Fabricating method of light guiding plate and backlight unit with the same

A manufacturing method of a light guiding plate and a backlight unit with the same for improving the photonic efficiency are provided to improve light efficiency and productivity of the light guide plate. A light source(110) comprises a linear shape light source(112) generating the white light and a reflector(114) reflecting the light generated from the light source. A light guide plate comprises the entrance face and exit face. A prism pattern has the cross section of the saw shape on the exit face. The prism pattern is arranged in order to maintain the gap angle with the light source.