Optical navigation module with capacitive sensor

Optical navigation modules and methods of operating the same to sense relative movement between the optical navigation module and a tracking surface are provided. In one embodiment, the optical navigation module comprises: (i) a light source to illuminate at least a portion of a surface relative to which the optical navigation module is moved; (ii) an integrated circuit (IC) including a photo-detector array (PDA) to detect a light pattern propagated onto the PDA from the surface, and a signal processor to translate changes in the light pattern propagated onto the PDA into data representing motion of the optical navigation module relative to the surface; and (iii) a substrate to which the light source and IC are mounted, the substrate including an aperture in a light path between the surface and the PDA. Other embodiments are also disclosed.