| 摘要 |
PROBLEM TO BE SOLVED: To obtain a pleasant zoom operation, while reducing errors and time for moving to a target position by detecting the movable part position of focus lens and updating a drive signal plural times, so as to move toward a focal position at a prescribed moving speed. SOLUTION: Corresponding to the switch state of a zoom switch 131, a lens control microcomputer 112 outputs the drive/stop and instruction signal for rotational direction of zoom motor 117 to a motor driver 118. The position of a focus lens 105 is detected by a position encoder 127 and outputted through an amplifier circuit 120 to a comparator circuit 121. Here, in comparison with a target signal from the microcomputer 112 for moving the focus lens 105 to the target position, the deviation signal corresponding to the difference between two signals is generated. Next, an adder circuit 124 adds the integrated result of deviation signal and the differentiated result of output from an encoder 127 and supplies the result through a motor driver 125 to a motor coil 126 and the drive amount for focus lens 105 is changed. The drive speed for focus lens 105 is fed back. |
