Patent ID: 7847856

Claim:
A digital camera comprising: a camera body; and a lens unit removably mounted on the camera body, wherein the lens unit includes: a focusing lens moving in an optical axis direction to adjust an imaging position of a light beam from a subject; a lens moving part for moving the focusing lens based on a lens moving command sent from the camera body; a lens position detecting part for detecting a lens position of the focusing lens; and a lens memory for storing information related to the lens unit, the camera body includes: an image pickup device for capturing a light image formed through the lens unit and outputting an electric image signal; a synchronization signal generating part for generating a synchronization signal to decide on an imaging timing so as to the image pickup device to perform imaging at a predetermined time interval; a focus evaluation value calculating part for calculating a focus evaluation value as a value for evaluating the degree of focusing of the subject image based on the electric image signal output from the image pickup device in synchronization with the synchronization signal; a lens position acquiring part for acquiring the lens position of the focusing lens from the lens position detecting part in synchronization with the synchronization signal; and a control part for sending the lens moving command to the lens moving part to move the focusing lens to an in-focus position by a hill-climbing method based on the focus evaluation value calculated by the focus evaluation value calculating part and the lens position of the focusing lens acquired by the lens position acquiring part, and the control part has a determination part for acquiring information related to the lens unit stored in the lens memory, and calculating an estimated time required to complete focusing based on the acquired information related to the lens unit to determine whether the estimated, required time is equal to or more than a predetermined time, and a speed control part for controlling movement of the focusing lens in a second mode for moving the focusing lens at a second speed when the determination part determines that the estimated, required time is equal to or more than the predetermined time, or in a first mode for moving the focusing lens at a first speed slower than the second speed when the determination part determines that the estimated, required time is less than the predetermined time.