Canon patents for a Canon 20-40mm F2.8 and 20-50mm F4 lens have been found. You can check them out below:
overview
- [Publication number] JP2025-68535 (P2025-68535A)
- [Release date] April 28, 2025 (2025.4.28)
- [Name of invention] Zoom lens and imaging device having the same
- [Application date] October 16, 2023 (October 16, 2023)
- [Applicant]
[Identification number] 000001007
[Name or company name] Canon Inc. - A compact zoom lens having high optical performance is provided.
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2. Description of the Related Art
In a zoom lens used in an image pickup apparatus, if the mass or amount of movement of a lens group that moves during zooming, or the number of lens groups that move, increases, the zoom lens tends to become large. -
However , the zoom lens of Patent Document 1 does not adequately correct
the various aberrations that occur during zooming, and therefore there is a demand for a compact zoom lens with high optical performance. - SUMMARY OF THE PRESENT EMBODIMENT
An object of the present invention is to provide a compact zoom lens having high optical performance.
Example 1
- Focal length: 20.61-38.72
- F-number: 2.90
- Half angle of view: 43.64-29.19
- Image height: 19.65-21.64
- Total length: 130.70
- Back focus: 31.45-40.28
Example 2
- Focal length: 20.61-48.39
- F-number: 4.10
- Half angle of view: 43.69-24.09
- Image height: 19.69-21.64
- Overall length: 133.51
- Back Focus: 12.18
Example 3
- Focal length: 15.47-28.82
- F-number: 4.10
- Half angle of view: 52.36-36.90
- Image height: 20.06-21.64
- Overall length: 97.47
- Back Focus: 11.75
Example 4
- Focal length: 12.37-33.97
- F-number: 2.35-3.60
- Half angle of view: 44.47-21.96
- Image height: 12.14-13.70
- Overall length: 113.77
- Back Focus: 11.50
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