CMOS automotive camera sensor reduces LED flicker

April 19, 2017 // By Graham Prophet
Sony (Tokyo, Japan) has disclosed details of a commercially-available CMOS image sensor for automotive cameras: at 2.45 (effective) megapixels, the IMX390CQV type 1/2.7 will begin sample shipping in May 2017.

This image sensor is equipped with an LED flicker mitigation function that reduces flickering when imaging LED signs and traffic signals, as well as an HDR function capable of 120 dB wide dynamic range imaging. Sony believes this is the first time both attributes have been available together, enabled by Sony’s pixel structure and exposure method. It also offers high-sensitivity performance capable of producing high-quality colour images even in light conditions as low as 0.1 lux, which is equivalent to moonlight.

In recent years, LEDs have been widely adopted for traffic signs and signals, and also for car components such as headlights and brake lights. Another trend has been the need for automotive cameras to be able to capture high-quality images with a wide dynamic range, even in situations of dramatic contrast, such as when entering or exiting tunnels during daylight hours.

This image sensor simultaneously uses both the LED flicker mitigation and HDR functions to deal with these types of situations, providing more precise recognition in the diverse real-world traffic environments that drivers encounter.

The IMX390CQV is planned to meet the requirements of the AEC-Q100 Grade 2 automotive electronic component reliability tests this fiscal year. With this new product, Sony also introduced a development process that complies with ISO26262 functional safety standards.

The sensor also meets the functional safety requirement level ASIL C. The product is ready for use in forward-sensing cameras for Advanced Driver Assistance Systems (ADAS) and cameras for Camera Monitoring Systems (CMS) that show persons and obstacles on an in-car monitor with clear visibility, an application expected to grow as a substitute for conventional rearview mirrors.

LED signs and the LED lights of cars in front and behind the vehicle can be accurately recognised while enabling wide dynamic range image capture with no highlight blowout or loss of shadow detail in situations of dramatic contrast, such as when entering or exiting tunnels.

LEDs are widely used