Patent ID: 8282226

Claim:
An interior rearview mirror system for a vehicle, said interior rearview mirror system comprising: an interior rearview mirror assembly comprising a mirror casing and a reflective element; wherein said reflective element provides a field of view rearward of the vehicle to a driver of the vehicle when said interior rearview mirror assembly is normally mounted in the vehicle and is adjusted to a viewing orientation; wherein a mounting structure mounts said interior rearview mirror assembly to an interior portion of the vehicle, and wherein said mirror casing is adjustable by the driver of the vehicle relative to the interior portion of the vehicle via at least one pivot element of said mounting structure to adjust the rearward field of view of said reflective element when said interior rearview mirror assembly is normally mounted in the vehicle; wherein said interior rearview mirror assembly comprises an application specific integrated compass chip; said application specific integrated compass chip comprising at least two magnetoresponsive sensing elements established on a semiconductor substrate; said application specific integrated compass chip further comprising associated circuitry commonly established with said magnetoresponsive sensing elements on said semiconductor substrate; wherein said application specific integrated compass chip has an area of less than approximately two square centimeters; wherein processing of an algorithm by a microprocessor of said interior rearview mirror system determines a directional heading of the vehicle responsive to a sensing of a magnetic field by said magnetoresponsive sensing elements and automatically compensates for a deviating magnetic field; and wherein an information display of said interior rearview mirror assembly displays the directional heading of the vehicle.