Patent ID: 7751701

Claim:
An imaging device comprising: an image sensor for taking a subject; a taking lens disposed at a subject side of said image sensor to form a subject image on said image sensor, said taking lens having a stop for regulating a subject-light amount and a focus lens used for focus adjustment, and said taking lens including a zoom lens capable of changing a focal length; a face detector for detecting a human face from said subject image; a subject-brightness measuring device for measuring the brightness of a region of the human face detected by said face detector as subject brightness; a first subject-distance calculator for calculating a first subject distance on the basis of the focal length of said taking lens and a size of the human face detected by said face detector; a depth-of-field calculator for calculating a depth of field on the basis of the focal length of said taking lens, a dimension of said stop and said first subject distance; a depth-of-field analyzer for judging whether or not a calculated value of said depth of field has a predetermined depth; and a controller for moving said focus lens based on said first subject distance with maintaining said dimension of said stop and sensitivity of said image sensor when it has been judged that the calculated value has the predetermined depth, and for making said dimension of said stop smaller than that corresponding to said subject brightness, heightening said sensitivity of said image sensor in accordance with the change in said dimension of said stop, and moving said focus lens based on said first subject distance when it has been judged that the calculated value does not have the predetermined depth.