| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an illumination device for nighttime in which insufficient charging is supplemented with a simple structure while avoiding an effect on the service-life. <P>SOLUTION: This illumination device 10 for nighttime includes: a solar cell 11; an illumination lamp 12 to illuminate in the lower direction; and a control unit 20 in which, when a control part 22 determines that it is daytime by a day/night determining part 21, electric power from the solar cell 11 is stored in an electric double layer capacitor 23 and also in a battery 24 and the electric power supply to the illumination light 12 is not carried out. When the day/night determining part 21 determines that it is nighttime, the electric power supply to the illumination lamp 12 is carried out from the electric double layer capacitor 23, and when a voltage of an electric power from the electric double layer capacitor 23 is reduced than a prescribed voltage, the electric power supply from the battery 24 to the illumination lamp 12 is carried out, and the illumination lamp 12 maintains lighting. <P>COPYRIGHT: (C)2011,JPO&INPIT |
