A backlight unit is provided to improve a brightness of light without additional devices for light diffusion by providing a lens sheet including a plurality of lens successively formed on one surface, and a light source having a plurality of channels arranged such that light emission regions face boundaries between the lens. A light source(210) includes at least one channel for light generation. A lens sheet(220) has first and second surfaces, and includes a plurality of lens on the first surface. Light emission regions of the respective channels face the first surface of the lens sheet toward boundaries between the adjacent lens. The lens includes a conve lens or a fresnel lens.
