaces of the first screen 10 and the second screen 20 is substantially close. The image lights L1 and L2 can be projected respectively.
Therefore, compared with the conventional general-purpose projector, the first video source LS1 and the second video source LS2 have a short projection distance to each screen and a large incident angle at which the projected video lights L1 and L2 enter each screen. The amount of change in the incident angle incident on each screen (the amount of change from the minimum value to the maximum value) is also large.

The first screen 10 reflects and displays a part of the video light L1 projected by the first video source LS1, and the scene beyond the first screen 10 when not in use when the video light L1 is not projected. Is a reflective screen having transparency.
Part of the video light L1 projected from the first video source LS1 is reflected by the first screen 10, passes through the second screen 20, and is in the front direction (first side) on the back side (+ Z side) of the second screen 20. It reaches the observer O1 located on the image source side (+ Z side front direction) of the screen 10. The observer O1 visually recognizes an image displayed on the first screen 10 through the second screen 20.

The second screen 20 reflects and displays a part of the video light L2 projected by the second video source LS2, and displays the scenery on the other side of the second screen 20 when not in use when the video light is not projected. It is a reflective screen having transparency that can be observed.
Part of the video light L2 projected from the second video source LS2 is reflected by the second screen 20, passes through the first screen 10, and is directed to the front side (first side) of the back side (−Z side) of the first screen 10. 2 reaches the observer O2 located on the image source side (the front side on the −Z side) of the screen 20. The observer O2 visually recognizes the image displayed on the second screen 20 through the first screen 10.

The screens (display areas) of the first screen 10 and the second screen 20 are rectangular and have the same size when viewed from the + Z-side observer O1 and the −Z-side observer O2 of the image display device. The long side direction is the left-right direction of the screen (X direction). Also, the points that become the geometric centers of both screens are points A1 and A2, respectively. The point A1 and the point A2 are symmetric with respect to a plane passing through the center of the video display device 1 in the Z direction and parallel to the XY plane.
The screen size of the first screen 10 and the second screen 20 is about 40 to 100 inches diagonal, and the aspect ratio of the screen is 16: 9. However, the present invention is not limited to this, and for example, the size may be 40 inches or less, and the size and shape can be appropriately selected according to the purpose of use, the usage environment, and the like.

  In general, the screen is a laminated body of thin layers made of resin, and the screen itself often does not have sufficient rigidity to maintain flatness. Therefore, for example, a support plate (not shown) is integrally joined (or partially fixed) to the −Z side or + Z side of the first screen 10 and the second screen 20 via a joint layer (not shown). The first screen 10 and the second screen 20 may be configured to maintain the flatness of the screen.

As the above-described support plate, a plate-like member having light transmittance and higher rigidity than the first screen 10 and the second screen 20 is preferable. As the support plate, a flat plate member made of resin such as acrylic resin or PC resin, or glass can be used. The bonding layer is preferably formed using an adhesive or pressure-sensitive adhesive having high light transmittance.
Further, it is preferable that the support plate and the bonding layer have no difference in refractive index from the layers on the surfaces of the first screen 10 and the second screen 20 to which they are bonded, or have a refractive index difference as small as possible.
The first screen 10 and the second screen 20 are not limited to the above-described example. For example, the four sides of the first screen 10 and the second screen 20 may be supported by a frame member (not shown) and the like, and the flatness of the screen may be maintained.

Hereinafter, first, each layer of the first screen 10 will be described.
FIG. 2 is a diagram illustrating the layer configuration of the first screen 10 of the present embodiment. In FIG. 2, it passes through a point A1 (see FIG. 1) which is the screen center (the geometric center of the screen) of the first screen 10, is parallel to the screen vertical direction (Y direction), and is perpendicular to the screen surface (thickness). A part of a cross section that is parallel to the Z direction, which is the direction, is shown enlarged.
The first screen 10 of the present embodiment includes a base material layer 11, an optical shape layer 12, a reflective layer 13, a resin layer 14, and a protective layer 15 in order from the + Z side (video source side, observer O1 side) in the thickness direction. Provided, and these are integrally laminated.

The base material layer 11 is a light-transmitting layer, and the optical shape layer 12 is integrally formed on the −Z side. The base material layer 11 is a layer serving as a base material (base) for forming the optical shape layer 12. The base material layer 11 has a function of protecting the + Z side of the first screen 10.
The base material layer 11 is made of, for example, polyester resin such as PET (polyethylene terephthalate) having high light transmittance, acrylic resin, styrene resin, acrylic styrene resin, PC (polycarbonate) resin, alicyclic polyolefin resin, TAC (triacetyl). A sheet-like member such as a cellulose resin can be used.
Further, the thickness of the base material layer 11 can be changed according to the screen size of the first screen 10 or the like.

FIG. 3 is a diagram illustrating the optical shape layer 12 of the first screen 10 of the present embodiment. In FIG. 3, the figure which looked at the optical shape layer 12 from the -Z side is shown.
The optical shape layer 12 is a light-transmitting layer formed on the −Z side of the base material layer 11. A plurality of unit optical shapes (unit lenses) 121 are arranged on the −Z side surface of the optical shape layer 12.
The unit optical shape 121 is a partial shape (arc shape) of a perfect circle, and as shown in FIG. 3, a plurality of concentric circles centered on a point C1 located outside the screen (display area) of the first screen 10. It is arranged. That is, the optical shape layer 12 has a circular Fresnel lens shape having a so-called offset structure with the point C1 as the center (Fresnel center).
As shown in FIG. 3, this point C1 is located at the center of the first screen 10 in the left-right direction (X direction) of the screen 10 and on the lower outside of the screen (−Y side). When viewed from above, the point C1 and the point A1 are located on the same straight line parallel to the Y direction.

As shown in FIG. 2, the unit optical shape 121 has a substantially triangular cross section in a cross section parallel to the arrangement direction.
The unit optical shape 121 is convex on the −Z side, and is a first inclined surface (lens surface) 121a that is an incident surface on which image light is incident, and a second inclined surface (non-lens surface) that is an opposing surface facing the first inclined surface. 121b. In one unit optical shape 121, the second inclined surface 121b is located below the first inclined surface 121a with the apex t1 interposed therebetween.
The angle formed by the first slope 121a and a plane parallel to the screen surface is θ1. The angle formed by the second inclined surface 121b and a plane parallel to the screen surface is θ2. The angles θ1 and θ2 satisfy the relationship θ2> θ1.
The first inclined surface 121a and the second inclined surface 121b of the unit optical shape 121 have fine and irregular uneven shapes on the surface.

The arrangement pitch of the unit optical shapes 121 is P1, and the height of the unit optical shapes 121 (the dimension from the vertex t1 in the thickness direction to the point v1 that is the valley bottom between the unit optical shapes 121) is h1.
For ease of understanding, FIG. 2 shows an example in which the arrangement pitch P1 and the angles θ1 and θ2 of the unit optical shapes 121 are constant in the arrangement direction of the unit optical shapes 121. However, the unit optical shape 121 of the present embodiment is actually constant in the arrangement pitch P1, but gradually increases as the angle θ1 moves away from the point C1 that becomes the Fresnel center in the arrangement direction of the unit optical shapes 121. .
The angles θ1, θ2, the arrangement pitch P1, and the like are the projection angle of the video light L1 from the first video source LS1 (the incident angle of the video light L1 on the first screen 10) and the pixels of the first video source LS1. May be set as appropriate according to the size of the first screen 10, the screen size of the first screen 10, the refractive index of each layer, and the like. For example, the arrangement pitch P1 or the like may be changed along the arrangement direction of the unit optical shapes 121.

The optical shape layer 12 is formed of an ultraviolet curable resin such as urethane acrylate, polyester acrylate, epoxy acrylate, polyether acrylate, polythiol, or butadiene acrylate having high light transmittance.
In the present embodiment, an ultraviolet curable resin is described as an example of the resin constituting the optical shape layer 12, but the present invention is not limited thereto. For example, other ionizing radiation curable resins such as an electron beam curable resin are used. You may form with resin.

The reflection layer 13 is a layer formed on the −Z side of the unit optical shape 121, that is, on the −Z side of the first inclined surface 121a and the second inclined surface 121b, reflects a part of incident light, and makes other incidents. This is a so-called half mirror that is a transflective reflective layer that transmits at least part of the light.
The reflective layer 13 is a rough surface having fine irregular irregular shapes on both surfaces. The reflection layer 13 is formed in a state where the uneven shape formed on the surface of the optical shape layer 12 on the reflection layer 13 side is maintained.
The fine concavo-convex shape is formed by irregularly arranging a convex shape and a concave shape in a two-dimensional direction. The convex shape and the concave shape are irregular in size, shape, height, and the like.
The reflective layer 13 diffuses and reflects a part of the incident light with a fine and irregular shape, and transmits at least a part of the other incident light without diffusing.

  The reflectance and transmittance of the reflective layer 13 can be set as appropriate according to the desired optical performance. However, the reflective layer 13 reflects the image light satisfactorily, and unnecessary external light other than the image light (for example, from outside such as sunlight). From the viewpoint of favorably transmitting the light), it is desirable that the transmittance is in the range of about 60 to 80% and the reflectance is about 5 to 40%.

The reflective layer 13 is a thin film formed of a metal having high light reflectivity, for example, aluminum, silver, nickel, etc., and the thickness thereof is about several tens of millimeters. The reflective layer 13 of this embodiment is formed by evaporating aluminum.
The reflective layer 13 is not limited to this, and may be formed, for example, by sputtering a metal having high light reflectivity. The reflective layer 13 may be formed by vapor-depositing a dielectric multilayer film.

The resin layer 14 is a light-transmitting resin layer provided on the −Z side (back side) with respect to the reflective layer 13.
The resin layer 14 is formed so as to fill valleys between the unit optical shapes 121, and the −Z side surfaces of the optical shape layer 12 and the reflective layer 13 are flattened by the resin layer 14.
The resin layer 14 is formed by arranging a plurality of unit optical shapes that are the reverse of the unit optical shapes 121 of the optical shape layer 12 on the surface on the + Z side (image source side).
By providing such a resin layer 14, the reflective layer 13 can be protected, and the protective layer 15 and the like can be easily laminated on the −Z side surface of the first screen 10. Further, when a support plate or the like is joined to the first screen 10, the support plate can be easily joined.

The refractive index of the resin layer 14 is desirably equal to or approximately equal to the refractive index of the optical shape layer 12 (the difference in refractive index is small enough to be regarded as equal). The resin layer 14 is preferably formed using the same ultraviolet curable resin as the optical shape layer 12 described above, but may be formed of a different material.
The resin layer 14 of the present embodiment is formed of the same material as the optical shape layer 12 described above, and the refractive index thereof is equal to the refractive index of the optical shape layer 12.

The protective layer 15 is a light transmissive layer formed on the −Z side of the resin layer 14. The protective layer 15 has a function of protecting the −Z side of the first screen 10.
The protective layer 15 can be formed using a resin-made sheet-like member having high light transmittance. For example, the protective layer 15 may be a sheet-like member formed using the same material as the base material layer 11 described above.
As described above, the first screen 10 of the present embodiment does not include a light diffusion layer containing a diffusing material such as particles having a function of diffusing light, and the image light is fine on the surface of the reflective layer 13. Moreover, it is diffusely reflected due to the irregular uneven shape.

Next, each layer of the second screen 20 will be described.
FIG. 4 is a diagram illustrating the layer configuration of the second screen 20 of the present embodiment. In FIG. 4, it passes through a point A2 (see FIG. 1) that is the screen center (the geometric center of the screen) of the second screen 20, is parallel to the screen vertical direction (Y direction), and is perpendicular to the screen surface (thickness). A part of a cross section that is parallel to the Z direction, which is the direction, is shown enlarged.
The second screen 20 of the present embodiment has a base material layer 21, an optical shape layer 22, a reflective layer 23, a resin layer 24, and a protective layer 25 in order from the −Z side (image source side, observer O2 side) in the thickness direction. These are integrally laminated.
As shown in FIGS. 2 and 4, the second screen 20 is equal to a shape obtained by inverting the first screen 10 in the Z direction about a straight line parallel to the Y direction. The first screen 10 and the second screen 20 are The shape is symmetrical in the Z direction. Accordingly, the second screen 20 may be used by inverting a screen having the same shape as the first screen 10 in the Z direction.

The base material layer 21 is a layer corresponding to the base material layer 11 of the first screen 10. For the base material layer 21, the same member as the base material layer 11 described above can be used.
FIG. 5 is a diagram illustrating the optical shape layer 22 of the second screen 20 of the present embodiment. FIG. 5 shows the optical shape layer 22 as viewed from the + Z side.
The optical shape layer 22 is a layer corresponding to the optical shape layer 12 of the first screen 10. The optical shape layer 22 is a light-transmitting layer formed on the + Z side of the base material layer 21, and a plurality of unit optical shapes (unit lenses) 221 are arranged on the + Z side surface. Yes.

The unit optical shape 221 corresponds to the unit optical shape 121 of the first screen 10 and is a part of a perfect circle (arc shape). As shown in FIG. 5, the unit optical shape 221 is outside the screen (display area) of the second screen 20. A plurality of concentric circles are arranged around the point C2 located at the center. The optical shape layer 22 has a circular Fresnel lens shape having an offset structure with the point C2 as the center (Fresnel center).
As shown in FIG. 4, this point C2 is located at the center of the second screen 20 in the left-right direction (X direction) and below the screen (−Y side). When viewed, the point C2 and the point A2 are located on the same straight line parallel to the Y direction.
In the present embodiment, the point C2 and the point C1, and the point A2 and the point A1 are symmetric with respect to a plane passing through the center in the Z direction of the video display device 1 and parallel to the XY plane.

As shown in FIGS. 4 and 5, the unit optical shape 221 has a substantially triangular cross section in a cross section parallel to the arrangement direction.
The unit optical shape 221 is convex on the + Z side, and is a first inclined surface (lens surface) 221a that is an incident surface on which image light is incident, and a second inclined surface (non-lens surface) 221b that is an opposing surface facing this. And have. In one unit optical shape 221, the second slope 221b is located below the first slope 221a with the apex t2 in between.
The first inclined surface 221a and the second inclined surface 221b of the unit optical shape 221 have fine and irregular uneven shapes on the surface.

The angle formed by the first inclined surface 221a and the plane parallel to the screen surface is θ3. The angle formed by the second inclined surface 221b and a plane parallel to the screen surface is θ4. The angles θ3 and θ4 satisfy the relationship θ4> θ3.
The arrangement pitch of the unit optical shapes 221 is P2, and the height of the unit optical shapes 221 (the dimension from the apex t2 in the thickness direction to the point v2 that becomes the valley bottom between the unit optical shapes 221) is h2.
For easy understanding, FIG. 4 shows an example in which the arrangement pitch P2 and the angles θ3 and θ4 of the unit optical shapes 221 are constant in the arrangement direction of the unit optical shapes 221. However, like the unit optical shape 121 of the first screen 10 described above, the unit optical shape 221 actually has a constant arrangement pitch P2, but the angle θ3 is a Fresnel center in the arrangement direction of the unit optical shape 221. As the distance from the point C2 increases, it gradually increases.

As described above, the unit optical shape 221 of the present embodiment is a shape obtained by inverting the unit optical shape 121 in the Z direction about the Y direction. Therefore, in the present embodiment, the arrangement pitch P1 = P2. Further, the angles θ1 and θ2 of the unit optical shape 121 at the position r from the point C1 and the angles θ3 and θ4 of the unit optical shape 221 at the same distance from the point C2 are θ3 = θ1. , Θ4 = θ2.
Note that the angles θ3, θ4, the arrangement pitch P2, and the like are the projection angle of the video light L2 from the second video source LS2 (the incident angle of the video light L2 on the second screen 20), and the pixels of the second video source LS2 ( May be set as appropriate according to the size of the pixel), the screen size of the second screen 20, the refractive index of each layer, and the like. For example, the arrangement pitch P2 or the like may be changed along the arrangement direction of the unit optical shapes 221.

The optical shape layer 22 can be formed of an ultraviolet curable resin having a high light transmittance similar to the optical shape layer 12 of the first screen 10 described above. The optical shape layer 22 may be formed of other ionizing radiation curable resin such as an electron beam curable resin.
In the present embodiment, the optical shape layer 22 is formed of the same ultraviolet curable resin as the optical shape layer 12 of the first screen 10.

The reflective layer 23 is a layer corresponding to the reflective layer 13 of the first screen 10 described above. The reflective layer 23 is formed on the + Z side of the unit optical shape 221, that is, on the + Z side of the first slope 221 a and the second slope 221 b. The reflective layer 23 is a so-called half mirror that reflects a part of incident light and transmits at least a part of other incident light.
The reflecting layer 23 is a rough surface having fine irregular irregular shapes on both surfaces. The fine concavo-convex shape is formed by irregularly arranging a convex shape and a concave shape in a two-dimensional direction. The convex shape and the concave shape are irregular in size, shape, height, and the like. The reflective layer 23 is formed in a state in which the uneven shape formed on the surface of the unit optical shape 221 is maintained.
The reflection layer 23 diffuses and reflects a part of the incident light by the uneven shape, and transmits at least a part of the other incident light without diffusing.

The transmittance and reflectance of the reflective layer 23 of the second screen 20 of the present embodiment are the same as those of the reflective layer 13 of the first screen 10 described above. The transmittance and reflectance of the reflective layer 23 of the second screen 20 may be different from those of the reflective layer 13 of the first screen 10 depending on the usage environment of the video display device 1 and the desired optical performance. Good.
The reflective layer 23 can be formed of the same material as that of the reflective layer 13 of the first screen 10 described above. The reflective layer 23 of the present embodiment is formed by evaporating aluminum in the same manner as the reflective layer 13.

The resin layer 24 is a layer corresponding to the resin layer 14 of the first screen 10. The resin layer 24 is a light-transmitting resin layer provided on the + Z side with respect to the reflective layer 23, and is formed so as to fill the concave and convex valleys of the unit optical shape 221. By this resin layer 24, the + Z side surfaces of the optical shape layer 22 and the reflective layer 23 are flat.
The resin layer 24 is formed by arranging a plurality of unit optical shapes that are the reverse of the unit optical shape 221 of the optical shape layer 22 on the −Z side surface.
By providing such a resin layer 24, the reflective layer 23 can be protected, and the protective layer 25 and the like can be easily laminated on the + Z side surface of the second screen 20. Moreover, when joining the 2nd screen 20 to a support plate, joining to a support plate also becomes easy.

The refractive index of the resin layer 24 is desirably equal to or approximately equal to the refractive index of the optical shape layer 22 (the difference in refractive index is small enough to be regarded as equal). The resin layer 24 is preferably formed using the same ultraviolet curable resin as the optical shape layer 22, but may be formed of a different material.
The resin layer 24 of the present embodiment is formed of the same material as the optical shape layer 22 described above, and its refractive index is equal to the refractive index of the optical shape layer 22.

The protective layer 25 is a layer corresponding to the protective layer 15 of the first screen 10. The protective layer 25 is a light-transmitting layer formed on the + Z side of the resin layer 24 and has a function of protecting the + Z side of the second screen 20.
As the protective layer 25, a sheet-like member made of a resin having high light transmittance can be used. As the protective layer 25, for example, a sheet-like member formed using the same material as the base material layer 21 described above may be used.
As described above, the second screen 20 of the present embodiment does not include a light diffusion layer containing a diffusing material such as particles having a function of diffusing light, and the image light is fine on the surface of the reflective layer 23. Moreover, it is diffusely reflected due to the irregular uneven shape.

The first screen 10 is manufactured by the following manufacturing method, for example.
UV is prepared by preparing a base material layer 11 and laminating one surface of the base layer 11 in a state in which a mold for shaping the unit optical shape 121 is filled with an ultraviolet curable resin, and irradiating ultraviolet rays to cure the ultraviolet curable resin. The optical shape layer 12 is formed by a molding method. At this time, fine and irregular concavo-convex shapes are formed on the surfaces on which the first inclined surface 121a and the second inclined surface 121b of the mold for forming the unit optical shape 121 are formed. This uneven shape can be formed by performing surface treatment a plurality of times on the surfaces that shape the first inclined surface 121a and the second inclined surface 121b of the mold. This surface processing is, for example, plating, etching, blasting, or the like. Further, the surface processing may be performed a plurality of times by changing various conditions.
After the optical shape layer 12 is formed on one surface of the base material layer 11, the reflective layer 13 is formed by vapor-depositing aluminum on the first inclined surface 121a and the second inclined surface 121b.

Thereafter, an ultraviolet curable resin is applied from above the reflective layer 13 so as to fill the uneven valleys of the unit optical shape 121 so as to be flat, and the protective layer 15 is laminated, and ultraviolet rays are irradiated to cure the ultraviolet rays. The mold resin is cured, and the resin layer 14 and the protective layer 15 are integrally formed. Thereafter, the first screen 10 is completed, for example, by cutting into a predetermined size.
In addition, the base material layer 11 and the protective layer 15 are good also as a sheet form, and good also as a web form.
The second screen 20 can also be manufactured by the same manufacturing method as the first screen 10 described above.

As a method for forming a fine and irregular uneven shape on the surfaces of the reflective layers 13 and 23, for example, a diffusion particle or the like is applied on the first inclined surfaces 121a and 221a and the second inclined surfaces 121b and 221b, and the reflective layer is formed thereon. A method of forming the reflective layers 13 and 23 after forming the first and third inclined surfaces 121a and 221a and the second inclined surfaces 121b and 221b is known.
However, in such a manufacturing method, the dispersion | variation in a diffusion characteristic, quality, etc. in each screen is large, and stable manufacture cannot be performed. On the other hand, as described above, the minute and irregular uneven shapes of the first inclined surfaces 121a and 221a and the second inclined surfaces 121b and 221b of the unit optical shapes 121 and 221 are formed by the molding die, By forming 23, even when a large number of first screens 10 and second screens 20 are manufactured, there is an advantage that there is little variation in quality and stable manufacturing is possible.

FIG. 6 is a diagram illustrating a state of image light and external light in the image display device 1 of the present embodiment. 6 shows a cross section of the first screen 10 and the second screen 20 in the cross section of the video display device 1 shown in FIG. Further, in FIG. 6, for easy understanding, it is assumed that there is no refractive index difference at the interface of each layer in each screen.
First, image light will be described.
Of the video light L11 projected from the first video source LS1 positioned below the first screen 10 and incident on the first screen 10, a part of the video light L12 is reflected by the surface of the first screen 10, and Heading upward on the + Z side of one screen 10. The first screen 10 and the second screen 20 are arranged with a sufficient distance in the Z direction, and the image light L12 does not enter the second screen 20, and the image light L12 Is not absorbed by the observer and does not reach the observers O1 and O2.

In addition, part of the image light L13 out of the image light L11 is incident on the first inclined surface 121a of the unit optical shape 121, is diffusely reflected by the reflective layer 13, and is emitted toward the + Z side. Then, the light passes through the second screen 20 and reaches the observer O1. Thereby, the observer O1 can visually recognize the image displayed on the first screen 10.
Part of the image light L14 that has not been reflected among the image light incident on the first slope 121a is transmitted through the reflection layer 13 and emitted upward from the first screen 10 to the −Z side. Such image light L14 does not reach the observer O2 located in the front direction on the −Z side of the first screen 10.

Similarly, a part of the image light L22 projected from the second image source LS2 positioned below the second screen 20 and incident on the second screen 20 is reflected by the surface of the second screen 20. Then, the second screen 20 moves upward on the −Z side. The first screen 10 and the second screen 20 are arranged with a sufficient distance in the Z direction, and the image light L22 does not enter the first screen 10, and the image light L22 Is not absorbed by the observer and does not reach the observers O1 and O2.
In addition, part of the image light L <b> 23 out of the image light L <b> 21 is incident on the first inclined surface 221 a of the unit optical shape 221, is diffusely reflected by the reflective layer 23, and is emitted to the −Z side. Then, the light passes through the first screen 10 and reaches the observer O2. Thereby, the observer O2 can visually recognize the image displayed on the second screen 20.
Of the image light incident on the first inclined surface 221a, a part of the image light L24 that is not reflected is transmitted through the reflection layer 23 and emitted from the second screen 20 to the + Z side upward. Such image light L24 does not reach the observer O1 positioned in the front direction on the + Z side of the second screen 20.

  In the present embodiment, the first video source LS1 and the second video source LS2 are positioned below the first screen 10 and the second screen 20, and the video lights L11 and L21 are the first screen 10 and the second screen 20, respectively. The angles θ2 and θ4 (see FIGS. 2 and 4) of the second inclined surfaces 121b and 221b are incident angles of image light at respective points in the vertical direction of the first screen 10 and the second screen 20. Therefore, the image light does not directly enter the second inclined surfaces 121b and 221b, and the second inclined surfaces 121b and 221b hardly affect the reflection of the image light.

Next, external light (light from the outside such as sunlight) other than the image light incident on the first screen 10 and the second screen 20 of the video display device 1 will be described.
As shown in FIG. 6, external light G <b> 1 enters the first screen 10 from above the −Z side. A part of the external light G 1 is reflected by the surface of the first screen 10 and the like, and travels downward from the first screen 10.
A part of the external light G <b> 1 that has entered the first screen 10 is reflected by the reflective layer 13 and is emitted upward from the −Z side of the first screen 10.
Further, a part of the external light G4 that has not been reflected by the reflective layer 23 passes through the reflective layer 13 and is emitted downward on the + Z side of the first screen 10 to be absorbed in the housing 30 or the first screen 10. The light is reflected by the + Z side surface of the first screen 10 and travels downward in the first screen 10 to be attenuated.
Accordingly, external light that enters the first screen 10 from above the −Z side does not reach the viewers O1 and O2.

Further, as shown in FIG. 6, external light G <b> 5 enters the second screen 20 from above the + Z side. Among the external light G5, a part of the external light G6 is reflected by the surface of the second screen 20 or the like and travels to the lower side of the second screen 20.
Among the external light G5, a part of the external light G7 incident on the first screen 10 is reflected by the reflective layer 23 and emitted upward on the + Z side of the second screen 20.
Further, a part of the external light G8 that has not been reflected by the reflective layer 23 is transmitted through the reflective layer 23 and emitted downward to the −Z side of the second screen 20 to be absorbed in the housing 30 or the second screen. The light is reflected by the surface on the −Z side of 20 and travels downward in the second screen 20 to be attenuated.
Accordingly, external light that enters the second screen 20 from above the + Z side does not reach the viewers O1 and O2.

In the present embodiment, the upper portion between the first screen 10 and the second screen 20 is shielded by the housing 30, so that external light incident on the first screen 10 from above the + Z side or −Z on the second screen 20. There is no external light incident from the upper side.
From the above, in the video display device 1, it is possible to greatly suppress a reduction in video contrast due to external light.

  Further, other external lights G9 and G10 having a small incident angle on the first screen 10 and the second screen 20 are transmitted through the first screen 10 and the second screen 20, but the first screen 10 and the second screen 20 are The light diffusing layer containing the diffusing particles having the function of diffusing light is not provided, so that it is not diffused. Therefore, when the scenery on the other side of the video display device 1 is observed through the first screen 10 and the second screen 20, the scenery is observed with high transparency without blurring or whitening. be able to.

  In a transflective reflective screen having a diffusion layer containing conventional diffusion particles, image light is diffused twice before and after reflection by the reflection layer, so that a good viewing angle can be obtained while image resolution is improved. There is a problem that decreases. Moreover, since the outside light is also diffused by the diffusing particles, the scenery on the other side of the screen is observed as blurred or whitened, and the transparency is lowered.

However, in the present embodiment, in the first screen 10 and the second screen 20, only the light reflected by the reflective layers 13 and 23 is diffused and transmitted by the fine irregular irregular shapes on the surfaces of the reflective layers 13 and 23. Light is not diffused.
Therefore, in the video display device 1 of the present embodiment, the first screen 10 and the second screen 20 can display a video having a good viewing angle and resolution, and have high transparency, so that the scenery beyond the screen can be displayed. Does not bleed white or blur, and is well visible to the viewers O1 and O2.
Note that the video display device 1 of the present embodiment can project video light on both the first screen 10 and the second screen 20 and display the video on both screens simultaneously. It is also possible to use such that the image is displayed and no image is projected on the other screen. The images displayed on both screens may be the same or different.
In the video display device 1 of the present embodiment, even when video is displayed on both screens, the video displayed on the screen is not visually recognized from the back side of the screen, and is displayed on the other screen facing the screen. You can see the video.

In the video display device 1 of the present embodiment, the observers O1 and O2 are transparent when the first screen 10 and the second screen 20 are not projected on the first screen 10 and the second screen 20. It is possible to visually recognize the scenery on the other side of the video display device 1 through the two screens.
Note that, in the video display device 1 of the present embodiment, even when video light is projected on each screen, the viewers O1 and O2 can partially view the scenery on the other side of the two screens. is there.
From the above, according to the present embodiment, it is possible to provide the video display device 1 that has a highly transparent screen on two opposing surfaces and can display an image on the two opposing screens.

(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) Although the 1st screen 10 and the 2nd screen 20 showed the example which is a symmetrical shape in a Z direction centering on a Y direction, it is not restricted to this, Asymmetrical may be sufficient.
Moreover, the 1st screen 10 and the 2nd screen 20 may be formed with the material from which each corresponding layer differs.

(2) An antireflection layer is provided on the image source side surfaces (surfaces of the base material layers 11 and 21) and the back side surfaces (surfaces of the protective layers 15 and 25) of the first screen 10 and the second screen 20. The incident light quantity of the image light incident on each screen may be increased, or the reflected light quantity at the air interface may be reduced when entering or exiting the screen that is transmitted after being reflected by the reflective layer. By providing such an antireflection layer, an image can be displayed more clearly.
Note that, in the video display device 1 of the embodiment, as described above, the video displayed on the other screen is observed through one screen. The first screen 10 and the second screen 20 are preferably provided with an antireflection layer (not shown) on both sides from the viewpoint of displaying a clear image.

In addition, a hard coat layer may be provided on the back surface of the first screen 10 and the second screen 20 (surfaces of the protective layers 15 and 25) for the purpose of preventing damage. The hard coat layer can be formed by applying an ultraviolet curable resin (for example, urethane acrylate) having a hard coat function. Further, not only the hard coat layer but also the antireflection layer, the ultraviolet absorbing layer, the antifouling layer, the antistatic layer, the touch panel layer, etc. One or more layers having a necessary function may be selected and provided as appropriate.
Further, when a support plate is bonded to the back side (outside of the housing 30) in the thickness direction of each screen, a hard coat layer and ultraviolet ray absorption are applied to the surface of the support plate (outside of the housing 30). A layer, an antifouling layer, an antistatic layer, a touch panel layer, or the like may be provided.

(3) The first video source LS1 and the second video source LS2 have been described by taking an example of being located at the center in the horizontal direction of each screen and below the screen. It is good also as a form which is arrange | positioned diagonally below a screen etc. and projects image light from the diagonal direction in the screen left-right direction with respect to the 1st screen 10 and the 2nd screen 20.
At this time, the positions of the points C1 and C2 serving as the Fresnel center of the circular Fresnel lens shape of the optical shape layers 12 and 22 are shifted according to the positions of the first video source LS1 and the second video source LS2.
By adopting such a configuration, the positions of the first video source LS1 and the second video source LS2 can be freely set, and the video display device 1 can be designed according to the use environment. It is possible to improve the design of the video display device 1.

(4) The video display device 1 has a shape in which the first screen 10 and the second screen 20 are inverted in the Y direction, and the first video source LS1 and the second video source LS2 are arranged above each screen, It is good also as a form which projects image light from.
Further, the video display device 1 may be configured such that one projection system projects video light from above the screen and the other projection system projects video light from below the screen, depending on the size of the housing. Good.

(5) The first slopes 121a and 221a and the second slopes 121b and 221b of the unit optical shapes 121 and 221 have been illustrated as being formed by planes. However, the present invention is not limited thereto, and for example, curved surfaces and planes are combined. It is good also as a form and it is good also as a folded surface shape.
The unit optical shapes 121 and 221 may be polygonal shapes formed by three or more surfaces.
Moreover, the reflective layers 13 and 23 are good also as a form formed in at least one part of 1st slope 121a, 221a, for example.
Moreover, although the 1st slope 121a, 221a and the 2nd slope 121b, 221b showed the example which is a rough surface in which the fine uneven | corrugated shape was formed, not only this but only the 1st slope 121a, 221a is a rough surface. It may be in a certain form.

(6) The optical shape layers 12 and 22 have a so-called linear Fresnel lens shape in which the unit optical shapes 121 and 221 are arranged in a plurality in the screen vertical direction (Y direction) with the screen horizontal direction (X direction) as the longitudinal direction. It is good also as a form to have.

(7) When the optical shape layers 12 and 22 and the resin layers 14 and 24 have sufficient thickness, rigidity, etc., the first screen 10 and the second screen 20 and the base material layers 11 and 21 and the protection It is good also as a form which does not provide the layers 15 and 25, and it is good also as a form which does not provide either one.
The first screen 10 and the second screen 20 are plate-like members having at least one of the base material layers 11 and 21 and the protective layers 15 and 25 having high translucency and higher rigidity than the other layers. (Glass plate or the like), and the flatness of the screens of the first screen 10 and the second screen 20 may be improved. At this time, the optical shape layers 12 and 22 may be bonded to a glass plate or the like via an adhesive layer or the like.

(8) The first video source LS1 and the second video source LS2 may project video light having a P-wave polarization component, for example.
At this time, the positions and angles of the first video source LS1 and the second video source LS2 are set so that the video light is projected onto the first screen 10 and the second screen 20 at an incident angle φ. This incident angle φ is (φb−10) ° or more and 85 °, where φb (°) is the incident angle (Brewster angle) at which the reflectance of the image light (P wave) projected onto each screen is zero. The following range is set. For example, when the incident angle φb at which the reflectance of the image light projected onto each screen is zero is 60 °, the incident angle φ of the image light is set in the range of 50 to 85 °.

In this way, by using the first video source LS1 and the second video source LS2 that project video light having a P-wave polarization component, the first screen 10, even when the incident angle φ to each screen is large. Specular reflection on the surface of the second screen 20 can be suppressed, and the degree of freedom in designing the projection system, such as the installation positions of the first video source LS1 and the second video source LS2, can be increased. Further, by using the first video source LS1 and the second video source LS2, reflection of video light on each screen surface can be reduced, and the brightness and clearness of the video can be improved.
The angle φb (Brewster angle) varies depending on the material of the surface of each screen on which the image light is projected.
Moreover, in the case of such a form, as the base material layers 11 and 21, TAC sheet-like members are suitable.

(9) The housing 30 has no external light incident on the first screen 10 and the second screen 20 from above, or when the housing 30 is disposed in an environment where it is not necessary to consider the influence thereof. The upper part of the body 30 may be an opening.

(10) The video display device 1 is applied to, for example, a show window such as a store, a video source is arranged in the store, and the first screen 10 and the second screen 20 are arranged on two opposing window glasses, It is good also as a form by which an image | video is displayed inside and outside a store.

  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 above-described embodiments and the like.

DESCRIPTION OF SYMBOLS 1 Image display apparatus 10 1st screen 20 2nd screen 11,21 Base material layer 12,22 Optical shape layer 121,221 Unit optical shape 121a, 221a 1st slope 121b, 221b 2nd slope 13,23 Reflective layer 14,24 Resin layer 15, 25 Protective layer LS1 First video source LS2 Second video source 30 Housing

Claims (4)

A first screen that has transparency and reflects and displays part of the projected image light;
A first video source for projecting video light onto the first screen;
A second screen that is transparent and that reflects and displays a portion of the projected image light;
A second video source for projecting video light onto the second screen;
A video display device comprising:
The first screen and the second screen are arranged with a predetermined distance facing a display surface for displaying an image,
The first video source and the second video source are disposed inside the video display device with respect to the first screen and the second screen,
The first screen is
A video source in which a first unit optical shape having a first surface on which light is incident and having a first surface on which video light is incident and a second surface facing the first surface is disposed in the thickness direction A plurality of first optical shape layers arranged on the back side opposite to the side;
At least part of the first surface of the first unit optical shape is formed, and the surface on the first unit optical shape side is a rough surface having irregular irregularities, and reflects a part of incident light. A first reflective layer that transmits at least part of the other incident light;
With
The second screen is
An image source having a second unit optical shape having a first surface on which image light is incident and a second surface facing the first surface is disposed in the thickness direction. A plurality of second optical shape layers arranged on the back side surface opposite to the side;
At least part of the first surface of the second unit optical shape is formed, and the surface on the second unit optical shape side is a rough surface having irregular irregularities, and reflects a part of incident light. A second reflective layer that transmits at least part of the other incident light;
With
The first video source is located outside the display area when viewed from the normal direction of the screen surface of the first screen,
The second video source is located outside the display area when viewed from the normal direction of the screen surface of the second screen;
The image displayed on the display surface by the first screen is visible through the second screen,
The video displayed on the display surface by the second screen is visible through the first screen;
A video display device characterized by the above. The video display device according to claim 1,
The first optical shape layer of the first screen has a Fresnel lens shape in which a plurality of the first unit optical shapes are arranged,
The second optical shape layer of the second screen has a Fresnel lens shape in which a plurality of the second unit optical shapes are arranged;
A video display device characterized by the above. In the video display device according to claim 1 or 2,
The first screen is light transmissive, and an uneven valley portion due to the first unit optical shape is provided on the back side of the first screen with respect to the first optical shape layer and the first reflective layer. A first resin layer laminated to fill,
The second screen is light transmissive, and an uneven valley portion due to the second unit optical shape is provided on the back side of the second screen with respect to the second optical shape layer and the second reflection layer. Comprising a second resin layer laminated to fill;
A video display device characterized by the above. In the video display device according to any one of claims 1 to 3,
The first screen and the second screen do not include a light diffusion layer containing diffusion particles having a function of diffusing light;
A video display device characterized by the above.

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