https://ipforce.jp/patent-jp-A-2020-86357
(in Japanese)
A few key highlights are as follows (Google Translated):
[Name or name] Ricoh Co., Ltd.
[0008]
However, in the zoom lens system of Patent Document 1, since the second lens group 2b, which is the image blur correction lens group, is close to the stop on the long focal length end side (tele end side), the long focal length end side (tele end is set at the time of image blur correction). The eccentric coma aberration generated on the side) tends to be large. Therefore, the second b group, which is the image blur correction lens group, is composed of three or more lenses, and there remains a problem in weight reduction of the image blur correction lens group.
(Table 5)
Short focal length end Medium focal length Long focal length end
Focal length 72.2 135.0 293.2
F number 4.43 4.88 5.34
(Table 8)
Short focal length end Medium focal length Long focal length end
Focal length 72.0 135.1 293.6
F number 4.59 4.96 5.52
A list of variants of the same design gene are patented. While the focal ranges are almost the same, the maximum apertures could vary a bit but the variations are insignificant.