Single sensor adaptive drive circuit for rearview mirror system
First Claim
1. An automatic rearview mirror system for a vehicle comprising:
- a reflective element that is actuatable between at least two different reflectance conditions;
a single light sensing means for sensing light incident to said reflective element; and
processing means responsive to said light sensing means for producing a slow-transient indication as a function of said light incident to said reflective element and for indicating a desired reflectance level of said reflective element as a function of said slow-transient indication and said light incident to said reflective element.
1 Assignment
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Accused Products
Abstract
An automatic rearview mirror system having a reflective element that is actuatable between at least two different reflective conditions by a control that discriminates between glare-causing and nonglare-causing light simultaneously sensed by a single light sensor. The control includes a processor that is more responsive to decreasing levels of light than to increasing levels of light to produce a signal that is indicative of the slow-transient characteristic of the light sensed by the single light sensor. The processor may include a very slow signal processor that is always operative and a somewhat faster-slow signal processor, which may be selectively inhibited when the mirror is fully colored, or when a differential circuit indicates that the difference between the glare and the non-glare light sensed by the light sensor exceeds a predetermined level. The differential circuit may additionally limit the differential between the glare and the nonglare lights sensed by the light sensor.
815 Citations
33 Claims
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1. An automatic rearview mirror system for a vehicle comprising:
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a reflective element that is actuatable between at least two different reflectance conditions; a single light sensing means for sensing light incident to said reflective element; and processing means responsive to said light sensing means for producing a slow-transient indication as a function of said light incident to said reflective element and for indicating a desired reflectance level of said reflective element as a function of said slow-transient indication and said light incident to said reflective element. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An automatic rearview mirror system for a vehicle comprising:
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a reflective element that is actuatable between at least two different reflectance conditions; a single light sensor that is responsive to light incident to said reflective element and adapted to produce a light signal; processing means responsive to said light sensor for producing a slow-transient signal as a function of said light signal; and means responsive to said light sensor and said processing means for indicating a desired reflectance level of said reflective element as a function of said slow-transient signal and an unprocessed value of said light signal. - View Dependent Claims (8, 9, 10, 11, 12, 13)
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14. An automatic rearview mirror system for a vehicle comprising:
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a reflective element actuatable between at least two reflective conditions; a single rearward facing light sensor that is responsive to light incident to said reflective element for producing a light signal; processing means for processing said light signal to produce a slow-transient signal, wherein said processing means is more responsive to levels of said light signal indicative of lower light levels, than to levels of said light signal indicative of higher light levels; and desired reflectance level circuit means responsive to said light sensor and said processing means for providing an indication of a desired reflectance level for said reflective element as a function of said slow-transient signal and an unprocessed value of said light signal. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23)
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24. An automatic rearview mirror system for a vehicle comprising:
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a reflective element that is actuatable between at least two reflectance conditions; a single light sensing means responsive to light incident to said reflective element for producing a light signal; processing means for processing said light signal to produce a slow-transient signal, wherein said processing means processes decreases in said light signal at a faster rate than said processing means processes increases in said light signal; and desired reflectance level circuit means responsive to said light sensing means and said processing means for providing an indication of a desired reflectance level for said reflective element as a function of said slow-transient signal and an unprocessed value of said light signal. - View Dependent Claims (25, 26, 27, 28, 29, 30, 31, 32, 33)
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Specification