IMAGING OPTICAL SYSTEMS, AND IMAGING DEVICE PROVIDED WITH SAME

WIPO Patent Application WO/2016/113920

A1

These imaging optical systems include at least two imaging optical systems having different focal distances. Each of the imaging optical systems has, provided in order from the object side, a front-side lens group (GF) having positive refractive power, a diaphragm member, a focus lens group (Fo) having negative refractive power, and a rear-side lens group (GR). The front-side lens group (GF) has a positive lens or a negative lens as a common lens. Each of the at least two imaging optical systems constituting the imaging optical systems is provided with at least one common lens. During focusing, only the focus lens group (Fo) moves along the optical axis. Each of the imaging optical systems satisfies conditional expression (1), namely 0.06<│ffo/f│<0.4. The imaging optical systems satisfy conditional expression (2), namely 1.02