| 摘要 |
PROBLEM TO BE SOLVED: To provide a mechanism capable of suppressing the density irregularities in a sub-scanning direction of an image obtained by developing an electrostatic latent image by exposure. SOLUTION: An optical scanning part 500 makes an adjustment for narrowing a time difference exposure area causing the occurrence of density irregularities due to a reciprocity failure by widening an interval between main scanning lines in the Nth exposure scanning and the (N+1)th exposure scanning. An assembling person for the optical scanning part 500 selects a cylindrical lens 510 from a plurality of kinds of cylindrical lenses 510 having different refractive indexes and further, adjusts the installation angle of a plane mirror 522, to adjust an interval between adjacent main scanning lines. The optical scanning part 500 is adjusted so that a second scanning pitch between the Nth exposure scanning and the (N+1)th exposure scanning is wider than a first scanning pitch in the Nth exposure scanning and the (N+1)th exposure scanning by about 10% to 30% (or 1.0μm to 3.0μm). COPYRIGHT: (C)2011,JPO&INPIT |
