| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To obtain certain control performance irrespective of the magnitude of a drive current value when adjusting the current upon dimming. <P>SOLUTION: A semiconductor light source driving device 100 has a current-driven semiconductor light source 110, a voltage source 170 for driving the semiconductor light source 110, an output voltage control circuit 160 for controlling an output voltage of the voltage source 170, thereby controlling a drive current value that drives the semiconductor light source 110, an output current detection circuit 120 for detecting an output current of the semiconductor light source 110, a current direction part 130 for directing a reference value of a driving current to be passed to the semiconductor light source 110, a current comparator circuit 140 for comparing an output current detected by the output current detection circuit 120 with the reference value issued by the current direction part 130, and an impedance detection circuit 150 for detecting the impedance of the semiconductor light source 110. The output voltage control circuit 160 controls the output voltage from the voltage source 170 based on the output of the current comparator circuit 140 and that of the impedance detection circuit 150. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
