Automatic focusing device

摘要

An automatic focusing device for moving a photographic lens to an optimum focusing position by detecting an object image contrast signal that changes with the varying position of the photographic lens. The device stops the photographic lens while it is being moved between an infinite distance photographing position to a least distance photographing position when the level of the detected contrast signal becomes less than a threshold level. The invention compares a first signal, which is set to correspond to a position at which the photographic lens is to be stopped, and a second signal, which is generated when the contrast signal level is less than the preset threshold level.