fig1 , 2 and 3 are the outline views of the outdoor display system 9 of the present invention . fig1 is its front perspective view , fig2 is its side view , and fig3 is its rear perspective view . as shown in these figures , the outdoor display system 9 has a case 91 which stores a display 4 , a battery unit 7 . under the case 91 , leg portions 92 for installing the system 9 on the ground are formed . in the lower surface 91 c of the case 91 , the openings 91 a and 91 b are formed . by these openings , the inside and the outside are the communicated so that the air can flow their between . the display 4 displays information or image . the display has an antenna which receives a wireless signal ( wimax and ieee802 . 11b / g etc .) from an external server ( asp server , personal computer , etc . ), or a signal from a broadcasting station . the display further demodulates the signal received by the antenna , extracts the mpeg2 - ts format signal and separates the extracted signal into the image signal and the audio signal . then decoding is performed before outputting signals from the lcd panel 44 or a speaker . moreover , the mpeg 2 - ts format signal may be stored temporality in the internal memory ( or hdd drive inside the display 4 ), and the content of the signal may be displayed on the lcd panel 44 triggered by operation of a user or a predetermined time schedule . in the front side or the rear side of the front glass 13 which is in front of the lcd panel 44 , a touch panel 46 comprising an electric capacity type touch sensor sheet is equipped . on the respective side of the display 4 , an intake duct 11 and an exhaust duct 12 are formed . under the duct 12 , an opening 91 a is formed . under the duct 11 , an opening 91 b is formed . above the case 91 , a solar cell 95 is installed . referring to fig2 , a supporting portion 93 is arranged on the upper surface of the case 91 . the portion 93 supports a stand 94 . on the stand 94 , solar cell 1 which receives sunlight is installed . the angle of the stand 94 is set so that it conforms with the incidence angle of the sunlight . inside the battery unit 7 , a battery 2 , a controller 3 , and an inverter 8 are stored in the case ( see fig7 ). the battery 2 is , for example , a lithium ion battery . the controller 3 controls so that the electric power generated by the solar cell 95 is supplied to the display 4 or the battery 2 . basically , the controller 3 supplies the most of the power from the solar cell 95 to the display 4 , and supplies the remainder to the battery 2 . however , when the solar cell 95 does not generate power ( such as nighttime or cloudy days ), the controller 3 controls so that the power is supplied to the display 4 from the battery 2 . referring to fig4 , a casing of the display 4 comprises a front cabinet 4 a and a back cabinet 4 b . inside these cabinets , a lcd panel and an electric circuit and other components are stored . on the right side of the cabinet , an intake duct 11 is attached . on the left side of the cabinet , the exhaust duct 12 is attached . fig5 is a horizontal sectional view of the display 4 . referring to this figure , the lcd panel 44 is formed inside the back cabinet 4 b . on the rear side of the panel 44 , a back light 45 is formed . to the front cabinet 4 a , a transparent front glass 13 is inserted so as to face the panel 44 . on the front surface of the glass 13 , a touch panel 46 is attached . the touch panel 46 may be attached on the rear side of the glass 13 ( i . e . on the side facing the panel 44 ). in the daytime of midsummer , the temperature inside the display may become high when it is installed outdoors , and this may hamper the performance of the display apparatus . in order to prevent the malfunction of touch panel 46 derived by the temperature condition , it is necessary to control the temperature of the panel 46 . thereby , the display 4 has fan on its both side and cools the lcd panel 44 and the touch panel 46 by making an air - flow in the front side of the lcd panel 44 . referring to fig5 again , between the lcd panel 44 and the front glass 13 , a space 81 is set . thereby , the ventilation from the inlet 14 to the outlet 14 is achieved . fig6 is a vertical sectional view of the display 4 . as shown in this figure , on the right - hand side of the display 4 , three inlets 14 are located in a vertical direction . on the left - hand side of the display 4 , three outlets 15 are located in a vertical direction as well . in each of the inlets 14 , intake fans 49 a are arranged . in each of the outlet 15 , exhaust fans 49 b are arranged . in the inlet 14 and the outlet 15 , a filter for preventing dust intruding into space 81 may be arranged . in the outside of the inlet 14 , the intake duct 11 is attached . the duct 11 is arranged vertically along the side - face of the back cabinet 4 b so as to cover these three inlets 14 . on the undersurface of the intake duct 11 , the inlet 11 a is arranged . generally , the rain falls downward , but the opening of the duct 11 ( inlet 11 a ) is arranged downward . thereby , it can prevent raindrops intruding into the duct 11 . in the outside of the outlet 15 , the exhaust duct 12 is attached . the duct 12 is arranged vertically along the side - face of the back cabinet 4 b so as to cover these three outlets 15 . on the undersurface of the exhaust duct 12 , the outlet 12 a is arranged . since the opening of the duct 12 ( outlet 12 a ) is arranged downward , it can prevent raindrops intruding into the duct 12 . these fans are driven when the illumination detected by the illumination sensor 50 b ( see fig4 ) arranged in front side of the display 4 ( i . e . in four corners of the lcd panel 44 ) exceeds a predetermined value . when the detected illumination is high , it means that strong sunlight is irradiating the panel 44 , and thus the temperature of the panel 44 may rise . therefore , in such case , the fan is driven to prevent the panel 44 from heated . further , the temperature sensor may be arranged on the display 4 as well . the fans may be driven when the temperature detected by this sensor exceeds a predetermined value . fig7 is a schematic diagram of the battery unit 7 . in the unit 7 , the battery 2 , the controller 3 , and the inverter 8 are stored in a case . fig8 is a vertical sectional view of the unit 7 . referring to the figure , in the right side portion of the unit 7 , three inlets 71 are set vertically . in the left side portion of the unit 7 , three outlets 72 are set vertically . in each of the inlets 71 , the intake fan 5 a is set . in each of the outlets 72 , the exhaust fan 5 b is set . when these fans are driven , air - flow between the inlet 71 and outlet 72 is generated . in this embodiment , the inverter 8 , in which the temperature tends to become high , is arranged in the inlet 71 side so that the inverter 8 is cooled with high priority . the battery unit 7 also has an intake duct 73 and an exhaust duct 74 . fig1 is a front perspective view of the outdoor display system 90 of the present embodiment . it differs from the system 9 that the intake duct 110 and the exhaust duct 120 are further stretching down from the side surface of the display 4 . this means that the lower portion of the ducts 110 and 120 are arranged also in the side of the battery unit 7 , the inlet or the outlet of these ducts are arranged above the opening 91 a or 91 b . thereby , inside of the display 4 can be performed much efficiently .