In kind of a curious patent application Canon goes back in time back to hybrid AF sensors. These were originally on the original M series camera bodies and some of the rebels, and certainly weren't known for their fast AF performance.
However, these sensors are generally more accurate than DPAF sensors or DSLR's simply because they do a combination of phase detection and contrast detection.
What's the difference you ask? in a hybrid AF sensor, only some of the pixels are split in half or have half their light gathering sides shaded. On a DPAF sensor, each pixel is split in half and can perform a dual role of phase detection.
In this patent they detail how to perform the AF operations quicker than before, whether or not this would ever reach a production level sensor is unknown. In theory it may be cheaper for Canon to produce than a full DPAF sensor and may be arguably sightly better for images than DPAF sensors.