JP2006301588A - Reflective screen and method of manufacturing reflective screen - Google Patents

Abstract

The present invention provides a reflection screen that can obtain an image with high contrast, high brightness, and no reflection, and a method for manufacturing the reflection screen.
A unit prism shape 12 having a substantially wedge shape having a width on the image source side wider than a width on the back surface side and formed side by side along the screen surface, and formed on the back surface side and passing through the unit prism shape 12 The reflection layer 13 that reflects the image light and the light absorbing portion formed between the unit prism shapes 12 are provided.
[Selection] Figure 1

Description

  The present invention relates to a reflective screen for observing image light from the front by reflecting it with a reflective surface, and a method for manufacturing the reflective screen.

  Conventionally, this type of reflection screen has been known in which a light transmission diffusion layer is provided on the front side of a transparent sheet and a linear Fresnel lens surface for light reflection is provided on the back side (for example, Patent Document 1). Patent Document 2 discloses a configuration of a reflective screen that can suppress a decrease in contrast due to external light and obtain a suitable viewing angle. Further, Patent Document 3 describes a reflective screen by combining a lenticular lens and a linear Fresnel lens arranged in a direction orthogonal to the back surface provided with a reflective portion.

However, there has been a request to obtain an image with higher contrast and a request to obtain an image with the highest possible brightness even when the amount of light from the projection-side light source is small. Even when a high-brightness image is obtained, it is always required to eliminate unnecessary reflections.
Furthermore, the above-described conventional reflective screen has a problem that the manufacturing process becomes complicated, resulting in an increase in manufacturing cost.

Further, Patent Document 4 relates to a reflective screen that reflects and observes light projected obliquely from the front, and a reflection surface and a light absorption surface are formed on a screen surface having a sawtooth cross section so that image light and external light can reach. A reflective screen having different surfaces is disclosed.
However, in the reflection screen described in Patent Document 4, it is necessary to manufacture the reflection surface and the light absorption surface clearly on a screen surface having a sawtooth cross section, but one of the sawtooth peaks is a reflection surface, It is difficult to make the other as a light-absorbing surface, and there is a problem that the manufacturing unit price becomes high.
JP-A-8-29875 Japanese Patent Laid-Open No. 10-62870 JP 2002-31507 A JP-A-2-262134

  An object of the present invention is to provide a reflective screen that can obtain an image with high contrast, high brightness, and no reflection, and that is easy to manufacture, and a method for manufacturing the reflective screen.

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 the Example of this invention is attached | subjected and demonstrated, it is not limited to this.
The invention according to claim 1 is a reflective screen that allows the image light projected from the image source (L) to be reflected and observed, and is a light transmissive portion capable of transmitting light in a cross section orthogonal to the screen surface. (12, 22) and a light absorption part (14, 24) for absorbing light, wherein the light transmission part and the light absorption part are alternately formed along the screen surface, On the back side of the light transmission part, there is a reflection screen provided with a reflection layer (13, 23) for reflecting the image light that has passed through the light transmission part.

According to a second aspect of the present invention, in the reflective screen according to the first aspect, the light transmission portion has a substantially wedge shape in which the width on the image source side is wider than the width on the back surface side in a cross section orthogonal to the screen surface. A reflection screen (10, 20) is characterized in that it has unit prism shapes (12, 22) formed in a large number along the screen surface.
According to a third aspect of the present invention, in the reflective screen according to the first or second aspect, the light absorbing portion (14, 24) is more than a refractive index of a material forming the unit prism shape (12, 22). A reflective screen (10, 20) characterized by a low refractive index.
According to a fourth aspect of the present invention, in the reflective screen according to the first or second aspect, the light absorbing portion (14, 24) includes micro beads that absorb light. 20).
According to a fifth aspect of the present invention, in the reflective screen according to the fourth aspect, the light absorbing portion is obtained by kneading the micro beads in a resin having a refractive index lower than that of the material forming the unit prism shape. It is a reflective screen characterized by being formed.
According to a sixth aspect of the present invention, in the reflective screen according to any one of the first to fifth aspects, the reflective layer (13, 23) has the light transmitting portion or the unit prism shape (12, 22). The reflective screen (10, 20) is characterized in that it is formed only at a portion corresponding to the top of the substantially wedge-shaped portion.
A seventh aspect of the present invention is the reflective screen according to any one of the second to sixth aspects, wherein the unit prism shape (22) is an asymmetric first prism surface (22a) in the direction in which the unit prisms are arranged. And a second prism surface (22b).
The invention of claim 8 is the reflecting screen according to claim 7, wherein the first prism surface (22a) is formed of one type of surface, and the second prism surface (22b) is at least The reflection screen is characterized by being formed by two types of surfaces (22b-1, 22b-2).
According to a ninth aspect of the present invention, in the reflective screen according to the seventh or eighth aspect, the first prism surface (22a) is formed by a single plane, and the second prism surface (22b). Are two types of planes: a first plane (22b-1) formed at a position close to the back surface and a second plane (22b-2) formed closer to the video source than the first plane. The first plane is formed by a plane symmetrical to the first prism surface, and the angle (15 °) between the second plane and the normal of the screen surface is A reflection screen (20) characterized in that the first plane is larger than the angle (5 °) made with the normal of the screen surface.
A tenth aspect of the present invention is the reflective screen according to any one of the first to ninth aspects, wherein a boundary surface between the light transmitting portion (82) and the light absorbing portion (84) is relative to the screen surface. A reflective screen (80) characterized by satisfying a relationship of 5 ° ≦ θ ≦ 15 °, where θ is an angle formed with a normal line.
An eleventh aspect of the present invention is the reflective screen according to any one of the first to tenth aspects, wherein an anti-glare process, an antireflection process (15, 25), and an antistatic process are performed on the surface on the image source side. The reflective screen (10, 20) is characterized by being subjected to at least one of a hard coat treatment and an antifouling treatment.

According to a twelfth aspect of the present invention, in the reflective screen according to any one of the first to eleventh aspects, a regular reflection preventing layer (35, 45) that reduces a component that is regularly reflected is provided on a surface on the image source side. , 55, 65) is formed, which is a reflective screen (30, 40, 50, 60).
According to a thirteenth aspect of the present invention, in the reflective screen according to the twelfth aspect, the haze value by the regular antireflection layer (35, 45, 55, 65) is in the range of 25% or more and 90% or less. This is a reflective screen (30, 40, 50, 60).
According to a fourteenth aspect of the present invention, in the reflective screen according to the twelfth or thirteenth aspect, the regular antireflection layer (35, 45, 55, 65) has a fine irregular shape formed on a surface thereof, and the fine screen It is a reflective screen (30, 40, 50, 60) characterized by reducing the component that is regularly reflected by the uneven shape.
According to a fifteenth aspect of the present invention, in the reflective screen according to the fourteenth aspect, the regular antireflection layer includes a large number of micro beads and a binder that fixes the micro beads, and the micro beads are fixed. The reflective screen is characterized in that the fine irregularities are formed so as to protrude toward the image source side from the portion where only the binder is not fixed and the fine beads are not fixed.
The invention of claim 16 is characterized in that, in the reflective screen according to claim 14 or claim 15, a flat surface parallel to the screen surface is not substantially formed in the fine uneven shape. It is a reflective screen (30, 40, 50, 60).
According to a seventeenth aspect of the present invention, in the reflective screen according to the twelfth or thirteenth aspect, the regular antireflection layer is formed with a lens array in which minute unit lens shapes are arranged one-dimensionally or two-dimensionally. The reflection screen is characterized in that a component regularly reflected by the lens array is reduced.
The invention of claim 18 is the reflecting screen according to claim 17, wherein the lens array is a lenticular lens array formed by arranging unit lens shapes in a one-dimensional direction, and the unit lens shapes have the same cross section. The direction extending in the shape is a reflective screen characterized in that the light transmitting portion and the light absorbing portion are substantially orthogonal to the direction extending in the same cross-sectional shape.
According to a nineteenth aspect of the present invention, in the reflective screen according to the seventeenth aspect, the lens array is a microlens array formed by arranging unit lens shapes in a two-dimensional direction. When viewed from the normal direction, the longitudinal direction is a reflective screen characterized in that the light transmission part and the light absorption part are substantially orthogonal to the direction in which the same cross-sectional shape extends.
According to a twentieth aspect of the present invention, in the reflective screen according to any one of the twelfth to nineteenth aspects, an antistatic treatment, a hard coat treatment, and an antifouling are further provided on the image source side of the regular antireflection layer. At least one of the treatments is applied along the surface shape of the regular antireflection layer, and the antireflection, hard coat, and antifouling properties are maintained while maintaining the function of reducing the regular reflection component of the regular antireflection layer. It is a reflective screen characterized by having a function.
The invention according to claim 21 is the reflection screen according to any one of claims 1 to 20, wherein the reflection layer (13, 23, 33, 43, 53, 63) has a reflectance of 40%. This is a reflective screen (10, 20, 30, 40, 50, 60) characterized by the above.
The invention according to claim 22 is the reflective screen according to any one of claims 1 to 21, wherein the reflective layer (13, 23, 33, 43, 53, 63) has a diffuse reflectance Rd. It is a reflective screen characterized by being in the range of 10% or more and 70% or less.
According to a twenty-third aspect of the present invention, in the reflective screen according to the twenty-second aspect, the reflective layer (53, 63) is subjected to a surface diffusion treatment on the surface thereof, so that the diffuse reflectance Rd is within the predetermined range. The reflection screen (50, 60) is characterized by being inside.
The invention of claim 24 is the reflecting screen (50, 60) according to claim 23, wherein the reflecting layer (53, 63) is different in intensity of diffusing action depending on the direction. .
The invention according to claim 25 is the reflecting screen according to claim 24, wherein the reflecting layer (53, 63) has a diffusing action in a horizontal direction stronger than a vertical direction in a use state of the screen. Screen (50, 60).
The invention of claim 26 is the reflecting screen according to any one of claims 1 to 25, wherein the reflecting layer is formed by combining a plurality of regions (73a, 73b) having different diffuse reflectances Rd. A reflective screen (70) characterized in that
The invention according to claim 27 is the reflective screen according to any one of claims 1 to 26, further comprising a deformed diffusion layer (48) for strongly diffusing transmitted light only in a specific direction, A reflective screen (40) characterized by
According to a twenty-eighth aspect of the present invention, in the reflective screen according to the twenty-seventh aspect, the light transmitting portion (42) and the light absorbing portion (44) are arranged in a direction in which the light transmitted by the irregular diffusion layer (48) is strongly diffused. Is a reflecting screen (40) characterized in that they coincide with the direction of extension with the same cross-sectional shape.
The invention of claim 29 is the reflecting screen according to any one of claims 1 to 28, wherein the reflecting layer (33, 43) is a reflecting film or a reflecting plate (33) having a high reflectivity. 43), and the reflective film or the reflective plate has an adhesive layer (37, 47) with respect to the light transmission part (32, 42) and the light absorption part (34, 44), Or it is a reflective screen (30, 40) characterized by being laminated | stacked using the adhesion layer.
The invention of claim 30 is the reflecting screen according to claim 29, wherein the reflecting film or the reflecting plate (33, 43), the light transmitting part (32, 42) and the light absorbing part (34, 44) are provided. The reflection screen (30, 40) is characterized in that the interval (t) is equal to or less than ½ of the width (A) of the light transmission part on the reflection layer side.
The invention of claim 31 is the reflecting screen according to claim 29 or 30, wherein a light diffusing material is mixed in the adhesive layer or the adhesive layer. is there.

The invention according to claim 32 is the reflective screen according to any one of claims 1 to 31, wherein the width of the rear surface side of the light transmission part (82) in a cross section orthogonal to the screen surface is set. The reflective screen (80) is characterized by satisfying a relation of 1/4 ≦ wt / wa ≦ 2 where wt is the width of the back side of the light absorbing portion (84) and wa.
According to a thirty-third aspect of the present invention, in the reflective screen according to any one of the first to thirty-second aspects, an ultraviolet absorbing layer (85) having an ultraviolet absorbing function is provided on the surface on the image source side. A reflective screen (80).

A 34th aspect of the present invention is the reflective screen according to any one of the 1st to 33rd aspects, wherein the reflective screen can be rolled up when not in use.
The invention of claim 35 is the reflecting screen according to any one of claims 2 to 34, wherein the second unit prism shape arranged in a direction orthogonal to the direction in which the unit prism shapes are arranged is the unit prism. It is a reflective screen characterized by being formed on the image source side further than the shape.

A thirty-sixth aspect of the present invention is the method of manufacturing a reflecting screen according to any one of the second to thirty-fourth aspects, wherein the unit prism shape (12, 22) is molded with a resin. A forming step, a reflecting layer forming step of forming the reflecting layer (13, 23) only in a portion corresponding to the substantially wedge-shaped top of the unit prism shape, and after forming the reflecting layer, And a light absorbing part forming step of forming the light absorbing part (14, 24).
The invention of claim 37 is the method of manufacturing a reflective screen according to any one of claims 2 to 34, wherein the unit prism shape (12, 22) is molded with a resin. A shaping step, a light absorbing portion forming step of forming the light absorbing portion (14, 24) between the formed unit prism shapes, and the reflective layer (13, 23) after forming the light absorbing portion. A reflective layer forming step of forming a reflective screen.
The invention of a thirty-eighth aspect is the method of manufacturing a reflective screen according to the thirty-sixth or thirty-seventh aspect, wherein the light absorbing portion forming step uses a material for forming the light absorbing portion (14, 24) by wiping as the unit. It is a manufacturing method of a reflective screen characterized by filling between prism shapes (12, 22).

According to the present invention, the following effects can be obtained.
(1) A light transmission part capable of transmitting light and a light absorption part that absorbs light, wherein the light transmission part and the light absorption part are alternately formed along a screen surface, Since the reflection layer that reflects the image light that has passed through the light transmission portion is provided, unnecessary external light can be absorbed and an image with high contrast can be displayed.

(2) Since a unit prism shape formed in a large number along the screen surface and a reflective layer formed on the back surface and reflecting the image light that has passed through the unit prism shape are provided, the image light is directed to a necessary observation direction. It can be reflected efficiently.

(3) Since the refractive index of the light absorbing portion is lower than the refractive index of the material forming the unit prism shape, the image light can be totally reflected at the boundary surface between the unit prism shape and the light absorbing portion. Bright images can be displayed with minimal loss.

(4) Since the light absorbing portion includes micro beads that absorb light, it is possible to easily and reliably obtain an external light absorbing action.

(5) The light absorbing portion is formed by kneading microbeads in a resin having a refractive index lower than the refractive index of the material forming the unit prism shape, so that the microbeads can be formed without forming a back surface protective layer. Can be fixed.

(6) Since the reflective layer is formed only in the portion corresponding to the light transmitting portion or the substantially wedge-shaped top portion of the unit prism shape, it can be easily manufactured.

(7) Since the unit prism shape has the first prism surface and the second prism surface that are asymmetric in the direction in which the unit prisms are arranged, the unit prism shape has an optimum shape according to the planned direction of the image light or the external light. can do. Therefore, the image light can be reflected more efficiently and the outside light can be absorbed more efficiently.

(8) Since the first prism surface is formed by one type of surface and the second prism surface is formed by at least two types of surfaces, the image light is more efficiently reflected and external light is reflected. It is possible to make the shape more convenient in order to absorb water more efficiently.

(9) The first prism surface is formed by a single plane, and the second prism surface has two types of planes, a first plane and a second plane. The plane is formed by a plane symmetrical to the first prism surface, and the angle formed by the second plane and the normal of the screen surface is larger than the angle formed by the first plane and the normal of the screen surface. The incident angle of external light with respect to the second plane can be reduced, and more external light can be absorbed. Moreover, since the frontage with respect to the lower side is widened, the image light can be more reliably taken into the unit prism shape.

(10) The angle θ formed by the boundary surface between the light transmitting portion and the light absorbing portion and the normal to the screen surface satisfies the relationship of 5 ° ≦ θ ≦ 15 °, so that a bright and high contrast image can be displayed.

(11) The surface on the image source side is subjected to at least one of anti-glare treatment, antireflection treatment, antistatic treatment, hard coat treatment, and antifouling treatment. By selecting, a higher quality reflective screen can be obtained.

(12) Since the regular reflection preventing layer for reducing the regular reflection component is formed on the surface on the image source side, the image source and the illumination light are prevented from being transferred to the reflection screen surface, so that it is clearer. An image can be displayed.

(13) Since the haze value by the regular reflection preventing layer is in the range of 25% or more and 90% or less, reflection can be effectively prevented without whitening.

(14) The regular antireflection layer has a fine concavo-convex shape formed on the surface and reduces the components that are specularly reflected by the fine concavo-convex shape, so that it is easy to manufacture and reliably prevents migration. Can do.

(15) The regular antireflection layer has a large number of microbeads and a binder to which the microbeads are fixed, and the portion where the microbeads are fixed is only the binder without the microbeads being fixed. Since the fine uneven shape is formed so as to protrude from the image source side to the image source side, the regular reflection preventing effect and the diffusion effect can be arbitrarily set by changing the mixing ratio of the fine beads.

(16) Since the flat surface that is parallel to the screen surface is not substantially formed in the fine concavo-convex shape, the reflection of the image source can be reliably prevented.

(17) The regular reflection preventing layer is formed with a lens array in which minute unit lens shapes are arranged one-dimensionally or two-dimensionally, and reduces the components that are regularly reflected by the lens array. The viewing zone can be arbitrarily set while preventing the image from being crowded.

(18) The lens array is a lenticular lens array formed by arranging unit lens shapes in a one-dimensional direction, and the direction in which the unit lens shapes extend in the same cross-sectional shape is determined by the light transmission unit and the light absorption unit. Since it is substantially orthogonal to the direction extending in the same cross-sectional shape, the viewing zone can be controlled in a direction orthogonal to the direction in which the viewing zone is controlled by the light transmission portion.

(19) The lens array is a microlens array formed by arranging unit lens shapes in a two-dimensional direction, and the longitudinal direction when the unit lens shape is observed from the normal direction of the screen is the light transmitting portion and Since the light absorption part is substantially orthogonal to the direction extending in the same cross-sectional shape, the viewing area can be controlled in a direction orthogonal to the direction in which the viewing area is controlled by the light transmission part.

(20) On the image source side of the regular antireflection layer, at least one of antistatic treatment, hard coat treatment, and antifouling treatment is applied along the surface shape of the regular antireflection layer. It has antistatic, hard coat, and antifouling functions while maintaining the function of reducing the regular reflection component of the layer, so it can reflect the image source by selecting the appropriate treatment according to the usage environment. Thus, it is possible to obtain a higher quality reflective screen.

(21) Since the reflection layer has a reflectance of 40% or more, it is possible to display an image with high luminance.

(22) Since the reflection layer has a diffuse reflectance Rd in the range of 10% or more and 70% or less, the reflection range does not become extremely narrow and the reflection efficiency is high and the reflection is balanced. Can do.

(23) Since the surface of the reflective layer is subjected to surface diffusion treatment, the diffuse reflectance Rd is within a predetermined range, so that the degree of diffusion of reflected light can be arbitrarily set.

(24) Since the intensity of the diffusing action differs depending on the direction, the reflective layer can minimize reflection that is directed toward the light absorbing portion while widening the viewing zone.

(25) Since the reflective layer has a stronger diffusing action in the horizontal direction than in the vertical direction in the usage state of the screen, the viewing area can be expanded in the horizontal direction in which a wider viewing area needs to be ensured.

(26) Since the reflective layer is formed by combining a plurality of regions having different diffuse reflectances Rd, the front peak luminance increases as the diffuse reflectance Rd decreases, and increases as the diffuse reflectance Rd increases. The luminance can be arbitrarily set and controlled between the luminance distribution distributed at the observation angle.

(27) Since the irregular diffusion layer that strongly diffuses the transmitted light only in a specific direction is provided, it is possible to easily and reliably give strong directivity to the light diffusion direction.

(28) The direction in which the light transmitted through the irregular diffusion layer is diffused strongly coincides with the direction in which the light transmission portion and the light absorption portion extend in the same cross-sectional shape. Even if it is disposed between the light absorbing portion and the light absorbing portion, the reflected light is not absorbed by the light absorbing portion after being largely diffused by the irregular diffusion layer, and the viewing area can be efficiently expanded.

(29) Since the reflective film or the reflective plate is laminated on the light transmitting part and the light absorbing part using an adhesive layer or an adhesive layer, the reflective layer can be formed more easily. . In addition, the characteristics of the reflective layer can be set freely.

(30) Since the distance between the reflective film or the reflective plate and the light transmission part and the light absorption part is ½ or less of the width of the light transmission part on the reflection layer side, the light transmission part is reflected again after being reflected by the reflection layer. Reflected light to be incident can be prevented from entering the light absorbing portion, and a reduction in reflection efficiency as a screen can be prevented.

(31) Since the light diffusing material is mixed in the adhesive layer or the adhesive layer, the viewing zone can be easily expanded.

(32) Since the relationship of 1/4 ≦ wt / wa ≦ 2 is satisfied, a bright and high-contrast image can be displayed.

(33) Since the surface on the image source side is provided with an ultraviolet absorbing layer having an ultraviolet absorbing function, yellowing due to ultraviolet rays can be prevented.

(34) Since it is possible to wind up when not in use, it is possible to provide a reflective screen that can be used in more scenes together with being less susceptible to the influence of external light.

(35) Since the second unit prism shape arranged in the direction orthogonal to the direction in which the unit prism shapes are arranged is formed further on the image source side than the unit prism shape, the external light from various directions is effectively removed. can do.

(36) A unit prism shape shaping step, a reflection layer forming step of forming a reflection layer only on a portion corresponding to the substantially wedge-shaped top of the unit prism shape, and a light absorption portion after forming the reflection layer Since the light absorption part forming step is formed, the light absorption part can be formed only by forming the light absorption part on the entire back surface, and the reflective screen can be easily manufactured.

(37) A unit prism shape shaping step, a light absorbing portion forming step for forming a light absorbing portion between the formed unit prism shapes, and a reflecting layer forming step for forming a reflecting layer after forming the light absorbing portion. Therefore, the reflective layer can be formed only by forming the reflective layer on the entire back surface, and the reflective screen can be easily manufactured.

(38) In the light absorption part forming step, the material for forming the light absorption part is filled between the unit prism shapes by wiping, so that the light absorption part can be reliably filled.

  For the purpose of obtaining a reflection screen and a reflection projection system capable of obtaining an image with high contrast, high brightness, and no reflection, by arranging a large number of unit prism shapes and providing a light absorbing portion therebetween, Realized in a form that is easy to manufacture.

FIG. 1 is a cross-sectional view illustrating a reflective screen 10 according to the first embodiment. In addition, each figure shown below including FIG. 1 exaggerated suitably the dimension of each part, a shape, etc. for description. In particular, FIG. 1 schematically shows the room illumination G, the image source L, and the reflection screen 10 together, so that the arrangement relationship is different from the actual one, and the incident angle of each light beam is different from the magnitude relationship in the description below. Part is included.
The reflective screen 10 in this embodiment is configured such that a projector optical engine unit (image source) L for projecting image light is disposed below the center of the screen 10 and image light is projected obliquely upward. Most of the screens were developed considering that the light enters the screen from above. Then, the image light from below is efficiently reflected to the viewer side, and unnecessary light from above is selectively absorbed by a light absorbing unit described later, so that the reflection screen for a front projector having a very high contrast can be obtained. It is a thing.
FIG. 1 shows a vertical cross-section when the screen is in use. The reflective screen 10 includes a base part 11, a unit prism shape 12, a reflective layer 13, a light absorbing part 14, a front treatment layer 15, a back protective layer 16, and the like.

  The base portion 11 is a portion that becomes a base material necessary for forming the unit prism shape 12, and is a light-transmitting portion formed from a resin sheet or film such as acrylic, polycarbonate, or polyethylene terephthalate. In this embodiment, acrylic is used. Note that the base portion 11 may be colored (tinted) with a dye, pigment, or the like such as gray so as to reduce the transmittance to a predetermined transmittance as necessary.

  The unit prism shape 12 has a substantially wedge shape in which the width on the image source side is wider than the width on the back surface side in the cross section of FIG. A large number of unit prism shapes 12 are formed along the screen surface (in the vertical direction in FIG. 1). The unit prism shape 12 is vertically symmetric in the vertical direction, and the angle between the upper and lower slopes and the normal of the screen surface is 5 °, the top width is 40 μm, and the valley bottom The height from the top to the top is 200 μm. The unit prism shape 12 is made of an ultraviolet curable resin having a refractive index of 1.56. Here, the screen surface indicates a surface in the plane direction of the screen when viewed as the entire screen, and is used as the same definition in the following description and in the claims.

The reflection layer 13 is a layer that is provided only at a portion corresponding to the top of the unit prism shape 12 that is substantially wedge-shaped, and reflects the image light and returns it to the front side (image source side).
The reflective layer 13 in this embodiment is formed by applying a highly reflective silver paint on the top of the unit prism shape 12, and the reflectance as the paint used is Rt = about 62.7 as the total light reflectance. %, Diffuse reflectance Rd = 39.1%.
As the silver paint for forming the reflective layer 13, in addition to the above, a paint having various reflectances such as a paint with Rt = about 68.9% and Rd = 56.8% can be selected and used. That's fine.

  The light absorbing portion 14 is a portion having an action of absorbing light formed while the unit prism shapes 12 are arranged. In this embodiment, the light absorbing portion 14 is formed by uniformly filling black beads (not shown). This black bead is a microbead having an action of absorbing light, and a gap where the bead does not exist in the light absorbing portion 14 is a void. With this configuration, the light absorbing portion 14 can be easily deformed, which is convenient for obtaining the necessary flexibility when the reflective screen 10 is a roll-up type.

  The front treatment layer 15 is a layer that is subjected to various surface treatments such as anti-glare treatment, antireflection treatment, antistatic treatment, hard coat treatment, and antifouling treatment. In this embodiment, antireflection treatment is carried out. . In addition, what is necessary is just to select the process performed to this front process layer 15 suitably as needed.

  The back surface protective layer 16 is a layer that covers the entire surface on the back surface side in order to hold black beads (not shown) filled in the light absorbing portion 14. It is difficult to keep the black beads filled in the light absorbing portion 14 stably in the gaps between the unit prism shapes 12 if the back surface protective layer 16 is not present. Therefore, in this example, the back surface protective layer 16 was formed by dripping and covering the entire surface of the back surface with an ultraviolet curable resin and irradiating it with ultraviolet light to be cured. In addition to the technique using an ultraviolet curable resin, an adhesive film or the like may be attached to fix the black beads, which increases the flexibility, which is more convenient at the time of winding.

Next, the manufacturing method of the reflective screen 10 in a present Example is demonstrated.
(Unit prism shape shaping process)
First, the unit prism shape 12 is shaped by applying an ionizing radiation curable resin on the base part 11 and irradiating and curing the ionizing radiation in a state where the mold is applied. The ionizing radiation curable resin used in this unit prism shape shaping process is UV and light mainly composed of polyfunctional monomers such as electron beam curable resin, acrylate, epoxy acrylate, silicon acrylate, and siloxane. A cross-linked type should be used. Here, the ionizing radiation means an electromagnetic wave or a charged particle beam having energy quanta capable of polymerizing and crosslinking molecules, and usually ultraviolet rays and electron beams are used.
The unit prism shape 12 may be formed not by ionizing radiation curing but by hot melt extrusion using acrylic resin, PET (polyethylene terephthalate) resin, or the like.

(Reflective layer forming process)
After the unit prism shape 12 was formed, a reflective layer 13 was formed on the wedge-shaped top of the unit prism shape 12 by gravure reverse coating. In this embodiment, the reflective layer 13 was coated with a silver paint having a film thickness of about 20 μm. By coating to this thickness, the above-described reflectance can be obtained.
Since the top portion of the unit prism shape 12 protrudes, the reflective layer 13 can be easily formed only on this top portion while preventing the silver paint from adhering to the valley portion where the light absorbing portion 14 is to be formed. .
In addition, the reflective layer 13 may be formed by spray coating, screen printing, comma coating, ink-jet coating, vapor deposition (preferably using a highly reflective metal such as aluminum, silver, or chromium). Can be used.
In addition to the silver paint, the paint used for forming the reflective layer 13 is a matte white paint with a matte surface after painting, and a large reflection on the surface after painting (strong shine). A gloss white paint, a silver paint (metallic) paint, a pearl paint, mica (mica) or a paint mixed with beads may be used. By appropriately using these, it is possible to control the observation region, the brightness, the effect of preventing the reflection of the light source, and the like.

(Light absorption part formation process)
Subsequent to the reflective layer forming step, black beads were dispersed on the entire back surface where the reflective layer 13 was formed. Then, squeezing (wiping) was performed in order to uniformly fill the space between the unit prism shapes 12. The diameter of the black beads is preferably about 1 to 10 μm. If it is smaller than that, scraping by squeezing becomes difficult, and if it exceeds 10 μm, it becomes difficult to fill the gaps in the unit prism shape 12 and the filling becomes insufficient. The light absorption part 14 which can fully block external light by this light absorption part formation process was obtained.
Since the reflective layer 13 is already formed only on the top of the unit prism shape 12, which is a necessary part, the light absorbing portion 14 may be attached to the entire back surface, and this light absorbing portion forming process is simplified. Can be done.
In this embodiment, since squeezing is performed, the black beads are formed only in the valley portions between the unit prism shapes 12 as shown in FIG. The top (rear surface side surface) may be covered with black beads.

(Back surface protection layer forming process)
After forming the light absorbing portion 14, an ultraviolet curable resin was dropped and covered so as to cover the entire back surface, and the back surface protective layer 16 was formed by irradiating and curing ultraviolet rays.
(Front treatment layer formation process)
Finally, the front treatment layer 15 was formed on the outermost surface on the front side. In this embodiment, the front treatment layer 15 is formed by laminating an antireflection sheet that has undergone antireflection treatment.
The reflective screen 10 was obtained by performing the above steps.

In the reflection screen 10 described above, the image light beams L1 and L2 projected from the image source L are guided in the unit prism shape 12 and totally reflected at the boundary surface with the light absorbing portion 14 as shown in FIG. Do. The light absorbing portion 14 is filled with black beads, but since the gap is a gap, the refractive index of the light absorbing portion 14 is lower than the refractive index of the unit prism shape 12, and therefore, Light incident at an angle larger than the critical angle at this interface is totally reflected.
Then, the image light totally reflected by the boundary surface between the unit prism shape 12 and the light absorbing portion 14 reaches the reflection layer 13 and is reflected, and then further totally reflected, for example, as an observable light ray toward the observer. Returned.

On the other hand, the external lights G1 and G2 from the room lighting G provided above the reflection screen 10 have a large incident angle with respect to the reflection screen 10, and therefore, incident on the boundary surface between the unit prism shape 12 and the light absorbing portion 14. The angle becomes smaller and there are many components that do not exceed the critical angle, and the light enters the light absorbing portion 14 without being totally reflected, and is absorbed by the black beads. Therefore, the rate at which external light returns to the observation position can be greatly reduced.
When the image light was actually projected onto the reflection screen 10, the projected image had a high reflectance and the outside light could be sufficiently absorbed.
Thus, according to the present embodiment, an image with high contrast, high luminance and no reflection can be obtained, and the reflection screen 10 can be easily manufactured as described above. .

FIG. 2 is a cross-sectional view illustrating the reflective screen 20 according to the second embodiment.
The second embodiment is an example in which the unit prism shape 12 is improved to the unit prism shape 22 in the first embodiment. Therefore, parts having the same functions as those of the first embodiment described above are denoted by the same reference numerals at the end, and redundant description is appropriately omitted.
FIG. 3 is a diagram showing a specific shape of the unit prism shape 22.
The unit prism shape 22 has an asymmetric shape in the direction in which the unit prisms are arranged (up and down direction in use), and has a first prism surface 22a located above and a second prism surface 22b located below. ing.

The first prism surface 22a is formed by one plane, and the angle formed with the normal to the screen surface is 5 °.
The second prism surface 22b includes a first plane 22b-1 formed at a position close to the back surface and a second plane 22b-2 formed closer to the image source than the first plane 22b-1. There are two types of planes.
The first plane 22b-1 is formed by a part of a plane symmetrical to the first prism surface 22a, and the angle formed with the normal to the screen surface is 5 °.
The angle formed by the second plane 22b-2 and the normal line of the screen surface is 15 °, and is larger than the angle formed by the first plane 22b-1 and the normal line of the screen surface.
The unit prism shape 22 has a top width of 40 μm, a height from the valley bottom to the top of 200 μm, and a width on the front side of 100 μm.

  In the present embodiment, the angle formed by the second plane 22b-2 and the normal of the screen surface is increased, so that the incident angle of the external light with respect to the second plane 22b-2 is reduced. However, it is easy to reach the light absorbing portion 24 without being totally reflected by the second plane 22b-2. Further, since the lower opening is widened, the image light from the lower side is easily incident on the unit prism shape 22.

FIG. 4 is a diagram illustrating a case where image light is projected from below at an incident angle of 30 degrees with respect to the reflective screen 20 in the second embodiment.
FIG. 5 is a diagram illustrating a case where image light is projected from below at an incident angle of 10 degrees with respect to the reflective screen 20 in the second embodiment.
FIG. 6 is a diagram illustrating a case where external light reaches the reflection screen 20 according to the second embodiment from above at an incident angle of 30 degrees.
4 to 6, the base portion 21 is not shown as a separate layer for the sake of simplicity, and the front treatment layer 25 is omitted.
The image light from below is reflected in the observation direction while being appropriately diffused (FIGS. 4 and 5), whereas most of the external light from above is absorbed and does not exit. (FIG. 6).

The angle dependence of the reflectance was evaluated for the reflective screen 20 in Example 2.
FIG. 7 is an evaluation result of the angle dependency of the reflectance of the reflective screen 20 in the second embodiment.
In FIG. 7, the + side of the horizontal axis indicates the reflectance with respect to incident light from above the screen, and the − side indicates the reflectance with respect to incident light from below the screen. The projection angle of a normal front projection projector is near the incident angle of 0 ° near the lower end of the screen, and is about −30 ° at the upper end. In the graph of FIG. 7, it is clear that the range of −30 ° to 0 ° on the horizontal axis corresponds to the incident angle range of the image light, and the high reflectance is maintained in that range. On the other hand, the external light mainly inserted from above corresponds to the + side in the horizontal axis in the graph of FIG. In the range corresponding to the incident angle of the external light, the reflectivity is less than 10% with respect to light having an angle exceeding 20 ° from above, and the external light blocking characteristic is sufficiently exhibited.

  According to the present embodiment, by further providing the second plane 22b-2, it is possible to further enhance the effect of reflecting the image light while preventing reflection of external light from above. Therefore, it is possible to observe an image with higher contrast, higher luminance, and no reflection.

FIG. 8 is a perspective view of the reflective screen 30 according to the third embodiment as viewed from above the image source side.
FIG. 9 is a cross-sectional view illustrating the reflective screen 30 according to the third embodiment.
The reflection screen 30 includes a base portion 31, a unit prism shape 32, a reflection layer 33, a light absorption portion 34, a regular reflection preventing layer 35, an adhesive layer 37, and the like.
Since the base part 31, the unit prism shape 32, and the light absorption part 34 are the same as the base part 21 and the unit prism shape 22 in the second embodiment, detailed description thereof is omitted.
The reflective layer 33 is an aluminum plate having a high reflectance (Rt = 70.6%, Rd = 60.8%), and the unit prism shape 32 and light are formed by an adhesive layer 37 formed of an ultraviolet curable adhesive. It is bonded and fixed to the back side of the absorbing portion 34. In order to obtain such a configuration, the light absorbing portion 34 is formed between the unit prism shapes 32 in advance, and then the reflective layer 33 is bonded by the adhesive layer 37 having high transparency. An adhesive layer can be used instead of the adhesive layer 37.

Here, the reflective layer 33 desirably has a reflectance of 40% or more, and further desirably has a diffuse reflectance Rd of 10% or more and 70% or less. If the diffuse reflectance Rd is too low, it is in a specular reflection state, so the viewing zone becomes very narrow and not suitable for practical use. On the other hand, if the diffuse reflectance Rd is too high, the viewing area is widened, but the proportion of the diffusely reflected light absorbed by the light absorbing portion increases, and the reflection efficiency decreases. As a result of the examination, it was found that this balance was good if it was 10 to 70%. Note that the conditions of the reflectance and diffuse reflectance Rd of the reflective layer are also preferable conditions in the above-described first and second embodiments.
In addition, the distance between the aluminum plate serving as the reflective layer 33 and the unit prism shape 32 and the light absorbing portion 34, that is, the thickness t of the adhesive layer 37 is the width of the unit prism shape 32 on the reflective layer 33 side (back side) ( It is desirable that it is ½ or less of the width A) in FIG. If the distance is longer than this, much of the reflected light that should be incident on the unit prism shape 32 again after being reflected by the reflective layer 33 is incident on the light absorbing portion 34, and the reflection efficiency as a screen is significantly reduced. Because it ends up.

  The regular reflection preventing layer 35 is a layer in which a number of fine irregularities are randomly formed on the surface. In this embodiment, the total transmission efficiency is approximately 90%, the diffuse transmittance is approximately 37%, and the haze value is approximately 42%. A certain commercially available diffusion film (TL-4 manufactured by Kimoto Co., Ltd.) was used. In FIG. 8, for the convenience of drawing, the surface of the regular antireflection layer 35 may appear as if many corrugated shapes are formed obliquely. The surface shape of the layer 35 does not have such a directivity, and a large number of irregular irregular shapes are randomly arranged like a so-called mat surface.

The regular reflection preventing layer 35 has the following functions.
(1) The projector light source engine unit is prevented from being reflected and observed on the outermost surface of the reflective screen.
(2) Widen the observable angle of the image projected on the reflective screen.
Here, the function (1) cannot be achieved by using a diffusion layer (diffusion film) of a type in which a diffusion material is mixed inside the layer. In order to achieve this function, it is necessary that the surface has a fine uneven shape. The degree of the reflection prevention effect of the image source can be adjusted according to the light diffusion degree due to the fine uneven shape. If the degree of diffusion is too small, the reflection cannot be suppressed. However, if the degree of diffusion is too strong, the screen is observed as white. Therefore, when a large number of diffusion films having different diffusivities were evaluated, the haze value of the regular antireflection layer 35 was 25% or more and 90% or less. It was found that it can be effectively prevented.
However, even if the haze value is in the above range, the function (1) may not be achieved depending on the shape of the surface.

FIG. 10 is a diagram for explaining a difference in the reflection prevention effect of the image source due to a difference in the surface shape of the regular reflection preventing layer.
If there are a large number of flat surfaces parallel to the screen surface as shown in FIG. 10A, there are many components that are regularly reflected on the flat surface, so that the reflection of the video source occurs. On the other hand, even if FIG. 10 (a) and FIG. 10 (b) show the same value as the haze value, a flat surface parallel to the screen surface is substantially formed as shown in FIG. 10 (b). In order to prevent the reflection of the image source of (1) above, it is desirable that the entire surface is covered with an uneven shape. Note that even if there are many flat surfaces facing the same direction even if they are not parallel to the screen surface, the image source may be reflected when observed from a specific direction. It is more desirable not to be too much.

  According to this embodiment, since the aluminum plate is bonded to form the reflective layer, the reflective layer can be formed very easily and stably. Further, since the regular reflection preventing layer is provided, the viewing area can be widened, and the reflection of the image source can be completely prevented.

FIG. 11 is a perspective view of the reflective screen 40 according to the fourth embodiment as viewed from above the image source side.
FIG. 12 is a cross-sectional view showing the reflective screen 40 in the fourth embodiment.
The reflection screen 40 includes a base portion 41, a unit prism shape 42, a reflection layer 43, a light absorption portion 44, a regular reflection preventing layer 45, an adhesive layer 47, an irregular diffusion layer 48, and the like.
Regarding the base portion 41, the unit prism shape 42, the reflection layer 43, the light absorption portion 44, the regular reflection preventing layer 45, and the adhesive layer 47, the unit prism shape 32, the reflection layer 33, the light absorption portion 34, and the regular reflection in the third embodiment. Since it is the same as that of the prevention layer 35 and the adhesive layer 37, detailed description is abbreviate | omitted.
The irregular diffusion layer 48 is a holographic diffuser in which an interference fringe pattern of approximately 5 μm is recorded as a concavo-convex shape, which is affixed between the base portion 41 and the regular reflection preventing layer 45 with an adhesive (not shown). , It has the effect of strongly diffusing transmitted light only in a specific direction. The irregular diffusion layer 48 of this embodiment is arranged so that the haze value in the horizontal direction is approximately 70% and the haze value in the vertical direction is approximately 35%.
According to the present embodiment, since the deformed diffusion layer 48 is provided, in addition to the control of the vertical method by the unit prism shape 42, the light diffusion can be appropriately controlled also in the horizontal direction, and the viewing area is widened. can do.

FIG. 13 is a perspective view of the state before the reflective layer 53 is formed on the reflective screen 50 in Example 5 as viewed from above the back side.
FIG. 14 is a cross-sectional view illustrating the reflective screen 50 according to the fifth embodiment.
The reflection screen 50 includes a base part 51, a unit prism shape 52, a reflection layer 53, a light absorption part 54, a regular reflection preventing layer 45, and the like.
Since the base 51, the unit prism shape 52, the light absorbing portion 54, and the regular reflection preventing layer 55 are the same as the unit prism shape 32, the light absorbing portion 34, and the regular reflection preventing layer 35 in the third embodiment, detailed description will be given. Is omitted.

  As shown in FIG. 13, in the state before the reflective layer 53 is formed, the longitudinal direction of the unit prism shape 52 and the light absorbing portion 54 extends on the upper bottom surface 52 c of the back side of the unit prism shape 52 ( Finished so that fine lines remain intentionally in the direction (horizontal direction) and the direction perpendicular (vertical direction) (hairline processing). In the present example, streaks (scratch streaks) were formed in the vertical direction by rubbing the upper bottom surface 52c with # 400 sandpaper. Then, the reflective layer 53 was formed by spraying a highly reflective paint having a reflectance of approximately 68% and a diffuse reflectance of approximately 52% on the upper bottom surface 52c on which the streaks were formed.

By forming the reflection layer 53 on the upper bottom surface 52c in which the streaks are formed in the vertical direction as described above, fine streaks are formed on the reflection surface. As described above, the surface diffusion treatment is performed on the surface of the reflective layer 53, so that the intensity of the diffusing action in the horizontal direction is much higher than that in the vertical direction.
According to the present embodiment, it is possible to widen the viewing area in the horizontal direction and to make the reflective screen easy to view from any position.

FIG. 15 is a perspective view of the reflective screen 60 according to the sixth embodiment as viewed from above the image source side.
FIG. 16 is a cross-sectional view illustrating the reflective screen 60 in the sixth embodiment.
The reflection screen 60 includes a base portion 61, a unit prism shape 62, a reflection layer 63, a light absorption portion 64, a regular reflection prevention layer 65, a lenticular lens layer 69, and the like.
Regarding the base portion 61, the unit prism shape 62, the reflection layer 63, the light absorption portion 64, and the regular reflection preventing layer 65, the unit prism shape 52, the reflection layer 53, the light absorption portion 54, and the regular reflection prevention layer 55 in the fifth embodiment are used. Since it is the same, detailed description is abbreviate | omitted.

The lenticular lens layer 69 has a lenticular lens shape provided in place of the vertical streak formed in the upper bottom surface 52c in the fifth embodiment. The lens shape of the lenticular lens layer 69 is such that a part of an elliptic cylinder is a unit shape, and a large number of elliptic cylinders of this unit shape are arranged in the horizontal direction. Therefore, the shape of the horizontal cross section extends in the vertical direction while maintaining the same cross sectional shape.
After forming the lenticular lens layer 69, the reflective layer 63 was formed in the same manner as in Example 5.
According to the present embodiment, the diffusing action in the horizontal direction can be controlled more finely by adopting a lenticular lens shape.

FIG. 17 is a diagram illustrating the reflective screen 70 according to the seventh embodiment. FIG. 17A is a view seen from the back side, and FIG. 17B is a cross-sectional view.
The reflective screen 70 in Example 7 has the same form as that of Example 1 except that a reflective layer 73 obtained by improving the reflective layer 13 in Example 1 is used. Therefore, the same reference numerals are given to the portions that perform the same functions as those of the first embodiment described above, and repeated descriptions are omitted as appropriate.
The reflection layer 73 is formed by combining a regular reflection layer 73a and a diffuse reflection layer 73b.
The regular reflection layer 73a is a reflection layer having a diffuse reflectance Rd (73a) smaller than the diffuse reflectance Rd (73b) of the diffuse reflection layer 73b, and forms the light absorbing portion 14 before forming the reflective layer, and then In addition, it is a layer formed by screen printing and partially printing (for example, dot shape or mesh shape as shown in FIG. 17).
As described above, the diffuse reflection layer 73b is a layer having a diffuse reflectance Rd (73b) higher than the diffuse reflectance Rd (73a) of the regular reflection layer 73a, and is printed on the entire surface after the regular reflection layer 73a is formed. Is the layer to be played.
Since the reflective layer is formed by combining a plurality of regions having different diffuse reflectances Rd in this way, by changing the area ratio occupied by each of these regions, the reflected light having strong regular reflection and the reflected light having strong diffuse reflection can be obtained. The ratio can be set as appropriate. Therefore, the front peak luminance and the ratio of the observation angle distribution can be arbitrarily controlled.

FIG. 18 is a cross-sectional view showing a reflective screen 80 in the eighth embodiment.
The eighth embodiment is an example in which the unit prism shape 12 in the first embodiment is improved to a unit prism shape 82 and the form of the reflective layer is changed. Therefore, parts having the same functions as those of the first embodiment described above are denoted by the same reference numerals at the end, and redundant description is appropriately omitted.

  The base part 81 of this example is the same part as the base part 11 of Example 1, and uses a film made of polyethylene terephthalate resin in which the surface on the observation surface side in the use state of the screen is subjected to mat processing. ing.

The unit prism shape 82 has a substantially wedge shape in which the width on the image source side is wider than the width on the back surface side in the cross section of FIG. A number of unit prism shapes 82 are formed side by side along the screen surface (in the up and down direction when the screen shown in FIG. 18 is used). The unit prism shape 82 has an upper slope 82a and a lower slope 82b that are normal to the screen surface, among the slopes that serve as a boundary surface with the light absorbing portion 84 formed between the unit prism shapes 82. The angles to be formed are all equal to θ, and have a vertically symmetric shape when the screen is used.
The width of the upper bottom surface 82c, which is the top of the trapezoid forming the back surface of the unit prism shape 82, is wt.

The unit prism shape 82 is formed with the above-described shape by, for example, applying an ultraviolet curable resin on the base part 81 and irradiating and curing the ultraviolet ray in a state where the mold is applied. The material of the unit prism shape 82 is not limited to an ultraviolet curable resin, but a photocurable resin such as an ionizing radiation curable resin, for example, a polyfunctional monomer such as acrylate, epoxy acrylate, silicon acrylate, or siloxane. A photocrosslinking resin as a component can be used. Here, the ionizing radiation means an electromagnetic wave or a charged particle beam having an energy quantum capable of polymerizing and crosslinking molecules.
In this embodiment, an ultraviolet curable resin having a refractive index of 1.56 is dropped on the base substrate portion 81, a mold is applied, and the resin is irradiated with ultraviolet rays to be cured.
The unit prism shape 82 may be formed by hot melt extrusion using an acrylic resin, polyethylene terephthalate resin, or the like, instead of being formed by ultraviolet curing.

The light absorbing portion 84 is formed by alternately arranging the unit prism shapes 82 along the screen surface, and has a function of absorbing light. In the present embodiment, the light absorption unit 84 wipes (squeezes) an ultraviolet curable resin (refractive index: 1.49) containing a black pigment having an average particle diameter of 6 μm as fine beads that absorb light. Thus, the unit prism shape 82 is filled and irradiated with ultraviolet rays.
The width of the base part 84a of the substantially isosceles triangle forming the back surface of the light absorption part 84 is defined as wa.

The reflective layer 83 of the present embodiment is formed by comma-coating a white paint having high reflectivity so as to cover the entire back surface of the reflective screen 80, and the film thickness thereof is 20 μm. In addition, the reflectance of the white paint used is the total light reflectance Rt = 83% and the diffuse reflectance Rd = 72%.
In addition, as a formation method of the reflective layer 83, spray coating, gravure reverse coating, screen printing, application | coating by an inkjet system, vapor deposition (it is desirable to use metals with high reflectance, such as aluminum, silver, chromium, etc.) etc. Can be used.

  The ultraviolet absorption layer 85 is a layer having an ultraviolet absorption function for absorbing ultraviolet rays contained in the image source and external light, and is disposed on the most image source side. The ultraviolet absorbing layer 85 of this embodiment is formed by coating an ultraviolet absorber on the image source side of the base portion 81 by gravure coating. By providing the ultraviolet absorbing layer 85, yellowing of the base portion 81 and the unit prism shape 82 due to ultraviolet rays can be prevented. In addition, since the reflective layer 83 is formed on the back side, it is not necessary to consider the influence of ultraviolet rays from the back side.

Here, in this embodiment, the unit prism shape 82 and the light absorbing portion are set so that the ratio wt / wa of the width wt of the upper bottom surface 82c and the width wa of the bottom portion 84a satisfies the following relational expression. 84 is formed.
1/4 ≦ wt / wa ≦ 2 Formula (1)
Further, the unit prism shape 82 is set so that the angle θ formed by the inclined surfaces 82a, 82b, which are the boundary surfaces between the unit prism shape 82 and the light absorbing portion 84, and the normal to the screen surface satisfies the following relational expression. And the light absorption part 84 is formed.
5 ° ≦ θ ≦ 15 ° (2)

In this example, the reflective screens of Specific Example 1 to Specific Example 5 were created as specific forms satisfying the above formulas (1) and (2).
In the reflective screen of Example 1, the unit prism shape 82 and the light absorbing portion 84 are formed so that wt = 13 μm, wa = 52 μm (wt / wa = 1/4), and θ = 9 °.
In the reflection screen of Example 2, the unit prism shape 82 and the light absorbing portion 84 are formed so that wt = 22 μm, wa = 43 μm (wt / wa≈1 / 2), and θ = 9 °.
In the reflective screen of Example 3, the unit prism shape 82 and the light absorbing portion 84 are formed so that wt = 32.5 μm, wa = 32.5 μm (wt / wa = 1), and θ = 9 °. .
In the reflective screen of Example 4, the unit prism shape 82 and the light absorbing portion 84 are formed so that wt = 43.3 μm, wa = 21.7 μm (wt / wa≈2), and θ = 9 °. .
In the reflective screen of Example 5, the unit prism shape 82 and the light absorbing portion 84 are formed so that wt = 26 μm, wa = 39 μm (wt / wa = 2/3), and θ = 5 °.
In the reflective screen of Example 6, the unit prism shape 82 and the light absorbing portion 84 are formed so that wt = 26 μm, wa = 39 μm (wt / wa = 2/3), and θ = 12 °.
In the reflective screen of Example 7, the unit prism shape 82 and the light absorbing portion 84 are formed so that wt = 26 μm, wa = 39 μm (wt / wa = 2/3), and θ = 15 °.

Moreover, in order to compare with these, the reflective screens of Comparative Examples 1 to 4 were prepared.
In the reflective screen of Comparative Example 1, the unit prism shape 82 and the light absorbing portion 84 are formed so that wt = 26 μm, wa = 156 μm (wt / wa = 1/6), and θ = 9 °.
In the reflection screen of Comparative Example 2, the unit prism shape 82 and the light absorbing portion 84 are formed so that wt = 57 μm, wa = 8 μm (wt / wa = 57/8), and θ = 9 °.
In the reflective screen of Comparative Example 3, the unit prism shape 82 and the light absorbing portion 84 are formed so that wt = 26 μm, wa = 39 μm (wt / wa = 2/3), and θ = 3 °.
In the reflective screen of Comparative Example 4, the unit prism shape 82 and the light absorbing portion 84 are formed so that wt = 26 μm, wa = 39 μm (wt / wa = 2/3), and θ = 20 °.

The specific examples 1 to 7 and the comparative examples 1 to 4 were evaluated by comparing the contrast.
The contrast was evaluated by projecting light from the image source L onto each reflection screen and measuring the luminance of each reflection screen using a luminance meter.
Here, the contrast is a ratio between the luminance of the reflective screen when the image source L projects light that reproduces white and the luminance of the reflective screen when the image source L projects light that reproduces black. . The larger the ratio, the higher the contrast and the clearer the image. The lower the ratio, the lower the contrast and the image becomes whitish and unclear.

The reflective screen 80 of the present Example used for the measurement of the reflective screens of Specific Examples 1 to 4 and Comparative Examples 1 and 2 was 90 cm in the vertical direction when the screen was used, and large in the horizontal direction. Is 120 cm.
The image source L is fixed at a position 230 cm away from the screen surface of the reflective screens of specific examples 1 to 4, comparative examples 1 and 2, and the luminous flux is 15 cm below the center of each reflective screen. Is projected horizontally with respect to a position (referred to as position P). The image source L used for this measurement is EMPTW200H (manufactured by Seiko Epson Corporation), and the projected light flux is 1500 lm.

The luminance meter measured the luminance at a position where the angle formed by the normal line passing through the position P described above and a straight line passing through the position P and the luminance meter was 5 ° from the screen surface of each screen. Note that the measurement was performed while shifting the angle by 5 ° in order to prevent the projected light beam from being blocked by the luminance meter. The luminance meter used for this measurement is LS110 (Minolta Co., Ltd.). Note that the image source L, the luminance meter, and the position P are all 100 cm in height from the floor and are arranged in the same plane having the same height from the floor.
The measurement is performed in a bright room environment where the brightness (illuminance) by illumination (external light source) at a height of 100 cm from the floor surface is 1000 lx, and the distance from the floor surface to the ceiling is 300 cm.

In addition to measuring the contrast, the gain was also measured and evaluated.
Here, the gain is a relative luminance of each reflection screen when compared with a reflection diffusion plate having a complete diffusion surface, and a brighter image can be observed as the gain increases.
The gain measurement conditions were the same as the above-described contrast measurement conditions. However, contrast measurement was performed in a bright room environment (1200 lx), while gain measurement was performed in a dark room environment (1 lx). Under this condition, in addition to each reflection screen, the luminance of the reflection diffusion plate having a complete diffusion surface was measured, and the gain was calculated.
Regarding the contrast and gain, if the contrast is 9 or more and the gain is 1.5 or more, a sufficiently high-quality image can be obtained. If the gain is 1.7 or more, a brighter and higher quality image can be obtained.

Table 1 summarizes the results of Specific Examples 1 to 4, Comparative Example 1, and Comparative Example 2 with a focus on wt / wa. As can be seen from the results in Table 1, in specific examples 1 to 4, wt / wa satisfies the above-described equation (1), and the contrast and the gain are high.
In order to obtain higher contrast and gain, it can be seen from the results of specific examples 2 and 3 that wt / wa should satisfy the following relational expression.
1/2 ≦ wt / wa ≦ 1 Formula (3)

Table 2 summarizes the results of Specific Example 3, Specific Example 5 to Specific Example 7, and Comparative Example 3 and Comparative Example 4 with a focus on θ. As can be seen from the results in Table 2, in specific example 3, specific example 5 to specific example 7, θ satisfies Equation (2) shown above, and the contrast and gain are high.
And, in order to obtain higher contrast, it can be seen from the results of Specific Example 3, Specific Example 5, and Specific Example 6 that θ should satisfy the following relational expression.
5 ° ≦ θ ≦ 12 ° ・ ・ ・ Formula (4)

According to the present embodiment, a bright and high-contrast image can be displayed by satisfying at least one of the expressions (1) and (2). In addition, by satisfying at least one of the expressions (3) and (4), it is possible to display a brighter and higher-contrast video with higher contrast.
In addition, according to this embodiment, since the ultraviolet absorption layer 85 is formed, yellowing of the reflection screen due to the influence of ultraviolet rays can be prevented.
As described above, the reflective screen of the present invention having the unit prism shape and the light absorbing portion eliminates the influence of external light and can display a bright image with high contrast even in a bright room environment. . Therefore, it is often used in a bright environment, and a case where it is permanently installed in a bright environment is also assumed. Even in such a case, by forming the ultraviolet absorbing layer 85, it is possible to maintain the original appearance for a long time without yellowing.

(Modification)
The present invention is not limited to the embodiments described above, and various modifications and changes are possible, and these are also within the equivalent scope of the present invention.
(1) In each embodiment, the unit prism shape is an example of a shape combining planes. However, the unit prism shape is not limited to this. For example, a part or all of the unit prism shapes may be a shape combining curved surfaces. . Further, instead of the unit prism shape, it may be a simple light transmitting portion having the same width on the back surface side and the image source side.

(2) In each embodiment, the example in which the light absorbing portion forming step is performed after the reflecting layer forming step has been described. However, the present invention is not limited thereto, and for example, the reflecting layer forming step may be performed after the light absorbing portion forming step. . By adopting such a process order, it is only necessary to form the reflective layer on the entire back surface after filling the light absorbing portion between unit prism shapes by wiping or the like. This is a particularly effective method.

(3) In each of the embodiments, the unit prism shape and the light absorbing portion extend in the horizontal direction with the same cross-sectional shape and are arranged in a large number in the vertical direction. If the direction of the image light is the horizontal direction, the image light may be rotated by 90 degrees, or two combinations of the unit prism shape and the light absorbing portion may be provided so as to be orthogonal to each other.

(4) In each Example, although the light absorption part showed the example formed by filling black beads, you may form not only this but the resin which knead | mixed black beads, for example. In that case, the light absorbing portion may be formed by kneading black beads in a resin having a refractive index lower than that of the material forming the unit prism shape.

(5) In each of the embodiments, the example of the fixed type reflection screen has been described. However, the present invention is not limited to this. For example, a winding type that can be wound up and stored when not in use may be used.

(6) In Examples 3 to 6, an example in which a commercially available diffusion film is used as the regular antireflection layer is shown. However, the present invention is not limited to this example. The fine irregularity shape may be formed by kneading the binder to be protruded and projecting the portion where the fine beads are fixed to the image source side rather than the portion where the fine beads are not fixed and only the binder is formed.

(7) In Example 3 to Example 6, an example in which an irregular mat-like fine uneven shape was used as the regular antireflection layer was shown, but the present invention is not limited to this, and for example, a minute unit lens shape is one-dimensional. Alternatively, a lens array arranged in a two-dimensional direction may be formed, and the components that are regularly reflected by this lens array may be reduced.
Further, in this case, using the lenticular lens array formed by arranging the unit lens shapes in a one-dimensional direction, the light transmitting part and the light absorbing part have the same cross section in the direction in which the unit lens shape extends in the same cross sectional shape. The viewing zone may also be controlled so as to be substantially orthogonal to the direction extending in the shape.
Further, in the above case, when a microlens array formed by arranging unit lens shapes in a two-dimensional direction is used, the longitudinal direction when the unit lens shape is observed from the normal direction of the screen is the light transmitting portion and the light. The viewing zone may also be controlled in such a manner that the absorption section is substantially orthogonal to the direction of extension with the same cross-sectional shape.

(8) In Example 3 to Example 6, at least one of antistatic treatment, hard coat treatment, and antifouling treatment is applied to the image source side of the regular antireflection layer along the surface shape of the regular antireflection layer. You may give it. By doing so, it is possible to add antistatic, hard coating and antifouling functions while maintaining the function of reducing the specularly reflecting component of the regular antireflection layer.

(9) In Example 3 or Example 4, a light diffusing material may be mixed in the adhesive layers 37 and 47 to widen the viewing area.

(10) Although the example in which the irregular diffusion layer 48 is formed at a position adjacent to the regular antireflection layer 45 is shown in the fourth embodiment, the present invention is not limited to this. For example, if the reflection on the surface of the irregular diffusion layer is small, the irregular diffusion layer 48 is irregular. The diffusion layer may be disposed on the most image source side or may be disposed adjacent to the reflective layer.

(11) In the eighth embodiment, the example in which the formula (1) to the formula (4) are satisfied in the reflecting screen whose unit prism shape is the target shape is shown. However, the present invention is not limited to this. In the reflection sheet in which the unit prism shape is asymmetrical such as 2 or the like, either of these formulas may be satisfied.

(12) In Example 8, although the example which satisfy | fills both Formula (1) and Formula (2) was shown, it is not restricted to this, For example, only Formula (1) may be satisfy | filled, Formula (2) ) Only.

(13) In Example 8, the ultraviolet absorbing layer 85 was formed by coating the base portion 81 directly. However, the present invention is not limited to this. For example, the ultraviolet absorbing agent is included in the front treatment layer in Example 1 or the like. Or an ultraviolet absorber may be included in the regular reflection preventing layer in Example 3 or the like to form a front treatment layer and a regular reflection preventing layer that also serve as the ultraviolet absorbing layer. Further, an ultraviolet absorbing layer may be formed on the surface of the front treatment layer and the regular antireflection layer.

(14) Although the example in which the ultraviolet absorbing layer 85 is formed by coating has been described in Example 8, the present invention is not limited thereto, and for example, the ultraviolet absorbing layer 85 may be formed by attaching a film having an ultraviolet absorbing function. In that case, for example, after forming the unit prism shape 82, a film having an ultraviolet absorbing effect by a roll-to-roll (a general term for a processing method in which a material wound into a roll shape is processed and then wound into a roll shape again). Laminate. Alternatively, after cutting into sheets, the reflective layer may be coated and then laminated.
Further, an ultraviolet absorber may be included in an adhesive used when a film having an ultraviolet absorbing action or the like is bonded to a base portion or the like.

1 is a cross-sectional view showing a reflective screen 10 in Example 1. FIG. 6 is a cross-sectional view showing a reflective screen 20 in Example 2. FIG. It is a figure which shows the specific shape of the unit prism shape 22. FIG. It is a figure which shows the case where image light is projected from the downward direction at the incident angle of 30 degree | times with respect to the reflective screen 20 in Example 2. FIG. It is a figure which shows the case where image light is projected from the downward direction with respect to the reflective screen 20 in Example 2 at the incident angle of 10 degree | times. It is a figure which shows the case where external light reaches | attains from upper direction with respect to the reflective screen 20 in Example 2 with the incident angle of 30 degree | times. It is an evaluation result of the angle dependence of the reflectance of the reflective screen 20 in Example 2. It is the perspective view which looked at the reflective screen 30 in Example 3 from the image source side upper direction. 6 is a cross-sectional view showing a reflective screen 30 in Embodiment 3. FIG. It is a figure explaining the difference in the reflection prevention effect of the image source by the difference in the surface shape of a regular reflection prevention layer. It is the perspective view which looked at the reflective screen 40 in Example 4 from the image source side upper direction. 6 is a cross-sectional view showing a reflective screen 40 in Example 4. FIG. It is the perspective view which looked at the state before forming the reflective layer 53 in the reflective screen 50 in Example 5 from the back side upper direction. 10 is a cross-sectional view showing a reflective screen 50 in Example 5. FIG. It is the perspective view which looked at the reflective screen 60 in Example 6 from the image source side upper side. 10 is a cross-sectional view showing a reflective screen 60 in Example 6. FIG. FIG. 10 is a diagram showing a reflective screen 70 in Example 7. FIG. 10 is a cross-sectional view showing a reflective screen 80 in Example 8.

Explanation of symbols

10, 20, 30, 40, 50, 60, 70 Reflective screen 11, 21, 31, 41, 51, 61 Base portion 12, 22, 32, 42, 52, 62 Unit prism shape 22a, 32a, 42a, 52a, 62a First prism surface 22b, 32b, 42b, 52b, 62b Second prism surface 22b-1 First plane 22b-2 Second plane 13, 23, 33, 43, 53, 63 Reflective layers 14, 24 , 34, 44, 54, 64 Light absorbing portion 15, 25 Front treatment layer 35, 45, 55, 65 Regular reflection preventing layer 16, 26 Back surface protection layer 37, 47 Adhesive layer 48 Deformed diffusion layer 69 Lenticular lens layer

Claims (38)

A reflecting screen that reflects image light projected from an image source and enables observation;
In the cross section orthogonal to the screen surface,
A light transmitting portion capable of transmitting light;
A light absorbing part that absorbs light;
With
The light transmission part and the light absorption part are alternately formed along the screen surface,
A reflective screen comprising a reflective layer that reflects the image light that has passed through the light transmission part, at least on the back side of the light transmission part. The reflective screen according to claim 1.
The light transmission part has a substantially wedge shape in which the width on the image source side is wider than the width on the back surface side in a cross section perpendicular to the screen surface, and a unit prism shape formed in a large number along the screen surface. thing,
Reflective screen featuring. The reflective screen according to claim 1 or 2,
The light absorbing portion has a refractive index lower than the refractive index of the material forming the unit prism shape;
Reflective screen featuring. The reflective screen according to claim 1 or 2,
The light absorbing portion includes micro beads that absorb light;
Reflective screen featuring. The reflective screen according to claim 4.
The light absorbing portion is formed by kneading the micro beads in a resin having a refractive index lower than that of the material forming the unit prism shape,
Reflective screen featuring. The reflection screen according to any one of claims 1 to 5,
The reflective layer is formed only on a portion corresponding to the top portion of the light transmitting portion or the substantially prism-shaped top portion of the unit prism shape,
Reflective screen featuring. The reflective screen according to any one of claims 2 to 6,
The unit prism shape has a first prism surface and a second prism surface which are asymmetric in the direction of alignment;
Reflective screen featuring. The reflective screen according to claim 7.
The first prism surface is formed of one type of surface,
The second prism surface is formed of at least two types of surfaces;
Reflective screen featuring. The reflecting screen according to claim 7 or 8,
The first prism surface is formed by one plane,
The second prism surface has two types of planes: a first plane formed at a position close to the back surface and a second plane formed closer to the video source than the first plane. And
The first plane is formed by a plane symmetrical to the first prism surface,
The angle formed by the second plane and the normal of the screen surface is greater than the angle formed by the first plane and the normal of the screen surface;
Reflective screen featuring. The reflective screen according to any one of claims 1 to 9,
When the angle between the boundary surface of the light transmitting portion and the light absorbing portion and the normal to the screen surface is θ,
5 ° ≦ θ ≦ 15 °
Satisfying the relationship
Reflective screen featuring. The reflective screen according to any one of claims 1 to 10,
The surface on the image source side is subjected to at least one of anti-glare treatment, antireflection treatment, antistatic treatment, hard coat treatment, and antifouling treatment,
Reflective screen featuring. The reflective screen according to any one of claims 1 to 11,
A specular antireflection layer that reduces specular reflection components is formed on the image source side surface.
Reflective screen featuring. The reflective screen according to claim 12.
The haze value by the regular antireflection layer is 25% or more and 90% or less.
Reflective screen featuring. The reflective screen according to claim 12 or claim 13,
The regular antireflection layer has a fine concavo-convex shape formed on the surface, and reduces the component that is specularly reflected by the fine concavo-convex shape,
Reflective screen featuring. The reflective screen according to claim 14.
The regular antireflection layer has a large number of microbeads and a binder for fixing the microbeads,
The portion where the microbeads are fixed is protruded to the image source side from the portion where only the binder is not fixed and the microbeads are formed, and the fine uneven shape is formed,
Reflective screen featuring. The reflective screen according to claim 14 or 15,
The fine uneven shape has substantially no flat surface parallel to the screen surface,
Reflective screen featuring. The reflective screen according to claim 12 or claim 13,
The regular reflection preventing layer is formed with a lens array in which minute unit lens shapes are arranged in a one-dimensional or two-dimensional direction, and the component that is regularly reflected by the lens array is reduced.
Reflective screen featuring. The reflective screen according to claim 17.
The lens array is a lenticular lens array formed by arranging unit lens shapes in a one-dimensional direction,
The direction in which the unit lens shape extends in the same cross-sectional shape is substantially orthogonal to the direction in which the light transmission portion and the light absorption portion extend in the same cross-sectional shape,
Reflective screen featuring. The reflective screen according to claim 17.
The lens array is a microlens array formed by arranging unit lens shapes in a two-dimensional direction,
The longitudinal direction when the unit lens shape is observed from the normal direction of the screen is substantially orthogonal to the direction in which the light transmission part and the light absorption part extend in the same cross-sectional shape,
Reflective screen featuring. The reflective screen according to any one of claims 12 to 19,
Further on the image source side of the regular antireflection layer, at least one of antistatic treatment, hard coat treatment, and antifouling treatment is applied along the surface shape of the regular antireflection layer,
Having anti-static, hard coat and anti-staining functions while maintaining the function of reducing the specular reflection component of the regular anti-reflective layer;
Reflective screen featuring. The reflective screen according to any one of claims 1 to 20,
The reflective layer has a reflectance of 40% or more;
Reflective screen featuring. The reflective screen according to any one of claims 1 to 21,
The reflective layer has a diffuse reflectance Rd of 10% or more and 70% or less;
Reflective screen featuring. The reflective screen according to claim 22,
The reflective layer has the diffuse reflectance Rd within the predetermined range by performing a surface diffusion treatment on the surface thereof,
Reflective screen featuring. The reflective screen according to claim 23.
The reflective layer has a different diffusion intensity depending on the direction;
Reflective screen featuring. The reflective screen of claim 24.
The reflective layer has a higher diffusive action in the horizontal direction than in the vertical direction when the screen is used;
Reflective screen featuring. The reflective screen according to any one of claims 1 to 25,
The reflective layer is formed by combining a plurality of regions having different diffuse reflectances Rd;
Reflective screen featuring. The reflective screen according to any one of claims 1 to 26,
Providing an irregular diffusion layer that diffuses transmitted light strongly only in a specific direction,
Reflective screen featuring. The reflective screen according to claim 27.
The direction in which the light transmitted through the irregular diffusion layer is diffused strongly matches the direction in which the light transmission part and the light absorption part extend in the same cross-sectional shape,
Reflective screen featuring. The reflective screen according to any one of claims 1 to 28, wherein:
The reflective layer is formed of a reflective film having a high reflectance, or a reflective plate,
The reflective film or the reflective plate is laminated with an adhesive layer or an adhesive layer on the light transmission part and the light absorption part,
Reflective screen featuring. 30. The reflective screen of claim 29.
The interval between the reflection film or the reflection plate and the light transmission part and the light absorption part is ½ or less of the width of the light transmission part on the reflection layer side,
Reflective screen featuring. The reflective screen according to claim 29 or claim 30,
A light diffusing material is mixed in the adhesive layer or the adhesive layer;
Reflective screen featuring. The reflective screen according to any one of claims 1 to 31,
When the width on the back side of the light transmission part in a cross section orthogonal to the screen surface is wt, and the width on the back side of the light absorption part is wa,
1/4 ≦ wt / wa ≦ 2
Satisfying the relationship
Reflective screen featuring. The reflective screen according to any one of claims 1 to 32,
The surface on the image source side is provided with an ultraviolet absorbing layer having an ultraviolet absorbing function,
Reflective screen featuring. The reflective screen according to any one of claims 1 to 33,
It can be rolled up when not in use,
Reflective screen featuring. The reflective screen according to any one of claims 2 to 34,
A second unit prism shape arranged in a direction perpendicular to the direction in which the unit prism shapes are arranged is further formed on the image source side than the unit prism shape;
Reflective screen featuring. A method for manufacturing a reflective screen according to any one of claims 2 to 34, wherein:
A unit prism shape shaping step of shaping the unit prism shape with a resin;
A reflective layer forming step of forming the reflective layer only at a portion corresponding to the top of the unit prism shape that is formed in a substantially wedge shape;
A light absorption part forming step of forming the light absorption part after forming the reflective layer;
A method for manufacturing a reflective screen. A method for manufacturing a reflective screen according to any one of claims 2 to 34, wherein:
A unit prism shape shaping step of shaping the unit prism shape with a resin;
A light absorption part forming step of forming the light absorption part between the formed unit prism shapes;
A reflective layer forming step of forming the reflective layer after forming the light absorbing portion;
A method for manufacturing a reflective screen. The method of manufacturing a reflective screen according to claim 36 or claim 37,
In the light absorbing portion forming step, a material for forming the light absorbing portion is filled between the unit prism shapes by wiping.
A manufacturing method of a reflective screen characterized by the above.

Images