As advanced automotive markets begin to demand driver monitoring systems (DMS), STMicroelectronics (ST) is equipping automakers with the necessary technologies. While DMS promises greater road safety by assessing the driver's alertness, ST's next-generation dual image sensor monitors the entire interior of the vehicle, covering the driver and all passengers.
ST's new image sensor is enabling new applications including passenger seat belt checks, vital sign monitoring, left child detection, gesture recognition and high-quality video/image recording.
“The DMS market is growing at a double-digit pace. ST’s new image sensor is poised to drive this forward, enabling brands to create new services and provide even greater value to vehicle users by leveraging full in-cabin monitoring that covers multiple occupants,” said Eric Aussedat, Vice President executive of GM's imaging subgroup. , STMicroelectronics.
The new sensor, the VD/VB1940, offers a cost-effective solution that combines the sensitivity and high resolution of the infrared sensor with high dynamic range (HDR) color imaging in a single component. It can capture frames alternatively in shutter and global shutter modes. At 5.1 megapixels, it captures high dynamic range (HDR) color images required for an occupant monitoring system, in addition to the high-quality near-infrared (NIR) images typically captured by standard DMS sensors. DMS uses NIR images to analyze the driver's head and eye movements in all lighting conditions.
Offered on single wafers (VDB1940) and packaged in BGAs (VB1940), samples are now available and mass production is planned to meet demand for the 2024 model year vehicles now being designed. .
Technical information
The new automotive image sensor uses ST's second-generation back-side illuminated (BSI) 3D stacked wafer technology, which maximizes optical area and on-chip processing relative to die size. This allows the sensor to run sophisticated algorithms locally for optimal performance in color and NIR images, saving power and alleviating the demand for an external coprocessor.
Algorithms running on the chip include Bayer conversion and HDR fusion for optimal image quality and frame rate. On-chip Bayerization processing allows the user to rearrange color pixels from the RGB NIR 4X4 standard into the RGGB format compatible with a wide range of SoCs. Additionally, local processing also handles independent color and exposure optimization of NIR pixels to achieve optimal image quality in both modes, as well as intelligent upscaling to maximize NIR image resolution by capturing extra NIR information from RGB pixels.
The embedded processor also manages enhanced cybersecurity to ensure privacy in connected vehicle applications, including mutual authentication and camera and electronic control unit pairing and video stream authentication.
The sensor captures NIR images in global shutter mode, which allows synchronization with the infrared LED emitter to capture fast-moving scenes without motion blur. By also supporting shutter mode, which reads pixel data line by line, the VD/VB1940 delivers great color image performance. Taking advantage of the on-chip HDR blending feature in shutter mode, the VB/VD1940 produces a full-resolution 100dB color image.
