Optical element, optical system and methods of manufacturing the same as well as optical equipment

Abstract

An optical element has a marker provided in the form of an optical fault at a predetermined location in the effective optical area thereof for positioning. The optical fault is a marker 1a provided at a specific location on the effective optical area of the optical element 1 preferably in the form of a projection, a recess, a tinted portion, a different refraction portion, an air bubble, or a particle on or in the optical element 1. More preferably, the marker 1a is located at or around the center of the optical element 1 and its area size is not greater than 0.4% of the effective optical area of the lens 1.

Dependencies are inferred from the claim text.