| 摘要 |
PROBLEM TO BE SOLVED: To obtain a device capable of eliminating adjustment at the time of attaching a reference position detection mechanism in extending a lens frame by providing a cam mechanism with a dead area where the rotation of a motor is not converted into parallel motion within a specified range from a reference position. SOLUTION: The cam mechanism is provided with the dead area where the rotation of the motor is not converted into the parallel motion within the specified range from the reference position. Relating to this automatic focusing device; when a photographer starts photographing operation and deprsses a release, autofocusing operation is started and a cam frame 2 is rotated by a stepping motor 6 through a gear 6-a. The positional relation between a cam receiver 1-a and a cam surface 2-a is changed and a front lens frame 1 is moved forth or back. In the midst of the movement, a home position detected part 2-b deciding the reference position provided on a fixed frame 3 shields to detect the reference position. A reference position detection signal is transmitted to a motor control part, which receives the signal and stops energizing the motor 6. |
