  Fast and accurate depth sensing has long been a significant research
challenge. Event camera, as a device that quickly responds to intensity
changes, provides a new solution for structured light (SL) systems. In this
paper, we introduce Gray code into event-based SL systems for the first time.
Our setup includes an event camera and Digital Light Processing (DLP)
projector, enabling depth estimation through high-speed projection and decoding
of Gray code patterns. By employing spatio-temporal encoding for point
matching, our method is immune to timestamp noise, realizing high-speed depth
estimation without loss of accuracy. The binary nature of events and Gray code
minimizes data redundancy, enabling us to fully utilize sensor bandwidth at
100%. Experimental results show that our approach achieves accuracy comparable
to state-of-the-art scanning methods while surpassing them in data acquisition
speed (up to 41 times improvement) without sacrificing accuracy. Our proposed
approach offers a highly promising solution for ultra-fast, real-time, and
high-precision dense depth estimation. Code and dataset will be publicly
available.
