JP2017156696A - Reflection screen and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reflection screen having high transparency and capable of displaying an image in good conditions, and a display device having the screen.SOLUTION: A screen 10 includes a semi-transmissive reflection layer 13 that reflects a part of light incident to the screen and transmits the rest of the light. When a total quantity Sp of light incident from an image source side to the screen at an incident angle of 0° is set to 100%, the sum of a transmittance Tp (%) and a reflectance Rp (%) is 90% or less, an absorptivity Ap (%) is 10% or more, the transmittance Tp is from 10 to 85%, and the absorptivity Ap is from 10 to 30%. An absorptivity for light in a back side region Sb with respect to light incident from the back side to the screen surface of the screen 10 at an incident angle of 0° is greater than an absorptivity for light in an image source side region Sa with respect to light incident from the image source side to the screen surface of the screen 10 at an incident angle of 0°.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a reflection screen that reflects and displays a projected image light, and an image 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, it can be used as a reflective screen that can be used to reflect the projected image light, such as by attaching it to a highly translucent member such as a window glass, so that the image can be seen well, and does not project the image light. There is an increasing demand for a transflective reflective screen that allows the scenery on the other side of the screen to be seen through when used, because of its high design.

Japanese Patent Laid-Open No. 9-11003

However, such a transflective reflective screen has a diffusing layer containing diffusing particles, etc., and the scenery on the other side of the screen is observed as whitish and blurred. Improvement has been an issue. Moreover, it is always required to make various screens thinner and to display good images with high contrast.
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 any measures for improving the transparency.

  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 invention of claim 1 is a transflective reflective screen that displays video by reflecting video light (L) projected from a video source, and reflects part of incident light and transmits others. A transflective reflection layer (13), a light-transmitting image source side layer (11, 12) provided at least one layer on the image source side of the reflection layer, and at least 1 on the back side of the reflection layer A total amount Sp of light incident on the screen surface of the reflective screen at an incident angle of 0 ° from the image source side. Is 100%, the sum of the transmittance Tp (%) transmitted to the back side and the reflectance Rp (%) reflected by the reflective layer and emitted to the image source side is 90% or less, The light absorption rate Ap (%) in the reflection screen is 10% or more, From the image source side surface (10a) to the back side surface (13b) of the reflection layer in the thickness direction of the reflection screen is defined as an image source side region (Sa), and from the image source side surface (13a) of the reflection layer. When the back side surface (10b) is the back side region (Sb), the light absorptance of the back side region with respect to the light incident on the screen surface of the reflective screen from the back side with an incident angle of 0 ° is the reflection The reflection screen (10, 20) is characterized in that it is larger than the light absorptance of the image source side region with respect to light incident on the screen surface of the screen from the image source side at an incident angle of 0 °.
According to a second aspect of the present invention, in the reflective screen according to the first aspect, the transmittance of light incident on the screen surface of the reflective screen at an incident angle of 0 ° is 10 to 85%, and the screen surface of the reflective screen The reflection screen (10, 20) is characterized in that the absorptance of light incident at 0 ° is 0 to 30%.
According to a third aspect of the present invention, in the reflective screen according to the first or second aspect, light incident on the screen surface of the reflective screen from the back side at an incident angle of 0 ° is reflected by the reflective layer (13). The reflectance emitted from the back side is smaller than the reflectance that is incident on the screen surface of the reflection screen at an incident angle of 0 ° from the image source side and reflected from the reflection layer and emitted from the image source side. This is a characteristic reflection screen (10, 20).

According to a fourth aspect of the present invention, in the reflective screen according to any one of the first to third aspects, the image source side layer has light transmittance, and a unit optical shape ( 121) includes a plurality of optical shape layers (12), and the unit optical shape includes a first surface (121a) on which image light is incident and a second surface (121b) facing the first surface (121b). And the reflection layer (13) is formed on at least a part of the first surface of the unit optical shape.
According to a fifth aspect of the present invention, in the reflective screen according to any one of the first to fourth aspects, the reflective layer (13) has a fine irregular irregular shape formed on the surface thereof. This is a reflective screen (10, 20).
A sixth aspect of the present invention is the reflective screen according to any one of the first to fifth aspects, wherein the reflective screen is disposed on the image source side of the reflective layer from the back surface (10b) in the thickness direction of the reflective screen. The back side region (Sb) up to the surface (13a) includes at least one light absorption layer (15, 26) that absorbs light and sets the light transmittance of the reflection screen to a predetermined value. The reflective screen (10, 20).
A seventh aspect of the present invention is the reflective screen according to any one of the first to sixth aspects, wherein the luminance is halved from an emission angle that is a peak luminance of reflected light of the reflective screen. The reflection screen (10, 20) is characterized in that 5 ° ≦ α ≦ 45 °, where + α1, −α2 and the average absolute value thereof is α.
According to an eighth aspect of the present invention, in the reflective screen according to any one of the first to seventh aspects, the image source side layer has light transmittance, and a unit optical shape ( 121) includes a plurality of optical shape layers (12), and the unit optical shape includes a first surface (121a) on which image light is incident and a second surface (121b) facing the first surface (121b). 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 its absolute value And α <arcsin (n × sin (2 × (2 × ()) in at least a partial region of the reflective screen, where α is an average value of θ and an angle between the first surface and a plane parallel to the screen surface is θ1. satisfying the relationship of θ1))) The reflective screen (10, 20).
According to a ninth aspect of the present invention, the reflective screen according to any one of the first to eighth aspects and the video source side layer are light transmissive, and video light is incident on the back side surface. An optical shape layer (12) in which a circular Fresnel lens shape is formed by arranging a plurality of unit optical shapes (121) having an incident first surface (121a) and a second surface (121b) facing the first surface (121a). And the optical center (C) of the circular Fresnel lens shape is outside the display area of the reflective screen, and the reflective layer (13) is at least part of the first surface of the unit optical shape. A reflective screen (10, 20) characterized by being formed.

A tenth aspect of the invention includes the reflecting screen (10, 20) according to any one of the first to ninth aspects, and an image source (LS) that projects image light onto the reflecting screen. A video display device (1).
According to an eleventh aspect of the present invention, in the video display device according to the tenth aspect, the incident angle of the video light (L) projected by the video source (LS) to the screen surface of the reflective screen (10, 20) is: The video display device (1) is characterized by being larger than 0 °.

  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 explaining the layer structure of the screen 10 of 1st Embodiment. It is the figure which looked at the 1st optical shape layer 12 of a 1st embodiment from the back side (-Z side). It is a figure explaining the relationship between 1/2 angle (alpha), incident angle (phi) of image light, and angle (theta) 1 of the 1st slope 121a. It is a figure explaining the transmittance | permeability of light and the absorptivity of the screen 10 of 1st Embodiment. 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 explaining the layer structure of the screen 20 of 2nd Embodiment. It is a figure explaining the layer structure of the screen 30 of a deformation | transformation form. It is a figure which shows the video display apparatus 1A of a deformation | transformation form.

Embodiments of the present invention will be described below with reference to the drawings. In addition, each figure shown below including FIG. 1 is the figure shown typically, and the magnitude | size and shape of each part are exaggerated suitably for easy understanding.
In 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.
In the present embodiment, as an example, the video display device 1 is applied to a shop show window, and the screen 10 is fixed to the glass of the show window.

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 direction toward the right side in the horizontal direction when viewed from the observer O1 positioned in the front direction on the image source side of the screen 10 is the + X direction, the direction toward the upper side in the vertical direction is the + Y direction, and the back side (back side) in the thickness direction. ) To the image source 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 from a position where the distance from the surface of the screen 10 in the depth direction (Z direction) is significantly closer than that of a general-purpose projector positioned in the screen front direction of a conventional screen. . Therefore, compared with the conventional general-purpose projector, the video source LS has a short projection distance to the screen 10 and a large incident angle at which the projected video light enters the screen 10.

The screen 10 reflects the image light L projected by the image source LS toward the viewer O1 located in the front direction on the image source side, and can display an image, and the other side of the screen 10 (rear side, − This is a transflective reflective screen that allows observation of the scenery on the Z side).
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 large screen with a diagonal size of about 80 to 100 inches, and the aspect ratio of the screen is 16: 9. However, the present invention is not limited to this. For example, the size may be about 40 inches or less, and the size and shape can be appropriately selected according to the purpose of use and the use environment.

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, as shown in FIG. 1B or the like, the screen 10 of the present embodiment is joined (or partially fixed) to the support plate 50 integrally on the back side of the screen 10 via a light-transmitting joining layer 51. The flatness is maintained.
The support plate 50 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.
In the present embodiment, the support plate 50 is a window glass of a show window such as a store. However, the present invention is not limited to this, and the screen 10 may be configured such that its four sides are supported by a frame member (not shown) and the like so as to maintain its flatness.

FIG. 2 is a diagram illustrating the 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. In FIG. 2, only the screen 10 is shown, and the support plate 50 and the like are omitted.
FIG. 3 is a view of the first optical shape layer 12 of the first embodiment viewed from the back side (−Z side). In order to facilitate understanding, the reflective layer 13, the second optical shape layer 14, the protective layer 15 and the like are omitted.
As shown in FIG. 2, the screen 10 has a base layer 11, a first optical shape layer 12, a reflection layer 13, and a second optical shape in order from the image source side (+ Z side) in the thickness direction (Z direction). Layer 14 and protective layer 15 are provided.

The base material layer 11 is a light-transmitting sheet-like member, and the first optical shape layer 12 is integrally formed on the back side (−Z side) thereof. 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 formed of, for example, a polyester resin such as PET (polyethylene terephthalate), an acrylic resin, a styrene resin, an acrylic styrene resin, a PC (polycarbonate) resin, an alicyclic polyolefin resin, a TAC (triacetyl cellulose) resin, or the like. Is done.
The thickness of the base material layer 11 may be selected according to the screen size of the screen 10 or 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 (unit lenses) 121 are arranged on the back surface (−Z side) of the first optical shape layer 12. As shown in FIG. 3, a plurality of unit optical shapes 121 are arranged concentrically around a point C located outside the screen (display area) of the screen 10. That is, the first optical shape layer 12 has a circular Fresnel lens shape on the back side.
The circular Fresnel lens shape of the first optical shape layer 12 is a circular Fresnel lens shape having a so-called offset structure with the point C as the center (Fresnel center). Therefore, as shown in FIG. 3, when the first optical shape layer 12 is viewed from the back side in the normal direction of the screen surface, a unit optical shape (unit lens) 121 having a partial shape (arc shape) of a perfect circle is formed. Observed as multiple arrays. As shown in FIG. 3, this point C is located at the center in the horizontal direction of the screen and below the screen. Therefore, when the screen 10 is viewed from the front direction, the point C and the point A are located on the same straight line.

  In the present embodiment, an example in which a circular Fresnel lens shape is formed on the back surface of the first optical shape layer 12 is shown. However, the present invention is not limited thereto, and the back surface side of the first optical shape layer 12 is not limited thereto. A linear Fresnel lens shape in which the unit optical shape 121 is arranged in the horizontal direction (X direction) of the screen in the longitudinal direction and in the vertical direction of the screen (Y direction) may be formed on the surface.

As shown in FIG. 2, the unit optical shape 121 is parallel to the direction orthogonal to the screen surface (Z direction), and the cross-sectional shape in a cross section parallel to the arrangement direction of the unit optical shapes 121 is a substantially triangular shape. .
The unit optical shape 121 is convex on the back side, and has a first inclined surface (lens surface) 121a on which image light is incident and a second inclined surface (non-lens surface) 121b facing the first inclined surface (lens surface) 121b. In one unit optical shape 121, the first slope 121a is located on the upper side (+ Y side) of the second slope 121b with the apex t interposed therebetween.
The angle formed by the first slope 121a and a plane parallel to the screen surface is θ1. The angle formed by the second inclined surface 121b and a plane parallel to the screen surface is θ2. The angles θ1 and θ2 satisfy the relationship θ2> θ1.
The first inclined surface 121a and the second inclined surface 121b of the unit optical shape 121 have fine and irregular uneven shapes. The fine concavo-convex shape is formed by irregularly arranging convex shapes and concave shapes in a two-dimensional direction, and the convex shapes and concave shapes are irregular in size, shape, height and the like.

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.
For ease of understanding, FIG. 2 shows an example in which the arrangement pitch P and the angles θ1 and θ2 of the unit optical shapes 121 are constant in the arrangement direction of the unit optical shapes 121. However, in the unit optical shape 121 of this embodiment, the arrangement pitch P is actually constant, but gradually increases as the angle θ1 moves away from the point C that becomes the Fresnel center in the arrangement direction of the unit optical shapes 121. .
Further, the angles θ1 and θ2, the arrangement pitch P, and the like are 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 10 Depending on the screen size, the refractive index of each layer, etc., it may be set as appropriate. For example, the arrangement pitch P may be changed along the arrangement direction of the unit optical shapes 121, and the angles θ1 and θ2 may be changed.

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 constituting the first optical shape layer 12 will be described using an ultraviolet curable resin as an example, but 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 formed on the unit optical shape 121 (on the first slope 121a and the second slope 121b). The reflective layer 13 is a so-called half mirror that reflects a part of incident light and transmits the other part.
As described above, the first inclined surface 121a and the second inclined surface 121b are formed with fine uneven shapes, and the reflective layer 13 is formed following the fine uneven shapes. In addition, the thickness of the reflective layer 13 is sufficiently thinner than the fine irregularities. Therefore, the image-source-side surface (surface on the first optical shape layer 12 side) and the back-side surface (surface on the second optical shape layer 14 side) of the reflective layer 13 have fine and irregular irregular shapes. It has a matte surface.
The reflection layer 13 has a function of diffusing and reflecting a part of incident light by a fine concavo-convex shape and transmitting other light that does not reflect without diffusing.

As for the surface roughness of the reflective layer 13 on the image source side (that is, the surface roughness of the first slope 121a), the arithmetic average roughness Ra (JIS B0601-2001) is about 0.10 to 0.50 μm. This is preferable from the viewpoint of satisfactorily displaying an image by reflected light. Note that the arithmetic average roughness Ra, which is the surface roughness of the reflective layer 13 on the image source side (that is, the surface roughness of the first inclined surface 121a), may be appropriately selected according to the desired optical performance and the like.
The ratio of the reflectance and the transmittance of the reflective layer 13 can be appropriately set according to the desired optical performance.

In addition, the reflective layer 13 is not a rough surface, that is, does not have a fine uneven shape, the image source side surface (the surface on the first optical shape layer 12 side) is mirror-like, and incident. The specular region where the image light is specularly reflected is 5% or less per unit area of the reflective layer 13 formed on the first inclined surface 121a in order to sufficiently diffuse the image light and obtain a good viewing angle. Ideally, it is 0%.
If the mirror surface area that is not a rough surface exceeds 5% per unit area of the reflective layer 13 formed on the first inclined surface 121a, a bright line is generated due to the component of the image light that is reflected without being diffused, and the viewing angle is reduced. This is not preferable.

Such a reflective layer 13 is formed of a metal having high light reflectivity, for example, aluminum, silver, nickel or the like, and the thickness thereof is about several tens of millimeters. The reflective layer 13 of this embodiment is formed by evaporating aluminum.
The reflective layer 13 is not limited to this, and may be formed, for example, by sputtering a metal having high light reflectivity, transferring a metal foil, or applying a paint containing a metal thin film. . The reflective layer 13 may be formed by depositing a dielectric multilayer film.

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 valleys between the unit optical shapes 121. Yes. 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 surface on the back side of the screen 10. Joining is also easy.
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. In the present embodiment, the second optical shape layer 14 is formed of the same resin as 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 is a sheet-like member having a function of protecting the back side of the screen 10. The protective layer 15 is a light absorbing layer that is colored with a coloring material such as a gray or black dye or a pigment, and has light absorption. Further, the color density and layer thickness of the protective layer 15 are set so that the light transmittance of the screen 10 becomes a predetermined value. The protective layer 15 absorbs unnecessary external light such as illumination light incident on the screen 10 and stray light, and has a function of improving the contrast of the image.

As a base material of the protective layer 15, polyester resin such as PET, acrylic resin, styrene resin, acrylic styrene resin, PC resin, alicyclic polyolefin resin, TAC resin, MS (methacryl styrene) resin, MBS (methacryl butadiene styrene) Resins and the like are preferred. Further, the base material of the protective layer 15 may be the same material as the base material layer 11 described above.
Examples of the coloring material contained in the protective layer 15 include dark dyes and pigments such as gray and black, and metal salts such as carbon black, graphite, and black iron oxide.
The protective layer 15 may adjust the thickness, light transmittance, absorption rate, and the like as appropriate according to the screen size of the screen 10 and desired optical performance.
As described above, the screen 10 of this embodiment does not include a light diffusion layer containing a diffusing material such as particles having a diffusing action, and the diffusing action is caused by fine irregularities on the reflecting surface of the reflecting layer 13. Only the shape.

The screen 10 is formed 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, a fine uneven shape is formed on the surface forming the first inclined surface 121a and the second inclined surface 121b of the mold for forming the unit optical shape 121. This fine concavo-convex shape can be formed by repeating plating under different conditions twice or more on the surface forming the first inclined surface 121a and the second inclined surface 121b of the mold or performing an etching process.
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 slope 121a and the second slope 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. For example, when the base material layer 11 and the protective layer 15 have a web shape and the first optical shape layer 12 has a linear Fresnel lens shape, the screen 10 in a state before cutting can be continuously manufactured. It is possible to improve the production efficiency of the screen 10 and reduce the production cost.

  Further, for example, as a method of forming rough surfaces on the first inclined surface 121a and the second inclined surface 121b, diffusing particles or the like are applied on the first inclined surface 121a and the second inclined surface 121b, and the reflective layer 13 is formed thereon. A method of performing blasting on the first slope 121a and the second slope 121b after forming the first optical shape layer 12 is known. However, when the reflective surface of the reflective layer 13 is roughened by such a manufacturing method, there are large variations in diffusion characteristics, quality, and the like on the individual screens 10, and stable production cannot be performed. On the other hand, as described above, by forming the fine concavo-convex shapes of the first inclined surface 121a and the second inclined surface 121b of the unit optical shape 121 with a molding die, a large number of first optical shape layers 12 and screens 10 are formed. Also in the case of manufacturing, there is an advantage that quality can be stably manufactured with little variation in quality.

  Here, the arrangement direction of the unit optical shapes 121 (this embodiment) with respect to the angle K of the peak luminance of the light (reflected light) incident on the reflecting layer 13 from the first inclined surface 121a and diffusely reflected and emitted from the screen 10 (this embodiment). Then, in the vertical direction of the screen, the angles at which the luminance becomes 1/2 are K1 and K2, and the angle change amount from the peak luminance angle K to the angles K1 and K2 at which the luminance becomes 1/2 is + α1 (where K + α1). = K1), −α2 (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 (hereinafter referred to as ½ angle α). The half angle α preferably satisfies 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 reduced, the blur of the image is increased, and the contrast of the image is reduced due to reflection of the external light on the screen 10, which is preferable. Absent. Accordingly, the ½ angle α is preferably in the above range.
In the screen 10 of the present embodiment, since the uneven shape of the reflective layer 13 is irregular, the ½ angle α in the horizontal direction of the screen is equal to or substantially equal to the ½ angle α in the vertical direction of the screen. .

FIG. 4 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 inclined surface 121a. In FIG. 4, in order to facilitate understanding, the configuration in the screen 10 is simplified, and the base material layer 11 and the protective layer 15 are omitted. In FIG. 4, regarding the angles α and φ, the upper side of the screen is indicated as + and the lower side of the screen is indicated as − with respect to the normal line of the screen surface.
The angle θ1 of the first inclined surface 121a is such that the image light is most efficiently reflected by an observer located in the front direction of the screen 10, that is, the angle K at which the peak luminance of the reflected light becomes 0 °. Furthermore, 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 (the 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 an incident angle of −φ, and the refractive index n is the first. The first optical shape layer 12 travels, enters the first inclined surface 121a having an angle θ1 with respect to the screen surface, is reflected by the reflective layer 13, and exits from the screen 10 in a direction perpendicular 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 (Formula 1), in the vertical direction of the screen (the arrangement direction of the unit optical shapes 121), the 1/2 angle α and the angle θ1 of the first inclined surface 121a are to prevent the reflection of the image source. It is preferable that at least a part of the screen 10 (for example, the center of the screen) satisfies the following (Equation 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 and the angle θ1 of the first inclined surface 121a satisfy the above (Equation 2) over the entire area of the screen 10.
By adopting a form in which the angle θ1 and the half angle α satisfy the above (formula 2), the direction in which the light reflected on the surface of the screen 10 mainly enters (the direction of + φ) when entering the screen 10 is as follows. This is outside the range (−α to + α) in which the image light reflected by the reflective layer 13 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.

FIG. 5 is a diagram for explaining light transmittance and absorption rate of the screen 10 of the first embodiment. In FIG. 5, for easy understanding, the unit optical shape 121 of the first optical shape layer 12 is omitted, and the reflection layer 13 is described as a planar shape.
With respect to the light incident on the screen surface of the screen 10 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 10 (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 90% or less, and the absorption rate Ap is 10% or more. That is, they satisfy the following formula.
Tp + Rp ≦ 90 (Formula 3)
Ap = Sp− (Tp + Rp) ≧ 10 (Formula 4)

Further, in the screen 10 of the present embodiment, the transmittance of the light La incident on the screen surface at an incident angle of 0 ° (corresponding to the above-described Tp) may be incident from the video source side or from the back side. 10 to 85%. That is, the transmittance Tp satisfies 10 ≦ Tp ≦ 85.
When the transmittance is less than 10%, the transparency of the screen 10 is lost, which is not preferable. On the other hand, if the transmittance is higher than 85%, the brightness of the image displayed by reflection is lowered, which is not preferable. Therefore, the transmittance Tp preferably satisfies the above range.

Further, in the screen 10 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 10 when incident from the video source side and from the rear side. -30%, more preferably 10-20%. That is, the absorption rate Ap preferably satisfies 10 ≦ Ap ≦ 30, and more preferably satisfies 10 ≦ Ap ≦ 20.
If the absorptance is less than 10%, the contrast of the image is lowered, which is not preferable. On the other hand, if the absorptance is higher than 30%, the brightness of the image that is reflected and displayed is lowered or the transparency of the screen is lowered, which is not preferable. Therefore, it is preferable that the absorption rate satisfies the above range.

  Further, in the thickness direction of the screen 10, a region from the image source side surface 10 a of the screen 10 to the back side (−Z side) surface 13 b of the reflective layer 13 is defined as an image source side region Sa, and the back side surface 10 b of the screen 10. When the area from the image source side (+ Z side) surface 13a of the reflective layer 13 to the back side area Sb is an absorptance of light that is incident on the screen surface at an incident angle of 0 ° and is transmitted through the back side area Sb (Hereinafter referred to as the light absorption rate of the back side region Sb) is the absorption rate of light incident on the screen surface at an incident angle of 0 ° and transmitted through the image source side region Sa (hereinafter referred to as the light absorption rate of the image source side region Sa). Larger than the absorption rate).

Here, the light absorptance of the image source side region Sa and the light absorptance of the back side region Sb are incident on the screen surface from the image source side (+ Z side) and the back side (−Z side), respectively. Comparison can be made by the reflectivity when the light incident at an angle is reflected by the reflective layer 13 and emitted to the image source side and the back side. The reflection layer 13 itself has the same reflectivity of light incident from the image source side and reflectivity of light incident from the back side.
The reflectance of the light Lc incident on the rear surface of the screen 10 of this embodiment at an incident angle of 0 ° (hereinafter referred to as the reflectance of the light in the rear region Sb) is incident on the image source side surface 10a of the screen 10. It is smaller than the reflectance of the light Lb incident at 0 ° (hereinafter referred to as the reflectance of the image source side region Sa). That is, the amount of light incident on the rear surface 10b of the screen 10 at an incident angle of 0 °, reflected by the reflective layer 13 and emitted to the rear surface of the screen 10 is incident on the image source side surface 10a of the screen 10 at an incident angle of 0 °. The amount of light that is incident, reflected by the reflective layer 13 and emitted from the screen 10 to the image source side is smaller.

In the present embodiment, the light reflectance of the image source side region Sa is about 40%, the light reflectance of the back side region Sb is about 30%, and the light transmittance Tp of the entire screen 10. The incident light from the back side and the incident light from the image source side are the same 40%. Therefore, the screen 10 has a higher reflectance in the image source side region Sa and a higher light absorption rate in the back side region Sb.
By adopting such a form, when the other side (image source side) of the screen 10 is viewed from the back side, or the other side of the screen 10 (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 protective layer 15 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.

FIG. 6 is a diagram illustrating a state of image light and external light on the screen 10 of the first embodiment. In FIG. 6, a part of the cross section in a cross section parallel to the arrangement direction (Y direction) of the unit optical shapes 121 and the thickness direction (Z direction) of the screen is shown in an enlarged manner. Further, in FIG. 6, for easy understanding, it is assumed that there is no refractive index difference at the interface of each layer in the screen 10.
Among the image light L1 projected from the image source LS located below the screen 10 and incident on the screen 10, a part of the image light L2 is incident on the first inclined surface 121a of the unit optical shape 121, and the reflective layer 13 Is diffused and reflected and emitted to the observer O side.

Of the image light incident on the first inclined surface 121a, the other image light L3 that has not been reflected is transmitted through the reflective layer 13 and 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 on the back side of the screen 10.
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 inclined surface 121b, and the second inclined surface 121b hardly affects the reflection of the image light.

Next, light from the outside such as sunlight other than the image light incident on the screen 10 from the back side (−Z side) or the image source side (+ Z side) (hereinafter referred to as external light) will be described.
As shown in FIG. 4, out of the external lights G1 and G5 incident on the screen 10, some of the external lights G2 and G6 are reflected by the surface of the screen 10 and travel downward. Further, of the external light G1, a part of the external light G3 is reflected by the reflective layer 13 and part of the light is emitted below the screen 10, but a part of it is on the image source side (+ Z side) surface of the screen 10. It is totally reflected and goes downward in the screen 10 and attenuates. In addition, a part of the external light G5 is partially absorbed by the protective layer 15 and then reflected by the reflective layer 13 and emitted to the upper side outside the screen on the back side (−Z side). The 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.

In addition, although not shown, a part of the external light incident on the screen 10 from the image source side and the back side is totally reflected on the surface of the screen 10 on the back side and the image source side, and is attenuated toward the lower side inside the screen. To do.
Further, the other external lights G9 and G10 are transmitted through the reflective layer 13, a part of the light is absorbed by the protective layer 15 having a light absorption property, and the other light is emitted to the back side and the image source side, respectively. To do. Since the screen 10 does not contain a diffusing material containing diffusing particles, 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 diffusion layer containing conventional diffusion particles, image light is diffused twice before and after reflection by the reflection layer, so that a good viewing angle can be obtained while image resolution is improved. There is a problem that decreases. 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 surface of the reflective layer 13 is a rough surface having fine irregular irregular shapes. . 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 of the present embodiment, the reflectance of the back side region Sb is smaller than the reflectance of the image source side region Sa. That is, the light absorptance of the back side region Sb is larger than the light absorptivity of the image source side region Sa.
Therefore, it can enter from the back side (−Z side) and pass to the image source side (+ Z side), absorb external light that adversely affects the viewing of the image of the observer O1, and has high transparency as a screen. High contrast images can be displayed. In addition, since the protective layer 15 does not absorb the image light that is incident from the image source side and is reflected by the reflective layer 13 to display the image, the use efficiency of the image light is high and a bright and clear image can be displayed.

  Further, in the screen 10 of the present embodiment, the angle θ1 of the first inclined surface 121a is the above-described (Expression 2) with respect to the ½ angle α of the image light (reflected light) diffusely reflected by the reflective layer 13. Therefore, the image light reflected on the image source side surface of the screen 10 goes outside the half angle α, and the image source LS is not reflected, and a good image can be displayed.

(Second Embodiment)
FIG. 7 is a diagram illustrating the layer configuration of the screen 20 according to the second embodiment. In FIG. 7, a part of the cross section of the screen 20 of the second embodiment is shown enlarged. The cross section of the screen 20 shown in FIG. 7 corresponds to the cross section of the screen 10 of the first embodiment shown in FIG.
The screen 20 of the second embodiment includes a base material layer 11, a first optical shape layer 12, a reflective layer 13, and a second optical shape layer in order from the image source side (+ Z side) along the thickness direction (Z direction). 14, a light absorption layer 26 and a protective layer 25 are provided. The screen 20 of the second embodiment can be used in the video display device 1 in place of the screen 10 of the first embodiment described above.
The screen 20 of the second embodiment has the same form as the screen 10 of the first embodiment described above except that the protective layer 25 does not contain a colorant and is provided with a light absorption layer 26. 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.

The light absorption layer 26 is a layer provided between the second optical shape layer 14 and the protective layer 15 and colored with a coloring material such as a dye or pigment such as gray or black, and has a light absorption property. It is a layer which has. The thickness and the density of the light absorption layer 26 are set so that the transmittance of the screen 10 becomes a predetermined value.
This light absorption layer 26 has a function of absorbing unnecessary external light such as illumination light incident on the screen 10 and stray light and improving the contrast of the image.

Examples of the resin used as the base material of the light absorption layer 26 include PET resin, PC resin, MS resin, MBS resin, acrylic resin, TAC resin, and PEN (polyethylene naphthalate) resin. Examples of the colorant of the light absorbing layer 26 include dark dyes and pigments such as gray and black, and metal salts such as carbon black, graphite, and black iron oxide.
The light absorbing layer 26 of the present embodiment can be integrally laminated by, for example, co-extrusion molding with a protective layer 25 described later.
The light absorption layer 26 is not limited to the above example, and may be formed by vapor-depositing a material having a light absorption function on one surface of the protective layer 25 or may be formed by coating. Good.

The light absorption layer 26 may set its thickness, light transmittance and absorption rate according to the screen size of the screen 10 and desired optical performance.
In the present embodiment, the light absorption layer 26 is disposed on the video source side (+ Z side) of the protective layer 25. However, the present invention is not limited thereto, and for example, the back side (−Z) of the protective layer 25 is used. It is good also as a form arrange | positioned in the side.

The protective layer 25 is a sheet-like member having optical transparency. Unlike the protective layer 15 of the first embodiment, the protective layer 25 is a transparent layer that does not contain a colorant and is not colored.
The protective layer 25 is formed of, for example, a polyester resin such as PET, an acrylic resin, a styrene resin, an acrylic styrene resin, a PC resin, an alicyclic polyolefin resin, a TAC resin, or the like.

Also in the present embodiment, the transmittance Tp (%) transmitted to the back side when the total amount Sp of light incident on the screen surface of the screen 20 from the image source side (+ Z side) at an incident angle of 0 ° is 100%. ), The reflectance Rp (%) reflected by the reflective layer 13 and emitted to the image source side, and the absorption rate Ap (%) absorbed in the screen 10 are the above-described (Equation 3) and (Equation 4). Meet.
Further, the screen 20 has a transmittance (corresponding to the above-described Tp) of light incident on the screen surface at an incident angle of 0 °, which is 10% to 85% when incident from the video source side and from the rear side. is there.
The screen 20 has an absorptance (corresponding to the aforementioned Ap) of light incident on the screen surface at an incident angle of 0 °, 10% to 30% when incident from the video source side and from the rear side. More preferably, it is 10 to 20%.
Furthermore, the light transmittance and absorption rate of the base material layer 11 and the first optical shape layer 12 of the present embodiment are equal to the light transmittance and absorption rate of the protective layer 25 and the second optical shape layer 14. Since the screen 20 of the present embodiment includes the light absorption layer 26 in the back side region Sb, the light absorptance of the back side region Sb is the same as that of the video source side region Sa as in the first embodiment described above. It is larger than the light absorption rate.
According to the present embodiment, the screen 20 and the image display device 1 that can display a bright and good image with high contrast while maintaining high transparency can be realized, as in the first embodiment.

(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 1st Embodiment, although the protective layer 15 contained the coloring material and showed the example used as the light absorption layer which has a light absorption effect, it is not restricted to this, For example, not the protective layer 15 but 2nd optical The shape layer 14 may include a colorant and the like and may have a light absorption function, or the protective layer 15 and the second optical shape layer 14 may include a colorant and have a light absorption function.
In the second embodiment, in addition to the light absorption layer 26, at least one of the protective layer 25 and the second optical shape layer 14 may be colored with a coloring material to have a light absorption function.
In the second embodiment, in addition to the light absorption layer 26, the screen 20 has a higher light transmittance than the light absorption layer 26 on the image source side (+ Z side) than the reflection layer 13 (the absorption rate is low). It is good also as a form which has a 2nd light absorption layer. The same applies to the first embodiment, and a layer corresponding to the second light absorption layer may be further provided on the image source side with respect to the reflective layer 13.

In the second embodiment, a light absorption layer may be provided between the reflective layer 13 and the second optical shape layer 14. In this case, the second optical shape layer 14 in which a plurality of second unit optical shapes that are opposite to the unit optical shape 121 are arranged on the image source side surface is formed of an ultraviolet curable resin or the like, and the light absorption layer is It can be formed by vapor-depositing a material having a light absorption effect on the second unit optical shape.
In each embodiment, the layer having a light absorption function is not colored and may be a transparent layer having a light absorption function.
In the first embodiment and the second embodiment, the protective layer 15 and the light absorption layer 26 may be configured to increase the light absorptance and shield most of the external light from the back side.

(2) In each embodiment, the reflection layers 13 and 33 are formed on the unit optical shape 121. However, the present invention is not limited to this. For example, the reflection layers 13 and 33 are layers parallel to the screen surface. Further, a fine and irregular uneven shape may be formed on the image source side surface and the back side surface.

(3) In each embodiment, although the protective layer 15 and the light absorption layer 26 were colored and the example which has a light absorptivity was shown, it is not restricted to this, For example, as a form which a reflection layer has a function which absorbs light Also good.
FIG. 8 is a diagram for explaining a modified screen 30. The cross section of the screen 30 of the modification shown in FIG. 8 corresponds to the cross section of the screen 10 shown in FIG. 2 of the first embodiment described above.
The protective layer 35 of the screen 30 in this modified form does not contain a colorant or the like and is a transparent layer. The light transmittance and absorption rate of the protective layer 35 and the second optical shape layer 14 of the screen 30 are equal to the light transmittance and absorption rate of the base material layer 11 and the first optical shape layer 12.
The reflective layer 33 in the modified form has an absorptance at the time of reflection of light incident from the back side (−Z side) larger than that at the time of reflection of light incident from the image source side (+ Z side). In addition, the reflection layer 33 has the same reflectance for light incident on the screen surface from the image source side at an incident angle of 0 ° and the reflectance for light incident on the screen surface from the back side at an incident angle of 0 °.
The reflective layer 33 is formed of, for example, a metal vapor deposition film such as aluminum or silver.

Since the reflective layer 33 as described above is provided, the screen 30 according to the modified embodiment has a light absorption rate of the back side region Sb larger than that of the image source side region Sa.
Even in such a form, it is possible to realize a screen and a video display device capable of displaying a high-contrast video while maintaining high transparency.
Further, in such a form, each layer on the image source side and the back side from the reflective layer 33 is transparent, and the transmittance and the like are the same, so that the screen is either on the image source side or the back side. High transparency can be achieved when viewed from above.

(4) In each embodiment, a hard coat layer for the purpose of preventing scratches may be provided on the image source side (+ Z side) surface of the screens 10 and 20. For the hard coat layer, for example, an ultraviolet curable resin (for example, urethane acrylate) having a hard coat function is applied to the image source side surface of the screens 10 and 20 (image source side surface of the base material layer 11). It is formed by forming.
Further, not only the hard coat layer but also a layer having necessary functions as appropriate, such as an antireflection function, an ultraviolet absorption function, an antifouling function, an antistatic function, etc., depending on the use environment or purpose of use of the screens 10 and 20. 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, the antireflection layer is displayed as if, for example, the image light reflected by the reflection layer 13 is reflected from the interface with the air on the image source side, is emitted from the back side, and the image leaks to the back side. Can be prevented.
The screens 10 and 20 are not limited to the image source side (+ Z side) surface, and a layer having a hard coat function, an antireflection function, or the like may be provided on the back surface.

(5) In each embodiment, the video source LS has been described by taking an example in which the video source LS is located at the center in the left-right direction of the screens 10 and 20 and is located on the lower side in the vertical direction. , 20 may be arranged so as to project the image light from the oblique direction light in the horizontal direction of the screen with respect to the screens 10, 20.
FIG. 9 is a diagram showing a modified video display apparatus 1A.
In FIG. 9, for ease of understanding, the first optical shape layer of the screen 10A has an example in which the columnar unit optical shapes 221A are arranged on the back side and have a linear Fresnel lens shape. Instead, it may have a circular Fresnel lens shape as in the above-described embodiments, or a plurality of columnar unit prisms may be provided.
As shown in FIG. 9, for example, when the video source LS is arranged below the left side (−X side) of the screen 10 </ b> A in the left-right direction, the unit optical shape 121 has the arrangement direction and the longitudinal direction of the video source LS. According to the position, the screen is inclined with respect to the vertical direction of the screen (Y direction) and the horizontal direction of the screen (X direction). By adopting such a form, the position of the video source LS and the like can be freely set.
Even when the first optical shape layer has a circular Fresnel lens shape as in the screens 10 and 20 shown in the above-described embodiments, the arrangement direction of the unit optical shapes 121 is inclined according to the position of the image source LS. By adopting a different form, such a modified form is applicable.

(6) In each embodiment, although the unit optical shape 121 showed the example in which the 1st slope 121a and the 2nd slope 121b were formed by a plane, it is not restricted to this, For example, the curved surface and the plane were combined. It is good also as a form and it is good also as a folded surface shape.
In each embodiment, the unit optical shape 121 may be a polygonal shape formed by a plurality of three or more surfaces.
Moreover, in each embodiment, although the reflection layer 13 showed the example formed in the 1st slope 121a and the 2nd slope 121b, it is not restricted to this, For example, it forms in at least one part of the 1st slope 121a. It is good also as a form.
Moreover, in each embodiment, although the 1st slope 121a and the 2nd slope 121b showed the example which is a rough surface in which the fine uneven | corrugated shape was formed, not only this but the 1st slope 121a is a rough surface. It is good also as a form.

(7) In the second embodiment, when the first optical shape layer 12 and the second optical shape layer 14 have sufficient thickness, rigidity, etc., the screen 20 has the base material layer 11 and the protective layer 25. It is good also as a form which is not provided, and it is good also as a form which is not provided with either one.
In the first embodiment, when the first optical shape layer 12 and the second optical shape layer 14 have sufficient thickness, rigidity, etc., the screen 10 does not include the base material layer 11. Also good.
Moreover, in each embodiment, the screens 10 and 20 are good also considering the at least one of the base material layer 11 and the protective layer 25 as a plate-shaped member which has light transmittances, such as a glass plate. At this time, the first optical shape layer 12 or the like may be bonded to a glass plate or the like via an adhesive layer or the like.

(8) 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 and 20 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 and 20 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 and 20 is zero is 60 °, the incident angle φ of the image light is set in the range of 50 to 85 °.
Thus, 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 and 20 is large, specular reflection on the surfaces of the screens 10 and 20 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, the reflection of the image light on the screen surface when entering the screens 10 and 20 can be reduced, and the brightness and clearness of the image can be improved.
Note that the angle θb (Brewster angle) varies depending on the material of the surfaces of the screens 10 and 20 onto which the image light is projected.
Moreover, in the case of such a form, as the base material layer 11 and the protective layers 15 and 25, the TAC sheet-like member is suitable.

(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 screens 10 and 20 may be bonded to the windshield, and the video display device 1 may be applied to an automobile head-up display (HUD) or a vehicle other than an automobile. Good.

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

DESCRIPTION OF SYMBOLS 1 Image display apparatus 10,20 Screen 11 Base material layer 12 1st optical shape layer 13 Reflective layer 14 2nd optical shape layer 15,25 Protective layer 26 Light absorption layer LS Image source

Claims (11)

A transflective reflective screen that reflects video light projected from a video source to display an image,
A transflective reflective layer that reflects some of the incident light and transmits others;
An image source side layer having light transmissivity provided at least one layer on the image source side of the reflective layer;
A light-transmitting back side layer provided at least one layer on the back side of the reflective layer;
With
When the total amount Sp of light incident on the screen surface of the reflecting screen from the image source side at an incident angle of 0 ° is 100%,
The sum of the transmittance Tp (%) transmitted to the back side and the reflectance Rp (%) reflected by the reflective layer and emitted to the image source side is 90% or less,
The light absorption rate Ap (%) in the reflection screen is 10% or more,
In the thickness direction of the reflective screen, the area from the image source side surface to the back side surface of the reflection layer is the image source side area, and the area from the image source side surface to the back surface of the reflection layer is the back side area. The absorptance of the light in the back side region with respect to the light incident on the screen surface of the reflective screen from the back side is 0.degree. Greater than the light absorption rate of the image source side region with respect to
Reflective screen featuring. The reflective screen according to claim 1.
The transmittance of light incident on the screen surface of the reflective screen at an incident angle of 0 ° is 10 to 85%,
The absorptance of light incident on the screen surface of the reflecting screen at an incident angle of 0 ° is 10 to 30%.
Reflective screen featuring. The reflective screen according to claim 1 or 2,
The reflectance of the light incident on the screen surface of the reflective screen from the back side with an incident angle of 0 ° is reflected by the reflective layer and emitted from the back side. The reflectance is 0 ° to the screen surface of the reflective screen from the image source side. The light incident on is reflected by the reflective layer and smaller than the reflectance emitted from the image source side,
Reflective screen featuring. The reflective screen according to any one of claims 1 to 3,
The image source side layer has optical transparency, and has an optical shape layer in which a plurality of unit optical shapes are arranged on the back side surface,
The unit optical shape has a first surface on which image light is incident and a second surface facing the first surface,
The reflective layer is formed on a part of at least the first surface of the unit optical shape;
Reflective screen featuring. The reflective screen according to any one of claims 1 to 4, wherein:
The reflective layer has a fine and irregular concavo-convex shape formed on the surface thereof,
Reflective screen featuring. The reflection screen according to any one of claims 1 to 5,
In the thickness direction of the reflective screen, a light absorbing layer that absorbs light and makes the light transmittance of the reflective screen a predetermined value in the back side region from the back side surface to the image source side surface of the reflective layer Having at least one
Reflective screen featuring. The reflective screen according to any one of claims 1 to 6,
When the amount of change in angle from the exit angle at which the reflected screen has the peak brightness to the exit angle at which the brightness is ½ is + α1, −α2, and the average of the absolute values is α, 5 ° ≦ α ≦ 45 °,
Reflective screen featuring. In the reflective screen of any one of Claim 1 to Claim 7,
The image source side layer has optical transparency, and has an optical shape layer in which a plurality of unit optical shapes are arranged on the back side surface,
The unit optical shape has a first surface on which image light is incident and a second surface facing the first surface,
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. A reflective screen according to any one of claims 1 to 8,
The image source side layer has optical transparency, and a plurality of unit optical shapes each having a first surface on which image light is incident and a second surface opposite to the first surface are arranged on the back side surface. It has an optical shape layer formed with a Fresnel lens shape,
The optical center of the circular Fresnel lens shape is outside the display area of the reflective screen,
The reflective layer is formed on at least a part of the first surface of the unit optical shape;
Reflective screen featuring. A reflective screen according to any one of claims 1 to 9,
An image source for projecting image light onto the reflective screen;
A video display device comprising: The video display device according to claim 10, wherein
The incident angle of the image light projected by the image source to the screen surface of the reflective screen is greater than 0 °;
A video display device characterized by the above.

Images