| 摘要 |
An f- theta lens is disclosed which is particularly suitable for use with a color laser printer in which beams of different wavelengths are combined into a single combined beam. The combined beam is scanned by a rotating polygon onto a receiving medium. The f- theta is adapted to operate with optics for shaping the beam in a scan direction prior to the polygon and a cylindrical element after the f- theta lens to image the beam in a cross-scan direction onto the receiving medium. In order to provide an f- theta lens which is color corrected, the lens includes means for correcting in a scan direction for lateral color aberrations in each of the beams, and means for correcting in a cross-scan direction for axial color aberrations in each of the beams.
|
