Mirrorless cameras typically use a pretty different way to detect focus, relying on special pixels salted throughout the sensor to detect the phase of light coming back. Most mirrorless systems do this along one axis, typically the vertical direction, which can make for frustrating focus experiences when a horizontal subject is near a vertical structure, like a bird in flight in front of a tree. While creating another lattice of sensing pixels looking at the other axis is one solution – and the subject of much patent activity – Canon one-upped everyone with a patent application showing two overlapping lattices of four-axes each.
Canon News, a great source for patent activity, first pointed out the published application. The machine translation of the Japanese patent proved a bit inscrutable, but some hard staring revealed the meat of the method. The four axes are referred to as D1… through D4. The shading patterns within each square indicate the relevant lattice or lattices.
The degree of overkill on phase detection demonstrated in the patent may mean the tech is geared more for nighttime security cameras rather than a theoretical R1 flagship sports camera. In the early days of phase detect, the presence of large numbers of those pixels replacing normal photo sites could affect image quality, although in recent years much has been done to mitigate that with software interpolation.
The fact that the sensor is not a bayer pattern sensor also supports the notion that any device using this technology is not likely to be spitting out .CR3 files.