| 摘要 |
<p>PURPOSE: A light emitting device and an LED driving method using the same are provided to improve driving efficiency by successively lighting a part of LED groups according to the size of rectified power supply voltage and minimizing a section in which all LEDs are not turned on. CONSTITUTION: A rectifier(10) changes an AC power source inputted from outside into DC power supply. A light source part(20) comprises LED groups which are successively connected in series. A driving control part(30) creates an input signal by detecting a current flowing in an output terminal of the light source part. The driving control part comprises a comparator(31) outputting a control signal, a switch controller(32), and a switch(33). The switch controller outputs a signal in order to change the number of LED groups which drive.</p> |
