When it comes to estimating object distance and recording depth information, many Android manufacturers have equipped ToF (Time-of-Flight) sensors on some of their models to achieve these two functions.
For example, the P40 Pro has a 3D depth-sensing camera (ToF) that can deeply sense the depth information of objects to achieve a blockbuster-like depth-of-field effect. Currently, some cell phone manufacturers mostly use iToF (indirect time-of-flight sensor), while LiDAR belongs to dTof (direct time-of-flight sensor). iToF and LiDAR are both ToF, but the difference is not small.
First, the “signal” sent out is different.
The iToF emits a light signal that is modulated by a sinusoidal wave and has a regular shift in intensity between light and dark.
Second, the principle of distance estimation is different.
LiDAR is a direct measurement of distance by laser.
Third, the accuracy range, measurement rate, and anti-interference capability are different.
The iToF signal is easily interfered with, and the accuracy of the measurement decreases as the distance gets farther, and the measurement is relatively slow.
LiDAR’s laser beam is highly resistant to interference, and theoretically the accuracy of the measurement does not decrease with distance, and the measurement is faster and more suitable for long-distance ranging.
Finally, iToF is easier to miniaturize, while dToF is more difficult to integrate and miniaturize, so the two have more obvious differences in commercial scenarios. iToF is mostly used in cell phones, while dToF is more commonly used in large devices such as cars and drones.
LiDAR is faster, more accurate, and farther away than iToF, but it is more difficult and expensive to integrate. Apple must have put a lot of thought into integrating LiDAR into the iPhone 12 camera module.