Patent ID: 9297984
Filing Date: 2016-03-29
CPC Classification: G02B,H04N

Claim Text:
1. An image forming lens system comprising: an aperture stop; and an image-side lens unit group which is disposed on an image side of the aperture stop, wherein the image-side lens unit group includes in order from the aperture stop to the image side along an optical axis, a first image-side lens unit having a negative refractive power, a second image-side lens unit having a positive refractive power, and a third image-side lens unit having a negative refractive power, and any one of the first image-side lens unit, the second image-side lens unit, and the third image-side lens unit is a focusing lens unit which moves along the optical axis at the time of focusing from an object at infinity to an object at a close distance, and the following conditional expression (3) is satisfied: where, f f denotes a focal length of the image forming lens system at the time of focusing at an object at infinity.