The present invention is directed to a light pipe having an improved structure of prisms. According to one embodiment of the present invention, a hollow light pipe comprises an inner-surface including a linear array of prisms; and a substantially smooth outer-surface, wherein a pitch of prisms in a first region is wider than a pitch of prisms in a second region. According to another embodiment of the present invention, a hollow light pipe comprises a hollow base pipe; and an insertion inserted into the base pipe and having a structured surface including an array of prisms, wherein a pitch of prisms in a first region is wider than a pitch of prisms in a second region.