Patent ID: 7600878

Claim:
An interior rearview mirror system for a vehicle, said interior rearview mirror system comprising: an interior rearview mirror assembly; a mirror casing and a reflective element, said reflective element comprising a transflective reflective element having a transflective reflector that is partially transmitting of light therethrough and partially reflecting of light incident thereon; wherein said reflective element is at least 15 percent transmissive of visible light incident at a rear of said reflective element; an information display disposed behind said reflective element whereby information displayed by said information display is viewable through said transflective reflector by a driver of a vehicle when said interior rearview mirror assembly is normally mounted in the vehicle and when said information display is displaying information, and wherein said information display is substantially non-viewable through said tansflective reflector by the driver of the vehicle when said information display is not displaying information; 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 wherein said mirror casing is adjustable relative to a mounting structure that mounts said interior rearview mirror assembly to an interior portion of the vehicle, said mirror casing being adjustable to adjust the rearward field of view of said reflective element when said interior rearview mirror assembly is normally mounted in the vehicle; a compass sensor disposed behind said reflective element and in said mirror casing, said compass sensor comprising a sensing element and control circuitry established thereon, said sensing element comprising at least a first magnetoresponsive sensing element and a second magnetoresponsive sensing element; wherein said control circuitry is responsive to a sensing of a magnetic field by said first magnetoresponsive sensing element, and wherein said control circuitry is responsive to a sensing of a magnetic field by said second magnetoresponsive sensing element; wherein said control circuitry determines a directional heading of the vehicle responsive to said sensings by said first and second magnetoresponsive sensing elements, said control circuitry automatically compensating for a deviating magnetic field of the vehicle and generating a signal indicative of the directional heading of the vehicle; and wherein said information display displays said directional heading of the vehicle.