JP6702462B2 - Reflective screen, video display system - Google Patents

Description

The present invention relates to a reflection screen and an image display system that reflect projected image light to display an image.

Conventionally, reflective screens having various configurations have been developed and used in video display systems. In recent years, a short-focus type image projection device (projector) that projects a large amount of image light from a close range to a reflection screen at a relatively large projection angle and is widely used. Reflection screens and the like have been developed to display the image light projected by the short focus type image projection device in a good condition.
The short focus type image projection device can project image light on the reflection screen from above or below at a projection angle larger than that of a conventional image source, and the distance between the image projection device and the reflection screen in the depth direction. Since it can be shortened, it can contribute to space saving of an image display system using a reflection screen.
Some reflection screens used in such image projection devices are provided with a reflection layer for reflecting a larger amount of image light toward the viewer side (for example, Patent Document 1).

The reflection screen of Patent Document 1 includes a light absorption layer and a reflection layer. The light absorption layer of this reflection screen is formed so that a plurality of unit shapes each of which is composed of two inclined surfaces are convex toward the image source side, and absorbs light by containing a pigment such as carbon black. Have the function to The reflection layer is formed of white resin on one inclined surface of the unit shape of the light absorption layer, and reflects the image light projected from the image source to the observer side.
In such a reflective screen, since the reflective layer is formed of the white resin as described above, the brightness of the reflected image light (screen gain) may be low and the contrast may be low.
When manufacturing such a reflection screen, white resin is applied to the unit shape of the light absorbing layer by a rotating roller. In that case, the white resin attached to the rotating roller is applied to the inclined surface of the unit shape. In order to apply properly, it is necessary that the rotating roller be easily attached to the inclined surface of the unit shape. Therefore, the light absorption layer has a low hardness (softness) and is formed of a material that is easily deformed. When a reflective layer is formed on such a light absorption layer, the unit shape or the reflective layer formed on the inclined surface may be damaged by a small external force or light contact, or the reflective layer may be removed from the inclined surface. It may be peeled off.

JP, 2006-23693, A

An object of the present invention is to provide a reflection screen and an image display system capable of suppressing scratches on the reflection layer and the light absorption layer and peeling of the reflection layer.

The present invention solves the above problems by the following means. It should be noted that, for ease of understanding, reference numerals corresponding to the embodiments of the present invention will be given and described, but the present invention is not limited thereto.
A first aspect of the present invention is a reflection screen (20) that reflects image light projected from an image source (LS) and displays the image light on a screen, and includes a first inclined surface (232) and a second inclined surface (233). A plurality of unit convex shapes (231) that are convex toward the image source (LS) side are arranged, and a light absorbing layer (23) that absorbs light and a valley bottom from the top side of the first inclined surface (232). A reflective layer (22) which is formed up to the front of the site and reflects light, and a surface of the light absorbing layer (23) and the reflective layer (22) on the image source (LS) side has a refractive index of 1. It is formed of a material having a low refractive index of 490 to 1.549 to have a substantially constant thickness along the surfaces of the light absorption layer (23) and the reflection layer (22) on the image source (LS) side. A reflective screen (20) comprising a light absorbing layer (23) and a protective layer (21) for protecting the reflective layer (22).
A second invention is the reflective screen (20) according to the first invention, wherein the reflective layer (22) is formed of a resin containing a plurality of scale-like metal thin films (22a). It is a reflective screen (20) characterized by.
A third invention is the reflective screen (20) according to the second invention, wherein the reflective layer (22) has eight or more layers of the metal thin film (22a) laminated on the first inclined surface (232). The reflective screen (20) is characterized in that
A fourth invention is the reflection screen (20) according to any one of the first invention to the third invention, an image source (LS) for projecting image light on the reflection screen (20), It is a video display system (1) provided with.

According to the present invention, it is possible to provide a reflection screen and an image display system capable of suppressing scratches on the reflection layer and the light absorption layer and peeling of the reflection layer.

It is a figure explaining the image display system of embodiment. It is a figure explaining the layer structure of the reflective screen of embodiment. It is a figure explaining the detail of the light absorption layer of an embodiment, a reflective layer, and a protective layer. It is a figure explaining an example of the manufacturing method of the reflective screen of embodiment. It is a figure which shows the layer structure of the reflective screen of a modification.

Hereinafter, embodiments of the present invention will be described with reference to the drawings and the like.
Each of the following drawings including FIG. 1 is a schematic view, and the size and shape of each portion are exaggerated as appropriate for easy understanding.
Although the terms plate, sheet, etc. are used, these are generally used in the order of increasing thickness in the order of plate, sheet, film. I'm using it. However, since there is no technical meaning in such proper use, these words can be appropriately replaced.
Furthermore, the numerical values such as the dimensions of each member and the material names described in the present specification are merely examples of the embodiment, and the present invention is not limited thereto and may be appropriately selected and used.

In the present specification, terms that specify a shape or a geometric condition, for example, terms such as parallel and orthogonal, mean that in addition to strict meaning, they have similar optical functions and can be regarded as parallel and orthogonal. It also includes the state with the error of.
In the present specification, the sheet surface (plate surface, film surface) refers to the plane direction of the sheet (plate, film) in each sheet (plate, film) when viewed as the sheet (plate, film) as a whole. It is assumed to indicate the surface that becomes.

(Embodiment)
FIG. 1 is a diagram illustrating a video display system 1 of this embodiment. FIG. 1A is a perspective view of the video display system 1, and FIG. 1B is a side view of the video display system 1.
The image display system 1 includes a reflection screen unit 10 including a reflection screen 20, an image source LS, and the like. In the image display system 1 of the present embodiment, the image light L projected from the image source LS is reflected by the reflection screen 20 and an image is displayed on the screen.
The image display system 1 can be used as, for example, a front projection television system that projects the image light L from the image source LS.

The image source LS is an image light projection device that projects the image light L onto the reflection screen 20. The image source LS of this embodiment is a general-purpose short focus type projector. The image source LS is the center of the screen of the reflective screen 20 in the left-right direction of the screen when the screen of the reflective screen 20 is viewed from the normal direction (the normal direction of the screen surface) in the use state, and It is arranged at a position lower than the (display area).
The screen surface indicates a surface in the plane direction of the reflective screen 20 when the reflective screen 20 is viewed as a whole.
The image source LS can project the image light L from a position where the distance from the reflection screen 20 in the direction orthogonal to the screen of the reflection screen 20 (thickness direction of the reflection screen 20) is significantly smaller than that of a conventional general-purpose projector. .. That is, the image source LS has a shorter projection distance to the reflection screen 20 and a larger incident angle of the image light L with respect to the screen surface of the reflection screen 20 than the conventional general-purpose projector.

The reflection screen 20 is a screen that reflects the image light L projected by the image source LS toward the observer O side and displays an image. In the use state, the observation screen of the reflection screen 20 has a substantially rectangular shape whose long side direction is the left-right direction of the screen when viewed from the observer O side.
In the following description, the screen up-down direction, the screen left-right direction, and the thickness direction are the screen up-down direction (vertical direction), the screen left-right direction (horizontal direction), and the thickness when the reflective screen 20 is used, unless otherwise specified. Direction (depth direction).
The reflective screen 20 has a large screen (display area) having a diagonal size of 100 inches or 120 inches, for example.

The image display system 1 according to the present embodiment includes an image source LS that is a short focus type projector, and a reflection screen 20 that reflects the image light projected from the image source LS to display an image. However, the present invention is not limited to this, and the image source LS is a conventional general-purpose projector having a long projection distance and a small projection angle of the image light (that is, the angle of incidence of the image light on the screen), and the reflection screen 20 is configured as such. It may also correspond to the video source LS.

FIG. 2 is a diagram illustrating the layer structure of the reflection screen 20 of the present embodiment.
In FIG. 2, a point A (see FIGS. 1A and 1B), which is the geometric center (screen center) of the observation screen (display area) of the reflection screen 20, passes through and is parallel to the vertical direction of the screen. , A part of the cross section perpendicular to the screen surface (parallel to the thickness direction) is shown enlarged.
As shown in FIG. 1, the reflection screen unit 10 includes a reflection screen 20, a flat plate-shaped support plate 30 arranged on the back side of the reflection screen 20, and a bonding layer 40. The reflection screen 20 and the support plate 30 are integrally joined via the joining layer 40.

The material of the support plate 30 is not particularly limited as long as it is a member having high rigidity, but, for example, a metal plate material such as aluminum or a resin plate material such as an acrylic resin is preferably used. .. In addition, the front and back surfaces are thin plates made of aluminum or the like, and a honeycomb structure formed of thin plates made of aluminum or the like is provided as a core material inside, so that the weight of the whole plate material is reduced (a so-called honeycomb panel). Etc. may be used. Further, the support plate 30 is preferably a member having no light transmissive property from the viewpoint of preventing reflection of external light, reduction in contrast due to external light, and the like.
The thickness of the support plate 30 is preferably 0.2 to 5.0 mm, more preferably 1.0 to 3.0 mm. If the thickness is less than 0.2 mm, the rigidity for supporting the flatness is insufficiently provided, and if it is more than 5.0 mm, the weight of the support plate 30 becomes heavy.
The reflective screen 20 is often thin and, by itself, does not have sufficient rigidity to maintain planarity. Therefore, the reflection screen 20 maintains the flatness of the screen by being integrally joined to the support plate 30.

The bonding layer 40 is a layer having a function of integrally bonding the reflection screen 20 and the support plate 30. The bonding layer 40 is formed of a pressure sensitive adhesive, an adhesive, or the like.

As shown in FIG. 2, the reflection screen 20 includes a protective layer 21, a reflection layer 22, a light absorption layer 23, and a base material layer 24 in this order from the image source side (observer side) in the thickness direction.
The base material layer 24 is a sheet-shaped member that is a base of the reflection screen 20, and the light absorption layer 23 is integrally formed on the image source side thereof.
The base material layer 24 is, for example, PET (polyethylene terephthalate) resin, PC (polycarbonate) resin, MS (methyl methacrylate/styrene) resin, MBS (methyl methacrylate/butadiene/styrene) resin, TAC (triacetyl cellulose) resin, PEN (polyethylene naphthalate) resin, acrylic resin and the like are preferably used.
The thickness of the base material layer 24 depends on the screen size of the reflection screen 20 and the like, but is preferably about 20 to 300 μm.

FIG. 3 is a diagram illustrating details of the light absorption layer 23, the reflection layer 22, and the protection layer 21 of the present embodiment.
FIG. 3A shows a state in which the light absorption layer 23 is observed from the front direction on the image source side, and the reflection layer 22 and the protection layer 21 are omitted for easy understanding. FIG. 3B shows a part of the cross section shown in FIG. 2 in a further enlarged manner. FIG. 3C shows an enlarged perspective view of the light absorption layer on which the reflection layer is formed. 3(b) and 3(c), the base material layer 24 located on the back side of the light absorption layer 23 is omitted for easy understanding.

The light absorbing layer 23 is a layer provided on the image source side (observer side) of the base material layer 24 and having a light absorbing property, and as shown in FIG. , A plurality of unit convex shapes 231 are arranged concentrically around the point C. The unit convex shape 231 is formed as a shape of a circular Fresnel lens in which a plurality of concentric circular unit lenses are arranged, and thus is formed in a shape corresponding to the unit lens. In this circular Fresnel lens shape, the point C which is the Fresnel center is located outside the screen (display area) of the reflection screen 20 and below the reflection screen 20.

In the present embodiment, the unit convex shape 231 of the light absorption layer 23 is formed on the surface on the image source side in a shape corresponding to the circular Fresnel lens-shaped unit lens by using the circular Fresnel lens shape as a shaping mold. However, the present invention is not limited to this. For example, the unit convex shape 231 is formed into a shape corresponding to the unit lens of the linear Fresnel lens shape by using a linear Fresnel lens shape arranged along the screen surface in the vertical direction of the screen as a shaping mold. Good.

As shown in FIG. 2 and FIG. 3B, the unit convex shape 231 is a cross section parallel to the direction orthogonal to the screen surface (thickness direction of the reflection screen 20) and parallel to the arrangement direction of the unit convex shape 231. The cross-sectional shape at is a substantially triangular shape.
The unit convex shape 231 is convex toward the image source, and includes a first inclined surface 232 and a second inclined surface 233 facing the first inclined surface 232.
In the present embodiment, in the usage state of the reflection screen 20, the unit convex shape 231 is positioned such that the first inclined surface 232 is vertically below the second inclined surface 233 with the top t interposed therebetween.
In the light absorption layer 23, the reflection layer 22 is formed on at least a part of the first inclined surface 232, the image light emitted from the image source LS is reflected to the viewer side through the reflection layer 22, and Unwanted external light such as illumination light is absorbed by the portion of the inclined surface or the first inclined surface where the reflective layer is not formed.

As shown in FIG. 3B, the angle formed by the first inclined surface 232 of the unit convex shape 231 and the surface parallel to the screen surface is α. The angle formed by the second inclined surface 233 and the surface parallel to the screen surface is β (β>α). Further, the arrangement pitch of the unit convex shapes 231 is P, and the height of the unit convex shape 231 (the dimension from the top t in the thickness direction of the screen to the portion v which is the valley bottom between the unit convex shapes 231) is h. is there.
For ease of understanding, FIG. 2 and the like show that the arrangement pitch P of the unit convex shapes 231 and the angles α and β are constant in the arrangement direction of the unit convex shapes 231. However, in the unit convex shape 231 of the present embodiment, the arrangement pitch P and the like are actually constant, but the angle α gradually increases as the distance from the point C that is the Fresnel center in the arrangement direction of the unit convex shape 231 increases. There is. Further, the height h also changes accordingly. The unit convex shape 231 of the present embodiment is formed such that the array pitch P is in the range of 50 to 200 μm, the height h is in the range of 0.5 to 60 μm, and the angle α of the first inclined surface 232 is 0. It is formed in the range of 5 to 50°, and the angle β of the second inclined surface 233 is formed in the range of 45 to 90°.
However, the arrangement pitch P is not limited to this, and the arrangement pitch P may gradually change along the arrangement direction of the unit convex shapes 231, and the size of the pixel of the image source LS that projects the image light L and the image. The projection angle of the light source LS (angle of incidence of image light on the screen surface of the reflection screen 20), the screen size of the reflection screen 20, the refractive index of each layer, and the like can be appropriately changed.

The light absorbing layer 23 is integrally formed on the surface of the base material layer 24 on the image source side. For the light absorption layer 23, a thermoplastic resin is used as a constituent material, and for example, it is desirable to use an elastic thermoplastic elastomer such as urethane resin, polyolefin resin, vinyl chloride resin or the like. The light absorption layer 23 is colored in a dark color by adding a colorant to the above-mentioned constituent materials. As the colorant, a dark-colored dye or pigment such as gray or black or a metal salt such as carbon black, graphite or black iron oxide is preferably used.
The light absorption layer 23 may be formed by a press molding method or the like depending on the shape of the unit convex shape 231. In the case of such a light absorption layer 23, a configuration may be adopted in which the light absorption layer 23 is laminated on the image source side of the base material layer 24 via a bonding layer or the like (not shown). In addition, when the extrusion molding method is possible, the light absorption layer 23 and the base material layer 24 may be integrally laminated.

The reflective layer 22 is a layer having a function of reflecting light. The reflective layer 22 has a sufficient thickness to reflect light, and is formed on at least a part of the first inclined surface 232 of the unit convex shape 231.
As shown in FIG. 2 and FIG. 3B, the reflective layer 22 of the present embodiment is a part of the first inclined surface 232, that is, a portion v that is a valley bottom from the top t side of the first inclined surface 232. Is formed up to. The reflection layer 22 is preferably formed from the top t side with a width of 20% or more of the width of the first inclined surface 232 in the arrangement direction of the unit convex shapes 231. Thereby, the image light projected from the lower side of the reflection screen 20 can be properly reflected to the observer side. The reflective layer 22 may be formed on the entire surface of the first inclined surface 232.

The reflective layer 22 is formed by spray-coating the first inclined surface 232 with a paint containing a scale-like metal thin film 22a having a high light reflectivity such as aluminum on the first inclined surface 232. The scale-like metal thin film 22a is arranged such that the surface perpendicular to the thickness direction is substantially parallel to the first inclined surface 232. Here, the term “substantially parallel” means not only that the plane perpendicular to the thickness direction of the metal thin film 22a is completely parallel to the first inclined surface 232, but also that the inclination with respect to the first inclined surface 232 is −10° to +10. It also includes the case in the range of °. Further, the scale-like metal thin film 22a means that the shape (outer shape) viewed from the thickness direction of the metal thin film 22a is a scale-like shape. , A circular shape, a polygonal shape, an amorphous shape obtained by crushing a thin film, and the like.

The reflective layer 22 is preferably formed with a thickness in the range of 0.5 to 5 μm in order to obtain good reflection characteristics of image light. In addition, the metal thin film 22a of the reflection layer 22 improves the reflection efficiency of the image light and prevents the light absorption layer 23 on the back side of the reflection layer 22 from being seen through, and the plurality of unit convex shapes 231 are provided. It is desirable that the entire surface of the first inclined surface 232 is laminated with an average of 8 layers or more.
Further, in order to efficiently reflect the incident image light, the reflective layer 22 has a regular reflectance Rt of 50%<Rt<70% and a diffuse reflectance Rd of 10%<Rd<50%. desirable.

The paint forming the reflective layer 22 is composed of a scale-like metal thin film 22a, a binder, a drying auxiliary agent, a control agent and the like. From the viewpoint of ease of application with a spray gun, this coating material preferably has a viscosity within the range of 50 to 1000 [cp] (measurement temperature: 23 degrees).
The metal thin film 22a is aluminum formed in a scale shape, and the thickness dimension thereof is formed in the range of 15 to 150 nm, more preferably 20 to 80 nm. The metal thin film 22a is formed to have an average value of 1 to 3 μm in the dimension in the vertical direction and the horizontal direction orthogonal to the thickness direction (hereinafter referred to as the vertical dimension and the horizontal dimension).
The metal thin film 22a is preferably contained within a range of 3 to 15% by weight ratio with respect to the weight of the entire coating material from the viewpoint of ensuring the light reflection function as the reflection layer.

The binder is a transparent bonding agent composed of a thermosetting resin. In the present embodiment, as the binder, a urethane thermosetting resin is used, but the binder is not limited to this, an epoxy thermosetting resin may be used, and an ultraviolet curable resin or the like may be used. May be. The binder may be used as a two-component curing type by adding a curing agent. If the resin is a urethane resin, polyisocyanate or the like can be used. If the resin is an epoxy resin, amines, etc. can be used. Can be used.
The drying auxiliary agent is a solvent that adjusts the drying time of the coating material applied to the lens layer to a predetermined time, and is a so-called slow-drying solvent. In this embodiment, a predetermined amount is included in the paint so that the time required for the paint applied to the back surface of the light absorption layer 23 to dry is about 1 hour. As the drying aid, for example, a mixed solvent of propylene glycol monomethyl ether acetate, ethylene glycol monobutyl ether, diisobutyl ketone and 3-methoxy-1-butyl acetate can be used.
The control agent is a solvent that controls the orientation of the metal thin film 22a contained in the paint. By including the control agent in the paint, the metal thin film 22a can be arranged substantially parallel to the first inclined surface 232. As the control agent, for example, silica, alumina, aluminum hydroxide, acrylic oligomer, silicone or the like can be used.

The protective layer 21 is a layer provided on the image source side (observer side) of the light absorption layer 23 and the reflection layer 22, and is formed transparent or substantially transparent. The protective layer 21 forms the outermost surface of the reflective screen 20 on the image source side.
The protective layer 21 has a hard coat function for protecting the light absorbing layer 23 and the reflective layer 22. Further, the protective layer 21 is formed of a material having a low refractive index in order to appropriately reflect the light incident from the image source LS to the viewer side via the reflective layer 22. In this embodiment, the protective layer 21 is formed by applying an epoxy acrylate resin having a hard coat function and low refractive index characteristics. Here, that the refractive index of the protective layer is low means that the refractive index of the protective layer is 1.490 to 1.549, which allows the image light projected from the image source LS to be appropriate. It can be reflected to the observer side.

The protective layer 21 of the present embodiment is formed to have a substantially constant thickness along the surfaces of the light absorption layer 23 and the reflection layer 22 on the image source side, and the thickness thereof is set to about 5 to 15 μm. Is desirable. When the thickness of the protective layer 21 is smaller than 5 μm, the thickness of the protective layer is too thin to sufficiently exhibit the function of the hard coat, which is not desirable. Further, if the thickness of the protective layer 21 is larger than 15 μm, the thickness of the protective layer becomes too thick, the weight of the entire reflective screen becomes too heavy, and the material cost for forming the protective layer increases, which is not desirable. .

Here, as described above, the light absorbing layer 23 is extremely soft because the thermoplastic elastomer having elasticity is used, and the hardness thereof is the pencil hardness test (JIS K5600-5-4 (1994)). Is less than “6B”. Therefore, when a small external force is applied, the unit convex shape 231 formed on the image source side or the reflection layer 22 formed on the first inclined surface 232 is damaged, or the reflection layer 22 is formed on the first inclined surface 232. The surface of the reflective screen on the image source side has very low scratch resistance.
Therefore, in the reflection screen 20 of the present embodiment, the protective layer 21 is provided on the image source side of the light absorption layer 23 and the reflection layer 22 to improve the scratch resistance of the image source side surface of the reflection screen 20. It suppresses the occurrence of problems.
Here, from the viewpoint of more effectively improving the scratch resistance, the thickness of the protective layer 21 and the material to be used are appropriately determined, and the hardness of the surface of the reflection screen 20 on the image source side is determined by a pencil hardness test. It is desirable to be formed so as to be “H” or more.

In addition to the above-mentioned hard coat function, the protective layer 21 can be provided by appropriately selecting one or more necessary functions such as an antiglare function, an ultraviolet absorbing function, an antifouling function and an antistatic function.
In addition, a layer having the above-mentioned antiglare function, ultraviolet ray absorbing function, antifouling function, antistatic function, etc. is provided between the protective layer 21, and the light absorbing layer 23 and the reflective layer 22 as another layer. Good.

Returning to FIG. 2, the states of the image light and the external light incident on the reflection screen 20 of the present embodiment will be described.
As shown in FIG. 2, most of the image light L1 projected from the image source LS enters from below the reflection screen 20, passes through the protective layer 21, and enters the unit convex shape 231 of the light absorption layer 23. ..

Then, the image light L1 is reflected by the reflection layer 22 formed on the first inclined surface 232, and is emitted toward the viewer O side from the reflection screen 20 in a substantially front direction. Therefore, the image light L1 is efficiently reflected and reaches the observer O, so that a bright image can be displayed.
Since the image light L1 is projected from below the reflection screen 20 and the angle β (see FIG. 3B) is larger than the incident angle of the image light L1 at each point of the reflection screen 20 in the vertical direction of the screen, The image light L1 does not directly enter the second inclined surface 233, and the second inclined surface 233 does not affect the reflection of the image light L1.

On the other hand, unnecessary external light G (G1, G2, G3) such as illumination light mainly enters from above the reflection screen 20, passes through the protective layer 21, and is a unit of the light absorption layer 23, as shown in FIG. It is incident on the convex shape 231.
Then, a part of the external light G1 is reflected by the reflective layer 22 on the first inclined surface 232 and mainly travels toward the lower side of the reflective screen 20, so that it does not directly reach the observer O side, and also reaches it. In that case, the amount of light is significantly smaller than that of the image light L1. Further, a part of the external light G2 enters the second inclined surface 233 of the light absorption layer 23 and is absorbed. Further, a part of the external light G3 is incident on and absorbed by the portion of the first inclined surface 232 of the light absorption layer 23 where the reflective layer 22 is not formed. Therefore, in the reflective screen 20, it is possible to suppress the deterioration of the image contrast caused by the external light G1, G2, and G3.
From the above, the reflective screen 20 of the present embodiment can display a bright and excellent image with high contrast even in a bright room environment.

Here, an example of a method of manufacturing the reflection screen 20 of the present embodiment will be described.
FIG. 4 is a diagram illustrating an example of a method for manufacturing the reflection screen 20 of this embodiment.
As shown in FIG. 4A, a base material layer 24 cut into a predetermined size is prepared.
Next, as shown in FIG. 4B, the light absorption layer 23 is formed on the surface of the base material layer 24, which is the image source side, by an ultraviolet molding method or the like.
The light absorption layer 23 presses the image source side surface of the base material layer 24 against a circular Fresnel lens-shaped mold filled with a thermoplastic resin containing a colorant, and after releasing the mold, the mold is released from the mold. Are formed. The method for forming the light absorption layer 23 may be appropriately selected and is not limited to this.

Next, as shown in FIG. 4C, a coating material containing a scale-like metal thin film 22a is sprayed onto the image source side of the light absorption layer 23 to form the reflection layer 22. The application of the paint is performed by moving the spray gun in parallel with the horizontal direction of the screen of the light absorbing layer 23 and moving it from the lower end of the vertical direction of the screen to the upper end at a predetermined moving pitch (for example, 70 mm pitch). At this time, the direction of the spray gun is preferably substantially perpendicular to the first inclined surface 232 in order to easily arrange the metal thin film 22a substantially parallel to the first inclined surface 232.
Finally, as shown in FIG. 4D, an epoxy acrylate resin is applied and cured on the image source side of the light absorption layer 23 and the reflection layer 22 to form the protective layer 21, and the reflection screen 20 is completed. To do.

From the above, the reflective screen of the present embodiment has the following effects.
(1) In the reflective screen 20, the reflective layer 22 is formed on at least a part of the first inclined surface 232, and the surface of the light absorbing layer 23 and the reflective layer 22 on the image source side is formed of a low refractive index material for protection. The layer 21 is formed. As a result, the reflection screen 20 can prevent the light absorption layer 23 and the reflection layer 22 from being damaged and the reflection layer 22 from being separated from the first inclined surface 232. In particular, the hardness of the light absorption layer 23 is low, which is effective when scratches or peeling are likely to occur.

(2) Since the reflective layer 22 of the reflective screen 20 is formed of a resin containing a plurality of scale-shaped metal thin films 22a, the reflective screen 20 is more reflective than a reflective screen formed of a white resin. The regular reflectance of the layer can be improved, and the brightness of the image light (gain of the screen) and the contrast can be improved.
Further, since the reflective layer 22 can be formed not only by the roll coater method but also by spray coating, the manufacturing efficiency of the reflective screen 20 can be improved.
When the reflective layer 22 is formed by spray coating, it is not necessary to bring the rotating roller into close contact with the first inclined surface 232. Therefore, the light absorption layer 23 is made of the above-mentioned elastic thermoplastic elastomer, etc. Need not be formed low. Therefore, the light absorption layer 23 may be formed of an ultraviolet curable resin such as urethane acrylate or epoxy acrylate. Even in such a case, the protective layer can prevent the light absorption layer and the reflection layer from being damaged.

(3) In the reflective screen 20, since the reflective layer 22 has eight or more metal thin films 22a laminated on the first inclined surface 232, the reflective efficiency of the image light is improved and the rear side of the reflective layer 22 is improved. It is possible to prevent the light absorption layer 23 of FIG.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and changes can be made as in the modifications described later, which are also included in the present invention. It is within the technical scope. Further, the effects described in the embodiments are merely enumerations of the most suitable effects generated by the present invention, and the effects according to the present invention are not limited to those described in the embodiments. It should be noted that the above-described embodiment and the modification described later can be appropriately combined and used, but detailed description thereof will be omitted.

(Variation)
FIG. 5 is a diagram showing a layer structure of the reflection screen 20 of the modified embodiment, and is a diagram corresponding to FIG. 2.

(1) In the above-described embodiment, the reflective screen 20 shows an example in which the protective layer 21 is formed with a substantially constant thickness along the surfaces of the light absorbing layer 23 and the reflective layer 22 on the image source side. But. It is not limited to this. For example, as shown in FIG. 5, the protective layer 21 may fill the boundary between the adjacent unit convex shapes 231 so that the surface of the reflective screen 20 on the image source side is formed substantially flat. Thereby, the hardness of the surface of the reflection screen 20 on the image source side can be further improved.
In this case, the protective layer 21 has a thicker layer than that of the above-described embodiment, and thus it is desirable to provide an antiglare function in addition to the hard coat function. The anti-glare function can be realized by, for example, transferring a fine uneven shape (matte shape) to the surface of the resin film to cure it, and forming the fine uneven shape on the surface. You can
Further, since the protective layer 21 is made of a material having a low refractive index, the image light projected from the image source can be appropriately reflected to the observer side via the reflective layer 22.

(2) The paint forming the reflective layer 22 of the present embodiment may contain a dark color material. Thereby, at least a part of the light that is incident on the reflective layer 22 in the direction parallel to the first inclined surface or the light that is diffusely reflected by the edge of the scale-like metal thin film 22a included in the reflective layer 22 is absorbed. Therefore, the image displayed on the reflection screen can be improved.
Here, as the dark-colored material, a dark-colored pigment or dye can be used, and for example, carbon black (carbon particles), fibrous carbon, scale-like carbon, or the like can be used. Further, the dark-colored material is preferably contained within a range of 10 to 30% by weight ratio with respect to the weight of the entire coating material from the viewpoint of achieving both the light reflection function and the light absorption function described above. If the weight ratio is less than 10%, the amount of dark-colored material becomes too small with respect to the entire reflective layer 22, and the above-described light absorption effect cannot be sufficiently exerted. On the other hand, if the weight ratio is more than 30%, the amount of the dark-colored material with respect to the base material (binder) of the reflective layer 22 becomes too large, and the light reflecting function of the reflective layer 22 deteriorates.

(3) Although the metal thin film 22a of the reflective layer 22 of the present embodiment has been described by using an example of using scaly aluminum, the present invention is not limited to this, and for example, a metal such as silver or nickel is used. It is also possible.
(4) The reflection screen 20 of the present embodiment may be made of glass or resin and may be provided with a highly rigid transparent substrate layer in order to maintain the flatness of the screen.

(5) In the present embodiment, the example in which the first inclined surface 232 and the second inclined surface 233 are planar as shown by a straight line in FIG. 2 and the like is shown, but the present invention is not limited to this, and the first inclined surface Part of the surface 232 or the second inclined surface 233 may be curved.
Further, in the present embodiment, the example in which the first inclined surface 232 and the second inclined surface 233 of the unit convex shape 231 are both single surfaces is shown, but the present invention is not limited to this, and for example, at least one surface is Alternatively, it may be configured by a plurality of surfaces.

(6) In the present embodiment, the example in which the reflective layer 22 is formed by spray coating a coating material containing a scale-shaped metal thin film 22a is shown, but the present invention is not limited to this. For example, the reflective layer 22 may be formed by a so-called roll coater method in which a rotating roller to which paint is attached is pressed against the surface of the light absorption layer 23 on the image source side to apply.

(7) In this embodiment, the image source LS is located below the reflection screen 20 (reflection screen unit 10) in the vertical direction, and the image light L is projected obliquely from below the reflection screen 20. However, not limited to this, for example, the image source LS may be positioned above the reflection screen 20 in the vertical direction, and the image light L may be obliquely projected from above the reflection screen 20.

It should be noted that the above-described embodiments and modifications can be used in combination as appropriate, but detailed description thereof will be omitted. Further, the present invention is not limited to the above-described embodiments and the like.

DESCRIPTION OF SYMBOLS 1 Image display system 10 Reflective screen unit 20 Reflective screen 21 Protective layer 22 Reflective layer 22a Metal thin film 23 Light absorbing layer 231 Unit convex shape 232 First inclined surface 233 Second inclined surface 24 Base material layer 30 Support plate 40 Bonding layer LS Image source

Claims (3)

A reflective screen that reflects the image light projected from the image source and displays it on the screen,
A light absorbing layer that has a first inclined surface and a second inclined surface, and that has a plurality of unit convex shapes that are convex toward the image source side and that absorbs light;
A reflective layer that is formed between the top side of the first inclined surface and before the part that becomes the valley bottom and reflects light;
The surface of the light absorption layer and the reflection layer on the image source side is made of a material having a low refractive index of 1.490 to 1.549 so as to extend along the surface of the light absorption layer and the reflection layer on the image source side. And a protective layer formed with a substantially constant thickness to protect the light absorbing layer and the reflective layer,
Equipped with
The reflective layer is formed of a resin containing a plurality of scale-shaped metal thin films, and the regular reflectance Rt is 50%<Rt<70%, and the diffuse reflectance Rd is 10%<Rd<50%. Is a reflective screen. The reflective screen according to claim 1 ,
In the reflective layer, eight or more layers of the metal thin film are laminated on the first inclined surface,
Reflective screen featuring. A reflective screen according to claim 1 or claim 2 ,
An image source for projecting image light on the reflection screen,
Video display system including.

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