Patent ID: 6195208
Filing Date: 2001-02-27
Classification: G02B

Abstract:
An aspherical lens for converting a diverging input light beam having a non-circular cross section perpendicular to an optical path and having astigmatism, into a collimated light beam having its astigmatism corrected and having a circular cross-section perpendicular to the optical path, the aspherical lens comprising:a lens body having opposing first and second surfaces which respectively receive the input light beam having astigmatism and output the collimated light beam with its astigmatism corrected, the collimated light beam having a circular cross-section perpendicular to an optical axis of the lens body, the first surface having a configuration in which transverse and longitudinal components of the input light beam are refracted into the aspherical lens forming one apparent virtual source point on the optical axis in front of the aspherical lens, the second surface having a configuration in which the refracted transverse and longitudinal components of the input light beam reach the second surface at equal distances from the optical axis and exit the second surface in a direction parallel to the optical axis.