초록 ▼

An automatic focusing device for automatically controlling the focused state of an optical system on the basis of a video signal obtained within a focus detecting area which is set on an image sensing plane comprises: a tracing area setting circuit arranged to movably set, within said image sensing

An automatic focusing device for automatically controlling the focused state of an optical system on the basis of a video signal obtained within a focus detecting area which is set on an image sensing plane comprises: a tracing area setting circuit arranged to movably set, within said image sensing plane, an inner tracing area and an outer tracing area which surrounds the inner tracing area; a computing circuit arranged to compute information on a difference in a given frequency component of the video signal obtained from the inner and outer tracing areas in each of their different positions to which they are moved within the image sensing plane; determining means for determining the position or size of an object's image formed within the image sensing plane from the difference information computed by the computing circuit; and a circuit which is arranged to shift the focus detecting area to the position of the object's image determined by the determining circuit and to change the size of the focus detecting area according to the size of the object's image.

대표청구항 ▼

[ What is claimed is:] [1.] A video camera apparatus, comprising:(A) image sensing means for photoelectrically converting an object image formed on an image sensing plane to produce and output an image signal;(B) area setting means for setting a detecting area for detecting a photographing state of

[ What is claimed is:] [1.] A video camera apparatus, comprising:(A) image sensing means for photoelectrically converting an object image formed on an image sensing plane to produce and output an image signal;(B) area setting means for setting a detecting area for detecting a photographing state of the object image on said image sensing plane;(C) detecting means for detecting a variation of a feature of the object image on the basis of the image signal corresponding to said detecting area in a first period of time;(D) control means for controlling said area setting means in a second period of time longer than said first period of time in accordance with an output of said detecting means and for causing the position and size of said detecting area on said image sensing plane to follow the variation of the feature of said object image, to independently change said detecting area in the first period;(E) focus detecting area setting means for setting a position of a focus detecting area in the second period of time at a center of said detecting area on said image sensing plane on the basis of the output of said detecting means; and(F) focus control means for adjusting a focus condition in the second period on the basis of the image signal corresponding to said focus detecting area.