| 摘要 |
PROBLEM TO BE SOLVED: To provide a light-emitting element driver circuit having a high power source efficiency which is capable of stably driving the light emitting element if the power voltage is lower than the forward voltage of the element. SOLUTION: A switched capacitor circuit 10 is connected between a driving power source 1 and light-emitting element 2. A capacitor 9 in the circuit 10 is charged up to a power voltage VCC when switches 7 and 8 are turned to charging terminals a. When the switches 7 and 8 are turned to discharging terminals b, the source 1 and capacitor 9 are connected in series to supply a driving current to the element 2. By changing the number of switching times of the switches 7 and 8, the value of the driving current fed to the element 2 can be changed. |
