| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To avoid a non-lighting state of a light emitting element (a state wherein the light emitting element is not lit even in a lighting necessary time zone). <P>SOLUTION: A light emitting device includes a solar cell 10 which converts light energy into electric energy, an electric double layer capacitor 60 in which the electric energy obtained by the solar cell 10 is accumulated, a light emitting element 120, driving means 90 and 100 of driving the light emitting element 120 using the electric energy accumulated in the electric double layer capacitor 60, a detecting means 40 of detecting the self-discharging amount of the electric double layer capacitor 60, and a driving condition determining means 110 of determining a driving current of the light emitting element 120 based on the self-discharging amount detected by the detecting means 40 and a remaining time for which the light emitting element 120 should be lit. The driving means 90 and 100 drive the light emitting element 120 with the driving current determined by the driving condition determining means 110. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
