Reflection screen, reflection screen unit, and image display device

Abstract

The present invention provides a reflective screen with improved close adhesion 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) in the shape of a Fresnel lens having a plurality of unit lenses (111) arranged therein; and a reflective layer (12) formed on the unit lenses (111) of the lens layer (11) and reflecting light. 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) having a flat surface (f) on the back side at at least one edge. In the thickness direction of the lens layer (11), the maximum lens height (h1max) among the lens heights (h1), which is the distance from the position closest to the image source side of the unit lens (111) to the position closest to the back side, and the flat surface height (h2), which is the distance from the position closest to the image source side of the unit lens (111) to the flat surface (f) of the flat portion (114), satisfy h2≥h1max.

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 that has a reflective layer 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 Patent Application Laid-Open 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 a lens layer having a substantially triangular cross-sectional shape is exposed on the back side of the reflective screen, irregularities are formed on the surface of the joining layer laminated on the back side of the reflective screen. Therefore, due to the irregularities on the surface of the joining layer, the reflective screen and the support plate cannot be sufficiently closely attached, and sometimes the two are peeled off.

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

[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 are 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 (10) that reflects image light projected from an image source (2) and displays it in an observable manner. The reflective screen includes: a lens layer (11) in the shape of a Fresnel lens, which is arranged with a plurality of unit lenses (111); 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) having a flat surface (f) on the back side at least at one edge. In the thickness direction of the lens layer, the maximum lens height h1max of the lens height h1, which is the distance from the position (v) closest to the image source side to the position (t) closest to the back side of the unit lens, and the flat surface height h2, which is the distance from the position (v) closest to the image source side of the unit lens to the flat surface of the flat portion, satisfy h2≥h1max.

[0012] The second invention relates to a reflective screen. In the reflective screen (10) of the first invention, the flat surface height h2 varies according to the position of the flat portion (114), and the minimum flat surface height h2min of the flat surface height h2 satisfies h2min≥h1max.

[0013] The third invention relates to a reflective screen. In the reflective screen of the first or second invention, the lens layer is a horizontally long quadrilateral when viewed from the image source side, and the flat portion is formed at least at one edge on the long side of the lens layer.

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

[0015] The fifth invention relates to a reflective screen. In the reflective screen (10) of any one of the first to fourth inventions, the unit lens (111) has: a lens surface (112) for incident image light; and a non-lens surface (113) adjacent to the lens surface in the arrangement direction of the unit lenses. The flat portion (114) is provided at least at the edge of the lens layer (11) that is closer to the lens surface than the non-lens surface in the arrangement direction of the unit lenses.

[0016] The sixth invention relates to a reflective screen unit (1), which includes: a reflective screen according to any one of the first to fifth inventions; a frame-shaped border (20) provided on the image source side of the reflective screen to cover 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.

[0017] The seventh invention relates to an image display device (100), which includes the reflective screen unit of the sixth invention and an image source (2) that projects image light toward the reflective screen.

[0018] Advantages of the Invention

[0019] According to the present invention, the close adhesion between the support plate and the reflective screen can be improved, so that the peeling between the two can be suppressed. Description of the Drawings

[0020] Figure 1 It is a diagram showing the image display device 100 of the embodiment.

[0021] Figure 2 It is a diagram for explaining the layer structure of the reflective screen unit 1 and the reflective screen 10 of the embodiment.

[0022] Figure 3 It is a diagram of observing the reflective screen 10 from the back side (-Z side).

[0023] Figure 4 It is an exploded perspective view of the reflective screen unit 1.

[0024] Figure 5 It is a diagram showing an example of a molding die 200 for molding the lens layer 11. Detailed Embodiments

[0025] Hereinafter, embodiments of the present invention will be described with reference to the drawings and the like. In addition, including Figure 1 among them, the drawings shown below are schematically represented, and for easy understanding, the sizes and shapes of each part are appropriately exaggerated.

[0026] In this specification, regarding terms for determining shapes and geometric conditions (such as terms like parallel and orthogonal), in addition to the strict meaning, it also includes a state that has the same optical function and has an error to the extent that it can be regarded as parallel or orthogonal.

[0027] In this specification, the numerical values such as the dimensions of each component described and the material names and the like are examples of the embodiments, and are not limited thereto, and can be appropriately selected and used.

[0028] In this specification, the screen surface refers to the surface that is the planar direction of the screen when observed as a whole screen, and is parallel to the screen image (display surface).

[0029] Figure 1 FIG. shows the image display device 100 of the present embodiment. Figure 1 (A) of FIG. is a perspective view of the image display device 100. Figure 1 FIG. (B) is a view of the image display device 100 observed from the side.

[0030] 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., reflects the image light L projected from the image source 2, and displays an image on the image source side screen (display surface). The details of the reflective screen unit 1 will be described later.

[0031] In each of the following figures including Figure 1 etc., an orthogonal coordinate system of XYZ is appropriately shown. In this coordinate system, the left - right direction (horizontal direction) of the screen of the reflective screen unit 1 (reflective 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 reflective screen unit 1 is set as the Z - direction. The screen of the reflective screen unit 1 is parallel to the XY plane, and the thickness direction (Z - direction) of the reflective screen unit 1 is orthogonal to the screen of the reflective screen unit 1.

[0032] In addition, when observed from an observer O1 in the front direction on the image source side of the reflective 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.

[0033] 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 respectively correspond to the up - down direction (vertical direction), the left - right direction (horizontal direction), and the thickness direction (depth direction) of the reflective screen unit 1 in the usage state. These directions are respectively parallel to the Y - direction, the X - direction, and the Z - direction. In addition, in this specification, “~direction” is also referred to as “~side”.

[0034] The image source 2 is an image projection device (projector) that projects the image light L onto the reflective screen unit 1. The image source 2 of the present embodiment is a short - focus type projector.

[0035] In the usage state of the image display device 100, when observing the screen (display area) of the reflective screen unit 1 from the front direction (the normal direction of the screen surface) on the image source side (+Z side), the image source 2 is disposed at the center in the left - right direction of the screen of the reflective screen unit 1 and is located on the lower side (-Y side) in the vertical direction than the screen of the reflective screen unit 1.

[0036] The image source 2 can obliquely project image light L from a position where the distance from the surface on the image source side (+Z side) of the reflective screen unit 1 in the depth direction (Z direction) is much closer than that of a conventional general - purpose projector. Therefore, for the image source 2, compared with a conventional general - purpose projector, the projection distance to the reflective screen unit 1 is shorter, the incident angle of the projected image light on the reflective screen unit 1 is larger, and the variation amount of the incident angle (the variation amount from the minimum value to the maximum value) is also larger.

[0037] The reflective 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.

[0038] In the usage state, when observed from the observer O1 side on the image source side (+Z side), the screen (display area) of the reflective 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 reflective screen unit 1 (reflective screen 10) in the present embodiment is a horizontally long quadrilateral when observed from the image source side.

[0039] Figure 2 It is a diagram for explaining the layer structure of the reflective screen unit 1 and the reflective screen 10 of the present embodiment. Figure 2 A part of the cross - section (Y - Z plane) that magnifies the lower side (-Y side) region of the reflective screen unit 1, that is, a cross - section passing through the geometric center A of the reflective screen 10, parallel to the arrangement direction of the unit lenses 111 (described later), and parallel to the thickness direction (Z direction) is shown.

[0040] Figure 3 It is a diagram for observing the reflective screen 10 from the back side (-Z side). In addition, in Figure 3 the illustration of the reflective layer 12 provided on the back side of the lens layer 11 is omitted.

[0041] Figure 4 It is an exploded perspective view of the reflective screen unit 1. In Figure 4 the appearance, shape, etc. of each part are simplified.

[0042] As shown in Figure 2 and Figure 4 the reflective screen unit 1 sequentially includes a frame 20, a reflective screen 10, a bonding layer 40, and a support plate 30 from the image source side (+Z side).

[0043] <Reflective screen 10>

[0044] The reflective screen 10 is a sheet member (laminate) that reflects the image light projected from the image source 2 and enables it to be visibly displayed. The reflective screen 10 of the present embodiment includes a lens layer 11, a reflective layer 12, and a light diffusion layer 13. In addition, as the reflective screen 10, it is sufficient to include at least the lens layer 11 and the reflective layer 12.

[0045] <Lens layer 11>

[0046] 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 shown, 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 reflective screen 10 and on the lower side (-Y side) of the reflective screen 10. In the present embodiment, as Figure 3 shown, the optical center C is set on the line ( Figure 3 the single-dashed line in Figure 3 ) that passes through the geometric center A of the reflective screen 10 and is parallel to the vertical direction (Y direction) of the screen, and the circular Fresnel lens shape is formed to be line-symmetric with respect to this line (

[0047] the single-dashed line in Figure 2 ).

[0048] 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 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 that faces (adjacent to) the lens surface 112 in the arrangement direction of the unit lenses 111. In the usage state of the reflective screen unit 1, the lens surface 112 of the unit lens 111 is located on the upper side (+Y side) in the vertical direction with respect to the non-lens surface 113 with the vertex t in between. The vertex t represents the position that becomes the most back side (-Z side) of the unit lens 111.

[0049] In addition, in Figure 2 , the arrangement pitch P, angles α, and β of the unit lenses 111 are shown in a fixed manner in the arrangement direction of the unit lenses 111. However, the unit lenses 111 are 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 that is the Fresnel center (refer to Figure 3 ). That is, the lens height h1 of the unit lenses 111 gradually increases as it moves away from the point C that is the Fresnel center in the arrangement direction of the unit lenses 111.

[0050] 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.

[0051] As Figure 3 shown, at the edges in the left - right direction (X - direction) and the up - down direction (Y - direction) of the screen of the lens layer 11 (reflection screen 10), flat portions 114 with a flat surface f on the back side are formed. The flat portions 114 are provided so as to surround the arranged unit lenses 111 and are formed of the same material as the unit lenses 111. That is, in the reflection screen 10, the unit lenses 111 and the flat portions 114 are formed integrally.

[0052] As Figure 2 shown, the flat portion 114 is formed such that in the thickness direction (Z - direction) of the lens layer 11, when the distance from the point v closest to the image source side of the unit lens 111 to the flat surface f is defined as the flat surface height h2, the relationship h2≥h1 (lens height) is satisfied.

[0053] Here, the lens height h1 is preferably 0.1 mm or less, for example. In addition, the width w of the flat portion 114 (refer to Figure 2 ) is, for example, about 0.5 - 1.0% of the longitudinal and / or lateral dimension of the screen of the reflection screen 10.

[0054] In addition, the above dimensions and ranges are merely examples and are not limited thereto.

[0055] Here, as configured as described above, the angle α of the unit lens 111 gradually increases as it moves away from the point C that is the Fresnel center. Therefore, the lens height h1 also gradually increases accordingly. The flat surface height h2 of the flat portion 114 is formed such that it satisfies the relationship h2≥h1 with respect to the maximum lens height h1max among the lens heights h1 of the respective unit lenses 111, that is, it satisfies the relationship h2≥h1max.

[0056] In addition, in the present embodiment, at the edges in each direction of the screen, the flat surface height h2 of the flat portion 114 is set to the same value (fixed value). However, as will be described later, the flat surface height h2 can also be different values in each direction of the screen. In this case, at the minimum flat surface height h2min among the flat surface heights h2, it is formed to satisfy the relationship h2≥h1, that is, it satisfies the relationship h2min≥h1max.

[0057] The function and role of the flat portion 114 will be described later.

[0058] Figure 5 FIG. is an example of a molding die for the molded lens layer 11.

[0059] The lens layer 11 is formed of an ultraviolet curable resin such as a highly light-transmissive polyurethane acrylate, polyester acrylate, epoxy acrylate, polyether acrylate, polythiol, or polydiene acrylate. The lens layer 11 is manufactured by an ultraviolet molding method as follows: pressing the light diffusion layer 13 (described later) against a molding die 200 that is filled with an ultraviolet curable resin and shaped into a circular Fresnel lens shape, irradiating ultraviolet rays to cure it, and then demolding from the molding die.

[0060] Thereby, in the lens layer 11, 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. Here, as Figure 5 shown, the molding die 200 used in the molding of the lens layer 11 is formed with concavo-convex shapes 201 corresponding to the shapes of the unit lenses 111. In addition, the molding die 200 forms flat surfaces 202 where no concavo-convex shapes are formed at the outer peripheral edge surrounding the concavo-convex shapes 201, that is, at positions corresponding to the edges in the left-right direction and up-down direction of the screen of the lens layer 11, so that flat portions 114 can be formed at the edges in the left-right direction and up-down direction of the screen of the lens layer 11.

[0061] In addition, the lens layer 11 can also be formed of an ionizing radiation-curable resin such as an electron beam-curable resin. In addition, the lens layer 11 can be formed of a thermoplastic resin, and can also be manufactured by a stamping method or the like according to the Fresnel lens shape of the lens layer 11. 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 together.

[0062] <Reflective layer 12>

[0063] 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.

[0064] 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. 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. For the reflective layer 12, as long as a thickness sufficient to reflect light can be ensured, the thickness can also be appropriately set according to the material or the like.

[0065] <Light diffusion layer 13>

[0066] The light diffusion layer 13 is a layer having a light-transmissive resin as a base material 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

[0067] As the diffusing agent contained in the light diffusing layer 13, for example, acrylic resins, epoxy resins, resin particles such as silicone-based resins, inorganic particles, etc. 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 diffusing layer 13 also depends on the screen size of the reflection screen 10, and is preferably about 100 to 2000 μm, for example. In addition, although not shown, a coloring layer, a surface layer, etc. may be provided on the image source side (+Z side) of the light diffusing layer 13.

[0068] <Frame 20>

[0069] 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 region of the reflection screen 10 corresponding to the flat portion 114 (the outer region of the dotted line in the figure). The frame 20 is made of, for example, plastic, metal, wood, etc. In addition, the frame 20 may also be in the shape of a box frame that covers the entire side surface of the reflection screen unit 1.

[0070] <Support plate 30>

[0071] 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).

[0072] 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, a metal plate having a honeycomb structure with a core material made of a thin plate such as aluminum (for example, a honeycomb plate) can also be used. From the viewpoint of suppressing the entry of external light and the reduction of contrast caused by external light, etc., the support plate 30 is preferably a component that does not have light transmissivity.

[0073] <Joining layer 40>

[0074] The joining layer 40 is a layer having the function of joining the reflection screen 10 and the support plate 30 into one body. 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 heat curable resin, etc. can be used. The joining layer 40 is preferably a black or low light transmissivity joining layer.

[0075] In addition, in Figure 4In [the figure], the bonding layer 40 is shown as a sheet, but adhesives such as adhesives that form the bonding layer 40 are coated (applied) on the back side (-Z side) of the reflective screen 10. Therefore, if an adhesive or the like that forms the bonding layer 40 is coated on the back side (-Z side) of the reflective screen 10, then as Figure 2 shown, irregularities caused by the irregular shape of the unit lens 111 are formed on the back side (-Z side) of the bonding layer 40.

[0076] As Figure 3 shown, in the reflective screen 10 of the present embodiment, flat portions 114 are formed at the edges in the left - right direction (X - direction) and the up - down direction (Y - direction) of the screen on the back side of the lens layer 11 (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 surface of the bonding layer 40 provided on the back side (-Z side) of the reflective screen 10, at the flat portions 114 formed at each edge, the reflective screen 10 and the support plate 30 can be more sufficiently and closely attached to the bonding layer 40. Thus, according to the reflective screen 10 of the present embodiment, the close - attachment property with the support plate 30 can be improved by the flat surface f of the flat portion 114, and therefore peeling between the two after attachment can be suppressed.

[0077] In addition, on the back side of the lens layer 11 (front side in the figure), flat portions 114 are formed at the edges in the left - right direction (X - direction) and the up - down direction (Y - direction) of the screen, whereby during the manufacturing process of the lens layer 11, the molded lens layer 11 can be easily peeled off from the molding die.

[0078] Assume that unit lenses 111 are also formed in the area of the flat portion 114 (the flat portion 114 is not provided on the lens layer 11), then it is difficult to demold the lens layer 11 (sheet) from the molding die. In this case, if the lens layer 11 is forcibly peeled off from the molding die, an excessive force is applied to the lens layer 11 during demolding, so there is a possibility that the lens layer 11 whitens; or cracks are generated on the unit lens 111. On the other hand, in order to make the lens layer 11 easily demold from the molding die, a mold release agent is sometimes used. However, when the mold release agent is coated on the molding die, the deterioration of the molding die may be promoted due to the components of the mold release agent. In addition, when the mold release agent is added to the resin material that becomes the lens layer 11, the close - attachment property with the bonding layer 40 may be reduced due to exudation.

[0079] On the contrary, as described above, since the reflective screen 10 of the present embodiment forms flat portions 114 (flat surfaces f) at the respective edges of the lens layer 11, it is easy to demold from the molding die. If it is easy to demold from the molding die, an excessive force will not be applied to the lens layer 11 during demolding, so that it is possible to suppress the whitening of the lens layer 11 or the occurrence of cracks on the unit lens 111. In addition, since a mold release agent is not used or the amount used can be significantly reduced, it is possible to suppress the deterioration of the molding die or the occurrence of a decrease in the close adhesion to the bonding layer 40 due to bleeding.

[0080] Here, the flat portion 114 (flat surface f) is preferably formed at the edge of the lens layer 11, particularly at the edge on the lens surface 112 side rather than the non-lens surface 113 in the arrangement direction of the unit lens 111. That is, in Figure 2 and Figure 3 In the example shown, as described above, in one unit lens 111, the lens surface 112 is located above the non-lens surface 113 (+Y side) with the vertex t in between. Therefore, the edge on the lens surface 112 side rather than the non-lens surface 113 in the arrangement direction of the unit lens 111 becomes the upper edge (+Y side) in the vertical direction (Y direction) of the screen. Therefore, the flat portion 114 is preferably formed at least at the upper edge (+Y side).

[0081] Thus, during the manufacturing process of the lens layer 11, when demolding the molded lens layer 11 from the molding die, by using the flat portion 114 at the upper edge (+Y side) as the peeling start portion, the lens layer 11 can be peeled off from the molding die more easily and smoothly.

[0082] Assuming that the flat portion 114 provided at an edge other than the upper edge (+Y side) is used as the peeling start portion, during the peeling process, there is a possibility that the top t of the unit lens 111 formed on the lens layer 11 comes into contact with the molding die, resulting in damage to the lens layer 11 and the remaining demolding marks or breakage.

[0083] 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 described 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. Furthermore, the above-described embodiments and the following deformation modes can be appropriately combined for use, but detailed descriptions are omitted.

[0084] (Deformation Modes)

[0085] 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 reflection screen 10 may also be formed at any one of the edges in the left-right direction (X direction) or the up-down direction (Y direction) of the screen. In addition, the flat portions 114 may be formed at the edges in either the left-right direction and / or the up-down direction of either one of the sides (+X direction or -X direction, +Y direction or -Y direction). Moreover, the positions of the edges where the flat portions 114 are formed may also be the above combinations.

[0086] The flat surface height h2 of the flat portion 114 (refer to Figure 2 ) may be the same (fixed) for all of the reflection screen 10, or may vary depending on the position of the edge. For example, the flat portion 114 may be inclined corresponding to a change in the lens height h1 of the unit lens 111. Specifically, when the lens height h1 of the unit lens 111 gradually decreases from the upper direction (+Y direction) to the lower direction (-Y direction) of the screen, the flat surface height h2 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.

[0087] In the reflection screen 10, different forms of bonding layers 40 may be bonded to the regions where the unit lenses 111 are formed and the regions where the flat portions 114 are formed, respectively. For example, an adhesive or the like may be applied to 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 to the region where the flat portions 114 are formed to form the bonding layer 40.

[0088] The lens layer 11 of the reflection screen 10 is not limited to a circular Fresnel lens shape, and may also be in a form of a linear Fresnel lens shape in which the unit lenses 111 are arranged in the up-down direction or the like along the screen surface.

[0089] The light diffusion layer 13 is not limited to a form in which a light diffusing agent is contained in the resin that is the base material, and may also be a form in which a surface on the image source side (+Z side) of the resin that is the base material is subjected to an anti-glare process. In addition, it may also be a method in which the surface on the image source side of the lens layer 11 is subjected to an anti-glare process. In this case, the light diffusion layer 13 as a single layer can be omitted.

[0090] The screen (display area) of the reflection screen unit 1 may also be in a rectangular shape such that, in the use state, when viewed from the observer O1 side on the image source side (+Z side) (refer to Figure 1 ), the long side direction is the up-down direction (Y direction) of the screen.

[0091] In addition, the screen of the reflection screen unit 1 can also be a square as follows: when observed from the side of the observer O1 on the image source side, each side is equal in the horizontal and vertical directions of the screen.

[0092] Reference Numeral Explanation

[0093] 1: Reflection screen unit;

[0094] 2: Image source;

[0095] 10: Reflection screen;

[0096] 11: Lens layer;

[0097] 12: Reflection layer;

[0098] 13: Light diffusion layer;

[0099] 20: Frame;

[0100] 30: Support plate;

[0101] 40: Bonding layer;

[0102] 100: Image display device;

[0103] 111: Unit lens;

[0104] 112: Lens surface;

[0105] 113: Non-lens surface;

[0106] 114: Flat 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 in the shape of a Fresnel lens, which arranges a plurality of unit lenses; 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 having a flat surface on the back side at at least one edge, in the thickness direction of the lens layer, the maximum lens height h1max among the lens heights h1 and the flat surface height h2 satisfy h2≥h1max, where the lens height h1 is the distance from the position closest to the image source side of the unit lens to the position closest to the back side, and the flat surface height h2 is the distance from the position closest to the image source side of the unit lens to the flat surface of the flat portion.

2. The reflective screen according to claim 1, wherein, the flat surface height h2 varies according to the position of the flat portion, the minimum flat surface height h2min among the flat surface heights h2 satisfies h2min≥h1max.

3. The reflective screen according to claim 1 or 2, 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.

4. The reflective screen according to claim 1 or 2, 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.

5. The reflective screen according to any one of claims 1 to 4, wherein, the unit lens has: a lens surface for image light to enter; and a non-lens surface, which is adjacent to the lens surface in the arrangement direction of the unit lens, the flat portion is provided at least at the edge of the lens layer that is closer to the lens surface than the non-lens surface in the arrangement direction of the unit lens.

6. A reflective screen unit, wherein, the reflective screen unit includes: the reflective screen according to any one of claims 1 to 5; a window frame-shaped border, which is provided on the image source side of the reflective screen and covers the flat portion; a support plate, which is provided on the back side of the reflective screen and maintains the flatness of the screen of the reflective screen; and a bonding layer, which is provided between the reflective screen and the support plate and bonds the reflective screen and the support plate together.

7. An image display device, wherein, the image display device includes: the reflective screen unit according to claim 6; and an image source, which projects image light toward the reflective screen.

Images