A LIGHT VOLUME ADJUSTER AND AN OPTICAL INSTRUMENT USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a light volume adjuster that can be miniaturized, and to provide an optical instrument that has a light volume adjuster and lenses.SOLUTION: A diaphragm blade 103 moves along a curved path formed between a convex lens as a first optical member and a concave lens as a second optical member. The blade driving means that drives the diaphragm blade 103 along the curved path includes: a drive ring 102 as a rotation member for rotating the diaphragm blade 103; and a drive part 105 connected to the outer peripheral edge part of the drive ring 102. An optical instrument has the light volume adjuster and lenses.