| 摘要 |
FIELD: electrical engineering.SUBSTANCE: in the flat illumination device backlight device (20), on the light-emitting surface (23b) of the lightguide unit (23) multiple prisms (23 e) are arranged, fabricated and positioned so that to gradually reduce the light incidence angle relative to the lightguide unit rear surface (23c). On the rear surface (24a) of the low refraction layer (24) there are also multiples prisms (24b) having the function of direct and complete reflection of light from the LEDs (21) on the division surface between the rear surface of the low refraction layer and the air layer.EFFECT: enhanced efficiency of using light and brightness thereof for heterogeneous brightness suppression, reduced growth of costs associated with fabrication and reduction of the thickness of the flat illumination element.28 cl, 20 dwg |
