Lighting apparatus

摘要

A lighting apparatus is provided, which has a not lowered light output and a long life even service time is prolonged. The lighting apparatus includes a light source having a phosphor and a resin including the phosphor, and having a characteristic that as a provided electric power is increased, a decreased rate of a lumen maintenance factor is increased, and an electric-to-optical conversion efficiency is reduced; a radiation element, directly or indirectly disposed on the light source; a power source, capable of changing the electric power supplied to the light source; and a controller, reducing the electric power provided to the light source at an initial period, and making the provided electric power increase as a function of time.