| 摘要 |
PROBLEM TO BE SOLVED: To facilitate changing and adjusting imaging magnification while securing sufficient torque to rotate a torque wire in an endoscope which drives lenses using the torque wire. SOLUTION: The torque of a motor 22 is transmitted to a gear 20 engaging with a cam ring 19 through the torque wire 21. The position of a lens 18 is adjusted by detecting rotation of the motor 22 and determining the position of the cam ring 19 from the detected amount of rotation. Driving signals U, V and W are periodically applied to the motor 22 at a predetermined duty ratio to rotate the motor 22 intermittently. The tip of the torque wire 21 is rotated smoothly and continuously at low speed using the lag of rotational rate change at the tip of the torque wire 21 to facilitate adjustment of the position of the lens 18. COPYRIGHT: (C)2011,JPO&INPIT |
