Patent ID: 8659242

Claim:
A light source apparatus configured by a light source having a semiconductor device, a light intensity of which deteriorates with a lighting time period, comprising: a lighting time period measuring section that measures a lighting time period of the light source; a junction temperature calculating section that calculates a junction temperature of the light source; a light intensity deterioration characteristic storing section that stores a light intensity deterioration characteristic based on the junction temperature of the light source; a light source drive characteristic storing section that stores characteristics of power that drives the light source and a light intensity; a deteriorated light intensity calculating section that, every time a total use time period of the light source reaches a predetermined total use time period, calculates a deteriorated light intensity based on the lighting time period measured by the lighting time period measuring section, the junction temperature calculated by the junction temperature calculating section, and the light intensity deterioration characteristic stored in the light intensity deterioration characteristic storing section; and a light source power control section that controls power that drives the light source, based on the deteriorated light intensity calculated by the deteriorated light intensity calculating section, and the characteristics stored in the light source drive characteristic storing section.