Patent ID: 8797298

Claim:
An optical finger navigation device comprising: a light guide film (LGF), wherein at least a portion of the LGF exhibits total internal reflection (TIR); a light source in optical communication with the LGF and configured to inject light into the LGF; a sensor configured to detect light that exits from the LGF after being reflected from a finger that is proximate the LGF; and a navigation engine configured to generate lateral movement information, which is indicative of lateral movement of the finger relative to the sensor, in response to light that is reflected from the finger and detected by the sensor; wherein the LGF is between 10 microns and 100 microns thick; and further comprising a circuit board substrate, wherein the light source, the sensor, and the navigation engine are attached to the circuit board substrate and wherein the LGF is laminated directly to the circuit board substrate with no intervening optical lenses between the circuit board substrate and the LGF.