Gesture recognition by sensing touch and finger movement has become a well-known technology, such as the touch-screen smart phone that is used every day. However, 3D sensing technology has a broader application scene.
The infrared light source is diffused into a structural pattern by optical elements, and then the system captures the depth information of the projected object by measuring the reflected light of the object. With the support of this technology, consumers can control the whole game or entertainment center through “space separation” without touching the screen or needing other control devices. With the joint development of mobile devices and 3D sensing technology, 3D sensing will be used even on mobile devices to enhance the camera’s ability to realize object recognition, depth data, higher accuracy and object position.
It should be noted that it is one thing to track finger movements on the touch screen, and it is quite another to detect gesture changes in rooms of dozens of square meters. The detection system requires higher power and higher recognition ability. One of the many methods currently used to identify a few meters is “TOF,” or Time of flight technology. The technical issue by the modulation of near-infrared light sensors, on the object after reflection, the sensor through calculating the transmission and reflection light or phase difference, between the conversion was the distance of the shooting scene, to create depth information, in addition, combining camera three-dimensional contours of objects can be in different colors represent different distance way of topographic map.
Compared with other lasers, VCSEL combines low cost and optical efficiency while occupying less space. Moreover, the wavelength stability of VCSEL has little influence with the temperature change, and it can maintain very high output efficiency continuously. In addition, the VCSEL emits laser light from the chip surface, which makes it easier to design optical components and light paths. It can be directly attached to various heat sinks and circuit boards.