Lens and method for manufacturing same

摘要

A lens including a lens portion having two opposite oblong surfaces at least one of which is a curved lens surface having a refractive power is disclosed. At both ends in a longitudinal direction of the lens portion, first and second flange portions are provided each of which tapers toward the lens portion and has a slant surface slanting with respect to the longitudinal direction of the lens portion and connected with one of the oblong surfaces. An angle of the slant surface of the first flange portion with respect to the longitudinal direction of the lens portion is different from an angle of the slant surface of the second flange portion with respect to the longitudinal direction of the lens portion.