IMAGE READING LENS, AND IMAGE READING DEVICE AND IMAGE FORMING APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide an image reading lens that has a wide half viewing angle of 33° or more, and can increase resolution of a meridional image surface without using a non-rotationally symmetric lens to obtain resolution substantially the same as resolution of a sagittal image surface; an image reading device; and an image forming apparatus.SOLUTION: An image reading lens has a half viewing angle of 33° or more, and is formed of a plurality of lenses having a rotationally symmetric surface shape and a diaphragm; and the shape of the diaphragm is a non-arc shape that is wide in a longitudinal direction of a line sensor.