Optimal use of F-TIR issues in finger mouse

摘要

An optical navigation device (400) for a computer application, comprising: a radiation source (202) capable of producing a beam of radiation; a sensor (206) for receiving an image; and an optical element (106) for identifying movement of the feature to thereby enable a computer action to be carried out; wherein the optical element is formed from a single piece and includes at least one frustrated total internal reflection (F-TIR) surface (112) capable of affecting frustrated total internal reflection of the beam of radiation in the presence of the feature (812) to thereby generate the image.