Patent ID: 7609314

Claim:
An image pickup apparatus on which and from which an accessory device can be mounted and removed, comprising: an optical member disposed in front of an image pickup element on a photographic optical axis; a foreign substance removing unit configured to remove foreign substance attached to said optical member; an accessory type/state-detecting unit configured to detect at least one of a type and a state of an accessory mounted on the image pickup apparatus, immediately before a power-off of the image pickup apparatus, and detect at least a corresponding one of a type and a state of an accessory mounted on the image pickup apparatus, immediately after a next power-on of the image pickup apparatus; a determining unit configured to determine whether the at least one of the type and the state of the accessory mounted on the image pickup apparatus, detected immediately before the power-off by said accessory type/state-detecting unit is identical to or different from the at least the corresponding one of the type and the state of the accessory mounted on the image pickup apparatus, detected immediately after the next power-on by said accessory type/state-detecting unit; and a control unit configured to cause said foreign substance removing unit to operate when said determining unit determines that the at least one of the type and the state of the accessory mounted on the image pickup apparatus, detected immediately before the power-off is different from the at least the corresponding one of the type and the state of the accessory mounted on the image pickup apparatus, detected immediately after the next power-on of the image pickup apparatus.