| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a laser scanning optical apparatus capable of suppressing thickening of a light beam even when a material in which high birefringence is generated is used for a scanning lens. <P>SOLUTION: It is assumed that: a phase difference of a light beam passing through an individual scanning lense 23 positioned on the downmost stream side in the light pass of the light beam is the difference in phase between an azimuth in which light advancing speed is high and an azimuth in which light advancing speed is low; and furthermore, in a light beam B passing through the individual scanning lense 23, the phase difference at a passage position of a principal ray B0 is R-principal, the phase difference at a passage position of an upper side ray Bu is R-upper, and the phase difference at a passage position of a lower side ray Bl is R-lower. In this case, ¾R-principal-(R-upper+R-lower)/2¾<50 nm and R-principal>500 nm are satisfied. <P>COPYRIGHT: (C)2013,JPO&INPIT |
