JP6969107B2 - Transmissive screen, video display device - Google Patents

Description

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

Conventionally, as one of the image display devices, a transmissive screen that transmits an image light projected from an image source and displays an image, and a rear projection type image display device provided with the transmissive screen are known. Various developments have been made for the transmissive screen and the rear projection type image display device, such as improving the contrast of the image and improving the viewing angle.
Traditional transmissive screens have very low transparency and are on the other side of the screen in order to prevent the underlying image source from being seen through (see-through phenomenon) and to improve the contrast of the image. It is common that you cannot see the scenery of.

In recent years, there has been a demand for a highly transparent screen that can be installed in a shop window or the like to display an image and that the scenery on the other side of the screen can be clearly seen when the image light is not projected. It is increasing. Also, a transmissive screen having such transparency is being developed (see, for example, Patent Document 1).

Japanese Patent No. 4847329

The above-mentioned Patent Document 1 discloses a transmissive screen in which a transparent binder is provided with a light diffusion layer containing fine particles having a refractive index different from that of the transparent binder.
However, in the transmissive screen provided with such a light diffusion layer, both the image light and the outside light such as sunlight and illumination light other than the image light are diffused in the same manner, so that the environment with a lot of outside light, that is, bright Under the environment, the transmissive screen itself looks whitish, and there is a problem that the transparency is impaired.

An object of the present invention is to provide a transmissive screen having high transparency and an image display device including the transmissive screen.

The present invention solves the above-mentioned problems by the following solution means. In addition, in order to facilitate understanding, the description will be given with reference numerals corresponding to the embodiments of the present invention, but the present invention is not limited thereto.
The first invention is a transmissive screen that transmits and displays at least a part of the image light, and the image light is emitted so as to face the incoming surface (10a) on which the image light is incident and the incoming surface. The light emitting surface (10b) is located between the light entering surface and the light emitting surface in the thickness direction of the transmissive screen, and a plurality of light emitting surfaces are arranged along the screen surface in a predetermined direction and intersect in the arrangement direction. A reflective layer (13, 23, 33) extending in a band shape in the direction, reflecting at least a part of the image light incident from the incoming surface and directing the image light to the outgoing surface, and the reflective layer thereof. It is a transmissive screen (10, 20, 30) characterized in that both sides are curved surfaces having periodic irregularities.
The second invention is the transmissive screen of the first invention, in which the unevenness is periodically formed in two directions intersecting in a plane on which the image light of the reflective layer (13, 23, 33) is incident. This is a transmissive screen (10, 20, 30) characterized by the above.
The third invention is the transmissive screen of the first invention or the second invention, in a cross section parallel to the thickness direction of the transmissive screen and the arrangement direction of the reflective layers (13, 23, 33). The transmissive screen (10, 20, 30) is characterized in that the angle (α) formed by the tangent of the curved surface of the layer with the normal direction of the screen surface of the transmissive screen is 0 ° or more and 30 ° or less. ).
A fourth aspect of the invention is a transmissive screen according to any one of the first to third aspects, wherein the unevenness has a period along the extending direction and the width direction of the reflective layer (13, 23, 33). A transmissive screen (10, 20, 30) characterized by being arranged in a linear manner.
According to a fifth aspect of the present invention, in the transmissive screen of the fourth invention, the unevenness has a period in the extending direction of the reflective layer (13, 23, 33) larger than a period in the width direction of the reflective layer. , A transmissive screen (10, 20, 30).
A sixth invention relates to a lens surface (121a, 221a, 321a) and a non-lens surface (121b, 221b, 321b) facing the lens surface (121a, 221a, 321a) in any of the transmissive screens from the first invention to the fifth invention. The reflective layer (13,23,33) is provided with an optical shape layer (12,22,32) having a Frenel lens shape in which a plurality of unit lenses (121,221,321) having the above are arranged on the surface on the light emitting surface side. ) Is a transmissive screen (10, 20, 30) formed on at least a part of the non-lens surface and extending along the extending direction of the unit lens.
A seventh aspect of the invention is a transmissive screen according to any one of the first to sixth aspects, wherein the transmissive screen includes a light absorption layer that absorbs a part of incident light. ..
The eighth invention projects image light onto any of the transmissive screens (10, 20, 30) from the first invention to the seventh invention and the transmissive screen from the back side of the transmissive screen. A video display device (1) including a video source (LS).

According to the present invention, it is possible to provide a transmissive screen having high transparency and an image display device including the transmissive screen.

It is a figure which shows the image display device 1 of 1st Embodiment. It is a figure which shows the layer structure of the screen 10 of 1st Embodiment. It is a figure explaining the unit optical shape 121 and the reflection layer 13 of 1st Embodiment. It is a figure explaining the curved surface of the reflective layer 13 of 1st Embodiment. It is a figure explaining the curved surface of the reflective layer 13 of 1st Embodiment. It is a figure which shows the state of the image light and the outside light on the screen 10 of 1st Embodiment. It is a figure explaining the screen 20 of the 2nd Embodiment. It is a figure which shows the layer structure of the screen 30 of 3rd Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings and the like. In addition, each figure shown below including FIG. 1 is a diagram schematically shown, and the size and shape of each part are exaggerated as appropriate for easy understanding.
In the present specification, terms that specify a shape or a geometric condition, for example, terms such as parallel and orthogonal, have the same optical function in addition to their strict meanings and can be regarded as parallel or orthogonal. The state with the error of is also included.
Further, the numerical values such as the dimensions of each member and the material names described in the present specification are examples as an embodiment, and are not limited to these, and may be appropriately selected and used.

In this specification, terms such as board and sheet are used, but as a general usage, these are used in the order of thickness, board, sheet, and film, and these are used in this specification. Above all, it is used following that. However, since there is no technical meaning in such proper use, these words 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 a whole screen, and is assumed to be parallel to the screen (display surface) of the screen.

(First Embodiment)
FIG. 1 is a diagram showing a video display device 1 of the first embodiment. FIG. 1 shows a state in which the image display device 1 is viewed from the side surface.
The image display device 1 has a screen 10, an image source LS, and the like, and projects and transmits image light from an image source LS located on the back side (back side) of the screen 10 to transmit an image on the screen of the screen 10. It is a rear projection type display device that displays.

Here, in order to facilitate understanding, in each of the figures shown below including FIG. 1, an XYZ Cartesian coordinate system is appropriately provided and shown. In this coordinate system, the screen horizontal direction (horizontal direction) of the screen 10 is the X direction, the screen vertical direction (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.
Further, the direction toward the right side in the left-right direction of the screen is the + X direction, the direction toward the upper side in the vertical direction of the screen is the + Y direction, and the thickness direction when viewed from the observer O1 located in the front direction of the light emitting side (observer side) of the screen 10. In, the direction from the incoming light side (image source side) to the outgoing light side (observer side) is defined as the + Z direction.
Further, in the following description, the screen vertical direction, the screen horizontal direction, and the thickness direction are the screen vertical direction (vertical direction), the screen horizontal direction (horizontal direction), and the screen vertical direction in the usage state of the screen 10, unless otherwise specified. It is assumed that it is the thickness direction (depth direction) and is parallel to the Y direction, the X direction, and the 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 type projector.
This image source LS is a screen when the screen (display area) of the screen 10 is viewed from the front direction (normal direction of the screen surface) of the image source side (−Z side) in the usage state of the image display device 1. It is located at the center of the screen 10 in the left-right direction, and is located on the lower side (−Y side) in the vertical direction with respect to the screen of the screen 10.
The image source LS can project the image light L diagonally in the depth direction (Z direction) from a position where the distance from the surface of the screen 10 is significantly closer than that of the conventional general-purpose projector. Therefore, as compared with the conventional general-purpose projector, the image source LS has a shorter projection distance of the image light L to the screen 10, a large incident angle at which the projected image light L is incident on the screen 10, and a change amount (incident) thereof. The amount of change from the minimum value to the maximum value of the angle) is also large.

The screen 10 is a transmissive screen that transmits and displays the image light L projected by the image source LS. The screen 10 has transparency so that the scenery on the other side of the screen 10 can be observed from both the light emitting side (+ Z side) and the incoming light side (-Z side) when the screen 10 is not projected and the image light is not projected. There is.
The screen 10 has an incoming light surface 10a on which the video light L is incident, and an outgoing light surface 10b facing the incoming light surface 10a from which the video light L is emitted. The light entering surface 10a and the light emitting surface 10b are parallel to each other and parallel to the screen surface (XY surface).
The screen (display area) of the screen 10 has a substantially rectangular shape in which the long side direction is the left-right direction of the screen when viewed from the observer O1 side on the light emitting side (+ Z side) in the used state.
The screen size of the screen 10 is about 40 to 100 inches diagonally, and the aspect ratio of the screen is 16: 9. Not limited to this, the screen size of the screen 10 may be, for example, 40 inches or less, and the size and shape of the screen of the screen 10 can be appropriately selected according to the purpose of use, the environment of use, and the like.

In general, the screen 10 is a laminate of thin layers made of resin or the like, and often does not have sufficient rigidity to maintain flatness by itself. Therefore, the screen 10 is integrally joined (or partially fixed) to a support plate (not shown) via a joining layer (not shown) having light transmission on the light emitting side and the light entering side, and the flatness of the screen is maintained. Is preferable.
The support plate is a flat plate-like member having light transmittance and high rigidity. As the support plate, a plate-shaped member made of a resin such as acrylic resin or PC resin, or made of glass is suitable.
The video display device 1 of the present embodiment is applied to, for example, a show window of a store or the like. Therefore, as the support plate as described above, a window glass (glass plate) or the like constituting a show window of a store or the like is suitable.
Further, the screen 10 may be in a form in which the four sides and the like are supported by a frame member (not shown) and the like, and the flatness of the screen 10 is maintained.

FIG. 2 is a diagram showing a layer structure of the screen 10 of the first embodiment. In FIG. 2, the screen 10 passes through a point A (see FIG. 1), which is the center of the screen (geometric center of the screen) on the light emitting side (observer side, + Z side), and is parallel to the vertical direction (Y direction) of the screen. Therefore, a part of the cross section perpendicular to the screen surface (parallel to the Z direction, which is the thickness direction) is shown in an enlarged manner.
As shown in FIG. 2, the screen 10 has a base material layer 11, a first optical shape layer 12, a reflection layer 13, and a second optical shape layer 14, in order from the light entry side (−Z side, image source side). A protective layer 15 is provided.

The base material layer 11 is a sheet-like member having light transmission. The base material layer 11 has a first optical shape layer 12 integrally formed on the light emitting side (observer side, + Z side). The base material layer 11 is a layer that serves as a base material (base) that forms the first optical shape layer 12.
The base material layer 11 is, for example, a polyester resin such as PET (polyethylene terephthalate) having high light transmittance, an acrylic resin, a styrene resin, an acrylic styrene resin, a PC (polycarbonate) resin, an alicyclic polyolefin resin, and a TAC (triacetyl). Cellulose) Formed from resin or the like.

FIG. 3 is a diagram illustrating the unit optical shape 121 and the reflective layer 13 of the first embodiment. In FIG. 3, the cross-sectional view of the screen 10 shown in FIG. 2 is further enlarged, and the base material layer 11 and the protective layer 15 are omitted for easy understanding.
The first optical shape layer 12 is a layer having light transmittance formed on the light emitting side (+ Z side) of the base material layer 11. The surface of the first optical shape layer 12 on the light emitting side has a linear Fresnel lens shape formed by arranging a plurality of unit optical shapes (unit lenses) 121.

The unit optical shape 121 has a substantially triangular prism shape, and a plurality of units are arranged in the vertical direction of the screen with the left-right direction of the screen as the longitudinal direction. As shown in FIGS. 2 and 3, the unit optical shape 121 has a cross section in a cross section parallel to the direction orthogonal to the screen surface (Z direction) and parallel to the arrangement direction (Y direction) of the unit optical shape 121. The shape is a substantially triangular shape that is convex toward the light emitting side (+ Z side).
The unit optical shape 121 has a first surface (lens surface) 121a on which video light is incident and a second surface (non-lens surface) 121b facing the first surface (lens surface) 121a. In one unit optical shape 121, the second surface 121b is located below the first surface 121a with the apex t interposed therebetween.
Further, in the cross section of the screen 10 shown in FIGS. 2 and 3, the points that are the valley bottoms between the adjacent unit optical shapes 121 are defined as points v1 and v2, respectively. The point v1 is located above the apex t in one unit optical shape 121 and is a point on the incoming light side end of the first surface 121a. The point v2 is located below the apex t in one unit optical shape 121 and is a point on the incoming light side end of the second surface 121b.

In the present embodiment, the first surface 121a is a flat surface, and the second surface 121b is a curved surface having periodic smooth irregularities. Further, in the present embodiment, the reflective layer 13 is formed on the light emitting side of the second surface 121b.
The angle formed by the first surface 121a with the surface parallel to the screen surface, that is, the angle formed by the plane passing through the apex t and the point v1 and perpendicular to the YZ surface with the surface parallel to the screen surface is θ1.
Further, the angle formed by the second surface 121b with the surface parallel to the screen surface, that is, the plane H passing through the points t and v2 and perpendicular to the YZ plane (shown by the broken line in FIGS. 2 and 3) is parallel to the screen surface. The angle formed with the surface is θ2.
The angles θ1 and θ2 satisfy the relationship θ2> θ1.

The arrangement pitch of the unit optical shape 121 is P, and the height of the unit optical shape 121 (dimension from the apex t to the valley bottom point v2 in the thickness direction) is h.
For ease of understanding, FIGS. 2 and 3 show an example in which the arrangement pitch P and the angles θ1 and θ2 of the unit optical shape 121 are constant in the arrangement direction of the unit optical shape 121. However, in the unit optical shape 121 of the present embodiment, the arrangement pitch P is actually constant, but as the unit optical shape 221 is arranged toward the upper side in the vertical direction of the screen (as the distance from the image source LS). The angle θ2 is gradually decreasing.

The angles θ1, θ2, the arrangement pitch P, etc. are the projection angle of the image light from the image source LS (the angle of incidence of the image light on the screen 10), the size of the pixels of the image source LS, and the screen of the screen 10. It may be appropriately set according to the size, the refractive index of each layer, and the like. For example, the arrangement pitch P may be changed along the arrangement direction of the unit optical shape 121.

The first optical shape layer 12 is formed of an ultraviolet curable resin such as urethane acrylate-based, polyester acrylate-based, epoxy acrylate-based, polyether acrylate-based, polythiol-based, and butadiene acrylate-based resin having high light transmittance.
In the present embodiment, the ultraviolet curable resin will be described as an example of the resin forming the first optical shape layer 12, but the present invention is not limited to this, and for example, other ionizing radiation such as an electron beam curable resin is used. It may be formed of a curable resin.

The reflective layer 13 is a semi-transmissive reflective layer that reflects a part of the incident light and transmits at least a part of the other incident light, and is a so-called half mirror. The reflective layer 13 of the present embodiment is formed on the second surface 121b of the unit optical shape 121 (the light emitting side of the second surface 121b).
As described above, the second surface 121b is a curved surface having smooth unevenness having periodicity, and the reflective layer 13 is formed following this curved surface, and is formed in a state where the unevenness of the curved surface is maintained. ing. Therefore, the surface of the reflection layer 13 on the first optical shape layer 12 side (light entry side) and the surface on the second optical shape layer 14 side (light emission side) are curved surfaces having smooth irregularities having periodicity. ..
The reflective layer 13 diffuses and reflects a part of the incident light due to the unevenness of the curved surface, and transmits the other incident light without diffusing.

4 and 5 are views for explaining the curved surface of the reflective layer 13 of the first embodiment.
FIG. 4A is a further enlargement of a part of the cross section of the screen 10 shown in FIG. 2, and FIG. 4B is a screen horizontal direction (X direction) and a screen vertical direction (Y direction) of the screen 10. ) Is a part of the cross section parallel to). FIG. 5 schematically shows the reflective layer 13 in the screen. Note that FIGS. 4 and 5 show only the reflective layer 13 in the screen 10 for ease of understanding.

As shown in FIG. 4, both sides of the reflective layer 13 (the surface on the side of the first optical shape layer 12 and the surface on the side of the second optical shape layer 14) are curved surfaces having smooth irregularities having periodicity. This unevenness is periodic in two directions, the extending direction of the reflective layer 13 (longitudinal direction, equal to the longitudinal direction of the unit optical shape 121) and the width direction of the reflective layer 13 (direction intersecting the extending direction). It is formed by arranging multiple pieces in. In the present embodiment, the longitudinal direction of the reflective layer 13 is the screen left-right direction (X direction), and the width direction of the reflective layer 13 is a plane H including points t and v2 and perpendicular to the YZ plane. The directions are parallel.

The periodic unevenness in the width direction and the periodic unevenness in the extending direction of the reflective layer 13 are directions in which the direction of the unevenness (direction of peaks and valleys) is orthogonal to the above-mentioned plane H.
Further, as shown in FIG. 4A, the reflective layer 13 has a cross section parallel to the arrangement direction (Y direction) and the thickness direction (Z direction) of the screen 10, and the point k1 at which the unevenness is maximum and the minimum. There is at least one point k2 to be. Further, as shown in FIG. 4A, the reflective layer 13 is formed so that the minimum point k2 is on the incoming light side (−Z side).

In the width direction of the reflective layer 13 (plane H direction shown in FIG. 4), the dimension between the point k1 at which the unevenness is maximum and the point k2 at which the unevenness is minimum is D1, and the longitudinal direction of the reflective layer 13 (unit optical shape 121). The dimension between the maximum point k3 and the minimum point k4 in the longitudinal direction of) is D2. These dimensions D1 and D2 correspond to 1/2 of the period of unevenness in each direction. The dimensions D1 and D2 are D2> D1, and the dimension D2 is about 2 to 3 times the dimension D1.
In the present embodiment, the dimension D1 is several tens of μm, and the dimension D2 is about several tens of μm to several hundreds of μm.

Further, in the width direction and the longitudinal direction of the reflective layer 13, the height of the unevenness (dimension between the maximum point and the minimum point in the height direction of the unevenness) is several μm to several tens of μm.
Further, in each reflective layer 13, from the viewpoint of efficiently directing the image light to the light emitting side, it is preferable that the point k2 having the minimum size is located on the incoming light side (−Z side) in the width direction thereof.

Further, as shown in FIG. 4A, in the width direction of the reflective layer 13, the tangent line of the reflective layer 13 (particularly, the tangent line of the surface of the reflective layer 13 on the second optical shape layer 14 side) is the screen surface method. Let α be the angle formed with the line direction. At this time, it is preferable that the angle α is 0 ° or more and 30 ° or less from the viewpoint of reflecting the image light by the reflection layer 13 and directing the image light toward the observer O1 located in the front direction on the light emitting side.
When the angle α is out of this range, the image light incident on the screen 10 does not enter the reflection layer 13, or even if the image light is reflected by the reflection layer 13, it reaches the observer O1 located in the front direction on the light emitting side. There is a problem such as going in the wrong direction. Therefore, the angle α is preferably within the above range.

Although a plurality of reflective layers 13 are provided in the screen 10, the period of the unevenness of the reflective layer 13 and the height (depth) of the unevenness may be the same in all the reflective layers 13. It may be different. Further, for example, the phases of the irregularities of the adjacent reflective layers 13 may be different or coincide with each other, and the phases of the irregularities may be gradually or gradually different along the arrangement direction of the reflective layers 13. You may.

The reflective layer 13 is formed by depositing a metal having high light reflectivity such as aluminum, silver, and nickel, or by sputtering a metal having high light reflectivity. Further, the reflective layer 13 may be formed of a dielectric multilayer film having high transparency, low light absorption loss, and high reflectance.
The reflective layer 13 of the present embodiment is formed by depositing aluminum on the second surface 121b.

The second optical shape layer 14 is a layer having light transmittance provided on the light emitting side (+ Z side) of the first optical shape layer 12 and the reflection layer 13.
The second optical shape layer 14 is formed so as to fill the valley portion of the unevenness due to the unit optical shape 121, and the surface of the first optical shape layer 12 and the reflection layer 13 on the light emitting side (+ Z side) is flat. Therefore, the surface of the second optical shape layer 14 on the incoming light side (−Z side) is formed by arranging a plurality of substantially inverted shapes of the unit optical shape 121.
By providing such a second optical shape layer 14, the reflective layer 13 can be protected. Further, by providing the second optical shape layer 14, it becomes easier to stack the protective layer 15 or the like on the light emitting side, and it becomes easier to join the protective layer 15 or the like to the support plate or the like.

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

The protective layer 15 is a layer having light transmittance formed on the light emitting side (+ Z side) of the second optical shape layer 14, and has a function of protecting the light emitting side of the screen 10.
The protective layer 15 is formed of a sheet-like member made of a resin having high light transparency. As the protective layer 15, for example, a sheet-like member formed of the same material as the base material layer 11 may be used.
As described above, the screen 10 of the present embodiment does not include a light diffusing layer containing a diffusing material such as particles having a function of diffusing light, and the image light incident on the screen 10 is the reflective layer 13. It is diffused by reflection on a curved surface having irregularities having periodicity.

The screen 10 of the present embodiment is manufactured by, for example, the following manufacturing method.
By a UV molding method, a base material layer 11 is prepared, laminated on one surface of a molding mold having a unit optical shape 121 filled with an ultraviolet curable resin, and irradiated with ultraviolet rays to cure the resin. The first optical shape layer 12 is formed.
At this time, the surface forming the second surface 121b of the molding die forming the unit optical shape 121 has irregularities having periodicity in the direction corresponding to the above-mentioned plane H and the two directions corresponding to the left-right direction of the screen. It has a curved surface. This unevenness is formed by moving the cutting tool in a wavy shape, cutting with a cutting tool having waviness, or the like when the molding die forming the unit optical shape 121 is cut with a cutting tool or the like. The forming direction of this curved surface is not limited to the above, and may be appropriately selected and applied.

After the first optical shape layer 12 is formed on one surface of the base material layer 11, aluminum is vapor-deposited on the second surface 121b to form the reflective layer 13.
After that, the ultraviolet curable resin is applied from above the reflective layer 13 so as to fill the valley portion between the unit optical shapes 121 so as to be flat, and the protective layer 15 is laminated to cure the ultraviolet curable resin. , The second optical shape layer 14 and the protective layer 15 are integrally formed. After that, the screen 10 is completed by cutting it to a predetermined size or the like.
The base material layer 11 and the protective layer 15 may be in the form of a single leaf or in the form of a web.
In the present embodiment, by shaping the curved surface shape of the second surface 121b of the unit optical shape 121 by a molding die, even when a large number of screens 10 are manufactured, there is little variation in quality and stable manufacturing can be performed. ..

Here, the state of the image light incident on the unit optical shape 121 of the present embodiment will be described.
As shown in FIG. 3, a part of the image light (image light La) projected from the image source LS and incident on the screen 10 from the light entry side (−Z side) is the light entry side end of the first surface 121a. An observer O1 (see FIG. 1) that passes through the region B of the portion (point v1 side end portion), is incident on the reflective layer 13, is reflected, and is located in the front direction on the light emitting side (+ Z side) of the screen 10. The image is emitted in a visible direction. At this time, since the reflective layer 13 has a curved surface having irregularities having periodicity as described above, the reflected light is appropriately diffused in the vertical direction of the screen and the horizontal direction of the screen as shown in FIG.
Further, a part of the image light La incident on the screen 10 passes through the first surface 121a, but is emitted upward on the light emitting side of the screen 10 (for example, the image light Lb), so that it does not reach the observer O1. ..

Further, the external light Ga such as sunlight and illumination light incident on the screen 10 from above the outgoing light side (+ Z side) and the external light Gc incident from above the incoming light side (−Z side) are all on the first surface. It passes through 121a and emits light below the incoming light side and the outgoing light side of the screen 10. Further, some of the external light Gb and Gd are reflected by the reflective layer 13 and emitted above the screen 10, and are gradually attenuated in the screen 10 by repeating total reflection at the interface between the screen 10 and air. Or Therefore, these external lights do not reach the observer O1 located in the front direction on the light emitting side, and the contrast decrease of the image due to the external light can be suppressed.

FIG. 6 is a diagram showing the state of video light and external light on the screen 10 of the first embodiment. In FIG. 6, as in FIG. 2, a part of the cross section of the screen 10 passing through the point A at the center of the screen and parallel to the arrangement direction (Y direction) and the thickness direction (Z direction) of the unit optical shape 121 is enlarged. Is shown. In FIG. 6, in order to facilitate understanding, there is a difference in refractive index between the interface between the base material layer 11 and the first optical shape layer 12 and the interface between the second optical shape layer 14 and the protective layer 15 in the screen 10. It is shown as having no.
Of the video light L1 projected from the video source LS located below the screen 10 and incident on the screen 10 from the light input side (−Z side), a part of the video light L2 is on the light input surface 10a of the screen 10. It reflects and heads upward. This image light L2 does not reach the observer O2 located in the front direction of the light entering side (image source side) of the screen 10.

Further, of the video light L1 incident on the screen 10, a part of the video light L3 passes through the region B on the point v1 side (upper side in the vertical direction of the screen) of the first surface 121a of the unit optical shape 121, and is a reflective layer. It is incident on 13 and reflected, and is emitted toward the observer O1 side located in the front direction of the light emitting side (+ Z side) of the screen 10. The image light L3 is diffused in the vertical direction of the screen and the horizontal direction of the screen due to the unevenness of the reflective layer 13, and can display an image having a good viewing angle on the observer O1 located in the front direction on the light emitting side of the screen 10. ..
Although some of the video light L4 passes through the reflective layer 13, the amount of light is small and the light is emitted above the light emitting side of the screen 10, so that it is located in the front direction of the light emitting side and the light entering side. Observers O1 and O2 do not visually recognize the image light L4.

Next, light from the outside world (hereinafter referred to as external light) such as sunlight and illumination light other than the image light incident on the screen 10 from above the incoming light side (-Z side) or the outgoing light side (+ Z side) will be described. do.
As shown in FIG. 6, among the external light G1 and G4 incident on the screen 10, some of the external light G2 and G5 are reflected by the light emitting surface 10b and the light entering surface 10a of the screen 10 and are reflected by the screen 10 respectively. It goes downward and neither reaches the observers O1 and O2.
Further, of the external light G1, a part of the external light G3 incident on the screen 10 passes through the first surface 121a, goes downward on the incoming light side of the screen 10, and exits downward on the incoming light side of the screen 10. Or, it is reflected by the light entering surface 10a of the screen 10 and proceeds downward inside the screen 10 and gradually attenuates.

Further, among the external light G4, the external light G6 incident on the screen 10 passes through the first surface 121a, heads downward on the light emitting side of the screen 10, and is emitted downward on the light emitting side of the screen 10 or the screen 10. It is reflected by the light emitting surface 10b of the screen 10 and travels downward inside the screen 10 and gradually attenuates.
Further, as in the case of the external light Gc and Gd shown in FIG. 3 described above, a part of the external light is incident on the screen 10 and reflected by the reflection layer 13, and is emitted to the upper side of the incoming light side of the screen 10. , Proceeds upward inside the screen 10, repeats reflection (including total reflection) at the interface between the screen 10 and air, and gradually attenuates.
As described above, none of the external light incident on the screen 10 from above reaches the observers O1 and O2, so that the contrast decrease of the image due to the external light can be suppressed.

Further, since the screen 10 does not have a light diffusion layer containing diffuse particles or the like that diffuses light, the external light G7 and G8 that are incident on the screen surface at a small incident angle and pass through the screen 10 are not diffused. .. Therefore, when the observers O2 and O1 observe the scenery on the other side of the screen 10 through the screen 10 from the incoming light side (−Z side) and the outgoing light side (+ Z side), the scenery on the other side of the screen 10 is displayed. It can be observed with high transparency without blurring or bleeding white.

In the conventional transmissive screen, the transparency of the screen is designed to be very low so that the image source side cannot be seen through, and the scenery on the other side of the screen cannot be seen. Further, the conventional transmissive screen often includes a light diffusing layer or the like containing diffusing particles or the like that diffuses light in order to provide an image having a sufficient viewing angle, and the transparency of other layers is provided. Even if the above is improved, there is a problem that the scenery on the other side of the screen is blurred or blurred in white because the diffused particles of the light diffusing layer also diffuse the outside light.

However, the screen 10 of the present embodiment does not have a light diffusion layer containing diffuse particles or the like, and is a curved surface having irregularities on both sides of the reflection layer 13 having periodicity, and the image light is the reflection layer 13. When reflected, it is diffused by unevenness. Further, in the screen 10 of the present embodiment, the light transmitted through the reflective layer 13 is not diffused.
Therefore, according to the present embodiment, the screen 10 can display an image having a good viewing angle, brightness, and resolution on the observer O1 on the light emitting side (+ Z side), and the screen 10 does not project the image light. Even in an environment with a lot of outside light, the scenery on the other side (−Z side) of the screen 10 is not blurred or blurred, and is well visible to the observer O1 and high transparency can be realized.

Further, according to the present embodiment, the light transmitted through the reflective layer 13 is not diffused, and the screen 10 has high transparency. Therefore, in a state where the image light is not projected or the like, the light input side of the screen 10. The observer O2 on the (-Z side) can also see the scenery on the other side (+ Z side) of the screen 10 well. Further, even when the image light is projected on the screen 10, the observers O1 and O2 can partially see the scenery on the other side (incoming light side and outgoing light side) of the screen 10.

Further, according to the present embodiment, by adjusting the period of the unevenness having the periodicity of the curved surface of the reflective layer 13 and the height (depth) of the unevenness, the light in the left-right direction of the screen and the vertical direction of the screen of the screen 10 is adjusted. The degree of diffusion can be adjusted. As a result, the screen 10 can easily control the viewing angle in the horizontal direction of the screen and the vertical direction of the screen.
Further, according to the present embodiment, it is easier to control the viewing angle as compared with, for example, a light diffusion layer containing particles that diffuse light, a matte surface having a fine uneven shape, and the like.

(Second Embodiment)
FIG. 7 is a diagram illustrating the screen 20 of the second embodiment. FIG. 7A is an enlarged view of a part of the cross section of the screen 20 which passes through a point at the center of the screen and is parallel to the vertical direction and the thickness direction of the screen. The cross section of the screen 20 shown in FIG. 7A corresponds to the cross section of the screen 10 shown in FIG. 2 described above. FIG. 7B shows a state in which the first optical shape layer 22 of the screen 20 is viewed from the light emitting side (+ Z side). In FIG. 7B, the reflective layer 23, the second optical shape layer 24, and the protective layer 15 are omitted for ease of understanding.
The screen 20 of the second embodiment has substantially the same form as the screen 20 of the first embodiment described above, but the first optical shape layer 22 has a circular Fresnel lens shape on the surface on the light emitting side (+ Z side). The point is different.
Therefore, the same reference numerals or the same reference numerals are given to the portions that perform the same functions as those of the first embodiment described above, and duplicate description will be omitted as appropriate.

The screen 20 of the second embodiment includes a base material layer 11, a first optical shape layer 22, a reflection layer 23, a second optical shape layer 24, and a protective layer 15 in this order from the light entry side (−Z side). .. The screen 20 of the second embodiment can be applied to the image display device 1 shown in the first embodiment.
The first optical shape layer 22 has a circular Fresnel lens shape in which unit optical shapes 221 are concentrically arranged on a surface on the light emitting side.
Further, the second optical shape layer 24 is a layer having light transmittance provided on the light emission side (+ Z side) of the first optical shape layer 22 and the reflection layer 23, and is a surface on the light entry side (−Z side). In addition, a plurality of substantially inverted shapes of the unit optical shape 221 are arranged and formed.

As shown in FIG. 7B, the unit optical shape 221 is a partial shape (arc shape) of a perfect circle when viewed from the front direction (Z direction), and is located outside the screen (display area) of the screen 20. A plurality of concentric circles are arranged around the point C. That is, the first optical shape layer 22 has a circular Fresnel lens shape having a so-called offset structure centered on the point C (Fresnel center).
The unit optical shape 221 has a first surface 221a and a second surface 221b, and has a substantially triangular shape in which the cross-sectional shape parallel to the thickness direction and the arrangement direction is convex toward the light emitting side (+ Z side).
In the present embodiment, as shown in FIG. 7B, the point C is located at the center of the screen 20 in the left-right direction (X direction) of the screen 20 and below the outside of the screen. Further, 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. 3 when the screen 10 is viewed from the front direction.

The second surface 221b is a curved surface having irregularities having periodicity, similar to the second surface 121b of the first embodiment described above.
The reflective layer 23 is formed by depositing aluminum on the second surface 221b.
The reflective layer 23 is formed following the curved surface of the second surface 221b, and is formed in a state where the curved surface is maintained. The reflective layer 23 has a surface on the side of the first optical shape layer 22 and a surface on the side of the second optical shape layer 24 in the width direction of the reflective layer 23 in the cross section shown in FIG. 7, as in the first embodiment described above. It is a curved surface having smooth irregularities having periodicity in two directions of (the direction of the straight line S connecting the point t and the point v2) and the extending direction (the extending direction of the second surface 221b).

Similar to the first embodiment, the period of the unevenness in the extending direction of the reflective layer 23 is larger than the period of the unevenness in the width direction of the reflective layer 23, and is about 2 to 3 times the period of the unevenness in the width direction. Further, as in the first embodiment, in the cross section shown in FIG. 7, the angle α formed by the tangent line of the reflective layer 23 with the normal direction of the screen surface is 0 ° or more and 30 ° or less.

According to the present embodiment, the screen 20 and the image display device 1 capable of displaying a good image with high transparency can be obtained as in the first embodiment described above. Further, according to the present embodiment, the viewing angle of the screen 20 can be controlled to a desired size by controlling the curved surface shape of the reflective layer 13 as in the first embodiment.
Further, according to the present embodiment, in the first optical shape layer 22, the point C serving as the Fresnel center is located outside the display area of the screen 10 and is located on the lower side in the vertical direction of the screen, and is a circular having a so-called offset structure. It has a Fresnel lens shape. Therefore, even if the image light has a large incident angle and is projected from the short focus type image source LS located outside the display area of the screen 10 and located on the lower side in the vertical direction of the screen, the image in the horizontal direction of the screen becomes dark. It is possible to display a good image with high surface uniformity of brightness.

(Third Embodiment)
FIG. 8 is a diagram showing a layer structure of the screen 30 of the third embodiment. In FIG. 8, a part of the cross section of the screen 30 which passes through the point A at the center of the screen and is parallel to the screen vertical direction (arrangement direction of the unit optical shape 321) and the thickness direction is shown in an enlarged manner. The cross section of the screen 30 shown in FIG. 8 corresponds to the cross section of the screen 10 of the first embodiment shown in FIG.
The screen 30 of the third embodiment has substantially the same form as the screen 10 of the first embodiment, but the reflective layer 33 is formed of a resin having high transparency, and its refractive index is the first optical shape. The difference is that the refractive index is lower than that of the layer 32 and the second optical shape layer 34. Therefore, the same reference numerals or the same reference numerals are given to the portions that perform the same functions as those of the first embodiment described above, and duplicate description will be omitted as appropriate.
The screen 30 of the third embodiment includes a base material layer 11, a first optical shape layer 32, a reflection layer 33, a second optical shape layer 34, and a protective layer 15 in this order from the light entry side (−Z side). ..
The screen 30 of the third embodiment is applicable to the video display device 1 of the first embodiment.

The first optical shape layer 32 has a linear Fresnel lens shape in which a plurality of unit optical shapes 321 are arranged on a surface on the light emitting side (+ Z side). The unit optical shape 321 has a first surface 321a and a second surface 321b, and has a triangular prism shape that is convex on the light emitting side. ..
The linear Fresnel lens shape of the first optical shape layer 32 is the same as the linear Fresnel lens shape of the first optical shape layer 12 of the first embodiment. Further, the second surface 321b is a curved surface having smooth unevenness having periodicity, similar to the second surface 121b of the first embodiment.

As the first optical shape layer 32, an ultraviolet curable resin having high light transmittance and a higher refractive index than a general ultraviolet curable resin is used. For example, the first optical shape layer 32 is formed of an epoxy acrylate-based ultraviolet curable resin or a urethane-based ultraviolet curable resin having a high refractive index added with a metal oxide. Further, as the first optical shape layer 32, _{an ultraviolet curable resin to which titanium oxide (TiO 2} ) is added to have a high refractive index may be used.
The refractive index of the first optical shape layer 32 is preferably about 1.56 to 1.7.

The reflective layer 33 has light transmittance and has a lower refractive index than the adjacent first optical shape layer 32 and second optical shape layer 34. The reflective layer 33 of the present embodiment is formed on the second surface 321b, and both sides thereof have a curved surface having smooth irregularities having periodicity in the width direction of the reflective layer 33 and the extending direction of the reflective layer 33. It has become.
Light incident on the reflective layer 33 at an incident angle equal to or higher than the critical angle is diffused when totally reflected due to the uneven shape, and at least a part of light incident on the reflective layer 33 at an incident angle less than the critical angle is not diffused. It is transparent with.
In the present embodiment, the interface K between the reflection layer 33 and the adjacent second optical shape layer 34 is a total reflection surface that totally reflects at least a part of the image light (image light incident at an angle equal to or higher than the critical angle). This interface K is also a curved surface.

Similar to the first embodiment, the curved surface of the reflective layer 33 having irregularities on both sides is a plane H passing through the width direction of the reflective layer 33 (in FIG. 8, points t and v2 and perpendicular to the YZ plane). The period of unevenness in the longitudinal direction of the reflective layer 33 (the left-right direction of the screen of the screen 30, the X direction) is larger than the period of unevenness in the direction parallel to), which is about 2 to 3 times the period of unevenness in the width direction. be.
Further, in the cross section shown in FIG. 8, the angle α formed by the tangent line of the reflective layer 33 with the normal direction of the screen 30 is 0 ° or more and 30 ° or less as in the first embodiment.

The reflective layer 33 is made of a material having high light transmittance and a lower refractive index than the adjacent first optical shape layer 32 and second optical shape layer 34. As the reflective layer 33, for example, _{metal fluoride such as magnesium fluoride (MgF 2} ) and aluminum fluoride (AlF ₃ ), silicon oxide (SiO ₂ ), and a silicon-based resin are suitable.
The reflective layer 33 is formed by depositing or sputtering the above-mentioned material. Further, the reflective layer 33 may be formed by transferring a foil such as the above-mentioned metal fluoride or applying a paint containing a thin film such as the above-mentioned metal fluoride.

The refractive index of the reflective layer 33 is preferably about 1.35 to 1.45 from the viewpoint of efficiently totally reflecting the image light at the interface K with the second optical shape layer 34.
The thickness of the reflective layer 33 is preferably 0.3 μm or more and 10 μm or less, and more preferably 1 μm or more and 10 μm or less.
If the thickness of the reflective layer 33 is 0.3 μm or less, the total reflection of the image light at the interface K becomes insufficient, or interference occurs when the image light is totally reflected and the image is deteriorated. , Not preferable. Further, from the viewpoint of enhancing the effect of sufficiently totally reflecting the image light at the interface K and suppressing the interference that may occur when the image light is totally reflected, the thickness of the reflection layer 33 is 1 μm or more. More preferred.
Further, when the thickness of the reflective layer 33 becomes larger than 10 μm, it becomes difficult to form the reflective layer 33 by vapor deposition or the like, or the uneven shape of the curved surface of the second surface 321b is filled and flattened, so that the reflective layer 33 is flattened. 2 The interface K on the optical shape layer 34 side becomes flat, which is not preferable.

The second optical shape layer 34 is a layer having light transmittance provided on the light emitting side (+ Z side) of the first optical shape layer 32 and the reflection layer 33. The second optical shape layer 34 has a higher refractive index than the reflective layer 33. The interface K between the second optical shape layer 34 and the reflection layer 33 totally reflects at least a part of the incident image light (the image light incident on the interface K at an angle equal to or higher than the critical angle), and the light emitting side (+ Z side). ) Has a function of facing the observer O1 side.
The second optical shape layer 34 is formed so as to fill the valley portion of the unevenness due to the unit optical shape 321 from the light emitting side of the first optical shape layer 32 and the reflection layer 33, and is formed on the light emitting side (observer) of the first optical shape layer 32. The surface on the side) is flat. The surface of the second optical shape layer 34 on the incoming light side (−Z side) is formed by arranging a plurality of substantially inverted shapes of the unit optical shape 321 of the first optical shape layer 32.

The second optical shape layer 34 is an ultraviolet curable resin having high light transmittance and a higher refractive index than a general ultraviolet curable resin, for example, an epoxy which is the same material as the first optical shape layer 12 described above. An acrylate-based ultraviolet curable resin, a urethane-based ultraviolet curable resin having a high refractive index added with a metal oxide, and an ultraviolet curable resin having a high refractive index added with titanium oxide (TiO ₂ ). Etc. are formed.
The refractive index of the second optical shape layer 34 is preferably about 1.56 to 1.7 from the viewpoint of efficiently totally reflecting the image light at the interface K with the reflective layer 33. Further, it is desirable that the refractive index of the second optical shape layer 34 is equal to or substantially equal to the refractive index of the first optical shape layer 32 (the difference in refractive index is small enough to be regarded as equal).

In the present embodiment, the second optical shape layer 34 is formed of the same resin as the first optical shape layer 32. Not limited to this, the second optical shape layer 34 and the first optical shape layer 32 may be formed of different resins.
Further, in the present embodiment, the second optical shape layer 34 will be described with reference to an example of being formed of an ultraviolet curable resin, but the present invention is not limited to this, and for example, other ionizing radiation curing such as an electron beam curable resin. It may be formed of a mold resin.

According to the present embodiment, the screen 30 and the image display device 1 capable of displaying a good image with high transparency can be obtained as in the first embodiment described above. Further, according to the present embodiment, the viewing angle of the screen 30 can be controlled to a desired size by controlling the curved surface shape of the reflective layer 33 as in the first embodiment.
Further, according to the present embodiment, since the image light is totally reflected at the interface K and directed to the light emitting side (+ Z side), the image light is reflected at the time of reflection as compared with the case where the image light is reflected by the reflective layer made of a normal metal thin film or the like. The light loss is small, and a brighter image can be displayed.
Further, according to the present embodiment, since the reflective layer 33 is formed of a resin having high transparency, the transparency of the screen 30 is further improved as compared with the case where the reflective layer is formed by a normal metal thin film or the like. Can be made to.

(Deformed form)
Not limited to each of 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 light emitting side (+ Z side) and the light entering side (−Z side) of the screens 10, 20, and 30. The hard coat layer can be formed, for example, by applying an ultraviolet curable resin having a hard coat function (for example, urethane acrylate or the like) to the surface of the screen on the light emitting side.
Further, not limited to the hard coat layer, depending on the usage environment and purpose of use of the screens 10, 20 and 30, for example, antireflection function, ultraviolet absorption function, antifouling function, etc. One or a plurality of layers having necessary functions such as an antistatic function may be selected and provided. Further, a touch panel layer or the like may be provided on the light emitting side (+ Z side) of the screens 10, 20, and 30.

For example, by providing an antireflection layer on the surface of the screens 10, 20, and 30 on the incoming light side, it is possible to suppress the reflection of the image light when it is incident on the screen and increase the amount of incident light. Further, when the antireflection layer is provided on the surface of the screens 10, 20 and 30 on the light emitting side, a part of the image light is reflected on the surface of the screen on the light emitting side and emitted from the light input side. It is also possible to prevent the image from being partially leaked to the observer O2 on the light side.

(2) In each embodiment, the screens 10, 20, and 30 have a case where the first optical shape layers 12, 22, 32 and the second optical shape layers 14, 24, 34 have sufficient thickness, rigidity, and the like. May not include at least one of the base material layer 11 and the protective layer 15.
Further, the screens 10, 20 and 30 may be a plate-shaped member having sufficient rigidity so that at least one of the base material layer 11 and the protective layer 15 can maintain the flatness of the screen. In this case, the support plate or the like to be joined in order to maintain the flatness of the screen can be omitted.

(3) In each embodiment, the image source LS may be arranged on the diagonally lower side of the screens 10, 20, 30 or the like, for example.
At this time, in the first embodiment and the third embodiment, the screens 10 and 30 have a form in which the arrangement direction and the longitudinal direction of the unit optical shapes 121 and 321 are tilted according to the position of the image source LS. Further, in the second embodiment, the screen 20 has a form in which the unit optical shape 221 is arranged by shifting the position of the point C serving as the Fresnel center according to the position of the image source LS. With such a form, the degree of freedom such as the position of the image source LS is improved.
Further, in each embodiment, when the screen is used in an environment where the influence of external light from above the screen is small, for example, the image source LS is the screens 10 and 20 when viewed from the normal direction of the screen surface. , 30 may be located at the center of the screen in the left-right direction and above the outside of the screen. At this time, the screens 10, 20, and 30 have a form in which the vertical direction of the screen is inverted from the form shown in each embodiment.

(4) In each embodiment, the first surface and the second surface of the unit optical shapes 121, 221 and 321 may have a folded surface shape. Further, the unit optical shapes 121, 221 and 321 may be polygonal shapes formed by a plurality of three or more surfaces.
Further, the reflective layers 13, 23, 33 may be formed on at least a part of the first surfaces 121a, 221a, 321a in addition to the second surfaces 121b, 221b, 321b. In particular, the reflective layer 33 of the third embodiment may be formed on the first surface 321a and the second surface 321b.
Further, the unit optical shapes 121, 221 and 321 may be formed by a curved surface having a concavo-convex shape having the same periodicity as the second surface as the first surface.

(5) In each embodiment, the screens 10, 20, and 30 show an example in which the screen (display area) has a rectangular shape, but the screen (display area) is not limited to this, and is not limited to this, for example, other quadrangular shapes such as a square and a parallelogram. It may be a polygonal shape, a circle, an oval shape, an oval shape, or the like.

(6) In each embodiment, light is transmitted to the light emitting side (+ Z side) of the reflective layers 13, 23, 33, but is colored with a dark colorant such as black or gray to improve light absorption. In the form of having a light absorption layer, the black brightness of the image may be reduced, external light may be absorbed from the image source side, and the contrast of the image may be improved.
Further, in each embodiment, a light absorption layer as described above is provided on the light entry side (−Z side) of the reflection layers 13, 23, 33 to absorb external light incident from the back surface side, and the image is displayed. You may try to improve the contrast.
The above-mentioned light absorbing layer may be a transparent layer having a light absorbing action without containing a coloring material.

(7) In each embodiment, the image source LS may project, for example, image light having a polarization component of a P wave.
The position and angle of the image source LS are set so that the image light is projected onto each screen portion at an incident angle φ. This incident angle φ is (φb-10) ° or more and 85 when the incident angle (Brewster angle) at which the reflectance of the image light (P wave) projected on each screen portion becomes zero is φb (°). ° Set to the range below. For example, when the incident angle φb at which the reflectance of the video light projected on each screen portion becomes zero is 60 °, the incident angle φ of the video light is set in the range of 50 to 85 °.

In this way, by using the image source that projects the image light having the polarization component of the P wave, the specular reflection on the surface of the screens 10, 20, and 30 is suppressed even when the incident angle φ to each screen portion is large. It is possible to increase the degree of freedom in designing the projection system, such as the installation position of the image source. Further, by using such an image source, it is possible to reduce the reflection of the image light on the incident surface when incident on each screen portion or the transparent layer, and it is possible to improve the brightness and sharpness of the image.
The angle φb (Brewster's angle) differs depending on the surface of each screen portion on which the image light is projected or the material of the transparent layer.
Further, in such a form, for example, a sheet-shaped member made of TAC is suitable as the base material layer constituting the light receiving side surface of the screen.

Although the present embodiment and the modified form can be used in combination as appropriate, detailed description thereof will be omitted. Further, the present invention is not limited to each of the embodiments described above.

1 Video display device 10, 20, 30 Screen 11 Base material layer 12, 22, 32 First optical shape layer 121,221,321 Unit optical shape 121a, 221a, 321a First surface 121b, 221b, 321b Second surface 13,23,33 Reflective layer 14,24,34 Second optical shape layer 15 Protective layer LS image source

Claims (4)

A transmissive screen that transmits and displays at least part of the image light.
The incoming surface on which the image light is incident and the
The light emitting surface facing the incoming surface and emitting the image light,
In the thickness direction of the transmissive screen, the Fresnel lens shape is formed by arranging a plurality of unit lenses located between the incoming surface and the outgoing surface and having a lens surface and a non-lens surface facing the lens surface. The optical shape layer on the surface side surface and
It is formed on at least a part of the non-lens surface, extends in a band shape along the extending direction of the unit lens, reflects at least a part of the image light incident from the incoming surface, and directs it toward the emitted surface. Reflective layer and
Equipped with
The reflective layer, both sides of that is, Ri curved der with periodic roughness in the two directions intersecting,
The two directions are
The extending direction of the reflective layer and
In a cross section parallel to the thickness direction of the transmissive screen and the arrangement direction of the unit lens, the linear direction is a linear direction passing through the apex of the unit lens and the most incoming point of the non-lens surface passing through the apex. In the width direction of the reflective layer,
And
In a cross section parallel to the thickness direction of the transmissive screen and the arrangement direction of the unit lens, tangents at arbitrary points on the curved surface on both sides of the reflective layer form the normal direction of the screen surface of the transmissive screen. The angle must be 0 ° or more and 30 ° or less.
A transmissive screen featuring. In the transmissive screen according to claim 1,
The unevenness means that the period of the reflective layer in the extending direction is larger than the period of the reflective layer in the width direction.
A transmissive screen featuring. In the transmissive screen according to claim 1 or 2.
Provided with a light absorption layer that absorbs a part of the incident light,
A transmissive screen featuring. The transmissive screen according to any one of claims 1 to 3, and the transmissive screen.
An image source that projects image light onto the transmissive screen from the back side of the transmissive screen,
A video display device equipped with.

Images