Optical navigation device

Abstract

An optical navigation device includes a case, an illumination light source, an illumination lens, an optical detector and a first optical element. The case is movably located above a navigation surface. The illumination light source is disposed inside the case and adapted to emit an illumination beam. The illumination lens is disposed under the illumination light source and has an output surface. The illumination beam passes through the output surface to project onto the navigation surface. The optical detector is disposed inside the case and adapted to detect a reflection beam from the navigation surface. The first optical element is disposed adjacent to the output surface of the illumination lens and extended to an outer edge of the illumination lens, and adapted to eliminate a stray light beam generated by the illumination beam propagated between the illumination lens and the navigation surface from reaching the navigation surface.

Dependencies are inferred from the claim text.