Lens with low birefringence, method of fabricating the lens, and light scanning unit including the lens

摘要

There are provided a lens, a method of fabricating the lens, and a light scanning unit. The lens includes a lens portion having an effective optical surface, and a gate-side flange portion between the lens portion and a gate-side end of the lens. If the lens is disposed between two polarizers configured to polarize light linearly in perpendicular directions and is illuminated in an optical axis direction, interference fringes are generated on the lens, and peripheral interference fringes of the interference fringes extend continuously from the gate-side end and are longer than the gate-side flange portion.

主权项

1. A lens comprising:
a lens portion comprising an effective optical surface; a gate-side flange portion between the lens portion and a gate-side end of the lens; and a second flange portion between the lens portion and a second end of the lens, wherein the lens has a structure so that a degree of birefringence at the gate-side flange portion is greater than a degree of birefringence at the second flange portion, and to generate interference fringes on the lens if the lens is disposed between two polarizers configured to polarize light linearly in perpendicular directions and is illuminated in an optical axis direction, and peripheral interference fringes of the interference fringes extend continuously from the gate-side end and are longer than the gate-side flange portion.