While CMOS sensors have higher output data rates compared to other sensors, CW sensors require 4 samples of the correlation function at multiple modulation frequencies and use multi-frame processing to calculate depth. Longer exposure times may limit the overall frame rate of the system, or cause motion blur, so it should only be used in a limited type of application. This higher processing complexity may require the use of an external application processor, which may exceed the needs of the application.
● For scenarios with longer measurement distances or stronger ambient light, higher continuous optical power (compared to pulsed ToF systems) is necessary; such a high-intensity continuous optical signal may cause heat dissipation and reliability problems new question.
The advantages of ToF technology system:
ToF sensor technology systems typically rely on emitting high-energy light pulses within a very short time window. It has the following advantages:
(1) It is easier to design a robust system, so it is more suitable for outdoor use.
(2) The shorter the exposure time, the smaller the effect of motion blur.
The signal duty cycle in a ToF sensor system is usually much lower than in a comparable continuous wave system, and therefore has the following advantages:
(1) For long-term work applications, the total power consumption of the system can be reduced.
(2) Avoid interference from other ToF sensor systems by placing the bursts at different frame positions from other systems. This can be achieved by coordinating various systems to choose different positions for the laser pulses in a frame, or using external photodetectors to determine the position of pulses from other systems. Another approach is to dynamically randomize the positions of the bursts so that there is no need to coordinate timing between systems, but this approach does not completely eliminate interference.
● Since the pulse timing and width do not need to be the same, different timing schemes can be used to support functions such as wider dynamic range and automatic exposure
