Patent ID: 8179361

Claim:
A backlight device comprising: (a) a light guide plate that propagates, reflects and diffuses light, disposed at a rear surface side of a display device, wherein the light guide plate comprises (i) an entry face that light enters at one side of the light guide plate; (ii) an exit face disposed on a side of the light guide plate adjacent to a liquid crystal display device; and (iii) a lower face disposed opposing the side of the light guide plate nearest to the liquid crystal display device; (b) a light source disposed at least one end of the light guide plate; and (c) a reflector that comprises a structured face that includes an iteration of prism elements of trapezoidal section, a crest line direction of the prism elements being disposed orthogonally to the entry face of the light guide plate, wherein the reflector is disposed at the lower face of the light guide plate and reflects light from the light guide plate at the structured face.