Fig.1. slow motion of the camera aperture(left) and components of the Iris mechanism(right)
As a part of the camera lens, the aperture controls the amount of light entering the lens. The moving mechanism of this aperture is called "Iris Mechanism".
The Iris iris mechanism consists of three main parts such as Base plate, Blades, and Blade actuating ring.
Each blade structure has a four-bar linkage mechanism and all blades moved simultaneously by a single actuator or input force(outer ring rotation).
...