| 摘要 |
PROBLEM TO BE SOLVED: To restrain nonuniformity of a refractive index of a construction material of a lens, and to easily provide excellent image forming performance by molding an anamorphic lens by injecting an injection material from an edge part thickest in the optical axis directional width of the anamorphic lens or a gate arranged in the vicinity when molding the anamorphic lens by using a mold. SOLUTION: A negative fifth lens 15 of an image forming lens is composed of an anamorphic lens having at least one surface (an object side lens surface) formed of a rotational symmetry shape to the optical axis. This anamorphic lens 15 is molded by injecting an injection material (for example, a material by forming plastic as a fluid by intense heat or pressure) from an edge part (a lens outer peripheral surface: an edge surface) thickest in the optical axis directional width or a gate arranged in the vicinity by using a mold. Thus, molding pressure can be relatively set high, and fluidity of a material inside the mold can be suitably secured to prevent nonuniformity of a refractive index.
|
