Canon Patent Applications: Canon Zoom lenses

This patent application (Japan 2023-125903) has a lot of esoteric fast zoom lenses in some very nontraditional focal lengths. Many of the embodiments are missing the image height, however since we also have the half angle of view, we can work backward to verify if these lenses are meant for full frame or for APS-C. As an example, 48mm has a half angle of view of 15.5 degrees for APS-C and 24 degrees for full frame.

There is quite a collection of APS-C and Full frame fast zoom lenses in these embodiments with some interesting designs.

While Canon doesn't suggest that it could be used only for video (as they mention stills, video, and surveillance as possible use cases), the most probable use case for Canon is the Cinema EOS lineup, especially with the larger back focus distance shown on the embodiments. Canon does show a video camera in Figure 15, which would also seem to indicate that is their objective with these lenses. The lenses are also quite large as the embodiments show a lens physical length of around 200 to 270mm in length while comparative lenses are around 100mm shorter in length. Canon has also in the past shown images of stills cameras on lens designs that were never going to be put on a stills camera. It's most likely safe to guess that these lenses are for the Cinema EOS series, but it's always difficult without a clear indication in the applications.

Canon 45-135mm F2.8

Focal length       46.51   60.60  133.99
F number            2.90    2.90    2.90
Half angle of view 24.95   19.65    9.17
Lens length       320.01  320.01  320.01
BF                 50.01   50.01   50.01

Canon 50-145mm F4.0

Focal length        48.50  63.81  145.38
F number             4.00   4.00    4.00
Half angle of view  24.04  18.73    8.46 
Image height        21.64  21.64   21.64
Lens length        293.60 293.60  293.60 
BF                  50.00  50.00   50.00

Canon 45-135mm F2.8

Focal length        46.50  60.59  134.00
F number             2.90   2.90    2.90
Half angle of view  24.95  19.65    9.17
Lens length        309.00 309.00  309.00
BF                  39.00  42.89   47.01

Canon APS-C 30-100mm F2.0

Focal length         31.01  40.92   94.00
F number              2.00   2.00    2.00
Half angle of view   25.51  19.89    8.95
Lens length         277.66 277.66  277.66
BF                   39.29  39.29   39.29

Canon APS-C 30-100mm F4.0

Focal length         31.00  40.91   94.00
F number              4.00   4.00    4.00
Half angle of view   25.52  19.89    8.95
Lens length         249.95 249.95  249.95
BF                   50.00  50.00   50.00

Canon 45mm-135mm F2.8

focal length         46.52  60.60  133.99
F number              2.90   2.90    2.90
Half angle of view   24.94  19.65    9.17 
Lens total length   289.99 289.99  289.99
BF                   49.99  49.99   49.99

As with all patent applications, this may never become a patent and even if it does, it may never make it past the idea stage into an actual product. However, it's interesting to see what Canon is researching.

Source: Japan Patent Office 2023-125903

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