Traditional image sensors can only shoot 2D plane images without the ability to sense the distance between the object to be photographed and the sensor. But 3D image sensors can give machines stereoscopic vision. This text will introduce the principle, applications, and solutions of 3D image sensors for you, as well as provide a reference for relevant product development.
ToF technology provides depth information of cameras
The 3D image sensor applies Time of Flight (TOF) technology to calculate the distance between the object to be photographed and the 3D image sensor. With the function of sending modulating near-infrared light, the sensor can calculate the time difference or phase difference between light emission and reflection after the light reflects off of an object. Thus, the distance between the sensor and the view to be photographed can be converted and depth information will be produced. Combined with traditional camera shooting, the 3D shape of the object can be reflected in the mode of the image with different colors representing different distances.
For example, the recently hot advanced driver assistance system (ADAS) and self-driving automobile applications require precise information about the driver’s focal point and what’s happening inside the vehicle. This is the place for the sensing application of the 3D camera inside the automobile. This system can recognize the driver's behavior and send the information to the ADAS system in order to have the relevant response. The application of the 3D image sensing system can improve the safety of automobile driving and the comfort level of drivers. In addition, the 3D camera supports the brand-new HMI concept and consumer experience, such as conducting gesture recognition and infotainment system controlling.
Among the 3D image sensors in the market, the IRS10x0C from Infineon is the most complex ToF imager with the highest integration level, which can directly measure the depth and amplitude value of each pixel. Adopting the high-performance ToF pixel matrix with pmd technology and CMOS manufacturing technology after the mass production verification of Infineon, it has a highly integrated single chip with a minimal imager and strong performance, which is able to integrate the photosensitive zone and mixed signal circuit into a single chip, as well as endow the product with compact volume, accuracy, and flexibility.
Collecting all the components required by 3D image sensors, IRS10x0C allows a large batch of consumer applications to be able to adopt ToF technology with minimal overall dimensions and low system cost. Even in bright ambient light conditions, it can also have the optimum sensitivity and contrast ratio. With the function of implanting the patented Suppression of Background Illumination (SBI), the IRS10x0C is suitable for indoor and outdoor operation. Regardless of being in the sunlight, the darkness and ceaselessly changing light conditions, it can operate reliably in all kinds of ambient light conditions. It can also optimize infrared photo-sensitivity and contrast ratio, as well as provide highly reliable 3D data based on ToF principle with excellent depth performance and minimum power consumption.
With the highest integration level, the IRS10x0C from Infineon can achieve a full-digital readout of on-chip ADC through high-speed interface. Combining integrated control logic used for autonomous depth image capture, it has the highest flexibility and functions to rapidly read out time data and minimize motion artifacts. With dynamic reconfiguration of chips achieved via I²C, it has a completely configurable Region-of-Interest (ROI) and can conduct on-chip digital binning of pixels.
IRS10x0C adopts a single chip design and monocular 3D camera architecture with minimum footprint and without any baseline between moving parts. Thus, there won’t be any dislocation risk caused by temperature fluctuation or vibration. With the function of minimizing calibration work, it can shorten the computing time regardless of the color, pattern and structure of the objects to be photographed. The IRS10x0C has low noise depth data that can fundamentally simplify the detection mode of objects and thus achieve minimum delay and highest robustness, which is the key factor of excellent user experience.
Being a perfect 3D image sensor specially designed for depth cameras, the IRS10x0C can be applied in non-contact user interfaces to conduct air gesture recognition including finger and hand tracking. The suitable products include All-in-One PCs, laptop, set top box, as well as multiple finger, hand and body tracking in game application programs. This kind of non-contact natural user interface is very appropriate to be used in gesture controlling of vehicle-mounted infotainment systems, as well as in the tracking and monitoring applications of industrial engineering.
Infineon also provides the reference design for the smallest CamBoard pico 3D camera in the world at present, adopting IRS1010C as the design core. The minimum shape of it reflects the integration of the ToF camera, fashionable All-in-One PCs and laptop. Supporting the lateral resolution of QQVGA (160 x 120 px) and the depth resolution of <4mm @ 70cm (75% reflectivity), CamBoard pico has a module size of 85 x 17 x8 mm with a USB 2.0 port, maximum power consumption of 2.5 W (USB 2.0), maximum measurement range of 100 centimeters, 90° field of view and can be developed by using C / C ++ / Matlab SDK software.
In the aspect of system development support, the cooperative partnership between pmd Technology and Infineon can be finished through the strong system partnership network of a third-party company. The partner can provide gesture detection middleware, optical components, LEDs and laser, USB bridges and other components in order to help the manufacturer accelerate the development rate of products.