| 摘要 |
A position detecting system including a detecting system for detecting positions, at different points on a surface of a reticle having a predetermined pattern formed thereon, with respect to a direction substantially perpendicular to the reticle surface, wherein the detecting system includes a light projecting portion for directing light from a light source to the reticle surface and a light receiving portion for receiving reflection light from the reticle surface, and wherein the angle of incidence of light from the light projecting portion, being incident on the reticle surface, is not less than 45 degrees.
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