A directional backlight with narrow angular luminance distribution for widening the viewing angle for an LCD with a front-surface light-scattering film

A directional backlight unit has been developed to widen the viewing angle of a TN-LCD with a front-surface light-scattering film/layer. The novel directional backlight has a diagonal of 34 cm and is structured by light-direction-control optical micro-features and an inverted prism film. The backlight has a symmetrical round luminance cone of +/- 9 degrees and a uniform spatial distribution of 88%. By using this backlight unit in combination with an LCD, the narrow cone resulted in widening of the TN-LCD's viewing angle up to 120 degrees at full width at half-maximum.