A method for assembling a touch sensing apparatus comprising a display panel, a plate comprising a top surface and a bottom surface opposite the top surface, and a frame assembly, wherein the plate has a first curvature along at least a first edge of the top surface of the plate when uncoupled with the frame assembly. The method comprises the steps of arranging a plurality of light emitters alongside a periphery of the plate, the plurality of light emitters configured to emit light propagating over the top surface; arranging a plurality of detectors alongside the periphery of the plate, the plurality of detectors configured to receive light emitted from the plurality of light emitters; and coupling the display panel, the plate, and the frame assembly, wherein the step of coupling causes the first curvature of the plate to change to a second curvature.