| 摘要 |
PURPOSE:To attain accurate focusing operation by converting the rotation of a focus ring into a pulse signal, detecting the rotational amount of the focus ring from the pulse signal and controlling a lens driving source on the basis of the detected value. CONSTITUTION:When a photographer rotates the focus ring 1, a pulse generating means 6 generates a pulse signal interlocking with the ring 1. The pulse signal is inputted to a focus ring rotational amount detecting means 8 to detect the rotational amount of the ring 1. An extent of driving setting means 10 sets up the driving variable of the lens driving source 4 based on the detected value and impresses a signal indicating the set value to a driving source control means 14 and the driving source 4 is controlled based on the impressed signal. Since the rotation of the ring 1 is converted into a pulse signal, the rotational variable of the ring 1 is detected as a digital value and the driving source 4 is controlled based on the detected value, the driving source 4 can be driven so as to faithfully follow the ring 1 and accurate and rapid focusing operation can be attained. |
