Patent ID: 8328407

Claim:
A light guide plate, comprising: an incident surface to receive incident light from a light source; an exit section to output exit light having a light distribution different from a light distribution of the incident light; a reflective section opposite to the exit section; a plurality of first patterns disposed on the exit section and arranged in a first direction to distribute the exit light with maximum brightness in a direction perpendicular to the exit section; and a plurality of second patterns disposed on the reflective section to scatter the incident light, wherein the second patterns comprise: a first unit pattern, a second unit pattern adjacent to the first unit pattern in the first direction and at a first interval, and a third unit pattern and a fourth unit pattern adjacent to the first unit pattern, wherein the third unit pattern and the fourth unit pattern are spaced apart from each other by a second interval in a second direction that crosses the first direction, and wherein the first interval is smaller than the second interval, wherein each first pattern comprises a triangle-like shape in a view taken along a plane in a direction perpendicular to the exit section and perpendicular to the first direction, an angle between a side of the triangle-like shape and the exit section is θ 1 , a thickness between the exit section and the reflective section is t, a refractive index of each first pattern is n 1st pattern , the first interval has a value of x+ α, and the second interval has a value of x+α, wherein x>α, 0<α2·t·tan θ, θ=θ 1 −sin −1 (sin θ 1 /n 1st pattern ).