Patent ID: 8089466

Claim:
A system for performing optical navigation, the system comprising; an illumination optical element having a concave surface on a first side and a convex surface on a second side, the first and second sides being opposite sides of the illumination optical element, the illumination optical element being orientated such that that a beam of light is received at the concave surface and transmitted into the illumination optical element and the beam of light is emitted out of the convex surface toward a navigation surface; an image sensor array positioned to receive light from the beam of light incident on the navigation surface, the image sensor array being configured to capture frames of image data from the received light for displacement estimation; and an imaging optical element positioned between the navigation surface and the image sensor array, wherein the imaging optical element is positioned such that the optical axis of the imaging optical element and an axis normal to the navigation surface defines a first plane perpendicular to the navigation surface and an optical axis of the beam of light incident on the navigation surface and an optical axis of the beam of light that is specularly reflected from the navigation surface defines a second plane perpendicular to the navigation surface, where the second plane does not contain the optical axis of the imaging optical element and where the angle between the first plane and the second plane is between approximately eighty to one hundred degrees.