Patent ID: 7576915

Claim:
A display device ( 100 ), comprising: a light emitting picture element ( 120 ); and a contrast enhancing element ( 110 ), the contrast enhancing element comprising a substrate having a plurality of wave guides ( 216 ), the wave guides including a first material of a first refractive, index adjacent said picture element ( 120 ), and interstitial regions ( 212 ) including a second material of a lower refractive index than the first refractive index, the interstitial regions ( 212 ) being arranged between the wave guides ( 216 ) and formed narrowing in the direction of the picture, element; and a reflective layer ( 214 ) provided on an interface between a wave guide ( 216 ) and an interstitial region ( 212 ), wherein the reflective layer is configured to reflect ambient light entering the interstitial regions between the wave guides; wherein a cross-section length of an exit surface of a wave guide is in the order of magnitude of a wavelength of light in the visible range.