| 摘要 |
PROBLEM TO BE SOLVED: To obtain a compact photographic lens, having high resolution, constituted of a small number of lenses, having long back focus and made excellent in telecentricity on image side. SOLUTION: This photographic lens is constituted, by arranging an aperture diaphragm nearest to an object side and then arranging four lenses, that is, a 1st lens, a 2nd lens, a 3rd lens and a 4th lens in order from the object side, and the 1st lens is a meniscus lens having convex shape on the image side, the 2nd lens is a lens (hereinafter to be referred to as a positive lens) having positive refractive power, and the 3rd lens is a lens having negative refractive power and the 4th lens is a positive lens constituted by cementing the 3rd lens. |
