AUTOMATIC FOCUSING DEVICE FOR CAMERA

摘要

PURPOSE:To provide a simple and small automatic focusing device which can accurately detect the focusing and confirm the distance measuring range for a camera by focusing part of a photo-image in a view finder optical system at a single focusing element for focusing the photo-image through a half mirror and first optical system. CONSTITUTION:A distance measuring range is confirmed by visually confirming a photo-image focused via an eyepiece 8 through the half mirror 4 of a view finder optical system. The photo-image reflected on the half mirror 4 and then reflected on the hlaf mirror 2 of first optical system is focused at a single focusing element 6 for focusing the photo-image through the first optical system to generate a contrast detection signal or the like therefrom due to the superimposition of both the photo- images to thereby focus via the movement of an objective lens interlocking with the rotation of the mirror 4 by the signal. This automatic focusing device can dedetect highly accurate focusing with a configuration without a plurality of focusing elements of this different characteristics.