Lighting device for solid-state light source, and illumination apparatus and system including same

摘要

A lighting device for a solid-state light source includes a DC power source circuit unit for performing power transform of an input DC power source by using a switching device and allowing a thus-generated current to flow through the solid-state light source; and a current control unit configured to control the switching device to adjust the current flowing through the solid-state light source. The current control unit includes a first switching control unit for varying an on-time width of the switching device; and a second switching control unit for performing activation and inactivation of the switching device. An activating period of the second switching control unit is longer than one cycle of the first switching control unit, and the dimming control is achieved by the first switching control unit and the second switching control unit.