Canon file a patent application July 13, 2023, publication number P2023099391 for a compact, lightweight and high performance zoom lens. The Canon patent application includes several embodiments of which the 20-50mm F4.5-6.3 and 20-60mm F/4.5-6.3 are most notable.
Applicant: Canon Inc.
Publication number: P2023099391
Application number: P 2022000019
Publication date: 2023-07-13
The Canon patent application is for a lightweight, compact zoom lens with very good optical performance, along with an imaging device and imaging system incorporating into the lens.
While a mount isn't specified, the technology would likely be applied to the RF mount.
The reasoning behind the patent is having a zoom lens that captures a wide field of view while maintaining a small and lightweight design. To achieve this, a negative lead type wide-angle zoom lens is utilized.
This lens configuration involves arranging a lens group with negative refractive power closest to the object side.
The patent application describes a zoom lens comprising a first lens group with negative refractive power, a second lens group with positive refractive power, a third lens group with negative refractive power and a fourth lens group with positive refractive power, all arranged in sequential order from the object side to the image side.
However, the patent doesn't taken into account various aberrations or how to resolve them which would likely result in suboptimal optical performance, despite its reduced size and weight.
The present confidential invention aims to overcome these limitations by providing a compact, lightweight zoom lens with superior optical performance, along with an imaging apparatus and imaging system incorporating this advanced zoom lens.
Example 5: 20-50mm F/4.5-6.3
Zoom ratio 2.35
Focal length 20.61 33.70 48.50
F value 4.63 5.88 6.49
Half angle of view 41.17 30.56 23.03 Image
height 18.02 19.90 20.61
Overall length 120.00 104.38 1 00.66
Back focus 10.49 20.91 31.34
Example 6: 20-60mm F/4.5-6.3
Zoom ratio 2.84
Focal length 20.61 39.47 58.50
F value 4.64 5.88 6.49
Half angle of view 41.17 26.75 19.41 Image
height 18.02 19.90 20.61
Overall length 135.00 120.11 1 25.50
back focus 10.49 11.09 11.70
While this Canon patent application might seem plausible without he 20-50mm being the most realistic embodiment, canon files patents on a regular basis and not all of them make it to market,. Sometimes a patent is filed simply to protect research and development effort with he technology coming to other lenses in the future.
The title image is of the Canon CN-E20-50mm T2.4 L F / FP.