Patent ID: 8451226

Claim:
A user input device for use with a computing device, the user input device comprising: a housing with a bottom portion including a substrate that includes a transparent portion; and an optical tracking engine mounted in the housing proximate the substrate and being configured to transmit and detect light for tracking movement of the user input device through the transparent portion of the substrate; wherein the transparent portion of the substrate through which light is transmitted and detected by the optical tracking engine is positioned in a concave depression formed in the bottom portion of the user input device, the concave depression sized to position the transparent portion of the substrate outside of a depth of field of the optical tracking engine such that the transparent portion is closer to a focusing lens of the optical tracking engine than an innermost reach of the depth of field of the optical tracking engine; and wherein the substrate is configured as a touch sensitive input device, and includes a touch sensitive layer formed of capacitive or resistive sensing material.