Backlighting for optical finger navigation

An optical finger navigation (OFN) device includes an OFN sensor module, a light source, and a vertical light guide. The OFN sensor module is coupled to a circuit substrate. The OFN sensor module generates a navigation signal in response to a movement detected at a navigation surface based on light reflected from a user's finger. The light source is also coupled to the circuit substrate. The light source generates light (which is separate from the light generated for the OFN sensor module). The vertical light guide is disposed to circumscribe a perimeter of the OFN sensor module. The vertical light guide receives the light from the light source and guides the light toward a light emission surface at a perimeter surface area circumscribing the navigation surface.