SURFACE LIGHTING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a surface lighting device applicable to a front light and the like of high brightness and capable of reducing thickness. SOLUTION: This surface lighting device includes a light guide plate 2 that introduces light from an outside and after forming a micro prism 2c on an observation surface, irradiates light to opposite side of the observation surface. The light guide plate 2 is formed of a luminous part 2b forming the micro prism 2c and an introduction part 2a projecting obliquely downward in line with the luminous part 2b. A light source unit 3 is arranged on a side surface of the introduction part 2a and a diffusion layer 2d diffusing light from the light source unit 3 and entering it into the luminous part 2b is formed on an upper surface of the introduction part 2a.