JP5780112B2 - Reflective screen, video display system - Google Patents

Description

  The present invention relates to a reflective screen and a video display system including the same.

In recent years, as a video source for projecting an image on a reflective screen, a short focus type video projection device (projector) that projects a video light at a relatively large incident angle from a close distance to realize a large screen display has been widely used. Yes.
Such a short focal point type image projection apparatus can project on the reflection screen from above or below at a larger incident angle than a conventional image source, and saves space in an image display system using the reflection screen. Etc.
In order to satisfactorily display the image light projected by such a short focus type image projection device, the surface of the lens layer having a linear Fresnel lens shape or a circular Fresnel lens shape formed by arranging a plurality of unit lenses is used. Various reflective screens and the like on which a reflective layer is formed have been developed (for example, Patent Documents 1 and 2).

JP-A-8-29875 JP 2008-76523 A

In the reflective screen as described above, the Fresnel lens shape of the lens layer has irregularities due to the unit lens. Therefore, when the reflective layer is formed of a highly reflective paint or the like, the thickness of the reflective layer near the top of the unit lens tends to be thin. If the thickness of the reflective layer near the top of this unit lens is insufficient, no protective layer or light-shielding layer was provided on the back side of the reflective layer in order to reduce production costs and reduce the weight and thickness of the reflective screen. In this case, there is a problem that external light from the back side of the reflective screen is observed as light leakage on the viewer side.
Such light leakage is observed when an image is not projected or when a dark image is projected, and degrades the quality of the reflective screen.
Although the above-described Patent Documents 1 and 2 describe a reflective screen having a Fresnel lens shape, no countermeasures against light leakage as described above are disclosed.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a reflective screen that can greatly reduce appearance defects such as light leakage due to external light, and that can display a good image at low cost, and an image display system including the same.

The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected and demonstrated, it is not limited to this.
The invention according to claim 1 is a reflection screen that reflects the image light projected from the image source and displays the image light so as to be observable, and has a lens layer having a Fresnel lens shape in which a plurality of unit lenses (121) are arranged on the back side. (12) and a reflection layer (11) that is formed on the back side of the lens layer and reflects light. The unit lens is convex on the back side and is parallel to the arrangement direction of the unit lenses. A lens whose cross-sectional shape in a cross-section parallel to the direction perpendicular to the screen surface is substantially quadrangular, and that is opposed to the top surface (121b), which is the top located on the back side, in the arrangement direction across the top surface A reflective screen (1) including a surface (121a) and a non-lens surface (121c), wherein the reflective layer is formed so as to cover at least the lens surface and the top surface. ) It is.

According to a second aspect of the present invention, in the reflective screen according to the first aspect, the Fresnel lens shape is a circular Fresnel lens shape, and the point (F) serving as the optical center thereof is outside the display area of the reflective screen. A reflective screen (10) characterized in that it is positioned.
According to a third aspect of the present invention, in the reflective screen according to the first or second aspect, the dimension (W) of the top surface (121b) in the arrangement direction as the distance from the image source increases in the arrangement direction. Is a reflective screen (10) characterized by the fact that
According to a fourth aspect of the present invention, in the reflective screen according to any one of the first to third aspects, the unit lens (121) absorbs light on at least a part of the non-lens surface (121c). A reflection screen characterized in that a portion is formed.

  The invention of claim 5 is characterized in that the reflecting screen (10) according to any one of claims 1 to 4 and an image source (50) for projecting image light onto the reflecting screen. This is a video display system.

  According to the present invention, it is possible to significantly reduce appearance defects such as light leakage due to external light, and to provide a reflective screen capable of displaying a good image at low cost and an image display system including the same.

It is a figure showing picture display system 1 of an embodiment. It is a figure explaining the layer structure of the reflective screen 10 of embodiment. It is a figure which shows a mode that the lens layer 12 of the reflective screen 10 of embodiment was observed from the back side front direction. It is a figure which shows an example of the manufacturing method of the concave shape which shapes the unit lens. It is a figure which shows the lens layer 12 and the reflection layer 91 of the reflection screen 10 of embodiment, and the reflection layer 90 of the reflection screen 90 of a comparative example.

Embodiments of the present invention will be described below with reference to the drawings. In addition, each figure shown below including FIG. 1 is the figure shown typically, and the magnitude | size, shape, etc. of each part are exaggerated suitably for easy understanding.
In addition, the terms “plate”, “sheet”, “film” and the like are used, but these are generally used in the order of thickness, “plate”, “sheet”, “film”. I am using it. However, there is no technical meaning for such use. Accordingly, the terms “sheet”, “plate”, and “film” can be appropriately replaced. For example, the sheet-like member may be a film-like member or a plate-like member.
Furthermore, numerical values such as dimensions and material names of each member described in the present specification are examples of the embodiment, and the present invention is not limited thereto, and may be appropriately selected and used.

  In addition, in this specification and a claim, a screen surface shows the surface used as the plane direction of a reflective screen when it sees as the whole reflective screen in this reflective screen, This screen surface is The plane is parallel to the plane direction of the screen (display screen).

(Embodiment)
FIG. 1 is a diagram illustrating a video display system 1 according to an embodiment. FIG. 1A is a perspective view of the video display system 1, and FIG. 1B shows the video display system 1 viewed from the side.
The video display system 1 includes a reflective screen 10, a video source 50, and the like.
In the present embodiment, a general video display system in which the reflective screen 10 reflects the video light L projected from the video source 50 and displays the video on the screen will be described. The system 1 may be, for example, a front projection television system that reflects image light projected from the image source 50 and displays an image on the reflection screen, or the reflection screen in addition to the reflection screen 10 and the image source 50. The interactive board system may include a position detection unit that detects positions on the 10 screens, a personal computer, and the like.

The video source 50 is a video projection device that projects the video light L onto the reflective screen 10, and is a short focus general-purpose projector or the like.
When the image source 50 is viewed from the normal direction (normal direction of the screen surface) in the use state, the image source 50 is the center in the left-right direction of the reflection screen, and the image of the reflection screen 10 ( It is arranged at a position below the display area.
The video source 50 can project the video light L from a position where the distance from the reflective screen 10 in a direction (depth direction) orthogonal to the screen of the reflective screen 10 is much closer than that of a conventional general-purpose projector. That is, the image source 50 has a shorter projection distance to the reflection screen 10 than a conventional general-purpose projector, and the incident angle of the image light L with respect to the reflection screen 10 is also large.

The reflection screen 10 is a screen that displays the image by reflecting the image light L projected by the image source 50 toward the observer O side. In the state of use, the screen (observation surface) on which the reflection screen 10 displays an image is planar, and when viewed from the observer O side, the observation surface is substantially rectangular with the long side direction being the left-right direction of the screen. is there.
In the following description, unless otherwise specified, the screen vertical direction, screen horizontal direction, and thickness direction are the screen vertical direction (vertical direction) and screen horizontal direction (horizontal direction) when the reflective screen 10 is used. The thickness direction (depth direction) is assumed.
The reflective screen 10 has a large screen (display area) such as 80 inches or 100 inches. In the reflective screen 10 of the present embodiment, for example, the screen size is a diagonal size of 80 inches (1771 × 996 mm).
The reflective screen 10 of this embodiment is supported by a frame member (not shown).

FIG. 2 is a diagram illustrating the layer configuration of the reflective screen 10 according to the embodiment. In FIG. 2A, it passes through the point C (refer to FIGS. 1A and 1B) which is the geometric center of the observation surface of the reflective screen 10, is parallel to the vertical direction of the screen, and is orthogonal to the screen surface. A part of a cross section (parallel to the thickness direction) is shown enlarged. 2B is an enlarged view of the unit lens 121 and the reflective layer 11 in the cross section shown in FIG. 2A, and FIG. 2C is a cross section corresponding to FIG. A unit lens 121 and a unit lens 121A are shown.
FIG. 3 is a diagram illustrating a state in which the lens layer 12 of the reflective screen 10 according to the embodiment is observed from the front side on the back side. In FIG. 3, the reflective layer 11 is omitted for easy understanding.
As shown in FIG. 2A, the reflective screen 10 includes a surface functional layer 14, a base material layer 13, a lens layer 12, a reflective layer 11, and the like in order from the image source side (observer side).
The base material layer 13 is a transparent or translucent sheet-like member that becomes the base material of the reflective screen 10. The surface functional layer 14 is integrally formed on the image source side (observer side) of the base material layer 13, and the lens layer 12 is integrally formed on the back side (back side).

Examples of the base material layer 13 include PET (polyethylene terephthalate) resin, PC (polycarbonate) resin, MS (methyl methacrylate / styrene) resin, MBS (methyl methacrylate / butadiene / styrene) having a thickness of 100 to 200 μm. A resin-made sheet-like member such as a resin, an acrylic resin, or a TAC (triacetyl cellulose) resin can be used. The base material layer 13 of the present embodiment uses a sheet-like member made of PET resin having a thickness of 100 μm.
In addition, the base material layer 13 is good also as a form which contains dyes and pigments, such as gray for making it a predetermined transmittance | permeability, and coloring agents, such as carbon black, and is colored. Moreover, the base material layer 13 may contain a light diffusing material such as particulates having a function of diffusing light from the viewpoint of widening the viewing angle. Furthermore, the base material layer 13 is good also as a form containing both a light-diffusion material and a coloring agent. In addition, the base material layer 13 may have a form in which a plurality of layers such as two or three layers are integrally laminated instead of a single layer.

The lens layer 12 is a light-transmitting layer provided on the back side (back side) of the base material layer 13, and a Fresnel lens shape is provided on the back side (opposite side of the base material layer 13). Is formed.
The Fresnel lens shape of the lens layer 12 of the present embodiment is a circular Fresnel lens shape, and a plurality of unit lenses 121 are formed along the screen surface around a point F (see FIG. 3) located outside the display area of the reflective screen 10. Are arranged concentrically adjacent to each other. That is, the circular Fresnel lens shape of the lens layer 12 is a circular Fresnel lens shape having a so-called offset structure in which the point F is an optical center (Fresnel center).
Therefore, as shown in FIG. 3, the lens layer 12 includes a plurality of unit lenses 121 having a partially circular shape (arc) when viewed from the front direction on the back side (direction orthogonal to the screen surface). Observed as is. However, the present invention is not limited to this. For example, a plurality of partially shaped unit lenses 121 such as a shape close to an ellipse may be arranged.
Further, a linear Fresnel lens shape in which the unit lenses 121 are arranged in one direction may be used according to the use environment of the reflection screen 10, the optical characteristics of the video source 50, or the like, and can be appropriately selected and used.

In the present embodiment, as shown in FIG. 3, when the lens layer 12 is viewed from the front side on the back side, it passes through the point C, which is the geometric center of the display area of the observation surface, and is parallel to the vertical direction of the screen. On the virtual plane A parallel to the thickness direction of the reflective screen 10, a point F serving as the optical center of the circular Fresnel lens shape is located below the display area of the reflective screen 10, and further on the virtual plane A In addition, below the point F, a point E serving as an image light projection port of the image source 50 is located.
In the present embodiment, as an example, when the lens layer 12 is viewed from the front direction on the back side, the dimensions of the points C and F in the vertical direction of the screen are the lower end of the screen in the vertical direction of the screen and the left and right sides of the screen. The size is about 1.2 times the size of the point D at the center of the direction.

The lens layer 12 of this embodiment is formed of an ultraviolet curable resin such as urethane acrylate or epoxy acrylate.
The lens layer 12 presses the other surface of the base material layer 13 against a molding die for shaping a circular Fresnel lens shape filled with an ultraviolet curable resin, and is cured by irradiating with ultraviolet rays. It is formed by an ultraviolet molding method or the like. Thus, by forming the lens layer 12 (unit lens 121) by the ultraviolet molding method, the unit lens 121 with finer pitch and higher shape accuracy can be formed.
The method for forming the lens layer 12 may be selected as appropriate, and is not limited to this. The lens layer 12 may be formed of other ionizing radiation curable resin such as an electron beam curable resin.

2A, 2B, and 2C, the unit lens 121 is parallel to the direction orthogonal to the screen surface (thickness direction of the reflective screen 10) and parallel to the arrangement direction of the unit lenses 121. The cross-sectional shape in a simple cross-section is a substantially square shape.
The unit lens 121 is convex on the back side, a lens surface 121a which is a Fresnel lens-shaped lens surface, a top surface 121b which is a top surface located on the back side, and a lens surface across the top surface 121b. 121a and a non-lens surface 121c facing each other. The lens surface 121a corresponds to a part of the lens surface of a convex lens that is convex on the back side.
In the usage state of the reflective screen 10, in the unit lens 121, the lens surface 121a is located on the upper side in the vertical direction with respect to the non-lens surface 121c with the top surface 121b interposed therebetween.
The top surface 121b of the present embodiment is parallel to the screen surface and the surface on the back side of the base material layer 13, and the cross-sectional shape of the unit lens 121 shown in FIG.

In the unit lens 121, as shown in FIG. 2B, the angle formed by the lens surface 121a and the surface parallel to the screen surface is α, and the angle formed by the non-lens surface 121c and the surface parallel to the screen surface is β (β> α).
Further, the arrangement pitch of the unit lenses 121 is P, and the dimension of the top surface 121b in the arrangement direction of the unit lenses 121 is W. The lens height of the unit lens 121 (the dimension from the top surface 121b in the thickness direction of the screen to the point v that becomes the valley bottom between the unit lenses 121) is h.

In order to facilitate understanding, in FIG. 2, the arrangement pitch P and the angles α and β of the unit lenses 121 are shown to be constant in the arrangement direction of the unit lenses 121. However, the unit lens 121 of the present embodiment actually has a constant arrangement pitch P and an angle β, but the angle α gradually increases with distance from the image source 50 in the arrangement direction of the unit lenses 121. Further, the dimension W and the lens height h of the top surface 121b also gradually increase as the distance from the video source 50 increases in the arrangement direction of the unit lenses 121.
However, the present invention is not limited to this, and the angle α and the dimension W may be constant, or the arrangement pitch P and the angle β may be gradually changed along the arrangement direction of the unit lenses 121, and image light is projected. According to the size of the picture element (pixel) of the video source 50, the projection angle of the video source 50 (the incident angle of video light on the screen surface of the reflective screen 10), the screen size of the reflective screen 10, the refractive index of each layer, etc. It can be changed as appropriate.

  In the present embodiment, as an example, the arrangement pitch P is 100 μm, and the angle α is about 7 ° at the central lower end in the horizontal direction of the screen of the reflective screen 10 and about 23 ° at the central upper end in the horizontal direction of the screen. Is 90 °, and the dimension W of the top surface 121b is about 4.1 μm at the center lower end in the left-right direction of the screen and about 19.9 μm at the center upper end in the left-right direction of the screen. In addition, the lens layer 12 of the present embodiment is made of an acrylic ultraviolet curable resin, and its refractive index is 1.55.

As shown in FIGS. 2B and 2C, the unit lens 121 has lens surfaces 121a and 121d, non-lens surfaces 121c and 121e, and a vertex 121t, and is parallel to the arrangement direction and in the thickness direction. The cross-sectional shape in the parallel cross-section corresponds to a shape obtained by cutting the top of the unit lens 121A having a substantially triangular shape (the broken line portion shown in FIG. 2C).
In this unit lens 121A, a surface 121d indicated by a broken line is a surface on the apex 121t side obtained by extending the lens surface 121a, and corresponds to a part of the lens surface of the unit lens 121A. However, the image light L is projected from below the reflection screen 10 at a predetermined projection angle, and the angle β is designed to be larger than the incident angle of the image light L at each point in the vertical direction of the screen of the reflection screen 10. Therefore, the image light L does not reach the surface 121d.
The unit lens 121 of the present embodiment has an apex portion (a broken line portion shown in FIG. 2C) having the surface 121d and a surface 121e corresponding to an extended portion of the non-lens surface 121c facing the surface 121d. This corresponds to a shape cut by a plane parallel to the arrangement direction 121 and the screen surface.
Accordingly, since the image light does not reach the top surface 121b, the top surface 121b does not affect the reflection of the image light L. Therefore, the width of the lens surface 121a is shorter than that of the conventional unit lens 121A, and the unit lens 121 of this embodiment having the top surface 121b does not reduce the reflectance of the image light.

Here, the mold 80 for shaping the lens layer 12 can be manufactured by the following manufacturing method as an example.
FIG. 4 is a diagram showing an example of a concave manufacturing method for shaping the unit lens 121.
The molding die 80 (mold) for shaping the Fresnel lens shape of the lens layer 12 is formed with a concave die for shaping the unit lens 121 by cutting the surface with a cutting tool b.
Like the unit lens 121 of the lens layer 12 of the present embodiment, when the dimension W of the top surface 121b is increased along the arrangement direction of the unit lenses 121, the vicinity of the point F serving as the Fresnel center (the screen of the reflective screen 10) On the lower end in the vertical direction, as shown in FIG. 4A, the cutting amount in the depth direction and the arrangement direction by the cutting tool b is small. However, as shown in FIGS. 4B and 4C, as the distance from the point F increases (as it goes toward the upper side in the vertical direction of the screen of the reflective screen 10), the angle of the bit b with respect to the mold 80 is changed while changing the inclination of the bit b. By increasing the cutting amount in the depth direction and the arrangement direction, it is possible to produce a shaping mold that shapes the unit lens 121 while using the same cutting tool b.
By using the manufacturing method as described above, the mold 80 having a concave mold capable of shaping the unit lens 121 of the present embodiment can be easily manufactured.

The reflective layer 11 has a function of reflecting light and is a layer formed on the back side of the lens layer 12. The reflective layer 11 covers at least the lens surface 121a and the top surface 121b, and in this embodiment, covers the lens surface 121a, the top surface 121b, and the non-lens surface 121c.
The reflective layer 11 pulverizes a white or silver paint, an ultraviolet curable resin or thermosetting resin containing a white or silver pigment or beads, a metal vapor-deposited film such as silver or aluminum, a metal foil, or the like. It is formed by a paint containing fine particles or fine flakes.
As a method for forming the reflective layer 11, various coating methods such as spray coating, die coating, screen printing, and groove filling by wiping can be selected. In the case of wiping, the lens surface 121a and the non-lens surface 121c can be easily covered with the reflective layer 11.
In order to display a bright image, the reflective layer 11 preferably has a reflectance of 40% or more, and more preferably 70% or more.

The reflective layer 11 of this embodiment is formed by spraying a silver paint containing a metal foil such as aluminum on the surface of the lens layer 12 on which the unit lenses 121 are formed.
As shown in FIG. 2A, the reflective layer 11 of the present embodiment fills the valleys between the unit lenses 121, covers the top surface 121b with a predetermined thickness, and the surface on the back side thereof Although the example which becomes substantially planar shape was shown, not only this but the form formed with predetermined thickness along the uneven shape of unit lens 121 may be sufficient, and if it has sufficient reflective characteristics The thickness may not be uniform.

The surface functional layer 14 is a layer provided on the viewer O side (image source side) of the base material layer 13.
The surface functional layer 14 may be provided with one or more appropriate functions such as an antireflection function, an antiglare function, an ultraviolet absorption function, an antifouling function, an antistatic function, a hard coat function, and a touch panel function. it can.
The surface functional layer 14 is a layer separate from the base material layer 13 and may be bonded to the base material layer 13 by an adhesive material (not shown) or the opposite side of the base material layer 13 from the lens layer 12. It may be formed directly on the surface.
The surface functional layer 14 of the present embodiment has an antiglare function and a hard coat function (scratch resistance function), and an ionizing radiation curable type having a hard coat function on the surface of the base material layer 13 on the viewer O side. A resin (for example, urethane acrylate) is applied with a film thickness of about 10 to 100 μm, and a fine uneven shape (mat shape) is cured by transferring it to the surface of the resin film. Is formed.

Here, the state of the image light and the external light incident on the reflection screen 10 of the present embodiment will be described.
As shown in FIG. 2A, the image light L projected from the image source 50 is incident from below the reflection screen 10, passes through the surface functional layer 14 and the base material layer 13, and is a unit lens of the lens layer 12. It enters into 121.
2A, the image light L enters the lens surface 121a, is reflected by the reflective layer 11, and is emitted from the reflective screen 10 toward the observer O side. Although the reflective layer 11 is also formed on the top surface 121b and the non-lens surface 121c, the angle β is larger than the incident angle of the image light L at each point in the vertical direction of the reflective screen 10 (preferably 90). °), and the image light L is projected from below the reflection screen 10, so that the image light L1 hardly enters the top surface 121b or the non-lens surface 121c and does not affect the reflection of the image light L. .

  On the other hand, unnecessary external light G such as illumination light enters mainly from above the reflection screen 10, passes through the surface functional layer 14 and the base material layer 13, and enters the unit lens 121 of the lens layer 12. Then, as shown in FIG. 2A, the external light G is reflected by the lens surface 121 a and travels mainly to the lower side of the reflective screen 10. Accordingly, when the external light G enters the reflective screen 10 and is reflected by the reflective layer 11, it does not reach the observer O side directly. Significantly less than that. Therefore, the reflective screen 10 can reduce a decrease in image contrast due to external light.

  Therefore, according to the reflective screen 10 of the present embodiment, the image light can be efficiently reflected to the observer O side by the reflective layer 11 formed on the lens surface 121a, and the outside light is the observer O side. Since the light is reflected in different directions, it is possible to display a good image with high brightness and contrast even in a bright room environment.

  FIG. 5 is a diagram illustrating the lens layer 12 and the reflective layer 11 of the reflective screen 10 of the embodiment and the lens layer 92 and the reflective layer 91 of the reflective screen 90 of the comparative example. FIG. 5A shows the lens layer 12 and the reflective layer 11 of the reflective screen 10 of this embodiment, and FIG. 5B shows the lens layer 92 and the reflective layer 91 of the reflective screen 90 of the comparative example. . In FIG. 5, in order to facilitate understanding, the base material layer and the surface functional layer in the reflective screen 10 of the embodiment and the reflective screen 90 of the comparative example are omitted.

The reflective screen 90 of the comparative example has the same configuration as that of the present embodiment, except that the cross-sectional shape of the unit lens 921 is a substantially triangular shape and the top surface 121b is not provided.
As shown in FIG. 5B, in the reflective screen 90 of the comparative example, the thickness of the reflective layer 91 near the vertex 921t of the unit lens 921 is thin.
Therefore, the thickness of the reflection layer 91 in the vicinity of the vertex 921t of the unit lens 921 is insufficient for the reflection characteristics of the image light and the light shielding property of the external light from the back side, and when displaying a dark scene image, When an image is not displayed, a phenomenon of light leakage occurs in which external light from the back side is shining out to the viewer side and is visually recognized. This is particularly likely to occur at the peripheral edge of the reflective screen 90 which is far from the point F serving as the Fresnel center and has a large angle α.
Such light leakage deteriorates the appearance of the reflective screen, lowers the quality, and degrades the image quality when displaying images of dark scenes.

In order to prevent this phenomenon, it is conceivable to increase the coating amount of the material forming the reflective layer 91 and increase the layer thickness. However, in order to form a thick reflective layer having a sufficient thickness even at the apex 921t, it is necessary to repeat the coating, drying, and curing processes a plurality of times, which leads to an increase in production cost and a reduction in work efficiency.
Further, although a method of forming a vapor deposition film as the reflective layer 91 is conceivable, it costs production cost. In particular, with a large screen reflective screen, it is difficult to form such a large area reflective layer, and the production cost is greatly increased. To increase.

On the other hand, since the reflective screen 10 of this embodiment has the top surface 121b, the reflective layer 91 having a predetermined layer thickness on the top surface 121b can be easily and stably applied by spray coating or the like. It can be formed and man-hours can be reduced. Therefore, it is possible to reduce production costs and man-hours, and to significantly improve light leakage due to external light from the back side.
Further, as described above, the mold 80 can be easily manufactured by using the single cutting tool b and changing the cutting amount without performing special processing, and the manufacturing cost of the mold 80 is reduced. be able to.

  As described above, according to the present embodiment, a good reflective screen that can display a good image with high brightness and high contrast, and that greatly reduces appearance defects due to light leakage due to external light, and a video display system including the same are provided. be able to. Moreover, according to this embodiment, such a favorable reflective screen and image display device can be manufactured at low cost.

(Deformation)
The present invention is not limited to the embodiment described above, and various modifications and changes are possible, and these are also within the scope of the present invention.
(1) In the present embodiment, an example in which the reflective layer 11 is formed on the non-lens surface 121c has been described. However, the present invention is not limited thereto, and for example, a black paint having an action of absorbing light on the non-lens surface 121c You may form a light absorption part by apply | coating. By forming such a light absorbing portion on the non-lens surface 121c, external light that mainly enters from above the reflective screen 10 and stray light generated inside the reflective screen 10 can be absorbed by the light absorbing layer. The improvement effect can be enhanced.

(2) In the present embodiment, the example in which the reflective screen 10 includes the surface functional layer 14, the base material layer 13, the lens layer 12, the reflective layer 11, and the like has been described. A light diffusing layer containing a diffusing material, a glass or resin substrate layer for increasing the rigidity of the reflecting screen and maintaining flatness, a colored layer for improving contrast, and the like may be provided.

(3) In the present embodiment, the unit lens 121 has an example in which the lens surface 121a, the top surface 121b, and the non-lens surface 121c are all flat. However, the present invention is not limited to this. For example, at least one surface is provided. It may be a curved surface, or a part of one of the surfaces may be a curved surface or the like. For example, when the top surface 121b is a gentle concave curved surface, the coating film of the reflective layer 11 applied on the top surface 121b is stabilized, and the coating property is improved.
Further, the lens surface 121a, the non-lens surface 121c, and the like are configured from a plurality of surfaces, and the cross-sectional shape of the cross section orthogonal to the sheet surface and parallel to the arrangement direction of the unit lenses is, for example, a substantially pentagonal prism shape, It is good also as a shape used as a substantially hexagonal column shape.

(4) In this embodiment, in the usage state of the reflection screen 10, the main incident direction of the image light is from below the reflection screen 10, and the point F serving as the Fresnel center is located below the reflection screen 10. An example is shown. However, the present invention is not limited to this. For example, the video source 50 is arranged above the reflective screen 10, the main incident direction of video light is from the top of the screen, and the point F serving as the Fresnel center is located above the reflective screen 10. In other words, the video display system 1 of the embodiment may be turned upside down.

(5) In the present embodiment, an example in which the lens layer 12 is integrally formed on one surface of the base material layer 13 by the ultraviolet molding method has been shown. However, the present invention is not limited thereto, and the lens layer 12 is formed by, for example, an extrusion molding method. May be. At this time, if the lens layer 12 has a sufficient thickness, the base material layer 13 may not be provided, or the lens layer 12 and the base material layer 13 may be extruded and molded together. Thereby, mass production becomes easier and can be provided at low cost.

(6) In the present embodiment, the reflective screen 10 has a substantially flat plate shape and its planarity is supported by a frame member (not shown). However, the present invention is not limited thereto, and for example, an adhesive layer It is good also as a form joined to a support plate or a wall surface via etc.
Moreover, in this embodiment, although the reflective screen 10 showed the example which is substantially flat form in a use condition and a non-use state, it is not restricted to this, As a form which can be wound up and can be stored when not in use Good. In the case of such a form, the back side of the reflective screen 10 may be covered with a cloth or resin light-shielding curtain that hardly transmits light or a protective layer that improves scratch resistance.

(7) In the present embodiment, an example in which a circular Fresnel lens shape is formed on the back side of the lens layer 12 of the reflective screen 10 and the Fresnel center is located outside the reflective screen 10 is shown. For example, a linear Fresnel lens shape in which the unit lenses 121 are arranged in the vertical direction of the screen may be formed.

  In addition, although this embodiment and modification can also be used in combination as appropriate, detailed description is abbreviate | omitted. Further, the present invention is not limited by the embodiments described above.

DESCRIPTION OF SYMBOLS 1 Video display system 10 Reflective screen 11 Reflective layer 12 Lens layer 121 Unit lens 121a Lens surface 121b Top surface 121c Non-lens surface 13 Base material layer 14 Surface functional layer

Claims (5)

A reflection screen that reflects the image light projected from the image source and displays the image light so as to be observable;
A lens layer having a Fresnel lens shape in which a plurality of unit lenses are arranged on the back side;
A reflective layer that is formed on the back side of the lens layer and reflects light;
With
The unit lens is
Convex to the back side, the cross-sectional shape in a cross section parallel to the direction orthogonal to the screen surface parallel to the arrangement direction of the unit lenses is a substantially square shape,
A top surface that is a top portion located on the back side, and a lens surface and a non-lens surface that face each other in the arrangement direction across the top surface,
The reflective layer is formed so as to cover at least the lens surface and the top surface;
Reflective screen featuring. The reflective screen according to claim 1.
The Fresnel lens shape is a circular Fresnel lens shape, and its optical center point is located outside the display area of the reflective screen.
Reflective screen featuring. The reflective screen according to claim 1 or 2,
In the arrangement direction, as the distance from the image source increases, the dimension of the top surface in the arrangement direction increases.
Reflective screen featuring. The reflective screen according to any one of claims 1 to 3,
The unit lens has a light absorbing portion formed on at least a part of the non-lens surface;
Reflective screen featuring. A reflective screen according to any one of claims 1 to 4,
An image source for projecting image light onto the reflective screen;
A video display system characterized by

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