| 摘要 |
PROBLEM TO BE SOLVED: To provide a single focus lens whose entire length is short and which provides optical performance optimum for a photographic lens in spite of extremely inexpensive and simple constitution. SOLUTION: This single focus lens 1 is equipped with a 1st meniscus lens L1 which has positive refractive power, a 2nd meniscus lens L2, at least whose one surface is constituted of an aspherical surface, a 3rd lens L3 whose convex surface faces to an image surface side and which has positive refractive power, and a 4th meniscus lens L4 whose concave surface faces to the image surface side and at least whose one surface is constituted of an aspherical surface in order from an object side. It is desirable to constitute the 2nd lens L2 and the 4th lens L4 of optical resin.
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