Patent ID: 10386617

Abstract:
An image forming lens system includes a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, and a third lens unit. The first lens unit includes a front-side lens unit having a positive refractive power and a rear-side lens unit in order from the object side. The second lens unit moves at a time of focusing. The third lens unit includes a positive lens element. Each lens element in the front-side lens unit is a lens element that satisfies following Conditional Expression (a). The rear-side lens unit includes a negative lens element and a positive lens element. The front-side lens unit includes a diffractive lens component having a diffractive lens surface. The diffractive lens component has a positive refractive power. Following Conditional Expression (1) is satisfied: −0.7≤f/fLens  (a)0.015≤ΔGFGR/f≤0.25  (1).