| 摘要 |
PURPOSE:To decide on the accurate quantity of defocusing of an objective lens to any object by calculating an evaluated value W satisfying a specific equation in case of far/close contention. CONSTITUTION:If far/close contention occurs, the conformance between two images which vary in relative position relation according to the focus state of a photographic lens 1 is lower than usual within the whole observation visual field, so this conformance is evaluated to decide whether the far/close contention occurs within the observation visual field or not. The evaluated quantity (w) is calculated from an equation I, where a(i) and b(i) are the (i)th photoelectric conversion outputs for detecting the 1st and the 2nd images, min{x,y} is a smaller real number between (x) and (y), and max{x,y} is a larger number; when the quantity of relative displacement decreases below a specific value, a decision on the reliability of the quantity of relative displacement is made on the basis of the evaluated value. |
