Optical system for light beam scanning

• Main Authors: MADDOX; RANDALL ADRIAN, ROUTT, JR.; WILSON MORGAN
• Format: Patent
• Language: English
• Published: 21.12.1999
• Edition: 6
• Subjects: OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; PHYSICS

An optical system for light scanning devices in which a beam of light travels from an origin to an object along a light path and has along that path a scan direction and a cross-scan direction. The optical system includes a light source at the origin of the light path, a polygonal reflector located along the light path and having adjacent peripheral mirror surfaces rotatable in the scan direction, and a pre-scan optical sub-system located along the light path between the light source and the polygonal reflector. The pre-scan optical sub-system includes, in order of light travel from the light source, a collimating lens and a pre-scan lens having a convex cylindrical lens entrance surface aligned in the scan direction for converging the light beam in the cross-scan direction, and a convex lens exit surface for converging the light beam in the scan direction. An aperture stop may be provided between the collimating lens and the pre-scan lens to further truncate or reduce the diameter of the collimated beam. The optical system has a post-scan optical sub-system located along the light path between the rotatable polygonal reflector and the object and including a first f-theta lens and a second f-theta lens.