Canon Patent: RF 20mm f/1.8, RF 24mm f/1.8, RF 28mm f/1.8 Lenses

February 1, 2022
Canon Patents
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Drawing from the patent literature

A new Canon patent application, once more for RF mount lenses.

Canon patent application 2022-20096 (Japan) discusses optical formulas for a bunch of RF mount lenses: RF 20mm f/1.8, RF 24mm f/1.8, RF 28mm f/1.8.

From the patent literature:

PROBLEM TO BE SOLVED: To provide an optical system having good optical performance, easy to manufacture and compact. However, when the optical system of Patent Document 1 is widened, the off-axis aberration increases as the angle of view increases. In order to satisfactorily correct the increased off-axis aberration, it is necessary to arrange a lens having a large diameter in the front group, which is the focus group, on the object side, which leads to an increase in the size of the optical system. Furthermore, since the mass of the focus group also increases, a high-output actuator is required when performing autofocus, which may lead to an increase in the size of the actuator. An object of the present invention is to provide an optical system having good optical performance, easy to manufacture, and a small size, and a lens device and an image pickup device having the same.

Example 1

Focal length: 28.60
F value: 1.85
Half angle of view: 37.1
Image height: 20.15
Overall length: 81.00
Back focus: 13.20

Example 2

Focal length: 20.60
F value: 1.85
Half angle of view: 46.4
Image height: 18.71
Overall length: 84.87
Back focus: 11.00

Example 3

Focal length: 24.72
F value: 1.85
Half angle of view: 41.2
Image height: 19.34
Overall length: 81.00
Back focus: 11.00

The patent application was spotted by asobinet.com. More Canon patent applications are listed here. Some particularly interesting patent applications we think might get into production are these: