Patent ID: 8810515
Filing Date: 2014-08-19
Classification: G06F

Abstract:
1. An optical navigation device, comprising: a radiation source capable of producing a beam of radiation; a sensor for receiving an image; and an optical element for identifying movement of a feature to thereby enable a control action to be carried out; wherein the optical element comprises at least one biconic surface for directing radiation from the radiation source to at least one F-TIR surface, wherein the at least one biconic surface and the F-TIR surface are angled with respect to each other; wherein the optical element comprises at least one additional planar surface for directing radiation from the F-TIR surface to the sensor, wherein the at least one additional planar surface and the F-TIR surface are angled with respect to each other; wherein the radiation measured at the sensor is radiation which is totally internally reflected at the at least one biconic surface, the F-TIR surface, and the at least one additional planar surface; wherein an imaged area of the F-TIR surface is stretched along a first direction corresponding to a direction of a longitudinal axis of the imaged area, and the image received on the sensor is compressed along the longitudinal axis; and wherein radiation from the F-TIR surface is reflected off the at least one additional planar surface and focused on the sensor between a circle of least confusion and a position where spatial frequencies in a second direction appear sharper than spatial frequencies in said first direction.