A head mounted display includes a head suspension apparatus and a display coupled thereto. In a stationary state, the display is maintained in a desired position relative to the head suspension apparatus. Further, in a release state, the display is always freely movable both vertically and horizontally...http://www.google.fr/patents/US5954642?utm_source=gb-gplus-shareBrevet US5954642 - Adjustable head mounted display and system
