Patent ID: 7714843

Claim:
A method for tracking a point of contact of an optical output of a computer input device having a housing with a wall portion and a base portion, the base portion disposed to support the computer input device on a support surface, the method comprising steps of: transmitting an optical output from the computer input device, the optical output transmitted through the wall portion of the housing of the computer input device; tracking a position of the point of contact of the optical output on an interactive surface in communication with a computer, when the optical output is within the field of view of a camera contained within the computer input device, wherein the interactive surface enables tracking the position of the point of contact of the optical output while simultaneously changing a computer function, the computer function comprising zooming an image, and wherein the field of view senses a working field comprising at least one boundary, the working field further comprising an active area of sensing for the camera; transmitting the position of the point of contact of the optical output to the computer; applying the position of the point of contact of the optical output as an input to an application operating on the computer; determining whether the optical output is being transmitted by the computer input device; determining whether the point of contact of the optical output is within the working field; and enabling a warning indicator upon determining that the point of contact is not within the working field, wherein the point of contact is not within the working field upon the at least one boundary being passed through when the optical output starts from within the field of view of the camera, and wherein the warning indicator comprises an audio/visual indicator indicating that the working field is no longer in the field of view of the camera.