Reflection type screen and projection system

Abstract

To provide a reflection type screen that can easily control the diffusion angle of projected light.SOLUTION: A reflection type screen of the present invention comprises: a translucent substrate that has a first surface directed to an observation side and a second surface directed to the opposite side of the observation side; a plurality of protrusions that are provided on a side of the second surface of the translucent substrate; and reflection layers that are provided respectively on the plurality of protrusions. Each of the plurality of protrusions has a first surface inclined relative to the first surface, a second surface extending in a predetermined direction, and a third surface extending in the predetermined direction and located between the first surface and the second surface. The reflection layer is provided at least on the first surface and the third surface. The third surface is formed of a curved surface having a shape projecting toward the observation side, or a shape projecting toward the opposite side of the observation side. When the radius of curvature of the curved surface is defined as r, and the pitch of the protrusions in the arrangement direction of the plurality of protrusions as p, r / p is 0.1 or more.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a reflective screen and a projection system.

Background Art

[0002] A reflective screen that reflects projection light projected from a projection device and displays an image on the observation side has been conventionally known. As this type of reflective screen, a screen having a Fresnel lens portion in which a plurality of arc-shaped reflecting surfaces are arranged concentrically has been proposed. According to this screen, projection light incident obliquely on the screen from the projection device can be reflected in a certain direction, that is, the direction in which the observer exists, by the lens effect. Patent Document 1 below discloses a reflective screen including a lens layer, a reflective layer, and a surface lens layer, wherein the lens layer has a Fresnel lens shape.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the reflective screen of Patent Document 1, since the diffusion angle of the projection light is adjusted by the configuration of the lenticular lens constituting the surface lens layer, only the diffusion angle in the arrangement direction of the lenticular lens, that is, the horizontal direction of the screen, can be adjusted. Further, Patent Document 1 also describes a configuration in which a diffusion layer is provided in addition to the above configuration. However, since this diffusion layer diffuses the projection light isotropically, when trying to adjust the diffusion angle, the diffusion angle in the horizontal direction and the diffusion angle in the vertical direction of the screen change simultaneously. Therefore, there is a problem that it is difficult to independently adjust only the diffusion angle in the vertical direction of the screen.

Means for Solving the Problems

[0005] In order to solve the above problems, a reflective screen according to one aspect of the present invention is a reflective screen that reflects projection light projected from a projection device to display an image on the observation side, and includes a translucent base material having a front surface facing the observation side and a back surface facing the side opposite to the observation side, a plurality of convex portions provided on the back surface side of the translucent base material, and a reflective layer provided on each of the plurality of convex portions for reflecting the projection light. Each of the plurality of convex portions has a first surface extending in a predetermined direction and inclined with respect to the front surface, a second surface extending in the predetermined direction, and a third surface extending in the predetermined direction and positioned between the first surface and the second surface. The reflective layer is provided on at least the first surface and the third surface. The third surface is configured by a curved surface having a shape protruding toward the observation side or a shape protruding toward the side opposite to the observation side. When the radius of curvature of the curved surface is r and the pitch of the convex portions in the arrangement direction of the plurality of convex portions is p, r / p is 0.1 or more.

[0006] A projection system according to one aspect of the present invention includes a reflective screen according to one aspect of the present invention and a projection device that projects the projection light toward the reflective screen.

Brief Description of the Drawings

[0007]

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Figure 8D

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Figure 9C

Best Mode for Carrying Out the Invention

[0008] [First Embodiment] Hereinafter, the first embodiment of the present invention will be described with reference to the drawings. In the following drawings, for the sake of easy viewing of each component, the scale of the dimensions may be varied depending on the component.

[0009] FIG. 1 is a schematic configuration diagram of the projection system 10 of the present embodiment. As shown in FIG. 1, the projection system 10 of the present embodiment includes a reflective screen 11 and a projection device 12. Hereinafter, the reflective screen 11 is simply referred to as the screen 11. The projection device 12 projects projection light L toward the screen 11. The screen 11 reflects the projection light L projected from the projection device 12 and displays an image on the observation side. The screen 11 includes a Fresnel lens portion 13, and reflects the projection light L obliquely incident on the screen 11 from the projection device 12 in parallel in the direction where the observer is present by the action of the Fresnel lens portion 13. In the following description, the axis along the horizontal direction of the screen 11 is defined as the X-axis, the axis along the vertical direction of the screen 11 is defined as the Y-axis, and the axis along the front direction of the screen 11 is defined as the Z-axis. That is, as viewed from the observer, the left-right direction corresponds to the X-axis direction, the up-down direction corresponds to the Y-axis direction, and the depth direction corresponds to the Z-axis direction.

[0010] FIG. 2 is a front view of the screen 11. As shown in FIG. 2, the screen 11 has a rectangular shape in which the length in the X-axis direction is longer than the length in the Y-axis direction. The screen 11 includes a plurality of convex portions 14 protruding toward the front side of the paper surface of FIG. 2. The plurality of convex portions 14 have arc-shaped shapes with different radii. The plurality of convex portions 14 constitute a Fresnel lens portion 13 in which the arc-shaped convex portions 14 are arranged concentrically, that is, a so-called circular type Fresnel lens portion. The Fresnel lens portion 13 reflects the projection light L emitted from the projection device 12 toward the observer side for each of the plurality of convex portions 14.

[0011] FIG. 3 is a cross-sectional view of the screen 11 along line III-III in FIG. 2. FIG. 4 is an enlarged view of the convex portion 14. In FIG. 4, the illustration of the diffusion layer 16 and the translucent base material 17 is omitted. As shown in FIG. 3, the screen 11 includes a first translucent substrate 19, a diffusion layer 16, an adhesive layer 22, a second translucent substrate 20, a plurality of convex portions 14, and a reflective layer 21. In the description of each of the following members, the surface facing the observation side is referred to as the front surface, and the surface facing the side opposite to the observation side is referred to as the back surface.

[0012] The first light-transmissive substrate 19 is made of a resin material such as polyethylene terephthalate (PET). The diffusion layer 16 is provided on the front surface 19a of the first light-transmissive substrate 19. The diffusion layer 16 is composed of, for example, a surface relief type diffusion layer having a random uneven structure, a diffusion layer in which particles having a refractive index different from that of the base material are dispersed, and the like. The diffusion layer 16 can be formed, for example, by applying a UV curable resin to the front surface 19a of the first light-transmissive substrate 19, then transferring the uneven structure of the mold to the UV curable resin, and irradiating the UV light to cure the UV curable resin. The diffusion layer 16 may have a diffusion characteristic of diffusely scattering the projected light L isotropically, or may have a diffusion characteristic of diffusely scattering the projected light L anisotropically.

[0013] The second light-transmissive substrate 20 is made of a resin material such as PET, similar to the first light-transmissive substrate 19. The plurality of convex portions 14 are provided on the front surface 20a of the second light-transmissive substrate 20. The plurality of convex portions 14 are made of, for example, a UV curable resin such as an epoxy-based or acrylic-based resin.

[0014] The convex portion 14 has a first surface 14a, a second surface 14b, and a third surface 14c. The first surface 14a extends along the circumferential direction of the arc that is the planar shape of the convex portion 14 and is inclined at a predetermined angle with respect to the front surface 20a of the second light-transmissive substrate 20. The second surface 14b extends along the circumferential direction of the arc that is the planar shape of the convex portion 14. The third surface 14c extends along the circumferential direction of the arc that is the planar shape of the convex portion 14 and is located between the first surface 14a and the second surface 14b.

[0015] The angle formed between the front surface 20a of the second light-transmissive substrate 20 and the first surface 14a is defined as the inclination angle θ1 of the first surface. The inclination angle θ1 of the first surface 14a is not constant across all the convex portions 14, but gradually increases from the lower part to the upper part of the screen 11. Specifically, the minimum value of the inclination angle θ1 of the first surface 14a is about 0.1°, and the maximum value of the inclination angle θ1 of the first surface 14a is about 20°. The angle formed between the front surface 20a of the second light-transmissive substrate 20 and the second surface 14b is defined as the inclination angle θ2 of the second surface 14b. The inclination angle θ2 of the second surface 14b is constant across all the convex portions 14 and is about 90°. Note that the inclination angle θ2 may be smaller than 90°.

[0016] The first surface 14a and the second surface 14b are configured as substantially flat surfaces. In contrast, the third surface 14c is configured as a curved surface having a shape that protrudes toward the observation side and is smoothly continuous with the first surface 14a and the second surface 14b.

[0017] As shown in FIG. 4, the length of one convex portion 14 in the arrangement direction (Y-axis direction) of the plurality of convex portions 14 is defined as the pitch p of the convex portions 14. The pitch p of the convex portions 14 is not constant across all the convex portions 14, but gradually decreases from the lower part to the upper part of the screen 11. Specifically, the minimum value of the pitch p of the convex portions 14 is about 0.1 mm, and the maximum value of the pitch p of the convex portions 14 is about 10 mm. Also, the length along the Z-axis direction from the front surface 20a of the second light-transmissive substrate 20 to the apex of the convex portion 14 is defined as the height t of the convex portion 14. The height t of the convex portion 14 is preferably constant across all the convex portions 14, but errors may occur in manufacturing.

[0018] The reflective layer 21 is provided to cover the first surface 14a, the second surface 14b, and the third surface 14c of the convex portion 14. The reflective layer 21 is composed of, for example, a metal film with high reflectivity such as aluminum, a dielectric multilayer film, a coating film containing a reflective metal material, etc. The reflective layer 21 can be formed, for example, by forming a metal film such as aluminum on the surface of the convex portion by a vapor deposition method or the like. The reflective layer 21 desirably has a reflectivity of 60% or more, preferably 80% or more, with respect to light in the wavelength band of 400 to 700 nm. The reflective layer 21 needs to be provided to cover at least the first surface 14a and the third surface 14c.

[0019] In the case of this embodiment, since the second light-transmissive substrate 20 covers the reflective layer 21 from the back side, it functions as a protective member for protecting the reflective layer 21. According to this configuration, deterioration and damage of the reflective layer 21 can be suppressed.

[0020] The first light-transmissive substrate 19 provided with the diffusion layer 16 and the second light-transmissive substrate 20 provided with a plurality of convex portions 14 are joined via an adhesive layer 22. The adhesive layer 22 is composed of, for example, an optical adhesive made of a UV-curable resin. The first light-transmissive substrate 19 and the second light-transmissive substrate 20 are joined in such a direction that both the diffusion layer 16 and the plurality of convex portions 14 face the observation side.

[0021] In the case of this embodiment, the first light-transmissive substrate 19 and the adhesive layer 22 function as a light-transmissive base material 17 that transmits the projected light L. When the front surface 19a of the first light-transmissive substrate 19 is taken as the front surface of the light-transmissive base material 17 and the back surface 22b of the adhesive layer 22 is taken as the back surface of the light-transmissive base material 17, the diffusion layer 16 is provided on the front surface side of the light-transmissive base material 17. The plurality of convex portions 14 are provided on the back surface side of the light-transmissive base material 17.

[0022] Hereinafter, the behavior of light in the screen 11 of this embodiment will be described. As shown in FIG. 4, the projection light L emitted from the projection device 12 enters the screen 11 obliquely from below, passes through the diffusion layer 16 and the translucent base material 17, and reaches the convex portion 14. At this time, the projection light L1 incident on the first surface 14a is reflected by the reflection layer 21 on the first surface 14a and travels in a direction substantially parallel to the Z axis. On the other hand, since the projection light L2 incident on the second surface 14b is reflected by the reflection layer 21 on the curved second surface 14b, it travels in a direction not parallel to the Z axis.

[0023] In a conventional reflective screen having a Fresnel lens portion, the top of the convex portion is sharp and does not have a curved surface like the third surface 14c of the present embodiment. Therefore, all of the projection light reflected by the screen travels in a direction substantially parallel to the Z axis. On the other hand, according to the screen 11 of the present embodiment, by providing the convex portion 14 constituting the Fresnel lens portion 13 with the third surface 14c having a curved surface, it is possible to generate the projection light L traveling in a direction not parallel to the Z axis. Thereby, the diffusion angle in the vertical direction of the screen 11 can be made wider than in the conventional case.

[0024] Here, the inventor performed a simulation to obtain the diffusion angle distribution of the projection light when the radius of curvature of the third surface was changed. As simulation conditions, a diffusion layer having a Gaussian scattering characteristic of σ = 10° was disposed on the screen surface, the pitch p of the convex portions was set to 5 mm, the inclination angle of the first surface was set to 15°, and the radius of curvature r of the convex portions was changed to three types of 0 mm, 0.5 mm, and 1 mm. That is, the ratio r / p of the radius of curvature to the pitch was changed to three types of 0, 0.1, and 0.2. The incident angle of the projection light with respect to the screen was set to 40°.

[0025] FIG. 5 is a diagram showing the simulation results and is a graph showing the diffusion angle distribution of the projection light when r / p is changed. FIG. 6 is an enlarged graph in the vicinity of -50° in FIG. 5. The horizontal axis of the graph is the diffusion angle (°) in the vertical direction of the screen. The normal direction (front direction) of the screen is set as 0°, with the downward direction represented as positive and the upward direction represented as negative. The vertical axis of the graph is the intensity (relative value) of the reflected light. The graph with the symbol A is the graph when r / p = 0, that is, when the convex portion has no curved surface. The graph with the symbol B is the graph when r / p = 0.1. The graph with the symbol C is the graph when r / p = 0.2.

[0026] As shown in FIG. 5, when comparing the three graphs, when r / p = 0, that is, when the convex portion has no curved surface, the peak intensity of the reflected light in the front direction of the screen is the highest, and the larger the r / p, the lower the peak intensity. On the other hand, in the tail region of the graph, that is, in the region where the diffusion angle is large, the intensity of the reflected light increases as r / p increases. The above tendency can be understood because as r / p increases, the proportion of the curved surface portion in the convex portion increases, so the proportion of the light reflected in the front direction of the screen relatively decreases, and the proportion of the light reflected in the direction deviating from the front direction of the screen relatively increases.

[0027] According to the findings of the present inventor, when the intensity of the reflected light from the screen is less than 1 / 10 of the peak intensity, it becomes difficult to identify the projected image. Also, when the observer is located near the screen, the upper part of the screen forms an angle of about -50 degrees from the observer's eyes. From the above, in order for the observer to sufficiently identify the image on the upper part of the screen, it is desirable to ensure that the intensity of the reflected light at a diffusion angle of -50 degrees is 1 / 10 or more of the peak intensity.

[0028] From this perspective, when r / p = 0, the peak intensity is about 2.3, while the intensity of the reflected light at -50 degrees is about 0.17, so the above conditions are not satisfied. In contrast, when r / p = 0.1, the peak intensity is about 2.1, while the intensity of the reflected light at -50 degrees is about 0.21, so the above conditions are satisfied. Furthermore, when r / p = 0.2, the peak intensity is about 1.6, while the intensity of the reflected light at -50 degrees is about 0.27, so the above conditions are satisfied.

[0029] From the above simulation results, it was found that in order for an observer located near the screen to identify the image at the lower part of the screen, it is necessary to satisfy at least r / p = 0.1. Also, if r / p = 0.2 is satisfied, the observer can more reliably identify the image at the lower part of the screen. Thus, by changing the value of r / p, the vertical diffusion angle distribution of the screen can be adjusted.

[0030] Also, it is desirable that r / p is less than 0.5. When r / p is 0.5 or more, the ratio of the area of the first surface when the third surface is provided to the area of the first surface when the third surface is not provided becomes less than half, so the original function of the Fresnel lens portion is impaired. As a result, the brightness of the screen decreases.

[0031] (Effect of the First Embodiment) The screen 11 of the present embodiment includes a light-transmissive base material 17 having a front surface facing the observation side and a back surface facing the side opposite to the observation side, a plurality of convex portions 14 provided on the side of the second surface of the light-transmissive base material 17, and a reflection layer 21 provided on each of the plurality of convex portions 14 for reflecting the projection light L. Each of the plurality of convex portions 14 has a first surface 14a extending in a predetermined direction and inclined with respect to the front surface of the light-transmissive base material 17, a second surface 14b extending in a predetermined direction, and a third surface 14c extending in a predetermined direction and located between the first surface 14a and the second surface 14b. The reflection layer 21 is provided on at least the first surface 14a and the third surface 14c. The third surface 14c is formed of a curved surface having a shape protruding toward the observation side, and the ratio r / p of the radius of curvature r of the third surface 14c to the pitch p of the convex portion 14 is 0.1 or more.

[0032] In a conventional screen, since the diffusion layer diffuses the projected light isotropically, when attempting to adjust the diffusion angle, the horizontal diffusion angle and the vertical diffusion angle of the screen change simultaneously. Therefore, there is a problem that it is difficult to independently adjust only the vertical diffusion angle of the screen. In response to this problem, according to the screen 11 of the present embodiment, by changing the configuration of the third surface 14c formed of a curved surface, the vertical diffusion angle of the screen 11 can be independently adjusted. Further, by setting r / p to 0.1 or more, an observer can sufficiently distinguish an image at the lower part of the screen 11.

[0033] In the case of the present embodiment, the screen 11 is provided on the front side of the translucent base material 17 and further includes a diffusion layer 16 that diffuses the projected light L. According to this configuration, the diffusion layer 16 can diffuse the projected light L in directions other than the vertical direction of the screen 11. In particular, when the diffusion layer 16 has anisotropy and the horizontal diffusibility of the screen 11 is greater than the vertical diffusibility, the horizontal diffusion angle of the screen 11 can be appropriately adjusted by changing the configuration of the diffusion layer 16. In this case, since the projected light L directed in the vertical direction in which there is no observer decreases, a bright image can be obtained.

[0034] Further, in the case of the present embodiment, since the third surface 14c is configured by a curved surface having a shape protruding toward the observation side, the reflective layer 21 on the third surface 14c also has a shape of a curved surface protruding toward the observation side, and the reflective layer 21 functions as a so-called convex mirror. Thereby, the projected light can be diffused over a wide angular range in the vertical direction of the screen 11.

[0035] The projection system 10 of the present embodiment includes the screen 11 of the present embodiment and a projection device 12 that projects the projected light L toward the screen 11. According to this configuration, a projection system 10 with excellent visibility of an image can be provided.

[0036] [Second Embodiment] Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. Since the basic configuration of the screen in this embodiment is the same as that in the first embodiment, the description of the common parts will be omitted. FIG. 7 is a cross-sectional view of the screen 31 of the second embodiment. In FIG. 7, the same reference numerals are given to the components common to the drawings used in the first embodiment.

[0037] As shown in FIG. 7, the screen 31 of this embodiment includes a first light-transmissive substrate 19, a diffusion layer 16, a plurality of convex portions 14, and a reflection layer 21. The first light-transmissive substrate 19 of this embodiment corresponds to the light-transmissive base material in the claims.

[0038] The diffusion layer 16 is provided in contact with the front surface 19a of the first light-transmissive substrate 19. The plurality of convex portions 14 are provided in contact with the back surface 19b of the first light-transmissive substrate 19. Each of the plurality of convex portions 14 has a first surface 14a, a second surface 14b, and a third surface 14c. The third surface 14c is configured by a curved surface that protrudes toward the side opposite to the observation side. The reflection layer 21 is provided so as to cover the first surface 14a, the second surface 14b, and the third surface 14c of the convex portion 14.

[0039] Hereinafter, a method for manufacturing the screen 31 of this embodiment will be described with reference to FIGS. 8A to 8F. As shown in FIG. 8A, a liquid UV-curable resin such as an epoxy-based or acrylic-based resin is applied to the front surface 19a of the first light-transmissive substrate 19 made of PET or the like to form a first resin layer 33.

[0040] Next, as shown in FIG. 8B, while pressing the mold 34 for forming the diffusion layer against the first resin layer 33, UV light M is irradiated from the back surface 19b of the first light-transmissive substrate 19 to the first resin layer 33. As a result, an uneven structure that is the reverse of the uneven structure of the mold 34 is transferred to the first resin layer 33, and the diffusion layer 16 is formed.

[0041] Next, as shown in FIG. 8C, after removing the mold 34 from the first resin layer 33, a liquid UV curable resin such as an epoxy-based or acrylic-based resin is applied to the back surface 19b of the first light-transmissive substrate 19 to form the second resin layer 36.

[0042] Next, as shown in FIG. 8D, with the convex portion forming mold 37 pressed against the second resin layer 36, UV light M is irradiated from the front surface 19a of the first light-transmissive substrate 19 through the diffusion layer 16 to the second resin layer 36. At this time, as the mold 37, a mold having no curved surface portion for forming the third surface 14c and having a saw blade-shaped cross section can be used. Also, the irradiation conditions of the UV light M are set to an integrated light amount slightly exceeding the minimum integrated light amount at which the UV curable resin cures.

[0043] Next, when the mold 37 is removed from the second resin layer 36, as shown in FIG. 8E, the saw blade-shaped uneven structure of the mold 37 is not completely reflected in the uneven structure transferred to the second resin layer 36, and a plurality of convex portions 14 having a curved surface portion near the apex are formed.

[0044] Next, as shown in FIG. 8F, a metal film such as aluminum is formed on the surfaces of the plurality of convex portions 14 by vapor deposition to form the reflective layer 21. Note that after forming the reflective layer 21, a protective member for protecting the reflective layer 21 may be formed by a method such as forming a silicon oxide film or attaching a protective film. Thereby, deterioration and breakage of the reflective layer 21 can be suppressed. Through the above steps, the screen 31 of the present embodiment is completed.

[0045] The inventor conducted an experiment to change the curing conditions of the UV curable resin and examine the relationship between the curing conditions and the shape of the convex portions. As experimental conditions, TB3018 (product number) manufactured by Sribond was used for the UV curable resin, and the following three types of irradiation conditions were set. Condition 1: Irradiation power density: 75 mW / cm 2 , Irradiation time: 2 minutes. Condition 2: Irradiation power density: 68.5 mW / cm 2 , Irradiation time: 1.5 minutes. Condition 3: Irradiation power density: 62 mW / cm 2 , Irradiation time: 1 minute.

[0046] Figures 9A to 9C are diagrams showing cross-sectional profiles of a plurality of convex portions fabricated under the above three types of curing conditions. Figure 9A corresponds to the convex portion shape under Condition 1, Figure 9B corresponds to the convex portion shape under Condition 2, and Figure 9C corresponds to the convex portion shape under Condition 3.

[0047] As shown in Figure 9A, in the case of Condition 1 where the irradiation power density of UV light is high and the irradiation time is long, the shape of the convex portion substantially reflects the saw blade-like uneven shape of the mold, and almost no curved surface portion is formed. In contrast, in the case of Condition 2 where the irradiation power density of UV light is lower and the irradiation time is shorter compared to Condition 1, it can be seen that the top of the convex portion is slightly rounded and a curved surface portion is formed. In the case of Condition 3 where the irradiation power density of UV light is even lower and the irradiation time is even shorter compared to Condition 2, it was found that the shape of the convex portion is overall sagging and the radius of curvature of the curved surface portion is larger than that of Condition 2. Thus, according to the manufacturing method of the reflective screen of the present embodiment, without changing the uneven shape of the mold, the shape of the convex portion can be controlled only by adjusting the irradiation conditions of UV light.

[0048] (Effect of the Second Embodiment) Also in the present embodiment, by changing the configuration of the third surface 14c formed of a curved surface, the vertical diffusion angle of the screen 31 can be independently adjusted, and the same effect as that of the first embodiment can be obtained, that is, a screen 31 can be provided in which an observer can sufficiently distinguish an image in a wide range.

[0049] In the case of the present embodiment, different from the first embodiment, since the plurality of convex portions 14 are directly formed on the back surface 19b of the first light-transmissive substrate 19, the thickness of the screen 31 can be reduced. As a result, the distance between the diffusion layer 16 and the Fresnel lens portion 13 becomes shorter, and thus image blurring can be reduced.

[0050] Also, in the case of the present embodiment, since the third surface 14c is a curved surface having a shape that protrudes toward the side opposite to the observation side, the reflective layer 21 on the third surface 14c also has a shape that protrudes toward the side opposite to the observation side and becomes a curved surface. The reflective layer 21 functions as a so-called concave mirror. As a result, since the angular range of the projection light L reflected by the screen 31 is limited, unnecessary projection light traveling in a direction where no observer exists can be suppressed.

[0051] Note that the technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. In the above embodiment, an example of a reflective screen including a circular Fresnel lens portion was given. Instead of this configuration, a reflective screen including a linear Fresnel lens portion in which each of a plurality of convex portions extends linearly in the horizontal direction and the plurality of convex portions are arranged in the vertical direction may be used. Further, a reflective screen that does not have a Fresnel lens portion and simply includes a striped reflective portion in which a plurality of convex portions are arranged in one direction may be used.

[0052] In the screen of the first embodiment, the configuration may be such that the portion of the UV curable resin constituting the convex portion is removed while leaving the shape of the convex portion the same as in the first embodiment. Even with this configuration, if the shape of the convex portion remains on the back surface of the light-transmitting base material and the reflective layer is provided on the front surface, the same operations and effects as those of the screen of the first embodiment can be obtained.

[0053] In addition, specific descriptions of the shape, number, arrangement, material, etc. of each component of the reflective screen are not limited to the above embodiment and can be appropriately changed.

[0054] [Summary of the Present Disclosure] Hereinafter, a summary of the present disclosure will be appended.

[0055] (Appended Note 1) A reflective screen that reflects projection light projected from a projection device and displays an image on the observation side, A translucent substrate having a front surface facing the observation side and a back surface facing the side opposite to the observation side; A plurality of convex portions provided on the back surface side of the translucent substrate; A reflection layer provided on each of the plurality of convex portions for reflecting the projected light; Comprising; Each of the plurality of convex portions has a first surface extending in a predetermined direction and inclined with respect to the front surface, a second surface extending in the predetermined direction, and a third surface extending in the predetermined direction and located between the first surface and the second surface; The reflection layer is provided on at least the first surface and the third surface; The third surface is configured by a curved surface having a shape protruding toward the observation side or a shape protruding toward the side opposite to the observation side; A reflective screen, where when the radius of curvature of the curved surface is r and the pitch of the convex portions in the arrangement direction of the plurality of convex portions is p, r / p is 0.1 or more.

[0056] According to the configuration of Supplementary Note 1, since each of the plurality of convex portions has a third surface configured by a curved surface, the diffusion angle in the arrangement direction of the plurality of convex portions can be independently adjusted by changing the configuration of the third surface. Thereby, a screen that enables an observer to sufficiently identify an image in a wide range can be provided.

[0057] (Supplementary Note 2) The reflective screen according to Supplementary Note 1, wherein the third surface is a curved surface having a shape protruding toward the observation side.

[0058] According to the configuration of Supplementary Note 2, the projected light can be diffused over a wide angular range in the arrangement direction of the plurality of convex portions.

[0059] (Supplementary Note 3) The reflective screen according to Supplementary Note 1, wherein the third surface is a curved surface having a shape protruding toward the side opposite to the observation side.

[0060] According to the configuration of Supplementary Note 3, since the angular range of the projected light reflected by the screen is limited, unnecessary projected light directed in the direction where there is no observer can be suppressed.

[0061] (Supplementary Note 4) The reflective screen according to any one of Supplementary Notes 1 to 3, wherein r / p is 0.2 or more.

[0062] According to the configuration of Supplementary Note 4, an observer can more surely identify an image at the end of the screen.

[0063] (Supplementary Note 5) The reflective screen according to any one of Supplementary Notes 1 to 4, further comprising a diffusion layer provided on the front side of the light-transmissive base material for diffusing the projected light.

[0064] According to the configuration of Supplementary Note 5, the projected light diffused in the arrangement direction of the plurality of convex portions can be diffused over a wider range by the diffusion layer.

[0065] (Supplementary Note 6) The diffusion characteristics of the diffusion layer have anisotropy, The reflective screen according to Supplementary Note 5, wherein the diffusibility in the extending direction of the convex portion is greater than the diffusibility in the arrangement direction of the plurality of convex portions.

[0066] According to the configuration of Supplementary Note 6, the diffusibility in the extending direction of the convex portion and the diffusibility in the arrangement direction of the plurality of convex portions can be changed independently. Thereby, the projected light directed in the arrangement direction of the plurality of convex portions where there is no observer can be reduced, and a bright image can be obtained.

[0067] (Supplementary Note 7) The reflective screen according to any one of Supplementary Notes 1 to 6, wherein the plurality of convex portions constitute a Fresnel lens portion.

[0068] According to the configuration of Supplementary Note 7, the projected light incident obliquely on the screen can be reflected in a predetermined direction, that is, the direction where the observer exists.

[0069] (Appendix 8) The plurality of convex portions are provided in contact with the back surface of the light-transmissive substrate, and the reflective screen according to any one of Appendices 1 to 7.

[0070] According to the configuration of Appendix 8, the thickness of the screen can be reduced, so that image blurring can be reduced.

[0071] (Appendix 9) The reflective screen according to any one of Appendices 1 to 8, further comprising a protective member covering the reflective layer.

[0072] According to the configuration of Appendix 9, deterioration and damage of the reflective layer can be suppressed.

[0073] (Appendix 10) The reflective screen according to any one of Appendices 1 to 9, A projection device that projects the projection light toward the reflective screen, and a projection system comprising the same.

[0074] According to the configuration of Appendix 10, a projection system excellent in image visibility can be provided.

Explanation of Reference Numerals

[0075] 10... Projection system, 11, 31... Reflective screen, 12... Projection device, 13... Fresnel lens portion, 14... Convex portion, 14a... First surface, 14b... Second surface, 14c... Third surface, 16... Diffusion layer, 17... Light-transmissive substrate, 19... First light-transmissive substrate, 20... Second light-transmissive substrate (protective member), 21... Reflective layer.

Claims

1. A reflective screen that reflects the projection light projected from a projection device and displays an image on the observation side, a translucent substrate having a front surface facing the observation side and a back surface facing the side opposite to the observation side, a plurality of convex portions provided on the back side of the translucent substrate, a reflective layer provided on each of the plurality of convex portions for reflecting the projection light, comprising: each of the plurality of convex portions has a first surface extending in a predetermined direction and inclined with respect to the front surface, a second surface extending in the predetermined direction, and a third surface extending in the predetermined direction and located between the first surface and the second surface, the reflective layer is provided on at least the first surface and the third surface, the third surface is configured by a curved surface having a shape protruding toward the observation side or a shape protruding toward the side opposite to the observation side, a reflective screen, wherein when the radius of curvature of the curved surface is r and the pitch of the convex portions in the arrangement direction of the plurality of convex portions is p, r / p is 0.1 or more.

2. The reflective screen according to claim 1, wherein the third surface is a curved surface having a shape protruding toward the observation side.

3. The reflective screen according to claim 1, wherein the third surface is a curved surface having a shape protruding toward the side opposite to the observation side.

4. The reflective screen according to any one of claims 1 to 3, wherein r / p is 0.2 or more.

5. The reflective screen according to any one of claims 1 to 3, further comprising a diffusion layer provided on the front side of the translucent substrate for diffusing the projection light.

6. The diffusion characteristics of the diffusion layer have anisotropy, and the diffusibility in the extending direction of the convex portions is greater than the diffusibility in the arrangement direction of the plurality of convex portions. The reflective screen according to claim 5.

7. The plurality of convex portions constitute a Fresnel lens portion. The reflective screen according to any one of claims 1 to 3.

8. The plurality of convex portions are provided in contact with the back surface of the translucent substrate. The reflective screen according to any one of claims 1 to 3.

9. The reflective screen according to any one of claims 1 to 3, further comprising a protective member covering the reflective layer.

10. The reflective screen according to any one of claims 1 to 3, and a projection device that projects the projection light toward the reflective screen. A projection system comprising

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