Canon Patent: 24-300mm F4-5.6, 24-400mm F4-5.6 And 20-240mm F4-6.3 Lenses

Here is a new Canon patent application for what appears to be a bunch of slow zoom lenses. Kit lenses?

Canon patent application 2024005834 (Japan, published 01/17/2024) discusses optical formulas for three zoom lenses:

• 24-300mm F4-5.6
• 24-400mm F4-5.6
• 20-240mm F4-6.3

From the patent literature:

• [Problem] To obtain a high-performance zoom lens with a high zoom ratio while the entire system is compact.
• [Background Art] In recent years, as an imaging optical system used in an imaging device, a small zoom lens with a high zoom ratio (high zoom ratio), high optical performance over the entire zoom range, and a short overall lens length has been used. That is what is required.
• However, in the zoom lens disclosed in Patent Document 1, the Abbe number of the positive lens included in the first lens group is small, and when the zoom ratio is increased, the longitudinal chromatic aberration becomes large, especially at the telephoto end.
• Accordingly, an object of the present invention is to provide a zoom lens having a high zoom ratio and high optical performance, while the entire system is small.

Example 1

• Focal length: 24.72-291
• F value: 4.12-5.77
• Half angle of view: 37.35-4.25
• Image height: 21.64
• Total length: 175-258.9
• Back focus: 13.81-68.61

Example 2

• Focal length: 24.72-390
• F value: 4.12-5.77
• Half angle of view: 37.35-3.18
• Image height: 21.64
• Total length: 180-300.09
• Back focus: 14.63-81.63

Example 3

• Focal length: 20.6-240
• F value: 4.12-6.3
• Half angle of view: 42.48-5.15
• Image height: 21.64
• Total length: 174.99-284.99
• Back focus: 14.63-81.63

[via asobinet]