Patent ID: 9581735
Date: 2017-02-28
CPC Classifications: G02B,G02F

Claim:
1. A backlight unit comprising: a light source; and a micro lens array (MLA) sheet comprising a plurality of lens units two-dimensionally arranged thereon, wherein the light source has the micro lens array (MLA) sheet, a prism sheet, and a reflective polarizing film, sequentially stacked thereon or, wherein the light source has a prism sheet, the micro lens array (MLA) sheet, and a reflective polarizing film, sequentially stacked thereon, wherein each lens unit has a conic lens shape of which a vertical cross-section taken in a lens center is represented by the following Expression 1: where k is a conic constant, and r is a radius of curvature at a peak of the lens unit, wherein, k≦−1.