A postobjective optical deflector comprising: a polygonal optical deflector (polygonal rotating mirror) having a plurality of convex reflecting surfaces each being curved surface other than a spherical surface or a portion of a cylindrical surface; and a pseudocylindrical lens disposed between the polygonal...http://www.google.com/patents/US5204769?utm_source=gb-gplus-sharePatent US5204769 - Postobjective optical deflector
