Samsung combines small and large photodiodes in automotive camera sensor

Samsung presents a camera sensor for use in cars: the Isocell Auto 4AC. The sensor, which can be incorporated into rear-view cameras or in the mirrors, for example, has photodiodes of two different sizes. That is used for HDR playback.

The Isocell Auto 4AC is Samsung’s first camera sensor optimized for use in cars. It is a small sensor of the 1/3.7″ format, with a resolution of 1280×960 pixels. The sensor can suppress annoying flickering of LED lighting, such as street lamps. This makes the sensor suitable, according to Samsung, for rear-view cameras in, for example, the rear bumper, or cameras incorporated into e-mirrors.

The sensor features what Samsung calls CornerPixel technology. That is a pixel structure in which each pixel block is provided with two photodiodes; a 3-µm pixel for displaying low-light images and a 1-µm pixel at the corner of the larger pixel for brighter environments. By combining those two exposures, the sensor can display HDR images.

Due to this pixel combination, a sharper HDR image can be shown with little motion blur and the transition from dark to light environments must be shown without a sudden transition. According to Samsung, this makes the image in digital mirrors clearer, even when the light situation keeps changing, for example when entering a tunnel.

The double photodiodes also prevent the flashing of LED lighting in the image. The shutter speed of the smaller diode can be increased, so that the blinking of LED lights cannot be seen.

According to Samsung, the Isocell Auto 4AC is the kick-off for the development of a larger line-up of automotive sensors, mainly aimed at camera monitor systems, autonomous driving and in-cabin monitoring. At this time, the sensor is being produced. It is not yet known in which cars the chip will be used.