| 摘要 |
PURPOSE:To improve the operability of mounting by coupling an aperture signal member with a diaphragm presetting device and a diaphragm device associatively with the mounting of a lens barrel on a camera. CONSTITUTION:A helicoid mechanism consists of a lens barrel body 1, distance ring 2, intermediate helicoid ring 2' coupling with the ring 2 in one body, and internal cylinder 3 which supports lenses. A preset cam ring 17 is supported rotatably on the lens barrel body, and a preset cam 17a is formed at its outer circumference. A diaphragm blade driving ring 20 which holds diaphragm blades 21 by an original method is energized by a spring 22 to rotate in a stop-down direction. A bell crank lever 18 equipped with a cam follower 19 which engages the cam 17a and a specifying pin which engages the cut edge 20' of the blade driving ring 20 rotates according to the rotation of the preset cam ring 17, and the rotation of the blade driving ring 20 is specified. |
