A new Canon patent application. Canon patent 2024023099 (Japan, published 2/21/2024) discusses optical formulas for three wide angle zoom lenses.

• 10-20mm f/4
• 10-20mm f/2.8-4
• 9-18mm f/4

From the patent literature:

• An object of the present invention is to provide a zoom lens that is small and has good optical characteristics, and an imaging device and an imaging system including the zoom lens.
• BACKGROUND ART: Zoom lenses used in imaging devices are required to have a wide angle of view, be compact, and have good optical characteristics. As a wide-angle zoom lens, a so-called negative lead type zoom lens in which a lens group with a negative refractive power is arranged closest to the object side is known.
• A negative lead type zoom lens has the characteristics that it is relatively easy to widen the angle of view and easily obtain a long back focus. However, negative lead type zoom lenses tend to have an asymmetrical lens configuration with respect to the aperture stop. Therefore, it is difficult to correct various aberrations, for example, it is difficult to suppress aberration fluctuations during focusing, and it is very difficult to obtain high optical performance.
• In particular, in the inner focus type, in which focusing is performed using a small and lightweight lens group located closer to the image side than the first lens group in order to perform high-speed focusing, aberration fluctuations during focusing tend to increase.
• The present invention provides a zoom lens that is compact and has good optical characteristics, and an imaging device and an imaging system having the zoom lens.

Example 1

• Focal length: 10.33-19.39
• F value: 4.08-4.12
• Half angle of view: 61.36-48.13
• Image height: 18.92-21.64
• Total length: 128.82-123.27
• Back focus: 12.13

Example 2

• Focal length: 9.20-17.90
• F value: 4.08-4.12
• Half angle of view: 64.04-50.40
• Image height: 18.90-21.64
• Total length: 125.26-119.35
• Back focus: 10.50

Example 3

• Focal length: 11.30-23.90
• F value: 4.08-4.12
• Half angle of view: 59.29-42.15
• Image height: 19.02-21.64
• Total length: 129.79-129.33
• Back focus: 14.54-10.54

Example 4

• Focal length: 10.30-19.80
• F value: 2.89-4.12
• Half angle of view: 61.76-47.54
• Image height: 19.18-21.64
• Total length: 132.94-127.01
• Back focus: 11.35

More Canon patents are listed here.

[via asobinet]

Canon patent application 2024007656 (Japan, published 19/01/2024) discusses optical formulas for two wide angle zoom lenses.

• 10-18mm f4.5-6.3
• 10-20mm f/4 with internal zoom mechanism

From the patent literature:

• An object of the present invention is to provide a zoom lens that has high optical performance, is compact, and has a wide angle of view.
• BACKGROUND ART
  Wide-angle lenses are widely used for landscape photography, astronomical photography, and the like. Wide-angle lenses are required to have high optical performance and realize a wide angle of view while being compact.
• Generally, in a negative read optical system, the constituent lens groups are arranged asymmetrically, making it difficult to correct various aberrations such as astigmatism. In particular, when widening the angle of view or downsizing the lens, the refractive power of the lens group closest to the object, which has a negative refractive power, becomes stronger, so that many of the above-mentioned aberrations occur.
• For this reason, in order to achieve a wide angle of view and miniaturization in a negative lead type optical system, and to properly correct various aberrations such as curvature of field and obtain high optical performance, the refractive power of each lens group must be adjusted. It is important to set these appropriately.
• In Patent Document 1, various aberrations such as astigmatism and field curvature are corrected by weakening the refractive power of each lens group, but this increases the size of the optical system, which is undesirable.
• Accordingly, an object of the present invention is to provide a zoom lens that has high optical performance, is small in size, and has a wide angle of view.

Example 1

• Focal length: 10.30-17.50
• F value: 4.63-6.13
• Half angle of view: 53.0-38.0
• Image height: 11.28-12.95
• Total length: 74.63-73.78
• Back focus: 10.97

Example 2

• Focal length: 15.00-29.10
• F value: 4.63-6.42
• Half angle of view: 55.-36.3
• Image height: 17.85-21.46
• Total length: 122.37-109.82
• Back focus: 13.33

Example 3

• Focal length: 10.30-21.35
• F value: 4.63-6.33
• Half angle of view: 53.0-32.5
• Image height: 11.38-13.66
• Total length: 84.74-75.36
• Back focus: 10.97-14.95

Example 4

• Focal length: 10.30-19.40
• F value: 4.12
• Half angle of view: 52.9-35.2
• Image height: 11.38-13.52
• Total length: 75.89-75.89
• Back focus: 10.97

All featured Canon patents are listed here.

[via asobinet]