A light guide film comprising: a light entering part (a) at a first side; a light reflecting part (c) disposed at a second side; and a light guiding part (b) between the light entering part (a) and the light reflecting part (c); wherein the light entering part (a) is configured to guide incident expanded light that satisfies a total reflection condition for total reflection within the light guiding part (b) toward the light guiding part (b), the light guide film further comprising: a high refractive film disposed in the light entering part (a), the light guiding part (b) and the light reflecting part (c), the high refractive film having a cuboid shape with one of the surfaces being inclined, and wherein a first surface of the high refractive film forms an acute wedge angle with the inclined surface; wherein the inclined surface is a reflective surface disposed at the light reflecting part (c) and configured to collimate the incident light in a first direction; a first reflective pattern disposed on the first surface of the high refractive film and facing the reflective surface at the light reflecting part (c) and configured to collimate the collimated incident light in a second direction different from the first direction; a second reflective pattern disposed on the reflective surface; wherein the light reflecting part (c) is configured to convert the incident light provided from the light guiding part (b) into a collimated light collimated in the first and second direction and to guide it back to the light guiding part (b), wherein the collimated light reentering into the light guiding part (b) from the light reflecting part (c) has an incident angle for breaking the total reflection condition at the first surface of the high refractive film; and a light radiating pattern disposed on the first surface of the high refractive film at the light guiding part (b) and configured to radiate a back light using a first portion of the collimated light and to reflect a second portion of the collimated light into the light guiding part (b). a light entering part (a) at a first side; a light reflecting part (c) disposed at a second side; and a light guiding part (b) between the light entering part (a) and the light reflecting part (c); wherein the light entering part (a) is configured to guide incident expanded light that satisfies a total reflection condition for total reflection within the light guiding part (b) toward the light guiding part (b), the light guide film further comprising: a high refractive film disposed in the light entering part (a), the light guiding part (b) and the light reflecting part (c), the high refractive film having a cuboid shape with one of the surfaces being inclined, and wherein a first surface of the high refractive film forms an acute wedge angle with the inclined surface; wherein the inclined surface is a reflective surface disposed at the light reflecting part (c) and configured to collimate the incident light in a first direction; a first reflective pattern disposed on the first surface of the high refractive film and facing the reflective surface at the light reflecting part (c) and configured to collimate the collimated incident light in a second direction different from the first direction; a second reflective pattern disposed on the reflective surface; wherein the light reflecting part (c) is configured to convert the incident light provided from the light guiding part (b) into a collimated light collimated in the first and second direction and to guide it back to the light guiding part (b), wherein the collimated light reentering into the light guiding part (b) from the light reflecting part (c) has an incident angle for breaking the total reflection condition at the first surface of the high refractive film; and a light radiating pattern disposed on the first surface of the high refractive film at the light guiding part (b) and configured to radiate a back light using a first portion of the collimated light and to reflect a second portion of the collimated light into the light guiding part (b). a high refractive film disposed in the light entering part (a), the light guiding part (b) and the light reflecting part (c), the high refractive film having a cuboid shape with one of the surfaces being inclined, and wherein a first surface of the high refractive film forms an acute wedge angle with the inclined surface; wherein the inclined surface is a reflective surface disposed at the light reflecting part (c) and configured to collimate the incident light in a first direction; a first reflective pattern disposed on the first surface of the high refractive film and facing the reflective surface at the light reflecting part (c) and configured to collimate the collimated incident light in a second direction different from the first direction; a second reflective pattern disposed on the reflective surface; wherein the light reflecting part (c) is configured to convert the incident light provided from the light guiding part (b) into a collimated light collimated in the first and second direction and to guide it back to the light guiding part (b), wherein the collimated light reentering into the light guiding part (b) from the light reflecting part (c) has an incident angle for breaking the total reflection condition at the first surface of the high refractive film; and a light radiating pattern disposed on the first surface of the high refractive film at the light guiding part (b) and configured to radiate a back light using a first portion of the collimated light and to reflect a second portion of the collimated light into the light guiding part (b).