Canon patent application US20190369372 discusses optical formulas for various zoom lenses for the Canon EOS R system.
Among the discussed optics in this Canon patent application is a 28-280mm f/2.8 lens. All lenses seem to be designed for the EOS R full frame mirrorless system.
A zoom lens includes, in order from an object side, a positive first unit, a negative second unit, a positive intermediate group consisting of one or two units and including a third unit located on a most object side, a negative unit, and a rear group consisting of one or two units including a positive unit located on a most object side. Conditional expressions are satisfied with respect to amounts of movement of the second and third units from a wide angle end to a telephoto end, a distance at the wide angle end from a most object side surface vertex in the first unit to a most object side surface vertex in the third unit, an Abbe number of a most object side lens in the first unit, a focal length of the second unit, and focal lengths at the wide angle end and at the telephoto end.[…]
A zoom lens of the disclosure includes a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, an intermediate lens group having a positive refractive power and including one or two lens units inclusive of a third lens unit located on an object side, a lens unit having a negative refractive power, and a rear lens group including one or two lens units inclusive of a lens unit which is located on the object side and has a positive refractive power, which are arranged in order from the object side to an image side. Here, an interval between every two adjacent lens units is configured to be variable for zooming. In the meantime, a total length of the zoom lens is reduced by keeping the first lens unit unmoved relative to an image plane while varying the intervals between the lens units during the zooming. The first lens unit includes three or more lenses and mainly corrects a spherical aberration and an axial chromatic aberration on a telephoto side. The second lens unit includes three or more lenses and mainly suppresses variations in curvature of field and in chromatic aberration of magnification during the zooming. In order to achieve correction of aberrations and reduction in size at the same time, it is preferable to form each of the first lens unit and the second lens unit by use of three or four lenses.
More Canon patent applications are listed here. Some particularly interesting patent applications we think might get into production are these:
- A 8mm f/4 circular fisheye lens for the Canon EOS R system
- A battery grip that works with differently siszed cameras
- A 100-400mm f/5.5-7.1 lens for APS-C cameras. EOS M or DSLR?
- RF 17-70mm lens for EOS R system
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- Patent Application: mirrorless camera with large display and virtual control wheel
- Patent Application: IBIS and Lens IS Working Together
- Patent application for high speed mirror movement and control
- Patent application for an RF 14-28mm f/2 lens
- Patent application for an RF 50mm f/1.8 lens
- Patent application for a smart lens cap
- Patent application for celestial auto-focus
- Patent application describing a Pop-Up Flash With LED
- Patent application describing the optical formula for a RF 70-300mm F/4-5.6 IS lens for EOS R systems
- Patent application describing how to improve burst rate by compressing raw files
- Patent application describing a new way to review photos from a sequential shot
- Patent application that describes technology to improve wireless communication while reducing power consumption
- Patent application to spot and reduce moire artefacts in image data
- Patent application for weather sealed lens adapter
- Patent application for AI powered predictive camera control system
- Patent application for 18-55mm kit lens with LCD display
- Patent application to reduce noise in image files
Source: Canon News