(under subclass 4.01) Subject matter that includes a determination of the distance of a remote point or observed object by the degree of image focus through relative characteristics of in-and-out-of-focus intensity, blur circle size, lateral split image displacement, etc., of an image generated at some fixed location from focusing optics along its optical axis relative to the same characteristic under a focused condition at the same location along the optical axis.
SEE OR SEARCH THIS CLASS, SUBCLASS:
3.14, for split images of a single object directed to two detectors separated by a baseline, unlike split-image focus detection here in subclass 4.04 where there is no baseline separation.
4.03, for a focused image feature measurement(s).
4.05, for mechanically searching for the focal point based on the same or other characteristics as in subclass 4.04.
