Patent ID: 8866958

Claim:
A focusing apparatus comprising: a focus lens; a focus lens driving unit configured to drive the focus lens; an imaging device configured to capture light passed through the focus lens and incident on the imaging device and to generate an image signal; a focus evaluation value calculating unit configured to receive an image signal from the imaging device and to calculate a focus evaluation value of a captured image; a difference calculating unit configured to calculate a difference between a current focus evaluation value and a previous focus evaluation value; a first determining unit configured to compare the difference to each of a plurality of threshold values different from each other; a counter configured to count results of comparing the difference to each of the plurality of threshold values; generate first count information regarding a result of comparing the difference to a first threshold value, generate second count information regarding a result of comparing the difference to a second threshold value, increase the first count information by a predetermined value, if the focus lens is driven in a direction toward a near side and the difference is greater than the first threshold value, decrease the first count information by the predetermined value, if the focus lens is driven in a direction toward the near side and the difference is smaller than the first threshold value, decrease the first count information by the predetermined value, if the focus lens is driven in a direction toward a far side and the difference is greater than the first threshold value, and increase the first count information by the predetermined value, if the focus lens is driven in a direction toward the far side and the difference is smaller than the first threshold value; and a second determining unit configured to compare at least one of the first count information and the second count information to threshold count information and to determine a target drive direction in which the focus lens is to be driven.