  3D flash LIDAR is an alternative to the traditional scanning LIDAR systems,
promising precise depth imaging in a compact form factor, and free of moving
parts, for applications such as self-driving cars, robotics and augmented
reality (AR). Typically implemented using single-photon, direct time-of-flight
(dToF) receivers in image sensor format, the operation of the devices can be
hindered by the large number of photon events needing to be processed and
compressed in outdoor scenarios, limiting frame rates and scalability to larger
arrays. We here present a 64x32 pixel (256x128 SPAD) dToF imager that overcomes
these limitations by using pixels with embedded histogramming, which lock onto
and track the return signal. This reduces the size of output data frames
considerably, enabling maximum frame rates in the 10 kFPS range or 100 kFPS for
direct depth readings. The sensor offers selective readout of pixels detecting
surfaces, or those sensing motion, leading to reduced power consumption and
off-chip processing requirements. We demonstrate the application of the sensor
in mid-range LIDAR.
