Fundamentals of Wearable Computers and Augmented Reality, 2nd Edition

100 Fundamentals of Wearable Computers and Augmented Reality

or exit pupil (an eye box of 10mm horizontally and 8mm vertically is often used as

a standard requirement for today’s smart glasses). Designing a thin optical combiner

producing a large eyebox is usually not easy: when using conventional free-space

optics, the eye box scales with the thickness of combiner (see, e.g., Figure 5.11), as in

most of the architectures presented in the previous section, expect for architecture #6

(Figure5.6g), which is based on waveguide optics using cascaded planar extractors.

For holographic combiner and extraction (both free space—Figure 5.6c and

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