| 摘要 |
PURPOSE:To obtain an LED drive circuit which can reduce cost and uniform the light quantity of an LED. CONSTITUTION:LED on-signals a-n from outside are inputted to PNP-type transistors 4a-4n via the respective base resistors with the result that a constant current flows from a constant current power source 3 by ON of the PNP-type transistors 4a-4n to turn off LEDs 1a-1n, or that a constant current flows from the constant current power source to the LEDs 1a-1n by OFF of the PNP-type transistors 4a-4n to turn on the LEDs 1a-1n. |
