US Patent 7486331 Auto focus methods and auto focus devices for electronic cameras using the same

Auto focus methods for electronic cameras are disclosed. The method of the present invention obtains and compares evaluation values (high frequency component (HFC)) corresponding to desired image signals from left or right locations relative to a center of a zoom lens of an electronic camera, thereby locating the maximal evaluation value. The location corresponding to the located maximal evaluation value is an optimum focus location.