JP6621148B2 - Display device - Google Patents

Description

  The present invention relates to an internally illuminated display device provided with a solar cell.

  2. Description of the Related Art Among display devices such as advertising boards, information display boards, and signboards, there is an internally illuminated display device having a light source for emitting light from the inside to the outside of the display device. Among the internally illuminated display devices, there is a self-luminous display device having a solar cell as an electric supply source without being connected to an external power supply. For example, Patent Document 1 describes a display device including a solar cell module including a plurality of solar cells. The display device has a thin plate-like base, a transparent thin plate-like display plate having display contents, a solar cell module attached to a surface of the mount, and a transparent plate disposed between the display plate and the solar cell module. And a plurality of light sources.

  The display content of the display panel is formed of a paint having good diffuse reflection on the back surface of the display panel. The shielding plate is black-painted so as to hide the frame other than the solar cell and the wiring member of the solar cell when viewed from the display panel side. The plurality of light sources can be turned on using electric power generated by the solar cells. Further, the plurality of light sources are provided at one end of a rectangular display plate. Light from the light source enters from one end surface of the display panel, and travels inside the display panel toward the other end surface of the display panel. The traveling light causes diffuse reflection at a display content portion formed of a paint having good diffuse reflection properties. As a result, light emission occurs in the display content portion.

JP-A-11-282389

  The light-emitting region of the display panel of the display device described in Patent Literature 1 is limited to a portion coated with a paint having good diffuse reflection properties. Further, the solar cell module of the display device is configured to receive sunlight only from one surface of the display device having the display plate. For this reason, in the above display device, the time during which sunlight can be received is limited to a short time. Therefore, when the light source is turned on using the power generated by the solar cell module at night, sufficient power may not be obtained.

  The present invention has been made in order to solve the above-described problems, and enables an increase in the time in which a solar cell module, that is, a solar cell panel can receive sunlight, and an increase in a light emitting area on a display surface. To provide an internally illuminated display device.

  In order to solve the above problems, a display device according to the present invention is an internally illuminated display device having a display surface, and includes a double-sided light receiving type solar cell that converts light incident on both sides into electric power. -Type solar cell panel, a diffusion light-guiding panel having two opposing main surfaces, one of which is arranged on the light-receiving surface of the solar cell panel, and the other of the diffusion light-guiding panel A light-transmitting film disposed on the main surface and forming a display surface; and a light source provided on a side of the diffusion light-guiding panel with respect to a stacking direction of the diffusion light-guiding panel and the solar cell panel. Is provided so as to be able to use the power generated by the solar cell panel, the diffused light guide panel has a side surface located on the side in the stacking direction with respect to the main surface, and the diffused light guide panel is Guides and spreads light incident on the side surface to the main surface. It is possible, and configured to be guided through the light incident on the main surface to the opposite major surfaces.

  In the display device having the above-described configuration, sunlight is converted into electric power by the solar cell panel regardless of which of the light receiving surfaces on both sides of the solar cell panel is incident. Further, the light emitted from the light source enters the diffusion light guide panel from the side surface, is diffused and guided, and is emitted from the main surface of the diffusion light guide panel to a wide area such as the entire main surface. The emitted light irradiates the light-transmitting film over a wide area. Therefore, the display device enables an increase in light-receiving time of the solar cell panel and an increase in a light-emitting area on the display surface. Furthermore, since the solar cell panel includes a solar cell of a double-sided light receiving type, the thickness and weight of the solar cell panel can be reduced. Therefore, a display device formed by laminating the solar cell panel, the diffusion light guide panel, and the light-transmitting film as described above can be reduced in thickness and weight.

  The solar cell panel includes a plurality of solar cells, and the plurality of solar cells may be arranged side by side in a plane between light receiving surfaces on both sides of the solar cell panel. In the solar cell panel having the above-described configuration, the double-sided light receiving solar cells are arranged side by side in a plane, so that the solar cell panel can be made thinner.

  A plurality of light sources may be provided side by side along the side surface. With the configuration described above, the entire side surface of the diffusion light guide panel is brightly illuminated by the plurality of light sources.

  A diffusion light guide panel may be provided on each of the light receiving surfaces of the solar cell panel. With the above configuration, the display device can emit light from any of the two diffused light guide panels provided on the light receiving surface, that is, enables light emission from both surfaces.

  A plurality of light sources are provided side by side in the laminating direction, and the plurality of light sources arranged in the laminating direction are separated into a light source for irradiating one diffused light guide panel and a light source for irradiating the other diffused light guide panel. A partition may be provided. With the above configuration, a light source that irradiates only one diffused light guide panel and a light source that irradiates only the other diffused light guide panel are provided. By selectively turning on the light source, the two diffused light guide panels can selectively emit light.

  The display device may include a blocking body that blocks light from a light source that enters one of the diffusion light guide panels or the other diffusion light guide panel. With the above configuration, it is possible to configure so that only one of the two diffusion light guide panels emits light.

  The display device includes a light director for directing light from a light source in a predetermined direction, and the light director includes a direction for directing light from the light source to one of the two diffusion light guide panels, and a light source. May be variably provided in a direction in which light from the light source is directed to both diffused light guide panels. According to the above-described configuration, it is possible to selectively cause one or both of the two diffused light guide panels to emit light by a mechanical operation of changing the direction of the light director.

  The translucent film includes, on the surface of the translucent film, a display object drawn so as to have a transmissive property to the surface opposite to the surface, and the two translucent light guide panels disposed on the two diffusion light guide panels. The display of the light-sensitive film may be symmetric with respect to the solar cell panel. In the above configuration, the display object can be recognized from both sides of the light-transmitting film. Therefore, two translucent films on which the same display object is drawn can be arranged on two diffusion light guide panels. Therefore, it is possible to reduce the manufacturing cost of the translucent film.

  Further, the display device according to the present invention is an internally illuminated display device having a display surface, and has a dual-sided light receiving type solar cell panel and two main surfaces located at opposite positions. A light-diffusing light-guiding panel having one main surface overlapped with the light-receiving surface, a light-transmitting film arranged on the other main surface of the diffusion light-guiding panel and forming a display surface, and a diffusion light-guiding panel. On the other hand, a light source provided on the side of the stacking direction of the diffusion light guide panel and the solar cell panel, the light source is provided so as to be able to use the power generated by the solar cell panel, the diffusion light guide panel has a main surface Has a side surface located on the side with respect to the lamination direction, and the diffusion light guide panel can guide and diffuse light incident on the side surface from the light source to the main surface, and enter the main surface. It is configured so that light can be guided to the opposite main surface

  In the display device having the above-described configuration, sunlight incident on any of the light receiving surfaces on both sides of the solar cell panel is converted into electric power by the solar cell panel. Further, light emitted from the light source and incident on the diffusion light guide panel from the side surface is emitted over a wide area such as the main surface of the diffusion light guide panel over the entire main surface, and irradiates the light transmissive film over a wide area. Therefore, the display device enables an increase in light-receiving time of the solar cell panel and an increase in a light-emitting area on the display surface.

  ADVANTAGE OF THE INVENTION According to the display apparatus which concerns on this invention, the increase of the time which can receive sunlight of a solar cell panel and the expansion of the light emission area on a display surface are attained.

FIG. 1 is a perspective view schematically showing an appearance of a display device according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of the display device of FIG. FIG. 3 is a cross-sectional side view of the display device of the display device of FIG. 1, which is perpendicular to the wide side wall of the housing and passes through the center of the wide side wall, as viewed in a direction III. FIG. 4 is a cross-sectional view of the double-sided solar cell of FIG. 2, taken along a cross section similar to FIG. 3. FIG. 5 is a perspective view showing an example of a display object on the two translucent films of the display device of FIG. FIG. 6 is a diagram schematically showing a front view of the first diffusion light guide panel and the LED substrate of FIG. 3 as viewed from the first light transmitting film side. FIG. 7 is a perspective view showing an installation example of the display device of FIG. FIG. 8 is a cross-sectional side view showing a configuration of Modification Example 1 of the display device according to the embodiment, similarly to FIG. FIG. 9 is a cross-sectional side view showing a configuration of Modification 2 of the display device according to the embodiment, similarly to FIG. 3. FIG. 10 is a cross-sectional side view showing a configuration of Modification 3 of the display device according to the embodiment, similarly to FIG. 3.

  Hereinafter, a display device according to an embodiment of the present invention will be described with reference to the drawings. Each of the embodiments described below shows a comprehensive or specific example. Numerical values, shapes, materials, constituent elements, arrangement positions of constituent elements, connection forms, and the like shown in the following embodiments are merely examples, and do not limit the present invention. Further, among the components in the following embodiments, components not described in the independent claims indicating the highest concept are described as arbitrary components.

  In addition, each drawing in the accompanying drawings is a schematic diagram, and is not necessarily strictly illustrated. Further, in each drawing, the same or similar components are denoted by the same reference numerals. In the following description of the embodiments, expressions with “substantially” such as substantially parallel and substantially orthogonal may be used. For example, “substantially parallel” means not only completely parallel but also substantially parallel, that is, including, for example, a difference of about several percent. The same applies to expressions with other “abbreviations”.

[Embodiment]
In the embodiment, an internally illuminated display device that stores power generated by a dual-sided photovoltaic cell in a storage battery and emits light from the inside using a light source using power supplied from the storage battery will be described.

  FIG. 1 is a perspective view schematically illustrating an appearance of a display device 100 according to an embodiment. FIG. 2 is an exploded perspective view of the display device 100 of FIG. Referring to FIG. 1 and FIG. 2 together, the display device 100 includes a flat rectangular parallelepiped box-shaped housing 1. In the housing 1, a display element accommodation room 2 and an electric device accommodation room 3 divided by a partition wall 1e are formed. The housing 1 has two flat and wide side walls 1a and 1b at opposing positions, and has openings 1c and 1d for communicating the display element housing chamber 2 with the outside of the housing 1, respectively. The openings 1c and 1d are display windows for displaying display surfaces A and A 'including display objects B and B' on both sides of the display device 100 to the outside (note that the display objects B 'and display For plane A ′, see FIG. 5). Further, the housing 1 has an insertion opening 1f on one side adjacent to the side walls 1a and 1b, for communicating the display element housing 2 with the outside of the housing 1. The insertion opening 1f can be closed by a lid side wall 1g constituting a part of the housing 1.

  Further, the display device 100 includes a storage battery 51 and a control unit 52 that controls the operation of the display device 100 in the electric device housing room 3. The control unit 52 can be configured by a circuit centered on a microcomputer, a circuit having no microcomputer, or the like. The storage battery 51 can be a secondary battery capable of storing and discharging power. The storage battery 51 is, for example, a nickel hydride battery, a lithium ion battery, a lead storage battery, a lithium ion polymer secondary battery, a nickel cadmium storage battery, a nickel iron storage battery, a nickel zinc storage battery, a silver zinc oxide storage battery, a flywheel battery, a large capacity capacitor, and the like. Secondary battery. Moreover, the storage battery 51 may be configured to include a battery socket to which a secondary battery can be attached and detached, and a secondary battery.

  In addition, the display device 100 includes a first light-transmitting film 11, a first diffused light guide panel 21, a double-sided light receiving solar cell panel 31, and a second diffused light guide panel 22 in the display element housing chamber 2. And the second translucent film 12 are provided in a laminated state. The lamination is performed in the order of the first light-transmitting film 11, the first diffusion light-guiding panel 21, the solar cell panel 31, the second diffusion light-guiding panel 22, and the second light-transmitting film 12.

  Further, the display device 100 includes four LED boards 41 in the display element housing 2. The four LED substrates 41 are arranged to face four elongated rectangular edge surfaces 31c around the rectangular solar cell panel 31. Each LED board 41 has an elongated rectangular plate shape, and is arranged so that its longitudinal direction is along the longitudinal direction of the edge surface 31c. Each LED board 41 has a plurality of LEDs (light emitting diodes) 42 arranged in a line along the longitudinal direction of the LED board 41. In the present embodiment, four LEDs 42 that emit white light are arranged on each LED board 41. Here, the LED 42 is an example of a light source. In addition, a cold cathode ray tube, an EL light emitting element, various light bulbs, and other light emitting elements may be used instead of the LED 42 as the light source.

  The first light-transmitting film 11, the first diffusion light-guiding panel 21, the solar cell panel 31, the second diffusion light-guiding panel 22, the second light-transmitting film 12, and the LED substrate 41 as described above are inserted into the insertion opening 1f. Can be inserted into the housing 1 and installed.

  Referring to FIG. 2 and FIG. 3 together, the double-sided light receiving type solar cell panel 31 has a flat rectangular plate shape. FIG. 3 shows a cross section perpendicular to the wide side walls 1a and 1b and the partition wall 1e of the housing 1 in the display device 100 of FIG. 1 and passing through the center of the side walls 1a and 1b in a direction III toward the insertion opening 1f. FIG. 2 is a cross-sectional side view of the display device 100 as viewed from above. The solar cell panel 31 has two flat and wide rectangular main surfaces 31a and 31b at opposing positions as light receiving surfaces (hereinafter, the main surfaces 31a and 31b are also referred to as light receiving surfaces 31a and 31b). . The light receiving surfaces 31a and 31b are located back to back, and face in opposite directions. Further, the solar cell panel 31 has four elongated rectangular edge surfaces 31c surrounding the periphery of the solar cell panel 31 between the light receiving surface 31a and the light receiving surface 31b. The solar cell panel 31 is configured to convert light incident on both the light receiving surfaces 31a and 31b into electric power. The solar cell panel 31 is formed by a solar cell module having a plurality of rectangular plate-shaped double-sided light-receiving solar cells 32. The double-sided light-receiving solar cell 32 has two flat and wide rectangular main surfaces at opposing positions as light-receiving surfaces, and converts light incident on the two light-receiving surfaces on both sides into electric power. In the solar cell panel 31, each of the two main surfaces of the plurality of double-sided light receiving solar cells 32 is adjacent to the two main surfaces of the adjacent double-sided light receiving solar cell 32 to form a flat surface. Are arranged side by side in a plane and are arranged in a lattice. The solar cell panel 31 includes double-sided light-receiving solar cells 32 arranged in a single layer in a direction from the light receiving surface 31a to the light receiving surface 31b between the light receiving surfaces 31a and 31b.

  Any available double-sided solar cell may be used as the double-sided solar cell 32. As the double-sided solar cell 32, for example, a thin solar cell having a thickness equal to or close to the thickness of a single-sided solar cell having one light-receiving surface is preferable. The thickness of the double-sided light receiving solar cell 32 is a thickness in a direction from the light receiving surface 31a of the solar cell panel 31 to the light receiving surface 31b. The double-sided light-receiving solar cell 32 can be, for example, a single-crystal silicon-based, polycrystalline silicon-based, amorphous silicon-based, compound-based, or organic solar cell. It may have a configuration, or may have a configuration of a dye-sensitized solar cell.

  For example, FIG. 4 shows an example of a double-sided light receiving type solar cell 32 in the case of a pn junction type solar cell. Note that the double-sided light receiving solar cell 32 shown in FIG. 4 is shown by a cross section similar to the cross section of the display device 100 shown in FIG. 4 includes a layered silicon substrate 32a as a p-type semiconductor, and two diffusion layers 32b as n-type semiconductors stacked on both surfaces of the silicon substrate 32a. Further, the double-sided light receiving type solar cell 32 includes an antireflection film 32c laminated on each diffusion layer 32b on the side opposite to the silicon substrate 32a, and an electrode 32d penetrating through each antireflection film 32c and reaching the diffusion layer 32b. including. Furthermore, the double-sided light receiving solar cell 32 includes a protective layer 32e, and the protective layer 32e is laminated on each antireflection film 32c on the side opposite to the diffusion layer 32b so as to cover the antireflection film 32c together with the electrode 32d. Have been. The silicon substrate 32a, the diffusion layer 32b, the antireflection film 32c, and the protective layer 32e extend so that the respective laminated surfaces face and follow the light receiving surfaces 31a and 31b of the solar cell panel 31 shown in FIG. ing. The two-sided photovoltaic cell 32 can convert light incident from the outer surface of the protective layer 32e into electric power, and output the converted electric power through the electrode 32d. Note that the details of the photoelectric conversion function of converting light energy into electric power in the pn junction type solar cell are known, and thus description thereof is omitted.

  Referring to FIG. 2 and FIG. 3 together, the first diffused light guide panel 21 and the second diffused light guide panel 22 have the same configuration, and have a flat rectangular thin plate shape. The first diffused light guide panel 21 and the second diffused light guide panel 22 have the same planar shape and planar dimensions as the solar cell panel 31. The first diffused light guide panel 21 and the second diffused light guide panel 22 are made of resin such as acrylic, nylon, polyethylene, polypropylene, polyester, polystyrene, ABS resin, polyethylene terephthalate, polyvinyl alcohol, polyvinyl chloride, polycarbonate, and fluororesin; It can be made from materials such as glass. The first diffused light guide panel 21 and the second diffused light guide panel 22 have translucency so that light can pass through them. Furthermore, the first diffused light guide panel 21 and the second diffused light guide panel 22 may be colorless and transparent so that light can easily pass through the inside.

  The first diffusion light guide panel 21 surrounds the first diffusion light guide panel 21 between two flat and wide rectangular main surfaces 21a and 21b at opposing positions, and between the main surfaces 21a and 21b. And four elongated edge surfaces 21c. The first diffusion light guide panel 21 is stacked on the solar cell panel 31 in such a manner that its main surface 21b is directly overlapped on the light receiving surface 31a of the solar cell panel 31 without leaving a gap. . Thereby, the thickness of the first diffusion light guide panel 21 and the solar cell panel 31 in the stacking direction can be minimized. There may be. Here, the edge surface 21c is an example of a side surface of the first diffusion light guide panel 21 located on the side in the stacking direction of the first diffusion light guide panel 21 and the solar cell panel 31 with respect to the main surfaces 21a and 21b. is there.

  Further, the first diffusion light guide panel 21 can make light incident on all areas of the main surface 21a, the main surface 21b, and the four edge surfaces 21c. The first diffused light guide panel 21 is configured to diffuse and guide light that has entered the inside from the edge surface 21c, and to emit the light from the main surfaces 21a and 21b in a planar manner. Further, the first diffused light guide panel 21 is configured to emit light incident on the main surface 21a from the main surface 21b and to emit light incident on the main surface 21b from the main surface 21a. Have been.

  The second diffused light guide panel 22 surrounds the second diffused light guide panel 22 between two flat and wide rectangular main surfaces 22a and 22b at opposing positions, and between the main surfaces 22a and 22b. And four elongated edge surfaces 22c. The second diffused light guide panel 22 is laminated on the solar cell panel 31 in such a manner that its main surface 22a is directly overlapped on the light receiving surface 31b of the solar cell panel 31 without leaving a gap. . Thereby, the thickness of the second diffusion light guide panel 22 and the solar cell panel 31 in the stacking direction can be minimized, but a gap is provided between the second diffusion light guide panel 22 and the solar cell panel 31. There may be. Here, the edge surface 22c is an example of a side surface of the second diffusion light guide panel 22 located on the side in the stacking direction of the solar cell panel 31 and the second diffusion light guide panel 22 with respect to the main surfaces 22a and 22b. is there.

  Further, the second diffusion light guide panel 22 can make light incident on all areas of the main surface 22a, the main surface 22b, and the four edge surfaces 22c. The second diffused light guide panel 22 is configured to diffuse and guide light that has entered the inside from the edge surface 22c, and to emit the light from the main surfaces 22a and 22b in a planar manner. Further, the second diffused light guide panel 22 is configured to emit light incident on the main surface 22b from the main surface 22a, and to emit light incident on the main surface 22a from the main surface 22b. Have been. The detailed configuration of the first diffused light guide panel 21 and the second diffused light guide panel 22 will be described later.

  The first light-transmitting film 11 and the second light-transmitting film 12 have the same configuration, and have a rectangular planar shape. The first light transmissive film 11 and the second light transmissive film 12 have the same planar shape and planar dimensions as the first diffused light guide panel 21 and the second diffused light guide panel 22. As the first light-transmitting film 11 and the second light-transmitting film 12, any film material or sheet material having a light-transmitting property can be used. For example, the first light-transmitting film 11 and the second light-transmitting film 12 are made of acrylic, nylon, polyethylene, polypropylene, polyester, polystyrene, ABS resin, polyethylene terephthalate, polyvinyl alcohol, polyvinyl chloride, polycarbonate, fluororesin, etc. It can be made of resin, glass, and the like. Further, the first light-transmitting film 11 and the second light-transmitting film 12 may be colorless and transparent so that light can easily pass therethrough.

  The first translucent film 11 has two rectangular main surfaces 11a and 11b at opposing positions. The first light-transmitting film 11 can transmit light incident on all regions of one of the main surfaces 11a and 11b through the inside, and can emit the light from the other of the main surfaces 11a and 11b. The first translucent film 11 is laminated on the first diffusion light guide panel 21 so that its main surface 11b is directly overlapped with the main surface 21a of the first diffusion light guide panel 21. You. The first translucent film 11 may be simply placed on the first diffusion light guide panel 21 or may be attached to the first diffusion light guide panel 21. In addition, there may be a gap between the first light transmitting film 11 and the first diffusion light guide panel 21. Thereby, diffusion of light passing between the first translucent film 11 and the first diffusion light guide panel 21 is promoted.

  The second translucent film 12 has two rectangular main surfaces 12a and 12b located at opposing positions. The second translucent film 12 can transmit light incident on all areas of one of the main surfaces 12a and 12b through the inside, and can emit the light from the other of the main surfaces 12a and 12b. The second translucent film 12 is laminated on the second diffusion light guide panel 22 in such a manner that its main surface 12a is directly overlapped with the main surface 22b of the second diffusion light guide panel 22. You. The second translucent film 12 may be simply placed on the second diffusion light guide panel 22 or may be attached to the second diffusion light guide panel 22. In addition, there may be a gap between the second translucent film 12 and the second diffusion light guide panel 22. Thereby, diffusion of light passing between the second translucent film 12 and the second diffusion light guide panel 22 is promoted.

  As shown in FIG. 5, on the main surface 11a or 11b of the first translucent film 11, a display object B indicating the content to be displayed is drawn by means such as drawing or printing. A display object B 'similar to the display object B is also drawn on the main surface 12a or 12b of the second translucent film 12. FIG. 5 is a perspective view showing an example of the display objects B and B ′ on the two translucent films 11 and 12 of the display device 100 of FIG. FIG. 5 shows the relationship between the display objects B and B ′ in the two translucent films 11 and 12 and the housing 1. In the present embodiment, the display object B is drawn on the main surface 11a of the first light-transmitting film 11, and the display object B 'is drawn on the main surface 12b of the second light-transmitting film 12. . The display objects B and B 'may be drawn with a sparse density so that the display objects B and B' themselves have translucency. Alternatively, the display objects B and B 'may be drawn by a number of dots having a gap between each other, and light may be transmitted through the gap between the dots. Thus, the first light-transmitting film 11 and the second light-transmitting film 12 have light transmittance as a whole.

  When the translucent films 11 and 12 are housed in the housing 1 through the insertion opening 1f, the main surfaces 11b of the first translucent film 11 and the main surfaces 12a of the second translucent film 12 Are arranged facing each other. At this time, substantially the entirety of the main surface 11a of the first light transmissive film 11 and substantially the entirety of the main surface 12b of the second light transmissive film 12 are separated from the opening 1c and the opening 1d of the housing 1, respectively. Exposed. Such main surfaces 11a and 12b constitute display surfaces A and A 'of the display device 100, respectively. Then, the display objects B and B ′ can be seen from the outside of the display device 100 via the exposed main surfaces 11a and 12b, respectively. The first light-transmitting film 11 and the second light-transmitting film 12 may be turned upside down and housed in the housing 1 such that the main surfaces 11b and 12a are exposed.

  Further, for example, when the main surface 11a of the first translucent film 11 and the main surface 12b of the second translucent film 12 constitute the display surfaces A and A ′ of the display device 100, respectively, the main surfaces 11a and 12b On top of this, a film having a UV (ultraviolet) cut effect may be attached, or a paint having a UV cut effect may be applied. Furthermore, when the display object B or B 'is drawn on the main surface 11a or 12b, the film and the paint are applied on the display object B or B'. The film and the paint reduce the fading of the display objects B and B ′ due to ultraviolet rays. The same applies to the case where the main surface 11b of the first translucent film 11 and the main surface 12a of the second translucent film 12 constitute the display surfaces A and A 'of the display device 100, respectively.

  Further, in the present embodiment, the contents of the display objects B and B 'indicate the direction in which the person should proceed. Therefore, the display object B of the first light-transmitting film 11 and the display object B ′ of the second light-transmitting film 12 have a mirror image relationship, that is, a surface when the main surface 11b and the main surface 12a are overlapped. The relationship is symmetric. In this way, by using the display objects B and B 'having a mirror image relationship, a user who views the display device 100 from any of the openings 1c and 1d is guided in the same direction. Further, when the display objects B and B ′ can be seen through the main surface opposite to the main surface on which the display objects B and B ′ are drawn, that is, the display objects B and B ′ have transparency, In the case where it can be similarly recognized from any of the main surfaces, the first light-transmitting film 11 can be used as the second light-transmitting film 12. That is, the display surfaces A and A ′ can be configured using the two first light-transmitting films 11.

  Referring to FIG. 2 and FIG. 3 together, the four LED boards 41 are housed in the display element housing chamber 2 of the housing 1 and fixed to the housing 1. The four LED boards 41 housed in the display element housing chamber 2 are formed in a flat rectangular parallelepiped shape formed by laminating the translucent films 11 and 12, the diffusion light guide panels 21 and 22, and the solar cell panel 31. Are arranged so as to surround four narrow edge surfaces 60a in the stacked body 60 of FIG. In addition, the edge surface 60 a is a surface along the stacking direction of elements such as the solar cell panel 31 included in the stacked body 60.

  A plurality of LEDs 42 are arranged on a front surface 41 a of each LED substrate 41 facing the edge surface 60 a of the stacked body 60. On the surface 41 a of each LED board 41, the plurality of LEDs 42 are arranged in a line and at equal intervals along the longitudinal direction of the LED board 41. Each LED 42 is oriented to emit light toward the stack 60. The plurality of LEDs 42 of each LED board 41 are arranged so as to irradiate the entire opposing edge surface 60 a with a substantially uniform light amount along the longitudinal direction of the LED board 41. That is, the LEDs 42 constitute an edge light type light source for the stacked body 60.

  In addition, on the surface 41a of each LED board 41, a reflection shade 43 extending along the longitudinal direction of the LED board 41 is provided. The reflection shade 43 has a mountain-shaped cross-sectional shape. The reflection shade 43 has an elongated rectangular plate-like first reflection member 43a and a second reflection member 43b that form a mountain-shaped cross section. The first reflection member 43a and the second reflection member 43b extend so that their respective longitudinal directions are along the rows of the LEDs 42, and protrude from the LED substrate 41 toward the stacked body 60. The first reflection member 43a is located on the front surface 41a of the LED board 41 adjacent to the LED 42 on the side of the side wall 1a of the housing 1, and is inclined so as to approach the side wall 1a as the distance from the LED board 41 increases. . The second reflection member 43b is located on the surface 41a of the LED board 41 adjacent to the LED 42 on the side of the side wall 1b of the housing 1, and is inclined so as to approach the side wall 1b as the distance from the LED board 41 increases. . Therefore, the first reflection member 43a and the second reflection member 43b extend on the surface 41a of the LED board 41 so as to surround the entire row of the LEDs 42 from both sides, and separate from each other as the distance from the LEDs 42 increases. It is inclined in the shape of the end. Light-reflective coating is applied to the surfaces of the first reflection member 43a and the second reflection member 43b on the LED 42 side. Therefore, the reflection shade 43 directs toward the stacked body 60 while reflecting the light of the adjacent LED 42 to itself.

  Referring to FIG. 6, a detailed configuration of the first diffusion light guide panel 21 is shown. 6 is a diagram schematically showing a front view of the first diffusion light guide panel 21 and the LED substrate 41 of FIG. 3 as viewed from the first light transmissive film 11 side. Further, in FIG. 6, the reflection shade 43 is omitted.

  Similarly to the solar cell panel 31, each edge surface 21c of the first diffusion light guide panel 21 faces the LED substrate 41 and is positioned so that its longitudinal direction is along the longitudinal direction of the LED substrate 41.

  On the main surface 21a of the first diffusion light guide panel 21, a plurality of recesses 23 are formed in a dot shape. For simplicity, in FIG. 6, the size of the concave portion 23 with respect to the main surface 21a and the interval between the concave portions 23 are drawn largely large, and the number of the concave portions 23 is also drawn largely small. The concave portion 23 on the main surface 21a may have a shape such as a pyramid, a cone, or a wedge that tapers inward from the main surface 21a. The recess 23 can be formed by etching, laser processing, or the like.

  On the main surface 21a, the concave portions 23 are arranged such that the surface density of the concave portions 23 increases from the edge surface 21c toward the center of the main surface 21a. That is, the concave portion 23 is arranged such that the surface density increases as the distance from the LED substrate 41 increases. The recesses 23 are arranged in the same arrangement form from the center of the main surface 21a toward each edge surface 21c, that is, are arranged so as to be radially distributed from the center of the main surface 21a.

  In this case, the recesses 23 may have the same shape and dimensions. At this time, the recesses 23 are arranged such that the distance between the recesses 23 becomes narrower from the edge surface 21c toward the center of the main surface 21a.

  Alternatively, the plurality of recesses 23 may be distributed such that the planar shape, that is, the area of the recesses 23 when the main surface 21a is viewed from the front increases from the edge surface 21c toward the center of the main surface 21a. At this time, the interval between the concave portions 23 may be constant, narrower or wider as going from the edge surface 21c toward the center of the main surface 21a.

  Also, a plurality of recesses 23 having the same shape and size as the recesses 23 of the main surface 21a are formed on the main surface 21b of the first diffusion light guide panel 21. The arrangement of the recesses 23 on the main surface 21b is the same as the arrangement of the recesses 23 on the main surface 21a. For example, the arrangement of the recesses 23 on the main surface 21b and the arrangement of the recesses 23 on the main surface 21a may have a mirror image relationship with respect to the main surfaces 21a and 21b, that is, a plane-symmetric relationship. Alternatively, the arrangement of the recesses 23 on the main surface 21b is shifted from the arrangement of the recesses 23 on the main surface 21a and the arrangement symmetric with respect to the main surfaces 21a and 21b in the direction along the main surfaces 21a and 21b. It may be in a form. That is, the concave portion 23 on the main surface 21a and the concave portion 23 on the main surface 21b having the same arrangement may be offset in a direction along the main surfaces 21a and 21b. However, the concave portion 23 on the main surface 21a and the concave portion 23 on the main surface 21b do not need to have the same arrangement form, and are further arranged offset in the direction along the main surfaces 21a and 21b. Is also good.

  For example, when light of a plurality of LEDs 42 of one LED board 41 enters from one edge surface 21c of the first diffusion light guide panel 21 as described above, the incident light And travels along the main surfaces 21a and 21b toward the opposite edge surface 21c. The light from the plurality of LEDs 42 is incident on the entire edge surface 21c with a substantially uniform light amount along the longitudinal direction of the edge surface 21c. The traveling light is refracted and travels in various directions toward the main surfaces 21a and 21b on the wall surfaces of the concave portions 23 on the main surfaces 21a and 21b, that is, is guided and diffused. Incident light guided and diffused by the plurality of recesses 23 can cause the main surfaces 21a and 21b to emit light in a planar manner. Then, since the light of the four LED substrates 41 enters the first diffusion light guide panel 21 via the four edge surfaces 21c, the entire main surfaces 21a and 21b can emit light in a planar manner.

  Further, as the distance from the LED substrate 41 increases, the amount of light reaching the concave portions 23 decreases, so that the brightness of light guided and diffused by each concave portion 23 decreases. However, since the surface density of the concave portion 23 increases as the distance from the LED substrate 41 increases, the main surfaces 21a and 21b can emit light with substantially uniform luminance from the edge surface 21c to the center. The main surfaces 21a and 21b of the first diffusion light guide panel 21 that receives light from the four edge surfaces 21c can emit light with substantially uniform luminance over the entirety.

  Furthermore, since concave portions 23 are formed in both main surfaces 21a and 21b, the amount of light that is refracted by concave portions 23 increases. The light refracted by the concave portion 23 of the main surface 21a may reach the main surface 21b, or may reach the concave portion 23 of the main surface 21b and be further refracted and proceed to the main surface 21a. Similarly, the light refracted by the concave portion 23 of the main surface 21b may reach the main surface 21a or may reach the concave portion 23 of the main surface 21a to be further refracted and proceed to the main surface 21b. Therefore, the amount of light guided and diffused to the main surfaces 21a and 21b increases, that is, the main surfaces 21a and 21b emit light with high luminance.

  When the concave portion 23 on the main surface 21a and the concave portion 23 on the main surface 21b are offset in a direction along the main surfaces 21a and 21b, the light refracted by the concave portion 23 on each of the main surfaces 21a and 21b becomes It is easy to directly reach the main surfaces 21b and 21a. Therefore, the main surfaces 21a and 21b emit light with higher luminance.

  Therefore, the first diffusion light guide panel 21 guides and diffuses the light incident on the four edge surfaces 21c to the main surfaces 21a and 21b, and makes the whole of the main surfaces 21a and 21b emit light with high uniform luminance. . The first diffused light guide panel 21 can also emit light incident on the main surface 21a to the solar cell panel 31 through the main surface 21b, and can emit light incident on the main surface 21b from the main surface 21a.

  Also, the main surface 22a and 22b of the second diffused light guide panel 22 shown in FIG. 3 having the same shape as the first diffused light guide panel 21 have the same shape and dimensions as the first diffused light guide panel 21. A plurality of recessed portions 23 are formed. The arrangement of the recesses 23 on the main surfaces 22a and 22b is the same as the arrangement of the recesses 23 on the main surfaces 21a and 21b of the first diffused light guide panel 21. Each edge surface 22c of the second diffused light guide panel 22 also faces the LED substrate 41 and is positioned so that its longitudinal direction is along the longitudinal direction of the LED substrate 41. Therefore, when the light of the LED 42 of the LED substrate 41 enters the inside from the four edge surfaces 22c of the second diffused light guide panel 22, the entire main surfaces 22a and 22b can emit light with substantially uniform luminance. In addition, the second diffused light guide panel 22 can emit light incident on the main surface 22b to the solar cell panel 31 through the main surface 22a, and can emit light incident on the main surface 22a from the main surface 22b.

  The arrangement of the recesses 23 on the main surfaces 22a and 22b of the second diffusion light guide panel 22 may be different from the arrangement of the recesses 23 on the main surfaces 21a and 21b of the first diffusion light guide panel 21. . Thereby, the light emission form of the first diffusion light guide panel 21 and the light emission form of the second diffusion light guide panel 22 can be made different.

  Referring to FIG. 2 and FIG. 3 together, the storage battery 51 stores electric power generated by photoelectric conversion in the solar cell panel 31. The control unit 52 performs control to switch between charging the storage battery 51 from the solar cell panel 31 and discharging from the storage battery 51 to the LED board 41. For example, the control unit 52 charges the storage battery 51 with the power generated by the solar cell panel 31 when the electromotive force generated by the photoelectric conversion of the solar cell panel 31, that is, the voltage is equal to or greater than the charge / discharge switching threshold. It may be controlled. Furthermore, when the electromotive force is less than the charge / discharge switching threshold, the control unit 52 may perform control to supply power from the storage battery 51 to the LED board 41. That is, the controller 52 does not turn on the LED 42 by charging the storage battery 51 in a bright situation where there is sufficient sunlight such that the electromotive force of the solar cell panel 31 is equal to or greater than the charge / discharge switching threshold. On the other hand, the controller 52 turns on the LED 42 using the power of the storage battery 51 in a dark state where there is little sunlight or no sunlight such that the electromotive force of the solar cell panel 31 is less than the charge / discharge switching threshold. Let it.

  Further, the control unit 52 may control turning on and off the LED 42 based on an input signal given to the display device 100. The input signal is a signal from an input unit mounted on the display device 100 or provided outside the display device 100, a signal from an illuminance sensor mounted on the display device 100 or provided outside the display device 100, or the like. It may be. For example, when the signal of the illuminance sensor indicates a predetermined illuminance or higher, that is, when the periphery of the display device 100 is bright, the control unit 52 does not supply power to the LED 42 and the signal of the illuminance sensor indicates less than the predetermined illuminance. That is, when the surroundings of the display device 100 are dark, control may be performed to supply power to the LEDs 42.

  In the display device 100 having the above-described configuration, regardless of whether the sunlight is incident on any of the display surfaces A and A ′, substantially all of the translucent film 11 or 12 and the diffused light guide panel 21 or 22 are exposed to sunlight. The light passes through substantially the entire surface and is incident on substantially the entire light receiving surface 31a or 31b of the solar cell panel 31. The incident sunlight is converted into electric power by the solar cell panel 31 and supplied to the storage battery 51. On the other hand, in the display device 100, the illumination of the display surfaces A and A 'is performed by causing the LED 42 to emit light using the power of the storage battery 51. When the LED 42 emits light, specifically, when all the LEDs 42 of all the LED boards 41 emit light, the light from the LED 42 has a substantially uniform light amount over the entire edge surface 21 c of the first diffusion light guide panel 21. At the same time, the light enters the entire surface 22c of the second diffused light guide panel 22 with a substantially uniform light amount. The incident light is guided and diffused in each of the first diffused light guide panel 21 and the second diffused light guide panel 22, and the entire main surfaces 21 a and 21 b of the first diffused light guide panel 21 and the second diffused light guide panel 21. The entire main surfaces 22a and 22b of the two-diffusion light guide panel 22 emit light substantially uniformly. As a result, the entirety of the first light-transmitting film 11 and the entirety of the second light-transmitting film 12 emit light substantially uniformly, and the display objects B and B ′ shown in FIG. 5 are illuminated.

  Since the display objects B and B 'are drawn on the thin film material of the first light-transmitting film 11 and the second light-transmitting film 12, they can easily transmit sunlight and illuminated light. This increases the amount of power generated by the solar cell panel 31, while the display objects B and B 'themselves emit light by the illuminated light. Furthermore, when the display objects B and B ′ have translucency, that is, when the display objects B and B ′ are drawn with transparency so as to have translucency or are drawn with a large number of dots with a gap between each other, The amount of power generated by the solar cell panel 31 further increases, and the display objects B and B ′ themselves emit brighter light by the illuminated light. When nothing is drawn around the display objects B and B ', the periphery emits light in the color of the LED 42 or the color of the translucent films 11 and 12 themselves. When the surroundings of the display objects B and B 'are colored with transparency so as to have translucency, the periphery emits light in the colored color.

  Further, the display device 100 having the above-described configuration can reduce the thickness in the direction from the side wall 1a of the housing 1 to the side wall 1b. For example, the thickness of the solar cell panel 31 formed by one layer of the double-sided light receiving solar cells 32 can be about 3 mm to about 5 mm, specifically, about 5 mm. The thickness of the first diffused light guide panel 21 and the second diffused light guide panel 22 can be about 3 mm to about 8 mm, specifically about 5 mm. The thickness of the first light-transmitting film 11 and the second light-transmitting film 12 can be about 0.1 mm to about 3 mm. The display device 100 has substantially only the thickness obtained by laminating the translucent films 11 and 12, the diffusion light guide panels 21 and 22, and the solar cell panel 31 having the above-described thicknesses. Absent.

  Further, as shown in FIG. 7, the display device 100 can be used by being incorporated in a support frame 200 installed on the ground outdoors, for example. FIG. 7 is a perspective view showing an example of installation of the display device 100 of FIG. At this time, for example, the display device 100 sets the direction of the display surface A ′ to the east of the azimuth (the direction indicated by “E” in FIG. 7), and sets the direction of the display surface A to the west of the azimuth (“ W ”) may be oriented together with the support frame 200. Thereby, the light receiving surfaces 31b and 31a of the solar cell panel 31 shown in FIG. 3 are oriented east and west, respectively. Therefore, the solar cell panel 31 can receive sunlight from at least one of the light receiving surfaces 31a and 31b for a long time from sunrise to sunset to generate power. This makes it possible to increase the amount of power stored in the storage battery 51.

  As described above, the display device 100 according to the embodiment is an internally illuminated display device having the display surfaces A and A '. The display device 100 has a two-sided light receiving type solar cell panel 31 and first diffusion surfaces each having main surfaces 21 a and 21 b located at positions facing each other and arranged such that the main surface 21 b overlaps the light receiving surface 31 a of the solar cell panel 31. A light guide panel 21, a second diffused light guide panel 22 having opposing main surfaces 22a and 22b and arranged with the main surface 22a superimposed on the light receiving surface 31b of the solar cell panel 31, and a first diffused light guide panel A first light-transmitting film 11 and a second light-transmitting film 12, which are disposed on the main surface 21a of the first light-emitting panel 21 and the main surface 22b of the second diffused light-guiding panel 22 and form the display surfaces A and A '; For one diffused light guide panel 21 and second diffused light guide panel 22, LEDs 42 provided on the side of the stacking direction of first diffused light guide panel 21, solar cell panel 31 and second diffused light guide panel 22 are provided. Prepare. The LED 42 is provided so that the power generated by the solar cell panel 31 can be used. The first diffused light guide panel 21 has an edge surface 21c located on the side in the stacking direction with respect to the main surfaces 21a and 21b, and the second diffused light guide panel 22 has a main surface 22a and 22b with respect to the main surfaces 22a and 22b. It has an edge surface 22c located on the side with respect to the laminating direction. The first diffusion light guide panel 21 can guide and diffuse light incident on the edge surface 21c from the LED 42 to the main surface 21a, and can guide light incident on the main surface 21a to the opposing main surface 21b. It is configured to be. The second diffused light guide panel 22 can guide and diffuse light incident on the edge surface 22c from the LED 42 to the main surface 22b, and can guide light incident on the main surface 22b to the opposing main surface 22a. It is configured to be. Furthermore, the solar cell panel 31 includes a double-sided light-receiving solar cell 32 that converts light incident on both sides into electric power.

  In the display device 100 having the above-described configuration, the external light can be converted into electric power by the solar cell panel 31 irrespective of whether the light enters the light receiving surfaces 31a and 31b on both sides of the solar cell panel 31. The light emitted from the LED 42 is diffused and guided after entering the first diffused light guide panel 21 and the second diffused light guide panel 22 from the edge surfaces 21 c and 22 c. The light is emitted from the surface 21a and the main surface 22b of the second diffused light guide panel 22 over a wide area such as the entire main surface. Then, the emitted light irradiates the first light transmitting film 11 and the second light transmitting film 12 over a wide area. The display device 100 as described above makes it possible to increase the time during which the solar cell panel 31 can receive sunlight, and to enlarge the light emitting area on the display surfaces A and A '. Further, the thin light-transmitting films 11 and 12 easily transmit light. For this reason, the display surfaces A and A 'formed by the translucent films 11 and 12 and the display objects B and B' inside the display surfaces A and A 'easily emit light. Further, since the solar cell panel 31 includes the double-sided light receiving solar cells 32, the thickness and weight of the solar cell panel 31 can be reduced. Therefore, the display device 100 formed by stacking the solar cell panel 31, the diffusion light guide panels 21 and 22, and the translucent films 11 and 12 as described above can be made thinner and lighter. .

  For example, when the display device 100 is used for an advertisement board, a guidance display board, a signboard, or the like, a display surface having a large area is required, and the display device 100 having such a surface is enlarged. Furthermore, the display device 100 is installed in various forms, such as being placed upright on the ground, being suspended from a ceiling or a roof, or extending from a wall and attached to the wall. The display device 100 that can be made thinner and lighter is suitable for the above-mentioned use, and can further reduce and simplify a support for installation. Further, in the display device 100, the sizes of the light receiving surfaces 31a and 31b of the solar cell panel 31 can be made equal to the sizes of the main surfaces of the diffusion light guide panels 21 and 22 and the translucent films 11 and 12. That is, the size of the display device 100 can be made substantially equal to the size of the display surfaces A and A '. Thus, the display device 100 can be reduced in size and weight.

  Further, in the display device 100 according to the embodiment, by providing the first diffused light guide panel 21 and the second diffused light guide panel 22 on each of the light receiving surfaces 31a and 31b of the solar cell panel 31, the display device 100 The two diffused light guide panels 21 and 22, that is, the two surfaces can emit light. Further, by providing the first light-transmissive film 11 and the second light-transmissive film 12 on each of the first diffused light guide panel 21 and the second diffused light guide panel 22, the display device 100 has two surfaces. It can be a display surface.

  Further, in the display device 100 according to the embodiment, the solar cell panel 31 includes a plurality of double-sided light-receiving solar cells 32, and the plurality of double-sided light-receiving solar cells 32 is a light-receiving surface on both sides of the solar cell panel 31. It is arranged side by side in a plane between 31a and 31b. In the solar cell panel 31 having the above-described configuration, the double-sided light receiving solar cells 32 are arranged side by side in a plane, so that the thickness of the solar cell panel 31 can be reduced.

  In the display device 100 according to the embodiment, the plurality of LEDs 42 are provided side by side along the edge surface 21c of the first diffusion light guide panel 21 and the edge surface 22c of the second diffusion light guide panel 22. With the above-described configuration, the entire edge surface 21c of the first diffusion light guide panel 21 and the entire edge surface 22c of the second diffusion light guide panel 22 are brightly illuminated by the plurality of LEDs 42. Further, when a plurality of LEDs 42 are arranged in a line, both the first diffused light guide panel 21 and the second diffused light guide panel 22 can emit light by the LEDs 42. Thereby, power saving becomes possible.

  In the display device 100 according to the embodiment, the first light-transmitting film 11 and the second light-transmitting film 12 have transmissivity to the opposite main surfaces 11b and 12a on the respective main surfaces 11a and 12b. Of the first light-transmitting film 11 and the second light-transmitting film 12 disposed on the first diffusion light-guiding panel 21 and the second diffusion light-guiding panel 22 including the display objects B and B ′ drawn as described above. Objects B and B ′ are symmetric with respect to solar panel 31. In the above-described configuration, the display objects B and B ′ can be recognized from both main surfaces of the first light transmitting film 11 and the second light transmitting film 12, respectively. Therefore, the two first translucent films 11 on which the same display object B is drawn can be arranged on the first diffused light guide panel 21 and the second diffused light guide panel 22. Therefore, the manufacturing cost of the translucent films 11 and 12 can be reduced.

[Modification 1]
Further, as a first modified example of the display device 100 according to the embodiment, the following configuration is exemplified. As shown in FIG. 8, the display device 101 according to the first modification is configured so that the LED 42 does not irradiate the second diffusion light guide panel 22 and the second light transmitting film 12. FIG. 8 is a cross-sectional side view showing a configuration of a display device 101 which is a first modification of the display device 100 according to the embodiment, similarly to FIG. Further, in the following description of the modified example, components having the same reference numerals as those in the above-described drawings are the same or similar components, and thus detailed description thereof will be omitted.

  The display device 101 has a reflection shade 143 in the housing 1 instead of the reflection shade 43 of the display device 100 according to the embodiment. The reflection shade 143 has a mountain-shaped cross-sectional shape, and further has an elongated rectangular plate-shaped first reflection member 43a and a second reflection member 143b that form a mountain-shaped cross-section.

  The first reflection member 43a of the reflection shade 143 is located adjacent to the LED 42 on the LED substrate 41 on the side of the side wall 1a of the housing 1, and is similar to the first reflection member 43a of the reflection shade 43 shown in FIG. It has a configuration.

  The second reflection member 143b is positioned adjacent to the LED 42 on the LED board 41 on the side of the side wall 1b of the housing 1, and is arranged in a row of the plurality of LEDs 42 on the LED board 41 in the longitudinal direction of the second reflection member 143b. To extend along. Further, the second reflecting member 143b protrudes from the LED substrate 41 and extends to the edge surface 31c of the solar cell panel 31 facing the LED substrate 41. Therefore, the second reflection member 143 b blocks the light from the LED 42 so as not to reach the second diffused light guide panel 22 and the second translucent film 12. Here, the second reflection member 143b is an example of a blocking body.

  The first reflection member 43a and the second reflection member 143b as described above form a divergent shape that is separated from each other as the distance from the LED substrate 41 increases, and the entire row of the LEDs 42 on the LED substrate 41 is viewed from both sides. It extends to surround. Further, a light-reflective coating is also applied to the surface of the second reflection member 143b on the LED 42 side. Therefore, the reflection shade 143 directs the light of the adjacent LED 42 toward the first diffusion light guide panel 21 and the first light transmissive film 11 while reflecting the light to itself.

  Therefore, in the display device 101, when the LED 42 is turned on, the first light-transmissive film 11 constituting the display surface A of the display device 101 emits light. Other configurations and operations of the display device 101 are the same as those of the display device 100 according to the embodiment, and thus description thereof will be omitted.

  As described above, according to the display device 101 according to the first modification, the same effects as those of the display device 100 according to the embodiment can be obtained except that only one display surface A of the display device 101 emits light. On the other hand, the display device 101 according to the first modification includes the second reflection member 143b that blocks the light of the LED 42 incident on the second diffusion light guide panel 22. With the above-described configuration, it is possible to configure so that only the first diffusion light guide panel 21 of the first diffusion light guide panel 21 and the second diffusion light guide panel 22 emits light. For example, it is possible to cope with a case where only the display surface A of the display device 101 needs to emit light due to a factor such as an installation location. Thereby, power saving of the display device 101 is also possible. Furthermore, by exchanging the configuration of the first reflection member 43a and the configuration of the second reflection member 143b, it is also possible to configure so that only the second diffusion light guide panel 22 emits light. Therefore, only one of the display surfaces A and A 'can emit light by a simple operation of rearranging the two reflecting members.

[Modification 2]
Modification 2 of the display device 100 according to the embodiment includes the following configuration. As illustrated in FIG. 9, in the display device 102 according to Modification 2, the LED 42 includes the first diffused light guide panel 21 and the first light transmissive film 11, the second diffused light guide panel 22, and the second light transmissive film. And the irradiating film 12 is selectively irradiated. FIG. 9 is a cross-sectional side view showing a configuration of a display device 102 which is a modified example 2 of the display device 100 according to the embodiment, similarly to FIG.

  The display device 102 has two rows of LEDs 42 along the longitudinal direction of the LED board 241 on a flat surface 241 a of each of the elongated rectangular plate-shaped LED boards 241 in the housing 1. On the surface 241a of the LED board 241, two rows of the LEDs 42 form a first LED group 42a and a second LED group 42b. Each of the first LED group 42a and the second LED group 42b includes a plurality of LEDs 42 arranged in a line along the longitudinal direction of the LED board 241. The first LED group 42a and the second LED group 42b are adjacent to each other at intervals in the short direction orthogonal to the longitudinal direction of the LED substrate 241, that is, in the stacking direction of the stacked body 60, and extend substantially parallel to each other. I have.

  The LED substrate 241 of the display device 102 has the same shape and dimensions as the LED substrate 41 of the display device 100 according to the embodiment. Further, the arrangement of the LED boards 241 of the display device 102 in the housing 1 is the same as the LED board 41 of the display device 100 according to the embodiment. Each LED substrate 241 is arranged so that the front surface 241a faces each edge surface 60a of the stacked body 60.

  The first LED group 42a is located at a position facing the edge surface 21c of the first diffused light guide panel 21, and the second LED group 42b is located at a position facing the edge surface 22c of the second diffused light guide panel 22.

  On the surface 241a of each LED board 241, a long and narrow rectangular plate-shaped partition plate 244 is provided. The partition plate 244 extends from a position on the surface 241a between the first LED group 42a and the second LED group 42b to the edge 31c of the solar cell panel 31 facing the surface 241a. Further, the partition plate 244 extends along the longitudinal direction of the LED substrate 241 so as to partition the first LED group 42a and the second LED group 42b. Here, the partition plate 244 is an example of a partition body.

  The partition plate 244 as described above blocks the light of the LEDs 42 of the first LED group 42a so as not to reach the second diffused light guide panel 22 and the second light transmissive film 12, and controls the LEDs 42 of the second LED group 42b. Light is blocked so as not to reach the first diffusion light guide panel 21 and the first light transmissive film 11.

  In addition, the control unit 52 illustrated in FIG. 1 is configured to separately control lighting and extinguishing operations of the LEDs 42 of the first LED group 42a and lighting and extinguishing operations of the LEDs 42 of the second LED group 42b. . Further, the control unit 52 may control to turn on one or both of the first LED group 42a and the second LED group 42b based on the state of charge (also referred to as SOC) of the storage battery 51. The SOC is the ratio of the remaining charge to the charge capacity of the storage battery 51, and is often expressed in units of%. For example, when the SOC of the storage battery 51 is equal to or more than the two lighting thresholds, the control unit 52 controls both the first LED group 42a and the second LED group 42b to be turned on, and the SOC of the storage battery 51 is less than both the lighting thresholds. In this case, control may be performed so that only one of the first LED group 42a and the second LED group 42b is turned on.

  In the display device 102 as described above, the display surface A and the display surface A ′ can be selectively emitted, that is, one or both of the display surface A and the display surface A ′ can be arbitrarily selected to emit light. . Other configurations and operations of the display device 102 are the same as those of the display device 100 according to the embodiment, and thus description thereof will be omitted.

  As described above, according to the display device 102 according to Modification 2, the same effects as those of the display device 100 according to the embodiment can be obtained. Further, in the display device 102 according to Modification 2, the plurality of LEDs 42 are provided side by side in the stacking direction of the stacked body 60, and the partition plate 244 connects the plurality of LEDs 42 aligned in the stacking direction to the first diffusion light guide panel. 21 and a second LED group 42b that irradiates the second diffusion light guide panel 22. With the above configuration, the first LED group 42a that irradiates only the first diffused light guide panel 21 and the second LED group 42b that irradiates only the second diffused light guide panel 22 are provided. By selectively lighting the first LED group 42a and the second LED group 42b, the first diffusion light guide panel 21 and the second diffusion light guide panel 22 can selectively emit light. That is, in the display device 102, a display surface to emit light can be selected from the two display surfaces A and A 'to emit light. Thereby, power saving of the display device 102 is also possible.

  In the display device 102 according to Modification 2, the LED 42 is not provided with the reflection shade 43, but is not limited thereto. In the LED board 241, the reflection shade 43 may be provided for each of the LEDs 42 of the first LED group 42a and the LEDs 42 of the second LED group 42b.

[Modification 3]
Modification 3 of the display device 100 according to the embodiment includes the following configuration. As shown in FIG. 10, the display device 103 according to the third modification is configured so that the irradiation direction of the LED 42 can be changed. FIG. 10 is a cross-sectional side view showing a configuration of a display device 103 which is a third modification of the display device 100 according to the embodiment, similarly to FIG.

  The display device 103 has a reflection shade 343 in the housing 1 instead of the reflection shade 43 of the display device 100 according to the embodiment. Here, the reflection shade 343 is an example of a light directing body. The reflection shade 343 has an elongated rectangular plate-like first reflection member 343a and a second reflection member 343b that form a mountain-shaped cross section. The first reflecting member 343a and the second reflecting member 343b extend so that the longitudinal direction thereof is along the longitudinal direction of the LED board 41, and extend so that the longitudinal direction of the LED board 41 is along the axial direction. It is attached to the peripheral surface of the rotating shaft 345 so as to rotate integrally.

  A bearing 346 is provided on the surface 41 a of the LED board 41. The bearing 346 supports the rotating shaft 345 such that the rotating shaft 345 can rotate around its axis. The rotating shaft 345 may be configured to be rotated manually, or may be configured to be rotated electrically using a driving device such as a motor or an actuator. Further, the control unit 52 shown in FIG. 1 may control the operation of the driving device.

  The first reflection member 343a and the second reflection member 343b protrude from the rotary shaft 345 in such a manner that the first reflective member 343a and the second reflective member 343b spread apart from each other as the distance from the rotary shaft 345 increases. On the rotating shaft 345, the first reflecting member 343a is located closer to the side wall 1a of the housing 1 than the second reflecting member 343b. A light-reflective coating is applied to the surfaces of the first reflecting member 343a and the second reflecting member 343b on the side of the laminate 60.

  A plurality of LEDs 42 are provided in a row along the axial direction of the rotating shaft 345 on the inner side of the angled cross section formed by the first reflecting member 343a, the rotating shaft 345, and the second reflecting member 343b, that is, on the laminate 60 side. Have been. For this reason, while the light from the plurality of LEDs 42 is substantially restricted by the reflector 343 to the area of the fan-shaped cross section formed inside between the first reflecting member 343a and the second reflecting member 343b, 343.

  Therefore, by rotating the rotating shaft 345 to change the direction of the reflection shade 343, the irradiation area of the LED 42 on the edge surface 60a of the stacked body 60 can be changed. Specifically, the light of the LED 42 is transmitted between the set of the first diffusion light guide panel 21 and the first light transmissive film 11 and the set of the second diffusion light guide panel 22 and the second light transmissive film 12. The illuminated area can be changed to illuminate one or both sets.

  Thereby, in the display device 103, the display surface A and the display surface A 'can be selectively emitted, that is, one or both of the display surface A and the display surface A' can be arbitrarily selected to emit light. Other configurations and operations of the display device 103 are the same as those of the display device 100 according to the embodiment, and thus description thereof will be omitted.

  As described above, according to the display device 103 according to the third modification, the same effect as that of the display device 102 according to the second modification can be obtained. Further, the display device 103 according to Modification 3 includes a reflection shade 343 that directs the light from the LED 42 in a predetermined direction, and the reflection shade 343 transmits the light from the LED 42 to the first diffusion light guide panel 21 and the second diffusion light guide panel 21. The direction is variably provided in a direction in which the light is directed to one of the light guide panels 22 and a direction in which the light from the LED 42 is directed to both the first diffused light guide panel 21 and the second diffused light guide panel 22. With the above-described configuration, it is possible to cause one or both of the first diffusion light guide panel 21 and the second diffusion light guide panel 22 to selectively emit light by a mechanical operation of changing the direction of the reflection shade 343. Become. Furthermore, in the display device 103, in both the case where both the display surface A and the display surface A ′ are caused to emit light and the case where one of the display surfaces A ′ is caused to emit light, the LEDs 42 in one row of the LED substrate 41 may be turned on. Become.

[Other Modifications]
As described above, the display device according to the embodiment and the modification of the present invention have been described, but the present invention is not limited to the embodiment and the modification. In other words, the embodiments and the modifications disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  Then, with respect to the display device according to the embodiment and the modification, on the main surfaces on both sides of each of the first diffused light guide panel 21 and the second diffused light guide panel 22, the plurality of concave portions 23 have a surface density as the distance from the LED 42 increases. , While being distributed radially from the center of the main surface, but is not limited to this. The plurality of concave portions 23 may be arranged so as to form a pattern such as a lattice shape or a line shape. In this case, the width of the grid and the width of the line may be configured to increase as the distance from the LED 42 increases.

  In the display device according to the embodiment and the modified example, the first diffused light guide panel 21 and the second diffused light guide panel 22 reduce incident light by the plurality of concave portions 23 formed on the main surfaces on both sides. Light was guided and diffused, but is not limited thereto. The first diffused light guide panel and the second diffused light guide panel are configured such that a plurality of diffused particles are dispersed and contained inside the first diffused light guide panel and the second diffused light guide panel, so that light incident from an edge surface is provided. May be configured so that the diffusion particles guide and diffuse the light to the main surface. Alternatively, the first diffused light guide panel and the second diffused light guide panel each have a plurality of dots colored, for example, white, instead of the recesses 23 on one main surface or both main surfaces. It may be printed. The dots may be formed in the same planar shape and arrangement as the concave portions 23. The dots on the main surface can diffuse the light incident from the edge surface of the diffusion light guide panel from the main surface and emit the light. Printing of dots on the main surface can be performed by inkjet printing, silk screen printing, or the like.

  In the display device according to the embodiment and the modification, the first diffused light guide panel 21 and the second diffused light guide panel 22 are provided for each of the two light receiving surfaces 31a and 31b of the solar cell panel 31. However, the present invention is not limited to this. Only one of the first diffused light guide panel 21 and the second diffused light guide panel 22 may be provided. In this case, the display device has one display surface while allowing the solar cell panel 31 to receive light from both of the two light receiving surfaces 31a and 31b. For example, the display device 100 according to the embodiment may have a configuration in which any one of the first diffusion light guide panel 21 and the second diffusion light guide panel 22 is removed. The display device 101 according to Modification 1 may have a configuration in which the second diffusion light guide panel 22 in which light from the LED 42 is blocked by the second reflection member 143b is removed. Further, a translucent film may be directly disposed on the light receiving surface of the solar cell panel 31 from which the diffusion light guide panel has been removed.

  In the display device according to the embodiment and the modified example, the first light-transmitting film 11 and the second light-transmitting film 12 are provided for the first diffusion light-guiding panel 21 and the second diffusion light-guiding panel 22, respectively. However, the present invention is not limited to this. Only one of the first light transmitting film 11 and the second light transmitting film 12 may be provided. In this case, a diffusion light guide panel without a light-transmitting film can be used as mere illumination.

  Furthermore, in the diffusion light guide panel provided with no translucent film, the arrangement of the plurality of recesses 23 may be the same as the display. That is, a display object may be formed by the arranged plurality of concave portions 23. In this case, when the LED 42 is turned on, the display object formed by the concave portion 23 emits light.

  In the display device according to the embodiment and the modification, the display objects B and B ′ are drawn on the first light-transmitting film 11 and the second light-transmitting film 12, respectively. However, the present invention is not limited to this. . A display object may not be drawn on one of the first light-transmitting film 11 and the second light-transmitting film 12, or a display object may not be drawn on both. In this case, a display surface of the display device on which a light-transmitting film on which a display object is not drawn can be used as illumination. When the light-transmitting film includes a color, colored illumination can be used.

  In the display device according to the embodiment and the modified example, the double-sided light receiving solar cell panel 31 is configured by the double-sided light receiving solar cell 32. However, the present invention is not limited to this. The double-sided light-receiving solar cell panel may be formed by arranging two single-sided light-receiving solar cells back to back and arranging them side by side in a plane.

  In the display device according to the embodiment and the modified example, the four edge surfaces 60 a of the stacked body 60 including the solar cell panel 31, the first diffusion light guide panel 21, the second diffusion light guide panel 22, etc. Although two LED substrates are provided, the present invention is not limited to this. Only one LED substrate may be provided, and this one LED substrate may illuminate one edge surface 60 a of the stacked body 60. Alternatively, two LED boards may be provided, and these two LED boards may illuminate two edge surfaces 60 a of the stacked body 60. Alternatively, three LED substrates may be provided, and these three LED substrates may irradiate three edge surfaces 60 a of the stacked body 60. The number of LED boards includes the size such as the area of the first diffusion light guide panel 21 and the second diffusion light guide panel 22, the brightness required for the display surface of the display device, the number of LEDs provided on one LED board, and the like. Can be determined according to

  Regarding the display device according to the embodiment and the modification, as an example of the control of the control unit 52, the storage battery 51 is charged when the electromotive force of the solar cell panel 31 is equal to or greater than the charge / discharge switching threshold, and the electromotive force is equal to the charge / discharge switching threshold. The example in which the power is supplied to the LED substrate when the value is less than the above is described. Instead of the charge / discharge switching threshold or in combination with the charge / discharge switching threshold, the lighting start time, the lighting end time, the time from the lighting start to the end, the charging start time, the charging end time, the charging start At least one of the times from to the end may be determined in advance, and the charging of the storage battery 51 and the light emission of the LED substrate may be switched as appropriate. Thereby, the control of the lighting time / time becomes possible, that is, for example, lighting for 30 minutes before and after the train departure time at night, lighting for one hour before and after the entrance and exit time of the theater, and the like become possible. Furthermore, it is not necessary to secure the capacity of the storage battery 51 excessively.

  In the display device according to the embodiment and the modification, as an example of the control of the control unit 52, an example in which the storage device 51 is switched to one of charging and the light emission of the LED substrate has been described. However, the control unit 52 may perform control such that charging and light emission are performed simultaneously. For example, when the display device is configured to include a plurality of storage batteries 51, the control unit 52 simultaneously performs charging of one storage battery 51 and supply of power from another storage battery 51 to the LED board. Control to be implemented. Further, the control unit 52 may perform control to change the storage battery 51 to be charged and the storage battery 51 for power supply. Accordingly, the display device can continuously perform illumination with constant brightness for a long time.

  Further, in the display device according to the embodiment and the modification, an upper limit threshold value of the SOC indicating that the storage battery 51 is overcharged and a lower limit threshold value of the SOC indicating the lower limit value of the remaining battery capacity of the storage battery 51 are determined. You may. The control unit 52 stops or inhibits charging of the storage battery 51 when the SOC of the storage battery 51 has reached the upper limit threshold, and stops power supply to the LED board when the SOC of the storage battery 51 has reached the lower limit threshold. Or you may make it prohibit.

  In the display devices 102 and 103 according to Modifications 2 and 3, an illuminance sensor may be provided on the housing 1 or the like near each of the display surfaces A and A '. And the control part 52 may control so that either of the 1st diffused light guide panel 21 and the 2nd diffused light guide panel 22 may be irradiated with LED42 based on the signal received from an illuminance sensor. For example, when the detected illuminance of the illuminance sensor on the display surface A side is equal to or greater than a predetermined illuminance and the detected illuminance of the illuminance sensor on the display surface A ′ side is less than the predetermined illuminance, that is, the display surface A is brighter due to sunlight or the like, When the display surface A ′ is dark, the control unit 52 controls the LED 42 to irradiate only the second diffused light guide panel 22. That is, the control unit 52 may selectively illuminate the display surface A or A 'according to whether or not illumination is required for the display surfaces A and A'.

  Further, in the display device according to the embodiment and the modification, a temperature sensor may be provided in the housing 1 or the like near each of the display surfaces A and A 'or near each of the display surfaces A and A'. And control part 52 may control lighting of LED42 based on a signal received from a temperature sensor. For example, when the temperature detected by the temperature sensor on the display surface A side or the display surface A 'side is equal to or higher than a predetermined temperature, the control unit 52 may control the LED 42 to be turned off. That is, the control unit 52 controls the LED 42 to be turned off while the display surface is irradiated with the sunlight, based on the determination that the sunlight is radiated on the display surface having the predetermined temperature or higher. Alternatively, in the display devices 102 and 103 according to Modifications 2 and 3, if the temperature detected by only one of the temperature sensors on the display surface A side and the display surface A ′ side is higher than a predetermined temperature, the control unit 52 It is also possible to control so that the LED is not radiated to the diffusion light guide panel on the display surface side of the display surface, and the LED is radiated to the diffusion light guide panel on the display surface side lower than the predetermined temperature. That is, the control unit 52 may selectively illuminate the display surface A or A 'according to the determination whether or not the display surfaces A and A' are irradiated with sunlight.

  In the display device according to the embodiment and the modified example, the LED substrate includes the white LED 42, but is not limited thereto, and may include a red, green, or blue LED. Further, the LED substrate may include at least some of white, red, green, and blue LEDs in combination. The control unit 52 is configured to individually control turning on and off the LEDs of each color, and turns on and off the LEDs according to a preset program regarding the order of turning on and off, the lighting time, and the like. You may. Accordingly, the display device can exhibit various illumination effects, and can enhance the display on the display surface. For example, as the illumination effect, not only the effect of changing the brightness, but also the effect of expressing various colors by combining red, blue, and green light at an arbitrary ratio, and the ratio of red, blue, and green light dynamically Dynamic lighting effects are also possible.

  In the display device according to the embodiment and the modified example, all the LEDs 42 of all the LED boards are configured to be turned on at the same time, but the present invention is not limited to this. The control unit 52 may be configured to individually control the turning on and off of the LEDs 42 of the individual LED boards. The control unit 52 may turn on and off the LEDs 42 according to a preset program regarding the order of turning on and off the LEDs 42 and the lighting time. Thus, a change or fluctuation in illumination can be given to the display surface of the display device, and the display on the display surface can be made to stand out.

  In the display device according to the embodiment and the modification, the LED 42 is configured to be turned on using only the power of the storage battery 51, but is not limited thereto. The LED 42 may be configured to directly use the power generated by the solar cell panel 31 in addition to the power of the storage battery 51, or may be configured to use the power of a power source other than the storage battery 51.

  In the display device according to the embodiment and the modification, the storage battery 51 and the control unit 52 are housed in the electric device housing room 3 adjacent to the display element housing room 2 in the housing 1, but are not limited thereto. It is not done. One or both of the storage battery 51 and the control unit 52 may be arranged separately from the housing 1. For example, one or both of the storage battery 51 and the control unit 52 may be arranged in a case separate from the housing 1, a frame or a support supporting the housing 1, or the like.

  In the display device according to the embodiment and the modified example, the translucent films 11 and 12, the diffusion light guide panels 21 and 22, the solar cell panel 31, and the LED substrate 41 are connected to the housing 1 through the insertion opening 1f of the housing 1. 1, but it is not limited to this. The casing is configured to be divided, and the translucent films 11 and 12, the diffusion light guide panels 21 and 22, the solar cell panel 31, the LED board 41, and the like, and the casing are assembled together. Is also good.

  Further, a mode constructed by arbitrarily combining the embodiments and the modified examples is also included in the scope of the present invention. Further, the present invention can be realized not only as the above-described display device, but also in various devices including a combination of the display device and another device.

11 First translucent film 11a, 11b Main surface (surface of translucent film)
12 Second translucent film 12a, 12b Main surface (surface of translucent film)
21 First Diffusion Light Guide Panel 21a, 21b Main Surface (Diffuse Light Guide Panel Main Surface)
21c Edge surface (side surface of diffusion light guide panel)
22 Second Diffusion Light Guide Panel 22a, 22b Main Surface (Diffuse Light Guide Panel Main Surface)
22c Edge surface (side surface of diffusion light guide panel)
31 solar cell panel 31a, 31b light receiving surface 32 double-sided light receiving solar cell 42 LED (light source)
100, 101, 102, 103 Display device 143b Second reflective member (blocker)
244 Partition plate (partition body)
343 Reflector shade (light directing body)
A, A 'display surface B, B' display object

Claims (9)

An internally illuminated display device having a display surface,
A double-sided solar panel including a double-sided solar cell that converts light incident on both sides into electric power,
A first diffusion having a main surface located at two opposing positions and being arranged on the one light receiving surface so as to directly face the one main surface to the one light receiving surface of the solar cell panel; A light guide panel,
A second diffusion having a main surface located at two opposing positions and being arranged on the other light receiving surface so as to directly face one main surface to the other light receiving surface of the solar cell panel A light guide panel,
A light-transmitting film that is disposed so as to directly overlap on the other main surface of at least one of the first diffusion light guide panel and the second diffusion light guide panel, and forms the display surface,
For the first diffused light guide panel and the second diffused light guide panel, the first diffused light guide panel, a light source provided laterally to the stacking direction of the solar cell panel and the second diffused light guide panel ,
A storage battery that stores the power generated by the solar cell panel,
And a control unit,
The light source is provided to be able to use the power of the storage battery,
The light source includes a first light source that irradiates the first diffused light guide panel, and a second light source that irradiates the second diffused light guide panel,
Each of the first diffused light guide panel and the second diffused light guide panel has a side surface located on the side in the stacking direction with respect to the main surface,
The first diffused light guide panel and the second diffused light guide panel are each capable of guiding and diffusing light incident on the side surface from the light source to the main surface, and light incident on the main surface. Is configured to be able to guide light to the opposing main surface,
The display device, wherein the control unit turns on one or both of the first light source and the second light source based on a power storage state of the storage battery. The solar cell panel includes a plurality of the solar cells,
The display device according to claim 1, wherein the plurality of solar cells are arranged side by side in a plane between the light receiving surfaces on both sides of the solar cell panel. A first illuminance sensor arranged near the first diffusion light guide panel,
A second illuminance sensor disposed near the second diffused light guide panel,
The control unit acquires a signal indicating illuminance from the first illuminance sensor and the second illuminance sensor, and based on the illuminance indicated by the signals of the first illuminance sensor and the second illuminance sensor, the first light source and the Control the lighting of the second light source,
The display device according to claim 1, wherein the first light source and the second light source are provided side by side along the side surface. Each of the first diffused light guide panel and the second diffused light guide panel has a plurality of recesses arranged on at least one of the main surfaces so that the surface density increases as the distance from the light source increases.
The display device according to any one of claims 1 to 3, wherein the light-transmitting film is provided on each of the first diffusion light-guiding panel and the second diffusion light-guiding panel so as to directly overlap with each other. The first light source and the second light source are provided side by side in the stacking direction,
The display device according to claim 1, wherein a partition body that separates the first light source and the second light source is provided. The display device according to any one of claims 1 to 5, further comprising a blocking body that blocks light of the light source that enters the second diffusion light guide panel. A light directing body that directs light from the light source in a predetermined direction,
The light directing body is configured to direct light from the light source to one of the first diffused light guide panel and the second diffused light guide panel, and to direct light from the light source to the first diffused light guide panel. The display device according to any one of claims 1 to 6, wherein a direction is variably provided in a direction directed to both the panel and the second diffused light guide panel. The translucent film, on the surface of the translucent film, includes a display object drawn to have a transmissivity to the surface opposite to the surface,
The said display thing of two said translucent films arrange | positioned at the said 1st diffused light guide panel and the said 2nd diffused light guide panel is symmetrical with respect to the said solar cell panel. A display device according to claim 1. An internally illuminated display device having a display surface,
A dual-sided solar panel,
A first diffusion having a main surface located at two opposing positions and being arranged on the one light receiving surface so as to directly face the one main surface to the one light receiving surface of the solar cell panel; A light guide panel,
A second diffusion having a main surface located at two opposing positions and being arranged on the other light receiving surface so as to directly face one main surface to the other light receiving surface of the solar cell panel A light guide panel,
A light-transmitting film that is disposed so as to directly overlap on the other main surface of at least one of the first diffusion light guide panel and the second diffusion light guide panel, and forms the display surface,
For the first diffused light guide panel and the second diffused light guide panel, the first diffused light guide panel, a light source provided laterally to the stacking direction of the solar cell panel and the second diffused light guide panel ,
A storage battery that stores the power generated by the solar cell panel,
And a control unit,
The light source is provided to be able to use the power of the storage battery,
The light source includes a first light source that irradiates the first diffused light guide panel, and a second light source that irradiates the second diffused light guide panel,
Each of the first diffused light guide panel and the second diffused light guide panel has a side surface located on the side in the stacking direction with respect to the main surface,
The first diffused light guide panel and the second diffused light guide panel are each capable of guiding and diffusing light incident on the side surface from the light source to the main surface, and light incident on the main surface. Is configured to be able to guide light to the opposing main surface,
The display device, wherein the control unit turns on one or both of the first light source and the second light source based on a power storage state of the storage battery.

Images