US Patent 10143272 Electronic strap for watch case

The invention relates to an electronic strap for a timepiece, comprising:a printed circuit boardan insert disposed on the printed circuit board, comprising a guide element provided to be placed between and fixed to a pair of horns of a watch case (BM), the guide element comprising a lightwave guide comprising:an input disposed on an interface between the guide element and the printed circuit boarda first output disposed so as to be opposite a first zone of the watch case (BM) between the two horns when the guide element is placed between and fixed to the pair of hornsa first portion connecting the input to the first outputa lightwave emitter installed on the printed circuit board, at the level of the input of the wave guide.