Time of Flight (ToF) is a technology that measures the distance of a photographed object to generate depth information, and has been applied to consumer, personal calculator, and industrial markets with great market development potential. This article will show you the characteristics of ToF technology and solutions from STMicroelectronics, for your reference in developing related application products.
ToF technology has a more extensive application market
ToF technology converts the distance of a photographed object by calculating the time difference or phase difference between light emission and reflection after the sensor emits modulated infrared light which is reflected when encountering the object and receives the returned light to generate depth information. If combined with traditional camera shooting, the three-dimensional outline of the object can be presented in a way so that different colors represent different distances.
Through the ToF technology, it is possible to detect the distance and depth information between the sensor and the photographed object. Therefore, this technology may be applied to application fields such as AR/VR experience, human body sensing, face recognition, gesture sensing, reversing radar, car surrounding view detection, machine vision, etc, with an increasingly wide application market.
Highly integrated for optimal ranging performance
STMicroelectronics has been innovating imaging and optical sensing solutions for more than 20 years, offering a variety of products and services to the market. Recently, it has introduced a new generation of high-performance proximity and ranging sensors based on FlightSense™ ToF technology. At present, STMicroelectronics has launched four generations of products and cooperated with more than 50 OEMs. There have been more than 42,000 development kits, and more than 1 billion shipments of ToF products.
FlightSense ToF is a laser transmitter module that emits light or photons to the target and then reflects them back to another opening in the ToF solution, i.e. the sensor or receiver. Its application principle is quite simple. As long as the calculation speed is multiplied by the time of travel of light back and forth, the distance can be obtained, regardless of the color, size, or reflectivity of the object. Even when objects in black, white, or other colors are ranging, the same ranging accuracy can be obtained. The FlightSense ToF module transmitter is characterized by high performance distance measurement, easy and fast integration capability, low power consumption, ultra-long distance measurement, multi-target detection, dynamic smudge correction, etc.
In the future, there will be more and more demands for non-touch applications, such as elevators and hospitals, which can avoid infection caused by contact and make life more convenient when used in smart homes. STMicroelectronics's FlightSense family of products may be widely used in consumer, personal computer, and industrial markets. The unique vertically integrated manufacturing mode can ensure first-class service level, quality, customer support, and performance.
Not affected by target reflectivity, material, and color
The FlightSense ToF module transmitter includes multiple product lines, of which the VL53L3CX is one of the newest ToF products from STMicroelectronics. Built with STMicroelectronics's third generation FlightSense patented technology, VL53L3CX integrates high-performance proximity and ranging sensors, multi-target distance measurement, and automatic smudge correction. The miniature reflowable package integrates a single photon avalanche diode (SPAD) array and physical infrared filter to achieve the optimal ranging performance under various ambient lighting conditions, and has various cover glass windows.
VL53L3CXV0DH/1
The VL53L3CX combines the advantages of a high-performance proximity sensor, excellent short distance linearity, and ranging capability up to 3 m. With a patented algorithm and ingenious module construction, the VL53L3CX may also detect different objects within a Field-of-View (FoV) through depth understanding. STMicroelectronics's histogram algorithm allows crosstalk immunity of cover glass beyond 80 cm, and has a dynamic smudge compensation feature. Available in a small package, it is easy to integrate. The laser emitter, SPAD receiving array, and microcontroller are combined in a reflowable package in a single module, and can be hidden behind various covering materials and colors, which is convenient for creative industrial design. Unlike traditional infrared proximity sensors, the VL53L53CX is not subject to target reflectivity, material, and color.
Another newly introduced VL53L1CB is a new ToF sensor based on STMicroelectronics's patented FlightSense technology. The maximum distance at which the sensor can detect the target color or material is 8 m. STMicroelectronics's histogram algorithm allows detection of different targets in FoV. The algorithm also has immunity capability to allow cover glass crosstalk beyond 80 cm. The SPAD array zone selection is adopted to allow advanced multi-zone scanning. VL53L1CB also has a programmable FoV from 15° to 27°, depending on the size of the SPAD array zone selection.
Multi-zone reading opens up application possibility
Recently, STMicroelectronics has introduced its VL53L5 ToF laser ranging sensor, which is the world's first all-in-one, multi-zone, direct time-of-flight (DTOF) module. Available in a miniature reflowable package, it integrates a SPAD array, physical infrared filter, and diffractive optical elements (DOE), and uses various cover glass materials to achieve the optimal ranging performance under various ambient lighting conditions.
With fourth generation FlightSense technology, the VL53L5CX may support a 64 zone ranging of up to 15 frames per second, and have a very powerful 8X8/64 zone reading output, with a maximum FoV of 61 degrees, and may identify the distance of multiple objects. Previous FlightSense products are all single-zone, while the VL53L5CX is a brand-new ToF product with multi-zone detection. Single-zone may focus on the application of single-action On/Off, whereas multi-zone provides more possibilities. For example, gesture application involves very complex movements, so it is not just an application of single-zone reading. In addition, a wider FoV may allow the display range to be turned on and off, and also opens up many new possibilities for applications.
As a fourth generation product, the VL53L5CX has been upgraded from the process design. The previous generation products are all using 65 or 90nm processes, while the VL53L5CX uses 40nm process. Process reduction means that more diodes and circuits may be integrated on the same area, so as to meet the needs of multi-zone detection. The multi-zone detection requires output of more photons at the same time, because if you use 64 points, you have to output information of 64 points at the same time. In this case, certain converters or MCU calculations are needed, i.e., the calculations of a single chip must be placed on a sensor.
Conclusion
STMicroelectronics took the lead in transitioning ToF technology from its research laboratory to a fully industrialized market, and introduced a variety of leading product lines, with more competitive products and services for application in more market segments, which will expand the application scope and business opportunities of products. It is time to explore the blue ocean market for ToF applications!
Ähnliches Produkt:
