The present invention aims at providing a blue-aimed phosphor powder which is more excellent in emission characteristic than the conventional rare-earth activated sialon phosphors and which is more excellent in durability than the conventional oxide phosphors. In one embodiment, the blades of the spherical turbine curve in an approximately 180 degree arc in a plane that is at an inclined angle relative to the rotational axis of a central shaft. If it is detected based on the second source ID list that the content reproduction apparatus is not yet registered in a management server and a recorder ID of the content processing apparatus is not yet registered in the second source ID list, the content processing apparatus recommends registration.