ToF sensor emits modulated near-infrared light, which is reflected after encountering an object, and then obtains the distance of the captured scene by calculating the time difference or phase difference between light emission and reflection to generate depth information.
ToF technology does not emit speckle, but a surface light source, so within a certain distance, the light information of the ToF sensor will not be attenuated a lot. At the same time, the Pixel of the ToF sensor photosensitive element is very large, reaching 10um, which is suitable for light collection. With enough guarantees, theoretically, as long as the power of the transmitter is increased, the ToF can be used very far away. Its measurement range can reach several meters, the accuracy is less than 2cm, and the update frequency per second can reach 30~60 fps. It can be used for face recognition, financial payment, depth detection, AR modeling and somatosensory games in smartphones. Some smartphones are already equipped with ToF sensors, such as iPhone 13, iPhone 12 Pro, Samsung S20+/Ultra, Huawei P30 Pro, OPPO RX17 Pro, etc.
tof sensor enables smartphones from plane vision to stereo vision. There are currently three mainstream 3D vision technologies in the industry, including binocular stereo vision solutions, 3D structured light solutions and ToF sensor solutions. The binocular stereo vision solution is a passive acquisition solution, and the 3D structured light solution and the ToF sensor are active acquisition solutions. The active collection is further subdivided into application scenarios. 3D structured light is suitable for close-range 3D information collection, while ToF sensor is suitable for relatively long-distance 3D information collection. The application scope and imagination space of the ToF sensor are also wider.
