Waveguide design incorporating reflective optics

An input device for an electronic device comprising:

• at least one light source;
• at least one multi-element light detector to detect light intensity at a plurality of light detecting elements;
• an input area defining a plane;
• and
• a waveguide structure including a first set of waveguides with associated first set of reflective elements, a third set of waveguides with associated third set of reflective elements, a second set of waveguides, and a fourth set of waveguides, each composed of a material with first refractive index, wherein:
• said light source couples light into said first and third sets of waveguides with associated first and third sets of reflective elements;
• said first and third sets of waveguides direct the light onto said associated first and third sets of reflective elements;
• said associated first and third sets of reflective elements collimate the light in the plane of the input area to produce first and second grids of light beams;
• said first grid of light beams traverses the input area in a first direction and is directed to a first set of light detecting elements of said multi-element light detector by said second set of waveguides;
• and
• said second grid of light beams traverses the input area in a second direction, different to said first direction, and is directed to a second set of light detecting elements of said multi-element light detector by said fourth set of waveguides.