| 摘要 |
<p>An illumination system having a plurality of reflective elements, the reflective elements being movable between different orientations which direct radiation towards different locations in a pupil plane, thereby forming different illumination modes. Each reflective element is moveable to a first orientation in which it directs radiation to a location in an inner illumination location group, to a second orientation in which it directs radiation to a location in an intermediate illumination location group, and to a third orientation in which it directs radiation to a location in an outer illumination location group. The reflective elements are configured to be oriented to direct equal amounts of radiation towards the inner, intermediate and outer illumination location groups, and are configured to be oriented such that they can direct substantially no radiation into the outer illumination location group and direct substantially equal amounts of radiation towards the inner and intermediate illumination location groups.</p> |
