Patent ID: 7932681
Filing Date: 2011-04-26
Classification: H05B,Y02B

Abstract:
1. A lighting device comprising: at least two lines connected in parallel, a constant current source for a in a constant current to at least one of the at least two lines, an ON/OFF controller, and a voltage detector for measuring a value of voltage flowing in each line of the at least two lines, wherein each line of the at least two lines is formed by one or more light-emitting diodes and a switch for turning ON/OFF the current flowing in the light-emitting diodes connected in series and according to the voltage value of each line of the at least two lines measured by the voltage detector, the ON/OFF controller controls a duty ratio of the one or more light-emitting diodes of each line in accordance with the voltage measured, further comprising a selector for selectively outputting a voltage value of each line of the at least two lines to the voltage detector.