| 摘要 |
PURPOSE:To form a minute light spot without deviation of the position of optical scanning in a wide scanning region on a face to be scanned, by arranging a cylindrical lens, which corrects optically the deviation of the position of optical scanning, between the optical scanner and the face to be scanned. CONSTITUTION:The laser light from a laser light source 1 is reflected by a polarizing beam splitter 5 and is converted to an elliptic beam through a prism 11 and is condensed onto a mirror 3 of a focus controlling element 2 through a lambda/4 plate 12 by a lens 4. The reflected light passes the polarizing beam splitter 5 through the reverse course and becomes an isotropic beam shape shown by an arrow of a broken line. This beam is converted to an elliptic beam (shown by an arrow of a broken line) through two cylindrical lenses 10 arranged in the no- focus type and passes through a lens 6 and an optical scanner 7 and is condensed to a face 8 to be scanned in the direction of the longer axis of the ellipse by a cylindrical lens 9. Consequently, a minute spot without deviation of optical scanning throughout a wide scanning region is obtained. |
