Reflection screen, reflection screen unit, and image display device

Abstract

The present invention provides a reflective screen with improved close fitting property to a support plate. The reflective screen (10) reflects image light projected from an image source and displays it in an observable manner, and includes: a lens layer (11) having a Fresnel lens shape in which a plurality of unit lenses (111) are arranged; and a reflective layer (12) that reflects light, which is formed on the unit lenses (111) of the lens layer (11). The unit lenses (111) protrude from the image source side toward the back side in the thickness direction of the lens layer (11). The lens layer (11) is formed with a flat portion (114) at least at one edge where a part of the back side becomes a flat surface (114f). In the thickness direction of the lens layer (11), the minimum height h1min among the heights (h1) from the position closest to the image source side of the lens layer (11) to the position closest to the back side of the unit lens (111), and the height h2 from the flat surface (114f) of the flat portion (114) to the position closest to the back side of the unit lens (111) satisfy h1min - h2 > 0.

Description

Technical Field

[0001] The present invention relates to a reflective screen that reflects and displays projected image light, a reflective screen unit including the reflective screen, and an image display device including the reflective screen unit. Background Art

[0002] Conventionally, in order to display image light projected from a short-focus image source well, a reflective screen has been developed in which a reflective layer is formed on a lens layer having a Fresnel lens shape in which a plurality of unit lenses are arranged (for example, refer to Patent Document 1).

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2013-171114 Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] In the above-described reflective screen, a frame is joined to the image source side, and a support plate is joined to the back side. The reflective screen, the frame, and the support plate are joined by a joining layer (adhesive, bonding agent, etc.). However, since unit lenses having a substantially triangular cross-sectional shape are exposed on the back side of the reflective screen, irregularities caused by the irregular shape of the unit lenses are formed on the back side of the joining layer laminated on the back side of the reflective screen. Therefore, due to the irregularities on the back side of the joining layer, the reflective screen and the support plate cannot be sufficiently closely adhered to each other, and sometimes the two are peeled off.

[0008] An object of the present invention is to provide a reflective screen having improved close adhesion to a support plate, a reflective screen unit including the reflective screen, and an image display device.

[0009] Means for Solving the Problems

[0010] The present invention solves the problems by the following means. In addition, for easy understanding, reference numerals corresponding to embodiments of the present invention are used for description, but the present invention is not limited thereto. In addition, the structures described with reference numerals can be appropriately modified, and at least a part thereof can be replaced with other structures.

[0011] The first invention relates to a reflective screen that reflects image light projected from an image source and displays it in an observable manner. The reflective screen includes: a lens layer (11) having a Fresnel lens shape in which a plurality of unit lenses (111) are arranged; and a reflective layer (12) that reflects light, which is formed on the unit lenses of the lens layer. The unit lenses protrude from the image source side toward the back side in the thickness direction of the lens layer. The lens layer is formed with a flat portion (114) at least at one edge, where a part of the back side becomes a flat surface (114f). In the thickness direction of the lens layer, the minimum height h1min among the heights h1 and the height h2 satisfy h1min - h2 > 0, where the height h1 is the distance from the position closest to the image source side of the lens layer to the position closest to the back side of the unit lens, and the height h2 is the distance from the flat surface of the flat portion to the position closest to the back side of the unit lens.

[0012] The second invention relates to a reflective screen. In the reflective screen of the first invention, in the lens layer where the flat surface of the flat portion is formed between the position closest to the back side of the unit lens and the position closest to the image source side of the unit lens, h1min - h2 = 10 - 90 μm.

[0013] The third invention relates to a reflective screen. In the reflective screen of the first invention, in the lens layer where the flat surface of the flat portion is formed between the position closest to the image source side of the unit lens and the position closest to the image source side of the lens layer, h1min - h2 = 20 - 60 μm.

[0014] The fourth invention relates to a reflective screen. In the reflective screen of the first invention, the lens layer is a horizontally long quadrilateral when viewed from the image source side, and the flat portion is formed at at least one edge on the long side of the lens layer.

[0015] The fifth invention relates to a reflective screen. In the reflective screen of the fourth invention, the lens layer has a first long side on the lens surface side and a second long side on the non-lens surface side in the arrangement direction of the unit lenses, and the flat portion is formed at one edge of the first long side.

[0016] The sixth invention relates to a reflective screen. In the reflective screen of the fourth invention, the flat portion is formed at the edge of the lens layer on the side far from the optical center of the Fresnel lens shape.

[0017] The seventh invention relates to a reflective screen. In the reflective screen of the first invention, the lens layer is a horizontally long quadrilateral when viewed from the image source side, and the flat portion is formed at at least one end edge on the long side and at least one end edge on the short side of the lens layer.

[0018] The eighth invention relates to a reflective screen unit, which includes: a reflective screen according to any one of the first to seventh inventions; a frame (20) provided on the image source side of the reflective screen and covering at least the flat portion; a support plate (30) provided on the back side of the reflective screen to maintain the flatness of the screen of the reflective screen; and a bonding layer (40) provided between the reflective screen and the support plate to bond the reflective screen and the support plate.

[0019] The ninth invention relates to an image display device, which includes the reflective screen unit of the eighth invention and an image source that projects image light onto the reflective screen unit.

[0020] Advantages of the Invention

[0021] According to the present invention, the close adhesion between the support plate and the reflective screen can be improved, so the peeling between the two can be suppressed. Description of the Drawings

[0022] Figure 1 It is a diagram showing the image display device 100 of the first embodiment.

[0023] Figure 2 It is a diagram for explaining the layer structure of the reflective screen unit 1 and the reflective screen 10 of the first embodiment.

[0024] Figure 3 It is a diagram of the lens layer 11 of the reflective screen 10 viewed from the back side (-Z side).

[0025] Figure 4 It is an exploded perspective view of the reflective screen unit 1.

[0026] Figure 5 It is a perspective view showing the appearance of the roller plate 50.

[0027] Figure 6 (A) and (B) thereof are diagrams for explaining the pasting direction of the mold plate 52 in the roller plate 50.

[0028] Figure 7 (A) to (C) thereof are diagrams for explaining the molding of the lens layer 11.

[0029] Figure 8 It is a diagram for explaining the manufacturing process of the lens sheet 11a using the roller plate 50.

[0030] Figure 9This is a diagram showing the layer structure of the reflective screen unit 1 and the reflective screen 10 of the second embodiment.

[0031] Figure 10 (A) to (C) thereof are diagrams illustrating the molding of the lens layer 11 of the modified mode. Detailed Embodiment

[0032] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings and the like. In addition, including Figure 1 the following figures are schematically shown, and for easy understanding, the sizes and shapes of each part are appropriately exaggerated.

[0033] In this specification, terms for determining shapes and geometric conditions (such as terms like parallel and orthogonal) include, in addition to the strict meaning, states that have the same optical function and have errors to the extent that they can be regarded as parallel or orthogonal.

[0034] In this specification, the numerical values such as the sizes of the components described, and the material names, etc. are examples of the embodiments, and are not limited thereto, and can be appropriately selected and used.

[0035] In this specification, the screen surface refers to the surface in the plane direction of the screen when observing the screen as a whole, and is parallel to the screen image (display surface).

[0036] [First Embodiment]

[0037] Figure 1 This is a diagram showing the image display device 100 of the first embodiment. Figure 1 (A) thereof is a perspective view of the image display device 100. Figure 1 (B) thereof is a view of the image display device 100 observed from the side.

[0038] As Figure 1 shown, the image display device 100 includes a reflective screen unit 1, an image source 2, etc. The reflective screen unit 1 includes a reflective screen 10 (described later), etc., and reflects the image light L projected from the image source 2, thereby displaying an image on the screen (display surface) on the image source side. Details of the reflective screen unit 1 will be described later.

[0039] In addition, in the reflective screen unit 1 and the reflective screen 10, there is no particular specification for up, down, left, and right, but except for Figure 5 and Figure 6In each of the other figures, an orthogonal coordinate system of XYZ is appropriately shown. In this coordinate system, the left - right direction (horizontal direction) of the screen of the reflection screen unit 1 (reflection screen 10) is set as the X - direction, the up - down direction (vertical direction) of the screen is set as the Y - direction, and the thickness direction of the reflection screen unit 1 is set as the Z - direction. The screen of the reflection screen unit 1 is parallel to the XY plane, and the thickness direction (Z - direction) of the reflection screen unit 1 is orthogonal to the screen of the reflection screen unit 1.

[0040] In addition, when observed from an observer O1 in the front direction on the image source side of the reflection screen unit 1, the direction toward the right side in the left - right direction of the screen is set as the +X - direction, and the direction toward the left side is set as the - X - direction. The direction toward the upper side in the up - down direction of the screen is set as the +Y - direction, and the direction toward the lower side is set as the - Y - direction. In the thickness direction, the direction from the back side (dorsal side) toward the image source side is set as the +Z - direction, and the direction from the image source side toward the back side is set as the - Z - direction.

[0041] And, in the following description, unless otherwise specified, the up - down direction of the screen, the left - right direction of the screen, and the thickness direction correspond to the up - down direction (vertical direction), the left - right direction (horizontal direction), and the thickness direction (depth direction) of the screen of the reflection screen unit 1 in the usage state. These respective directions are parallel to the Y - direction, the X - direction, and the Z - direction. In addition, in this specification, “~direction” is also referred to as “~side”.

[0042] The image source 2 is an image projection device (projector) that projects image light L onto the reflection screen unit 1. The image source 2 of the present embodiment is a short - focus type projector.

[0043] In the usage state of the image display device 100, when observing the screen (display area) of the reflection screen unit 1 from the front direction on the image source side (+Z side) (the normal direction of the screen surface), the image source 2 is disposed at the center in the left - right direction of the screen of the reflection screen unit 1 and is on the lower side in the vertical direction (-Y side) than the screen of the reflection screen unit 1.

[0044] The image source 2 can project the image light L obliquely from a position where the distance from the surface on the image source side (+Z side) of the reflection screen unit 1 in the depth direction (Z - direction) is much closer than that of a conventional general - purpose projector. Therefore, compared with a conventional general - purpose projector, the projection distance from the image source 2 to the reflection screen unit 1 is short, the incident angle of the projected image light on the reflection screen unit 1 is large, and the change amount of the incident angle (the change amount from the minimum value to the maximum value) is also large.

[0045] The reflection screen unit 1 reflects the image light L projected by the image source 2 toward the observer O1 side on the image source side (+Z side) to display an image.

[0046] In the state of use, when observed from the side of the observer O1 on the image source side (+Z side), the screen (display area) of the reflection screen unit 1 is rectangular with the long side direction being the left - right direction (X direction) of the screen. That is, the screen of the reflection screen unit 1 (reflection screen 10) of the present embodiment is a horizontally long quadrilateral when observed from the image source side.

[0047] Figure 2 It is a diagram showing the layer structure of the reflection screen unit 1 and the reflection screen 10 of the first embodiment. Figure 2 An enlarged view shows a region on the lower side (-Y side) of the reflection screen unit 1, that is, a part of the following cross - section (Y - Z plane), which passes through the geometric center A of the reflection screen 10 (refer to Figure 3 ), is parallel to the arrangement direction of the unit lenses 111 (described later) and parallel to the thickness direction (Z direction). Figure 3 It is a diagram of observing the lens layer 11 of the reflection screen 10 from the back side (-Z side). In addition, in Figure 3 , the illustration of the reflection layer 12 provided on the back side of the lens layer 11 is omitted. Figure 4 It is an exploded perspective view of the reflection screen unit 1. In Figure 4 , it is a diagram of observing the reflection screen unit 1 from the back side (-Z side), simplifying the appearance, shape, etc. of each part.

[0048] As Figure 2 and Figure 4 show, the reflection screen unit 1 sequentially includes a frame 20, a reflection screen 10, a bonding layer 40, and a support plate 30 from the image source side (+Z side).

[0049] <Reflection screen 10>

[0050] The reflection screen 10 is a sheet member (laminate) that reflects the image light projected from the image source 2 and displays it in an observable manner. As Figure 2 shows, the reflection screen 10 of the present embodiment includes a lens layer 11, a reflection layer 12, and a light diffusion layer 13. In addition, as the reflection screen 10, it is sufficient to have at least the lens layer 11 and the reflection layer 12.

[0051] <Lens layer 11>

[0052] The lens layer 11 is a light - transmissive sheet formed on the back side (-Z side) of the light diffusion layer 13. As Figure 3 shows, the lens layer 11 has a circular Fresnel lens shape in which a plurality of unit lenses 111 are arranged concentrically with point C as the center. In the circular Fresnel lens shape, the point C that becomes the optical center (Fresnel center) is located outside the area of the screen (display area) of the reflection screen 10 and is located on the lower side (-Y side) of the reflection screen 10. In the present embodiment, as Figure 3As shown, the optical center C is set on a line ( Figure 3 the dash-dotted line in) parallel to the vertical direction (Y direction) of the screen passing through the geometric center A of the reflection screen 10, and the circular Fresnel lens shape is formed symmetric with respect to this line ( Figure 3 the dash-dotted line in).

[0053] As Figure 2 shown, the shape of the unit lens 111 in a cross-section parallel to the thickness direction (Z direction) orthogonal to the screen surface and parallel to the arrangement direction (Y direction) of the unit lenses 111 is substantially triangular. The unit lens 111 is formed to protrude from the image source side (+Z side) toward the back side (-Z side). The unit lens 111 includes: a lens surface 112; and a non-lens surface 113 opposed (adjacent) to the lens surface 112 in the arrangement direction of the unit lenses 111. In the use state of the reflection screen unit 1, the lens surface 112 of the unit lens 111 is located on the upper side (+Y side) in the vertical direction than the non-lens surface 113 with the vertex t in between. The vertex t represents the position of the rearmost side (-Z side) of the unit lens 111.

[0054] As Figure 2 shown, in the unit lens 111, the angle formed by the lens surface 112 and the plane parallel to the screen surface (in the figure, the dashed line (X-Y plane)) is α. The angle formed by the non-lens surface 113 and the plane parallel to the screen surface is β (β > α). The arrangement pitch of the unit lenses 111 is P. In addition, the lens height of the unit lens 111 is h0. The lens height h0 is the distance from the point v closest to the image source side of the unit lens 111 to the vertex t. The point v represents the position where the vertex t in the thickness direction of the reflection screen 10 becomes the bottom of the valley between the unit lenses 111.

[0055] In addition, in Figure 2 , the arrangement pitch P, angles α, β of the unit lenses 111 are shown in a fixed manner in the arrangement direction of the unit lenses 111. However, the unit lens 111 is actually configured such that the arrangement pitch P, etc. are fixed, but the angle α gradually increases as it moves away from the point C (refer to Figure 3 ) that becomes the Fresnel center in the arrangement direction of the unit lenses 111. That is, the lens height h0 of the unit lens 111 gradually increases as it moves away from the point C that becomes the Fresnel center in the arrangement direction of the unit lenses 111.

[0056] In addition, not limited to the above structure, a structure in which the arrangement pitch P gradually changes along the arrangement direction of the unit lenses 111 may also be adopted. That is, the arrangement pitch P can be appropriately changed according to the size of the pixels of the image source 2 that projects the image light, the projection angle of the image source 2 (the incident angle at which the image light is incident on the screen surface of the reflection screen 10), the screen size of the reflection screen 10, the refractive index of each layer, etc.

[0057] As shown Figure 3 in the figure, at the respective edges of the lens layer 11 (reflective screen 10) in the horizontal direction (X direction) and vertical direction (Y direction) of the screen, a flat portion 114 is formed with a flat surface (114f) on the back side. The flat portion 114 is provided so as to surround the arranged unit lenses 111 and is formed of the same material as the unit lenses 111. That is, in the reflective screen 10, the unit lenses 111 and the flat portion 114 are integrally formed.

[0058] Figure 3 The lens layer 11 shown in the figure has, in the arrangement direction of the unit lenses 111, a first long-side edge LS1 on the lens surface 112 (refer to Figure 2 ) side and a second long-side edge LS2 on the non-lens surface 113 (refer to Figure 2 ) side, which are closer to the lens surface 112 than the non-lens surface 113. In the lens layer 11 in which the unit lenses 111 having the cross-sectional shape shown in Figure 2 are arranged in the vertical direction (Y direction) of the screen, the flat portion 114 is preferably formed at least at the first long-side edge LS1. That is, the flat portion 114 is preferably formed at the edge on the side away from the point C that is the optical center of the lens layer 11.

[0059] By forming the flat portion 114 at the first long-side edge LS1 and using the flat portion 114 formed at the +Y side edge LS1 of the lens layer 11 as the peeling start portion when peeling the lens layer 11 from the molding die, the lens layer 11 can be peeled from the molding die more easily and smoothly.

[0060] In the reflective screen 10 of the first embodiment, as Figure 2 shown in the figure, the flat surface 114f of the flat portion 114 is formed in the thickness direction (Z direction) of the lens layer 11 between near the vertex t on the back side of the unit lens 111 and near the point v on the image source side of the unit lens 111. "Near the point v" means that in the thickness direction of the lens layer 11, the flat surface 114f of the flat portion 114 is formed at a position on the back side (-Z side) of the point v on the image source side of the unit lens 111.

[0061] In the reflective screen 10 of the first embodiment, in the thickness direction of the lens layer 11, the minimum height h1min of the distance h1 from the position 11e on the image source side of the lens layer 11 to the vertex t on the back side of the unit lens 111 and the distance h2 from the flat surface 114f to the vertex t on the back side of the unit lens 111 satisfy h1min - h2 > 0. In the lens layer 11 of the first embodiment, h1min - h2 is preferably 10 to 90 μm, more preferably 30 to 70 μm.

[0062] The width w of the pars plana 114 (refer to Figure 2 ) also depends on the screen size of the reflection screen 10, but is preferably within 10 mm.

[0063] In addition, the above dimensions and ranges are merely examples and are not limited thereto.

[0064] Furthermore, as described above, the angle α of the unit lens 111 is configured to gradually increase as it moves away from the point C that is the Fresnel center, so the lens height h0 also gradually increases accordingly. In addition, as the lens height h0 increases, the distance from the position 11e of the lens layer 11 to the vertex t of the unit lens 111, that is, the height h1, also increases. Therefore, the pars plana 114 is formed to satisfy the relationship of h1min - h2 > 0 with respect to the minimum height h1min. In addition, in the present embodiment, at the edges in each direction of the screen, h1min - h2 that defines the position of the pars plana 114 is set to the same value. However, as will be described later, the value of h1min - h2 may also be different in each direction of the screen. The functions and effects of the pars plana 114 will be described later.

[0065] The lens layer 11 is formed of an ultraviolet curable resin such as a polyurethane acrylate-based, polyester acrylate-based, epoxy acrylate-based, polyether acrylate-based, polythiol-based, or polydiene acrylate-based resin with high light transmittance.

[0066] Regarding the lens layer 11, by using a roller plate (described later), it can be formed into a continuous lens sheet.

[0067] In the lens layer 11 formed by using a roller plate, a plurality of unit lenses 111 are arranged in a concentric circle shape to form a circular Fresnel lens shape as follows: its shape in a cross-section parallel to the direction orthogonal to the screen surface (thickness direction) and parallel to the arrangement direction of the unit lenses 111 is substantially triangular. In addition, in the roller plate, by providing flat surfaces 52a (described later) that do not form concavo-convex shapes for shaping the unit lenses 111 at portions opposed to the edges in the left-right direction (X direction) and up-down direction (Y direction) of the screen of the lens layer 11, the pars plana 114 can be formed at the positions of the above-mentioned edges of the lens layer 11.

[0068] As described later, the lens layer 11 can be formed of a thermoplastic resin composition or an ionizing radiation curable resin such as an electron beam curable resin. In addition, the lens layer 11 can also be produced by a stamping method or the like according to the Fresnel lens shape. In this case, a light diffusion layer 13 or the like can be laminated on the image source side with an intervening bonding layer (not shown). In addition, in the case where an extrusion molding method can be performed, molding can also be performed in a state where the lens layer 11 and the light diffusion layer 13 are laminated integrally. The molding of the lens layer 11 (lens sheet 11a) will be described later.

[0069] <Reflective layer 12>

[0070] The reflective layer 12 is a layer having a function of reflecting light. The reflective layer 12 has a thickness sufficient to reflect light and is formed on at least the lens surface 112 of the unit lens 111. In the present embodiment, as Figure 2 shown, the reflective layer 12 is formed on the lens surface 112 but not on the non-lens surface 113. In addition, as long as the reflective layer 12 has a thickness that does not reflect light, it can also be formed on at least a part of the non-lens surface 113.

[0071] The reflective layer 12 can be formed by vapor-depositing a metal with high light reflectivity such as aluminum, silver, or nickel on the lens surface 112 of the lens layer 11 formed into a lens sheet. In addition, the reflective layer 12 can also be formed, for example, by sputtering a metal with high light reflectivity such as aluminum, silver, or chromium, or transferring a metal foil thereof. As long as the reflective layer 12 can ensure a thickness sufficient to reflect light, the thickness can also be appropriately set according to the material or the like.

[0072] <Light diffusion layer 13>

[0073] The light diffusion layer 13 is a layer based on a resin having translucency and containing a diffusing agent that diffuses light. The light diffusion layer 13 has a function of expanding the viewing angle and improving the in-plane uniformity of brightness. Examples of the resin that becomes the base material of the light diffusion layer 13 include PET (polyethylene terephthalate) resin, PC (polycarbonate) resin, MS (methyl methacrylate-styrene) resin, MBS (methyl methacrylate-butadiene-styrene) resin, TAC (triacetyl cellulose) resin, PEN (polyethylene naphthalate) resin, and acrylic resin.

[0074] As the diffusing agent contained in the light diffusion layer 13, for example, acrylic resins, epoxy resins, etc., resin particles such as silicone-based, and inorganic particles can be cited. It should be noted that as the diffusing agent, an inorganic diffusing agent and an organic diffusing agent can be used in combination. The diffusing agent is preferably a substantially spherical diffusing agent with an average particle diameter of about 1 to 50 μm. The thickness of the light diffusion layer 13 also depends on the screen size of the reflection screen 10, but for example, it is preferably about 100 to 2000 μm. In addition, although not shown, a coloring layer, a surface layer, etc. can also be provided on the image source side (+Z side) of the light diffusion layer 13.

[0075] <Frame 20>

[0076] The frame 20 is a component disposed on the image source side (+Z side) of the reflection screen unit 1. As Figure 4 shown, the frame 20 is configured in a frame shape so as to cover the area corresponding to the flat portion 114 (the area outside the dotted line in the figure) of the reflection screen 10. Hereinafter, in the reflection screen 10, the portion not covered by the frame 20 is also referred to as the "effective area". The frame 20 is made of, for example, plastic, metal, wood, etc. In addition, the frame 20 can also be in the shape of a box frame that covers not only the flat portion 114 of the reflection screen 10 but also the entire side surface of the reflection screen unit 1.

[0077] <Support plate 30>

[0078] The support plate 30 is a component disposed on the back side (-Z side) of the reflection screen 10 in the reflection screen unit 1. The reflection screen 10 and the support plate 30 are joined via a joining layer 40 (described later).

[0079] The support plate 30 only needs to be a component having sufficient rigidity to support the reflection screen 10, and its material is not particularly limited. As the support plate 30, for example, a metal plate such as aluminum, a resin plate such as an acrylic resin, etc. can be used. In addition, as the support plate 30, a thin plate with aluminum or the like on both sides, or a metal plate having a honeycomb structure (for example, a honeycomb plate) with a core material made of a thin plate of aluminum or the like can also be used. From the viewpoint of suppressing the entry of external light and the reduction of contrast caused by external light, the support plate 30 is preferably a component that does not have light transmissivity.

[0080] <Joining layer 40>

[0081] The joining layer 40 is a layer having a function of joining the reflection screen 10 and the support plate 30 integrally. The joining layer 40 is formed of an adhesive, a bonding agent, etc. As the joining layer 40, for example, an ultraviolet curable resin, a thermosetting resin, etc. can be used. The joining layer 40 is preferably a black or low light transmissive joining layer. It should be noted that in Figure 4In the figure, the bonding layer 40 is shown as a sheet, but adhesives such as adhesives and bonding agents that form the bonding layer 40 are coated on the back side (-Z side) of the reflective screen 10. If the bonding layer 40 is coated on the back side (-Z side) of the reflective screen 10, then as Figure 2 shown, within the effective area of the reflective screen 10, irregularities caused by the cross-sectional shape (substantially triangular shape) of the unit lens 111 are formed on the surface of the back side (-Z side) of the bonding layer 40.

[0082] As Figure 3 shown, the reflective screen 10 of the above-described first embodiment has flat portions 114 formed at the edges in the left-right direction (X direction) and up-down direction (Y direction) of the screen on the back side of the lens layer 11 (the front side in the figure). Therefore, when the support plate 30 is bonded to the reflective screen 10 via the bonding layer 40, as Figure 2 shown, even if irregularities corresponding to the unit lens 111 of the lens layer 11 are formed on the back side of the bonding layer 40 provided on the back side (-Z side) of the reflective screen 10, at the flat portions 114 formed at the respective edges, the reflective screen 10 and the support plate 30 can be more fully and tightly bonded to the bonding layer 40. Thus, according to the reflective screen 10 of the first embodiment, the tight bonding property with the support plate 30 can be improved through the flat surface 114f of the flat portion 114, and therefore peeling between the two after bonding can be suppressed.

[0083] <Roller plate 50>

[0084] Next, the roller plate 50 used for forming the lens layer 11 (refer to Figure 2 ) will be described. Figure 5 is a perspective view showing the appearance of the roller plate 50. Figure 6 The (A) and (B) of

[0085] Figure 6 are diagrams for explaining the pasting direction of the mold plate 52 in the roller plate 50. Figure 3 The up-down direction (Y direction) and left-right direction (X direction) of the screen of the mold plate 52 shown in the (A) and (B) of

[0086] As Figure 5As shown, the embossing plate 50 includes a roller 51 and an engraved plate (molding die) 52. The roller 51 includes a cylindrical roller body 51a and a rotating shaft 51b that protrudes along the axis from the end face of the roller body 51a. The roller 51 can rotate around the rotating shaft 51b. The roller body 51a is the part around which the engraved plate 52 is wound. Since the roller body 51a needs to ensure rigidity, it is preferably made of an iron-based material for mechanical structures. In addition, from the viewpoints of ensuring the necessary rigidity and achieving weight reduction, the roller body 51a may also be a cylindrical shape with bottoms on both sides. Further, in order to be able to adjust the temperature of the surface of the roller body 51a, a circulation mechanism (not shown) for cold water, warm water, steam, or high-temperature oil may be provided inside the roller body. In addition, the diameter of the roller body 51a is, for example, about 300 to 650 mm. The roller length (width) of the roller body 51a is, for example, about 1650 to 1850 mm.

[0087] The engraved plate 52 is a sheet-like mold that transfers the concavo-convex shape corresponding to the circular Fresnel lens shape of the lens layer 11 to the resin composition described later. In Figure 5 the specific illustration of the concavo-convex shape 52b as the mold is omitted. Figure 6 The engraved plate 52 shown in (A) of Figure 6 is adhered to the roller body 51a such that the vertical direction (Y direction) of the screen is parallel to the circumferential direction C of the roller body 51a. On the other hand,

[0088] If the engraved plate 52 is adhered to the roller body 51a in the Figure 6 direction shown in (A) of Figure 6 then the long side ends in the vertical direction (Y direction) of the engraved plate 52 become opposing shapes. Therefore, regarding the lens sheet 11a (described later) formed by the embossing plate 50 shown in (A) of Figure 6 as shown in the right-hand figure of (A) of

[0089] the winding direction T toward the take-up roller (not shown) is the same as the vertical direction (Y direction) of the screen. Figure 6 In addition, if the engraved plate 52 is adhered to the roller body 51a in the Figure 6 direction shown in (B) of Figure 6 then the short side ends in the horizontal direction (X direction) of the engraved plate 52 become opposing shapes. Therefore, regarding the lens sheet 11a formed by the embossing plate 50 shown in (B) of Figure 5 and Figure 6In [the figure], a state is shown in which one master plate 52 is wound around the roller 51, but it may also be a state in which multiple master plates 52 are wound around the roller 51.

[0090] The master plate 52 is adhered to the surface of the roller body 51a. As Figure 5 shown, the gaps at the seams between the ends are filled with resin 53. A flat surface 52a that does not form the concavo-convex shape 52b for shaping the unit lens 111 is provided on the master plate 52. By providing the flat surface 52a on the master plate 52, it is possible to form flat portions 114 (refer to Figure 2 ) at the positions of the edges in the horizontal and vertical directions of the image plane of the lens layer 11 formed using the roller plate 50.

[0091] Figure 7 (A) to (C) of

[0092] Figure 7 are diagrams for explaining the shaping of the lens layer 11. Figure 7 (A) to (C) of Figure 5 are diagrams for explaining the flat surface 52a and the concavo-convex shape 52b formed on the master plate 52 and the surface shape of the lens layer 11 formed by the master plate 52. Therefore, a part of the description using Figure 7 (A) to (C) of

[0093] As Figure 7 (A) of Figure 5 shown, a concavo-convex shape 52b corresponding to the shape of the unit lens 111 is formed on the master plate 52 used for shaping the lens layer 11. The master plate 52 forms a flat surface 52a where the concavo-convex shape 52b is not formed at the outer peripheral edge surrounding the concavo-convex shape 52b, that is, at positions corresponding to the edges in the vertical and horizontal directions of the image plane of the lens layer 11 (refer to

[0094] As Figure 7 (B) of Figure 7 shown, the molten thermoplastic resin composition 64 is filled on the surfaces of the flat surface 52a and the concavo-convex shape 52b of the master plate 52. The thermoplastic resin composition 64 is cured by cooling. After the thermoplastic resin composition 64 is cured, the molded product is peeled off from the surface of the master plate 52. Thus, as

[0095] (C) of shown, it is possible to obtain a lens piece 11a having flat portions 114 (flat surfaces 114f) formed at the edges in the vertical and horizontal directions of the image plane (only a part of the edges is shown in this figure).

[0095] <Method for manufacturing lens layer 11>

[0096] Next, a method for manufacturing the lens layer 11 using the gravure roll 50 will be described. Figure 8 It is a diagram illustrating the manufacturing process of the lens sheet 11a (lens layer 11) using the gravure roll 50.

[0097] As Figure 8 shown, the molten thermoplastic resin composition 64 is made to flow from the nozzle 65 between the first roll 61 and the gravure roll 50 arranged at a prescribed interval with respect to the first roll 61. The flowing-in thermoplastic resin composition 64 is preferably in the form of a strip having a size (width) approximately the same as the size in the width direction of the gravure roll 50. Thereby, the material can be uniformly supplied in the width direction of the gravure roll 50.

[0098] The thermoplastic resin composition 64 flows into the space between the first roll 61 and the gravure roll 50 at a prescribed pressure. Thereby, the thermoplastic resin composition 64 is filled into the unevenness (not shown) formed on the surface of the gravure roll 50, and is cooled and solidified by the gravure roll 50 and the atmosphere (external air, working environment of the manufacturing apparatus, etc.) to become a shape following the unevenness of the gravure roll 50. Then, the thermoplastic resin composition 64 is further cooled by passing through the second roll 62 and the third roll 63, and the final shape is fixed. Thereby, a lens sheet 11a having a circular Fresnel lens shape in which a plurality of unit lenses 111 are arranged in a concentric circle (refer to Figure 3 ) can be obtained. On the lens sheet 11a, for example, as shown in the right-side diagrams of (A) and (B) of Figure 6 , a plurality of lens layers 11 are continuously formed.

[0099] The lens sheet 11a continuously formed in this way is wound up by a winding roll (not shown). Then, by subjecting the lens sheet 11a to processes such as blanking and cutting, the lens layer 11 separated individually can be obtained.

[0100] In the case of the lens sheet 11a shown in (A) of Figure 6 , the winding direction is the vertical direction (Y direction) of the screen. In addition, in the case of the lens sheet 11a shown in (B) of Figure 6 , the winding direction is the horizontal direction (X direction) of the screen. The height of the flat portion 114 can also be changed according to the winding direction of the lens sheet 11a.

[0101] Note that, in the manufacturing process of the lens layer 11 using the gravure roll 50, other processes can be further added, or a part of the manufacturing process can be replaced with other processes.

[0102] As Figure 3As shown, the reflective screen 10 of the above-described first embodiment has flat portions 114 formed at the back side (the near front side in the figure) of the lens layer 11 and at the edges in the horizontal direction (X direction) and vertical direction (Y direction) of the screen. Therefore, during the manufacturing process of the lens layer 11, by using the flat portion 114 as the peeling start portion, the molded lens layer 11 can be easily peeled off from the molding die.

[0103] In the lens sheet 11a formed by the rotary press 50, if it is assumed that the unit lens 111 is formed up to the area of the flat portion 114 (when the flat portion 114 is not formed in the lens layer 11), it is difficult to demold the lens sheet 11a from the molding die (rotary press 50). In this case, if the lens sheet 11a is forcibly peeled off from the molding die, an excessive force will be applied to the lens sheet 11a during demolding, so there is a possibility that the lens layer 11 whitens or cracks occur in the unit lens 111.

[0104] In contrast, as described above, the reflective screen 10 of the present embodiment has flat portions 114 (flat surfaces 114f) formed at the respective edges of the lens layer 11. Therefore, by using the flat portion 114 as the peeling start portion, it is easy to demold from the molding die. If it is easy to demold from the rotary press 50, an excessive force will not be applied to the lens sheet 11a during demolding, so it is possible to suppress the occurrence of defects such as whitening of the lens layer 11 or cracking in the unit lens 111.

[0105] In the lens layer 11 formed on the lens sheet 11a, the flat portion 114 (flat surface 114f) is preferably formed at the edge of the lens layer 11, particularly at the edge LS1 on the lens surface 112 side rather than the non-lens surface 113 of the unit lens 111 (refer to Figure 3 ). That is, in the unit lens 111 shown in Figure 2 , at the edge LS1 on the +Y side in the vertical direction (Y direction) of the screen, the non-lens surface 113 is adjacent to the flat surface 114f of the flat portion 114. Therefore, the flat portion 114 is preferably formed at the edge LS1 on the +Y side.

[0106] By forming the structure as described above, during the manufacturing process of the lens layer 11, when peeling the lens layer 11 (lens sheet 11a) from the molding die, by using the flat portion 114 formed at the edge LS1 on the +Y side as the peeling start portion, the lens layer 11 can be peeled off from the molding die more easily and smoothly.

[0107] In addition, in the molding of the lens sheet 11a based on the rotary press 50, as shown in Figure 5As shown, the gaps at the joints between the ends of the mold plate 52 are filled with the resin 53. In the lens sheet 11a, assuming that the unit lens 111 is formed up to the area of the flat portion 114, the resin 53 filled in the gaps at the joints between the ends may flow into the concave-convex side for molding the unit lens 111 due to capillary action. In this case, the resin 53 at the gaps of the joints becomes thinner, and there is a concern that a part of the mold plate 52 may peel off from the roller 51 during molding. In addition, a part of the concave-convex for molding the unit lens 111 is filled with the resin, and molding defects or the like may occur.

[0108] In contrast, in the mold plate 52 of the present embodiment, flat surfaces 52a are formed at the respective end edges. Therefore, the resin 53 filled in the gaps at the joints between the ends is less likely to flow into the concave-convex side for molding the unit lens 111 due to capillary action. Thus, it is possible to suppress the following adverse conditions: a part of the mold plate 52 peels off from the roller 51 during molding, or a part of the concave-convex for molding the unit lens 111 is filled with the resin and molding defects or the like occur.

[0109] [Second Embodiment]

[0110] Regarding the reflective screen 10 of the second embodiment, in the thickness direction of the lens layer 11, the range where the flat portion 114 is formed is different from that of the first embodiment. In the reflective screen 10 of the second embodiment, the other structures are the same as those of the first embodiment. Therefore, in Figure 9 only the reflective screen 10 is illustrated, and the illustration of the entire image display device 100 is omitted. In addition, in the description and the drawings of the second embodiment, the same components as those of the first embodiment are labeled with the same reference numerals as those of the first embodiment, and repeated descriptions are omitted.

[0111] Figure 9 is a diagram for explaining the layer structure of the reflective screen unit 1 and the reflective screen 10 of the second embodiment.

[0112] In the reflective screen 10 of the second embodiment, as Figure 9 shown, the flat surface 114f of the flat portion 114 is formed in the thickness direction (Z direction) of the lens layer 11 between the point v closest to the image source side of the unit lens 111 and the position 11e closest to the image source side of the lens layer 11.

[0113] In the reflective screen 10 of the second embodiment, in the thickness direction of the lens layer 11, the minimum height h1min of the distance h1 from the position 11e closest to the image source side of the lens layer 11 to the vertex t closest to the back side of the unit lens, and the distance h2 from the flat surface 114f to the vertex t closest to the back side of the unit lens 111 satisfy h1min - h2 > 0. In the lens layer 11 of the second embodiment, h1min - h2 is preferably 10 to 90 μm, more preferably 30 to 70 μm. In the reflective screen 10 of the second embodiment, other structures are the same as those of the first embodiment.

[0114] In the reflective screen 10 of the second embodiment, similarly to the first embodiment, the flat surface 114f of the flat portion 114 can improve the close adhesion with the support plate 30, so that peeling between the two after adhesion can be suppressed.

[0115] In addition, in the lens layer 11 of the second embodiment, during the manufacturing process, when the lens layer 11 (lens sheet 11a) is peeled off from the molding die, by using the flat portion 114 formed at the edge LS1 on the +Y side as the peeling start portion, the lens layer 11 can be peeled off from the molding die more easily and smoothly.

[0116] Furthermore, according to the reflective screen 10 of the second embodiment, the amount of resin for forming the lens layer 11 can be made less than that of the first embodiment.

[0117] The embodiments of the present disclosure have been described above, but the present disclosure is not limited to the foregoing embodiments and can be variously deformed and changed as in the following deformation modes, and they are also included in the technical scope of the present disclosure. In addition, the effects described in the embodiments are merely the most preferable effects resulting from the present disclosure and are not limited to the effects described in the embodiments. Moreover, the above-described embodiments and the following deformation modes can be appropriately combined for use, but detailed descriptions are omitted.

[0118] (Deformation mode)

[0119] Figure 10 (A) to (C) are diagrams for explaining the molding of the lens layer 11 in the deformation mode.

[0120] In the reflective screen 10 of the deformation mode, the shape of the flat portion 114 is different from that of the first embodiment. In the reflective screen 10 of the deformation mode, other structures are the same as those of the first embodiment. In addition, in the description and drawings of the second embodiment, the same components as those of the first embodiment are labeled with the same reference numerals as those of the first embodiment, and repeated descriptions are omitted. In Figure 10 (A) to (C), the mold plate 52 and the lens sheet 11a during molding are also shown in a plan view.

[0121] As shown in (A) of Figure 10 , the mold plate 52 of the deformation method has a flat surface 52a, a protrusion 52c, and a bank 52d. The protrusion 52c is a portion having a substantially triangular cross-sectional shape. The bank 52d is a portion having a substantially trapezoidal cross-sectional shape. Both the protrusion 52c and the bank 52d are portions protruding outward from the flat surface 52a. Although not shown, in the mold plate 52 of the deformation method, at positions corresponding to the outer peripheral edge surrounding the concavo-convex shape 52b, that is, the upper and lower edges and the left and right edges of the screen of the lens layer 11, a flat surface 52a, a protrusion 52c, and a bank 52d are formed. The protrusion 52c and the bank 52d extend along each edge.

[0122] When using the mold plate 52 of this method, as shown in (B) of Figure 10 , a molten thermoplastic resin composition 64 is filled on the flat surface 52a, the concavo-convex shape 52b, the protrusion 52c, and the bank 52d of the mold plate 52. Then, if the molded product is peeled off from the surface of the mold plate 52 after hardening, as shown in (C) of Figure 10 , a lens sheet 11a (lens layer 11) having flat portions 114 formed at the upper and lower edges and the left and right edges of the screen (only a part of the edges is shown in this figure) can be obtained. The flat portion 114 has a flat surface 114f, a concave portion 114g, and a stepped portion 114h. As in this method, it is sufficient that at least a part of the flat surface 114f is formed on the flat portion 114 provided on the lens layer 11, and it is not limited to the method where the entire surface is the flat surface 114f.

[0123] If a reflective screen 10 is produced using the lens layer 11 separated from the lens sheet 11a and bonded to the support plate 30 via the bonding layer 40, then more resin is filled between the concave portion 114g and the stepped portion 114h formed in the flat portion 114 and the support plate 30 (refer to Figure 2 , Figure 9 ) than in the portion of the flat surface 114f. Therefore, the close adhesion between the reflective screen 10 and the support plate 30 can be further improved.

[0124] In addition, if the mold plate 52 of this method is pasted on the surface of the roller body 51a (refer to Figure 5 ), the movement of the resin 53 filled in the gaps between the ends is blocked by the protrusion 52c and the bank 52d, so it is difficult to flow into the concave-convex side for forming the unit lens 111. Therefore, it is possible to more effectively suppress the following defects: a part of the mold plate 52 is peeled off from the roller 51 during molding, or a part of the concave-convex of the unit lens 111 is filled with resin and molding defects occur, etc.

[0125] In the above-described embodiment, an example is shown in which the flat portions 114 are formed at all four edges of the lens layer 11, but it is not limited thereto. The flat portions 114 of the lens layer 11 may also be formed at any one of the edges in the left-right direction (X direction) and the up-down direction (Y direction) of the screen. Additionally, the flat portions 114 may be formed at the edges in either the left-right direction and / or the up-down direction on either side (+X direction or -X direction, +Y direction or -Y direction). Moreover, regarding the positions of the edges where the flat portions 114 are formed, the above combinations are also possible.

[0126] In the thickness direction of the lens layer 11, h1min - h2 (refer to Figure 2 ) that defines the position of the flat surface f of the flat portion 114 may be the same for all in one reflective screen 10, or may vary according to the positions of the edges. For example, the flat portion 114 may be inclined corresponding to the change in the lens height h0 of the unit lens 111 formed in the lens layer 11. Specifically, when the lens height h0 of the unit lens 111 gradually decreases from the upper direction (+Y direction) to the lower direction (-Y direction) of the screen, the flat surfaces f of the flat portions 114 formed at both ends in the left-right direction (X direction) of the screen may be inclined so as to decrease from the upper direction to the lower direction of the screen.

[0127] In the reflective screen 10, different forms of the bonding layer 40 may be adopted in the regions where the unit lenses 111 are formed and the regions where the flat portions 114 are formed, respectively. For example, an adhesive may be coated in the region where the unit lenses 111 are formed to form the bonding layer 40, and a double-sided tape may be pasted in a frame shape in the region where the flat portions 114 are formed to form the bonding layer 40.

[0128] The lens layer 11 of the reflective screen 10 is not limited to the shape of a circular Fresnel lens, and may also be in the following form: having a linear Fresnel lens shape in which the unit lenses 111 are arranged in the up-down direction of the screen surface, etc.

[0129] The light diffusion layer 13 is not limited to the form in which a light diffusing agent is contained in the base resin, and may also be in the form of applying a matte finish to the surface on the image source side (+Z side) of the base resin. Additionally, it may also be in the form of applying a matte finish to the surface on the image source side of the lens layer 11. In this case, the light diffusion layer 13 as a single layer can be omitted.

[0130] The bonding layer 40 is not limited to the example of coating an adhesive, bonding agent, etc. on the back side of the reflective screen 10. For example, it may also be: pasting a sheet having an adhesive, bonding agent, etc. coated on its surface on the back side of the reflective screen 10, and forming the bonding layer 40 on the back side of the reflective screen 10 by peeling off the sheet.

[0131] The screen (display area) of the reflective screen unit 1 can also be rectangular as follows: in the use state, when observed from the side of the observer O1 on the image source side (+Z side) (refer to Figure 1 ), the long side direction is the up-down direction of the screen (Y direction).

[0132] In addition, the screen of the reflective screen unit 1 can also be square as follows: when observed from the side of the observer O1 on the image source side, each side is equal in the left-right direction and the up-down direction of the screen.

[0133] Reference Numeral Explanation

[0134] 1: Reflective screen unit;

[0135] 2: Image source;

[0136] 10: Reflective screen;

[0137] 11: Lens layer;

[0138] 12: Reflective layer;

[0139] 13: Light diffusion layer;

[0140] 20: Frame;

[0141] 30: Support plate;

[0142] 40: Bonding layer;

[0143] 50: Roller plate;

[0144] 52: Engraved plate;

[0145] 100: Image display device;

[0146] 111: Unit lens;

[0147] 112: Lens surface;

[0148] 113: Non-lens surface;

[0149] 114: Flat part;

[0150] 114f: Flat surface;

[0151] 114g: Concave part;

[0152] 114h: Step part.

Claims

1. A reflective screen that reflects image light projected from an image source and displays it in an observable manner, wherein, the reflective screen includes: a lens layer having a Fresnel lens shape in which a plurality of unit lenses are arranged; and a reflective layer that reflects light, which is formed on the unit lenses of the lens layer, the unit lenses protrude from the image source side toward the back side in the thickness direction of the lens layer, the lens layer is formed with a flat portion at at least one edge where a part of the back side becomes a flat surface, in the thickness direction of the lens layer, the minimum height h1min among the heights h1 and the height h2 satisfy h1min - h2 > 0, where the height h1 is the distance from the position closest to the image source side of the lens layer to the position closest to the back side of the unit lens, and the height h2 is the distance from the flat surface of the flat portion to the position closest to the back side of the unit lens.

2. The reflective screen according to claim 1, wherein, in the lens layer where the flat surface of the flat portion is formed between near the position closest to the back side of the unit lens and near the position closest to the image source side of the unit lens, h1min - h2 = 10 μm to 90 μm.

3. The reflective screen according to claim 1, wherein, in the lens layer where the flat surface of the flat portion is formed between near the position closest to the image source side of the unit lens and near the position closest to the image source side of the lens layer, h1min - h2 = 20 μm to 60 μm.

4. The reflective screen according to claim 1, wherein, the lens layer is a horizontally long quadrilateral when viewed from the image source side, the flat portion is formed at at least one edge on the long side of the lens layer.

5. The reflective screen according to claim 4, wherein, the lens layer has: a first long side closer to the lens surface than the non-lens surface in the arrangement direction of the unit lenses; and a second long side closer to the non-lens surface than the lens surface in the arrangement direction of the unit lenses, the flat portion is formed at one edge of the first long side.

6. The reflective screen according to claim 4, wherein, the flat portion is formed at the edge of the lens layer on the side far from the optical center of the Fresnel lens shape.

7. The reflective screen according to claim 1, wherein, the lens layer is a horizontally long quadrilateral when viewed from the image source side, the flat portion is formed at at least one edge on the long side and at least one edge on the short side of the lens layer.

8. A reflective screen unit, wherein, the reflective screen unit includes: the reflective screen according to any one of claims 1 to 7; a frame provided on the image source side of the reflective screen and covering at least the flat portion; a support plate provided on the back side of the reflective screen to maintain the flatness of the screen of the reflective screen; and a bonding layer provided between the reflective screen and the support plate to bond the reflective screen and the support plate together.

9. An image display device, wherein, the image display device includes: The reflective screen unit according to claim 8; and An image source that projects image light toward the reflective screen unit.

Images