OPTICAL FILTER, LIGHT VOLUME ADJUSTING DEVICE AND IMAGE PICKUP DEVICE HAVING SAME

摘要

The optical filter (20) includes a filter edge portion (20a) forming a boundary between a region through which a light flux is transmitted and a region through which the light flux is not transmitted. The filter edge portion has a concavo-convex shape whose edge outline is formed by a continuous curved line including convex portions (20b) and concave portions (20c) alternately arranged in a direction in which the boundary extends. The curved line includes part satisfying ¸a>60°. ¸a represents an angle formed by a tangent (LM) at an arbitrary point on the curved line between a top point (T) of one convex portion and a bottom point (B) of one concave portion adjacent to the one convex portion with a tangent (LT) at the top point of the one convex portion, the angle ¸a becoming larger as the arbitrary point becomes farther from the top point.