1 ToF
similar radar ranging. ToF distance is calculated as shown in FIG.
Figure 1-1 ToF calculated distance 
D: distance
c: speed of light
PHI: retardation
fmod: Frequency Modulation
Figure 1-2 OPT8241
2 3D structured light
generated bitmap, similar to the play spot.
3 binocular vision
by calibration in advance using the calculated angular difference.
URLs 4
ToF 3D sensing solutions contests, and how system vendors choose?
http://m.elecfans.com/article/976284.html
. 5 Abbreviations
the ToF: Time of the Flight
