Abstract: A normally white (NW) twisted nematic liquid crystal display (LCD) outputs improved viewing characteristics which are defined by high contrast ratios and/or reduced inversion. The display includes a pair of negative tilted retarders (#2 and #6) located on one side of the liquid crystal layer (#10), each of the tilted retarders including a tilt or incline angle which varies throughout the thickness of the layer. Additionally, one or two negative uniaxial or biaxial retarders (#4 and #7) are provided on the same side of the liquid crystal layer as the tilted retarders. As a result of the particular orientations, alignments, and retardation values described in the different embodiments, the display exhibits improved contrast and reduced inversion.

Abstract: An LCD backlight (30) comprises generally rectangular parallelepiped light guide (36) with an exit aperture (31) that is smaller than the surface area light guide (36) and illuminates a LCD (49). The light guide is illuminated by a plurality of Light Emitting Diodes (LED) dies (32) disposed along at least one edge of the light guide. A translucent fluorescent film (40) is disposed immediately above the exit aperture to diffuse the light exiting the exit aperture and also the change in the dominant wavelengths. Further, the light guide (36), the LEDs (32), fluorescent film (40), and additional light redirecting layers (42 and 44) are completely surrounded by and optically coupled to a diffusively reflective film (50), which covers the back surface, the edges, and the front surface of the light guide except for the exit aperture. This diffusively reflective shielding is covered by a conventional reflective material layer (51) to ensure no light escapes the backlight except through the exit aperture.