| 摘要 |
An imaging lens includes a first lens having positive refractive power; a second lens having negative refractive power; a third lens; a fourth lens having negative refractive power; a fifth lens having positive refractive power; and a sixth lens, arranged in this order from an object side to an image plane side. The first lens is formed so that a surface thereof on the object side has a positive curvature radius. The second lens is formed so that a surface thereof on the image plane side has a positive curvature radius. The fifth lens is formed so that a surface thereof on the object side and a surface thereof on the image plane side have negative curvature radii. Each of the third lens, the fourth lens, the fifth lens, and the sixth lens has refractive power weaker than that of each of the first lens and the second lens. |
