COLLIMATOR LENS, OPTICAL SCANNER AND IMAGE-FORMING DEVICE USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a collimator lens with a temperature compensation function having excellent imaging performance.SOLUTION: A collimator lens 23 comprises: a first surface 231 which a ray enters; a second surface 232 from which the ray emits; and a diffraction structure that is formed on the second surface 232. Assuming that divergent light emitted from a position P1 at a distance S1 from the second surface 232 enters and forms an image at a position P2 at a distance S2 from the first surface 231 within a temperature range between 0°C and 60°C, the collimator lens 23 has a relation of WF1