| 摘要 |
PURPOSE:To prevent a shutter chance from being missed even for a subject having no contrast, a fast moving subject, etc., by employing a result of integer arithmetic individually after a lens is inhibited from being driven by judging that reliability is not obtained by integer part reliability inspection and friction part reliability inspection. CONSTITUTION:Subject luminous flux which is passed between two parts arranged across the optical axis of the photographic lens is photodetected, an integer part arithmetic means 103 performs arithmetic, and a friction part arithmetic means 105 calculates the friction part of the quantity of deviation in interval between two images. An integer part reliability inspecting means 104 and a friction part reliability inspecting means 106 judges that there is no reliability from the arithmetic results of them and the judgement is counted by a counting means 107 to inhibit the lens from being driven. Further, it is judged whether or not the result of the integer part arithmetic is reliable enough for focus detection from data on a contrast component and the inhibition of the driving of the lens which is determined as above is released, so the shutter chance when a high-contrast subject enter the visual field is not missed. |
