AUTOMATIC FOCUS ADJUSTMENT DEVICE AND VIDEO CAMERA PROVIDED WITH THE SAME

摘要

PURPOSE:To provide the automatic focus adjustment device with excellent response whose stability is improved. CONSTITUTION:A lens control section 6 decides a drive direction and a drive quantity of a focus adjustment lens group 1a based on a focus signal for one field period in an output signal generated by a focus signal detection means 5 and a motor 8 is used to adjust the focus automatically. In parallel with above, a maximum level of a focus signal in the horizontal scanning direction and its position signal among output signals generated by a focus signal detection means 5 are inputted to a tracking arithmetic operation means 9, in which the level is compared with a setting level to judge the validity of the input signal and then the movement of an object is decided and the moving direction and the moving quantity are outputted to a gate control means to move the focus detection area to the object.