Automatic focus and indirect illumination camera system

In a camera, range finding and automatic focus control apparatus for a camera imaging lens comprising:

• active scene range finder means, including first electromagnetic radiation emitting means for directing radiation at a scene, and first electromagnetic radiation detecting means for detecting electromagnetic radiation reflected from the scene, for providing a first signal related to the distance between said camera imaging lens and a subject in the scene;
• passive multi-spot range finder means comprising at least a first pair of linear photosensitive element arrays each comprising a first plurality of photosensitive elements and a pair of focusing lens elements for focusing a central portion of the scene onto the photosensitive elements of the first pair of arrays and a second pair of linear photosensitive element arrays each comprising a second plurality of photosensitive elements positioned with respect to said pair of lens elements and said first plurality of photosensitive elements so that said lens elements focus a peripheral portion of the scene onto the photosensitive elements of the second pair of arrays;
• and
• range finder selection means for selectively operating said active range finder means under first scene illumination conditions and said passive range finder means under second scene illumination conditions.

In a camera, a method of operating an active single-spot range finder and a passive multi-spot for combined scene range finder and auto focus control of a camera imaging lens comprising the steps of:

• enabling said active scene range finder means, including a first electromagnetic radiation emitting means for directing radiation at a scene, and first electromagnetic radiation detecting means for detecting electromagnetic radiation reflected from the scene, for providing a first central scene range signal related to the distance between said camera imaging lens and a subject in the scene;
• enabling said passive multi-spot range finder means comprising at least a first pair of linear photosensitive element arrays each comprising a first plurality of photosensitive elements and a pair of focusing lens elements for focusing a central portion of the scene onto the photosensitive elements of the first pair of arrays to provide a second central scene range signal and a second pair of linear photosensitive element arrays each comprising a second plurality of photosensitive elements positioned with respect to said pair of lens elements and said first plurality of photosensitive elements so that said lens elements focus a peripheral portion of the scene onto the photosensitive elements of the second pair of arrays to provide a peripheral scene range signal;
• detecting errors in the second central or the peripheral scene range signals;
• and
• selectively employing said first central scene range signals upon detection of an error for setting the automatic focus of the camera lens.