| 摘要 |
A surface position detection apparatus for detecting a surface position on a surface to be detected, comprises a projection pattern formed on a first surface, a projection optical system for projecting the pattern from an oblique direction onto the surface to be detected, a condensing optical system for condensing a light beam reflected by the surface to be detected, and forming an image of the pattern on a second surface, and a detector for photoelectrically detecting the image of the pattern. The first surface and the surface to be detected are arranged to satisfy a Scheimpflug condition in association with a principal plane of the projection optical system. The surface to be detected and the second surface are arranged to satisfy a Scheimpflug condition in association with a principal plane of the condensing optical system. |
