| 摘要 |
PURPOSE:To save electric power by determining the constant of the change function of a signal and predicting the time before focusing in accordance with said constant. CONSTITUTION:This focusing method judges focusing and out-of-focusing by the distance measurement signal obtd. from discrete time series signals changing according to the action of a photographing lens 7 and moves the lens continuously from the out-of-focusing state toward the focusing. The constant of the change function of the signals is determined and the time before the focusing is predicted in accordance with said constant in the above-mentioned method. Generation of inching and hunting during the action of the lens 7 is thus obviated by interrupting the distance measurement action during said time; in addition, the saving of the electric power and the change of a motor speed near the focal point are permitted in such automatic focusing method. |
