| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an LED illumination apparatus which has no increase in cost when a plurality of LED series units are connected in parallel and can control an average value of current in each LED series unit at a constant value. <P>SOLUTION: The LED illumination apparatus includes one or a plurality of LED blocks each of which is a parallel combination of the LED series units (exemplified by units 11a-11n) wherein a plurality of LEDs 11 are connected in series. Beside the LED series units 11a-11n, one of the LED blocks is also equipped with a constant-voltage circuit 21 for supplying voltage to each of the LED series units 11a-11n connected in parallel from a power circuit 20, a current detection circuit 22 for detecting the total amount of currents in the LED series units 11a-11n in the LED block, and a voltage control circuit 23 for controlling the voltage supplied by the constant-voltage circuit 21 so that the total amount of currents detected by the current detection circuit 22 or the average current value of each LED series unit may be constant. <P>COPYRIGHT: (C)2007,JPO&INPIT |
