Patent ID: 8427602
Filing Date: 2013-04-23
Classification: G02B

Abstract:
1. A backlight unit comprising: a light source; a polarization conversion unit configured to convert polarization of light incident from the light source; and a light guide plate having a light guide portion and a plurality of light emitting portions protruding from an upper surface of the light guide portion, the light guide portion configured to reflect light incident through the polarization conversion unit within the light guide portion and the light emitting portions configured to emit light through specular reflection, wherein a top cross-section of each of the plurality of light emitting portions where the light is emitted is larger than a base cross-section where the light is incident from the light guide portion, wherein the polarization conversion unit is disposed between the light source and the light guide plate, light from the light source being incident to the light guide plate via the polarization conversion unit, wherein the light guide portion and the light emitting portions are formed as a single body, or formed without optical boundary between the light guide portion and each of the light emitting portions, wherein the polarization conversion unit is configured to convert the light incident from the light source into a first polarized light that is linearly polarized in a first direction, the first direction being parallel to the upper surface of the light guide portion and perpendicular to a direction from the light source toward the light guide portion, and wherein the light guide plate is configured such that the first polarized light maintains its polarization state and is emitted from the light guide plate while being linearly polarized in the first direction.