Canon Patent: RF 28-70mm f/2.8 Lens That Retracts When Zooming

Rather interesting Canon patent for a 28-70mm f/2.8 lens that becomes shorter when zoomed to the telephoto end, i.e. it retracts.

Canon patent 2022147945 (Japan, published 10/6/2022) discusses a rather interesting optical formula for a retracting 28-70mm f/2.8 zoom lens for the RF mount. A pretty unique optical design.

From the patent literature:

A zoom lens is provided which is compact and lightweight and capable of achieving high optical performance over the entire zoom range and all object distances.

Example 1

• Focal length: 28.84-67.90
• F-value: 2.91
• Half angle of view: 32.65-17.67
• Image height: 18.48-21.64
• Overall length: 149.46-115.94
• Back focus: 13.48-27.78

Example 2

• Focal length: 24.72-67.90
• F-value: 2.91
• Half angle of view: 35.02-17.67
• Image height: 17.32-21.64
• Overall length: 150.00-130.39
• Back focus: 9.87-27.17

Example 3

• Focal length: 28.84-67.90
• F-value: 2.91
• Half angle of view: 34.77-17.67
• Image height: 20.02-21.64
• Overall length: 152.61-120.01
• Back focus: 22.71-41.28

More Canon patent applications are listed here. Some particularly interesting patent applications we think might get into production are these:

• RF 16-28mm lens with either f/2.8, f/2.8-4, or f/4
• Automatic shutter silencing based on subject and distance
• A bunch of prime lenses for the RF mount
• An improved Electronic Viewfinder
• Patent application for RF 50mm F1.4 and an RF 35mm f/1.4 lenses
• A zoom lens that might be for an EOS R with APS-C sensor
• A smaller IBIS unit.
• A cooling adapter for the RF mount (R5 overheating?)
• A bunch of macro lenses for the RF mount.
• 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
• IBIS coming to the EOS M and PowerShot lineup?
• 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

[via asobinet]