| 摘要 |
PURPOSE:To offer the range finding device for the automatic focusing device which is reduced in the number of components as much as possible and can measure the distance to a subject speedily with high accuracy so that secure focusing is possible even if there are plural subjects. CONSTITUTION:One line sensor 8 is divided into three parts 10b-30b, which acquire the subject respectively to calculate and detect the zero-cross points of secondary differences of brightness distributions ; and data regarding the zero cross points are stored in a memory corresponding to the three parts and then read out of the memory in sequence. On the basis of zero-cross behavior of one of the three parts, other two data are properly shifted to detect the coincidence point of zero-cross behavior among the three parts, thereby calculating the distance to the subject from the quantity of deviation in zero- cross behavior between the two parts at the time of coincidence. |
