BACKLIGHT UNIT AND DISPLAY DEVICE EMPLOYING THE SAME

摘要

A backlight unit and a display device employing the same are provided to efficiently supply a vertical light to a display panel by sequentially collimating a light emitted from a light source in an azimuth direction and an altitude direction. A first collimating unit(146) collimates a light incident from a light source(110) in a first direction to emit the collimated light. A second collimating unit(157) collimates the light emitted from the first collimating unit in a second direction different from the first direction to emit the collimated light. A light incident from the light source is sequentially collimated in two directions and is then emitted. The first collimating unit includes a first light guide plate(140) and a first prism sheet(160). The first light guide plate includes a first light entrance surface(140a) to which a light incident from the light source, and a first light emitting surface(140b) to which the incident light is emitted. The first light guide plate collimates the incident light in a direction for reducing a range of an azimuth angle distribution. The first prism sheet shifts the azimuth angle distribution of the light emitted from the first light emitting surface. The second collimating unit includes a second light guide plate(150) and a second prism sheet(170). The second light guide plate includes a second light entrance surface(150a) to which a light incident from the first light emitting surface and a second light emitting surface(150b) to which the incident light is emitted. The second light guide plate collimates the incident light in a direction for reducing a range of an altitude angle distribution. The second prism sheet shifts the altitude angle distribution of the light emitted from the second light emitting surface.