Abstract: Light sensors having a wide dynamic range are used in a variety of applications. A wide dynamic range light sensor includes an exposed photodiode light transducer accumulating charge in proportion to light incident over an integration period. Sensor logic determines a light integration period prior to the beginning of integration and the charge is reset. Charge accumulated by the exposed light transducer over the light integration period is measured and a pulse having a width based on the accumulated charge is determined.

Abstract: An electrochromic mirror is disclosed for use in a vehicle rearview mirror assembly having a light source positioned behind the electrochromic mirror for selectively projecting light through the mirror. The electrochromic mirror includes front and rear spaced elements each having front and rear surfaces and being sealably bonded together in a spaced-apart relationship to define a chamber, a layer of transparent conductive material disposed on the rear surface of the front element, at least one solution-phase electrochromic material contained within the chamber, and a second electrode overlying the front surface of the rear element in contact with the electrochromic material. The second electrode includes a layer of reflective material and a coating of electrically conductive material that is at least partially transmissive and is disposed over substantially all of the front surface of the rear element.

Abstract: Moisture detection permits moisture removal equipment, such as automotive windshield wipers and defogger systems, to be operated automatically. A system for detecting moisture on a surface includes a light emitter directed at the surface. The presence of moisture is based on the intensity of light from the emitter reflected by the surface and received by a light sensor. The light sensor accumulates charge in response to incident light over a variable integration period.

Abstract: An automatic vehicle headlamp dimming system which includes an optical system and an imaging processing system. The optical system is configured to discriminate between headlamps and tail lamps, and focus the light rays from the headlamps and tail lamps on different portions of a pixel sensor array. The optical system as well as the image processing system provides for relatively increased discrimination of headlamps and tail lamps of other vehicles and also enables the high beam headlamps of the control vehicle to be controlled as a function of the distance as well as horizontal angular position of other vehicles relative to the controlled vehicle.

Abstract: Moisture detection permits moisture removal equipment, such as automotive windshield wipers and defogger systems, to be operated automatically. A system for detecting moisture on a surface includes a light emitter directed at the surface. The presence of moisture is based on the intensity of light from the emitter reflected by the surface and received by a light sensor. The light sensor accumulates charge in response to incident light over a variable integration period.

Abstract: An imaging system for use in a vehicle headlamp control system includes an opening, an image sensor, a red lens blocking red complement light between the opening and the image sensor, and a red complement lens blocking red light between the opening and the image sensor. Each lens focuses light onto a different subwindow of the image sensor. The imaging system allows processing and control logic to detect the presence of headlamps on oncoming vehicles and tail lights on vehicles approached from the rear for the purpose of controlling headlamps. A light sampling lens may be used to redirect light rays from an arc spanning above the vehicle to in front of the vehicle into substantially horizontal rays. The light sampling lens is imaged by the image sensor to produce an indication of light intensity at various elevations. The processing and control logic uses the light intensity to determine whether headlamps should be turned on or off.

Abstract: Continuously variable headlamps offer greater flexibility for roadway illumination but offer challenges in automatic control design. Each continuously variable headlamp has an effective illumination range varied by changing at least one parameter from a set including horizontal direction aimed, vertical direction aimed, and intensity emitted. A system for automatically controlling continuously variable headlamps on a controlled vehicle includes an imaging system capable of determining lateral and elevational locations of headlamps from oncoming vehicles and tail lamps from leading vehicles. The system also includes a control unit that can acquire an image from in front of the controlled vehicle. The image covers a glare area including points at which drivers of oncoming and leading vehicles would perceive the headlamps to cause excessive glare. The image is processed to determine if at least one oncoming or leading is within the glare area.

Abstract: A control system for automatically detecting moisture on the windshield of a vehicle. The automatic moisture detecting system includes an optical system for imaging a portion of the windshield on to an image array sensor, such as a CMOS active pixel sensor. The voltages of each of the pixels which represents the illumination level is converted to a corresponding gray scale value by an analog digital converter. The gray scale values corresponding to the image are stored in memory. The spatial frequency composition of the gray scale values are analyzed to determine the amount of rain present. In order to provide a control signal to control the operation of the windshield wipers of the vehicle as a function of the amount of moisture present. The system is also adapted to detect the level of fog both on the interior of the windshield as well as the exterior of the windshield.

Abstract: A rearview mirror assembly is disclosed including a housing adapted to be mounted to the vehicle, a mirror disposed in the housing, at least one electrically powered device disposed in the housing, and a power supply for receiving power from a vehicle power source having a voltage in excess of about 24 V and for supplying power at a voltage of about 5 V or less to the electrically powered device. The electrically powered device and the power supply exhibit an electromagnetic interference level of less than about 41 dB&mgr;V/m for emissions in the frequency range from about 0.4 MHz to about 20 MHz. The mirror is preferably an electrochromic mirror, and the electrically powered device may be a control circuit for the electrochromic mirror.

Abstract: An automatic vehicle head lamp dimming system which includes an optical system and an imaging processing system. The optical system is configured to discriminate between head lamps and tail lamps and focus the light rays from the head lamps and tail lamps on different portions of a pixel sensor array. The optical system as well as the image processing system provides for relatively increased discrimination of head lamps and tail lamps of other vehicles and also enables the high beam head lamps of the control vehicle to be controlled as a function of the distance as well as horizontal angular position of other vehicles relative to the controlled vehicle.

Abstract: An electrochromic element driver has a feedback loop that imparts a negative output resistance wherein the drive voltage across the electrochromic element varies in response to changes in current draw by the electrochromic element. The amount of current drawn by the electrochromic element varies as a function of temperature. At high temperatures, the drive voltage increases, enabling the electrochromic element to darken uniformly at high temperatures. At lower temperatures, the drive voltage decreases, improving the useful life of the electrochromic element. Transitions between the opaque and non-opaque states are achieved quickly, and steady state currents are lower than in many conventional implementations, decreasing power consumption.

Abstract: A rearview mirror assembly is disclosed for use in a vehicle that includes a mirror housing, a mounting structure for pivotally mounting the mirror housing to the vehicle such that the mirror housing may be both vertically and horizontally tilted, a compass sensor disposed in the mirror housing and coupled to a compass processing circuit, and a tilt detector for detecting when the mirror housing has been tilted from a prior position and for generating and transmitting a tilt detection signal to the compass processing circuit. The compass processing circuit may then respond to the reception of the tilt detecting signal by compensating the compass reading and/or display or by recalibrating the compass.

Abstract: An imaging system for use in a vehicle headlamp control system includes an opening, an image sensor, a red lens blocking red complement light between the opening and the image sensor, and a red complement lens blocking red light between the opening and the image sensor. Each lens focuses light onto a different subwindow of the image sensor. The imaging system allows processing and control logic to detect the presence of headlamps on oncoming vehicles and tail lights on vehicles approached from the rear for the purpose of controlling headlamps. A light sampling lens may be used to redirect light rays from an arc spanning above the vehicle to in front of the vehicle into substantially horizontal rays. The light sampling lens is imaged by the image sensor to produce an indication of light intensity at various elevations. The processing and control logic uses the light intensity to determine whether headlamps should be turned on or off.

Abstract: A control system for automatically detecting moisture on the windshield of a vehicle. The automatic moisture detecting system includes an optical system for imaging a portion of the windshield on to an image array sensor, such as a CMOS active pixel sensor. The voltages of each of the pixels which represents the illumination level is converted to a corresponding gray scale value by an analog digital converter. The gray scale values corresponding to the image are stored in memory. The spatial frequency composition of the gray scale values are analyzed to determine the amount of rain present. In order to provide a control signal to control the operation of the windshield wipers of the vehicle as a function of the amount of moisture present. The system is also adapted to detect the level of fog both on the interior of the windshield as well as the exterior of the windshield.

Abstract: Continuously variable headlamps offer greater flexibility for roadway illumination but offer challenges in automatic control design. Each continuously variable headlamp has an effective illumination range varied by changing at least one parameter from a set including horizontal direction aimed, vertical direction aimed, and intensity emitted. A system for automatically controlling continuously variable headlamps on a controlled vehicle includes an imaging system capable of determining lateral and elevational locations of headlamps from oncoming vehicles and tail lamps from leading vehicles. The system also includes a control unit that can acquire an image from in front of the controlled vehicle. The image covers a glare area including points at which drivers of oncoming and leading vehicles would perceive the headlamps to cause excessive glare. The image is processed to determine if at least one oncoming or leading is within the glare area.

Abstract: A system and method is described for increasing effective integration time of an optical sensor including holding a first signal within each pixel cell, proportional to light integrated by the pixel cell over the previous frame period, generating a second signal within each pixel cell proportional to light integrated by the pixel cell over the current frame period, and summing the first signal and the second signal from each pixel, thereby producing an output signal representing the light integrated by each pixel over two frame periods.

Abstract: A control system is provided for controlling the energization of the headlamps on a first automotive vehicle, the headlamps being electrically energizable and each having a high beam state and a low beam state. The system includes means for collecting light emanating from a second vehicle and means for collecting ambient light. Sensing means is provided which is effective to selectively sense the intensity of the collected light emanating from the second vehicle and the collected ambient light. In addition, the system includes means controlling the state of the beams of the headlamps as a function of the sensed intensity of the beam of light emanating from said second vehicle, and means controlling the electrical energization of the headlamps as a function of the sensed ambient light.

Abstract: A control system for controlling an image array sensor and controlling communication between the image array sensor and a microcontroller by way of a serial communication interface. The control system is able to efficiently control various aspects of the image array sensor such as windowing, mode of operation, sensitivity as well as other parameters in order to reduce the data throughput. An important aspect of the invention relates to the fact that the control circuit can be rather easily and efficiently configured in CMOS with rerlatively few output pins which enables the control circuit to be rather easily and efficiently intergrated with CMOS based image array sensors and even the microcontroller to reduce the part count and thus, the overall cost of the system.

Abstract: A control system for automatically detecting moisture on the windshield of a vehicle. The automatic moisture detecting system includes an optical system for imaging a portion of the windshield on to an image array sensor, such as a CMOS active pixel sensor. The voltages of each of the pixels which represents the illumination level is converted to a corresponding gray scale value by an analog digital converter. The gray scale values corresponding to the image are stored in memory. The spatial frequency composition of the gray scale values are analyzed to determine the amount of rain present. In order to provide a control signal to control the operation of the windshield wipers of the vehicle as a function of the amount of moisture present. The system is also adapted to detect the level of fog both on the interior of the windshield as well as the exterior of the windshield.

Abstract: An improved alarm system particularly adapted for use in attracting the attention of hearing impaired persons and/or for use in attracting the attention of persons in high decibel areas, it being understood that the system is applicable to other uses. The system incorporates an improved light reflector and improved Fresnel lenses which cooperate with a flash tube whereby the system projects as much of the available light as possible into a predetermined profile so that UL requirements are met with a minimum of wasted light.