Patent ID: 6252695
Filing Date: 2001-06-26
Classification: G02B

Abstract:
A raster output scanner (ROS) imaging system comprising:a light source for generating a coherent collimated light beam output along an optical path,a photosensitive image plane,a rotatable multifaceted polygon interposed in the optical path between the light source and said photosensitive image plane for reflecting said light beam directed onto the facets of said polygon and scanning said light beam in a scan and cross-scan direction across a scan line on said photosensitive image plane,a pre-polygon optical system positioned in the optical path between said light source and said polygon, said pre-polygon optical system for focusing said light beam in the cross-scan direction onto said polygon while maintaining the collimation of the focused light beam in the scan direction onto said polygon, anda post-polygon optical system positioned in the optical path between said polygon and said photosensitive image plane, said post-polygon optical system includinga first wobble correction optical element and a second wobble correction element for focusing said diverging light beam in said cross-scan direction from said polygon to a point on said photosensitive image plane, said first wobble correction element and said second wobble correction element further correcting for wobble of said light beam at said scan line on said photosensitive image plane, said first wobble correction optical element substantially collimates said diverging light beam in said cross-scan direction from said polygon, said second wobble correction optical element focuses said substantially collimated light beam in said cross-scan direction from said first wobble correction optical element to a point on said photosensitive image plane, anda f-theta scan lens focusing said substantially collimated light beam in said scan direction to a point on said photosensitive image plane, said f-theta scan lens further providing a linear scan for said light beam at said scan line on said photosensitive image plane.