| 摘要 |
PROBLEM TO BE SOLVED: To provide a compact scanning optical system at low cost capable of performing high-speed scanning without a curvature even when a surface to be scanned is flat and performing power variation by the simple constitution. SOLUTION: This optical system is provided with a lens group Gr2 on the object side converging a light beam from a filmy screen 1, a mirror M performing main scanning for picking up the image of the filmy screen 1 by deflecting a light beam transmitted through the lens group Gr2 on the object side and a lens group Gr1 on the image side forming the images of an on-axis light beam, off-axis light beam in the sub-scanning direction (z-axis direction), deflected by the mirror M, together on the image pickup surface of a line CCD 3. A zooming optical system is used for the lens group Gr1 on the image side, the speed/range of main scanning are made to be variable by the rotation control of the mirror M and the exit pupil of the lens group Gr2 on the object side is made almost coincident with the entrance pupil of the lens group Gr1 on the image side. |
