ILLUMINATION DEVICE Russian patent published in 2011 - IPC G02F1/1335 

FIELD: physics.

SUBSTANCE: backlighting device includes a plurality of light-emitting diodes (LED) having a light-emitting surface with light scattering angle in the angular aperture of up to ±90° from the normal to said light-emitting surface, a light guide plate made from transparent optical material and having a first surface which has light incidence zones. Each light incidence zone has a central area, a well as lateral areas in the immediate vicinity of the light incidence zones; a second surface having a plurality of concave areas interfaced with said zones and having a plane of symmetry. The lateral surfaces of the said concave areas have a shape which facilitates reflection owing to the effect of total internal reflection of part of the light coming from the light incidence zone within the angular aperture up to α=±arcsin (1/n) from the normal to the said light incidence zones, where n is the refraction index of the transparent substance. The device also has light output apparatus and a reflecting surface under the said light guide plate. The LEDs are placed under the light guide plate, and said central areas have a common plane of symmetry with interfaced concave areas and formed from two surfaces, the angle between which ranges from 120° to 60°.

EFFECT: improved design of the backlighting device.

3 cl, 6 dwg