Patent ID: 8272771

Claim:
A backlight device comprising: a light emitting element; a lens having an incident surface on which light emitted by said light emitting element is incident, and an outgoing surface configured to converge light and from which the light incident on said incident surface is transmitted out; a light guide plate having a light incidence plane and introducing through said incidence plane light transmitted out from said outgoing surface, so as to perform surface light emission; and a reflective member operative to reflect a portion of the light having already been transmitted through said outgoing surface of said lens toward said incidence plane of said light guide plate, the reflective member including a base part having an end edge portion that is disposed a distance furthest from the light guide plate relative to other portions of the reflective member, wherein the end edge portion of the base part is closer to the light guide plate than the light emitting element is to the light guide plate and said incident surface includes a principal surface having an ability to converge light and a projected surface provided at an end portion of said principal surface and projected from said principal surface, and wherein light emitted by said light emitting element is incident on the projected surface prior to reflection by the base part of the reflective member.