IMAGE FORMING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an image forming device that can ensure uniformity of a resolution in the lens arrangement direction while maintaining a high basic resolution thereby making an uneven gray scale inconspicuous even in the case of processing half-tone. SOLUTION: An object face 14 is placed to be opposed to a one lens end face of a rod lens array 10 and an image face 16 is placed to be opposed to the other lens end face and the operating distance of the object side and that of the image side are selected optically nearly equal to each other. An actual distance TC0 between the object face and the image face is limited between a conjugate length TC1 maximizing the average value MTFave of an MTF (modulation transfer function) of the rod lens array single body in the lens arrangement direction and a conjugate length TC2 minimizingΔMTF (=(MTFmax-MTFmin)/MTFave) and the offsetΔTC (=|TC0-TC1|) with respect to the conjugate length TC1 maximizing the MTFave is selected within a range of 0 mm<ΔTC<+0.2 mm.