Picture projection surface e.g. for video projection

摘要

The projection surface (10) includes two parallel transparent discs between which a partly transparent and reflecting material flows. The discs are arranged in a frame (22). Preferably, the material which causes the projection is controllably supplied and removed. The surface is reversibly changeable from one transparent state in a state in which the surface serves as a projection surface. The material between the discs consists of transparent, semi-transparent or refracting gases, vapour, smoke or solid particles. The particles are actuated in a carrier such as a fluid or a gas to flow or oscillate using a pump (28).