JP2023006602A - Screen and picture display device - Google Patents

Abstract

To provide a transmissive screen and a picture display device that have a sufficient transparency and can display a bright and excellent picture.SOLUTION: A screen 10 includes: a picture light deflection unit 10A for changing the direction of a part of at least incident picture light; and a picture light diffusion unit 10B for diffusing a part of at least incident picture light. The picture light deflection unit 10A and the picture light diffusion unit 10B are located in different positions in the thickness direction of the screen 10. The picture display device includes a screen 10 and a picture source for projecting picture light on the screen 10.SELECTED DRAWING: Figure 2

Description

The present invention relates to screens and image display devices.

2. Description of the Related Art Transmissive or reflective screens that display images by image light projected from an image source, and image display devices using such screens have been known. Also, in recent years, there has been a shift to highly transparent screens that are installed in shop windows, etc., to display images, and that allow the scenery on the other side of the screen to be clearly visible when image light is not projected. Demand is growing.

As a screen having transparency, various transmissive screens including a diffusion layer containing a diffusion material for diffusing light have been developed (see, for example, Patent Documents 1 and 2).

JP 2017-027026 A JP 2019-174546 A

In a transmissive screen provided with such a light diffusion layer, although the image displayed on the screen can be brightened by increasing the diffusion strength of the light diffusion layer, the contrast of the image is lowered and the transparency is lowered, resulting in the screen being distorted. There is a problem that the background image observed through the lens becomes white and cloudy.
Further, in such a screen, if the diffusion intensity is reduced in order to maintain high transparency, the image light reaches the viewer without being diffused when the image is projected from the front direction of the screen. To avoid this, if the image light is projected obliquely from the bottom of the screen, etc., most of the image light will be directed diagonally upward of the screen. The utilization efficiency of is significantly reduced. In such a screen, there is a problem that it is difficult to achieve both contrast and brightness of an image and to maintain transparency.

SUMMARY OF THE INVENTION An object of the present invention is to provide a transmissive screen and an image display device that have sufficient transparency and display bright and favorable images.

The present invention solves the above problems by means of the following solutions. In order to facilitate understanding, reference numerals corresponding to the embodiments of the present invention are used for explanation, but the present invention is not limited to these.
A first invention comprises an image light deflector (10A, 20A) that changes the direction of at least part of the incident image light, and an image light diffuser (10B, 30B) that diffuses at least part of the incident image light. wherein the image light deflection section and the image light diffusion section are provided at different positions in the thickness direction of the screen (10, 30).
In a second aspect of the invention, in the screen of the first aspect, the image light diffusion section (10B) is arranged on the light entrance side of the image light deflection section (10A, 20A) in the thickness direction of the screen, The screen (10) is characterized by diffusing light incident obliquely more than light incident at an incident angle of 0°.
A third invention is the screen according to the first invention or the second invention, wherein the image light diffusion section (10B) receives more light than the image light deflection sections (10A, 20A) in the thickness direction of the screen. A light control layer (16) arranged on the side of the light control layer (16) that diffuses and transmits light incident at an incident angle within a specific angular range to a greater extent than light incident at an incident angle outside the specific angular range. A screen (10) characterized by:
A fourth invention is the screen according to the third invention, in which light incident at an incident angle outside the specific angle range is transmitted without being diffused or diffused so small that it can be regarded as substantially not diffused. A screen (10) characterized by:
A fifth aspect of the present invention is a screen according to any one of the first to fourth aspects, wherein a light incident surface (M1) on which image light is incident, and a light incident surface (M1) facing the light incident surface, from which the image light is emitted. and a light exit surface (M2), wherein the image light deflector (10A, 20A) includes a resin layer (12, 22) having light transmittance, and a plurality of resin layers (12, 22) arranged inside the resin layer to deflect incident light. and a reflecting surface (13) that reflects at least part of the screen ( 10, 30).
In a sixth invention based on the screen of the fifth invention, the reflecting surface (13) forms an angle θ1 with respect to a plane parallel to the screen surface in a cross section parallel to the arrangement direction and the thickness direction of the screen. , the angle θ1 is 70° or more.
A seventh invention is the screen according to the sixth invention, characterized in that the angle θ1 becomes smaller toward one side along the arrangement direction of the reflecting surfaces (13) (10, 30). is.
An eighth invention is the screen according to any one of the fifth invention to the seventh invention, wherein the reflecting surfaces (13) are adjacent to each other in the arrangement direction when viewed from the normal direction of the screen surface of the screen. A screen (10, 30) characterized in that it has a gap with said reflective surface.
A ninth invention is the screen according to any one of the fifth invention to the eighth invention, wherein the reflecting surface (13) is outside the display area of the screen when viewed from the normal direction of the screen surface of the screen. A screen (10, 30) characterized in that it is arranged concentrically around a point (C) located at .
A tenth invention is the screen according to any one of the fifth invention to the ninth invention, wherein the resin layer (12, 22) comprises a first resin layer (121, 221) positioned on the light incident side; and a second resin layer (122, 222) disposed adjacent to the light output side of the first resin layer, wherein the first resin layer has a unit optical shape (122, 222) on the interface with the second resin layer 121a, 221a) are arranged in plurality, the unit optical shape is polygonal in a cross section parallel to the arrangement direction and the thickness direction of the screen, and the reflecting surface (13) is at least in the unit optical shape A screen (10, 30) characterized in that it is formed on a part of a plane that forms an angle with respect to a plane parallel to the plane of the screen.
In an eleventh aspect of the invention, in the screen of the tenth aspect, the unit optical shape (121a) has a triangular shape in a cross section parallel to the arrangement direction and the thickness direction of the screen, and the first surface (121b) and a second surface (121c) that intersects with the screen surface, and the angle (θ1) formed between the first surface and a surface parallel to the screen surface is The screen (10) is characterized in that the reflecting surface is formed on at least a part of the first surface and is larger than the angle (θ2) formed.
In a twelfth aspect of the invention, in the screen of the tenth aspect, the unit optical shape (221a) has a trapezoidal shape in a cross section parallel to the arrangement direction and the thickness direction of the screen, and the first surface (221b) and a second surface (221c) facing the first surface in the arrangement direction of the unit optical shapes, and a vertex located between the first surface and the second surface and closest to the light output side. a surface (221d), said first surface being angled with respect to a plane parallel to the screen surface, said reflecting surface being formed on at least a portion of said first surface; A screen (10) characterized by
A thirteenth invention is the screen according to any one of the fifth invention to the twelfth invention, wherein the screen has transparency, the reflective surface (13) has light transparency, and the resin A screen (10) characterized by being provided by a low refractive index layer having a lower refractive index than a layer (12).
A fourteenth invention is the screen according to any one of the fifth invention to the twelfth invention, wherein the screen has transparency, and the reflecting surface (13) reflects part of the incident light. A screen (10) characterized in that it is provided by a semi-transmissive reflective layer that transmits part of the incident light.
In a fifteenth aspect of the invention, in the screen according to the first aspect or the second aspect, the image light diffusion section (30B) is located on the light exit side of the image light deflection section (10A, 20A) in the thickness direction of the screen. Alternatively, the screen (30) is characterized by being a light diffusion layer (38) that is arranged on the light incident side and contains a diffusion material that diffuses light.
A sixteenth invention is the screen according to any one of the first invention to the fifteenth invention, comprising: a light incident surface (M1) for receiving image light; and a light exit surface (M2) for emitting light, the screen (10 , 30).
A seventeenth invention is an image display device (1 ).

According to the present invention, it is possible to provide a transmissive screen and an image display device that have sufficient transparency and display bright and favorable images.

It is a figure which shows the video display apparatus 1 of 1st Embodiment. It is a figure which shows the layer structure of the screen 10 of 1st Embodiment. It is a figure explaining image light deflection part 10A of a 1st embodiment. It is a figure explaining the reflective surface 13 of 1st Embodiment. It is a figure explaining the image light which injected into 10 A of image light deflection parts of 1st Embodiment. 4A and 4B are diagrams for explaining the light control action of the light control layer 16; FIG. 4A and 4B are diagrams showing an example of image light and external light incident on the screen 10 of the first embodiment; FIG. It is a figure explaining image light deflection part 20A of a 2nd embodiment. FIG. 10 is a diagram showing a layer structure of a screen 30 of a third embodiment; FIG. It is a figure explaining image light deflection part 60A of a modification. It is a figure explaining image light deflection part 70A of a modification. It is a figure explaining image light deflection part 80A of a modification.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, each figure shown below including FIG. 1 is a schematic diagram, and the size and shape of each part are appropriately exaggerated for easy understanding.
In this specification, terms that specify shapes and geometric conditions, for example, terms such as parallel and orthogonal, have the same optical function and can be regarded as parallel or orthogonal in addition to the strict meaning. It also includes a state with an error of (substantially equal state).

In this specification, numerical values such as dimensions and material names of each member described are examples as an embodiment, and are not limited to these, and may be appropriately selected and used.
In this specification, terms such as plate, sheet and film are used. In general, the order of thickness is plate, sheet, and film, and this is also used in this specification. However, since there is no technical meaning in such proper use, these words can be replaced as appropriate.
In this specification, the screen surface refers to a surface in the plane direction of the screen when the screen is viewed as a whole, and is parallel to the screen (display surface) of the screen.

(First embodiment)
FIG. 1 is a diagram showing an image display device 1 according to the first embodiment. FIG. 1 shows the image display device 1 viewed from the side (+X side, which will be described later).
The image display device 1 has a screen 10, an image source LS, and the like. Image light is projected onto the screen 10 from the image source LS from one side of the screen 10 and transmitted therethrough. It is a so-called rear projection type image display device that displays an image so that the observer O1 can visually recognize it.
In this embodiment, as an example, the image display device 1 is applied to a show window of a store, and the screen 10 is fixed by being attached to the glass of the show window. Note that the image display device 1 is not limited to this, and can be applied to, for example, an indoor partition, an image display at an exhibition, or the like.

Here, in order to facilitate understanding, an XYZ orthogonal coordinate system is appropriately provided and shown in each figure shown below including FIG. In this coordinate system, the horizontal direction of the screen 10 is the X direction, the vertical 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 of the screen 10 .
In addition, the +X direction is the direction toward the right side in the horizontal direction of the screen as viewed from the observer O1 positioned in the front direction on the light exit side (observer side) of the screen 10, the +Y direction is the direction toward the upper side in the vertical direction of the screen, and the thickness direction. , the direction from the light input side (image source side) to the light output side (observer side) is the +Z direction.
Furthermore, in the following description, unless otherwise specified, the vertical direction of the screen, the horizontal direction of the screen, and the thickness direction refer to the vertical direction of the screen (vertical direction) and the horizontal direction of the screen when the video display device 1 and the screen 10 are used. (horizontal direction) and thickness direction (depth direction), which are parallel to the Y direction, X direction, and Z direction, respectively.

The image source LS is an image projection device that projects the image light L onto the screen 10, and is, for example, a short-focus projector.
When the screen (display area) of the screen 10 is viewed from the front direction (the normal direction of the screen surface) on the light output side (+Z side) in the usage state of the image display device 1, the image source LS is as follows: It is located in the center of the screen in the left-right direction and on the lower side (-Y side) in the vertical direction than the screen of the screen 10 .
The image source LS can obliquely project the image light L from a position that is significantly closer to the surface of the screen 10 in the depth direction (Z direction) than a conventional general-purpose projector. Therefore, compared with the conventional general-purpose projector, the image source LS has a short projection distance of the image light L to the screen 10, a large incident angle of the projected image light L on the screen 10, and a change amount (minimum The amount of change from the value to the maximum value) is also large.

The screen 10 is a transmissive screen that transmits and displays the image light L projected by the image source LS. and a light exit surface M2. This screen 10 has transparency so that the scenery on the other side of the screen 10 can be observed from both the light exit side and the light entrance side when the screen 10 is not used for projecting image light.
In the present embodiment, the screen (display area) of the screen 10 has a substantially rectangular shape in which the long side direction is the horizontal direction of the screen when viewed from the observer O1 on the light exit side (+Z side) in the usage state. to explain.
The screen 10 has a diagonal screen size of about 40 to 100 inches and a screen aspect ratio of 16:9. Note that the screen size of the screen 10 is not limited to this, and may be smaller than 40 inches, for example, and the size and shape can be appropriately selected according to the purpose of use, environment of use, and the like.

In the screen 10 of the present embodiment, for example, a light-transmitting support plate (not shown) is integrally bonded (or partially fixed) via a light-transmitting bonding layer (not shown) on the light exit side (+Z side) surface. ) to maintain the flatness of the screen. It should be noted that the configuration is not limited to this, and a configuration in which a support plate (not shown) is arranged on the surface of the screen 10 on the light incident side (−Z side) may be employed.
The support plate is a plate-shaped member having light transmission properties and high rigidity, and a plate-shaped member made of resin such as acrylic resin or PC resin, glass, or the like can be used. In this embodiment, the support plate is a glass plate of a show window of a store or the like.
The screen 10 is not limited to this, and the screen 10 may be configured such that its four sides and the like are supported by frame members and the like (not shown) to maintain its flatness.

FIG. 2 is a diagram showing the layer structure of the screen 10 of the first embodiment. In FIG. 2, a point A (see FIG. 1), which is the center of the screen (geometric center of the screen) on the light exit side (observer side, +Z side) of the screen 10, is parallel to the vertical direction (Y direction) of the screen. A part of the cross section perpendicular to the screen surface (parallel to the Z direction, which is the thickness direction) is shown enlarged.
The screen 10 includes an image light deflector 10A that changes (deflects) the traveling direction of image light, and an image light diffuser 10B that diffuses at least the image light. located in different positions. In this embodiment, the image light deflector 10A is provided on the light exit side of the image light diffuser 10B.
As shown in FIG. 2, the screen 10 of the present embodiment has a light control layer 16, a bonding layer 17, a first substrate layer 11, a resin layer 12, and a reflective surface 13 in this order from the light incident side (-Z side). , a second substrate layer 15 . The image light deflector 10A is the resin layer 12 and the reflecting surface 13, and the image light diffuser 10B is the light control layer 16. As shown in FIG.

The first base material layer 11 is a sheet-like member having optical transparency. A resin layer 12 is integrally formed on the light exit side (observer side, +Z side) of the first base material layer 11 .
The first 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. It is made of (triacetyl cellulose) resin or the like.

The resin layer 12 is a layer having optical transparency formed on the light exit side (+Z side) of the first base material layer 11 . The resin layer 12 has a plurality of reflective surfaces 13 arranged therein.
The resin layer 12 of this embodiment is made of an ultraviolet curable resin having high light transmittance. Moreover, it is not limited to this, and may be formed of other ionizing radiation curable resin such as electron beam curable resin.
The reflective surface 13 is a reflective surface that reflects at least part of incident light. The reflective surfaces 13 of the present embodiment are arranged inside the resin layer 12 at predetermined intervals.

FIG. 3 is a diagram for explaining the image light deflection section 10A of the first embodiment. In FIG. 3, the image light deflector 10A in the cross section of the screen 10 shown in FIG. 2 is further enlarged and shown.
FIG. 4 is a diagram illustrating the reflecting surface 13 of the first embodiment. FIG. 4 shows the image light deflection section 10A viewed from the light output side (+Z side), and only the image light deflection section 10A is shown for easy understanding.
As shown in FIG. 4, the reflecting surface 13 of the present embodiment has a shape of a part of a perfect circle (arcuate shape), and concentrically with a point C located outside the screen (display area) of the screen 10 as the center. multiple arrays. This point C is located outside the display area of the screen 10 . The arrangement pitch of the reflecting surfaces 13 is P.

In this embodiment, as shown in FIG. 4, the point C is located at the center of the screen in the horizontal direction (X direction) and outside the screen (-Y side). When the screen 10 is viewed from the front, the points C and A are located on the same straight line parallel to the vertical direction (Y direction) of the screen, as shown in FIG.
Note that the positional relationship between the image source LS and the observer with respect to the screen 10 is not limited to this, and can be appropriately set according to the usage environment of the image display device 1. Accordingly, the position of the point C with respect to the screen 10 is can also be set appropriately.

In the cross section shown in FIG. 3, the reflecting surface 13 of the present embodiment has an image source in the arrangement direction of the reflecting surface 13 more than the light incident side (−Z side) end of the light exiting side (+Z side). It is inclined so as to be positioned on the LS side (the lower side in the vertical direction of the screen). The angle formed by the reflecting surface 13 with a plane parallel to the screen surface is θ1.
In the cross section shown in FIG. 3, the end of the reflecting surface 13 on the light incident side and the end of the reflecting surface 13 on the light emitting side adjacent to the lower side (image source side) of the reflecting surface 13 in the arrangement direction of the reflecting surface 13 The angle between the plane (the plane indicated by the dashed line in FIG. 3 and hereinafter referred to as the connecting plane) connecting the portion (point t1) and the plane parallel to the screen plane is θ2. Although this connection surface is indicated by a dashed line, it is actually difficult to visually recognize it.
The angle θ1 is preferably 70° or more from the viewpoint of efficiently directing the image light toward the observer O1 positioned in the front direction on the light exit side (+Z side).
Further, in the present embodiment, the angle θ1 is larger than the angle θ2, and θ1>θ2.

As shown in FIG. 3, in a cross section parallel to the arrangement direction of the reflective surfaces 13 and the thickness direction of the screen 10, the reflective surface 13 and the connecting surface intersect at a point t1. A unit optical shape that is convex on the light output side is formed.
That is, the resin layer 12 of the present embodiment includes a first resin layer 121 located on the first substrate layer side (−Z side) and a second substrate layer side (+Z side) adjacent to the first resin layer 121. ), and a plurality of unit optical shapes 121a are arranged on the interface between the first resin layer 121 and the second resin layer 122. As shown in FIG.
The first resin layer 121 and the second resin layer 122 are made of the same material, have the same refractive index, and are connected at the connection surface.

The image light deflection section 10A in which a plurality of reflecting surfaces 13 are arranged inside the resin layer 12 as in the present embodiment is formed by molding a first resin layer in which a plurality of unit optical shapes as described above are arranged on one side, for example. Alternatively, a layer or the like for forming the reflecting surface 13 is formed on a predetermined surface of the unit optical shape, and a second resin layer is formed thereon so as to fill the irregularities of the unit optical shape.
In this embodiment, an example will be described in which the cross-sectional shape of the unit optical shape is triangular in the cross section parallel to the arrangement direction of the unit optical shapes and the thickness direction of the image light deflection section. Note that the cross-sectional shape of such a unit optical shape may be a trapezoidal shape or other polygonal shape.

The unit optical shape 121a is, like the reflecting surface 13 shown in FIG. are arranged in multiple numbers.
The unit optical shape 121a has a cross-sectional shape in the cross section shown in FIG. 3 that is a substantially triangular shape that is convex on the light output side, and the first surface located below (−Y side) the point t1 that is the vertex. 121b, and a second surface 121c that intersects with the first surface 121b at point t1 and is positioned above (+Y side) with respect to point t1. The reflecting surface 13 is provided on the first surface 121b, and the second surface 121c corresponds to the connecting surface.
The arrangement pitch of the unit optical shapes 121a is equal to the arrangement pitch P of the reflecting surface 13, and the angle formed by the first surface 121b and the plane parallel to the screen surface (XY plane) is θ1. The angle formed by the second surface 121c and a plane parallel to the screen surface (XY plane) is θ2.

Further, as shown in FIG. 3, in the arrangement direction of the reflecting surfaces 13, if the width occupied by the reflecting surfaces 13 is W1 and the width of the connecting surface is W2, then P=W1+W2. It's becoming That is, when viewed from the front direction of the screen, the reflecting surfaces 13 are arranged with gaps in the arrangement direction.

For ease of understanding, FIGS. 2 and 3 show an example in which the arrangement pitch P, the angle θ1, etc. of the reflecting surfaces 13 are constant in the arrangement direction of the reflecting surfaces 13 (unit optical shapes 121a). . However, in this embodiment, although the arrangement pitch P of the reflecting surfaces 13 is actually constant, the angle θ2 gradually increases and the angle θ1 gradually decreases as the distance from the point C in the arrangement direction increases.
The angle θ1, the array pitch P, etc. 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 of the image source LS, the screen size of the screen 10, It may be appropriately set according to the refractive index of each layer. For example, a form in which the arrangement pitch P changes along the arrangement direction of the reflecting surfaces 13 may be adopted.

The reflection surface 13 has its reflection performance and means for reflecting image light on the reflection surface 13 (that is, means for providing the reflection surface 13) depending on the desired use environment of the screen 10 and the desired optical performance. You can choose.
For example, the reflective surface 13 has a high light transmittance, and a low refractive index layer formed of a material having a lower refractive index than the resin layer 12 (the first resin layer 121 and the second resin layer 122) is provided on the first surface 121b. It may be provided by the refractive index difference between the resin layer 12 and the low refractive index layer. Such a low refractive index layer can be formed by, for example, depositing or sputtering a metal fluoride such as magnesium fluoride (MgF ₂ ) or aluminum fluoride (AlF ₃ ), silicon oxide (SiO ₂ ), silicon-based resin, or the like. It is formed by In this case, the refractive index of the low refractive index layer is preferably about 1.35 to 1.45.

When the reflective surface 13 is provided by the refractive index difference between the low refractive index layer and the resin layer 12, light incident on the reflective surface 13 at an incident angle equal to or greater than the critical angle is totally reflected, and light incident at an incident angle less than the critical angle is totally reflected. Most of the incident light passes through the reflecting surface 13 .
Such a low-refractive-index layer preferably has a thickness sufficient to fully reflect the image light at the interface K1.

In addition, when the reflecting surface 13 is provided by the refractive index difference between the low refractive index layer and the resin layer 12, the resin layer 12 has high light transmittance and is an ultraviolet curable resin having a higher refractive index than general ultraviolet curable resins. Resins, for example, epoxy acrylate-based UV-curable resins, urethane-based UV-curable resins to which metal oxides are added to increase the refractive index, and titanium oxide (TiO ₂ ) is added to increase the refractive index. It is preferably formed using an ultraviolet curable resin or the like. Also, in this case, the refractive index of the resin layer 12 is preferably about 1.56 to 1.7.

The reflective surface 13 may be provided by forming on the first surface 121b a semi-transmissive reflective layer (a so-called half mirror) that partially reflects and partially transmits incident light. Such a transflective reflective layer may be formed by vapor-depositing a highly light-reflective metal such as aluminum, silver, nickel, chromium, etc. may be formed by sputtering, transferring a metal foil, or applying a paint containing a metal thin film. Furthermore, such a transflective reflective layer is formed by vapor deposition of a dielectric multilayer film or a dielectric single-layer film that has high transparency, small light absorption loss, and high reflectance. may

When the reflective surface 13 is provided by forming a semi-transmissive reflective layer as described above on the first surface 121b, at least a portion of the image light incident on the reflective surface 13 is reflected, and at least a portion of the image light is reflected. It penetrates the plane 13 .
The reflectance and transmittance of such a semi-transmissive reflective layer can be appropriately set according to the desired optical performance. From the viewpoint of good reflection of image light and good transmission of light other than image light (for example, light from the outside world such as sunlight), the transmittance is about 30 to 80% and the reflectance is 5 to 60%. It is desirable to have a degree.

When the reflective surface 13 is provided by a semi-transmissive reflective layer, the resin layer 12 is made of highly light-transmissive urethane acrylate, polyester acrylate, epoxy acrylate, polyether acrylate, polythiol, butadiene acrylate, or the like. is preferably made of an ultraviolet curable resin.
The semi-transmissive reflective layer may have a very low transmittance depending on the environment in which the screen 10 is used. Such a reflective layer with low transmittance can be formed by adjusting the transmittance to be low by using the same material as the above-described semi-transmissive reflective layer and increasing the thickness thereof.

The image light deflection section 10A of the present embodiment is formed by, for example, the following method.
First, the first resin layer 121 in which the unit optical shapes 121a are arranged is formed on the light output side surface of the first base material layer 11 by a UV molding method or the like. Then, on the first surface 121b of the unit optical shape 121a, a low refractive index layer or a semi-transmissive reflective layer as described above is formed by vapor deposition or the like, and a reflective function is imparted to the first surface 121b to form a reflective surface. 13 is provided. After the reflection surface 13 is formed, a material for forming the second resin layer 122 is laminated so as to fill the unevenness of the unit optical shape 121a and be flattened, and the second resin layer 122 is formed by curing. As a result, the reflective surface 13 is formed inside the resin layer 12 .

In this manner, the transparency of the screen 10 is improved by forming the reflecting surface 13 inside the resin layer 12 . In this embodiment, the refractive index of the second resin layer 122 is equal to or substantially equal to the refractive index of the first resin layer 121 (the refractive index difference is small enough to be regarded as equal). is desirable from the viewpoint of improving Although the second resin layer 122 has the same refractive index as the first resin layer 121, it may be made of a different resin.
Further, by providing the reflecting surface 13 inside the resin layer 12, the reflecting surface 13 can be protected.
In addition, since the first resin layer 121 and the second resin layer 122 are connected at the connecting surface (the second surface 121c), peeling of the second resin layer 122 is unlikely to occur.

Here, the state of the image light incident on the image light deflector 10A of the present embodiment will be described.
FIG. 5 is a diagram for explaining the image light incident on the image light deflection section 10A of the first embodiment. FIG. 5 shows a cross section similar to that of FIG. 3 described above. In addition, in FIG. 5 and the related description, for ease of understanding, the image lights La and Ld are applied to the image light diffuser 10B (light control layer 16) located on the light entrance side of the image light deflector 10A. A case in which no effect is received will be described as an example.
As shown in FIG. 5, the image light La projected from the image source LS and incident on the image light deflector 10A from the incident side (-Z side) is incident on the reflecting surface 13. As shown in FIG.

When the reflection surface 13 is provided due to the refractive index difference between the low refractive index layer and the resin layer 12, the image light La is incident on the reflection surface 13 at an incident angle equal to or greater than the critical angle, is totally reflected, and is reflected on the light output side of the screen 10. The image is emitted (image light Lb) in a direction in which an observer O1 (see FIG. 1) positioned in the front direction (+Z side) can visually recognize the image.
Further, when the reflecting surface 13 is provided by forming a semi-transmissive reflecting layer, part of the image light La is reflected by the reflecting surface 13 and is reflected in the front direction on the light exit side (+Z side) of the screen 10. A positioned observer O1 (see FIG. 1) emits an image (image light Lb) in a direction in which the image can be viewed, and part of the image light La passes through the reflecting surface 13 and travels upward on the light exit side of the screen 10 (see FIG. 1). 5, the image light Lc) indicated by a dashed line. Most of such image light Lc is emitted outside the visible range of the observer O1. If the transmittance of the semi-transmissive reflection layer is extremely low, the light amount of the image light Lc is extremely small.
Also, part of the image light Ld does not enter the reflecting surface 13 and travels upward on the light exit side of the screen 10 .

Returning to FIG. 2, the second base material layer 15 is a layer having optical transparency formed on the light exit side (+Z side) of the resin layer 12 . This second base material layer 15 has a function of protecting the light output side of the screen 10 .
A sheet-like member made of resin having high light transmittance is used for the second base material layer 15 . For the second base layer 15, for example, a sheet-like member formed using the same material as the first base layer 11 described above may be used.
When the second base material layer 15 is located on the most light emitting side (+Z side) of the screen 10 as in the present embodiment, the second base material layer 15 has a hard coat function, an antifouling function, an antistatic function, and the like. may have.

The bonding layer 17 is a layer having a function of integrally bonding the light control layer 16 and the first base material layer 11 . For the bonding layer 17, an adhesive material, an adhesive material, or the like having high optical transparency can be used.
The light control layer 16 is a layer positioned closer to the light incident side (image source side, -Z side) than the first base material layer 11 in the thickness direction (Z direction). In this embodiment, the light control layer 16 is integrally provided on the light incident side (image source side) of the first base material layer 11 via the bonding layer 17 .

The light control layer 16 corresponds to the image light diffusion portion 10B, and is a portion that selectively diffuses image light. The light control layer 16 has a greater diffusion effect on light incident from a specific angular range than on light incident from other angular ranges. This specific angle range is larger than 0° or near 0° with respect to the normal line direction of the light incident surface (surface parallel to the screen surface) of the light control layer 16, and is oblique to the light control layer 16. This is the incident angle range. That is, the light control layer 16 has a function of diffusing and transmitting obliquely incident light more than light incident at an incident angle of 0°. The specific angular range in which the light control layer 16 exerts the diffusing action can be appropriately set according to the position of the image source LS with respect to the screen 10, that is, the incident angle of the main image light.

6A and 6B are diagrams for explaining the light control action of the light control layer 16. FIG. FIG. 6 shows a cross section of the light control layer 16 parallel to the vertical direction of the screen (Y direction) and the thickness direction (Z direction). In FIG. 6, the light incident side (image source side, −Z side) and light exit side (viewer side, +Z side) surfaces of the light control layer 16 are parallel to the screen surface (XY plane). , a straight line H indicated by a dashed line is a straight line orthogonal to the light-incident side surface and the light-outgoing side surface of the light control layer 16 .

In the cross section shown in FIG. 6, the light control layer 16 diffuses the light incident from the air on the light incident side (−Z side) at an incident angle within the first incident angle range R1 to the light emitting side (+Z side). , and the light incident at an incident angle within the second incident angle range R2, which is an incident angle other than the first incident angle range R1, is transmitted to the light output side without or slightly diffused. have. In the light control layer 16, the degree of diffusion for light incident at an incident angle within the second incident angle range R2 is significantly greater than the degree of diffusion for light incident at an incident angle within the angle range of the first incident angle range R1. small.
In the cross section shown in FIG. 5, the light control layer 16 diffuses the incident light from the air on the light output side (+Z side) at an incident angle within the third incident angle range R3 to the light input side (-Z side). side) and enters at an incident angle within the fourth incident angle range R4, which is an incident angle other than the third incident angle range R3, is transmitted to the light incident surface side without or slightly diffused. It has the function of In the light control layer 16, the degree of diffusion for light incident at an incident angle within the fourth incident angle range R4 is significantly greater than the degree of diffusion for light incident at an incident angle within the third incident angle range R3. to small.

The first incident angle range R1 includes the main incident angle range of the image light L projected from the image source LS and incident on the screen 10 (light control layer 16).
In the present embodiment, the first incident angle range R1 is a range of 25° or more and 55° or less downward (−Y side) with respect to the straight line H on the incident side (image source side, −Z side). be. Also, the second incident angle range R2 is an angle other than the first incident angle range R1 on the light incident side of the light control layer 16 .
In the present embodiment, the third incident angle range R3 is a range of 25° or more and 55° or less upward (+Y side) with respect to the straight line H on the light output side (+Z side). Further, the fourth incident angle range R4 is an angle other than the third incident angle range R3 on the light exit side of the light control layer 16 .

Therefore, the light control layer 16 selectively receives light incident at an incident angle of 25° or more and 55° or less from the lower side (−Y side) of the screen at any point on the light incident side (−Z side). , and the incident light from other angular ranges is transmitted to the light output side (+Z side) without being diffused or diffused much weaker than the above angular range. In addition, the light control layer 16 selectively diffuses and transmits light incident at an incident angle of 25° or more and 55° or less from the upper side of the screen in the vertical direction (+Y side) at an arbitrary point on the surface on the light exit side. Light incident from other angle ranges is transmitted to the light incident side without being diffused or diffused much weaker than the above angle range.

The haze value (diffuse transmittance) of the light that is incident on the light control layer 16 at an incident angle within the first incident angle range R1 from the light control layer 16 and is emitted to the light output side is side) at an incident angle within the second incident angle range R2 (in particular, an incident angle of 0°) and is larger than the haze value (diffuse transmittance) of light emitted to the light exit side.
Similarly, the haze value of light incident on the light control layer 16 from the light output side at an incident angle within the third incident angle range R3 and emitted to the light input side is within the fourth incident angle range R4. It is larger than the haze value of the light that is incident at an incident angle (in particular, an incident angle of 0°) and is emitted to the light exit side.
The haze value is expressed as a ratio of diffuse transmittance to total light transmittance, and means the diffusion rate of light in transmitted light. The haze value of the light control layer 16 can be measured with a haze meter (eg, HM-150 manufactured by Murakami Color Research Laboratory).

For incident light within the ranges of the first incident angle range R1 and the third incident angle range R3, the first incident angle range R1 and the third incident angle range R3 of the present embodiment are 25° or more and 55° or less. Therefore, the assumed incident angle is 40°, and the transmittance when the light is incident at this angle is the total light transmittance. The diffuse transmittance is defined as the ratio of the light emitted with a spread of 2.5° or more with respect to the light.
The haze value (diffuse transmittance) of the light incident from the light incident side (−Z side) of the light control layer 16 at an incident angle of 0° within the second incident angle range R2 and emitted to the light emitting side (+Z side) is , is preferably low, ideally 0%. Similarly, the haze value of light incident on the light control layer 16 at an incident angle of 0°, which is within the fourth incident angle range R4, is preferably low, and ideally 0%.

As such a light control layer 16, a plurality of transparent resin layers having different refractive indices are laminated in a predetermined thickness in a predetermined direction, and the irradiation direction of ultraviolet rays during curing of each layer is changed. A visibility control film (for example, visibility control film Y-2555 manufactured by Lintec Corporation) is suitable.

FIG. 7 is a diagram showing an example of image light and external light incident on the screen 10 of the first embodiment. FIG. 7 shows an enlarged part of a cross section similar to the cross section of the screen 10 shown in FIG. In addition, in FIG. 7 and the description related thereto, for ease of understanding, the interface between the light control layer 16 and the bonding layer 17, the interface between the bonding layer 17 and the first base layer 11, the first base layer 11 and the resin layer 12 and the interface between the resin layer 12 and the second base material layer 15 do not have a refractive index difference.
The image light L11 projected from the image source LS positioned below the screen 10 is incident on the light control layer 16 at an incident angle within the first incident angle range R1 and diffused to pass through the bonding layer 17 and the first base material layer. 11 and enters the resin layer 12 .

Then, the image light L11 is reflected (including total reflection) by the reflecting surface 13 and emitted toward the observer O1 positioned in the front direction on the light exit side (+Z side) of the screen 10 . As a result, the screen 10 has a sufficient viewing angle for the observer O1 positioned in the front direction on the light output side, and can display a bright and favorable image. Although not shown, if the reflecting surface 13 is provided by forming a semi-transmissive reflecting layer, part of the image light L11 passes through the reflecting surface 13 and travels upward on the light exit side of the screen 10. (See image light Lc in FIG. 4).
Further, when entering from the light incident side of the screen 10, part of the image light L11 (not shown) is reflected by the surface of the screen 10 on the light incident side and directed upward. It hardly reaches the observer O2 who is positioned in the front direction of the incident side of 10 .

Further, part of the image light L12 of the image light incident on the screen 10 passes through the resin layer 12 and the second base material layer 15 without entering the reflecting surface 13 and is emitted upward on the light exit side of the screen 10. do. This image light L12 hardly reaches the observer O1 who is positioned in the front direction on the light exit side of the screen 10 .
In the present embodiment, the image light is projected from below the screen 10, and the angle θ1 (see FIGS. 3, 5, etc.) formed by the reflecting surface 13 and a plane parallel to the screen surface is the vertical direction of the screen 10. is larger than the incident angle of the image light at each point, the image directly incident on the reflecting surface 13 from the side opposite to the image source LS side (upper side in the vertical direction of the screen) along the arrangement direction of the reflecting surface 13 The amount of light is very small, and the image light that enters from that direction and is reflected by the reflecting surface 13 is hardly seen by the observer O2 on the incident side.

Next, external light (hereinafter referred to as external light) such as sunlight and illumination light other than image light entering the screen 10 from above the light incident side (−Z side) or the light exit side (+Z side) will be described. do.
Of the external light G11, G12, and G13 incident on the screen 10, some of the external light (not shown) is reflected by the light-incident side surface and the light-exiting side surface of the screen 10, and travels downward from the screen 10. .

The external light G11 incident on the screen 10 from above the light incident side (−Z side) enters the light control layer 16 from the light incident side at an incident angle within the second incident angle range R2. The light passes through the light control layer 16 without being blocked and travels through the screen 10 toward the light output side (+Z side).
Then, the external light G11 enters the reflecting surface 13 within the resin layer 12 .

When the reflective surface 13 is provided by the refractive index difference between the low refractive index layer and the resin layer 12, the external light G11 enters the reflective surface 13 at an angle of incidence less than the critical angle, and most of it is transmitted through the reflective surface 13. , and travels downward on the light exit side within the screen 10 (outside light G11a). The external light G11a is emitted downward on the light exit side of the screen 10, or is totally reflected by the surface of the screen 10 on the light exit side, travels further downward inside the screen 10, and gradually attenuates.
Further, when the reflecting surface 13 is provided with a semi-transmissive reflecting layer, part of the external light G11 incident on the reflecting surface 13 is transmitted through the reflecting surface 13 and travels downward on the light exit side of the screen 10 (external light G11a ), part of the external light G11 is reflected by the reflecting surface 13 and travels upward on the light incident side of the screen 10 (external light G11b).

In addition, the external light G12 incident on the screen 10 from above the light incident side (−Z side) enters the light control layer 16 from the light incident side at an incident angle within the second incident angle range R2. , the light passes through the light control layer 16 without being diffused, advances through the screen 10 toward the light exit side, passes through the resin layer 12 without entering the reflecting surface 13, and travels downward through the screen 10 toward the light exit side. The external light G12 is emitted downward on the light exit side of the screen 10, or totally reflected by the surface of the screen 10 on the light exit side, travels further downward inside the screen 10, and gradually attenuates.

External light G13 incident on the screen 10 from above the light exit side (+Z side) passes through the second base material layer 15, passes through the resin layer 12 without entering the reflecting surface 13, and enters the screen 10. Go downward on the light side. The external light G13 is emitted downward on the light incident side of the screen 10, or is totally reflected by the surface of the screen 10 on the light incident side, travels further downward inside the screen 10, and gradually attenuates.
As described above, most of the external light that enters from above the light incident side and the light exit side of the screen 10 is directed downward on the light exit side and the light incident side of the screen 10, and the amount of light that reaches the observers O1 and O2 is is significantly smaller. Therefore, the screen 10 can suppress deterioration of image contrast due to external light.

In addition, external light G14 and G15 that enter the screen 10 at a small incident angle such as an incident angle of 0° enter the screen 10 and do not enter the reflecting surface 13, and exit to the light entrance side and the light exit side, respectively. In this embodiment, the external light G15 is incident on the light control layer 16 at an incident angle within the second incident angle range R2 from the light incident side, and the external light G14 is incident on the light control layer 16 on the light output side. , at an incident angle corresponding to an angle within the fourth incident angle range R4. Therefore, the external lights G14 and G15 are transmitted through the screen 10 without being diffused by the light control layer 16. FIG.
Part of the external light (not shown) that enters the screen 10 at a small incident angle such as an incident angle of 0° enters the reflecting surface 13 and is reflected. Since it is very small, it has little effect on the contrast of the image and the transparency of the screen 10. FIG.

From the above, when the observers O2 and O1 observe the scenery on the other side of the screen 10 through the screen 10 from the light entrance side (−Z side) and the light exit side (+Z side), The scenery can be observed with high transparency without blurring or whitening, and the screen 10 can exhibit high transparency.

In a transmissive screen that has a light diffusion layer containing a diffusion material such as particles that diffuse light, but does not have the image light deflection section 10A, if the diffusion strength of the light diffusion layer is increased, the image is displayed on the screen. While the image can be brightened, the contrast of the image decreases, and the background image observed through the screen becomes white and cloudy due to the diffusion of unnecessary external light and the decrease in transparency.
Further, in such a transmissive screen, when an image is projected from the front direction, if an attempt is made to maintain high transparency by reducing the diffusion intensity, the image light reaches the viewer without diffusing. Therefore, a method of obliquely projecting the image light from the bottom of the screen or the like is adopted, but in this case, most of the image light is diffused obliquely upward of the screen, so that the image is dark and difficult for the observer to observe. Become.

On the other hand, according to the screen 10 of the present embodiment, the image light is diffused by the light control layer 16 (image light diffusion section 10B) and then deflected by the image light deflection section 10A toward the observer O1. Therefore, the observer O1 has a sufficient viewing angle and can display a bright image.
In addition, the screen 10 selectively diffuses a large amount of image light incident from oblique directions by the light control layer 16 (image light diffusion portion 10B), and most of the outside light passes through the screen 10 without being diffused. The light is transmitted or emitted out of the visible range of the observers O1 and O2. Therefore, according to the present embodiment, the transparency of the screen 10 can be maintained, and the decrease in image contrast due to diffusion of external light can be greatly suppressed.
As described above, according to the present embodiment, it is possible to display a bright and clear image while maintaining the transparency of the screen 10 .

Further, according to the present embodiment, the reflecting surfaces 13 are arranged concentrically around the point C located outside the display area (screen) of the screen 10 and below the screen in the vertical direction (image source side). ing. Therefore, even if the image light with a large incident angle is projected from the short focus type image source LS located outside the display area of the screen 10 and positioned below the screen in the vertical direction, the image in the horizontal direction of the screen becomes dark. Therefore, it is possible to display a good image with high surface uniformity of brightness.

(Second embodiment)
FIG. 8 is a diagram for explaining the image light deflection section 20A of the second embodiment.
In FIG. 8, as in FIG. 2 of the first embodiment described above, a point (corresponding to point A shown in FIG. 1) that is the center of the screen (the geometric center of the screen) of the screen 10 is passed through, and A part of the cross section parallel to the direction (Y direction) and orthogonal to the screen surface (parallel to the Z direction) is shown enlarged.
The image light deflection section 20A of the second embodiment is the same as the image light deflection section 10A shown in the first embodiment, except that the means for providing the reflecting surface 13 and the shape of the unit optical shape 221a are different. Therefore, in the following description, portions that perform 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 overlapping explanations are omitted as appropriate.
The image light deflection section 20A of the second embodiment can be applied to the screen 10 and the image display device 1 in place of the image light deflection section 10A of the first embodiment.

The image light deflector 20A of this embodiment includes a plurality of reflecting surfaces 13 arranged inside the resin layer 22 . The refractive index of the first resin layer 221 of the resin layer 22 is smaller than the refractive index of the second resin layer 222, and part of the interface between the first resin layer 221 and the second resin layer 222 reflects the image light. It is a reflecting surface 13 that changes its direction by pressing.
Further, as shown in FIG. 8, the first resin layer 221 has a plurality of unit optical shapes 221a arranged on the light output side. The unit optical shape 221a has a trapezoidal cross-sectional shape that is convex toward the light output side, and includes a top surface 221d located on the light output side, a first surface 221b located below the top surface 221d, and a top surface 221d. and a second surface 221c located above the surface 221d. In FIG. 8, the first surface 221b, the top surface 221d, and the second surface 221c are indicated by broken lines for easy understanding, but in reality, it is difficult to visually recognize each surface. .

The unit optical shapes 221a of this embodiment are arranged in the vertical direction of the screen (Y direction) along a plane parallel to the screen surface, with the screen horizontal direction (X direction) as the longitudinal direction. be.
The first surface 221b is closer to the image source LS ( It is tilted so that it is positioned at the bottom of the screen in the vertical direction). The first surface 221b forms an angle θ1 with respect to a plane parallel to the screen surface. This angle θ1 is preferably 70° or more as in the first embodiment.
In this embodiment, an example in which the angle θ1 is constant in the arrangement direction of the unit optical shapes 221a (reflection surfaces 13) will be described. It should be noted that the angle θ1 may gradually decrease along the direction in which the unit optical shapes 221a are arranged (toward the upper side in the vertical direction of the screen) away from the image source LS.

The second surface 221c is a surface facing the first surface 221b in the arrangement direction of the unit optical shapes 221a, and forms an angle θ2 with respect to a surface parallel to the screen surface. The second surface 221c has an inclination direction opposite to that of the first surface 221b. ) on the side of the image source LS (lower side in the vertical direction of the screen).
In addition, the top surface 221d is a surface positioned closest to the light output surface in the unit optical shape 221a, between the first surface 221b and the second surface 221c in the arrangement direction of the unit optical shape 221a.

The second surface 221c of the present embodiment is orthogonal to a plane parallel to the screen surface (θ2=90°), and the top surface 221d is a surface parallel to the screen surface (XY plane). By forming the second surface 221c and the top surface 221d in such a manner, the transparency of the screen 10 can be maintained at a high level. The angle θ2 is preferably 90° or an angle close to 90° from the viewpoint of maintaining transparency and suppressing stray light.

The unit optical shapes 221a may be arranged concentrically around the point C (see FIG. 4) located outside the display area of the screen 10, similarly to the unit optical shapes 121a of the first embodiment. Further, at this time, the angle θ1 may gradually decrease as the distance from the point C in the arrangement direction of the unit optical shapes 221a increases.

In this embodiment, the first resin layer 221 and the second resin layer 222 have different refractive indexes, and the first resin layer 221 has a smaller refractive index than the second resin layer 222 . Due to the difference in refractive index between the first resin layer 221 and the second resin layer 222, the first surface 221b serves as the reflecting surface 13 that reflects at least part of the image light.
In such an image light deflector 20A, part of the image light (image light Lg) passes through the second surface 221c and enters the second resin layer 222 as shown in FIG. 1 surface 221b) at an angle equal to or greater than the critical angle, is totally reflected, and travels toward the observer O1 on the light output side.
Even when the image light deflection unit 20A is used as in the present embodiment, the screen 10 can sufficiently direct the image light toward the observer O1, has sufficient transparency, and can display a bright and favorable image. A video display device 1 can be used.

(Third embodiment)
FIG. 9 is a diagram showing the layer structure of the screen 30 of the third embodiment.
In FIG. 9, as in FIG. 2 of the first embodiment described above, a point (a point corresponding to point A shown in FIG. 1) that is the screen center (the geometric center of the screen) of the screen 10 is passed through, and A part of the cross section parallel to the direction (Y direction) and orthogonal to the screen surface (parallel to the Z direction) is shown enlarged.
In the screen 30 of the third embodiment, the light diffusion layer 38 containing a diffusion material is arranged as the image light diffusion portion 30B on the light exit side (+Z side) of the image light deflection portion 10A. Except for being different from the screen 10 shown in the first embodiment, it has the same form as the screen 10 of the above-described first embodiment. Therefore, in the following description, portions that perform 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 overlapping explanations are omitted as appropriate.

As shown in FIG. 9, the screen 30 of the third embodiment includes a first base layer 11, It has a resin layer 12 , a reflecting surface 13 , a second base layer 15 , a bonding layer 37 and a light diffusion layer 38 .
In the screen 30, the image light diffusion portion 30B is the light diffusion layer 38, and the image light deflection portion 10A is the resin layer 12 and the reflecting surface 13. As shown in FIG.
This screen 30 can be applied to the image display device 1 in place of the screen 10 of the first embodiment.

The bonding layer 37 is a layer having a function of bonding the second base material layer 15 and the light diffusion layer 38 together. For the bonding layer 37, similarly to the bonding layer 17 of the first embodiment described above, an adhesive material, a pressure-sensitive adhesive, or the like having high optical transparency can be used.
The light diffusing layer 38 is a layer in which a highly light-transmissive resin is used as a base material and a particulate diffusing material is kneaded. As such a light diffusion layer 38, a known diffusion layer, diffusion sheet, or the like can be used. The haze value and the like of the light diffusion layer 38 can be appropriately set, and the diffusion characteristics may be omnidirectional or anisotropic.
In the present embodiment, the image light diffusion section 30B made up of the light diffusion layer 38 is arranged on the light output side (+Z side) of the image light deflection section 10A. It may be arranged on the light incident side (-Z side) of the deflection section 10A.

A bright and clear image can be displayed even on the screen 30 having the image light diffusing section 30B as in this embodiment. Further, even in the screen 30 including the image light diffusing section 30B as in this embodiment, a usable degree of transparency can be realized.

(deformed form)
Various modifications and changes are possible without being limited to the embodiments described above, and they are also within the scope of the present invention.

(1) In the first embodiment, the image light deflector 10A may have a configuration in which the layer forming the reflecting surface 13 is also formed on the connecting surface (second surface 121c).
FIG. 10 is a diagram for explaining the image light deflection section 60A of a modified form. FIG. 10 shows a section of an image light deflection section 60A corresponding to the section of the image light deflection section 10A shown in FIG. The image light deflection section 60A has a form in which a first resin layer 121, a reflective surface forming layer 130, and a second resin layer 122 are laminated in the thickness direction.
When the reflective surface forming layer 130 is a low refractive index layer, even in such a configuration, the image light passes through the reflective surface forming layer 130 (the layer 132 shown in FIG. 10) on the second surface 121c at an angle less than the critical angle. The light is incident at an angle and transmitted, and is totally reflected by the reflective surface forming layer 130 (the layer 131 shown in FIG. 10, which forms the reflective surface 13 in this embodiment) on the first surface 121b to the viewer side. Go (image light Le). Therefore, such an image light deflector 60A can also be used as a transmissive screen similar to the screen 10 of the above-described first embodiment.

When the reflecting surface 13 is formed of a semi-transmissive reflecting layer and its transmittance is small, the angle θ2 formed between the second surface 121c and a plane parallel to the screen surface is adjusted to the position of the image source LS. , a portion of the image light is reflected by the reflective surface forming layer 130 (the layer 132, the portion forming the reflective surface 13 in this embodiment) on the second surface 121c, and is reflected in the front direction of the light incident side. Directed toward (image light Lf indicated by a dashed line in FIG. 10), a reflective screen having transparency can be used.

Further, when the reflective surface 13 is formed of a semi-transmissive reflective layer, the reflective surface forming layer 130 (layer 131) on the first surface 121b and the reflective surface forming layer 130 (layer 131) on the second surface 121c By adjusting the reflectance and transmittance of the layer 132), part of the image light is reflected by the reflective surface forming layer 130 (layer 132) on the second surface 121c and directed to the front direction of the light incident side ( Image light Lf indicated by a broken line in FIG. 10), part of the image light is reflected by the reflective surface forming layer 130 (layer 131) on the first surface 121b and directed toward the observer on the light exit side (image light Le). be able to.
As a result, a screen having transparency and capable of displaying on both sides can be obtained. In this case, in addition to the image light diffusion section 10B provided on the light entrance side of the image light deflection section 10A, it is preferable to provide the image light diffusion section 30B as shown in the third embodiment on the light exit side.

When a double-sided display is possible, the angle θ1 is set so that the image light Le reflected by the reflective surface forming layer 130 (layer 131) on the first surface 121b is directed in the front direction on the light exit side. θ2 is set so that the image light (image light Lf) reflected by the reflective surface forming layer 130 (layer 132) on the second surface 121c is directed toward the front direction on the incident side. From the viewpoint of displaying a good image to an observer positioned in the front direction on the light exit side and the light entrance side, the apex angle θ3 of the unit optical shape 121a is preferably close to 90°, more preferably 90°. .

(2) In the first and third embodiments, the reflection surface 13 in the cross section parallel to the arrangement direction of the unit optical shapes 121a and the thickness direction of the screens 10 and 30 may be curved.
FIG. 11 is a diagram for explaining the image light deflection section 70A of a modified form. FIG. 11 shows a cross section of an image light deflector 70A corresponding to the cross section of the image light deflector 10A shown in FIG. When the reflective surface 13 has a gently curved shape in the cross section shown in FIG. 11, the angle θ1 formed by the reflective surface 13 with the direction parallel to the screen surface (XY plane) is the end of the reflective surface 13 on the light output side. A straight line passing through the point t1 and the point t2, which is the light incident side end of the reflecting surface 13, corresponds to the angle formed by the plane parallel to the screen surface.

(3) In the first embodiment, the shape of the unit optical shape 121a may be changed as appropriate.
FIG. 12 is a diagram for explaining the image light deflector 80A of a modified form. 12A to 12C show cross sections of the image light deflector 80A corresponding to the cross section of the image light deflector 10A shown in FIG. .
In the modified image light deflection section 80A, a plurality of reflecting surfaces 13 are arranged in the resin layer 82 . Also, the resin layer 82 includes a first resin layer 821 and a second resin layer 822 .
As shown in FIG. 12A, the unit optical shape 821a has a triangular cross-sectional shape in the arrangement direction and the thickness direction of the screen that is convex toward the light exit side. , a configuration in which a gap 821e of a predetermined size is provided. At this time, the unit optical shape 821a has a first surface 821b and a second surface 821c, and the reflecting surface 13 is provided on the first surface 821b.
The gap 821e is parallel to the screen surface, and the second surface 821c is perpendicular or nearly perpendicular to the plane parallel to the screen surface. , it is possible to prevent the layer forming the reflecting surface 13 from being formed on unintended portions of the second surface 821c and the like without masking or the like when depositing the layer forming the reflecting surface 13 on the first surface 821b.

Also, as shown in FIG. 12(b), the unit optical shape 821a has a triangular shape similar to the shape shown in FIG. 12(a). A configuration in which adjacent unit optical shapes 821a are adjacent to each other may be adopted.
At this time, the second surface 821c may be in a form orthogonal to the plane parallel to the screen surface (angle θ2=90°) or an angle close to the orthogonal. This is preferable because it is possible to suppress formation of the film on unintended portions such as the second surface 821c without masking the first surface 821b.
In this form shown in FIG. 12(b), when viewed from the normal direction of the screen surface, there is no gap in the arrangement direction of the reflective surface 13, but the transmittance of the layer forming the reflective surface 13 can be adjusted. This maintains a usable degree of screen transparency. Alternatively, the angle θ2 may be adjusted so that a gap exists between the reflecting surfaces 13 when viewed from the normal direction of the screen surface.

Further, as shown in FIG. 12(c), the unit optical shape 821a has a cross-sectional shape in the arrangement direction and the thickness direction of the screen, which is a trapezoidal shape convex toward the light exit side as shown in the second embodiment. , a top surface 821d, a first surface 821b, and a second surface 821c. The top surface 821d is parallel to the screen surface, and the second surface 821c is orthogonal (θ2=90°) or nearly orthogonal to the plane parallel to the screen surface. When a layer that maintains transparency and forms the reflective surface 13 is vapor-deposited on the first surface 821b, it can be formed even on unintended locations such as the second surface 821c without masking or the like. can be suppressed.
In addition, in the form shown in FIG. 12C, the layer forming the reflecting surface 13 may be formed on at least a part of the top surface 821d in addition to the first surface 821b. In particular, when the reflective surface 13 is provided by the refractive index difference between the low refractive index layer and the resin layer 82, in addition to the first surface 821b, the top surface 821d and at least a part of the second surface 821c also have the A mode in which a low refractive index layer is formed may be employed. Even in such a form, the transmittance of the screen can be maintained.

In the cross section shown in FIG. 12(c), the second surface 821c and the top surface 821d are L-shaped, and the first resin layer 821 and the second Since the second resin layer 822 is connected to the second resin layer 822, peeling of the second resin layer 822 is unlikely to occur. 12A, the second surface 821c and the gap 821e are L-shaped, and similarly, the effect of suppressing peeling of the second resin layer 822 can be obtained.

In addition, although FIG. 12(c) shows that the second surface 821c forms an angle that is orthogonal or nearly orthogonal to a surface parallel to the screen surface, the second surface 821c is not limited to this. may form an angle with respect to the direction orthogonal to the screen surface in the cross section shown in FIG.
12(a) to 12(c), the image light diffusing unit 30B shown in the third embodiment is used as the image light diffusing unit. Good images can be viewed even when placed on the side.

(4) In each embodiment, the reflecting surface 13 may be a rough surface having fine and irregular irregularities. With such a shape, the light incident on the reflecting surface 13 is diffusely reflected. Thereby, the viewing angle of the image can be widened.
Further, at this time, when the reflecting surface 13 is formed of a semi-transmissive reflecting layer, part of the light incident on the reflecting surface 13 is transmitted without being diffused, so transparency can be maintained. Further, when the reflective surface 13 is provided with a low refractive index layer, the light incident at an angle less than the critical angle is transmitted without being diffused, so transparency can be maintained.

In addition, by adopting such a shape, it is possible to reduce unpleasant glare (so-called speckle, scintillation, etc.) and color unevenness in an image.
In addition, as shown in the above-described modification (1), when the reflective surface forming layer 130 is also provided on the connection surface (second surface 121c), depending on the desired screen performance, The reflective surface forming layer 130 may also have fine and irregular unevenness on its surface.

(5) In the first embodiment, the light control layer 16 may transmit light incident from the light output side (+Z side) without diffusing it regardless of the incident angle. That is, the light control layer 16 may have a form that does not have the third incident angle range R3.

(6) In the first embodiment, the light control layer 16 selectively diffuses the incident light according to the incident angle in the vertical direction of the screen in the cross section parallel to the vertical direction of the screen and the thickness direction. However, the light control layer 16 may be configured to selectively diffuse incident light depending on the angle of incidence in the arrangement direction of the reflecting surfaces 13 in a cross section parallel to the arrangement direction and the thickness direction of the reflecting surfaces 13. . When the reflecting surfaces 13 are arranged concentrically around the point C as in the first embodiment, the optical performance of the light control layer 16 is also distributed concentrically around the point C. Light can be effectively diffused, and a sufficient viewing angle can be ensured for areas where the viewing angle tends to decrease, such as the left and right ends of the upper side of the screen.

In the first embodiment, the light control layer 16 has a constant specific angular range for diffusing and transmitting incident light in a cross section parallel to the vertical direction and the thickness direction of the screen. Alternatively, the specific angle range may change continuously or stepwise along the vertical direction of the screen. By adopting such a form, it is possible to more effectively diffuse the light corresponding to the incident angle of the image light that changes in the vertical direction of the screen, and to display a good image.

(7) In the first and third embodiments, the image light deflector 10A may have a configuration in which the reflecting surfaces 13 are arranged in the vertical direction of the screen with the horizontal direction (X direction) of the screen being the longitudinal direction.
In such a configuration, the angle θ1 formed between the reflecting surface 13 and a plane parallel to the screen surface may be constant or varied in the direction in which the reflecting surfaces 13 are arranged.

(8) In each of the embodiments, the screens 10 and 30 may have a light absorption layer that partially transmits incident light and partially absorbs the incident light to achieve a predetermined transmittance. By providing such a light absorption layer, it is possible to reduce the black brightness of the image, absorb external light, and improve the contrast of the image.
For example, such a light absorbing layer may be newly laminated on the screens 10 and 30, or may be, for example, a light absorbing layer on the bonding layers 17 and 37, the first base layer 11, the second base layer 15, or the like. You may give the function as Alternatively, the layer forming the reflecting surface 13 may have a function of absorbing part of the incident light. At this time, for example, the reflective surface side that reflects the image light in the thickness direction of the layer forming the reflective surface 13 is formed by a layer with high reflectance, and the other surface in the thickness direction is formed by a layer with high light absorption. A laminated structure may be formed.
Also, the light absorbing layer may be a layer colored with a dark coloring material such as black or gray.

(9) In each embodiment, the reflective surface 13 may have a shape in which a curved surface and a flat surface are combined, or may have a folded surface shape.

(10) In the first and third embodiments, the image source LS is located at the center of the screens 10 and 30 in the horizontal direction and below the screen. For example, it may be located above the screens 10,30. In this case, the screens 10 and 30 are reversed in the vertical direction (Y direction).
In addition, the image source LS may project image light onto the screens 10 and 30 from oblique direction light. In this case, the above-mentioned point C is arranged according to the position of the image source LS. By adopting such a form, the position of the image source LS and the like can be freely set.

(11) In each embodiment, when the resin layer 12 has sufficient thickness, rigidity, etc., at least one of the first base material layer 11 and the second base material layer 15 is used in the screens 10 and 30. It is good also as a form which does not have. Further, for example, in the first embodiment, when the surface of the screen 10 on the light exit side (+Z side) is bonded to a support plate (not shown), the screen 10 does not include the second base material layer 15, and the resin A configuration in which a bonding layer is provided between the layer 12 and the support plate may be employed.
In addition, in the first and second embodiments, the screen 10 may be configured such that the light control layer 16 is integrally provided adjacent to the resin layer 12 and the first base material layer 11 and the like are not provided.
Furthermore, at least one of the first base material layer 11 and the second base material layer 15 may contain a diffusion material that diffuses light.

(12) In each embodiment, the surfaces of the screens 10 and 30 on the light entrance side (+Z side) and the light exit side (−Z side) may be provided with a hard coat layer for the purpose of preventing scratches. The hard coat layer is formed, for example, by applying an ultraviolet curable resin (for example, urethane acrylate, etc.) having a hard coat function to the surfaces of the screens 10 and 30 on the light entrance side and the light exit side.
In addition to the hard coat layer, depending on the usage environment and the purpose of use of the screens 10 and 30, the surfaces of the screens 10 and 30 on the light entrance side and the light exit side may be provided with, for example, an antireflection function, an ultraviolet absorption function, and an anti-reflection layer. One or a plurality of layers having appropriate necessary functions such as a staining function and an antistatic function may be selected and provided. Furthermore, a touch panel layer or the like may be provided at a position on the screens 10 and 30 closest to the light output side (observer side).

In particular, when the antireflection layer is provided at the position closest to the light incident side of the screens 10 and 30, the reflection of the image light on the light incident side surface of the screens 10 and 30 is reduced and the reflection of the image light to the screens 10 and 30 is reduced. It is possible to increase the amount of incident light and improve the brightness of the image.
The layers having various functions such as the hard coat layer may be provided on either the light incident side or the light exiting side of the screens 10 and 30 .

Although the present embodiment and modifications can be used in combination as appropriate, detailed description thereof will be omitted. Moreover, the present invention is not limited to each embodiment described above.

Reference Signs List 1 image display device 10, 30 screen 11 first base material layer 12 resin layer 13 reflective surface 15 second base material layer 16 light control layer 17, 37 bonding layer 38 light diffusion layer 10A image light deflection section 10B, 30B image light diffusion Department

Claims (17)

an image light deflector that changes the direction of at least part of incident image light;
an image light diffusing section that diffuses at least part of incident image light;
A screen comprising
the image light deflector and the image light diffuser are provided at different positions in the thickness direction of the screen;
A screen characterized by The screen of claim 1, wherein
The image light diffusing unit is arranged closer to the light incident side than the image light deflecting unit in the thickness direction of the screen, and diffuses light incident from an oblique direction more than light incident at an incident angle of 0°. ,
A screen characterized by In the screen according to claim 1 or claim 2,
The image light diffusing unit is arranged on the light incident side of the image light deflecting unit in the thickness direction of the screen, and diffuses light incident at an incident angle within a specific angle range to outside the specific angle range. A light control layer that diffuses and transmits light incident at an incident angle of
A screen characterized by 4. The screen of claim 3, wherein
Light incident at angles of incidence outside the specified angular range is transmitted without being diffused or diffused so small that it can be regarded as substantially undiffused;
A screen characterized by In the screen according to any one of claims 1 to 4,
a light entrance surface into which image light enters, and a light exit surface facing the light entrance surface and from which image light exits,
The image light deflector is
a resin layer having optical transparency;
a plurality of reflecting surfaces arranged inside the resin layer for reflecting at least part of incident light;
with
At least part of the image light is reflected by the reflective surface to change the direction toward the light exit surface;
A screen characterized by 6. The screen of claim 5, wherein
The reflective surface forms an angle θ1 with respect to a plane parallel to the screen surface in a cross section parallel to the arrangement direction and the thickness direction of the screen,
The angle θ1 is 70° or more,
A screen characterized by 7. The screen of claim 6, wherein
the angle θ1 becomes smaller toward one side along the direction in which the reflecting surfaces are arranged;
A screen characterized by A screen according to any one of claims 5 to 7,
When viewed from the normal direction of the screen surface of the screen, the reflective surface has a gap between the reflective surfaces adjacent to each other in the arrangement direction;
A screen characterized by A screen according to any one of claims 5 to 8,
The reflecting surfaces are arranged concentrically around a point located outside the display area of the screen when viewed from the normal direction of the screen surface of the screen;
A screen characterized by A screen according to any one of claims 5 to 9,
The resin layer has a first resin layer positioned on the light input side and a second resin layer positioned adjacent to the light output side of the first resin layer,
The first resin layer has a plurality of unit optical shapes arranged on a boundary surface with the second resin layer,
The unit optical shape has a polygonal shape in a cross section parallel to the arrangement direction and the thickness direction of the screen,
the reflective surface is formed on at least a portion of a surface forming an angle with respect to a surface parallel to the screen surface in the unit optical shape;
A screen characterized by 11. The screen of claim 10, wherein
The unit optical shape has a triangular shape in a cross section parallel to the arrangement direction and the thickness direction of the screen, and has a first surface and a second surface intersecting the first surface,
an angle formed by the first surface with a surface parallel to the screen surface is larger than an angle formed by the second surface with a surface parallel to the screen surface;
The reflective surface is formed on at least a portion of the first surface;
A screen characterized by 11. The screen of claim 10, wherein
The unit optical shape has a trapezoidal shape in a cross section parallel to the arrangement direction and the thickness direction of the screen, and has a first surface and a second surface facing the first surface in the arrangement direction of the unit optical shape. and a top surface located between the first surface and the second surface and closest to the light output side,
said first surface being angled with respect to a plane parallel to the plane of the screen;
The reflective surface is formed on at least a portion of the first surface;
A screen characterized by A screen according to any one of claims 5 to 12,
The screen has transparency,
The reflective surface is provided with a low refractive index layer having optical transparency and a refractive index lower than that of the resin layer;
A screen characterized by A screen according to any one of claims 5 to 12,
The screen has transparency,
The reflective surface is provided by a semi-transmissive reflective layer that reflects part of the incident light and transmits part of the incident light;
A screen characterized by In the screen according to claim 1 or claim 2,
wherein the image light diffusing portion is a light diffusing layer that is disposed on the light exit side or the light entrance side of the image light deflecting portion in the thickness direction of the screen and contains a diffusion material that diffuses light;
A screen characterized by A screen according to any one of claims 1 to 15,
a light entrance surface into which image light enters, and a light exit surface facing the light entrance surface and from which image light exits,
A transmissive screen that displays an image by emitting image light projected onto the light incident surface from the light exit surface;
A screen characterized by a screen according to any one of claims 1 to 16;
an image source that projects image light onto the screen;
A video display device.

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