A new wide-angle zoom lens EF 20-45mm f/2.8-4 patent has been filed Canon Japan, the lens is for the DSLR camera.
Detail translated by Google:
Patent Publication No. 2015-197593
Published 2015.11.9
Filing date 2014.4.1
Example
Zoom ratio 2.25
Focal length f = 20.00 23.60 45.00
Fno. 2.75 2.90 4.16
Half angle of 47.25 42.51 25.68
Image height 21.64 21.64 21.64
Overall length 158.28 156.32 173.36
BF 42.05 46.10 73.14
Via- Egami