| 摘要 |
PURPOSE:To reduce the working of parts which requires high accuracy and to obtain an inexpensive device by engaging a guide pin which is fitted in a cam groove with a cam groove for variable power and a cam groove for correction through a guide hole for a driving rotary ring which has a guide hole made of an oblong hole extending in the direction of an optical axis. CONSTITUTION:The guide hole 22 which extends in the direction of the optical axis is bored in the driving rotary ring 21 provided with the cam groove 15 for correction and the guide pin 16 fixed to a rotary ring 19 at one end is fitted in the cam groove 14 for variable power and the cam groove 15 for correction through the guide hole 22. A zoom ring 17 is rotated to generate a force operating on the guide pin 16 fitted in the guide hole 22 of the driving rotary ring 21, so the rotary ring 19 to which this guide pin 16 is fixed rotates. A lens holder 1 for variable power and a lens holder 5 for correction moves in the direction of the optical axis along the cam groove 14 for variable power and the cam groove 15 for correction provided to a lens barrel 10 according to the rotation of this rotary ring 19, thereby performing zooming operation. |
