A planar surface illuminator (20) for installation below a liquid crystal display panel includes a light guide plate (22) and a plurality of point light sources (21). The light guide plate has an optical input surface (221) and an optical output surface (222). The point light sources are positioned adjacent to the optical input surface. A number of scattering dots (23) are positioned on and integrated with the optical input surface. At least three scattering dots corresponding to each one point light source are provided, for converting a beam having a Gaussian distribution received from the point light source to a beam having a uniform light intensity which illuminates the light guide plate. This promotes uniform intensity light emission from the optical output surface to illuminate the liquid crystal display panel.