| 摘要 |
PROBLEM TO BE SOLVED: To provide a spontaneous emission device which can prevent break in lighting during night due to non-sunshine and may be provided even at such a place that a shield screening sunlight is present. SOLUTION: A secondary cell 4 is so constructed that it is charged by at least a primary cell charging circuit part 50 when the terminal voltage of the secondary cell 4 is lowered to a prescribed value while a day-night judging circuit part 80 judges it to be a day, and a driving current is supplied to a phosphor 6 through an emission circuit part 20 from the secondary cell 4 while the day-night judging circuit part 80 judges it to be a night. |
