JP2017156452A - Reflective screen and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reflective screen that is highly transparent and capable of displaying good images, and to provide an image display device having the same.SOLUTION: A screen 10 displays an image by reflecting image light projected by an image source and includes; a light-transmissive first optical shape layer 12 having a plurality of unit optical shapes 121 arranged on a rear surface thereof, each unit optical shape comprising a first sloped surface 121a that receives image light and a second sloped surface 121b facing the first sloped surface; and a reflective layer 13 formed at least on portions of the first sloped surfaces 121a of the unit optical shapes 121. Each unit optical shape 121 has a fine irregular rugged pattern on a surface thereof, and each surface of the reflective layer 13 on a side of the first optical shape layer 12 has a rugged pattern corresponding to the rugged pattern on the respective optical shape. The reflective layer 13 has a function to reflect a portion of incident light and transmit the rest, and is formed of a dielectric multilayer film.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, it can be used as a reflective screen that can be seen well by projecting image light by sticking it to a highly transparent member such as a window glass, etc. The demand for transflective reflective screens that allow the scenery on the other side of the screen to be seen is increasing due to its high design.

Japanese Patent Laid-Open No. 9-11003

However, when such a transflective reflective screen is provided with a diffusion layer containing diffusing particles or the like, the scenery on the other side of the screen may be observed as whitish and blurred, resulting in deterioration in design. Therefore, improvement of transparency has been an issue. Moreover, it is always required to make various screens thinner and to display good images with high contrast.
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 reflective screen that reflects video light (L) projected from a video source and displays a video, has a light transmission property, and has a first surface (121a) on which video light is incident. , 221a) and a second surface (121b, 221b) opposite to the optical shape layer (12, 22) in which a plurality of unit optical shapes (121, 221) are arranged on the rear surface, A reflective layer (13) formed on at least a part of the first surface of a unit optical shape, and the unit optical shape has a fine and irregular concavo-convex shape on a surface thereof, and the reflective layer The surface on the unit optical shape side has a concavo-convex shape corresponding to the concavo-convex shape, and the reflective layer has a function of reflecting a part of incident light and transmitting the other, a dielectric multilayer A reflective screen characterized by being formed of a film (10 20).
According to a second aspect of the present invention, in the reflective screen according to the first aspect, the total light transmittance of light incident on the reflective screen at an incident angle of 0 ° is 70 to 85%. (10, 20).
According to a third aspect of the present invention, in the reflective screen according to the first or second aspect, the diffuse reflectance of light incident on the reflective screen from the image source side at an incident angle of 0 ° is 5 to 35%. Are reflective screens (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 peak gain of the reflective screen is 5 to 3.5. (10, 20).
The invention of claim 5 is characterized in that, in the reflection screen according to any one of claims 1 to 4, the haze value of the reflection screen is 0.1 to 4.0%. Reflective screen (10, 20).
According to a sixth aspect of the present invention, in the reflective screen according to any one of the first to fifth aspects, the dielectric multilayer film forming the reflective layer (13) is made of silicon dioxide, titanium dioxide, pentoxide. A reflective screen (10, 20) comprising at least one of niobium, tantalum pentoxide, and magnesium fluoride.
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 ≦ 20 °, where + α1, −α2 and the average absolute value thereof is α.
The invention according to claim 8 is the reflecting screen according to any one of claims 1 to 7, wherein the reflecting screen is not provided with a diffusing layer containing diffusing particles (10, 20). ).
A ninth aspect of the present invention is the reflective screen according to any one of the first to eighth aspects, wherein the reflective optical screen is light transmissive and the unit optical shape of the optical shape layer (12, 22) is formed. The reflective screen (10, 20) is characterized in that a second optical shape layer (14) laminated so as to fill a valley between the unit optical shapes is provided on the surface on the formed side.
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 the present invention, it is possible to achieve the effects of a reflective screen that is highly transparent 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 which shows the mode of the image light and external light in the screen 10 of 1st Embodiment. It is a figure explaining the screen 20 of 2nd Embodiment. It is a figure which shows the video display apparatus 1A of a deformation | transformation form. 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.

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 reflects the image light L projected from the image source LS and can display an image on a screen (display surface) on the image source side. 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 video source side is defined as + 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 (projector) that projects the video light L onto the screen 10. The video source LS of the present embodiment is a short focus type projector.
The video source LS is displayed when the screen (display area) of the screen 10 is viewed from the front direction (normal direction of the screen surface) on the video source side (+ Z side) when the video display device 1 is in use. Is located at the center in the left-right direction of the screen and on the lower side in the vertical direction (−Y side) than the screen of the screen 10.
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 image source side (+ Z side) 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 and a large incident angle at which the projected video light enters the screen 10.

The screen 10 is a reflection screen that displays a video by reflecting a part of the video light L projected by the video source LS toward the observer O1 located on the video source side (+ Z side). This is a transflective reflective screen having transparency so that the scenery on the other side of the screen 10 can be observed when not in use.
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 viewer O1 side on the video source side (+ Z 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. 1, the screen 10 of this 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, thereby improving the flatness of the screen. 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.
The support plate 50 of this embodiment is a window glass of a show window such as a store. However, the support plate 50 may be a flat plate partition made of transparent glass or resin, and the screen 10 is supported on its four sides by a frame member (not shown). It is good also as a form which maintains.

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 FIG. 1) that is the screen center (the geometric center of the screen) on the image source side (+ Z side) of the screen 10, and is parallel to the screen vertical direction (Y direction). A part of a cross section perpendicular to the screen surface (parallel to the Z direction which is the thickness direction) is enlarged. In FIG. 2, the support plate 50 and the like are omitted for easy understanding.
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 of the screen 10 are omitted.
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 (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.
In addition, the thickness of the base material layer 11 can be changed according to the screen size of the screen 10, and the thickness in the present embodiment is about 100 μm.

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. 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.
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. 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 second inclined surface 121b is positioned below the first inclined surface 121a 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 irregularities on the surface. 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 221. .
The angles θ1, θ2, the array 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 pixels (pixels) of the image source LS, the screen of the screen 10 You may set suitably according to a size, the refractive index of each layer, etc. 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.

FIG. 7 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. FIG. 7 corresponds to the cross section of the screen 10 shown in FIG. 2, and for ease of understanding, the configuration of the screen 10 is simplified, and the base material layer 11 and the protective layer 15 are omitted. In FIG. 7, with respect to the angles α and φ, the upper side (+ Y side) of the screen vertical direction (Y direction) with respect to the direction orthogonal to the screen surface is indicated as plus, and the lower side (−Y side) is indicated as minus. .
Here, the angle of the peak luminance of light (reflected light) projected from the image source LS, incident on the screen 10, incident on the reflective layer 13 formed on the first inclined surface 121 a, diffusely reflected, and emitted from the screen 10. With respect to K, in the vertical direction of the screen (the arrangement direction of the unit optical shapes 121 in FIG. 7), the angles at which the luminance is halved are K1 and K2, and the angle at which the luminance is halved from the peak luminance angle K When the angle change amount from K1 to K2 is + α1 (where K + α1 = K1) and −α2 (K−α2 = K2), the absolute value of the angle change amount from the peak brightness to the brightness becomes ½ Let the average value be α (hereinafter referred to as ½ angle α).

The angle θ1 of the first slope 121a is such that the image light L is reflected most efficiently to the observer O1 positioned in the front direction on the image source side (+ Z side) of the screen 10, that is, the peak luminance of the reflected light. Is designed based on the refractive index of each layer and the like so that the angle K becomes 0 °. Further, the range from −α to + α is a range in which it is assumed that the observer O1 located in front of the screen observes the image satisfactorily.
Here, at a certain point in the vertical direction of the screen (the arrangement direction of the unit optical shapes 121 in FIG. 7), the image light L is incident from below the screen 10 at an incident angle −φ, and the first optical shape layer 12 having a refractive index n. , The light is incident on the first inclined surface 121a having an angle θ1 with respect to the screen surface, is reflected by the reflective layer 13, and is emitted from the screen 10 in a direction perpendicular to the screen surface (exit angle 0 °). Is expressed by the following (formula 1).
θ1 = 1/2 × arcsin ((sin (φ)) / n) (Formula 1)

When the image light L is projected from the image source LS to the screen 10 and the image is displayed on the screen 10 which is a reflection screen, the light source of the image source LS that projects the image light L is reflected, and the contrast of the image is lowered. Problem may occur. This reflection of the image source is mainly caused by the image light reflected by the surface of the screen reaching the observer O1.
In order to prevent such reflection of the image source, the screen 10 is positioned outside the angle range (−α to + α) that is a range in which the observer O1 mainly observes the image favorably on the surface of the screen 10. It is preferable that the image light reflected on the surface of the light travels. When a part Lr of the image light L incident at the incident angle −φ is reflected by the surface of the screen 10, 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), 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 inclined surface 121a are at least a partial region of the screen 10 (for example, In the center of the screen), it is preferable to satisfy 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 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. The image light reflected by the reflective layer 13 is outside the angle range (−α to + α) mainly emitted from the screen 10 and traveling. Thereby, on the image source side (+ Z side), it is possible to reduce the reflection of the image source LS in the range (angle −α to + α) in which the observer O1 visually recognizes the image and display a good image with high contrast. it can.

Returning to FIG. 2 and the like, the reflective layer 13 is a layer having a function of reflecting light, and 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 surface on the first optical shape layer 12 side (image source side) and the surface on the second optical shape layer 14 side (back side) of the reflection layer 13 of the reflection layer 13 are mat surfaces having fine uneven shapes. ing.
The reflection layer 13 has a function of diffusing and reflecting a part of incident light by a fine uneven shape and transmitting other light that does not reflect without diffusing.

  The surface roughness of the reflective layer 13 on the image source side (that is, the surface roughness of the first slope 121a) is an arithmetic average roughness Ra (JIS B 0601: 2001) of about 0.10 to 0.50 μm. It is preferable from the viewpoint of realizing a good viewing angle and displaying a good image. Note that the surface roughness of the reflective layer 13 on the image source side (that is, the surface roughness of the unit optical shape 121) may be appropriately selected according to the desired optical performance or the like.

In addition, in the first inclined surface 121a, a region that is not a rough surface, that is, a region where a fine uneven shape is not formed and the surface on the image source side of the reflective layer 13 formed on the first inclined surface 121a (first surface). The mirror surface region where the optical shape layer 12 side is mirror-like and the incident image light is specularly reflected is per unit area of the reflective layer 13 formed on the first slope 121a (per unit area of the first slope 121a). ) 5% or less is necessary for sufficiently diffusing the image light and obtaining a good viewing angle, and ideally 0%.
If the mirror surface area 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 image source side, or a viewing angle is lowered.

  The reflectance and transmittance of the reflective layer 13 can be appropriately set according to the desired optical performance. However, the reflective layer 13 reflects the image light well and emits light other than the image light (for example, light from the outside such as sunlight). From the viewpoint of transmitting the light well, it is desirable that the transmittance is about 55 to 85% and the reflectance is about 5 to 45%.

The reflective layer 13 is formed of a dielectric multilayer film that can achieve higher transparency and reflectivity than a metal vapor deposition film or the like. 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 these are formed by alternately laminating about 2 to 10 layers. The total thickness of the dielectric multilayer film is 10 to 1000 nm.
The reflection layer 13 has 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.

The reflective layer 13 formed of a dielectric multilayer film has higher transparency than a reflective layer formed of a metal vapor deposition film such as aluminum, and has a small light absorption loss and high reflection. Rate can be realized.
The reflective layer 13 is formed with a predetermined thickness on the unit optical shape 121 (on the first inclined surface 121a and the second inclined surface 121b) by vapor-depositing the dielectric multilayer film as described above, sputtering, or the like. Is done.
The reflective layer 13 of the present embodiment has a total of five layers of high refractive index dielectric films formed of TiO 2 (titanium dioxide) and low refractive index dielectric films formed of SiO 2 alternately (high refractive index dielectric). The film is formed of three layers and two low refractive index dielectric films.

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 rear surface of the screen 10 and can be easily joined to the support plate 50 and the like. It becomes.

The refractive index of the second optical shape layer 14 is preferably equal to or substantially equal to the refractive index of the first optical shape layer 22 (the difference in refractive index is small enough to be considered equal). The second optical shape layer 14 is preferably formed using the same ultraviolet curable resin as the first optical shape layer 12 described above, but may be formed of a different material.
The second optical shape layer 14 of the present embodiment is formed of the same material as the first optical shape layer 12 described above, and its refractive index is equal to the refractive index of the first optical shape layer 12.

The protective layer 15 is a light-transmitting layer formed on the back side (−Z side) of the second optical shape layer 14 and has a function of protecting the back side (−Z side) of the screen 10. ing.
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.
The protective layer 15 may not be provided when the support plate 50 or the like is joined to the back side as in this embodiment.
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 only the fine uneven shape of the reflective layer 13 has a diffusing action. is there.

The screen 10 is formed by the following manufacturing method, for example.
UV is prepared by preparing a base material layer 11 and laminating one surface of the base layer 11 in a state in which a mold for shaping the unit optical shape 121 is filled with an ultraviolet curable resin, and irradiating ultraviolet rays to cure the ultraviolet curable resin. The first optical shape layer 12 is formed by a molding method. 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 uneven shape is formed by repeating plating under different conditions twice or more, performing etching treatment, blasting treatment, etc. on the surfaces forming the first slope 121a and the second slope 121b of the mold. it can.
After the first optical shape layer 12 is formed on one surface of the base material layer 11, the reflective layer 13 is formed by depositing a dielectric multilayer film on the first slope 121a and the second slope 121b.

Thereafter, an ultraviolet curable resin is applied from above the reflective layer 13 so as to fill the valleys between the unit optical shapes 121 so as to have a planar shape, a protective layer 15 is laminated, and ultraviolet rays are irradiated to form an ultraviolet curable type. The resin is cured, and 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.
In addition, the base material layer 11 and the protective layer 15 are good also as a sheet form, and good also as a web form. Further, as described above, the screen 10 may be configured such that the protective layer 15 is not provided.

As a method for forming rough surfaces on the first slope 121a and the second slope 121b, for example, a diffusion layer or the like is applied on the first slope 121a and the second slope 121b, and the reflective layer 13 is formed thereon. A method of blasting the first inclined surface 121a and the second inclined surface 121b after forming one optical shape layer 12 is conventionally known.
However, when the first slope 121a and the second slope 121b are formed into a rough surface by forming a fine and irregular concavo-convex shape by such a manufacturing method, there are variations in diffusion characteristics, quality, and the like on each screen 10. Large 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.

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 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. 4, 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 O1 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 video source LS is positioned below the screen 10, the video light L1 is projected from below the screen 10, and the angle θ2 (see FIG. 2) of the second inclined surface 121b is the screen 10's. Since it is larger than the incident angle of the image light at each point in the vertical direction of the screen, the image 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, 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 O, it is possible to suppress a reduction in the contrast of the video.

Further, a part of the external light incident on the screen 10 is totally reflected on the image source side and back side surfaces of the screen 10 and attenuates toward the lower side inside the screen.
The other external lights G9 and G10 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 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. Moreover, since the outside light is also diffused by the diffusing particles, the scenery on the other side of the screen is observed as blurred or whitened, and the transparency is lowered.

  However, in the 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 on the image source side of the reflective layer 13 has a fine uneven shape. 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, in the screen 10 of the present embodiment, the observer O2 located on the back side has high transparency of the scene on the image source side (+ Z side) through the screen 10 regardless of whether image light is projected. Can be seen well.

Here, various optical performances related to the screen 10 of the present embodiment will be described.
The screen 10 has a diffuse reflectance of 5 to 35% with respect to incident light from a direction orthogonal to the screen surface (incidence angle 0 ° to the screen surface).
The diffuse reflectance is the ratio of diffusely reflected light in the reflected light that is incident on the screen 10 from the image source side at an incident angle of 0 ° and reflected by the reflective layer 13, and is obtained by measurement with a spectrophotometer or the like having an integrating sphere. It is done. When this diffuse reflectance is less than 5%, the viewing angle of the image displayed on the screen 10 is too narrow, which hinders good visual recognition of the image. Further, when the diffuse reflectance is larger than 35%, the brightness of the image is lowered. Therefore, the above range is preferable for the diffuse reflectance of the screen 10.

Further, the screen 10 has a total light transmittance of 70 to 85% of incident light from a direction orthogonal to the screen surface (incidence angle 0 ° to the screen surface).
The total light transmittance is a ratio of the total transmitted light to the light incident on the screen 10 at an incident angle of 0 °, and can be obtained by measurement using a haze meter or the like. When the total light transmittance is less than 70%, the transparency as a screen is lowered, which is not preferable. Further, if the total light transmittance is larger than 85%, the amount of transmitted light becomes too large, and the displayed image becomes dark. Therefore, the total light transmittance of the screen 10 is preferably in the above range.
In the screen of the present embodiment, the total light transmittance when incident from the image source side is equal to the total light transmittance when incident from the back side.

The screen 10 preferably has a haze value of 0.1% or more and 4.0% or less.
This haze value is the ratio of the diffuse transmittance in the total light transmittance, and can be obtained by measurement with a haze meter or the like. If the haze value is less than 0.1%, there is a high possibility that a hot spot is generated in the image, which is not preferable. If it exceeds 4.0%, the transparency of the screen 10 is lowered, the scenery on the other side of the screen is observed whitish, and the contrast of the image is lowered, which is not preferable. Therefore, the haze value of the screen 10 is preferably in the above range.

The peak gain of the screen 10 is preferably 0.5 to 3.5.
The gain is a numerical value indicating the reflection characteristic of the screen 10, and is the same when the luminance of the reflected light when a complete diffuser plate (pure white plate fired with magnesium oxide, etc.) is irradiated with a light source (white light) is 1. The luminance value measured from each angle in the horizontal direction (horizontal direction) of the point A, which is the center of the screen on the image source side surface of the screen 10 irradiated with an incident angle of 32 ° from the front direction on the image source side by the light source. Obtained by ratio. The highest numerical value of this gain is called peak gain, and in this embodiment, it is a value measured from the image source side front direction. When the peak gain of the screen 10 is 0.5 or less, the brightness of the image is lowered, which is not preferable. Further, when the peak gain of the screen 10 is larger than 3.5, the viewing angle becomes too narrow, which is not preferable. Therefore, the peak gain of the screen 10 is preferably in the above range.

The half angle α of the screen 10 preferably satisfies 5 ° ≦ α ≦ 20 °.
As described above, the half angle α is incident on the screen 10, diffused and reflected by the reflective layer 13, and the screen vertical direction (unit optical in FIG. 7) with respect to the angle K that becomes the peak luminance of the light emitted from the screen 10. In the shape 121 arrangement direction), the angles at which the luminance is halved 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 is ½ is + α1 (where K + α1). = K1), -α2 (K-α2 = K2), it is the average value of the absolute values of the amount of change in angle from the peak luminance until the luminance is halved.
In the screen 10 of this 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. Therefore, it is preferable that the half angle α in the horizontal direction of the screen also satisfies 5 ° ≦ α ≦ 20 °.

If α <5 °, the viewing angle for displaying a good image for the observer O1 becomes too narrow and the image becomes difficult to see, which is not preferable. Further, when α <5 °, the specular reflection component in the reflected light increases, and the reflection of the image source occurs, which is not preferable.
When α> 20 °, the viewing angle for displaying a good image with respect to the observer O1 is widened, but the brightness of the image is reduced, the blur of the image is strong, or the screen 10 of external light The contrast of the image is lowered by reflection, which is not preferable.
Therefore, the above range is preferable for the half angle α of the screen 10 in the horizontal direction of the screen and the vertical direction of the screen.

Here, screens of Measurement Examples 1 to 7 having different total light transmittance, haze value, diffuse reflectance, peak gain, and half angle α are prepared, and the illuminance is about 700 lx at the point A that is the center of the screen. In the bright room environment, the image was observed from a position of 2 m from the point A to the image source side (+ Z side), and the appearance of the image and the transparency of the screen were evaluated.
Note that the screens of each measurement example have the same configuration except that the total light transmittance, haze value, diffuse reflectance, peak gain, and ½ angle α are different.
Further, the total light transmittance, haze value, diffuse reflectance, and peak gain were measured at point A, which is the center of the screen of each measurement example.
Moreover, the haze meter used for the measurement is HM-150 manufactured by Murakami Color Research Laboratory Co., Ltd., and the spectrophotometer is an ultraviolet-visible near-infrared spectrophotometer (V-670) manufactured by JASCO Corporation. . For the measurement of the peak gain, a three-dimensional variable angle spectrocolorimetry system (GCMS-11) manufactured by Murakami Color Research Laboratory Co., Ltd. was used.

As described above, the screens of Measurement Examples 2 to 6 in which the total light transmittance, haze value, diffuse reflectance, peak gain, and ½ angle α satisfy the preferred range are bright and good images are observed. The viewing angle was also sufficient.
However, in the screen of Measurement Example 1 in which the total light transmittance and the haze value do not satisfy the preferable ranges, the transparency of the screen is low, and the scenery on the other side of the screen is observed whitish. It was not preferable because it decreased.
Further, in the screen of Measurement Example 7 in which the total light transmittance, haze value, diffuse reflectance, peak gain, and ½ angle α do not satisfy the preferable ranges, the transparency of the screen was obtained, but the brightness of the image. Decreased, and the image became dark.

From the above, the screen 10 of the present embodiment satisfies the preferable ranges with respect to the total light transmittance, haze value, diffuse reflectance, peak gain, and ½ angle α, so that it is bright while maintaining transparency. A good image with a sufficient viewing angle can be displayed.
Further, in the screen 10 of the present embodiment, the 1/2 angle α and the angle θ1 of the image light (reflected light) diffusely reflected by the reflective layer 13 satisfy the above-described (Equation 2). The image light reflected on the source-side surface is directed outward from the ½ angle α, and there is no reflection of the image source LS, and a good image can be displayed.

  Further, according to the present embodiment, the first optical shape layer 12 has a point C serving as a Fresnel center located outside the display area and on the image source LS side, and has a circular Fresnel lens shape having a so-called offset structure. Therefore, even in the case of the image light L having a large incident angle projected from the image source LS which is a short focus type projector, the image in the horizontal direction of the screen is not darkened, and the surface uniformity of the brightness High quality images can be displayed.

(Second Embodiment)
FIG. 5 is a diagram illustrating the screen 20 according to the second embodiment. FIG. 5A is a view of the first optical shape layer 22 of the screen 20 as viewed from the back side (−Z side). For easy understanding, the reflective layer 13, the second optical shape layer 14, The protective layer 15 and the like are omitted. FIG. 5B shows an enlarged part of the cross section of the screen 20 of the second embodiment corresponding to the cross section of the screen 10 of the first embodiment shown in FIG.
The screen 20 shown in the second embodiment has the same form as that of the first embodiment, except that the unit optical shape 221 of the first optical shape layer 22 is different. 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 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 14, and a protective layer 15.
The first optical shape layer 22 is provided with a plurality of unit optical shapes 221 arranged on the back side (−Z side) surface.
The unit optical shapes 221 extend in the left-right direction (X direction) of the screen 10 and are arranged in a plurality along the vertical direction of the screen (Y direction). The unit optical shape 221 is a so-called prism shape in which the 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 triangular. .

The unit optical shape 221 has a first inclined surface 221a on which image light is directly incident and a second inclined surface 221b facing the first inclined surface 221a. In one unit optical shape 221, the second inclined surface 221b is located on the lower side (−Y side) than the first inclined surface 221a across the vertex t.
In the present embodiment, as shown in FIG. 5, 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.

  In the unit optical shape 221, as shown in FIG. 5B, the angle formed by the first inclined surface 221a and the surface parallel to the screen surface is θ1, and the angle formed by the second inclined surface 221b and the surface parallel to the screen surface. Is θ2. At this time, the angles θ1 and θ2 satisfy the relationship θ2> θ1. This angle θ1 satisfies the above-described (Formula 2) with respect to the half angle α.

In the screen 20 of the present embodiment, the total light reflectance, diffuse reflectance, haze value, peak gain, and ½ angle α satisfy the preferred ranges, similar to the screen 10 of the first embodiment described above.
Therefore, according to the present embodiment, as in the first embodiment described above, it is possible to provide the transflective screen 20 and the display device 1 that have high transparency and can display a good image.
In addition, according to the present embodiment, the unit optical shapes 221 are arranged in the screen vertical direction (Y direction) with the screen horizontal direction (X direction) as the longitudinal direction, so the first optical shape layer 22 and the screen 20 are arranged. The large screen 20 can be easily manufactured. In addition, for example, the web-like base material layer 11 and the protective layer 15 can be used to easily and continuously produce the screen 20 in a state before cutting, thereby improving the production efficiency of the screen 10 and reducing the production cost. Can be reduced.

(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 for the purpose of preventing scratches may be provided on the image source side (+ Z side) surfaces 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 (+ Z side) of the base material layer 11.
For example, when an antireflection layer is provided on the image source side surface of the screens 10 and 20, a part of the light reflected by the reflection layer 13 is reflected by the image source side surface and emitted from the back side. Thus, it is possible to prevent a part of the video from being seen by the viewer O2 on the back side.

(2) In each embodiment, the reflective layer 13 is an example of a semi-transmissive reflective layer in the form of a half mirror (magic mirror). However, the present invention is not limited to this. For example, the thickness of each film increases the number of layers. For example, the reflection layer may have a high ratio of reflecting incident light and a low ratio of transmitting light by adjusting the thickness.

(3) In each embodiment, the video source LS has been described with 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 below the screen. However, the present invention is not limited to this. , 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. 6 is a diagram illustrating a video display device 1A according to a modification. FIG. 6 shows an example using the screen 20 of the second embodiment as an example.
As shown in FIG. 6, for example, when the video source LS is arranged below the left side of the screen 10 in the left-right direction (−X side), 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 screen vertical direction (Y direction) and the screen horizontal direction (X direction). By adopting such a form, the position of the video source LS and the like can be freely set.
In addition, even when the first optical shape layer 12 has a circular Fresnel lens shape as in the screen 10 shown in the first embodiment, the arrangement direction of the unit optical shapes 221 is inclined according to the position of the image source LS. Thus, such a modification can be applied.

(4) In each embodiment, although unit optical shape 121,221 showed the example in which the 1st slope 121a, 221a and the 2nd slope 121b, 221b were formed by a plane, it is not restricted to this, For example, it is a curved surface. It is good also as a form with which the plane was combined, and it is good also as a folded surface shape.
Further, in each embodiment, the unit optical shapes 121 and 221 may be polygonal shapes formed by a plurality of three or more surfaces.
Moreover, in each embodiment, although the reflective layer 13 showed the example formed in 1st slope 121a, 221a and 2nd slope 121b, 221b, it is not restricted to this, For example, at least 1st slope 121a, 221a is shown. It is good also as a form formed in part.
Moreover, in each embodiment, although 1st slope 121a, 221a and 2nd slope 121b, 221b showed the example which is a rough surface in which the fine uneven | corrugated shape was formed, not only this but 1st slope 121a, Only 221a may have a rough surface.

(5) In each embodiment, when the first optical shape layer 12 and the second optical shape layer 14 have sufficient thickness, rigidity, etc., the screens 10 and 20 are the base material layer 11 and the protective layer. 15 may be provided, or one of them may be provided.
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 15 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.

(6) 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.
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 layer 15, the TAC sheet-like member is suitable.

(7) 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 a room partition or 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 121 Unit optical shape 121a 1st slope 121b 2nd slope 13 Reflective layer 14 2nd optical shape layer 15 Protective layer LS Image source

Claims (10)

A reflective screen that reflects video light projected from a video source to display an image;
An optical shape layer having a plurality of unit optical shapes having a light transmittance and having a first surface on which image light is incident and a second surface facing the first surface;
A reflective layer formed on at least part of the first surface of the unit optical shape;
With
The unit optical shape has a fine and irregular uneven shape on its surface,
The surface on the unit optical shape side of the reflective layer has an uneven shape corresponding to the uneven shape,
The reflective layer has a function of reflecting a part of incident light and transmitting the other, and is formed of a dielectric multilayer film;
Reflective screen featuring. The reflective screen according to claim 1.
The total light transmittance of light incident on the reflecting screen at an incident angle of 0 ° is 70 to 85%;
Reflective screen featuring. The reflective screen according to claim 1 or 2,
The diffuse reflectance of light incident on the reflection screen from the image source side at an incident angle of 0 ° is 5 to 35%.
Reflective screen featuring. The reflective screen according to any one of claims 1 to 3,
The peak gain of the reflecting screen is 0.5 to 3.5;
Reflective screen featuring. The reflective screen according to any one of claims 1 to 4, wherein:
The haze value of the reflective screen is 0.1 to 4.0%;
Reflective screen featuring. The reflection screen according to any one of claims 1 to 5,
The dielectric multilayer film forming the reflective layer contains at least one of silicon dioxide, titanium dioxide, niobium pentoxide, tantalum pentoxide, and magnesium fluoride.
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 ≦ 20 °,
Reflective screen featuring. In the reflective screen of any one of Claim 1 to Claim 7,
Not having a diffusion layer containing diffusing particles,
Reflective screen featuring. The reflective screen according to any one of claims 1 to 8,
A second optical shape layer that has optical transparency and is laminated on the surface of the optical shape layer on the side where the unit optical shape is formed so as to fill a valley between the unit optical shapes; ,
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:

Images