Abstract: An automatic switching device for flourescent light has a light sensing element that reacts to ambient light and a switching unit designed to react to an output signal from the light sensing element and to activate or deactivate the flourescent light. The switching unit has a reference threshold generator. The flourescent light is activated or deactivated depending on whether the output signal from the light sensing element exceeds or falls below a threshold generated by the reference threshold generator and the threshold level depends on the luminosity sensed by the light sensing element. The switching unit further includes a delay designed for preventing signal processing by the switching unit for a present period of time upon switching on of the flourescent light.

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 system is disclosed for sensing selected conditions particularly adjacent to an unoccupied commercial business building and taking the appropriate action. Corrective action may include shutting down a system, sending a signal to an occupied location for evaluation of the selected abnormal condition, or making a record of the abnormal condition for rectification at a later time. The system includes one or more light level sensors including microcomputer controlled photocell units directed to observe the light level at selected locations and to transmit signals indicating sensed light values below a desired value, and includes a receiver receiving the transmitted signals and which responds to such signals to produce a correction signal. If the commercial establishment is a bank and the light level is at an ATM (automatic teller machine) the system may respond to the correction signal by temporarily shutting the ATM machine down and illuminating a sign to indicate that the ATM is not open.

Abstract: A device and method permits detecting, measuring, and recording the intensity of radiation corresponding to a green plant's photoactive spectrum striking a selected site, and utilizing such information alphanumerically and graphically displaying the photoactive radiation exposure in sols incident at the site during a particular portion of a day, an entire day, a week, or an month. The photoactive radiation information provided by the invention device allows gardeners, farmers, researchers and others to match the types of trees, shrubs, crops or other plants that would grow best under the radiation conditions usually incident at the site over a desired, extended time period.

Abstract: A light sensitive dimmer switch circuit for controlling the illumination level of a light as a function of the ambient illumination level surrounding the dimmer switch circuit by selectively controlling an AC power signal provided to the light includes a photocell and a phase control circuit. The photocell is responsive to the ambient illumination level and has a conduction state associated therewith. The conduction state changes, in response to the ambient illumination level, such that the photocell effectively exhibits either a substantially open circuit or a substantially short circuit. The phase control circuit selectively varies a conduction phase angle associated with the AC power signal which correspondingly causes a variation in the illumination level of the light.

Abstract: A vehicle headlamp control method and apparatus includes providing an imaging sensor that senses light in spatially separated regions of a field of view forward of the vehicle. Light levels sensed in individual regions of the field of view are evaluated in order to identify light sources of interest, such as oncoming headlights and leading taillights. The vehicle's headlights are controlled in response to identifying such particular light sources or absence of such light sources. Spectral signatures of light sources may be examined in order to determine if the spectral signature matches that of particular light sources such as the spectral signatures of headlights or taillights. Sensed light levels may also be evaluated for their spatial distribution in order to identify light sources of interest.

Abstract: A solar sensor for a vehicle that is incorporated as part of the vehicle climate control system is disclosed. The solar sensor include a photo diode assembly including a sensing surface. The photo diode assembly is mounted on a horizontally extending portion of a dashboard of a vehicle with the sensing surface oriented substantially parallel to the plane that an occupant's body lies within when seated in the vehicle. The sensing surface is preferably oriented within a range of between about 16.degree. and 40.degree. above horizontal toward the front of a vehicle. Optimally, the sensing surface is oriented at an angle of 28.degree. above horizontal relative to the front of the vehicle. The photo diode assembly includes a housing having a base surface mounted to the dashboard that is configured to hold the sensing surface of the photo diode in the desired angular orientation.

Abstract: A system for automatic regulation of daylight admitted by a window in the presence of artificial illumination produced by a high-efficiency (e.g., fluorescent-type) electric lamp. A preferred embodiment, adaptive window covering system 10, consists of an illuminance sensor 11, a conventional control apparatus 12, and a conventional shading means 13. System 10 is used in conjunction with a conventional, high-efficiency, electric lamp 14 and a conventional window 18, in a room 19.Sensor 11 produces a signal dependent on power contained in a portion of the daylight spectrum, but substantially insensitive to power contained in the spectrum of artificial illumination produced by lamp 14. In a preferred embodiment, sensor 11 includes a silicon photodiode and optical low-pass filter to provide a spectral response which extends from approximately 800 to 1200 nanometers, which falls outside the spectrum produced by typical fluorescent lamps (e.g, 300 to 750 nanometers).

Abstract: A thermostat for controlling the actuation of a heating, ventilation and air conditioning system includes a light discriminator that determines the occupancy of an occupancy space by sensing the presence of artificial light and adjusts the temperature set point of the thermostat accordingly. The light discriminator includes a photodetection device, such as a photodiode, that provides an output current that is proportional to the radiant flux of the ambient light of the occupancy space where it is mounted. A filter circuit cancels the undesirable frequency components of the output signal of the photodiode, such as the frequency components associated with sunlight. The filtered signal is therefore representative of the artificial light used to illuminate the occupancy space. A controller adjusts the temperature set point of the thermostat in response to the filtered signal.

Abstract: A screening device (3) for screening exterior light (2) which illuminates a room (1), is controlled such that in the room on the one hand, user comfort with regard to freedom from dazzling and room temperature is optimal and, on the other hand, energy consumption for artificial lighting within the room or for heating and cooling the room is minimized.

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: An illumination control system uses two photocells, one directed toward an illuminated lamp and the other directed from the ceiling downwardly into the illuminated zone. A feedback signal is derived from the two photocell signals and a reference intercept signal. The feedback signal and a reference set point signal are input into an error amplifier. The error amplifier generates a control signal for setting the illumination in controlled lamps. The photocell signals are variously scaled to provide balancing between them and matching with the intercept signal. Scaling factors and intercept signal level arc set in a calibration procedure that establishes feedback circuit response consistent with a design set point transfer function.

Abstract: A light level sensor for use in controlling the switching of artificial lighting. The sensor comprises a photoelectric transducer which provides an output signal at a level which is significant of the illumination level of incident light. An A-D converter and a microprocessor are located in circuit with the transducer for detecting the level of the transducer output signal and for any cyclic variation of the transducer output signal resulting from cyclic variation of the level of incident light. Further circuit means are provided for generating a sensor output signal if either (a) the level of the transducer output signal is below a predetermined level or (b) the level of the output signal is above the predetermined level and, at the same time, cyclic variations occur in the level of the transducer output signal.

Abstract: A portable directional multi-channel receiver comprises a non-visual communicator, a self-contained source of electrical energy, a detector for receiving an amplitude modulated lightwave signal with at least two different frequency modulated subcarrier frequencies, and electronics converting the received signals into intelligible non-visual communication emanating from the communicator both in the presence and in the absence of an ambient background of light energy, such as sunlight. The device is adapted for use by the visually impaired, as well as those who are not fluent in the relevant printed language, in finding desired locations from which suitable modulated infrared signals are emitted.

Abstract: A system and method for optimizing the signal range of a photocell for all ambient lighting conditions. A switched resistor circuit is serially connected to the photocell. The duty cycle of the switched resistor circuit is controlled to provide an optimal signal range for the photocell in both light and dark ambient light conditions.

Abstract: A system having a sensor, a feedback loop comprising a controllable load and an integrator, and a comparator. The light filter is matched to the sensor to allow enough light to be sensed while appearing dark. Current produced by the sensor is received by the controllable load, across which a voltage is detected. Upon a relative change in light intensity, a difference between the detected voltage and a reference voltage is integrated by the integrator over an integration time to produce a feedback signal. The feedback signal completes the feedback loop by controlling the controllable load's impedance and adjusting the value of the detected voltage back to the value of the reference voltage. Thus, relative changes in light intensities are detected while thereafter adjusting to the ambient light conditions. When the difference between the detected voltage and the reference voltage is greater than a preset value, the comparator alters an output voltage.

Abstract: The present invention relates to an electronic shelf display device which includes an optical device and an ambient light detector circuitry. The electronic shelf display device includes an independent power source, and a housing. The electronic shelf display device also includes a processor disposed in the housing, and a display device supported by the housing and coupled to the processor. The display device is capable of displaying information to a user. The optical device is coupled to the processor for at least receiving optical communications. The ambient light detector circuitry is also coupled to the processor. The processor is operative to regulate the power state of the electronic shelf display device based on ambient lighting conditions determined by the ambient light detector circuitry. By having the optical device include the ambient light detector, only one port is required for receiving light by the electronic shelf display device thus resulting in substantial space savings.

Abstract: A photoelectric load control system for applying power to a light or load as a function of ambient light level and as a function of the length of daylight or darkness. The system includes a switching circuit for selectively applying power to the light or load for turning the light or load on and off; an ambient light level sensor for providing a signal which varies between a first state and a second state in response to the ambient light level; and a uniquely programmed processor responsive to this signal for activating the switching circuit.

Abstract: A lighting system having at least one light source for supplying artificial light and a control unit for controlling the light source. The light source is of the type having an adjustable color temperature. The control unit is provided with a control signal form a signal from a signal generator. The signal generator is dependent on the mean daylight level. The control unit is arranged to adjust the color temperature of the light source in dependence on a predetermined relationship between the mean daylight level and the color temperature of the artificial light. The lighting system will provide artificial light which will when the daylight level, as measured on an office desk, increases from approximately 400 lux to approximately 800 lux, increase the color temperature from approximately 3300 K to approximately 4300 K.

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: A sensor implemented with a single light sensing device detects ambient light levels and object motion. The sensor comprises an optical component assembly composed of a linear array of light sensitive elements, preferably photodiodes, positioned downstream of a segmented slit aperture device comprising a single, segmented slit, the slit length of which is oriented perpendicular to the length of the linear array. The individual photodiodes of the array provide motion detection capability in a direction perpendicular to the slit length. The slit aperture is segmented along the slit length to form multiple zones of sensor light responsivity that provide motion detection capability in a direction parallel to the slit length. An object moving in a direction parallel to the multiple slit aperture passes through one or more zones of sensor responsivity and thereby produces from the photodiodes a varying electrical signal from which object motion can be detected.

Abstract: A color printing system includes a central processing unit for generating color image data, a color monitor for displaying color image data generated by the central processing unit and a color temperature sensing device for sensing color temperature of viewing light in which color images displayed on the monitor and color images printed by the printer are viewed. A first light source has a light output intensity controllable by the central processing unit. The central processing unit is adapted to control the intensity of the first light source in accordance with the color temperature sensed by the sensing device so as to match the color temperature sensed by the sensing device to a potential color temperature. Additionally, a second light source may be provided. The second light source has a different color temperature than the first light source and the central processor can adjust the intensity of the first and second light source based on relative color temperatures.

Abstract: An anti-burn device which can prevent a floor lamp from burning material covering thereon is disclosed. The anti-burn device includes a photoresistor and a detecting control circuit. The photoresistor has a photo-sensitive surface receiving light reflected back to the floor lamp. When the photoresistor receives the reflected light, the detecting control circuit will cut off the power supply to the halogen bulb. Therefore, burning of the material draped on or against the floor lamp can be avoided.

Abstract: Apparatus for monitoring and controlling the operation of one or more high intensity discharge (HID) lamps. An electronic HID lamp power supply is electrically connected to a power source and to the HID lamps. For each lamp, one or more sensors produce one or more output signals respectively representative of one or more parameters (such as light intensity, color temperature, power consumption, temperature, arc voltage, etc.) which respectively define one or more operational characteristics of the lamps.

Abstract: An automatic lighting control device installed in a decorative light string is controlled by the intensity of ambient light detected by a photo-electric control device, the latter being shaped like a lamp bulb. The device includes hollow base installed in a lamp socket of the decorative light string which holds the photo-electric control device. The base has a ring contact and a tip contact insulated from the ring contact for connection to the two opposite terminals of the lamp socket. A cover is located on the base and a transparent cap is fastened to the cover to let outside light pass to the photoelectric control device.

Abstract: A timing device which is associated with a light level sensor and which is arranged to provide a time-out signal to a relay after a predetermined time has elapsed following detection of a low light condition and initial energization of the relay. The device provides for synchronization of an initiation time T.sub.1 and, hence, a time-out signal generating time T.sub.2 with respect to a periodically occurring event time T.sub.3 (for example, sunset time) in order that the desired time of generating the time-out signal might be re-established following interruption of power to the device. Should loss of power occur, the last entered event time T.sub.3 is employed to synchronize the initiation time T.sub.1 and, hence, the signal generating time T.sub.2, when detection of a predetermined light level next occurs following re-establishment of power to the device.

Abstract: A device controller synchronizes a counter to the detection of sunrise or sunset by photoelectrically sensing daylight, thereby establishing an approximate time reference for scheduling the timing of device activations to occur at any time of day or night. An uncalibrated method of measuring sunlight yields more reliable scheduling, relative to sunrise and sunset events. The integral approximate time reference is kept synchronized, even if occasional faults in detection of sunrise or sunset occur. The rules employed to establish and maintain synchronization, and the dynamically variable rules for evaluating changes in light intensity, contribute to the reliable performance of the controller apparatus. Inherently self-adapting and automatic, a potentiometer for setting a time parameter input and a push-button for setting a time parameter input are combined in the apparatus in such a way to yield further utility without complicating the programmability.

Abstract: A regulating apparatus for a motor vehicle air conditioner which automatically influences a cab temperature set by a vehicle operator dependent upon sunshine striking the vehicle, wherein, an intensity of sun rays is determined from, an intensity of daylight brightness and an intensity of an infrared portion of the daylight. The daylight is led to one or more sensors by one or more light conductors.

Abstract: A halogen torchiere lamp comprises a grid-like guard arranged across the lampshade opening for preventing flammable material from making contact with the hot glass shield of the bulb or the bulb itself. A temperature sensor is installed within the lampshade near the bulb to sense the rise in ambient temperature within the lampshade should its opening be covered by any material. The sensor comprises a thermostat that de-energizes the bulb when the sensed ambient temperature reaches a predetermined value. The sensor may also comprise a thermistor that operates the dimmer switch of the lamp to dim the bulb when the sensed ambient temperature reaches a predetermined value. The sensor may further comprise a photocell-powered thermistor that varies the bias of a transistor, which in turn causes the bulb to dim, thereby lowering the ambient temperature within the lampshade.

Abstract: A vehicle headlamp control method and apparatus includes providing an imaging sensor that senses light in spatially separated regions of a field of view forward of the vehicle. Light levels sensed in individual regions of the field of view are evaluated in order to identify light sources of interest, such as oncoming headlights and leading taillights. The vehicle's headlights are controlled in response to identifying such particular light sources or absence of such light sources. Spectral signatures of light sources may be examined in order to determine if the spectral signature matches that of particular light sources such as the spectral signatures of headlights or taillights. Sensed light levels may also be evaluated for their spatial distribution in order to identify light sources of interest.

Abstract: A timed photocell switching circuit is disclosed which senses a light-to-dark transition and applies power to a lamp load for a preset period of time. After the preset period has expired the timed photocell circuit turns the lamp load off for the remainder of the night until a dark-to-light transition resets the circuit after which it can be triggered for another timing cycle. Once the light-to-dark transition triggers the timing cycle the ambient light level cannot disrupt the circuit. In addition, the circuit can be reset regardless of its timing position by momentarily cycling power to the circuit.

Abstract: A light sensitive dimmer switch circuit for controlling the illumination level of a light as a function of the ambient illumination level surrounding the dimmer switch circuit by selectively controlling an AC power signal provided to the light includes a photocell and a phase control circuit. The photocell is responsive to the ambient illumination level and has a conduction state associated therewith. The conduction state changes, in response to the ambient illumination level, such that the photocell effectively exhibits either a substantially open circuit or a substantially short circuit. The phase control circuit selectively varies a conduction phase angle associated with the AC power signal which correspondingly causes a variation in the illumination level of the light.

Abstract: A night light device provides a low level illumination using electro-phosphorescent lighting which is automatically turned on when motion near the device is detected by the device and if the ambient lighting level is low. When the ambient light level is above a specified level so that it is possible to see without artificial light, the device is inactive. A high intensity lighting feature allows the device to be used as a flashlight in emergencies since the device is fastened to a wall in such a way that it is easily and quickly removed. The front face of the device provides a downwardly directed surface for projecting light toward the floor, and sideways directed surfaces for projecting light to each side. Spherical Fresnel lenses enable the device to detect motion over a 180 degree azimuth. The device may have phosphorescent doping within its case structure so as to provide a dim light even when not energized.

Abstract: Described are apparatus for transmitting light wave signals, the apparatus being capable of adjusting their signal strength to automatically adapt to changes in the ambient light conditions of their surrounding environment. In one embodiment, the apparatus for transmitting lightwave signals comprises (a) an emitter for sending a frequency modulated lightwave signal of variable intensity, (b) a light energy receiver for detecting a change in the level of surrounding ambient light energy and for producing a response to such change in proportion to the change detected, and (c) a controller for adjusting, directly or indirectly, the frequency modulated lightwave signal in response to the light energy receiver response to the change detected. Audio transmission systems employing apparatus of this invention are also described.

Abstract: A continuously active artificial light source, such as a light-emitting diode (LED), is supported in a housing that also contains a photocell, and is directed at the operating detection surface of the photocell. A light-transmitting diffuser, such as made of translucent plastic, covers the detection surface of the photocell and allows ambient light to pass to the surface, which thereby detect a combination of external ambient light and light from the artificial source. The light source thereby biases the photocell, so that, in normal operation, the photocell produces an output voltage that does not exceed a predetermined value. The predetermined value is set at a level approximating the output voltage measured during total darkness outside the photocell housing. If an open-circuit condition occurs, the voltage of the photocell will exceed that predetermined value, thus permitting the checking circuit to recognize a faulty photocell.

Abstract: Dimmable fluorescent lamp apparatus includes a dimming control element housed in an integral adapter having a base which installs directly on an existing incandescent or other lighting fixture. The adapter mounts a fluorescent illumination element either fixedly or removably and replaceably. The lamp apparatus includes a manually accessible adjustment element connected with the control element and mounted on the adapter. The adjustment element can be an electrical adjustment element or an optical adjustment element.

Abstract: A lighting system having at least one light source for supplying artificial light and a control unit for controlling the light source. The light source is of the type having an adjustable color temperature. The control unit is provided with a control signal from a signal generator. The signal generator is dependent on the mean daylight level. The control unit is arranged to adjust the color temperature of the light source in dependence on a predetermined relationship between the mean daylight level and the color temperature of the artificial light. The lighting system will provide artificial light which will when the daylight level, as measured on an office desk, increases from approximately 400 lux to approximately 800 lux, increase the color temperature from approximately 3300 K to approximately 4300 K.

Abstract: A proximity detector and ambient light monitor (PALM) is provided, comprising a light source for generating an optical composite signal, a light detector for providing a detected signal, a circuit for separating the ac component from the detected signal, and a switch for providing a control signal when the ac component is outside a preset range. The PALM further comprises an ambient light detector which also receives the detected signal and provides an ambient light level signal. The ambient light detection circuit rejects the signals that relate to the proximity monitoring and provides sufficient gain to overcome daylight filtering lens currently provided on the light detectors. The ambient light monitoring circuit provides either a continuous varying voltage proportional to the ambient light, or a simple binary signal indicating that the light is above a threshold.

Abstract: An improved wall plate incorporating an electroluminescent lamp for providing illumination to the immediate area proximate the wall plate. The electroluminescent (EL) panel is activated and deactivated by a photoconductive cell, in response to the intensity of ambient light falling on the wall plate. A further embodiment provides for an easily accessible regulating means for regulating the intensity of the light emitted by the EL panel.

Abstract: A vehicle structural accessory includes one or more electronic accessories. One electrical accessory which may be provided is an electronically trainable transmitter which is trainable to generate a control signal which will actuate a garage door opening mechanism. Another electronic accessory which may be included is an electronic compass. Yet another device is an electronically adjustable mirror having parameters set for each driver of a vehicle. The electronically adjustable rearview mirror and the electronically trainable garage door opener may be advantageously provided with a keyless entry system.

Abstract: An artificial lighting system comprises a daylight sensor for sensing a level of daylight, artificial light source means for providing a level of artificial light, daylight control means for control of the level of daylight and a controller for control of the level of artificial light dependent on the sensed level of daylight. The controller decreases the level of artificial light with increasing level of daylight when the sensed daylight level is below a threshold, and reduces the amount of daylight through control of the daylight control means when the sensed daylight level is above the threshold.

Abstract: Described is a portable directional receiver. It comprises a non-visual communicator, a self-contained source of electrical energy, a detector for receiving a sensed continuous frequency modulated infrared signal, and electronics converting the sensed signal into intelligible non-visual communication emanating from the communicator both in the presence and in the absence of an ambient background of light energy, such as sunlight. The device is adapted for use by the visually impaired in finding desired locations from which suitable modulated infrared signals are continuously emitted.

Abstract: A system for the automatic operation of window coverings which is responsive to the presence of artificial illumination. A preferred embodiment, automatic window covering system 10, consists of a conventional optical flicker detector 11, a conventional control apparatus 12, and a conventional motorized window covering 13. Control apparatus 12 and motorized window covering 13 constitute an automatic window covering system capable of regulating the illumination passing through a host window, and of operating in a plurality of modes, including a thermal management mode (the object of which is to reduce heating and cooling loads) and a daylighting mode (the object of which is to reduce the need for artificial illumination). Optical flicker detector 11 detects the presence of the periodic variation, or flicker, in the illumination produced by electric lamps powered by alternating current.

Abstract: A reflector lamp assembly having an integral photo-sensor and sensing circuit arrangement associated therewith provides for sensing the ambient light conditions at a point adjacent the top surface of the lamp envelope. The photo-sensor element is disposed within a sensor housing member mounted along an edge portion of the top surface of the lamp. A channel pathway is integrally formed with the sensor housing member and extends along the side lamp envelope to protect the sensor lead wires extending from the photo-sensor device to the sensing circuitry contained in the threaded screw base. The sensing circuitry is disposed vertically within a cavity formed in the bottom of the screw base so as to achieve optimum thermal dissipation properties for the sensing circuit. A collimator tube can be inserted into an opening formed at the top of the sensor housing member so as to control the field of view for sensing the ambient light conditions occurring near the top surface of the lamp assembly.

Abstract: A system for operating electronic audio equipment and other components located inside a closed cabinet receives an infrared signal from a hand held remote control device anywhere in the room, and transmits the signal directly to the signal receiver of each component inside the cabinet. An infrared receiver eye of the system is positioned where it is optically exposed to the infrared signals within the room, such as in an exposed bore of the cabinet adjacent to the gap between doors of the cabinet. The signal received at the receiver eye is repeated by a main transceiver and delivered to individual emitters at the electronic components such as VCR or stereo audio components. In a preferred embodiment the transceiver has a repeater which receives the infrared signal and repeats it in an electrical signal sent through wires to infrared emitters dedicated to each component, where the same infrared signal received by the transceiver is repeated at the components.

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 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 to accommodate physiological changes in the driver's eyes.

Abstract: An improved lamp for use with travel trailers, motorhomes, recreational vehicles, temporary shelters, and the like, has an automatic photosensor-actuated on/off control circuit and shielding to protect the photosensor from the effects of stray light sources.

Abstract: An optical reader, such as a bar code reader, includes improved circuitry to enable the bar code reader to respond more quickly and more accurately to signal variations due to changes in the ambient light condition and in the contrast presented by the information being read. In particular, the reader includes "slice" circuitry to sense the transitions of signals corresponding to the black-to-white and white-to-black edges of a bar code. The slice circuit includes two ideal diodes whose inputs are connected to an analog input terminal and whose outputs are respectively connected to first and second capacitors to sense and peak detect the values ofincreasing and decreasing signals. Two diodes are connected in series between the postive peak detector and the negative peak detector and the junction of the two series connected diodes functions as an output terminal at which is produced a reference voltage applied to a comparator.

Abstract: The present invention relates to an ambient light detector, a laser lighting control device using the same suitable for a bar code reader, and a bar code reader. The object is to require no explanation on a special operation and to realize an easy device design and a low manufacturing cost. Each device includes an ambient light detector to detect light around a peripheral device, and judging device to provide a signal indicating that an ambient light detected by the ambient light detector has exceeded a predetermined value over a predetermined time.

Abstract: In a device for driving an EC antiglare mirror in which reflectivity is variably controlled by an EC element, a surrounding light quantity detection circuit detects quantity of light surrounding a vehicle. A rear light quantity detection circuit detects quantity of light in the rear of the vehicle. An oscillation circuit is constructed so that duration of an "H" level of an oscillation signal and duration of an "L" level of the oscillation signal are individually controlled. An inversion period control circuit variably controls duration of one of the "H" and "L" levels of the oscillation signal generated by the oscillation circuit in response to light quantity detected by the surrounding light quantity detection circuit and also variably controls duration of the other level in response to light quantity detected by the rear light quantity detection circuit.