| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a lens for performing effective astigmatism correction by a sufficient non-axial symmetry in compact shape in which a space in a direction of an optical axis is effectively used without expanding a flange part externally. <P>SOLUTION: In a lens for astigmatism correction in which a main body part 100 of a lens and a flange part 110 are formed in one body by a plastic injection molding, the non-axial symmetry of the main body part 100 of the lens is obtained by forming projecting parts 120 which are projected in the direction of the optical axis on the side face of the flange part 110 and by controlling the behavior of the contraction of resin in the molding die in the resin molding by these projecting parts 120. The projecting parts 120 have, for example, structure to be used as a lens protector for protecting the lens and are formed in symmetrical circular-arc shape in both sides across the optical axis of the lens as projecting parts which correct, for example, the astigmatism by 90 degrees in the direction of the circumference of the optical axis. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
