Tobii X1 Light Eye Tracker, Руководство пользователя

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Tobii X1 Light User Manual
47
7.5 Appendix E: Recommended display sizes
The eye tracker can only do accurate eye tracking of a person’s eyes if the visual
angle as seen from the person’s eyes does not exceed 27 degrees between the
center of the eye tracker and any point on what the person is looking at. This is valid
as long as the person stays within the area in front of the eye tracker difined as the
“track box” which roughly is between 55-80 cm from the center of the eye tracker
when seen from the side (read more about this in chapter 4.3.1 Track Box on page
23).
Max 27 °
65 cm 26’’
This means that depending on the position of the eye tracker in relation to the display,
it can track different sizes of displays. If the display is positioned further away from the
user, a larger area can be tracked. However, small objects shown on the display might
be difficult to see for the user at a greater distance.
Max
27 °
Max
27 °
Max
27 °
Another aspect to consider is illustrated in
the image seen on the left: the aspect ratio
of the display is also important. Since the
optimally tracked area is a half circle, the eye
tracker can track displays with a large width
to height ratio better than displays where this
ratio is small.
Chapter 7 Appendices
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Centimeters