Focus adjusting apparatus, camera system, and focus adjusting method

摘要

Lh indicates the amount of image-surface movement of a photographic subject; Ls, a scan driving range; Lps, a scan driving range required to detect a peak; Li, the amount of initial position driving. Based on the speed of a photographic subject (inclination of a photographic-subject movement amount profile H), a body controlling unit sets Li as a driving amount and a driving direction of initial position driving in such a manner as to satisfy Lh<(Ls−Lps+Li), and performs initial position driving to move a focus lens, with the result that the profile H and a scan driving amount profile S of the focus lens intersect with each other within a section k4 where contrast AF is performed. Then, a scan driving operation is performed within the section k4, thereby detecting an in-focus position without fail regardless of the image-surface movement speed of the photographic subject (inclination of the profile H).

主权项

1. A focus adjusting apparatus that controls movement of a focus lens movable in an optical axis direction and included in a photographing optical system that forms an image from light from a photographic subject, the focus adjusting apparatus comprising:
an imager that generates an image signal by imaging a photographic-subject image formed by the photographing optical system; a lens driving unit that moves the focus lens; and a controlling unit that causes the lens driving unit to move the focus lens, that causes the imager to perform an imaging operation, that performs a scan operation so as to detect, on the basis of the image signal output by the imager, a position where the focus lens is to be located to cause a contrast of the photographic-subject image to reach a peak, and that controls locating of the focus lens at a position where the focus lens is in focus, wherein the controlling unit includes
a photographic-subject-speed detecting unit that detects a movement speed of the photographic subject, anda scan controlling unit that, based on the movement speed of the photographic subject detected by the photographic-subject-speed detecting unit, determines whether to perform initial position driving to move the focus lens before the scan operation is performed.