In the field of consumer electronics, there are three main categories of 3D imaging and sensing modules: stereo vision, structured light, and time of flight (ToF). However, it is difficult to find stereo vision on smart phones, mainly due to the competition between structured light and ToF. Both structured light and ToF belong to the active light detection scheme, which includes two parts: the transmitting end and the receiving end. Taking a typical 3D iToF camera module as an example, the core components of the transmitting end include a vertical cavity surface emitting laser (VCSEL) and a diffuser (diffuser). ) And lenses. The core components of the receiving end include ToF image sensors, narrow-band filters and lenses. The "stage" of structured light is the front camera of the mobile phone, and ToF can "take all front and rear", especially the use of the rear camera of the mobile phone to realize the augmented reality (AR) function is the world of ToF. Although the structured light used in iPhone X is considered to be the starting point of the era of 3D imaging and sensing. However, more and more smart phone 3D modules are developing towards ToF, thereby increasing the screen-to-body ratio (full screen trend) and anti-sunlight performance, and reducing the amount of calculation and cost.
In terms of 3D ToF, applications such as face recognition, gesture recognition, and augmented reality have become the driving force for growth. Thanks to the back-illuminated (BSI) technology, the iToF image sensor has now been greatly improved, with a resolution of up to VGA (640 pixels x 480 pixels) or even higher. In the mature 3D vision ecosystem, the iToF solution also has cost advantages. These are the main reasons why iToF has won the favor of Android smartphone manufacturers. In addition to smart phones, 3D ToF has broad development prospects in the fields of smart driving, robots, smart glasses, smart TVs, and smart security.