Display unit and display device

Abstract

To provide a display unit capable of forming not only a flat display screen but also a curved display screen with ease while suppressing the degradation of contrast, and a display device having such a display unit.SOLUTION: In a display unit 700, a circuit substrate 200 has flexibility. Light-emitting elements 100 are arranged on a surface 200a of the circuit substrate 200. A waterproof layer 300 covers the surface 200a of the circuit substrate 200 and each of the light-emitting elements 100. A mask layer 400 covers the waterproof layer 300. In the mask layer 400, an opening 410 through which the emitted light from the light-emitting elements 100 passes is formed for each light-emitting element 100. Not only the waterproof layer 300 but also the mask layer 400 have flexibility and elasticity that allow them to bend together with the circuit substrate 200 while maintaining surface adhesion to an underlying surface when the circuit substrate 200 is bent.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a display unit and a display device. [Background technology]

[0002] There is known a display device that includes a plurality of display units, as disclosed in Patent Document 1. The plurality of display units are arranged in a matrix to form one display screen as a whole.

[0003] Each display unit includes a plurality of light-emitting elements, a circuit board on whose surface the plurality of light-emitting elements are arranged, a waterproof layer covering the surface of the circuit board and each of the light-emitting elements, and a mask plate arranged opposite the waterproof layer.

[0004] The mask plate has an opening formed at a location facing each light emitting element, through which the visible light emitted from the light emitting element passes. The mask plate having such a shape is manufactured by a thermosetting resin or by injection molding of a thermosetting resin.

[0005] The mask plate absorbs external light that is about to enter the circuit board from the outside, thereby suppressing reflection of the external light and thereby suppressing a decrease in contrast, which represents the difference between light and dark in the image displayed on the display screen. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2018 / 138892 Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present disclosure is to provide a display unit that is capable of constructing not only a flat display screen but also a curved display screen easily while suppressing a decrease in contrast, and a display device equipped with the display unit. [Means for solving the problem]

[0008] The display unit according to the present disclosure comprises: A flexible circuit board; A plurality of light emitting elements arranged on a surface of the circuit board, each of which emits visible light; a waterproof layer that is transparent to the radiated light, which is the visible light radiated from the light-emitting element, and is waterproof, and covers the surface of the circuit board and each of the light-emitting elements; a mask layer that has an absorbency for external light, which is visible light that is about to be incident on the circuit board from the outside, and the radiated light, covers the waterproof layer, and has an opening formed for each of the light-emitting elements, through which the radiated light emitted by the light-emitting elements passes; Equipped with the waterproof layer is in planar contact with the surface of the circuit board, which is a base surface for the waterproof layer, and the mask layer is in planar contact with the waterproof layer, which is a base surface for the mask layer; Not only the waterproof layer but also the mask layer has flexibility and stretchability that allows them to bend together with the circuit board when the circuit board is bent while maintaining planar adhesion to the base surface. Effect of the Invention

[0009] According to the above configuration, not only the waterproof layer but also the mask layer has the flexibility and stretchability to bend together with the circuit board, so that not only can a flat display screen be constructed, but a curved display screen can also be easily constructed while suppressing reduction in contrast. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a front view of a display screen of a display device according to a first embodiment; [Diagram 2] FIG. 1 is a perspective view showing a configuration of a display unit according to a first embodiment; [Diagram 3] 1 is a cross-sectional view of a light-emitting device according to a first embodiment. [Figure 4] FIG. 4 is a local cross-sectional view of the display unit according to the first embodiment taken along line IV-IV in FIG. 2 . [Diagram 5] FIG. 1 is a conceptual diagram for explaining a method for forming an eaves portion according to the first embodiment. [Figure 6] 1 is a flowchart of a display unit manufacturing method according to the first embodiment. [Figure 7] 1 is a plan view of a display unit according to a second embodiment, as viewed in the Y-axis direction; [Figure 8] 11 is a plan view of a display unit according to a third embodiment, as viewed in the Y-axis direction; [Figure 9] 11 is a plan view of a display unit according to a fourth embodiment, as viewed in the Y-axis direction; [Figure 10] 11 is a plan view of a display unit according to a fifth embodiment, as viewed in the Y-axis direction; [Figure 11] 13 is a plan view of a display unit according to a sixth embodiment, as viewed in the Y-axis direction; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, a display device according to an embodiment will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals.

[0012] [Embodiment 1] As shown in FIG. 1, a display device 800 according to this embodiment is configured by combining a plurality of display units 700, each of which displays an image.

[0013] The multiple display units 700 are arranged vertically and horizontally in a matrix. As a result, the multiple display units 700 as a whole form one display screen 810. In other words, each display unit 700 forms a part of the display screen 810.

[0014] To facilitate the following explanation, a right-handed UVW Cartesian coordinate system is defined for the display device 800, in which the left-right direction when viewing the display screen 810 from the front is the U-axis direction, the up-down direction is the V-axis direction, and the direction perpendicular to the U-axis and V-axis directions is the W-axis direction. The direction from left to right is the positive direction of the U-axis.

[0015] In this embodiment, the U axis is parallel to the rows of the matrix formed by the multiple display units 700, and the V axis is parallel to the columns of the matrix. The V axis typically extends vertically at a site where the display device 800 is installed.

[0016] 1 is a front view of display screen 810 as viewed in the W-axis direction. Display screen 810 may have a curved shape as viewed in the V-axis direction, or may have a flat shape extending straight in the U-axis direction. When display screen 810 has a curved shape, the W-axis is typically parallel to a normal to the display screen 810 at a central local area in a UV virtual plane.

[0017] The configuration of each display unit 700 will be specifically described below.

[0018] As shown in Fig. 2, an XYZ orthogonal coordinate system is defined for each display unit 700. The X-axis is parallel to the U-axis direction on the display screen 810 in Fig. 1 configured by the display unit 700. The Y-axis is parallel to the V-axis direction on the display screen 810 in Fig. 1 configured by the display unit 700. The Z-axis is perpendicular to the X-axis and Y-axis.

[0019] The XYZ Cartesian coordinate system is a right-handed system like the UVW Cartesian coordinate system. The direction from the display screen 810 in FIG. 1 toward the front of the display screen 810, that is, the positive direction of the W axis, is defined as the positive direction of the Z axis.

[0020] The display unit 700 includes a plurality of light-emitting elements 100 each emitting visible light, and a holding structure 600 that holds the plurality of light-emitting elements 100. Each light-emitting element 100 constitutes a pixel on the display screen 810 of FIG.

[0021] 3, each light emitting element 100 has a red LED (Light Emitting Diode) 111R that emits red light, a green LED 111G that emits green light, and a blue LED 111B that emits blue light. Each of the red LED 111R, the green LED 111G, and the blue LED 111B is a radiation source of visible light.

[0022] The light emitting element 100 also includes a package member 120 that holds the red LED 111R, the green LED 111G, and the blue LED 111B, and a lead frame 130 that supplies the red LED 111R, the green LED 111G, and the blue LED 111B with power required for light emission.

[0023] The package member 120 has a bottomed recess having a depth in the thickness direction of the holding structure 600 shown in Fig. 2. The red LED 111R, the green LED 111G, and the blue LED 111B are arranged on the bottom surface of the recess.

[0024] The recess is filled with a transparent sealing member 140. The transparent sealing member 140 covers the red LED 111R, the green LED 111G, and the blue LED 111B. The transparent sealing member 140 is made of a resin that transmits visible light.

[0025] 4, the holding structure 600 that holds the light emitting element 100 has a circuit board 200. The circuit board 200 has a front surface 200a on which the light emitting element 100 is mounted, a back surface 200b opposite to the front surface 200a in the thickness direction of the circuit board 200, and a side surface 200c that connects the back surface 200b and the front surface 200a.

[0026] The plurality of light-emitting elements 100 are arranged on the surface 200a of the circuit board 200. Specifically, the plurality of light-emitting elements 100 are distributed in a matrix on the surface 200a of the circuit board 200. An electrode pad (not shown) is formed on the surface 200a of the circuit board 200 for each light-emitting element 100, and the light-emitting elements 100 are electrically and mechanically connected to the electrode pad.

[0027] Each of the red LED 111R, the green LED 111G, and the blue LED 111B shown in FIG.

[0028] Returning to Fig. 4, the description will continue. Meanwhile, a control circuit 210 and metal wiring (not shown) are provided on the rear surface 200b of the circuit board 200. The metal wiring and the control circuit 210 are electrically connected to the electrode pads through metal plating formed in via holes extending in the thickness direction of the circuit board 200.

[0029] The control circuit 210 electrically connected to the light emitting element 100 in this manner controls the intensity ratio between the three primary color light components emitted by the red LED 111R, the green LED 111G, and the blue LED 111B shown in Fig. 3. This realizes the display of an image on the display screen 810 shown in Fig. 1. The control circuit 210 is composed of a rectangular integrated circuit element.

[0030] The holding structure 600 also has a waterproof layer 300 that covers at least the front surface 200a of the circuit board 200 and each of the light-emitting elements 100. The waterproof layer 300 according to this embodiment covers not only the front surface 200a of the circuit board 200 and the light-emitting elements 100, but also the side surface 200c of the circuit board 200, the rear surface 200b of the circuit board 200, and the control circuit 210.

[0031] The waterproof layer 300 is made of a waterproof resin sheet. Therefore, even if the display unit 700 is installed outdoors, the waterproof layer 300 plays a role in protecting the circuit board 200 and the light emitting element 100 from rainwater, condensation water, moisture in the air, and the like.

[0032] In addition, the JIS (Japanese Industrial Standards) distinguishes between films that are less than 250 μm thick and sheets that are 250 μm thick or more, but in this specification, the concept of sheets also includes the film defined by the JIS.

[0033] The waterproof layer 300 is in planar contact with the front surface 200a of the circuit board 200, which is the base surface for the waterproof layer 300. The waterproof layer 300 according to this embodiment is also in planar contact with the back surface 200b and side surface 200c of the circuit board 200. This prevents sand, dust, moisture, and the like from entering between the waterproof layer 300 and the front surface 200a, back surface 200b, and side surface 200c of the circuit board 200.

[0034] However, gaps may exist between the waterproof layer 300 and the side surface 200c of the circuit board 200, between the waterproof layer 300 and the periphery of the light emitting element 100, between the waterproof layer 300 and the periphery of the control circuit 210, and the like.

[0035] The waterproof layer 300 is transparent to visible light (hereinafter referred to as radiated light) emitted from the light emitting element 100. Therefore, the radiated light emitted from the light emitting element 100 passes through the waterproof layer 300 without being blocked by the waterproof layer 300.

[0036] The holding structure 600 also has a mask layer 400 covering the waterproof layer 300. The mask layer 400 is in planar contact with the waterproof layer 300, which is the base surface for the mask layer 400. This prevents sand, dust, moisture, etc. from entering between the mask layer 400 and the waterproof layer 300.

[0037] The mask layer 400 is formed at least in a region facing the front surface 200a of the circuit board 200. Specifically, the mask layer 400 according to this embodiment extends not only to the region facing the front surface 200a of the circuit board 200, but also to a region facing the side surface 200c of the circuit board 200 and a region facing the peripheral portion of the back surface 200b of the circuit board 200.

[0038] In this manner, the mask layer 400 formed in the region facing the front surface 200a of the circuit board 200 wraps around to the region facing the back surface 200b of the circuit board 200. Therefore, the mask layer 400 is less likely to fall off the circuit board 200, compared to a case in which the mask layer 400 is formed only in the region facing the front surface 200a of the circuit board 200.

[0039] The mask layer 400 may extend over the entire area facing the rear surface 200 b of the circuit board 200 and the control circuit 210 .

[0040] The mask layer 400 has an absorptivity for sunlight, light from illumination, other visible light (hereinafter collectively referred to as external light), and the above-mentioned radiant light, which are incident on the circuit board 200 from the outside. Since the mask layer 400 absorbs external light, reflection of the external light by the display unit 700 is suppressed, and as a result, a decrease in the contrast of the image displayed on the display screen 810 shown in FIG. 1 is suppressed.

[0041] In order to further enhance the effect of suppressing the decrease in contrast, the light absorptance of the mask layer 400 with respect to the above-mentioned emitted light is preferably 20% or more and 100% or less. The mask layer 400 is made of a black resin sheet. The light absorptance can be increased by adding a light absorbing agent to the resin constituting the mask layer 400.

[0042] As described above, in this embodiment, the mask layer 400 extends to the region facing the side surface 200c of the circuit board 200 and the region facing the peripheral portion of the rear surface 200b of the circuit board 200. Therefore, the boundaries between the display units 700 adjacent to each other in the U-axis direction and the V-axis direction can be made less noticeable on the display screen 810 shown in FIG. 1. This contributes to improving the image quality of the display screen 810.

[0043] In addition, in the mask layer 400, an opening 410 through which the light emitted by the light emitting element 100 passes is formed for each light emitting element 100. In other words, the opening 410 is formed in a portion of the mask layer 400 overlapping with each light emitting element 100.

[0044] The mask layer 400 also has an eaves portion 420 that suppresses incidence of external light into each opening 410. The eaves portion 420 is formed for each opening 410. The eaves portion 420 rises outward from the edge of each opening 410. Specifically, the eaves portion 420 is disposed on the upper portion of each opening 410, that is, on the edge in the positive direction of the Y axis.

[0045] Canopy portion 420 prevents external light from entering opening 410, thereby contributing to improving the contrast of the image displayed on display screen 810 shown in FIG. 1 and suppressing changes in color tone of the image.

[0046] In the following, the structure formed by the circuit board 200, the waterproof layer 300 in contact with the surface of the circuit board 200, and the mask layer 400 in contact with the surface of the waterproof layer 300 will be referred to as a flexible structure 610.

[0047] The holding structure 600 has, in addition to the flexible structure 610, a holding plate 620 that holds the flexible structure 610. The holding plate 620 is made of stainless steel or another metal.

[0048] The holding plate 620 has a back plate portion 621 arranged at a position facing the back surface 200b of the circuit board 200, and a side plate portion 622 rising from an edge of the back plate portion 621. The side plate portion 622 is arranged at a position facing the side surface 200c of the circuit board 200. The area of ​​the holding plate 620 facing the front surface 200a of the circuit board 200 is left open.

[0049] The side plate portion 622 of the holding plate 620 is in close contact with the flexible structure 610. This prevents moisture, dust, and the like from entering between the flexible structure 610 and the back plate portion 621 from the outside.

[0050] Specifically, in this embodiment, the side plate portion 622 of the holding plate 620 is in close contact with the mask layer 400. However, the side plate portion 622 of the holding plate 620 may be in close contact with the waterproof layer 300 or the side surface 200c of the circuit board 200.

[0051] The greatest feature of the display unit 700 according to this embodiment is that the flexible structure 610 has flexibility as a whole. In other words, when the circuit board 200 is bent, not only the waterproof layer 300 but also the mask layer 400 has the flexibility and stretchability to bend together with the circuit board 200 while maintaining planar adhesion to the base surface.

[0052] Therefore, according to the display unit 700 of this embodiment, it is possible to configure not only a flat display screen 810 but also a curved display screen 810. The holding plate 620 plays a role in determining the shape of the flexible structure 610.

[0053] That is, when it is desired to configure a flat display screen 810, the back plate portion 621 of the holding plate 620 is also formed flat, and the holding plate 620 holds the flexible structure 610 in a flat state.

[0054] On the other hand, when it is desired to configure a curved display screen 810, the back plate portion 621 of the holding plate 620 is also formed in a curved shape, and the holding plate 620 holds the flexible structure 610 in a bent state along the back plate portion 621.

[0055] In this specification, the concept of a "curved shape" includes not only a smoothly curved curved shape but also a folded bent shape, and the concept of a "flexed state" includes not only a smoothly curved curved shape but also a folded bent shape.

[0056] As an example, a plurality of display units 700, each having a holding plate 620 holding a flexible structure 610 bent into a curved shape, are combined together. This makes it easy to configure a curved display screen 810 that fits the wall of a building, the wall of a stadium, or the like.

[0057] It is preferable that control circuit 210, which is configured with an integrated circuit element having a rectangular shape, is attached to circuit board 200 with the longitudinal direction of the rectangle aligned parallel to the Y axis. This makes it difficult for control circuit 210 to get in the way when circuit board 200 is bent locally or entirely around the Y axis.

[0058] As described above, the flexible structure 610 according to this embodiment has versatility that allows it to be commonly applied to holding plates 620 of various shapes.

[0059] Furthermore, the mask layer 400, which is not only flexible but also stretchable, can be formed thinner than a conventional mask plate that has rigidity. This contributes to making the display unit 700 lighter.

[0060] Furthermore, by using a sheet-like circuit board 200 made of polyimide resin, the weight of the circuit board 200 can be reduced compared to the rigid boards having rigidity that have been used conventionally. This also contributes to reducing the weight of the display unit 700.

[0061] A method for manufacturing the mask layer 400 will now be described with reference to FIG.

[0062] 5, first, a mask sheet MS that will form the mask layer 400 is manufactured. The thickness of the mask sheet MS is the same as the thickness of the mask layer 400. In order to impart sufficient flexibility and stretchability to the mask layer 400, the thickness of the mask sheet MS is preferably 0.1 mm or more and 3.0 mm or less.

[0063] The material of the mask sheet MS may be a resin such as polyethylene terephthalate, polycarbonate, acrylic, silicone, etc. Fibers may be present in the structure of the mask sheet MS.

[0064] The mask sheet MS may have a laminated structure in which a plurality of partial layers made of different materials are laminated. As an example, the mask sheet MS may have a laminated structure in which a partial layer made of resin and a partial layer made of fiber are laminated. The partial layer made of fiber contributes to increasing the structural strength of the mask layer 400.

[0065] In addition, the mask sheet MS may have a foamed structure in which voids are dispersed in the resin structure. The foamed structure may be present in the entire mask sheet MS, or in the above-mentioned partial layers. The foamed structure is also called a porous structure. The foamed structure contributes to further reducing the weight of the mask layer 400, improving its flexibility and stretchability, and improving its heat insulation. Giving the mask layer 400 heat insulation helps to suppress thermal deformation of the mask layer 400 itself, the circuit board 200, the holding plate 620, etc., caused by heat received from sunlight.

[0066] In addition, the surface of the mask sheet MS may be subjected to a surface treatment to scatter external light. The mask layer 400, in which the surface onto which the external light is incident, is surface-treated, thereby preventing the external light from being strongly reflected only in a specific direction. This further improves the contrast of the display screen 810.

[0067] Examples of the surface treatment include unevenness treatment to impart unevenness, and embossing treatment to impart texture. The unevenness imparted by the unevenness treatment may be periodically repeated. In this case, the period is preferably 1 μm or more and 5 mm or less.

[0068] Next, a U-shaped cut SL is formed in the mask sheet MS so as to surround the cut-and-raised portion 420A that will constitute the eaves portion 420. The cut-and-raised portion 420 is connected to the main body portion 400A of the mask sheet MS other than the cut-and-raised portion 420A via a connecting portion 430 that does not have a cut SL.

[0069] The cuts SL can be formed by Thomson machining, which forms the cuts SL by pressing a blade, laser machining, which forms the cuts SL by laser light, etc. According to these machining methods, the eaves portion 420 can be formed without using an expensive mold, so that the production cost can be reduced.

[0070] Next, the cut-and-raised portion 420A is folded outward. As a result, the cut-and-raised portion 420A standing from the main body portion 400A of the mask sheet MS forms the eaves portion 420. At the same time, the opening 410 through which the above-mentioned emitted light passes is formed at the location where the cut-and-raised portion 420A was disposed.

[0071] Before folding the cut-and-raised portion 420A outward, a groove (not shown) may be formed in the connecting portion 430 located at the boundary between the cut-and-raised portion 420A surrounded by the slit SL and the main body portion 400A of the mask sheet MS other than the cut-and-raised portion 420A. By forming the groove, the cut-and-raised portion 420A can be easily folded outward.

[0072] Furthermore, the connecting portion 430 may be reinforced with resin, which allows the eaves portion 420 to be fixed at a desired bending angle.

[0073] Hereinafter, the display unit manufacturing method according to this embodiment will be described with reference to FIG.

[0074] 6, first, a plurality of light emitting elements 100 are mounted on a circuit board 200 (light emitting element mounting step S1). A control circuit 210 is also mounted on the circuit board 200. The circuit board 200 may be formed in a sheet shape. Examples of materials for the circuit board 200 include polyimide resin and other resins.

[0075] Next, a waterproof layer 300 is formed to cover at least the mounted light emitting element 100 and the front surface 200a of the circuit board 200 (waterproof layer forming step S2). It is preferable that the waterproof layer 300 also covers the rear surface 200b and the control circuit 210 of the circuit board 200, and the side surface 200c of the circuit board 200.

[0076] The waterproof layer 300 may be bonded to the light emitting element 100, the surface 200a of the circuit board 200, etc. using an adhesive, double-sided tape, etc. In this case, the concept of the waterproof layer 300 includes the adhesive, double-sided tape, etc.

[0077] 5, a mask sheet MS is manufactured (mask sheet manufacturing step S3), and a plurality of cuts SL are formed in the mask sheet MS (cut forming step S4). The cuts SL are formed in the same number as the number of the light emitting elements 100.

[0078] Next, the mask sheet MS having the multiple cuts SL formed therein is placed over the circuit board 200 covered with the waterproof layer 300, and the placed mask sheet MS is bonded to the waterproof layer 300 (mask layer forming step S5). In this way, the mask layer 400 is completed.

[0079] The mask sheet MS is placed on the circuit board 200 in a positioning state in which each cut-and-raised portion 420A faces the light-emitting element 100. In the process of placing the mask sheet MS on the circuit board 200, the cut-and-raised portions 420A are naturally folded outward by the light-emitting element 100. In this way, the light-emitting element 100 fits into the opening 410, and the eaves portion 420 stands up.

[0080] The mask sheet MS may be joined to the waterproof layer 300 using an adhesive, double-sided tape, or the like. In this case, the concept of the mask sheet MS includes adhesive, double-sided tape, and the like. The mask sheet MS may be joined to the waterproof layer 300 by welding through heating. The mask sheet MS may be fixed to the circuit board 200 together with the waterproof layer 300 by fasteners such as screws, rivets, clips, or the like.

[0081] This completes the flexible structure 610 that holds the light emitting element 100. Next, the flexible structure 610 is fixed to the holding plate 620 in a bent state as necessary (holding step S6). This completes the display unit 700 according to this embodiment.

[0082] [Embodiment 2] In the configuration according to the above-mentioned embodiment 1, the light emitting element 100 may be one in which the intensity distribution of the radiated light follows a Lambertian distribution (hereinafter, referred to as a Lambertian distribution-type light emitting element 100). In this case, the radiated light may have a component traveling in a direction perpendicular to the optical axis of the light emitting element 100.

[0083] Here, the optical axis of the light-emitting element 100 refers to an imaginary line parallel to the normal to the circuit board 200 at the location where the light-emitting element 100 is provided, and refers to an imaginary line passing through the center of the light-emitting element 100 when viewed in the direction of the normal. The direction perpendicular to the optical axis of the light-emitting element 100 specifically refers to a direction parallel to the radiation surface 100a shown in FIG.

[0084] A configuration suitable for the case where a Lambertian distribution type light emitting element 100 is used will be described below.

[0085] 7, the display unit 700 according to this embodiment has a repeating shape in which concave portions 600a protruding in the negative direction of the Z axis and convex portions 600b protruding in the positive direction of the Z axis are alternately repeated in a direction parallel to the X axis when viewed in the Y axis direction. In this embodiment, the repeating shape is a sine wave shape whose amplitude direction is the Z axis direction.

[0086] The repeating period of the repeating shape, specifically the dimension in the X-axis direction representing the period of the sine wave, is longer than the amplitude representing the depth of the recess 600a of the repeating shape, specifically the dimension in the Z-axis direction representing the amplitude of the sine wave.

[0087] In this embodiment, the Lambertian distribution type light emitting elements 100 are disposed only at the portions of the front surface 200a of the circuit board 200 that constitute the bottoms of the respective recesses 600a.

[0088] The light emitting elements 100 are lined up in the Y-axis direction at the locations constituting the bottoms of the respective recesses 600a on the front surface 200a of the circuit board 200. Therefore, when viewed in the Z-axis direction, the light emitting elements 100 are distributed in a matrix pattern.

[0089] The significance of the configuration according to this embodiment will be described below.

[0090] Conventionally, when using Lambertian distribution type light emitting elements 100, a component (hereinafter referred to as an in-plane component) of the light emitted from a certain light emitting element 100 (hereinafter referred to as a first light emitting element 100) propagating in a direction perpendicular to the optical axis of the first light emitting element 100 may illuminate another light emitting element 100 (hereinafter referred to as a second light emitting element 100). In such a case, the color tone of the pixel formed by the second light emitting element 100 on the display screen 810 may change compared to the case where the in-plane component is not irradiated.

[0091] In contrast, according to the present embodiment, a convex portion 600b is interposed between a certain light-emitting element 100 and an adjacent light-emitting element 100 in the X-axis direction of the certain light-emitting element 100. Therefore, even if the light emitted from the light-emitting element 100 has the above-mentioned in-plane direction component, the in-plane direction component is blocked from entering the adjacent light-emitting element 100 in the X-axis direction by the presence of the convex portion 600b.

[0092] 4 is absorbent not only for external light but also for radiated light. Therefore, the in-plane direction component incident on the convex portion 600b is absorbed by the mask layer 400. In this way, most of the in-plane direction components propagating in a direction intersecting the Y-axis are absorbed in the regions of the mask layer 400 that constitute the convex portions 600b.

[0093] Moreover, among the in-plane direction components, those propagating in the Y-axis direction are incident on the eaves portion 420 of the mask layer 400 shown in Fig. 4. Therefore, the in-plane direction components radiated from the light-emitting element 100 are also prevented from being incident on the adjacent light-emitting element 100 in the Y-axis direction.

[0094] For the above reasons, according to this embodiment, despite the use of Lambertian distribution type light-emitting elements 100, it is possible to avoid changes in color tone caused by the in-plane direction component of the emitted light from one light-emitting element 100 being incident on another light-emitting element 100, and to display a normal image without changes in color tone on the display screen 810.

[0095] [Embodiment 3] The arrangement suitable for the Lambertian distribution type light emitting device 100 is not limited to the aspect shown in Fig. 7. Other configurations suitable for the Lambertian distribution type light emitting device 100 will be described below.

[0096] As shown in FIG. 8, in the display unit 700 of this embodiment, the Lambertian distribution type light-emitting elements 100 are arranged only at a portion on the surface 200a of the circuit board 200 that forms the middle portion from the top of each convex portion 600b to the bottom of the concave portion 600a located adjacent to that convex portion 600b in the positive direction of the X-axis (hereinafter referred to as the right middle portion).

[0097] A plurality of light emitting elements 100 are lined up in the Y-axis direction in the middle part on the right side of the front surface 200a of the circuit board 200. Therefore, when viewed in the Z-axis direction, the plurality of light emitting elements 100 are distributed in a matrix pattern.

[0098] In this embodiment, most of the in-plane components of the light emitted from each light-emitting element 100 that propagate in a direction intersecting the Y-axis are absorbed by the region that constitutes the bottom of the recess 600a in the mask layer 400. Moreover, of the in-plane components, those that propagate in the Y-axis direction are absorbed by the eaves portion 420 of the mask layer 400 shown in FIG.

[0099] As a result, in the configuration of this embodiment, as in embodiment 2, it is possible to avoid changes in color tone caused by the in-plane direction component of the emitted light from a certain light-emitting element 100 being incident on another light-emitting element 100, and it is possible to display a normal image without changes in color tone on the display screen 810.

[0100] [Embodiment 4] A modification of the configuration shown in FIG. 8 will be described below.

[0101] As shown in FIG. 9, in the display unit 700 of this embodiment, the Lambertian distribution type light-emitting elements 100 are arranged only at a portion on the surface 200a of the circuit board 200 that forms the middle portion from the top of each convex portion 600b to the bottom of the concave portion 600a located adjacent to that convex portion 600b in the negative direction of the X-axis (hereinafter referred to as the left middle portion).

[0102] In the middle left portion of the front surface 200a of the circuit board 200, the plurality of light emitting elements 100 are lined up in the Y-axis direction. Therefore, when viewed in the Z-axis direction, the plurality of light emitting elements 100 are distributed in a matrix pattern. In this embodiment, the same effects as those in the third embodiment can be obtained.

[0103] [Embodiment 5] 7 to 9 show an example in which the repeating shape of the display unit 700 is a sine wave shape. Other examples of repeating shapes will be described below.

[0104] As shown in FIG. 10, in this embodiment, the repeating shape in which the recesses 600a and the protrusions 600b are alternately repeated in the X-axis direction is a triangular wave shape with the Z-axis direction as the amplitude direction when viewed in the Y-axis direction.

[0105] As in the second embodiment, the light emitting elements 100 are disposed only at the portions constituting the bottoms of the recesses 600a on the front surface 200a of the circuit board 200. Therefore, the present embodiment also provides the same advantageous effects as the second embodiment.

[0106] In addition, even when the repeating shape is a triangular wave shape, the light emitting element 100 may be arranged only in the middle of the right side of the front surface 200a of the circuit board 200 as shown in Fig. 8. In this case, the same effects as those of the third embodiment can be obtained.

[0107] Furthermore, even when the repeating shape is a triangular wave shape, the light emitting element 100 may be arranged only in the middle left part of the front surface 200a of the circuit board 200 as shown in Fig. 9. In this case, the same effects as those of the fourth embodiment can be obtained.

[0108] [Embodiment 6] Further examples of repeating shapes are described below.

[0109] As shown in FIG. 11, in this embodiment, the repeating shape in which the recesses 600a and the protrusions 600b are alternately repeated in the X-axis direction is a rectangular wave shape with the Z-axis direction as the amplitude direction when viewed in the Y-axis direction.

[0110] As in the second embodiment, the light emitting elements 100 are disposed only at the portions constituting the bottoms of the recesses 600a on the front surface 200a of the circuit board 200. Therefore, the present embodiment also provides the same advantageous effects as the second embodiment.

[0111] [Embodiment 7] 4 may have an integral single-layer structure in the thickness direction of the mask layer 400, or may have a layered structure in which a plurality of partial layers are layered in the thickness direction of the mask layer 400. A specific example of the mask layer 400 having a layered structure will be described below.

[0112] The mask layer 400 according to this embodiment has a laminated structure in which a first partial layer and a second partial layer, each of which is in the form of a sheet, are stacked on top of each other. A first eaves portion constituting a part of each eaves portion 420 constituted by the mask layer 400 is formed in the first partial layer. A second eaves portion constituting the remaining part of each eaves portion 420 constituted by the mask layer 400 is formed in the second partial layer.

[0113] The first eaves portion and the second eaves portion have different shapes. By overlapping the first partial layer and the second partial layer, the first eaves portion and the second eaves portion form one eaves portion 420. Therefore, compared to the case where a mask layer 400 with a single layer structure is used, it is possible to easily form a complex-shaped eaves portion 420 that is excellent in the effect of suppressing a decrease in contrast.

[0114] [Embodiment 8] 4 illustrates an example of the display unit 700 including the holding plate 620, but the holding plate 620 is not essential to the display unit 700. Below, a configuration suitable for the case where the holding plate 620 is omitted will be described.

[0115] In this embodiment, the circuit board 200 has plasticity in addition to flexibility. Therefore, when the circuit board 200 on which the waterproof layer 300 and the mask layer 400 are formed is bent into a shape required to configure the display screen 810, the circuit board 200 undergoes plastic deformation into the bent shape.

[0116] That is, the circuit board 200 itself maintains the bent shape. The shapes of the waterproof layer 300 and the mask layer 400 are determined by the circuit board 200. For this reason, the holding plate 620 can be omitted.

[0117] Metal can be used as the material of the circuit board 200, which has not only flexibility but also plasticity. As an example, the circuit board 200 can be made of an aluminum sheet. An insulating layer is formed on the front surface 200a and the back surface 200b of the circuit board 200 made of an aluminum sheet. Then, electrode pads and metal wiring are formed on the insulating layer.

[0118] The above describes the first to eighth embodiments. The following modifications are also possible.

[0119] 3 illustrates the light emitting element 100 having three types of LEDs, the light emitting element 100 may have only one type of LED. In addition, as a visible light radiation source constituting the light emitting element 100, in addition to the LED, an LD (Laser Diode), an organic EL (Electro-Luminescence), or the like may be used.

[0120] 7 to 9 show an example of a sine wave shape as the aforementioned repeating shape, while Fig. 10 shows an example of a triangular wave shape as the repeating shape, and Fig. 11 shows an example of a rectangular wave shape as the repeating shape. The repeating shape is not limited to these shapes. The repeating shape may be a step wave shape, a sawtooth wave shape, or the like.

[0121] In the eighth embodiment, a configuration has been described in which the holding plate 620 is omitted by using the circuit board 200 having plasticity. Even if the circuit board 200 does not have plasticity, for example, when the installation surface on which the display screen 810 is installed plays a role in determining the shape of the flexible structure 610, the holding plate 620 may be omitted. That is, the flexible structure 610 is bent to fit the installation surface and attached to the installation surface. The flexible structure 610 may be directly attached to the installation surface, or a rubber sheet or other protective member may be interposed between the installation surface and the flexible structure 610. The installation surface typically refers to a wall surface of a building.

[0122] Various aspects of the present disclosure are described below.

[0123] (Appendix 1) A flexible circuit board; A plurality of light emitting elements arranged on a surface of the circuit board, each of which emits visible light; a waterproof layer that is transparent to the radiated light, which is the visible light radiated from the light-emitting element, and is waterproof, and covers the surface of the circuit board and each of the light-emitting elements; a mask layer that has an absorbency for external light, which is visible light that is about to be incident on the circuit board from the outside, and the radiated light, covers the waterproof layer, and has an opening formed for each of the light-emitting elements, through which the radiated light emitted by the light-emitting elements passes; Equipped with the waterproof layer is in planar contact with the surface of the circuit board, which is a base surface for the waterproof layer, and the mask layer is in planar contact with the waterproof layer, which is a base surface for the mask layer; When the circuit board is bent, not only the waterproof layer but also the mask layer has flexibility and stretchability such that the mask layer bends together with the circuit board while maintaining planar adhesion to the base surface. Display unit. (Appendix 2) the circuit board has a back surface opposite to the front surface in a thickness direction of the circuit board, and a side surface connecting the back surface and the front surface, the mask layer extends not only to an area facing the front surface of the circuit board, but also to an area facing the side surface of the circuit board and an area facing at least a peripheral portion of the rear surface of the circuit board; 2. A display unit as described in appended claim 1. (Appendix 3) a holding plate that holds the circuit board, the waterproof layer, and the mask layer in a bent state; 3. The display unit according to claim 1 or 2, further comprising: (Appendix 4) When an XYZ orthogonal coordinate system is defined for the display unit, the system has an X axis parallel to the left-right direction on a display screen configured using the display unit, a Y axis parallel to the up-down direction on the display screen, and a Z axis perpendicular to the X axis and the Y axis, and the positive direction of the Z axis is the direction from the display screen to the front of the display screen, When viewed in the Y-axis direction, a convex portion protruding in the positive direction of the Z-axis and a concave portion protruding in the negative direction of the Z-axis have a repeating shape that is alternately and repeatedly configured in a direction parallel to the X-axis. 4. A display unit according to any one of claims 1 to 3. (Appendix 5) the light emitting elements are disposed only at portions of the surface of the circuit board that constitute bottoms of the respective recesses; 6. A display unit as described in appended claim 4. (Appendix 6) the light-emitting elements are arranged only at portions on the surface of the circuit board that form a middle portion from a top of each of the protrusions to a bottom of the recess that is adjacent to the protrusion in the positive direction of the X-axis; 6. A display unit as described in appended claim 4. (Appendix 7) the light-emitting elements are arranged only at portions on the surface of the circuit board that form a portion from a top of each of the protrusions to a bottom of the recess that is adjacent to the protrusion in the negative direction of the X-axis; 6. A display unit as described in appended claim 4. (Appendix 8) The repeating shape refers to a sine wave, a triangular wave, or a rectangular wave shape, each of which has an amplitude direction parallel to the Z axis when viewed in the Y axis direction. 6. A display unit according to claim 4 or 5. (Appendix 9) A display device comprising a plurality of display units according to any one of appendixes 1 to 8, A plurality of the display units are combined together. Display device. [Explanation of symbols]

[0124] 100 light emitting element, 100a radiation surface, 111R red LED, 111G green LED, 111B blue LED, 120 package member, 130 lead frame, 140 transparent sealing member, 200 circuit board, 200a front surface, 200b rear surface, 200c side surface, 210 control circuit, 300 waterproof layer, 400 mask layer, 400A main body, 410 opening, 420 eaves portion, 420A cut-and-raised portion, 430 connecting portion, 600 holding structure, 600a recess, 600b protrusion, 610 flexible structure, 620 holding plate, 621 back plate portion, 622 side plate portion, 700 display unit, 800 display device, 810 display screen, MS mask sheet, SL notch.

Claims

1. A flexible circuit board; A plurality of light emitting elements arranged on a surface of the circuit board, each of which emits visible light; a waterproof layer that is transparent to the radiated light, which is the visible light radiated from the light-emitting element, and is waterproof, and covers the surface of the circuit board and each of the light-emitting elements; a mask layer that has an absorbency for external light, which is visible light that is about to be incident on the circuit board from the outside, and the radiated light, covers the waterproof layer, and has an opening formed for each of the light-emitting elements, through which the radiated light emitted by the light-emitting elements passes; Equipped with the waterproof layer is in planar contact with the surface of the circuit board, which is a base surface for the waterproof layer, and the mask layer is in planar contact with the waterproof layer, which is a base surface for the mask layer; When the circuit board is bent, not only the waterproof layer but also the mask layer has flexibility and stretchability such that the mask layer bends together with the circuit board while maintaining planar adhesion to the base surface. Display unit.

2. the circuit board has a back surface opposite to the front surface in a thickness direction of the circuit board, and a side surface connecting the back surface and the front surface, the mask layer extends not only to an area facing the front surface of the circuit board, but also to an area facing the side surface of the circuit board and an area facing at least a peripheral portion of the rear surface of the circuit board; The display unit according to claim 1 .

3. a holding plate that holds the circuit board, the waterproof layer, and the mask layer in a bent state; The display unit of claim 1 further comprising:

4. When an XYZ orthogonal coordinate system is defined for the display unit, the system has an X axis parallel to the left-right direction on a display screen configured using the display unit, a Y axis parallel to the up-down direction on the display screen, and a Z axis perpendicular to the X axis and the Y axis, and the positive direction of the Z axis is the direction from the display screen to the front of the display screen, When viewed in the Y-axis direction, a convex portion protruding in the positive direction of the Z-axis and a concave portion protruding in the negative direction of the Z-axis have a repeating shape that is alternately and repeatedly configured in a direction parallel to the X-axis. A display unit according to any one of claims 1 to 3.

5. the light emitting elements are disposed only at portions of the surface of the circuit board that constitute bottoms of the respective recesses; A display unit according to claim 4.

6. the light-emitting elements are arranged only at portions on the surface of the circuit board that form a middle portion from a top of each of the protrusions to a bottom of the recess that is adjacent to the protrusion in the positive direction of the X-axis, A display unit according to claim 4.

7. the light-emitting elements are disposed only at portions on the surface of the circuit board that form a middle portion from a top of each of the protrusions to a bottom of the recess that is adjacent to the protrusion in the negative direction of the X-axis, A display unit according to claim 4.

8. The repeating shape refers to a sine wave, a triangular wave, or a rectangular wave shape, each of which has an amplitude direction parallel to the Z axis when viewed in the Y axis direction. A display unit according to claim 4.

9. A display device comprising a plurality of display units according to any one of claims 1 to 3, A plurality of the display units are combined together. Display device.

Images