WO2025150168A1 - Led display device - Google Patents

Abstract

An LED display device (1) comprises: an LED display layer (10) that has surfaces (10A, 10B) positioned on mutually opposite sides in the thickness direction, the LED display layer (10) including a plurality of LED elements (11) disposed along one of the surfaces; a photovoltaic layer (20) that is disposed side by side with one of the surfaces of the LED display layer (10); and a battery unit (30) that is electrically connected to the LED display layer (10) and the photovoltaic layer (20), the battery unit (30) including a plurality of batteries (31). Power generated in the photovoltaic layer (20) is stored in the battery unit (30), and the LED display layer (10) is driven by the power stored in the battery unit (30).

Description

LED display device

This disclosure relates to an LED display device.

A display device including a display screen and a rechargeable battery is known (see, for example, International Publication No. WO 2019/130025 (Patent Document 1)). With such a display device, the battery is charged in advance and power is supplied from the battery to the display screen, allowing the display device to operate even in a location far from a power source.

International Publication No. 2019/130025

However, with display devices such as those described above, the operating time of the display is limited by the battery capacity, making it difficult to operate for long periods of time. This disclosure addresses this issue, and one of its objectives is to provide an LED display device that allows for long-term operation.

The LED display device according to the present disclosure comprises an LED display layer having surfaces opposite each other in the thickness direction and including a plurality of LED elements arranged along one of the surfaces, a photovoltaic cell layer arranged alongside one of the surfaces of the LED display layer, and a battery unit including a plurality of batteries electrically connected to the LED display layer and the photovoltaic cell layer. Electricity generated in the photovoltaic cell layer is stored in the battery unit, and the LED display layer is driven by the power stored in the battery unit.

The above LED display device can provide an LED display device that can operate for long periods of time.

FIG. 1 is a schematic perspective view showing a structure of an LED display device according to a first embodiment of the present invention. FIG. 2 is a schematic perspective view showing a state in which the LED display device is deformed. FIG. 3 is a schematic perspective view showing a state in which the LED display device is deformed. FIG. 4 is a schematic plan view showing the structure of the surface of the LED display layer. FIG. 5 is a schematic plan view showing the structure of the surface of the battery unit. FIG. 6 is a schematic cross-sectional view showing the structure of the LED display device according to the first embodiment. FIG. 7 is a schematic perspective view showing the appearance of the battery. FIG. 8 is a schematic cross-sectional view showing the structure of the battery. FIG. 9 is a schematic cross-sectional view showing the structure of the battery. FIG. 10 is a schematic perspective view showing a structure of an LED display device according to the second embodiment. FIG. 11 is a schematic cross-sectional view showing the structure of an LED display device according to the second embodiment. FIG. 12 is a schematic perspective view showing a structure of an LED display device according to the third embodiment. FIG. 13 is a schematic perspective view showing a state in which the LED display device is deformed. FIG. 14 is a schematic perspective view showing a state in which the LED display device is deformed. FIG. 15 is a schematic cross-sectional view showing the structure of an LED display device according to the third embodiment.

[Overview of the embodiment]
First, the embodiments of the present disclosure will be described. The LED display device of the present disclosure includes an LED display layer having surfaces opposite to each other in a thickness direction and including a plurality of LED elements arranged along one of the surfaces, a photovoltaic cell layer arranged alongside one of the surfaces of the LED display layer, and a battery unit including a plurality of batteries electrically connected to the LED display layer and the photovoltaic cell layer. Electricity generated in the photovoltaic cell layer is stored in the battery unit, and the LED display layer is driven by the electric power stored in the battery unit.

In the LED display device of the present disclosure, the power generated in the photovoltaic cell layer is stored in the battery unit, and the LED display layer is driven by the power stored in the battery unit. When the photovoltaic cell layer is irradiated with light such as sunlight, power is generated. Therefore, the LED display device of the present disclosure can be used in an environment where the photovoltaic cell layer is irradiated with light, such as outdoors, and can operate with power generated in the photovoltaic cell layer in addition to the power originally stored in the battery unit. As a result, the LED display device of the present disclosure can operate for a long period of time. Note that the photovoltaic cell layer is not limited to sunlight, and can also generate power from other light sources, including artificially generated light. The photovoltaic cell layer generates power when irradiated with at least one of visible light, infrared light, and ultraviolet light.

In the above LED display device, at least one of the LED display layer, the photovoltaic cell layer, and the battery unit may be elastic. This configuration improves the freedom of installation of the LED display device.

In the above LED display device, the LED display layer, the photovoltaic cell layer, and the battery unit may be elastic. This configuration improves the freedom of installation of the LED display device. It also makes it easier to transport the LED display device.

In the above LED display device, the LED elements may be arranged in a matrix. This configuration makes it easy to display various images on the LED display layer.

In the LED display device, the battery may be a lithium-ion battery. Lithium-ion batteries are compact, have high output, and are less susceptible to deterioration due to repeated charging and discharging, making them suitable as batteries for constituting the battery unit of the LED display device of the present disclosure.

In the above LED display device, the batteries may be arranged in an array. This configuration allows a large number of batteries to be arranged efficiently.

In the above LED display device, the photovoltaic cell layer has surfaces located on opposite sides in the thickness direction, and one of the surfaces of the photovoltaic cell layer faces one of the surfaces of the LED display layer. By arranging the photovoltaic cell layer and the LED display layer in a stacked manner in this manner, it is easy to make the LED display device compact.

In the above LED display device, the LED display layer and the photovoltaic cell layer are laminated, and each cell may have a plate-like shape with surfaces located on opposite sides in the thickness direction. The cells may be arranged side by side so that they face either the LED display layer or the photovoltaic cell layer. This configuration makes it easy to make the LED display device compact.

In the above LED display device, the thickness of each battery may be 1.0 mm or less. This configuration makes it easy to make the LED display device thinner.

In the above LED display device, the capacity of each battery as viewed in the thickness direction may be 70 mWh or more per 100 ^mm2 . With this configuration, the operating time of the LED display device can be further extended.

In the above LED display device, each battery may include a separator, a positive electrode layer and a negative electrode layer sandwiched between the separator, an electrolyte impregnated in the separator, the positive electrode layer, and the negative electrode layer, and an exterior material that contains the separator, the positive electrode layer, the negative electrode layer, and the electrolyte. A battery with such a structure is suitable as a battery that constitutes a battery unit of the LED display device of the present disclosure.

In the above LED display device, the positive electrode layer may be made of a sintered body. This configuration makes it easier to achieve a low resistance and large capacity battery.

In the LED display layer of the LED display device, the distance between two adjacent LED elements may be 4 mm or less. This configuration makes it easy to display high-definition images on the LED display layer.

In the LED display layer of the LED display device, the spacing may be 1.27 mm or less. This configuration makes it easier to display higher-definition images on the LED display layer.

In the above LED display device, the LED display layer, the photovoltaic cell layer, and the battery unit may be stacked in this order. The LED display layer may be light-transmitting. The LED elements may be on the surface of the LED display layer, opposite the other side to which the photovoltaic cell layer is attached. With this configuration, an image can be displayed by the light emitted by the LED elements on the surface of the LED display layer, and light transmitted through the LED display layer can be supplied to the photovoltaic cell layer.

In the above LED display device, the photovoltaic cell layer may generate electricity from light transmitted through the LED display layer. This configuration makes it easy to extend the operating time of the LED display device by using the electricity generated in the photovoltaic cell layer.

In the above LED display device, the battery unit may reflect light. With this configuration, the light reflected by the battery unit can be supplied to the photovoltaic cell layer.

In the above LED display device, the photovoltaic cell layer may also generate power from light that is transmitted through the LED display layer and the photovoltaic cell layer and reflected by the battery unit. This configuration makes it easier to further extend the operating time of the LED display device by using the power generated in the photovoltaic cell layer.

In the above LED display device, the photovoltaic cell layer, the LED display layer and the battery unit may be stacked in this order. The LED element may be on one of the surfaces of the LED display layer and mounted adjacent to the photovoltaic cell layer. This configuration makes it easy to supply light to the photovoltaic cell layer for power generation.

In the above LED display device, the photovoltaic cell layer may be translucent. The image provided by the LED display layer may be visible through the photovoltaic cell layer. With this configuration, it is possible to provide an LED display device in which an image is visible through the photovoltaic cell layer.

In the above LED display device, the photovoltaic cell layer may have a plurality of through holes penetrating the photovoltaic cell layer in the thickness direction. The through holes may correspond to LED elements. An image provided by the LED display layer may be visible through the through holes. This configuration makes it easy to view an image through the photovoltaic cell layer.

In the above LED display device, the LED display layer and the photovoltaic cell layer may be stacked. The battery unit may have a rod-like shape including a pair of end faces and an outer circumferential surface connecting the pair of end faces. The battery unit may be attached to the LED display layer or the photovoltaic cell layer at the outer circumferential surface. The LED display layer and the photovoltaic cell layer may be elastic. With this configuration, the LED display device can be deformed so that the stacked LED display layer and the photovoltaic cell layer are wrapped around the rod-shaped battery body. As a result, the LED display device can be easily transported and stored.

[Specific Example of the Embodiment]
Next, specific embodiments of the LED display device of the present disclosure will be described with reference to the drawings. In the following drawings, the same or corresponding parts are designated by the same reference characters and the description thereof will not be repeated.

(Embodiment 1)
FIG. 1 is a schematic perspective view showing the structure of the LED display device of the first embodiment. FIG. 2 and FIG. 3 are schematic perspective views showing a state in which the LED display device is deformed. Referring to FIG. 1, the LED display device 1 of the present embodiment includes an LED display layer 10, a photovoltaic cell layer 20, and a battery unit 30. The LED display layer 10, the photovoltaic cell layer 20, and the battery unit 30 each have a sheet-like shape. The LED display layer 10, the photovoltaic cell layer 20, and the battery unit 30 are laminated in this order. Other layers and other members may be interposed between the LED display layer 10 and the photovoltaic cell layer 20, but in this embodiment, the two are in contact with each other. Other layers and other members may be interposed between the photovoltaic cell layer 20 and the battery unit 30, but in this embodiment, the two are in contact with each other. The LED display layer 10 and the photovoltaic cell layer 20 are bonded together. The means of bonding is not particularly limited, but means such as adhesion by adhesive and fusion bonding can be used. Instead of bonding, the relative positions may be fixed by, for example, a frame member (not shown) that fixes the outer periphery. The photovoltaic cell layer 20 and the battery unit 30 are bonded. The means of bonding is not particularly limited, but means such as adhesion by adhesive or fusion can be used. Instead of bonding, the relative positions may be fixed by, for example, a frame member (not shown) that fixes the outer periphery.

In this embodiment, at least one of the LED display layer 10, the photovoltaic cell layer 20, and the battery unit 30 has elasticity. The LED display layer 10, the photovoltaic cell layer 20, and the battery unit 30 have elasticity. The LED display layer 10, the photovoltaic cell layer 20, and the battery unit 30 have flexibility. The LED display layer 10, the photovoltaic cell layer 20, and the battery unit 30 can be deformed into a curved shape. Therefore, the LED display device 1 of this embodiment can be in a flat state as shown in FIG. 1 and in a curved state as shown in FIG. 2. As a result, the LED display device 1 of this embodiment can be installed not only on a flat wall surface, but also on a curved wall surface (for example, the surface of a cylindrical column). In addition, the LED display device 1 of this embodiment can be deformed so as to be wound into a spiral shape as shown in FIG. 3. As a result, the LED display device 1 of this embodiment is easy to store and transport. The LED display layer 10, the photovoltaic cell layer 20, and the battery unit 30 may have rigidity rather than elasticity or flexibility.

Figure 4 is a schematic plan view showing the structure of the surface of the LED display layer. Figure 4 is a view of the first main surface 10A of the LED display layer 10, viewed in a direction perpendicular to the first main surface 10A. Figure 5 is a schematic plan view showing the structure of the surface of the battery unit. Figure 5 is a view of the second main surface 30B of the battery unit 30, viewed in a direction perpendicular to the second main surface 30B. Figure 6 is a schematic cross-sectional view showing the structure of the LED display device of embodiment 1.

1, 4 and 6, the LED display layer 10 has a first main surface 10A and a second main surface 10B, which are surfaces located opposite each other in the thickness direction. The LED display layer 10 includes a plurality of LED elements 11 arranged along the first main surface 10A. The LED display layer 10 includes a base layer 12 having a sheet-like shape and a plurality of LED elements 11 arranged on the base layer 12. As shown in FIG. 4, the plurality of LED elements 11 are arranged in a matrix. With reference to FIG. 6, in the LED display layer 10, the interval g ₁ between two adjacent LED elements 11 can be appropriately set according to the use, size, etc. of the LED display device 1, and may be, for example, 4 mm or less, 1 mm or less, 0.8 mm or less, 0.7 mm or less, 0.6 mm or less, 0.5 mm or less, 0.4 mm or less, 0.3 mm, or even 1.27 mm or less. The plurality of LED elements 11 are arranged over the entire area except for the outer periphery of the first main surface 10A. The base layer 12 includes a circuit board that is electrically connected to the LED element 11 and drives the LED element 11 .

The LED display layer 10 is translucent. Specifically, for example, the LED display layer 10 may transmit 60% or more, preferably 80% or more, of light (visible light) having a wavelength of 360 nm or more and 830 nm or less that is incident perpendicularly to the first main surface 10A. The LED element 11 is present on the first main surface 10A, which is opposite to the second main surface 10B, which is the surface on the side where the photovoltaic cell layer 20 is attached. The LED element 11 is disposed on the first main surface 10A, which is the surface opposite in the thickness direction to the second main surface 10B, which is the surface facing the photovoltaic cell layer 20.

1 and 6, the photovoltaic cell layer 20 has a first main surface 20A and a second main surface 20B, which are surfaces located opposite each other in the thickness direction. The photovoltaic cell layer 20 is arranged side by side with the second main surface 10B, which is one of the above-mentioned surfaces of the LED display layer 10. The first main surface 20A, which is one of the above-mentioned surfaces of the photovoltaic cell layer 20, faces the second main surface 10B of the LED display layer 10. The first main surface 20A of the photovoltaic cell layer 20 and the second main surface 10B of the LED display layer 10 are in contact with each other. The photovoltaic cell layer 20 includes a photovoltaic cell that generates electric power by photoelectric effect when light such as sunlight including visible light is irradiated. As described above, the LED display layer 10 of this embodiment has translucency. Referring to FIG. 6, when light such as sunlight is irradiated to the first main surface 10A of the LED display layer 10, a part of the light, light B, passes through the LED display layer 10 and reaches the photovoltaic cell layer 20. The photovoltaic cell layer 20 generates electricity from this light B. Note that the photovoltaic cell layer 20 is not limited to sunlight, and can generate electricity from other light sources, including artificially generated light. The photovoltaic cell layer 20 generates electricity when irradiated with at least one of visible light, infrared light, and ultraviolet light. The photovoltaic cell layer 20 may be a matrix of multiple cells that are electrically connected to each other.

1, 5 and 6, the battery unit 30 has a first main surface 30A and a second main surface 30B, which are surfaces located opposite each other in the thickness direction. The battery unit 30 includes a plurality of batteries 31 arranged along the second main surface 30B. The first main surface 30A of the battery unit 30 faces the second main surface 20B of the photovoltaic cell layer 20. The battery unit 30 includes a base layer 32 having a sheet-like shape and a plurality of batteries 31 arranged on the base layer 32. As shown in FIG. 5, the plurality of batteries 31 are arranged in an array. As shown in FIG. 5, the plurality of batteries 31 may be arranged to form a plurality of parallel rows with intervals 33 therebetween. As shown in FIG. 6, the thickness t ₃ of each battery 31 can be appropriately set in consideration of the required capacity depending on the application of the LED display device 1, and may be, for example, 1.0 mm or less, 0.5 mm or less, or even 0.4 mm or less. The battery 31 is a secondary battery that is a battery that can be charged and discharged. In this embodiment, the battery 31 is a lithium ion battery (lithium ion secondary battery).

Each battery 31 has a plate-like shape including a first main surface 31A and a second main surface 31B, which are surfaces located opposite each other in the thickness direction. The batteries 31 are arranged side by side with the photovoltaic cell layer 20 in between, with the first main surface 31A facing the second main surface 10B of the LED display layer 10. More specifically, the base layer 32 is arranged so as to contact the second main surface 20B of the photovoltaic cell layer 20. The battery 31 is arranged on the base layer 32 so as to contact the base layer 32 at the first main surface 31A. Note that the presence of the base layer 32 is not essential and may be omitted. In other words, the battery 31 may be arranged directly on the photovoltaic cell layer 20 so as to contact the second main surface 20B of the photovoltaic cell layer 20 at the first main surface 31A.

When viewed in the thickness direction of the battery 31 (from the viewpoint of FIG. 5), the capacity of each battery 31 is, for example, 70 mWh or more per 100 mm ² , preferably 85 mWh or more, and further preferably 100 mWh or more. In this embodiment, the photovoltaic cell layer 20 may have translucency. Specifically, for example, the photovoltaic cell layer 20 may transmit 60% or more, preferably 80% or more, of light (visible light) having a wavelength of 360 nm or more and 830 nm or less, which is visible light that is perpendicularly incident on the first main surface 20A. The battery unit 30 may also reflect light. In this case, referring to FIG. 6, when light such as sunlight is irradiated on the first main surface 10A of the LED display layer 10, a part of the light, light C, passes through the LED display layer 10 and the photovoltaic cell layer 20 and reaches the battery unit 30. The base layer 32 of the battery unit 30 has translucency similar to the photovoltaic cell layer 20. On the other hand, the first main surface 31A of the battery 31 has, for example, a metallic luster. As a result, the light C is reflected by the first main surface 31A of the cell 31 and reaches the photovoltaic cell layer 20. The photovoltaic cell layer 20 generates electric power by the light C.

Next, the internal structure of the battery 31 will be described. Figure 7 is a schematic perspective view showing the appearance of the battery (lithium ion secondary battery). Figure 8 is a schematic cross-sectional view showing a cross section along line VIII-VIII in Figure 7. Figure 9 is a schematic cross-sectional view showing a cross section along line IX-IX in Figure 7.

Referring to Figures 7 to 9, battery 31, which is a lithium ion secondary battery, includes a pair of exterior films 310, a battery body 320, a positive electrode tab terminal 331, and a negative electrode tab terminal 332. Each exterior film 310 has the same rectangular shape when viewed in the thickness direction. The surface of each exterior film 310 has a metallic luster. In the pair of exterior films 310, first outer edges 311 corresponding to the first short sides of the rectangle, second outer edges 312 corresponding to the first long sides, third outer edges 313 corresponding to the second short sides, and fourth outer edges 314 corresponding to the second long sides are joined to each other.

To explain in more detail, the first outer edges 311 are joined to each other over the entire area except for the portions facing each other with the positive electrode tab terminal 331 and the negative electrode tab terminal 332 in between (see FIG. 9). The second outer edges 312 are joined to each other, the third outer edges 313 are joined to each other, and the fourth outer edges 314 are joined to each other over the entire area in the circumferential direction. In this embodiment, the outer edges 311 to 314 are joined by fusion. The joining can be achieved by heat fusion. That is, in the pair of exterior films 310, the outer edges 311 to 314 are joined (fused) to each other in a stacked state. Referring to FIG. 8, the pair of exterior films 310 each include an inner surface 310A that is a surface facing each other, and an outer surface 310B that is a main surface opposite to the inner surface 310A. An internal space 310C is formed between the opposing inner surfaces 310A of the pair of exterior films 310.

Referring to FIG. 8, the battery body 320 is housed within the internal space 310C. The battery body 320 includes a separator film 321, a positive electrode layer 322, a negative electrode layer 323, a positive electrode current collector foil 324, a negative electrode current collector foil 325, and an electrolyte 326.

The separator film 321 is a resin film. Examples of resins that can be used to form the separator film 321 include polyolefin, polyimide, polyester (e.g., polyethylene terephthalate (PET)), cellulose, and the like.

The positive electrode layer 322 is laminated on a first main surface 321A, which is one of the main surfaces of the separator film 321. The positive electrode layer 322 of this embodiment is composed of a plate-shaped sintered body of lithium composite oxide. The positive electrode layer 322 does not contain a binder. The lithium composite oxide refers to an oxide represented by Li _x MO ₂ (0.05<x<1.10, M is at least one type of transition metal, and M typically includes one or more of Co (cobalt), Ni (nickel), and Mn (manganese)).

The negative electrode layer 323 is laminated on the second main surface 321B, which is located on the opposite side in the thickness direction to the first main surface 321A of the separator film 321. The negative electrode layer 323 contains carbon such as graphite as a negative electrode active material, and a binder such as styrene butadiene rubber (SBR) or polyvinylidene fluoride (PVDF).

The positive electrode current collector foil 324 is laminated on the side of the positive electrode layer 322 opposite the separator film 321. The positive electrode current collector foil 324 is a metal foil that is a conductor. The metal constituting the positive electrode current collector foil 324 may be, for example, Al (aluminum). The positive electrode current collector foil 324 is disposed between the positive electrode layer 322 and the inner surface 310A of the exterior film 310. The positive electrode current collector foil 324 is disposed along the inner surface 310A of the exterior film 310.

The negative electrode current collector foil 325 is laminated on the negative electrode layer 323 on the side opposite the separator film 321. The negative electrode current collector foil 325 is a metal foil that is a conductor. The metal that constitutes the negative electrode current collector foil 325 may be, for example, Cu (copper) or Al. The negative electrode current collector foil 325 is disposed between the negative electrode layer 323 and the inner surface 310A of the exterior film 310. The negative electrode current collector foil 325 is disposed along the inner surface 310A of the exterior film 310.

The electrolyte 326 is impregnated into the separator film 321, the positive electrode layer 322, and the negative electrode layer 323. As the electrolyte 326, a solution in which a lithium salt (e.g., LiPF 6 ) is dissolved in an organic solvent (e.g., a mixed solvent of ethylene carbonate (EC) and methyl ethyl carbonate (MEC), a mixed solvent of ethylene carbonate (EC) and diethyl carbonate (DEC), or a mixed solvent of ethylene carbonate ( _EC ) and ethyl methyl carbonate (EMC)) can be used.

The positive electrode tab terminal 331 is connected to the battery body 320 between a pair of exterior films 310 and extends to the outside. The negative electrode tab terminal 332 is connected to the battery body 320 between a pair of exterior films 310 and extends to the outside. The positive electrode tab terminal 331 is connected to the positive electrode current collector foil 324. The negative electrode tab terminal 332 is connected to the negative electrode current collector foil 325. The positive electrode tab terminal 331 and the negative electrode tab terminal 332 have a band-like shape. With reference to FIG. 9, the positive electrode tab terminal 331 includes a body portion 331A made of a conductor and a resin protective layer 331B arranged to cover the surface of the body portion 331A. The negative electrode tab terminal 332 includes a body portion 332A made of a conductor and a resin protective layer 332B arranged to cover the surface of the body portion 332A. Metals such as Al (aluminum) and Ni (nickel) can be used as the conductors that make up the main body portions 331A and 332A.

Referring to FIG. 6, the battery unit 30 is electrically connected to the LED display layer 10 by a wiring 91. The battery unit 30 is electrically connected to the photovoltaic cell layer 20 by a wiring 92. Note that the wiring 91 and wiring 92 are examples, and the above-mentioned electrical connection may be achieved by wiring exposed to the outside as shown in FIG. 6, or by joining conductive pads formed on the surfaces of the LED display layer 10, the photovoltaic cell layer 20, and the battery unit 30 by solder or the like. In addition, each of the LED display layer 10, the photovoltaic cell layer 20, and the battery unit 30 may be electrically connected to a control board separate from these. The battery unit 30 may be indirectly connected to at least one of the LED display layer 10 and the photovoltaic cell layer 20 via the control board. In this case, the control board may be responsible for voltage conversion of the power described later. In addition, the control board may not be a separate body, but may be incorporated into the LED display layer 10, the photovoltaic cell layer 20, or the battery unit 30 as a part thereof.

Referring to FIG. 6, in the LED display device 1 of this embodiment, the power generated in the photovoltaic cell layer 20 is stored in the battery unit 30. The LED display layer 10 is driven by the power stored in the battery unit 30. More specifically, the LED elements 11 included in the LED display layer 10 emit light along the arrow A. As a result, a desired image is formed on the first main surface 10A of the LED display layer 10. Therefore, the LED display device 1 can be operated by the power generated in the photovoltaic cell layer 20 in addition to the power originally stored in the battery unit 30 by being used in an environment where light is irradiated, such as outdoors. In particular, the photovoltaic cell layer 20 can generate power not only by the light B that passes through the LED display layer 10 and reaches the photovoltaic cell layer 20, but also by the light C that passes through the LED display layer 10 and the photovoltaic cell layer 20, is reflected by the battery unit 30 (the first main surface 30A of the battery 31), and reaches the photovoltaic cell layer 20. As a result, the LED display device 1 of this embodiment is an LED display device that can operate for a long time. In addition, a portion of the power generated in the photovoltaic cell layer 20 may be used directly to drive the LED display layer 10 without being stored in the battery unit 30.

(Embodiment 2)
Next, a second embodiment, which is another embodiment of the present disclosure, will be described. FIG. 10 is a schematic perspective view showing the structure of an LED display device of the second embodiment. FIG. 11 is a schematic cross-sectional view showing the structure of an LED display device of the second embodiment. FIG. 10 and FIG. 11 are views corresponding to FIG. 1 and FIG. 6 in the first embodiment. With reference to FIG. 10 and FIG. 11 and FIG. 1 and FIG. 6, the LED display device 1 of the second embodiment basically has the same configuration as the LED display device 1 of the first embodiment, and achieves the same effects. However, the LED display device 1 of the second embodiment is different from the first embodiment in the stacking order of the LED display layer 10, the photovoltaic cell layer 20, and the battery unit 30. The differences from the first embodiment will be mainly described below.

Referring to Figures 10 and 11, in the LED display device 1 of the second embodiment, the photovoltaic cell layer 20, the LED display layer 10, and the battery unit 30 are laminated in this order. The first main surface 10A of the LED display layer 10 faces the second main surface 20B of the photovoltaic cell layer 20. As a result, the LED elements 11 arranged on the first main surface 10A are attached in the vicinity of the photovoltaic cell layer 20. The first main surface 30A of the battery unit 30 faces the second main surface 10B of the LED display layer 10. The batteries 31 are arranged side by side facing the LED display layer 10 with the base layer 32 in between.

Referring to FIG. 11, in the LED display device 1 of this embodiment, when light such as sunlight is irradiated onto the first main surface 20A of the photovoltaic cell layer 20, electricity is generated by a part of the light, light D. Also, the LED display layer 10 and photovoltaic cell layer 20 of this embodiment are translucent. Therefore, when light such as sunlight is irradiated onto the first main surface 20A of the photovoltaic cell layer 20, a part of the light, light E, passes through the photovoltaic cell layer 20 and LED display layer 10, is reflected by the battery unit 30 (first main surface 31A of battery 31), and then passes further through the LED display layer 10 to reach the photovoltaic cell layer 20. Electricity is also generated by this light E.

11, the battery unit 30 is electrically connected to the LED display layer 10 by a wiring 93. The battery unit 30 is electrically connected to the photovoltaic cell layer 20 by a wiring 94. The wiring 93 and wiring 94 are examples, and the electrical connection may be achieved by wiring exposed to the outside as shown in FIG. 11, or by joining conductive pads formed on the surfaces of the LED display layer 10, the photovoltaic cell layer 20, and the battery unit 30 by solder or the like. The LED display layer 10, the photovoltaic cell layer 20, and the battery unit 30 may each be electrically connected to a control board separate from these. The battery unit 30 may be indirectly connected to at least one of the LED display layer 10 and the photovoltaic cell layer 20 via the control board. In this case, the control board may be responsible for voltage conversion of the power described later. The control board may not be a separate body, but may be incorporated as a part of the LED display layer 10, the photovoltaic cell layer 20, or the battery unit 30.

Referring to FIG. 11, in the LED display device 1 of this embodiment, the power generated in the photovoltaic cell layer 20 is also stored in the battery unit 30. The LED display layer 10 is driven by the power stored in the battery unit 30. More specifically, the LED elements 11 included in the LED display layer 10 emit light along the arrow A. The photovoltaic cell layer 20 of this embodiment has a plurality of through holes 29 penetrating the photovoltaic cell layer 20 in the thickness direction. The through holes 29 are arranged corresponding to the LED elements 11. Therefore, the light emitted along the arrow A passes through the through holes 29 and reaches the outside of the LED display device 1. As a result, the image provided by the LED display layer 10 is visible through the photovoltaic cell layer 20. More specifically, the image provided by the LED display layer 10 is visible through the through holes 29.

In this way, the LED display device 1 of this embodiment can also be operated by the power generated in the photovoltaic cell layer 20 in addition to the power stored in the battery unit 30 from the beginning, by being used in an environment exposed to light, such as outdoors. As a result, the LED display device 1 of this embodiment is an LED display device that can operate for long periods of time.

(Embodiment 3)
Next, a third embodiment of the present disclosure will be described. FIG. 12 is a schematic perspective view showing the structure of the LED display device of the third embodiment. FIG. 13 and FIG. 14 are schematic perspective views showing a state in which the LED display device is deformed. FIG. 15 is a schematic cross-sectional view showing the structure of the LED display device of the third embodiment. FIG. 12, FIG. 13, FIG. 14, and FIG. 15 are views corresponding to FIG. 1, FIG. 2, FIG. 3, and FIG. 6 in the first embodiment, respectively. With reference to FIG. 12 to FIG. 15 and FIG. 1 to FIG. 3 and FIG. 6, the LED display device 1 of the third embodiment basically has the same configuration as the LED display device 1 of the first embodiment and achieves the same effects. However, the LED display device 1 of the third embodiment is different from the first embodiment in the structure and arrangement of the battery unit. Hereinafter, the differences from the first embodiment will be mainly described.

Referring to FIG. 12, the battery unit 34 of this embodiment has a rod-like shape including a pair of end faces 35A and an outer peripheral surface 35B connecting the pair of end faces 35A. The battery unit 34 may have a structure in which a plurality of cylindrical batteries 35 are arranged and connected in the axial direction, as shown in FIG. 12, for example. The battery unit 34, which is composed of a plurality of batteries 35, is attached to the LED display layer 10 at the outer peripheral surface 35B. The controller 36 is attached to the LED display layer 10. The battery unit 34 (a plurality of batteries 35) and the controller 36 may be attached to the photovoltaic cell layer 20 instead of the LED display layer 10. The battery unit 34 and the LED display layer 10 are electrically connected by wiring 95. The battery unit 34 and the photovoltaic cell layer 20 are electrically connected by wiring 96.

In this embodiment, the LED display layer 10 and the photovoltaic cell layer 20 have elasticity. The LED display layer 10 and the photovoltaic cell layer 20 have flexibility. The LED display layer 10 and the photovoltaic cell layer 20 can be deformed into a curved shape. Therefore, the LED display device 1 of this embodiment can be in a flat state as shown in FIG. 12 and a curved state as shown in FIG. 13. As a result, the LED display device 1 of this embodiment can be installed not only on a flat wall surface but also on a curved wall surface (for example, the surface of a cylindrical pillar). In addition, the LED display device 1 of this embodiment can be deformed to be wound in a spiral shape as shown in FIG. 14. More specifically, it can be deformed to be wound in a spiral shape in the circumferential direction of the outer circumferential surface 35B so as to surround the outer circumferential surface 35B of the battery unit 34 (multiple batteries 35). As a result, the LED display device 1 of this embodiment is easy to store and transport.

Referring to FIG. 15, in the LED display device 1 of this embodiment, the power generated in the photovoltaic cell layer 20 is stored in the battery unit 34. The LED display layer 10 is driven by the power stored in the battery unit 34. Therefore, when the LED display device 1 is used in an environment where light is irradiated, such as outdoors, it can operate with the power generated in the photovoltaic cell layer 20 in addition to the power that was originally stored in the battery unit 34. As a result, the LED display device 1 of this embodiment, like the first embodiment, is an LED display device that can operate for long periods of time.

It should be understood that the embodiments disclosed herein are illustrative in all respects and are not restrictive in any respect. The scope of the present disclosure is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims.

1 LED display device, 10 LED display layer, 10A first main surface, 10B second main surface, 11 LED element, 12 base layer, 20 photovoltaic cell layer, 20A first main surface, 20B second main surface, 29 through hole, 30 battery unit, 30A first main surface, 30B second main surface, 31 battery, 31A first main surface, 31B second main surface, 32 base layer, 34 battery unit, 35 battery, 35A end surface, 35B outer peripheral surface, 36 controller, 91 wiring, 92 wiring, 95 wiring, 96 wiring, 31 0: exterior film, 310A: inner surface, 310B: outer surface, 310C: internal space, 311: first outer edge, 312: second outer edge, 313: third outer edge, 314: fourth outer edge, 320: battery body, 321: separator film, 321A: first main surface, 321B: second main surface, 322: positive electrode layer, 323: negative electrode layer, 324: positive electrode current collector foil, 325: negative electrode current collector foil, 326: electrolyte, 331: positive electrode tab terminal, 331A: body, 331B: protective layer, 332: negative electrode tab terminal, 332A: body, 332B: protective layer.

Claims (21)

an LED display layer having opposing surfaces in a thickness direction, the LED display layer including a plurality of LED elements disposed along one of the surfaces;
a photovoltaic cell layer disposed alongside one of said surfaces of said LED display layer;
a battery unit including a plurality of batteries, the battery unit being electrically connected to the LED display layer and the photovoltaic cell layer;
An LED display device, wherein power generated in the photovoltaic cell layer is stored in the battery unit, and the LED display layer is driven by the power stored in the battery unit. The LED display device of claim 1, wherein at least one of the LED display layer, the photovoltaic cell layer, and the battery unit is elastic. The LED display device according to claim 1, wherein the LED elements are arranged in a matrix. The LED display device of claim 1, wherein the battery is a lithium ion battery. The LED display device of claim 1, wherein the batteries are arranged in an array. The LED display device of claim 1, wherein the photovoltaic cell layer has surfaces that are opposite each other in a thickness direction, and one of the surfaces of the photovoltaic cell layer faces one of the surfaces of the LED display layer. The LED display layer and the photovoltaic cell layer are laminated together,
2. The LED display device of claim 1, wherein each of the batteries has a plate-like shape having surfaces opposite each other in the thickness direction, and the batteries are arranged side by side so as to face either the LED display layer or the photovoltaic cell layer. The LED display layer and the photovoltaic cell layer are laminated together,
the battery unit has a rod-like shape including a pair of end faces and an outer circumferential surface connecting the pair of end faces,
2. The LED display device of claim 1, wherein the battery unit is attached to the LED display layer or the photovoltaic cell layer at the outer circumferential surface. The LED display device of claim 1, wherein the thickness of each of the batteries is 1.0 mm or less. 2. The LED display device of claim 1, wherein the capacity of each of said batteries in the thickness direction is 70 mWh or more per 100 ^mm2 . The LED display device of claim 1, wherein each of the batteries includes a separator, a positive electrode layer and a negative electrode layer sandwiched by the separator, an electrolyte impregnated in the separator, the positive electrode layer, and the negative electrode layer, and an exterior material that contains the separator, the positive electrode layer, the negative electrode layer, and the electrolyte. The LED display device according to claim 11, wherein the positive electrode layer is made of a sintered body. The LED display device according to claim 1, wherein the distance between two adjacent LED elements in the LED display layer is 4 mm or less. The LED display device of claim 13, wherein the spacing is 1.27 mm or less. the LED display layer, the photovoltaic cell layer and the battery unit are laminated in this order;
the LED display layer is light-transmitting;
2. The LED display device of claim 1, wherein said LED elements are on said surface of said LED display layer opposite the other side to which said photovoltaic cell layer is attached. The LED display device of claim 15, wherein the photovoltaic cell layer generates power from light transmitted through the LED display layer. The LED display device of claim 15, wherein the battery unit reflects light. The LED display device of claim 17, wherein the photovoltaic cell layer also generates power from light that is transmitted through the LED display layer and the photovoltaic cell layer and reflected by the battery unit. the photovoltaic cell layer, the LED display layer and the battery unit are laminated in this order;
2. The LED display apparatus of claim 1, wherein said LED elements are mounted on one of said surfaces of said LED display layer and adjacent to said photovoltaic cell layer. the photovoltaic cell layer is light-transmitting;
20. The LED display device of claim 19, wherein the image provided by said LED display layer is viewable through said photovoltaic cell layer. the photovoltaic cell layer has a plurality of through holes penetrating the photovoltaic cell layer in a thickness direction, the through holes corresponding to the LED elements;
20. The LED display device of claim 19, wherein an image provided by the LED display layer is viewable through the through-holes.