STMicroelectronics is offering 20+ years innovation in Imaging & optical sensing solutions. ST Imaging has a long history in providing products and services to the market. ST has introduced a new generation of high-performance proximity and ranging sensors, based on FlightSense™ Time-of-Flight (ToF) technology.
In a recent media briefing, Jerry CHANG, Technical Marketing Manager, Imaging Division, Greater China & South Asia, STMicroelectronics and Vincent LIN, Technical Marketing Manager, Imaging Division, Greater China and South Asia, STMicroelectronics discussed more about this technology, its features , benefits, products and key applications.
1. How do you see ST leadership in ToF sensors
ST has pioneered and transitioned Time-of-Flight technology from its research labs to a fully industrialized family of market-leading products. Up till today, we have 4 generations of products, and working with more than 50 OEMs. We have more than 42,000 development kits, circulating among customers and in the market. Most importantly, we have made more than 1 billion unit shipment for ToF at the end of last year. This number keeps on increasing with more competitive products and services serving more segments to the market.
Recently we have introduced product VL53L5 which is world’s first All-in-One, Multi-Zone, Direct Time-of-Flight module. The VL53L5 is a state of the art, Time-of-Flight (ToF), laser-ranging sensor enhancing the ST FlightSense product family. Housed in a miniature reflowable package, it integrates a SPAD array, physical infrared filters, and diffractive optics (DOE) to achieve the best ranging performance in various ambient lighting conditions with a range of cover glass materials.
2. Tell us more about ST proprietary FlightSense™ technology
FlightSense or Time-of-Flight is based on the module emitter, which is a laser emitter that needs light or photons to go out and reach the target and bounces back to the other opening of ST ToF solution, which is a sensor or receiver. The principle is quite straightforward. ST is preparing the technology that is based on speed, multiplying by time of travel. And then you will get the distance. It is a very important and fundamental design guideline that we use to measure distance. What you will get is the exact/ accurate distance, independent from colors, sizes or reflectance of the objects. When you range objects that are black, white or other colors, you get the same ranging accuracy.
• High performance distance measurement
• Easy and quick integration
• Low power consumption
• Extra-long-distance measurement
• Multi-target detection
• Dynamic smudge correction
3. Please detail about your latest ToF product families.
The VL53L3CX is the latest Time-of-Flight (ToF) product from STMicroelectronics and embeds ST’s third generation FlightSense patented technology. It combines a high performance proximity and ranging sensor, with multi target distance measurements and automatic smudge correction. The miniature reflowable package integrates a single photon avalanche diode (SPAD) array and physical infrared filters to achieve the best ranging performance in various ambient lighting conditions, with a wide range of cover glass windows.
The VL53L1CB is the new Time-of-Flight sensor based on the ST patented FlightSense technology. The sensor is able to range up to 8m impendent of the target color or material.
The ST Histogram algorithm permits detection of different targets within the Field-of View (FoV). The algorithm also provides immunity to cover glass cross-talk beyond 80cm.
The SPAD array zone selection allows advanced multi-zone scanning. The VL53L1CB also has a programmable FoV from 15° to 27° dependent on the size of the SPAD array zone selection.
VL53L3CX ToF embeds ST’s third-generation FlightSense patented technology. It combines a high-performance proximity and ranging sensor with multi-target distance measurements and automatic smudge correction. The miniature reflowable package integrates a single-photon avalanche diode (SPAD) array and physical infrared filters to achieve the best ranging performance in various ambient lighting conditions, with a wide range of cover glass windows.
The VL53L3CX combines the benefits of a high-performance proximity sensor with excellent short distance linearity, together with ranging capability up to 3 m. With patented algorithms and ingenious module construction, the VL53L3CX is also able to detect different objects within the field of view (FoV) with depth understanding. The ST histogram algorithms allow cover glass crosstalk immunity beyond 80 cm and dynamic smudge compensation.
• Long distance and accurate ranging up to 3 m
• Excellent short distance linearity
• ST histogram algorithms allow multi-target distance measurement and cover glass crosstalk immunity beyond 80 cm
• ST algorithms enable dynamic smudge compensation
• Very small package for easy integration (single module combining laser emitter, SPAD receiving array, and micro-controller in a reflowable package)
• Can be hidden behind various cover window material and colors (Creative ID)
• Not affected by target reflectance, material and color, or unlikely traditional IR proximity sensors
4. Which are FlightSense key applications
ST FlightSense™ families of products are in high-volume production for consumer, personal computer, and industrial markets. ST’s unique vertically integrated manufacturing model for the Time-of-Flight sensors ensures best-in-class levels of service, quality, customer support, and performance.
5. Compared with other competitors, what advantages does ST VL53L5 have? How will VL53L5 differentiate itself?
When we look at ST’s own product offer, VL53L5 is the highest ranking product we have so far. It has a brand new design, with very strong 8X8/64 zone reading output that opens up a lot of possibilities to applications. For example, as we have mentioned, the gesture application involves very sophisticated movement, so it is not a single reading application. And wider FoV allowed to display on and off which opens up a lot of new possibilities. So we compare L5 with ST’s other product offers, obviously it is high end, strong, new features, multiple ones.
6. Have not seen ST active in India in this segment？What are your major strategies to strengthen the market presence?
I agree that ST’s image sensor/ToF sensor presence in India is somewhat limited. Our strategy will be utilizing our channel partners. So our next item next year and in the next few years will be to start to build partnerships with distributors in India. This will require technical capability in doing the design and rendering support. So we want to understand how well the hardware, software and optical are today. When we get real projects, it can be a variety of questions and items to be taken. We rely on our partners in India to do that. Today we are at the earliest stage and we have sped ourselves up to built it up step by step over the next few years.
7. What are the upcoming trends ST sees in the ToF sensor market?
From ST’s perspective, we see that the market for ToF applications continues to grow and grow fast. If I refer back to our part numbers or roadmap, you will see the basic part number that is 180, the new part number like VL53L3, or the advanced number L1CB, even next year the new model L5. They all bring in tremendous attention. Typical part numbers all have specific applications and Business perspectives. They are all popular. They told us the demand is growing. As I have mentioned, the demand of touching the application with no touch buttons does not go away as the time went by. Instead, we can see that though it started two or 4 years ago, more and more demand is coming. It could be from elevators, hospitals, for smart home. So we see the trend for growth is tremendous. Of course, we are not limiting ourselves to our old part numbers. As what we have shared today, longer ranging and multiple zones also open up new possibilities for new applications. So we see the trend really opens up people’s mind, and opens up new applications. More and more opportunities are coming; many of our customers and partners actually bring their applications that we were not aware earlier. For instance, parking, car wash and so on, those are the things we did not plan at the very beginning. But now we are pleased to say we are able to deliver those solutions to provide different segments of applications.
8. Have you launched any product for 3D ToF sensors?
3D ToF is in our roadmap under development. We have not made any press release for it. There is no roadmap to share with any partner yet. But it is in our development roadmap internally. I do not have the exact date here, but I know we will have that offer in the market place very soon.
While talking about the specific 3D ToF, let’s look back at L5 64 zones, which is actually the basic model of 3D sensor already. Considering the 64 zones, you can do 64 readings out of one single ranging. So if you are talking about a hand or a person movement, it has already been identified in the ticket. Let me rephrase that L5 is the beginning of our 3D sensor offering. We do have other models to come in the next few months and next few years.
9. What will be ST’s next strategy in terms of ToF technology?
For the future ST ToF product development trends, we see two directions. One will be on DToF, which is the continuity of our current product offers; yes we are already developing from one single zone to 64 zones ranging and it makes sense for us to continue that. So it is possible that we offer products with even more zones. As for the distance varieties we are offering, please note that we have short distance and long distance up to 8 meters ranging today. This is also another direction we will do with DToF. The other aspect will be the introduction of IToF solutions. We expect to launch our first IToF product in the next few months. We are observing the market development very carefully, and we see a proper aspect.