Interactive video display system (the Krueger patent)
"The Kinect from 1986": controller-free, camera-based full-body tracking, patented by artist and researcher Myron Krueger a quarter-century before Microsoft shipped one in a box.
US4843568 · Myron Krueger · Lapsed for nonpayment around 2006
Myron Krueger built VIDEOPLACE, an interactive art installation that tracked a participant's silhouette on camera and let them interact with projected graphics using nothing but their body — no controller, no markers. US4843568, filed in the mid-1980s and granted in 1989, covers the underlying interactive video display system.
Two decades before Microsoft's Kinect made 'wave your arms at the screen, no controller' a mainstream living-room pitch, Krueger had already built and patented the concept. The patent lapsed for nonpayment of maintenance fees around 2006 — a few years before Kinect shipped in 2010.
By the time the world got its consumer version of controller-free body tracking, the original patent on the idea had already quietly expired.