Patent ID: 8237684
Filing Date: 2012-08-07
Classification: G06F

Abstract:
1. A user input device comprising: an optical element comprising a finger interface surface, wherein at least a portion of the optical element exhibits total internal reflection (TIR); a light source in optical communication with the finger interface surface to provide light from the light source to the finger interface surface; a sensor array configured to detect light reflected from the finger interface surface in response to contact between a finger and the finger interface surface, wherein the contact between the finger and the finger interface surface disrupts the TIR and causes light to be reflected out of the optical element towards the sensor array; a lens located in an optical path between the finger interface surface and the sensor array; wherein the finger interface surface, the lens, and the sensor array are linearly aligned; and a navigation engine configured to generate lateral movement information, which is indicative of lateral movement of the finger relative to the sensor array, in response to the detected light; wherein the finger interface surface of the optical element comprises a major surface with a substantially planar portion and a finger contact portion which is at least partially out-of-plane with the substantially planar portion; wherein the finger interface surface further comprises a transition portion between the substantially planar portion and the finger contact portion, wherein the transition portion is at an angle relative to the planar portion and the finger contact portion to allow light to exit the optical element and illuminate the finger at the finger contact portion of the optical element; wherein the transition portion generates an intensity of reflected light to compensate for a light intensity pattern of the lens between the finger interface surface and the sensor array, wherein the transition portion causes the intensity of reflected light to be higher at the transition portion.