| 摘要 |
PROBLEM TO BE SOLVED: To provide an image pickup lens unit whose optical length is made shorter with respect to a focal distance, and which has sufficient resolution and is miniaturized and thinned. SOLUTION: The image pickup lens unit is equipped with a 1st lens 30, an aperture diaphragm 40 and a 2nd lens 50 successively arranged. When it is assumed that spaces between a convex surface 31 and a concave surface 32, the surface 32 and the aperture diaphragm 40, the diaphragm 40 and a concave surface 52, and the surface 52 and a convex surface 51 are d1 to d4, the radii of curvature of the surfaces 31, 32, 52 and 51 are r1 to r4, the refractive indexes of the 1st and the 2nd lenses 30 and 50 are n1 and n4, and the focal distance of an entire system is f, relation 0.057<ä(n<SB>1</SB>-1)/r<SB>1</SB>}/f<0.14, -0.14<ä(n<SB>1</SB>-1)/-r<SB>2</SB>}/f<-0.057, -0.1<ä(n<SB>4</SB>-1)/r<SB>4</SB>}/f<-0.05, -0.095<ä(n<SB>4</SB>-1)/-r<SB>5</SB>}/f<0.14 holds. COPYRIGHT: (C)2004,JPO
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