Canon Patent Application: Canon RF 40mm F1.8

This is a curious patent application, and which also shows that at times you simply cant use the diagrams in which they give you as a clue to the implementation of the patent application.

This patent application is clearly for a full frame mirrorless camera and for some reason they show a DSLR in the illustrations.  Trust me, I don't get it either.

While we already have a RF 35mm F1.8 macro, this patent application also includes a 42mm or what I guess would be a 40mm F1.8 as well.

Canon RF 40mm F1.8

Focal Length  41.92
F-Number       1.85
Angle of View 27.30
Image Height  21.64
Lens length   71.50
BF            13.97

Canon RF 35mm F1.8

focal length  36.00
F-number       1.85
Angle of view 31.00
Image height  21.64
Lens length   79.97
BF            11.65

Basically this patent application is about keeping the lens small and reducing the AF motor noise at the same time.  Instead of really drilling into the optical design, most of the patent application describes the mechanical design.

Japan Patent Application 2020-034851