Fundamentals of Wearable Computers and Augmented Reality, 2nd Edition

120 Fundamentals of Wearable Computers and Augmented Reality

The rst reection (the glint) is usually the most used one (see also Figure 5.29).

Single or multiple IR ood sources may be used to increase the resolution of the

tracking (e.g., 4 IR sources located symmetrically to produce good vertical and hori-

zontal gaze tracking).

In many combiner architectures, it is desirable to use the same optical path for the

display as for the glint imaging. However, as the display uses an innite conjugate

(image at innity) and the gaze tracking nite conjugates, it is necessary to use either

an additional objective lens on the IR CMOS sensor or to posi ...