Magnetic positioning mechanism for fluid-supported self-rotating displays

摘要

A self-rotating display device (1) includes and outer light transmissive container (2) containing a light transmissive fluid (6) and a body (4) containing an electric motor (14) for rotating the body with respect to the outer container. The body also carries a compass magnet (18) as a source of counter-torque for the motor to operate against. A magnetic positioning structure (20) made of ferromagnetic material secured to the container interacts with the magnetic field of the compass magnet to cause the body to migrate toward a location minimizing the distance between the magnetic positioning structure and compass magnet, so that the body can remain centered within the display while rotating.