This video is about a new kind of robotic head. Through back-projection of a computer generated video into a half-translucent mask, the LightHead robotic head has many advantages compared to tradition mechatronic robotic faces. These advantages are most notably the versatility and ease of controlling facial expressions and creating new faces, the total weight and the low costs. By mounting the head on a robotic arm and equipping it with face detection software, the robot can interact with people in a natural manner.

Reading gaze direction is important in human-robot interactions as it supports, among others, joint attention and non-linguistic interaction. While most previous work focuses on implementing gaze direction reading on the robot, little is known about how the human partner in a human-robot interaction is able to read gaze direction from a robot. The purpose of this paper is twofold: (1) to introduce a new technology to implement robotic face using retro-projected animated faces and (2) to test how well this technology supports gaze reading by humans. We briefly discuss the robot design and discuss parameters influencing the ability to read gaze direction. We present an experiment assessing the user's ability to read gaze direction for a selection of different robotic face designs, using an actual human face as baseline. Results indicate that it is hard to recreate human-human interaction performance. If the robot face is implemented as a semi sphere, performance is worst. While robot faces having a human-like physiognomy and, perhaps surprisingly, video projected on a flat screen perform equally well and seem to suggest that these are the good candidates to implement joint attention in HRI.

This paper presents a new implementation of a robot face using retro-projection of a video stream onto a semitransparent facial mask. The technology is contrasted against mechatronic robot faces, of which Kismet is a typical example, and android robot faces, as used on the Ishiguro robots. The paper highlights the strengths of Retro-projected Animated Faces (RAF) technology (with cost, flexibility and robustness being notably strong) and discusses potential developments.