Patent ID: 11953662
Assignee: RICOH COMPANY, LTD.
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 10:
11. The zoom lens according to claim 1,
wherein the second sub-first lens group includes one or more negative lens components and one or more positive lens components, and
wherein a negative lens component closest to an image among the one or more negative lens components and a positive lens component, which is closer to the image than and adjacent to the negative lens component, among the one or more positive lens components serve as a vibration-isolating lens group movable in the direction perpendicular to the optical axis to correct image blurring, and
wherein at least one of conditional expressions (7), (8), and (9) is satisfied:

−1.0<fA1/fA2<−0.01  (7)

0.5<A1_RR/A2_RF<2.0  (8)

0.001<D2RF/D2FR<0.6  (9)

where
fA1 denotes a focal length of the negative lens component,
fA2 denotes a focal length of the positive lens component,
A1_RR denotes a radius of curvature of a refractive surface closest to an image within the negative lens component,
A2_RF denotes a radius of curvature of a refractive surface closest to an object within the positive lens component,
D2RF denotes a distance along the optical axis between the refractive surface closest to the image within the negative lens component and the refractive surface closest to the object within the positive lens component, and
D2FR denotes a distance along the optical axis between a refractive surface closest to the object within the negative lens component and a refractive surface closest to the image within the positive lens component.