Direct-illumination backlight apparatus having transparent plate acting as light guide plate

Abstract

A direct-illumination backlight apparatus uses LEDs as a light source. This backlight apparatus comprises: a flat reflective plate; an LED light source arranged on the reflective plate; a transparent plate arranged above the LED light source; a scattering pattern arranged on an underside of the transparent plate in a position corresponding to the LED light source; and a light guide made of transparent material, and arranged around the scattering pattern to introduce light incident from below into the transparent plate so that the light is internally reflected by the transparent plate. The light guide serves to introduce a partial light from an LED light source at such an angle that the partial light is trapped inside the transparent plate, and the scattering pattern serves to scatter the trapped light beam at a position directly above the LED light source so that the scattered light beam escapes out of the transparent plate toward an LCD panel. This can remove any dark area above the LED light source in the transparent plate and thus reduce the thickness of the direct-illumination backlight apparatus.

Dependencies are inferred from the claim text.