| 摘要 |
PROBLEM TO BE SOLVED: To provide a photographic lens composed of two lenses, the photographic lens being designed so as to have high optical performance by selecting a proper lens material, imparting the optimum power, and correcting aberrations appropriately. SOLUTION: The photographic lens is composed of two lenses arranged in order from the object side, an aperture diaphragm 1, a first lens 2, and a second lens 3. The first lens 2 is a positive meniscus lens the convex face of which is directed to the object side. The second lens 3 is a negative meniscus lens the convex face of which is directed to the image side. Each of the first and second lenses 2 and 3 is a plastic lens both faces of which are aspherical and satisfies conditional formulae as follows: (1) 0.55<f<SB>1</SB>/f<0.95, (2)-0.2<f<SB>2</SB>/f<-1.0, (3) 27.0<ν<SB>1</SB>-ν<SB>2</SB>, wherein: f represents the focal distance of the entire system of the lens; f<SB>1</SB>represents the focal distance of the first lens; f<SB>2</SB>represents the focal distance of the second lens;ν<SB>1</SB>is the Abbe number of the first lens; andν<SB>2</SB>is the Abbe number of the second lens. COPYRIGHT: (C)2009,JPO&INPIT
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