Abstract: An illuminating device is provided with a plurality of light source modules (LM) each of which has a light emitting element and a driver circuit for driving the light emitting element, and the illuminating device controls the driver circuit of each light source module individually. All the light. source modules are grouped by having a plurality of light source modules arranged at intervals (d) as one group. A step of lighting light emitting bodies of the light source modules in the same group (for instance, LM (1, 1)·LM (1, 9)) simultaneously under predetermined conditions is performed in turn for all the groups. Based on the obtained light emitting quantity of the light emitting element of each light source module (LM), the driver circuit of the light source module is controlled. Thus, in a backlight device provided with a plurality of illuminating areas, the light emitting quantity in each illuminating area can be accurately corrected in a short time.

Abstract: A circuit arrangement for controlling at least one light source comprises a photodetector (2), a sampling circuit (6) for selectively sampling a photodetector signal (lin2) generated by the photodetector (2) as a function of a first and a second light source (10, 12), and a control unit (5), which is coupled on the input side to the sampling circuit (6). The circuit arrangement further comprises a first power-supply source (7), which is coupled to the control unit (5) and is designed for controlling at least one parameter of a first light source (12), and at least one second power-supply source (11), which is coupled to the control unit (5) and is designed for controlling at least one parameter of a second light source (12). The circuit arrangement is suitable, for example, for RGB lighting.

Abstract: A system and device for and a method of programming and controlling light fixtures is disclosed. A system in accordance with the present invention includes a stationary controller unit that is electrically coupled to the light fixtures. The stationary controller unit is configured to be remotely programmed with a portable commissioning device to automatically control the lights fixtures. The stationary controller unit and the portable commissioning device include light sensors, micro-computers and transceivers for measuring light levels, running programs, storing data and transmitting data between the stationary controller unit and the portable commissioning device. In operation, target light levels selected with the portable commissioning device and the controller unit is remotely programmed to automatically maintain the target level.

Abstract: A lighting system for delivering a dynamic, fully customized, and automatic illumination to a subject. The lighting system comprises a programmable light unit for emitting a programmed pattern and spectra of illumination, a sensor pod comprising an array of sensors for detecting ambient lighting conditions and subject characteristics, a control unit for allowing a user to program the lighting system, and a processing unit for analyzing data from the sensor pod and control unit to construct an optimal lighting profile in accordance therewith. The lighting system generates light in accordance with the lighting profile which is fully optimized in spectrum, intensity, color, contrast, temperature, angle, and focus for any given environment, subject and task.

Abstract: The invention specifies a light-emitting diode module (20) having at least two light-emitting diode chips (1), a memory unit (2), in which values for the brightness and the color locus of each light-emitting diode chip (1) are stored, and a control unit (3), which is suitable for controlling an operating current through each light-emitting diode chip (1) as a function of the stored values. Such a light-emitting diode module (20) makes particularly precise and reproducible white point representation possible. Furthermore, the invention specifies a method for producing a light-emitting diode module (20) and an optical projection apparatus having such a light-emitting diode module (20).

Abstract: A light sheet module includes a light sheet having LEDs on a substrate and a driver circuit for the LEDs. The driver circuit includes a first control loop and a second control loop. The first loop contains TRIACS for regulating current from an external AC power source to the LEDs in response to trigger signals. A constant current circuit receives a command signal indicative of a target current in the LEDs, and generates the trigger signals. Current feedback circuitry generates a current feedback signal indicative of the actual current in the LEDs. The constant current circuit responds to the current feedback circuitry and adjusts the trigger signals so that the actual current in the LEDs more closely approaches the target current. The second control loop contains a Driver controller that generates the command signal and that is responsive to an input device for the Driver controller.

Abstract: An illumination system (1) comprises a plurality of light sources (11, 12, 13), each provided with a driver (21, 22, 23); a controller (30) for generating control signals (Sc1, Sc2>Sc3) for controlling the respective drivers; temperature feed forward means (60, 61, 62, 63, 81) for establishing a temperature feed forward (TFF) correction mechanism; flux feedback means (71, 82, 83, 84) for establishing a flux feedback (FFB) correction mechanism. The controller is capable of operating in a first mode of operation wherein both the temperature feed forward correction mechanism and the flux feedback correction mechanism are active, and is capable of operating in a second mode of operation wherein the temperature feed forward correction mechanism is active and the flux feedback correction mechanism is inactive. The controller is designed to monitor the duty cycles of the control signals and to select its mode of operation based on said duty cycles.

Abstract: A multi-zone daylight harvesting method and apparatus having a closed loop system utilizing a single light sensor is disclosed herein. This light control system includes an ambient light sensor connected to a detection circuit for detecting the amount of ambient light within a given zone and converting the light signal to an digital one. A control device couples to receive a predetermined rate of change for each respective zone from a storage unit along with the converted digital signal. The control device connects each zone of a plurality of electrical loads to control the power supplied to the electrical load at the predetermined corresponding rate of change and responsive to the amount of ambient light detected.

Abstract: An application for nightly outdoor lamps, road lamps, advertising lamps and nightly warning lights using daytime and nighttime as the period, wherein during daytime, it is at a preparation status of no power output to drive the lamps, and the AC to DC power is charged to the charge/discharge device, while during nighttime, the lamps are commonly driven by the parallel output of an AC to DC power and the discharged power from the charge/discharge device.

Abstract: The present invention provides a method and apparatus for optical feedback control for an illumination device, wherein the control signal for each array of one or more light-emitting elements corresponding to a particular colour, is independently configured using a modification signal whose frequency is different for each colour. Electronic filters whose center frequencies are substantially equal to the modification signal frequencies of the drive currents for the light-emitting elements are used to discriminate between the radiant flux corresponding to each of the different colours of light-emitting elements, from a sample of the mixed radiant flux output collected by one or more optical sensors. The output of an individual electronic filter is substantially directly proportional to the radiant flux output of the light-emitting elements of the associated colour, which together with the desired luminous flux and chromaticity of the output light, the controller can use to adjust the control signals.

Abstract: The present invention relates to a method for providing control signals for a light whose colour or colour temperature is variable. The invention also relates to a corresponding control apparatus and a corresponding lighting system. In the method, a series of at least three colour locations (F1, F2, F3) is determined, which lie on a predetermined colour change curve (K1) in a corresponding coordinate system. By way of example, the colour change curve may be the Planck curve train or a straight line. The colour locations (F1, F2, F3) are in this case chosen such that the respectively corresponding colours have a colour distance (d) which, at least approximately, is subjectively perceived as in each case being of the same magnitude. This makes it easier to adjust the light to give a specific desired light impression.

Abstract: A light source device and a display device are disclosed of which high display quality can be maintained by correcting luminance or a color tone without making a user feel strangeness or inconvenience. A light source device is disclosed in at least one embodiment, including light source blocks each of which has red-color light-emitting diodes, green-color light-emitting diodes and blue-color light-emitting diodes and is capable of independently adjusting luminance of the three color diodes, a photo-receiving mechanism arranged to photo-receive light, and a correcting operation control mechanism arranged to calculate correction amounts of the luminance of the light sources in each of the blocks based on photo-receiving amounts of the photo-received light in order to maintain uniform luminance or a uniform color tone among the blocks, wherein the mechanism controls the mechanism to photo-receive the light when a termination operation of the light source device is performed.

Abstract: A solar-powered parking space barrier block is configured as a one-piece molded housing of a high strength, transparent plastic material in which a photovoltaic solar panel and a DC energy storage module are inclosed. A pair of white light LED lamps provide end panel marker illumination, two yellow light LED lamps provide hazard warning illumination and a rechargeable supercapacitor storage module provides operating power. A power control circuit enables use of the solar panel as a photosensor to automatically energize the LED lamps when ambient skylight falls below a predetermined safe visibility level, and removes operating power from the LED lamps when ambient skylight rises above a predetermined safe visibility level.

Abstract: A lighting system and a method of operating the lighting system are described. A plurality of lighting units (10, 10?) each comprise, a lighting element (12) with a lighting control unit (14) for controlling its light output, and a communication unit (16, 16?) for communicating over a communication medium, e.g. RF or power line communication. The units (10, 10?) further have an optical receiver (18) for receiving light from other lighting units (10, 10?). A controller unit (20) is connected to the optical receiver (18), the communication unit (16, 16?) and the lighting control unit (14). In order to allow easy, automated set-up, at least in a configuration phase, the lighting units (10, 10?) send information by operating the lighting elements (12) in a modulated manner, and this information is received by a further lighting unit (10, 10?) observing the generated light.

Abstract: An electronic device includes a case, a display panel and a backlight module. The case has at least a hole. The display panel is disposed in the case to display information. The backlight module is disposed in the case as a light source of the display panel. The backlight module has at least a light emitting element, a light-guide plate and at least a light-guide tube. The light-guide plate guides the light emitted by the light emitting element to the display panel. The light-guide tube has a light input end and a light output end. The light input end is disposed at the hole of the case and is exposed outside, and the light output end is located at one side of the light-guide plate. Therefore, the light-guide tube can guide external environment light to the light-guide plate.

Abstract: A system to provide radiant energy of selectable spectral characteristic (e.g. a selectable color combination) uses an integrating cavity to combine energy of different wavelengths from different sources. The cavity has a diffusely reflective interior surface and an aperture for allowing emission of combined radiant energy. Sources of radiant energy of different wavelengths, typically different-color LEDs, supply radiant energy into the interior of the integrating cavity. In the examples, the points of entry of the energy into the cavity typically are located so that they are not directly visible through the aperture. The cavity effectively integrates the energy of different wavelengths, so that the combined radiant energy emitted through the aperture includes the radiant energy of the various wavelengths. The apparatus also includes a control circuit coupled to the sources for establishing output intensity of radiant energy of each of the sources.

Abstract: The present invention provides a luminaire system and method for creating white light having a desired colour temperature. The system comprises one or more white light light-emitting elements for generating white light having a particular colour temperature. The system further comprises one or more first colour light-emitting elements and one or more second colour light-emitting elements. The luminaire system mixes the coloured light generated by the first and second colour light-emitting elements with the white light of a particular colour temperature, in order to create white light having a desired correlated colour temperature.

Abstract: A photo detector is disclosed. The photo detector has a substrate, a semiconductor layer disposed on the substrate, an insulating layer covered on the semiconductor layer, an interlayer dielectric layer covered on the insulating layer, and two electrodes formed on a portion of the interlayer dielectric layer. The semiconductor layer has a first doping region, a second doping region, and an intrinsic region located between the first doping region and the second doping region. The interlayer dielectric layer has at least three holes to expose a portion of the insulating layer, a portion of the first doping region, and the second doping region. The electrodes are connected to the first doping region and the second doping region through two of the holes.

Abstract: A lighting control system comprises a plurality of toggle switches, a plurality of pushbuttons, a plurality of timer circuits, a plurality of relays, and a plurality of photocells to control a first plurality of lights, a second plurality of lights, a third plurality of lights and a fourth plurality of lights. The toggle switches and pushbuttons either control the lights directly or activate the timers to control the lights. The relays may be energized to switch on the lights. The photocells may be used to control the lights that are located in an outside setting.

Abstract: A garden light 10 having a body (11) with a post (12), the lower end of which is provided with a spike (13). The upper end of the post (11) receives a lens assembly (12). Secured to the lens assembly (12) is a cap assembly (24) that has three LEDs that are activated to produce a varying color light.

Abstract: A remotely controlled LED light fixture system is disclosed. The system includes a series of light fixtures featuring LED electrically connected in series to an electrical source. In a preferred embodiment, the series of light fixtures are connected using a quick secure electro/mechanical connection. The system also includes an infrared remote receiver for receiving control signals from a remote control transmitter. The infrared remote receiver is positioned between the electrical source and the series of LED light fixtures, and controls the flow of electricity between the electrical source and the series of LED light fixtures. The remote control transmitter is configured to send a variety of different signals to the infrared remote receiver. In one embodiment the electrical source is an electrical transformer connected to standard house current. In another embodiment, the electrical source is a solar panel.

Abstract: An illumination brightness and color control system for adjusting the illumination of a plurality of point light sources and method therefor are provided, implemented in a time division manner. A single photosensor senses and samples a point light source for the luminous intensity signal value. Then, the luminous intensity signal value at each wavelength and a target brightness/color value are compute to acquire a corrected current value, and the corrected current value is fed back to a light source driver. Therefore, the brightness/color value of the point light sources is adjusted to be in a steady state.

Abstract: A solar powered outdoor flicker light includes a plurality of light emitting diodes behind a light diffusing lens portion. The flickering of a portion of the emitting diodes is controlled by an astable multi-vibrator circuit. The flickering of the light emitting diodes gives the appearance of a flickering candle flame when viewed through the light diffusing lens portion.

Abstract: A circuit includes a converter for converting an a.c. voltage into a d.c. voltage. The converter has a diode half-bridge, a switch half-bridge, and two d.c. rails. Further, the converter has a second converter for converting the a.c. voltage into a second d.c. voltage.

Abstract: A system for the throughput detection and feedback of optical energy for making sure of white balance of the LED array in a flat fluorescent light source when the LED array in emitting light by respectively connecting in series a selected LED lamp respectively from RGB LED groups in an LED array to an optical energy sensor to convert optical energy into equivalent amperage, then voltage analog signals to digital signals for a CPU to compare and solve the difference of optical energy to improve voltage output, which then regulated by a driver and fed back to the LED array.

Abstract: A light display power box receives a string of clear and a string of colored lights thereby displaying clear and colored lights simultaneously to form selected light display patterns. The light display power box includes a plurality of outlets for receiving at least one string of clear lights and at least one string of colored lights. Additionally, the light display power box includes electronic circuitry including a microprocessor programmed to receive, process, and use received command signals to program selected light patterns. In one embodiment, a remote control transmitter transmits wireless command signals associated with selected light patterns to a sensor unit housed within or in proximity to the light display power box.

Abstract: A controlling device for use with an exterior landscape lighting assembly. The lighting assembly includes a transformer having an input line connected to an electrical power source. The transformer converts a primary electrical load to a secondary electrical load which is in turn outputted though an output line connecting to a plurality of individual lighting units. The controlling device is capable of being mounted at an appropriate location indoors or outdoors. An enclosure unit includes a power supply circuit, a switch, a relay and control circuitry. The power supply circuit converts the secondary transformer output to a filtered direct current suitable for powering the control circuitry. The control circuitry interfaces with remote momentary switches and alternately activates and deactivates the lighting units. The control circuitry further includes an optional receiver for wireless operation. The controlling device can be incorporated into the transformer assembly.

Abstract: A system and method for automatic configuration of devices that comprises a receiver for receiving information from a device that uniquely identifies the device, a controller capable of assigning an address to the device, and a communication link for transmitting said information from the receiver to the controller.

Abstract: An electronic lighting apparatus with at least one multiple position adjustable lighting pod. Each lighting pod includes at least one variable intensity light source and a proximity sensor for detecting objects interposed between the lighting pod and a work field. Each variable intensity light source is powered by a controllable pulse width modulated power supply or other suitable power supply which can be utilized to vary the intensity of the light source. In response to detection of an object interposed between a particular lighting pod and the work surface, the power to that lighting pod is increased, increasing the illumination of the work field. Alternatively, power to that lighting pod may be decreased and power to alternate lighting pods is increased, thereby minimizing shadows within the work field.

Abstract: A switching system using laser induced discharge is provided which is capable of reliable switching with a simple structure, multiple switching for a number of circuits, good synchronization and no switching time delay among circuits. In the switching system for controlling conduction between electrodes of a switch by discharge between the electrodes, a laser beam is applied to one of the electrodes to make discharge from the other of the electrodes be induced by the laser beam and application of the laser beam is controlled to switch the conduction.

Abstract: A discharge lamp lighting circuit 1 has a DC power supply circuit 3 for outputting a DC voltage and a DC-AC conversion circuit 4 for converting the output voltage of the DC power supply circuit 3 into an AC voltage and then supplying the AC voltage to a discharge lamp 6. To light the discharge lamp 6, a predetermined period of time over which the polarity of the voltage supplied from the DC-AC conversion circuit 4 to the discharge lamp 6 is defined as either positive or negative and is provided before the discharge lamp 6 is lighted. The voltage polarity is forcibly inverted to limit the duration of the period so as not to exceed the predetermined time. The circuit reduces costs and prevents short life and degradation of a discharge lamp by placing a time limit on the duration of the period over which the supply voltage polarity is temporarily fixed before the discharge lamp is lighted.

Abstract: A monitoring system for a display unit includes phototransistors for detecting light emitted from a plurality of selectively energizable light-emitting diode (LED) segments in an energized state and for generating a voltage which is representative of the light emitted from the LED segments in the energized state. A glass filter filters ambient light from the phototransistors and passes the light emitted from the LED segments in the energized state. A comparator for each of the LED segments generates a comparison signal, with the comparison signal being representative of a comparison between a predetermined reference voltage and the voltage for each of the LED segments. A conditional power supply conditionally energizes the LED segments in response to an energizing signal. A routine of a central processing unit generates display data.

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 electrical flasher circuit has improved operating characteristics, in particular by providing continuous illumination for a long period of time from a fully charged solar battery. The circuit employs a solar battery recharging circuit component that achieves full charge in a short period of time. The flasher circuit may be used in roadside warning device having a sign member with a warning image. Placed around the warning image are a plurality of light emitters for providing a visual warning during evening and night hours. The light emitters are powered by a solar energy source connected to a flasher circuit including an oscillator for causing the light emitters to be energized in a particular sequence. When the device is exposed to sunlight, the battery is disconnected to avoid unnecessary draining of the battery.

Abstract: A two color, light emitting diode having a green diode and a red diode therein is incorporated with a control switch for an automotive accessory. The control switch is normally green in color providing a finger target when the system is not operated because only the green diode emits light. The diode is amber in color upon closing the switch because the red diode and green diode are both illuminated. The two color, light emitting diode is used for accessory systems such as electric windows, traction control systems, rear window defrosters and other accessory systems.

Abstract: A variable color luminaire is arranged for controlling a plurality of light sources of different emission colors to be at predetermined dimming levels by means of dimmers, performing a comparison operation to obtain a quantity-of-light ratio and a reference quantity-of-light ratio from detection signals with respect to light outputs of the light sources detected by detectors, and subjecting the light sources to a quantity-of-light correction by means of a corrector according to results of the comparison operation so as to attain a blended color light as set, whereby the resultant blended color light can be prevented from deviating from the set blended color light even when dimming quantity of the respective light sources is close to upper and lower dimming limits.

Abstract: An electrical device such as a lamp is energized and deenergized remotely by a system in which pulses of different duration are transmitted to a receiver unit capable of discriminating between the length of the pulses in order to switch between an "on" mode and an "off" mode. A battery energizing the receiver unit is recharged by a photovoltaic cell. Advantageously associated with the battery charging circuit is an ambient lights sensing device capable of interrupting current from the battery to a load whenever the battery is being charged by the photovoltaic cell.

Abstract: A lighting system for use in a vehicle cabin comprises a plurality of first lamps which are arranged between a roof and a plane including an eye point of a seat occupant for illuminating predetermined surfaces, and at least one second lamp for illuminating a floor. Luminance levels of the predetermined surfaces are controlled by, for example, an illuminance measuring apparatus, a luminance measuring apparatus, and a lighting controller.

Abstract: An automatic focus position adjusting unit for use in a shadowless lighting device for medical purposes includes a sensor, a start switch, a start processor, and a direction adjuster. The unit also includes a focus mover, a peak detector, and an adjustment completion unit. The shadowless lighting device for medical purposes has a housing, illuminating bulbs arranged in the housing, and a drive system for inclining the illuminating bulbs so that the optical axes of the illuminating bulbs may converge, and form a focus, on a predetermined position along a focus moving axis. The automatic focus position adjusting unit permits, with a simple operation, an accurate focus position adjustment at a desired position. This is because it is possible to move the focus to a position at which the amount of light, reflected from the predetermined region at the center of the range of light, becomes a maximum.

Abstract: A display assembly particularly for the point-of-purchase field utilizes a light source to power the display. A solar cell is electrically connected, through a simple flashing circuit, to an array of light emitting diodes (LEDs). The diodes have a current usage of about 2 ma or less; e.g., they may be double heterojunction AlGaAs/GaAs material. The circuit has a current drain of about 0.1 ma or less. The solar cell may be mounted between an artificial light source (such as a fluorescent bulb) and a surrounding metal housing by sheet material having an undulating (e.g., accordion) configuration. Transparent UV inhibited plastic film tape may attach the solar cell to a central undulation of the sheet material while magnets strips attach side edges of the sheet material to a metal housing, so that the solar cell is in close proximity to (e.g., touches) the light source.

Abstract: A chromatic lighting display utilizes a plurality of light-producing elements positioned to be visually accessed by a user, the elements arranged in co-extensive and diverse positions, controlled in light-emitting intensities and colors by a centrally located control mechanism coupled thereto. A plurality of light sensors are disposed to receive natural external light, each adapted with suitable color filters. The signals generated by the light-receiving sensors are transmitted to the control device which, in turn, operating upon a predetermined color-responsive algorithm, provides energization to each of the plurality of light-emitting devices, providing the display of different colors of light, at different intensities, accessible to the user.

Abstract: To provide for automatic adjustment of the light field of an operating room light in accordance with manual positioning of the light, an electrical servo control loop positions the respective lamps and/or deflection mirrors of circularly placed light sources (2) in the housing (1) to iluminate a given field in a given plane. The distance of the lamp from the given field is determined by an ultrasonic distance sensor (5; 5a, 5b, 5c) to provide one input to the servo loop, for comparison of the positioning of the light source to illuminate said field. If the distance of the illuminated field increases, the angular position of the light sources is automatically adjusted to provide the field at the increased distance. If the distance decreases, however, no adjustment is carried out unless an operator touches an operating handle. This is transformed into a manual readjustment signal which releases the servo system to then readjust the position of the light sources.

Abstract: The illumination device includes a charging part, an energy storage device, a flash tube and an amplitude control device, by means of which the energy storage device can be charged to different voltages. A time control device is superposed upon the amplitude control device. In consequence of the two control devices, the flash tube emits light with a predetermined color temperature as a function of the set amplitude and of the set flash duration. The color temperature can thereby be influenced in a controlled manner, with the maintenance of a very fine setting of the quantity of light, and can also be maintained constant independent of the quantity of light emitted.

Abstract: A multicolor optical device having at least three optically stable states includes a plurality of pairs of associated light sensors and light sources for emitting light of respectively different colors when activated. Each light source is divided by an opaque wall into a first light emitting portion and a second light emitting portion. The light signals from the first light emitting portions of all light sources are blended to obtain a composite light signal of a variable color. Separate optical feedbacks are established between the second light emitting portions and light sensors in pairs tending to stabilize the light sources in their conditions to thereby maintain the color of the composite light signal.

Abstract: An apparatus for flash photography being of the type in which for one shot a number of different flash tubes are time-serially fired and the amount of flash light emitted from each flash tube is controlled in accordance with a respective arbitrarily chosen individual value independently of the others.In the above-described arrangement, one and the same comparator is sufficient for controlling the firing operation of all the flash tubes, thereby giving an advantage of simplifying the construction of the apparatus.

Abstract: An automatic vehicle headlamp dimming control is the type having an operator controlled first voltage divider across a power supply, a light sensitive resistance connected in electrical series with an electrically controlled variable resistance in a second voltage divider across the output of the first voltage divider, an energizing circuit adapted to energize the headlamp system from the power supply at high or low intensity in response to the output of the second voltage divider compared to a fixed reference voltage and first electric feedback means from the energizing circuit to the electrically controlled variable resistance for producing hysteresis feedback.

Abstract: A multicolor display device having seven illuminated optically stable states includes three triads of associated electro-optical components. In each triad, a light sensor is electrically coupled with a display light emitting diode and auxiliary light emitting diode. An optical feedback is established in each triad between the auxiliary light emitting diode and the light sensor tending to maintain its associated display light emitting diode either in the illuminated or extinguished condition. Light signals of respectively different colors emitted by three display light emitting diodes are blended to obtain a composite light signal of a color in accordance with the conditions of respective display light emitting diodes.

Abstract: A display dimming circuit is disclosed which provides a coordinated automatic display brightness level adjustment for a plurality of instruments associated within the same general region. Its use in an aircraft cockpit, for example, allows the left, or captain's instruments, to be coordinated to be responsive to the ambient light in that region of the cockpit and the co-pilot's bank of instruments, or right region, of the aircraft is separately coordinated such that both regions exhibit appropriate brightness levels on all instruments. In this manner, gas discharge displays, for example, are installed adjacent cathode ray tube displays or vacuum fluorescent displays and all are effectively maintained at an appropriate lighting level.

Abstract: In an electronic flash device for use in a still camera, a calculation circuit means calculates a ratio of the amounts of light to be emitted by a plurality of flash light tubes on the basis of color temperature information and control circuit means controls the emission of light of the respective flash light tubes in such a manner that the ratio of light amount emitted from the respective flash light tubes corresponds to the ratio calculated by the calculation circuit means.

Abstract: A photographic system including a flash unit wirelessly controlled. The system comprises a controller interlocked with the photographic camera and a flash unit operable in response to the controller to illuminate object. Start and stop of flashing of the flash unit are controlled by control means in a particularly determined manner so as to prevent maloperation of the unit.