Patent ID: 7988308
Filing Date: 2011-08-02
Classification: B60R

Abstract:
1. A vehicle rearview mirror control system comprising: an interior rearview mirror element able to be varied in reflectance; an exterior rearview mirror element able to be varied in reflectance mounted in an exterior rearview mirror housing; an ambient light sensor (ALS) positioned to detect a light intensity from a direction forward of the interior rearview mirror element; a glare light sensor positioned to detect a light intensity from a direction rearward of the interior rearview minor element; a register for storing predetermined electronically encoded window tinting information; a drive circuit coupled to the exterior rearview mirror element for generating a glare signal derived from the ALS and glare light sensor and selectively varying a drive signal to the exterior rearview mirror element as a function of the glare signal based upon the predetermined electronically encoded window tinting information; and wherein the reflectance of the interior rearview mirror element begins to decrease based on a first minimum light intensity detected by the glare light sensor and the reflectance of the exterior rearview mirror element begins to decrease based on a second minimum light intensity detected by the glare light sensor and the first minimum light intensity is different from the second minimum light intensity thereby allowing reflected light levels at a predetermined reference point to be approximately equal.