Autofocus device and method

An autofocus method comprising:

• a focal-point-position detecting step of detecting a position of a focal point of a lens;
• a distance-measuring step of measuring a distance to a subject;
• a focus-evaluation-value-calculating step of calculating a focus evaluation value using a frequency component of an image signal in a particular region that is provided in an imaging frame;
• a lens-driving step of performing a focus operation to drive the lens based on any of the focus evaluation value and the focus evaluation value, the position of a focal point of the lens, and a measured distance result measured by the distance measurement sensor, thereby meeting the position of the focal point of the lens detected by the focal-point-detecting step to an in-focus position thereof;
• and
• an operation-switching step of switching operations in the lens-driving step, the distance-measuring step and the focus-evaluation-value-calculating step based on the autofocus content set by the user interface, thereby achieving a focus operation according to the set content.

A computer program product that allows a computer to execute an autofocus method, said method comprising:

• a focal-point-position detecting step of detecting a position of a focal point of a lens;
• a distance-measuring step of measuring a distance to a subject;
• a focus-evaluation-value-calculating step of calculating a focus evaluation value using a frequency component of an image signal in a particular region that is provided in an imaging frame;
• a lens-driving step of performing a focus operation to drive the lens based on any of the focus evaluation value and the focus evaluation value, the position of a focal point of the lens, and a measured distance result measured by the distance measurement sensor, thereby meeting the position of the focal point of the lens detected by the focal-point-detecting step to an in-focus position thereof;
• and
• an operation-switching step of switching operations in the lens-driving step, the distance-measuring step and the focus-evaluation-value-calculating step based on the autofocus content set by the user interface, thereby achieving a focus operation according to the set content.