Through a screen and a display system

Abstract

To provide a transmission screen which can improve the contrast of an image to be displayed.SOLUTION: A transmission screen includes a first portion and a second portion arranged alternately in a first direction. The first portion includes a first surface and a second surface that form an interface with the second portion. The first surface and the second surface face each other in the first direction. A distance along the first direction between the first surface and the second surface is larger on the light emission side than on the light incident side. The second surface of the first portion is located on the second side closer to an image light source in the first direction. The first surface of the first portion is located on the first side apart from the image light source in the first direction. The first portion includes a light diffusion part having a light diffusion function. The magnitude of the first angle between the first surface and the first direction is equal to or greater than 40° and less than the magnitude of the second angle between the second surface and the first direction.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a transmissive screen and a display system.

Background Art

[0002] As disclosed in Patent Document 1, a transmissive screen is known. The transmissive screen includes a light incident side surface and a light emitting side surface. A video light source projects video light onto the light incident side surface of the transmissive screen. The transmissive screen diffuses and transmits the video light. By the diffusion in the transmissive screen, an observer can observe a video on the light emitting side surface.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The transmissive screen disclosed in Patent Document 1 has a light diffusion function of diffusing video light over its entire area. Therefore, external light other than the video light incident on the transmissive screen is also diffused by the transmissive screen. As a result, the contrast of the video is reduced due to the diffusion of the external light. The present disclosure aims to improve the contrast of the video displayed on the transmissive screen.

Means for Solving the Problems

[0005] A transmissive screen according to an embodiment of the present disclosure is a transmissive screen onto which video light is projected from a video light source, comprising a first portion and a second portion alternately arranged in a first direction, wherein the first portion includes a first surface and a second surface that form an interface with the second portion, and the first surface and the second surface face each other in the first direction, The distance along the first direction of the first surface and the second surface is larger on the light-emitting side than on the light-incident side. The second surface of the first portion is located on the second side closer to the video light source in the first direction, and the first surface of the first portion is located on the first side farther from the video light source in the first direction. The first portion includes a light diffusion portion having a light diffusion function. The magnitude of the first angle between the first surface and the first direction may be 40° or more and less than the magnitude of the second angle between the second surface and the first direction.

[0006] In the transmissive screen according to an embodiment of the present disclosure, the first portion may include a light-shielding portion that constitutes the first surface, and the light-shielding portion may have visible light-shielding properties.

[0007] In the transmissive screen according to an embodiment of the present disclosure, the first portion may include a light absorption portion that constitutes the first surface, and the light absorption portion may have visible light absorption properties.

[0008] In the transmissive screen according to an embodiment of the present disclosure, the first portion may include a light reflection portion located between the light absorption portion and the light diffusion portion, and the light reflection portion may have visible light reflection properties.

[0009] In the transmissive screen according to an embodiment of the present disclosure, the first portion may include a light reflection portion that constitutes the first surface, and the light reflection portion may have visible light reflection properties.

[0010] In the transmissive screen according to an embodiment of the present disclosure, the light reflection portion may include a metal layer.

[0011] In the transmissive screen according to an embodiment of the present disclosure, the refractive index of the portion constituting the second surface of the first portion may be higher than the refractive index of the second portion.

[0012] In the transmissive screen according to an embodiment of the present disclosure, The first part may include a low refractive index portion that constitutes the first surface. The refractive index of the low refractive index portion may be lower than the refractive index of a portion adjacent to the low refractive index portion of the first part.

[0013] In a transmissive screen according to an embodiment of the present disclosure, The first part may include a low refractive index portion that constitutes the first surface. The refractive index of the low refractive index portion may be lower than the refractive index of the second part.

[0014] In a transmissive screen according to an embodiment of the present disclosure, the refractive index of a portion of the first part that constitutes the first surface may be higher than the refractive index of the second part.

[0015] In a transmissive screen according to an embodiment of the present disclosure, the magnitude of the first angle may be greater than Arccos(1 / n), where n is the refractive index of the second part, and may be 80° or less.

[0016] In a transmissive screen according to an embodiment of the present disclosure, the magnitude of the first angle of one first part may be greater than the magnitude of the first angle of another one of the first parts located on the first side in the first direction relative to the one first part.

[0017] In a transmissive screen according to an embodiment of the present disclosure, the magnitude of the first angle of any one of the first parts may be greater than or equal to the magnitude of the first angle of any other one of the first parts located on the first side in the first direction relative to the one first part.

[0018] In a transmissive screen according to an embodiment of the present disclosure, the magnitude of the second angle may be 85° or more and 90° or less.

[0019] In a transmissive screen according to an embodiment of the present disclosure, a light control layer including the first part and the second part; and a light shielding layer located on the light emitting side of the light control layer may be provided. The light-shielding layer may have visible light-shielding properties. The light-shielding layer may face the light-emitting side surface of the second portion from the light-emitting side.

[0020] In a transmissive screen according to an embodiment of the present disclosure, a light control layer including the first portion and the second portion; and a light absorption layer located on the light-emitting side of the light control layer may be provided. The light absorption layer may have visible light absorption properties. The light absorption layer may face the light-emitting side surface of the second portion from the light-emitting side.

[0021] In a transmissive screen according to an embodiment of the present disclosure, a light control layer including the first portion and the second portion; and a light reflection layer located on the light-emitting side of the light control layer may be provided. The light reflection layer may have visible light reflection properties. The light reflection layer may face the light-emitting side surface of the second portion from the light-emitting side.

[0022] In a transmissive screen according to an embodiment of the present disclosure, a light control layer including the first portion and the second portion; and a decorative layer located on the light-emitting side of the light control layer for displaying a design may be provided. The decorative layer may face the light-emitting side surface of the second portion from the light-emitting side.

[0023] In a transmissive screen according to an embodiment of the present disclosure, a light control layer including the first portion and the second portion; and a light-shielding layer located on the light-emitting side of the light control layer may be provided. The light-shielding layer may have visible light-shielding properties. The light-shielding layer may face only a part of the light-emitting side surface of the second portion from the light-emitting side. The said part may include the end portion on the first side in the first direction of the light-emitting side surface and may be away from the end portion on the second side in the first direction of the light-emitting side surface.

[0024] In a transmissive screen according to an embodiment of the present disclosure, a light control layer including the first portion and the second portion, and a light absorption layer located on the light-emitting side of the light control layer may be provided. The light absorption layer may have visible light absorption properties. The light absorption layer may face, from the light-emitting side, only a part of the light-emitting side surface of the second portion. The said part may include the end portion on the first side in the first direction of the light-emitting side surface and may be away from the end portion on the second side in the first direction of the light-emitting side surface.

[0025] In a transmissive screen according to an embodiment of the present disclosure, a light control layer including the first portion and the second portion, and a light reflection layer located on the light-emitting side of the light control layer may be provided. The light reflection layer may have visible light reflection properties. The light reflection layer may face, from the light-emitting side, only a part of the light-emitting side surface of the second portion. The said part may include the end portion on the first side in the first direction of the light-emitting side surface and may be away from the end portion on the second side in the first direction of the light-emitting side surface.

[0026] A transmissive screen according to an embodiment of the present disclosure includes a first portion and a second portion alternately arranged in a first direction. The first portion includes a first surface and a second surface that form an interface with the second portion. The first surface and the second surface face each other in the first direction. The first portion includes a light diffusing portion having a light diffusing function and a light shielding portion that constitutes the first surface. The light-shielding portion has visible light-shielding properties, and the magnitude of the first angle between the first surface and the first direction may be less than the magnitude of the second angle between the second surface and the first direction.

[0027] A transmissive screen according to an embodiment of the present disclosure includes a first portion and a second portion alternately arranged in a first direction, the first portion includes a first surface and a second surface that form an interface with the second portion, the first surface and the second surface face each other in the first direction, the first portion includes a light diffusing portion having a light diffusing function and a light absorbing portion that constitutes the first surface, the light absorbing portion has visible light absorbability, the magnitude of the first angle between the first surface and the first direction may be less than the magnitude of the second angle between the second surface and the first direction.

[0028] A transmissive screen according to an embodiment of the present disclosure includes a first portion and a second portion alternately arranged in a first direction, the first portion includes a first surface and a second surface that form an interface with the second portion, the first surface and the second surface face each other in the first direction, the first portion includes a light diffusing portion having a light diffusing function and a light reflecting portion that constitutes the first surface, the light reflecting portion has visible light reflectivity, the magnitude of the first angle between the first surface and the first direction may be less than the magnitude of the second angle between the second surface and the first direction.

[0029] A transmissive screen according to an embodiment of the present disclosure includes a first portion and a second portion alternately arranged in a first direction, the first portion includes a first surface and a second surface that form an interface with the second portion, the first surface and the second surface face each other in the first direction, The first portion includes a light diffusing portion having a light diffusing function and a low refractive index portion forming the first surface. The magnitude of the first angle between the first surface and the first direction is less than the magnitude of the second angle between the second surface and the first direction. The refractive index of the low refractive index portion may be lower than the refractive index of a portion adjacent to the low refractive index portion of the first portion.

[0030] A transmissive screen according to an embodiment of the present disclosure includes a first portion and a second portion alternately arranged in a first direction. The first portion includes a first surface and a second surface that form an interface with the second portion. The first surface and the second surface face each other in the first direction. The first portion includes a light diffusing portion having a light diffusing function and a low refractive index portion forming the first surface. The magnitude of the first angle between the first surface and the first direction is less than the magnitude of the second angle between the second surface and the first direction. The refractive index of the low refractive index portion may be lower than the refractive index of the second portion.

[0031] A transmissive screen according to an embodiment of the present disclosure includes a first portion and a second portion alternately arranged in a first direction. The first portion includes a first surface and a second surface that form an interface with the second portion. The first surface and the second surface face each other in the first direction. The first portion includes a light diffusing portion having a light diffusing function. The magnitude of the first angle between the first surface and the first direction is less than the magnitude of the second angle between the second surface and the first direction. The refractive index of a portion forming the first surface of the first portion may be higher than the refractive index of the second portion.

[0032] A display system according to an embodiment of the present disclosure any one of the transmissive screens according to an embodiment of the present disclosure; and It may also include a video light source that projects video light onto the transmissive screen.

Advantages of the Invention

[0033] According to the present invention, the contrast of the video displayed on the transmissive screen can be improved.

Brief Description of the Drawings

[0034]

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Figure 4B

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Figure 12B

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Figure 14A

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Figure 15

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Figure 17A

Figure 17B

Figure 17C

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Figure 19

Figure 20

Mode for Carrying Out the Invention

[0035] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In the drawings attached to this specification, for the convenience of illustration and easier understanding, the scale, the aspect ratio of the vertical and horizontal dimensions, etc. are appropriately changed and exaggerated from those of the actual object. Also, in some of the drawings, the configurations and the like shown in one drawing may be omitted in other drawings.

[0036] In this specification, terms that specify shapes, geometric conditions, and their degrees, such as "parallel", "orthogonal", "identical", etc., and values of lengths and angles are not limited to strict meanings, but are interpreted to include ranges that can be expected to have similar functions.

[0037] In this specification, the normal direction of a sheet-like (sheet-like, plate-like) member refers to the normal direction to the sheet surface of the target sheet-like (film-like, plate-like) member. The "sheet surface (film surface, plate surface)" refers to the surface that coincides with the plane direction of the target sheet-like (film-like, plate-like) member when the target sheet-like (film-like, plate-like) member is viewed as a whole and globally.

[0038] To clarify the relationship of directions between the drawings, in some drawings, the first direction D1, the second direction D2, and the third direction D3 are shown as common directions by arrows with common reference numerals. As shown in FIG. 2, the symbol with an "×" inside the circle indicates an arrow directed into the depth of the drawing paper along the direction perpendicular to the drawing paper. As shown in FIG. 6, the symbol with a dot inside the circle indicates an arrow directed forward from the drawing paper along the direction perpendicular to the drawing paper. The tip side of the arrow in the first direction D1 is the first side in the first direction, and the side opposite to the first side in the first direction is the second side.

[0039] Figs. 1 to 20 are diagrams for explaining an embodiment. Figs. 1 and 2 are diagrams showing a display system 10. The display system 10 includes an image light source 15 and a transmissive screen 20. The image light source 15 projects image lights L11 and L21 onto the transmissive screen 20. The image lights L11 and L21 pass through the transmissive screen 20. The image lights L11 and L21 are diffused by the transmissive screen 20. An observer 9 can observe the image displayed on the transmissive screen 20 from a direction within the diffusion range of the image light. In particular, the transmissive screen 20 described in this embodiment is devised to improve the contrast of the displayed image.

[0040] The contrast is the bright contrast. The contrast is evaluated as the ratio value of the luminance (white luminance) when white is displayed under the condition that ambient light exists to the luminance (black luminance) when black is displayed under the condition that ambient light exists. The higher the ratio value, the better the contrast is evaluated.

[0041] Hereinafter, the display system 10 and the transmissive screen 20 in an embodiment will be described with reference to the illustrated specific examples. First, with reference to Figs. 1 to 16, the basic aspect of an embodiment will be described.

[0042] The imaging light source 15 projects imaging light. When the imaging light is diffused by the transmissive screen 20, an image observable by the observer 9 is displayed on the transmissive screen 20. The image may be a moving image or a still image. The image may be composed of multiple colors or a single color. The imaging light source 15 is not particularly limited. Various forms can be applied to the imaging light source 15. The imaging light source 15 may include a transmissive microdisplay or a reflective microdisplay as a spatial light modulator. As the transmissive microdisplay, a liquid crystal display panel is exemplified. As the reflective microdisplay, MEMS elements such as DMD (Digital Micromirror Device) are exemplified. The imaging light source 15 may include a laser light source as a light source for illuminating the spatial light modulator. The imaging light source 15 may include a laser light source and a scanning device that scans the light from the laser light source with the transmissive screen 20.

[0043] In the illustrated example, a short-focus imaging light source 15 is used. The imaging light source 15 is disposed at a position not facing the transmissive screen 20. As shown in FIG. 6, in the observation from the third direction D3 which is the normal direction of the transmissive screen 20, the light source center 15C which is the center of the emission surface of the imaging light source 15 is not located on the transmissive screen 20. The light source center 15C does not overlap with the transmissive screen 20 in the projection onto the third direction D3 which is the normal direction of the transmissive screen 20. As shown in FIG. 2, the incident angle θa of the imaging light is greater than 0°. The incident angle θa is the smaller angle among the angles between the traveling direction of the light and the normal direction of the incident surface. The incident angle θa is 90° or less. The incident angle θa of the imaging light varies according to the incident position on the transmissive screen 20. In the illustrated example, the incident angle θa ranges from 20° to 70°.

[0044] The image light is projected from the image light source 15 through the transmissive screen 20. The image light passes through the transmissive screen 20. The transmissive screen 20 diffuses the image light. The transmissive screen 20 is in a sheet shape. The transmissive screen 20 is transmissive and includes an incident light side surface 21 and an exit light side surface 22. The incident light side surface 21 and the exit light side surface 22 constitute a pair of main surfaces of the sheet-shaped transmissive screen 20.

[0045] The incident light side surface 21 and the exit light side surface 22 face each other in the third direction D3. The third direction D3 coincides with the normal direction of the transmissive screen 20. In the illustrated example, the tip side of the arrow indicating the third direction D3 is the exit light side, and the opposite of the exit light side in the third direction D3 is the incident light side.

[0046] In the illustrated example, the transmissive screen 20 is planar. The transmissive screen 20 may be curved. The illustrated transmissive screen 20 extends in the first direction D1 and the second direction D2. The first direction D1 and the second direction D2 are perpendicular to each other. In the illustrated example, the third direction D3 is perpendicular to both the first direction D1 and the second direction D2. In the illustrated example, the transmissive screen 20 has a rectangular shape when observed from the third direction D3. The transmissive screen 20 includes an edge extending in the first direction D1 and an edge extending in the second direction D2.

[0047] As shown in FIG. 3, the transmissive screen 20 includes a light control layer 40. The light control layer 40 includes a first portion 50 and a second portion 60 alternately arranged in the first direction D1. The first portion 50 includes a first surface 51 and a second surface 52 that form an interface with the second portion 60. The first surface 51 and the second surface 52 face each other in the first direction D1. That is, the first surface 51 and the second surface 52 face each other in the first direction D1. The first portion 50 includes a light diffusing portion 55 having a light diffusing function.

[0048] In the example shown in FIG. 3, the transmissive screen 20 includes a functional layer 35, a substrate 31, a bonding layer 33, a light control layer 40, and a functional layer 35 in this order from the light incident side surface 21 toward the light emitting side surface 22. The functional layer 35, the substrate 31, and the bonding layer 33 may be omitted from the transmissive screen 20. The transmissive screen 20 may be a transparent screen that allows the view through the back of the transmissive screen 20. When the transmissive screen 20 is a transparent screen, the functional layer 35, the substrate 31, and the bonding layer 33 may have visible light transmissivity.

[0049] "Having visible light transmissivity" means that the visible light transmittance is greater than 30%, preferably the visible light transmittance is 50% or more, and more preferably the visible light transmittance is 80% or more. The visible light transmittance is specified as the average value of the total light transmittance at each wavelength when measured at an incident angle of 0° every 1 nm within the range of a measurement wavelength of 380 nm or more and 780 nm or less using a spectrophotometer ("UV-3100PC" manufactured by Shimadzu Corporation, compliant with JIS K 0115).

[0050] The substrate 31 functions as a support for supporting the light control layer 40. The substrate 31 may be a glass plate. The glass plate may be a blue plate glass. The substrate 31 may be a resin plate. The resin plate may be a plate made of an acrylic resin or a plate made of polycarbonate. The substrate 31 may be a window glass. As an example, the thickness of the substrate 31 may be 0.5 mm or more and 10 mm or less.

[0051] The bonding layer 33 bonds the light control layer 40 to the substrate 31. The bonding layer 33 may be formed using various adhesives and adhesives applied to optical members. The bonding layer 33 may bond the light control layer 40 removably from the substrate 31. The bonding layer 33 may be capable of re-bonding the light control layer 40 removed from the substrate 31 to the substrate 31. For example, depending on the position of the video light source 15, the arrangement of the light control layer 40 with respect to the substrate 31 may be changed. As the material of the bonding layer 33, known adhesives, adhesives, photocurable resins, thermosetting resins, etc. may be used. More specifically, as the material of the bonding layer 33, an acrylic adhesive combining an acrylic copolymer and an isocyanate compound may be used.

[0052] A functional layer is a layer expected to exhibit a specific function. One functional layer 35 may exhibit two or more functions. The functional layer is not particularly limited, but examples include a hard coat layer that exhibits scratch resistance, an antifouling layer having an antifouling function, an antiglare layer having an antiglare function, an antireflection layer having an antireflection function, and the like. In the example shown in FIG. 3, the functional layer 35 is a surface layer 36 that constitutes the surface of the transmissive screen 20. The transmissive screen 20 shown in FIG. 3 includes a first surface layer 36A that constitutes the incident light side surface 21 and a second surface layer 36B that constitutes the outgoing light side surface 22.

[0053] In the example shown in FIG. 3, the transmissive screen 20 may constitute a window glass of a building. In the example shown in FIG. 3, the substrate 31 is disposed on the incident light side of the light control layer 40. As shown in FIG. 4A, the substrate 31 may be disposed on the outgoing light side of the light control layer 40. In the example shown in FIG. 4A, the transmissive screen 20 includes, in order from the incident light side surface 21 to the outgoing light side surface 22, a functional layer 35, a light control layer 40, a bonding layer 33, a substrate 31, and a functional layer 35. The transmissive screen 20 shown in FIG. 4A includes, as the functional layer 35, a first surface layer 36A located on the incident light side and a second surface layer 36B located on the outgoing light side. In the example shown in FIG. 4A, the functional layer 35, the substrate 31, and the bonding layer 33 may be configured in the same manner as the functional layer 35, the substrate 31, and the bonding layer 33 of the transmissive screen 20 shown in FIG. 3, respectively.

[0054] As shown in FIG. 4B, the substrate 31 may be disposed on both the light incident side and the light emitting side of the light control layer 40. In the example shown in FIG. 4B, the transmissive screen 20 includes, in order from the light incident surface 21 toward the light emitting surface 22, the functional layer 35, the substrate 31, the bonding layer 33, the light control layer 40, the bonding layer 33, the substrate 31, and the functional layer 35. The transmissive screen 20 includes, as the functional layer 35, a first surface layer 36A located on the light incident side and a second surface layer 36B located on the light emitting side. The transmissive screen 20 includes, as the substrate 31, a first substrate 31A located on the light incident side and a second substrate 31B located on the light emitting side. The transmissive screen 20 includes, as the bonding layer 33, a first bonding layer 33A located on the light incident side and a second bonding layer 33B located on the light emitting side. In the example shown in FIG. 4B, the functional layer 35, the substrate 31, and the bonding layer 33 may be configured in the same manner as the functional layer 35, the substrate 31, and the bonding layer 33 of the transmissive screen 20 shown in FIG. 3, respectively. When the first substrate 31A and the second substrate 31B are glass plates, the transmissive screen 20 constitutes a so-called laminated glass.

[0055] The transmissive screen 20 may have a rigidity such that it can stand on its own. The transmissive screen 20 may have a flexibility such that it can be wound up, as shown in FIG. 5. In the example shown in FIG. 5, the transmissive screen 20 may be wound around a winding core 39 when not in use.

[0056] The light control layer 40 is in a sheet form. The video light passes through the light control layer 40. The light control layer 40 includes a light incident surface 41 and a light emitting surface 42 with respect to the video light. The light incident surface 41 and the light emitting surface 42 form a pair of main surfaces in the sheet-like light control layer 40.

[0057] As shown in FIG. 8, the light control layer 40 includes a plurality of first portions 50 arranged in the first direction D1. The first portion 50 includes a light diffusing portion 55. The light diffusing portion 55 diffuses incident light. The light diffusing portion 55 diffuses the video light L81. The light control layer 40 includes a plurality of second portions 60 arranged in the first direction D1. The second portion 60 has visible light transmissivity. The second portion 60 serves as a path for the video light L81 incident on the first portion 50. When the transmissive screen 20 is a transparent screen, the second portion 60 serves as a transmission path for the backlight L82. As shown in FIGS. 2 and 8, the backlights L22, L82 are lights other than the video lights L21, L81 that travel from the light incident side to the light emitting side. Due to the transmission of the backlights L22, L82, the observer 9 can observe the background 7 through the transmissive screen 20.

[0058] As shown in FIG. 8, the first portions 50 and the second portions 60 are alternately arranged in the first direction D1. The first portions 50 and the second portions 60 may linearly extend in a direction non-parallel to the first direction D1. As shown in FIG. 6, each first portion 50 may linearly extend in a second direction D2 perpendicular to the first direction D1. In the example shown in FIG. 6, each second portion 60 linearly extends in a second direction D2 perpendicular to the first direction D1. As shown in FIG. 7, the first portion 50 may extend in a curved shape. As shown in FIG. 7, the second portion 60 may extend in a curved shape. In the example shown in FIG. 7, the plurality of first portions 50 extend along concentric circles. In the example shown in FIG. 7, the plurality of second portions 60 extend along concentric circles. The plurality of first portions 50 and the plurality of second portions 60 may extend along concentric circles centered at the same position. In a projection onto the third direction D3, the center of the concentric circles coincides with the light source center 15C, which is the center of the light emitting surface of the video light source 15.

[0059] The first direction D1 may be parallel to the vertical direction. The second direction D2 and the third direction D3 may be parallel to the horizontal direction.

[0060] As shown in FIG. 8, the light control layer 40 may further include a sheet-like base portion (land portion) 48 in addition to the first portion 50 and the second portion 60. The base portion 48 supports the first portion 50 and the second portion 60. The base portion 48 is sheet-like. The base portion 48 may be integrally formed with a plurality of second portions 60. The base portion 48 may be connected to the second portion 60 without a joint. In the example shown in FIG. 8, the base portion 48 constitutes the light control layer main body 45 together with the second portion 60. In other words, the light control layer 40 has a light control layer main body 45 in which a plurality of grooves 45a are formed, and first portions 50 respectively formed in the plurality of grooves 45a of the light control layer main body 45. And, the portion between adjacent grooves 45a of the light control layer main body 45 constitutes the second portion 60.

[0061] As shown in FIG. 8, the light control layer 40 may be joined to the base material 38. The transmission screen 20 may further include the base material 38 joined to the light control layer 40. In the example shown in FIG. 8, the base material 38 is joined to the base portion 48 of the light control layer main body 45. The base material 38 may be constituted by a polyethylene terephthalate film, a polycarbonate film, etc. having a thickness of 30 μm or more and 300 μm or less.

[0062] The base portion 48 and the base material 38 have visible light transmissivity. The base portion 48 and the base material 38 serve as transmission paths for the video light L81 and the backlight L82. The base portion 48 and the base material 38 are not essential components of the light control layer 40 and can be omitted.

[0063] FIG. 8 shows a main cutting plane of the light control layer 40. The main cutting plane of the light control layer 40 is a cross-section parallel to both the first direction D1, which is the arrangement direction of the first portion 50 and the second portion 60, and the third direction D3, which is the normal direction of the light control layer 40. The first portion 50 includes a first surface 51 and a second surface 52 that form an interface with the second portion 60. The first surface 51 and the second surface 52 face each other in the first direction D1. In one first portion 50, the first surface 51 is located on the first side in the first direction D1, and the second surface 52 is located on the second side in the first direction D1. The first side is the side spaced apart from the video light source 15 in the first direction D1. The second side is the side approaching the video light source 15 in the first direction D1. The second side is the opposite side of the first side in the first direction D1. The distance D along the first direction D1 between the first surface 51 and the second surface 52 is longer on the light-emitting side in the third direction D3 than on the light-incident side in the third direction D3. In the illustrated example, the distance along the first direction D1 between the first surface 51 and the second surface 52 gradually increases from the light-incident side to the light-emitting side in the third direction D3.

[0064] The magnitude of the first angle θ1 between the first surface 51 and the first direction D1 is 40° or more. The magnitude of the first angle θ1 may be 45° or more, 60° or more, or 70° or more. The magnitude of the first angle θ1 is less than the magnitude of the second angle θ2 between the second surface 52 and the first direction D1. The magnitude of the first angle θ1 may be 85° or less, 80° or less. The magnitude of the second angle θ2 may be 85° or more and 90° or less, or 90°. By setting the first angle θ1 and the second angle θ2 in this way, the contrast of the video can be improved.

[0065] The first angle θ1 is the angle between the first surface 51 and the first direction D1 specified in the main cutting plane of the light control layer 40. The angle between the first surface 51 and the first direction D1 in the main cutting plane specifies two angles whose sum is 180°. The first angle θ1 is the smaller of the two angles. The magnitude of the first angle θ1 is greater than 0° and 90° or less.

[0066] The second angle θ2 is the angle between the second plane 52 specified in the main cutting plane of the light control layer 40 and the first direction D1. Two angles with a total of 180° are specified as the angle between the second plane 52 and the first direction D1 in the main cutting plane. The second angle θ2 is the smaller of the two angles. The magnitude of the second angle θ2 is greater than 0° and less than or equal to 90°.

[0067] As will be described later, when the first plane 51 is a folded surface or a curved surface, the first angle θ1 is specified at the position that is the center in the third direction D3 on the first plane 51. When the first plane 51 is a curved surface, the angle between the tangent line to the first plane 51 in the main cutting plane of the light control layer 40 and the first direction D1 is defined as the first angle. When the second plane 52 is a folded surface or a curved surface, the second angle θ2 is specified at the position that is the center in the third direction D3 on the second plane 52. When the second plane 52 is a curved surface, the angle between the tangent line to the second plane 52 in the main cutting plane of the light control layer 40 and the first direction D1 is defined as the second angle.

[0068] In the example shown in FIG. 8, the first portion 50 includes a light-emitting side surface 54 in addition to the first plane 51 and the second plane 52. The light-emitting side surface 54 constitutes a part of the light-emitting side surface 42 of the light control layer 40. The first plane 51 is connected to the light-emitting side surface 54 on the light-emitting side in the third direction D3. The second plane 52 is connected to the light-emitting side surface 54 on the light-emitting side in the third direction D3. The first plane 51 and the second plane 52 are connected to each other on the light-incident side in the third direction D3. The illustrated first portion 50 has a triangular shape in the main cutting plane.

[0069] The first plane 51 and the second plane 52 may be inclined to the opposite side with respect to the third direction D3. As shown in the first portion 50A shown in FIG. 9, the first plane 51 and the second plane 52 may be inclined to the same side with respect to the third direction D3.

[0070] As shown in FIG. 8, the first portions 50 may be arranged at equal intervals in the first direction D1. The first portion 50 may extend linearly without changing the cross-sectional shape. The multiple first portions 50 included in the light control layer 40 may be configured identically to each other.

[0071] The first surface 51 and the second surface 52 form an interface with the second portion 60. Accordingly, the second portion 60 is adjacent to each of two adjacent first portions 50 in the first direction D1. Along with the configuration of the first portion 50, in the illustrated example, the second portions 60 included in the light control layer 40 may be arranged at equal intervals along the first direction D1. The second portion 60 may extend linearly without changing its cross-sectional shape. The second portions 60 may be identically configured to each other.

[0072] The second portion 60 shown in FIG. 8 includes a light incident side surface 61 and a light exit side surface 62. The second portion 60 is connected to the base portion 48 at the light incident side surface 61. The light exit side surface 62 constitutes the light exit side surface 54 of the first portion 50 and the light exit side surface 42 of the light control layer 40. The light exit side surface 62 is parallel to the light exit side surface 54. The light exit side surface 62, together with the light exit side surface 54, forms a flat light exit side surface 42. The illustrated second portion 60 has a trapezoidal shape in the main cutting plane. The trapezoid forming the second portion 60 includes a wide lower base formed by the light exit side surface 62 and a narrow upper base formed by the light incident side surface 61.

[0073] As an example, each dimension in the main cutting plane may be set as follows. The arrangement pitch P of the first portion 50 along the first direction D1 may be 1 mm or less. The height H of the first portion 50 along the third direction D3 may be 1 mm or less. The thickness T of the light control layer 40 along the third direction D3 may be 100 μm or more and 2 mm or less. The aspect ratio of the first portion 50 may be greater than 1, may be 2 or more, or may be 5 or more. The aspect ratio of the first portion 50 is represented by the ratio of the height H of the first portion 50 along the third direction D3 to the width W of the first portion 50 along the first direction D1, that is, H / W. The aspect ratio of the first portion 50 may be 10 or less in consideration of manufacturing stability.

[0074] The above specific configurations regarding the first portion 50 and the second portion 60 are merely illustrative. It is possible to appropriately change them in consideration of the function of the transmission screen 20 described later.

[0075] Like the first part 50B shown in FIG. 9, the first part 50 may include an incident light surface 53. The incident light surface 53 faces the light emitting surface 54 in the third direction D3. The incident light surface 53 may extend along the first direction D1. The incident light surface 53 may be connected to the end portion on the incident light side of the first surface 51. The incident light surface 53 may be connected to the end portion on the incident light side of the second surface 52. The first part 50B may be trapezoidal in the main cutting plane.

[0076] Like the first part 50C shown in FIG. 9, the second surface 52 may be a concavo-convex surface. The second surface 52 as a concavo-convex surface may have a light diffusing function of diffusing incident light. The first surface 51 may also be a concavo-convex surface. The first surface 51 may be a flat surface, a curved surface, or a folded surface. The second surface 52 may be a flat surface, a curved surface, or a folded surface. The shapes and arrangements may be different among the plurality of first parts 50 included in the light control layer 40. The shapes and arrangements may be different among the plurality of second parts 60 included in the light control layer 40.

[0077] The first part 50 serves as a light passing path. As shown in FIG. 8, the first part 50 mainly serves as a passing path for the video light L81. The first part 50 may be formed of a material having visible light transmissibility. As described above, the first part 50 includes a light diffusing portion 55 at a position between the first surface 51 and the second surface 52. The light diffusing portion 55 diffuses incident light. In particular, the light diffusing portion 55 is intended to diffuse video light. The light diffusing portion 55 may be the second surface 52 as a concavo-convex surface like the first part 50C shown in FIG. 9. The light diffusing portion 55 may be the first surface 51 as a concavo-convex surface.

[0078] As shown in FIG. 8, the light diffusing portion 55 may include a base portion 55A and light diffusing elements 55B. The light diffusing elements 55B are dispersed in the base portion 55A. In the example shown in FIG. 8 and the like, the first portion 50 is constituted only by the light diffusing portion 55. In this example, the light diffusing portion 55 constitutes the entire area between the first surface 51 and the second surface 52. The material of the base portion 55A may be a resin. More specifically, the material of the base portion 55A may be an ionizing radiation curable resin that cures by irradiation with ionizing radiation. Examples of the ionizing radiation curable resin include an ultraviolet curable resin, an electron beam curable resin, a visible light curable resin, and a near infrared curable resin. Examples of the resin material include an acrylic resin. Examples of the light diffusing element 55B include a metal compound, a porous material containing a gas, resin beads holding a metal compound therearound, white fine particles, and simply air bubbles.

[0079] In the illustrated example, the base portion 48 may be integrally formed with the second portion 60 using the same material as the second portion 60. Examples of the material of the light control layer main body 45 including the second portion 60 and the base portion 48 include a resin material. More specifically, the material of the light control layer main body 45 including the second portion 60 and the base portion 48 may be an ionizing radiation curable resin that cures by irradiation with ionizing radiation. Examples of the ionizing radiation curable resin include an ultraviolet curable resin, an electron beam curable resin, a visible light curable resin, and a near infrared curable resin. Examples of the resin material include an acrylic resin.

[0080] The light control layer 40 may be manufactured as follows. First, a light control layer body 45 forming the second portion 60 and the base portion 48 is fabricated. For fabricating the light control layer body 45, for example, a curable material (resin composition) such as epoxy acrylate that cures upon irradiation with ionizing radiation such as electron beams or ultraviolet rays may be used. A mold roll having a convex portion corresponding to the configuration (arrangement, shape, dimensions, etc.) of the groove 45a of the light control layer body 45 is prepared. In other words, a mold roll having a concave portion corresponding to the configuration (arrangement, shape, dimensions, etc.) of the second portion 60 is prepared. A sheet that will become the base material 38 is fed between the mold roll and the nip roll. In accordance with the feeding of the sheet, the curable material is supplied between the mold roll and the base material 38. Thereafter, the curable material is pressurized between the mold roll and the nip roll so that the uncured, liquid curable material supplied onto the base material 38 fills the concave portion of the mold roll. At this time, the curable material is supplied onto the base material 38 so as to be thicker than the depth of the concave portion of the mold roll, that is, so that the mold roll and the base material 38 do not come into contact. Thereby, the above-described base portion (land portion) 48 is integrally formed from the curable material with the second portion 60. After filling the uncured, liquid curable material between the base material 38 and the mold roll as described above, the light control layer body 45 is formed by irradiating light to cure (solidify) the curable material.

[0081] Next, the first portion 50 may be fabricated using a resin composition that forms the first portion 50. This resin composition includes a curable resin material that forms the base portion 55A upon curing, and a light diffusing element 55B. Examples of the curable resin material that forms the base portion 55A include curable materials such as urethane acrylate that are cured by ionizing radiation. First, the resin composition is supplied onto the previously formed light control layer body 45. Then, while using a doctor blade, the resin composition is filled into the groove 45a formed between adjacent second portions 60, that is, the portion corresponding to the convex portion of the mold roll. At this time, the excess resin composition that has overflowed outside the groove 45a is scraped off by the doctor blade. Thereafter, the first portion 50 is formed by irradiating the resin composition between the second portions 60 with ionizing radiation to cure it. Thereby, the light control layer 40 having the base portion 48, the first portion 50 provided on the base portion 48, and the second portion 60 is fabricated on the base material 38.

[0082] Next, the operation during the use of the display system 10 and the transmissive screen 20 will be described.

[0083] As shown in FIGS. 1 and 2, video light L11, L21 is emitted from the video light source 15. The video light L11, L21 enters the transmissive screen 20 from the incident light side surface 21. The video light travels through the transmissive screen 20 in the third direction D3 and heads toward the light control layer 40. As shown in FIGS. 8 and 10, the video light L81, L101 passes through the incident light side surface 41 and enters the light control layer 40. The video light L81, L101 passes through the base portion 48 and enters the second portion 60 from the incident light side surface 61.

[0084] In FIG. 8, an example where the video light L81 is incident from the air layer onto the base material 38 and the light control layer 40 is shown. In FIG. 10, an example where the video light L101 is incident from the air layer onto the light control layer 40 is shown.

[0085] As shown in FIG. 2, the video light source 15 is located on the second side in the first direction D1. And, as shown in FIG. 2, the incident angle θa (°) of the video light on the transmission screen 20 is large. As an example, the incident angle θa is 20° or more and 70° or less. For this reason, the video light traveling within the light control layer 40 travels from the second side to the first side in the first direction D1, from the light incident side to the light exit side in the third direction D3. As shown in FIGS. 8 and 10, the video lights L81 and L101 traveling within the second portion 60 pass through the second surface 52 and enter the first portion 50.

[0086] The first portion 50 includes a light diffusion portion 55. The video lights L81 and L101 are diffused by the light diffusion portion 55. The diffused video lights L81 and L101 pass through the light exit side surface 42 and are emitted from the light control layer 40. As shown in FIG. 2, the diffused video lights L81 and L101 pass through the light exit side surface 22 and are emitted from the transmission screen 20. The observer 9 can observe the video on the transmission screen 20 from various directions.

[0087] The video light transmitted through the transmission screen 20 is diffused by the light diffusion portion 55. On the other hand, external light such as ambient light in the environment where the transmission screen 20 is installed also enters the transmission screen 20. The external light can also enter the light diffusion portion 55 and be diffused. When the external light is diffused, the contrast of the video displayed on the transmission screen 20 decreases.

[0088] On the other hand, in the above-described embodiment, the interval D (see FIG. 8) along the first direction D1 between the first surface 51 and the second surface 52 of the first portion 50 is larger on the light exit side than on the light incident side. The magnitude of the first angle θ1 between the first surface 51 and the first direction D1 is 40° or more, and is less than the magnitude of the second angle θ2 between the second surface 52 and the first direction D1.

[0089] That is, the first surface 51 is inclined from the second side to the first side in the first direction D1 from the light incident side to the light emitting side in the third direction D3 which is the normal direction of the transmissive screen 20. In the main cutting plane, with respect to the first direction D1, the first surface 51 and the traveling directions of the video lights L81 and L101 are inclined to the same side. Therefore, a long optical path length of the video lights L81 and L101 in the first portion 50 including the light diffusing portion 55 can be ensured. By lengthening the optical path length of the video lights L81 and L101 in the first portion 50, the video lights L81 and L101 can be efficiently diffused in the first portion 50. For this reason, it is not necessary to provide the light diffusing portion 55 having strong light diffusing properties over a wide range of the transmissive screen 20. In this way, while efficiently diffusing the video lights L81 and L101, diffusion of external light by the transmissive screen 20 can be suppressed. As a result, according to one embodiment, the contrast of the video displayed on the transmissive screen 20 can be improved. The observer 9 can observe a high-quality video.

[0090] In addition, since the magnitude of the second angle θ2 is larger than the magnitude of the first angle θ1, the area of the first portion 50 when observing the transmissive screen 20 from the third direction D3 can be reduced while efficiently diffusing the video lights L81 and L101 in the first portion 50. Therefore, it is possible to suppress the background lights L82 and L102 other than the video lights L81 and L101 that pass through the transmissive screen 20 from the light incident side to the light emitting side from being diffused by the light diffusing portion 55. Thereby, the observer 9 can observe a high-contrast video.

[0091] Also, in the examples shown in FIGS. 8 and 10, the transmissive screen 20 functions as a transparent screen. That is, through the transmissive screen 20, the back of the transmissive screen 20 can be seen through. The transmissive screen 20 according to the present embodiment can efficiently diffuse the video light and effectively suppress the diffusion of the background lights L82 and L102. Therefore, through the transmissive screen 20, the background 7 (see FIG. 2) behind the transmissive screen 20 can be clearly seen through. That is, the transparency of the transmissive screen 20 as a transparent screen can be improved.

[0092] Incidentally, the traveling direction angle between the traveling directions of a lot of video light that advances to the light diffusing portion 55 and the first direction D1 is likely to be within a predetermined angle range. As shown in FIG. 8, the traveling direction angle θx (°) within the second portion 60 of the light L83 that has entered the transmission screen 20 at the maximum incident angle θa of 90° is Arccos(1 / n), where n is the refractive index of the second portion 60. When the incident angle θa becomes smaller, the traveling direction angle θx within the second portion 60 becomes larger. From this point, the magnitude of the first angle θ1 may be larger than Arccos(1 / n), where n is the refractive index of the second portion 60.

[0093] According to an example where the magnitude of the first angle θ1 is made larger than Arccos(1 / n), with respect to the traveling direction angle θx between the traveling direction of the video light and the first direction D1, the magnitude of the first angle θ1 is not too small and is of sufficient size. That is, while suppressing the size of the first portion 50 including the light diffusing portion 55, the optical path length of the video light can be efficiently ensured. Thereby, while efficiently diffusing the video light in the first portion 50, the area of the first portion 50 when observed from the third direction D3 through the transmission screen 20 can be made smaller. Therefore, the backlights L82 and L102 that transmit through the transmission screen 20 from the light incident side to the light emitting side other than the video light can be more effectively suppressed from being diffused by the light diffusing portion 55. As a result, the contrast of the video displayed on the transmission screen 20 can be further improved.

[0094] The magnitude of the first angle θ1 may also be 80° or less. When the magnitude of the first angle θ1 becomes larger than 80°, the video light is likely to transmit through the first portion 50 in the first direction D1 without being diffused by the light diffusing portion 55. Also, when the magnitude of the first angle θ1 is made larger than 80°, it is accompanied by manufacturing difficulties.

[0095] The magnitude of the second angle θ2 may be 85° or more and 90° or less. According to this example, when observing the transmissive screen 20 from the third direction D3D3, the area of the first portion 50 can be reduced. Therefore, it is possible to suppress the backlights L82 and L102 that transmit through the transmissive screen 20 from the incident light side to the outgoing light side other than the video light from being diffused by the light diffusing portion 55. As a result, the contrast of the video displayed on the transmissive screen 20 can be improved. In addition, the observer 9 can clearly observe the background 7 behind the transmissive screen 20.

[0096] From the viewpoint of improving the contrast, the refractive index of the portion constituting the first surface 51 of the first portion 50 may be larger than the refractive index of the second portion 60. As in the example shown in FIG. 8, when 55 including the base material portion 55A and the light diffusing element 55B constitutes the first surface 51, the refractive index of the base material portion 55A may be larger than the refractive index of the second portion 60.

[0097] According to this example, the first surface 51 serves as an interface having a refractive index difference and functions as a reflection surface. As shown in FIG. 11, the video light L111 that has not been diffused by the light diffusing portion 55 of the first portion 50 can be reflected by the first surface 51 and directed toward the outgoing light side. As a result, the utilization efficiency of the video light from the video light source 15 can be improved, and the video can be displayed brightly. As a result, the contrast of the video displayed on the transmissive screen 20 can be improved.

[0098] In addition, the traveling direction of the light traveling in the light control layer 40 is inclined to the same side as the first surface 51 with respect to the first direction D1. Therefore, the incident angle of the video light L111 that has not been diffused by the light diffusing portion 55 of the first portion 50 to the first surface 51 becomes large. And the refractive index of the portion constituting the first surface 51 of the first portion 50 is larger than the refractive index of the second portion 60. The refractive index of the base material portion 55A is larger than the refractive index of the second portion 60. Therefore, it is also possible to make the reflection of the video light L111 at the first surface 51 a total reflection. According to the total reflection, the utilization efficiency of the video light from the video light source 15 can be greatly improved, and the video can be displayed more brightly. As a result, the contrast displayed on the transmissive screen 20 can be further improved.

[0099] In the embodiment described above, the transmissive screen 20 projects image light from the image light source 15. The transmissive screen 20 includes a first portion 50 and a second portion 60 alternately arranged in the first direction D1. The first portion 50 includes a first surface 51 and a second surface 52 that form an interface with the second portion 60. The first surface 51 and the second surface 52 face each other in the first direction D1. The second surface 52 of the first portion 50 is located on the second side closer to the image light source 15 in the first direction D1. The first surface 51 of the first portion 50 is located on the first side away from the image light source 15 in the first direction D1. The first portion 50 includes a light diffusing portion 55 having a light diffusing function. The distance D along the first direction D1 between the first surface 51 and the second surface 52 is larger on the light-emitting side than on the light-incident side. The magnitude of the first angle θ1 between the first surface 51 and the first direction D1 is 40° or more and less than the magnitude of the second angle θ2 between the second surface 52 and the first direction D1. According to this embodiment, while efficiently diffusing the image light, the diffusion of external light can be suppressed. Therefore, the contrast of the image can be improved, and the image can be displayed brightly and clearly. In addition, since the diffusion of the backlight that passes through the transmissive screen 20 other than the image light can be suppressed, the background 7 behind the transmissive screen 20 can be clearly seen through the transmissive screen 20. That is, the transparency of the transmissive screen 20 as a transparent screen can be improved.

[0100] Also, in the above-described embodiment, the transmissive screen 20 includes a first portion 50 and a second portion 60 that are alternately arranged in the first direction D1. The first portion 50 includes a first surface 51 and a second surface 52 that form an interface with the second portion 60. The first surface 51 and the second surface 52 face each other in the first direction D1. The first portion 50 includes a light diffusing portion 55 having a light diffusing function. The magnitude of the first angle θ1 between the first surface 51 and the first direction D1 is less than the magnitude of the second angle θ2 between the second surface 52 and the first direction D1. According to this embodiment, the first surface 51 is an interface having a refractive index difference and functions as a reflecting surface. Therefore, the video light that has not been diffused by the light diffusing portion 55 of the first portion 50 can be reflected by the first surface 51 and directed toward the light emitting side. Thereby, the utilization efficiency of the video light from the video light source 15 can be improved, and the video can be displayed brightly. As a result, the contrast of the video displayed on the transmissive screen 20 can be improved.

[0101] Although the basic aspects of an embodiment have been described with reference to specific examples, the above-described specific examples do not limit the basic aspects of an embodiment. The basic aspects of the above-described embodiment can be implemented with various other specific examples, and various omissions, replacements, changes, additions, etc. can be made without departing from the gist thereof.

[0102] Hereinafter, with reference to the drawings, an example of a modification to the basic aspect will be described. In the following description and the drawings used in the following description, for parts that can be configured in the same manner as the above-described specific examples, the same reference numerals as those used for the corresponding parts in the above-described specific examples are used, and redundant descriptions are omitted.

[0103] In the above specific example, an example was shown in which the magnitude of the first angle θ1 is adjusted according to the traveling direction angle θx between the traveling direction of the video light and the first direction D1. On the other hand, as shown in FIGS. 12A and 12B, the incident angle θa of the video lights L12A1 and L12B1 on the transmission screen 20 changes according to the position of the transmission screen 20. Along with the change in the incident angle θa, the traveling direction angle θx of the video light also changes according to the position of the transmission screen 20. The incident angle θa and the traveling direction angle θx of the video lights L12A1 and L12B1 change according to the distance between the incident position on the transmission screen 20 and the video light source 15. When the distance between the incident position on the transmission screen 20 and the video light source 15 is long, the incident angle θa becomes large and the traveling direction angle θx becomes small. From the viewpoint of suppressing the size of the first portion 50 while ensuring the optical path length of the video light, when the traveling direction angle θx is large, the magnitude of the first angle θ may also be increased. When the magnitude of the first angle θ increases, the area of the first portion 50 in the observation from the third direction D3 can be reduced, and the diffusion of the backlight can be suppressed.

[0104] Therefore, as shown in FIGS. 12A and 12B, the magnitude of the first angle θ1 of one first portion 50 may be made smaller than the magnitude of the first angle θ1 of another first portion 50 located on the second side in the first direction D1 with respect to the one first portion 50. In other words, the magnitude of the first angle θ1 of one first portion 50 may be made larger than the magnitude of the first angle θ1 of another first portion 50 located on the first side in the first direction D1 with respect to the one first portion 50. Further, the magnitude of the first angle θ1 of any one first portion 50 may be equal to or less than the magnitude of the first angle θ1 of any other first portion 50 located on the second side in the first direction D1 with respect to the one first portion 50. In other words, the magnitude of the first angle θ1 of any one first portion 50 may be equal to or greater than the magnitude of the first angle θ1 of any other first portion 50 located on the first side in the first direction D1 with respect to the one first portion 50.

[0105] According to these examples, according to the position in the first direction D1, the magnitude of the first angle θ1 can be appropriately set so as not to be too small with respect to the traveling direction angle θx between the traveling direction of the image light and the first direction D1. Therefore, the area of the first portion 50 when observing the transmissive screen 20 from the third direction D3 can be reduced. As a result, the backlight that transmits through the transmissive screen 20 from the light incident side to the light exit side other than the image light can be more effectively suppressed from being diffused by the light diffusing portion 55. As a result, the contrast of the image displayed on the transmissive screen 20 can be improved. The transparency of the transmissive screen 20 as a transparent screen can be more effectively improved.

[0106] In the example shown in FIG. 12A, the length W of the first portion 50 along the first direction D1 is constant. In the example shown in FIG. 12A, the arrangement pitch P of the first portion 50 along the first direction D1 is constant. In the example shown in FIG. 12A, the length H of the first portion 50 along the third direction D3 is changing. In the example shown in FIG. 12B, the length H of the first portion 50 along the third direction D3 is constant. In the example shown in FIG. 12B, the length W of the first portion 50 along the first direction D1 is changing. In the example shown in FIG. 12B, the arrangement pitch P of the first portion 50 along the first direction D1 is changing.

[0107] As another modification, as shown in FIGS. 13A and 13B, the transmissive screen 20 may include a light shielding layer 65 located on the light exit side of the light control layer 40. The light shielding layer 65 faces only a part of the light exit side surface 62 of the second portion 60 from the light exit side in the third direction D3. A part of the light exit side surface 62 facing the light shielding layer 65 includes a first end portion 62a that is the first side in the first direction D1 of the light exit side surface 62, and is away from a second end portion 62b that is the second side in the first direction D1 of the light exit side surface 62. According to the light shielding layer 65 that faces only a part of the light exit side surface 62, the image lights L13A1 and L13B1 that do not enter the first portion 50 can be shielded by the light shielding layer 65. The light shielding layer 65 can shield the image lights L13A1 and L13B1 that have not been diffused by the light diffusing portion 55. As a result, it is possible to suppress the image from being brightly observed from an unintended direction.

[0108] The light-shielding layer 65 has visible light-shielding properties. "Having visible light-shielding properties" means that the visible light transmittance is 30% or less, preferably 10% or less. The visible light transmittance is specified as described above.

[0109] As a more specific configuration, in the example shown in FIG. 13A, the light-shielding layer 65 is a light absorption layer 66 having visible light absorbability. "Having visible light absorbability" means that both the visible light transmittance and the visible light reflectance are 30% or less, preferably 10% or less. The visible light transmittance is specified as described above. The visible light reflectance is specified as the average value of the total light reflectance at each wavelength when measured at an incident angle of 45° every 1 nm in the range of a measurement wavelength of 380 nm or more and 780 nm or less using a spectrophotometer ("UV-3100PC" manufactured by Shimadzu Corporation, compliant with JIS K 0115).

[0110] The light absorption layer 66 may be a resin layer containing a dark-colored pigment such as carbon black. In the example shown in FIG. 13A, the light absorption layer 66 can be produced by patterning a coating film formed on the light-emitting side surface 42 by patterning using photolithography technology. The light absorption layer 66 can be produced by pattern printing a resin composition.

[0111] The light absorption layer 66 may be a dielectric multilayer film or a metal compound film. The dielectric multilayer film and the metal compound film can be produced on the light-emitting side surface 42 by a dry process such as pattern vapor deposition. As the metal compound film, a metal vapor deposition film containing tungsten oxide is exemplified.

[0112] That is, in the example shown in FIG. 13A, the transmissive screen 20 includes a light absorption layer 66 positioned on the light-emitting side of the light control layer 40. The light absorption layer 66 faces only a part of the light-emitting side surface 62 of the second portion 60 from the light-emitting side in the third direction D3. A part of the light-emitting side surface 62 facing the light absorption layer 66 includes a first end portion 62a that is the first side in the first direction D1 of the light-emitting side surface 62, and is separated from a second end portion 62b that is the second side in the first direction D1 of the light-emitting side surface 62. According to the light absorption layer 66 that faces only a part of the light-emitting side surface 62, the video light L13A1 that does not enter the first portion 50 can be absorbed by the light absorption layer 66. According to such an example, it is possible to suppress the video from being brightly observed from an unintended direction. Further, a part of the light L13A2 incident on the transmissive screen 20 from the light-emitting side can be absorbed by the light absorption layer 66. Therefore, the contrast of the video displayed on the transmissive screen 20 can be improved.

[0113] In the example shown in FIG. 13B, the light shielding layer 65 is a light reflection layer 67 having visible light reflectivity. "Having visible light reflectivity" means that the visible light reflectance is 50% or more, preferably 80% or more. The visible light reflectance is specified as described above. The reflection at the light reflection layer 67 may be specular reflection, diffuse reflection, or directional diffuse reflection. The light reflection layer 67 may be a metal layer. The light reflection layer 67 as a metal layer can be formed by pattern vapor deposition using a mask or the like. The light reflection layer 67 may be a dielectric multilayer film. The dielectric multilayer film can be formed on the light-emitting side surface 42 by a dry process such as pattern vapor deposition. The light reflection layer 67 may be a resin layer containing a scattering material such as titanium oxide. The light absorption layer 66 as a resin layer can be formed by pattern printing a resin composition.

[0114] That is, in the example shown in FIG. 13B, the transmissive screen 20 includes a light reflection layer 67 located on the light-emitting side of the light control layer 40. The light reflection layer 67 faces only a part of the light-emitting side surface 62 of the second portion 60 from the light-emitting side in the third direction D3. A part of the light-emitting side surface 62 facing the light reflection layer 67 includes a first end portion 62a that is the first side in the first direction D1 of the light-emitting side surface 62 and is away from a second end portion 62b that is the second side in the first direction D1 of the light-emitting side surface 62. According to the light reflection layer 67 that faces only a part of the light-emitting side surface 62, the video light L13B1 that does not enter the first portion 50 can be reflected by the light reflection layer 67. According to this example, it is possible to suppress the video from being brightly observed from an unintended direction. Further, by the reflection at the light reflection layer 67, the video light L13B1 can be guided to the first portion 50 including the light diffusion portion 55. Thereby, the utilization efficiency of the video light from the video light source 15 can be improved, and the video can be displayed brightly. As a result, the contrast of the video displayed on the transmissive screen 20 can be further improved.

[0115] As another modification, as shown in FIGS. 14A and 14B, a light shielding layer 65 located on the light-emitting side of the light control layer 40 may face the entire light-emitting side surface 62 of the second portion 60 from the light-emitting side in the third direction D3. The light shielding layer 65 has visible light shielding properties as described above. According to this specific example, the backlights L14A2 and L14B2 incident from the light-incident side on the transmissive screen 20 other than the video lights L14A1 and L14B1 can be shielded by the light shielding layer 65. Therefore, the video can be displayed brightly and clearly, and the contrast of the video can be significantly improved.

[0116] As a more specific configuration, the light-shielding layer 65 may be a light absorption layer 66 having visible light absorbability. The light absorption layer 66 has visible light absorbability as described above. In the example shown in FIG. 14A, the light absorption layer 66 located on the light-emitting side of the light control layer 40 faces the entire light-emitting side surface 62 of the second portion 60 from the light-emitting side in the third direction D3. According to this specific example, the light L14A2 incident on the transmission screen 20 from the light-incident side other than the video light L14A1 can be absorbed by the light absorption layer 66. Also, the light L14A3 incident on the light absorption layer 66 from the light-emitting side is absorbed. Therefore, the video can be displayed brightly and clearly, and the contrast of the video displayed on the transmission screen 20 can be significantly improved.

[0117] The light-shielding layer 65 may be a light reflection layer 67 having visible light reflectivity. The light reflection layer 67 has visible light reflectivity as described above. In the example shown in FIG. 14B, the light reflection layer 67 located on the light-emitting side of the light control layer 40 faces the entire light-emitting side surface 62 of the second portion 60 from the light-emitting side in the third direction D3. According to this specific example, the light L14B2 incident on the transmission screen from the light-incident side other than the video light L14B1 can be shielded by the light reflection layer 67. Therefore, the video can be displayed brightly and clearly, and the contrast of the video can be significantly improved. Also, the light L14B3 incident on the light reflection layer 67 from the light-emitting side is reflected. When no video is being displayed, the transmission screen 20 functions as a mirror.

[0118] In the examples shown in FIGS. 13A to 14B, the light-shielding layer 65, the light absorption layer 66, and the light reflection layer 67 are adjacent to the light control layer 40. The light-shielding layer 65, the light absorption layer 66, and the light reflection layer 67 may be located away from the light control layer 40 and on the light-emitting side of the light control layer 40 in the third direction D3.

[0119] As another example, the transmissive screen 20 may have a decorative layer 68 that displays a design. As shown in FIG. 15, the decorative layer 68 is located on the light-emitting side of the light control layer 40 in the third direction D3. The decorative layer 68 faces the light-emitting side surface 62 of the second portion 60 from the light-emitting side. According to the decorative layer 68, when no video is being displayed, an observer can observe the decorative layer 68. Therefore, the design property of the transmissive screen 20 can be improved. Also, by the decorative layer 68 expressing a design, the transmissive screen 20 can be arranged in harmony with the surrounding environment. Further, some of the light L152 that enters the transmissive screen 20 from the light-incident side other than the video light L151 can be blocked by the decorative layer 68. Therefore, the video can be displayed brightly and clearly, and the contrast of the video can be improved.

[0120] A design is formed on the decorative layer 68. The decorative layer 68 may be provided with a pattern such as a figure, a pattern, a design, a color, a picture, a photograph, a character, a mark, a pictogram, a character or a number as a design. The decorative layer 68 can also perform a design expression that displays a background. For example, as a design that can harmonize the transmissive screen 20 with the surrounding environment where the transmissive screen 20 is provided, a wood grain pattern, a marble pattern, a metallic texture, or a geometric pattern may be displayed by the decorative layer 68. The decorative layer 68 may be a resin layer containing a pigment. The decorative layer 68 may be formed by printing. The decorative layer 68 may be produced by pattern vapor deposition.

[0121] In the example shown in FIG. 15, the transmissive screen 20 includes a light-shielding layer 65 between the light control layer 40 and the decorative layer 68. The light-shielding layer 65 blocks the light L152 that enters the transmissive screen 20 from the light-incident side other than the video light L151. Therefore, the video can be displayed brightly and clearly, and the contrast of the video can be improved. Also, by the light-shielding layer 65 covering the decorative layer 68 from the back, the design formed by the decorative layer 68 can be displayed darkly and clearly. The light-shielding layer 65 may be a light absorption layer 66 or a light reflection layer 67. In the example shown in FIG. 15, the light-shielding layer 65 can be omitted.

[0122] In the example shown in FIG. 15, the decorative layer 68 is adjacent to the light control layer 40. The decorative layer 68 may be located away from the light control layer 40 and on the light-emitting side in the third direction D3 of the light control layer 40.

[0123] As another modification, as shown in FIG. 16, the transmissive screen 20 or the light control layer 40 may include a coloring layer 37. The coloring layer 37 can be used to adjust the color of the image displayed on the transmissive screen 20.

[0124] Next, the first and second modified embodiments with respect to the basic embodiment of the above-described embodiment will be described. The first and second modified embodiments add components to the above-described basic embodiment and its modifications. In the following description and the drawings used in the following description, the same reference numerals as those used in the above-described basic embodiment and its modifications are used for parts that can be configured in the same manner as the above-described basic embodiment and its modifications, and redundant descriptions are omitted.

[0125] In the first modified embodiment, as shown in FIGS. 17A to 19, the first portion 50 includes a light-shielding portion 56 that constitutes the first surface 51. The light-shielding portion 56 has visible light-shielding properties, similar to the above-described light-shielding layer 65. That is, the transmissive screen 20 according to the first modified embodiment includes the first portion 50 and the second portion 60 alternately arranged in the first direction D1. The first portion 50 includes a first surface 51 and a second surface 52 that form an interface with the second portion 60. The first surface 51 and the second surface 52 face each other in the first direction D1. The first portion 50 includes a light-diffusing portion 55 having a light-diffusing function and a light-shielding portion 56 that constitutes the first surface 51. The light-shielding portion 56 has visible light-shielding properties. The magnitude of the first angle θ1 between the first surface 51 and the first direction D1 is less than the magnitude of the second angle θ2 between the second surface 52 and the first direction D1.

[0126] According to the first modified embodiment provided with the light-shielding portion 56, the backlight that enters the transmission screen 20 from the incident light side in the third direction D3 and heads toward the first portion 50, other than the video light, is shielded by the light-shielding portion 56, and the incidence to the light diffusion portion 55 is suppressed. Therefore, the diffusion of the backlight other than the video light transmitted through the transmission screen 20 at the light diffusion portion 55 can be significantly suppressed. As a result, the contrast of the video displayed on the transmission screen 20 can be greatly improved. In addition, since the diffusion of the backlight is suppressed, the transparency of the transmission screen 20 as a transparent screen can be greatly improved. Furthermore, since the incidence of the backlight to the first portion 50 can be suppressed, the light diffusion function of the light diffusion portion 55 may be enhanced. Thereby, a high-contrast video can be displayed brightly and clearly.

[0127] As shown in FIGS. 17A and 18A, the light-shielding portion 56 is a layer that spreads along the first surface 51. The thickness of the light-shielding portion 56 may be constant or may not be constant. In the examples shown in FIGS. 17A to 18C, the light-shielding portion 56 is adjacent to the light diffusion portion 55. The first portion 50 is composed only of the light-shielding portion 56 and the light diffusion portion 55. As shown in FIGS. 17B and 18B, when the first portion 50 includes the incident light side surface 53, the incident light side surface 53 may also be constituted by the light-shielding portion 56. Further, when the light-shielding layer 65 described with reference to FIGS. 13A to 15 is provided on the light-emitting side surface 62, as shown in FIGS. 17C and 18C, the light-shielding portion 56 may be connected to the light-shielding layer 65. The light-shielding portion 56 may be formed of the same material as the light-shielding layer 65. The light-shielding portion 56 may be formed without a seam with the light-shielding layer 65. The light-shielding portion 56 may be integrally formed with the light-shielding layer 65.

[0128] In the example shown in FIGS. 17A to 17C, the light shielding portion 56 is the light absorption portion 57. The light absorption portion 57 has visible light absorbability, similar to the above-described light absorption layer 66. That is, the transmissive screen 20 includes a first portion 50 and a second portion 60 alternately arranged in the first direction D1. The first portion 50 includes a first surface 51 and a second surface 52 that form an interface with the second portion 60. The first surface 51 and the second surface 52 face each other in the first direction D1. The first portion 50 includes a light diffusing portion 55 having a light diffusing function and a light absorption portion 57 that constitutes the first surface 51. The light absorption portion 57 has visible light absorbability. The magnitude of the first angle θ1 between the first surface 51 and the first direction D1 is less than the magnitude of the second angle θ2 between the second surface 52 and the first direction D1.

[0129] In the transmissive screen 20 having the light absorption portion 57, the video lights L17A1 and L17C1 enter the first portion 50 through the second surface 52 as described in the basic mode. The video lights L17A1 and L17C1 are efficiently diffused by the light diffusing portion 55 of the first portion 50 and are emitted from the light control layer 40 and the transmissive screen 20.

[0130] Some of the video lights L17A3 and L17C3 go toward the first surface 51 without being diffused by the light diffusing portion 55. Such video lights L17A3 and L17C3 are absorbed by the light absorption portion 57. Therefore, it is possible to suppress the observation of the video from an unintended specific direction and the bright observation of the transmissive screen 20 from an unintended specific direction.

[0131] In addition, the backlights L17A2, L17B2, and L17C2 that enter the transmission screen 20 from the incident light side other than the video lights L17A1 and L17C1 and head towards the first portion 50 are absorbed by the light absorption portion 57. Many backlights L17A4 that pass through the transmission screen 20 pass through the second portion 60. That is, the diffusion of the backlights other than the video lights L17A1 and L17C1 that pass through the transmission screen 20 at the light diffusion portion 55 can be significantly suppressed. Also, a part of the external light incident on the transmission screen 20 from the light exit side is also absorbed by the light absorption portion 57. Thereby, the contrast of the video displayed on the transmission screen 20 can be significantly improved. The transparency of the transmission screen 20 as a transparent screen can be significantly improved.

[0132] In addition, in the examples shown in FIGS. 17A to 17C, since the incidence of the backlight on the first portion 50 can be suppressed, the light diffusion function of the light diffusion portion 55 may be strengthened. Thereby, a high-contrast video can be displayed brightly and clearly.

[0133] In the example shown in FIG. 17C, a light absorption layer 66 is provided. In this example, not only the backlights L17C2 and L17C5 but also the external light L17C6 incident on the transmission screen 20 from the light exit side is absorbed by the light absorption layer 66. Thereby, the contrast of the video displayed on the transmission screen 20 can be significantly improved.

[0134] The light shielding portion 56 may be configured in the same manner as the above-described light absorption layer 66. The light shielding portion 56 may be a resin layer containing a dark-colored pigment such as carbon black. The light shielding portion 56 may be a dielectric multilayer film or a metal compound film. The dielectric multilayer film and the metal compound film can be produced by a dry process such as pattern vapor deposition. As the metal compound film, a metal vapor deposition film containing tungsten oxide is exemplified.

[0135] In the example shown in FIGS. 18A to 18C, the light shielding portion 56 is the light reflecting portion 58. The light reflecting portion 58 has visible light reflectivity in the same manner as the above-described light reflecting layer 67. That is, the transmissive screen 20 includes a first portion 50 and a second portion 60 alternately arranged in the first direction D1. The first portion 50 includes a first surface 51 and a second surface 52 that form an interface with the second portion 60. The first surface 51 and the second surface 52 face each other in the first direction D1. The first portion 50 includes a light diffusing portion 55 having a light diffusing function and a light reflecting portion 58 that constitutes the first surface 51. The light reflecting portion 58 has visible light reflectivity. The magnitude of the first angle θ1 between the first surface 51 and the first direction D1 is less than the magnitude of the second angle θ2 between the second surface 52 and the first direction D1.

[0136] In the transmissive screen 20 having the light reflecting portion 58, the video lights L18A1 and L18C1 enter the first portion 50 through the second surface 52 as described in the basic mode. The video lights L18A1 and L18C1 are efficiently diffused by the light diffusing portion 55 of the first portion 50 and emitted from the light control layer 40 and the transmissive screen 20.

[0137] A part of the video lights L18A3 and L18C3 travels toward the first surface 51 without being diffused by the light diffusing portion 55. Such video lights L18A3 and L18C3 are reflected by the light reflecting portion 58. By the reflection at the light reflecting portion 58, the video lights L18A3 and L18C3 can be directed toward the light emitting side. Thereby, the utilization efficiency of the video light from the video light source 15 can be improved, and the video can be displayed brightly. As a result, the contrast of the video displayed on the transmissive screen 20 can be further improved. In addition, it is possible to suppress the video from being observed from an unintended specific direction and the transmissive screen 20 from being brightly observed from an unintended specific direction.

[0138] In addition, the backlights L18A2 and L18C2 that enter the transmission screen 20 other than the video lights L18A1 and L18C1 from the light incident side and head toward the first portion 50 are reflected by the light reflection portion 58, and the incidence to the light diffusion portion 55 is suppressed. The backlights L18A2 and L18C2 reflected by the light reflection portion 58 can be directed in a direction that is greatly inclined with respect to the third direction D3. Therefore, the diffusion of the backlight other than the video lights L18A1 and L18C1 that pass through the transmission screen 20 at the light diffusion portion can be significantly suppressed. As a result, the contrast of the video displayed on the transmission screen 20 can be greatly improved. The transparency of the transmission screen 20 as a transparent screen can be greatly improved.

[0139] In the example shown in FIG. 18C, a light reflection layer 67 is provided. In this example, not only the backlights L18C2 and L18C5 but also the external light L18C6 that enters the transmission screen 20 from the light exit side is reflected by the light reflection layer 67. Thereby, the contrast of the video displayed on the transmission screen 20 can be significantly improved. Also, when no video is being displayed, the transmission screen 20 functions as a mirror.

[0140] The reflection at the light reflection portion 58 may be specular reflection, diffuse reflection, or directional diffuse reflection, similar to the reflection at the light reflection layer 67. The light reflection portion 58 may be a resin layer containing a scattering material such as titanium oxide, similar to the light reflection layer 67 described above.

[0141] The light reflection portion 58 may be a metal layer or a dielectric multilayer film, similar to the light reflection layer 67 described above. The light reflection portion 58 may be a resin layer containing a scattering material such as titanium oxide. According to these light reflection portions 58, the video lights L18A3 and L18C3 can be reflected with a high reflectance and directed toward the light exit side. Therefore, the utilization efficiency of the video light from the video light source 15 can be further improved.

[0142] In the transmissive screen 20 shown in FIG. 19, the light-shielding portion 56 includes a light-absorbing portion 57 and a light-reflecting portion 58. The light-absorbing portion 57 constitutes the first surface 51. The light-reflecting portion 58 is located between the light-absorbing portion 57 and the light-diffusing portion 55. The light-reflecting portion 58 is adjacent to the light-absorbing portion 57. The light-reflecting portion 58 is adjacent to the light-diffusing portion 55.

[0143] In the transmissive screen 20 shown in FIG. 19, as described in the basic mode, the video light L191 passes through the second surface 52 and enters the first portion 50. The video light L191 is efficiently diffused by the light-diffusing portion 55 of the first portion 50 and exits from the light control layer 40 and the transmissive screen 20.

[0144] A part of the video light L193 heads toward the light-reflecting portion 58 without being diffused by the light-diffusing portion 55. This video light L193 is reflected by the light-reflecting portion 58. By the reflection at the light-reflecting portion 58, the video light L193 can be directed toward the light-emitting side. Thereby, the utilization efficiency of the video light from the video light source 15 can be improved, and the video can be displayed brightly. As a result, the contrast of the video displayed on the transmissive screen 20 can be further improved. Also, it is possible to suppress the video being observed from an unintended specific direction or the transmissive screen 20 being brightly observed from an unintended specific direction.

[0145] Also, the backlight L192 that enters from the light-incident side of the transmissive screen 20 other than the video light L191 and heads toward the first portion 50 is absorbed by the light-absorbing portion 57. Many backlights L194 that pass through the transmissive screen 20 pass through the second portion 60. That is, the diffusion of the backlight other than the video light L191 that passes through the transmissive screen 20 at the light-diffusing portion 55 can be significantly suppressed. Also, a part of the external light that enters the transmissive screen 20 from the light-emitting side is absorbed by the light-absorbing portion 57. Thereby, the contrast of the video displayed on the transmissive screen 20 can be significantly improved. The transparency of the transmissive screen 20 as a transparent screen can be significantly improved.

[0146] In addition, in the example shown in FIG. 19, since the incident of the backlight L192 on the first portion 50 can be suppressed, the light diffusion function of the light diffusion portion 55 may be enhanced. Thereby, a high-contrast video can be displayed brightly and clearly.

[0147] In the first modified form described above, the first surface 51 of the first portion 50 is constituted by the light-shielding portion 56. In this example, the refractive index of the portion constituting the second surface 52 of the first portion 50 may be larger than the refractive index of the second portion 60. When the light diffusion portion 55 including the base material portion 55A and the light diffusion element 55B constitutes the second surface 52, the refractive index of the base material portion 55A may be larger than the refractive index of the second portion 60. According to such a refractive index setting, as shown in FIGS. 18A, 18C, and 19, the angle between the traveling direction of the video light and the first direction D1 can be reduced by refraction at the second surface 52. Therefore, the video light can be guided to the light reflection portion 58 by refraction at the second surface 52. Thereby, the utilization efficiency of the video light from the video light source 15 can be further improved.

[0148] Also, as described in the above basic form, it is useful in the first modified form to make the magnitude of the first angle θ larger than Arccos(1 / n), where the refractive index of the second portion 60 is n. According to this angle setting, the magnitude of the first angle θ1 is not too small with respect to the traveling direction angle θx between the traveling direction of the video light and the first direction. Therefore, the video light can be guided to the light reflection portion 58. Thereby, the utilization efficiency of the video light from the video light source 15 can be further improved. In addition, the incident of the video light on the first surface 51 of the first portion 50 from the light incident side in the third direction D3 can be avoided. Therefore, for example, it is possible to suppress the video light from being absorbed by the light absorption portion 57 unintentionally.

[0149] In the examples shown in FIGS. 17A to 19, the entire surface of the first surface 51 is constituted by the light-shielding portion 56. Only a part of the first surface 51 may be constituted by the light-shielding portion 56. Also, although not shown, only the light incident side surface 53 may be constituted by the light-shielding portion 56.

[0150] Next, a second modification will be described. As a second modification, as shown in FIG. 20, the first portion 50 includes a low refractive index portion 59 that constitutes the first surface 51.

[0151] As an example of the second modification, the refractive index of the low refractive index portion 59 may be lower than the refractive index of the portion adjacent to the low refractive index portion 59 of the first portion 50. That is, this transmissive screen 20 includes the first portion 50 and the second portion 60 alternately arranged in the first direction D1. The first portion 50 includes a first surface 51 and a second surface 52 that form an interface with the second portion 60. The first surface 51 and the second surface 52 face each other in the first direction D1. The first portion 50 includes a light diffusing portion 55 having a light diffusing function and a low refractive index portion 59 that constitutes the first surface 51. The magnitude of the first angle θ1 between the first surface 51 and the first direction D1 is less than the magnitude of the second angle θ2 between the second surface 52 and the first direction D1. The refractive index of the low refractive index portion 59 may be lower than the refractive index of the portion adjacent to the low refractive index portion 59 of the first portion 50. In this example, when the light diffusing portion 55 including the base material portion 55A and the light diffusing element 55B is adjacent to the low refractive index portion 59, the refractive index of the base material portion 55A may be greater than the refractive index of the low refractive index portion 59.

[0152] According to this example, the interface on the light diffusing portion 55 side of the low refractive index portion 59 is an interface having a refractive index difference and functions as a reflecting surface. Therefore, the video light L20A2 that has not been diffused by the light diffusing portion 55 of the first portion 50 can be reflected, for example, totally reflected by the low refractive index portion 59 and directed toward the light emitting side. Thereby, the utilization efficiency of the video light from the video light source 15 can be improved and the video can be displayed brightly. As a result, the contrast of the video displayed on the transmissive screen 20 can be improved.

[0153] In another example of the second modification, the refractive index of the low refractive index portion 59 may be lower than the refractive index of the second portion 60. That is, this transmissive screen 20 includes a first portion 50 and a second portion 60 alternately arranged in the first direction D1. The first portion 50 includes a first surface 51 and a second surface 52 that form an interface with the second portion 60. The first surface 51 and the second surface 52 face each other in the first direction D1. The first portion 50 includes a light diffusing portion 55 having a light diffusing function and a low refractive index portion 59 that constitutes the first surface 51. The magnitude of the first angle θ1 between the first surface 51 and the first direction D1 is less than the magnitude of the second angle θ2 between the second surface 52 and the first direction D1. The refractive index of the low refractive index portion 59 may be lower than the refractive index of the second portion 60.

[0154] According to this example, a part of the backlight L203 that enters the transmissive screen 20 from the incident light side other than the video light L201 and travels toward the first portion 50 is reflected, for example, totally reflected, by the first surface 51, and the incidence on the light diffusing portion 55 is suppressed. This backlight L203 can be directed in a direction that is greatly inclined with respect to the third direction D3 by the reflection at the first surface 51. Therefore, the diffusion of the backlight L203 other than the video lights L201 and L202 that pass through the transmissive screen 20 at the light diffusing portion 55 can be suppressed. Thereby, the contrast of the video displayed on the transmissive screen 20 can be improved. Also, the transparency of the transmissive screen 20 as a transparent screen can be improved.

[0155] In the transmissive screen 20 shown in FIG. 20, the refractive index of the low refractive index portion 59 is lower than the refractive index of the portion adjacent to the low refractive index portion 59 of the first portion 50 and is also lower than the refractive index of the second portion 60. The refractive index of the low refractive index portion 59 may be lower than the refractive index of the portion adjacent to the low refractive index portion 59 of the first portion 50 and equal to or higher than the refractive index of the second portion 60. The refractive index of the low refractive index portion 59 may be equal to or higher than the refractive index of the portion adjacent to the low refractive index portion 59 of the first portion 50 and lower than the refractive index of the second portion 60.

Description of Reference Numerals

[0156] D1: First direction, D2: Second direction, D3: Third direction, 7: Background, 9: Observer, 10: Display system, 15: Image light source, 15C: Light source center, 20: Transmission screen, 21: Light incident side surface, 22: Light exit side surface, 31: Substrate, 31A: First substrate, 31B: Second substrate, 33: Bonding layer, 33A: First bonding layer, 33B: Second bonding layer, 35: Functional layer, 36: Surface layer, 36A: First surface layer, 36B: Second surface layer, 37: Coloring layer, 38: Base material, 39: Take-up core, 40: Light control layer, 41: Light incident side surface, 42: Light exit side surface, 45: Light control layer body, 45a: Groove, 48: Base part, 50: First part, 51: First surface, 52: Second surface, 53: Light incident side surface, 54: Light exit side surface, 55: Light diffusion part, 55A: Base material part, 55B: Light diffusion element, 56: Light shielding part, 57: Light absorption part, 58: Light reflection part, 59: Low refractive index part, 60: Second part, 61: Light incident side surface, 62: Light exit side surface, 62a: First end, 62b: Second end, 65: Light shielding layer, 66: Light absorption layer, 67: Light reflection layer, 68: Decoration layer

Claims

1. A transmissive screen onto which image light is projected from an image light source, comprising a first portion and a second portion alternately arranged in a first direction, wherein the first portion includes a first surface and a second surface that form an interface with the second portion, the first surface and the second surface face each other in the first direction, a distance along the first direction of the first surface and the second surface is larger on the light-emitting side than on the light-incident side, the second surface of the first portion is located on a second side closer to the image light source in the first direction, and the first surface of the first portion is located on a first side farther from the image light source in the first direction, the first portion includes a light diffusing portion having a light diffusing function, a magnitude of a first angle between the first surface and the first direction is 40° or more, and a magnitude of a second angle between the second surface and the first direction is less than that, the transmissive screen.

2. The transmissive screen according to claim 1, wherein the first portion includes a light-shielding portion that constitutes the first surface, and the light-shielding portion has visible light light-shielding property.

3. The transmissive screen according to claim 1 or 2, wherein the first portion includes a light-absorbing portion that constitutes the first surface, and the light-absorbing portion has visible light absorbing property.

4. The transmissive screen according to claim 3, wherein the first portion includes a light-reflecting portion located between the light-absorbing portion and the light-diffusing portion, and the light-reflecting portion has visible light reflecting property.

5. The transmissive screen according to claim 1 or 2, wherein the first portion includes a light-reflecting portion that constitutes the first surface, and the light-reflecting portion has visible light reflecting property.

6. The transmissive screen according to claim 4 or 5, wherein the light-reflecting portion includes a metal layer.

7. The transmissive screen according to any one of claims 4 to 6, wherein a refractive index of a portion constituting the second surface of the first portion is higher than a refractive index of the second portion.

8. The first portion includes a low refractive index portion that constitutes the first surface, and a refractive index of the low refractive index portion is lower than a refractive index of a portion adjacent to the low refractive index portion of the first portion, the transmissive screen according to claim 1.

9. The first portion includes a low refractive index portion that constitutes the first surface, and a refractive index of the low refractive index portion is lower than a refractive index of the second portion, the transmissive screen according to claim 1 or 8.

10. The transmissive screen according to claim 1, wherein a refractive index of a portion constituting the first surface of the first portion is higher than a refractive index of the second portion.

11. The magnitude of the first angle is greater than Arccos(1 / n) and not more than 80°, where n is the refractive index of the second part, for the transmissive screen according to any one of claims 1 to 10.

12. For the transmissive screen according to any one of claims 1 to 11, the magnitude of the first angle of one first part is greater than the magnitude of the first angle of another first part located on the first side in the first direction relative to the one first part.

13. For the transmissive screen according to claim 12, the magnitude of the first angle of any one first part is not less than the magnitude of the first angle of any other first part located on the first side in the first direction relative to the one first part.

14. The magnitude of the second angle is not less than 85° and not more than 90°, for the transmissive screen according to any one of claims 1 to 13.

15. A light control layer including the first part and the second part, and a light-shielding layer located on the light-emitting side of the light control layer, wherein the light-shielding layer has visible light-shielding properties, and the light-shielding layer faces the light-emitting side surface of the second part from the light-emitting side, for the transmissive screen according to any one of claims 1 to 14.

16. A light control layer including the first part and the second part, and a light absorption layer located on the light-emitting side of the light control layer, wherein the light absorption layer has visible light absorption properties, and the light absorption layer faces the light-emitting side surface of the second part from the light-emitting side, for the transmissive screen according to any one of claims 1 to 15.

17. A light control layer including the first part and the second part, and a light reflection layer located on the light-emitting side of the light control layer, wherein the light reflection layer has visible light reflection properties, and the light reflection layer faces the light-emitting side surface of the second part from the light-emitting side, for the transmissive screen according to any one of claims 1 to 15.

18. A light control layer including the first part and the second part, and a decorative layer located on the light-emitting side of the light control layer for displaying a design, wherein the decorative layer faces the light-emitting side surface of the second part from the light-emitting side, for the transmissive screen according to any one of claims 1 to 14.

19. A light control layer including the first part and the second part, and a light-shielding layer located on the light-emitting side of the light control layer, wherein the light-shielding layer has visible light-shielding properties, and the light-shielding layer faces only a part of the light-emitting side surface of the second part from the light-emitting side, The said part includes the end portion on the first side in the first direction of the light-emitting side surface, and is away from the end portion on the second side in the first direction of the light-emitting side surface. The transmissive screen according to any one of claims 1 to 14.

20. A light control layer including the first part and the second part; A light absorption layer located on the light-emitting side of the light control layer, The light absorption layer has visible light absorbability, The light absorption layer faces the light-emitting side only to a part of the light-emitting side surface of the second part, The said part includes the end portion on the first side in the first direction of the light-emitting side surface, and is away from the end portion on the second side in the first direction of the light-emitting side surface. The transmissive screen according to any one of claims 1 to 14.

21. A light control layer including the first part and the second part; A light reflection layer located on the light-emitting side of the light control layer, The light reflection layer has visible light reflectivity, The light reflection layer faces the light-emitting side only to a part of the light-emitting side surface of the second part, The said part includes the end portion on the first side in the first direction of the light-emitting side surface, and is away from the end portion on the second side in the first direction of the light-emitting side surface. The transmissive screen according to any one of claims 1 to 14.

22. A light control layer body having a plurality of grooves; A plurality of first parts located in the grooves, The light control layer body includes a sheet-like base part and a plurality of second parts arranged on the base part, The second part constitutes the part between adjacent grooves, The first part and the second part are alternately arranged in the first direction, The first part includes a first surface and a second surface that form an interface with the second part, The first surface and the second surface face each other in the first direction, The first part includes a light diffusion part located between the first surface and the second surface and having a light diffusion function, and a light shielding part constituting the first surface, The light shielding part has visible light shielding property, The magnitude of the first angle between the first surface and the first direction is less than the magnitude of the second angle between the second surface and the first direction. The transmissive screen.

23. A light control layer body having a plurality of grooves; A plurality of first parts located in the grooves, The light control layer body includes a sheet-like base part and a plurality of second parts arranged on the base part, The second part constitutes the part between adjacent grooves, The first part and the second part are alternately arranged in the first direction, The first part includes a first surface and a second surface that form an interface with the second part, the first surface and the second surface face each other in the first direction, the first part includes a light diffusing part having a light diffusing function and located between the first surface and the second surface, and a light absorbing part constituting the first surface, the light absorbing part has visible light absorbability, a transmissive screen, wherein a magnitude of a first angle between the first surface and the first direction is less than a magnitude of a second angle between the second surface and the first direction.

24. A light control layer body having a plurality of grooves, and a plurality of first parts located in the grooves, the light control layer body includes a sheet-like base part and a plurality of second parts arranged on the base part, the second part constitutes a part between adjacent grooves, the first part and the second part are alternately arranged in a first direction, the first part includes a first surface and a second surface that form an interface with the second part, the first surface and the second surface face each other in the first direction, the first part includes a light diffusing part having a light diffusing function and located between the first surface and the second surface, and a light reflecting part constituting the first surface, the light reflecting part has visible light reflectivity, a transmissive screen, wherein a magnitude of a first angle between the first surface and the first direction is less than a magnitude of a second angle between the second surface and the first direction.

25. A transmissive screen including a first part and a second part alternately arranged in a first direction, the first part includes a first surface and a second surface that form an interface with the second part, the first surface and the second surface face each other in the first direction, the first part includes a light diffusing part having a light diffusing function and a low refractive index part constituting the first surface, a magnitude of a first angle between the first surface and the first direction is less than a magnitude of a second angle between the second surface and the first direction, and a refractive index of the low refractive index part is lower than a refractive index of a part adjacent to the low refractive index part of the first part.

26. A transmissive screen including a first part and a second part alternately arranged in a first direction, the first part includes a first surface and a second surface that form an interface with the second part, the first surface and the second surface face each other in the first direction, the first part includes a light diffusing part having a light diffusing function and a low refractive index part constituting the first surface, a magnitude of a first angle between the first surface and the first direction is less than a magnitude of a second angle between the second surface and the first direction, A transmissive screen in which the refractive index of the low refractive index portion is lower than the refractive index of the second portion. **Claim 27** Comprising a first portion and a second portion alternately arranged in a first direction, The first portion includes a first surface and a second surface that form an interface with the second portion, The first surface and the second surface face each other in the first direction, The first portion includes a light diffusing portion having a light diffusing function, The magnitude of a first angle between the first surface and the first direction is less than the magnitude of a second angle between the second surface and the first direction, A transmissive screen in which the refractive index of the portion constituting the first surface of the first portion is higher than the refractive index of the second portion. **Claim 28** A display system comprising the transmissive screen according to any one of claims 1 to 27, and a video light source that projects video light onto the transmissive screen.

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