Autofocus device and method

An autofocus method comprising:

• a focal-point-position-detecting step of detecting a position of a focal point of the lens;
• a distance-measuring step of measuring a distance to a subject;
• a lens-drive-setting step of setting a driving direction of the lens and a driving speed of the lens based on the position of the focal point of the lens detected at the focal-point-position-detecting step and a distance measurement result measured at the distance-measuring step;
• and
• a lens-driving step of performing a focusing operation to start driving the lens based on the driving direction of lens and the driving speed of the lens, which are set by the lens-drive-setting step, thereby meeting the position of the focal point of the lens to an in-focus position thereof.

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 the lens;
• a distance-measuring step of measuring a distance to a subject;
• a lens-drive-setting step of setting a driving direction of the lens and a driving speed of the lens based on the position of the focal point of the lens detected at the focal-point-position-detecting step and a distance measurement result measured at the distance-measuring step;
• and
• a lens-driving step of performing a focusing operation to start driving the lens based on the driving direction of lens and the driving speed of the lens, which are set by the lens-drive-setting step, thereby meeting the position of the focal point of the lens to an in-focus position thereof.