Patent ID: 7223008

Claim:
A backlighting device for an information display element of a wristwatch, said device comprising a light guide plate having a front face and a rear face, a light reflector located on the rear face of the light guide plate, and a single source of visible light, which is a light emitting diode for feeding light beams to a boundary or edge of the light guide plate, which spread in the light guide plate and between said rear and front faces, wherein the device comprises a layer located above the front face of the light guide plate between the front face of said light guide plate and a rear face of the display element of the portable object, said layer having at least one zone with partial opacity decreasing from a limit located close to a boundary area of the light guide plate, which receives the light beams of the light emitting diode located below and close to a visible portion of the display element, in order to attenuate the intensity of a light halo crossing said zone, which is caused by the light source, and wherein the light guide plate has on a periphery thereof a rounded corner covered by a light-reflecting layer, said light emitting diode being disposed below the rounded corner in order to feed the light beams in a vertical direction in relation to the rear face of the light guide plate so that said beams are reflected by the reflecting layer at the edge of the light guide plate and spread into the light guide plate between the front and rear faces.