PLANAR LIGHTING DEVICE, ELECTRONIC DEVICE PROVIDED THEREWITH, AND LIQUID-CRYSTAL DISPLAY DEVICE

摘要

A light-guide plate (2) in the planar lighting device (1) in one embodiment of the present invention has: first connecting surfaces (21) that connect adjacent light-output surfaces; and second connecting surfaces (11) that connect adjacent opposing surfaces. Said light-guide plate satisfies one of the following conditions: the opposing surfaces (10b) of light-guide sections (2B) are higher in the light-output direction than the light-output surfaces (20c) of other light-guide sections (2C) (condition i); the opposing surfaces of light-guide sections are at the same height in the light-output direction as the light-output surfaces of adjacent light-guide sections (condition ii); or the opposing surfaces of light-guide sections are lower in the light-output direction than the light-output surfaces of adjacent light-guide sections and the height difference in the light-output direction between said opposing surfaces and said light-output surfaces is at most 35% of the height difference between the light-output surface and opposing surface of each light-guide section.