Canon Patent Application: EVF with Eye Control Focus

In this patent application, Canon describes how they would create eye control AF with an EVF. The main goal of this patent application is to prevent the deterioration of operation (I assume visibility) of the EVF while the camera is equipped with eye control (or line of sight) AF.

From Canon;

Therefore, an object of the present invention is to propose an optimum arrangement of the EVF in the image pickup apparatus, which is provided with the EVF and can suppress the deterioration of the operability of the image pickup apparatus provided with the line-of-sight input function.

To do this, Canon is employing a small image sensor (53) that is situated to the side of the main EVF display (19) and uses a diving prism along the optical path to direct light to the line of sight image sensor.

The IR LEDs that illuminate your eye are located around the EVF close to your eye (36 through 43).

That leads to the operation of the line of sight AF control as looking something like;

Where you can see the IR light being directed to your eye pupil (142), and the image directed to the line of a sight image sensor, while you are looking at the image in the EVF.

Japan Patent Application 2021-076832