UV lithography system

An optical lithography exposure apparatus comprising an image pattern generator and a projection system, wherein

• the projection system images an object plane onto an image plane without forming an intermediate image between the object and image planes;
• the image pattern generator generates an optical image pattern on the object plane, and the projection system conveys the image pattern to a printing surface at the image plane;
• the image pattern generator is either a microlens array, which condenses illuminating radiation onto an array of focus spots on the object plane, or a holographic projection mask, which is displaced from the object plane and produces a diffractive image pattern on the object plane, or a non-holographic mask located at the object plane;
• the projection system comprises primary and secondary mirrors in a flat-image Schwarzschild configuration, wherein the primary mirror is a back-surface reflector with a transmitting front surface and a reflecting back surface;
• the primary mirror's back surface has a central, non-reflective window for beam transmission, and the secondary mirror has a central open hole for beam transmission;
• optical radiation from the image pattern on the object plane transmits through the secondary mirror's central hole, is then reflected from the primary mirror, then reflects from the secondary mirror and transmits through the primary mirror's transmission window to the image plane.