Patent ID: 8848138

Claim:
A liquid crystal display device, comprising: an optical switching member which includes a first substrate and a second substrate sandwiching a liquid crystal layer; a light guide plate made of a thermoplastic material, which is disposed on a back side of the optical switching member and includes at least one light introducing portion on at least one side surface thereof; and a light source disposed on the at least one side surface of the light guide plate, wherein: the at least one light introducing portion includes, in plan view of the light guide plate: a first portion extending from a light incident surface, which is an end surface of the at least one light introducing portion, in a direction away from the light source while keeping a substantially constant width; and a second portion, which extends from the first portion and has a form which widens in the direction away from the light source; and at least the second portion is connected to a front surface of the light guide plate through an inclined surface which is smoothly continuous with the front surface of the light guide plate.