Canon Patent: 10-20mm f/4, 10-20mm f/2.8-4 And 9-18mm f/4 Lenses

A new Canon patent application. Canon patent 2024023099 (Japan, published 2/21/2024) discusses optical formulas for three wide angle zoom lenses.

From the patent literature:

An object of the present invention is to provide a zoom lens that is small and has good optical characteristics, and an imaging device and an imaging system including the zoom lens.
BACKGROUND ART: Zoom lenses used in imaging devices are required to have a wide angle of view, be compact, and have good optical characteristics. As a wide-angle zoom lens, a so-called negative lead type zoom lens in which a lens group with a negative refractive power is arranged closest to the object side is known.
A negative lead type zoom lens has the characteristics that it is relatively easy to widen the angle of view and easily obtain a long back focus. However, negative lead type zoom lenses tend to have an asymmetrical lens configuration with respect to the aperture stop. Therefore, it is difficult to correct various aberrations, for example, it is difficult to suppress aberration fluctuations during focusing, and it is very difficult to obtain high optical performance.
In particular, in the inner focus type, in which focusing is performed using a small and lightweight lens group located closer to the image side than the first lens group in order to perform high-speed focusing, aberration fluctuations during focusing tend to increase.
The present invention provides a zoom lens that is compact and has good optical characteristics, and an imaging device and an imaging system having the zoom lens.

Example 1