Patent ID: 8836896

Claim:
An optical sheet for controlling the direction of light rays comprising: a substrate film; a microlens group arranged on a first face of the substrate film; and a plurality of protuberances formed on a second face of the substrate film, wherein each protuberance comprises a reflective layer at a bottom thereof, and the plurality of protuberances comprise an aperture formed therebetween, wherein a unit microlens of the microlens group has a first side, a second side and a light emission control part formed at a highest part of the first face of the substrate film, and a radius of curvature (R1) of the first side is not greater than a radius of curvature (R2) of the second side to form an asymmetrically curved surface of the unit microlens, and wherein each of R1 and R2 is in the range of 10 μm to 1,000 μm, and a ratio of R1 to R2 is about 100:175.