US Patent 7850376 Image pickup apparatus

An image pickup apparatus which is capable of effectively removing dust attached to an optical member due to mounting/removing of a photographic lens in a power-off state, to thereby prevent degradation of image quality. In the image pickup apparatus, when position information of a contact brush that moves in a manner interlocked with mounting/removing of the photographic lens differs immediately after execution of power-on operation from position information obtained immediately after execution of power-off operation, it is determined that photographic lens mounting/removing operation was carried out during power-off, and a camera microcomputer outputs a warning advising cleaning of the optical member.