Method for manufacturing reflective screen, reflective screen, and projection system

Abstract

To provide a reflective screen which projects highly visible images in any usage environment.SOLUTION: The method for manufacturing a reflective screen according to the present invention includes: the step of forming a plurality of protruding parts with a first surface and a second surface in a main surface of a translucent substrate opposite to an observation side, the first surface and the main surface forming a first angle and the second surface and the main surface forming a second angle larger than the first angle; a first film formation step of forming a first reflection film in the first surface; and a second film formation step of forming a second reflection film in the second surface, the second reflection film presenting a lower reflectance than the first reflection film.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a reflective screen, 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 effect of the Fresnel lens portion. Patent Document 1 below discloses a reflective screen in which a convex strip portion having a triangular cross section is provided on the main surface of a base material, and a reflective layer is formed on one surface of the convex strip portion.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Patent Document 1 describes a configuration example in which the base material is formed of a black resin. In this case, among the convex strip portions, the surface of the black resin, which is the base material, is exposed on the surfaces other than the reflecting surface. Accordingly, it is described that since external light incident on the surfaces other than the reflecting surface is absorbed by the black resin, a screen with high contrast can be provided. However, when this screen is used in an environment with little external light, a part of the projection light incident on the surfaces other than the reflecting surface is also absorbed by the black resin, resulting in a problem that the utilization efficiency of the projection light is reduced and a bright image cannot be obtained.

Means for Solving the Problems

[0005] To solve the above problems, a method for manufacturing a reflective screen according to one aspect of the present invention is a method for manufacturing a reflective screen that reflects projection light projected from a projection device to display an image on the observation side, the method comprising: forming a plurality of convex portions having a first surface with an angle of a first angle with respect to the main surface and a second surface with an angle of a second angle larger than the first angle with respect to the main surface on the main surface of the translucent substrate on the side opposite to the observation side; a first film-forming step of forming a first reflective film on the first surface; and a second film-forming step of forming a second reflective film having a lower reflectance in visible light than the first reflective film on the second surface after the first film-forming step.

[0006] 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, the reflective screen comprising: a translucent substrate; a plurality of convex portions provided on the main surface of the translucent substrate on the side opposite to the observation side, the convex portions having a first surface with an angle of a first angle with respect to the main surface and a second surface with an angle of a second angle larger than the first angle with respect to the main surface; a first reflective film provided on the first surface; and a second reflective film provided on the second surface and having a lower reflectance in visible light than the first reflective film.

[0007] A projection system according to one aspect of the present invention comprises: 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

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6A

Figure 6B

Figure 6C

Figure 6D

Figure 6E

Figure 6F

Figure 7A

Figure 7B

Figure 8A

Figure 8B

Figure 9

Mode for Carrying Out the Invention

[0009] [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 shown differently depending on the component.

[0010] 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 from the projection device 12 to the screen 11 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.

[0011] 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 back 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 each of the plurality of convex portions 14 toward the observer side.

[0012] 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. As shown in FIG. 3, the screen 11 includes a translucent substrate 19, a diffusion layer 16, a plurality of convex portions 14, a first reflective film 21, and a second reflective film 22. 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.

[0013] The 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 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 may have a diffusion characteristic of isotropically diffusing the projected light L, or may have a diffusion characteristic of anisotropically diffusing the projected light L. By providing the diffusion layer 16, the projected light L can be appropriately diffused to widen the viewing angle of the projected image. In particular, when the diffusibility in the extending direction of the convex portions 14 is larger than the diffusibility in the arrangement direction of the plurality of convex portions 14, the viewing angle in the horizontal direction of the screen 11 can be widened.

[0014] The plurality of convex portions 14 are provided on the back surface 19b of the light-transmissive substrate 19. The plurality of convex portions 14 are made of a light-transmissive material made of a UV curable resin such as an epoxy-based or acrylic-based resin. The cross-sectional shape of the convex portion 14 cut by a YZ plane perpendicular to the X axis is triangular.

[0015] The convex portion 14 has a first surface 14a and a second surface 14b. 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 back surface 19b of the light-transmissive substrate 19. The second surface 14b extends along the circumferential direction of the arc that is the planar shape of the convex portion 14 and is a plane perpendicular to the back surface 19b of the light-transmissive substrate 19. Note that the second surface 14b may be inclined at a predetermined angle with respect to the back surface 19b of the light-transmissive substrate 19.

[0016] Define the angle formed between the back surface 19b of the light-transmissive substrate 19 and the first surface 14a as the first angle θ1. The first angle θ1 is not constant across all the convex portions 14, but rather increases sequentially from the lower part to the upper part of the screen 11. Specifically, the minimum value of the first angle θ1 is about 0.1°, and the maximum value of the first angle θ1 is about 20°. Define the angle formed between the back surface 19b of the light-transmissive substrate 19 and the second surface 14b as the second angle θ2. The second angle θ2 is constant across all the convex portions 14, and for example, it is 90°. Note that the second angle θ2 may be smaller than 90°. The second angle θ2 is larger than the first angle θ1.

[0017] As shown in FIG. 4, define the length of one convex portion 14 in the arrangement direction (Y-axis direction) of the plurality of convex portions 14 as the pitch p of the convex portion 14. The pitch p of the convex portion 14 is not constant across all the convex portions 14, but rather decreases sequentially from the lower part to the upper part of the screen 11. Specifically, the minimum value of the pitch p of the convex portion 14 is about 0.1 mm, and the maximum value of the pitch p of the convex portion 14 is about 10 mm. Also, define the length along the Z-axis direction from the back surface 19b of the light-transmissive substrate 19 to the apex of the convex portion 14 as the height t of the convex portion 14. Although it is preferable that the height t of the convex portion 14 is constant across all the convex portions 14, errors may occur during manufacturing.

[0018] The first reflective film 21 is provided on the first surface 14a of the convex portion 14. The first reflective film 21 is composed of a metal film with high reflectivity, such as aluminum or an aluminum alloy, for example. It is desirable that the first reflective film 21 has a reflectivity of 70 - 95% in visible light having a wavelength band of, for example, 400 - 700 nm.

[0019] It is desirable that the film thickness of the first reflective film 21 on the first surface 14a is 50 nm or more and 500 nm or less. If the film thickness of the first reflective film 21 is less than 50 nm, there is a possibility that the projected light L cannot be sufficiently reflected. If the film thickness of the first reflective film 21 exceeds 500 nm, the reflectivity becomes saturated and does not improve further, and there is a possibility that the load of the first film-forming process increases.

[0020] The second reflective film 22 is provided on the second surface 14b of the convex portion 14 and is provided overlapping the first reflective film 21 provided on the first surface 14a. In other words, the second reflective film 22 is provided across the first surface 14a and the second surface 14b of the convex portion 14. The second reflective film 22 is composed of a metal film such as chromium or a chromium alloy, for example. The second reflective film 22 desirably has a reflectance of 30 to 68% in visible light having a wavelength band of, for example, 400 to 700 nm. That is, the reflectance of the second reflective film 22 in visible light is lower than the reflectance of the first reflective film 21 in visible light. The difference between the reflectance of the first reflective film 21 in visible light and the reflectance of the second reflective film 22 in visible light is desirably 10% or more. If this difference is less than 10%, the functions of each reflective film cannot be sufficiently exhibited, and the effects of the present embodiment described later will be insufficient.

[0021] The film thickness of the second reflective film 22 on the second surface 14b is desirably 50 nm or more and 500 nm or less. If the film thickness of the second reflective film 22 is less than 50 nm, there is a possibility that external light cannot be sufficiently absorbed and the projected light L cannot be sufficiently reflected. If the film thickness of the second reflective film 22 exceeds 500 nm, the reflectance may saturate and not improve further, and the load of the second film formation process may increase.

[0022] Hereinafter, the behavior of light in the screen 11 of the present 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 substrate 19, and enters the convex portion 14. At this time, many projection lights L1 enter the first surface 14a, and a part of the projection light L2 diffused by the diffusion layer 16 enters the second surface 14b. The projection light L1 incident on the first surface 14a is reflected with a high reflectance by the first reflective film 21 on the first surface 14a, passes through the translucent substrate 19 and the diffusion layer 16, and is emitted forward from the screen 11. On the other hand, among the projection lights L2 incident on the second surface 14b, a part of the projection lights L2 are reflected with a low reflectance by the second reflective film 22 on the second surface 14b, pass through the translucent substrate 19 and the diffusion layer 16, and are emitted forward from the screen 11. Another part of the projection lights L2 are absorbed by the second reflective film 22 on the second surface 14b.

[0023] On the other hand, the external light G incident on the screen 11 obliquely from above, for example, from the direction of the ceiling, enters the second surface 14b of the convex portion 14, and a part of it is absorbed by the second reflective film 22 on the second surface 14b, and the other part is reflected.

[0024] Here, the inventor prototyped the screen of this embodiment and measured the reflection characteristics when the incident angle of the projection light on the screen was changed. FIG. 5 is a diagram showing the measurement results, and is a graph showing the relationship between the incident angle of the projection light and the reflection coefficient. In FIG. 5, the horizontal axis represents the incident angle (degrees), with the front direction of the screen, that is, the normal direction of the front surface of the translucent substrate, being 0 degrees, and the side where the traveling direction of the light faces the second surface of the convex portion being represented by a positive angle. The vertical axis represents the reflection coefficient (bidirectional scattering distribution function: BSDF), which is the measured value by a BSDF measuring device. Here, only the reflected light is measured, so the value of the BSDF represents in which direction and to what extent the light incident on the screen is reflected.

[0025] As shown in FIG. 5, when the incident angle of the projected light is increased from 0 degrees to 20 degrees, the reflection coefficient gradually increases. However, when it exceeds 20 degrees, the reflection coefficient decreases, and when it reaches 40 degrees or more, it shows the minimum value and becomes substantially constant. Thus, in the screen of this embodiment, it was found that as the incident direction of the projected light approaches the normal direction of the second surface, the reflectance decreases due to the action of the second reflective film on the second surface.

[0026] Hereinafter, a method for manufacturing the screen 11 of this embodiment will be described with reference to FIGS. 6A to 6F. As shown in FIG. 6A, a liquid UV curable resin such as an epoxy-based or acrylic-based resin is applied to the front surface 19a of the light-transmissive substrate 19 made of PET or the like to form the first resin layer 33.

[0027] Next, as shown in FIG. 6B, with the mold 34 for forming the diffusion layer pressed against the first resin layer 33, UV light M is irradiated from the back surface 19b of the light-transmissive substrate 19 to the first resin layer 33. As a result, a concavo-convex structure that is inverted from the concavo-convex structure of the mold 34 is transferred to the first resin layer 33, and the diffusion layer 16 is formed.

[0028] Next, as shown in FIG. 6C, 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 light-transmissive substrate 19 to form the second resin layer 36.

[0029] Next, as shown in FIG. 6D, with the mold 37 for forming the convex portions pressed against the second resin layer 36, UV light M is irradiated from the front surface 19a of the light-transmissive substrate 19 through the diffusion layer 16 to the second resin layer 36 to cure the UV curable resin. Thereafter, when the mold 37 is removed from the second resin layer 36, the concavo-convex structure of the mold 37 is transferred to the second resin layer 36, and a plurality of convex portions 14 are formed.

[0030] Next, as shown in FIG. 6E, as the first film formation step, aluminum A with a reflectance of 70 to 95%, which is the material of the first reflective film 21, is vapor-deposited from the normal direction of the back surface 19b of the translucent substrate 19 to form an aluminum film, and the first reflective film 21 is formed. At this time, the deposition time is appropriately set to form an aluminum film with a thickness of 50 nm or more and 500 nm or less on the first surface 14a of the convex portion 14. On the other hand, since the second surface 14b of the convex portion 14 faces in a direction perpendicular to the back surface 19b of the translucent substrate 19, almost no aluminum film is formed on the second surface 14b. Further, even if a slight amount of aluminum film is formed, the film thickness is not uniform, so the reflectance is in an extremely low state.

[0031] Next, as shown in FIG. 6F, as the second film formation step, chromium C with a reflectance of 30 to 68%, which is the material of the second reflective film 22, is vapor-deposited from a direction inclined from the normal direction of the back surface 19b of the translucent substrate 19 and facing the second surface 14b to form a chromium film, and the second reflective film 22 is formed. In the second film formation step, since oblique vapor deposition of chromium is performed from a direction facing the second surface 14b, the second reflective film 22 can be formed with high accuracy and efficiently. Thereby, the absorption effect of external light on the second surface 14b of the convex portion 14 can be enhanced. At this time, the deposition time is appropriately set to form a chromium film with a thickness of 50 nm or more and 500 nm or less on the second surface 14b.

[0032] As shown in FIG. 6F, the second reflective film 22 may be formed so as to overlap the first reflective film 21 formed on the first surface 14a. By doing so, the deterioration of the function due to corrosion, wear, oxidation, etc. of the aluminum film which is the first reflective film 21 can be suppressed by the second reflective film 22. Through the above steps, the screen 11 of the present embodiment is completed.

[0033] (Effect of the First Embodiment) The screen 11 of this embodiment includes a light-transmissive substrate 19, a plurality of convex portions 14 provided on the back surface 19b of the light-transmissive substrate 19, a first surface 14a that forms an angle of a first angle θ1 with the back surface 19b, and a second surface 14b that forms an angle of a second angle θ2 larger than the first angle θ1 with the back surface 19b, a first reflective film 21 provided on the first surface 14a, and a second reflective film 22 provided on the second surface 14b and having a lower reflectance in visible light than the first reflective film 21.

[0034] In a conventional reflective screen, a light absorption layer made of a black resin is provided at a position corresponding to the second surface of the convex portion of this embodiment. The reflectance of the light absorption layer is, for example, less than about 2 to 3%. According to this screen, when used in an environment with a lot of external light, a lot of external light can be absorbed by the light absorption layer, so the contrast of the projected image can be improved. However, when used in an environment with little external light, such as a room with high light-shielding properties, the demerit that the projected image becomes darker due to a part of the projected light being absorbed by the light absorption layer is greater than the merit of absorbing external light and enhancing the contrast.

[0035] On the other hand, in the screen 11 of this embodiment, a second reflective film 22 made of chromium, which has a lower reflectance than aluminum constituting the first reflective film 21, is provided on the second surface 14b of the convex portion 14. That is, the second reflective film 22 made of chromium has higher light absorption than the first reflective film 21 made of aluminum and higher light reflectivity than the black resin. Therefore, when used in an environment with a lot of external light, a part of the external light can be absorbed by the second reflective film 22, so the contrast of the projected image can be improved. Also, when used in an environment with little external light, a part of the projected light L incident on the second surface 14b of the convex portion 14 is reflected by the second reflective film 22, so the utilization efficiency of the projected light L is increased and the projected image can be brightened. Thus, according to this embodiment, it is possible to provide a screen 11 with excellent visibility of the projected image regardless of the use environment.

[0036] The manufacturing method of the screen 11 of the present embodiment includes a step of forming a plurality of convex portions 14 having a first surface 14a with an angle of the first angle θ1 with respect to the back surface 19b and a second surface 14b with an angle of the second angle θ2 greater than the first angle θ1 with respect to the back surface 19b on the back surface 19b of the translucent substrate 19, a first film forming step of forming a first reflective film 21 on the first surface 14a, and a second film forming step of forming a second reflective film 22 having a reflectance in visible light lower than that of the first reflective film 21 on the second surface 14b after the first film forming step.

[0037] According to this manufacturing method, the first reflective film 21 and the second reflective film 22 can be surely separated and formed on each of the surfaces 14a and 14b of the convex portion 14, and the screen 11 excellent in visibility can be efficiently manufactured regardless of the usage environment.

[0038] The projection system 10 of the present embodiment includes the screen 11 of the present embodiment and a projection device 12 that projects projection light L toward the screen 11. According to this configuration, a projection system 10 excellent in visibility of a projected image can be provided regardless of the usage environment.

[0039] [Second Embodiment] Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. The basic configuration of the screen and its manufacturing method of the present embodiment is the same as that of the first embodiment, and only the film forming method of each reflective film is different from that of the first embodiment. Therefore, the description of the common parts will be omitted. FIGS. 7A and 7B are diagrams showing a film forming step in the manufacturing method of the screen of the second embodiment. In FIGS. 7A and 7B, the same reference numerals are given to the components common to the drawings used in the first embodiment.

[0040] In the method for manufacturing a screen according to this embodiment, as shown in FIG. 7A, as a first film forming step, aluminum A is vapor-deposited from a direction inclined from the normal direction of the back surface 19b of the translucent substrate 19 and toward the first surface 14a of the convex portion 14 to form a first reflective film 21. In this way, since the oblique vapor deposition of aluminum is performed from the direction toward the first surface 14a of the convex portion 14, the first reflective film 21 can be efficiently formed with high precision. As a result, the reflectance of the projected light L on the first surface 14a of the convex portion 14 can be stably ensured.

[0041] Next, as shown in FIG. 7B, as a second film forming step, chromium C is vapor-deposited from the normal direction of the back surface 19b of the translucent substrate 19 to form a second reflective film 22 on the second surface 14b of the convex portion 14. In this case, although it is difficult to form a chromium film on the second surface 14b of the convex portion 14, a chromium film having a predetermined film thickness can be formed by appropriately setting the vapor deposition time.

[0042] (Effect of the Second Embodiment) Also in this embodiment, the same effect as that of the first embodiment can be obtained, that is, a screen excellent in visibility can be efficiently manufactured regardless of the usage environment.

[0043] [Third Embodiment] Hereinafter, the third embodiment of the present invention will be described with reference to the drawings. The basic configuration of the screen and its manufacturing method according to this embodiment is the same as that of the first embodiment, and only the film forming method of each reflective film is different from that of the first embodiment. Therefore, the description of the common parts will be omitted. FIGS. 8A and 8B are diagrams showing the film forming steps in the method for manufacturing a screen according to the third embodiment. In FIGS. 8A and 8B, the same reference numerals are given to the components common to the drawings used in the first embodiment.

[0044] In the method for manufacturing a screen according to this embodiment, as shown in FIG. 8A, as a first film forming step, aluminum A is vapor-deposited from a direction inclined from the normal direction of the back surface 19b of the translucent substrate 19 toward the first surface 14a of the convex portion 14, and the first reflective film 21 is formed. In this way, since the oblique vapor deposition of aluminum is performed from the direction toward the first surface 14a, the first reflective film 21 can be formed with high accuracy and efficiently. Thereby, the reflectance of the projected light L on the first surface 14a of the convex portion 14 can be stably ensured.

[0045] Next, as shown in FIG. 8B, as a second film forming step, chromium C is vapor-deposited from a direction inclined from the normal direction of the back surface 19b of the translucent substrate 19 toward the second surface 14b of the convex portion 14, and the second reflective film 22 is formed on the second surface 14b of the convex portion 14. In this way, since the oblique vapor deposition of chromium is performed from the direction toward the second surface 14b of the convex portion 14, the second reflective film 22 can be formed with high accuracy and efficiently. Thereby, the absorption effect of external light on the second surface 14b of the convex portion 14 can be stably ensured.

[0046] (Effect of the Third Embodiment) Also in this embodiment, the same effect as that of the first embodiment, that is, a screen excellent in visibility can be efficiently manufactured regardless of the usage environment, can be obtained.

[0047] [Fourth Embodiment] Hereinafter, a fourth embodiment of the present invention will be described with reference to the drawings. The basic configuration of the method for manufacturing a screen according to this embodiment is the same as that of the first embodiment, and is different from the first embodiment in that a protective layer and a support member are added. Therefore, the description of the common parts will be omitted. FIG. 9 is a cross-sectional view of a screen 31 according to the fourth embodiment. In FIG. 9, the same reference numerals are given to the components common to the drawings used in the first embodiment.

[0048] As shown in FIG. 9, the screen 11 according to this embodiment includes a translucent substrate 19, a diffusion layer 16, a plurality of convex portions 14, a first reflective film 21, a second reflective film 22, a protective layer 35, and a support member 32.

[0049] The protective layer 35 is provided to cover the first reflective film 21 and the second reflective film 22. The protective layer 35 is formed of an inorganic material such as a silicon oxide film, for example. The film thickness of the protective layer 35 is about 50 nm, for example. According to this configuration, the protective layer 35 can suppress a decrease in function due to corrosion, wear, oxidation, etc. of the first reflective film 21 and the second reflective film 22.

[0050] The support member 32 is provided on the back side of the protective layer 35. The support member 32 is composed of a resin material such as PET, for example. Note that the support member 32 does not necessarily have to be composed of a light-transmissive material. The support member 32 is joined to the protective layer 35 by an adhesive, for example. According to this configuration, the support member 32 protects the first reflective film 21, the second reflective film 22, and the protective layer 35, and also facilitates the handling of the screen 31.

[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. However, 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 including a stripe-shaped reflective portion in which a plurality of convex portions are simply arranged in one direction without having a Fresnel lens portion may be used.

[0052] In the method for manufacturing the screen of the above embodiment, oblique evaporation is employed in at least one of the first film formation step and the second film formation step. However, instead of this configuration, evaporation from the normal direction of the light-transmissive substrate may be employed in both the first film formation step and the second film formation step. According to this method, evaporation of the metal material can be easily performed.

[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 embodiments and can be changed as appropriate.

[0054] [Summary of the Present Disclosure] The summary of the present disclosure is appended below.

[0055] (Appendix 1) A method for manufacturing a reflective screen that reflects projection light projected from a projection device and displays an image on the observation side, forming a plurality of convex portions having a first surface with an angle of the first surface with respect to the main surface being a first angle and a second surface with an angle of the second surface with respect to the main surface being a second angle greater than the first angle on the main surface of the light-transmissive substrate on the side opposite to the observation side; a first film-forming step of forming a first reflective film on the first surface; a second film-forming step of forming a second reflective film having a lower reflectance in visible light than the first reflective film on the second surface after the first film-forming step; A method for manufacturing a reflective screen, comprising:

[0056] According to the configuration of Appendix 1, a screen excellent in visibility can be efficiently manufactured regardless of the use environment.

[0057] (Appendix 2) The method for manufacturing a reflective screen according to Appendix 1, wherein in the second film-forming step, the second reflective film is formed overlapping the first reflective film formed on the first surface.

[0058] According to the configuration of Appendix 2, deterioration due to corrosion, wear, oxidation, etc. of the first reflective film can be suppressed by the second reflective film.

[0059] (Appendix 3) In the first film-forming step, vapor deposition of the film-forming material of the first reflective film is performed from the normal direction of the main surface, In the second film-forming step, vapor deposition of the film-forming material of the second reflective film is performed from a direction inclined from the normal direction and toward the second surface. The method for manufacturing a reflective screen according to Appendix 1 or Appendix 2.

[0060] According to the configuration of Supplementary Note 3, the second reflective film can be formed with high precision and high efficiency, and the absorption effect of external light on the second surface of the convex portion can be enhanced.

[0061] (Supplementary Note 4) In the first film formation step, the deposition of the film formation material of the first reflective film is performed from a direction inclined from the normal direction of the main surface and toward the first surface. In the second film formation step, the deposition of the film formation material of the second reflective film is performed from the normal direction. The method for manufacturing a reflective screen according to Supplementary Note 1 or Supplementary Note 2.

[0062] According to the configuration of Supplementary Note 4, the first reflective film can be formed with high precision and high efficiency, and the reflectance of the projected light on the first surface of the convex portion can be stably ensured.

[0063] (Supplementary Note 5) In the first film formation step, the deposition of the film formation material of the first reflective film is performed from a direction inclined from the normal direction of the main surface and toward the first surface. In the second film formation step, the deposition of the film formation material of the second reflective film is performed from a direction inclined from the normal direction and toward the second surface. The method for manufacturing a reflective screen according to Supplementary Note 1 or Supplementary Note 2.

[0064] According to the configuration of Supplementary Note 5, the first reflective film can be formed with high precision and high efficiency, and the reflectance of the projected light on the first surface of the convex portion can be stably ensured. Also, the second reflective film can be formed with high precision and high efficiency, and the absorption effect of external light on the second surface of the convex portion can be enhanced.

[0065] (Supplementary Note 6) After the second film formation step, the method for manufacturing a reflective screen according to any one of Supplementary Notes 1 to 5 further includes a step of forming a protective layer covering the first reflective film and the second reflective film.

[0066] According to the configuration of Supplementary Note 6, it is possible to suppress a decrease in the functions of the first reflective film and the second reflective film due to corrosion, wear, oxidation, etc. by the protective layer.

[0067] (Supplementary Note 7) Before the first film formation step, a step of forming an ultraviolet curable resin layer on the main surface of the light-transmissive substrate on the observation side; A step of forming a diffusion layer by transferring the concavo-convex shape to the ultraviolet curable resin layer by pressing a mold having a concavo-convex shape against the ultraviolet curable resin layer and irradiating ultraviolet rays; The method for manufacturing a reflective screen according to any one of Supplementary Notes 1 to 6, further comprising:

[0068] According to the configuration of Supplementary Note 7, it is possible to easily form a diffusion layer by irradiating ultraviolet rays from the main surface on the side opposite to the observation side of the light-transmissive substrate at a stage where the first reflective film and the second reflective film are not formed.

[0069] (Supplementary Note 8) The film formation material of the first reflective film is aluminum or an aluminum alloy, The film formation material of the second reflective film is chromium or a chromium alloy, and the method for manufacturing a reflective screen according to any one of Supplementary Notes 1 to 7.

[0070] According to the configuration of Supplementary Note 8, it is possible to form a first reflective film excellent in reflectance and a second reflective film having light absorptivity and excellent in light resistance.

[0071] (Supplementary Note 9) A reflective screen that reflects projection light projected from a projection device and displays an image on the observation side, A light-transmissive substrate, A plurality of convex portions provided on the main surface of the light-transmissive substrate on the side opposite to the observation side, having a first surface whose angle with the main surface is a first angle and a second surface whose angle with the main surface is a second angle larger than the first angle; A first reflective film provided on the first surface; A second reflective film provided on the second surface and having a lower reflectance in visible light than the first reflective film; A reflective screen comprising:

[0072] According to the configuration of Supplementary Note 9, a screen excellent in visibility of a projected image can be provided regardless of the use environment.

[0073] (Supplementary Note 10) The reflectance of the first reflective film in visible light is 70 to 95%, The reflectance of the second reflective film in visible light is 30 to 68%, The difference between the reflectance of the first reflective film in visible light and the reflectance of the second reflective film in visible light is 10% or more. The reflective screen according to Supplementary Note 9.

[0074] According to the configuration of Supplementary Note 10, the first reflective film and the second reflective film that can each exhibit the required functions can be realized.

[0075] (Supplementary Note 11) The first reflective film is made of aluminum or an aluminum alloy, The second reflective film is made of chromium or a chromium alloy. The reflective screen according to Supplementary Note 9 or Supplementary Note 10.

[0076] According to the configuration of Supplementary Note 11, a first reflective film excellent in reflectance and a second reflective film having light absorptivity and excellent in light resistance can be realized.

[0077] (Supplementary Note 12) The film thickness of the first reflective film on the first surface is 50 nm or more, The film thickness of the second reflective film on the second surface is 50 nm or more. The reflective screen according to Supplementary Note 11.

[0078] According to the configuration of Supplementary Note 12, a first reflective film capable of sufficiently reflecting projected light and a second reflective film capable of sufficiently absorbing external light can be realized.

[0079] (Supplementary Note 13) The film thickness of the first reflective film on the first surface is 500 nm or less, The reflective screen according to Supplementary Note 12, wherein the film thickness of the second reflective film on the second surface is 500 nm or less.

[0080] According to the configuration of Supplementary Note 13, the load of the film forming process of each reflective film can be reduced while ensuring the function of each reflective film.

[0081] (Supplementary Note 14) The reflective screen according to any one of Supplementary Notes 9 to 13, further comprising a protective layer covering the first reflective film and the second reflective film.

[0082] According to the configuration of Supplementary Note 14, the protective layer can suppress the deterioration of the functions of the first reflective film and the second reflective film due to corrosion, wear, oxidation, etc.

[0083] (Supplementary Note 15) The reflective screen according to any one of Supplementary Notes 9 to 14, further comprising a diffusion layer provided on the main surface on the observation side of the light-transmissive substrate for diffusing the projected light.

[0084] According to the configuration of Supplementary Note 15, the diffusion layer can widen the viewing angle of the projected image.

[0085] (Supplementary Note 16) The diffusion characteristics of the diffusion layer are anisotropic, 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. The reflective screen according to Supplementary Note 15.

[0086] According to the configuration of Supplementary Note 16, the viewing angle of the projected image in the extending direction of the convex portion of the screen can be widened.

[0087] (Supplementary Note 17) The reflective screen according to any one of Supplementary Notes 9 to 16, further comprising a support member for supporting the first reflective film and the second reflective film.

[0088] According to the configuration of Supplementary Note 17, the first reflective film, the second reflective film, and the protective layer are protected by the support member, and the handling of the screen becomes easy.

[0089] (Supplementary Note 18) The reflective screen according to any one of Supplementary Notes 9 to 17, A projection device that projects the projection light toward the reflective screen, A projection system comprising:

[0090] According to the configuration of Supplementary Note 18, a projection system excellent in visibility of a projected image can be provided regardless of the use environment.

Explanation of Reference Numerals

[0091] 10…Projection system, 11, 31…Reflective screen, 12…Projection device, 14…Convex portion, 14a…First surface, 14b…Second surface, 16…Diffusion layer, 19…Light-transmissive substrate, 21…First reflective layer, 22…Second reflective layer, 32…Support member, 35…Protective layer, θ1…First angle, θ2…Second angle.

Claims

1. A method for manufacturing a reflective screen that reflects projection light projected from a projection device and displays an image on the observation side, comprising: forming a plurality of convex portions on a main surface of the translucent substrate on the side opposite to the observation side, the convex portions having a first surface that forms a first angle with the main surface and a second surface that forms a second angle with the main surface, the second angle being larger than the first angle; a first film-forming step of forming a first reflective film on the first surface; a second film-forming step of forming a second reflective film having a lower reflectance in visible light than the first reflective film on the second surface after the first film-forming step; A method for manufacturing a reflective screen, comprising the above steps.

2. The method for manufacturing a reflective screen according to claim 1, wherein in the second film-forming step, the second reflective film is formed so as to overlap the first reflective film formed on the first surface.

3. In the first film-forming step, the deposition of the film-forming material of the first reflective film is performed from the normal direction of the main surface, In the second film-forming step, the deposition of the film-forming material of the second reflective film is performed while being inclined from the normal direction and from a direction toward the second surface. The method for manufacturing a reflective screen according to claim 1 or claim 2.

4. In the first film-forming step, the deposition of the film-forming material of the first reflective film is performed while being inclined from the normal direction of the main surface and from a direction toward the first surface, In the second film-forming step, the deposition of the film-forming material of the second reflective film is performed from the normal direction. The method for manufacturing a reflective screen according to claim 1 or claim 2.

5. In the first film-forming step, the deposition of the film-forming material of the first reflective film is performed while being inclined from the normal direction of the main surface and from a direction toward the first surface, In the second film-forming step, the deposition of the film-forming material of the second reflective film is performed while being inclined from the normal direction and from a direction toward the second surface. The method for manufacturing a reflective screen according to claim 1 or claim 2.

6. The method for manufacturing a reflective screen according to claim 1 or claim 2, further comprising a step of forming a protective layer covering the first reflective film and the second reflective film after the second film-forming step.

7. Before the first film-forming step, a step of forming an ultraviolet curable resin layer on the main surface of the translucent substrate on the observation side; A step of forming a diffusion layer by transferring the uneven shape to the ultraviolet curable resin layer by pressing a mold having an uneven shape against the ultraviolet curable resin layer and irradiating ultraviolet rays; The method for manufacturing a reflective screen according to claim 1 or claim 2, further comprising the above steps.

8. The film-forming material of the first reflective film is aluminum or an aluminum alloy, The film-forming material of the second reflective film is chromium or a chromium alloy. The method for manufacturing a reflective screen according to claim 1 or claim 2.

9. A reflective screen that reflects the projection light projected from a projection device and displays an image on the observation side, A translucent substrate, A plurality of convex portions provided on the main surface of the translucent substrate on the side opposite to the observation side, having a first surface with an angle formed with the main surface being a first angle and a second surface with an angle formed with the main surface being a second angle larger than the first angle, A first reflective film provided on the first surface, A second reflective film provided on the second surface, having a reflectance in visible light lower than that of the first reflective film, Comprising a reflective screen.

10. The reflectance of the first reflective film in visible light is 70 to 95%, The reflectance of the second reflective film in visible light is 30 to 68%, The difference between the reflectance of the first reflective film in visible light and the reflectance of the second reflective film in visible light is 10% or more. The reflective screen according to claim 9.

11. The first reflective film is composed of aluminum or an aluminum alloy, The second reflective film is composed of chromium or a chromium alloy. The reflective screen according to claim 9 or claim 10.

12. The film thickness of the first reflective film on the first surface is 50 nm or more, The film thickness of the second reflective film on the second surface is 50 nm or more. The reflective screen according to claim 11.

13. The film thickness of the first reflective film on the first surface is 500 nm or less, The film thickness of the second reflective film on the second surface is 500 nm or less. The reflective screen according to claim 12.

14. Further comprising a protective layer covering the first reflective film and the second reflective film. The reflective screen according to claim 9 or claim 10.

15. Further comprising a diffusion layer provided on the main surface of the translucent substrate on the observation side for diffusing the projection light. The reflective screen according to claim 9 or claim 10.

16. The diffusion characteristics of the diffusion layer have anisotropy, 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 15.

17. The reflective screen according to claim 9 or claim 10, further comprising a support member for supporting the first reflective film and the second reflective film.

18. The reflective screen according to claim 9 or claim 10, and a projection device that projects the projection light toward the reflective screen, A projection system comprising:

Images