Re:DIY version? (Score 3, Informative)

Its the "one way reflective material" thats the cunning part, and what you pay all the money for. The surface treatment of the glass 'screen' is what is holographic in this instance, not the image that is generated, which is just a flat TV image. The hologram is such that from your viewing angle, light just passes straight through the glass plate, but from the projectors angle, the glass is opaque enough for an image to form on it like a conventional screen rather than passing straight through like it does the window on a projector booth at a cinema). I don't think you could generate the 40" hologram at home as a DIY solution!