PATENT ABSTRACT
Disclosed is an image display device, which is provided with an optical power generating section, which generates power when light is applied, a display section, which displays an image using the power obtained by the power generation performed by the optical power generating section, and a body section having the display section provided therein. The optical power generating section is provided vertically above the body section.

PATENT DESCRIPTION
TECHNICAL FIELD 
       [0001]    The present invention relates to image display devices for displaying images. 
       BACKGROUND ART 
       [0002]    Today, image display devices such as LCD displays are used in digital signage applications. In this connection, for example, Patent Document 1 discloses an image display device provided with, to cope with installation outdoors, a hermetic structure for preventing entry of water and dust and a cooling structure for suppressing a rise in temperature. 
         [0003]    On the other hand, Patent Document 2 discloses an image display device that is driven with electric power obtained through power generation by a solar cell. Patent Document 2 discloses, in  FIG. 1 , a solar cell provided on a side face of the base on which the image display device is installed, and a light admitting device for efficient irradiation of the solar cell with light. 
       LIST OF CITATIONS 
     Patent Literature 
       [0000]    
       
         Patent Document 1: Japanese Patent Application Publication No. 2009-294284 
         Patent Document 2: Japanese Patent Application Publication No. 2005-321738 
       
     
       SUMMARY OF THE INVENTION 
     Technical Problem 
       [0006]    Inconveniently, the image display device disclosed in Patent Document 2 requires separate installation of the light admitting device. Moreover, in a case where electric power needs to be supplied to a large display device and the solar cell needs to be accordingly large, a large installation area is required. Moreover, the light admitting device and the solar cell need to be installed in a particular positional relationship with respect to the sun, and this diminishes flexibility in installation. 
       Solution to the Problem 
       [0007]    According to one aspect of the invention, an image display device is provided with: 
         [0008]    a photovoltaic power generation portion which generates electric power when irradiated with light; 
         [0009]    a display portion which displays an image by using the electric power obtained through power generation by the photovoltaic power generation portion; and 
         [0010]    a body portion which is provided with a display portion, wherein 
         [0011]    the photovoltaic power generation portion is provided vertically over the body portion. 
         [0012]    According to another aspect of the invention, an image display device is provided with: 
         [0013]    a photovoltaic power generation portion which generates electric power when irradiated with light; 
         [0014]    a display portion which displays an image by using the electric power obtained through power generation by the photovoltaic power generation portion; and 
         [0015]    a body portion which is provided with a display portion, wherein 
         [0016]    the photovoltaic power generation portion is provided vertically over the body portion and can take a plurality of rotated states. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0017]      FIG. 1  is a front perspective view of an image display device  1 ; 
           [0018]      FIG. 2  is a rear perspective view of the image display device  1 ; 
           [0019]      FIG. 3  is a side view of the image display device  1 ; 
           [0020]      FIG. 4  is a front perspective view of an image display device  100 ; 
           [0021]      FIG. 5  is a rear perspective view of the image display device  100 ; 
           [0022]      FIG. 6  is a side view of the image display device  100 ; 
           [0023]      FIG. 7  is a plan view showing a flat plate member  131  of a support portion  130  provided in the image display device  100 ; 
           [0024]      FIG. 8  is a rear perspective view showing another example of how the photovoltaic power generation portion is fitted in the image display device  100 ; 
           [0025]      FIG. 9  is a front perspective view of an image display device  200 ; 
           [0026]      FIG. 10  is a rear perspective view of the image display device  200 ; 
           [0027]      FIG. 11  is a side view of the image display device  200 ; 
           [0028]      FIG. 12  is a rear perspective view showing another example of how the photovoltaic power generation portion is fitted in the image display device  200 ; 
           [0029]      FIG. 13  is a rear perspective view of an image display device  300 ; 
           [0030]      FIG. 14  is a rear perspective view showing another example of how the photovoltaic power generation portion is fitted in the image display device  300 ; 
           [0031]      FIG. 15  is a rear perspective view of an image display device  400 ; 
           [0032]      FIG. 16  is a side view of the image display device  400 ; and 
           [0033]      FIG. 17  is a rear perspective view showing another example of how the photovoltaic power generation portion is fitted in the image display device  400 . 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0034]    Embodiments of the present invention will be described below with reference to the accompanying drawings. 
       Embodiment 1 
       [0035]    First, an image display device  1  according to a first embodiment of the invention will be described with reference to the relevant drawings.  FIG. 1  is a front perspective view of the image display device  1 , and  FIG. 2  is a rear perspective view of the image display device  1 .  FIG. 3  is a side view of the image display device  1 . 
         [0036]    As shown in  FIGS. 1 to 3 , the image display device  1  is provided with a photovoltaic power generation portion  10 , a body portion  20  in the shape of a rectangular parallelepiped, support portions  30  arranged on the top face of the body portion  20  to support the photovoltaic power generation portion  10 , and leg portions  40  provided in four corners on the bottom face of the body portion  20  to support the image display device  1 . 
         [0037]    The photovoltaic power generation portion  10  is provided with four photovoltaic panels  11  which convert the energy of the light with which they are irradiated into electric power, a mounting base  13  in the shape of a flat plate on which the photovoltaic panels  11  are arranged, and fixing portions  12  provided on the mounting base  13  to fix the photovoltaic panels  11 . 
         [0038]    The fixing portions  12  are fixed to the mounting base  13  with bolts and nuts or the like. The photovoltaic panels  11  have their edge parts pressed against the mounting base  13  by the fixing portions  12 , and are thereby fixed to it. 
         [0039]    The body portion  20  is provided with a display portion  21  which displays an image, a window portion  22  provided in the front face of the body portion  20  to make the display portion  21  visible, a rechargeable battery  23  which is charged with electric power supplied from the photovoltaic power generation portion  10  and which supplies electric power to the display portion  21  etc., and a control device  24  which controls, among others, the charging of the rechargeable battery  23 . The body portion  20  may be further provided with, though not shown, a fan or the like for cooling the inside of the body portion  20 . 
         [0040]    The display portion  21  includes, for example, an LCD panel or the like, and is driven with the electric power obtained in the photovoltaic power generation portion  10 . The window portion  22  includes a transparent member, such as a sheet of glass, and is provided for the purpose of protecting the LCD panel from external impact, water, dust, etc. The display portion  21  may be provided with a touch panel on the front face side. 
         [0041]    The rechargeable battery  23  is charged with the electric power obtained in the photovoltaic power generation portion  10 . For example, the rechargeable battery  23  is charged with, of the electric power generated, the part that is not consumed by the image display device  1 . On the other hand, when the photovoltaic power generation portion  10  is not generating electric power as during the night or under cloudy weather, the rechargeable battery  23  discharges as necessary to supply electric power to the image display device  1 . 
         [0042]    The support portions  30  are arranged on the top face  20   u  of the body portion  20  and support the photovoltaic power generation portion  10 . With consideration given to the incident angle of the sunlight, the support portions  30  are so formed that the surface of the photovoltaic power generation portion  10  has a predetermined angle relative to the top face  20   u  of the body portion  20 . 
         [0043]    As shown in  FIG. 2  etc., the support portions  30  are each provided with a first member  31 , a second member  32 , a third member  33 , and a fourth member  34 , each of which is a beam-shaped member. Four sets of such members, that is, four support potions  30  are provided on top of the body portion  20 . The first members  31  are fixed to the top face  20   u  of the body portion  20 . The second members  32  are fixed to the back face of the mounting base  13 . The third members  33  connect together the lower ends of the first and second members  31  and  32 . The fourth members  34  connect together the upper ends of the first and second members  31  and  32 . The first, second, third, and fourth support members  31 ,  32 ,  33 , and  34  are each beam-shaped. 
         [0044]    The first, second, third, and fourth support members  31 ,  32 ,  33 , and  34  that constitute one set are located approximately on the same plane (a plane perpendicular to the top face of the body portion  20 ). 
         [0045]    As described above, in the image display device  1 , the photovoltaic power generation portion  10  which is large to serve the purpose of driving the display device is arranged over the body portion  20 . This helps reduce the installation area of the image display device  1  and improve flexibility in installation. 
         [0046]    On the other hand, the rechargeable battery  23  and the control device  24  are provided under the display portion  21 . This permits the display portion  21  to be arranged about the height of the human eye, making it easily viewable. In addition, the rechargeable battery  23  and the control device  24  can then be arranged in the vacant space left perpendicularly under the display portion  21 . The image display device  1  may instead be configured without leg portions  40  so that the body portion  20  is installed on the ground. How the photovoltaic panels  11  are arranged and fixed here is merely one example, and may be implemented in any other manner. Although four support portions  30  are used in the above example, the number of sets is not limited to four. 
       Embodiment 2 
       [0047]    Next, an image display device  100  according to a second embodiment of the invention will be described with reference to the relevant drawings.  FIG. 4  is a front perspective view,  FIG. 5  is a rear perspective view, and  FIG. 6  is a side view. 
         [0048]    The image display device  100  of this embodiment, as compared with the image display device of the first embodiment, has a differently structured support portion  130 . 
         [0049]    The support portion  130  is provided with one flat plate member  131 , four beam-shaped members  132 , and four column members  133 . The flat plate member  131  is a member in the shape of a flat plate which is fixed to the top face  20   u  of the body portion  20 . The beam-shaped members  132  are fixed to the back face of the mounting base  13  of the photovoltaic power generation portion  10  such that each beam-shaped member  132  forms one side of a rectangular that is geometrically similar to the photovoltaic power generation portion  10 . The column members  133  connect parts of the flat plate member  131  near its four corners to the vertices of the just-mentioned rectangular. Here, the column members  133  are connected together in such a combination that the distances between the four corners of the flat plate member  131  and the four corners of the beam-shaped members  132  are shortest. 
         [0050]      FIG. 7  is a plan view showing a bottom face part of the support portion  130 . 
         [0051]    At the center of the flat plate member  131 , a guide hole  131   a  is provided. Moreover, 16 fitting holes  131   b  are provided in a concentric arrangement about the guide hole  131   a  as the center. 
         [0052]    In the top face  20   u  of the body portion  20 , a threaded hole c is provided, and by putting a screw through this threaded hole c and the guide hole  131   a , the support portion  130  can be kept in fixed position on the top face  20   u.    
         [0053]    Moreover, in the top face  20   u , 16 threaded holes p are provided in a concentric arrangement around the threaded hole c. Thus, by rotating the support portion  130  about the guide hole  131   a  as the center, and putting screws through the 16 fitting holes  131   b  and the 16 threaded holes p respectively, it is possible to set the installation orientation of the support portion  130 . In this way, it is possible to change the orientation of the photovoltaic power generation portion  10  alone, without changing the orientation of the body of the image display device  1 . For example, by changing the direction of the flat plate member  131  through 90 degrees, it is possible to arrange the photovoltaic power generation portion  10  in a direction as shown in  FIG. 8 . 
         [0054]    The arrangement of the guide holes  131   a  and the fitting holes  131   b  in the flat plate member  131  may be other than as shown in  FIG. 7 . 
       Embodiment 3 
       [0055]    Next, an image display device  200  according to a third embodiment of the invention will be described with reference to the relevant drawings.  FIG. 9  is a front perspective view,  FIG. 10  is a rear perspective view, and  FIG. 11  is a side view. 
         [0056]    The image display device  200 , as compared with the image display device  1  of the first embodiment described previously, has a differently structured support portion  230 . The following description is focused on the support portion  230 . 
         [0057]    As shown in  FIGS. 9 to 11 , the support portion  230  is provided with a bottom face  231 , one back face  232 , and two side faces  233 . 
         [0058]    The bottom face  231  has a rectangular shape with four sides, and is fixed to the top face  20   u  of the body portion  20 . One of the four sides makes contact, over its entire length, with the back face of the photovoltaic power generation portion  10 . The back face  232  also has a rectangular shape with four sides, with the top side making contact, over its entire length, with the back face of the photovoltaic power generation portion  10  and the bottom side making contact, over its entire length, with the bottom face  231 . The two side faces  233  each have a triangular shape surrounded by the back face of the photovoltaic power generation portion  10 , the bottom face  231 , and the back face  232 . 
         [0059]    The support portion  230  (the bottom face portion  231 , the back face portion  232 , and the side face portions  233 ) and the photovoltaic power generation portion  10  together form a pentahedron as a whole. 
         [0060]    As in the second embodiment ( FIG. 7 ), by providing in the bottom face  231  one guide hole and a plurality of fitting holes in a concentric arrangement about it as the center, it is possible to fix the body portion  20  to the top face, and to change the fitting orientation of the bottom face  231 . In this embodiment, however, for structural reasons, fixing using screws cannot be done from above as in the image display device  100 ; fixing can instead be achieved by putting screws through the threaded holes, the guide holes, etc. in the top face  20   u  from inside the body portion  20 . Instead of providing threaded holes in the top face  20   u , projections may be formed on the top face  20   u  so that fixing can be achieved by fitting guide holes or the like around those projections. 
         [0061]    Also in, for example, the image display device  200 , as shown in a rear perspective view in  FIG. 12 , the photovoltaic power generation portion  10  can be fixed to the top face of the body portion  20  with the orientation of the former changed through 90 degrees relative to the example shown in  FIG. 9  etc. 
         [0062]    In the image display device  200 , the support portion  230  has a structure where a combination of flat plate members and the photovoltaic power generation portion  10  together form a polyhedron. This makes it possible to reduce the effect of wind (air flow), such as wind noise and wind pressure, through regulation of air flow. 
       Embodiment 4 
       [0063]    Next, an image display device  300  according to a fourth embodiment of the invention will be described with reference to the relevant drawings.  FIG. 13  is a rear perspective view of the image display device  300 . 
         [0064]    As shown in  FIG. 13 , the image display device  300  is provided with a photovoltaic power generation portion  310   a , a support portion  330   a  which supports it, a photovoltaic power generation portion  310   b , and a support portion  330   b  which supports it. The support portions  330   a  and  330   b  are each arranged on the top face  20   u  of the body portion  20 . That is, a difference from the image display device  100  of the second embodiment is the provision of a plurality of photovoltaic power generation portions and a plurality of support portions. 
         [0065]    The photovoltaic power generation portion  310   a  is provided with two photovoltaic panels  311   a , a mounting base  313   a  on which those photovoltaic panels are arranged, and fixing portions  312   a  which are provided on the mounting base  313   a  to fix the photovoltaic panels. Likewise, the photovoltaic power generation portion  310   b  is provided with two photovoltaic panels  311   b , a mounting base  313   b , and fixing portions  312   b ). Like the support portion  130  in the second embodiment, the support portion  330   a  is provided with one flat plate member  331   a , four beam-shaped members  332   a , and four column members  333   a . Likewise, the support portion  330   b  is provided with one flat plate member  331   b , four beam-shaped members  332   b , and four column members  333   b.    
         [0066]    In the flat plate members  331   a  and  331   b , as in the one shown in  FIG. 7 , guide holes and fitting holes are provided. This makes it possible to change the orientation of the photovoltaic power generation portions  310   a  and  310   b.    
         [0067]    For example, as shown in  FIG. 14 , each photovoltaic power generation portion can be fixed with its orientation changed through 90 degrees. In the example of the second embodiment, the four photovoltaic panels are put together into a single unit, resulting in a structure where changing the direction of the photovoltaic power generation portion causes it to protrude from the body of the image display device. By contrast, in this embodiment, since the photovoltaic power generation portions are divided into two parts, changing their direction does not cause them to protrude from the body of the image display device. This helps achieve space saving. 
         [0068]    The photovoltaic power generation portion and the support portion in the image display device  200  of the third embodiment may each be divided into two parts to obtain a structure similar to that of this embodiment. 
       Embodiment 5 
       [0069]    Next, an image display device  400  according to a fifth embodiment of the invention will be described with reference to the relevant drawings.  FIGS. 15 and 16  are a rear perspective view and a side view, respectively, of the image display device  400 . 
         [0070]    As shown in  FIG. 15 , the image display device  400  is provided with a photovoltaic power generation portion  10 , a body portion  420 , and a support portion  430 . The body portion  420  is provided with a display portion  421 , a window portion  422 , a rechargeable battery  423 , a control device  424 , and a column portion  425 . In this embodiment, the provision of the column portion  425  is a difference from the image display device  200  of the third embodiment. 
         [0071]    The column portion  425  is a column-shaped member with an approximately semicircular cross section. The column portion  425  is arranged on the back face side of the body portion  420 . As shown also in  FIG. 16 , the top face of the column portion  425  is located at approximately the same height as the top face of the body portion  420 . The bottom face of the column portion  425  is located at approximately the same height as the bottom face of the body portion  420 . For stable installation of the image display device  400 , a bottom part of the column portion  425  may be buried in the ground. 
         [0072]    Back in  FIG. 15 , the support portion  430  which supports the photovoltaic power generation portion is provided with a column portion  431 , side face portions  432 , and a bottom portion  433 . The column portion  431  is a hexahedral, columnar member, of which the top face, the bottom face, the front face (these three faces are hidden and not shown in  FIG. 15 ), and the back face are rectangular and the two side faces are trapezoid. The rear face is larger than the front face. That is, the column portion  431  has its top face inclined relative to its bottom face. The bottom face of the column portion  431  is arranged so as to sit on the top face of the body portion  420 . On the top face of the column portion  431 , the bottom portion  433  is arranged so as to sit on it. This makes it possible to support the photovoltaic power generation portion with an inclination angle relative to the ground. 
         [0073]    The side face portions  432  are divided into four faces, which along with the bottom portion  433  and the back face of the photovoltaic power generation portion form a quadrangular pyramid. 
         [0074]    By providing in the bottom face of the column portion  431   a  guide hole, fitting holes in a concentric arrangement, etc. as shown in  FIG. 7  directed to the second embodiment, and providing corresponding threaded holes in the top face of the column portion  425 , it is possible to fix the column portion  431  to the top face of the body portion  420 , and to change its orientation ( FIG. 17 ). 
         [0075]    The support portion  430  may be rotated dynamically. For example, the support portion  430  may be rotated in such a way that the surface of the photovoltaic power generation portion  10  points as close as possible in the direction of the sun all the time. 
       Modified Examples 
       [0076]    The image display device may be given any shape other than the shape of a rectangular parallelepiped. 
         [0077]    The embodiments by way of which the present invention has been described above are in no way meant to limit the scope of the invention; many modifications and variations are possible within the spirit of the invention.