Abstract: A drive circuit for the interior, and one or more of the exterior, mirrors in a vehicle mirror system provides a drive signal to each of the mirrors to establish the reflectance level of that mirror. Circuit protection is provided to sense a fault condition on one of the electrical conductors extending to the exterior mirrors and to take corrective action in response to a fault condition. The circuit protection may also respond to a fault condition in the electrical supply of the drive circuit and take suitable corrective action. In certain embodiments, each mirror in the mirror system is responsive to one of a plurality of output amplifiers, which is responsive to a distinct desired reflectance signal level in order to color that mirror to a reflectance level that is distinct from that of the other mirrors.

Abstract: A rearview mirror system for a vehicle having a reflective element with a reflective surface and a variable light transmission element includes an optical display device behind the reflective element in order to produce a visual display to the driver. A control is provided having a light sensor that senses light conditions in the vicinity of the vehicle and produces a continuously variable light signal indicative of such sensed light conditions. The control further includes a drive circuit that is responsive to the light signal in order to supply a drive signal to the reflective element and thereby establish the light transmission level of the light transmission element. The control further includes an intensity control circuit that varies the intensity of the optical display as a function of the value of the sensed light in the vicinity of the vehicle in order to accommodate physiological changes in the driver's eyes.

Abstract: A rearview mirror system for a vehicle having a reflective element with a reflective surface and a variable light transmission element includes an optical display device behind the reflective element in order to produce a visual display to the driver. A control is provided having a light sensor that senses light conditions in the vicinity of the vehicle and produces a continuously variable light signal indicative of such sensed light conditions. The control further includes a drive circuit that is responsive to the light signal in order to supply a drive signal to the reflective element and thereby establish the light transmission level of the light transmission element. The control further includes an intensity control circuit that varies the intensity of the optical display as a function of the value of the sensed light in the vicinity of the vehicle in order to accommodate physiological changes in the driver's eyes.

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.

Abstract: A control for a moisture sensing assembly, adapted for mounting on the inner surface of a vehicle window or windshield to control vehicle accessories such as windshield wipers, maximizes the window area being sensed in relationship to the size of the assembly and provides immunity to interference from environmental influences. In the preferred embodiment, moisture on the outer window surface is detected by first and second moisture sensors each including infrared energy radiating diodes and radiant energy detectors which detect and process radiant energy to produce a moisture signal that is a function of the moisture on the window. A synchronizing circuit intermittently actuates the radiating diode for the two sensors individually and alternatingly at equally-spaced intervals.

Abstract: An adaptive moisture sensor system includes a moisture sensor unit having a moisture sensor, which produces a moisture signal, a reference signal generating circuit and a comparator circuit for comparing the moisture signal with the reference signal and for producing an indication to the vehicle's wiper control of the relationship between the signals. The reference signal generating circuit indicates a fast positive signal processing circuit for rapidly processing changes in the moisture signal representing decreasing moisture and a slow signal processing circuit to process changes of the moisture signal in both directions at a slow rate. The fast positive signal processing circuit is only enabled during rain conditions due to a contaminant film on the sensed window.

Abstract: A moisture sensing assembly for controlling vehicle accessories such as windshield wipers is mounted on the inner surface of a vehicle window or windshield for detecting moisture on the outer window surface. A plurality of infrared energy emitting diodes and a sensor for receiving reflected infrared energy from the window and any moisture thereon are mounted at predetermined angles and spacing in a support. The support is biased against the window and enclosed in a protective housing detachably mounted to a window mounted plate preferably adjacent a rearview mirror on the front windshield. The support preferably includes an infrared energy monitoring sensor adjacent the emitting diodes which may be combined with or separate from an ambient infrared energy sensor. The monitoring and ambient sensors provide reference energy levels allowing compensation for varying diode output due to temperature and age and varying external vehicle light conditions.

Abstract: The specification discloses a modulated optical moisture sensor control circuit for a vehicle windshield wiper. The control system includes a first detector providing a signal indicative of moisture on the windshield and a second detector providing a reference signal indicative of system variables, such as ambient light. The control system includes improved circuitry for separating the steady-state portion of each detector signal due to ambient light from the modulated infrared IR signal. The system further includes a sensitivity adjustment accessible by the vehicle operator to alter the sensitivity of the circuit to at least one of the two variable detector signals. Additionally, the control system cooperates with a conventional off/intermittent/on wiper switch so that the wiper is responsive to the moisture sensor only when the conventional switch is in the intermittent position and a second manually actuated switch indicates preferred operation in the moisture sensor mode.