Abstract:
An improved diffraction grating scanner, in which anamorphic imaging techniques are utilized to correct the curvature of the scan, in the plane of the scan, as well as correction for field curvature so as to provide improved resolution and increased length of scan. Basically, the scanner system may comprise either refractive or reflective elements, including cylindrical lenses (13, 15, 36, 38) and reflectors (27, 33, 37, 39) of circular or elliptical cross-section and toroidal reflectors (20) and lenses as well. In addition, such system will customarily include one or more spherical elements, but at least one cylindrical or toroidal element must be provided. The anamorphic imaging correction apparatus can be utilized with reflector scanners, including polygonal and single-mirror scanners, as well as with diffraction grating-type scanners.