it is an object of the present invention to provide a light source apparatus having a rotation filter , in which brightness of an image and / or color reproducibility of rgb is improved , and miniaturization and simplification is attained . a light source apparatus comprising a rotation filter having a light condensing area , in which at least a first color area and a second color area are formed , a lens to which light passing through the light condensing area is incident , an image display device receiving light emitted from the rod integrator lens , a discharge lamp ; and a power supply controlling apparatus which controls power supply to the discharge lamp , wherein the power supply controlling apparatus shuts off or reduces current applied to the discharge lamp when a boundary between the first color area and the second color area is located at a position corresponding to the light condensing area .