JP2018146666A - Reflection screen and video display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reflection screen that has high transparency and can display a good video, and a display including the same.SOLUTION: A screen 10 comprises: a first optical shape layer 12 that has a plurality of unit optical shapes 121 arranged on the back side of the screen, the unit optical shapes each including a first surface 121a on which video light is made incident and a second surface 121b opposing to the first surface 121a; and a reflection layer 13 that is formed at least on the first surfaces 121a of the unit optical shapes 121. The unit optical shape 121 has a fine and irregular rugged shape on its surface, and a surface of the reflection layer 13 on the unit optical shape 121 has a fine and irregular rugged shape.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a reflective screen and a video display device including the same.

  Conventionally, various reflection screens that reflect and display image light projected from an image source have been developed (see, for example, Patent Document 1). In particular, a reflective screen having transparency can be attached to a highly transparent member such as a window glass to reflect the projected image light and the image can be seen well, and the image light can be seen. When the projector is not used and is not used, the scenery on the other side of the screen can be seen through. Therefore, demand is increasing due to its high design.

Japanese Patent Laid-Open No. 9-11003

  However, when such a transflective reflective screen having transparency is provided with a light diffusing layer containing diffusing particles that diffuse light, the scenery on the other side of the screen is observed as whitish and blurred. Therefore, improvement in transparency has been a problem. Moreover, it is always required to make various screens thinner and to display good images with high contrast.

In addition, in a reflective screen having transparency, some image light may be emitted from the back side of the reflective screen. When such light leakage occurs particularly in the upper part of the screen of the reflection screen, there is a problem that the image is reflected on the ceiling or the like on the back side, resulting in a decrease in design.
In addition, in the reflective screen having transparency as described above, there may be a case where part of the image light becomes stray light and image blurring occurs in a predetermined direction.
In addition, it is also required to display a bright and clear image on the reflective screen having the above-described transparency by suppressing a decrease in image contrast due to external light.

Patent Document 1 described above proposes a screen that can be used for both a transmissive type and a reflective type, and can transmit light from the back side.
However, this Patent Document 1 does not disclose anything about the improvement of the transparency of the screen, the countermeasure against the reflection of the image on the ceiling due to the passage of light, the countermeasure for suppressing the image blur, and the like.

  An object of the present invention is to provide a reflective screen having high transparency and capable of displaying a good image, and an image display device including the same.

The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected and demonstrated, it is not limited to this.
The first invention is a reflective screen that displays video by reflecting video light (L) projected from a video source, has a light transmission property, and has a first surface (121a, 121a, 221a, 521a, 621a) and a second optical surface (121b, 221b, 521b, 621b) opposite to the unit optical shape (121, 221, 521, 621) convex toward the back side A plurality of first optical shape layers (12, 22, 52, 62) arranged on the surface of the light source, and at least the first surface of the unit optical shape, reflecting a part of incident light, Transmitting transflective reflective layers (13, 33) and light-transmitting so that the back surface side of the first optical shape layer and the reflective layer is filled with uneven valleys due to the unit optical shape. The second optical shape layer (14, 24, 5) 64), and the unit optical shape has a concavo-convex shape on the surface thereof, and at least a surface on the unit optical shape side of the reflective layer has a concavo-convex shape corresponding to the concavo-convex shape, It is a characteristic reflective screen (10, 20, 30, 40, 50, 60).
According to a second aspect of the present invention, in the reflective screen of the first aspect, the top portion (622) of the unit optical shape is a curved surface convex toward the back side, and a trough (623 between the adjacent unit optical shapes). ) Is a curved surface convex toward the image source side, the radius of curvature of the top is larger than the radius of curvature of the valley, and the reflective layer (13) includes at least the first surface and the top. The reflective screen (60) is characterized by being formed as follows.
A third invention is characterized in that, in the reflective screen of the first invention or the second invention, the reflective layer (13) is formed on the entire surface along the unit optical shape (621). A reflective screen (60).
According to a fourth aspect of the present invention, there is provided a reflective screen (10, 20, 30, 40, 50, characterized in that the reflective screen of the first aspect of the present invention does not include a light diffusing layer containing diffusing particles for diffusing light. 60).
According to a fifth aspect of the invention, in the reflective screen of the first aspect, in the arrangement direction of the unit optical shapes (12, 22), the luminance is halved from the emission angle that is the peak luminance of the reflected light of the reflective screen. When the angle change amount up to the emission angle is + α1, −α2, the average absolute value is α, and the angle between the first surface and the plane parallel to the screen surface is θ1, at least the reflection screen In some areas, the reflective screen (10, 20) is characterized by satisfying a relationship of α <arcsin (n × sin (2 × (θ1))).
According to a sixth aspect of the present invention, in the reflective screen of the first aspect, a mirror surface area in which the uneven shape is not formed occupies per unit area of the reflective layer (13) on the first surface (121a, 221a). The reflective screen (10, 20) is characterized in that the ratio is 5% or less.
According to a seventh aspect of the invention, in the reflective screen of the first aspect, in the thickness direction of the reflective screen, the video source side region (Sa) from the video source side surface to the back side surface of the reflective layer, or the reflective In the thickness direction of the screen, light is absorbed in the back side region (Sb) from the back side surface to the image source side surface of the reflective layer, and the light transmittance of the reflective screen is set to a predetermined value. A reflective screen (30) characterized in that it comprises at least one layer (33).
An eighth invention is the reflective screen (30) according to the seventh invention, wherein the reflective layer (33) functions as the light absorbing layer (33).
A ninth invention is the reflecting screen (30) according to the seventh invention, wherein the light absorbing layer (33) has an absorptance to transmitted light of 5% or more.
According to a tenth aspect of the invention, in the reflective screen of the first aspect of the invention, the predetermined polarized light included in the image light is applied to the area on the back side of the reflective screen including the reflective layer (13) in the thickness direction of the reflective screen. The reflection screen (40) is characterized by comprising a light exit suppression layer (45) that absorbs or reflects and suppresses at least part of the image light from being emitted to the back side of the reflection screen.
An eleventh aspect of the invention is the reflective screen of the tenth aspect of the invention, wherein the light leakage suppression layer (45) has a function of absorbing the predetermined polarized light transmitted through the reflective layer and transmitting other light. The reflective screen (40) is provided on the back side of the reflective layer in the thickness direction of the reflective screen.
A twelfth aspect of the invention is the reflective screen of the tenth aspect of the invention, wherein the reflective layer has a function as the omission light suppression layer that reflects the predetermined polarized light and transmits other light. A reflective screen (40).
A thirteenth aspect of the invention is the reflective screen (40) of the tenth aspect of the invention, and an image source for projecting the predetermined polarized light as the image light to the reflective screen. And a video display device.
According to a fourteenth aspect, in the reflective screen according to the first aspect, a point (t) located closest to the rear surface side on the second surface (521b) and a point located closest to the image source side on the second surface ( v), the angle θ2 is 25 ° ≦ θ2 ≦ 65 °, where θ2 is an angle between a plane passing through v) and a direction parallel to the screen surface of the reflection screen. 50).
According to a fifteenth aspect, in the reflective screen according to the first aspect, at least a part of the second surface (521b) is a curved surface, and the tangent line (S) of the second surface or the second surface is Assuming that an angle formed with a direction parallel to the screen surface of the reflecting screen is an angle θ3, in the region satisfying 25 ° ≦ θ3 ≦ 65 ° in the second surface, the angle θ3 satisfies 0 ° ≦ θ3 <25 °. The reflective screen (50) is characterized in that the area of the filled region and the angle θ3 are larger than the sum of the area of the region satisfying 65 ° <θ3 ≦ 90 °.
According to a sixteenth aspect of the present invention, there is provided a reflection screen (10, 20, 30, 40, 50, 60) according to any one of the first to twelfth aspects, the fourteenth aspect, and the fifteenth aspect, and the reflection screen. An image display device (1) including an image source (LS) that projects image light.

  According to the present invention, it is possible to provide a reflective screen having high transparency and capable of displaying a good image, and an image display device including the same.

It is a figure which shows the video display apparatus 1 of 1st Embodiment. It is a figure which shows the layer structure of the screen 10 of 1st Embodiment. It is a figure explaining the relationship between 1/2 angle (alpha), incident angle (phi) of image light, and angle (theta) 1 of 1st surface 121a. It is a figure which shows the mode of the image light and external light in the screen 10 of 1st Embodiment. It is a figure which shows the brightness | luminance and diffusion angle of the reflected light of the screen 10 of the measurement examples 1-6. It is a figure explaining the screen 20 of 2nd Embodiment. It is a figure explaining the layer structure of the screen 30 of 3rd Embodiment. It is a figure which shows the layer structure of the screen 40 of 4th Embodiment. It is a figure explaining the omission light suppression layer 45 of 4th Embodiment. It is a figure explaining the layer structure of the screen 50 of 5th Embodiment. It is a figure explaining the unit optical shape 521 and the reflection layer 13 of 5th Embodiment. It is a figure explaining the relationship between angle (theta) 2 and external light in 5th Embodiment. It is a figure explaining the other form of the screen 50 of 5th Embodiment. It is a figure explaining the layer structure of the screen 60 of 6th Embodiment. It is a figure which compares the screen 60 of 6th Embodiment, and the screen 60B of a comparative example. It is a figure which shows the mode of the image light and external light on the screen 60 of 6th 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, words such as a plate and a sheet are used. In general, the plates are used in the order of thickness, in the order of plate, sheet, and film, and are used in this specification as well. 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.

(First embodiment)
FIG. 1 is a diagram illustrating a video display device 1 according to the first embodiment. 1A is a perspective view of the video display device 1, and FIG. 1B is a view of the video display device 1 as viewed from the side.
The video display device 1 includes a screen 10, a video source LS, and the like. The screen 10 of the present embodiment is a reflective screen that reflects the image light L projected from the image source LS and displays an image on the screen. Details of the screen 10 will be described later.

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 horizontal direction (left-right direction) of the screen 10 is the X direction, the vertical direction (up-down direction) is the Y direction, and the thickness direction of the screen 10 is the Z direction. The screen of the screen 10 is parallel to the XY plane, and the thickness direction (Z direction) of the screen 10 is orthogonal to the screen 10.
Further, the image source from the rear side (back side) in the thickness direction is the + X direction, the direction toward the upper side of the vertical direction is the + Y direction, and the direction toward the upper side in the vertical direction when viewed from the observer O1 positioned in the front direction of the screen 10. The direction toward the side (observer side) is the + 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), the screen horizontal direction (horizontal direction) in the usage state of the screen 10 unless otherwise specified, The thickness direction (depth direction) is parallel to the Y direction, the X direction, and the Z direction, respectively.

The video source LS is a video projection device that projects the video light L onto the screen 10, and is, for example, a short focus projector.
This video source LS is the center of the screen 10 in the left-right direction when the screen (display area) of the screen 10 is viewed from the front direction (normal direction of the screen surface) when the video display device 1 is in use. Thus, it is positioned below the screen 10 in the vertical direction.
The image source LS can project the image light L obliquely in a depth direction (Z direction) from a position where the distance from the surface of the screen 10 is significantly closer than that of a conventional general-purpose projector. Therefore, compared with the conventional general-purpose projector, the video source LS has a short projection distance to the screen 10, a large incident angle at which the projected video light is incident on the screen 10, and a change amount of the incident angle (minimum incident angle). The amount of change from the value to the maximum value is also large.

The screen 10 is a screen that reflects the image light L projected by the image source LS toward the observer O1 side and displays an image, and the scenery on the other side (back side, −Z side) of the screen 10 is displayed. This is a transflective reflective screen that can be observed.
The screen (display area) of the screen 10 has a substantially rectangular shape in which the long side direction is the left-right direction of the screen when viewed from the observer O1 side.
The screen 10 has a screen size of about 40 to 100 inches diagonal and a screen aspect ratio of 16: 9. The screen 10 is not limited to this, and the screen size may be, for example, 40 inches or less. The size and shape of the screen 10 can be appropriately selected according to the purpose of use, the usage environment, and the like.

In general, the screen 10 is a laminated body of thin layers made of a resin, etc., and the screen 10 alone often does not have sufficient rigidity to maintain flatness. Therefore, the screen 10 of this embodiment is joined (or partially fixed) to a support plate (not shown) through a bonding layer (not shown) having optical transparency on the back side thereof to maintain the flatness of the screen. It is good.
The support plate is a flat plate member having light transmittance and high rigidity, and a plate member made of resin such as acrylic resin or PC resin, or glass can be used.
The video display device 1 of the present embodiment is applied to a shop show window, for example. At this time, for example, the screen 10 is preferably in a form in which the glass of the show window is fixed as the above-described support plate.

FIG. 2 is a diagram illustrating a layer configuration of the screen 10 according to the first embodiment. In FIG. 2, it passes through a point A (see FIGS. 1A and 1B) which is the screen center (the geometric center of the screen) of the screen 10, and is parallel to the screen vertical direction (Y direction). A part of a cross section orthogonal to the plane (parallel to the Z direction) is shown enlarged.
As shown in FIG. 2, the screen 10 includes a base material layer 11, a first optical shape layer 12, a reflective layer 13, a second optical shape layer 14, and a protective layer 15 in order from the image source side (+ Z side). ing.

The base material layer 11 is a sheet-like member having optical transparency. As for the base material layer 11, the 1st optical shape layer 12 is integrally formed in the back side (-Z side). The base material layer 11 is a layer that becomes a base material (base) for forming the first optical shape layer 12.
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). Cellulose) resin or the like.
The thickness of the base material layer 11 can be selected according to the screen size and the like.

The first optical shape layer 12 is a light-transmitting layer formed on the back side (−Z side) of the base material layer 11. A plurality of unit optical shapes 121 are provided on the back side (−Z side) surface of the first optical shape layer 12.
The unit optical shapes 121 extend in the left-right direction (X direction) of the screen 10 and are arrayed along the vertical direction (Y direction) of the screen 10. A linear Fresnel lens shape is formed on the back side of the first optical shape layer 12. Is formed.
The unit optical shape 121 is a prism shape in which a cross-sectional shape in a cross section parallel to the thickness direction (Z direction) of the screen 10 and parallel to the arrangement direction (Y direction) of the unit optical shapes 121 is convex on the back side. is there.

The unit optical shape 121 has a first surface 121a on which image light is directly incident and a second surface 121b opposite to the first surface 121a. In one unit optical shape 121, the first surface 121a is located on the upper side (+ Y side) with respect to the second surface 121b across the vertex t.
The angle formed by the first surface 121a and a surface parallel to the screen surface is θ1. The angle formed by the second surface 121b and the surface parallel to the screen surface is θ2. The angles θ1 and θ2 satisfy the relationship θ2> θ1.
The first surface 121a and the second surface 121b of the unit optical shape 121 have fine and irregular uneven shapes.

In FIG. 2, the first surface 121a and the second surface 121b are planar, and the top portion of the unit optical shape 121 and the valley portion between adjacent unit optical shapes 121 have been described as examples. It is also assumed that at least a part of the first surface 121a and the second surface 121b is curved, or that the top of the unit optical shape 121 and the valley between adjacent unit optical shapes 121 are curved. .
In this case, the angle θ1 formed by the first surface 121a and the direction parallel to the screen surface is the first surface 121a in the cross section of the screen 10 in the direction parallel to the arrangement direction of the unit optical shapes 121 and the thickness direction of the screen 10. The angle between the tangent line at the midpoint of the region and the direction parallel to the screen surface.
In this case, the angle θ2 formed by the second surface 121b and the direction parallel to the screen surface is the second angle in the section of the screen 10 in the direction parallel to the arrangement direction of the unit optical shapes 121 and the thickness direction of the screen 10. An angle formed by a plane passing through a point on the most back side of the area to be the surface 521b (that is, the vertex t) and a point on the most image source side (that is, the point v that is the valley bottom) in a direction parallel to the screen surface And

The arrangement pitch of the unit optical shapes 121 is P, and the height of the unit optical shapes 121 (the dimension from the vertex t in the thickness direction to the point v that becomes the valley bottom between the unit optical shapes 121) is h.
In the present embodiment, as shown in FIG. 2, an example in which the angles θ1, θ2, the arrangement pitch P, and the like are constant is shown. However, the present invention is not limited thereto, and these angles and dimensions may include the projection angle of the image light from the image source LS (the incident angle of the image light to the screen 10), the size of the pixel (pixel) of the image source LS, the screen It may be set as appropriate according to the screen size of 10, the refractive index of each layer, and the like. For example, these angles and dimensions may change gradually or stepwise along the arrangement direction of the unit optical shapes 121.

The first 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, the resin for forming the first optical shape layer 12 will be described by taking an ultraviolet curable resin as an example. However, the present invention is not limited thereto, and other ionizing radiation such as an electron beam curable resin is used. You may form with curable resin.

The reflective layer 13 is a layer formed on at least the first surface 121 a of the unit optical shape 121. In the present embodiment, the reflective layer 13 is formed on the first surface 121 a and the second surface 121 b of the unit optical shape 121.
As described above, the first surface 121a and the second surface 121b are formed with fine and irregular concavo-convex shapes, and the reflective layer 13 is formed following this fine and irregular concavo-convex shape. ing. Further, the thickness of the reflective layer 13 is sufficiently thinner than the uneven shape. Therefore, the reflective surface of the reflective layer 13 (the surface on the first optical shape layer 12 side) and the back surface (the surface on the second optical shape layer 14 side) are mat surfaces having fine and irregular concavo-convex shapes. It has become.

  The surface roughness (that is, the surface roughness of the first surface 121a) of the reflective surface (image source side surface) of the reflective layer 13 is about 0.15 to arithmetic average roughness Ra (JIS B0601-2001). The thickness is preferably 0.3 μm from the viewpoint of displaying an image favorably by reflected light. The arithmetic average roughness Ra, which is the surface roughness (that is, the surface roughness of the first surface 121a) of the reflecting surface (image source side surface) of the reflecting layer 13, is appropriately determined according to the desired optical performance and the like. You may choose.

The reflective layer 13 is a so-called half mirror that reflects a part of incident light and transmits the other part.
The ratio between the reflectance and the transmittance of the reflective layer 13 can be set as appropriate, but the image light is favorably reflected and light other than the image light (for example, light from the outside such as sunlight) is favorably transmitted. From the viewpoint, it is desirable that the transmittance is 30 to 80% and the reflectance is 5 to 60%.
The reflective layer 13 of this embodiment is formed in a half mirror shape with a reflectance of about 40% and a transmittance of about 50%.
Therefore, the reflective layer 13 of the present embodiment has a function of diffusing and reflecting a part of incident light by the fine and irregular uneven shape of the reflecting surface and transmitting other light that does not reflect without diffusing. .

The reflective layer 13 is formed of a metal having high light reflectivity, for example, aluminum, silver, nickel or the like. 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 with high light reflectivity, transferring a metal foil, or applying a paint containing a metal thin film, For example, it may be formed by vapor-depositing a dielectric multilayer film.

A dielectric multilayer film is formed by alternately laminating a plurality of dielectric films having a high refractive index (hereinafter referred to as a high refractive index dielectric film) and dielectric films having a low refractive index (hereinafter referred to as a low refractive index dielectric film). Is formed.
The high refractive index dielectric film is formed of, for example, TiO ₂ (titanium dioxide), Nb ₂ O ₅ (niobium pentoxide), Ta ₂ O ₅ (tantalum pentoxide), or the like. The refractive index of the high refractive index dielectric film is about 2.0 to 2.6.
The low refractive index dielectric film is formed of, for example, SiO ₂ (silicon dioxide), MgF ₂ (magnesium fluoride), or the like. The refractive index of the low refractive index dielectric film is about 1.3 to 1.5.
The film thickness of the high-refractive index dielectric film and the low-refractive index dielectric film is about 5 to 100 nm, and a dielectric multilayer film is formed by alternately laminating about 2 to 10 layers as the reflective layer. The total thickness of the formed dielectric multilayer film is about 10 to 1000 nm.

The reflective layer formed of such a dielectric multilayer film has, for example, a reflectance of 5 to 45% and a transmittance of 55 to 85% with respect to light having a wavelength range of 400 to 800 nm.
A reflective layer formed of a dielectric multilayer film has the advantages of higher transparency and less light absorption loss than a reflective layer formed of a metal deposition film such as aluminum.

The second optical shape layer 14 is a light-transmitting layer provided on the back side (−Z side) of the first optical shape layer 12. The second optical shape layer 14 is provided to flatten the back side (−Z side) surface of the first optical shape layer 12 and is formed so as to fill the valleys of the irregularities due to the unit optical shape 121. ing. Accordingly, the image source side (+ Z side) surface of the second optical shape layer 14 is formed by arranging a plurality of substantially reverse shapes of the unit optical shapes 121 of the first optical shape layer 12.
By providing the second optical shape layer 14 as described above, the reflective layer 13 can be protected, and the protective layer 15 and the like can be easily laminated on the back surface of the first optical shape layer 12 of the screen 10. Further, it is easy to join the support plate or the like to the back side of the screen 10.
The refractive index of the second optical shape layer 14 is desirably equal to that of the first optical shape layer 22, and the second optical shape layer 14 is made of the same ultraviolet curable resin as that of the first optical shape layer 12 described above. It is preferable to form.
The second optical shape layer 14 of the present embodiment is formed of the same ultraviolet curable resin as the first optical shape layer 12, and the refractive index thereof is equal to that of the first optical shape layer 12.

The protective layer 15 is a layer formed on the back side (−Z side) of the second optical shape layer 14, and has a function of protecting the back side of the screen 10.
The protective layer 15 is made of a resinous 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 screen 10 of the present embodiment does not include a light diffusion layer containing a diffusing material such as particles having a diffusing action, and has a diffusing action because the reflective surface of the reflective layer 13 is fine and Only irregular irregular shapes.

In the screen 10 of the present embodiment, the reflective layer 13 is formed on the first surface 121a and the second surface 121b having fine and irregular concavo-convex shapes, and is a surface on the first optical shape layer 12 side serving as a reflective surface. Has a matte surface (rough surface). Therefore, a part of the light incident on the first surface 121a is diffusely reflected.
Here, the arrangement direction of the unit optical shapes 121 with respect to the angle K of the peak luminance of the light (reflected light) incident on the reflection layer 13 from the first surface 121a and diffusely reflected and emitted from the screen 10 (this embodiment) In the embodiment, the angle at which the luminance becomes 1/2 in the vertical direction of the screen is K1 and K2, and the angle change amount from the angle K of the peak luminance to the angles K1 and K2 at which the luminance becomes 1/2 is + α1 (however, When K + α1 = K1) and −α2 (where K−α2 = K2), the average value of the absolute value of the angle change amount from the peak luminance until the luminance becomes ½ is α (this is hereinafter referred to as 1 / The half angle α is preferably 5 ° or more and 45 ° or less (5 ° ≦ α ≦ 45 °).

If α <5 °, the viewing angle becomes too narrow and the image becomes difficult to see. Further, when α <5 °, the specular reflection component in the reflected light increases, and the reflection of the light source occurs, which is not preferable.
When α> 45 °, the viewing angle is widened, but the brightness of the image is decreased, the blur of the image is increased, or the contrast of the image is decreased due to reflection of the external light on the surface of the screen 10. Therefore, it is not preferable. Accordingly, the ½ angle α is preferably in the above range.

In addition, the reflective layer 13 is not a rough surface, that is, does not have a fine and irregular uneven shape, and the image source side surface (the surface on the first optical shape layer 12 side) is mirror-like. The mirror surface area where the incident image light is specularly reflected is 5% or less per unit area of the reflective layer 13 formed on the first surface 121a. It is necessary to obtain the corner and is ideally 0%.
If the mirror surface area that is not a rough surface exceeds 5%, it is not preferable because a bright line is generated due to a component of image light that is reflected without being diffused and reaches the observer O1 side, or the viewing angle is lowered.

FIG. 3 is a diagram for explaining the relationship between the ½ angle α, the incident angle φ of the image light, and the angle θ1 of the first surface 121a. In FIG. 3, for easy understanding, the configuration in the screen 10 is simplified, and the base material layer 11 and the protective layer 15 are omitted. In FIG. 3, with respect to the angles α and φ, the upper side of the screen is shown as + and the lower side of the screen is shown as − with respect to the normal of the screen surface.
The angle θ1 of the first surface 121a is such that the image light is most efficiently reflected by an observer positioned in the front direction of the screen 10, that is, the angle K at which the reflected light has the peak luminance is 0 °. Thus, it is designed based on the refractive index of each layer. Further, the range from −α to + α is a range in which it is assumed that an observer located in front of the screen observes the video satisfactorily.

Here, at a certain point in the vertical direction of the screen (direction passing through point A and parallel to the arrangement direction of the unit optical shapes 121), the image light L is incident from below the screen 10 at the incident angle φ, and the first refractive index n is obtained. Advancing through the optical shape layer 12, the light enters the first surface 121 a that forms an angle θ 1 with respect to the screen surface, is reflected by the reflective layer 13, and exits from the screen 10 in a direction orthogonal to the screen surface (emission angle 0 °). The angle θ1 is expressed by the following (formula 1).
θ1 = 1/2 × arcsin ((sinφ) / n) (Formula 1)

As in this embodiment, when the video light is projected from the video source LS and reflected by the screen 10 to display the video, the light source of the video source LS that projects the video light is reflected, and the contrast of the video is lowered. May arise. This reflection of the image source is mainly due to the image light reflected on the surface of the screen reaching the observer.
In order to prevent such reflection of the image source, the surface of the screen is placed outside the angle range (−α to + α) that is the range in which the observer mainly observes the image on the surface of the screen 10. It is preferable that the image light reflected by the light travels. When a part Lr of the image light L incident at an incident angle −φ is reflected on the screen surface, the reflection angle is + φ. Therefore, α <φ is preferable in order to prevent reflection of the image source.

Therefore, from the above (Equation 1) and α <φ, in the vertical direction of the screen (the arrangement direction of the unit optical shapes 121), the half angle α and the angle θ1 of the first surface 121a are the reflection of the image source. In order to prevent entrainment, it is preferable that at least a part of the screen 10 (for example, the center of the screen) satisfies the following (Formula 2).
α <arcsin (n × sin (2 × (θ1))) (Expression 2)
In order to prevent the reflection of the image source, it is more preferable that the ½ angle α satisfies the above (Equation 2) over the entire area of the screen 10 with respect to the angle θ1 of the first surface 121a.
By setting the angle θ1 to satisfy the above (formula 2) with respect to the half angle α, the direction in which the light reflected by the surface of the screen 10 is mainly directed when entering the screen 10 (the direction of + φ) is increased. The image light reflected by the reflective layer 13 is outside the range (−α to + α) that is emitted from the screen 10 and travels. Thereby, in the range from −α to + α, the reflection of the image source LS can be reduced, and a good image with high contrast can be displayed.

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

After that, an ultraviolet curable resin is applied from above the reflective layer 13 so as to fill the valleys between the unit optical shapes 121 and form a flat surface, and the protective layer 15 is laminated to cure the ultraviolet curable resin. The second optical shape layer 14 and the protective layer 15 are integrally formed. Thereafter, the screen 10 is completed by cutting into a predetermined size.
The base material layer 11 and the protective layer 15 may be a single wafer shape or a web shape. When the base material layer 11 and the protective layer 15 are formed in a web shape, the screen 10 in a state before cutting can be continuously manufactured, which can improve the production efficiency of the screen 10 and reduce the production cost. it can.

  Further, for example, as a method of forming a fine and irregular concavo-convex shape on the surface of the reflective layer 13, diffusing particles or the like are applied on the first surface 121a and the second surface 121b, and the reflective layer 13 is applied from above. A method of forming the reflective layer 13 after forming the first optical shape layer 12 or blasting the first surface 121a and the second surface 121b after forming the first optical shape layer 12 is known. However, in such a manufacturing method, dispersion | variation in the diffusion characteristic, quality, etc. in each screen 10 is large, and stable manufacture cannot be performed. On the other hand, as described above, the reflective layer 13 is formed after the fine irregular irregular shapes of the first surface 121a and the second surface 121b of the unit optical shape 121 are formed by the molding die. Therefore, even when a large number of first optical shape layers 12 and screens 10 are manufactured, there is an advantage that the quality can be stably manufactured with little variation in quality.

FIG. 4 is a diagram illustrating a state of image light and external light on the screen 10 according to the first embodiment. In FIG. 4, a part of a cross section passing through the point A and parallel to the arrangement direction (Y direction) of the unit optical shapes 121 and the thickness direction (Z direction) of the screen is shown enlarged. Further, in FIG. 4, for easy understanding, it is assumed that there is no refractive index difference at the interface of each layer in the screen 10.
Of the image light L1 projected from the image source LS positioned below the screen 10 and incident on the screen 10, a part of the image light L2 is incident on the first surface 121a of the unit optical shape 121, and the reflection layer. 13 is diffusely reflected and emitted to the observer O1 side.

Of the image light incident on the first surface 121a, the other image light L3 that has not been reflected passes through the reflective layer 13 and is emitted from the back side (−Z side) of the screen 10. At this time, the image light L3 is emitted upward from the screen 10 and does not reach the observer O2 positioned in the front direction of the screen 10 on the back side.
Further, out of the video light L1 projected from the video source LS, a part of the video light L4 is reflected by the surface of the screen 10 and travels upward. At this time, the reflection angle of the image light L4 is larger than the ½ angle α or more as described above, and thus does not hinder the viewer O1 from viewing the image.
In the present embodiment, the image light L1 is projected from below the screen 10, and the angle θ2 (see FIG. 2) is larger than the incident angle of the image light at each point in the screen vertical direction of the screen 10. Light does not directly enter the second surface 121b, and the second surface 121b hardly affects the reflection of the image light.

Next, light from the outside such as sunlight and illumination light other than image light incident on the screen 10 from the back side (−Z side) or the image source side (+ Z side) (hereinafter referred to as outside light) will be described.
As shown in FIG. 4, out of the external lights G1 and G5 incident on the screen 10 from above, some of the external lights G2 and G6 are reflected by the surface of the screen 10 and travel downward. Further, a part of the external light G3, G7 is reflected by the reflection layer 13. For example, the external light G3 is totally reflected on the surface of the screen 10 on the image source side (+ Z side) and goes downward in the screen 10, The external light G7 is emitted to the upper side outside the screen on the back side (−Z side). The other external lights G4 and G8 that are not reflected by the reflective layer 13 are transmitted through the reflective layer 13 and emitted to the back side and the video source side, respectively. At this time, since the external lights G2, G3, and G8 emitted to the video source side do not reach the observer O1, it is possible to suppress a reduction in the contrast of the video.

Although not shown, a part of the external light incident on the screen 10 from above is totally reflected by the surface of the screen 10 and attenuates toward the lower side inside the screen.
Further, other external lights G9 and G10 incident on the screen 10 at a small incident angle are transmitted through the reflective layer 13 and emitted to the back side and the video source side, respectively. Since the screen 10 does not include a light diffusing layer containing diffusing particles that diffuse light, the external lights G9 and G10 that pass through the screen 10 are not diffused. Therefore, when the scenery on the other side of the screen 10 is observed through the screen 10, the scenery on the other side of the screen 10 can be observed with high transparency without blurring or whitening.

In a transflective reflective screen having a conventional light diffusing layer containing diffusing particles, image light is diffused twice before and after reflection by the reflective layer, so that a good viewing angle can be obtained while the image is displayed. There is a problem that the resolution is lowered. Further, since the outside light is also diffused by the diffusing particles, the scenery on the other side of the screen is observed blurred or whitened.
However, in the screen 10 of the present embodiment, the image light is diffused only at the time of reflection because it has no diffusing action except that the reflection surface (image source side surface) of the reflection layer 13 is a rough surface. Moreover, in the screen 10 of this embodiment, only the light reflected by the reflective layer 13 is diffused, and the transmitted light is not diffused. Therefore, the screen 10 according to the present embodiment can display an image having a good viewing angle and resolution, and the scene on the other side of the screen 10 is not visually blurred or blurred, and is well visible to the observer O1. High transparency can be realized. Moreover, in the screen 10 of this embodiment, even when the image light is projected on the screen 10, the observer O1 can partially view the scenery on the other side (back side) of the screen 10. Further, on the screen 10, the observer O2 located on the back side can visually recognize the scene on the image source side (+ Z side) with high transparency through the screen 10 regardless of whether image light is projected. can do.

  Further, in the screen 10 of the present embodiment, the ½ angle α of the image light (reflected light) diffusely reflected by the reflective layer 13 is relative to the angle θ1 formed by the first surface 121a and a surface parallel to the screen surface. Therefore, since the above-described (Equation 2) is satisfied, the image light reflected on the image source side surface of the screen 10 is directed outward from the ½ angle α, and the image source LS is not reflected and a good image is obtained. Can be displayed.

  Here, the screens of Measurement Examples 1 to 6 including the first optical shape layers 12 having different ½ angles α were prepared, and images were projected from the image source LS to evaluate the appearance of the displayed images. The screens of the measurement examples 1 to 6 are substantially the same except that the half angle α and the surface roughness (arithmetic average roughness Ra) of the irregular irregular shape of the first surface 121a are different. Shape. The ½ angle α and the arithmetic average roughness Ra of the screens of Measurement Examples 1 to 6 are as described in Table 1 below.

In the screens of Measurement Examples 1 to 6, the dimensions and the like of the common parts such as the base material layer 11 are as follows.
The base material layer 11 is made of PET resin and has a thickness of about 100 μm.
The first optical shape layer 12 is a urethane acrylate ultraviolet curable resin (refractive index of 1.52).
The unit optical shape 121 has an arrangement pitch P of 100 μm.
The reflective layer 13 is formed of an aluminum vapor deposition film, and has a thickness of about 60 mm, a transmittance of 50%, and a reflectance of 40%.
The second optical shape layer 14 is a urethane acrylate ultraviolet curable resin (refractive index 1.52).
The protective layer 15 is made of PET resin and has a thickness of about 100 μm.
The video source LS was installed so that the luminance was maximum at a point A that was the center of the screen.

The screens of measurement examples 1 to 6 are prepared, image light is projected from the image source LS, the image is displayed, and the appearance of the image is visually observed from the image source side (+ Z side) of the screen 10. evaluated.
Table 1 summarizes the evaluation results of the screens of Measurement Examples 1 to 6.
FIG. 5 is a graph showing the brightness and diffusion angle of the reflected light of the screen 10 in Measurement Examples 1-6. In the graph shown in FIG. 5, the vertical axis represents the luminance (cd / m ² ) of the reflected light, and the horizontal axis represents the diffusion angle (°).

In the screen of Measurement Example 1 in which the ½ angle α is less than 5 °, the brightness of the image is good, but the viewing angle is too narrow and the image is difficult to view. Further, in the image light reflected by the reflective layer 13, the specular reflection component increased, and reflection of the light source of the image source LS was observed.
In the screens of Measurement Examples 5 and 6 where the half angle α is larger than 45 °, the viewing angle is sufficiently wide, but the light is diffused too much, and the brightness and resolution of the image are lowered, making it difficult to view the image. .
On the other hand, on the screens of Measurement Examples 2, 3, and 4 in which the ½ angle α is 5 ° or more and 45 ° or less, good images having a sufficient viewing angle and brightness were visually recognized.

  As described above, according to the present embodiment, a transflective reflective screen 10 and an image display device 1 that can display a good image having high transparency and sufficient viewing angle and brightness are provided. be able to.

(Second Embodiment)
FIG. 6 is a diagram illustrating the screen 20 according to the second embodiment. FIG. 6A is a view of the first optical shape layer 22 of the screen 20 as viewed from the back side (−Z side), and in order to facilitate understanding, the reflective layer 13, the second optical shape layer 14, The protective layer 15 and the like are not shown. In FIG.6 (b), a part of cross section of the screen 20 of 2nd Embodiment equivalent to the cross section of the screen 10 of 1st Embodiment shown in above-mentioned FIG. 2 is expanded and shown.
The screen 20 shown in the second embodiment has substantially the same form as the screen 10 of the first embodiment described above, but the first optical shape layer 22 has a circular Fresnel lens shape, and the second optical shape layer 24 has Corresponding to the first optical shape layer 22, the surface on the image source side has a shape that is the inverse of the circular Fresnel lens shape. Therefore, parts having the same functions as those of the first embodiment described above are denoted by the same reference numerals or the same reference numerals at the end thereof, and repeated descriptions are appropriately omitted. Similarly, in the second embodiment and third to sixth embodiments described later, differences from the first embodiment will be mainly described.
The screen 20 of the second embodiment can be used in place of the screen 10 in the video display device 1 of the first embodiment described above.

The screen 20 includes a base material layer 11, a first optical shape layer 22, a reflective layer 13, a second optical shape layer 24, and a protective layer 15.
A plurality of unit optical shapes (unit lenses) 221 are arranged on the back side of the first optical shape layer 22. The unit optical shape 221 is a partial shape (arc shape) of a perfect circle, and as shown in FIG. 6, a plurality of unit optical shapes 221 are arranged concentrically around the point C located outside the screen (display area) of the screen 20. ing. That is, the first optical shape layer 22 has a circular Fresnel lens shape having a so-called offset structure with the point C as the center (Fresnel center) on the back side.
In the present embodiment, as shown in FIG. 6, this point C is located at the center of the screen 20 (display area) in the left-right direction and below the screen, and the screen 10 is viewed from the front. The points C and A are located on the same straight line parallel to the vertical direction (Y direction) of the screen.
The second optical shape layer 24 is substantially the same as the second optical shape layer 14 of the first embodiment. However, the second optical shape layer 24 is a reverse type of the circular Fresnel lens shape of the first optical shape layer 22 on the image source side surface. An optical shape is formed.

According to the present embodiment, similar to the first embodiment described above, it is possible to display a good image with high transparency.
Further, according to the present embodiment, the first optical shape layer 22 has a so-called offset-structured circular Fresnel lens shape in which the point C serving as the Fresnel center is located below the display area of the screen 20. Therefore, even in the case of image light with a large incident angle projected from the short focus type image source LS located below the screen 20, the image in the horizontal direction of the screen is not darkened, and the brightness is uniform. High quality video can be displayed.

(Third embodiment)
The screen 30 of the third embodiment has the same form as the screen 10 shown in the first embodiment, but the circular Fresnel having the same offset structure as that of the second embodiment is used as the first optical shape layer and the second optical shape layer. Light having a first optical shape layer 22 having a lens shape and a second optical shape layer 24 corresponding to the first optical shape layer 22 and absorbing light into the screen 30 so that the light transmittance of the screen 30 is a predetermined value. It is characterized by comprising at least one absorption layer.

FIG. 7 is a diagram illustrating the layer configuration of the screen 30 according to the third embodiment. The cross section of the screen 30 shown in FIG. 7 corresponds to the cross section of the screen 10 shown in FIG. 2 of the first embodiment.
As shown in FIG. 7, the screen 30 of the present embodiment has a base material layer 11, a first optical shape layer 22, a reflective layer 33, in order from the image source side (+ Z side) in the thickness direction (Z direction). A second optical shape layer 24, a protective layer 15 and the like are provided. This screen 30 is applicable to the video display device 1 shown in the first embodiment.

  The reflective layer 33 of the present embodiment is substantially the same form as the reflective layer 13 of the first embodiment described above, but has a function as a light absorbing layer that sets the light transmittance of the screen 30 to a predetermined value. The reflective layer 33 will be described later.

For light incident on the screen surface of the screen 30 of the present embodiment from the image source side (+ Z side) at an incident angle of 0 °, the transmittance (total light transmittance) transmitted to the back side when the total amount Sp is 100%. ) Is Tp (%), the reflectance reflected by the reflective layer 13 and emitted to the image source side is Rp (%), and the absorption rate absorbed from the screen 30 (from the total amount Sp, the transmittance Tp and the reflectance). When the value obtained by subtracting the sum of Rp) is Ap (%), the sum of the transmittance Tp and the reflectance Rp is 95% or less, and the absorption rate Ap is 5% or more. That is, they satisfy the following formula.
Tp + Rp ≦ 95 (Formula 3)
Ap = Sp− (Tp + Rp) ≧ 5 (Formula 4)

Further, in the screen 30 of the present embodiment, the absorption rate of light incident on the screen surface at an incident angle of 0 ° (corresponding to the aforementioned Ap) is 5 regardless of whether it is incident from the video source side or the rear surface side. It is preferable that it is -50%, More preferably, it is 10-30%, More preferably, it is 10-20%. That is, the absorption rate Ap (%) preferably satisfies 5 ≦ Ap ≦ 50, more preferably satisfies 10 ≦ Ap ≦ 30, and still more preferably satisfies 10 ≦ Ap ≦ 20.
If the absorptance is less than 5%, the contrast of the image is lowered, which is not preferable. On the other hand, if the absorptance is higher than 50%, the brightness of the image reflected and displayed is lowered, and the transparency as a screen is lowered, which is not preferable. Therefore, it is preferable that the absorption rate satisfies the above range.

In the thickness direction of the screen 30 of the present embodiment, a region from the image source side surface 30a of the screen 30 to the back side (-Z side) surface 33b of the reflective layer 33 is defined as an image source side region Sa, and the back side of the screen 30 A region from the surface 30b to the image source side (+ Z side) surface 33a of the reflective layer 33 is defined as a back side region Sb. In the screen 30, the light transmittance and absorption rate of the protective layer 15 and the second optical shape layer 14 are equal to the light transmittance and absorption rate of the base material layer 11 and the first optical shape layer 12.
The reflection layer 33 of the present embodiment has a function as a light absorption layer as described above, and the absorption rate at the time of reflection of light incident from the back side (−Z side) is from the image source side (+ Z side). It is larger than the absorptance when the incident light is reflected.
Therefore, in the screen 30 of the present embodiment, the light absorption rate of the back side region Sb is larger than the light absorption rate of the image source side region Sa, and optically, the screen 30 absorbs light in the back side region Sb. This corresponds to a form having a layer having an action.

  By adopting such a configuration, when the other side (image source side) of the screen 30 is viewed from the back side, or the other side of the screen 30 (back side) is viewed from the image source side. While maintaining high transparency, external light such as unnecessary illumination light and sunlight incident from the back side can be absorbed, and the contrast of the image can be improved. Further, since the reflection layer 33 does not absorb the image light for displaying the image to the observer O1, the use efficiency of the image light necessary for displaying the image is maintained high, and a bright and clear image can be displayed.

Therefore, according to the present embodiment, similar to the first embodiment described above, it is possible to display a good image with high transparency.
In this embodiment, since the light absorption rate of the back side region Sb of the screen 30 is larger than the light absorption rate of the video source side region Sa, it enters from the back side (−Z side) and enters the video source side. Going to (+ Z side), it is possible to absorb external light or the like that adversely affects the viewing of the image of the observer O1, and display a high contrast image while having high transparency as a screen.
In addition, according to the present embodiment, the area closer to the image source side and the back side than the reflective layer 33 is transparent and has the same transmittance and the like, so that the screen is viewed from either the image source side or the back side. High transparency can be achieved even when

In the third embodiment described above, an example is shown in which the light absorption rate of the back side region Sb of the screen 30 is larger than the light absorption rate of the image source side region Sa. May be larger than the light absorptance of the back side region Sb. In addition, the position and the number of layers of the screen 30 are not particularly limited as long as the screen 30 includes at least one light absorption layer that absorbs light in the screen and sets the light transmittance of the reflection screen to a predetermined value.
For example, at least one of the protective layer 15, the second optical shape layer 24, the base material layer 11, and the first optical shape layer 22 may have a function as a light absorption layer, and is not illustrated between the layers. A light absorption layer may be provided, or a light absorption layer may be formed integrally with the reflection layer 33 on the image source side or back side of the reflection layer 33.
Further, the light absorption layer may be colored with a coloring material such as a dye or pigment such as gray or black, or it is not colored and is a transparent layer and has a light absorption function. It is good also as a form to have.

(Fourth embodiment)
The video display device of the fourth embodiment includes a video source and a screen 40.
The video display device of the fourth embodiment is similar to the video display device 1 of the first embodiment, but is characterized in that the video source projects light including a large amount of predetermined polarization onto the screen 40 as video light. To do. The screen 40 of the fourth embodiment is substantially the same form as the screen 10 of the first embodiment, but the first optical shape layer 22 having a circular Fresnel lens shape having the same offset structure as that of the second embodiment and Corresponding to this, a predetermined polarization included in the image light is absorbed or absorbed in a region on the back side up to the back side surface of the screen 40 including the reflection layer 13 in the thickness direction in which the second optical shape layer 24 is provided. It is characterized in that it includes an omission light suppression layer that reflects and suppresses at least part of the image light from being emitted to the back side of the screen 40.

The image source of the fourth embodiment is a short focus type projector, similar to the image source LS of the first embodiment described above, but projects light including a large amount of predetermined polarization as image light. As such an image source, a projector provided with a polarizing filter or the like at a projection port for image light, a liquid crystal projector, or the like is suitable. Further, the image light is not limited to light including a large amount of predetermined polarization, and may be predetermined polarization.
The image source of the present embodiment is a projector in which a polarizing filter is disposed at the image light projection port. The image source side surface 40a (see FIG. 8) of the screen 40 has a predetermined linearly polarized light (hereinafter referred to as the first light source). Projects image light that contains a large amount of polarized light.

FIG. 8 is a diagram illustrating a layer configuration of the screen 40 according to the fourth embodiment. The cross section of the screen 40 shown in FIG. 8 corresponds to the cross section of the screen 10 shown in FIG. 2 of the first embodiment described above.
The screen 40 has a base material layer 41, a first optical shape layer 22, a reflective layer 13, a second optical shape layer 24, a light leakage suppression layer 45, and the like in order from the image source side (+ Z side) in the thickness direction (Z direction). It has.
The base material layer 41 is substantially the same as the base material layer 11 shown in the first embodiment, but the retardation is preferably about 200 nm or less, and more preferably 100 nm or less.

FIG. 9 is a diagram for explaining the light leakage suppression layer 45 of the fourth embodiment. 9 shows only the light leakage suppression layer 45 in the cross section of the screen 40 shown in FIG.
The escape light suppression layer 45 is a layer provided on the back side (−Z side) from the second optical shape layer 14 and has a function of transmitting predetermined polarized light and absorbing other light. A polarizing plate can be used as such a light leakage suppression layer 45.
In the present embodiment, the mode in which the light exit suppression layer 45 is located on the most back side of the screen 40 is shown. However, the present invention is not limited to this, and the back side of the screen 40 is further provided on the back side of the light exit suppression layer 45. A protective layer (not shown) for protecting the surface of the film may be provided.

  The image source of the present embodiment projects image light including a large amount of first polarized light that is predetermined linearly polarized light on the image source side surface 40a (see FIG. 8) of the screen 40. Further, as shown in FIG. 9, the missing light suppression layer 45 absorbs the first polarized light and transmits linearly polarized light (hereinafter, second polarized light) having a polarization plane orthogonal to the polarization plane of the first polarization. It has a function to do. Accordingly, the first polarized light included in the image light transmitted through the reflective layer 13 is absorbed by the missing light suppression layer 45, and the second polarized light included in the image light transmitted through the reflective layer 13 is omitted from the lost light suppressing layer 45. The amount of light is small.

Further, the first polarized light included in the external light incident on the screen 40 from the upper side of the image source side or the upper side of the back surface is absorbed by the missing light suppression layer 45, and the second polarized light included in this external light is the missing light. The light passes through the suppression layer 45 but exits in a direction that does not reach the observers O1 and O2, or is totally reflected on the screen surface and attenuates downward in the screen. Therefore, about half of the amount of external light passes through the screen 40.
In addition, the first polarized light included in the external light incident on the screen 40 at a small incident angle is absorbed by the escape light suppression layer 45, and the second polarized light included in the external light is transmitted through the escape light suppression layer 45. To do. Therefore, about half of the outside light is transmitted through the screen 40 without being diffused.

  If the screen does not include the light suppression layer 45 and the image source does not irradiate the first polarized light as the image light, a part of the image light transmitted without being reflected by the reflection layer 13 is reflected on the back surface of the screen. There is a problem that the light is emitted upward from the side, and the image is reflected on the ceiling, resulting in deterioration of the design. Such reflection of the image on the ceiling is particularly likely to occur when the screen is a large screen.

On the other hand, according to the present embodiment, the image light projected by the image source includes a large amount of the first polarization, and the missing light suppression layer 45 absorbs the first polarization and transmits the second polarization. Therefore, the image light transmitted through the reflective layer 13 can be effectively absorbed. Therefore, the reflection of the image on the ceiling as described above can be greatly improved. Further, the light leakage suppression layer 45 absorbs the first polarized light but transmits the second polarized light, so that the transparency of the screen 40 can be maintained.
Moreover, since the screen 40 of this embodiment absorbs the 1st polarized light contained in the external light which injects from the back side upper side of the screen 40, the contrast of an image | video can be improved and a favorable image | video can be displayed.
From the above, according to the present embodiment, similar to the first embodiment, it has high transparency, can display a good image, further improves the contrast of the image, and displays the image on the ceiling or the like. Can be suppressed.

  In the above-described fourth embodiment, an example in which the predetermined polarization is linear polarization has been described. However, the present invention is not limited to this, and the case where the image source projects clockwise (or counterclockwise) circularly polarized light. The omission light suppression layer 45 may absorb the circularly polarized light and absorb the counterclockwise (or clockwise) circularly polarized light. At this time, it is preferable that a quarter wavelength plate is provided on the image source side of the light leakage suppression layer 45.

Moreover, as a missing light suppression layer, for example, a layer having a function of reflecting predetermined polarized light (linearly polarized light or circularly polarized light) and transmitting other light may be provided in the screen. A form having such a function may be adopted. In that case, a sheet-like member having polarization selective reflectivity that reflects predetermined polarized light and transmits the other can be used as the reflective layer. For example, at least one liquid crystal layer made of cholesteric liquid crystal And a sheet-like member in which a quarter-wave plate is laminated can be suitably used.
In such a form, a bright image can be displayed by efficiently reflecting the image light, and the transparency can be maintained high. Further, since the predetermined polarization contained in the image light is reflected by the reflection layer, the amount of light transmitted through the reflection layer can be greatly reduced, and the reflection of the image on the ceiling on the back side can be greatly improved.

(Fifth embodiment)
The screen 50 of the fifth embodiment has substantially the same shape as the screen 10 of the first embodiment, but the circular Fresnel lens shape having the same offset structure as that of the first optical shape layer 22 of the second embodiment is on the back side. The first optical shape layer 52 and the second optical shape layer 54 corresponding to the first optical shape layer 52, and the second surface 521b of the unit optical shape 521 intersect the normal direction of the screen surface. To do.
FIG. 10 is a diagram illustrating the layer configuration of the screen 50 according to the fifth embodiment. The cross section of the screen 50 shown in FIG. 10 corresponds to the cross section of the screen 10 shown in FIG. 2 of the first embodiment described above.
FIG. 11 is a diagram illustrating the unit optical shape 521 of the fifth embodiment. 11, a part of the cross section of the screen 50 shown in FIG. 10 is further enlarged. Further, in FIG. 11, only the first optical shape layer 52, the reflective layer 13, and the second optical shape layer 54 are shown for easy understanding.

As shown in FIG. 10, the screen 50 includes a base material layer 11, a first optical shape layer 52, a reflective layer 13, a second optical shape layer 54, and a protective layer 15 in order from the image source side (+ Z side). ing. This screen 50 is applicable to the video display device 1 of the first embodiment.
The first optical shape layer 52 and the unit optical shape 521 are substantially similar to the first optical shape layer 22 and the unit optical shape 221 shown in the second embodiment, but a preferable range of the angle θ2 is set. It is characterized by that.

As shown in FIGS. 10 and 11, the second surface 521b of the present embodiment is planar, and the second surface 521b has a point on the back side (that is, the vertex t) and the most video source side. An angle formed by a plane passing through the point (that is, the point v) and a direction parallel to the screen surface is an angle θ2. Further, the surface on the viewer side (+ Z side) of the reflective layer 13 formed on the second surface 521b also forms an angle θ2 with respect to the direction parallel to the screen surface.
From the viewpoint of improving the transparency of the screen 50, suppressing reduction in contrast of the image due to external light, and displaying a high-contrast image, the second surface 521b preferably intersects the normal direction of the screen surface, This angle θ2 more preferably satisfies 25 ° ≦ θ2 ≦ 65 °.
In the present embodiment, the angle θ2 satisfies 25 ° ≦ θ2 ≦ 65 °.

FIG. 12 is a diagram for explaining the relationship between the angle θ2 and the external light in the fifth embodiment. 12A to 12C, the cross section of the screen 50 shown in FIG. 11 is shown with the reflective layer 13 simplified.
As shown in FIG. 12A, when the angle θ2 is θ2 = 90 ° (when the second surface 521b is orthogonal to the direction parallel to the screen surface), the upper side of the image source side (+ Z side) A part of the external light G517 and G518 incident on the screen at a large incident angle from above on the back side (−Z side) is emitted upward on the image source side even when reflected by the reflective layer 13 on the second surface 521b. And does not reach the observer O1 located in the front direction on the image source side.

However, a part of the external light G516 and G515 incident on the screen at a small incident angle from the image source side or the back side is diffusely reflected when entering the reflection layer 13 on the second surface 521b, and is directed in the front direction on the back side. In some cases, it may reach the viewer O2 who is positioned or the viewer O1 positioned in the front direction on the image source side.
As a result, when the image light is not projected, the viewers O1 and O2 are observed with the scenery on the other side of the screen blurred or whitely blurred, and the transparency of the screen is lowered. Further, during the projection of the image light, the contrast of the image is lowered by the external light G515 emitted to the image source side.
Therefore, from the viewpoint of improving the transparency of the screen and improving the contrast of the image, the second surface 521b intersects the normal direction of the screen surface (that is, the angle θ2 is not 90 °). Is preferred.

  Next, as shown in FIG. 12B, a case where the angle θ2 is 65 ° <θ2 <90 ° will be described. In this case, a part of the external light G519 incident on the screen from above the image source side and a part of the external light G520 incident on the screen at a small incident angle from the image source side are reflected by the reflection layer 13 or the like. Since the light is emitted upward on the image source side and on the back side of the image, or moves upward in the screen, it does not reach the observer O1 or the like. Although not shown, most of the external light incident on the screen at a small incident angle from the back side is transmitted through the reflection layer 13 and is reflected by the reflection layer 13 on the second surface 521b. It does not reach the observer O1 on the image source side, for example, by being emitted to the lower side.

  However, as shown in FIG. 12 (b), a part of the external light G521 incident on the screen at a large incident angle from the upper rear side is transmitted through the reflective layer 13 on the first surface 521a, and the second surface. The light may enter the reflective layer 13 on 521b, diffusely reflect, and reach the observer O1 on the video source side, which may cause a reduction in the contrast of the video.

Next, as shown in FIG. 12C, a case where the angle θ2 is 0 ° <θ2 <25 ° will be described. In this case, a part of the external light G522 incident on the screen from the upper rear side at a large incident angle passes through the reflective layer 13 on the first surface 521a and is emitted downward on the video source side of the screen. It does not reach the observer O1 on the side.
Further, a part of the external light G523 incident on the screen at a small incident angle from the image source side is reflected by the reflective layer 13 on the second surface 521b, and is emitted to the upper side of the image source side of the screen. Or the like, it does not reach the observer O1 on the image source side. Although not shown, most of the external light incident on the screen at a small incident angle from the back side is transmitted through the reflective layer 13 and is reflected by the reflective layer 13 on the second surface 521b. It does not reach the observer O1 or the like because it is emitted downward or upward on the back side.

However, in this case, a part of the external light G524 incident on the screen at a large incident angle from above the image source side is incident on the reflection layer 13 on the second surface 521b and diffusely reflected, and the image source side observer O1 may be reached and the contrast of the video may be reduced.
In this case, in the unit optical shape 521, the area occupied by the second surface 521b becomes too large, and the area of the first surface 521a that reflects the image light toward the viewer becomes small. Therefore, the amount of image light reaching the observer O1 decreases, and the image becomes dark and unclear, which is not preferable.

  On the other hand, when the angle θ2 is 25 ° ≦ θ2 ≦ 65 ° as in the screen 50 shown in FIG. 11, some of the external lights G513 and G514 that enter the screen 50 at a small incident angle. Even if the light is reflected by the reflective layer 13 on the second surface 521b, it may reach the observer O1 on the image source side or the observer O2 on the back side by exiting the screen 50 upward or downward on the image source side. Absent. In addition, most of the external lights G513 and G514 are transmitted through the reflective layer 13 on the second surface 521b. Therefore, when the image light is not projected, the background over the screen 50 is blurred or whitened and is not visually recognized by an observer located on the image source side or the back side, and has high transparency, The screen 50 having high contrast and brightness of the image can be obtained.

In addition, the external light G511 and G512 incident on the screen 50 at a large incident angle from above the back side of the screen 50 or from the upper side of the image source may be partially reflected by the reflective layer 13 on the second surface 521b. The light does not reach the observer O1 located in the front direction on the image source side because it is emitted upward or downward on the image source side, or travels through the screen and attenuates. Accordingly, it is possible to suppress a decrease in the contrast of the image due to external light, and it is possible to display an image with a high contrast.
In the unit optical shape 521, the area of the first surface 521a that reflects the image light to the viewer side can be sufficiently secured, and the image light incident on the second surface 521b can be sufficiently reduced. Simple images can be displayed.
From the above, it is more preferable that the angle θ2 satisfies 25 ° ≦ θ2 ≦ 65 °.

According to the present embodiment, similar to the first embodiment described above, the screen 50 and the image display device 1 that are highly transparent and capable of displaying a good image can be obtained.
In this embodiment, since the angle θ2 satisfies 25 ° ≦ θ2 ≦ 65 °, external light incident on the screen at a large incident angle from the upper side of the video source side and the upper side of the rear surface is reflected on the second surface 521b. It is less likely that the light is diffusely reflected by the upper reflective layer 13 and reaches the observer O1 located in the front direction on the image source side. Further, it is possible to suppress a decrease in transparency of the screen 50 due to diffuse reflection of external light incident at a small incident angle by the reflective layer 13 on the second surface 521b. Therefore, according to the present embodiment, a bright image with high transparency and high contrast can be displayed.

(Other forms of the fifth embodiment)
FIG. 13 is a diagram illustrating another form of the screen 50 according to the fifth embodiment. FIG. 13 shows a cross section of another form of the screen 50 corresponding to the cross section of the screen 50 shown in FIG.
As shown in FIG. 13, in another form of the screen 50 of the fifth embodiment, at least a part of the first surface 521a and the second surface 521b is a gently curved surface, and between adjacent unit optical shapes 521. The valley portion (the vicinity including the point v) and the top of the unit optical shape 521 (the vicinity including the vertex t) are also curved. The reflective layer 13 is formed along the shape of the unit optical shape 521.

  At this time, the region to be the second surface 521b in the unit optical shape 521 is a region from the point v serving as the valley bottom to the vertex t. In addition, the angle θ2 formed by the second surface 521b and the direction parallel to the screen surface is the point closest to the back side (ie, vertex t) and the point closest to the video source side (ie, point v corresponding to the valley bottom). Is an angle formed by a plane M passing through a direction parallel to the screen surface, and this angle θ2 satisfies 25 ° ≦ θ2 ≦ 65 °.

Further, as shown in FIG. 13, the angle θ3 formed by the tangent S of the second surface 521b and the direction parallel to the screen surface is along the arrangement direction of the unit optical shapes 521 in one second surface 521b. It is changing gradually.
In one second surface 521b, the sum of the area of the region where the angle θ3 is 0 ° ≦ θ3 <25 ° and the area of the region where 65 ° <θ3 ≦ 90 ° is 25 ° ≦ θ3 ≦. It is smaller than the area of the region which is 65 °. By adopting such a form, the transparency of the screen 10 is improved, and the contrast and clarity of the video are improved.
Even in such a form, as in the fifth embodiment, high transparency and good video can be displayed, and the contrast of the video can be increased.

(Sixth embodiment)
FIG. 14 is a diagram illustrating the layer configuration of the screen 60 according to the sixth embodiment. The cross section of the screen 60 shown in FIG. 14 corresponds to the cross section of the screen 10 of the first embodiment shown in FIG. In FIG. 14, the shape of the reflective layer 13 is shown in a simplified manner for easy understanding.
The screen 60 of the sixth embodiment is substantially the same as the screen 10 of the first embodiment described above, but is a first having a circular Fresnel lens shape having an offset structure similar to that of the first optical shape layer 22 of the second embodiment. The optical shape layer 62 and the second optical shape layer 64 corresponding to the optical shape layer 62 and the top portion of the unit optical shape 621 and the valley portion 623 between the adjacent unit optical shapes 621 are curved. .

The screen 60 of this embodiment includes a base material layer 11, a first optical shape layer 62, a reflective layer 13, a second optical shape layer 64, and a protective layer 15 in this order from the image source side (+ Z side). The present invention can be applied to the video display device 1 shown in the first embodiment.
Similar to the first optical shape layer 22 of the second embodiment described above, the first optical shape layer 62 has a unit optical shape 621 that is a partial shape (arc shape) of a perfect circle on the surface on the back side. The circular Fresnel lens is arranged concentrically around a point (a point corresponding to the point C shown in FIG. 6A) located below the screen (display area). The unit optical shape 621 is convex on the back side (−Z side), and has a first surface 621a and a second surface 621b facing the first surface 621a.

The top portion 622 of the unit optical shape 621 is a curved surface that is convex on the back side (−Z side), and the valley portion 623 between the adjacent unit optical shapes 621 is convex on the image source side (+ Z side). It is a curved surface shape. And the curvature radius of the top part 622 is larger than the curvature radius of the trough part 623.
In general, the first surface 621a and the second surface 621b of the molding die for shaping the unit optical shape 621 of the first optical shape layer 62 are formed on the surfaces for shaping the first optical shape layer 62 as shown in the first embodiment. When surface processing such as plating, blasting, etching, or the like is performed in order to shape the uneven shape, portions corresponding to the top portion 622 and the valley portion 623 are likely to be curved.
In the present embodiment, using the above-described tendency, the mold is manufactured so that the curvature radius of the top portion 622 is larger than the curvature radius of the valley portion 623, and the first optical shape layer 62 is manufactured.

  The reflective layer 13 is formed on the unit optical shape 621 (on the first surface 621a and the second surface 621b). In this embodiment, the reflective layer 13 is preferably formed of a dielectric multilayer film. However, a highly light-reflective metal such as aluminum, silver, or nickel is vapor-deposited or a light-reflective metal is sputtered. Or may be formed.

FIG. 15 is a diagram comparing the screen 60 of the sixth embodiment and the screen 60B of the comparative example. FIG. 15A shows a cross section corresponding to FIG. 14 of the screen 60 of the present embodiment, and FIG. 15B shows a cross section corresponding to FIG. 14 of the screen 60B of the comparative example. In FIG. 15, for easy understanding, the base layer 11 and the protective layer 15 are omitted and the reflective layer 13 is simplified for each screen.
In the screen 60B of the comparative example shown in FIG. 15B, the curvature radius of the valley portion 623B between the adjacent unit optical shapes 621B is larger than the curvature radius of the top portion 622B.

When the reflective layer 13 is formed along the unit optical shape 621B of the comparative example, the reflective layer 13 is incident on the curved surface of the valley portion 623B at a large incident angle like a part of the image light Lg. Light that is reflected on the surface on the image source side, totally reflected on the surface on the back side of the screen 60, and so on, is emitted toward the viewer O1 on the image source side.
This image light Lg is not preferable because it causes an image blur that causes the image to blur in a direction along the optical axis direction (projection direction) of the image light.

On the other hand, in the screen 60 of the present embodiment shown in FIG. 15A, most of the image light Lh incident on the curved top 622 at the same incident angle is on the back side surface of the reflective layer 13. The light is reflected and emitted from the back side of the screen 10 to above the screen 60.
In the screen 60 of this embodiment, the top portion 622 is convex on the back side (−Z side) and is located on the back side with respect to the valley portion 623. Therefore, the amount of light incident on the top portion 622 of the screen 60 of this embodiment is significantly smaller than the amount of light incident on the valley portion 623B in the screen 60B of the comparative example, and is incident on the image source side of the top portion 622. The light that is reflected by the reflective layer 13 and is totally reflected by the surface on the back side of the screen 60 or the like and is emitted from the slightly higher side than the incident light point to the image source side to cause image blurring has a small amount of light. It is.

Further, in the screen 60 of the present embodiment, the curvature radius of the valley portion 623 is smaller than the curvature radius of the top portion 622. Therefore, the amount of image light (light corresponding to the image light Lg of the comparative example screen 60B) that enters the valley 623 and causes stray light to cause image blur is smaller than that of the comparative example screen 60B.
From the above, according to the present embodiment, stray light that causes image blur can be significantly reduced.

FIG. 16 is a diagram illustrating a state of image light and external light on the screen 60 of the sixth embodiment. FIG. 16 shows a cross section corresponding to the cross section of the screen 60 shown in FIG. In FIG. 16, for ease of understanding, it is assumed that there is no difference in refractive index at the interface between the base material layer 11 and the first optical shape layer 62 and at the interface between the second optical shape layer 64 and the protective layer 15. Show.
Of the image light L61 projected from the image source LS positioned below the screen 60 and incident on the screen 60, a part of the image light L62 is incident on the first surface 621a of the unit optical shape 621, and the reflection layer 13 is diffusely reflected and emitted to the observer O1 side.

Of the image light incident on the first surface 621a, the other image light L63 that has not been reflected passes through the reflective layer 13 and is emitted from the back side of the screen 60. At this time, the image light L63 exits above the screen 60 and does not reach the observer O2 on the back side of the screen 60.
In addition, among the image light L61 projected from the image source LS, a part of the image light L64 is reflected by the surface of the screen 60 and travels upward from the screen 60. It will not be.

In the present embodiment, the image light L61 is projected from below the screen 60, and the angle θ2 is larger than the incident angle of the image light at each point in the screen vertical direction of the screen 60. The light does not directly enter the surface 621b, and the second surface 621b hardly affects the reflection of the image light.
In addition, as described above, in the present embodiment, the image is incident on the top 622 from the image source side, reflected by the reflective layer 13, and totally reflected by the surface of the screen 60, and then emitted from the screen upper side to the image source side. Light has a small amount of light, and image blur along the projection direction (optical axis direction) of the image light caused by such image light can be reduced, and the sharpness of the image can be improved.

Next, external light that enters the screen 60 from above the back side (−Z side) or the video source side (+ Z side) will be described.
As shown in FIG. 16, some of the external lights G <b> 62 and G <b> 66 out of the external lights G <b> 61 and G <b> 65 that enter the screen 60 from above are reflected by the surface of the screen 60 and travel toward the lower side of the screen 60.
Among the external light G61, a part of the external light G63 is reflected by the reflective layer 13, a part of the external light G63 is totally reflected by the surface on the image source side of the screen 60, and goes downward in the screen 60 to be attenuated. Although not shown, the light is emitted below the screen 60. Further, of the external light G65, a part of the external light G67 is reflected by the reflective layer 13 and emitted to the upper side of the screen 60 on the back side.
The other external lights G64 and G68 that are not reflected by the reflective layer 13 are transmitted through the reflective layer 13 and emitted to the lower side on the back side of the screen 60 and the lower side on the image source side, respectively. At this time, the external lights G62, G63, and G68 emitted to the video source side go to the lower side of the screen 60 and do not reach the observer O1 positioned in the front direction, so that it is possible to suppress a reduction in image contrast due to external light. .

Further, although not particularly illustrated, a part of the external light incident on the screen 60 from the image source side and the back side is totally reflected on the surface on the back side and the image source side of the screen 60 and goes to the lower side inside the screen. Attenuates.
Further, other external lights G69 and G70 incident on the screen 60 at a small incident angle are transmitted through the reflective layer 13 and emitted to the back side and the video source side, respectively. The screen 60 does not include a light diffusing layer containing diffusing particles or the like for diffusing light, and the reflective layer 13 does not diffuse the transmitted light. Therefore, the external lights G69 and G70 transmitted through the screen 60 are Not spread. Therefore, when the scenery beyond the screen 60 is observed through the screen 60, the scenery can be observed with high transparency without blurring or blurring white.

  As described above, in a transflective reflective screen having a light diffusing layer containing diffusing particles or the like for diffusing conventional light, the image light is diffused twice before and after reflection by the reflecting layer. However, there is a problem that the resolution of the image is lowered while a wide viewing angle can be obtained. Further, since the outside light is also diffused by the diffusing particles, the scenery on the other side of the screen is observed blurred or whitened.

  However, in the screen 60 of the present embodiment, video light or the like is diffused when reflected by the reflective layer 13 due to the fine and irregular uneven shape of the surface of the reflective layer 13. In the present embodiment, light that passes through the reflective layer 13 is not diffused. Therefore, the screen 60 of the present embodiment can display an image having a good viewing angle and resolution, and the scene on the other side of the screen 60 is not visually blurred or blurred, and is well visible to the observer O1. High transparency can be realized.

Further, in the screen 60 of the present embodiment, even when the image light is projected on the screen 60, the observer O1 can visually recognize a part of the scenery on the other side (back side) of the screen 60. Further, on the screen 60, the viewer O2 located on the back side can see the scene on the image source side (+ Z side) with high transparency through the screen 60 regardless of whether or not the image light is projected. can do.
Further, in the screen 60 of the present embodiment, the radius of curvature of the top portion 622 is larger than the radius of curvature of the valley portion 623, so that the image blur can be reduced and the sharpness of the image can be improved.

  Therefore, according to this embodiment, similar to the first embodiment and the like, it is possible to display a bright and good video with high transparency. Furthermore, according to the present embodiment, it is possible to reduce image blur that blurs the image generated along the projection direction (optical axis direction) of the image light, and to improve the sharpness of the image.

(Deformation)
Without being limited to the embodiments described above, various modifications and changes are possible, and these are also within the scope of the present invention.
(1) In each embodiment, a hard coat layer may be provided on the image source side surface of the screens 10 to 60 for the purpose of preventing scratches. The hard coat layer is formed, for example, by applying an ultraviolet curable resin (urethane acrylate or the like) having a hard coat function to the image source side surface of the screens 10 to 60 (image source side surface of the base material layer 11). And so on.
Further, not only the hard coat layer but also a layer having a necessary function such as an antireflection function, an ultraviolet absorption function, an antifouling function, an antistatic function, etc. One or more may be selected and provided. Furthermore, a touch panel layer or the like may be provided on the image source side (observer side) of the base material layer 11.
In particular, when the antireflection layer is provided on the surface on the image source side, the amount of light incident on the screens 10 to 60 can be increased. Further, for example, the image light reflected by the reflection layer is reflected on the image source side. It is possible to prevent the image from being reflected from the air interface and emitted from the back side and appearing to leak on the back side.
Note that the screens 10 to 60 are not limited to the image source side (+ Z side) surface, but may include a layer having a hard coat function, an antireflection function, or the like on the back surface.

(2) In each embodiment, the video source LS is disposed, for example, obliquely below the screens 10 to 60, and projects video light from oblique light in the horizontal direction of the screen with respect to the screens 10 to 60. Also good.
For example, when the video source LS is arranged below the left side (−X side) of the screen in the left-right direction of the screen, the unit optical shape 121 has an arrangement direction and a longitudinal direction in the vertical direction of the screen according to the position of the video source LS. What is necessary is just to set it as the form inclined with respect to (Y direction) and a screen left-right direction (X direction).
In the case where the first optical shape layer 22 has a circular Fresnel lens shape as in the second to sixth embodiments, such a modified form is obtained by shifting the position of the point C serving as the Fresnel center. Is applicable.
By adopting such a form, the position of the video source LS can be freely set.

(3) In the third to sixth embodiments, the first optical shape layers 22, 52, and 62 are unit optics having a longitudinal direction in the horizontal direction of the screen (X direction) as in the first embodiment described above. A linear Fresnel lens shape in which the shapes 121 are arranged in the vertical direction (Y direction) of the screen may be provided on the back surface. The first optical shape layers 22, 52, 62 have a plurality of columnar unit prisms in the vertical direction (Y direction) of the screen on the back side. It is good also as a form.

(4) In each embodiment, the unit optical shapes 121, 221, 521, and 621 are examples in which the first surfaces 121a, 221a, 521a, and 621a and the second surfaces 121b, 221b, 521b, and 621b are formed by planes. However, the present invention is not limited to this. For example, a curved surface and a flat surface may be combined, or a folded surface may be used.
Further, in each embodiment, the unit optical shapes 121, 221, 521, 621 may be polygonal shapes formed by three or more surfaces.
Moreover, in each embodiment, the reflection layers 13 and 33 are good also as a form formed in at least one part of 1st surface 121a, 221a, 521a, 621a, for example.
In each embodiment, for example, only the first surfaces 121a, 221a, 521a, and 621a may be rough.

(5) In each embodiment, the surface of the reflective layers 13 and 33 (the surface of the unit optical shapes 121, 221, 521, 621) is irregular and irregular in size, shape, arrangement, etc. Although an example has been shown, any of the size, shape, and arrangement may have regularity.

(6) In each embodiment, in the screens 10 to 60, the first optical shape layers 12, 22, 52, and 62 and the second optical shape layers 14, 24, 54, and 64 have sufficient thickness and rigidity. When it exists, it is good also as a form which is not provided with the base material layer 11 and the protective layer 15, and is good also as a form which is not provided with either one.
Moreover, in each embodiment, the screens 10-60 are good also considering the at least one of the base material layers 11 and 41 and the protective layer 15 as a plate-shaped member which has light transmittances, such as a glass plate. At this time, the first optical shape layer or the like may be bonded to a glass plate or the like via an adhesive layer or the like.

(7) In each embodiment, the video source LS may project video light having a P-wave polarization component, for example.
At this time, the position and angle of the image source LS are set so that the image light is projected onto the screens 10 to 60 at an incident angle φ. This incident angle φ is (θb−10) ° or more when the incident angle (Brewster angle) at which the reflectance of the image light (P wave) projected onto the screens 10 to 60 is zero is Bb (°). The range is set to 85 ° or less. For example, when the incident angle θb at which the reflectance of the image light projected onto the screens 10 to 60 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 image source LS that projects image light having a P-wave polarization component, even when the incident angle φ to the screens 10 to 60 is large, specular reflection on the surfaces of the screens 10 to 60 is suppressed. It is possible to increase the degree of freedom in designing the projection system, such as the installation position of the image source LS. Further, by using such an image source LS, reflection of image light on the screen surface when entering the screens 10 to 60 can be reduced, and the brightness and clearness of the image can be improved.
In addition, angle (theta) b (Brewster angle) changes with the materials of the screens 10-60 surface on which image light is projected.
Moreover, in the case of such a form, as the base material layer 11 and the protective layer 15, the TAC sheet-like member is suitable.

(8) In each embodiment, video light may be projected from two or more video sources on one screen, and one video may be displayed on the screen of one screen. At this time, at least a part of the projection area of each image light projected by each image source overlaps.
Moreover, in each embodiment, it is good also as a form in which the some reflective layer exists in the thickness direction of a screen, ie, the form which laminated | stacked multiple screens which have transparency in the thickness direction.
By adopting such a form, it is possible to improve the image quality by reducing the scintillation of the image displayed on the screen, widen the viewing angle of the image in one direction, or improve the brightness of the image. it can.

(9) In each embodiment, the example in which the video display device 1 is arranged in a show window of a store or the like has been shown. However, the present invention is not limited to this. For example, for video display in an indoor partition, an exhibition, etc. Is also applicable. Further, the screen display device 1 may be applied to a head-up display (HUD: HEAD-Up Display) of an automobile by attaching the screens 10 to 60 to the windshield, or may be applied to a vehicle other than an automobile. Good.

  Each embodiment and modification may be used in appropriate combination, but detailed description is omitted. Further, the present invention is not limited to the above-described embodiment and the like.

DESCRIPTION OF SYMBOLS 1 Video display apparatus 10, 20, 30, 40, 50, 60 Screen 11, 41 Base material layer 12, 22, 52, 62 1st optical shape layer 121,221,521,621 Unit optical shape 121a, 221a, 521a, 621a First surface 121b, 221b, 521b, 621b Second surface 13, 33 Reflective layer 14, 24, 54, 64 Second optical shape layer 15 Protective layer 45 Omission light suppression layer LS Video source

Claims (16)

A reflective screen that reflects video light projected from a video source to display an image;
A plurality of unit optical shapes that are light-transmissive and have a first surface on which image light is incident and a second surface opposite to the first surface are convex on the back surface side. 1 optical shape layer;
A semi-transmissive reflective layer that is formed on at least the first surface of the unit optical shape, reflects a part of incident light, and transmits the other;
A second optical shape layer having optical transparency, provided on the back side of the first optical shape layer and the reflective layer so as to fill valleys of irregularities due to the unit optical shape;
With
The unit optical shape has an uneven shape on its surface,
At least the surface on the unit optical shape side of the reflective layer has an uneven shape corresponding to the uneven shape,
Reflective screen featuring. The reflective screen according to claim 1.
The top of the unit optical shape is a curved surface that is convex on the back side, and the valley between adjacent unit optical shapes is a curved surface that is convex on the image source side,
The curvature radius of the top is larger than the curvature radius of the valley,
The reflective layer is formed on at least the first surface and the top;
Reflective screen featuring. The reflective screen according to claim 2,
The reflective layer is formed on the entire surface along the unit optical shape;
Reflective screen featuring. The reflective screen according to claim 1.
Not having a light diffusing layer containing diffusing particles that diffuse light;
Reflective screen featuring. The reflective screen according to claim 1.
In the arrangement direction of the unit optical shapes, the amount of change in angle from the emission angle that is the peak luminance of the reflected light of the reflection screen to the emission angle at which the luminance is ½ is + α1, −α2, and the absolute value of the average value Is α and the angle between the first surface and the plane parallel to the screen surface is θ1, α <arcsin (n × sin (2 × (θ1))) in at least a partial region of the reflective screen. )
Reflective screen featuring. The reflective screen according to claim 1.
The proportion of the mirror region in which the uneven shape is not formed per unit area of the reflective layer on the first surface is 5% or less,
Reflective screen featuring. The reflective screen according to claim 1.
In the thickness direction of the reflection screen, the image source side region from the image source side surface to the back side surface of the reflection layer, or in the thickness direction of the reflection screen, from the back side surface to the image source side of the reflection layer. At least one light absorption layer that absorbs light and sets the light transmittance of the reflection screen to a predetermined value in a rear side region up to the surface;
Reflective screen featuring. The reflective screen according to claim 7.
The reflective layer has a function as the light absorbing layer;
Reflective screen featuring. The reflective screen according to claim 7.
The light absorption layer has an absorptance of 5% or more for transmitted light;
Reflective screen featuring. The reflective screen according to claim 1.
In the thickness direction of the reflection screen, a predetermined polarized light included in the image light is absorbed or reflected in a region on the back side of the reflection screen including the reflection layer, and at least a part of the image light is on the back side of the reflection screen. Comprising a missing light suppression layer that suppresses emission to
Reflective screen featuring. The reflective screen according to claim 10.
The omission light suppression layer is
A layer having a function of absorbing the predetermined polarized light transmitted through the reflective layer and transmitting other light;
Being provided on the back side of the reflective layer in the thickness direction of the reflective screen;
Reflective screen featuring. The reflective screen according to claim 10.
The reflective layer has a function as the light leakage suppression layer that reflects the predetermined polarized light and transmits other light;
Reflective screen featuring. A reflective screen according to claim 10;
For the reflection screen, as image light, light containing a large amount of the predetermined polarization, or an image source for projecting the predetermined polarization,
A video display device comprising: The reflective screen according to claim 1.
An angle formed by a plane passing through a point located closest to the rear surface on the second surface and a point located closest to the image source side on the second surface with a direction parallel to the screen surface of the reflective screen is defined as θ2. The angle θ2 satisfies 25 ° ≦ θ2 ≦ 65 °,
Reflective screen featuring. The reflective screen according to claim 1.
The second surface is at least partially curved.
When the angle formed by the tangent line of the second surface or the second surface and the direction parallel to the screen surface of the reflective screen is an angle θ3, the second surface satisfies 25 ° ≦ θ3 ≦ 65 °. The region is larger than the sum of the area of the region where the angle θ3 satisfies 0 ° ≦ θ3 <25 ° and the area of the region where the angle θ3 satisfies 65 ° <θ3 ≦ 90 °;
Reflective screen featuring. The reflective screen according to any one of claims 1 to 12, claim 14, and claim 15,
An image source for projecting image light onto the reflective screen;
A video display device comprising:

Images