Small-pixel pseudo-dToF image sensors with charge-domain signal compression

Time-compressive computational CMOS image sensors can realize a new implementation of light detection and ranging (LiDAR), i.e., pseudo-direct time-of-flight (pseudo-dToF) depth imaging. They are based on the multi-tap charge modulator used in indirect ToF (iToF) image sensors and compress high-speed optical temporal signals in the charge domain in pixel. Therefore, large digital circuits for time-to-digital conversion or histogram builder used in conventional dToF image sensors based on the single photon avalanche diode (SPAD) are unnecessary. Nevertheless, they can detect multiple reflections under multipath interference, which is one of the advantages of dToF. Exploiting the small pixel size of the pseudo-dToF image sensor, high-resolution image sensors will be possible. In my talk, I will show extended depth range and detection of multiple reflections in dynamic scenes. Finally, I will discuss their applications to automobiles and unmanned aerial vehicles.