Patent ID: 6272778
Filing Date: 2001-08-14
Classification: G09F

Abstract:
Display element for an electromagnetic display devicesaid display element having a main viewing direction and comprisinga frame and a disc mounted to the frame by means of a rotation bearing for pivoting of the disc about a pivoting axis, the pivoting axis running essentially in a display main plane which extends perpendicular to the main viewing direction,the disc having two differently colored sides, an ON-side the color of which contrasts against the background color of the frame and an OFF-side having a non-contrasting color, the bearing allowing pivoting of the disc about the pivoting axis between two operating positions, an ON-position where it rests against a first stop and its ON-side is directed towards the main viewing direction and an OFF-side position where it rests against a second stop and its OFF-side is directed towards the viewing direction,an electromagnetic drive system for driving the disc from one of the operating positions to the other of the operating positions and comprising a permanent magnet attached to the disc and an electromagnet attached to the frame and having a high remanence core and a coil surrounding the core,wherein,two portions of the disc extend in a disc plane on both sides of the pivoting axis,the permanent magnet is attached to the disc with its polar axis running essentially parallel to the disc and extending across the pivoting axis whereby its poles are located on differing sides thereof,the turning angle of the disc between the operating positions is less than 180.degree.,the electromagnetic drive system has a single electromagnet with a straight ferromagnetic core anda driving tip of the straight ferromagnetic core is located sidewise of the pivoting axis such that in each of the operating positions one of the poles of the permanent magnet is directed towards the driving tip and the driving tip is in one of the operating positions rearward and in the other of the operating positions forward relative to the disc plane.