Patent ID: 7388698

Claim:
A scanning optical lens for a laser scanning unit, which communicates a laser that is deflected by a beam deflection unit on a photosensitive body, comprising: a sub-scanning direction section of the scanning optical lens configured to have a meniscus shape such that an incidence surface and an exit surface have the same curvature sign at a center portion of the lens; both the incidence surface and the exit surface configured to always maintain a negative (−) curvature sign, and which have an asymmetric curvature at portions extending from the center portion; and the incidence surface further configured to have an absolute curvature value of the incidence surface that is maximal at the center, and has at least one minimal value at each of both sides in a main-scanning direction, wherein the minimal values at each of both sides differ from each other, and wherein at least one of the minimal values is more than zero and less than about 0.001.