Driving method of light source apparatus

A driving method of a light source apparatus comprising a primary light source, an optical fiber configured to guide primary light emitted from the primary light source, a light conversion unit configured to receive the primary light emitted from the primary light source and guided by the optical fiber, and convert at least one of a peak wavelength, a spectral shape, a radiation angle, and a light intensity included in optical properties of the primary light, and a photodetector configured to detect light radiated from the light conversion unit, the method comprising:

• causing the primary light source to emit checking light having light intensity sufficient to check a state of the light source apparatus and unharmful to a human body even when the checking light leaks, based on an output signal from the photodetector having detected the light radiated from the light conversion unit;
• and
• checking the state of the light source apparatus based on the output signal from the photodetector having detected light radiated from the light conversion unit and entering the photodetector based on the checking light.