STMicroelectronics sets scene for advanced in-car safety with hybrid sensor

While DMS promises greater road safety by assessing driver alertness, the next-gen dual image sensor ST announced monitors the full vehicle interior covering both the driver and all passengers. New applications enabled by ST’s new image sensor include passenger safety-belt checks, vital-sign monitoring, child-left detection, gesture recognition, and high-quality video/picture recording.

“The DMS market is growing at a double-digit pace. ST’s new image sensor is set to push that forward by enabling brands to create new services and deliver even greater value for vehicle users, leveraging complete in-cabin monitoring that covers multiple occupants,” said Eric Aussedat, Executive Vice President, Imaging Sub-Group General Manager, STMicroelectronics. “Our market-leading DMS sensor provided the perfect launchpad to take the technology further and empower new innovations.”

The new sensor, the VD/VB1940, delivers a cost-effective solution that combines the sensitivity and high resolution of infrared sensing with high dynamic range (HDR) color imaging in a single component. It can capture frames alternatively in rolling-shutter and global-shutter modes. With 5.1-megapixels, it captures the high-dynamic-range (HDR) color images needed for an occupant monitoring system (OMS) in addition to the high-quality near-infrared (NIR) images typically captured by standard DMS sensors. DMS uses NIR imaging to analyse driver head and eye movements in all lighting conditions.

Offered in both bare wafers (VDB1940) and packaged in BGAs (VB1940), samples are available now and mass production is planned to meet demand for the model-year 2024 vehicles being designed now. Please contact your local ST sales office for pricing information.

The new automotive image sensor uses ST’s second-generation 3D-stacked back-side illuminated (BSI) wafer technology, which maximizes the optical area and on-chip processing in relation to die size. This lets the sensor perform sophisticated algorithms locally for optimal performance in both color and NIR imaging, saving power and relieving demand for an external co-processor.

Algorithms performed on-chip include Bayer conversion and HDR merging for optimal image-quality and frame rate. On-chip Bayerization processing enables the user to reshuffle the color pixels of the RGB NIR 4X4 pattern into RGGB format compatible with a wide range of SoCs. In addition, local processing also handles independent color and NIR pixel-exposure optimization for optimum image quality in both modes, as well as smart upscaling to maximise 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 pairing of camera and electronic control unit (ECU), as well as video-stream authentication.

The sensor captures NIR images in global-shutter mode, which permits synchronising with the infrared LED emitter to capture fast-moving scenes without motion blur. By also supporting rolling-shutter mode, which reads pixel data row by row, the VD/VB1940 provides optimum color-imaging performance. Leveraging the on-chip HDR-merge feature in rolling-shutter mode, the VB/VD1940 produces a 100dB full-resolution color image.

Qualified to AEC-Q100, the VD/VB1940 is ISO 26262 compliant to facilitate use in functional-safety systems up to ASIL-B.