| 摘要 |
An endoscopic apparatus includes a semiconductor light source for generating illumination light and a light source control unit for generating driving pulses to drive and light the semiconductor light source. The light source control unit performs first, second and third pulse modulation controls in descending order of a target light quantity. In the first pulse modulation control, the number of the driving pulses is reduced so that a lighting time of the semiconductor light source is shortened to a predetermined lighting time for an exposure time of an electronic shutter within one frame. In the second pulse modulation control, the driving pulses are thinned at predetermined intervals so that pulse density is reduced in the lighting time. In the third pulse modulation control, pulse width of each of the driving pulses whose number is minimized in a region where the second pulse modulation control is performed is reduced. |
