Projection instruments; Projection screens; Projector screens; Projectors; Tables adapted for projectors; Video projectors; Overhead projectors; Optical projection apparatus; 3D spectacles; Video screens; Plasma televisions; Stands for televisions; Wall mountings adapted for television apparatus; Optical spectacles; Projection television apparatus; Video enhancers; Wearable video display monitors; Viewdata display terminals; Optical filters for use with visual display units; Display terminals