Patent ID: 7619833
Filing Date: 2009-11-17
Classification: G02B

Abstract:
1. A lens system comprising, sequentially in order from a magnifying side, a first lens group which makes up a substantially afocal optical system as a whole and a second lens group having a positive refractive power as a whole, wherein the first lens group comprises, sequentially in order from a magnifying side, a first sub-lens group ( wherein the second lens group comprises, sequentially in order from a magnifying side, a first sub-lens group ( wherein the following conditional expression (1) is satisfied with respect to a power set for the first lens group, the following conditional expression (2) is satisfied with respect to an afocal magnification set for the first lens group, the following conditional expression (3) is satisfied with respect to a power set for the first sub-lens group ( where: f: Composite focal length of the whole lens system; f h h f f f T