PURPOSE: A structure of an optic film having a light guide is provided to prevent damage to a prism film by forming a light guide on the surface with the microphone including the ridge. CONSTITUTION: An optical film comprises the surface(21) in which a plurality of rib-shaped micro light guides is formed. The rib-shaped micro light guide could be formed with the same or different material as/ the main body of the optical film(2). Each micro light guide(22) comprises at least two ridges. The ridges(221) of the micro light guide have different height.
