US Patent 7932951 Focus adjustment device, imaging device and focus adjustment method

A video camera constructed according to one aspect of the focus adjustment device moves a focus lens forward and backward and detects peak values of an AF evaluation value of the focus lens in the forward moving direction and in the backward moving direction. The video camera calculates a correction value based on a difference between the peak value of the evaluation value detected in the forward motion of the lens and the peak value of the evaluation value detected in the backward motion of the lens. The video camera corrects the AF evaluation value with the calculated correction value and detects a focused position of the lens based on the corrected AF evaluation value in moving the lens.