A back lighter (14) for illuminating a display (12) in electrical equipment, especially portable electrical equipment such as mobile telephones. The back lighter (14) comprises two light emitting diodes (26), two focussing elements (18), each of which is arranged to collect light from a respective one of the light emitting diodes (26), and a substantially planar light guide (20) arranged to receive light from the focussing elements (18). Each focussing element (18) is adapted to bend the light from the light emitting diode (26) into or towards the plane of the light guide (20). This arrangement enables the thickness of the light guide (20) to be under 0.7 mm.
|Publication status||Published - 26 Jan 2000|