| 摘要 |
PROBLEM TO BE SOLVED: To obtain high image quality and high stabilization by forming collimated laser beams so that the cross section thereof is almost polygonal at a prescribed position until the collimated laser beams are inputted to a lowest downstream-side image forming means forming the image of the collimated laser beams on an image forming member by utilizing a spatial phase modulation means. SOLUTION: A semiconductor laser generator 11, outputting laser beams modulated corresponding to binary image information based on a driving signal from a laser driving circuit 3, a collimator lens 12 collimating the laser beams, a transmission type spatial phase modulation element 10, a polygon mirror 15 and the like are arranged in the order, starting from the upstream side of an optical path. Then, the laser beams emitted from the generator 11 are transmitted through the element 10, after being collimated by the lens 12 as a parallel beams, whose cross section is circular. Thus, the shape of the cross section of the collimated beams is changed from circular to almost square form, and the light intensity of the collimated beams is changed from an almost Gaussian distribution to almost rectangular distribution.
|
