Automatic focusing camera

Abstract

An automatic focusing apparatus for a camera is provided with a movable focusing member which adjusts the focus of the photographic lens of a camera and which has a cam section comprising a set of cam-shaped portions which are disposed thereon to effect the positioning of the focusing member in positions corresponding to predetermined object distances. A first arresting mechanism is mounted for movement between a first range of positions in which it is engageable with any one of the cam-shaped portions and a second range of positions in which it cannot engage the cam-shaped portions. A second arresting mechanism moves in response to the movement of the first arresting mechanism into the second range of positions, from a rest position where it does not engage any cam-shaped portions to an operative position where it engages a predetermined one of the cap-shaped portions corresponding to a cam focus. A focus detecting circuit detects the object focus of an object to be photographed, however is unable to so detect the object focus under certain conditions such as insufficient brightness or contrast. An electromagnetic mechanism is responsive to the detection of the object focused for holding the first resting mechanism in the first range of positions at a position in which it engages the cam-shaped portion corresponding to the detected object focus distance. It is responsive to the inability of the focus detecting circuit to detect the object focus for effecting movement of the first arresting mechanism into the second range of positions and thereby the movement of the second arresting mechanism into the operative position whereby a cam focus of the lens will be obtained. In this way, the object will be capable of being photographed even under the aforementioned adverse conditions.

Dependencies are inferred from the claim text.