Patent ID: 8854701

Claim:
An image-forming lens, comprising: in order from an object side to an image side a first group having a negative power as a whole, the first group consisting of a positive meniscus lens having a convex surface on the object side and a negative meniscus lens having a convex surface on the object side, the positive meniscus lens and the negative meniscus lens being cemented; an aperture stop; a second group consisting of a positive meniscus lens having a convex surface on the image side; a third group consisting of a positive meniscus lens having a convex surface on the image side; a fourth group consisting of a lens having a negative power; and a fifth group consisting of a biconcave lens, wherein a backfocus BF, an entire length of the image-forming lens L, a focal length of e-line of the first group f 1 , a combined focal length of e-line of an entire system f, and a space interval between the fourth group and the fifth group d 10 satisfy the following conditions: −6.5< f 1/ f≦ 2.2, (1) 0.20< d 10/ f< 0.50, and (2) 0.01< BF/L< 0.14. (3)