A transparent holographic display screen for laser projection of at least one or more monochromatic wavelengths, is constructed to selectively diffuse an incident narrow-band laser beam at a predetermined solid angle and simultaneously to pass wide-band ambient light unobstructed through the display...http://www.google.co.uk/patents/US20020154349?utm_source=gb-gplus-sharePatent US20020154349 - Holographic display screen and method for producing the screen
