JP7395862B2 - Reflective screen, video display device - Google Patents

Description

The present invention relates to a reflective screen and an image display device equipped with the same.

Conventionally, various types of reflective screens have been developed that reflect and display image light projected from an image source (for example, see Patent Document 1). In particular, it can be used as a reflective screen to project image light and make images clearly visible by pasting it on highly translucent materials such as window glass, and when not in use when not projecting image light. Demand for semi-transparent reflective screens, which allow the scenery on the other side of the screen to be seen through, is increasing due to their high design quality.

Japanese Patent Application Publication No. 9-114003

Some of such transflective screens have a Fresnel lens shape or the like to deflect (focus) image light at a predetermined position so as to make it easier to see. However, in order to enhance the deflection effect of the image light, it is necessary to precisely set the relative position of the reflective screen and the image source, which sometimes makes it difficult to install the reflective screen and the image source. .

An object of the present invention is to provide a reflective screen and an image display device that have a high degree of freedom in the relative position of the reflective screen and the image source and can display good images.

The present invention solves the above problems by the following solving means. Note that, 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 reflective screen (10) that displays an image by reflecting a part of image light projected from an image source (LS), which has light transparency and has a unit optical shape (121). is formed on at least a part of the unit optical shape (121), and reflects a part of the incident light and reflects at least a part of the other part of the incident light. a reflective layer (13) that transmits the unit optical shapes (121); It is.

The second invention provides that in the reflective screen (10) according to the first invention, when the angular luminance distribution is measured in a situation where image light is projected under the condition that the maximum luminance is at the center of the screen and the front side. , a reflective screen (10) characterized in that a half-value angle in the arrangement direction of the unit optical shapes (121) is 5% or more larger than a half-value angle in a direction perpendicular to the arrangement direction.

A third invention is the reflective screen (10) according to the first invention or the second invention, in which the optically shaped layer (12) has a first surface (121a) on which image light is incident, and a first surface (121a) on which image light is incident; a second surface (121b) opposite to the first surface (121a); and a connecting surface (121c) configured with a curved surface connecting the first surface (121a) and the second surface (121b). A reflective screen (10) characterized in that it has the following.

A fourth invention is the reflective screen (10) according to the first invention or the second invention, in which the unit optical shape (121) is on a side opposite to the image source side in a cross-sectional shape cut in the arrangement direction. The optically shaped layer (12) has an apex portion (T) that is most protruding toward the image source, and a valley bottom portion (V) that is most recessed toward the image source, and the optically shaped layer (12) a first surface (121a) with a wider width as a border, and a second surface (121b) on a side opposite to the first surface (121a), and at least the first surface (121a) is a reflective screen (10) characterized by having a curved cross-sectional shape when cut in the arrangement direction.

A fifth invention is the reflective screen (10) according to any one of the first to fourth inventions, wherein the reflective layer has a rough surface at least on the image source side, and a portion of the incident light is A reflective screen (10) characterized in that it diffusely reflects light.

A sixth invention is the reflective screen (10) according to the fifth invention, wherein the unit optical shape (121) has a fine uneven shape on its surface, and the uneven shape is the unit optical shape (121). 121) is a shape in which the light diffusion effect in the arrangement direction of the unit optical shapes (121) is higher than the light diffusion effect in the direction perpendicular to the arrangement direction of the unit optical shapes (121), at least on the unit optical shape (121) side of the reflective layer. A reflective screen (10) characterized in that the surface has an uneven shape corresponding to the uneven shape.

A seventh invention is the reflective screen (10) according to the fifth invention, wherein the unit optical shape (121) has a fine and irregular uneven shape on its surface, and at least the unit of the reflective layer A reflective screen (10) characterized in that a surface on the optical shape (121) side has an uneven shape corresponding to the uneven shape.

An eighth invention is the reflective screen (10) according to any one of the first to seventh inventions, in which the reflective screen (10) is arranged in a direction in which the unit optical shapes (121) are arranged. When the angle change from the output angle at which the reflected light reaches its peak brightness to the output angle at which the brightness becomes 1/2 is +α _V 1, -α _V 2, and the average value of the absolute values is α _V , then 5° A reflective screen (10) characterized in that ≦α _V ≦45°.

A ninth invention is the reflective screen (10) according to any one of the first to eighth inventions, in which the reflective screen (10) is arranged in a direction in which the unit optical shapes (121) are arranged. The amount of angular change from the output angle at which the reflected light has the peak brightness to the output angle at which the brightness is 1/2 is defined as +α _V 1, -α _V 2, the average value of the absolute values is α _V , and the first When the angle between the surface and the plane parallel to the screen surface is θ1, the relationship α _V < arcsin(n×sin(2×(θ1))) is established in at least a part of the reflective screen (10). A reflective screen (10) characterized by:

A tenth invention provides a reflective screen (10) according to any one of the first to ninth inventions, in which the reflective screen (10) has a layer on the back side of the reflective layer (13) in the thickness direction of the reflective screen (10). This is a reflective screen (10) characterized by comprising a light absorption layer (60) provided on the reflective screen (10).

An eleventh invention provides the reflective screen (10) according to any one of the twenty-first inventions from the first invention to the tenth invention, wherein the reflective screen (10) has a back surface that is lower than the reflective layer (13) in the thickness direction of the reflective screen (10). A reflective screen (10) characterized by comprising a light control layer (20, 40, 210) provided on the side and changing the transmittance.

A twelfth invention is the reflective screen (10) according to the eleventh invention, in which the light control layer (20) is arranged to face a transparent first electrode (22A) and the first electrode (22A). a transparent second electrode (22B) arranged between the first electrode (22A) and the second electrode (22B); This is a reflective screen (10) characterized by having a light control material (26, 27) that changes transmittance depending on the potential difference between the two.

A thirteenth invention is the reflective screen (10) according to the twelfth invention, characterized in that the light control material (26, 27) is a liquid crystal having a dichroic dye. ).

A fourteenth invention is the reflective screen (10) according to the eleventh invention, characterized in that the light control layer (40) contains a photosensitive material.

A fifteenth invention is the reflective screen (10) according to the fourteenth invention, wherein the photosensitive material changes its transmittance by receiving ultraviolet light as excitation light, and guides the excitation light to the photosensitive material. A reflective screen (10) characterized by comprising a light guiding layer (214).

A 16th invention is the reflective screen (10) according to the 15th invention, in which the light control layer (210) is arranged at a position sandwiching the photosensitive material and the light guide layer (214) from both sides, and the excitation A reflective screen (10) characterized by comprising a shielding layer (212, 213) that shields at least a portion of light.

A seventeenth invention is the reflective screen (10) according to any one of the first to sixteenth inventions, wherein the reflective layer (13) is such that the image light of the unit optical shape (121) is incident on the reflective screen (10). This is a reflective screen (10) characterized in that a plurality of islands are formed at positions where the reflective screen (10)

An eighteenth invention is the reflective screen (10) according to any one of the first to seventeenth inventions, characterized in that the reflective layer (13) includes at least one dielectric film. This is a reflective screen (10).

A nineteenth invention is the reflective screen (10) according to any one of the first to eighteenth inventions, wherein the optical shape layer (12) includes a plurality of unit optical shapes (121) arranged concentrically. A reflective screen (10) characterized by having an arranged circular Fresnel lens shape.

A 20th invention is the reflective screen (10) according to the 19th invention, characterized in that the center of the circular Fresnel lens shape is provided outside the reflective screen (10). (10).

A twenty-first invention provides a reflective screen (10) according to any one of the first invention to the twentieth invention, wherein the reflective screen (10) has a rear surface that is lower than the reflective layer (13) in the thickness direction of the reflective screen (10). A reflective screen (10) characterized by comprising a second optical shape layer (14) having a light transmittance on the side and laminated so as to fill the valleys between the unit optical shapes (121). ).

A twenty-second invention is a reflective screen (10) according to any one of the first invention to the twenty-first invention, wherein the reflective screen (10) does not include a light diffusion layer containing diffusion particles having a function of diffusing light; A reflective screen (10) characterized by:

A twenty-third invention is the reflective screen (10) according to any one of the first invention to the twenty-second invention, wherein the reflective layer (13) has a predetermined thickness in the thickness direction of the reflective screen (10). This is a reflective screen (100) characterized in that a plurality of layers are provided with an interval of .

A twenty-fourth invention provides a reflective screen (10, 100) according to any one of the first to twenty-third inventions, and an image source (10, 100) that projects image light onto the reflective screen (10, 100). LS).

According to the present invention, it is possible to provide a reflective screen and an image display device that have a high degree of freedom in the relative position of the reflective screen and the image source and can display good images.

FIG. 1 is a perspective view showing a video display device 1 according to a first embodiment. 1 is a side view of the video display device 1. FIG. FIG. 3 is a diagram showing an example of the layered structure of the screen 10 according to the first embodiment. It is a figure explaining the 1st optical shape layer 12 of an embodiment. FIG. 4 is an enlarged view of a region A surrounded by a one-dot chain line circle in FIG. 3. FIG. FIG. 7 is a diagram illustrating the relationship between the 1/2 angle _αV , the incident angle φ of the image light, and the angle θ1 of the first slope 121a. FIG. 3 is a diagram showing the state of image light and external light on the screen 10 of the present embodiment. FIG. 4 is a diagram illustrating a modification of the first embodiment in a cross section similar to FIG. 3; It is a figure showing an example of layer composition of screen 10 of a 2nd embodiment. 10 is a diagram showing another example of the layer structure of the screen 10 of the second embodiment in the same manner as FIG. 9. FIG. FIG. 2 is a diagram collectively showing the transmittances of Example 1 and Example 2. It is a figure showing an example of layer composition of screen 10 of a 3rd embodiment. FIG. 7 is a diagram illustrating the area around the driver's seat of a car VC, as seen from inside the car, in an example in which the video display device 1 of the second embodiment is arranged in the front window of the car. 14 is a sectional view taken along line bb of the front window 2 in FIG. 13. FIG. It is a figure showing an example of layer composition of screen 10 of a 4th embodiment. It is a figure showing an example of layer composition of screen 10 of a 5th embodiment. It is a figure which shows the reflective layer 13 of 5th Embodiment. It is a figure which shows another form of the reflective layer 13 of 5th Embodiment. It is a figure which shows an example of the manufacturing method of the reflective layer 13 of 5th Embodiment. It is a figure explaining the layer structure of screen 100 of a 6th embodiment. It is a figure explaining another form of screen 100 of a 6th embodiment. It is a figure explaining the other form 2 of the screen 100 of 6th Embodiment, and is a figure which looked at the screen 100 from the upper side of a screen vertical direction. It is a figure explaining the other form 2 of the screen 100 of 6th Embodiment, and is a figure which looked at the screen 100 from the right side of the screen horizontal direction. It is a perspective view showing video display device 1 of a 7th embodiment. FIG. 7 is a top view of a video display device 1 according to a seventh embodiment. It is a figure which shows an example of the layered structure of the screen 10 of 8th Embodiment. 7 is a diagram illustrating an example of a modification of the unit optical shape 121. FIG.

Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings and the like. Note that each figure shown below, including FIG. 1, is a schematic diagram, and the size and shape of each part are appropriately exaggerated or simplified to facilitate understanding.
In this specification, numerical values such as dimensions and material names of each member described are examples of embodiments, and are not limited to these, and may be appropriately selected and used.
In this specification, terms that specify shapes or geometrical conditions, such as terms such as parallel and orthogonal, do not have a strict meaning, but also have a similar optical function and are used to the extent that they can be considered parallel or orthogonal. This also includes states with errors.
In this specification, terms such as plate, sheet, and film are used, but these terms are generally used in the order of thickness, such as plate, sheet, and film. This is also used in the specification. However, since there is no technical meaning in these different uses, these words can be replaced as appropriate.
In this specification, the sheet surface refers to the surface of each sheet that is in the planar direction of the sheet when the sheet is viewed as a whole. Note that the same applies to the plate surface and the film surface.

(First embodiment)
FIG. 1 is a perspective view showing a video display device 1 according to the first embodiment.
FIG. 2 is a side view of the video display device 1.
The video display device 1 includes a screen 10, a video source LS, and the like. The screen 10 of this embodiment is a reflective screen that reflects the image light L projected from the image source LS and displays an image on the screen. Details of this screen 10 will be described later.
In this embodiment, an example will be described in which the video display device 1 is applied to an indoor partition made of a transparent plate, and the screen 10 is fixed to the transparent plate. Note that as such a transparent plate, a highly transparent plate-shaped member made of glass, resin, or the like is used.

Here, in order to facilitate understanding, an XYZ orthogonal coordinate system is appropriately provided in each of the figures shown below, including FIGS. 1 and 2. In this coordinate system, the horizontal direction (horizontal direction) of the screen 10 is the X direction, the 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.
Furthermore, when viewed from the observer O1 located in the front direction on the image source side of the screen 10, the direction toward the right side in the horizontal direction is the +X direction, the direction toward the upper side in the vertical direction is the +Y direction, and the back side (back side) in the thickness direction. ) toward the video source side is defined as +Z direction.
Furthermore, in the following description, unless otherwise specified, the screen vertical direction, screen horizontal direction, and thickness direction refer to the screen vertical direction (vertical direction), screen horizontal direction (horizontal direction), and The thickness direction (depth direction) is assumed to be 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 projector.
This video source LS is located at the center of the screen 10 in the horizontal direction when the screen (display area) of the screen 10 is viewed from the front direction (normal direction of the screen surface) when the video display device 1 is in use. It is located vertically lower than the screen of the screen 10.
The image source LS can project the image light L diagonally from a position that is much closer to the surface of the screen 10 in the depth direction (Z direction) than a conventional general-purpose projector that is located in the front direction of the screen. . Therefore, compared to conventional general-purpose projectors, the image source LS has a shorter projection distance to the screen 10, a larger angle of incidence at which the projected image light L enters the screen 10, and a larger amount of change in the angle of incidence (the amount of change in the angle of incidence). The amount of change from the minimum value to the maximum value) is also large.

The screen 10 can display an image to the observer O1 by reflecting the image light L projected by the image source LS toward the observer O1 located in the front direction on the image source side (+Z side). It is a transflective screen with transparency that allows you to observe the scenery on the other side.
The screen (display area) of the screen 10 has a substantially rectangular shape in which the long side direction is the left-right direction of the screen when viewed from the observer O1 side. Further, the screen size of the screen 10 is approximately 40 to 100 inches diagonally, and the aspect ratio of the screen is 16:9.
Note that the screen 10 is not limited to this, and the screen 10 may have a different shape when viewed from the observer O1 side, or may have a screen size of 40 inches or less, depending on the purpose of use, usage environment, etc. The size and shape can be selected as appropriate.

If the screen 10 is a laminate of thin resin layers, it alone does not have sufficient rigidity to maintain flatness. Therefore, as shown in FIGS. 1 and 2, the screen 10 of this embodiment is integrally bonded (or partially fixed) to the support plate 50 via a light-transmissive bonding layer 51 on the back side thereof. Maintains the flatness of the screen.
The support plate 50 is a flat member having light transmittance and high rigidity, and may be a plate-like member made of resin such as acrylic resin or PC (polycarbonate) resin, glass, or the like. The support plate 50 of this embodiment is a transparent glass plate for an indoor partition.
Note that the present invention is not limited to this, and the screen 10 may be supported on its four sides by a frame member (not shown) or the like to maintain its flatness. Of course, it is also possible to use a highly rigid transparent sheet as the base material.

FIG. 3 is a diagram showing an example of the layered structure of the screen 10 of the first embodiment. In FIG. 3, the line passes through point A (see FIGS. 1 and 2), which is the screen center of the screen 10 (the geometric center of the screen), is parallel to the screen vertical direction (Y direction), and is perpendicular to the screen surface ( It is shown as a cross section (parallel to the Z direction). In addition, in FIG. 3, only the screen 10 is shown, and the support plate 50 and the like are omitted.
FIG. 4 is a diagram illustrating the first optically shaped layer 12 of the embodiment. FIG. 4 is a diagram of the first optically shaped layer 12 viewed from the back side (-Z side), and the reflective layer 13 and the like are omitted for ease of understanding.
As shown in FIG. 3, the screen 10 has a base material layer 11, a first optically shaped layer 12, a reflective layer 13, and a second optically shaped layer in order from the image source side (+Z side) in the thickness direction (Z direction). It includes a layer 14, a protective layer 15, and the like.

The base layer 11 is a sheet-like member having light transmittance, and a first optically shaped layer 12 is integrally formed on the back side (-Z side) thereof. This base material layer 11 is a layer that serves as a base material for forming the first optically shaped layer 12 .
The base material layer 11 is made of, for example, polyester resin such as PET (polyethylene terephthalate), which has high light transmittance, acrylic resin, styrene resin, acrylic/styrene resin, PC (polycarbonate) resin, alicyclic polyolefin resin, TAC (triolefin resin), etc. Acetyl cellulose) resin, etc.
The thickness of the base layer 11 may be set as appropriate depending on the screen size of the screen 10 and the like.

The first optically shaped layer 12 is a layer formed on the back side (−Z side) of the base material layer 11 and has a light transmittance. A plurality of unit optical shapes 121 are arranged and provided on the back side (-Z side) surface of the first optical shape layer 12.
As shown in FIG. 4, the unit optical shapes 121 have a partial shape (arc shape) of a perfect circle, and are arranged in plural concentrically around a point C located outside the screen (display area) of the screen 10. ing. That is, the first optically shaped layer 12 has a circular Fresnel lens shape with a so-called offset structure centered on point C (Fresnel center) on its back side.
In this embodiment, as shown in FIG. 4, when the first optically shaped layer 12 is viewed from the back side in the normal direction to the screen surface, the point C is located at the center in the left-right direction of the screen and below the outside of the screen. Point C and point A are located on the same straight line parallel to the Y direction.

FIG. 5 is an enlarged view of the region A surrounded by the one-dot chain line circle in FIG.
As shown in FIGS. 3 and 5, the unit optical shapes 121 have rounded apexes in a cross section parallel to the direction perpendicular to the screen surface (Z direction) and parallel to the arrangement direction of the unit optical shapes 121. It has a substantially triangular cross-sectional shape.
The unit optical shape 121 is convex on the back side (-Z side), and has a first slope (first surface) 121a on which the image light is incident, and a second slope (second surface) 121b opposite thereto. , and a connecting surface 121c formed of a curved surface connecting the first slope 121a and the second slope 121b. In one unit optical shape 121, the first slope 121a is located above the second slope 121b (+Y side) across the connection surface 121c formed at the apex a.

The angle that the first slope 121a makes with a plane parallel to the screen surface is θ1. The angle that the second slope 121b makes with a plane parallel to the screen surface is θ2. The angles θ1 and θ2 satisfy the relationship θ2>θ1.
The first slope 121a, the second slope 121b, and the connecting surface 121c of this unit optical shape 121 have minute and irregular uneven shapes formed therein. This fine uneven shape is formed by irregularly arranging convex shapes and concave shapes in a two-dimensional direction, and the convex shapes and concave shapes are irregular in size, shape, height, etc.

In this embodiment, the connection surface 121c is configured as a substantially cylindrical surface whose cross-sectional shape is substantially arc-shaped (when viewed macroscopically) except for the fine unevenness shown in FIG. By providing this connecting surface 121c, a portion of the image light is reflected not only by the first slope 121a but also by this connecting surface 121c, where the reflective layer 13, which will be described later, reflects the image light. The connecting surface 121c is configured by a curved surface that smoothly connects from the first slope 121a to the second slope 121b. Therefore, the reflective layer 13 formed on the connection surface 121c can expand the effective optical path of the image light in the vertical direction compared to the optical path when only the first slope 121a reflects the image light. Therefore, the light diffusion effect in the arrangement direction of the unit optical shapes 121 is larger than the light diffusion effect in the direction orthogonal to the arrangement direction.
In addition, in FIG. 5, the connection surface 12α1c is shown as an accurate circular arc to clearly show the connection surface 121c, but like the first slope 121a and the second slope 121b, there are fine irregularities on the connection surface 121c. A shape is provided. Note that although the fine unevenness shape and the reflective layer are also provided on the connection surface 121c, a configuration may be adopted in which they are not provided on the connection surface 121c.

The arrangement pitch of the unit optical shapes 121 is P, and the height of the unit optical shapes 121 (the dimension from the apex a in the thickness direction to the point b, which is the bottom of the valley between the unit optical shapes 121) is h.
To facilitate understanding, FIG. 2 shows an example in which the arrangement pitch P1 and angles θ1 and θ2 of the unit optical shapes 121 are constant in the arrangement direction of the unit optical shapes 121. However, in the unit optical shapes 121 of this embodiment, although the arrangement pitch P is actually constant, the angle θ1 gradually increases as it moves away from the point C, which is the Fresnel center, in the arrangement direction of the unit optical shapes 121. .
In addition, the angles θ1, θ2, the array pitch P, etc. are determined by the projection angle of the image light from the image source LS (the incident angle of the image light onto the screen 10), the size of the pixels of the image source LS, and the screen 10. It may be set as appropriate depending on the screen size, refractive index of each layer, etc. For example, the arrangement pitch P, angle θ1, etc. may vary along the arrangement direction of the unit optical shapes 121.

In this embodiment, an example is shown in which a circular Fresnel lens shape is formed on the back side surface of the first optically shaped layer 12. However, the invention is not limited to this, and on the back side surface of the first optical shape layer 12, unit optical shapes 121 are linear Fresnel lenses arranged in the screen vertical direction (Y direction) with the longitudinal direction of the unit optical shapes 121 being in the screen left and right direction (X direction). It may also be a form in which a shape is formed. Alternatively, a plurality of columnar unit prisms may be arranged in the vertical direction (Y direction) of the screen, with the longitudinal direction being the horizontal direction (X direction) of the screen.

The first optical shape layer 12 is made of an ultraviolet curable resin such as urethane acrylate, polyester acrylate, epoxy acrylate, polyether acrylate, polythiol, or butadiene acrylate, which has high light transmittance.
In this embodiment, the resin constituting the first optically shaped layer 12 will be described using an ultraviolet curable resin as an example; however, the present invention is not limited to this, and other ionizing radiation curable resins such as electron beam curable resins may be used. It may also be formed from a curable resin.

The reflective layer 13 is formed on the unit optical shape 121 (above the first slope 121a, the second slope 121b, and the connection surface 121c). The reflective layer 13 is a semi-transmissive reflective layer that reflects part of the incident light and transmits the rest, ie, a so-called half mirror.
As described above, fine irregularities are formed on the first slope 121a, the second slope 121b, and the connecting surface 121c (the surface of the unit optical shape 121), and the reflective layer 13 The film is formed to follow the uneven shape, and is also formed on the surface opposite to the unit optical shape 121 side with the fine and irregular uneven shape maintained. Therefore, the surface of the reflective layer 13 on the image source side (the surface on the first optically shaped layer 12 side) and the surface on the back side (the surface on the second optically shaped layer 14 side) have fine and irregular uneven shapes. It has a matte surface (rough surface).
This reflective layer 13 has the function of diffusing and reflecting a part of the incident light due to the fine unevenness of the reflective surface, and transmitting other light that is not reflected without being diffused.

In this embodiment, three types of reflective layers 13 were fabricated: a structure using a metal, a structure using a dielectric multilayer film, and a structure using a single layer dielectric film. Further, the reflective layer 13 can be formed by appropriately combining a metal film or a dielectric film as a single layer or a multilayer.
When using a metal, the reflective layer 13 is formed of a highly light-reflecting metal such as aluminum, silver, nickel, etc., and its thickness is approximately several tens of angstroms. The reflective layer 13 is not limited to this, and may be formed, for example, by sputtering a highly light-reflective metal as described above.
The reflectance and transmittance of the reflective layer 13 made of metal can be appropriately set according to the desired optical performance. From the viewpoint of good transmission of light (from the outside world), the transmittance can be set in a range of about 30 to 80%, and the reflectance can be set in a range of about 5 to 60%, for example. Note that the numerical values regarding the transmittance of each layer shown below, including the above transmittance, do not take into account reflection at the air interface. Further, although the reflection on the surface (air interface) of the screen 10 is largely influenced by the surface treatment, it is good to consider, for example, about 10%.
The reflective layer 13 made of metal in this embodiment is formed by vapor-depositing aluminum, and the reflective layer 13 alone has a transmittance of about 70%, a reflectance of about 5%, and an absorption rate of about 70%. It has a 25% half mirror shape.

Furthermore, when a dielectric multilayer film is used as the reflective layer 13, it is possible to achieve higher transparency and reflectance than a metal vapor deposited film or the like. A dielectric multilayer film is a structure in which dielectric films with a high refractive index (hereinafter referred to as high refractive index dielectric films) and dielectric films with a low refractive index (hereinafter referred to as low refractive index dielectric films) are alternately laminated. It is formed by
The high refractive index dielectric film is formed of, for example, TiO ₂ (titanium dioxide), Nb ₂ O ₅ (niobium pentoxide), Ta ₂ O ₅ (tantalum pentoxide), or the like. The refractive index of the high refractive index dielectric film is approximately 2.0 to 2.6.
The low refractive index dielectric film is formed of, for example, SiO ₂ (silicon dioxide), MgF ₂ (magnesium fluoride), or the like. The refractive index of the low refractive index dielectric film is approximately 1.3 to 1.5.
The film thickness of the high refractive index dielectric film and the low refractive index dielectric film is about 5 to 100 nm, and these are formed by stacking about 2 to 10 layers alternately, and the total thickness of the dielectric multilayer film is , about 10 to 1000 nm.
The reflective layer 13 constructed using this dielectric multilayer film has a transmittance of about 90% and a reflectance of about 10% for light in the wavelength range of 400 to 800 nm.

The reflective layer 13 formed of a dielectric multilayer film has higher transparency than a reflective layer formed of a metal vapor deposited film such as aluminum, and also has low light absorption loss and high reflection. rate can be achieved.
This reflective layer 13 is formed by depositing or sputtering a dielectric multilayer film as described above on the unit optical shape 121 (on the first slope 121a, second slope 121b, and connection surface 121c). It is formed with a predetermined thickness.
The reflective layer 13 of this embodiment configured using a dielectric multilayer film in this embodiment is a high refractive index dielectric film formed of TiO ₂ (titanium dioxide) and a low refractive index dielectric film formed of SiO ₂ . It is formed by alternately laminating five layers of body films (three layers of high refractive index dielectric films and two layers of low refractive index dielectric films), and has a transmittance of approximately 90% and a reflectance of approximately 10. It has a half mirror shape.

In addition, when the reflective layer 13 uses a single-layer dielectric film, for example, ZnS (zinc sulfide), TiO ₂ (titanium dioxide), Nb ₂ O ₅ (niobium pentoxide), Ta ₂ O ₅ (tantalum pentoxide) is used. ), SiO ₂ (silicon dioxide), MgF ₂ (magnesium fluoride), etc. The thickness of the dielectric film is about 20 to 100 nm.
This reflective layer 13 has a reflectance of approximately 5 to 20% and a transmittance of approximately 80 to 95% for light in the visible wavelength range. Note that when looking at the screen 10 as a whole, there is also a reflected component (about 10%) on the surface of the screen 10, so the transmittance of the screen 10 as a whole is about 70 to 85%.
The reflective layer 13 using a single-layer dielectric film has higher transparency than a reflective layer formed of a metal vapor deposited film such as aluminum, and also has low light absorption loss and high reflection. high efficiency in light use. The reflective layer 13 of this embodiment is formed of a dielectric film of ZnS (zinc sulfide).
Note that no matter which material is used, the thickness of the reflective layer 13 may be appropriately set depending on the material, desired optical performance, etc.

The second optically shaped layer 14 is a layer that is provided on the back side (-Z side) of the first optically shaped layer 12 and has a light transmittance.
The second optical shape layer 14 is filled so as to fill the valleys between the unit optical shapes 121, and flattens the back side (-Z side) surface of the first optical shape layer 12. The image source side (+Z side) surface of the second optically shaped layer 14 is formed by arranging a plurality of substantially inverse shapes of the unit optical shapes 121 of the first optically shaped layer 12. A material having the same refractive index as layer 12 is used.
By providing such a second optically shaped layer 14, the transparency of the screen 10 can be ensured and the reflective layer 13 can be protected. Moreover, by providing such a second optically shaped layer 14, it becomes easier to laminate the protective layer 15 and the like on the back side of the screen 10.

The refractive index of the second optically shaped layer 14 is preferably approximately equal to that of the first optically shaped layer 12 (a state in which the difference in refractive index is small enough to be regarded as equivalent), and it is desirable that the refractive index be the same. Further, the second optically shaped layer 14 may be formed using the same resin as the first optically shaped layer 12 described above, or may be formed using a different resin.
The second optically shaped layer 14 of this embodiment is made of the same ultraviolet curable resin as the first optically shaped layer 12.

The protective layer 15 is a light-transmissive layer formed on the back side (-Z side) of the second optically shaped layer 14, and has a function of protecting the back side (-Z side) of the screen 10. ing.
As the protective layer 15, a sheet-like member made of resin with high light transmittance is used. The protective layer 15 may be, for example, a sheet-like member formed using the same material as the base layer 11 described above. Note that the protective layer 15 may be omitted.

In the screen 10 of this embodiment, the reflective layer 13 is formed on the first slope 121a and the second slope 121b having a fine uneven shape, and the surface on the first optically shaped layer 12 side, which is the reflective surface, is a matte surface (rough surface). ). Therefore, a portion of the light incident on the first slope 121a is diffusely reflected.
Here, in the arrangement direction of the unit optical shapes 121, the unit optical In the arrangement direction of the shapes 121 (in this embodiment, the vertical direction of the screen), the angles at which the luminance becomes 1/2 are defined as K1 and K2, and the angles from the angle K of the peak luminance to the angles K1 and K2 at which the luminance becomes 1/2 are defined as K1 and K2. When the amount of angular change is +α _V 1 (however, K+α _V 1=K1), -α _V 2 (K-α _V 2=K2), the amount of angular change from peak brightness to 1/2 of brightness is When the average value of the absolute values is α _V (hereinafter referred to as 1/2 angle α _V ), this 1/2 angle α _V is 5° or more and 45° or less (5°≦α _V ≦45°) It is preferable that
If α _V <5°, the viewing angle becomes too narrow and the image becomes difficult to see, which is not preferable. Further, when α _V <5°, the specular reflection component increases in the reflected light, causing reflection of the light source, etc., which is not preferable.
If α _V >45°, the viewing angle becomes wider, but the brightness of the image decreases, the image becomes more blurred, and the contrast of the image decreases due to reflection of external light on the surface of the screen 10. Therefore, it is not desirable. Therefore, the 1/2 angle α _V is preferably within the above range.

In addition, the first slope 121a is a region that is not a rough surface, that is, a region in which fine irregularities are not formed, and the reflective surface of the reflective layer 13 is mirror-like, and the incident image light is mirror-reflected. It is necessary for the area to be 5% or less per unit area of the reflective layer 13 formed on the first slope 121a in order to sufficiently diffuse the image light and obtain a good viewing angle; Ideally, there is.
If the mirror surface area that is not a rough surface exceeds 5% per unit area of the first slope 121a, bright lines may occur due to components of the image light that are not diffused and are reflected and reach the observer O side, and the viewing angle may decrease. This is not desirable because it can cause

FIG. 6 is a diagram illustrating the relationship between the 1/2 angle _αV , the incident angle φ of the image light, and the angle θ1 of the first slope 121a.
In FIG. 6, in order to facilitate understanding, the structure inside the screen 10 is simplified, and the base material layer 11 and the protective layer 15 are omitted. In FIG. 6, regarding the angles α _V and φ, the upper side of the screen is shown as + and the lower side of the screen is shown as - with respect to the normal to the screen surface.
The angle θ1 of the first slope 121a is set so that the image light is most efficiently reflected to the observer located in the front direction of the screen 10, that is, the angle K at which the reflected light reaches its peak brightness is 0°. The design is based on the refractive index of each layer. Further, the range from -α _V to +α _V is a range in which it is assumed that an observer located in front of the screen can observe the image well.
Here, at a certain point in the screen vertical direction (the arrangement direction of the unit optical shapes 121), the image light L enters from below the screen 10 at an incident angle φ, travels through the first optical shape layer 12 having a refractive index n, and passes through the screen. When the light enters the first slope 121a forming an angle θ1 with respect to the surface, is reflected by the reflective layer 13, and is emitted from the screen 10 in a direction perpendicular to the screen surface (output angle 0°), the angle θ1 is calculated by the following formula. It is represented by 1.
θ1=1/2×arcsin((sinφ)/n)...(Formula 1)

As in this embodiment, when displaying an image by projecting image light from the image source LS and reflecting it on the screen 10, the light source of the image source LS that projects the image light is reflected, reducing the contrast of the image. This problem may arise. The main cause of this reflection of the image source is that the image light reflected from the surface of the screen reaches the viewer.
In order to prevent such reflection of the image source, it is necessary to place the screen on the surface of the screen 10 outside the angular range (-α _V to +α _V ) in which the viewer mainly observes the image. It is preferable that the image light reflected from the surface of the image beam travels. When part Lr of the image light L incident at an incident angle φ is reflected on the screen surface, the reflection angle is φ. Therefore, in order to prevent reflection of the image source, it is preferable that α _V <φ.

Therefore, from the above-mentioned (Formula 1), in the screen vertical direction (the arrangement direction of the unit optical shapes 121), the 1/2 angle α _V prevents reflection of the image source with respect to the angle θ1 of the first slope 121a. In order to do so, it is preferable that the following formula 2 is satisfied at least in a part of the screen 10 (for example, the center of the screen).
α _V < arcsin (n×sin(2×(θ1))) (Formula 2)
Further, in order to prevent reflection of the image source, it is more preferable that the 1/2 angle α _V satisfies the above formula 2 over the entire area of the screen 10 with respect to the angle θ1 of the first slope 121a.
By setting the angle θ1 to satisfy the above formula 2 with respect to the 1/2 angle _αV , the direction in which the light reflected on the surface of the screen 10 when it is incident on the screen 10 mainly goes (+φ direction) is This is outside the range (-α _V to +α _V ) in which the image light reflected by the reflective layer 13 exits from the screen 10 and travels. Thereby, in the range from −α _V to +α _V , reflection of the image source LS can be reduced and a good image with high contrast can be displayed.
Further, if the average value of the absolute value of the amount of change in angle from the peak brightness to the brightness becomes 1/2 in the extending direction of the unit optical shape 121 is α _H (hereinafter referred to as 1/2 angle α _H ), , the screen 10 of this embodiment satisfies the relationship α _V > α _H.

The screen 10 is formed, for example, by the following manufacturing method.
A base material layer 11 is prepared, and a mold for shaping a unit optical shape 121 is laminated on one side with an ultraviolet curable resin filled, and the resin is cured by irradiation with ultraviolet rays, using a UV molding method. A first optically shaped layer 12 is formed. At this time, fine irregularities are formed on the surfaces of the mold for shaping the unit optical shape 121 that shape the first slope 121a, the second slope 121b, and the connection surface 121c. This fine uneven shape can be formed by combining plating, etching, blasting, etc. on the surfaces forming the first slope 121a, second slope 121b, and connection surface 121c of the mold.
After forming the first optically shaped layer 12 on one surface of the base material layer 11, the reflective layer 13 is formed on the first slope 121a, the second slope 121b, and the connection surface 121c by vapor deposition or the like.

After that, an ultraviolet curable resin is applied from above the reflective layer 13 so as to fill the valleys between the unit optical shapes 121 to form a planar shape, the protective layer 15 is laminated, and the ultraviolet curable resin is cured. , the second optical shape layer 14 and the protective layer 15 are integrally formed. Thereafter, the screen 10 is completed by cutting it into a predetermined size or the like.
The base material layer 11 and the protective layer 15 may be sheet-like or web-like. When the base material layer 11 and the protective layer 15 are in the form of a web, the screens 10 in a state before cutting can be manufactured continuously, improving the production efficiency of the screens 10 and reducing production costs. can.

Further, for example, as a method of forming rough surfaces on the first slope 121a, the second slope 121b, and the connection surface 121c, diffusion particles or the like may be applied on the first slope 121a, the second slope 121b, and the connection surface 121c. There are known methods such as forming the reflective layer 13 thereon, or performing blasting on the first slope 121a, the second slope 121b, and the connecting surface 121c after forming the first optically shaped layer 12. However, if the reflective surface of the reflective layer 13 is made rough using such a manufacturing method, the diffusion characteristics, quality, etc. of each screen 10 will vary greatly, and stable manufacturing cannot be performed. On the other hand, as described above, by shaping the fine unevenness of the first slope 121a, second slope 121b, and connection surface 121c of the unit optical shape 121 with a mold, a large number of first optical shape layers are formed. 12 and the screen 10 also have the advantage that there is little variation in quality and that they can be manufactured stably.

FIG. 7 is a diagram showing the state of image light and external light on the screen 10 of this embodiment. In FIG. 7, a part of a cross section parallel to the arrangement direction (Y direction) of the unit optical shapes 121 and the thickness direction (Z direction) of the screen is shown in an enlarged manner. Further, in FIG. 7, in order to facilitate understanding, it is assumed that there is no difference in refractive index at the interface of each layer in the screen 10, including the adhesive layer 30 and the light control layer 20.
Of the image light L1 projected from the image source LS located below the screen 10 and incident on the screen 10, a part of the image light L2 enters the first slope 121a and the connection surface 121c of the unit optical shape 121. , is diffusely reflected by the reflective layer 13 and emitted toward the observer O1 side.

Among the image lights incident on the first slope 121a and the connection surface 121c, the other image light L3 that is not reflected passes through the reflective layer 13 and exits from the back side (−Z side) of the screen 10. At this time, the image light L3 is emitted above the screen 10 and does not reach the observer O2 located in the front direction on the back side of the screen 10.
In addition, some of the image light L4 of the image light L1 projected from the image source LS is reflected on the image source side surface of the screen 10, but since it heads upwards of the screen 10, it obstructs the visual recognition of the image by the observer O1. It won't be.
In this embodiment, the image source LS is located below the screen 10, the image light L1 is projected from below the screen 10, and the angle θ2 (see FIG. 3) of the second slope 121b is the same as that of the screen 10. Since it is larger than the incident angle of the image light at each point in the vertical direction of the screen, the image light does not directly enter the second slope 121b, and the second slope 121b has almost no effect on the reflection of the image light.

Next, light from the outside world such as sunlight (hereinafter referred to as external light) other than the image light that enters the screen 10 from the back side (-Z side) or the image source side (+Z side) will be explained.
As shown in FIG. 7, out of the external lights G1 and G5 that enter the screen 10, some of the external lights G2 and G6 are reflected on the surface of the screen 10 and head toward the lower side of the screen. Further, some of the external lights G3 and G7 are reflected by the reflective layer 13, and for example, the external light G3 is totally reflected by the surface of the screen 10 on the image source side (+Z side) and heads downward into the screen 10. The external light G7 is emitted to the upper side outside the screen on the back side (-Z side). Further, other external lights G4 and G8 that are not reflected by the reflective layer 13 are transmitted through the reflective layer 13 and exit toward the rear side and the image source side, respectively. At this time, the external lights G2, G3, and G8 emitted to the image source side do not reach the observer O, so it is possible to suppress a decrease in the contrast of the image.

Further, a part of the external light incident on the screen 10 is totally reflected on the image source side and rear side surfaces of the screen 10, moves toward the lower side inside the screen, and is attenuated.
Further, other external lights G9 and G10 pass through the reflective layer 13 and are emitted toward the back side and the image source side, respectively. Since the screen 10 does not contain a diffusion material containing diffusion particles, the external lights G9 and G10 that pass through the screen 10 are not diffused. Therefore, when the scenery on the other side of the screen 10 is observed through the screen 10, the scenery on the other side of the screen 10 can be observed with high transparency without being blurred or blurred.

Here, 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 diffusing effect, and it is the fine irregularities of the reflective layer 13 that have a diffusing effect. It is the shape.

In a conventional transflective screen with a diffusion layer containing diffusion particles, the image light is diffused twice before and after reflection on the reflection layer, which provides a good viewing angle while reducing the resolution of the image. There is a problem that the amount decreases. In addition, since outside light is also diffused by the diffusion particles, the scenery on the other side of the screen appears blurred or blurred, reducing transparency.

However, in the screen 10 of this embodiment, since the surface of the reflective layer 13 on the image source side has fine irregularities, the image light is diffused only when reflected. Further, in the screen 10 of this embodiment, only the light reflected by the reflective layer 13 is diffused, and the transmitted light is not diffused. Therefore, the screen 10 of the present embodiment can display an image having a good viewing angle and resolution, and the scenery on the other side of the screen 10 is not blurred or blurred, making it easily visible to the observer O1. This allows for a high degree of transparency. Further, in the screen 10 of the present embodiment, even when the image light is projected onto the screen 10, the observer O1 can partially view the scenery on the other side (back side) of the screen 10. Furthermore, in the screen 10 of this embodiment, the observer O2 located on the back side can see the scenery on the image source side (+Z side) through the screen 10 with high transparency, regardless of whether or not image light is projected. It can be clearly seen.

Furthermore, when measuring the angular luminance distribution in a situation where image light is projected under the condition that the front side has the maximum luminance at the center of the screen, the half-power angle in the arrangement direction of the unit optical shapes 121 is perpendicular to the arrangement direction. The angle is preferably 5% or more larger than the half-value angle in the direction, and more preferably 20% to 100% larger. Thereby, the degree of freedom in the position where the video source LS is installed can be increased.

As explained above, in the screen 10 of the first embodiment, by providing the connection surface 121c, the light diffusion effect in the arrangement direction of the unit optical shapes 121 is greater than the light diffusion effect in the direction perpendicular to the arrangement direction. big. Therefore, the screen 10 of the first embodiment has a high degree of freedom in the relative position of the screen 10 and the image source LS, and can display good images.

In addition, the screen 10 has a second optically shaped layer 14 on the back side surface of the first optically shaped layer 12 and the reflective layer 13, which has light transmittance and fills in the irregularities between the plurality of arranged unit optical shapes 121. Therefore, the reflective layer 13 on the back side can be protected. In addition, since the back surface of the screen 10 can be made flat, for example, when the screen 10 is sandwiched between two glass plates that make up laminated glass, or when the screen 10 is attached to a glass plate, In addition, the screen 10 can be placed against the glass plate without any gaps.

Furthermore, the screen 10 of the first embodiment has a circular Fresnel lens shape in which a plurality of unit optical shapes 121 of the first optical shape layer 12 are arranged concentrically, and the optical center C1 is outside the display area of the reflective screen. It is located in As a result, even if the image light with a large incident angle is projected from the short-focus image source LS located outside the display area of the screen 10 and at the bottom of the screen in the vertical direction, the screen 10 can It is possible to display a good image with high surface uniformity of brightness without the image becoming dark.
Further, when the reflective layer 13 is formed of a dielectric film, the screen 10 suppresses the absorption of light incident on the reflective layer 13 as much as possible, and reflects a part of the incident light while reflecting the other light. can be transmitted to the back side of the screen 10, and the efficiency of use of incident light can be improved.

(Modified form of the first embodiment)
In the first embodiment described above, by providing the connecting surface 121c configured with a curved surface between the first slope 121a and the second slope 121b of the unit optical shape 121, light is diffused in the arrangement direction of the unit optical shape 121. An example is shown in which the effect is greater than the light diffusion effect in the direction perpendicular to the arrangement direction.
The present invention is not limited to this, and a modification will be described below as a configuration that more actively controls the light distribution characteristics of the image light and provides anisotropy to the light diffusion (deflection) effect.

FIG. 8 is a cross-sectional view similar to FIG. 3 showing a modification of the first embodiment. In addition, in FIG. 8, in order to make it easy to understand the shapes of the first surface 121d and the second surface 121e, the thickness of the reflective layer 13 is shown by a single line without being expressed. Further, for the same reason, the fine unevenness provided in the unit optical shape 121 is also omitted in FIG. 8 .

The modified unit optical shape 121 shown in FIG. 8 has an apex T that most protrudes on the side opposite to the image source and a valley bottom V that is most concave toward the image source in a cross-sectional shape cut in the arrangement direction. have. Further, the unit optical shape 121 has a first surface 121d on the wide side in the arrangement direction and a second surface 121e on the narrow side with the apex T and the valley bottom V as boundaries. The first surface 121d and the second surface 121e are opposed to each other. In the example shown in FIG. 8, both the first surface 121d and the second surface 121e have a curved cross-sectional shape when cut in the arrangement direction. Further, the curved surface of the optically shaped layer 12 is continuous at the valley bottom V and discontinuous at the apex T. That is, in the above-mentioned cross-sectional shape, the valley bottom portion V has a curved shape, and the apex portion T has an acute angle shape. With this configuration, the light distribution characteristics of the image light can be controlled more actively, and the light diffusion effect in the arrangement direction of the unit optical shapes 121 is made better than the light diffusion effect in the direction perpendicular to the arrangement direction. can also be made larger.

(Second embodiment)
FIG. 9 is a diagram showing an example of the layered structure of the screen 10 of the second embodiment.
The screen 10 of the second embodiment has an adhesive layer 30 and a light control layer 20 instead of the protective layer 15 of the first embodiment, and the configuration other than these is the screen of the first embodiment. It is the same as 10. Therefore, parts that perform the same functions as those in the first embodiment described above are given the same reference numerals, and redundant explanations will be omitted as appropriate.
In the screen 10 of the second embodiment, the light control layer 20 is provided via the adhesive layer 30, so that the transmittance of transmitted light can be selectively changed.

The light control layer 20 shown in FIG. 9 is a film that can control the amount of transmitted light by changing the applied voltage.
This light control layer 20 is bonded to the back side of the second optically shaped layer 14 via an adhesive layer 30, and can control the amount of transmitted light. In the screen 10 of the present embodiment, the reflective screen portions (11 to 14) and the light control layer 20 are not provided separately but are joined together, so that the number of air interfaces for incident light is reduced by one. This is an advantageous configuration for increasing transmittance.

The light control layer 20 is a guest-host type liquid crystal cell using a dichroic dye, and is a liquid crystal cell that changes the amount of transmitted light by an electric field applied to the liquid crystal. The light control layer 20 is configured by sandwiching a liquid crystal layer 26 between a second film-like liquid crystal laminate 20B and a first liquid crystal laminate 20A.
The second laminate for liquid crystal 20B is formed by laminating a transparent electrode 22B, an alignment layer 23B, and a bead spacer 24 on a base material 21B.
The first laminate for liquid crystal 20A is formed by laminating a transparent electrode 22A and an alignment layer 23A on a base material 21A.
The light control layer 20 is formed by driving the transparent electrodes 22B and 22A provided in the first laminate 20A for liquid crystal and the second laminate 20B for liquid crystal, so that the liquid crystal material made of the guest-host liquid crystal composition provided in the liquid crystal layer 26 is formed. The orientation of the light beam is changed, thereby changing the amount of transmitted light.

Various transparent resin films can be applied to the base materials 21B and 21A, but transparent resin films with low optical anisotropy and a transmittance of 80% or more in the visible wavelength range (380 to 800 nm) are used. It is desirable to apply
Examples of materials for the transparent resin film include acetyl cellulose resins such as triacetyl cellulose (TAC), polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene (PE), and polypropylene (PP). , polyolefin resins such as polystyrene, polymethylpentene, and EVA, vinyl resins such as polyvinyl chloride and polyvinylidene chloride, acrylic resins, polyurethane resins, polysulfone (PEF), polyethersulfone (PES), polycarbonate ( Examples include resins such as PC), polysulfone, polyether (PE), polyether ketone (PEK), (meth)acronitrile, cycloolefin polymer (COP), and cycloolefin copolymer.
In particular, resins such as polycarbonate (PC), cycloolefin polymer (COP), and polyethylene terephthalate (PET) are preferred.
Transparent resin films of various thicknesses can be applied to the base materials 21B and 21A.

The transparent electrode (first electrode) 22A and the transparent electrode (second electrode) 22B are composed of a transparent conductive film laminated on a transparent resin film.
As the transparent conductive film, various transparent electrode materials applicable to this type of transparent resin film can be used, and examples include oxide-based transparent metal thin films with a total light transmittance of 50% or more. . Examples include tin oxide, indium oxide, and zinc oxide.

Examples of tin oxide (SnO ₂ )-based materials include NESA (tin oxide SnO ₂ ), ATO (antimony tin oxide), and fluorine-doped tin oxide.
Examples of indium oxide (In ₂ O ₃ )-based materials include indium oxide, ITO (Indium Tin Oxide), and IZO (Indium Zinc Oxide).
Examples of zinc oxide (ZnO)-based materials include zinc oxide, AZO (aluminum-doped zinc oxide), and gallium-doped zinc oxide.
In this embodiment, a transparent conductive film is formed of ITO (Indium Tin Oxide).

In this embodiment, a spherical bead spacer 24 is used as the spacer. The bead spacer 24 is provided to define the thickness (cell gap) of a portion of the liquid crystal layer 26 excluding the outer peripheral portion. The bead spacer 24 can be made of an inorganic material such as silica, an organic material, or a core-shell structure combining these materials. Further, the shape of the bead spacer 24 may be a rod shape having a cylindrical shape, a prismatic shape, or the like, in addition to the above-mentioned spherical shape.
However, the spacer that defines the thickness of the liquid crystal layer 26 is not limited to the bead spacer 24. For example, it may be formed into a cylindrical shape or the like by coating a photoresist on the base material 21A side, exposing and developing it. good.
In addition, although the above-mentioned description showed the example provided in the 2nd laminated body for liquid crystals 20B, it is not limited to this, and the spacer is provided in the 1st laminated body for liquid crystals 20A, the 2nd laminated bodies for liquid crystals 20B. Alternatively, it may be provided only in the first laminate for liquid crystal 20A.

The alignment layers 23A and 23B are films for aligning liquid crystal molecules in a certain direction. For example, the alignment layers 23A and 23B may be fabricated as photo-alignment layers, may be fabricated by rubbing instead of photo-alignment layers, or may be fabricated by forming fine line-like uneven shapes. An alignment layer may also be created. Note that the method for producing the alignment layers 23A and 23B is not limited to the method described above, and a different method may be used as appropriate.
In this embodiment, a photodimerizable material is used. Examples of photodimerizable materials include polymers containing cinnamate, coumarin, benzylidene phthalimidine, benzylidene acetophenone, diphenylacetylene, stilbazole, uracil, quinolinone, maleimide, or cinnamylidene acetic acid derivatives. Among these, polymers containing one or both of cinnamate and coumarin are preferably used because of their good alignment control ability. Specific examples of such photodimerizable materials include compounds described in JP-A-9-118717, PCT Publication No. 10-506420, PCT Publication No. 2003-505561, and WO2010/150748. can be mentioned.
Further, in this embodiment, the light control layer 20 is shown as having the alignment layers 23A and 23B, but the present invention is not limited to this, and the light control layer 20 may have a form that does not include the alignment layers 23A and 23B.

A guest host liquid crystal composition using a dichroic dye composition can be widely applied to the liquid crystal layer (liquid crystal material as a light control material) 26. The guest-host liquid crystal composition may contain a chiral agent so that when the liquid crystal material is horizontally aligned, it is oriented in a spiral shape in the thickness direction of the liquid crystal layer 26. In addition, in the light control layer 20, a sealing material 25 is arranged so as to surround the liquid crystal layer 26. This sealing material 25 holds the first liquid crystal laminate 20A and the second liquid crystal laminate 20B together and prevents leakage of the liquid crystal material. The sealing material 25 can be made of, for example, thermosetting resin such as epoxy resin or acrylic resin, or ultraviolet curable resin.

In the light control layer 20, the alignment layers 23B and 23A are configured as vertical alignment layers in which an alignment regulating force related to pretilt is set in a certain direction so that the alignment of the guest-host liquid crystal composition during light shielding is the same when an electric field is applied. This is configured by normally clear. Note that the setting during light transmission may be set to normally dark when an electric field is applied.
Here, normally dark is a structure in which the transmittance is at its minimum when no voltage is applied to the liquid crystal, resulting in a black screen. Normally clear is a structure in which the transmittance is maximum and becomes transparent when no voltage is applied to the liquid crystal.

Although the light control layer 20 of this embodiment is a guest-host type liquid crystal cell, it may be configured as a liquid crystal cell that does not use a dichroic dye composition. In this case, by further providing a linear polarizing layer, it can function as a light control cell. This will be explained in more detail below.

FIG. 10 is a diagram showing another example of the layer structure of the screen 10 of the second embodiment in the same manner as FIG. 9.
The liquid crystal layer 27 of the screen 10 shown in FIG. 10 uses a liquid crystal that is not a guest-host liquid crystal composition using the dichroic dye composition used in the liquid crystal layer 26 of the screen 10 shown in FIG. Hereinafter, this type of light control layer 20 will be referred to as a "non-guest host type", and the type of light control layer 20 shown in FIG. 2 will be referred to as a "guest host type".

For the liquid crystal layer 27, nematic liquid crystal compounds, smectic liquid crystal compounds, and cholesteric liquid crystal compounds can be used as liquid crystal compounds that do not have polymerizable functional groups.
Examples of nematic liquid crystal compounds include biphenyl compounds, terphenyl compounds, phenylcyclohexyl compounds, biphenylcyclohexyl compounds, phenylbicyclohexyl compounds, trifluoro compounds, phenyl benzoates, and phenyl cyclohexylbenzoates. , phenylbenzoate compounds, phenyl bicyclohexylcarboxylate compounds, azomethine compounds, azo compounds, azooxy compounds, stilbene compounds, tolan compounds, ester compounds, bicyclohexyl compounds, phenylpyrimidine compounds , biphenylpyrimidine compounds, pyrimidine compounds, and biphenylethine compounds.
Examples of the smectic liquid crystal compound include ferroelectric polymeric liquid crystal compounds such as polyacrylate, polymethacrylate, polychloroacrylate, polyoxirane, polysiloxane, and polyester.
Examples of cholesteric liquid crystal compounds include cholesteryl linoleate, cholesteryl oleate, cellulose, cellulose derivatives, and polypeptides.
Further, as a commercially available liquid crystal material, for example, MLC2166 manufactured by Merck & Co., Ltd. can be used.

Further, the non-guest-host type light control layer 20 shown in FIG. 10 is sandwiched between linear polarizing plates 29A and 29B on both sides. By providing the linear polarizing plates 29A and 29B, a dimming function can be realized even when the liquid crystal layer 27 includes a non-guest host type liquid crystal.

Furthermore, in the non-guest host type light control layer 20 shown in FIG. 10, the shape of the spacer 28 is different from that of the guest host type light control layer 20 shown in FIG. The spacer 28 shown in FIG. 10 was manufactured using photoresist. The spacer 28 is manufactured by coating a photoresist on the base material 21B, which is formed by manufacturing the transparent electrode 22B, and then exposing and developing the photoresist. Note that the form of this spacer may be configured using a photoresist in a guest-host type, or may be configured using a bead spacer in a non-guest-host type.
Furthermore, various driving methods such as the TN (Twisted Nematic) method, the VA (Vertical Alignment) method, and the IPS (In-Plane-Switching) method are known as liquid crystal driving methods. For any of the types, these known drive methods can be selected and used as appropriate.

Next, two more specific examples of the screen 10 of this embodiment will be illustrated, and their transmittance and effects will be described.
(Example 1)
In the screen 10 of Example 1, the light control layer 20 was of the guest-host type shown in FIG.
The unit optical shape 121 has an arrangement pitch P of 100 μm.
The reflective layer 13 is formed of a vapor-deposited aluminum film, has a thickness of about 5 Å, a transmittance of 70%, and a reflectance of 5%.
The base material layer 11 was made of PET resin and had a thickness t11=100 μm.
The first optically shaped layer 12 and the second optically shaped layer 14 were made of urethane acrylate-based ultraviolet curable resin (refractive index: 1.52).
The combined thickness of the first optically shaped layer 12, the reflective layer 13, and the second optically shaped layer 14 was set to t121314=100 μm.
The shortest distance t14 from the back side surface of the second optically shaped layer 14 to the reflective layer 13 was set to 300 μm.
The adhesive layer 30 had a thickness t30=10 μm.
The base materials 21A and 21B were made of polycarbonate film and had a thickness t21=100 μm.
The transparent electrodes 22A and 22B were made of ITO and had a thickness t22 of 100 μm.
The alignment layers 23A and 23B were made of polyimide resin and had a thickness t23 of 0.1 μm.
The liquid crystal layer 26 is a liquid crystal using a guest-host liquid crystal composition using a dichroic dye composition, and has a thickness t26=6.2 μm. The liquid crystal layer 26 has a normally clear configuration.
With the above configuration, the shortest distance between the reflective layer 13 and the liquid crystal layer 26 is 0.1 mm, which is 0.5 mm or less.

(Example 2)
Regarding the screen 10 of the second embodiment, only the differences from the first embodiment will be described.
In the screen 10 of Example 2, the light control layer 20 was of the non-guest-host type shown in FIG.
The reflective layer 13 is composed of a dielectric multilayer film, and specifically has a structure in which TiO ₂ and SiO ₂ are laminated.
The linear polarizing plates 29A and 29B are made by impregnating polyvinyl alcohol (PVA) with iodine, etc., and then stretching it to form an optical functional layer that performs the optical function as a linear polarizing plate. The optical functional layer was sandwiched between base materials made of transparent film material, and the thickness t29 was 200 μm.
The liquid crystal layer 27 is a liquid crystal using a liquid crystal with negative dielectric anisotropy, and has a thickness t27=3.5 μm.
Note that, unlike the first embodiment, the liquid crystal layer 27 has a normally dark structure.
With the above configuration, the shortest distance between the reflective layer 13 and the liquid crystal layer 26 is 0.3 mm, which is also within 0.5 mm in Example 2.

In both Example 1 and Example 2, the shortest distance between the reflective layer 13 and the liquid crystal layer 26 was set to 0.5 mm or less, so that bonding during manufacturing could be easily performed, and Uniformity of thickness can be easily ensured.

FIG. 11 is a diagram collectively showing the transmittances of Example 1 and Example 2. ON and OFF in the light control layer section column in FIG. 11 indicate ON and OFF of energization to the light control layer 20, and the behavior is different between normally clear in Example 1 and normally dark in Example 2. It is constructed in the opposite way.
As shown in FIG. 11, in Example 1, by energizing the light control layer 20, the transmittance of the entire screen 10 can be lowered to 14%, and the area where no image is projected has a slight background. In the area where the image is projected, it is possible to observe a high-contrast image while suppressing the influence of the background. It is also possible to suppress light leakage to the background side.
Furthermore, in Example 2, if the power to the light control layer 20 is turned off, almost all transmitted light from the background can be blocked, and the image can be observed with almost completely eliminating the influence of the background. can. In Example 2, although the reflectance of the reflective layer 13 is reduced, the influence of the background is eliminated, so a sufficiently good image can be observed. However, if the light intensity of the image source LS is increased, a better image can be observed. Observable.

As shown in FIG. 11, by combining the configuration of the reflective layer 13 and the configuration of the light control layer 20 under appropriate conditions, the screen 10 is in a state where the transmittance of the light absorption layer exemplified as the light control layer 20 is the highest. The overall transmittance can be set in a range of 10% or more and 50% or less. Therefore, it is possible to sufficiently observe the background. Furthermore, when the transmittance of the light absorption layer (light control layer 20) is at its lowest, it is possible to create a state in which almost no background is transmitted, and images can be observed with almost no influence from the background. It is.

Furthermore, in both Example 1 and Example 2, the light control layer 20 is joined and integrated with the layer including the reflective layer, so there is no air gap between them. Thereby, high transmittance can be achieved as shown in FIG. 11.
Further, the light control layer 20 is provided over the entire surface of the screen 10, and can change the transmittance of the entire screen 10. The light control layer 20 can change the transmittance without being influenced by outside light such as external light.
Furthermore, in the second embodiment, by aligning the polarization states of the light sources, the linear polarizing plates 29A and 29B can prevent light leakage.

As described above, according to the second embodiment, the screen 10 includes the light control layer 20, so that the light transmittance can be selectively changed by switching the energization to the light control layer 20. can. Therefore, it is possible to set the transmittance to a high state when it is desired to see through the background, and to set the transmittance to a low state when it is desired to make the image easier to see, which is convenient for use.

(Third embodiment)
FIG. 12 is a diagram showing an example of the layered structure of the screen 10 of the third embodiment.
The screen 10 of the third embodiment has a structure in which the light control layer 20 of the second embodiment is replaced with a light control layer 40 that is simplified, and the structure other than the light control layer 40 is the same as that of the screen 10 of the second embodiment. It is similar to Therefore, parts that perform the same functions as those in the second embodiment described above are given the same reference numerals, and redundant explanations will be omitted as appropriate.

The light control layer 40 of the third embodiment is a layer containing a photosensitive material, and the light transmittance changes depending on the amount of ultraviolet light reaching the light control layer 40. Specifically, the light control layer 40 may be, for example, a light control glass layer containing silver halide, or a light control resin layer containing spirooxazine, and may appropriately utilize conventionally known photosensitive materials. can.

As described above, according to the third embodiment, the light control layer 40 includes a photosensitive material, so that the light control layer can be configured with a simpler structure.

(Transmittance of second embodiment and third embodiment)
The transmittance of the light control layers 20 and 40 in the second and third embodiments described above can be set as appropriate depending on the intended use. Here, a specific usage pattern will be illustrated, and the preferable transmittance of the light control layers 20 and 40 in that case will be illustrated.

FIG. 13 is a diagram illustrating the area around the driver's seat of a car VC, as seen from inside the car, in which the video display device 1 of the second embodiment is arranged in the front window of the car.
FIG. 14 is a cross-sectional view taken along line bb of the front window 2 in FIG.
Although FIG. 14 illustrates an example in which the screen 10 of the second embodiment is used, the screen 10 of the third embodiment can also be similarly arranged and used.

In the example of use shown in FIGS. 13 and 14, the video display device 1 is placed in and near the front window 2 of a car VC. Specifically, in the video display device 1, the screen 10 is placed on the entire surface of the front window 2 of the car VC, and the video source LS is placed inside the interior panel 3 of the car VC. A driver is seated in front of the steering wheel 4. As a result, the video display device 1 of the present embodiment displays information such as the speed of the vehicle, the status of the turn signal, and alerts such as approaching obstacles at a position on the front window 2 that does not obstruct the driver's view. Therefore, among the passengers of the automobile VC, mainly the driver, can check various information without significantly averting his/her line of sight.

Note that the screen 10 provided on the front window 2 displays an image by diffusing and reflecting image light projected from an image source LS (projector). Therefore, even if image light is projected from an image source such as a liquid crystal display device or an organic EL device, a clear image cannot be displayed on the screen 10.

As shown in FIG. 14, the front window 2 has a so-called laminated structure in which a first glass plate 61, a first intermediate layer 62, a screen 10, a second intermediate layer 63, and a second glass plate 64 are laminated in order from the inside of the vehicle. It is made up of glass.
The first glass plate 61 is a transparent member disposed closest to the driver (inside the vehicle) of the front window 2 . As the first glass plate 61, materials such as soda lime glass (blue plate glass), borosilicate glass (white plate glass), quartz glass, soda glass, potash glass, etc. can be used, for example. Further, the thickness of the first glass plate 61 is preferably in the range of 2 to 3 mm, for example.

The first intermediate layer 62 is a layer provided between the first glass plate 61 and the screen 10. The first glass plate 61 and the screen 10 are joined by a first intermediate layer 62. The first intermediate layer 62 is provided to prevent fragments of the first glass plate 61 from scattering when the front window 2 is damaged. As the first intermediate layer 62, for example, PVB (polyvinyl briral) can be used. The thickness of the first intermediate layer 62 is preferably in the range of 0.3 to 0.8 mm. Further, it is desirable that the refractive index of the first intermediate layer 62 is the same as that of the first glass plate 61 and the first optically shaped layer 12 of the screen 10.

The second intermediate layer 63 is a layer provided between the second glass plate 64 and the screen 10. The second glass plate 64 and the screen 10 are joined by the second intermediate layer 63. The second intermediate layer 63 is provided to prevent fragments of the second glass plate 64 from scattering when the front window 2 is damaged. Like the first intermediate layer 62, the second intermediate layer 63 can be made of, for example, PVB (polyvinyl briral), and the thickness of the second intermediate layer 63 is in the range of 0.3 to 0.8 mm. It is preferable. Further, it is desirable that the refractive index of the second intermediate layer 63 is the same as that of the second glass plate 64 and the second optically shaped layer 14 of the screen 10.

The second glass plate 64 is a transparent member disposed at the outermost side of the front window 2. As with the first glass plate 61, the second glass plate 64 can be made of materials such as soda lime glass (blue plate glass), borosilicate glass (white plate glass), quartz glass, soda glass, potash glass, or the like. Further, the thickness of the second glass plate 64 is preferably in the range of 2 to 3 mm, for example.

As described above, the screen 10 of this embodiment has a front window 2 formed of a laminated glass sandwiched between two glass plates (31, 34) with an intermediate layer (32, 33) in between. Although the explanation has been given using an example of a built-in device, the present invention is not limited to this. The screen 10 may be attached to the inside surface of the front window or the outside surface of the vehicle via a bonding layer.

With the above configuration, the passenger (driver) of the automobile VC can observe the scenery outside the vehicle through the entire surface of the front window 2 when the image light is not projected, and the image light is projected onto the front window 2. (screen 10), the image light can be seen in the area on which it is projected, and the scenery outside the vehicle cannot be observed in the other areas. can. In addition, even in the area where the image light is projected, the image can be viewed in a so-called see-through state, allowing some of the scenery outside the vehicle to be observed.

Here, when the screen 10 is applied to the window of a vehicle such as an automobile, the light absorption rate of the light control layers 20 and 40 is preferably within the following range.
First, if the light absorption rate of the screen 10 as a whole is too low, the screen 10 may appear cloudy due to external light from outside the vehicle. In order to suppress this clouding phenomenon, assuming that the light absorption rate of the light control layer is fixed, it is desirable that the light absorption rate is 50% or more.
Further, in order to satisfy both of the requirements that the forward visibility is good when the image light is not projected and that the image is easily recognizable when the image light is projected, it is desirable that the following conditions be satisfied.
The light absorption rate of the light control layers 20 and 40 is desirably low when image light is not projected, and most desirably is 0%.
The light absorption rate of the light control layers 20 and 40 is preferably 50% or more, and more preferably 70% or more when projecting image light.
It is desirable that the light control layers 20 and 40 have variable light absorption and satisfy at least one, more preferably both, of the above two conditions.

(Fourth embodiment)
FIG. 15 is a diagram showing an example of the layered structure of the screen 10 of the fourth embodiment.
The screen 10 of the fourth embodiment has a light absorption layer 60 which is a simpler version of the light control layer 20 of the third embodiment, and the structure other than this light absorption layer 60 is the screen 10 of the third embodiment. It is similar to Therefore, parts that perform the same functions as those in the third embodiment described above are given the same reference numerals, and redundant explanations will be omitted as appropriate.

The light absorption layer 60 of the fourth embodiment is colored with a colorant such as a gray or black dye or a pigment, and has light absorption properties. The color density and layer thickness of the light absorption layer 60 are set so that the light transmittance of the screen 10 becomes a predetermined value. The light absorption layer 60 has a function of absorbing unnecessary external light and stray light such as illumination light incident on the screen 10 and improving the contrast of the image. Note that similar effects can be obtained even if the protective layer 15 in the first embodiment has a light absorption function.

As described above, according to the fourth embodiment, since the light absorption layer 60 is provided, the contrast of the image can be improved with a simpler configuration.

(Fifth embodiment)
FIG. 16 is a diagram showing an example of the layered structure of the screen 10 of the fifth embodiment.
FIG. 17 is a diagram showing the reflective layer 13 of the fifth embodiment.
FIG. 18 is a diagram showing another form of the reflective layer 13 of the fifth embodiment.
The screen 10 of the fifth embodiment has the same configuration as the screen 10 of the first embodiment, except that the configuration of the reflective layer 13 is different from that of the first embodiment. Therefore, other than the description of the reflective layer 13, the same reference numerals are given to parts that perform the same functions as in the first embodiment, and redundant description will be omitted as appropriate.

As shown in FIG. 17, the reflective layer 13 of the fifth embodiment is formed in a plurality of island shapes on the first slope 121a. Here, a plurality of island shapes refers to a state in which a plurality of polygons such as circles, ellipses, rectangles, and other arbitrary shapes are arranged regularly or irregularly on the first slope 121a. .
In the reflective layer 13 of this embodiment, a plurality of circular reflective films 13a are regularly arranged along the first slope 121a. A portion on the first slope 121a where the reflective layer 13 (a plurality of circular reflective films 13a) is not formed becomes a light transmitting portion that transmits incident light.

Since the reflective layer of the transmission type screen shown in the first embodiment etc. was provided on the entire surface of the first slope, the reflectance and transmittance can be adjusted by changing the material used in the case of a dielectric film. It could be done by doing this. However, there have been cases in which it has not been possible to sufficiently adjust the reflectance and transmittance to desired values simply by changing the material.
On the other hand, the screen 10 of the present embodiment improves the reflectance and transmittance of light incident on the screen 10 by adjusting the ratio of the area occupied by the plurality of circular reflective films 13a to the area of the first slope 121a. The rate can be adjusted. This eliminates the need for adjustments such as changing the material of the dielectric film as described above, and the reflectance and transmittance of the reflective layer can be adjusted more efficiently.

In addition, in FIG. 17, the diameter of the circular reflective film 13a is smaller than the arrangement pitch P of the unit optical shapes 121 (width in the arrangement direction of the first slope 121a), and a plurality of circular reflection films are arranged on the first slope 121a. Although an example in which the reflective film 13a is formed has been shown, the invention is not limited to this. For example, as shown in FIG. 18, the diameter of the circular reflective film 13a is larger than the arrangement pitch P1 of the unit optical shapes 121 (width in the arrangement direction of the first slope 121a), and the circular reflective film 13a is It may be formed so as to straddle the adjacent first slopes 121a. Note that in the form shown in FIG. 17, each of the island-shaped reflective films can be formed smaller than in the form shown in FIG. 18, so that the shape of the reflective film is less visible to the observer and moire is less likely to occur.

Although omitted in FIG. 16, in the screen 10 of the fourth embodiment as well, fine particles are formed in a portion of the first slope 121a where the reflective layer 13 (a plurality of circular reflective films 13a) is formed. Moreover, an irregular uneven shape is formed, and the reflective layer 13 is formed to follow this fine and irregular uneven shape, and is deposited while maintaining the uneven shape. Therefore, the surface of the reflective layer 13 on the first optically shaped layer 12 side (image source side) and the surface on the second optically shaped layer 14 side (back side) are rough surfaces having fine and irregular uneven shapes. There is. Thereby, the reflective layer 13 diffuses and reflects a part of the incident light due to the fine and irregular uneven shape, and transmits other light that is not reflected without being diffused.
Here, the size of the island-shaped reflective film 13a (area in plan view, hereinafter the same) is configured to be larger than the size of one convex part and the size of one concave part having a fine and irregular uneven shape. There is. Therefore, the island-shaped reflective film 13a includes a plurality of convex portions and concave portions. If the island-shaped reflective film 13a becomes smaller than the convex portions and concave portions, the distribution of the direction of the light reflected by the reflective film 13a will increase, and the deflection effect of the light by the first slope 121a will not be sufficient. This is because you will not be able to obtain a proper image and will not be able to observe an appropriate image.
Note that this uneven shape is formed by fine convex shapes and concave shapes arranged irregularly in a two-dimensional direction, and the convex shapes and concave shapes are irregular in size, shape, height, etc. be.

The reflective layer 13 may have any of three types: a structure using metal as in the first embodiment, a structure using a dielectric multilayer film, and a structure using a single layer dielectric film. Further, the reflective layer 13 can be formed by appropriately combining a metal film or a dielectric film as a single layer or a multilayer.
Although the reflective layer 13 has been shown as an example in which a plurality of circular reflective films 13a are regularly arranged on the first slope 121a, the present invention is not limited to this, and the reflective layer 13 may be arranged irregularly. Alternatively, reflective films having shapes other than circular may be arranged regularly or irregularly.
Note that in this embodiment, an example is shown in which the reflective layer 13 is not provided on the second slope 121b because it does not directly contribute to the reflection of the image light toward the viewer, but the present invention is not limited to this. , the reflective layer 13 may also be provided on the second slope 121b.

Similar to the first embodiment, the second optically shaped layer 14 is a layer having light transmittance and provided on the back side (-Z side) of the first optically shaped layer 12 and the reflective layer 13.
As described above, the reflective layer 13 is composed of a plurality of island-shaped (circular reflective films 13a), and among the first slopes 121a of the first optically shaped layer 12, the circular reflective film 13a is formed. In the part where the optical shape is not formed (light transmitting part), the first optically shaped layer 12 and the second optically shaped layer 14 come into direct contact, and the adhesion of the second optically shaped layer 14 to the first optically shaped layer 12 is strengthened. It can be done.

The screen 10 of the fifth embodiment is manufactured, for example, by the following manufacturing method.
FIG. 19 is a diagram showing an example of a method for manufacturing the reflective layer 13 of the fifth embodiment.
First, the base material layer 11 is prepared, and a mold for shaping the unit optical shape 121 is laminated on one side with an ultraviolet curable resin filled therein, and the ultraviolet curable resin is cured by irradiating ultraviolet rays. The first optically shaped layer 12 is formed by a UV molding method. At this time, a fine and irregular uneven shape is formed on the surface that shapes the first slope 121a of the mold that shapes the unit optical shape 121. This fine and irregular uneven shape can be formed by performing plating treatment, etching treatment, blasting treatment, etc. one or more times on the surface of the mold on which the first slope 121a is formed.

Then, in preparation for the formation of the next reflective layer 13, as shown in FIG. Laminated and arranged on the first optical shape layer 12.
In addition, when the produced laminate consisting of the base material layer 11 and the first optically shaped layer 12 is in the form of a web, this laminate may be wound up into a roll body before the step of forming the reflective layer 13. be. In such a case, if the laminate is wound up together with the mask M, it is possible to prevent the first optical shape layer 12 from being soiled or damaged, and the subsequent step of forming the reflective layer 13 can be prevented. In this way, problems such as poor deposition of the reflective film can be prevented as much as possible.

Next, with the mask M placed on the unit optical shape 121, the reflective layer 13 (a plurality of circular reflective films 13a) having a predetermined thickness is formed by, for example, vapor depositing or sputtering a dielectric film. It is formed on the first slope 121a.
The reflective layer 13 is not limited to this, but may be formed by vapor-depositing a metal with high light reflectivity such as aluminum, chromium (Cr), silver, or nickel, by sputtering a metal with high light reflectivity, or by sputtering a metal with high light reflectivity, or by sputtering a metal with high light reflectivity, or by sputtering a metal with high light reflectivity. It may be formed by transferring or the like. For example, when aluminum is used for the reflective layer 13, by making the film sufficiently thick (0.1 μm or more), the reflectance of incident light will be about 70 to 80%, and the absorption rate of incident light will be about 20%. becomes. In this case, assuming that the area occupied by the reflective layer 13 on the first slope 121a is 20%, the reflectance of the reflective layer 13 on the entire surface of the first slope 121a is 14 to 16%, and the absorption rate is approximately 4%. Therefore, the ratio of reflection and transmission of the incident light can be adjusted while suppressing the absorption of the incident light in the reflective layer 13 as much as possible. Further, by making the thickness of the reflective layer 13 sufficiently thick in this way, it is possible to prevent uneven patterns and the like from occurring due to variations in the film thickness.
Note that the reflectance (transmittance) of the reflective layer 13 made of a metal material can be adjusted by changing its film thickness. Specifically, if the film thickness is made thinner, the transmittance improves, but the reflectance decreases, and if the film thickness is made thicker, the reflectance improves, but the transmittance decreases.

Next, an ultraviolet curable resin is applied from above the reflective layer 13 so as to fill the valleys between the unit optical shapes 121 to form a planar shape, and the ultraviolet curable resin is cured by irradiation with ultraviolet rays. 2 optically shaped layers 14 are formed. Through the above steps, the screen 10 is completed.
Note that, since the first slope 121a of the unit optical shape 121 has a fine uneven shape as described above, the fine uneven shape is formed on both sides of the reflective layer 13 formed on the first slope 121a. It is formed. Further, the uneven shape of the portion of the first slope 121a where the reflective layer 13 is not formed becomes almost inconspicuous by being filled with the resin of the second optically shaped layer 14, and in the completed screen 10, the uneven shape of the portion where the reflective layer 13 is not formed becomes almost inconspicuous. Light incident on the portion of 121a where the reflective layer 13 is not formed can be transmitted without being diffused.

As described above, the screen 10 of the fifth embodiment includes a plurality of reflective layers 13 formed in a plurality of island shapes at the position where the image light of the unit optical shape 121 is incident (first slope 121a), that is, a plurality of reflective layers 13 formed in a plurality of island shapes. A circular reflective film 13a is formed. As a result, the image light projected from the image source LS is reflected by the reflective layer 13 toward the observer O1 side, and a part of the external light such as the scenery on the back side of the screen 10 is reflected by the reflective layer and the unit optical shape. The light can be transmitted through the portion (light transmitting portion) where the reflective layer is not formed without being diffused, and can be emitted to the observer O1 side. Therefore, the image of the image source LS can be displayed for the observer O1, and the scenery on the back side of the screen 10 can be observed more clearly.

(Sixth embodiment)
FIG. 20 is a diagram illustrating the layer structure of the screen 100 of the sixth embodiment. FIG. 20 shows a cross section passing through point A at the center of the screen 100 and parallel to the screen vertical direction (Y direction) and thickness direction (Z direction).
The screen 100 of the sixth embodiment has the following features, except that two screens 10 of the fifth embodiment (hereinafter referred to as a first screen section 10A and a second screen section 10B) are joined together via a bonding layer 17. It has the same form as the screen 10 of the fifth embodiment described above. Therefore, parts that perform the same functions as those in the first embodiment are given the same reference numerals or the same suffixes, and redundant explanations will be omitted as appropriate.

As shown in FIG. 20, the screen 100 of the sixth embodiment includes a first screen section 10A and a second screen section 10B located on the back side of the first screen section 10A, which are integrated by a bonding layer 17. is joined to. More specifically, the second optically shaped layer 14 on the back side of the first screen section 10A and the base material layer 11 on the image source side of the second screen section 10B are bonded together by the bonding layer 17.
The bonding layer 17 is a layer formed of a pressure-sensitive adhesive or an adhesive with high light transmittance, and is provided between the first screen section 10A and the second screen section 10B in the thickness direction of the screen 100. This joining layer 17 joins the first screen section 10A and the second screen section 10B together.
The first screen section 10A and the second screen section 10B of the screen 100 of this embodiment are joined to each other so that their respective optical centers coincide.
Further, each unit optical shape of the first screen section 10A and the second screen section 10B is formed into the same shape. Therefore, the focal positions (light condensing points) of each screen section substantially match.

Here, a transparent screen tends to cause scintillation (speckle) when high-intensity image light is projected from an image source with a small projection pupil diameter.
However, in the screen 100 of this embodiment, the first screen section 10A and the second screen section 10B display the same image in the same display area, and the light for displaying the same image is transmitted through two different optical paths. Since the light passes through the screen and exits from the screen 10, scintillation (speckle) is reduced.
Therefore, the screen 100 and the video display device 1 can reduce the scintillation (speckle) of the video and can display a bright and good video.
Moreover, the screen 100 of this embodiment has the same effects as the screen 10 of the fifth embodiment described above.

(Another form 1 of the sixth embodiment)
In the above-mentioned sixth embodiment, an example was shown in which the focal positions (light condensing points) of the first screen section 10A and the second screen section 10B substantially coincide, but the present invention is not limited to this, and the following embodiments may also be used. good.
FIG. 21 is a diagram illustrating another form of the screen 100 of the sixth embodiment. FIG. 21 is a diagram showing focal positions (light condensing points) of the first screen section 10A and the second screen section 10B of the screen 100 of another form. FIG. 21 shows the screen 100 viewed from the right side (+X side) in the left-right direction of the screen.

In the screen 100, the focal positions (light condensing points) of the first screen section 10A and the second screen section 10B may be different in the thickness direction (Z direction).
In this embodiment, as shown in FIG. 21, the light convergence point F2 of the second screen part 10B is located on the side ( +Z side). That is, in the screen 100 of the present embodiment, the circular Fresnel lens shape of the first optically shaped layer 12 of the second screen section 10B is different from the circular Fresnel lens shape of the first optically shaped layer 12 of the first screen section 10A. , their shapes and optical designs are different, and the positions of the light focusing points are different.

Therefore, the angles θ1, θ2, etc. of the first slope and the second slope that form the unit optical shape 121 of the first optically shaped layer 12 of the second screen portion 10B are designed corresponding to this focal point F2. . Therefore, the angle θ1 is different between the unit optical shape 121 of the first screen section 10A and the unit optical shape 121 of the second screen section 10B, which are located at the same distance r from the optical center (C1). .

Further, in this embodiment, the value of the arrangement pitch P2 of the unit optical shapes 121 of the second screen section 10B is different from the value of the arrangement pitch P1 of the unit optical shapes 121 of the first screen section 10A. It is 1.4 times the value. In this way, by making the arrangement pitch P1 of the unit optical shapes 121 of the first screen section 10A different from the arrangement pitch P2 of the unit optical shapes 121 of the second screen section 10B, the image displayed on the first screen section 10A can be changed. Moiré caused by interference between the image light and the image light of the image displayed by the second screen section 10B can be improved. In order to improve moire, it is preferable that one arrangement pitch be 1.4 times or 2.4 times as large as the other arrangement pitch.
In this embodiment, an example has been shown in which the array pitch P1 and the array pitch P2 are different values, but they are not limited to this, and may be the same value.

With this configuration, the same image displayed by the first screen section 10A and the second screen section 10B can be focused on different positions, and a good image can be displayed to observers at different positions. .
Therefore, according to this other form, in addition to the effects obtained by the sixth embodiment described above, the image light can be further focused toward two different positions, and the observers at the two different positions can receive a good impression. Can display images.

Note that when the image light is focused on two different positions as described above, in the luminance distribution (viewing angle distribution) of the reflected light of the first screen section 10A and the second screen section 10B, the full width at half maximum with respect to the peak luminance is It is preferred that α _H is 20° or less. Thereby, it is possible to improve the convergence of the image light and display a brighter and clearer image to the observer located at the convergence point.

(Another form 2 of the sixth embodiment)
FIG. 22 is a diagram illustrating another form 2 of the screen 100 of the sixth embodiment, and is a diagram of the screen 100 viewed from above in the vertical direction of the screen.
As shown in FIG. 22, the focal positions (condensing points) F1 and F2 of the first screen section 10A and the second screen section 10B may be different in the left-right direction (X direction) of the screen. By adopting such a configuration, the viewing angle in the horizontal direction of the screen can be widened. Further, such a configuration is suitable for, for example, a horizontally long screen in which the horizontal dimension of the screen is larger than the vertical dimension of the screen.

FIG. 23 is a diagram illustrating another form 2 of the screen 100 of the sixth embodiment, and is a diagram of the screen 100 viewed from the right side in the left-right direction of the screen.
As shown in FIG. 23, the focal point F1 of the first screen section 10A and the focal point F2 of the second screen section 10B may be different in the vertical direction (Y direction) of the screen. By adopting such a configuration, the viewing angle in the vertical direction of the screen can be widened. Further, such a configuration is suitable, for example, for a vertically long screen in which the vertical dimension of the screen is larger than the horizontal dimension of the screen.
In addition, the focal points F1 and F2 may be different in the screen horizontal direction (X direction) and thickness direction (depth direction, Z direction), or may be different in the screen vertical direction (Y direction) and depth direction (Z direction). They may be different, or may be different in the vertical direction of the screen (Y direction) and the horizontal direction of the screen (X direction).
Further, either one of the focal points F1 and F2 may be infinitely far away.

When the focal points F1 and F2 are different in this way, the circular Fresnel lens shapes of the first optically shaped layer 12 of the first screen section 10A and the first optically shaped layer 12 of the second screen section 10B are adjusted accordingly. design. Therefore, the optical centers serving as Fresnel centers may or may not coincide when viewed from the normal direction of the screen surface, depending on the design.

For example, the first optically shaped layer 12 of the first screen section 10A and the first optically shaped layer 12 of the second screen section 10B have the same circular Fresnel lens shape; ) may be located at different positions when viewed from the normal direction of the screen surface. Further, the first optically shaped layer 12 of the first screen section 10A and the first optically shaped layer 12 of the second screen section 10B have different circular Fresnel lens shapes, and their Fresnel center (optical center) may be located at different positions when viewed from the normal direction of the screen surface.
Furthermore, for example, the positions of the condensing points F1 and F2 may match (or substantially match), but the angular distribution of the angle θ1 of the first slope of each screen portion or the position of the optical center may be different. .
In the sixth embodiment, the screen 10 of the fifth embodiment is exemplified in which two sheets (the first screen part 10A and the second screen part 10B) are joined via the bonding layer 17. A configuration similar to the provision of a plurality of reflective layers may be realized, for example, as a configuration in which a plurality of reflective layers are provided at predetermined intervals in the thickness direction of the reflective screen. Here, laminating multiple layers of reflective layers independently at a predetermined interval means that multiple independent reflective layers that act as reflective layers for image light are provided, rather than in the form of a multilayer reflective layer. It refers to that.

(Seventh embodiment)
FIG. 24 is a perspective view showing the video display device 1 of the seventh embodiment. In addition, in FIG. 24, in order to facilitate understanding, a circular arc shape corresponding to the circular Fresnel lens shape of the unit optical shape 121 is also shown on the surface of the screen 10.
FIG. 25 is a top view of the video display device 1 of the seventh embodiment.
Note that the screen 10 of the seventh embodiment appropriately utilizes the same configuration as the screen 10 of each of the embodiments described above. Therefore, description of the specific form of the screen 10 will be omitted.
In each of the embodiments described above, the screen 10 is used with the unit optical shapes 121 arranged in the vertical direction. In the seventh embodiment, the screen 10 is used with the unit optical shapes 121 arranged in the left-right direction (horizontal direction). Therefore, in the seventh embodiment, the video source LS is arranged diagonally to the side of the screen 10. In the screen 10, the light diffusion effect in the arrangement direction of the unit optical shapes 121 is larger than the light diffusion effect in the direction perpendicular to the arrangement direction. Therefore, in the seventh embodiment, even if the position of the observer O1 shifts in the left-right direction, it is possible to expand the range in which a good image can be provided.

(Eighth embodiment)
FIG. 26 is a diagram showing an example of the layered structure of the screen 10 of the eighth embodiment.
The screen 10 of the eighth embodiment has a light control layer 210 that is an improved version of the light control layer 40 of the third embodiment. This is similar to the screen 10 of the third embodiment. Therefore, parts that perform the same functions as those in the third embodiment described above are given the same reference numerals, and redundant explanations will be omitted as appropriate.

The light control layer 210 and the excitation light source 220 constitute a light control section 200, and the light control section 200 controls the transmittance of the photochromic layer 211 by controlling the excitation light source 220 by a control section (not shown). It has a configuration that can be adjusted.
The light control layer 210 includes a photochromic layer 211 , a first shielding layer 212 , a second shielding layer 213 , and a light guide layer 214 .

The photochromic layer 211 is a layer with photoresponsiveness that changes its transmittance when it receives excitation light in a specific wavelength range. The photochromic layer 211 of this embodiment usually has a high visible light transmittance and is substantially transparent to visible light, and upon receiving ultraviolet light, the photochromic layer 211 changes color to gray or black and has a reduced visible light transmittance. state. Further, the photochromic layer 211 that has received the ultraviolet light gradually increases its visible light transmittance and returns to a transparent state when the ultraviolet light reception ends.
The photochromic layer 211 is made of resin containing a photochromic material (photosensitive substance). Examples of photochromic materials include diarylethene compounds, spiropyran compounds, spiroperimidine compounds, fulgide compounds, hexaarylbiimidazole compounds, naphthopyran compounds, etc., but are not limited to these. It can be used as appropriate.

The photochromic layer 211 of this embodiment has a maximum transmittance of vertically incident visible light of 80% in the range of 430 nm to 700 nm when not discolored by ultraviolet light, and a minimum transmittance when the photochromic layer 211 is most deeply discolored by ultraviolet light. The ratio is 20% from 430 nm to 700 nm.

The first shielding layer 212 is disposed on the image source side of the photochromic layer 211, and is a layer that shields the transmission of ultraviolet light, which is excitation light. More specifically, the first shielding layer 212 may be configured as an ultraviolet absorbing layer or as an ultraviolet reflecting layer. The first shielding layer 212 transmits light in a band other than the ultraviolet light to be blocked (having a sufficiently high transmittance), and is therefore substantially transparent to visible light. In this embodiment, the first shielding layer 212 is arranged on the outermost surface of the light control layer 210 on the image source side (the position in contact with the adhesive layer 30).

The second shielding layer 213 is a layer that is disposed on the back side of the photochromic layer 211 and blocks transmission of ultraviolet light, which is excitation light. More specifically, the second shielding layer 213 may be configured as an ultraviolet absorbing layer or as an ultraviolet reflecting layer. The second shielding layer 213 transmits light in a band other than the ultraviolet light to be blocked (its transmittance is sufficiently high), and is therefore substantially transparent to visible light. In this embodiment, the second shielding layer 213 is arranged on the outermost surface of the light control layer 210 on the back side.

In this embodiment, the first shielding layer 212 and the second shielding layer 213 have the same structure and are configured as ultraviolet absorption layers, and absorb 90% or more of the vertically incident ultraviolet light in the range of 280 nm to 380 nm. Shield (absorb). More preferably, the first shielding layer 212 and the second shielding layer 213 shield (absorb) 95% or more of vertically incident ultraviolet light of 280 nm to 380 nm.

Since the photochromic layer 211 is sandwiched between the first shielding layer 212 and the second shielding layer 213, most of the ultraviolet light that reaches the light control layer 210 from the image source side and the back side is transmitted to the first shielding layer 213. 212 and the second shielding layer 213, and does not reach the photochromic layer 211. Therefore, the photochromic layer 211 does not cause a change in transmittance due to external light or image light.

The light guiding layer 214 is disposed between the first shielding layer 212 and the second shielding layer 213, and guides light incident from the end of the light control layer 210 to direct at least part of the light to the photochromic layer 211 side. emit to. In this embodiment, the light guide layer 214 is placed closer to the image source than the photochromic layer 211 is.
The light guide layer 214 includes a high refractive index layer 215, a first low refractive index layer 216, and a second low refractive index layer 217.

The high refractive index layer 215 is a region to which guided excitation light (in this embodiment, ultraviolet light) is guided, and has a refractive index higher than that of the first low refractive index layer 216 and the second low refractive index layer 217. also has a high refractive index. Furthermore, it is desirable that the high refractive index layer 215 be formed using a material that has high transmittance for visible light and ultraviolet light, which is excitation light.
The first low refractive index layer 216 is disposed adjacent to the high refractive index layer 215 on the image source side, and has a lower refractive index than the high refractive index layer 215.
The second low refractive index layer 217 is disposed adjacent to the back side of the high refractive index layer 215 and has a lower refractive index than the high refractive index layer 215.
It is desirable that both the first low refractive index layer 216 and the second low refractive index layer 217 be formed using a material that has high transmittance for visible light and ultraviolet light, which is excitation light. In this embodiment, the first low refractive index layer 216 and the second low refractive index layer 217 are made of the same material.
The light guide layer 214 has the above-described structure, that is, the structure in which the high refractive index layer 215 is sandwiched between the first low refractive index layer 216 and the second low refractive index layer 217, so that the high refractive index layer 215 and the second low refractive index layer Excitation light from the excitation light source 220 reaches the interface with the first low refractive index layer 216 and the interface between the high refractive index layer 215 and the second low refractive index layer 217 at an angle larger than the critical angle. is totally reflected. Thereby, the excitation light is guided in the light guiding direction (direction from bottom to top in FIG. 26).

Further, the light guiding layer 214 includes a course changing section 215a that changes the direction in which a portion of the guided light travels. The course changing portion 215a of this embodiment is configured as a groove provided on the image source side of the high refractive index layer 215. The course changing portion 215a extends in the direction perpendicular to the light guiding direction, that is, in the left-right direction of the screen, while maintaining the same groove shape. Moreover, a plurality of course changing parts 215a are arranged at intervals along the light guiding direction. Although the course changing portion 215a of this embodiment has a rectangular cross-sectional shape as shown in FIG. 26, it may have a triangular cross-sectional shape, a semicircular shape, a partial elliptical shape, etc. It may be changed as appropriate.
Furthermore, the inside of the groove shape of the course changing portion 215a may be filled with, for example, a resin forming the first low refractive index layer 216, or may be filled with another resin. However, if the groove-shaped interior of the course changing part 215a is made into a void, there is a risk that the course changing part 215a will be easily recognized due to dew condensation, etc., so it is desirable to fill it with some kind of resin.

The excitation light source 220 is disposed at the end 210a of the light control layer 210, emits ultraviolet light as excitation light, and irradiates the end 210a with the excitation light. The excitation light irradiated to the end portion 210a enters the high refractive index layer 215 from the end portion 210a and proceeds in the light guide direction. In this embodiment, the excitation light source 220 includes a plurality of LED (light emitting diode) light sources that are point light sources.

Regarding the end portion 210a, although not shown, a light-shielding film, a light-shielding member, or the like is arranged at the end other than the end of the high refractive index layer 215, especially at the end of the photochromic layer 211, so that the excitation light does not directly enter. It is desirable to do so. In addition, for example, an ultraviolet light reflective material that reflects excitation light is arranged on the end 210b opposite the end 210a and the left and right ends of the screen extending along the light guiding direction of the light control layer 210. The excitation light may be returned, or an ultraviolet light reflecting material that absorbs the excitation light may be provided.

When the excitation light source 220 emits light, the excitation light enters from the end 210a and travels as indicated by the arrow in FIG. As described above, the excitation light traveling through the high refractive index layer 215 is transmitted to the interface between the high refractive index layer 215 and the first low refractive index layer 216, and the interface between the high refractive index layer 215 and the second low refractive index layer. 217, when it reaches these interfaces at an angle larger than the critical angle, it is totally reflected. By repeating this, the excitation light is guided in the light guide direction. Furthermore, the direction of the excitation light that has reached the course changing section 215a is significantly changed. Here, the direction in which the excitation light is changed by the path changing section 215a varies, but some of the light is smaller than the critical angle at the interface between the high refractive index layer 215 and the second low refractive index layer 217. incident at an angle. This excitation light passes through this interface, exits from the light guide layer 214, reaches the photochromic layer 211, and the transmittance of the photochromic layer 211 decreases.

As described above, the path changing section 215a advances the excitation light toward the photochromic layer 211 by changing the path of the excitation light. Therefore, the distribution of the excitation light toward the photochromic layer 211 changes depending on the extent to which the excitation light hits the path changing portion 215a. In order to make the transmittance uniform throughout the photochromic layer 211, it is desirable to appropriately optimize the arrangement of the path changing portions 215a. Note that since the light guide layer 214 can be regarded as a surface light source of excitation light, a structure similar to that of a conventionally known surface light source device can be appropriately utilized as a specific structure of the path changing section 215a. For example, light diffusing particles may be included in the light guide layer 14 instead of the path changing portion 215a.

In the case of the form of the course changing part 215a as in this embodiment, by changing the depth of the groove of the course changing part 215a depending on the location, the distribution of the amount of emitted excitation light can be made uniform. Specifically, the depth of the groove in the path changing section 215a on the side closer to the excitation light source 220 may be made smaller than the depth of the groove in the path changing section 215a on the side farther from the excitation light source 220. Note that the depth of the grooves of the plurality of course changing parts 215a may be changed for each course changing part 215a along the light guiding direction, or the depth of the grooves of the plurality of course changing parts 215a may be changed for each course changing part 215a along the light guiding direction. The portions 215a may be changed stepwise in units of a plurality of portions 215a.
Note that the distribution of the amount of emitted excitation light can also be made uniform by changing the width (width in the light guide direction) of the course changing section 215a and the arrangement pitch thereof. However, it is desirable that the width of the course changing portion 215a and the arrangement pitch thereof be constant. This is to prevent the course changing section 215a from being visually recognized.

When the excitation light source 220 emits excitation light, the transmittance of the photochromic layer 211 decreases, making it possible to exhibit a so-called dimming effect. Since the decrease in the transmittance of the photochromic layer 211 occurs approximately at the same time as the excitation light source 220 emits excitation light, the response speed of the transmittance change is fast. Furthermore, as described above, the photochromic layer 211 has a maximum transmittance of 80% and a minimum transmittance of 20%, so it has a higher dynamic range of transmittance than a light control layer using liquid crystal, etc. There is a large difference between this and when the light is dimmed (when the transmittance decreases), making it highly useful.
Further, the light control layer 210 is configured with a first shielding layer 212 and a second shielding layer 213 sandwiching a photochromic layer 211 therebetween. Therefore, the photochromic layer 211 does not cause a change in transmittance due to image light or external light. Further, it is also possible to prevent the excitation light from being emitted from the light control layer 210.

Note that in the eighth embodiment, only the excitation light source 220 is provided, but for example, a light source that makes light (for example, visible light) that has the effect of increasing the transmittance of the photochromic layer 211 enter the light guide layer 14 may be further provided. You can.

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

(1) In each embodiment, in the cross section, the first slope 121a (first surface) and the second slope 121b (second surface) are straight lines (the first slope and the second slope are flat), and the connecting surface An example in which 121c is a curve has been described. For example, the first slope (first surface) may also be curved in cross section, that is, the first slope (first surface) may be a curved surface, and the second slope (second surface) may be curved. Also, the cross section may be curved, that is, the second slope (second surface) may be a curved surface.

(2) In each embodiment, a hard coat layer may be provided on the front or back surface of the screen 10 for the purpose of preventing scratches. The hard coat layer is formed, for example, by coating the surface of the screen 10 with an ultraviolet curable resin (for example, urethane acrylate) having a hard coat function.
In addition to the hard coat layer, the screen 10 may be provided with necessary functions, such as antireflection function, ultraviolet absorption function, antifouling function, antistatic function, etc., depending on the environment and purpose of use of the screen 10. One or more layers may be selected and provided. Furthermore, a touch panel layer or the like may be provided on the image source side of the base layer 11.
In particular, when an antireflection layer is provided on the surface of the screen 10 on the image source side, the image light reflected by the reflective layer 13 is reflected at the interface with the air on the image source side and exits from the back side. This can prevent images from appearing as if they are leaking on the back side.

(3) In the sixth embodiment, an example has been described in which the screens 10 (the first screen section 10A and the second screen section 10B) of the fifth embodiment are arranged in an overlapping manner. The present invention is not limited to this, and for example, the screens 10 of the first embodiment may be arranged one on top of the other.

(4) In each embodiment, an example has been shown in which the fine unevenness on the surface of the reflective layer 13 (the surface of the unit optical shape 121) is irregular in size, shape, arrangement, etc. Any of the sequences may have regularity.

(5) In each of the embodiments, the video source LS is located at the center of the screen 10 in the left-right direction and below the outside of the screen. It may be arranged on the lower side, etc., and project image light from an oblique direction to the screen 10 in the left and right directions of the screen.
In this case, the arrangement direction of the unit optical shapes 121 is inclined in accordance with the position of the image source LS. By adopting such a configuration, the position of the video source LS, etc. can be freely set.

(6) In each embodiment, the first slope 121a, the second slope 121b, and the connection surface 121c have shown an example in which fine and irregular uneven shapes are formed, but the present invention is not limited to this. A configuration may also be adopted in which fine and irregular uneven shapes are formed only on the slope 121a.
Further, although an example has been shown in which the reflective layer 13 is formed on the entire surface of the unit optical shape 121, the present invention is not limited thereto, and may be formed on at least a portion of the first slope 121a, for example.

(7) In the description of each embodiment, an example in which the video display device 1 is placed in an indoor partition will be mainly described, and in the second and third embodiments, an example will be described in which the video display device 1 is placed in a car window. Examples are also given. The present invention is not limited to this, and any of the embodiments may be applied to, for example, video displays at exhibitions, show windows of stores, etc. It may be applied to windows (front windows, side windows, rear windows, etc.) of ships, ships, etc.

(8) In the second embodiment, the light control layer 20 has been described using an example in which liquid crystal is used. For example, the light control layer is not limited to this, and the light control layer may be made of a material other than liquid crystal, such as an EC type, SPD type, or PDLC type light control film, in which the brightness and darkness (transmittance) changes depending on the potential difference between electrodes. It may be a device.
A light control film using the EC method (Electro chromic) has a structure in which a light control layer (electrolyte layer) is sandwiched between a pair of electrodes. Depending on the potential difference between the electrodes, the color of the light control layer changes between transparent and dark blue using an oxidation-reduction reaction.
A light control film using the SPD method (Suspended Particle Device) utilizes the orientation of fine particles and is normally colored dark blue, but when a voltage is applied, it changes to transparent, and when the potential is turned off, it returns to its original dark blue color. The density can be adjusted by changing the voltage.
A light control film using the PDLC method (Polymer Dispersed Liquid Crystal) has a network structure made of a special polymer formed in the liquid crystal layer, and the action of the polymer network prevents the arrangement of liquid crystal molecules from being irregular. induces light scattering. Then, by applying a voltage, the liquid crystal molecules are aligned in the direction of the electric field, and light is not scattered, resulting in a transparent state.

(9) In each embodiment, an example has been described in which the unit optical shape 121 of the screen 10 is formed in the shape of a circular Fresnel lens, but it is not limited to this, and may be in the shape of a linear Fresnel lens. Further, although an example has been described in which the optical center of the circular Fresnel lens shape is located outside the screen area of the screen 10, the optical center is not limited to this, and the optical center may be located within the screen area of the screen 10. You may also do so.

(10) In the sixth embodiment, the display area of the first screen unit 10A and the display area of the second screen unit 10B match the screen (display area) of the screen 100 when viewed from the front direction of the screen 100. However, the present invention is not limited to this. For example, the display area of the first screen section 10A and the display area of the second screen section 10B partially overlap, and The area of the overlapping region may be larger than 50% of the area of the screen (display area) of the screen 100 when viewed from the Z direction (the normal direction of the screen surface). Even with this form, improvement in scintillation can be expected.
In addition, from the viewpoint of reducing scintillation of the image displayed on the screen of the screen 10 and displaying a good image, the area of the overlapping area of the display area of the first screen section and the display area of the second screen section is as follows. More preferably, the area is 90% or more of the area of the screen (display area) of the screen 100.

(11) In the sixth embodiment, an example in which two screens 10 are stacked has been described, but the present invention is not limited to this, and three or more screens may be stacked. The light condensing points of the three screens may be the same or different.

(12) In each embodiment, an example has been described in which the image source LS is a projector and the screen 10 has a reflective layer 13 that diffusely reflects incident light, but the image display device 1 is not limited to this. Alternatively, the image source may be a microdisplay such as an LCD (Liquid Crystal Display), and the screen may be a so-called HUD (head-up display) comprising a reflective layer that specularly reflects incident light.

(13) In the first embodiment, an example is given in which the shape of the unit optical shapes 121 makes the light diffusing effect in the arrangement direction of the unit optical shapes 121 larger than the light diffusing action in the direction orthogonal to the arrangement direction. explained. The invention is not limited to this, and for example, by giving regularity and anisotropy to the fine unevenness formed on the surface of the unit optical shape 121, anisotropy may be imparted to the light diffusion effect, The reflective surface may be curved when providing the unevenness.

(14) In a modification of the first embodiment, as shown in FIG. 8, the unit optical shape 121 has a continuous curved surface at the valley bottom V and a discontinuous curved surface at the apex T. did. The shape of the unit optical shape 121 is not limited to this, and various deformations can be adopted.
FIG. 27 is a diagram showing an example of a modified form of the unit optical shape 121.
As shown in FIG. 27, the curved surface may be continuous at the apex T, and the curved surface may be discontinuous at the valley bottom V. Further, although not shown, the curved surface may be continuous in both the apex T and the valley bottom V. Further, the convex direction of the curved surface may be convex toward the viewer as shown in FIG. 8, or concave toward the viewer as shown in FIG. 27.

In addition, although each embodiment and modification can also be used in combination suitably, detailed description is abbreviate|omitted. Furthermore, the present invention is not limited to the embodiments described above.

1 Video display device 2 Front window 3 Interior panel 4 Handle 10 Screen 10A First screen part 10B Second screen part 11 Base material layer 12 First optically shaped layer 13 Reflective layer 13a Reflective film 14 Second optically shaped layer 15 Protective layer 17 Bonding layer 20 Light control layer 20A First laminate for liquid crystal 20B Second laminate for liquid crystal 21A, 21B Base materials 22A, 22B Transparent electrodes 23A, 23B Alignment layer 24 Bead spacer 25 Sealing material 26, 27 Liquid crystal layer 28 Spacer 29A, 29B Linear polarizing plate 30 Adhesive layer 40 Light control layer 50 Support plate 60 Light absorption layer 51 Bonding layer 61 First glass plate 62 First intermediate layer 63 Second intermediate layer 64 Second glass plate 100 Screen 121 Unit optical shape 121a 1st Slope 121b Second slope 121c Connection surface 200 Light control section 210 Light control layers 210a, 210b End section 211 Photochromic layer 212 First shielding layer 213 Second shielding layer 214 Light guiding layer 215 High refractive index layer 215a Course changing section 216 First Low refractive index layer 217 Second low refractive index layer 220 Excitation light source

Claims (23)

A reflective screen that displays an image by reflecting a part of the image light projected from the image source,
an optical shape layer having optical transparency and having a plurality of unit optical shapes arranged on a back side surface;
a reflective layer formed on at least a portion of the unit optical shape, reflecting a portion of the incident light and transmitting at least a portion of the other incident light;
Equipped with
The unit optical shape has, in a cross-sectional shape cut in the arrangement direction, an acute-angled apex that is most protruding toward the back side and a curved valley bottom that is most concave toward the image source side, or a curved shape that is most protruding toward the back side. It has the apex part and the most concave acute-angled valley bottom part on the image source side,
The optically shaped layer has the apex portion and the valley bottom portion as boundaries,
a first surface on which the image light is incident;
a second surface that is narrower in width than the first surface and is opposite to the first surface;
has
The first surface and the second surface of the optically shaped layer have a curved cross-sectional shape when cut in the arrangement direction,
The light diffusing effect in the arrangement direction of the unit optical shapes is greater than the light diffusing action in the direction perpendicular to the arrangement direction,
When measuring the angular luminance distribution in a situation where image light is projected at the center of the screen and at the front with maximum luminance, the half-value angle in the arrangement direction of the unit optical shapes is equal to Reflective screen, larger than half angle. The reflective screen according to claim 1,
When measuring the angular luminance distribution in a situation where image light is projected at the center of the screen and in front with the maximum luminance, the half-power angle in the arrangement direction of the unit optical shapes is equal to 20% to 100% larger than the half-value angle,
A reflective screen featuring The reflective screen according to claim 1 or 2,
The optically shaped layer is
the first surface on which the image light is incident;
the second surface facing the first surface;
a connecting surface configured with a curved surface connecting the first surface and the second surface;
to have,
A reflective screen featuring. The reflective screen according to any one of claims 1 to 3,
The reflective layer has a rough surface at least on the image source side, and diffusely reflects a portion of the incident light;
A reflective screen featuring. The reflective screen according to claim 4,
The unit optical shape has a fine uneven shape on its surface,
The uneven shape has a shape in which the light diffusion effect in the arrangement direction of the unit optical shapes is higher than the light diffusion effect in the direction perpendicular to the arrangement direction of the unit optical shapes,
At least a surface of the reflective layer on the side of the unit optical shape has an uneven shape corresponding to the uneven shape;
A reflective screen featuring The reflective screen according to claim 4,
The unit optical shape has a fine and irregular uneven shape on its surface,
At least a surface of the reflective layer on the side of the unit optical shape has an uneven shape corresponding to the uneven shape;
A reflective screen featuring. The reflective screen according to any one of claims 1 to 6,
In the arrangement direction of the unit optical shapes, the amount of angular change from the output angle at which the reflected light of the reflective screen has the peak brightness to the output angle at which the brightness becomes 1/2 is +α _V 1, −α _V 2, and its absolute value is When the average value of the values is _αV , 5°≦ _αV ≦45°,
A reflective screen featuring. The reflective screen according to any one of claims 1 to 7,
In the arrangement direction of the unit optical shapes, the amount of angular change from the output angle at which the reflected light of the reflective screen has the peak brightness to the output angle at which the brightness becomes 1/2 is +α _V 1, −α _V 2, and its absolute value is When the average value of the values is α _V and the angle between the first surface and a plane parallel to the screen surface is θ1, in at least a part of the reflective screen, α _V < arcsin(n×sin( 2×(θ1))),
A reflective screen featuring. In the reflective screen according to any one of claims 1 to 8,
comprising a light absorption layer provided on the back side of the reflective layer in the thickness direction of the reflective screen;
A reflective screen featuring. The reflective screen according to any one of claims 1 to 9,
In the thickness direction of the reflective screen, a light control layer is provided on the back side of the reflective layer and changes the transmittance;
A reflective screen featuring The reflective screen according to claim 10,
The light control layer is
a transparent first electrode;
a transparent second electrode disposed opposite to the first electrode;
a light control material that is disposed between the first electrode and the second electrode and changes transmittance depending on the potential difference between the first electrode and the second electrode;
to have,
A reflective screen featuring. The reflective screen according to claim 11,
The light control material is a liquid crystal having a dichroic dye;
A reflective screen featuring. The reflective screen according to claim 12,
The light control layer includes a photosensitive material;
A reflective screen featuring. The reflective screen according to claim 13,
The photosensitive material changes its transmittance by receiving ultraviolet rays as excitation light,
comprising a light guide layer that guides excitation light to the photosensitive material;
A reflective screen featuring The reflective screen according to claim 14,
The light control layer includes a shielding layer disposed at a position sandwiching the photosensitive material and the light guide layer from both sides and shielding at least a part of the excitation light;
A reflective screen featuring. The reflective screen according to any one of claims 1 to 15,
the reflective layer is formed in a plurality of islands at a position where the image light of the unit optical shape is incident;
A reflective screen featuring. The reflective screen according to any one of claims 1 to 16,
the reflective layer includes at least one dielectric film;
A reflective screen featuring. The reflective screen according to any one of claims 1 to 17,
The optical shape layer has a circular Fresnel lens shape in which a plurality of the unit optical shapes are arranged concentrically;
A reflective screen featuring. The reflective screen according to claim 18,
The center of the circular Fresnel lens shape is provided outside the reflective screen;
A reflective screen featuring The reflective screen according to any one of claims 1 to 19,
A second optical shape layer having light transmittance and laminated so as to fill the valleys between the unit optical shapes is provided on the back side of the reflective layer in the thickness direction of the reflective screen;
A reflective screen featuring The reflective screen according to any one of claims 1 to 20,
Not having a light diffusion layer containing diffusion particles having the function of diffusing light;
A reflective screen featuring. The reflective screen according to any one of claims 1 to 21,
The reflective layer is provided with a plurality of layers at predetermined intervals in the thickness direction of the reflective screen;
A reflective screen featuring. A reflective screen according to any one of claims 1 to 22,
an image source that projects image light onto the reflective screen;
A video display device comprising:

Images