| 摘要 |
PROBLEM TO BE SOLVED: To provide a light source drive device capable of making a relation between a level of a dimming instruction signal and a level of an output current be linear over a wider dimming region.SOLUTION: A light source drive device 1 outputs a dimming signal Sc from a dimming control part 5 to a drive circuit part 2 on the basis of a dimming instruction signal Sad that is a PWM signal to supply a current based on the dimming signal Sc from the drive circuit part 2 to an LED module 12. The dimming control part 5, in a case where an on-duty of the dimming instruction signal Sad is a predetermined value or more, outputs a DC voltage dimming signal corresponding to a first DC voltage signal generated on the basis of the dimming instruction signal Sad as the dimming signal Sc. The dimming control part 5, in a case where the on-duty of the dimming instruction signal Sad is less than the predetermined value, generates a PWM dimming signal using a value corresponding to a second DC voltage signal, that is a predetermined value, as a peak value on the basis of the dimming instruction signal Sad, and outputs the PWM dimming signal as the dimming signal Sc to the drive circuit part 2. |
