Canon Patent: 200-800mm F5.6-9, 100-600mm F5.6-9 And 20-150mm F4-8

September 7, 2023
Canon Patents
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A new Canon patent was spotted. Zoom lenses for full frame mirrorless cameras, i.e. the EOS R system.

Canon patent application 2023125584 (Japan, published 9/7/2023) discusses optical formulas for three zoom lenses:

200-800mm F5.6-9
100-600mm F5.6-9
20-150mm F4-8

From the patent literature:

A zoom lens is provided that is compact and lightweight and capable of suppressing variations in optical performance over the entire zoom range.

BACKGROUND ART

As an imaging optical system used in an imaging device, there is a demand for a small and lightweight zoom lens that has a high zoom ratio (variable magnification ratio) and high optical performance over the entire zoom range. As a zoom lens that satisfies this requirement, a positive lead type zoom lens in which a lens group with a positive refractive power is arranged closest to the object side is known.

In the zoom lens disclosed in Patent Document 1, the negative second lens group as the main variable magnification group is moved toward the image side during zooming from the wide-angle end to the telephoto end. In order to obtain a higher zoom ratio with this zoom lens, it is necessary to increase the overall length of the lens in order to ensure the amount of movement of the second lens group. As the total length increases, the diameter of the first lens group increases, which is not preferable from the viewpoint of miniaturization and weight reduction.

The present invention provides a zoom lens that is small and lightweight and capable of suppressing fluctuations in optical performance over the entire zoom range, and an imaging device having the same.

Example 1