| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an image pickup lens having high heat resistance, capable of mass production, and having good aberration performance. <P>SOLUTION: The first lens portion 1a having a convex shape on the object side is formed on the object side surface of the first lens substrate, the first lens portion 1b having a concave shape on the image side is formed on the image side surface of the first lens substrate, the second lens portion 2a having a concave shape on the object side is formed on the object side surface of the second lens substrate, the second lens portion 2b having an aspheric shape is formed on the image side surface of the second lens substrate, and an aperture diaphragm is disposed on the first lens substrate. The following conditional expressions should be satisfied: 1.51<N2b<2.0, 1.7<D[BK2]/D[BK1]<3.0, wherein N2b: a refractive index to line d of the second lens portion 2b, D[BK1]: a composite thickness of the first lens block, and D[BK2]: a composite thickness of the second lens block. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
