System controller (10) seeks a focus adjusting evaluating value which is
indicative of focus adjusting state as a criterion from object image
information, and searches a focus adjusted position where focus adjusting
evaluating value becomes the most appropriate and drives the focus
operating means to the focus adjusted position to perform a focus
adjusting by a focus adjusting scan to obtain a plurality of focus
adjusting evaluating value by operating the focus adjusting evaluating
value detecting means while driving focusing lens (1a) in at lease one way
of continuous way or intermittent way which varies focus adjusting state
of the object image.
System controller (10) shifts a scan starting point from an initial
locating position Po of the focusing lens (1a) in a first predetermined
amount of distance in a predetermined direction then initiate scan from
the initial locating position toward an opposite direction to the
predetermined direction.
