Patent ID: 8419258

Claim:
A backlight device, comprising; a first light guide including an upper surface, a first side surface having a first end coupled to a first end of the upper surface and perpendicular to the upper surface, and a first inclined surface coupled between a second end of the upper surface and a second end of the first side surface; a second light guide including a lower surface parallel to the upper surface of the first light guide, a second side surface having a first end coupled to a first end of the lower surface and being parallel to the first side surface of the first light guide and perpendicular to the lower surface, and a second inclined surface coupled between a second end of the lower surface and a second end of the second side surface, the first inclined surface of the first light guide being spaced apart from the second inclined surface of the second light guide; an optical device provided on the light guide plate; a first light emitting module positioned at the first side surface of the first light guide, the first light emitting module including a first substrate oriented in parallel to the first side surface of the first light guide and at least one light emitting diode mounted on the first substrate; a second light emitting module positioned at the second side surface of the second light guide, the second light emitting module including a second substrate oriented in parallel to the second side surface of the second light guide and at least one light emitting diode mounted on the second substrate; and a reflective device provided below the second light guide, wherein the at least one light emitting diode of the first light emitting module and the first light guide are disposed along a first horizontal line and the at least one light emitting diode of the second light emitting module and the second light guide are disposed along a second horizontal line that is positioned below the first horizontal line, and wherein a refractive index of the second light guide is higher than that of the first light guide.