Low-Latency Beaming Display: Implementation of Wearable, 133 $\mu$s Motion-to-Photon Latency Near-eye Display.

Abstract

This paper presents a low-latency Beaming Display system with 133 μs motion-to-photon (M2P) latency, the latency from head motion to the corresponding image motion. Beaming Display is a recent near-eye display paradigm consisting of a steerable remote projector and a passive wearable headset that aims to overcome the typical trade-offs of OST-HMDs such as weight and computational resources. However, because Beaming Display projects a small image onto a distant moving viewpoint, M2P latency has a significant effect on displacement. To reduce M2P latency, we propose a low-latency Beaming-Display system that can be modularized without expensive high-speed devices. In our system, a 2D position sensor, which is placed coaxially on the projector, detects the light from the IR-LED on the headset and generates a differential signal for tracking. Analog closed-loop control of the steering mirror based on this signal keeps projecting images onto the headset. We implement a proof-of-concept prototype, evaluate the latency and augmented reality experience through a user-perspective camera, and discuss the limitations and improvements of the prototype.