Pattern Generator

a system that takes CAD data and generates patterns. The system typically has a light source, a variable shape aperture, a reduction lens system, a blanking aperture and a stepping mechanism. At one time these systems were widely used to make masks. The systems form various sized shapes by moving a set of blades, the shapes are exposed onto the mask through the reduction optics system, once a shape is exposed the light source is blocked by the blanking aperture and the system steps to a new position. Repeating these actions over and over allows complex patterns to be built up.