Patent ID: 8258433

Claim:
An interior rearview mirror assembly suitable for use in a vehicle, said interior rearview mirror assembly comprising: an electro-optic reflective element comprising a front substrate and a rear substrate and an electro-optic medium disposed therebetween; wherein said front substrate has a first surface and a second surface, said second surface having a transparent second surface electrically conductive coating disposed thereon; wherein said rear substrate has a third surface and a fourth surface, said third surface having a third surface transflective metallic reflector disposed thereon; a photo sensor disposed behind said fourth surface of said rear substrate and operable to detect light passing through said third surface transflective metallic reflector and said electro-optic reflective element; and a light concentrator disposed between said photo sensor and said fourth surface of said rear substrate, wherein said light concentrator receives light passing through said third surface transflective metallic reflector of said electro-optic reflective element and concentrates light onto a light sensing surface of said photo sensor.