| 摘要 |
PROBLEM TO BE SOLVED: To provide a surface light source device which suppresses eyeball-like light emission or bright line occurring on an edge of an opening window of a rim sheet (light-shielding plate) due to leakage light.SOLUTION: A light guide plate 33 is made by continuously molding a thick light introducing part 34 and a thin light guide plate main body 35. An optical source 40 is oppositely arranged on a light incident edge surface 36 of the light introduction part 34. Three sheets of optical sheets, that is, a diffusion sheet 43 and two sheets of prism sheets 44, 45 are superposed on the upper surface (light emission surface 39) of the light guide plate main body 35. Further, a rim sheet 46 is superposed on the optical sheets and an opening window 47 through which light emitted from the light emission surface 39 passes is opened on the rim sheet 46. The edge part of the optical source side of the diffusion sheet 43 is extended from edges of the prism sheets 44, 45 and at least one side surface of the extended part of the diffusion sheet 43 is covered with a light shielding member 49. The edge part of the extended part of the diffusion sheet 43 is adhered and fixed to 41 on which a light source 40 is mounted. |
