| 摘要 |
PROBLEM TO BE SOLVED: To supply illumination light with directivity suitable for characteristics of a liquid crystal display panel, in relation to a light guiding plate, a side light type surface light source device and a liquid crystal display device, by applying them to, for instance, the case that a liquid crystal display device is composed by the use of a reflection type liquid crystal display panel. SOLUTION: Regarding multiple protrusions 13E formed on an outgoing radiation function surface 13B of a light guiding plate 13, each of the protrusions 13 is so formed that the surface on the opposite side 13EB to an incident surface 13A is in a reverse taper form, or a step is so formed between the incident surface side of the protrusion and its opposite side that the plate thickness is increased at a position where its side surface is connected to the outgoing radiation function surface on the opposite side as compared with that at a position where the side surface is connected to the outgoing radiation function surface on the incident surface side. |
