Patent ID: 8259255

Claim:
A liquid crystal display (LCD) comprising: an LCD panel comprising a first substrate, a second substrate facing the first substrate, a liquid crystal layer sandwiched between the two substrates, and an upper polarizer film being disposed at the first substrate, the upper polarizer film having a first polarization axis; a lower polarizer film being disposed at the second substrate, and comprising a second polarization axis substantially perpendicular to the first polarization axis of the upper polarizer film; and a backlight module adjacent to the second substrate and facing the LCD panel to illuminate the LCD panel, the backlight module comprising: a light guide plate comprising a light incident surface and a light emitting surface; a light source configured to emit polarized light with a first polarization orientation, the light source positioned at a side of the light incident surface; and a retardation layer disposed in an optical path between the light emitting surface and the second substrate, wherein the retardation layer is configured to rotate the first polarization orientation of all the polarized light emitted from the light source and transmitted to the retardation layer to a second polarization orientation, the second polarization orientation is substantially parallel to the first polarization axis of the upper polarizer film, and the rotated polarized light emitted from the retardation layer follows the optical path to the second substrate and subsequently undergoes a single pass only through the liquid crystal layer to be emitted out from the LCD via the first substrate.