Sony Semiconductor Solutions today announced the upcoming release of the IMX611, a direct time-of-flight (dToF) SPAD depth sensor for smartphones that delivers the industry’s highest photon detection efficiency. The Sony bIMX611 has a photon detection efficiency of 28%, the highest in the industry, thanks to its proprietary single-photon avalanche diode (SPAD) pixel structure. This reduces the power consumption of the entire system while enabling high-accuracy measurement of the distance of an object.
The IMX611 employs a stacked configuration, where a Cu-Cu connection is used to achieve conduction for each pixel between the back-illuminated SPAD pixel chip (top) and the logic chip equipped with a distance measuring processing circuit (bottom). By arranging the circuit under the pixel chip, SSS has achieved a pixel size of 10 μm square, which is quite small for an SPAD, while still securing a high aperture ratio.
The IMX611 uses a proprietary SPAD pixel structure that gives the sensor the industry’s highest photon detection efficiency, at 28%, which makes it possible to detect even very weak photons that have been emitted from the light source and reflected off the object. This allows for highly accurate measurement of object distance. It also means the sensor can offer high distance-measurement performance even with lower light source laser output, thereby helping to reduce the power consumption of the whole smartphone system.
The new sensor also enables 3D spatial recognition, AR occlusion, motion capture/gesture recognition, and other such functions. With the spread of the metaverse in the future, this sensor will contribute to the functional evolution of VR head mounted displays and AR glasses, which are expected to see increasing demand.
By incorporating a proprietary signal processing function into the logic chip inside the sensor, the RAW information acquired from the SPAD pixels is converted into distance information to output, and all this is done within the sensor. This approach makes it possible to reduce the load of post-processing, thereby simplifying overall system development. The new IMX611 sensor will generate opportunities to create new value in smartphones, including functions and applications that utilize distance information.
