PROBLEM TO BE SOLVED: To propose a lightweight and compact imaging lens which is advantageous in production and composed of a small number of elements by employing aspherical surfaces which have no inflection points as lens surfaces and correcting aberrations for adaptation to high pixels of megaorder.

SOLUTION: The imaging lens 1 comprises three elements in three groups and has an array of, in order from the object side, a 1st meniscus lens 1 which is convex to an object side and has positive power, a 2nd meniscus lens 2 which is concave to the object side and has positive or negative power, and a 3rd lens 3 which has positive power. Lens surfaces 1a and 1b, 2a and 2b, and 3a and 3b of the 1st to 3rd lenses 1 to 3 are aspherical surfaces on which no inflection points appear in their effective lens surface areas.

COPYRIGHT: (C)2005,JPO&NCIPI

【課題】 変曲点を含まない非球面をレンズ面に採用し、メガオーダの高画素に対応できるように収差補正を施して、生産に有利な、構成枚数が少ない軽量でコンパクトな撮像レンズを提案すること。
【解決手段】 撮像レンズ１は、３群３枚構成からなり、物体側より順に、物体側に凸面を向けた正のパワーを有するメニスカスの第１レンズ１と、物体側に凹面を向けた正または負のパワーを有するメニスカスの第２レンズ２と、正のパワーを有する第３レンズ３が配列されている。第１〜３レンズ１〜３のレンズ面１ａ、１ｂ、２ａ、２ｂおよび３ａ、３ｂの形状が、その有効レンズ面領域内に変曲点が現れない非球面形状とされている。
【選択図】 図１