Control system for automatic rearview mirrors
First Claim
1. An electronic control system for controlling a reflective state of an automatic rearview mirror for an automotive vehicle, said system including a rearview mirror comprising an electrochromic variable reflectance mirror element the reflectivity of which varies over a reflectance range as a function of electrical signal levels applied thereto, first sensing means effective to sense the ambient light level and produce a first electrical signal which is at least in part logarithmically related to the sensed ambient light level, second sensing means effective to sense glare causing light level and produce a second electrical signal which is at least in part logarithmically related to the sensed glare causing light level, means to combine signals derived from said first and second electrical signals to produce at least a third electrical signal which is at least in part indicative of the severity of the glare, and means responding at least in part to said third electrical signal to control the reflective state of said mirror element.
1 Assignment
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Accused Products
Abstract
An improved electronic control system for controlling the reflective state of automatic rearview mirrors for automative vehicles, the system including an electrochromic variable reflectance mirror element the reflectivity of which varies over a reflectance range as a function of electrical signal levels applied thereto. The system also includes a first sensing means effective to sense the ambient light level and produce a first electrical signal which is at least in part logarithmically related to the sensed ambient light level. A second sensing means is also provided which is effective to sense the glare causing light level and produce a second electrical signal which is at least in part logarithmically related to the sensed glare causing light level. Means is provided in the control system for combining the signals derived from the first and second electrical signals to produce a third electrical signal which is at least in part indicative of the severity of the glare, and the system also includes improved means which in response to the third electrical signal controls the reflective state of the electrochromic mirror element.
533 Citations
46 Claims
- 1. An electronic control system for controlling a reflective state of an automatic rearview mirror for an automotive vehicle, said system including a rearview mirror comprising an electrochromic variable reflectance mirror element the reflectivity of which varies over a reflectance range as a function of electrical signal levels applied thereto, first sensing means effective to sense the ambient light level and produce a first electrical signal which is at least in part logarithmically related to the sensed ambient light level, second sensing means effective to sense glare causing light level and produce a second electrical signal which is at least in part logarithmically related to the sensed glare causing light level, means to combine signals derived from said first and second electrical signals to produce at least a third electrical signal which is at least in part indicative of the severity of the glare, and means responding at least in part to said third electrical signal to control the reflective state of said mirror element.
- 33. An automatic rearview mirror for automotive vehicles, said mirror including an electrochromic reflective element the reflectivity of which varies as a function of electrical signal levels applied thereto, a first photodiode sensing means effective to sense the ambient light level and generate a first electrical signal indicative of the ambient light level, a second photodiode sensing means effective to sense glare causing light level and generate a second electrical signal indicative of the glare causing light level, first circuit means associated with said first sensing means and including low level signal processing means for said first electrical signal, second circuit means associated with said second sensing means and including low level signal processing means for said second electrical signal, means interconnecting said first and second circuit means, and means at least partially included in the circuit formed from the combined first and second circuit means and effective to create a third electrical signal which is at least partially dependent on said first and second electrical signals and which is effective at least in part to determine the reflectance of said reflective element.
- 43. An automatic rearview mirror system for automotive vehicles, said system including first and second electrochromic reflective elements the reflectivity of each of which varies over a reflectance range as a function of electrical signal levels applied thereto, first circuit means in series with said first reflective element and effective to create a first voltage drop, second circuit means in series with said second reflective element and effective to create a second voltage drop which is not always equal in value to the first voltage drop, the first and second voltage drops differing in a manner which results in a predetermined difference in the voltage applied to said first and second mirror elements.
Specification