Patent ID: 7329013

Claim:
An interior rearview mirror system for a vehicle, said interior rearview mirror system comprising: an interior rearview mirror assembly; a casing having a reflective element; said casing being adjustable relative to a mounting structure that mounts said interior rearview mirror assembly to an interior portion of the vehicle; a compass sensor having a first magnetoresponsive sensing element and a second magnetoresponsive sensing element, said compass sensor being disposed within said mirror casing; a control, said control receiving a first signal indicative of a magnetic field sensed by said first magnetoresponsive sensing element, said control receiving a second signal indicative of a magnetic field sensed by said second magnetoresponsive sensing element; said control determining a directional heading of the vehicle based on said first and second signals, said control automatically compensating for a deviating magnetic field of the vehicle and generating a signal indicative of the directional heading of the vehicle; and said control determining that said casing is adjusted by an occupant of the vehicle in response to a change in said first and second signals being indicative of an abrupt movement of said casing about said mounting structure by an occupant of the vehicle, said control being operable to enter a rapid compensating mode to compensate for the mirror adjustment in response to said control determining that said casing is adjusted by an occupant of the vehicle.