INTERCHANGEABLE LENS TYPE AUTOMATIC FOCUS ADJUSTING DEVICE AND ITS INTERCHANGEABLE LENS

摘要

PURPOSE:To increase the probability that a focusing state is entered without reference to whether a focus shifts to a front or rear focus side at the start of focus detection by setting the initial position of the lens to a nearly intermediate position in a movable range when a special lens is mounted. CONSTITUTION:When the interchangeable lens 1 is mounted, a data output means 14 outputs 1st data LCPR indicating that the rough focus adjustment lens of the interchangeable lens 1 is wider than its fine focus adjustment range, so a lens position determining means 13 determines the initial position Ns of the focus adjusting member 13 at the nearly intermediate position Nmax/2) of the movable range NL=0 to Nmax of the focus adjusting member 13. Then a lens driving means 22 is so controlled under the control of a control means so as to drive the focus adjusting member 13 to the initial position Ns determined by the initial position determining means 23 before a focus adjusting means 21 performs focus detecting operation. Consequently, the probability that focusing is successful is increased.